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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, Bounds, ClickEvent, DispatchPhase,
20    Display, Element, ElementId, Entity, EntityId, ExternalDragPayload, ExternalDragPayloadSource,
21    FocusHandle, Global, GlobalElementId, Hitbox, HitboxBehavior, HitboxId, InspectorElementId,
22    IntoElement, IsZero, KeyContext, KeyDownEvent, KeyUpEvent, KeyboardButton, KeyboardClickEvent,
23    LayoutId, ModifiersChangedEvent, MouseButton, MouseClickEvent, MouseDownEvent, MouseExitEvent,
24    MouseMoveEvent, MousePressureEvent, MouseUpEvent, OngoingScroll, Overflow, ParentElement,
25    PinchEvent, Pixels, Point, Render, ScrollWheelEvent, SharedString, Size, Style,
26    StyleRefinement, Styled, Task, TooltipId, Visibility, Window, WindowControlArea, point, px,
27    size,
28};
29use collections::HashMap;
30use gpui_util::ResultExt;
31use refineable::Refineable;
32use smallvec::SmallVec;
33use stacksafe::{StackSafe, stacksafe};
34use std::{
35    any::{Any, TypeId},
36    cell::RefCell,
37    cmp::Ordering,
38    fmt::Debug,
39    marker::PhantomData,
40    mem,
41    rc::Rc,
42    sync::Arc,
43    time::Duration,
44};
45
46use super::ImageCacheProvider;
47
48const DRAG_THRESHOLD: f64 = 2.;
49const DEFAULT_TOOLTIP_SHOW_DELAY: Duration = Duration::from_millis(500);
50const HOVERABLE_TOOLTIP_HIDE_DELAY: Duration = Duration::from_millis(500);
51
52/// The styling information for a given group.
53pub struct GroupStyle {
54    /// The identifier for this group.
55    pub group: SharedString,
56
57    /// The specific style refinement that this group would apply
58    /// to its children.
59    pub style: Box<StyleRefinement>,
60}
61
62/// An event for when a drag is moving over this element, with the given state type.
63pub struct DragMoveEvent<T> {
64    /// The mouse move event that triggered this drag move event.
65    pub event: MouseMoveEvent,
66
67    /// The bounds of this element.
68    pub bounds: Bounds<Pixels>,
69    drag: PhantomData<T>,
70    dragged_item: Arc<dyn Any>,
71}
72
73impl<T: 'static> DragMoveEvent<T> {
74    /// Returns the drag state for this event.
75    pub fn drag<'b>(&self, cx: &'b App) -> &'b T {
76        cx.active_drag
77            .as_ref()
78            .and_then(|drag| drag.value.downcast_ref::<T>())
79            .expect("DragMoveEvent is only valid when the stored active drag is of the same type.")
80    }
81
82    /// An item that is about to be dropped.
83    pub fn dragged_item(&self) -> &dyn Any {
84        self.dragged_item.as_ref()
85    }
86}
87
88impl Interactivity {
89    /// Create an `Interactivity`, capturing the caller location in debug mode.
90    #[cfg(any(feature = "inspector", debug_assertions))]
91    #[track_caller]
92    pub fn new() -> Interactivity {
93        Interactivity {
94            source_location: Some(core::panic::Location::caller()),
95            ..Default::default()
96        }
97    }
98
99    /// Create an `Interactivity`, capturing the caller location in debug mode.
100    #[cfg(not(any(feature = "inspector", debug_assertions)))]
101    pub fn new() -> Interactivity {
102        Interactivity::default()
103    }
104
105    /// Gets the source location of construction. Returns `None` when not in debug mode.
106    pub fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
107        #[cfg(any(feature = "inspector", debug_assertions))]
108        {
109            self.source_location
110        }
111
112        #[cfg(not(any(feature = "inspector", debug_assertions)))]
113        {
114            None
115        }
116    }
117
118    /// Bind the given callback to the mouse down event for the given mouse button, during the bubble phase.
119    /// The imperative API equivalent of [`InteractiveElement::on_mouse_down`].
120    ///
121    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
122    pub fn on_mouse_down(
123        &mut self,
124        button: MouseButton,
125        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
126    ) {
127        self.mouse_down_listeners
128            .push(Box::new(move |event, phase, hitbox, window, cx| {
129                if phase == DispatchPhase::Bubble
130                    && event.button == button
131                    && hitbox.is_hovered(window)
132                {
133                    (listener)(event, window, cx)
134                }
135            }));
136    }
137
138    /// Bind the given callback to the mouse down event for the given mouse button, and capture
139    /// the pointer for this element until the next mouse up event.
140    ///
141    /// While captured, mouse move and mouse up listeners on this element continue to receive
142    /// events when the pointer is outside its bounds. The pointer is captured before `listener`
143    /// runs and [`Window`] releases it automatically after dispatching the mouse up event.
144    /// Give the element an id to preserve capture when the gesture redraws the window.
145    ///
146    /// The imperative API equivalent of
147    /// [`InteractiveElement::on_mouse_down_with_pointer_capture`].
148    pub fn on_mouse_down_with_pointer_capture(
149        &mut self,
150        button: MouseButton,
151        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
152    ) {
153        self.mouse_down_listeners
154            .push(Box::new(move |event, phase, hitbox, window, cx| {
155                if phase == DispatchPhase::Bubble
156                    && event.button == button
157                    && hitbox.is_hovered(window)
158                {
159                    window.capture_pointer(hitbox.id);
160                    (listener)(event, window, cx)
161                }
162            }));
163    }
164
165    /// Bind the given callback to the mouse down event for any button, during the capture phase.
166    /// The imperative API equivalent of [`InteractiveElement::capture_any_mouse_down`].
167    ///
168    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
169    pub fn capture_any_mouse_down(
170        &mut self,
171        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
172    ) {
173        self.mouse_down_listeners
174            .push(Box::new(move |event, phase, hitbox, window, cx| {
175                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
176                    (listener)(event, window, cx)
177                }
178            }));
179    }
180
181    /// Bind the given callback to the mouse down event for any button, during the bubble phase.
182    /// The imperative API equivalent to [`InteractiveElement::on_any_mouse_down`].
183    ///
184    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
185    pub fn on_any_mouse_down(
186        &mut self,
187        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
188    ) {
189        self.mouse_down_listeners
190            .push(Box::new(move |event, phase, hitbox, window, cx| {
191                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
192                    (listener)(event, window, cx)
193                }
194            }));
195    }
196
197    /// Bind the given callback to the mouse pressure event, during the bubble phase
198    /// the imperative API equivalent to [`InteractiveElement::on_mouse_pressure`].
199    ///
200    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
201    pub fn on_mouse_pressure(
202        &mut self,
203        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
204    ) {
205        self.mouse_pressure_listeners
206            .push(Box::new(move |event, phase, hitbox, window, cx| {
207                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
208                    (listener)(event, window, cx)
209                }
210            }));
211    }
212
213    /// Bind the given callback to the mouse pressure event, during the capture phase
214    /// the imperative API equivalent to [`InteractiveElement::on_mouse_pressure`].
215    ///
216    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
217    pub fn capture_mouse_pressure(
218        &mut self,
219        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
220    ) {
221        self.mouse_pressure_listeners
222            .push(Box::new(move |event, phase, hitbox, window, cx| {
223                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
224                    (listener)(event, window, cx)
225                }
226            }));
227    }
228
229    /// Bind the given callback to the mouse up event for the given button, during the bubble phase.
230    /// The imperative API equivalent to [`InteractiveElement::on_mouse_up`].
231    ///
232    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
233    pub fn on_mouse_up(
234        &mut self,
235        button: MouseButton,
236        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
237    ) {
238        self.mouse_up_listeners
239            .push(Box::new(move |event, phase, hitbox, window, cx| {
240                if phase == DispatchPhase::Bubble
241                    && event.button == button
242                    && hitbox.is_hovered(window)
243                {
244                    (listener)(event, window, cx)
245                }
246            }));
247    }
248
249    /// Bind the given callback to the mouse up event for any button, during the capture phase.
250    /// The imperative API equivalent to [`InteractiveElement::capture_any_mouse_up`].
251    ///
252    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
253    pub fn capture_any_mouse_up(
254        &mut self,
255        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
256    ) {
257        self.mouse_up_listeners
258            .push(Box::new(move |event, phase, hitbox, window, cx| {
259                if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
260                    (listener)(event, window, cx)
261                }
262            }));
263    }
264
265    /// Bind the given callback to the mouse up event for any button, during the bubble phase.
266    /// The imperative API equivalent to [`Interactivity::on_any_mouse_up`].
267    ///
268    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
269    pub fn on_any_mouse_up(
270        &mut self,
271        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
272    ) {
273        self.mouse_up_listeners
274            .push(Box::new(move |event, phase, hitbox, window, cx| {
275                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
276                    (listener)(event, window, cx)
277                }
278            }));
279    }
280
281    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
282    /// when the mouse is outside of the bounds of this element.
283    /// The imperative API equivalent to [`InteractiveElement::on_mouse_down_out`].
284    ///
285    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
286    pub fn on_mouse_down_out(
287        &mut self,
288        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
289    ) {
290        self.mouse_down_listeners
291            .push(Box::new(move |event, phase, hitbox, window, cx| {
292                if phase == DispatchPhase::Capture
293                    && !window.has_active_prompt()
294                    && !hitbox.contains(&window.mouse_position())
295                {
296                    (listener)(event, window, cx)
297                }
298            }));
299    }
300
301    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
302    /// when the mouse is outside of the bounds of this element.
303    /// The imperative API equivalent to [`InteractiveElement::on_mouse_up_out`].
304    ///
305    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
306    pub fn on_mouse_up_out(
307        &mut self,
308        button: MouseButton,
309        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
310    ) {
311        self.mouse_up_listeners
312            .push(Box::new(move |event, phase, hitbox, window, cx| {
313                if phase == DispatchPhase::Capture
314                    && event.button == button
315                    && !hitbox.is_hovered(window)
316                {
317                    (listener)(event, window, cx);
318                }
319            }));
320    }
321
322    /// Bind the given callback to the mouse move event, during the bubble phase.
323    /// The imperative API equivalent to [`InteractiveElement::on_mouse_move`].
324    ///
325    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
326    pub fn on_mouse_move(
327        &mut self,
328        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
329    ) {
330        self.mouse_move_listeners
331            .push(Box::new(move |event, phase, hitbox, window, cx| {
332                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
333                    (listener)(event, window, cx);
334                }
335            }));
336    }
337
338    /// Bind the given callback to the mouse exit event, during the bubble phase.
339    /// The imperative API equivalent to [`InteractiveElement::on_mouse_exit`].
340    ///
341    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
342    pub fn on_mouse_exit(
343        &mut self,
344        listener: impl Fn(&MouseExitEvent, &mut Window, &mut App) + 'static,
345    ) {
346        self.mouse_exit_listeners
347            .push(Box::new(move |event, phase, hitbox, window, cx| {
348                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
349                    (listener)(event, window, cx);
350                }
351            }));
352    }
353
354    /// Bind the given callback to the mouse drag event of the given type. Note that this
355    /// will be called for all move events, inside or outside of this element, as long as the
356    /// drag was started with this element under the mouse. Useful for implementing draggable
357    /// UIs that don't conform to a drag and drop style interaction, like resizing.
358    /// The imperative API equivalent to [`InteractiveElement::on_drag_move`].
359    ///
360    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
361    pub fn on_drag_move<T>(
362        &mut self,
363        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
364    ) where
365        T: 'static,
366    {
367        self.mouse_move_listeners
368            .push(Box::new(move |event, phase, hitbox, window, cx| {
369                if phase == DispatchPhase::Capture
370                    && let Some(drag) = &cx.active_drag
371                    && drag.value.as_ref().type_id() == TypeId::of::<T>()
372                {
373                    (listener)(
374                        &DragMoveEvent {
375                            event: event.clone(),
376                            bounds: hitbox.bounds,
377                            drag: PhantomData,
378                            dragged_item: Arc::clone(&drag.value),
379                        },
380                        window,
381                        cx,
382                    );
383                }
384            }));
385    }
386
387    /// Bind the given callback to scroll wheel events during the bubble phase.
388    /// The imperative API equivalent to [`InteractiveElement::on_scroll_wheel`].
389    ///
390    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
391    pub fn on_scroll_wheel(
392        &mut self,
393        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
394    ) {
395        self.scroll_wheel_listeners
396            .push(Box::new(move |event, phase, hitbox, window, cx| {
397                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
398                    (listener)(event, window, cx);
399                }
400            }));
401    }
402
403    /// Bind the given callback to pinch gesture events during the bubble phase.
404    ///
405    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
406    pub fn on_pinch(&mut self, listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static) {
407        self.pinch_listeners
408            .push(Box::new(move |event, phase, hitbox, window, cx| {
409                if phase == DispatchPhase::Bubble && hitbox.is_hovered(window) {
410                    (listener)(event, window, cx);
411                }
412            }));
413    }
414
415    /// Bind the given callback to pinch gesture events during the capture phase.
416    ///
417    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
418    pub fn capture_pinch(
419        &mut self,
420        listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static,
421    ) {
422        self.pinch_listeners
423            .push(Box::new(move |event, phase, _hitbox, window, cx| {
424                if phase == DispatchPhase::Capture {
425                    (listener)(event, window, cx);
426                } else {
427                    cx.propagate();
428                }
429            }));
430    }
431
432    /// Bind the given callback to an action dispatch during the capture phase.
433    /// The imperative API equivalent to [`InteractiveElement::capture_action`].
