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gpui/elements/
div.rs

1//! Div is the central, reusable element that most GPUI trees will be built from.
2//! It functions as a container for other elements, and provides a number of
3//! useful features for laying out and styling its children as well as binding
4//! mouse events and action handlers. It is meant to be similar to the HTML `<div>`
5//! element, but for GPUI.
6//!
7//! # Build your own div
8//!
9//! GPUI does not directly provide APIs for stateful, multi step events like `click`
10//! and `drag`. We want GPUI users to be able to build their own abstractions for
11//! their own needs. However, as a UI framework, we're also obliged to provide some
12//! building blocks to make the process of building your own elements easier.
13//! For this we have the [`Interactivity`] and the [`StyleRefinement`] structs, as well
14//! as several associated traits. Together, these provide the full suite of Dom-like events
15//! and Tailwind-like styling that you can use to build your own custom elements. Div is
16//! constructed by combining these two systems into an all-in-one element.
17
18use crate::{
19    Action, AnyDrag, AnyElement, AnyTooltip, AnyView, App, BackGestureEvent, Bounds, ClickEvent,
20    DispatchPhase, Display, Element, ElementId, Entity, EntityId, ExternalDragPayload,
21    ExternalDragPayloadSource, FileDropEvent, FocusHandle, Global, GlobalElementId, Hitbox,
22    HitboxBehavior, HitboxId, InspectorElementId, IntoElement, IsZero, KeyContext, KeyDownEvent,
23    KeyUpEvent, KeyboardButton, KeyboardClickEvent, LayoutId, LongPressEvent,
24    ModifiersChangedEvent, MouseButton, MouseClickEvent, MouseDownEvent, MouseExitEvent,
25    MouseMoveEvent, MousePressureEvent, MouseUpEvent, OngoingScroll, Overflow, ParentElement,
26    PinchEvent, Pixels, Point, Render, ScrollEvent, SharedString, Size, Style, StyleRefinement,
27    Styled, Task, TooltipId, TouchPhase, Visibility, Window, WindowControlArea, point, px, size,
28};
29use collections::HashMap;
30use gpui_util::ResultExt;
31use refineable::Refineable;
32use smallvec::SmallVec;
33use std::{
34    any::{Any, TypeId},
35    cell::{Cell, RefCell},
36    cmp::Ordering,
37    fmt::Debug,
38    marker::PhantomData,
39    mem,
40    rc::Rc,
41    sync::Arc,
42    time::Duration,
43};
44
45use super::ImageCacheProvider;
46
47#[cfg(feature = "stacker")]
48type StackSafe<T> = stacksafe::StackSafe<T>;
49#[cfg(not(feature = "stacker"))]
50type StackSafe<T> = T;
51
52const DRAG_THRESHOLD: f64 = 2.;
53const DEFAULT_TOOLTIP_SHOW_DELAY: Duration = Duration::from_millis(500);
54const HOVERABLE_TOOLTIP_HIDE_DELAY: Duration = Duration::from_millis(500);
55
56/// The styling information for a given group.
57pub struct GroupStyle {
58    /// The identifier for this group.
59    pub group: SharedString,
60
61    /// The specific style refinement that this group would apply
62    /// to its children.
63    pub style: Box<StyleRefinement>,
64}
65
66/// An event for when a drag is moving over this element, with the given state type.
67pub struct DragMoveEvent<T> {
68    /// The mouse move event that triggered this drag move event.
69    pub event: MouseMoveEvent,
70
71    /// The bounds of this element.
72    pub bounds: Bounds<Pixels>,
73    drag: PhantomData<T>,
74    dragged_item: Arc<dyn Any>,
75}
76
77impl<T: 'static> DragMoveEvent<T> {
78    /// Returns the drag state for this event.
79    pub fn drag<'b>(&self, cx: &'b App) -> &'b T {
80        cx.active_drag
81            .as_ref()
82            .and_then(|drag| drag.value.downcast_ref::<T>())
83            .expect("DragMoveEvent is only valid when the stored active drag is of the same type.")
84    }
85
86    /// An item that is about to be dropped.
87    pub fn dragged_item(&self) -> &dyn Any {
88        self.dragged_item.as_ref()
89    }
90}
91
92impl Interactivity {
93    /// Create an `Interactivity`, capturing the caller location in debug mode.
94    #[cfg(any(feature = "inspector", debug_assertions))]
95    #[track_caller]
96    pub fn new() -> Interactivity {
97        Interactivity {
98            source_location: Some(core::panic::Location::caller()),
99            ..Default::default()
100        }
101    }
102
103    /// Create an `Interactivity`, capturing the caller location in debug mode.
104    #[cfg(not(any(feature = "inspector", debug_assertions)))]
105    pub fn new() -> Interactivity {
106        Interactivity::default()
107    }
108
109    /// Gets the source location of construction. Returns `None` when not in debug mode.
110    pub fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
111        #[cfg(any(feature = "inspector", debug_assertions))]
112        {
113            self.source_location
114        }
115
116        #[cfg(not(any(feature = "inspector", debug_assertions)))]
117        {
118            None
119        }
120    }
121
122    /// Bind the given callback to the mouse down event for the given mouse button, during the bubble phase.
123    /// The imperative API equivalent of [`InteractiveElement::on_mouse_down`].
124    ///
125    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
126    pub fn on_mouse_down(
127        &mut self,
128        button: MouseButton,
129        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
130    ) {
131        self.mouse_down_listeners
132            .push(Box::new(move |event, phase, hitbox, window, cx| {
133                if phase == DispatchPhase::Bubble
134                    && event.button == button
135                    && hitbox.is_hovered(window)
136                {
137                    (listener)(event, window, cx)
138                }
139            }));
140    }
141
142    /// Bind the given callback to the mouse down event for any button, during the capture phase.
143    /// The imperative API equivalent of [`InteractiveElement::capture_any_mouse_down`].
144    ///
145    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
146    pub fn capture_any_mouse_down(
147        &mut self,
148        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
149    ) {
150        self.mouse_down_listeners
151            .push(Box::new(move |event, phase, hitbox, window, cx| {
152                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
153                    (listener)(event, window, cx)
154                }
155            }));
156    }
157
158    /// Bind the given callback to the mouse down event for any button, during the bubble phase.
159    /// The imperative API equivalent to [`InteractiveElement::on_any_mouse_down`].
160    ///
161    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
162    pub fn on_any_mouse_down(
163        &mut self,
164        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
165    ) {
166        self.mouse_down_listeners
167            .push(Box::new(move |event, phase, hitbox, window, cx| {
168                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
169                    (listener)(event, window, cx)
170                }
171            }));
172    }
173
174    /// Bind the given callback to the mouse pressure event, during the bubble phase
175    /// the imperative API equivalent to [`InteractiveElement::on_mouse_pressure`].
176    ///
177    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
178    pub fn on_mouse_pressure(
179        &mut self,
180        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
181    ) {
182        self.mouse_pressure_listeners
183            .push(Box::new(move |event, phase, hitbox, window, cx| {
184                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
185                    (listener)(event, window, cx)
186                }
187            }));
188    }
189
190    /// Bind the given callback to the mouse pressure event, during the capture phase
191    /// the imperative API equivalent to [`InteractiveElement::on_mouse_pressure`].
192    ///
193    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
194    pub fn capture_mouse_pressure(
195        &mut self,
196        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
197    ) {
198        self.mouse_pressure_listeners
199            .push(Box::new(move |event, phase, hitbox, window, cx| {
200                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
201                    (listener)(event, window, cx)
202                }
203            }));
204    }
205
206    /// Bind the given callback to the mouse up event for the given button, during the bubble phase.
207    /// The imperative API equivalent to [`InteractiveElement::on_mouse_up`].
208    ///
209    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
210    pub fn on_mouse_up(
211        &mut self,
212        button: MouseButton,
213        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
214    ) {
215        self.mouse_up_listeners
216            .push(Box::new(move |event, phase, hitbox, window, cx| {
217                if phase == DispatchPhase::Bubble
218                    && event.button == button
219                    && hitbox.is_hovered(window)
220                {
221                    (listener)(event, window, cx)
222                }
223            }));
224    }
225
226    /// Bind the given callback to the mouse up event for any button, during the capture phase.
227    /// The imperative API equivalent to [`InteractiveElement::capture_any_mouse_up`].
228    ///
229    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
230    pub fn capture_any_mouse_up(
231        &mut self,
232        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
233    ) {
234        self.mouse_up_listeners
235            .push(Box::new(move |event, phase, hitbox, window, cx| {
236                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
237                    (listener)(event, window, cx)
238                }
239            }));
240    }
241
242    /// Bind the given callback to the mouse up event for any button, during the bubble phase.
243    /// The imperative API equivalent to [`Interactivity::on_any_mouse_up`].
244    ///
245    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
246    pub fn on_any_mouse_up(
247        &mut self,
248        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
249    ) {
250        self.mouse_up_listeners
251            .push(Box::new(move |event, phase, hitbox, window, cx| {
252                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
253                    (listener)(event, window, cx)
254                }
255            }));
256    }
257
258    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
259    /// when the mouse is outside of the bounds of this element.
260    /// The imperative API equivalent to [`InteractiveElement::on_mouse_down_out`].
261    ///
262    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
263    pub fn on_mouse_down_out(
264        &mut self,
265        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
266    ) {
267        self.mouse_down_listeners
268            .push(Box::new(move |event, phase, hitbox, window, cx| {
269                if phase == DispatchPhase::Capture
270                    && !window.has_active_prompt()
271                    && !hitbox.contains(&window.mouse_position())
272                {
273                    (listener)(event, window, cx)
274                }
275            }));
276    }
277
278    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
279    /// when the mouse is outside of the bounds of this element.
280    /// The imperative API equivalent to [`InteractiveElement::on_mouse_up_out`].
281    ///
282    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
283    pub fn on_mouse_up_out(
284        &mut self,
285        button: MouseButton,
286        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
287    ) {
288        self.mouse_up_listeners
289            .push(Box::new(move |event, phase, hitbox, window, cx| {
290                if phase == DispatchPhase::Capture
291                    && event.button == button
292                    && !hitbox.is_hovered(window)
293                {
294                    (listener)(event, window, cx);
295                }
296            }));
297    }
298
299    /// Bind the given callback to the mouse move event, during the bubble phase.
300    /// The imperative API equivalent to [`InteractiveElement::on_mouse_move`].
301    ///
302    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
303    pub fn on_mouse_move(
304        &mut self,
305        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
306    ) {
307        self.mouse_move_listeners
308            .push(Box::new(move |event, phase, hitbox, window, cx| {
309                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
310                    (listener)(event, window, cx);
311                }
312            }));
313    }
314
315    /// Bind the given callback to the mouse exit event, during the bubble phase.
316    /// The imperative API equivalent to [`InteractiveElement::on_mouse_exit`].
317    ///
318    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
319    pub fn on_mouse_exit(
320        &mut self,
321        listener: impl Fn(&MouseExitEvent, &mut Window, &mut App) + 'static,
322    ) {
323        self.mouse_exit_listeners
324            .push(Box::new(move |event, phase, hitbox, window, cx| {
325                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
326                    (listener)(event, window, cx);
327                }
328            }));
329    }
330
331    /// Bind the given callback to [`FileDropEvent::Exited`] when a platform file drag
332    /// leaves this element's window while the element is hovered.
333    ///
334    /// This is a window-local exit event, not notification that the platform drag session ended.
335    /// The imperative API equivalent to [`InteractiveElement::on_file_drop_exit`].
336    ///
337    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
338    pub fn on_file_drop_exit(
339        &mut self,
340        listener: impl Fn(&FileDropEvent, &mut Window, &mut App) + 'static,
341    ) {
342        self.file_drop_exit_listeners
343            .push(Box::new(move |event, phase, hitbox, window, cx| {
344                if phase == DispatchPhase::Bubble
345                    && matches!(event, FileDropEvent::Exited)
346                    && hitbox.id.is_hovered_ignoring_last_input(window)
347                {
348                    (listener)(event, window, cx);
349                }
350            }));
351    }
352
353    /// Bind the given callback to the mouse drag event of the given type. Note that this
354    /// will be called for all move events, inside or outside of this element, as long as the
355    /// drag was started with this element under the mouse. Useful for implementing draggable
356    /// UIs that don't conform to a drag and drop style interaction, like resizing.
357    /// The imperative API equivalent to [`InteractiveElement::on_drag_move`].
358    ///
359    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
360    pub fn on_drag_move<T>(
361        &mut self,
362        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
363    ) where
364        T: 'static,
365    {
366        self.mouse_move_listeners
367            .push(Box::new(move |event, phase, hitbox, window, cx| {
368                if phase == DispatchPhase::Capture
369                    && let Some(drag) = &cx.active_drag
370                    && drag.value.as_ref().type_id() == TypeId::of::<T>()
371                {
372                    (listener)(
373                        &DragMoveEvent {
374                            event: event.clone(),
375                            bounds: hitbox.bounds,
376                            drag: PhantomData,
377                            dragged_item: Arc::clone(&drag.value),
378                        },
379                        window,
380                        cx,
381                    );
382                }
383            }));
384    }
385
386    /// Bind the given callback to scroll events during the bubble phase.
387    /// The imperative API equivalent to [`InteractiveElement::on_scroll`].
388    ///
389    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
390    pub fn on_scroll(&mut self, listener: impl Fn(&ScrollEvent, &mut Window, &mut App) + 'static) {
391        self.scroll_listeners
392            .push(Box::new(move |event, phase, hitbox, window, cx| {
393                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
394                    (listener)(event, window, cx);
395                }
396            }));
397    }
398
399    /// The former name of [`Interactivity::on_scroll`].
400    #[deprecated(note = "renamed to `on_scroll`")]
401    pub fn on_scroll_wheel(
402        &mut self,
403        listener: impl Fn(&ScrollEvent, &mut Window, &mut App) + 'static,
404    ) {
405        self.on_scroll(listener);
406    }
407
408    /// Bind the given callback to pinch gesture events during the bubble phase.
409    ///
410    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
411    pub fn on_pinch(&mut self, listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static) {
412        self.pinch_listeners
413            .push(Box::new(move |event, phase, hitbox, window, cx| {
414                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
415                    (listener)(event, window, cx);
416                }
417            }));
418    }
419
420    /// Bind the given callback to back-navigation gestures that start over this element.
421    /// The imperative API equivalent to [`InteractiveElement::on_back_gesture`].
422    ///
423    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
424    pub fn on_back_gesture(
425        &mut self,
426        listener: impl Fn(&BackGestureEvent, &mut Window, &mut App) + 'static,
427    ) {
428        self.back_gesture_listeners
429            .push(Box::new(move |event, phase, hitbox, window, cx| {
430                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
431                    (listener)(event, window, cx);
432                    window.prevent_default();
433                    cx.stop_propagation();
434                }
435            }));
436    }
437
438    /// Bind the given callback to pinch gesture events during the capture phase.
439    ///
440    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
441    pub fn capture_pinch(
442        &mut self,
443        listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static,
444    ) {
445        self.pinch_listeners
446            .push(Box::new(move |event, phase, _hitbox, window, cx| {
447                if phase == DispatchPhase::Capture {
448                    (listener)(event, window, cx);
449                } else {
450                    cx.propagate();
451                }
452            }));
453    }
454
455    /// Bind the given callback to an action dispatch during the capture phase.
456    /// The imperative API equivalent to [`InteractiveElement::capture_action`].
457    ///
458    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
459    pub fn capture_action<A: Action>(
460        &mut self,
461        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
462    ) {
463        self.action_listeners.push((
464            TypeId::of::<A>(),
465            Box::new(move |action, phase, window, cx| {
466                let action = action.downcast_ref().unwrap();
467                if phase == DispatchPhase::Capture {
468                    (listener)(action, window, cx)
469                } else {
470                    cx.propagate();
471                }
472            }),
473        ));
474    }
475
476    /// Bind the given callback to an action dispatch during the bubble phase.
477    /// The imperative API equivalent to [`InteractiveElement::on_action`].
478    ///
479    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
480    #[track_caller]
481    #[inline(always)]
482    pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Window, &mut App) + 'static) {
483        self.action_listeners.push((
484            TypeId::of::<A>(),
485            Box::new(move |action, phase, window, cx| {
486                let action = action.downcast_ref().unwrap();
487                if phase == DispatchPhase::Bubble {
488                    (listener)(action, window, cx)
489                }
490            }),
491        ));
492    }
493
494    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
495    /// instead of a type parameter. Useful for component libraries that want to expose
496    /// action bindings to their users.
497    /// The imperative API equivalent to [`InteractiveElement::on_boxed_action`].
498    ///
499    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
500    pub fn on_boxed_action(
501        &mut self,
502        action: &dyn Action,
503        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
504    ) {
505        let action = action.boxed_clone();
506        self.action_listeners.push((
507            (*action).type_id(),
508            Box::new(move |_, phase, window, cx| {
509                if phase == DispatchPhase::Bubble {
510                    (listener)(&*action, window, cx)
511                }
512            }),
513        ));
514    }
515
516    /// Bind the given callback to key down events during the bubble phase.
517    /// The imperative API equivalent to [`InteractiveElement::on_key_down`].
518    ///
519    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
520    pub fn on_key_down(
521        &mut self,
522        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
523    ) {
524        self.key_down_listeners
525            .push(Box::new(move |event, phase, window, cx| {
526                if phase == DispatchPhase::Bubble {
527                    (listener)(event, window, cx)
528                }
529            }));
530    }
531
532    /// Bind the given callback to key down events during the capture phase.
533    /// The imperative API equivalent to [`InteractiveElement::capture_key_down`].
534    ///
535    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
536    pub fn capture_key_down(
537        &mut self,
538        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
539    ) {
540        self.key_down_listeners
541            .push(Box::new(move |event, phase, window, cx| {
542                if phase == DispatchPhase::Capture {
543                    listener(event, window, cx)
544                }
545            }));
546    }
547
548    /// Bind the given callback to key up events during the bubble phase.
549    /// The imperative API equivalent to [`InteractiveElement::on_key_up`].
550    ///
551    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
552    pub fn on_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static) {
553        self.key_up_listeners
554            .push(Box::new(move |event, phase, window, cx| {
555                if phase == DispatchPhase::Bubble {
556                    listener(event, window, cx)
557                }
558            }));
559    }
560
561    /// Bind the given callback to key up events during the capture phase.
562    /// The imperative API equivalent to [`InteractiveElement::on_key_up`].
563    ///
564    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
565    pub fn capture_key_up(
566        &mut self,
567        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
568    ) {
569        self.key_up_listeners
570            .push(Box::new(move |event, phase, window, cx| {
571                if phase == DispatchPhase::Capture {
572                    listener(event, window, cx)
573                }
574            }));
575    }
576
577    /// Bind the given callback to modifiers changing events.
578    /// The imperative API equivalent to [`InteractiveElement::on_modifiers_changed`].
579    ///
580    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
581    pub fn on_modifiers_changed(
582        &mut self,
583        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
584    ) {
585        self.modifiers_changed_listeners.push(Box::new(listener));
586    }
587
588    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element.
589    /// The imperative API equivalent to [`InteractiveElement::on_drop`].
590    ///
591    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
592    pub fn on_drop<T: 'static>(&mut self, listener: impl Fn(&T, &mut Window, &mut App) + 'static) {
593        self.drop_listeners.push((
594            TypeId::of::<T>(),
595            Box::new(move |dragged_value, window, cx| {
596                listener(dragged_value.downcast_ref().unwrap(), window, cx);
597            }),
598        ));
599    }
600
601    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element.
602    /// The imperative API equivalent to [`InteractiveElement::can_drop`].
603    pub fn can_drop(
604        &mut self,
605        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
606    ) {
607        self.can_drop_predicate = Some(Box::new(predicate));
608    }
609
610    /// Bind the given callback to click events of this element.
611    /// The imperative API equivalent to [`StatefulInteractiveElement::on_click`].
612    ///
613    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
614    #[inline(always)]
615    pub fn on_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
616    where
617        Self: Sized,
618    {
619        self.click_listeners.push(Rc::new(listener));
620    }
621
622    /// Bind the given callback to non-primary click events of this element.
623    /// The imperative API equivalent to [`StatefulInteractiveElement::on_aux_click`].
624    ///
625    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
626    pub fn on_aux_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
627    where
628        Self: Sized,
629    {
630        self.aux_click_listeners.push(Rc::new(listener));
631    }
632
633    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
634    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
635    /// the [`Self::on_drag_move`] API.
636    /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`].
637    ///
638    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
639    pub fn on_drag<T, W>(
640        &mut self,
641        value: T,
642        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
643    ) where
644        Self: Sized,
645        T: 'static,
646        W: 'static + Render,
647    {
648        debug_assert!(
649            self.drag_listener.is_none(),
650            "calling on_drag more than once on the same element is not supported"
651        );
652        self.drag_listener = Some(DragListener {
653            value: Arc::new(value),
654            render: Box::new(move |value, offset, window, cx| {
655                constructor(value.downcast_ref().unwrap(), offset, window, cx).into()
656            }),
657            external_payload: None,
658        });
659    }
660
661    /// Registers a callback resolving a payload to offer the platform if a drag started by this
662    /// element leaves the window. It is invoked at most once per drag gesture, when the pointer
663    /// exits the viewport. Must be called after [`Self::on_drag`], with the same dragged value
664    /// type `T`.
665    pub fn external_drag_payload<T>(
666        &mut self,
667        resolver: impl Fn(&T, &mut Window, &mut App) -> Option<ExternalDragPayload> + 'static,
668    ) where
669        Self: Sized,
670        T: 'static,
671    {
672        let Some(drag_listener) = self.drag_listener.as_mut() else {
673            debug_assert!(false, "external_drag_payload must be called after on_drag");
674            return;
675        };
676        debug_assert!(
677            drag_listener.value.as_ref().type_id() == TypeId::of::<T>(),
678            "external_drag_payload must use the same dragged value type as on_drag"
679        );
680        debug_assert!(
681            drag_listener.external_payload.is_none(),
682            "calling external_drag_payload more than once on the same element is not supported"
683        );
684        drag_listener.external_payload = Some(Box::new(move |value, window, cx| {
685            resolver(value.downcast_ref::<T>()?, window, cx)
686        }));
687    }
688
689    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
690    /// passed to the callback is true when the hover starts and false when it ends.
691    /// Transitions caused by layout changes under a stationary mouse also invoke the callback.
692    ///
693    /// By default, keyboard input suppresses hover until the next mouse move, mouse down, or touch. Set
694    /// [`HoverListenerMode::InputModalityIndependent`] with [`Self::hover_listener_mode`] to
695    /// continue hit-testing hover after keyboard input.
696    /// The imperative API equivalent to [`StatefulInteractiveElement::on_hover`].
697    ///
698    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
699    pub fn on_hover(&mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static)
700    where
701        Self: Sized,
702    {
703        debug_assert!(
704            self.hover_listener.is_none(),
705            "calling on_hover more than once on the same element is not supported"
706        );
707        self.hover_listener = Some(Box::new(listener));
708    }
709
710    /// Sets how [`Self::on_hover`] responds to key presses while the mouse is stationary.
711    /// This affects only the hover listener, not hover styles or tooltips. The imperative API
712    /// equivalent to [`StatefulInteractiveElement::hover_listener_mode`].
713    pub fn hover_listener_mode(&mut self, mode: HoverListenerMode)
714    where
715        Self: Sized,
716    {
717        self.hover_listener_mode = mode;
718    }
719
720    /// Constructs a tooltip when the element is hovered or long-pressed.
721    /// The imperative API equivalent to [`StatefulInteractiveElement::tooltip`].
722    pub fn tooltip(&mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static)
723    where
724        Self: Sized,
725    {
726        debug_assert!(
727            self.tooltip_builder.is_none(),
728            "calling tooltip more than once on the same element is not supported"
729        );
730        self.tooltip_builder = Some(TooltipBuilder {
731            build: Rc::new(build_tooltip),
732            hoverable: false,
733        });
734    }
735
736    /// Constructs a tooltip when the element is hovered or long-pressed.
737    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
738    /// the tooltip. The imperative API equivalent to [`StatefulInteractiveElement::hoverable_tooltip`].
739    pub fn hoverable_tooltip(
740        &mut self,
741        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
742    ) where
743        Self: Sized,
744    {
745        debug_assert!(
746            self.tooltip_builder.is_none(),
747            "calling tooltip more than once on the same element is not supported"
748        );
749        self.tooltip_builder = Some(TooltipBuilder {
750            build: Rc::new(build_tooltip),
751            hoverable: true,
752        });
753    }
754
755    /// Sets the delay before this element's tooltip is shown on hover.
756    ///
757    /// Touch long presses show the tooltip immediately once the gesture is recognized.
758    /// The imperative API equivalent to [`StatefulInteractiveElement::tooltip_show_delay`].
759    pub fn tooltip_show_delay(&mut self, delay: Duration) {
760        self.tooltip_show_delay = Some(delay);
761    }
762
763    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
764    /// `block_mouse_except_scroll` should be preferred.
765    ///
766    /// The imperative API equivalent to [`InteractiveElement::occlude`]
767    pub fn occlude_mouse(&mut self) {
768        self.hitbox_behavior = HitboxBehavior::BlockMouse;
769    }
770
771    /// Set the bounds of this element as a window control area for the platform window.
772    /// The imperative API equivalent to [`InteractiveElement::window_control_area`]
773    pub fn window_control_area(&mut self, area: WindowControlArea) {
774        self.window_control = Some(area);
775    }
776
777    /// Block non-scroll mouse interactions with elements behind this element's hitbox.
778    /// The imperative API equivalent to [`InteractiveElement::block_mouse_except_scroll`].