434    ///
435    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
436    pub fn capture_action<A: Action>(
437        &mut self,
438        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
439    ) {
440        self.action_listeners.push((
441            TypeId::of::<A>(),
442            Box::new(move |action, phase, window, cx| {
443                let action = action.downcast_ref().unwrap();
444                if phase == DispatchPhase::Capture {
445                    (listener)(action, window, cx)
446                } else {
447                    cx.propagate();
448                }
449            }),
450        ));
451    }
452
453    /// Bind the given callback to an action dispatch during the bubble phase.
454    /// The imperative API equivalent to [`InteractiveElement::on_action`].
455    ///
456    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
457    #[track_caller]
458    pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Window, &mut App) + 'static) {
459        self.action_listeners.push((
460            TypeId::of::<A>(),
461            Box::new(move |action, phase, window, cx| {
462                let action = action.downcast_ref().unwrap();
463                if phase == DispatchPhase::Bubble {
464                    (listener)(action, window, cx)
465                }
466            }),
467        ));
468    }
469
470    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
471    /// instead of a type parameter. Useful for component libraries that want to expose
472    /// action bindings to their users.
473    /// The imperative API equivalent to [`InteractiveElement::on_boxed_action`].
474    ///
475    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
476    pub fn on_boxed_action(
477        &mut self,
478        action: &dyn Action,
479        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
480    ) {
481        let action = action.boxed_clone();
482        self.action_listeners.push((
483            (*action).type_id(),
484            Box::new(move |_, phase, window, cx| {
485                if phase == DispatchPhase::Bubble {
486                    (listener)(&*action, window, cx)
487                }
488            }),
489        ));
490    }
491
492    /// Bind the given callback to key down events during the bubble phase.
493    /// The imperative API equivalent to [`InteractiveElement::on_key_down`].
494    ///
495    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
496    pub fn on_key_down(
497        &mut self,
498        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
499    ) {
500        self.key_down_listeners
501            .push(Box::new(move |event, phase, window, cx| {
502                if phase == DispatchPhase::Bubble {
503                    (listener)(event, window, cx)
504                }
505            }));
506    }
507
508    /// Bind the given callback to key down events during the capture phase.
509    /// The imperative API equivalent to [`InteractiveElement::capture_key_down`].
510    ///
511    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
512    pub fn capture_key_down(
513        &mut self,
514        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
515    ) {
516        self.key_down_listeners
517            .push(Box::new(move |event, phase, window, cx| {
518                if phase == DispatchPhase::Capture {
519                    listener(event, window, cx)
520                }
521            }));
522    }
523
524    /// Bind the given callback to key up events during the bubble phase.
525    /// The imperative API equivalent to [`InteractiveElement::on_key_up`].
526    ///
527    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
528    pub fn on_key_up(&mut self, listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static) {
529        self.key_up_listeners
530            .push(Box::new(move |event, phase, window, cx| {
531                if phase == DispatchPhase::Bubble {
532                    listener(event, window, cx)
533                }
534            }));
535    }
536
537    /// Bind the given callback to key up events during the capture phase.
538    /// The imperative API equivalent to [`InteractiveElement::on_key_up`].
539    ///
540    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
541    pub fn capture_key_up(
542        &mut self,
543        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
544    ) {
545        self.key_up_listeners
546            .push(Box::new(move |event, phase, window, cx| {
547                if phase == DispatchPhase::Capture {
548                    listener(event, window, cx)
549                }
550            }));
551    }
552
553    /// Bind the given callback to modifiers changing events.
554    /// The imperative API equivalent to [`InteractiveElement::on_modifiers_changed`].
555    ///
556    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
557    pub fn on_modifiers_changed(
558        &mut self,
559        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
560    ) {
561        self.modifiers_changed_listeners
562            .push(Box::new(move |event, window, cx| {
563                listener(event, window, cx)
564            }));
565    }
566
567    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element.
568    /// The imperative API equivalent to [`InteractiveElement::on_drop`].
569    ///
570    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
571    pub fn on_drop<T: 'static>(&mut self, listener: impl Fn(&T, &mut Window, &mut App) + 'static) {
572        self.drop_listeners.push((
573            TypeId::of::<T>(),
574            Box::new(move |dragged_value, window, cx| {
575                listener(dragged_value.downcast_ref().unwrap(), window, cx);
576            }),
577        ));
578    }
579
580    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element.
581    /// The imperative API equivalent to [`InteractiveElement::can_drop`].
582    pub fn can_drop(
583        &mut self,
584        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
585    ) {
586        self.can_drop_predicate = Some(Box::new(predicate));
587    }
588
589    /// Bind the given callback to click events of this element.
590    /// The imperative API equivalent to [`StatefulInteractiveElement::on_click`].
591    ///
592    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
593    pub fn on_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
594    where
595        Self: Sized,
596    {
597        self.click_listeners.push(Rc::new(move |event, window, cx| {
598            listener(event, window, cx)
599        }));
600    }
601
602    /// Bind the given callback to non-primary click events of this element.
603    /// The imperative API equivalent to [`StatefulInteractiveElement::on_aux_click`].
604    ///
605    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
606    pub fn on_aux_click(&mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static)
607    where
608        Self: Sized,
609    {
610        self.aux_click_listeners
611            .push(Rc::new(move |event, window, cx| {
612                listener(event, window, cx)
613            }));
614    }
615
616    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
617    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
618    /// the [`Self::on_drag_move`] API.
619    /// The imperative API equivalent to [`StatefulInteractiveElement::on_drag`].
620    ///
621    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
622    pub fn on_drag<T, W>(
623        &mut self,
624        value: T,
625        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
626    ) where
627        Self: Sized,
628        T: 'static,
629        W: 'static + Render,
630    {
631        debug_assert!(
632            self.drag_listener.is_none(),
633            "calling on_drag more than once on the same element is not supported"
634        );
635        self.drag_listener = Some(DragListener {
636            value: Arc::new(value),
637            render: Box::new(move |value, offset, window, cx| {
638                constructor(value.downcast_ref().unwrap(), offset, window, cx).into()
639            }),
640            external_payload: None,
641        });
642    }
643
644    /// Registers a callback resolving a payload to offer the platform if a drag started by this
645    /// element leaves the window. It is invoked at most once per drag gesture, when the pointer
646    /// exits the viewport. Must be called after [`Self::on_drag`], with the same dragged value
647    /// type `T`.
648    pub fn external_drag_payload<T>(
649        &mut self,
650        resolver: impl Fn(&T, &mut Window, &mut App) -> Option<ExternalDragPayload> + 'static,
651    ) where
652        Self: Sized,
653        T: 'static,
654    {
655        let Some(drag_listener) = self.drag_listener.as_mut() else {
656            debug_assert!(false, "external_drag_payload must be called after on_drag");
657            return;
658        };
659        debug_assert!(
660            drag_listener.value.as_ref().type_id() == TypeId::of::<T>(),
661            "external_drag_payload must use the same dragged value type as on_drag"
662        );
663        debug_assert!(
664            drag_listener.external_payload.is_none(),
665            "calling external_drag_payload more than once on the same element is not supported"
666        );
667        drag_listener.external_payload = Some(Box::new(move |value, window, cx| {
668            resolver(value.downcast_ref::<T>()?, window, cx)
669        }));
670    }
671
672    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
673    /// passed to the callback is true when the hover starts and false when it ends.
674    /// The imperative API equivalent to [`StatefulInteractiveElement::on_hover`].
675    ///
676    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
677    pub fn on_hover(&mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static)
678    where
679        Self: Sized,
680    {
681        debug_assert!(
682            self.hover_listener.is_none(),
683            "calling on_hover more than once on the same element is not supported"
684        );
685        self.hover_listener = Some(Box::new(listener));
686    }
687
688    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
689    /// The imperative API equivalent to [`StatefulInteractiveElement::tooltip`].
690    pub fn tooltip(&mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static)
691    where
692        Self: Sized,
693    {
694        debug_assert!(
695            self.tooltip_builder.is_none(),
696            "calling tooltip more than once on the same element is not supported"
697        );
698        self.tooltip_builder = Some(TooltipBuilder {
699            build: Rc::new(build_tooltip),
700            hoverable: false,
701        });
702    }
703
704    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
705    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
706    /// the tooltip. The imperative API equivalent to [`StatefulInteractiveElement::hoverable_tooltip`].
707    pub fn hoverable_tooltip(
708        &mut self,
709        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
710    ) where
711        Self: Sized,
712    {
713        debug_assert!(
714            self.tooltip_builder.is_none(),
715            "calling tooltip more than once on the same element is not supported"
716        );
717        self.tooltip_builder = Some(TooltipBuilder {
718            build: Rc::new(build_tooltip),
719            hoverable: true,
720        });
721    }
722
723    /// Set the delay before this element's tooltip is shown.
724    /// The imperative API equivalent to [`StatefulInteractiveElement::tooltip_show_delay`].
725    pub fn tooltip_show_delay(&mut self, delay: Duration) {
726        self.tooltip_show_delay = Some(delay);
727    }
728
729    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
730    /// `block_mouse_except_scroll` should be preferred.
731    ///
732    /// The imperative API equivalent to [`InteractiveElement::occlude`]
733    pub fn occlude_mouse(&mut self) {
734        self.hitbox_behavior = HitboxBehavior::BlockMouse;
735    }
736
737    /// Set the bounds of this element as a window control area for the platform window.
738    /// The imperative API equivalent to [`InteractiveElement::window_control_area`]
739    pub fn window_control_area(&mut self, area: WindowControlArea) {
740        self.window_control = Some(area);
741    }
742
743    /// Block non-scroll mouse interactions with elements behind this element's hitbox.
744    /// The imperative API equivalent to [`InteractiveElement::block_mouse_except_scroll`].
745    ///
746    /// See [`Hitbox::is_hovered`] for details.
747    pub fn block_mouse_except_scroll(&mut self) {
748        self.hitbox_behavior = HitboxBehavior::BlockMouseExceptScroll;
749    }
750
751    fn has_pinch_listeners(&self) -> bool {
752        !self.pinch_listeners.is_empty()
753    }
754}
755
756/// A trait for elements that want to use the standard GPUI event handlers that don't
757/// require any state.
758pub trait InteractiveElement: Sized {
759    /// Retrieve the interactivity state associated with this element
760    fn interactivity(&mut self) -> &mut Interactivity;
761
762    /// Assign this element to a group of elements that can be styled together
763    fn group(mut self, group: impl Into<SharedString>) -> Self {
764        self.interactivity().group = Some(group.into());
765        self
766    }
767
768    /// Assign this element an ID, so that it can be used with interactivity
769    fn id(mut self, id: impl Into<ElementId>) -> Stateful<Self> {
770        self.interactivity().element_id = Some(id.into());
771
772        Stateful { element: self }
773    }
774
775    /// Track the focus state of the given focus handle on this element.
776    /// If the focus handle is focused by the application, this element will
777    /// apply its focused styles.
778    fn track_focus(mut self, focus_handle: &FocusHandle) -> Self {
779        self.interactivity().focusable = true;
780        self.interactivity().tracked_focus_handle = Some(focus_handle.clone());
781        self
782    }
783
784    /// Set whether this element is a tab stop.
785    ///
786    /// When false, the element remains in tab-index order but cannot be reached via keyboard navigation.
787    /// Useful for container elements: focus the container, then call `window.focus_next(cx)` to focus
788    /// the first tab stop inside it while having the container element itself be unreachable via the keyboard.
789    /// Should only be used with `tab_index`.
790    fn tab_stop(mut self, tab_stop: bool) -> Self {
791        self.interactivity().tab_stop = tab_stop;
792        self
793    }
794
795    /// Set index of the tab stop order, and set this node as a tab stop.
796    /// This will default the element to being a tab stop. See [`Self::tab_stop`] for more information.
797    /// This should only be used in conjunction with `tab_group`
798    /// in order to not interfere with the tab index of other elements.
799    fn tab_index(mut self, index: isize) -> Self {
800        self.interactivity().focusable = true;
801        self.interactivity().tab_index = Some(index);
802        self.interactivity().tab_stop = true;
803        self
804    }
805
806    /// Designate this div as a "tab group". Tab groups have their own location in the tab-index order,
807    /// but for children of the tab group, the tab index is reset to 0. This can be useful for swapping
808    /// the order of tab stops within the group, without having to renumber all the tab stops in the whole
809    /// application.
810    fn tab_group(mut self) -> Self {
811        self.interactivity().tab_group = true;
812        if self.interactivity().tab_index.is_none() {
813            self.interactivity().tab_index = Some(0);
814        }
815        self
816    }
817
818    /// Set the keymap context for this element. This will be used to determine
819    /// which action to dispatch from the keymap.
820    fn key_context<C, E>(mut self, key_context: C) -> Self
821    where
822        C: TryInto<KeyContext, Error = E>,
823        E: std::fmt::Display,
824    {
825        if let Some(key_context) = key_context.try_into().log_err() {
826            self.interactivity().key_context = Some(key_context);
827        }
828        self
829    }
830
831    /// Apply the given style to this element when the mouse hovers over it
832    fn hover(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self {
833        debug_assert!(
834            self.interactivity().hover_style.is_none(),
835            "hover style already set"
836        );
837        self.interactivity().hover_style = Some(Box::new(f(StyleRefinement::default())));
838        self
839    }
840
841    /// Apply the given style to this element when the mouse hovers over a group member
842    fn group_hover(
843        mut self,
844        group_name: impl Into<SharedString>,
845        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
846    ) -> Self {
847        self.interactivity().group_hover_style = Some(GroupStyle {
848            group: group_name.into(),
849            style: Box::new(f(StyleRefinement::default())),
850        });
851        self
852    }
853
854    /// Bind the given callback to the mouse down event for the given mouse button.