779    ///
780    /// See [`Hitbox::is_hovered`] for details.
781    pub fn block_mouse_except_scroll(&mut self) {
782        self.hitbox_behavior = HitboxBehavior::BlockMouseExceptScroll;
783    }
784
785    fn has_pinch_listeners(&self) -> bool {
786        !self.pinch_listeners.is_empty()
787    }
788}
789
790/// A trait for elements that want to use the standard GPUI event handlers that don't
791/// require any state.
792pub trait InteractiveElement: Sized {
793    /// Retrieve the interactivity state associated with this element
794    fn interactivity(&mut self) -> &mut Interactivity;
795
796    /// Assign this element to a group of elements that can be styled together
797    fn group(mut self, group: impl Into<SharedString>) -> Self {
798        self.interactivity().group = Some(group.into());
799        self
800    }
801
802    /// Assign this element an ID, so that it can be used with interactivity
803    fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
804        self.interactivity().element_id = Some(id.into());
805
806        Stateful { element: self }
807    }
808
809    /// Track the focus state of the given focus handle on this element.
810    /// If the focus handle is focused by the application, this element will
811    /// apply its focused styles.
812    fn track_focus(mut self, focus_handle: &FocusHandle) -> Self {
813        self.interactivity().focusable = true;
814        self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
815        self
816    }
817
818    /// Set whether this element is a tab stop.
819    ///
820    /// When false, the element remains in tab-index order but cannot be reached via keyboard navigation.
821    /// Useful for container elements: focus the container, then call `window.focus_next(cx)` to focus
822    /// the first tab stop inside it while having the container element itself be unreachable via the keyboard.
823    /// Should only be used with `tab_index`.
824    fn tab_stop(mut self, tab_stop: bool) -> Self {
825        self.interactivity().tab_stop = tab_stop;
826        self
827    }
828
829    /// Set index of the tab stop order, and set this node as a tab stop.
830    /// This will default the element to being a tab stop. See [`Self::tab_stop`] for more information.
831    /// This should only be used in conjunction with `tab_group`
832    /// in order to not interfere with the tab index of other elements.
833    fn tab_index(mut self, index: isize) -> Self {
834        self.interactivity().focusable = true;
835        self.interactivity().tab_index = Some(index);
836        self.interactivity().tab_stop = true;
837        self
838    }
839
840    /// Designate this div as a "tab group". Tab groups have their own location in the tab-index order,
841    /// but for children of the tab group, the tab index is reset to 0. This can be useful for swapping
842    /// the order of tab stops within the group, without having to renumber all the tab stops in the whole
843    /// application.
844    fn tab_group(mut self) -> Self {
845        self.interactivity().tab_group = true;
846        if self.interactivity().tab_index.is_none() {
847            self.interactivity().tab_index = Some(0);
848        }
849        self
850    }
851
852    /// Set the keymap context for this element. This will be used to determine
853    /// which action to dispatch from the keymap.
854    fn key_context<C, E>(mut self, key_context: C) -> Self
855    where
856        C: TryInto<KeyContext, Error = E>,
857        E: std::fmt::Display,
858    {
859        if let Some(key_context) = key_context.try_into().log_err() {
860            self.interactivity().key_context = Some(key_context);
861        }
862        self
863    }
864
865    /// Apply the given style to this element when the mouse hovers over it
866    fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
867        debug_assert!(
868            self.interactivity().hover_style.is_none(),
869            "hover style already set"
870        );
871        self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
872        self
873    }
874
875    /// Apply the given style to this element when the mouse hovers over a group member
876    fn group_hover(
877        mut self,
878        group_name: impl Into<SharedString>,
879        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
880    ) -> Self {
881        self.interactivity().group_hover_style = Some(GroupStyle {
882            group: group_name.into(),
883            style: Box::new(f(StyleRefinement::default())),
884        });
885        self
886    }
887
888    /// Bind the given callback to the mouse down event for the given mouse button.
889    /// The fluent API equivalent to [`Interactivity::on_mouse_down`].
890    ///
891    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
892    #[inline(always)]
893    fn on_mouse_down(
894        mut self,
895        button: MouseButton,
896        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
897    ) -> Self {
898        self.interactivity().on_mouse_down(button, listener);
899        self
900    }
901
902    /// Set a key that can be used to look up this element's bounds
903    /// in the [`crate::VisualTestContext::debug_bounds`] map.
904    ///
905    /// Selectors are only recorded in debug builds with the `test-support`
906    /// feature. Elsewhere this is a no-op, so `test-support` can stay enabled
907    /// in release builds without the per-frame cost.
908    #[cfg(any(test, all(debug_assertions, feature = "test-support")))]
909    fn debug_selector(mut self, f: impl FnOnce() -> String) -> Self {
910        self.interactivity().debug_selector = Some(f());
911        self
912    }
913
914    /// Set a key that can be used to look up this element's bounds
915    /// in the [`crate::VisualTestContext::debug_bounds`] map.
916    ///
917    /// Selectors are only recorded in debug builds with the `test-support`
918    /// feature. Elsewhere this is a no-op, so `test-support` can stay enabled
919    /// in release builds without the per-frame cost.
920    #[cfg(not(any(test, all(debug_assertions, feature = "test-support"))))]
921    #[inline]
922    fn debug_selector(self, _: impl FnOnce() -> String) -> Self {
923        self
924    }
925
926    /// Bind the given callback to the mouse down event for any button, during the capture phase.
927    /// The fluent API equivalent to [`Interactivity::capture_any_mouse_down`].
928    ///
929    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
930    fn capture_any_mouse_down(
931        mut self,
932        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
933    ) -> Self {
934        self.interactivity().capture_any_mouse_down(listener);
935        self
936    }
937
938    /// Bind the given callback to the mouse down event for any button, during the capture phase.
939    /// The fluent API equivalent to [`Interactivity::on_any_mouse_down`].
940    ///
941    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
942    fn on_any_mouse_down(
943        mut self,
944        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
945    ) -> Self {
946        self.interactivity().on_any_mouse_down(listener);
947        self
948    }
949
950    /// Bind the given callback to the mouse up event for the given button, during the bubble phase.
951    /// The fluent API equivalent to [`Interactivity::on_mouse_up`].
952    ///
953    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
954    fn on_mouse_up(
955        mut self,
956        button: MouseButton,
957        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
958    ) -> Self {
959        self.interactivity().on_mouse_up(button, listener);
960        self
961    }
962
963    /// Bind the given callback to the mouse up event for any button, during the capture phase.
964    /// The fluent API equivalent to [`Interactivity::capture_any_mouse_up`].
965    ///
966    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
967    fn capture_any_mouse_up(
968        mut self,
969        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
970    ) -> Self {
971        self.interactivity().capture_any_mouse_up(listener);
972        self
973    }
974
975    /// Bind the given callback to the mouse pressure event, during the bubble phase
976    /// the fluent API equivalent to [`Interactivity::on_mouse_pressure`]
977    ///
978    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
979    fn on_mouse_pressure(
980        mut self,
981        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
982    ) -> Self {
983        self.interactivity().on_mouse_pressure(listener);
984        self
985    }
986
987    /// Bind the given callback to the mouse pressure event, during the capture phase
988    /// the fluent API equivalent to [`Interactivity::on_mouse_pressure`]
989    ///
990    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
991    fn capture_mouse_pressure(
992        mut self,
993        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
994    ) -> Self {
995        self.interactivity().capture_mouse_pressure(listener);
996        self
997    }
998
999    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
1000    /// when the mouse is outside of the bounds of this element.
1001    /// The fluent API equivalent to [`Interactivity::on_mouse_down_out`].
1002    ///
1003    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1004    fn on_mouse_down_out(
1005        mut self,
1006        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
1007    ) -> Self {
1008        self.interactivity().on_mouse_down_out(listener);
1009        self
1010    }
1011
1012    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
1013    /// when the mouse is outside of the bounds of this element.
1014    /// The fluent API equivalent to [`Interactivity::on_mouse_up_out`].
1015    ///
1016    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1017    fn on_mouse_up_out(
1018        mut self,
1019        button: MouseButton,
1020        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
1021    ) -> Self {
1022        self.interactivity().on_mouse_up_out(button, listener);
1023        self
1024    }
1025
1026    /// Bind the given callback to the mouse move event, during the bubble phase.
1027    /// The fluent API equivalent to [`Interactivity::on_mouse_move`].
1028    ///
1029    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1030    fn on_mouse_move(
1031        mut self,
1032        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
1033    ) -> Self {
1034        self.interactivity().on_mouse_move(listener);
1035        self
1036    }
1037
1038    /// Bind the given callback to the mouse exit event, during the bubble phase.
1039    /// The fluent API equivalent to [`Interactivity::on_mouse_exit`].
1040    ///
1041    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1042    fn on_mouse_exit(
1043        mut self,
1044        listener: impl Fn(&MouseExitEvent, &mut Window, &mut App) + 'static,
1045    ) -> Self {
1046        self.interactivity().on_mouse_exit(listener);
1047        self
1048    }
1049
1050    /// Bind the given callback to [`FileDropEvent::Exited`] when a platform file drag
1051    /// leaves this element's window while the element is hovered.
1052    ///
1053    /// This is a window-local exit event, not notification that the platform drag session ended.
1054    /// The fluent API equivalent to [`Interactivity::on_file_drop_exit`].
1055    ///
1056    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1057    fn on_file_drop_exit(
1058        mut self,
1059        listener: impl Fn(&FileDropEvent, &mut Window, &mut App) + 'static,
1060    ) -> Self {
1061        self.interactivity().on_file_drop_exit(listener);
1062        self
1063    }
1064
1065    /// Bind the given callback to the mouse drag event of the given type. Note that this
1066    /// will be called for all move events, inside or outside of this element, as long as the
1067    /// drag was started with this element under the mouse. Useful for implementing draggable
1068    /// UIs that don't conform to a drag and drop style interaction, like resizing.
1069    /// The fluent API equivalent to [`Interactivity::on_drag_move`].
1070    ///
1071    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1072    fn on_drag_move<T: 'static>(
1073        mut self,
1074        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
1075    ) -> Self {
1076        self.interactivity().on_drag_move(listener);
1077        self
1078    }
1079
1080    /// Bind the given callback to scroll events during the bubble phase.
1081    /// The fluent API equivalent to [`Interactivity::on_scroll`].
1082    ///
1083    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1084    fn on_scroll(
1085        mut self,
1086        listener: impl Fn(&ScrollEvent, &mut Window, &mut App) + 'static,
1087    ) -> Self {
1088        self.interactivity().on_scroll(listener);
1089        self
1090    }
1091
1092    /// The former name of [`InteractiveElement::on_scroll`].
1093    #[deprecated(note = "renamed to `on_scroll`")]
1094    fn on_scroll_wheel(
1095        self,
1096        listener: impl Fn(&ScrollEvent, &mut Window, &mut App) + 'static,
1097    ) -> Self {
1098        self.on_scroll(listener)
1099    }
1100
1101    /// Bind the given callback to pinch gesture events during the bubble phase.
1102    /// The fluent API equivalent to [`Interactivity::on_pinch`].
1103    ///
1104    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1105    fn on_pinch(mut self, listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static) -> Self {
1106        self.interactivity().on_pinch(listener);
1107        self
1108    }
1109
1110    /// Bind the given callback to back-navigation gestures that start over this
1111    /// element, such as the iOS swipe from the leading screen edge. The innermost
1112    /// element with a back listener claims the gesture and receives every phase.
1113    /// The fluent API equivalent to [`Interactivity::on_back_gesture`].
1114    ///
1115    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1116    fn on_back_gesture(
1117        mut self,
1118        listener: impl Fn(&BackGestureEvent, &mut Window, &mut App) + 'static,
1119    ) -> Self {
1120        self.interactivity().on_back_gesture(listener);
1121        self
1122    }
1123
1124    /// Bind the given callback to pinch gesture events during the capture phase.
1125    /// The fluent API equivalent to [`Interactivity::capture_pinch`].
1126    ///
1127    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1128    fn capture_pinch(
1129        mut self,
1130        listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static,
1131    ) -> Self {
1132        self.interactivity().capture_pinch(listener);
1133        self
1134    }
1135    /// Capture the given action, before normal action dispatch can fire.
1136    /// The fluent API equivalent to [`Interactivity::capture_action`].
1137    ///
1138    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1139    fn capture_action<A: Action>(
1140        mut self,
1141        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
1142    ) -> Self {
1143        self.interactivity().capture_action(listener);
1144        self
1145    }
1146
1147    /// Bind the given callback to an action dispatch during the bubble phase.
1148    /// The fluent API equivalent to [`Interactivity::on_action`].
1149    ///
1150    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1151    #[track_caller]
1152    #[inline(always)]
1153    fn on_action<A: Action>(
1154        mut self,
1155        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
1156    ) -> Self {
1157        self.interactivity().on_action(listener);
1158        self
1159    }
1160
1161    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
1162    /// instead of a type parameter. Useful for component libraries that want to expose
1163    /// action bindings to their users.
1164    /// The fluent API equivalent to [`Interactivity::on_boxed_action`].
1165    ///
1166    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1167    fn on_boxed_action(
1168        mut self,
1169        action: &dyn Action,
1170        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
1171    ) -> Self {
1172        self.interactivity().on_boxed_action(action, listener);
1173        self
1174    }
1175
1176    /// Bind the given callback to key down events during the bubble phase.
1177    /// The fluent API equivalent to [`Interactivity::on_key_down`].
1178    ///
1179    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1180    fn on_key_down(
1181        mut self,
1182        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
1183    ) -> Self {
1184        self.interactivity().on_key_down(listener);
1185        self
1186    }
1187
1188    /// Bind the given callback to key down events during the capture phase.
1189    /// The fluent API equivalent to [`Interactivity::capture_key_down`].
1190    ///
1191    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1192    fn capture_key_down(
1193        mut self,
1194        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
1195    ) -> Self {
1196        self.interactivity().capture_key_down(listener);
1197        self
1198    }
1199
1200    /// Bind the given callback to key up events during the bubble phase.
1201    /// The fluent API equivalent to [`Interactivity::on_key_up`].
1202    ///
1203    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1204    fn on_key_up(
1205        mut self,
1206        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
1207    ) -> Self {
1208        self.interactivity().on_key_up(listener);
1209        self
1210    }
1211
1212    /// Bind the given callback to key up events during the capture phase.
1213    /// The fluent API equivalent to [`Interactivity::capture_key_up`].
1214    ///
1215    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1216    fn capture_key_up(
1217        mut self,
1218        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
1219    ) -> Self {
1220        self.interactivity().capture_key_up(listener);
1221        self
1222    }
1223
1224    /// Bind the given callback to modifiers changing events.
1225    /// The fluent API equivalent to [`Interactivity::on_modifiers_changed`].
1226    ///
1227    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1228    #[inline(always)]
1229    fn on_modifiers_changed(
1230        mut self,
1231        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
1232    ) -> Self {
1233        self.interactivity().on_modifiers_changed(listener);
1234        self
1235    }
1236
1237    /// Apply the given style when the given data type is dragged over this element
1238    fn drag_over<S: 'static>(
1239        mut self,
1240        f: impl 'static + Fn(StyleRefinement, &S, &mut Window, &mut App) -> StyleRefinement,
1241    ) -> Self {
1242        self.interactivity().drag_over_styles.push((
1243            TypeId::of::<S>(),
1244            Box::new(move |currently_dragged: &dyn Any, window, cx| {
1245                f(
1246                    StyleRefinement::default(),
1247                    currently_dragged.downcast_ref::<S>().unwrap(),
1248                    window,
1249                    cx,
1250                )
1251            }),
1252        ));
1253        self
1254    }
1255
1256    /// Apply the given style when the given data type is dragged over this element's group
1257    fn group_drag_over<S: 'static>(
1258        mut self,
1259        group_name: impl Into<SharedString>,
1260        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1261    ) -> Self {
1262        self.interactivity().group_drag_over_styles.push((
1263            TypeId::of::<S>(),
1264            GroupStyle {
1265                group: group_name.into(),
1266                style: Box::new(f(StyleRefinement::default())),
1267            },
1268        ));
1269        self
1270    }
1271
1272    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element.
1273    /// The fluent API equivalent to [`Interactivity::on_drop`].
1274    ///
1275    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1276    fn on_drop<T: 'static>(
1277        mut self,
1278        listener: impl Fn(&T, &mut Window, &mut App) + 'static,
1279    ) -> Self {
1280        self.interactivity().on_drop(listener);
1281        self
1282    }
1283
1284    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element.
1285    /// The fluent API equivalent to [`Interactivity::can_drop`].
1286    fn can_drop(
1287        mut self,
1288        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
1289    ) -> Self {
1290        self.interactivity().can_drop(predicate);
1291        self
1292    }
1293
1294    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
1295    /// `block_mouse_except_scroll` should be preferred.
1296    /// The fluent API equivalent to [`Interactivity::occlude_mouse`].
1297    fn occlude(mut self) -> Self {
1298        self.interactivity().occlude_mouse();
1299        self
1300    }
1301
1302    /// Set the bounds of this element as a window control area for the platform window.
1303    /// The fluent API equivalent to [`Interactivity::window_control_area`].
1304    fn window_control_area(mut self, area: WindowControlArea) -> Self {
1305        self.interactivity().window_control_area(area);
1306        self
1307    }
1308
1309    /// Block non-scroll mouse interactions with elements behind this element's hitbox.
1310    /// The fluent API equivalent to [`Interactivity::block_mouse_except_scroll`].
1311    ///
1312    /// See [`Hitbox::is_hovered`] for details.
1313    fn block_mouse_except_scroll(mut self) -> Self {
1314        self.interactivity().block_mouse_except_scroll();
1315        self
1316    }
1317
1318    /// Set the given styles to be applied when this element, specifically, is focused.
1319    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1320    fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1321    where
1322        Self: Sized,
1323    {
1324        self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
1325        self
1326    }
1327
1328    /// Set the given styles to be applied when this element is inside another element that is focused.
1329    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1330    fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1331    where
1332        Self: Sized,
1333    {
1334        self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
1335        self
1336    }
1337
1338    /// Set the given styles to be applied when this element is focused via keyboard navigation.
1339    /// This is similar to CSS's `:focus-visible` pseudo-class - it only applies when the element
1340    /// is focused AND the user is navigating via keyboard (not mouse clicks).
1341    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1342    fn focus_visible(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1343    where
1344        Self: Sized,
1345    {
1346        self.interactivity().focus_visible_style = Some(Box::new(f(StyleRefinement::default())));
1347        self
1348    }
1349}
1350
1351/// A trait for elements that want to use the standard GPUI interactivity features
1352/// that require state.
1353pub trait StatefulInteractiveElement: InteractiveElement {
1354    /// Set the accessible role for this element.
1355    ///
1356    /// See the [accessibility guide](crate::_accessibility) for an overview.
1357    fn role(mut self, role: accesskit::Role) -> Self {
1358        debug_assert!(
1359            role != accesskit::Role::GenericContainer,
1360            "GenericContainer is filtered out of the a11y tree and has no effect"
1361        );
1362        self.interactivity().override_role = Some(role);
1363        self
1364    }
1365
1366    /// Set the author-provided identifier exposed to accessibility clients.
1367    ///
1368    /// Unlike the GPUI element ID, this value is visible outside the process.
1369    /// Keep it stable and unique within its accessibility tree.
1370    /// AccessKit maps it to platform identifiers where supported, including
1371    /// UIA `AutomationId` on Windows, `AXIdentifier` on macOS, and AT-SPI
1372    /// `AccessibleId` on Linux stacks whose deployed adapter exposes it.
1373    fn accessibility_id(mut self, id: impl Into<SharedString>) -> Self {
1374        self.interactivity().aria.author_id = Some(id.into());
1375        self
1376    }
1377
1378    /// Set the accessible label for this element.
1379    fn aria_label(mut self, label: impl Into<SharedString>) -> Self {
1380        self.interactivity().aria.label = Some(label.into());
1381        self
1382    }
1383
1384    /// Set the accessible description for this element. Unlike the label (which
1385    /// names the element), the description provides supplementary information
1386    /// that assistive technology announces after the name, role, and value -
1387    /// for example a settings subtitle or a hint.
1388    fn aria_description(mut self, description: impl Into<SharedString>) -> Self {
1389        self.interactivity().aria.description = Some(description.into());
1390        self
1391    }
1392
1393    /// Set the keyboard shortcut(s) that activate this element, announced by
1394    /// assistive technology (maps to AccessKit's `keyboard_shortcut`).
1395    ///
1396    /// Note that this does not create a keymap. It simply instructs assistive
1397    /// technology what the keymap is.
1398    fn aria_keyshortcuts(mut self, keyshortcuts: impl Into<SharedString>) -> Self {
1399        self.interactivity().aria.keyshortcuts = Some(keyshortcuts.into());
1400        self
1401    }
1402
1403    /// Report this element as the focused node in the accessibility tree,
1404    /// overriding the element that holds real keyboard focus — but only while
1405    /// one of its ancestors actually holds focus.
1406    ///
1407    /// This implements the `aria-activedescendant` pattern for composite
1408    /// widgets that keep keyboard focus on a container (e.g. a menu or
1409    /// listbox) while a child is "selected": set this on the selected child so
1410    /// assistive technology announces and highlights it as focused.
1411    ///
1412    /// The element must also have a [`role`][Self::role] (and an id) so it
1413    /// produces an accessibility node. Unlike the web's container-side
1414    /// `aria-activedescendant`, this is set on the descendant; GPUI honors it
1415    /// only when a focused ancestor is present in the tree, so it is safe to
1416    /// set unconditionally on the selected child — if the container isn't
1417    /// focused, the claim is ignored.
1418    fn aria_active_descendant(mut self) -> Self {
1419        self.interactivity().report_active_descendant_focus = true;
1420        self
1421    }
1422
1423    /// Contribute synthetic accessibility nodes — nodes that don't correspond
1424    /// to any element — as children of this element's a11y node. For example,
1425    /// text runs describing an editor's text content.
1426    ///
1427    /// The closure is called after this element is prepainted, and only if it
1428    /// contributed a node to the accessibility tree (i.e. it has an id and a
1429    /// [`role`][StatefulInteractiveElement::role]).
1430    ///
1431    /// See [`Element::a11y_synthetic_children`] for details.
1432    fn a11y_synthetic_children(
1433        mut self,
1434        f: impl FnOnce(&mut crate::A11ySubtreeBuilder) + 'static,
1435    ) -> Self {
1436        self.interactivity().a11y_synthetic_children = Some(Box::new(f));
1437        self
1438    }
1439
1440    /// Set the selected state for this element.
1441    fn aria_selected(mut self, selected: bool) -> Self {
1442        self.interactivity().aria.selected = Some(selected);
1443        self
1444    }
1445
1446    /// Set the expanded state for this element.
1447    fn aria_expanded(mut self, expanded: bool) -> Self {
1448        self.interactivity().aria.expanded = Some(expanded);
1449        self
1450    }
1451
1452    /// Set the toggled state for this element.
1453    fn aria_toggled(mut self, toggled: accesskit::Toggled) -> Self {
1454        self.interactivity().aria.toggled = Some(toggled);
1455        self
1456    }
1457
1458    /// Set the numeric value for this element.
1459    fn aria_numeric_value(mut self, value: f64) -> Self {
1460        self.interactivity().aria.numeric_value = Some(value);
1461        self
1462    }
1463
1464    /// Set the step by which assistive technology should expect the numeric
1465    /// value of this element to change (e.g. when incrementing a spin button).
1466    fn aria_numeric_value_step(mut self, step: f64) -> Self {
1467        self.interactivity().aria.numeric_value_step = Some(step);
1468        self
1469    }
1470
1471    /// Set the string value of this element, e.g. the text content of a simple
1472    /// text input.
1473    fn aria_value(mut self, value: impl Into<SharedString>) -> Self {
1474        self.interactivity().aria.value = Some(value.into());
1475        self
1476    }
1477
1478    /// Set the placeholder text reported to assistive technology for this
1479    /// element, shown when a text input is empty.
1480    fn aria_placeholder(mut self, placeholder: impl Into<SharedString>) -> Self {
1481        self.interactivity().aria.placeholder = Some(placeholder.into());
1482        self
1483    }
1484
1485    /// Set the minimum numeric value for this element.
1486    fn aria_min_numeric_value(mut self, value: f64) -> Self {
1487        self.interactivity().aria.min_numeric_value = Some(value);
1488        self
1489    }
1490
1491    /// Set the maximum numeric value for this element.
1492    fn aria_max_numeric_value(mut self, value: f64) -> Self {
1493        self.interactivity().aria.max_numeric_value = Some(value);
1494        self
1495    }
1496
1497    /// Set the orientation of this element.
1498    fn aria_orientation(mut self, orientation: accesskit::Orientation) -> Self {
1499        self.interactivity().aria.orientation = Some(orientation);
1500        self
1501    }
1502
1503    /// Set the heading level of this element.
1504    fn aria_level(mut self, level: usize) -> Self {
1505        self.interactivity().aria.level = Some(level);
1506        self
1507    }
1508
1509    /// Set the position in set of this element.
1510    fn aria_position_in_set(mut self, position: usize) -> Self {
1511        self.interactivity().aria.position_in_set = Some(position);
1512        self
1513    }
1514
1515    /// Set the size of set for this element.
1516    fn aria_size_of_set(mut self, size: usize) -> Self {
1517        self.interactivity().aria.size_of_set = Some(size);
1518        self
1519    }
1520
1521    /// Set the row index for this element.
1522    fn aria_row_index(mut self, index: usize) -> Self {
1523        self.interactivity().aria.row_index = Some(index);
1524        self
1525    }
1526
1527    /// Set the column index for this element.
1528    fn aria_column_index(mut self, index: usize) -> Self {
1529        self.interactivity().aria.column_index = Some(index);
1530        self
1531    }
1532
1533    /// Set the row count for this element.
1534    fn aria_row_count(mut self, count: usize) -> Self {
1535        self.interactivity().aria.row_count = Some(count);
1536        self
1537    }
1538
1539    /// Set the column count for this element.
1540    fn aria_column_count(mut self, count: usize) -> Self {
1541        self.interactivity().aria.column_count = Some(count);
1542        self
1543    }
1544
1545    /// Register a handler for an accessibility action on this element.
1546    /// The handler is called when a screen reader requests the given action.
1547    ///
1548    /// See the [accessibility guide](crate::_accessibility) for an overview.
1549    #[inline(always)]
1550    fn on_a11y_action(
1551        mut self,
1552        action: accesskit::Action,
1553        listener: impl FnMut(Option<&accesskit::ActionData>, &mut crate::Window, &mut crate::App)
1554        + 'static,
1555    ) -> Self {
1556        self.interactivity()
1557            .a11y_action_listeners
1558            .push((action, Box::new(listener)));
1559        self
1560    }
1561
1562    /// Set this element to focusable.
1563    fn focusable(mut self) -> Self {
1564        self.interactivity().focusable = true;
1565        self
1566    }
1567
1568    /// Set the overflow x and y to scroll.
1569    fn overflow_scroll(mut self) -> Self {
1570        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1571        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1572        self
1573    }
1574
1575    /// Set the overflow x to scroll.
1576    fn overflow_x_scroll(mut self) -> Self {
1577        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1578        self
1579    }
1580
1581    /// Set the overflow y to scroll.
1582    fn overflow_y_scroll(mut self) -> Self {
1583        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1584        self
1585    }
1586
1587    /// Restrict scrolling of this element to the axis of the input gesture.
1588    ///
1589    /// See [`Style::restrict_scroll_to_axis`](crate::Style::restrict_scroll_to_axis) for details.
1590    fn restrict_scroll_to_axis(mut self) -> Self {
1591        self.interactivity().base_style.restrict_scroll_to_axis = Some(true);
1592        self
1593    }
1594
1595    /// Track the scroll state of this element with the given handle.
1596    fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
1597        self.interactivity().tracked_scroll_handle = Some(scroll_handle.clone());
1598        self
1599    }
1600
1601    /// Track the scroll state of this element with the given handle.
1602    fn anchor_scroll(mut self, scroll_anchor: Option<ScrollAnchor>) -> Self {
1603        self.interactivity().scroll_anchor = scroll_anchor;
1604        self
1605    }
1606
1607    /// Set the given styles to be applied when this element is active.
1608    fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1609    where
1610        Self: Sized,
1611    {
1612        self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
1613        self
1614    }
1615
1616    /// Set the given styles to be applied when this element's group is active.
1617    fn group_active(
1618        mut self,
1619        group_name: impl Into<SharedString>,
1620        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1621    ) -> Self
1622    where
1623        Self: Sized,
1624    {
1625        self.interactivity().group_active_style = Some(GroupStyle {
1626            group: group_name.into(),
1627            style: Box::new(f(StyleRefinement::default())),
1628        });
1629        self
1630    }
1631
1632    /// Bind the given callback to click events of this element.
1633    /// The fluent API equivalent to [`Interactivity::on_click`].
1634    ///
1635    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1636    #[inline(always)]
1637    fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static) -> Self
1638    where
1639        Self: Sized,
1640    {
1641        self.interactivity().on_click(listener);
1642        self
1643    }
1644
1645    /// Bind the given callback to non-primary click events of this element.
1646    /// The fluent API equivalent to [`Interactivity::on_aux_click`].
1647    ///
1648    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1649    fn on_aux_click(
1650        mut self,
1651        listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static,
1652    ) -> Self
1653    where
1654        Self: Sized,
1655    {
1656        self.interactivity().on_aux_click(listener);
1657        self
1658    }
1659
1660    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
1661    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
1662    /// the [`InteractiveElement::on_drag_move`] API.
1663    /// The callback also has access to the offset of triggering click from the origin of parent element.
1664    /// The fluent API equivalent to [`Interactivity::on_drag`].
1665    ///
1666    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1667    fn on_drag<T, W>(
1668        mut self,
1669        value: T,
1670        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
1671    ) -> Self
1672    where
1673        Self: Sized,
1674        T: 'static,
1675        W: 'static + Render,
1676    {
1677        self.interactivity().on_drag(value, constructor);
1678        self
1679    }
1680
1681    /// Registers a callback resolving a payload to offer the platform if a drag started by this
1682    /// element leaves the window. It is invoked at most once per drag gesture, when the pointer
1683    /// exits the viewport. Must be called after [`Self::on_drag`], with the same dragged value
1684    /// type `T`.
1685    /// The fluent API equivalent to [`Interactivity::external_drag_payload`].
1686    fn external_drag_payload<T>(
1687        mut self,
1688        resolver: impl Fn(&T, &mut Window, &mut App) -> Option<ExternalDragPayload> + 'static,
1689    ) -> Self
1690    where
1691        Self: Sized,
1692        T: 'static,
1693    {
1694        self.interactivity().external_drag_payload(resolver);
1695        self
1696    }
1697
1698    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
1699    /// passed to the callback is true when the hover starts and false when it ends.
1700    /// Transitions caused by layout changes under a stationary mouse also invoke the callback.
1701    ///
1702    /// By default, keyboard input suppresses hover until the next mouse move, mouse down, or touch. Set
1703    /// [`HoverListenerMode::InputModalityIndependent`] with [`Self::hover_listener_mode`] to
1704    /// continue hit-testing hover after keyboard input.
1705    /// The fluent API equivalent to [`Interactivity::on_hover`].
1706    ///
1707    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1708    fn on_hover(mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static) -> Self
1709    where
1710        Self: Sized,
1711    {
1712        self.interactivity().on_hover(listener);
1713        self
1714    }
1715
1716    /// Sets how [`Self::on_hover`] responds to key presses while the mouse is stationary.
1717    /// This affects only the hover listener, not hover styles or tooltips. The fluent API
1718    /// equivalent to [`Interactivity::hover_listener_mode`].
1719    fn hover_listener_mode(mut self, mode: HoverListenerMode) -> Self
1720    where
1721        Self: Sized,
1722    {
1723        self.interactivity().hover_listener_mode(mode);
1724        self
1725    }
1726
1727    /// Constructs a tooltip when the element is hovered or long-pressed.
1728    /// The fluent API equivalent to [`Interactivity::tooltip`].
1729    fn tooltip(mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static) -> Self
1730    where
1731        Self: Sized,
1732    {
1733        self.interactivity().tooltip(build_tooltip);
1734        self
1735    }
1736
1737    /// Constructs a tooltip when the element is hovered or long-pressed.
1738    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
1739    /// the tooltip. The fluent API equivalent to [`Interactivity::hoverable_tooltip`].
1740    fn hoverable_tooltip(
1741        mut self,
1742        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
1743    ) -> Self
1744    where
1745        Self: Sized,
1746    {
1747        self.interactivity().hoverable_tooltip(build_tooltip);
1748        self
1749    }
1750
1751    /// Sets the delay before this element's tooltip is shown on hover.
1752    ///
1753    /// Touch long presses show the tooltip immediately once the gesture is recognized.
1754    /// The fluent API equivalent to [`Interactivity::tooltip_show_delay`].
1755    fn tooltip_show_delay(mut self, delay: Duration) -> Self
1756    where
1757        Self: Sized,
1758    {
1759        self.interactivity().tooltip_show_delay(delay);
1760        self
1761    }
1762}
1763
1764pub(crate) type MouseDownListener =
1765    Box<dyn Fn(&MouseDownEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1766pub(crate) type MouseUpListener =
1767    Box<dyn Fn(&MouseUpEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1768pub(crate) type MousePressureListener =
1769    Box<dyn Fn(&MousePressureEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1770pub(crate) type MouseMoveListener =
1771    Box<dyn Fn(&MouseMoveEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1772pub(crate) type MouseExitListener =
1773    Box<dyn Fn(&MouseExitEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1774
1775pub(crate) type FileDropExitListener =
1776    Box<dyn Fn(&FileDropEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1777
1778pub(crate) type ScrollListener =
1779    Box<dyn Fn(&ScrollEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1780
1781pub(crate) type PinchListener =
1782    Box<dyn Fn(&PinchEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1783
1784pub(crate) type BackGestureListener =
1785    Box<dyn Fn(&BackGestureEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1786
1787pub(crate) type ClickListener = Rc<dyn Fn(&ClickEvent, &mut Window, &mut App) + 'static>;
1788
1789/// Controls how [`StatefulInteractiveElement::on_hover`] responds to key presses while the mouse
1790/// is stationary.
1791#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
1792pub enum HoverListenerMode {
1793    /// Use input-modality-aware hit testing. Keyboard input suppresses hover until the mouse moves
1794    /// again, unless pointer capture or an active mouse-down interaction keeps the listener hovered.
1795    #[default]
1796    InputModalityAware,
1797    /// Use hit testing even when the last input was from the keyboard. This changes only
1798    /// keyboard-modality filtering; all other [`StatefulInteractiveElement::on_hover`] behavior
1799    /// remains unchanged.
1800    InputModalityIndependent,
1801}
1802
1803impl HoverListenerMode {
1804    fn is_hovered(self, hitbox: &Hitbox, window: &Window) -> bool {
1805        match self {
1806            Self::InputModalityAware => hitbox.is_hovered(window),
1807            Self::InputModalityIndependent => hitbox.id.is_hovered_ignoring_last_input(window),
1808        }
1809    }
1810}
1811
1812pub(crate) struct DragListener {
1813    value: Arc<dyn Any>,
1814    render: Box<dyn Fn(&dyn Any, Point<Pixels>, &mut Window, &mut App) -> AnyView + 'static>,
1815    external_payload: Option<ExternalDragPayloadResolver>,
1816}
1817
1818type ExternalDragPayloadResolver =
1819    Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> Option<ExternalDragPayload> + 'static>;
1820
1821type DropListener = Box<dyn Fn(&dyn Any, &mut Window, &mut App) + 'static>;
1822
1823type CanDropPredicate = Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static>;
1824
1825pub(crate) struct TooltipBuilder {
1826    build: Rc<dyn Fn(&mut Window, &mut App) -> AnyView + 'static>,
1827    hoverable: bool,
1828}
1829
1830pub(crate) type KeyDownListener =
1831    Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1832
1833pub(crate) type KeyUpListener =
1834    Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1835
1836pub(crate) type ModifiersChangedListener =
1837    Box<dyn Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static>;
1838
1839pub(crate) type ActionListener =
1840    Box<dyn Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
1841
1842/// Construct a new [`Div`] element
1843#[track_caller]
1844pub fn div() -> Div {
1845    Div {
1846        interactivity: Interactivity::new(),
1847        children: SmallVec::default(),
1848        prepaint_listener: None,
1849        image_cache: None,
1850        prepaint_order_fn: None,
1851    }
1852}
1853
1854/// A [`Div`] element, the all-in-one element for building complex UIs in GPUI
1855pub struct Div {
1856    interactivity: Interactivity,
1857    children: SmallVec<[StackSafe<AnyElement>; 2]>,
1858    prepaint_listener: Option<Box<dyn Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static>>,
1859    image_cache: Option<Box<dyn ImageCacheProvider>>,
1860    prepaint_order_fn: Option<Box<dyn Fn(&mut Window, &mut App) -> SmallVec<[usize; 8]>>>,
1861}
1862
1863impl Div {
1864    /// Add a listener to be called when the children of this `Div` are prepainted.
1865    /// This allows you to store the [`Bounds`] of the children for later use.
1866    pub fn on_children_prepainted(
1867        mut self,
1868        listener: impl Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static,
1869    ) -> Self {
1870        self.prepaint_listener = Some(Box::new(listener));
1871        self
1872    }
1873
1874    /// Add an image cache at the location of this div in the element tree.
1875    pub fn image_cache(mut self, cache: impl ImageCacheProvider) -> Self {
1876        self.image_cache = Some(Box::new(cache));
1877        self
1878    }
1879
1880    /// Specify a function that determines the order in which children are prepainted.
1881    ///
1882    /// The function is called at prepaint time and should return a vector of child indices
1883    /// in the desired prepaint order. Each index should appear exactly once.
1884    ///
1885    /// This is useful when the prepaint of one child affects state that another child reads.
1886    /// For example, in split editor views, the editor with an autoscroll request should
1887    /// be prepainted first so its scroll position update is visible to the other editor.
1888    pub fn with_dynamic_prepaint_order(
1889        mut self,
1890        order_fn: impl Fn(&mut Window, &mut App) -> SmallVec<[usize; 8]> + 'static,
1891    ) -> Self {
1892        self.prepaint_order_fn = Some(Box::new(order_fn));
1893        self
1894    }
1895}
1896
1897/// A frame state for a `Div` element, which contains layout IDs for its children.
1898///
1899/// This struct is used internally by the `Div` element to manage the layout state of its children
1900/// during the UI update cycle. It holds a small vector of `LayoutId` values, each corresponding to
1901/// a child element of the `Div`. These IDs are used to query the layout engine for the computed
1902/// bounds of the children after the layout phase is complete.
1903pub struct DivFrameState {
1904    child_layout_ids: SmallVec<[LayoutId; 2]>,
1905}
1906
1907/// Interactivity state displayed an manipulated in the inspector.
1908#[derive(Clone)]
1909pub struct DivInspectorState {
1910    /// The inspected element's base style. This is used for both inspecting and modifying the
1911    /// state. In the future it will make sense to separate the read and write, possibly tracking
1912    /// the modifications.
1913    #[cfg(any(feature = "inspector", debug_assertions))]
1914    pub base_style: Box<StyleRefinement>,
1915    /// Inspects the bounds of the element.
1916    pub bounds: Bounds<Pixels>,
1917    /// Size of the children of the element, or `bounds.size` if it has no children.
1918    pub content_size: Size<Pixels>,
1919}
1920
1921impl Styled for Div {
1922    fn style(&mut self) -> &mut StyleRefinement {
1923        &mut self.interactivity.base_style
1924    }
1925}
1926
1927impl InteractiveElement for Div {
1928    fn interactivity(&mut self) -> &mut Interactivity {
1929        &mut self.interactivity
1930    }
1931}
1932
1933impl ParentElement for Div {
1934    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1935        #[cfg(feature = "stacker")]
1936        self.children
1937            .extend(elements.into_iter().map(StackSafe::new));
1938        #[cfg(not(feature = "stacker"))]
1939        self.children.extend(elements);
1940    }
1941}
1942
1943impl Element for Div {
1944    type RequestLayoutState = DivFrameState;
1945    type PrepaintState = Option<Hitbox>;
1946
1947    fn id(&self) -> Option<ElementId> {
1948        self.interactivity.element_id.clone()
1949    }
1950
1951    fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
1952        self.interactivity.source_location()
1953    }
1954
1955    fn a11y_role(&self) -> Option<accesskit::Role> {
1956        // Nodes with `GenericContainer` should never be reported to accesskit.
1957        // Equivalent to an HTML div with no role.
1958        self.interactivity
1959            .override_role
1960            .filter(|role| *role != accesskit::Role::GenericContainer)
1961    }
1962
1963    fn write_a11y_info(&self, node: &mut accesskit::Node) {
1964        self.interactivity.write_a11y_info(node);
1965    }
1966
1967    fn a11y_synthetic_children(
1968        &mut self,
1969        _prepaint: &mut Self::PrepaintState,
1970        builder: &mut crate::A11ySubtreeBuilder,
1971    ) {
1972        if let Some(f) = self.interactivity.a11y_synthetic_children.take() {
1973            f(builder);
1974        }
1975    }
1976
1977    #[cfg_attr(feature = "stacker", stacksafe::stacksafe)]
1978    fn request_layout(
1979        &mut self,
1980        global_id: Option<&GlobalElementId>,
1981        inspector_id: Option<&InspectorElementId>,
1982        window: &mut Window,
1983        cx: &mut App,
1984    ) -> (LayoutId, Self::RequestLayoutState) {
1985        let mut child_layout_ids = SmallVec::new();
1986        let image_cache = self
1987            .image_cache
1988            .as_mut()
1989            .map(|provider| provider.provide(window, cx));
1990
1991        let layout_id = window.with_image_cache(image_cache, |window| {
1992            self.interactivity.request_layout(
1993                global_id,
1994                inspector_id,
1995                window,
1996                cx,
1997                |style, window, cx| {
1998                    window.with_text_style(style.text_style().cloned(), |window| {
1999                        child_layout_ids = self
2000                            .children
2001                            .iter_mut()
2002                            .map(|child| child.request_layout(window, cx))
2003                            .collect::<SmallVec<_>>();
2004                        window.request_layout(style, child_layout_ids.iter().copied(), cx)
2005                    })
2006                },
2007            )
2008        });
2009
2010        (layout_id, DivFrameState { child_layout_ids })
2011    }
2012
2013    #[cfg_attr(feature = "stacker", stacksafe::stacksafe)]
2014    fn prepaint(
2015        &mut self,
2016        global_id: Option<&GlobalElementId>,
2017        inspector_id: Option<&InspectorElementId>,
2018        bounds: Bounds<Pixels>,
2019        request_layout: &mut Self::RequestLayoutState,
2020        window: &mut Window,
2021        cx: &mut App,
2022    ) -> Option<Hitbox> {
2023        let image_cache = self
2024            .image_cache
2025            .as_mut()
2026            .map(|provider| provider.provide(window, cx));
2027
2028        let has_prepaint_listener = self.prepaint_listener.is_some();
2029        let mut children_bounds = Vec::with_capacity(if has_prepaint_listener {
2030            request_layout.child_layout_ids.len()
2031        } else {
2032            0
2033        });
2034
2035        let mut child_min = point(Pixels::MAX, Pixels::MAX);
2036        let mut child_max = Point::default();
2037        if let Some(handle) = self.interactivity.scroll_anchor.as_ref() {
2038            *handle.last_origin.borrow_mut() = bounds.origin - window.element_offset();
2039        }
2040        let content_size = if request_layout.child_layout_ids.is_empty() {
2041            bounds.size
2042        } else if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
2043            let mut state = scroll_handle.0.borrow_mut();
2044            state.child_bounds = Vec::with_capacity(request_layout.child_layout_ids.len());
2045            for child_layout_id in &request_layout.child_layout_ids {
2046                let child_bounds = window.layout_bounds(*child_layout_id);
2047                child_min = child_min.min(&child_bounds.origin);
2048                child_max = child_max.max(&child_bounds.bottom_right());
2049                state.child_bounds.push(child_bounds);
2050            }
2051            (child_max - child_min).into()
2052        } else {
2053            for child_layout_id in &request_layout.child_layout_ids {
2054                let child_bounds = window.layout_bounds(*child_layout_id);
2055                child_min = child_min.min(&child_bounds.origin);
2056                child_max = child_max.max(&child_bounds.bottom_right());
2057
2058                if has_prepaint_listener {
2059                    children_bounds.push(child_bounds);
2060                }
2061            }
2062            (child_max - child_min).into()
2063        };
2064
2065        if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
2066            scroll_handle.scroll_to_active_item();
2067        }
2068
2069        self.interactivity.prepaint(
2070            global_id,
2071            inspector_id,
2072            bounds,
2073            content_size,
2074            window,
2075            cx,
2076            |style, scroll_offset, hitbox, window, cx| {
2077                // skip children
2078                if style.display == Display::None {
2079                    return hitbox;
2080                }
2081
2082                window.with_image_cache(image_cache, |window| {
2083                    window.with_element_offset(scroll_offset, |window| {
2084                        if let Some(order_fn) = &self.prepaint_order_fn {
2085                            let order = order_fn(window, cx);
2086                            for idx in order {
2087                                if let Some(child) = self.children.get_mut(idx) {
2088                                    child.prepaint(window, cx);
2089                                }
2090                            }
2091                        } else {
2092                            for child in &mut self.children {
2093                                child.prepaint(window, cx);
2094                            }
2095                        }
2096                    });
2097
2098                    if let Some(listener) = self.prepaint_listener.as_ref() {
2099                        listener(children_bounds, window, cx);
2100                    }
2101                });
2102
2103                hitbox
2104            },
2105        )
2106    }
2107
2108    #[cfg_attr(feature = "stacker", stacksafe::stacksafe)]
2109    fn paint(
2110        &mut self,
2111        global_id: Option<&GlobalElementId>,
2112        inspector_id: Option<&InspectorElementId>,
2113        bounds: Bounds<Pixels>,
2114        _request_layout: &mut Self::RequestLayoutState,
2115        hitbox: &mut Option<Hitbox>,
2116        window: &mut Window,
2117        cx: &mut App,
2118    ) {
2119        let image_cache = self
2120            .image_cache
2121            .as_mut()
2122            .map(|provider| provider.provide(window, cx));
2123
2124        window.with_image_cache(image_cache, |window| {
2125            self.interactivity.paint(
2126                global_id,
2127                inspector_id,
2128                bounds,
2129                hitbox.as_ref(),
2130                window,
2131                cx,
2132                |style, window, cx| {
2133                    // skip children
2134                    if style.display == Display::None {
2135                        return;
2136                    }
2137
2138                    for child in &mut self.children {
2139                        child.paint(window, cx);
2140                    }
2141                },
2142            )
2143        });
2144    }
2145}
2146
2147impl IntoElement for Div {
2148    type Element = Self;
2149
2150    fn into_element(self) -> Self::Element {
2151        self
2152    }
2153}
2154
2155#[derive(Default)]
2156pub(crate) struct AriaProperties {
2157    pub(crate) author_id: Option<SharedString>,
2158    pub(crate) label: Option<SharedString>,
2159    pub(crate) description: Option<SharedString>,
2160    pub(crate) keyshortcuts: Option<SharedString>,
2161    pub(crate) selected: Option<bool>,
2162    pub(crate) expanded: Option<bool>,
2163    pub(crate) toggled: Option<accesskit::Toggled>,
2164    pub(crate) numeric_value: Option<f64>,
2165    pub(crate) min_numeric_value: Option<f64>,
2166    pub(crate) max_numeric_value: Option<f64>,
2167    pub(crate) numeric_value_step: Option<f64>,
2168    pub(crate) value: Option<SharedString>,
2169    pub(crate) placeholder: Option<SharedString>,
2170    pub(crate) orientation: Option<accesskit::Orientation>,
2171    pub(crate) level: Option<usize>,
2172    pub(crate) position_in_set: Option<usize>,
2173    pub(crate) size_of_set: Option<usize>,
2174    pub(crate) row_index: Option<usize>,
2175    pub(crate) column_index: Option<usize>,
2176    pub(crate) row_count: Option<usize>,
2177    pub(crate) column_count: Option<usize>,
2178}
2179
2180/// The interactivity struct. Powers all of the general-purpose
2181/// interactivity in the `Div` element.
2182#[derive(Default)]
2183pub struct Interactivity {
2184    /// The element ID of the element. In id is required to support a stateful subset of the interactivity such as on_click.
2185    pub element_id: Option<ElementId>,
2186    /// Whether the element was clicked. This will only be present after layout.
2187    pub active: Option<bool>,
2188    /// Whether the element was hovered. This will only be present after paint if an hitbox
2189    /// was created for the interactive element.
2190    pub hovered: Option<bool>,
2191    pub(crate) tooltip_id: Option<TooltipId>,
2192    pub(crate) content_size: Size<Pixels>,
2193    pub(crate) key_context: Option<KeyContext>,
2194    pub(crate) focusable: bool,
2195    pub(crate) tracked_focus_handle: Option<FocusHandle>,
2196    pub(crate) tracked_scroll_handle: Option<ScrollHandle>,
2197    pub(crate) scroll_anchor: Option<ScrollAnchor>,
2198    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
2199    pub(crate) ongoing_scroll: Option<Rc<RefCell<OngoingScroll>>>,
2200    pub(crate) group: Option<SharedString>,
2201    /// The base style of the element, before any modifications are applied
2202    /// by focus, active, etc.