855    /// The fluent API equivalent to [`Interactivity::on_mouse_down`].
856    ///
857    /// See [`Context::listener`](crate::Context::listener) to get access to the view state from this callback.
858    fn on_mouse_down(
859        mut self,
860        button: MouseButton,
861        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
862    ) -> Self {
863        self.interactivity().on_mouse_down(button, listener);
864        self
865    }
866
867    /// Bind the given callback to the mouse down event for the given mouse button, and capture
868    /// the pointer for this element until the next mouse up event.
869    ///
870    /// While captured, mouse move and mouse up listeners on this element continue to receive
871    /// events when the pointer is outside its bounds. The pointer is captured before `listener`
872    /// runs and [`Window`] releases it automatically after dispatching the mouse up event.
873    /// Give the element an id to preserve capture when the gesture redraws the window.
874    ///
875    /// The fluent API equivalent of [`Interactivity::on_mouse_down_with_pointer_capture`].
876    fn on_mouse_down_with_pointer_capture(
877        mut self,
878        button: MouseButton,
879        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
880    ) -> Self {
881        self.interactivity()
882            .on_mouse_down_with_pointer_capture(button, listener);
883        self
884    }
885
886    #[cfg(any(test, feature = "test-support"))]
887    /// Set a key that can be used to look up this element's bounds
888    /// in the [`crate::VisualTestContext::debug_bounds`] map
889    /// This is a noop in release builds
890    fn debug_selector(mut self, f: impl FnOnce() -> String) -> Self {
891        self.interactivity().debug_selector = Some(f());
892        self
893    }
894
895    #[cfg(not(any(test, feature = "test-support")))]
896    /// Set a key that can be used to look up this element's bounds
897    /// in the [`crate::VisualTestContext::debug_bounds`] map
898    /// This is a noop in release builds
899    #[inline]
900    fn debug_selector(self, _: impl FnOnce() -> String) -> Self {
901        self
902    }
903
904    /// Bind the given callback to the mouse down event for any button, during the capture phase.
905    /// The fluent API equivalent to [`Interactivity::capture_any_mouse_down`].
906    ///
907    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
908    fn capture_any_mouse_down(
909        mut self,
910        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
911    ) -> Self {
912        self.interactivity().capture_any_mouse_down(listener);
913        self
914    }
915
916    /// Bind the given callback to the mouse down event for any button, during the capture phase.
917    /// The fluent API equivalent to [`Interactivity::on_any_mouse_down`].
918    ///
919    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
920    fn on_any_mouse_down(
921        mut self,
922        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
923    ) -> Self {
924        self.interactivity().on_any_mouse_down(listener);
925        self
926    }
927
928    /// Bind the given callback to the mouse up event for the given button, during the bubble phase.
929    /// The fluent API equivalent to [`Interactivity::on_mouse_up`].
930    ///
931    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
932    fn on_mouse_up(
933        mut self,
934        button: MouseButton,
935        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
936    ) -> Self {
937        self.interactivity().on_mouse_up(button, listener);
938        self
939    }
940
941    /// Bind the given callback to the mouse up event for any button, during the capture phase.
942    /// The fluent API equivalent to [`Interactivity::capture_any_mouse_up`].
943    ///
944    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
945    fn capture_any_mouse_up(
946        mut self,
947        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
948    ) -> Self {
949        self.interactivity().capture_any_mouse_up(listener);
950        self
951    }
952
953    /// Bind the given callback to the mouse pressure event, during the bubble phase
954    /// the fluent API equivalent to [`Interactivity::on_mouse_pressure`]
955    ///
956    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
957    fn on_mouse_pressure(
958        mut self,
959        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
960    ) -> Self {
961        self.interactivity().on_mouse_pressure(listener);
962        self
963    }
964
965    /// Bind the given callback to the mouse pressure event, during the capture phase
966    /// the fluent API equivalent to [`Interactivity::on_mouse_pressure`]
967    ///
968    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
969    fn capture_mouse_pressure(
970        mut self,
971        listener: impl Fn(&MousePressureEvent, &mut Window, &mut App) + 'static,
972    ) -> Self {
973        self.interactivity().capture_mouse_pressure(listener);
974        self
975    }
976
977    /// Bind the given callback to the mouse down event, on any button, during the capture phase,
978    /// when the mouse is outside of the bounds of this element.
979    /// The fluent API equivalent to [`Interactivity::on_mouse_down_out`].
980    ///
981    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
982    fn on_mouse_down_out(
983        mut self,
984        listener: impl Fn(&MouseDownEvent, &mut Window, &mut App) + 'static,
985    ) -> Self {
986        self.interactivity().on_mouse_down_out(listener);
987        self
988    }
989
990    /// Bind the given callback to the mouse up event, for the given button, during the capture phase,
991    /// when the mouse is outside of the bounds of this element.
992    /// The fluent API equivalent to [`Interactivity::on_mouse_up_out`].
993    ///
994    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
995    fn on_mouse_up_out(
996        mut self,
997        button: MouseButton,
998        listener: impl Fn(&MouseUpEvent, &mut Window, &mut App) + 'static,
999    ) -> Self {
1000        self.interactivity().on_mouse_up_out(button, listener);
1001        self
1002    }
1003
1004    /// Bind the given callback to the mouse move event, during the bubble phase.
1005    /// The fluent API equivalent to [`Interactivity::on_mouse_move`].
1006    ///
1007    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1008    fn on_mouse_move(
1009        mut self,
1010        listener: impl Fn(&MouseMoveEvent, &mut Window, &mut App) + 'static,
1011    ) -> Self {
1012        self.interactivity().on_mouse_move(listener);
1013        self
1014    }
1015
1016    /// Bind the given callback to the mouse exit event, during the bubble phase.
1017    /// The fluent API equivalent to [`Interactivity::on_mouse_exit`].
1018    ///
1019    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1020    fn on_mouse_exit(
1021        mut self,
1022        listener: impl Fn(&MouseExitEvent, &mut Window, &mut App) + 'static,
1023    ) -> Self {
1024        self.interactivity().on_mouse_exit(listener);
1025        self
1026    }
1027
1028    /// Bind the given callback to the mouse drag event of the given type. Note that this
1029    /// will be called for all move events, inside or outside of this element, as long as the
1030    /// drag was started with this element under the mouse. Useful for implementing draggable
1031    /// UIs that don't conform to a drag and drop style interaction, like resizing.
1032    /// The fluent API equivalent to [`Interactivity::on_drag_move`].
1033    ///
1034    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1035    fn on_drag_move<T: 'static>(
1036        mut self,
1037        listener: impl Fn(&DragMoveEvent<T>, &mut Window, &mut App) + 'static,
1038    ) -> Self {
1039        self.interactivity().on_drag_move(listener);
1040        self
1041    }
1042
1043    /// Bind the given callback to scroll wheel events during the bubble phase.
1044    /// The fluent API equivalent to [`Interactivity::on_scroll_wheel`].
1045    ///
1046    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1047    fn on_scroll_wheel(
1048        mut self,
1049        listener: impl Fn(&ScrollWheelEvent, &mut Window, &mut App) + 'static,
1050    ) -> Self {
1051        self.interactivity().on_scroll_wheel(listener);
1052        self
1053    }
1054
1055    /// Bind the given callback to pinch gesture events during the bubble phase.
1056    /// The fluent API equivalent to [`Interactivity::on_pinch`].
1057    ///
1058    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1059    fn on_pinch(mut self, listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static) -> Self {
1060        self.interactivity().on_pinch(listener);
1061        self
1062    }
1063
1064    /// Bind the given callback to pinch gesture events during the capture phase.
1065    /// The fluent API equivalent to [`Interactivity::capture_pinch`].
1066    ///
1067    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1068    fn capture_pinch(
1069        mut self,
1070        listener: impl Fn(&PinchEvent, &mut Window, &mut App) + 'static,
1071    ) -> Self {
1072        self.interactivity().capture_pinch(listener);
1073        self
1074    }
1075    /// Capture the given action, before normal action dispatch can fire.
1076    /// The fluent API equivalent to [`Interactivity::capture_action`].
1077    ///
1078    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1079    fn capture_action<A: Action>(
1080        mut self,
1081        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
1082    ) -> Self {
1083        self.interactivity().capture_action(listener);
1084        self
1085    }
1086
1087    /// Bind the given callback to an action dispatch during the bubble phase.
1088    /// The fluent API equivalent to [`Interactivity::on_action`].
1089    ///
1090    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1091    #[track_caller]
1092    fn on_action<A: Action>(
1093        mut self,
1094        listener: impl Fn(&A, &mut Window, &mut App) + 'static,
1095    ) -> Self {
1096        self.interactivity().on_action(listener);
1097        self
1098    }
1099
1100    /// Bind the given callback to an action dispatch, based on a dynamic action parameter
1101    /// instead of a type parameter. Useful for component libraries that want to expose
1102    /// action bindings to their users.
1103    /// The fluent API equivalent to [`Interactivity::on_boxed_action`].
1104    ///
1105    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1106    fn on_boxed_action(
1107        mut self,
1108        action: &dyn Action,
1109        listener: impl Fn(&dyn Action, &mut Window, &mut App) + 'static,
1110    ) -> Self {
1111        self.interactivity().on_boxed_action(action, listener);
1112        self
1113    }
1114
1115    /// Bind the given callback to key down events during the bubble phase.
1116    /// The fluent API equivalent to [`Interactivity::on_key_down`].
1117    ///
1118    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1119    fn on_key_down(
1120        mut self,
1121        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
1122    ) -> Self {
1123        self.interactivity().on_key_down(listener);
1124        self
1125    }
1126
1127    /// Bind the given callback to key down events during the capture phase.
1128    /// The fluent API equivalent to [`Interactivity::capture_key_down`].
1129    ///
1130    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1131    fn capture_key_down(
1132        mut self,
1133        listener: impl Fn(&KeyDownEvent, &mut Window, &mut App) + 'static,
1134    ) -> Self {
1135        self.interactivity().capture_key_down(listener);
1136        self
1137    }
1138
1139    /// Bind the given callback to key up events during the bubble phase.
1140    /// The fluent API equivalent to [`Interactivity::on_key_up`].
1141    ///
1142    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1143    fn on_key_up(
1144        mut self,
1145        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
1146    ) -> Self {
1147        self.interactivity().on_key_up(listener);
1148        self
1149    }
1150
1151    /// Bind the given callback to key up events during the capture phase.
1152    /// The fluent API equivalent to [`Interactivity::capture_key_up`].
1153    ///
1154    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1155    fn capture_key_up(
1156        mut self,
1157        listener: impl Fn(&KeyUpEvent, &mut Window, &mut App) + 'static,
1158    ) -> Self {
1159        self.interactivity().capture_key_up(listener);
1160        self
1161    }
1162
1163    /// Bind the given callback to modifiers changing events.
1164    /// The fluent API equivalent to [`Interactivity::on_modifiers_changed`].
1165    ///
1166    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1167    fn on_modifiers_changed(
1168        mut self,
1169        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
1170    ) -> Self {
1171        self.interactivity().on_modifiers_changed(listener);
1172        self
1173    }
1174
1175    /// Apply the given style when the given data type is dragged over this element
1176    fn drag_over<S: 'static>(
1177        mut self,
1178        f: impl 'static + Fn(StyleRefinement, &S, &mut Window, &mut App) -> StyleRefinement,
1179    ) -> Self {
1180        self.interactivity().drag_over_styles.push((
1181            TypeId::of::<S>(),
1182            Box::new(move |currently_dragged: &dyn Any, window, cx| {
1183                f(
1184                    StyleRefinement::default(),
1185                    currently_dragged.downcast_ref::<S>().unwrap(),
1186                    window,
1187                    cx,
1188                )
1189            }),
1190        ));
1191        self
1192    }
1193
1194    /// Apply the given style when the given data type is dragged over this element's group
1195    fn group_drag_over<S: 'static>(
1196        mut self,
1197        group_name: impl Into<SharedString>,
1198        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1199    ) -> Self {
1200        self.interactivity().group_drag_over_styles.push((
1201            TypeId::of::<S>(),
1202            GroupStyle {
1203                group: group_name.into(),
1204                style: Box::new(f(StyleRefinement::default())),
1205            },
1206        ));
1207        self
1208    }
1209
1210    /// Bind the given callback to drop events of the given type, whether or not the drag started on this element.
1211    /// The fluent API equivalent to [`Interactivity::on_drop`].
1212    ///
1213    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1214    fn on_drop<T: 'static>(
1215        mut self,
1216        listener: impl Fn(&T, &mut Window, &mut App) + 'static,
1217    ) -> Self {
1218        self.interactivity().on_drop(listener);
1219        self
1220    }
1221
1222    /// Use the given predicate to determine whether or not a drop event should be dispatched to this element.
1223    /// The fluent API equivalent to [`Interactivity::can_drop`].
1224    fn can_drop(
1225        mut self,
1226        predicate: impl Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static,
1227    ) -> Self {
1228        self.interactivity().can_drop(predicate);
1229        self
1230    }
1231
1232    /// Block the mouse from all interactions with elements behind this element's hitbox. Typically
1233    /// `block_mouse_except_scroll` should be preferred.
1234    /// The fluent API equivalent to [`Interactivity::occlude_mouse`].