2203    pub base_style: Box<StyleRefinement>,
2204    pub(crate) focus_style: Option<Box<StyleRefinement>>,
2205    pub(crate) in_focus_style: Option<Box<StyleRefinement>>,
2206    pub(crate) focus_visible_style: Option<Box<StyleRefinement>>,
2207    pub(crate) hover_style: Option<Box<StyleRefinement>>,
2208    pub(crate) group_hover_style: Option<GroupStyle>,
2209    pub(crate) active_style: Option<Box<StyleRefinement>>,
2210    pub(crate) group_active_style: Option<GroupStyle>,
2211    pub(crate) drag_over_styles: Vec<(
2212        TypeId,
2213        Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> StyleRefinement>,
2214    )>,
2215    pub(crate) group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
2216    pub(crate) mouse_down_listeners: Vec<MouseDownListener>,
2217    pub(crate) mouse_up_listeners: Vec<MouseUpListener>,
2218    pub(crate) mouse_pressure_listeners: Vec<MousePressureListener>,
2219    pub(crate) mouse_move_listeners: Vec<MouseMoveListener>,
2220    pub(crate) mouse_exit_listeners: Vec<MouseExitListener>,
2221    pub(crate) file_drop_exit_listeners: Vec<FileDropExitListener>,
2222    pub(crate) scroll_listeners: Vec<ScrollListener>,
2223    pub(crate) pinch_listeners: Vec<PinchListener>,
2224    pub(crate) back_gesture_listeners: Vec<BackGestureListener>,
2225    pub(crate) key_down_listeners: Vec<KeyDownListener>,
2226    pub(crate) key_up_listeners: Vec<KeyUpListener>,
2227    pub(crate) modifiers_changed_listeners: Vec<ModifiersChangedListener>,
2228    pub(crate) action_listeners: Vec<(TypeId, ActionListener)>,
2229    pub(crate) drop_listeners: Vec<(TypeId, DropListener)>,
2230    pub(crate) can_drop_predicate: Option<CanDropPredicate>,
2231    pub(crate) click_listeners: Vec<ClickListener>,
2232    pub(crate) aux_click_listeners: Vec<ClickListener>,
2233    pub(crate) drag_listener: Option<DragListener>,
2234    pub(crate) hover_listener: Option<Box<dyn Fn(&bool, &mut Window, &mut App)>>,
2235    pub(crate) hover_listener_mode: HoverListenerMode,
2236    pub(crate) tooltip_builder: Option<TooltipBuilder>,
2237    pub(crate) tooltip_show_delay: Option<Duration>,
2238    pub(crate) window_control: Option<WindowControlArea>,
2239    pub(crate) hitbox_behavior: HitboxBehavior,
2240    pub(crate) tab_index: Option<isize>,
2241    pub(crate) tab_group: bool,
2242    pub(crate) tab_stop: bool,
2243
2244    pub(crate) a11y_action_listeners:
2245        Vec<(accesskit::Action, crate::window::a11y::A11yActionListener)>,
2246    pub(crate) a11y_synthetic_children: Option<Box<dyn FnOnce(&mut crate::A11ySubtreeBuilder)>>,
2247    pub(crate) report_active_descendant_focus: bool,
2248    pub(crate) override_role: Option<accesskit::Role>,
2249    pub(crate) aria: AriaProperties,
2250
2251    #[cfg(any(feature = "inspector", debug_assertions))]
2252    pub(crate) source_location: Option<&'static core::panic::Location<'static>>,
2253
2254    #[cfg(any(test, all(debug_assertions, feature = "test-support")))]
2255    pub(crate) debug_selector: Option<String>,
2256}
2257
2258impl Interactivity {
2259    /// Layout this element according to this interactivity state's configured styles
2260    pub fn request_layout(
2261        &mut self,
2262        global_id: Option<&GlobalElementId>,
2263        _inspector_id: Option<&InspectorElementId>,
2264        window: &mut Window,
2265        cx: &mut App,
2266        f: impl FnOnce(Style, &mut Window, &mut App) -> LayoutId,
2267    ) -> LayoutId {
2268        #[cfg(any(feature = "inspector", debug_assertions))]
2269        window.with_inspector_state(
2270            _inspector_id,
2271            cx,
2272            |inspector_state: &mut Option<DivInspectorState>, _window| {
2273                if let Some(inspector_state) = inspector_state {
2274                    self.base_style = inspector_state.base_style.clone();
2275                } else {
2276                    *inspector_state = Some(DivInspectorState {
2277                        base_style: self.base_style.clone(),
2278                        bounds: Default::default(),
2279                        content_size: Default::default(),
2280                    })
2281                }
2282            },
2283        );
2284
2285        window.with_optional_element_state::<InteractiveElementState, _>(
2286            global_id,
2287            |element_state, window| {
2288                let mut element_state =
2289                    element_state.map(|element_state| element_state.unwrap_or_default());
2290
2291                if let Some(element_state) = element_state.as_ref()
2292                    && cx.has_active_drag()
2293                {
2294                    if let Some(pending_mouse_down) = element_state.pending_mouse_down.as_ref() {
2295                        *pending_mouse_down.borrow_mut() = None;
2296                    }
2297                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
2298                        *clicked_state.borrow_mut() = ElementClickedState::default();
2299                    }
2300                }
2301
2302                // Ensure we store a focus handle in our element state if we're focusable.
2303                // If there's an explicit focus handle we're tracking, use that. Otherwise
2304                // create a new handle and store it in the element state, which lives for as
2305                // as frames contain an element with this id.
2306                if self.focusable
2307                    && self.tracked_focus_handle.is_none()
2308                    && let Some(element_state) = element_state.as_mut()
2309                {
2310                    let mut handle = element_state
2311                        .focus_handle
2312                        .get_or_insert_with(|| cx.focus_handle())
2313                        .clone()
2314                        .tab_stop(self.tab_stop);
2315
2316                    if let Some(index) = self.tab_index {
2317                        handle = handle.tab_index(index);
2318                    }
2319
2320                    self.tracked_focus_handle = Some(handle);
2321                }
2322
2323                if let Some(scroll_handle) = self.tracked_scroll_handle.as_ref() {
2324                    let scroll_handle_state = scroll_handle.0.borrow();
2325                    self.scroll_offset = Some(scroll_handle_state.offset.clone());
2326                    self.ongoing_scroll = Some(scroll_handle_state.ongoing_scroll.clone());
2327                } else if (self.base_style.overflow.x == Some(Overflow::Scroll)
2328                    || self.base_style.overflow.y == Some(Overflow::Scroll))
2329                    && let Some(element_state) = element_state.as_mut()
2330                {
2331                    self.scroll_offset = Some(
2332                        element_state
2333                            .scroll_offset
2334                            .get_or_insert_with(Rc::default)
2335                            .clone(),
2336                    );
2337                    self.ongoing_scroll = Some(
2338                        element_state
2339                            .ongoing_scroll
2340                            .get_or_insert_with(|| Rc::new(RefCell::new(OngoingScroll::default())))
2341                            .clone(),
2342                    );
2343                }
2344
2345                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
2346                let layout_id = f(style, window, cx);
2347                (layout_id, element_state)
2348            },
2349        )
2350    }
2351
2352    /// Commit the bounds of this element according to this interactivity state's configured styles.
2353    pub fn prepaint<R>(
2354        &mut self,
2355        global_id: Option<&GlobalElementId>,
2356        _inspector_id: Option<&InspectorElementId>,
2357        bounds: Bounds<Pixels>,
2358        content_size: Size<Pixels>,
2359        window: &mut Window,
2360        cx: &mut App,
2361        f: impl FnOnce(&Style, Point<Pixels>, Option<Hitbox>, &mut Window, &mut App) -> R,
2362    ) -> R {
2363        self.content_size = content_size;
2364
2365        #[cfg(any(feature = "inspector", debug_assertions))]
2366        window.with_inspector_state(
2367            _inspector_id,
2368            cx,
2369            |inspector_state: &mut Option<DivInspectorState>, _window| {
2370                if let Some(inspector_state) = inspector_state {
2371                    inspector_state.bounds = bounds;
2372                    inspector_state.content_size = content_size;
2373                }
2374            },
2375        );
2376
2377        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
2378            window.set_focus_handle(focus_handle, cx);
2379
2380            if window.a11y.is_active() {
2381                if let Some(global_id) = global_id {
2382                    let node_id = global_id.accesskit_node_id();
2383                    window.a11y.set_focusable(node_id, focus_handle.id);
2384                    if focus_handle.is_focused(window) {
2385                        window.a11y.set_focus(node_id);
2386                    }
2387                } else if focus_handle.is_focused(window) {
2388                    // Focusable, but with no element id it can't have an
2389                    // accessibility node, so screen readers fall back to the
2390                    // whole window.
2391                    window
2392                        .a11y
2393                        .note_focus_without_node(focus_handle.id, "it has no element id");
2394                }
2395            }
2396        }
2397
2398        if self.report_active_descendant_focus && window.a11y.is_active() {
2399            if let Some(global_id) = global_id {
2400                window
2401                    .a11y
2402                    .set_active_descendant(global_id.accesskit_node_id());
2403            }
2404        }
2405        window.with_optional_element_state::<InteractiveElementState, _>(
2406            global_id,
2407            |element_state, window| {
2408                let mut element_state =
2409                    element_state.map(|element_state| element_state.unwrap_or_default());
2410                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
2411
2412                if let Some(element_state) = element_state.as_mut() {
2413                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
2414                        let clicked_state = clicked_state.borrow();
2415                        self.active = Some(clicked_state.element);
2416                    }
2417                    if self.hover_style.is_some() || self.group_hover_style.is_some() {
2418                        element_state
2419                            .hover_state
2420                            .get_or_insert_with(Default::default);
2421                    }
2422                    if let Some(active_tooltip) = element_state.active_tooltip.as_ref() {
2423                        if self.tooltip_builder.is_some() {
2424                            self.tooltip_id = set_tooltip_on_window(active_tooltip, window);
2425                        } else {
2426                            // If there is no longer a tooltip builder, remove the active tooltip.
2427                            if let Some(long_press_tooltip_active) =
2428                                element_state.long_press_tooltip_active.as_ref()
2429                            {
2430                                long_press_tooltip_active.set(false);
2431                            }
2432                            element_state.active_tooltip.take();
2433                        }
2434                    }
2435                }
2436
2437                window.with_text_style(style.text_style().cloned(), |window| {
2438                    window.with_content_mask(
2439                        style.overflow_mask(bounds, window.rem_size()),
2440                        |window| {
2441                            let hitbox = if self.should_insert_hitbox(&style, window, cx) {
2442                                Some(window.insert_hitbox(bounds, self.hitbox_behavior))
2443                            } else {
2444                                None
2445                            };
2446
2447                            let scroll_offset =
2448                                self.clamp_scroll_position(bounds, &style, window, cx);
2449                            let result = window.with_element_opacity(style.opacity, |window| {
2450                                f(&style, scroll_offset, hitbox, window, cx)
2451                            });
2452                            (result, element_state)
2453                        },
2454                    )
2455                })
2456            },
2457        )
2458    }
2459
2460    fn should_insert_hitbox(&self, style: &Style, window: &Window, cx: &App) -> bool {
2461        self.hitbox_behavior != HitboxBehavior::Normal
2462            || self.window_control.is_some()
2463            || style.mouse_cursor.is_some()
2464            || self.group.is_some()
2465            || self.scroll_offset.is_some()
2466            || self.tracked_focus_handle.is_some()
2467            || self.hover_style.is_some()
2468            || self.group_hover_style.is_some()
2469            || self.hover_listener.is_some()
2470            || !self.mouse_up_listeners.is_empty()
2471            || !self.mouse_pressure_listeners.is_empty()
2472            || !self.mouse_down_listeners.is_empty()
2473            || !self.mouse_move_listeners.is_empty()
2474            || !self.mouse_exit_listeners.is_empty()
2475            || !self.file_drop_exit_listeners.is_empty()
2476            || !self.click_listeners.is_empty()
2477            || !self.aux_click_listeners.is_empty()
2478            || !self.scroll_listeners.is_empty()
2479            || self.has_pinch_listeners()
2480            || !self.back_gesture_listeners.is_empty()
2481            || self.drag_listener.is_some()
2482            || !self.drop_listeners.is_empty()
2483            || !self.drag_over_styles.is_empty()
2484            || self.tooltip_builder.is_some()
2485            || window.is_inspector_picking(cx)
2486    }
2487
2488    fn clamp_scroll_position(
2489        &self,
2490        bounds: Bounds<Pixels>,
2491        style: &Style,
2492        window: &mut Window,
2493        _cx: &mut App,
2494    ) -> Point<Pixels> {
2495        fn round_to_two_decimals(pixels: Pixels) -> Pixels {
2496            const ROUNDING_FACTOR: f32 = 100.0;
2497            (pixels * ROUNDING_FACTOR).round() / ROUNDING_FACTOR
2498        }
2499
2500        if let Some(scroll_offset) = self.scroll_offset.as_ref() {
2501            let mut scroll_to_bottom = false;
2502            let mut tracked_scroll_handle = self
2503                .tracked_scroll_handle
2504                .as_ref()
2505                .map(|handle| handle.0.borrow_mut());
2506            if let Some(scroll_handle_state) = tracked_scroll_handle.as_deref_mut() {
2507                scroll_handle_state.overflow = style.overflow;
2508                scroll_to_bottom = mem::take(&mut scroll_handle_state.scroll_to_bottom);
2509            }
2510
2511            let rem_size = window.rem_size();
2512            // Taffy lays the box out with the padding snapped to the device pixel
2513            // grid (`to_taffy`); recomputed unsnapped, e.g. py_1 at a fractional
2514            // rem size, it exceeds `bounds` and leaves the box scrollable by the
2515            // sub-pixel difference.
2516            let padding = style
2517                .padding
2518                .to_pixels(bounds.size.into(), rem_size)
2519                .map(|edge| window.pixel_snap(*edge));
2520            let padding_size = size(padding.left + padding.right, padding.top + padding.bottom);
2521            // The floating point values produced by Taffy and ours often vary
2522            // slightly after ~5 decimal places. This can lead to cases where after
2523            // subtracting these, the container becomes scrollable for less than
2524            // 0.00000x pixels. As we generally don't benefit from a precision that
2525            // high for the maximum scroll, we round the scroll max to 2 decimal
2526            // places here.
2527            let padded_content_size = self.content_size + padding_size;
2528            let scroll_max = Point::from(padded_content_size - bounds.size)
2529                .map(round_to_two_decimals)
2530                .max(&Default::default());
2531            // Clamp scroll offset in case scroll max is smaller now (e.g., if children
2532            // were removed or the bounds became larger).
2533            let mut scroll_offset = scroll_offset.borrow_mut();
2534
2535            scroll_offset.x = scroll_offset.x.clamp(-scroll_max.x, px(0.));
2536            if scroll_to_bottom {
2537                scroll_offset.y = -scroll_max.y;
2538            } else {
2539                scroll_offset.y = scroll_offset.y.clamp(-scroll_max.y, px(0.));
2540            }
2541
2542            if let Some(mut scroll_handle_state) = tracked_scroll_handle {
2543                scroll_handle_state.max_offset = scroll_max;
2544                scroll_handle_state.bounds = bounds;
2545            }
2546
2547            *scroll_offset
2548        } else {
2549            Point::default()
2550        }
2551    }
2552
2553    /// Paint this element according to this interactivity state's configured styles
2554    /// and bind the element's mouse and keyboard events.
2555    ///
2556    /// content_size is the size of the content of the element, which may be larger than the
2557    /// element's bounds if the element is scrollable.
2558    ///
2559    /// the final computed style will be passed to the provided function, along
2560    /// with the current scroll offset
2561    pub fn paint(
2562        &mut self,
2563        global_id: Option<&GlobalElementId>,
2564        _inspector_id: Option<&InspectorElementId>,
2565        bounds: Bounds<Pixels>,
2566        hitbox: Option<&Hitbox>,
2567        window: &mut Window,
2568        cx: &mut App,
2569        f: impl FnOnce(&Style, &mut Window, &mut App),
2570    ) {
2571        self.hovered = hitbox.map(|hitbox| hitbox.is_hovered(window));
2572        window.with_optional_element_state::<InteractiveElementState, _>(
2573            global_id,
2574            |element_state, window| {
2575                let mut element_state =
2576                    element_state.map(|element_state| element_state.unwrap_or_default());
2577
2578                let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
2579
2580                #[cfg(any(test, all(debug_assertions, feature = "test-support")))]
2581                if let Some(debug_selector) = &self.debug_selector {
2582                    window
2583                        .next_frame
2584                        .record_debug_bounds(debug_selector.clone(), bounds);
2585                }
2586
2587                self.paint_hover_group_handler(window, cx);
2588
2589                if style.visibility == Visibility::Hidden {
2590                    return ((), element_state);
2591                }
2592
2593                let mut tab_group = None;
2594                if self.tab_group {
2595                    tab_group = self.tab_index;
2596                }
2597
2598                window.with_element_opacity(style.opacity, |window| {
2599                    style.paint(bounds, window, cx, |window: &mut Window, cx: &mut App| {
2600                        window.with_text_style(style.text_style().cloned(), |window| {
2601                            window.with_content_mask(
2602                                style.overflow_mask(bounds, window.rem_size()),
2603                                |window| {
2604                                    window.with_tab_group(tab_group, |window| {
2605                                        // Register the container's own focus handle *inside* its
2606                                        // tab group, so that focusing the container and then
2607                                        // calling `focus_next` descends into this group's first
2608                                        // item. Inserting it before `with_tab_group` would give the
2609                                        // container a shallower tab path than its children; with
2610                                        // sibling groups every container would then sort ahead of
2611                                        // every item, and `focus_next` from a container would jump
2612                                        // to the first item in the whole window instead of its own.
2613                                        if let Some(focus_handle) = &self.tracked_focus_handle {
2614                                            window.next_frame.tab_stops.insert(focus_handle);
2615                                        }
2616                                        if let Some(hitbox) = hitbox {
2617                                            #[cfg(debug_assertions)]
2618                                            self.paint_debug_info(
2619                                                global_id, hitbox, &style, window, cx,
2620                                            );
2621
2622                                            if let Some(drag) = cx.active_drag.as_ref() {
2623                                                if let Some(mouse_cursor) = drag.cursor_style {
2624                                                    window.set_window_cursor_style(mouse_cursor);
2625                                                }
2626                                            } else {
2627                                                if let Some(mouse_cursor) = style.mouse_cursor {
2628                                                    window.set_cursor_style(mouse_cursor, hitbox);
2629                                                }
2630                                            }
2631
2632                                            if let Some(group) = self.group.clone() {
2633                                                GroupHitboxes::push(group, hitbox.id, cx);
2634                                            }
2635
2636                                            if let Some(area) = self.window_control {
2637                                                window.insert_window_control_hitbox(
2638                                                    area,
2639                                                    hitbox.clone(),
2640                                                );
2641                                            }
2642
2643                                            self.paint_mouse_listeners(
2644                                                hitbox,
2645                                                element_state.as_mut(),
2646                                                window,
2647                                                cx,
2648                                            );
2649                                            self.paint_scroll_listener(hitbox, &style, window, cx);
2650                                        }
2651
2652                                        self.paint_keyboard_listeners(window, cx);
2653
2654                                        if window.a11y.is_active() {
2655                                            if let Some(global_id) = global_id {
2656                                                if !self.a11y_action_listeners.is_empty() {
2657                                                    let node_id = global_id.accesskit_node_id();
2658                                                    for (action, listener) in
2659                                                        self.a11y_action_listeners.drain(..)
2660                                                    {
2661                                                        window.on_a11y_action(
2662                                                            node_id, action, listener,
2663                                                        );
2664                                                    }
2665                                                }
2666                                            }
2667                                        }
2668
2669                                        f(&style, window, cx);
2670
2671                                        if let Some(_hitbox) = hitbox {
2672                                            #[cfg(any(feature = "inspector", debug_assertions))]
2673                                            window.insert_inspector_hitbox(
2674                                                _hitbox.id,
2675                                                _inspector_id,
2676                                                cx,
2677                                            );
2678
2679                                            if let Some(group) = self.group.as_ref() {
2680                                                GroupHitboxes::pop(group, cx);
2681                                            }
2682                                        }
2683                                    })
2684                                },
2685                            );
2686                        });
2687                    });
2688                });
2689
2690                ((), element_state)
2691            },
2692        );
2693    }
2694
2695    #[cfg(debug_assertions)]
2696    fn paint_debug_info(
2697        &self,
2698        global_id: Option<&GlobalElementId>,
2699        hitbox: &Hitbox,
2700        style: &Style,
2701        window: &mut Window,
2702        cx: &mut App,
2703    ) {
2704        use crate::{BorderStyle, TextAlign};
2705
2706        if let Some(global_id) = global_id
2707            && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
2708            && hitbox.is_hovered(window)
2709        {
2710            const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
2711            let element_id = format!("{global_id:?}");
2712            let str_len = element_id.len();
2713
2714            let render_debug_text = |window: &mut Window| {
2715                if let Some(text) = window
2716                    .text_system()
2717                    .shape_text(
2718                        element_id.into(),
2719                        FONT_SIZE,
2720                        &[window.text_style().to_run(str_len)],
2721                        None,
2722                        None,
2723                    )
2724                    .ok()
2725                    .and_then(|mut text| text.pop())
2726                {
2727                    text.paint(hitbox.origin, FONT_SIZE, TextAlign::Left, None, window, cx)
2728                        .ok();
2729
2730                    let text_bounds = crate::Bounds {
2731                        origin: hitbox.origin,
2732                        size: text.size(FONT_SIZE),
2733                    };
2734                    if let Some(source_location) = self.source_location
2735                        && text_bounds.contains(&window.mouse_position())
2736                        && window.modifiers().secondary(cx)
2737                    {
2738                        let secondary_held = window.modifiers().secondary(cx);
2739                        window.on_key_event({
2740                            move |e: &crate::ModifiersChangedEvent, _phase, window, cx| {
2741                                if e.modifiers.secondary(cx) != secondary_held
2742                                    && text_bounds.contains(&window.mouse_position())
2743                                {
2744                                    window.refresh();
2745                                }
2746                            }
2747                        });
2748
2749                        let was_hovered = hitbox.is_hovered(window);
2750                        let current_view = window.current_view();
2751                        window.on_mouse_event({
2752                            let hitbox = hitbox.clone();
2753                            move |_: &MouseMoveEvent, phase, window, cx| {
2754                                if phase == DispatchPhase::Capture {
2755                                    let hovered = hitbox.is_hovered(window);
2756                                    if hovered != was_hovered {
2757                                        cx.notify(current_view)
2758                                    }
2759                                }
2760                            }
2761                        });
2762
2763                        window.on_mouse_event({
2764                            let hitbox = hitbox.clone();
2765                            move |e: &crate::MouseDownEvent, phase, window, cx| {
2766                                if text_bounds.contains(&e.position)
2767                                    && phase.capture()
2768                                    && hitbox.is_hovered(window)
2769                                {
2770                                    cx.stop_propagation();
2771                                    let Ok(dir) = std::env::current_dir() else {
2772                                        return;
2773                                    };
2774
2775                                    eprintln!(
2776                                        "This element was created at:\n{}:{}:{}",
2777                                        dir.join(source_location.file()).to_string_lossy(),
2778                                        source_location.line(),
2779                                        source_location.column()
2780                                    );
2781                                }
2782                            }
2783                        });
2784                        window.paint_quad(crate::outline(
2785                            crate::Bounds {
2786                                origin: hitbox.origin
2787                                    + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
2788                                size: crate::Size {
2789                                    width: text_bounds.size.width,
2790                                    height: crate::px(1.),
2791                                },
2792                            },
2793                            crate::red(),
2794                            BorderStyle::default(),
2795                        ))
2796                    }
2797                }
2798            };
2799
2800            window.with_text_style(
2801                Some(crate::TextStyleRefinement {
2802                    color: Some(crate::red()),
2803                    line_height: Some(FONT_SIZE.into()),
2804                    background_color: Some(crate::white()),
2805                    ..Default::default()
2806                }),
2807                render_debug_text,
2808            )
2809        }
2810    }
2811
2812    fn paint_mouse_listeners(
2813        &mut self,
2814        hitbox: &Hitbox,
2815        element_state: Option<&mut InteractiveElementState>,
2816        window: &mut Window,
2817        cx: &mut App,
2818    ) {
2819        let is_focused = self
2820            .tracked_focus_handle
2821            .as_ref()
2822            .map(|handle| handle.is_focused(window))
2823            .unwrap_or(false);
2824
2825        // If this element can be focused, register a mouse down listener
2826        // that will automatically transfer focus when hitting the element.
2827        // This behavior can be suppressed by using `cx.prevent_default()`.
2828        if let Some(focus_handle) = self.tracked_focus_handle.clone() {
2829            let hitbox = hitbox.clone();
2830            window.on_mouse_event(move |_: &MouseDownEvent, phase, window, cx| {
2831                if phase == DispatchPhase::Bubble
2832                    && hitbox.is_hovered(window)
2833                    && !window.default_prevented()
2834                {
2835                    window.focus(&focus_handle, cx);
2836                    // If there is a parent that is also focusable, prevent it
2837                    // from transferring focus because we already did so.