1235    fn occlude(mut self) -> Self {
1236        self.interactivity().occlude_mouse();
1237        self
1238    }
1239
1240    /// Set the bounds of this element as a window control area for the platform window.
1241    /// The fluent API equivalent to [`Interactivity::window_control_area`].
1242    fn window_control_area(mut self, area: WindowControlArea) -> Self {
1243        self.interactivity().window_control_area(area);
1244        self
1245    }
1246
1247    /// Block non-scroll mouse interactions with elements behind this element's hitbox.
1248    /// The fluent API equivalent to [`Interactivity::block_mouse_except_scroll`].
1249    ///
1250    /// See [`Hitbox::is_hovered`] for details.
1251    fn block_mouse_except_scroll(mut self) -> Self {
1252        self.interactivity().block_mouse_except_scroll();
1253        self
1254    }
1255
1256    /// Set the given styles to be applied when this element, specifically, is focused.
1257    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1258    fn focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1259    where
1260        Self: Sized,
1261    {
1262        self.interactivity().focus_style = Some(Box::new(f(StyleRefinement::default())));
1263        self
1264    }
1265
1266    /// Set the given styles to be applied when this element is inside another element that is focused.
1267    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1268    fn in_focus(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1269    where
1270        Self: Sized,
1271    {
1272        self.interactivity().in_focus_style = Some(Box::new(f(StyleRefinement::default())));
1273        self
1274    }
1275
1276    /// Set the given styles to be applied when this element is focused via keyboard navigation.
1277    /// This is similar to CSS's `:focus-visible` pseudo-class - it only applies when the element
1278    /// is focused AND the user is navigating via keyboard (not mouse clicks).
1279    /// Requires that the element is focusable. Elements can be made focusable using [`InteractiveElement::track_focus`].
1280    fn focus_visible(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1281    where
1282        Self: Sized,
1283    {
1284        self.interactivity().focus_visible_style = Some(Box::new(f(StyleRefinement::default())));
1285        self
1286    }
1287}
1288
1289/// A trait for elements that want to use the standard GPUI interactivity features
1290/// that require state.
1291pub trait StatefulInteractiveElement: InteractiveElement {
1292    /// Set the accessible role for this element.
1293    ///
1294    /// See the [accessibility guide](crate::_accessibility) for an overview.
1295    fn role(mut self, role: accesskit::Role) -> Self {
1296        debug_assert!(
1297            role != accesskit::Role::GenericContainer,
1298            "GenericContainer is filtered out of the a11y tree and has no effect"
1299        );
1300        self.interactivity().override_role = Some(role);
1301        self
1302    }
1303
1304    /// Set the accessible label for this element.
1305    fn aria_label(mut self, label: impl Into<SharedString>) -> Self {
1306        self.interactivity().aria.label = Some(label.into());
1307        self
1308    }
1309
1310    /// Set the accessible description for this element. Unlike the label (which
1311    /// names the element), the description provides supplementary information
1312    /// that assistive technology announces after the name, role, and value -
1313    /// for example a settings subtitle or a hint.
1314    fn aria_description(mut self, description: impl Into<SharedString>) -> Self {
1315        self.interactivity().aria.description = Some(description.into());
1316        self
1317    }
1318
1319    /// Set the keyboard shortcut(s) that activate this element, announced by
1320    /// assistive technology (maps to AccessKit's `keyboard_shortcut`).
1321    ///
1322    /// Note that this does not create a keymap. It simply instructs assistive
1323    /// technology what the keymap is.
1324    fn aria_keyshortcuts(mut self, keyshortcuts: impl Into<SharedString>) -> Self {
1325        self.interactivity().aria.keyshortcuts = Some(keyshortcuts.into());
1326        self
1327    }
1328
1329    /// Report this element as the focused node in the accessibility tree,
1330    /// overriding the element that holds real keyboard focus — but only while
1331    /// one of its ancestors actually holds focus.
1332    ///
1333    /// This implements the `aria-activedescendant` pattern for composite
1334    /// widgets that keep keyboard focus on a container (e.g. a menu or
1335    /// listbox) while a child is "selected": set this on the selected child so
1336    /// assistive technology announces and highlights it as focused.
1337    ///
1338    /// The element must also have a [`role`][Self::role] (and an id) so it
1339    /// produces an accessibility node. Unlike the web's container-side
1340    /// `aria-activedescendant`, this is set on the descendant; GPUI honors it
1341    /// only when a focused ancestor is present in the tree, so it is safe to
1342    /// set unconditionally on the selected child — if the container isn't
1343    /// focused, the claim is ignored.
1344    fn aria_active_descendant(mut self) -> Self {
1345        self.interactivity().report_active_descendant_focus = true;
1346        self
1347    }
1348
1349    /// Contribute synthetic accessibility nodes — nodes that don't correspond
1350    /// to any element — as children of this element's a11y node. For example,
1351    /// text runs describing an editor's text content.
1352    ///
1353    /// The closure is called after this element is prepainted, and only if it
1354    /// contributed a node to the accessibility tree (i.e. it has an id and a
1355    /// [`role`][StatefulInteractiveElement::role]).
1356    ///
1357    /// See [`Element::a11y_synthetic_children`] for details.
1358    fn a11y_synthetic_children(
1359        mut self,
1360        f: impl FnOnce(&mut crate::A11ySubtreeBuilder) + 'static,
1361    ) -> Self {
1362        self.interactivity().a11y_synthetic_children = Some(Box::new(f));
1363        self
1364    }
1365
1366    /// Set the selected state for this element.
1367    fn aria_selected(mut self, selected: bool) -> Self {
1368        self.interactivity().aria.selected = Some(selected);
1369        self
1370    }
1371
1372    /// Set the expanded state for this element.
1373    fn aria_expanded(mut self, expanded: bool) -> Self {
1374        self.interactivity().aria.expanded = Some(expanded);
1375        self
1376    }
1377
1378    /// Set whether this element is unavailable for interaction.
1379    fn aria_disabled(mut self, disabled: bool) -> Self {
1380        self.interactivity().aria.disabled = disabled;
1381        self
1382    }
1383
1384    /// Set whether this element exposes text that cannot be edited.
1385    fn aria_read_only(mut self, read_only: bool) -> Self {
1386        self.interactivity().aria.read_only = read_only;
1387        self
1388    }
1389
1390    /// Set whether this element is a modal surface.
1391    fn aria_modal(mut self, modal: bool) -> Self {
1392        self.interactivity().aria.modal = modal;
1393        self
1394    }
1395
1396    /// Set whether this element's value is invalid.
1397    fn aria_invalid(mut self, invalid: bool) -> Self {
1398        self.interactivity().aria.invalid = invalid;
1399        self
1400    }
1401
1402    /// Set whether this element requires a value.
1403    fn aria_required(mut self, required: bool) -> Self {
1404        self.interactivity().aria.required = required;
1405        self
1406    }
1407
1408    /// Set whether this element is currently being updated.
1409    fn aria_busy(mut self, busy: bool) -> Self {
1410        self.interactivity().aria.busy = busy;
1411        self
1412    }
1413
1414    /// Set how updates to this element should be announced.
1415    fn aria_live(mut self, politeness: accesskit::Live) -> Self {
1416        self.interactivity().aria.live = Some(politeness);
1417        self
1418    }
1419
1420    /// Set whether a live-region update should announce the whole region.
1421    fn aria_live_atomic(mut self, atomic: bool) -> Self {
1422        self.interactivity().aria.live_atomic = atomic;
1423        self
1424    }
1425
1426    /// Set the toggled state for this element.
1427    fn aria_toggled(mut self, toggled: accesskit::Toggled) -> Self {
1428        self.interactivity().aria.toggled = Some(toggled);
1429        self
1430    }
1431
1432    /// Set the numeric value for this element.
1433    fn aria_numeric_value(mut self, value: f64) -> Self {
1434        self.interactivity().aria.numeric_value = Some(value);
1435        self
1436    }
1437
1438    /// Set the step by which assistive technology should expect the numeric
1439    /// value of this element to change (e.g. when incrementing a spin button).
1440    fn aria_numeric_value_step(mut self, step: f64) -> Self {
1441        self.interactivity().aria.numeric_value_step = Some(step);
1442        self
1443    }
1444
1445    /// Set the string value of this element, e.g. the text content of a simple
1446    /// text input.
1447    fn aria_value(mut self, value: impl Into<SharedString>) -> Self {
1448        self.interactivity().aria.value = Some(value.into());
1449        self
1450    }
1451
1452    /// Set the placeholder text reported to assistive technology for this
1453    /// element, shown when a text input is empty.
1454    fn aria_placeholder(mut self, placeholder: impl Into<SharedString>) -> Self {
1455        self.interactivity().aria.placeholder = Some(placeholder.into());
1456        self
1457    }
1458
1459    /// Set the minimum numeric value for this element.
1460    fn aria_min_numeric_value(mut self, value: f64) -> Self {
1461        self.interactivity().aria.min_numeric_value = Some(value);
1462        self
1463    }
1464
1465    /// Set the maximum numeric value for this element.
1466    fn aria_max_numeric_value(mut self, value: f64) -> Self {
1467        self.interactivity().aria.max_numeric_value = Some(value);
1468        self
1469    }
1470
1471    /// Set the orientation of this element.
1472    fn aria_orientation(mut self, orientation: accesskit::Orientation) -> Self {
1473        self.interactivity().aria.orientation = Some(orientation);
1474        self
1475    }
1476
1477    /// Set the heading level of this element.
1478    fn aria_level(mut self, level: usize) -> Self {
1479        self.interactivity().aria.level = Some(level);
1480        self
1481    }
1482
1483    /// Set the position in set of this element.
1484    fn aria_position_in_set(mut self, position: usize) -> Self {
1485        self.interactivity().aria.position_in_set = Some(position);
1486        self
1487    }
1488
1489    /// Set the size of set for this element.
1490    fn aria_size_of_set(mut self, size: usize) -> Self {
1491        self.interactivity().aria.size_of_set = Some(size);
1492        self
1493    }
1494
1495    /// Set the row index for this element.
1496    fn aria_row_index(mut self, index: usize) -> Self {
1497        self.interactivity().aria.row_index = Some(index);
1498        self
1499    }
1500
1501    /// Set the column index for this element.
1502    fn aria_column_index(mut self, index: usize) -> Self {
1503        self.interactivity().aria.column_index = Some(index);
1504        self
1505    }
1506
1507    /// Set the row count for this element.
1508    fn aria_row_count(mut self, count: usize) -> Self {
1509        self.interactivity().aria.row_count = Some(count);
1510        self
1511    }
1512
1513    /// Set the column count for this element.
1514    fn aria_column_count(mut self, count: usize) -> Self {
1515        self.interactivity().aria.column_count = Some(count);
1516        self
1517    }
1518
1519    /// Register a handler for an accessibility action on this element.
1520    /// The handler is called when a screen reader requests the given action.
1521    ///
1522    /// See the [accessibility guide](crate::_accessibility) for an overview.
1523    fn on_a11y_action(
1524        mut self,
1525        action: accesskit::Action,
1526        listener: impl FnMut(Option<&accesskit::ActionData>, &mut crate::Window, &mut crate::App)
1527        + 'static,
1528    ) -> Self {
1529        self.interactivity()
1530            .a11y_action_listeners
1531            .push((action, Box::new(listener)));
1532        self
1533    }
1534
1535    /// Set this element to focusable.
1536    fn focusable(mut self) -> Self {
1537        self.interactivity().focusable = true;
1538        self
1539    }
1540
1541    /// Set the overflow x and y to scroll.
1542    fn overflow_scroll(mut self) -> Self {
1543        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1544        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1545        self
1546    }
1547
1548    /// Set the overflow x to scroll.
1549    fn overflow_x_scroll(mut self) -> Self {
1550        self.interactivity().base_style.overflow.x = Some(Overflow::Scroll);
1551        self
1552    }
1553
1554    /// Set the overflow y to scroll.
1555    fn overflow_y_scroll(mut self) -> Self {
1556        self.interactivity().base_style.overflow.y = Some(Overflow::Scroll);
1557        self
1558    }
1559
1560    /// Restrict scrolling of this element to the axis of the input gesture.
1561    ///
1562    /// See [`Style::restrict_scroll_to_axis`](crate::Style::restrict_scroll_to_axis) for details.
1563    fn restrict_scroll_to_axis(mut self) -> Self {
1564        self.interactivity().base_style.restrict_scroll_to_axis = Some(true);
1565        self
1566    }
1567
1568    /// Track the scroll state of this element with the given handle.
1569    fn track_scroll(mut self, scroll_handle: &ScrollHandle) -> Self {
1570        self.interactivity().tracked_scroll_handle = Some(scroll_handle.clone());
1571        self
1572    }
1573
1574    /// Track the scroll state of this element with the given handle.
1575    fn anchor_scroll(mut self, scroll_anchor: Option<ScrollAnchor>) -> Self {
1576        self.interactivity().scroll_anchor = scroll_anchor;
1577        self
1578    }
1579
1580    /// Set the given styles to be applied when this element is active.
1581    fn active(mut self, f: impl FnOnce(StyleRefinement) -> StyleRefinement) -> Self
1582    where
1583        Self: Sized,
1584    {
1585        self.interactivity().active_style = Some(Box::new(f(StyleRefinement::default())));
1586        self
1587    }
1588
1589    /// Set the given styles to be applied when this element's group is active.
1590    fn group_active(
1591        mut self,
1592        group_name: impl Into<SharedString>,
1593        f: impl FnOnce(StyleRefinement) -> StyleRefinement,
1594    ) -> Self
1595    where
1596        Self: Sized,
1597    {
1598        self.interactivity().group_active_style = Some(GroupStyle {
1599            group: group_name.into(),
1600            style: Box::new(f(StyleRefinement::default())),
1601        });
1602        self
1603    }
1604
1605    /// Bind the given callback to click events of this element.
1606    /// The fluent API equivalent to [`Interactivity::on_click`].
1607    ///
1608    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1609    fn on_click(mut self, listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static) -> Self
1610    where
1611        Self: Sized,
1612    {
1613        self.interactivity().on_click(listener);
1614        self
1615    }
1616
1617    /// Bind the given callback to non-primary click events of this element.
1618    /// The fluent API equivalent to [`Interactivity::on_aux_click`].
1619    ///
1620    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1621    fn on_aux_click(
1622        mut self,
1623        listener: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static,
1624    ) -> Self
1625    where
1626        Self: Sized,
1627    {
1628        self.interactivity().on_aux_click(listener);
1629        self
1630    }
1631
1632    /// On drag initiation, this callback will be used to create a new view to render the dragged value for a
1633    /// drag and drop operation. This API should also be used as the equivalent of 'on drag start' with
1634    /// the [`InteractiveElement::on_drag_move`] API.
1635    /// The callback also has access to the offset of triggering click from the origin of parent element.
1636    /// The fluent API equivalent to [`Interactivity::on_drag`].
1637    ///
1638    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1639    fn on_drag<T, W>(
1640        mut self,
1641        value: T,
1642        constructor: impl Fn(&T, Point<Pixels>, &mut Window, &mut App) -> Entity<W> + 'static,
1643    ) -> Self
1644    where
1645        Self: Sized,
1646        T: 'static,
1647        W: 'static + Render,
1648    {
1649        self.interactivity().on_drag(value, constructor);
1650        self
1651    }
1652
1653    /// Registers a callback resolving a payload to offer the platform if a drag started by this
1654    /// element leaves the window. It is invoked at most once per drag gesture, when the pointer
1655    /// exits the viewport. Must be called after [`Self::on_drag`], with the same dragged value
1656    /// type `T`.
1657    /// The fluent API equivalent to [`Interactivity::external_drag_payload`].
1658    fn external_drag_payload<T>(
1659        mut self,
1660        resolver: impl Fn(&T, &mut Window, &mut App) -> Option<ExternalDragPayload> + 'static,
1661    ) -> Self
1662    where
1663        Self: Sized,
1664        T: 'static,
1665    {
1666        self.interactivity().external_drag_payload(resolver);
1667        self
1668    }
1669
1670    /// Bind the given callback on the hover start and end events of this element. Note that the boolean
1671    /// passed to the callback is true when the hover starts and false when it ends.
1672    /// The fluent API equivalent to [`Interactivity::on_hover`].
1673    ///
1674    /// See [`Context::listener`](crate::Context::listener) to get access to a view's state from this callback.
1675    fn on_hover(mut self, listener: impl Fn(&bool, &mut Window, &mut App) + 'static) -> Self
1676    where
1677        Self: Sized,
1678    {
1679        self.interactivity().on_hover(listener);
1680        self
1681    }
1682
1683    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1684    /// The fluent API equivalent to [`Interactivity::tooltip`].
1685    fn tooltip(mut self, build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static) -> Self
1686    where
1687        Self: Sized,
1688    {
1689        self.interactivity().tooltip(build_tooltip);
1690        self
1691    }
1692
1693    /// Use the given callback to construct a new tooltip view when the mouse hovers over this element.
1694    /// The tooltip itself is also hoverable and won't disappear when the user moves the mouse into
1695    /// the tooltip. The fluent API equivalent to [`Interactivity::hoverable_tooltip`].
1696    fn hoverable_tooltip(
1697        mut self,
1698        build_tooltip: impl Fn(&mut Window, &mut App) -> AnyView + 'static,
1699    ) -> Self
1700    where
1701        Self: Sized,
1702    {
1703        self.interactivity().hoverable_tooltip(build_tooltip);
1704        self
1705    }
1706
1707    /// Set the delay before this element's tooltip is shown.
1708    /// The fluent API equivalent to [`Interactivity::tooltip_show_delay`].
1709    fn tooltip_show_delay(mut self, delay: Duration) -> Self
1710    where
1711        Self: Sized,
1712    {
1713        self.interactivity().tooltip_show_delay(delay);
1714        self
1715    }
1716}
1717
1718pub(crate) type MouseDownListener =
1719    Box<dyn Fn(&MouseDownEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1720pub(crate) type MouseUpListener =
1721    Box<dyn Fn(&MouseUpEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1722pub(crate) type MousePressureListener =
1723    Box<dyn Fn(&MousePressureEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1724pub(crate) type MouseMoveListener =
1725    Box<dyn Fn(&MouseMoveEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1726pub(crate) type MouseExitListener =
1727    Box<dyn Fn(&MouseExitEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1728
1729pub(crate) type ScrollWheelListener =
1730    Box<dyn Fn(&ScrollWheelEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1731
1732pub(crate) type PinchListener =
1733    Box<dyn Fn(&PinchEvent, DispatchPhase, &Hitbox, &mut Window, &mut App) + 'static>;
1734
1735pub(crate) type ClickListener = Rc<dyn Fn(&ClickEvent, &mut Window, &mut App) + 'static>;
1736
1737pub(crate) struct DragListener {
1738    value: Arc<dyn Any>,
1739    render: Box<dyn Fn(&dyn Any, Point<Pixels>, &mut Window, &mut App) -> AnyView + 'static>,
1740    external_payload: Option<ExternalDragPayloadResolver>,
1741}
1742
1743type ExternalDragPayloadResolver =
1744    Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> Option<ExternalDragPayload> + 'static>;
1745
1746type DropListener = Box<dyn Fn(&dyn Any, &mut Window, &mut App) + 'static>;
1747
1748type CanDropPredicate = Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> bool + 'static>;
1749
1750pub(crate) struct TooltipBuilder {
1751    build: Rc<dyn Fn(&mut Window, &mut App) -> AnyView + 'static>,
1752    hoverable: bool,
1753}
1754
1755pub(crate) type KeyDownListener =
1756    Box<dyn Fn(&KeyDownEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1757
1758pub(crate) type KeyUpListener =
1759    Box<dyn Fn(&KeyUpEvent, DispatchPhase, &mut Window, &mut App) + 'static>;
1760
1761pub(crate) type ModifiersChangedListener =
1762    Box<dyn Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static>;
1763
1764pub(crate) type ActionListener =
1765    Box<dyn Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
1766
1767/// Construct a new [`Div`] element
1768#[track_caller]
1769pub fn div() -> Div {
1770    Div {
1771        interactivity: Interactivity::new(),
1772        children: SmallVec::default(),
1773        prepaint_listener: None,
1774        image_cache: None,
1775        prepaint_order_fn: None,
1776    }
1777}
1778
1779/// A [`Div`] element, the all-in-one element for building complex UIs in GPUI
1780pub struct Div {
1781    interactivity: Interactivity,
1782    children: SmallVec<[StackSafe<AnyElement>; 2]>,
1783    prepaint_listener: Option<Box<dyn Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static>>,
1784    image_cache: Option<Box<dyn ImageCacheProvider>>,
1785    prepaint_order_fn: Option<Box<dyn Fn(&mut Window, &mut App) -> SmallVec<[usize; 8]>>>,
1786}
1787
1788impl Div {
1789    /// Add a listener to be called when the children of this `Div` are prepainted.
1790    /// This allows you to store the [`Bounds`] of the children for later use.
1791    pub fn on_children_prepainted(
1792        mut self,
1793        listener: impl Fn(Vec<Bounds<Pixels>>, &mut Window, &mut App) + 'static,
1794    ) -> Self {
1795        self.prepaint_listener = Some(Box::new(listener));
1796        self
1797    }
1798
1799    /// Add an image cache at the location of this div in the element tree.
1800    pub fn image_cache(mut self, cache: impl ImageCacheProvider) -> Self {
1801        self.image_cache = Some(Box::new(cache));
1802        self
1803    }
1804
1805    /// Specify a function that determines the order in which children are prepainted.
1806    ///
1807    /// The function is called at prepaint time and should return a vector of child indices
1808    /// in the desired prepaint order. Each index should appear exactly once.
1809    ///
1810    /// This is useful when the prepaint of one child affects state that another child reads.
1811    /// For example, in split editor views, the editor with an autoscroll request should
1812    /// be prepainted first so its scroll position update is visible to the other editor.
1813    pub fn with_dynamic_prepaint_order(
1814        mut self,
1815        order_fn: impl Fn(&mut Window, &mut App) -> SmallVec<[usize; 8]> + 'static,
1816    ) -> Self {
1817        self.prepaint_order_fn = Some(Box::new(order_fn));
1818        self
1819    }
1820}
1821
1822/// A frame state for a `Div` element, which contains layout IDs for its children.
1823///
1824/// This struct is used internally by the `Div` element to manage the layout state of its children
1825/// during the UI update cycle. It holds a small vector of `LayoutId` values, each corresponding to
1826/// a child element of the `Div`. These IDs are used to query the layout engine for the computed
1827/// bounds of the children after the layout phase is complete.
1828pub struct DivFrameState {
1829    child_layout_ids: SmallVec<[LayoutId; 2]>,
1830}
1831
1832/// Interactivity state displayed an manipulated in the inspector.
1833#[derive(Clone)]
1834pub struct DivInspectorState {
1835    /// The inspected element's base style. This is used for both inspecting and modifying the
1836    /// state. In the future it will make sense to separate the read and write, possibly tracking
1837    /// the modifications.
1838    #[cfg(any(feature = "inspector", debug_assertions))]
1839    pub base_style: Box<StyleRefinement>,
1840    /// Inspects the bounds of the element.
1841    pub bounds: Bounds<Pixels>,
1842    /// Size of the children of the element, or `bounds.size` if it has no children.
1843    pub content_size: Size<Pixels>,
1844}
1845
1846impl Styled for Div {
1847    fn style(&mut self) -> &mut StyleRefinement {
1848        &mut self.interactivity.base_style
1849    }
1850}
1851
1852impl InteractiveElement for Div {
1853    fn interactivity(&mut self) -> &mut Interactivity {
1854        &mut self.interactivity
1855    }
1856}
1857
1858impl ParentElement for Div {
1859    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1860        self.children
1861            .extend(elements.into_iter().map(StackSafe::new))
1862    }
1863}
1864
1865impl Element for Div {
1866    type RequestLayoutState = DivFrameState;
1867    type PrepaintState = Option<Hitbox>;
1868
1869    fn id(&self) -> Option<ElementId> {
1870        self.interactivity.element_id.clone()
1871    }
1872
1873    fn source_location(&self) -> Option<&'static std::panic::Location<'static>> {
1874        self.interactivity.source_location()
1875    }
1876
1877    fn a11y_role(&self) -> Option<accesskit::Role> {
1878        // Nodes with `GenericContainer` should never be reported to accesskit.
1879        // Equivalent to an HTML div with no role.