2838                    window.prevent_default();
2839                }
2840            });
2841        }
2842
2843        for listener in self.mouse_down_listeners.drain(..) {
2844            let hitbox = hitbox.clone();
2845            window.on_mouse_event(move |event: &MouseDownEvent, phase, window, cx| {
2846                listener(event, phase, &hitbox, window, cx);
2847            })
2848        }
2849
2850        for listener in self.mouse_up_listeners.drain(..) {
2851            let hitbox = hitbox.clone();
2852            window.on_mouse_event(move |event: &MouseUpEvent, phase, window, cx| {
2853                listener(event, phase, &hitbox, window, cx);
2854            })
2855        }
2856
2857        for listener in self.mouse_pressure_listeners.drain(..) {
2858            let hitbox = hitbox.clone();
2859            window.on_mouse_event(move |event: &MousePressureEvent, phase, window, cx| {
2860                listener(event, phase, &hitbox, window, cx);
2861            })
2862        }
2863
2864        for listener in self.mouse_move_listeners.drain(..) {
2865            let hitbox = hitbox.clone();
2866            window.on_mouse_event(move |event: &MouseMoveEvent, phase, window, cx| {
2867                listener(event, phase, &hitbox, window, cx);
2868            })
2869        }
2870
2871        for listener in self.mouse_exit_listeners.drain(..) {
2872            let hitbox = hitbox.clone();
2873            window.on_mouse_event(move |event: &MouseExitEvent, phase, window, cx| {
2874                listener(event, phase, &hitbox, window, cx);
2875            })
2876        }
2877
2878        for listener in self.file_drop_exit_listeners.drain(..) {
2879            let hitbox = hitbox.clone();
2880            window.on_mouse_event(move |event: &FileDropEvent, phase, window, cx| {
2881                listener(event, phase, &hitbox, window, cx);
2882            })
2883        }
2884
2885        for listener in self.scroll_listeners.drain(..) {
2886            let hitbox = hitbox.clone();
2887            window.on_mouse_event(move |event: &ScrollEvent, phase, window, cx| {
2888                listener(event, phase, &hitbox, window, cx);
2889            })
2890        }
2891
2892        for listener in self.pinch_listeners.drain(..) {
2893            let hitbox = hitbox.clone();
2894            window.on_mouse_event(move |event: &PinchEvent, phase, window, cx| {
2895                listener(event, phase, &hitbox, window, cx);
2896            })
2897        }
2898
2899        for listener in self.back_gesture_listeners.drain(..) {
2900            let hitbox = hitbox.clone();
2901            window.on_mouse_event(move |event: &BackGestureEvent, phase, window, cx| {
2902                listener(event, phase, &hitbox, window, cx);
2903            })
2904        }
2905
2906        if self.hover_style.is_some()
2907            || self.base_style.mouse_cursor.is_some()
2908            || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
2909        {
2910            let hitbox = hitbox.clone();
2911            let hover_state = self.hover_style.as_ref().and_then(|_| {
2912                element_state
2913                    .as_ref()
2914                    .and_then(|state| state.hover_state.as_ref())
2915                    .cloned()
2916            });
2917            let current_view = window.current_view();
2918
2919            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2920                let hovered = hitbox.is_hovered(window);
2921                let was_hovered = hover_state
2922                    .as_ref()
2923                    .is_some_and(|state| state.borrow().element);
2924                if phase == DispatchPhase::Capture && hovered != was_hovered {
2925                    if let Some(hover_state) = &hover_state {
2926                        hover_state.borrow_mut().element = hovered;
2927                        cx.notify(current_view);
2928                    }
2929                }
2930            });
2931        }
2932
2933        if let Some(group_hover) = self.group_hover_style.as_ref() {
2934            if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
2935                let hover_state = element_state
2936                    .as_ref()
2937                    .and_then(|element| element.hover_state.as_ref())
2938                    .cloned();
2939                let current_view = window.current_view();
2940
2941                window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2942                    let group_hovered = group_hitbox_id.is_hovered(window);
2943                    let was_group_hovered = hover_state
2944                        .as_ref()
2945                        .is_some_and(|state| state.borrow().group);
2946                    if phase == DispatchPhase::Capture && group_hovered != was_group_hovered {
2947                        if let Some(hover_state) = &hover_state {
2948                            hover_state.borrow_mut().group = group_hovered;
2949                            cx.notify(current_view);
2950                        }
2951                    }
2952                });
2953            }
2954        }
2955
2956        let drag_cursor_style = self.base_style.as_ref().mouse_cursor;
2957
2958        let mut drag_listener = mem::take(&mut self.drag_listener);
2959        let drop_listeners = mem::take(&mut self.drop_listeners);
2960        let click_listeners = mem::take(&mut self.click_listeners);
2961        let aux_click_listeners = mem::take(&mut self.aux_click_listeners);
2962        let can_drop_predicate = mem::take(&mut self.can_drop_predicate);
2963
2964        if !drop_listeners.is_empty() {
2965            let hitbox = hitbox.clone();
2966            window.on_mouse_event({
2967                move |_: &MouseUpEvent, phase, window, cx| {
2968                    if let Some(drag) = &cx.active_drag
2969                        && phase == DispatchPhase::Bubble
2970                        && hitbox.is_hovered(window)
2971                    {
2972                        let drag_state_type = drag.value.as_ref().type_id();
2973                        for (drop_state_type, listener) in &drop_listeners {
2974                            if *drop_state_type == drag_state_type {
2975                                let drag = cx
2976                                    .active_drag
2977                                    .take()
2978                                    .expect("checked for type drag state type above");
2979
2980                                let mut can_drop = true;
2981                                if let Some(predicate) = &can_drop_predicate {
2982                                    can_drop = predicate(drag.value.as_ref(), window, cx);
2983                                }
2984
2985                                if can_drop {
2986                                    listener(drag.value.as_ref(), window, cx);
2987                                    window.refresh();
2988                                    cx.stop_propagation();
2989                                }
2990                            }
2991                        }
2992                    }
2993                }
2994            });
2995        }
2996
2997        if let Some(element_state) = element_state {
2998            if !click_listeners.is_empty()
2999                || !aux_click_listeners.is_empty()
3000                || drag_listener.is_some()
3001            {
3002                let pending_mouse_down = element_state
3003                    .pending_mouse_down
3004                    .get_or_insert_with(Default::default)
3005                    .clone();
3006
3007                let pending_keyboard_down = element_state
3008                    .pending_keyboard_down
3009                    .get_or_insert_with(Default::default)
3010                    .clone();
3011
3012                let clicked_state = element_state
3013                    .clicked_state
3014                    .get_or_insert_with(Default::default)
3015                    .clone();
3016
3017                window.on_mouse_event({
3018                    let pending_mouse_down = pending_mouse_down.clone();
3019                    let hitbox = hitbox.clone();
3020                    let has_aux_click_listeners = !aux_click_listeners.is_empty();
3021                    move |event: &MouseDownEvent, phase, window, _cx| {
3022                        if phase == DispatchPhase::Bubble
3023                            && (event.button == MouseButton::Left || has_aux_click_listeners)
3024                            && hitbox.is_hovered(window)
3025                        {
3026                            *pending_mouse_down.borrow_mut() = Some(event.clone());
3027                            window.refresh();
3028                        }
3029                    }
3030                });
3031
3032                window.on_mouse_event({
3033                    let pending_mouse_down = pending_mouse_down.clone();
3034                    let hitbox = hitbox.clone();
3035                    move |event: &MouseMoveEvent, phase, window, cx| {
3036                        if phase == DispatchPhase::Capture {
3037                            return;
3038                        }
3039
3040                        let mut pending_mouse_down = pending_mouse_down.borrow_mut();
3041                        if let Some(mouse_down) = pending_mouse_down.clone()
3042                            && !cx.has_active_drag()
3043                            && (event.position - mouse_down.position).magnitude() > DRAG_THRESHOLD
3044                            && let Some(listener) = drag_listener.take()
3045                            && mouse_down.button == MouseButton::Left
3046                        {
3047                            *clicked_state.borrow_mut() = ElementClickedState::default();
3048                            let cursor_offset = event.position - hitbox.origin;
3049                            let drag = (listener.render)(
3050                                listener.value.as_ref(),
3051                                cursor_offset,
3052                                window,
3053                                cx,
3054                            );
3055                            let external_payload_source =
3056                                listener.external_payload.map(|external_payload| {
3057                                    let value = listener.value.clone();
3058                                    Box::new(move |window: &mut Window, cx: &mut App| {
3059                                        external_payload(value.as_ref(), window, cx)
3060                                    })
3061                                        as ExternalDragPayloadSource
3062                                });
3063                            cx.active_drag = Some(AnyDrag {
3064                                view: drag,
3065                                value: listener.value,
3066                                cursor_offset,
3067                                cursor_style: drag_cursor_style,
3068                                external_payload_source,
3069                            });
3070                            pending_mouse_down.take();
3071                            window.refresh();
3072                            cx.stop_propagation();
3073                        }
3074                    }
3075                });
3076
3077                if is_focused {
3078                    // Record the focus generation at which an enter/space key
3079                    // down event happened on this element. The next key up
3080                    // event will be mapped to a click event if both of the
3081                    // following are true:
3082                    // - no other key events happen in between
3083                    // - the focus generation is the same (implying focus did not move)
3084                    //
3085                    // This design avoids an ABA problem that happens if you
3086                    // store the focus handle that registered the keypress.
3087                    window.on_key_event({
3088                        let pending_keyboard_down = pending_keyboard_down.clone();
3089                        move |event: &KeyDownEvent, phase, window, _cx| {
3090                            if phase.bubble() && !window.default_prevented() {
3091                                let stroke = &event.keystroke;
3092                                let is_activation_key = (stroke.key.eq("enter")
3093                                    || stroke.key.eq("space"))
3094                                    && !stroke.modifiers.modified();
3095                                *pending_keyboard_down.borrow_mut() =
3096                                    is_activation_key.then_some(window.focus_generation);
3097                            }
3098                        }
3099                    });
3100
3101                    // Press enter, space to trigger click, when the element is focused.
3102                    window.on_key_event({
3103                        let click_listeners = click_listeners.clone();
3104                        let hitbox = hitbox.clone();
3105                        move |event: &KeyUpEvent, phase, window, cx| {
3106                            if phase.bubble() && !window.default_prevented() {
3107                                let stroke = &event.keystroke;
3108                                let keyboard_button = if stroke.key.eq("enter") {
3109                                    Some(KeyboardButton::Enter)
3110                                } else if stroke.key.eq("space") {
3111                                    Some(KeyboardButton::Space)
3112                                } else {
3113                                    None
3114                                };
3115
3116                                if let Some(button) = keyboard_button
3117                                    && !stroke.modifiers.modified()
3118                                {
3119                                    let pending =
3120                                        std::mem::take(&mut *pending_keyboard_down.borrow_mut());
3121                                    if pending != Some(window.focus_generation) {
3122                                        return;
3123                                    }
3124
3125                                    let click_event = ClickEvent::Keyboard(KeyboardClickEvent {
3126                                        button,
3127                                        bounds: hitbox.bounds,
3128                                    });
3129
3130                                    for listener in &click_listeners {
3131                                        listener(&click_event, window, cx);
3132                                    }
3133                                } else {
3134                                    // Releasing any other key mid-press means
3135                                    // this isn't a clean activation, so cancel
3136                                    // the pending keydown.
3137                                    *pending_keyboard_down.borrow_mut() = None;
3138                                }
3139                            }
3140                        }
3141                    });
3142                }
3143
3144                window.on_mouse_event({
3145                    let mut captured_mouse_down = None;
3146                    let hitbox = hitbox.clone();
3147                    move |event: &MouseUpEvent, phase, window, cx| match phase {
3148                        // Clear the pending mouse down during the capture phase,
3149                        // so that it happens even if another event handler stops
3150                        // propagation.
3151                        DispatchPhase::Capture => {
3152                            let mut pending_mouse_down = pending_mouse_down.borrow_mut();
3153                            if pending_mouse_down.is_some() && hitbox.is_hovered(window) {
3154                                captured_mouse_down = pending_mouse_down.take();
3155                                window.refresh();
3156                            } else if pending_mouse_down.is_some() {
3157                                // Clear the pending mouse down event (without firing click handlers)
3158                                // if the hitbox is not being hovered.
3159                                // This avoids dragging elements that changed their position
3160                                // immediately after being clicked.
3161                                // See https://github.com/zed-industries/zed/issues/24600 for more details
3162                                pending_mouse_down.take();
3163                                window.refresh();
3164                            }
3165                        }
3166                        // Fire click handlers during the bubble phase.
3167                        DispatchPhase::Bubble => {
3168                            if let Some(mouse_down) = captured_mouse_down.take() {
3169                                let btn = mouse_down.button;
3170
3171                                let mouse_click = ClickEvent::Mouse(MouseClickEvent {
3172                                    down: mouse_down,
3173                                    up: event.clone(),
3174                                });
3175
3176                                match btn {
3177                                    MouseButton::Left => {
3178                                        for listener in &click_listeners {
3179                                            listener(&mouse_click, window, cx);
3180                                        }
3181                                    }
3182                                    _ => {
3183                                        for listener in &aux_click_listeners {
3184                                            listener(&mouse_click, window, cx);
3185                                        }
3186                                    }
3187                                }
3188                            }
3189                        }
3190                    }
3191                });
3192            }
3193
3194            if let Some(hover_listener) = self.hover_listener.take() {
3195                let was_hovered = element_state
3196                    .hover_listener_state
3197                    .get_or_insert_with(Default::default)
3198                    .clone();
3199                let has_mouse_down = element_state
3200                    .pending_mouse_down
3201                    .get_or_insert_with(Default::default)
3202                    .clone();
3203                let hover_listener = Rc::new(hover_listener);
3204                let hover_listener_state = was_hovered.clone();
3205                let update_hover = move |is_hovered: bool, window: &mut Window, cx: &mut App| {
3206                    let mut was_hovered = hover_listener_state.borrow_mut();
3207                    if is_hovered != *was_hovered {
3208                        *was_hovered = is_hovered;
3209                        drop(was_hovered);
3210                        hover_listener(&is_hovered, window, cx);
3211                    }
3212                };
3213                let hover_listener_mode = self.hover_listener_mode;
3214
3215                if has_mouse_down.borrow().is_none() {
3216                    let is_hovered =
3217                        !cx.has_active_drag() && hover_listener_mode.is_hovered(hitbox, window);
3218                    if is_hovered != *was_hovered.borrow() {
3219                        let update_hover = update_hover.clone();
3220                        window.defer(cx, move |window, cx| {
3221                            update_hover(is_hovered, window, cx);
3222                        });
3223                    }
3224                }
3225
3226                window.on_mouse_event({
3227                    let update_hover = update_hover.clone();
3228                    let hitbox = hitbox.clone();
3229                    move |_: &MouseMoveEvent, phase, window, cx| {
3230                        if phase == DispatchPhase::Bubble {
3231                            let is_hovered = has_mouse_down.borrow().is_none()
3232                                && !cx.has_active_drag()
3233                                && hover_listener_mode.is_hovered(&hitbox, window);
3234                            update_hover(is_hovered, window, cx);
3235                        }
3236                    }
3237                });
3238
3239                // The pointer can leave the window without a final MouseMove, so also
3240                // clear hover on MouseExited.
3241                window.on_mouse_event(move |_: &MouseExitEvent, phase, window, cx| {
3242                    if phase == DispatchPhase::Bubble {
3243                        update_hover(false, window, cx);
3244                    }
3245                });
3246            }
3247
3248            if let Some(tooltip_builder) = self.tooltip_builder.take() {
3249                let active_tooltip = element_state
3250                    .active_tooltip
3251                    .get_or_insert_with(Default::default)
3252                    .clone();
3253                let pending_mouse_down = element_state
3254                    .pending_mouse_down
3255                    .get_or_insert_with(Default::default)
3256                    .clone();
3257                let long_press_tooltip_active = element_state
3258                    .long_press_tooltip_active
3259                    .get_or_insert_with(Default::default)
3260                    .clone();
3261
3262                let tooltip_is_hoverable = tooltip_builder.hoverable;
3263                let build_tooltip = Rc::new(move |window: &mut Window, cx: &mut App| {
3264                    Some(((tooltip_builder.build)(window, cx), tooltip_is_hoverable))
3265                });
3266                // Use bounds instead of testing hitbox since this is called during prepaint.
3267                let check_is_hovered_during_prepaint = Rc::new({
3268                    let pending_mouse_down = pending_mouse_down.clone();
3269                    let source_bounds = hitbox.bounds;
3270                    move |window: &Window| {
3271                        !window.last_input_was_keyboard()
3272                            && pending_mouse_down.borrow().is_none()
3273                            && source_bounds.contains(&window.mouse_position())
3274                    }
3275                });
3276                let check_is_hovered = Rc::new({
3277                    let hitbox = hitbox.clone();
3278                    move |window: &Window| {
3279                        pending_mouse_down.borrow().is_none() && hitbox.is_hovered(window)
3280                    }
3281                });
3282                register_tooltip_mouse_handlers(
3283                    &active_tooltip,
3284                    self.tooltip_id,
3285                    build_tooltip,
3286                    check_is_hovered,
3287                    check_is_hovered_during_prepaint,
3288                    long_press_tooltip_active,
3289                    self.tooltip_show_delay,
3290                    window,
3291                );
3292            }
3293
3294            // We unconditionally bind both the mouse up and mouse down active state handlers
3295            // Because we might not get a chance to render a frame before the mouse up event arrives.
3296            let active_state = element_state
3297                .clicked_state
3298                .get_or_insert_with(Default::default)
3299                .clone();
3300
3301            {
3302                let active_state = active_state.clone();
3303                window.on_mouse_event(move |_: &MouseUpEvent, phase, window, _cx| {
3304                    if phase == DispatchPhase::Capture && active_state.borrow().is_clicked() {
3305                        *active_state.borrow_mut() = ElementClickedState::default();
3306                        window.refresh();
3307                    }
3308                });
3309            }
3310
3311            {
3312                let active_group_hitbox = self
3313                    .group_active_style
3314                    .as_ref()
3315                    .and_then(|group_active| GroupHitboxes::get(&group_active.group, cx));
3316                let hitbox = hitbox.clone();
3317                window.on_mouse_event(move |_: &MouseDownEvent, phase, window, _cx| {
3318                    if phase == DispatchPhase::Bubble && !window.default_prevented() {
3319                        let group_hovered = active_group_hitbox
3320                            .is_some_and(|group_hitbox_id| group_hitbox_id.is_hovered(window));
3321                        let element_hovered = hitbox.is_hovered(window);
3322                        if group_hovered || element_hovered {
3323                            *active_state.borrow_mut() = ElementClickedState {
3324                                group: group_hovered,
3325                                element: element_hovered,
3326                            };
3327                            window.refresh();
3328                        }
3329                    }
3330                });
3331            }
3332        }
3333    }
3334
3335    fn paint_keyboard_listeners(&mut self, window: &mut Window, _cx: &mut App) {
3336        let key_down_listeners = mem::take(&mut self.key_down_listeners);
3337        let key_up_listeners = mem::take(&mut self.key_up_listeners);
3338        let modifiers_changed_listeners = mem::take(&mut self.modifiers_changed_listeners);
3339        let action_listeners = mem::take(&mut self.action_listeners);
3340        if let Some(context) = self.key_context.clone() {
3341            window.set_key_context(context);
3342        }
3343
3344        for listener in key_down_listeners {
3345            window.on_key_event(move |event: &KeyDownEvent, phase, window, cx| {
3346                listener(event, phase, window, cx);
3347            })
3348        }
3349
3350        for listener in key_up_listeners {
3351            window.on_key_event(move |event: &KeyUpEvent, phase, window, cx| {
3352                listener(event, phase, window, cx);
3353            })
3354        }
3355
3356        for listener in modifiers_changed_listeners {
3357            window.on_modifiers_changed(move |event: &ModifiersChangedEvent, window, cx| {
3358                listener(event, window, cx);
3359            })
3360        }
3361
3362        for (action_type, listener) in action_listeners {
3363            window.on_action(action_type, listener)
3364        }
3365    }
3366
3367    fn paint_hover_group_handler(&self, window: &mut Window, cx: &mut App) {
3368        let group_hitbox = self
3369            .group_hover_style
3370            .as_ref()
3371            .and_then(|group_hover| GroupHitboxes::get(&group_hover.group, cx));
3372
3373        if let Some(group_hitbox) = group_hitbox {
3374            let was_hovered = group_hitbox.is_hovered(window);
3375            let current_view = window.current_view();
3376            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
3377                let hovered = group_hitbox.is_hovered(window);
3378                if phase == DispatchPhase::Capture && hovered != was_hovered {
3379                    cx.notify(current_view);
3380                }
3381            });
3382        }
3383    }
3384
3385    fn paint_scroll_listener(
3386        &self,
3387        hitbox: &Hitbox,
3388        style: &Style,
3389        window: &mut Window,
3390        _cx: &mut App,
3391    ) {
3392        if let Some(scroll_offset) = self.scroll_offset.clone() {
3393            let ongoing_scroll = self.ongoing_scroll.clone();
3394            let overflow = style.overflow;
3395            let allow_concurrent_scroll = style.allow_concurrent_scroll;
3396            let restrict_scroll_to_axis = style.restrict_scroll_to_axis;
3397            let line_height = window.line_height();
3398            let hitbox = hitbox.clone();
3399            let current_view = window.current_view();
3400            window.on_mouse_event(move |event: &ScrollEvent, phase, window, cx| {
3401                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
3402                    let mut scroll_offset = scroll_offset.borrow_mut();
3403                    let old_scroll_offset = *scroll_offset;
3404                    let mut delta = event.delta.pixel_delta(line_height);
3405
3406                    if restrict_scroll_to_axis
3407                        && event.delta.precise()
3408                        && let Some(ongoing_scroll) = &ongoing_scroll
3409                    {
3410                        ongoing_scroll
3411                            .borrow_mut()
3412                            .filter(&mut delta, event.touch_phase);
3413                    }
3414
3415                    let mut delta_x = match overflow.x {
3416                        Overflow::Scroll if !delta.x.is_zero() => delta.x,
3417                        Overflow::Scroll
3418                            if !restrict_scroll_to_axis && overflow.y != Overflow::Scroll =>
3419                        {
3420                            delta.y
3421                        }
3422                        _ => Pixels::ZERO,
3423                    };
3424                    let mut delta_y = match overflow.y {
3425                        Overflow::Scroll if !delta.y.is_zero() => delta.y,
3426                        Overflow::Scroll
3427                            if !restrict_scroll_to_axis && overflow.x != Overflow::Scroll =>
3428                        {
3429                            delta.x
3430                        }
3431                        _ => Pixels::ZERO,
3432                    };
3433                    if !allow_concurrent_scroll && !delta_x.is_zero() && !delta_y.is_zero() {
3434                        if delta_x.abs() > delta_y.abs() {
3435                            delta_y = Pixels::ZERO;
3436                        } else {
3437                            delta_x = Pixels::ZERO;
3438                        }
3439                    }
3440                    scroll_offset.y += delta_y;
3441                    scroll_offset.x += delta_x;
3442                    if *scroll_offset != old_scroll_offset {
3443                        cx.notify(current_view);
3444                    }
3445                }
3446            });
3447        }
3448    }
3449
3450    /// Compute the visual style for this element, based on the current bounds and the element's state.
3451    pub fn compute_style(
3452        &self,
3453        global_id: Option<&GlobalElementId>,
3454        hitbox: Option<&Hitbox>,
3455        window: &mut Window,
3456        cx: &mut App,
3457    ) -> Style {
3458        window.with_optional_element_state(global_id, |element_state, window| {
3459            let mut element_state =
3460                element_state.map(|element_state| element_state.unwrap_or_default());
3461            let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
3462            (style, element_state)
3463        })
3464    }
3465
3466    /// Called from internal methods that have already called with_element_state.
3467    fn compute_style_internal(
3468        &self,
3469        hitbox: Option<&Hitbox>,
3470        element_state: Option<&mut InteractiveElementState>,
3471        window: &mut Window,
3472        cx: &mut App,
3473    ) -> Style {
3474        let mut style = Style::default();
3475        style.refine(&self.base_style);
3476
3477        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
3478            if let Some(in_focus_style) = self.in_focus_style.as_ref()
3479                && focus_handle.within_focused(window, cx)
3480            {
3481                style.refine(in_focus_style);
3482            }
3483
3484            if let Some(focus_style) = self.focus_style.as_ref()
3485                && focus_handle.is_focused(window)
3486            {
3487                style.refine(focus_style);
3488            }
3489
3490            if let Some(focus_visible_style) = self.focus_visible_style.as_ref()
3491                && focus_handle.is_focused(window)
3492                && window.last_input_was_keyboard()
3493            {
3494                style.refine(focus_visible_style);
3495            }
3496        }
3497
3498        if !cx.has_active_drag() {
3499            if let Some(group_hover) = self.group_hover_style.as_ref() {
3500                let is_group_hovered =
3501                    if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
3502                        !window.last_input_was_touch() && group_hitbox_id.is_hovered(window)
3503                    } else if let Some(element_state) = element_state.as_ref() {
3504                        !window.last_input_was_touch()
3505                            && element_state
3506                                .hover_state
3507                                .as_ref()
3508                                .map(|state| state.borrow().group)
3509                                .unwrap_or(false)
3510                    } else {
3511                        false
3512                    };
3513
3514                if is_group_hovered {
3515                    style.refine(&group_hover.style);
3516                }
3517            }
3518
3519            if let Some(hover_style) = self.hover_style.as_ref() {
3520                let is_hovered = if let Some(hitbox) = hitbox {
3521                    !window.last_input_was_touch() && hitbox.is_hovered(window)
3522                } else if let Some(element_state) = element_state.as_ref() {
3523                    !window.last_input_was_touch()
3524                        && element_state
3525                            .hover_state
3526                            .as_ref()
3527                            .map(|state| state.borrow().element)
3528                            .unwrap_or(false)
3529                } else {
3530                    false
3531                };
3532
3533                if is_hovered {
3534                    style.refine(hover_style);
3535                }
3536            }
3537        }
3538
3539        if let Some(hitbox) = hitbox {
3540            if let Some(drag) = cx.active_drag.take() {
3541                let mut can_drop = true;
3542                if let Some(can_drop_predicate) = &self.can_drop_predicate {
3543                    can_drop = can_drop_predicate(drag.value.as_ref(), window, cx);
3544                }
3545
3546                if can_drop {
3547                    for (state_type, group_drag_style) in &self.group_drag_over_styles {
3548                        if let Some(group_hitbox_id) =
3549                            GroupHitboxes::get(&group_drag_style.group, cx)
3550                            && *state_type == drag.value.as_ref().type_id()
3551                            && group_hitbox_id.is_hovered(window)
3552                        {
3553                            style.refine(&group_drag_style.style);
3554                        }
3555                    }
3556
3557                    for (state_type, build_drag_over_style) in &self.drag_over_styles {
3558                        if *state_type == drag.value.as_ref().type_id() && hitbox.is_hovered(window)
3559                        {
3560                            style.refine(&build_drag_over_style(drag.value.as_ref(), window, cx));
3561                        }
3562                    }
3563                }
3564
3565                style.mouse_cursor = drag.cursor_style;
3566                cx.active_drag = Some(drag);
3567            }
3568        }
3569
3570        if let Some(element_state) = element_state {
3571            let clicked_state = element_state
3572                .clicked_state
3573                .get_or_insert_with(Default::default)
3574                .borrow();
3575            if clicked_state.group
3576                && let Some(group) = self.group_active_style.as_ref()
3577            {
3578                style.refine(&group.style)
3579            }
3580
3581            if let Some(active_style) = self.active_style.as_ref()
3582                && clicked_state.element
3583            {
3584                style.refine(active_style)
3585            }
3586        }
3587
3588        style
3589    }
3590
3591    pub(crate) fn write_a11y_info(&self, node: &mut accesskit::Node) {
3592        if let Some(id) = &self.aria.author_id {
3593            node.set_author_id(id.to_string());
3594        }
3595        if let Some(label) = &self.aria.label {
3596            node.set_label(label.to_string());
3597        }
3598        if let Some(description) = &self.aria.description {
3599            node.set_description(description.to_string());
3600        }
3601        if let Some(keyshortcuts) = &self.aria.keyshortcuts {
3602            node.set_keyboard_shortcut(keyshortcuts.to_string());
3603        }
3604        if let Some(selected) = self.aria.selected {
3605            node.set_selected(selected);
3606        }
3607        if let Some(expanded) = self.aria.expanded {
3608            node.set_expanded(expanded);
3609        }
3610        if let Some(toggled) = self.aria.toggled {
3611            node.set_toggled(toggled);
3612        }
3613        if let Some(value) = self.aria.numeric_value {
3614            node.set_numeric_value(value);
3615        }
3616        if let Some(value) = self.aria.min_numeric_value {
3617            node.set_min_numeric_value(value);
3618        }
3619        if let Some(value) = self.aria.max_numeric_value {
3620            node.set_max_numeric_value(value);
3621        }
3622        if let Some(step) = self.aria.numeric_value_step {
3623            node.set_numeric_value_step(step);
3624        }
3625        if let Some(value) = &self.aria.value {
3626            node.set_value(value.to_string());
3627        }
3628        if let Some(placeholder) = &self.aria.placeholder {
3629            node.set_placeholder(placeholder.to_string());
3630        }
3631        if let Some(orientation) = self.aria.orientation {
3632            node.set_orientation(orientation);
3633        }
3634        if let Some(level) = self.aria.level {
3635            node.set_level(level);
3636        }
3637        if let Some(position) = self.aria.position_in_set {
3638            node.set_position_in_set(position);
3639        }
3640        if let Some(size) = self.aria.size_of_set {
3641            node.set_size_of_set(size);
3642        }
3643        if let Some(index) = self.aria.row_index {
3644            node.set_row_index(index);
3645        }
3646        if let Some(index) = self.aria.column_index {
3647            node.set_column_index(index);
3648        }
3649        if let Some(count) = self.aria.row_count {
3650            node.set_row_count(count);
3651        }
3652        if let Some(count) = self.aria.column_count {
3653            node.set_column_count(count);
3654        }
3655        if !self.click_listeners.is_empty() {
3656            node.add_action(accesskit::Action::Click);
3657        }
3658        if self.tracked_focus_handle.is_some() || self.focusable {
3659            node.add_action(accesskit::Action::Focus);
3660        }
3661        for (action, _) in &self.a11y_action_listeners {
3662            node.add_action(*action);
3663        }
3664    }
3665}
3666
3667/// The per-frame state of an interactive element. Used for tracking stateful interactions like clicks
3668/// and scroll offsets.