1880        self.interactivity
1881            .override_role
1882            .filter(|role| *role != accesskit::Role::GenericContainer)
1883    }
1884
1885    fn write_a11y_info(&self, node: &mut accesskit::Node) {
1886        self.interactivity.write_a11y_info(node);
1887    }
1888
1889    fn a11y_synthetic_children(
1890        &mut self,
1891        _prepaint: &mut Self::PrepaintState,
1892        builder: &mut crate::A11ySubtreeBuilder,
1893    ) {
1894        if let Some(f) = self.interactivity.a11y_synthetic_children.take() {
1895            f(builder);
1896        }
1897    }
1898
1899    #[stacksafe]
1900    fn request_layout(
1901        &mut self,
1902        global_id: Option<&GlobalElementId>,
1903        inspector_id: Option<&InspectorElementId>,
1904        window: &mut Window,
1905        cx: &mut App,
1906    ) -> (LayoutId, Self::RequestLayoutState) {
1907        let mut child_layout_ids = SmallVec::new();
1908        let image_cache = self
1909            .image_cache
1910            .as_mut()
1911            .map(|provider| provider.provide(window, cx));
1912
1913        let layout_id = window.with_image_cache(image_cache, |window| {
1914            self.interactivity.request_layout(
1915                global_id,
1916                inspector_id,
1917                window,
1918                cx,
1919                |style, window, cx| {
1920                    window.with_text_style(style.text_style().cloned(), |window| {
1921                        child_layout_ids = self
1922                            .children
1923                            .iter_mut()
1924                            .map(|child| child.request_layout(window, cx))
1925                            .collect::<SmallVec<_>>();
1926                        window.request_layout(style, child_layout_ids.iter().copied(), cx)
1927                    })
1928                },
1929            )
1930        });
1931
1932        (layout_id, DivFrameState { child_layout_ids })
1933    }
1934
1935    #[stacksafe]
1936    fn prepaint(
1937        &mut self,
1938        global_id: Option<&GlobalElementId>,
1939        inspector_id: Option<&InspectorElementId>,
1940        bounds: Bounds<Pixels>,
1941        request_layout: &mut Self::RequestLayoutState,
1942        window: &mut Window,
1943        cx: &mut App,
1944    ) -> Option<Hitbox> {
1945        let image_cache = self
1946            .image_cache
1947            .as_mut()
1948            .map(|provider| provider.provide(window, cx));
1949
1950        let has_prepaint_listener = self.prepaint_listener.is_some();
1951        let mut children_bounds = Vec::with_capacity(if has_prepaint_listener {
1952            request_layout.child_layout_ids.len()
1953        } else {
1954            0
1955        });
1956
1957        let mut child_min = point(Pixels::MAX, Pixels::MAX);
1958        let mut child_max = Point::default();
1959        if let Some(handle) = self.interactivity.scroll_anchor.as_ref() {
1960            *handle.last_origin.borrow_mut() = bounds.origin - window.element_offset();
1961        }
1962        let content_size = if request_layout.child_layout_ids.is_empty() {
1963            bounds.size
1964        } else if let Some(scroll_handle) = self.interactivity.tracked_scroll_handle.as_ref() {
1965            let mut state = scroll_handle.0.borrow_mut();
1966            state.child_bounds = Vec::with_capacity(request_layout.child_layout_ids.len());
1967            for child_layout_id in &request_layout.child_layout_ids {
1968                let child_bounds = window.layout_bounds(*child_layout_id);
1969                child_min = child_min.min(&child_bounds.origin);
1970                child_max = child_max.max(&child_bounds.bottom_right());
1971                state.child_bounds.push(child_bounds);
1972            }
1973            (child_max - child_min).into()
1974        } else {
1975            for child_layout_id in &request_layout.child_layout_ids {
1976                let child_bounds = window.layout_bounds(*child_layout_id);
1977                child_min = child_min.min(&child_bounds.origin);
1978                child_max = child_max.max(&child_bounds.bottom_right());
1979
1980                if has_prepaint_listener {
1981                    children_bounds.push(child_bounds);
1982                }
1983            }
1984            (child_max - child_min).into()
1985        };
1986
1987        self.interactivity.prepaint(
1988            global_id,
1989            inspector_id,
1990            bounds,
1991            content_size,
1992            window,
1993            cx,
1994            |style, scroll_offset, hitbox, window, cx| {
1995                // skip children
1996                if style.display == Display::None {
1997                    return hitbox;
1998                }
1999
2000                window.with_image_cache(image_cache, |window| {
2001                    window.with_element_offset(scroll_offset, |window| {
2002                        if let Some(order_fn) = &self.prepaint_order_fn {
2003                            let order = order_fn(window, cx);
2004                            for idx in order {
2005                                if let Some(child) = self.children.get_mut(idx) {
2006                                    child.prepaint(window, cx);
2007                                }
2008                            }
2009                        } else {
2010                            for child in &mut self.children {
2011                                child.prepaint(window, cx);
2012                            }
2013                        }
2014                    });
2015
2016                    if let Some(listener) = self.prepaint_listener.as_ref() {
2017                        listener(children_bounds, window, cx);
2018                    }
2019                });
2020
2021                hitbox
2022            },
2023        )
2024    }
2025
2026    #[stacksafe]
2027    fn paint(
2028        &mut self,
2029        global_id: Option<&GlobalElementId>,
2030        inspector_id: Option<&InspectorElementId>,
2031        bounds: Bounds<Pixels>,
2032        _request_layout: &mut Self::RequestLayoutState,
2033        hitbox: &mut Option<Hitbox>,
2034        window: &mut Window,
2035        cx: &mut App,
2036    ) {
2037        let image_cache = self
2038            .image_cache
2039            .as_mut()
2040            .map(|provider| provider.provide(window, cx));
2041
2042        window.with_image_cache(image_cache, |window| {
2043            self.interactivity.paint(
2044                global_id,
2045                inspector_id,
2046                bounds,
2047                hitbox.as_ref(),
2048                window,
2049                cx,
2050                |style, window, cx| {
2051                    // skip children
2052                    if style.display == Display::None {
2053                        return;
2054                    }
2055
2056                    for child in &mut self.children {
2057                        child.paint(window, cx);
2058                    }
2059                },
2060            )
2061        });
2062    }
2063}
2064
2065impl IntoElement for Div {
2066    type Element = Self;
2067
2068    fn into_element(self) -> Self::Element {
2069        self
2070    }
2071}
2072
2073#[derive(Default)]
2074pub(crate) struct AriaProperties {
2075    pub(crate) label: Option<SharedString>,
2076    pub(crate) description: Option<SharedString>,
2077    pub(crate) keyshortcuts: Option<SharedString>,
2078    pub(crate) selected: Option<bool>,
2079    pub(crate) expanded: Option<bool>,
2080    pub(crate) disabled: bool,
2081    pub(crate) read_only: bool,
2082    pub(crate) modal: bool,
2083    pub(crate) invalid: bool,
2084    pub(crate) required: bool,
2085    pub(crate) busy: bool,
2086    pub(crate) live: Option<accesskit::Live>,
2087    pub(crate) live_atomic: bool,
2088    pub(crate) toggled: Option<accesskit::Toggled>,
2089    pub(crate) numeric_value: Option<f64>,
2090    pub(crate) min_numeric_value: Option<f64>,
2091    pub(crate) max_numeric_value: Option<f64>,
2092    pub(crate) numeric_value_step: Option<f64>,
2093    pub(crate) value: Option<SharedString>,
2094    pub(crate) placeholder: Option<SharedString>,
2095    pub(crate) orientation: Option<accesskit::Orientation>,
2096    pub(crate) level: Option<usize>,
2097    pub(crate) position_in_set: Option<usize>,
2098    pub(crate) size_of_set: Option<usize>,
2099    pub(crate) row_index: Option<usize>,
2100    pub(crate) column_index: Option<usize>,
2101    pub(crate) row_count: Option<usize>,
2102    pub(crate) column_count: Option<usize>,
2103}
2104
2105/// The interactivity struct. Powers all of the general-purpose
2106/// interactivity in the `Div` element.
2107#[derive(Default)]
2108pub struct Interactivity {
2109    /// The element ID of the element. In id is required to support a stateful subset of the interactivity such as on_click.
2110    pub element_id: Option<ElementId>,
2111    /// Whether the element was clicked. This will only be present after layout.
2112    pub active: Option<bool>,
2113    /// Whether the element was hovered. This will only be present after paint if an hitbox
2114    /// was created for the interactive element.
2115    pub hovered: Option<bool>,
2116    pub(crate) tooltip_id: Option<TooltipId>,
2117    pub(crate) content_size: Size<Pixels>,
2118    pub(crate) key_context: Option<KeyContext>,
2119    pub(crate) focusable: bool,
2120    pub(crate) tracked_focus_handle: Option<FocusHandle>,
2121    pub(crate) tracked_scroll_handle: Option<ScrollHandle>,
2122    pub(crate) scroll_anchor: Option<ScrollAnchor>,
2123    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
2124    pub(crate) ongoing_scroll: Option<Rc<RefCell<OngoingScroll>>>,
2125    pub(crate) group: Option<SharedString>,
2126    /// The base style of the element, before any modifications are applied
2127    /// by focus, active, etc.
2128    pub base_style: Box<StyleRefinement>,
2129    pub(crate) focus_style: Option<Box<StyleRefinement>>,
2130    pub(crate) in_focus_style: Option<Box<StyleRefinement>>,
2131    pub(crate) focus_visible_style: Option<Box<StyleRefinement>>,
2132    pub(crate) hover_style: Option<Box<StyleRefinement>>,
2133    pub(crate) group_hover_style: Option<GroupStyle>,
2134    pub(crate) active_style: Option<Box<StyleRefinement>>,
2135    pub(crate) group_active_style: Option<GroupStyle>,
2136    pub(crate) drag_over_styles: Vec<(
2137        TypeId,
2138        Box<dyn Fn(&dyn Any, &mut Window, &mut App) -> StyleRefinement>,
2139    )>,
2140    pub(crate) group_drag_over_styles: Vec<(TypeId, GroupStyle)>,
2141    pub(crate) mouse_down_listeners: Vec<MouseDownListener>,
2142    pub(crate) mouse_up_listeners: Vec<MouseUpListener>,
2143    pub(crate) mouse_pressure_listeners: Vec<MousePressureListener>,
2144    pub(crate) mouse_move_listeners: Vec<MouseMoveListener>,
2145    pub(crate) mouse_exit_listeners: Vec<MouseExitListener>,
2146    pub(crate) scroll_wheel_listeners: Vec<ScrollWheelListener>,
2147    pub(crate) pinch_listeners: Vec<PinchListener>,
2148    pub(crate) key_down_listeners: Vec<KeyDownListener>,
2149    pub(crate) key_up_listeners: Vec<KeyUpListener>,
2150    pub(crate) modifiers_changed_listeners: Vec<ModifiersChangedListener>,
2151    pub(crate) action_listeners: Vec<(TypeId, ActionListener)>,
2152    pub(crate) drop_listeners: Vec<(TypeId, DropListener)>,
2153    pub(crate) can_drop_predicate: Option<CanDropPredicate>,
2154    pub(crate) click_listeners: Vec<ClickListener>,
2155    pub(crate) aux_click_listeners: Vec<ClickListener>,
2156    pub(crate) drag_listener: Option<DragListener>,
2157    pub(crate) hover_listener: Option<Box<dyn Fn(&bool, &mut Window, &mut App)>>,
2158    pub(crate) tooltip_builder: Option<TooltipBuilder>,
2159    pub(crate) tooltip_show_delay: Option<Duration>,
2160    pub(crate) window_control: Option<WindowControlArea>,
2161    pub(crate) hitbox_behavior: HitboxBehavior,
2162    pub(crate) tab_index: Option<isize>,
2163    pub(crate) tab_group: bool,
2164    pub(crate) tab_stop: bool,
2165
2166    pub(crate) a11y_action_listeners:
2167        Vec<(accesskit::Action, crate::window::a11y::A11yActionListener)>,
2168    pub(crate) a11y_synthetic_children: Option<Box<dyn FnOnce(&mut crate::A11ySubtreeBuilder)>>,
2169    pub(crate) report_active_descendant_focus: bool,
2170    pub(crate) override_role: Option<accesskit::Role>,
2171    pub(crate) aria: AriaProperties,
2172
2173    #[cfg(any(feature = "inspector", debug_assertions))]
2174    pub(crate) source_location: Option<&'static core::panic::Location<'static>>,
2175
2176    #[cfg(any(test, feature = "test-support"))]
2177    pub(crate) debug_selector: Option<String>,
2178}
2179
2180impl Interactivity {
2181    /// Layout this element according to this interactivity state's configured styles
2182    pub fn request_layout(
2183        &mut self,
2184        global_id: Option<&GlobalElementId>,
2185        _inspector_id: Option<&InspectorElementId>,
2186        window: &mut Window,
2187        cx: &mut App,
2188        f: impl FnOnce(Style, &mut Window, &mut App) -> LayoutId,
2189    ) -> LayoutId {
2190        #[cfg(any(feature = "inspector", debug_assertions))]
2191        window.with_inspector_state(
2192            _inspector_id,
2193            cx,
2194            |inspector_state: &mut Option<DivInspectorState>, _window| {
2195                if let Some(inspector_state) = inspector_state {
2196                    self.base_style = inspector_state.base_style.clone();
2197                } else {
2198                    *inspector_state = Some(DivInspectorState {
2199                        base_style: self.base_style.clone(),
2200                        bounds: Default::default(),
2201                        content_size: Default::default(),
2202                    })
2203                }
2204            },
2205        );
2206
2207        window.with_optional_element_state::<InteractiveElementState, _>(
2208            global_id,
2209            |element_state, window| {
2210                let mut element_state =
2211                    element_state.map(|element_state| element_state.unwrap_or_default());
2212
2213                if let Some(element_state) = element_state.as_ref()
2214                    && cx.has_active_drag()
2215                {
2216                    if let Some(pending_mouse_down) = element_state.pending_mouse_down.as_ref() {
2217                        *pending_mouse_down.borrow_mut() = None;
2218                    }
2219                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
2220                        *clicked_state.borrow_mut() = ElementClickedState::default();
2221                    }
2222                }
2223
2224                // Ensure we store a focus handle in our element state if we're focusable.
2225                // If there's an explicit focus handle we're tracking, use that. Otherwise
2226                // create a new handle and store it in the element state, which lives for as
2227                // as frames contain an element with this id.
2228                if self.focusable
2229                    && self.tracked_focus_handle.is_none()
2230                    && let Some(element_state) = element_state.as_mut()
2231                {
2232                    let mut handle = element_state
2233                        .focus_handle
2234                        .get_or_insert_with(|| cx.focus_handle())
2235                        .clone()
2236                        .tab_stop(self.tab_stop);
2237
2238                    if let Some(index) = self.tab_index {
2239                        handle = handle.tab_index(index);
2240                    }
2241
2242                    self.tracked_focus_handle = Some(handle);
2243                }
2244
2245                if let Some(scroll_handle) = self.tracked_scroll_handle.as_ref() {
2246                    let scroll_handle_state = scroll_handle.0.borrow();
2247                    self.scroll_offset = Some(scroll_handle_state.offset.clone());
2248                    self.ongoing_scroll = Some(scroll_handle_state.ongoing_scroll.clone());
2249                } else if (self.base_style.overflow.x == Some(Overflow::Scroll)
2250                    || self.base_style.overflow.y == Some(Overflow::Scroll))
2251                    && let Some(element_state) = element_state.as_mut()
2252                {
2253                    self.scroll_offset = Some(
2254                        element_state
2255                            .scroll_offset
2256                            .get_or_insert_with(Rc::default)
2257                            .clone(),
2258                    );
2259                    self.ongoing_scroll = Some(
2260                        element_state
2261                            .ongoing_scroll
2262                            .get_or_insert_with(|| Rc::new(RefCell::new(OngoingScroll::default())))
2263                            .clone(),
2264                    );
2265                }
2266
2267                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
2268                let layout_id = f(style, window, cx);
2269                (layout_id, element_state)
2270            },
2271        )
2272    }
2273
2274    /// Commit the bounds of this element according to this interactivity state's configured styles.
2275    pub fn prepaint<R>(
2276        &mut self,
2277        global_id: Option<&GlobalElementId>,
2278        _inspector_id: Option<&InspectorElementId>,
2279        bounds: Bounds<Pixels>,
2280        content_size: Size<Pixels>,
2281        window: &mut Window,
2282        cx: &mut App,
2283        f: impl FnOnce(&Style, Point<Pixels>, Option<Hitbox>, &mut Window, &mut App) -> R,
2284    ) -> R {
2285        self.content_size = content_size;
2286
2287        #[cfg(any(feature = "inspector", debug_assertions))]
2288        window.with_inspector_state(
2289            _inspector_id,
2290            cx,
2291            |inspector_state: &mut Option<DivInspectorState>, _window| {
2292                if let Some(inspector_state) = inspector_state {
2293                    inspector_state.bounds = bounds;
2294                    inspector_state.content_size = content_size;
2295                }
2296            },
2297        );
2298
2299        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
2300            window.set_focus_handle(focus_handle, cx);
2301
2302            if window.a11y.is_active() {
2303                if let Some(global_id) = global_id {
2304                    let node_id = global_id.accesskit_node_id();
2305                    window.a11y.set_focusable(node_id, focus_handle.id);
2306                    if focus_handle.is_focused(window) {
2307                        window.a11y.set_focus(node_id);
2308                    }
2309                } else if focus_handle.is_focused(window) {
2310                    // Focusable, but with no element id it can't have an
2311                    // accessibility node, so screen readers fall back to the
2312                    // whole window.
2313                    window
2314                        .a11y
2315                        .note_focus_without_node(focus_handle.id, "it has no element id");
2316                }
2317            }
2318        }
2319
2320        if self.report_active_descendant_focus && window.a11y.is_active() {
2321            if let Some(global_id) = global_id {
2322                window
2323                    .a11y
2324                    .set_active_descendant(global_id.accesskit_node_id());
2325            }
2326        }
2327        window.with_optional_element_state::<InteractiveElementState, _>(
2328            global_id,
2329            |element_state, window| {
2330                let mut element_state =
2331                    element_state.map(|element_state| element_state.unwrap_or_default());
2332                let style = self.compute_style_internal(None, element_state.as_mut(), window, cx);
2333
2334                if let Some(element_state) = element_state.as_mut() {
2335                    if let Some(clicked_state) = element_state.clicked_state.as_ref() {
2336                        let clicked_state = clicked_state.borrow();
2337                        self.active = Some(clicked_state.element);
2338                    }
2339                    if self.hover_style.is_some() || self.group_hover_style.is_some() {
2340                        element_state
2341                            .hover_state
2342                            .get_or_insert_with(Default::default);
2343                    }
2344                    if let Some(active_tooltip) = element_state.active_tooltip.as_ref() {
2345                        if self.tooltip_builder.is_some() {
2346                            self.tooltip_id = set_tooltip_on_window(active_tooltip, window);
2347                        } else {
2348                            // If there is no longer a tooltip builder, remove the active tooltip.
2349                            element_state.active_tooltip.take();
2350                        }
2351                    }
2352                }
2353
2354                window.with_text_style(style.text_style().cloned(), |window| {
2355                    window.with_content_mask(
2356                        style.overflow_mask(bounds, window.rem_size()),
2357                        |window| {
2358                            let hitbox = if self.should_insert_hitbox(&style, window, cx) {
2359                                Some(window.insert_hitbox(bounds, self.hitbox_behavior))
2360                            } else {
2361                                None
2362                            };
2363                            if let (Some(global_id), Some(hitbox)) = (global_id, hitbox.as_ref()) {
2364                                window.register_pointer_capture_hitbox(global_id, hitbox.id);
2365                            }
2366
2367                            let scroll_offset =
2368                                self.clamp_scroll_position(bounds, &style, window, cx);
2369                            let result = f(&style, scroll_offset, hitbox, window, cx);
2370                            (result, element_state)
2371                        },
2372                    )
2373                })
2374            },
2375        )
2376    }
2377
2378    fn should_insert_hitbox(&self, style: &Style, window: &Window, cx: &App) -> bool {
2379        self.hitbox_behavior != HitboxBehavior::Normal
2380            || self.window_control.is_some()
2381            || style.mouse_cursor.is_some()
2382            || self.group.is_some()
2383            || self.scroll_offset.is_some()
2384            || self.tracked_focus_handle.is_some()
2385            || self.hover_style.is_some()
2386            || self.group_hover_style.is_some()
2387            || self.hover_listener.is_some()
2388            || !self.mouse_up_listeners.is_empty()
2389            || !self.mouse_pressure_listeners.is_empty()
2390            || !self.mouse_down_listeners.is_empty()
2391            || !self.mouse_move_listeners.is_empty()
2392            || !self.mouse_exit_listeners.is_empty()
2393            || !self.click_listeners.is_empty()
2394            || !self.aux_click_listeners.is_empty()
2395            || !self.scroll_wheel_listeners.is_empty()
2396            || self.has_pinch_listeners()
2397            || self.drag_listener.is_some()
2398            || !self.drop_listeners.is_empty()
2399            || !self.drag_over_styles.is_empty()
2400            || self.tooltip_builder.is_some()
2401            || window.is_inspector_picking(cx)
2402    }
2403
2404    fn clamp_scroll_position(
2405        &self,
2406        bounds: Bounds<Pixels>,
2407        style: &Style,
2408        window: &mut Window,
2409        _cx: &mut App,
2410    ) -> Point<Pixels> {
2411        fn round_to_two_decimals(pixels: Pixels) -> Pixels {
2412            const ROUNDING_FACTOR: f32 = 100.0;
2413            (pixels * ROUNDING_FACTOR).round() / ROUNDING_FACTOR
2414        }
2415
2416        if let Some(scroll_offset) = self.scroll_offset.as_ref() {
2417            let scroll_to_bottom = if let Some(scroll_handle) = &self.tracked_scroll_handle {
2418                let mut scroll_handle_state = scroll_handle.0.borrow_mut();
2419                scroll_handle_state.overflow = style.overflow;
2420                mem::take(&mut scroll_handle_state.scroll_to_bottom)
2421            } else {
2422                false
2423            };
2424
2425            let rem_size = window.rem_size();
2426            let padding = style.padding.to_pixels(bounds.size.into(), rem_size);
2427            let padding_size = size(padding.left + padding.right, padding.top + padding.bottom);
2428            // The floating point values produced by Taffy and ours often vary
2429            // slightly after ~5 decimal places. This can lead to cases where after
2430            // subtracting these, the container becomes scrollable for less than
2431            // 0.00000x pixels. As we generally don't benefit from a precision that
2432            // high for the maximum scroll, we round the scroll max to 2 decimal
2433            // places here.
2434            let padded_content_size = self.content_size + padding_size;
2435            let scroll_max = Point::from(padded_content_size - bounds.size)
2436                .map(round_to_two_decimals)
2437                .max(&Default::default());
2438            if let Some(scroll_handle) = &self.tracked_scroll_handle {
2439                {
2440                    let mut scroll_handle_state = scroll_handle.0.borrow_mut();
2441                    scroll_handle_state.max_offset = scroll_max;
2442                    scroll_handle_state.bounds = bounds;
2443                }
2444                scroll_handle.scroll_to_active_item();
2445            }
2446            // Clamp scroll offset in case scroll max is smaller now (e.g., if children
2447            // were removed or the bounds became larger).
2448            let mut scroll_offset = scroll_offset.borrow_mut();
2449
2450            scroll_offset.x = scroll_offset.x.clamp(-scroll_max.x, px(0.));
2451            if scroll_to_bottom {
2452                scroll_offset.y = -scroll_max.y;
2453            } else {
2454                scroll_offset.y = scroll_offset.y.clamp(-scroll_max.y, px(0.));
2455            }
2456
2457            *scroll_offset
2458        } else {
2459            Point::default()
2460        }
2461    }
2462
2463    /// Paint this element according to this interactivity state's configured styles
2464    /// and bind the element's mouse and keyboard events.
2465    ///
2466    /// content_size is the size of the content of the element, which may be larger than the
2467    /// element's bounds if the element is scrollable.
2468    ///
2469    /// the final computed style will be passed to the provided function, along
2470    /// with the current scroll offset
2471    pub fn paint(
2472        &mut self,
2473        global_id: Option<&GlobalElementId>,
2474        _inspector_id: Option<&InspectorElementId>,
2475        bounds: Bounds<Pixels>,
2476        hitbox: Option<&Hitbox>,
2477        window: &mut Window,
2478        cx: &mut App,
2479        f: impl FnOnce(&Style, &mut Window, &mut App),
2480    ) {
2481        self.hovered = hitbox.map(|hitbox| hitbox.is_hovered(window));
2482        window.with_optional_element_state::<InteractiveElementState, _>(
2483            global_id,
2484            |element_state, window| {
2485                let mut element_state =
2486                    element_state.map(|element_state| element_state.unwrap_or_default());
2487
2488                let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
2489
2490                #[cfg(any(feature = "test-support", test))]
2491                if let Some(debug_selector) = &self.debug_selector {
2492                    window
2493                        .next_frame
2494                        .debug_bounds
2495                        .insert(debug_selector.clone(), bounds);
2496                }
2497
2498                self.paint_hover_group_handler(window, cx);
2499
2500                if style.visibility == Visibility::Hidden {
2501                    return ((), element_state);
2502                }
2503
2504                let mut tab_group = None;
2505                if self.tab_group {
2506                    tab_group = self.tab_index;
2507                }
2508
2509                window.with_element_opacity(style.opacity, |window| {
2510                    style.paint(bounds, window, cx, |window: &mut Window, cx: &mut App| {
2511                        window.with_text_style(style.text_style().cloned(), |window| {
2512                            window.with_content_mask(
2513                                style.overflow_mask(bounds, window.rem_size()),
2514                                |window| {
2515                                    window.with_tab_group(tab_group, |window| {
2516                                        // Register the container's own focus handle *inside* its
2517                                        // tab group, so that focusing the container and then
2518                                        // calling `focus_next` descends into this group's first
2519                                        // item. Inserting it before `with_tab_group` would give the
2520                                        // container a shallower tab path than its children; with
2521                                        // sibling groups every container would then sort ahead of
2522                                        // every item, and `focus_next` from a container would jump
2523                                        // to the first item in the whole window instead of its own.
2524                                        if let Some(focus_handle) = &self.tracked_focus_handle {
2525                                            window.next_frame.tab_stops.insert(focus_handle);
2526                                        }
2527                                        if let Some(hitbox) = hitbox {
2528                                            #[cfg(debug_assertions)]
2529                                            self.paint_debug_info(
2530                                                global_id, hitbox, &style, window, cx,
2531                                            );
2532
2533                                            if let Some(drag) = cx.active_drag.as_ref() {
2534                                                if let Some(mouse_cursor) = drag.cursor_style {
2535                                                    window.set_window_cursor_style(mouse_cursor);
2536                                                }
2537                                            } else {
2538                                                if let Some(mouse_cursor) = style.mouse_cursor {
2539                                                    window.set_cursor_style(mouse_cursor, hitbox);
2540                                                }
2541                                            }
2542
2543                                            if let Some(group) = self.group.clone() {
2544                                                GroupHitboxes::push(group, hitbox.id, cx);
2545                                            }
2546
2547                                            if let Some(area) = self.window_control {
2548                                                window.insert_window_control_hitbox(
2549                                                    area,
2550                                                    hitbox.clone(),
2551                                                );
2552                                            }
2553
2554                                            self.paint_mouse_listeners(
2555                                                hitbox,
2556                                                element_state.as_mut(),
2557                                                window,
2558                                                cx,
2559                                            );
2560                                            self.paint_scroll_listener(hitbox, &style, window, cx);
2561                                        }
2562
2563                                        self.paint_keyboard_listeners(window, cx);
2564
2565                                        if window.a11y.is_active() {
2566                                            if let Some(global_id) = global_id {
2567                                                if !self.a11y_action_listeners.is_empty() {
2568                                                    let node_id = global_id.accesskit_node_id();
2569                                                    for (action, listener) in
2570                                                        self.a11y_action_listeners.drain(..)