3669#[derive(Default)]
3670pub struct InteractiveElementState {
3671    pub(crate) focus_handle: Option<FocusHandle>,
3672    pub(crate) clicked_state: Option<Rc<RefCell<ElementClickedState>>>,
3673    pub(crate) hover_state: Option<Rc<RefCell<ElementHoverState>>>,
3674    pub(crate) hover_listener_state: Option<Rc<RefCell<bool>>>,
3675    pub(crate) pending_mouse_down: Option<Rc<RefCell<Option<MouseDownEvent>>>>,
3676    /// Set to the window's [`focus_generation`](crate::Window::focus_generation)
3677    /// when an Enter/Space keydown is received while this element is focused,
3678    /// recording that we are waiting for the matching keyup to fire a keyboard
3679    /// click. On keyup the click only fires if the stored generation still
3680    /// matches the window's current one, i.e. focus never moved during the
3681    /// press (mirroring the browser clearing a control's pressed state on
3682    /// blur). `None` means no activation key is pending.
3683    pub(crate) pending_keyboard_down: Option<Rc<RefCell<Option<u64>>>>,
3684    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
3685    ongoing_scroll: Option<Rc<RefCell<OngoingScroll>>>,
3686    pub(crate) active_tooltip: Option<Rc<RefCell<Option<ActiveTooltip>>>>,
3687    long_press_tooltip_active: Option<Rc<Cell<bool>>>,
3688}
3689
3690/// Whether or not the element or a group that contains it is clicked by the mouse.
3691#[derive(Copy, Clone, Default, Eq, PartialEq)]
3692pub struct ElementClickedState {
3693    /// True if this element's group has been clicked, false otherwise
3694    pub group: bool,
3695
3696    /// True if this element has been clicked, false otherwise
3697    pub element: bool,
3698}
3699
3700impl ElementClickedState {
3701    fn is_clicked(&self) -> bool {
3702        self.group || self.element
3703    }
3704}
3705
3706/// Whether or not the element or a group that contains it is hovered.
3707#[derive(Copy, Clone, Default, Eq, PartialEq)]
3708pub struct ElementHoverState {
3709    /// True if this element's group is hovered, false otherwise
3710    pub group: bool,
3711
3712    /// True if this element is hovered, false otherwise
3713    pub element: bool,
3714}
3715
3716pub(crate) enum ActiveTooltip {
3717    /// Currently delaying before showing the tooltip.
3718    WaitingForShow { _task: Task<()> },
3719    /// Tooltip is visible, element was hovered or for hoverable tooltips, the tooltip was hovered.
3720    Visible {
3721        tooltip: AnyTooltip,
3722        is_hoverable: bool,
3723    },
3724    /// Tooltip is visible and hoverable, but the mouse is no longer hovering. Currently delaying
3725    /// before hiding it.
3726    WaitingForHide {
3727        tooltip: AnyTooltip,
3728        _task: Task<()>,
3729    },
3730}
3731
3732pub(crate) fn clear_active_tooltip(
3733    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3734    window: &mut Window,
3735) {
3736    match active_tooltip.borrow_mut().take() {
3737        None => {}
3738        Some(ActiveTooltip::WaitingForShow { .. }) => {}
3739        Some(ActiveTooltip::Visible { .. }) => window.refresh(),
3740        Some(ActiveTooltip::WaitingForHide { .. }) => window.refresh(),
3741    }
3742}
3743
3744pub(crate) fn clear_active_tooltip_if_not_hoverable(
3745    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3746    window: &mut Window,
3747) {
3748    let should_clear = match active_tooltip.borrow().as_ref() {
3749        None => false,
3750        Some(ActiveTooltip::WaitingForShow { .. }) => false,
3751        Some(ActiveTooltip::Visible { is_hoverable, .. }) => !is_hoverable,
3752        Some(ActiveTooltip::WaitingForHide { .. }) => false,
3753    };
3754    if should_clear {
3755        active_tooltip.borrow_mut().take();
3756        window.refresh();
3757    }
3758}
3759
3760pub(crate) fn set_tooltip_on_window(
3761    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3762    window: &mut Window,
3763) -> Option<TooltipId> {
3764    let tooltip = match active_tooltip.borrow().as_ref() {
3765        None => return None,
3766        Some(ActiveTooltip::WaitingForShow { .. }) => return None,
3767        Some(ActiveTooltip::Visible { tooltip, .. }) => tooltip.clone(),
3768        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => tooltip.clone(),
3769    };
3770    Some(window.set_tooltip(tooltip))
3771}
3772
3773pub(crate) fn register_tooltip_mouse_handlers(
3774    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3775    tooltip_id: Option<TooltipId>,
3776    build_tooltip: Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
3777    check_is_hovered: Rc<dyn Fn(&Window) -> bool>,
3778    check_is_hovered_during_prepaint: Rc<dyn Fn(&Window) -> bool>,
3779    long_press_tooltip_active: Rc<Cell<bool>>,
3780    show_delay: Option<Duration>,
3781    window: &mut Window,
3782) {
3783    let current_view = window.current_view();
3784    let show_delay = show_delay.unwrap_or(DEFAULT_TOOLTIP_SHOW_DELAY);
3785
3786    window.on_mouse_event({
3787        let active_tooltip = active_tooltip.clone();
3788        let build_tooltip = build_tooltip.clone();
3789        let check_is_hovered = check_is_hovered.clone();
3790        let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
3791        move |_: &MouseMoveEvent, phase, window, cx| {
3792            handle_tooltip_mouse_move(
3793                &active_tooltip,
3794                &build_tooltip,
3795                &check_is_hovered,
3796                &check_is_hovered_during_prepaint,
3797                tooltip_id,
3798                current_view,
3799                phase,
3800                show_delay,
3801                window,
3802                cx,
3803            )
3804        }
3805    });
3806
3807    window.on_mouse_event({
3808        let active_tooltip = active_tooltip.clone();
3809        move |_: &MouseDownEvent, _phase, window: &mut Window, _cx| {
3810            if !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)) {
3811                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
3812            }
3813        }
3814    });
3815
3816    window.on_mouse_event({
3817        let active_tooltip = active_tooltip.clone();
3818        let build_tooltip = build_tooltip.clone();
3819        let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
3820        move |event: &LongPressEvent, phase, window, cx| {
3821            if !phase.bubble() {
3822                return;
3823            }
3824
3825            match event.phase {
3826                TouchPhase::Started if !window.default_prevented() && check_is_hovered(window) => {
3827                    if show_tooltip(
3828                        &active_tooltip,
3829                        &build_tooltip,
3830                        &check_is_hovered_during_prepaint,
3831                        Some(long_press_tooltip_active.clone()),
3832                        window,
3833                        cx,
3834                    ) {
3835                        long_press_tooltip_active.set(true);
3836                        window.prevent_default();
3837                        cx.stop_propagation();
3838                    }
3839                }
3840                TouchPhase::Ended | TouchPhase::Cancelled
3841                    if long_press_tooltip_active.replace(false) =>
3842                {
3843                    clear_active_tooltip(&active_tooltip, window);
3844                    cx.stop_propagation();
3845                }
3846                TouchPhase::Started
3847                | TouchPhase::Moved
3848                | TouchPhase::Ended
3849                | TouchPhase::Cancelled => {}
3850            }
3851        }
3852    });
3853
3854    window.on_mouse_event({
3855        let active_tooltip = active_tooltip.clone();
3856        move |_: &ScrollEvent, _phase, window: &mut Window, _cx| {
3857            if !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)) {
3858                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
3859            }
3860        }
3861    });
3862}
3863
3864/// Handles displaying tooltips when an element is hovered.
3865///
3866/// The mouse hovering logic also relies on being called from window prepaint in order to handle the
3867/// case where the element the tooltip is on is not rendered - in that case its mouse listeners are
3868/// also not registered. During window prepaint, the hitbox information is not available, so
3869/// `check_is_hovered_during_prepaint` is used which bases the check off of the absolute bounds of
3870/// the element.
3871///
3872/// TODO: There's a minor bug due to the use of absolute bounds while checking during prepaint - it
3873/// does not know if the hitbox is occluded. In the case where a tooltip gets displayed and then
3874/// gets occluded after display, it will stick around until the mouse exits the hover bounds.
3875fn handle_tooltip_mouse_move(
3876    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3877    build_tooltip: &Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
3878    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
3879    check_is_hovered_during_prepaint: &Rc<dyn Fn(&Window) -> bool>,
3880    tooltip_id: Option<TooltipId>,
3881    current_view: EntityId,
3882    phase: DispatchPhase,
3883    show_delay: Duration,
3884    window: &mut Window,
3885    cx: &mut App,
3886) {
3887    // Separates logic for what mutation should occur from applying it, to avoid overlapping
3888    // RefCell borrows.
3889    enum Action {
3890        None,
3891        CancelShow,
3892        ScheduleShow,
3893        CheckVisible,
3894    }
3895
3896    let action = match active_tooltip.borrow().as_ref() {
3897        None => {
3898            let is_hovered = check_is_hovered(window);
3899            if is_hovered && phase.bubble() {
3900                Action::ScheduleShow
3901            } else {
3902                Action::None
3903            }
3904        }
3905        Some(ActiveTooltip::WaitingForShow { .. }) => {
3906            let is_hovered = check_is_hovered(window);
3907            if is_hovered {
3908                Action::None
3909            } else {
3910                Action::CancelShow
3911            }
3912        }
3913        Some(ActiveTooltip::Visible { is_hoverable, .. }) => {
3914            if phase.capture()
3915                && !check_is_hovered(window)
3916                && (!*is_hoverable
3917                    || !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)))
3918            {
3919                Action::CheckVisible
3920            } else {
3921                Action::None
3922            }
3923        }
3924        Some(ActiveTooltip::WaitingForHide { .. }) => {
3925            if phase.capture()
3926                && (check_is_hovered(window)
3927                    || tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)))
3928            {
3929                Action::CheckVisible
3930            } else {
3931                Action::None
3932            }
3933        }
3934    };
3935
3936    match action {
3937        Action::None => {}
3938        Action::CancelShow => {
3939            // Cancel waiting to show tooltip when it is no longer hovered.
3940            active_tooltip.borrow_mut().take();
3941        }
3942        Action::ScheduleShow => {
3943            let delayed_show_task = window.spawn(cx, {
3944                let weak_active_tooltip = Rc::downgrade(active_tooltip);
3945                let build_tooltip = build_tooltip.clone();
3946                let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
3947                async move |cx| {
3948                    cx.background_executor().timer(show_delay).await;
3949                    let Some(active_tooltip) = weak_active_tooltip.upgrade() else {
3950                        return;
3951                    };
3952                    cx.update(|window, cx| {
3953                        show_tooltip(
3954                            &active_tooltip,
3955                            &build_tooltip,
3956                            &check_is_hovered_during_prepaint,
3957                            None,
3958                            window,
3959                            cx,
3960                        );
3961                    })
3962                    .ok();
3963                }
3964            });
3965            active_tooltip
3966                .borrow_mut()
3967                .replace(ActiveTooltip::WaitingForShow {
3968                    _task: delayed_show_task,
3969                });
3970        }
3971        Action::CheckVisible => cx.notify(current_view),
3972    }
3973}
3974
3975fn show_tooltip(
3976    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3977    build_tooltip: &Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
3978    check_is_hovered_during_prepaint: &Rc<dyn Fn(&Window) -> bool>,
3979    long_press_tooltip_active: Option<Rc<Cell<bool>>>,
3980    window: &mut Window,
3981    cx: &mut App,
3982) -> bool {
3983    let new_tooltip = build_tooltip(window, cx).map(|(view, tooltip_is_hoverable)| {
3984        let weak_active_tooltip = Rc::downgrade(active_tooltip);
3985        let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
3986        ActiveTooltip::Visible {
3987            tooltip: AnyTooltip {
3988                view,
3989                mouse_position: window.mouse_position(),
3990                check_visible_and_update: Rc::new(move |tooltip_bounds, window, cx| {
3991                    if long_press_tooltip_active
3992                        .as_ref()
3993                        .is_some_and(|active| active.get())
3994                    {
3995                        return true;
3996                    }
3997                    let Some(active_tooltip) = weak_active_tooltip.upgrade() else {
3998                        return false;
3999                    };
4000                    handle_tooltip_check_visible_and_update(
4001                        &active_tooltip,
4002                        tooltip_is_hoverable,
4003                        &check_is_hovered_during_prepaint,
4004                        tooltip_bounds,
4005                        window,
4006                        cx,
4007                    )
4008                }),
4009            },
4010            is_hoverable: tooltip_is_hoverable,
4011        }
4012    });
4013    let did_show = new_tooltip.is_some();
4014    *active_tooltip.borrow_mut() = new_tooltip;
4015    window.refresh();
4016    did_show
4017}
4018
4019/// Returns a callback which will be called by window prepaint to update tooltip visibility. The
4020/// purpose of doing this logic here instead of the mouse move handler is that the mouse move
4021/// handler won't get called when the element is not painted (e.g. via use of `visible_on_hover`).
4022fn handle_tooltip_check_visible_and_update(
4023    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
4024    tooltip_is_hoverable: bool,
4025    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
4026    tooltip_bounds: Bounds<Pixels>,
4027    window: &mut Window,
4028    cx: &mut App,
4029) -> bool {
4030    // Separates logic for what mutation should occur from applying it, to avoid overlapping RefCell
4031    // borrows.
4032    enum Action {
4033        None,
4034        Hide,
4035        ScheduleHide(AnyTooltip),
4036        CancelHide(AnyTooltip),
4037    }
4038
4039    let is_hovered = check_is_hovered(window)
4040        || (tooltip_is_hoverable && tooltip_bounds.contains(&window.mouse_position()));
4041    let action = match active_tooltip.borrow().as_ref() {
4042        Some(ActiveTooltip::Visible { tooltip, .. }) => {
4043            if is_hovered {
4044                Action::None
4045            } else {
4046                if tooltip_is_hoverable {
4047                    Action::ScheduleHide(tooltip.clone())
4048                } else {
4049                    Action::Hide
4050                }
4051            }
4052        }
4053        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => {
4054            if is_hovered {
4055                Action::CancelHide(tooltip.clone())
4056            } else {
4057                Action::None
4058            }
4059        }
4060        None | Some(ActiveTooltip::WaitingForShow { .. }) => Action::None,
4061    };
4062
4063    match action {
4064        Action::None => {}
4065        Action::Hide => clear_active_tooltip(active_tooltip, window),
4066        Action::ScheduleHide(tooltip) => {
4067            let delayed_hide_task = window.spawn(cx, {
4068                let weak_active_tooltip = Rc::downgrade(active_tooltip);
4069                async move |cx| {
4070                    cx.background_executor()
4071                        .timer(HOVERABLE_TOOLTIP_HIDE_DELAY)
4072                        .await;
4073                    let Some(active_tooltip) = weak_active_tooltip.upgrade() else {
4074                        return;
4075                    };
4076                    if active_tooltip.borrow_mut().take().is_some() {
4077                        cx.update(|window, _cx| window.refresh()).ok();
4078                    }
4079                }
4080            });
4081            active_tooltip
4082                .borrow_mut()
4083                .replace(ActiveTooltip::WaitingForHide {
4084                    tooltip,
4085                    _task: delayed_hide_task,
4086                });
4087        }
4088        Action::CancelHide(tooltip) => {
4089            // Cancel waiting to hide tooltip when it becomes hovered.
4090            active_tooltip.borrow_mut().replace(ActiveTooltip::Visible {
4091                tooltip,
4092                is_hoverable: true,
4093            });
4094        }
4095    }
4096
4097    active_tooltip.borrow().is_some()
4098}
4099
4100#[derive(Default)]
4101pub(crate) struct GroupHitboxes(HashMap<SharedString, SmallVec<[HitboxId; 1]>>);
4102
4103impl Global for GroupHitboxes {}
4104
4105impl GroupHitboxes {
4106    pub fn get(name: &SharedString, cx: &mut App) -> Option<HitboxId> {
4107        cx.default_global::<Self>()
4108            .0
4109            .get(name)
4110            .and_then(|bounds_stack| bounds_stack.last())
4111            .cloned()
4112    }
4113
4114    pub fn push(name: SharedString, hitbox_id: HitboxId, cx: &mut App) {
4115        cx.default_global::<Self>()
4116            .0
4117            .entry(name)
4118            .or_default()
4119            .push(hitbox_id);
4120    }
4121
4122    pub fn pop(name: &SharedString, cx: &mut App) {
4123        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
4124    }
4125}
4126
4127/// A wrapper around an element that can store state, produced after assigning an ElementId.
4128pub struct Stateful<E> {
4129    pub(crate) element: E,
4130}
4131
4132impl<E> Styled for Stateful<E>
4133where
4134    E: Styled,
4135{
4136    fn style(&mut self) -> &mut StyleRefinement {
4137        self.element.style()
4138    }
4139}
4140
4141impl<E> StatefulInteractiveElement for Stateful<E>
4142where
4143    E: Element,
4144    Self: InteractiveElement,
4145{
4146}
4147
4148impl<E> InteractiveElement for Stateful<E>
4149where
4150    E: InteractiveElement,
4151{
4152    fn interactivity(&mut self) -> &mut Interactivity {
4153        self.element.interactivity()
4154    }
4155}
4156
4157impl<E> Element for Stateful<E>
4158where
4159    E: Element,
4160{
4161    type RequestLayoutState = E::RequestLayoutState;
4162    type PrepaintState = E::PrepaintState;
4163
4164    fn id(&self) -> Option<ElementId> {
4165        self.element.id()
4166    }
4167
4168    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
4169        self.element.source_location()
4170    }
4171
4172    fn a11y_role(&self) -> Option<accesskit::Role> {
4173        self.element.a11y_role()
4174    }
4175
4176    fn write_a11y_info(&self, node: &mut accesskit::Node) {
4177        self.element.write_a11y_info(node);
4178    }
4179
4180    fn a11y_synthetic_children(
4181        &mut self,
4182        prepaint: &mut Self::PrepaintState,
4183        builder: &mut crate::A11ySubtreeBuilder,
4184    ) {
4185        self.element.a11y_synthetic_children(prepaint, builder);
4186    }
4187
4188    fn request_layout(
4189        &mut self,
4190        id: Option<&GlobalElementId>,
4191        inspector_id: Option<&InspectorElementId>,
4192        window: &mut Window,
4193        cx: &mut App,
4194    ) -> (LayoutId, Self::RequestLayoutState) {
4195        self.element.request_layout(id, inspector_id, window, cx)
4196    }
4197
4198    fn prepaint(
4199        &mut self,
4200        id: Option<&GlobalElementId>,
4201        inspector_id: Option<&InspectorElementId>,
4202        bounds: Bounds<Pixels>,
4203        state: &mut Self::RequestLayoutState,
4204        window: &mut Window,
4205        cx: &mut App,
4206    ) -> E::PrepaintState {
4207        self.element
4208            .prepaint(id, inspector_id, bounds, state, window, cx)
4209    }
4210
4211    fn paint(
4212        &mut self,
4213        id: Option<&GlobalElementId>,
4214        inspector_id: Option<&InspectorElementId>,
4215        bounds: Bounds<Pixels>,
4216        request_layout: &mut Self::RequestLayoutState,
4217        prepaint: &mut Self::PrepaintState,
4218        window: &mut Window,
4219        cx: &mut App,
4220    ) {
4221        self.element.paint(
4222            id,
4223            inspector_id,
4224            bounds,
4225            request_layout,
4226            prepaint,
4227            window,
4228            cx,
4229        );
4230    }
4231}
4232
4233impl<E> IntoElement for Stateful<E>
4234where
4235    E: Element,
4236{
4237    type Element = Self;
4238
4239    fn into_element(self) -> Self::Element {
4240        self
4241    }
4242}
4243
4244impl<E> ParentElement for Stateful<E>
4245where
4246    E: ParentElement,
4247{
4248    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
4249        self.element.extend(elements)
4250    }
4251}
4252
4253/// Represents an element that can be scrolled *to* in its parent element.
4254/// Contrary to [ScrollHandle::scroll_to_active_item], an anchored element does not have to be an immediate child of the parent.
4255#[derive(Clone)]
4256pub struct ScrollAnchor {
4257    handle: ScrollHandle,
4258    last_origin: Rc<RefCell<Point<Pixels>>>,
4259}
4260
4261impl ScrollAnchor {
4262    /// Creates a [ScrollAnchor] associated with a given [ScrollHandle].
4263    pub fn for_handle(handle: ScrollHandle) -> Self {
4264        Self {
4265            handle,
4266            last_origin: Default::default(),
4267        }
4268    }
4269    /// Request scroll to this item on the next frame.
4270    pub fn scroll_to(&self, window: &mut Window, _cx: &mut App) {
4271        let this = self.clone();
4272
4273        window.on_next_frame(move |_, _| {
4274            let viewport_bounds = this.handle.bounds();
4275            let self_bounds = *this.last_origin.borrow();
4276            this.handle.set_offset(viewport_bounds.origin - self_bounds);
4277        });
4278    }
4279}
4280
4281#[derive(Default, Debug)]
4282struct ScrollHandleState {
4283    offset: Rc<RefCell<Point<Pixels>>>,
4284    ongoing_scroll: Rc<RefCell<OngoingScroll>>,
4285    bounds: Bounds<Pixels>,
4286    max_offset: Point<Pixels>,
4287    child_bounds: Vec<Bounds<Pixels>>,
4288    scroll_to_bottom: bool,
4289    overflow: Point<Overflow>,
4290    active_item: Option<ScrollActiveItem>,
4291}
4292
4293#[derive(Default, Debug, Clone, Copy)]
4294struct ScrollActiveItem {
4295    index: usize,
4296    strategy: ScrollStrategy,
4297}
4298
4299#[derive(Default, Debug, Clone, Copy)]
4300enum ScrollStrategy {
4301    #[default]
4302    FirstVisible,
4303    Top,
4304}
4305
4306/// A handle to the scrollable aspects of an element.
4307/// Used for accessing scroll state, like the current scroll offset,
4308/// and for mutating the scroll state, like scrolling to a specific child.
4309#[derive(Clone, Debug)]
4310pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
4311
4312impl Default for ScrollHandle {
4313    fn default() -> Self {
4314        Self::new()
4315    }
4316}
4317
4318impl ScrollHandle {
4319    /// Construct a new scroll handle.
4320    pub fn new() -> Self {
4321        Self(Rc::default())
4322    }
4323
4324    /// Get the current scroll offset.
4325    pub fn offset(&self) -> Point<Pixels> {
4326        *self.0.borrow().offset.borrow()
4327    }
4328
4329    /// Get the maximum scroll offset.
4330    pub fn max_offset(&self) -> Point<Pixels> {
4331        self.0.borrow().max_offset
4332    }
4333
4334    /// Get the top child that's scrolled into view.
4335    pub fn top_item(&self) -> usize {
4336        let state = self.0.borrow();
4337        let top = state.bounds.top() - state.offset.borrow().y;
4338
4339        match state.child_bounds.binary_search_by(|bounds| {
4340            if top < bounds.top() {
4341                Ordering::Greater
4342            } else if top > bounds.bottom() {
4343                Ordering::Less
4344            } else {
4345                Ordering::Equal
4346            }
4347        }) {
4348            Ok(ix) => ix,
4349            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
4350        }
4351    }
4352
4353    /// Get the bottom child that's scrolled into view.
4354    pub fn bottom_item(&self) -> usize {
4355        let state = self.0.borrow();
4356        let bottom = state.bounds.bottom() - state.offset.borrow().y;
4357
4358        match state.child_bounds.binary_search_by(|bounds| {
4359            if bottom < bounds.top() {
4360                Ordering::Greater
4361            } else if bottom > bounds.bottom() {
4362                Ordering::Less
4363            } else {
4364                Ordering::Equal
4365            }
4366        }) {
4367            Ok(ix) => ix,
4368            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
4369        }
4370    }
4371
4372    /// Return the bounds into which this child is painted
4373    pub fn bounds(&self) -> Bounds<Pixels> {
4374        self.0.borrow().bounds
4375    }
4376
4377    /// Get the bounds for a specific child.
4378    pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
4379        self.0.borrow().child_bounds.get(ix).cloned()
4380    }
4381
4382    /// Update [ScrollHandleState]'s active item for scrolling to in prepaint
4383    pub fn scroll_to_item(&self, ix: usize) {
4384        let mut state = self.0.borrow_mut();
4385        state.active_item = Some(ScrollActiveItem {
4386            index: ix,
4387            strategy: ScrollStrategy::default(),
4388        });
4389    }
4390
4391    /// Update [ScrollHandleState]'s active item for scrolling to in prepaint
4392    /// This scrolls the minimal amount to ensure that the child is the first visible element
4393    pub fn scroll_to_top_of_item(&self, ix: usize) {
4394        let mut state = self.0.borrow_mut();
4395        state.active_item = Some(ScrollActiveItem {
4396            index: ix,
4397            strategy: ScrollStrategy::Top,
4398        });
4399    }
4400
4401    /// Scrolls the minimal amount to either ensure that the child is
4402    /// fully visible or the top element of the view depends on the
4403    /// scroll strategy
4404    fn scroll_to_active_item(&self) {
4405        let mut state = self.0.borrow_mut();
4406
4407        let Some(active_item) = state.active_item else {
4408            return;
4409        };
4410
4411        let active_item = match state.child_bounds.get(active_item.index) {
4412            Some(bounds) => {
4413                let mut scroll_offset = state.offset.borrow_mut();
4414
4415                match active_item.strategy {
4416                    ScrollStrategy::FirstVisible => {
4417                        if state.overflow.y == Overflow::Scroll {
4418                            let child_height = bounds.size.height;
4419                            let viewport_height = state.bounds.size.height;
4420                            if child_height > viewport_height {
4421                                scroll_offset.y = state.bounds.top() - bounds.top();
4422                            } else if bounds.top() + scroll_offset.y < state.bounds.top() {
4423                                scroll_offset.y = state.bounds.top() - bounds.top();
4424                            } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
4425                                scroll_offset.y = state.bounds.bottom() - bounds.bottom();
4426                            }
4427                        }
4428                    }
4429                    ScrollStrategy::Top => {
4430                        scroll_offset.y = state.bounds.top() - bounds.top();
4431                    }
4432                }
4433
4434                if state.overflow.x == Overflow::Scroll {
4435                    let child_width = bounds.size.width;
4436                    let viewport_width = state.bounds.size.width;
4437                    if child_width > viewport_width {
4438                        scroll_offset.x = state.bounds.left() - bounds.left();
4439                    } else if bounds.left() + scroll_offset.x < state.bounds.left() {
4440                        scroll_offset.x = state.bounds.left() - bounds.left();
4441                    } else if bounds.right() + scroll_offset.x > state.bounds.right() {
4442                        scroll_offset.x = state.bounds.right() - bounds.right();
4443                    }
4444                }
4445                None
4446            }
4447            None => Some(active_item),
4448        };
4449        state.active_item = active_item;
4450    }
4451
4452    /// Scrolls to the bottom.
4453    pub fn scroll_to_bottom(&self) {
4454        let mut state = self.0.borrow_mut();
4455        state.scroll_to_bottom = true;
4456    }
4457
4458    /// Set the offset explicitly. The offset is the distance from the top left of the
4459    /// parent container to the top left of the first child.
4460    /// As you scroll further down the offset becomes more negative.
4461    pub fn set_offset(&self, position: Point<Pixels>) {
4462        let state = self.0.borrow();
4463        *state.offset.borrow_mut() = position;
4464    }
4465
4466    /// Get the logical scroll top, based on a child index and a pixel offset.
4467    pub fn logical_scroll_top(&self) -> (usize, Pixels) {
4468        let ix = self.top_item();
4469        let state = self.0.borrow();
4470
4471        if let Some(child_bounds) = state.child_bounds.get(ix) {
4472            (
4473                ix,
4474                child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
4475            )
4476        } else {
4477            (ix, px(0.))
4478        }
4479    }
4480
4481    /// Get the logical scroll bottom, based on a child index and a pixel offset.
4482    pub fn logical_scroll_bottom(&self) -> (usize, Pixels) {
4483        let ix = self.bottom_item();
4484        let state = self.0.borrow();
4485
4486        if let Some(child_bounds) = state.child_bounds.get(ix) {
4487            (
4488                ix,
4489                child_bounds.bottom() + state.offset.borrow().y - state.bounds.bottom(),
4490            )
4491        } else {
4492            (ix, px(0.))
4493        }
4494    }
4495
4496    /// Get the count of children for scrollable item.
4497    pub fn children_count(&self) -> usize {
4498        self.0.borrow().child_bounds.len()
4499    }
4500}
4501
4502#[cfg(test)]
4503mod tests {
4504    use super::*;
4505    use crate::{
4506        AnyWindowHandle, AppContext as _, Context, GestureTuning, InputEvent, Keystroke,
4507        MouseMoveEvent, TestAppContext, TouchEvent, TouchId, canvas, util::FluentBuilder as _,
4508    };
4509    use std::{cell::Cell, rc::Weak};
4510
4511    struct GroupHoverTestView {
4512        render_count: Rc<Cell<usize>>,
4513        anonymous_paint_count: Rc<Cell<usize>>,
4514        stateful_width: Rc<Cell<Pixels>>,
4515    }
4516
4517    impl Render for GroupHoverTestView {
4518        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4519            self.render_count.set(self.render_count.get() + 1);
4520            let anonymous_paint_count = self.anonymous_paint_count.clone();
4521            let stateful_width = self.stateful_width.clone();
4522            div().size_full().child(
4523                div()
4524                    .ml(px(20.))
4525                    .mt(px(20.))
4526                    .size(px(50.))
4527                    .relative()
4528                    .group("hover-group")
4529                    .child(
4530                        div()
4531                            .absolute()
4532                            .size_full()
4533                            .invisible()
4534                            .group_hover("hover-group", |style| style.visible())
4535                            .child(canvas(
4536                                |_, _, _| {},
4537                                move |_, _, _, _| {
4538                                    anonymous_paint_count.set(anonymous_paint_count.get() + 1)
4539                                },
4540                            )),
4541                    )
4542                    .child(
4543                        div()
4544                            .id("stateful-group-hover-target")
4545                            .absolute()
4546                            .top_0()
4547                            .left_0()
4548                            .size(px(10.))
4549                            .group_hover("hover-group", |style| style.size(px(20.)))
4550                            .child(canvas(
4551                                move |bounds, _, _| stateful_width.set(bounds.size.width),
4552                                |_, _, _, _| {},
4553                            )),
4554                    ),
4555            )
4556        }
4557    }
4558
4559    #[gpui::test]
4560    fn group_hover_styles_update_only_on_transitions(cx: &mut TestAppContext) {
4561        let render_count = Rc::new(Cell::new(0));
4562        let anonymous_paint_count = Rc::new(Cell::new(0));
4563        let stateful_width = Rc::new(Cell::new(px(0.)));
4564        let window = cx.add_window({
4565            let render_count = render_count.clone();
4566            let anonymous_paint_count = anonymous_paint_count.clone();
4567            let stateful_width = stateful_width.clone();
4568            move |_, _| GroupHoverTestView {
4569                render_count,
4570                anonymous_paint_count,
4571                stateful_width,
4572            }
4573        });
4574        let window = AnyWindowHandle::from(window);
4575
4576        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
4577            .unwrap();
4578        assert_eq!(anonymous_paint_count.get(), 0);
4579        assert_eq!(stateful_width.get(), px(10.));
4580
4581        let move_mouse = |cx: &mut TestAppContext, position| {
4582            cx.update_window(window, |_, window, cx| {
4583                window.simulate_mouse_move(position, cx)
4584            })
4585            .unwrap();
4586        };
4587
4588        let initial_render_count = render_count.get();
4589        move_mouse(cx, point(px(25.), px(25.)));
4590        assert_eq!(render_count.get(), initial_render_count + 1);
4591        assert_eq!(anonymous_paint_count.get(), 1);
4592        assert_eq!(stateful_width.get(), px(20.));
4593
4594        move_mouse(cx, point(px(30.), px(30.)));
4595        assert_eq!(render_count.get(), initial_render_count + 1);
4596        assert_eq!(anonymous_paint_count.get(), 1);
4597        assert_eq!(stateful_width.get(), px(20.));
4598
4599        move_mouse(cx, point(px(5.), px(5.)));
4600        assert_eq!(render_count.get(), initial_render_count + 2);
4601        assert_eq!(anonymous_paint_count.get(), 1);
4602        assert_eq!(stateful_width.get(), px(10.));
4603
4604        move_mouse(cx, point(px(10.), px(10.)));
4605        assert_eq!(render_count.get(), initial_render_count + 2);
4606        assert_eq!(anonymous_paint_count.get(), 1);
4607        assert_eq!(stateful_width.get(), px(10.));
4608    }
4609
4610    struct HoverListenerLayoutTestView {
4611        target_left: Pixels,
4612        hover_transitions: Rc<RefCell<Vec<bool>>>,
4613    }
4614
4615    impl Render for HoverListenerLayoutTestView {
4616        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4617            let hover_transitions = self.hover_transitions.clone();
4618            div().relative().size_full().child(
4619                div()
4620                    .id("hover-target")
4621                    .absolute()
4622                    .left(self.target_left)
4623                    .top_0()
4624                    .size(px(20.))
4625                    .on_click(|_, _, _| {})
4626                    .on_hover(move |is_hovered, _, _| {
4627                        hover_transitions.borrow_mut().push(*is_hovered);
4628                    }),
4629            )
4630        }
4631    }
4632
4633    #[gpui::test]
4634    fn default_hover_listener_updates_when_layout_changes_under_stationary_mouse(
4635        cx: &mut TestAppContext,
4636    ) {
4637        let hover_transitions = Rc::new(RefCell::new(Vec::new()));
4638        let window = cx.add_window({
4639            let hover_transitions = hover_transitions.clone();
4640            move |_, _| HoverListenerLayoutTestView {
4641                target_left: px(40.),
4642                hover_transitions,
4643            }
4644        });
4645        let any_window = AnyWindowHandle::from(window);
4646
4647        cx.update_window(any_window, |_, window, cx| {
4648            window.draw(cx).clear(cx);
4649            window.simulate_mouse_move(point(px(10.), px(10.)), cx);
4650        })
4651        .unwrap();
4652        assert!(hover_transitions.borrow().is_empty());
4653
4654        window
4655            .update(cx, |view, _, cx| {
4656                view.target_left = px(0.);
4657                cx.notify();
4658            })
4659            .unwrap();
4660        cx.update_window(any_window, |_, window, cx| window.draw(cx).clear(cx))
4661            .unwrap();
4662        assert_eq!(*hover_transitions.borrow(), [true]);
4663
4664        window
4665            .update(cx, |view, _, cx| {
4666                view.target_left = px(40.);
4667                cx.notify();
4668            })
4669            .unwrap();
4670        cx.update_window(any_window, |_, window, cx| window.draw(cx).clear(cx))
4671            .unwrap();
4672        assert_eq!(*hover_transitions.borrow(), [true, false]);
4673    }
4674
4675    #[gpui::test]
4676    fn default_hover_listener_ends_after_key_press(cx: &mut TestAppContext) {
4677        let hover_transitions = Rc::new(RefCell::new(Vec::new()));
4678        let window = cx.add_window({
4679            let hover_transitions = hover_transitions.clone();
4680            move |_, _| HoverListenerLayoutTestView {
4681                target_left: px(0.),
4682                hover_transitions,
4683            }
4684        });
4685        let any_window = AnyWindowHandle::from(window);
4686
4687        cx.update_window(any_window, |_, window, cx| {
4688            window.draw(cx).clear(cx);
4689            window.simulate_mouse_move(point(px(10.), px(10.)), cx);
4690        })
4691        .unwrap();
4692        assert_eq!(*hover_transitions.borrow(), [true]);
4693
4694        key_down(cx, any_window, "a");
4695        cx.update_window(any_window, |_, window, cx| window.draw(cx).clear(cx))
4696            .unwrap();
4697        assert_eq!(*hover_transitions.borrow(), [true, false]);
4698    }
4699
4700    struct HoverListenerModeLayoutTestView {
4701        target_left: Pixels,
4702        hover_transitions: Rc<RefCell<Vec<bool>>>,
4703    }
4704
4705    impl Render for HoverListenerModeLayoutTestView {
4706        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4707            let hover_transitions = self.hover_transitions.clone();
4708            div().relative().size_full().child(
4709                div()
4710                    .id("hover-target")
4711                    .absolute()
4712                    .left(self.target_left)
4713                    .top_0()
4714                    .size(px(20.))
4715                    .hover_listener_mode(HoverListenerMode::InputModalityIndependent)
4716                    .on_hover(move |is_hovered, _, _| {
4717                        hover_transitions.borrow_mut().push(*is_hovered);
4718                    }),
4719            )
4720        }
4721    }
4722
4723    #[gpui::test]
4724    fn input_modality_independent_hover_listener_updates_after_key_press(cx: &mut TestAppContext) {
4725        let hover_transitions = Rc::new(RefCell::new(Vec::new()));
4726        let window = cx.add_window({
4727            let hover_transitions = hover_transitions.clone();
4728            move |_, _| HoverListenerModeLayoutTestView {
4729                target_left: px(40.),
4730                hover_transitions,
4731            }
4732        });
4733        let any_window = AnyWindowHandle::from(window);
4734        let pointer_position = point(px(10.), px(10.));
4735
4736        cx.update_window(any_window, |_, window, cx| {
4737            window.draw(cx).clear(cx);
4738            window.simulate_mouse_move(pointer_position, cx);
4739        })
4740        .unwrap();
4741        assert!(hover_transitions.borrow().is_empty());
4742
4743        key_down(cx, any_window, "a");
4744        window
4745            .update(cx, |view, _, cx| {
4746                view.target_left = px(0.);
4747                cx.notify();
4748            })
4749            .unwrap();
4750        cx.update_window(any_window, |_, window, cx| window.draw(cx).clear(cx))
4751            .unwrap();
4752        assert_eq!(*hover_transitions.borrow(), [true]);
4753
4754        key_down(cx, any_window, "b");
4755        cx.update_window(any_window, |_, window, cx| window.draw(cx).clear(cx))
4756            .unwrap();
4757        assert_eq!(*hover_transitions.borrow(), [true]);
4758
4759        cx.update_window(any_window, |_, window, cx| {
4760            window.simulate_mouse_move(point(px(30.), px(10.)), cx);
4761        })
4762        .unwrap();
4763        assert_eq!(*hover_transitions.borrow(), [true, false]);
4764
4765        cx.update_window(any_window, |_, window, cx| {
4766            window.simulate_mouse_move(pointer_position, cx);
4767            window.dispatch_event(
4768                MouseExitEvent {
4769                    position: pointer_position,
4770                    ..Default::default()
4771                }
4772                .to_platform_input(),
4773                cx,
4774            );
4775        })
4776        .unwrap();
4777        assert_eq!(*hover_transitions.borrow(), [true, false, true, false]);
4778    }
4779
4780    #[gpui::test]
4781    fn default_hover_listener_remains_hovered_during_stationary_mouse_press(
4782        cx: &mut TestAppContext,
4783    ) {
4784        let hover_transitions = Rc::new(RefCell::new(Vec::new()));
4785        let window = cx.add_window({
4786            let hover_transitions = hover_transitions.clone();
4787            move |_, _| HoverListenerLayoutTestView {
4788                target_left: px(0.),
4789                hover_transitions,
4790            }
4791        });
4792        let any_window = AnyWindowHandle::from(window);
4793        let mouse_position = point(px(10.), px(10.));
4794
4795        cx.update_window(any_window, |_, window, cx| {
4796            window.draw(cx).clear(cx);
4797            window.simulate_mouse_move(mouse_position, cx);
4798        })
4799        .unwrap();
4800        assert_eq!(*hover_transitions.borrow(), [true]);
4801
4802        cx.update_window(any_window, |_, window, cx| {
4803            window.dispatch_event(
4804                MouseDownEvent {
4805                    position: mouse_position,
4806                    button: MouseButton::Left,
4807                    modifiers: Default::default(),
4808                    click_count: 1,
4809                    first_mouse: false,
4810                }
4811                .to_platform_input(),
4812                cx,
4813            );
4814            window.draw(cx).clear(cx);
4815        })
4816        .unwrap();
4817        assert_eq!(*hover_transitions.borrow(), [true]);
4818
4819        cx.update_window(any_window, |_, window, cx| {
4820            window.dispatch_event(
4821                MouseUpEvent {
4822                    position: mouse_position,
4823                    button: MouseButton::Left,
4824                    modifiers: Default::default(),
4825                    click_count: 1,
4826                }
4827                .to_platform_input(),
4828                cx,
4829            );
4830            window.draw(cx).clear(cx);
4831        })
4832        .unwrap();
4833        assert_eq!(*hover_transitions.borrow(), [true]);
4834    }
4835
4836    struct TestTooltipView;
4837
4838    impl Render for TestTooltipView {
4839        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4840            div().w(px(20.)).h(px(20.)).child("tooltip")
4841        }
4842    }
4843
4844    type CapturedActiveTooltip = Rc<RefCell<Option<Weak<RefCell<Option<ActiveTooltip>>>>>>;
4845
4846    struct TooltipCaptureElement {
4847        child: AnyElement,
4848        captured_active_tooltip: CapturedActiveTooltip,
4849    }
4850
4851    impl IntoElement for TooltipCaptureElement {
4852        type Element = Self;
4853
4854        fn into_element(self) -> Self::Element {
4855            self
4856        }
4857    }
4858
4859    impl Element for TooltipCaptureElement {
4860        type RequestLayoutState = ();
4861        type PrepaintState = ();
4862
4863        fn id(&self) -> Option<ElementId> {
4864            None
4865        }
4866
4867        fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
4868            None
4869        }
4870
4871        fn request_layout(
4872            &mut self,
4873            _id: Option<&GlobalElementId>,
4874            _inspector_id: Option<&InspectorElementId>,
4875            window: &mut Window,
4876            cx: &mut App,
4877        ) -> (LayoutId, Self::RequestLayoutState) {
4878            (self.child.request_layout(window, cx), ())
4879        }
4880
4881        fn prepaint(
4882            &mut self,
4883            _id: Option<&GlobalElementId>,
4884            _inspector_id: Option<&InspectorElementId>,
4885            _bounds: Bounds<Pixels>,
4886            _request_layout: &mut Self::RequestLayoutState,
4887            window: &mut Window,
4888            cx: &mut App,
4889        ) -> Self::PrepaintState {
4890            self.child.prepaint(window, cx);
4891        }
4892
4893        fn paint(
4894            &mut self,
4895            _id: Option<&GlobalElementId>,
4896            _inspector_id: Option<&InspectorElementId>,
4897            _bounds: Bounds<Pixels>,
4898            _request_layout: &mut Self::RequestLayoutState,
4899            _prepaint: &mut Self::PrepaintState,
4900            window: &mut Window,
4901            cx: &mut App,
4902        ) {
4903            self.child.paint(window, cx);
4904            window.with_global_id("target".into(), |global_id, window| {
4905                window.with_element_state::<InteractiveElementState, _>(
4906                    global_id,
4907                    |state, _window| {
4908                        let state = state.unwrap();
4909                        *self.captured_active_tooltip.borrow_mut() =
4910                            state.active_tooltip.as_ref().map(Rc::downgrade);
4911                        ((), state)
4912                    },
4913                )
4914            });
4915        }
4916    }
4917
4918    struct TooltipOwner {
4919        captured_active_tooltip: CapturedActiveTooltip,
4920        show_delay_override: Option<Duration>,
4921    }
4922
4923    impl Render for TooltipOwner {
4924        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4925            TooltipCaptureElement {
4926                child: div()
4927                    .size_full()
4928                    .child(
4929                        div()
4930                            .id("target")
4931                            .w(px(50.))
4932                            .h(px(50.))
4933                            .tooltip(|_, cx| cx.new(|_| TestTooltipView).into())
4934                            .when_some(self.show_delay_override, |this, delay| {
4935                                this.tooltip_show_delay(delay)
4936                            }),
4937                    )
4938                    .into_any_element(),
4939                captured_active_tooltip: self.captured_active_tooltip.clone(),
4940            }
4941        }
4942    }
4943
4944    #[test]
4945    fn scroll_handle_aligns_wide_children_to_left_edge() {
4946        let handle = ScrollHandle::new();
4947        {
4948            let mut state = handle.0.borrow_mut();
4949            state.bounds = Bounds::new(point(px(0.), px(0.)), size(px(80.), px(20.)));
4950            state.child_bounds = vec![Bounds::new(point(px(25.), px(0.)), size(px(200.), px(20.)))];
4951            state.overflow.x = Overflow::Scroll;
4952            state.active_item = Some(ScrollActiveItem {
4953                index: 0,
4954                strategy: ScrollStrategy::default(),
4955            });
4956        }
4957
4958        handle.scroll_to_active_item();
4959
4960        assert_eq!(handle.offset().x, px(-25.));
4961    }
4962
4963    #[test]
4964    fn scroll_handle_aligns_tall_children_to_top_edge() {
4965        let handle = ScrollHandle::new();
4966        {
4967            let mut state = handle.0.borrow_mut();
4968            state.bounds = Bounds::new(point(px(0.), px(0.)), size(px(20.), px(80.)));
4969            state.child_bounds = vec![Bounds::new(point(px(0.), px(25.)), size(px(20.), px(200.)))];
4970            state.overflow.y = Overflow::Scroll;
4971            state.active_item = Some(ScrollActiveItem {
4972                index: 0,
4973                strategy: ScrollStrategy::default(),
4974            });
4975        }
4976
4977        handle.scroll_to_active_item();
4978
4979        assert_eq!(handle.offset().y, px(-25.));
4980    }
4981
4982    #[test]
4983    fn long_press_shows_tooltip_until_touch_ends() {
4984        let (mut test_app, any_window, captured_active_tooltip) = create_tooltip_owner_test(None);
4985        let active_tooltip = captured_active_tooltip
4986            .borrow()
4987            .clone()
4988            .unwrap()
4989            .upgrade()
4990            .unwrap();
4991        let touch_id = TouchId(1);
4992        let touch_position = point(px(49.), px(10.));
4993
4994        test_app
4995            .update_window(any_window, |_, window, cx| {
4996                window.dispatch_event(
4997                    TouchEvent {
4998                        id: touch_id,
4999                        phase: TouchPhase::Started,
5000                        position: touch_position,
5001                        predicted_position: None,
5002                        force: None,
5003                    }
5004                    .to_platform_input(),
5005                    cx,
5006                );
5007            })
5008            .unwrap();
5009        test_app
5010            .dispatcher
5011            .advance_clock(GestureTuning::default().long_press_duration + Duration::from_millis(1));
5012        test_app.run_until_parked();
5013
5014        assert!(matches!(
5015            active_tooltip.borrow().as_ref(),
5016            Some(ActiveTooltip::Visible { .. })
5017        ));
5018
5019        let moved_position = point(px(55.), px(10.));
5020        test_app
5021            .update_window(any_window, |_, window, cx| {
5022                window.dispatch_event(
5023                    TouchEvent {
5024                        id: touch_id,
5025                        phase: TouchPhase::Moved,
5026                        position: moved_position,
5027                        predicted_position: None,
5028                        force: None,
5029                    }
5030                    .to_platform_input(),
5031                    cx,
5032                );
5033                window.draw(cx).clear(cx);
5034            })
5035            .unwrap();
5036        assert!(matches!(
5037            active_tooltip.borrow().as_ref(),
5038            Some(ActiveTooltip::Visible { .. })
5039        ));
5040
5041        test_app
5042            .update_window(any_window, |_, window, cx| {
5043                window.dispatch_event(
5044                    TouchEvent {
5045                        id: touch_id,
5046                        phase: TouchPhase::Ended,
5047                        position: moved_position,
5048                        predicted_position: None,
5049                        force: None,
5050                    }
5051                    .to_platform_input(),
5052                    cx,
5053                );
5054            })
5055            .unwrap();
5056
5057        assert!(active_tooltip.borrow().is_none());
5058    }
5059
5060    fn setup_tooltip_owner_test(
5061        show_delay_override: Option<Duration>,
5062    ) -> (
5063        TestAppContext,
5064        crate::AnyWindowHandle,
5065        CapturedActiveTooltip,
5066    ) {
5067        let (mut test_app, any_window, captured_active_tooltip) =
5068            create_tooltip_owner_test(show_delay_override);
5069
5070        test_app
5071            .update_window(any_window, |_, window, cx| {
5072                window.dispatch_event(
5073                    MouseMoveEvent {
5074                        position: point(px(10.), px(10.)),
5075                        modifiers: Default::default(),
5076                        pressed_button: None,
5077                    }
5078                    .to_platform_input(),
5079                    cx,
5080                );
5081            })
5082            .unwrap();
5083
5084        test_app
5085            .update_window(any_window, |_, window, cx| {
5086                window.draw(cx).clear(cx);
5087            })
5088            .unwrap();
5089
5090        (test_app, any_window, captured_active_tooltip)
5091    }
5092
5093    fn create_tooltip_owner_test(
5094        show_delay_override: Option<Duration>,
5095    ) -> (
5096        TestAppContext,
5097        crate::AnyWindowHandle,
5098        CapturedActiveTooltip,
5099    ) {
5100        let mut test_app = TestAppContext::single();
5101        let captured_active_tooltip: CapturedActiveTooltip = Rc::new(RefCell::new(None));
5102        let window = test_app.add_window({
5103            let captured_active_tooltip = captured_active_tooltip.clone();
5104            move |_, _| TooltipOwner {
5105                captured_active_tooltip,
5106                show_delay_override,
5107            }
5108        });
5109        let any_window = window.into();
5110
5111        test_app
5112            .update_window(any_window, |_, window, cx| {
5113                window.draw(cx).clear(cx);
5114            })
5115            .unwrap();
5116
5117        (test_app, any_window, captured_active_tooltip)
5118    }
5119
5120    #[test]
5121    fn tooltip_waiting_for_show_is_released_when_its_owner_disappears() {
5122        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
5123
5124        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
5125        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
5126        assert!(matches!(
5127            active_tooltip.borrow().as_ref(),
5128            Some(ActiveTooltip::WaitingForShow { .. })
5129        ));
5130
5131        test_app
5132            .update_window(any_window, |_, window, _| {
5133                window.remove_window();
5134            })
5135            .unwrap();
5136        test_app.run_until_parked();
5137        drop(active_tooltip);
5138
5139        assert!(weak_active_tooltip.upgrade().is_none());
5140    }
5141
5142    #[test]
5143    fn tooltip_respects_custom_show_delay() {
5144        let extra_delay = Duration::from_secs(1);
5145        let show_delay_override = DEFAULT_TOOLTIP_SHOW_DELAY + extra_delay;
5146        let (test_app, _any_window, captured_active_tooltip) =
5147            setup_tooltip_owner_test(Some(show_delay_override));
5148
5149        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
5150        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
5151
5152        test_app
5153            .dispatcher
5154            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
5155        test_app.run_until_parked();
5156
5157        assert!(matches!(
5158            active_tooltip.borrow().as_ref(),
5159            Some(ActiveTooltip::WaitingForShow { .. })
5160        ));
5161
5162        test_app.dispatcher.advance_clock(extra_delay);
5163        test_app.run_until_parked();
5164
5165        assert!(matches!(
5166            active_tooltip.borrow().as_ref(),
5167            Some(ActiveTooltip::Visible { .. })
5168        ));
5169    }
5170
5171    #[test]
5172    fn tooltip_is_released_when_its_owner_disappears() {
5173        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
5174
5175        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
5176        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
5177
5178        test_app
5179            .dispatcher
5180            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
5181        test_app.run_until_parked();
5182
5183        assert!(matches!(
5184            active_tooltip.borrow().as_ref(),
5185            Some(ActiveTooltip::Visible { .. })
5186        ));
5187
5188        test_app
5189            .update_window(any_window, |_, window, _| {
5190                window.remove_window();
5191            })
5192            .unwrap();
5193        test_app.run_until_parked();
5194        drop(active_tooltip);
5195
5196        assert!(weak_active_tooltip.upgrade().is_none());
5197    }
5198
5199    #[test]
5200    fn tooltip_hides_after_mouse_leaves_origin() {
5201        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
5202
5203        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
5204        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
5205
5206        test_app
5207            .dispatcher
5208            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
5209        test_app.run_until_parked();
5210
5211        assert!(matches!(
5212            active_tooltip.borrow().as_ref(),
5213            Some(ActiveTooltip::Visible { .. })
5214        ));
5215
5216        test_app
5217            .update_window(any_window, |_, window, cx| {
5218                window.dispatch_event(
5219                    MouseMoveEvent {
5220                        position: point(px(75.), px(75.)),
5221                        modifiers: Default::default(),
5222                        pressed_button: None,
5223                    }
5224                    .to_platform_input(),
5225                    cx,
5226                );
5227            })
5228            .unwrap();
5229
5230        assert!(active_tooltip.borrow().is_none());
5231    }
5232
5233    struct MouseDownOutOwner {
5234        mouse_down_out_count: Rc<RefCell<usize>>,
5235    }
5236
5237    impl Render for MouseDownOutOwner {
5238        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
5239            let mouse_down_out_count = self.mouse_down_out_count.clone();
5240            div()
5241                .size_full()
5242                .child(div().id("target").w(px(50.)).h(px(50.)).on_mouse_down_out(
5243                    move |_, _, _| {
5244                        *mouse_down_out_count.borrow_mut() += 1;
5245                    },
5246                ))
5247        }
5248    }
5249
5250    #[test]
5251    fn mouse_down_out_is_suppressed_while_window_prompt_is_active() {
5252        let mut test_app = TestAppContext::single();
5253        let mouse_down_out_count = Rc::new(RefCell::new(0));
5254        let window = test_app.add_window({
5255            let mouse_down_out_count = mouse_down_out_count.clone();
5256            move |_, _| MouseDownOutOwner {
5257                mouse_down_out_count,
5258            }
5259        });
5260        let any_window: AnyWindowHandle = window.into();
5261
5262        fn dispatch_mouse_down_outside_target(
5263            test_app: &mut TestAppContext,
5264            any_window: AnyWindowHandle,
5265        ) {
5266            test_app
5267                .update_window(any_window, |_, window, cx| {
5268                    window.dispatch_event(
5269                        MouseDownEvent {
5270                            position: point(px(75.), px(75.)),
5271                            button: MouseButton::Left,
5272                            modifiers: Default::default(),
5273                            click_count: 1,
5274                            first_mouse: false,
5275                        }
5276                        .to_platform_input(),
5277                        cx,
5278                    );
5279                })
5280                .unwrap();
5281        }
5282
5283        test_app
5284            .update_window(any_window, |_, window, cx| {
5285                window.draw(cx).clear(cx);
5286            })
5287            .unwrap();
5288
5289        dispatch_mouse_down_outside_target(&mut test_app, any_window);
5290        assert_eq!(
5291            *mouse_down_out_count.borrow(),
5292            1,
5293            "mouse down outside the element should fire mouse-down-out listeners"
5294        );
5295
5296        test_app
5297            .update_window(any_window, |_, window, cx| {
5298                cx.set_prompt_builder(crate::fallback_prompt_renderer);
5299                let _receiver =
5300                    window.prompt(crate::PromptLevel::Warning, "message", None, &["Ok"], cx);
5301                assert!(window.has_active_prompt());
5302                window.draw(cx).clear(cx);
5303            })
5304            .unwrap();
5305
5306        dispatch_mouse_down_outside_target(&mut test_app, any_window);
5307        assert_eq!(
5308            *mouse_down_out_count.borrow(),
5309            1,
5310            "mouse down over an active prompt should not fire mouse-down-out listeners"
5311        );
5312    }
5313
5314    #[test]
5315    fn touch_tap_out_fires_once_after_release() {
5316        let mut test_app = TestAppContext::single();
5317        let mouse_down_out_count = Rc::new(RefCell::new(0));
5318        let window = test_app.add_window({
5319            let mouse_down_out_count = mouse_down_out_count.clone();
5320            move |_, _| MouseDownOutOwner {
5321                mouse_down_out_count,
5322            }
5323        });
5324        let any_window: AnyWindowHandle = window.into();
5325
5326        test_app
5327            .update_window(any_window, |_, window, cx| {
5328                window.draw(cx).clear(cx);
5329                let started = TouchEvent {
5330                    id: TouchId(1),
5331                    phase: TouchPhase::Started,
5332                    position: point(px(75.), px(75.)),
5333                    force: None,
5334                    predicted_position: None,
5335                };
5336                window.dispatch_event(started.clone().to_platform_input(), cx);
5337                assert_eq!(*mouse_down_out_count.borrow(), 0);
5338                window.dispatch_event(
5339                    TouchEvent {
5340                        phase: TouchPhase::Ended,
5341                        ..started
5342                    }
5343                    .to_platform_input(),
5344                    cx,
5345                );
5346            })
5347            .unwrap();
5348
5349        assert_eq!(
5350            *mouse_down_out_count.borrow(),
5351            1,
5352            "a touch tap outside the element should use mouse-down-out listeners"
5353        );
5354    }
5355
5356    #[crate::test]
5357    fn touch_pan_and_cancel_do_not_fire_mouse_down_out(cx: &mut TestAppContext) {
5358        let mouse_down_out_count = Rc::new(RefCell::new(0));
5359        let window = cx.add_window({
5360            let mouse_down_out_count = mouse_down_out_count.clone();
5361            move |_, _| MouseDownOutOwner {
5362                mouse_down_out_count,
5363            }
5364        });
5365        cx.update_window(window.into(), |_, window, cx| {
5366            window.draw(cx).clear(cx);
5367            for (id, samples) in [
5368                (
5369                    TouchId(1),
5370                    [
5371                        (TouchPhase::Started, 100.),
5372                        (TouchPhase::Moved, 75.),
5373                        (TouchPhase::Ended, 75.),
5374                    ],
5375                ),
5376                (
5377                    TouchId(2),
5378                    [
5379                        (TouchPhase::Started, 100.),
5380                        (TouchPhase::Moved, 100.),
5381                        (TouchPhase::Cancelled, 100.),
5382                    ],
5383                ),
5384            ] {
5385                for (phase, vertical_position) in samples {
5386                    window.dispatch_event(
5387                        TouchEvent {
5388                            id,
5389                            phase,
5390                            position: point(px(75.), px(vertical_position)),
5391                            predicted_position: None,
5392                            force: None,
5393                        }
5394                        .to_platform_input(),
5395                        cx,
5396                    );
5397                }
5398            }
5399        })
5400        .unwrap();
5401        assert_eq!(*mouse_down_out_count.borrow(), 0);
5402    }
5403
5404    #[test]
5405    fn test_accessibility_id_builder_writes_author_id() {
5406        let mut element = div()
5407            .id("buffer-font-size")
5408            .accessibility_id("settings.buffer-font-size");
5409        let mut node = accesskit::Node::new(accesskit::Role::SpinButton);
5410
5411        element.interactivity().write_a11y_info(&mut node);
5412
5413        assert_eq!(node.author_id(), Some("settings.buffer-font-size"));
5414    }
5415
5416    #[test]
5417    fn test_write_a11y_info_string_and_numeric_properties() {
5418        let mut interactivity = Interactivity::default();
5419        interactivity.aria.author_id = Some("settings.buffer-font-size".into());
5420        interactivity.aria.label = Some("Buffer Font Size".into());
5421        interactivity.aria.value = Some("15".into());
5422        interactivity.aria.placeholder = Some("Search".into());
5423        interactivity.aria.numeric_value = Some(15.0);
5424        interactivity.aria.min_numeric_value = Some(6.0);
5425        interactivity.aria.max_numeric_value = Some(72.0);
5426        interactivity.aria.numeric_value_step = Some(1.0);
5427
5428        let mut node = accesskit::Node::new(accesskit::Role::SpinButton);
5429        interactivity.write_a11y_info(&mut node);
5430
5431        assert_eq!(node.author_id(), Some("settings.buffer-font-size"));
5432        assert_eq!(node.label(), Some("Buffer Font Size"));
5433        assert_eq!(node.value(), Some("15"));
5434        assert_eq!(node.placeholder(), Some("Search"));
5435        assert_eq!(node.numeric_value(), Some(15.0));
5436        assert_eq!(node.min_numeric_value(), Some(6.0));
5437        assert_eq!(node.max_numeric_value(), Some(72.0));
5438        assert_eq!(node.numeric_value_step(), Some(1.0));
5439    }
5440
5441    /// Two focusable, clickable elements ("a" and "b") used to exercise the
5442    /// Enter/Space -> synthesized click press/release pairing.
5443    struct KeyboardActivationTest {
5444        focus_a: FocusHandle,
5445        focus_b: FocusHandle,
5446        clicks: Rc<RefCell<Vec<&'static str>>>,
5447    }
5448
5449    impl Render for KeyboardActivationTest {
5450        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
5451            let clicks_a = self.clicks.clone();
5452            let clicks_b = self.clicks.clone();
5453            div()
5454                .size_full()
5455                .child(
5456                    div()
5457                        .id("a")
5458                        .w(px(50.))
5459                        .h(px(50.))
5460                        .track_focus(&self.focus_a)
5461                        .on_click(move |_, _, _| clicks_a.borrow_mut().push("a")),
5462                )
5463                .child(
5464                    div()
5465                        .id("b")
5466                        .w(px(50.))
5467                        .h(px(50.))
5468                        .track_focus(&self.focus_b)
5469                        .on_click(move |_, _, _| clicks_b.borrow_mut().push("b")),
5470                )
5471        }
5472    }
5473
5474    fn setup_keyboard_activation_test() -> (
5475        TestAppContext,
5476        AnyWindowHandle,
5477        Rc<RefCell<Vec<&'static str>>>,
5478        FocusHandle,
5479        FocusHandle,
5480    ) {
5481        let mut cx = TestAppContext::single();
5482        let (focus_a, focus_b) = cx.update(|cx| (cx.focus_handle(), cx.focus_handle()));
5483        let clicks: Rc<RefCell<Vec<&'static str>>> = Rc::new(RefCell::new(Vec::new()));
5484        let window = cx.add_window({
5485            let focus_a = focus_a.clone();
5486            let focus_b = focus_b.clone();
5487            let clicks = clicks.clone();
5488            move |_, _| KeyboardActivationTest {
5489                focus_a,
5490                focus_b,
5491                clicks,
5492            }
5493        });
5494        (cx, window.into(), clicks, focus_a, focus_b)
5495    }
5496
5497    /// Move focus to `handle`, flush effects, then paint so the newly focused
5498    /// element registers its key handlers for the next dispatched event.
5499    fn focus_and_draw(cx: &mut TestAppContext, window: AnyWindowHandle, handle: &FocusHandle) {
5500        cx.update_window(window, |_, window, cx| window.focus(handle, cx))
5501            .unwrap();
5502        cx.run_until_parked();
5503        cx.update_window(window, |_, window, cx| {
5504            window.draw(cx).clear(cx);
5505        })
5506        .unwrap();
5507    }
5508
5509    fn key_down(cx: &mut TestAppContext, window: AnyWindowHandle, key: &str) {
5510        let os = cx.read(|cx| cx.platform_info().os);
5511        let keystroke = Keystroke::parse_with_os(key, os).unwrap();
5512        cx.update_window(window, |_, window, cx| {
5513            window.dispatch_event(
5514                KeyDownEvent {
5515                    keystroke,
5516                    is_held: false,
5517                    prefer_character_input: false,
5518                }
5519                .to_platform_input(),
5520                cx,
5521            );
5522        })
5523        .unwrap();
5524    }
5525
5526    fn key_up(cx: &mut TestAppContext, window: AnyWindowHandle, key: &str) {
5527        let os = cx.read(|cx| cx.platform_info().os);
5528        let keystroke = Keystroke::parse_with_os(key, os).unwrap();
5529        cx.update_window(window, |_, window, cx| {
5530            window.dispatch_event(KeyUpEvent { keystroke }.to_platform_input(), cx);
5531        })
5532        .unwrap();
5533    }
5534
5535    /// Pressing and releasing Enter on the same focused element fires a click.
5536    #[test]
5537    fn keyboard_activation_fires_click_on_same_element() {
5538        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5539
5540        focus_and_draw(&mut cx, window, &focus_a);
5541        key_down(&mut cx, window, "enter");
5542        key_up(&mut cx, window, "enter");
5543
5544        assert_eq!(*clicks.borrow(), vec!["a"]);
5545    }
5546
5547    /// A key-down whose key-up lands on a *different* element (because focus
5548    /// moved in between) must not leak a synthesized click onto the newly
5549    /// focused element. This is the core regression: previously the key-up
5550    /// handler fired unconditionally on whatever was focused at key-up time.
5551    #[test]
5552    fn keyboard_activation_does_not_leak_across_focus_change() {
5553        let (mut cx, window, clicks, focus_a, focus_b) = setup_keyboard_activation_test();
5554
5555        // Enter pressed while "a" is focused...
5556        focus_and_draw(&mut cx, window, &focus_a);
5557        key_down(&mut cx, window, "enter");
5558
5559        // ...focus moves to "b" before the release (as a confirm action would)...
5560        focus_and_draw(&mut cx, window, &focus_b);
5561        key_up(&mut cx, window, "enter");
5562
5563        // ...so neither element is clicked: "a" never saw the up, and "b"
5564        // never saw the down.
5565        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5566    }
5567
5568    /// A keydown whose flag is left pending because focus moved away before
5569    /// the keyup must not fire a click when focus later *returns* to the same
5570    /// element (the menu trigger reopening case). The stamped focus generation
5571    /// no longer matches, so the stale pending state is ignored.
5572    #[test]
5573    fn keyboard_activation_does_not_leak_when_focus_returns() {
5574        let (mut cx, window, clicks, focus_a, focus_b) = setup_keyboard_activation_test();
5575
5576        // Enter pressed on "a"...
5577        focus_and_draw(&mut cx, window, &focus_a);
5578        key_down(&mut cx, window, "enter");
5579
5580        // ...focus leaves "a" before its keyup (so the pending state is never
5581        // consumed), then comes back to "a"...
5582        focus_and_draw(&mut cx, window, &focus_b);
5583        focus_and_draw(&mut cx, window, &focus_a);
5584        key_up(&mut cx, window, "enter");
5585
5586        // ...and the now-stale pending keydown must not fire a click.
5587        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5588    }
5589
5590    /// A non-activation key *released* during the press must cancel the pending
5591    /// activation. For the sequence escape-down, space-down, escape-up,
5592    /// space-up the space forms a clean down/up pair, but the intervening
5593    /// escape-up means this isn't a plain space activation, so no click fires.
5594    #[test]
5595    fn keyboard_activation_cleared_by_intervening_key_release() {
5596        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5597
5598        focus_and_draw(&mut cx, window, &focus_a);
5599        key_down(&mut cx, window, "escape");
5600        key_down(&mut cx, window, "space");
5601        key_up(&mut cx, window, "escape");
5602        key_up(&mut cx, window, "space");
5603
5604        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5605    }
5606
5607    /// The flag is a single activation marker, not keyed by which activation
5608    /// key was used, so a Space down paired with an Enter up on the same
5609    /// element still fires a click.
5610    #[test]
5611    fn keyboard_activation_does_not_distinguish_space_and_enter() {
5612        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5613
5614        focus_and_draw(&mut cx, window, &focus_a);
5615        key_down(&mut cx, window, "space");
5616        key_up(&mut cx, window, "enter");
5617
5618        assert_eq!(*clicks.borrow(), vec!["a"]);
5619    }
5620
5621    /// A non-activation key pressed between the activation down and up clears
5622    /// the pending flag, suppressing the click.
5623    #[test]
5624    fn keyboard_activation_cleared_by_intervening_keydown() {
5625        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5626
5627        focus_and_draw(&mut cx, window, &focus_a);
5628        key_down(&mut cx, window, "enter");
5629        key_down(&mut cx, window, "a");
5630        key_up(&mut cx, window, "enter");
5631
5632        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5633    }
5634
5635    /// A modified Enter (e.g. cmd-enter) is not treated as an activation key,
5636    /// so it neither sets the pending flag nor fires a click on release.
5637    #[test]
5638    fn keyboard_activation_ignores_modified_keys() {
5639        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5640
5641        focus_and_draw(&mut cx, window, &focus_a);
5642        key_down(&mut cx, window, "cmd-enter");
5643        key_up(&mut cx, window, "cmd-enter");
5644
5645        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5646    }
5647
5648    /// Two sibling tab groups, each a focusable container that is *not* itself a
5649    /// tab stop and holds a single tab stop. Mirrors how the title bar and
5650    /// status bar expose their controls as ARIA toolbars.
5651    struct TabGroupFocus {
5652        group_a: FocusHandle,
5653        item_a: FocusHandle,
5654        group_b: FocusHandle,
5655        item_b: FocusHandle,
5656    }
5657
5658    impl Render for TabGroupFocus {
5659        fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
5660            fn group(container: &FocusHandle, item: &FocusHandle) -> Div {
5661                div()
5662                    .track_focus(container)
5663                    .tab_group()
5664                    .child(div().track_focus(item))
5665            }
5666            div()
5667                .child(group(&self.group_a, &self.item_a))
5668                .child(group(&self.group_b, &self.item_b))
5669        }
5670    }
5671
5672    /// Focusing a tab-group container and pressing Tab (`focus_next`) must move
5673    /// focus to the first tab stop *inside that container*, as documented on
5674    /// [`InteractiveElement::tab_stop`].
5675    #[test]
5676    fn focus_next_from_tab_group_container_enters_that_group() {
5677        let mut cx = TestAppContext::single();
5678        let (group_a, item_a, group_b, item_b) = cx.update(|cx| {
5679            (
5680                cx.focus_handle(),
5681                cx.focus_handle().tab_stop(true),
5682                cx.focus_handle(),
5683                cx.focus_handle().tab_stop(true),
5684            )
5685        });
5686        let window: AnyWindowHandle = cx
5687            .add_window({
5688                let (group_a, item_a, group_b, item_b) =
5689                    (group_a, item_a, group_b.clone(), item_b.clone());
5690                move |_, _| TabGroupFocus {
5691                    group_a,
5692                    item_a,
5693                    group_b,
5694                    item_b,
5695                }
5696            })
5697            .into();
5698        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
5699            .unwrap();
5700
5701        // Focus the *second* group's container, then advance like Tab would.
5702        let focused = cx
5703            .update_window(window, |_, window, cx| {
5704                window.focus(&group_b, cx);
5705                window.focus_next(cx);
5706                window.focused(cx).map(|handle| handle.id)
5707            })
5708            .unwrap();
5709
5710        assert_eq!(focused, Some(item_b.id));
5711    }
5712
5713    #[gpui::test]
5714    fn test_fractional_padding_does_not_make_a_fitting_container_scrollable(
5715        cx: &mut TestAppContext,
5716    ) {
5717        struct PaddedContainer {
5718            scroll_handle: ScrollHandle,
5719        }
5720
5721        impl Render for PaddedContainer {
5722            fn render(
5723                &mut self,
5724                _window: &mut Window,
5725                _cx: &mut Context<Self>,
5726            ) -> impl IntoElement {
5727                // 4.25px of padding snaps to 4px in layout, so a 42px child
5728                // fits the 50px box exactly.
5729                div().size_full().child(
5730                    div()
5731                        .id("container")
5732                        .h(px(50.))
5733                        .w(px(100.))
5734                        .py(px(4.25))
5735                        .overflow_y_scroll()
5736                        .track_scroll(&self.scroll_handle)
5737                        .child(div().w_full().h(px(42.))),
5738                )
5739            }
5740        }
5741
5742        let scroll_handle = ScrollHandle::new();
5743        let window: AnyWindowHandle = cx
5744            .add_window({
5745                let scroll_handle = scroll_handle.clone();
5746                move |_, _| PaddedContainer { scroll_handle }
5747            })
5748            .into();
5749        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
5750            .unwrap();
5751
5752        assert_eq!(scroll_handle.max_offset().y, px(0.));
5753    }
5754
5755    struct ContentSizedGrid;
5756
5757    impl Render for ContentSizedGrid {
5758        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
5759            let widths = [px(100.), px(200.), px(50.)];
5760            div().size_full().child(
5761                div()
5762                    .w_full()
5763                    .grid()
5764                    .grid_cols_max_content(widths.len() as u16)
5765                    .children(widths.into_iter().enumerate().map(|(index, width)| {
5766                        div()
5767                            .debug_selector(move || format!("cell-{index}"))
5768                            .w(width)
5769                            .h(px(10.))
5770                    })),
5771            )
5772        }
5773    }
5774
5775    #[gpui::test]
5776    fn grid_cols_max_content_sizes_columns_to_their_content(cx: &mut TestAppContext) {
5777        let window = cx.add_window(|_, _| ContentSizedGrid);
5778        cx.update_window(window.into(), |_, window, cx| window.draw(cx).clear(cx))
5779            .unwrap();
5780
5781        let mut bounds = |selector: &'static str| {
5782            cx.update_window(window.into(), |_, window, _| {
5783                window.rendered_frame.debug_bounds.get(selector).copied()
5784            })
5785            .unwrap()
5786            .unwrap_or_else(|| panic!("{selector} was not rendered"))
5787        };
5788
5789        assert_eq!(bounds("cell-0").origin.x, px(0.));
5790        assert_eq!(bounds("cell-1").origin.x, px(100.));
5791        assert_eq!(bounds("cell-2").origin.x, px(300.));
5792    }
5793}