2571                                                    {
2572                                                        window.on_a11y_action(
2573                                                            node_id, action, listener,
2574                                                        );
2575                                                    }
2576                                                }
2577                                            }
2578                                        }
2579
2580                                        f(&style, window, cx);
2581
2582                                        if let Some(_hitbox) = hitbox {
2583                                            #[cfg(any(feature = "inspector", debug_assertions))]
2584                                            window.insert_inspector_hitbox(
2585                                                _hitbox.id,
2586                                                _inspector_id,
2587                                                cx,
2588                                            );
2589
2590                                            if let Some(group) = self.group.as_ref() {
2591                                                GroupHitboxes::pop(group, cx);
2592                                            }
2593                                        }
2594                                    })
2595                                },
2596                            );
2597                        });
2598                    });
2599                });
2600
2601                ((), element_state)
2602            },
2603        );
2604    }
2605
2606    #[cfg(debug_assertions)]
2607    fn paint_debug_info(
2608        &self,
2609        global_id: Option<&GlobalElementId>,
2610        hitbox: &Hitbox,
2611        style: &Style,
2612        window: &mut Window,
2613        cx: &mut App,
2614    ) {
2615        use crate::{BorderStyle, TextAlign};
2616
2617        if let Some(global_id) = global_id
2618            && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
2619            && hitbox.is_hovered(window)
2620        {
2621            const FONT_SIZE: crate::Pixels = crate::Pixels(10.);
2622            let element_id = format!("{global_id:?}");
2623            let str_len = element_id.len();
2624
2625            let render_debug_text = |window: &mut Window| {
2626                if let Some(text) = window
2627                    .text_system()
2628                    .shape_text(
2629                        element_id.into(),
2630                        FONT_SIZE,
2631                        &[window.text_style().to_run(str_len)],
2632                        None,
2633                        None,
2634                    )
2635                    .ok()
2636                    .and_then(|mut text| text.pop())
2637                {
2638                    text.paint(hitbox.origin, FONT_SIZE, TextAlign::Left, None, window, cx)
2639                        .ok();
2640
2641                    let text_bounds = crate::Bounds {
2642                        origin: hitbox.origin,
2643                        size: text.size(FONT_SIZE),
2644                    };
2645                    if let Some(source_location) = self.source_location
2646                        && text_bounds.contains(&window.mouse_position())
2647                        && window.modifiers().secondary()
2648                    {
2649                        let secondary_held = window.modifiers().secondary();
2650                        window.on_key_event({
2651                            move |e: &crate::ModifiersChangedEvent, _phase, window, _cx| {
2652                                if e.modifiers.secondary() != secondary_held
2653                                    && text_bounds.contains(&window.mouse_position())
2654                                {
2655                                    window.refresh();
2656                                }
2657                            }
2658                        });
2659
2660                        let was_hovered = hitbox.is_hovered(window);
2661                        let current_view = window.current_view();
2662                        window.on_mouse_event({
2663                            let hitbox = hitbox.clone();
2664                            move |_: &MouseMoveEvent, phase, window, cx| {
2665                                if phase == DispatchPhase::Capture {
2666                                    let hovered = hitbox.is_hovered(window);
2667                                    if hovered != was_hovered {
2668                                        cx.notify(current_view)
2669                                    }
2670                                }
2671                            }
2672                        });
2673
2674                        window.on_mouse_event({
2675                            let hitbox = hitbox.clone();
2676                            move |e: &crate::MouseDownEvent, phase, window, cx| {
2677                                if text_bounds.contains(&e.position)
2678                                    && phase.capture()
2679                                    && hitbox.is_hovered(window)
2680                                {
2681                                    cx.stop_propagation();
2682                                    let Ok(dir) = std::env::current_dir() else {
2683                                        return;
2684                                    };
2685
2686                                    eprintln!(
2687                                        "This element was created at:\n{}:{}:{}",
2688                                        dir.join(source_location.file()).to_string_lossy(),
2689                                        source_location.line(),
2690                                        source_location.column()
2691                                    );
2692                                }
2693                            }
2694                        });
2695                        window.paint_quad(crate::outline(
2696                            crate::Bounds {
2697                                origin: hitbox.origin
2698                                    + crate::point(crate::px(0.), FONT_SIZE - px(2.)),
2699                                size: crate::Size {
2700                                    width: text_bounds.size.width,
2701                                    height: crate::px(1.),
2702                                },
2703                            },
2704                            crate::red(),
2705                            BorderStyle::default(),
2706                        ))
2707                    }
2708                }
2709            };
2710
2711            window.with_text_style(
2712                Some(crate::TextStyleRefinement {
2713                    color: Some(crate::red()),
2714                    line_height: Some(FONT_SIZE.into()),
2715                    background_color: Some(crate::white()),
2716                    ..Default::default()
2717                }),
2718                render_debug_text,
2719            )
2720        }
2721    }
2722
2723    fn paint_mouse_listeners(
2724        &mut self,
2725        hitbox: &Hitbox,
2726        element_state: Option<&mut InteractiveElementState>,
2727        window: &mut Window,
2728        cx: &mut App,
2729    ) {
2730        let is_focused = self
2731            .tracked_focus_handle
2732            .as_ref()
2733            .map(|handle| handle.is_focused(window))
2734            .unwrap_or(false);
2735
2736        // If this element can be focused, register a mouse down listener
2737        // that will automatically transfer focus when hitting the element.
2738        // This behavior can be suppressed by using `cx.prevent_default()`.
2739        if let Some(focus_handle) = self.tracked_focus_handle.clone() {
2740            let hitbox = hitbox.clone();
2741            window.on_mouse_event(move |_: &MouseDownEvent, phase, window, cx| {
2742                if phase == DispatchPhase::Bubble
2743                    && hitbox.is_hovered(window)
2744                    && !window.default_prevented()
2745                {
2746                    window.focus(&focus_handle, cx);
2747                    // If there is a parent that is also focusable, prevent it
2748                    // from transferring focus because we already did so.
2749                    window.prevent_default();
2750                }
2751            });
2752        }
2753
2754        for listener in self.mouse_down_listeners.drain(..) {
2755            let hitbox = hitbox.clone();
2756            window.on_mouse_event(move |event: &MouseDownEvent, phase, window, cx| {
2757                listener(event, phase, &hitbox, window, cx);
2758            })
2759        }
2760
2761        for listener in self.mouse_up_listeners.drain(..) {
2762            let hitbox = hitbox.clone();
2763            window.on_mouse_event(move |event: &MouseUpEvent, phase, window, cx| {
2764                listener(event, phase, &hitbox, window, cx);
2765            })
2766        }
2767
2768        for listener in self.mouse_pressure_listeners.drain(..) {
2769            let hitbox = hitbox.clone();
2770            window.on_mouse_event(move |event: &MousePressureEvent, phase, window, cx| {
2771                listener(event, phase, &hitbox, window, cx);
2772            })
2773        }
2774
2775        for listener in self.mouse_move_listeners.drain(..) {
2776            let hitbox = hitbox.clone();
2777            window.on_mouse_event(move |event: &MouseMoveEvent, phase, window, cx| {
2778                listener(event, phase, &hitbox, window, cx);
2779            })
2780        }
2781
2782        for listener in self.mouse_exit_listeners.drain(..) {
2783            let hitbox = hitbox.clone();
2784            window.on_mouse_event(move |event: &MouseExitEvent, phase, window, cx| {
2785                listener(event, phase, &hitbox, window, cx);
2786            })
2787        }
2788
2789        for listener in self.scroll_wheel_listeners.drain(..) {
2790            let hitbox = hitbox.clone();
2791            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
2792                listener(event, phase, &hitbox, window, cx);
2793            })
2794        }
2795
2796        for listener in self.pinch_listeners.drain(..) {
2797            let hitbox = hitbox.clone();
2798            window.on_mouse_event(move |event: &PinchEvent, phase, window, cx| {
2799                listener(event, phase, &hitbox, window, cx);
2800            })
2801        }
2802
2803        if self.hover_style.is_some()
2804            || self.base_style.mouse_cursor.is_some()
2805            || cx.active_drag.is_some() && !self.drag_over_styles.is_empty()
2806        {
2807            let hitbox = hitbox.clone();
2808            let hover_state = self.hover_style.as_ref().and_then(|_| {
2809                element_state
2810                    .as_ref()
2811                    .and_then(|state| state.hover_state.as_ref())
2812                    .cloned()
2813            });
2814            let current_view = window.current_view();
2815
2816            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2817                let hovered = hitbox.is_hovered(window);
2818                let was_hovered = hover_state
2819                    .as_ref()
2820                    .is_some_and(|state| state.borrow().element);
2821                if phase == DispatchPhase::Capture && hovered != was_hovered {
2822                    if let Some(hover_state) = &hover_state {
2823                        hover_state.borrow_mut().element = hovered;
2824                        cx.notify(current_view);
2825                    }
2826                }
2827            });
2828        }
2829
2830        if let Some(group_hover) = self.group_hover_style.as_ref() {
2831            if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
2832                let hover_state = element_state
2833                    .as_ref()
2834                    .and_then(|element| element.hover_state.as_ref())
2835                    .cloned();
2836                let current_view = window.current_view();
2837
2838                window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
2839                    let group_hovered = group_hitbox_id.is_hovered(window);
2840                    let was_group_hovered = hover_state
2841                        .as_ref()
2842                        .is_some_and(|state| state.borrow().group);
2843                    if phase == DispatchPhase::Capture && group_hovered != was_group_hovered {
2844                        if let Some(hover_state) = &hover_state {
2845                            hover_state.borrow_mut().group = group_hovered;
2846                            cx.notify(current_view);
2847                        }
2848                    }
2849                });
2850            }
2851        }
2852
2853        let drag_cursor_style = self.base_style.as_ref().mouse_cursor;
2854
2855        let mut drag_listener = mem::take(&mut self.drag_listener);
2856        let drop_listeners = mem::take(&mut self.drop_listeners);
2857        let click_listeners = mem::take(&mut self.click_listeners);
2858        let aux_click_listeners = mem::take(&mut self.aux_click_listeners);
2859        let can_drop_predicate = mem::take(&mut self.can_drop_predicate);
2860
2861        if !drop_listeners.is_empty() {
2862            let hitbox = hitbox.clone();
2863            window.on_mouse_event({
2864                move |_: &MouseUpEvent, phase, window, cx| {
2865                    if let Some(drag) = &cx.active_drag
2866                        && phase == DispatchPhase::Bubble
2867                        && hitbox.is_hovered(window)
2868                    {
2869                        let drag_state_type = drag.value.as_ref().type_id();
2870                        for (drop_state_type, listener) in &drop_listeners {
2871                            if *drop_state_type == drag_state_type {
2872                                let drag = cx
2873                                    .active_drag
2874                                    .take()
2875                                    .expect("checked for type drag state type above");
2876
2877                                let mut can_drop = true;
2878                                if let Some(predicate) = &can_drop_predicate {
2879                                    can_drop = predicate(drag.value.as_ref(), window, cx);
2880                                }
2881
2882                                if can_drop {
2883                                    listener(drag.value.as_ref(), window, cx);
2884                                    window.refresh();
2885                                    cx.stop_propagation();
2886                                }
2887                            }
2888                        }
2889                    }
2890                }
2891            });
2892        }
2893
2894        if let Some(element_state) = element_state {
2895            if !click_listeners.is_empty()
2896                || !aux_click_listeners.is_empty()
2897                || drag_listener.is_some()
2898            {
2899                let pending_mouse_down = element_state
2900                    .pending_mouse_down
2901                    .get_or_insert_with(Default::default)
2902                    .clone();
2903
2904                let pending_keyboard_down = element_state
2905                    .pending_keyboard_down
2906                    .get_or_insert_with(Default::default)
2907                    .clone();
2908
2909                let clicked_state = element_state
2910                    .clicked_state
2911                    .get_or_insert_with(Default::default)
2912                    .clone();
2913
2914                window.on_mouse_event({
2915                    let pending_mouse_down = pending_mouse_down.clone();
2916                    let hitbox = hitbox.clone();
2917                    let has_aux_click_listeners = !aux_click_listeners.is_empty();
2918                    move |event: &MouseDownEvent, phase, window, _cx| {
2919                        if phase == DispatchPhase::Bubble
2920                            && (event.button == MouseButton::Left || has_aux_click_listeners)
2921                            && hitbox.is_hovered(window)
2922                        {
2923                            *pending_mouse_down.borrow_mut() = Some(event.clone());
2924                            window.refresh();
2925                        }
2926                    }
2927                });
2928
2929                window.on_mouse_event({
2930                    let pending_mouse_down = pending_mouse_down.clone();
2931                    let hitbox = hitbox.clone();
2932                    move |event: &MouseMoveEvent, phase, window, cx| {
2933                        if phase == DispatchPhase::Capture {
2934                            return;
2935                        }
2936
2937                        let mut pending_mouse_down = pending_mouse_down.borrow_mut();
2938                        if let Some(mouse_down) = pending_mouse_down.clone()
2939                            && !cx.has_active_drag()
2940                            && (event.position - mouse_down.position).magnitude() > DRAG_THRESHOLD
2941                            && let Some(listener) = drag_listener.take()
2942                            && mouse_down.button == MouseButton::Left
2943                        {
2944                            *clicked_state.borrow_mut() = ElementClickedState::default();
2945                            let cursor_offset = event.position - hitbox.origin;
2946                            let drag = (listener.render)(
2947                                listener.value.as_ref(),
2948                                cursor_offset,
2949                                window,
2950                                cx,
2951                            );
2952                            let external_payload_source =
2953                                listener.external_payload.map(|external_payload| {
2954                                    let value = listener.value.clone();
2955                                    Box::new(move |window: &mut Window, cx: &mut App| {
2956                                        external_payload(value.as_ref(), window, cx)
2957                                    })
2958                                        as ExternalDragPayloadSource
2959                                });
2960                            cx.active_drag = Some(AnyDrag {
2961                                view: drag,
2962                                value: listener.value,
2963                                cursor_offset,
2964                                cursor_style: drag_cursor_style,
2965                                external_payload_source,
2966                            });
2967                            pending_mouse_down.take();
2968                            window.refresh();
2969                            cx.stop_propagation();
2970                        }
2971                    }
2972                });
2973
2974                if is_focused {
2975                    // Record the focus generation at which an enter/space key
2976                    // down event happened on this element. The next key up
2977                    // event will be mapped to a click event if both of the
2978                    // following are true:
2979                    // - no other key events happen in between
2980                    // - the focus generation is the same (implying focus did not move)
2981                    //
2982                    // This design avoids an ABA problem that happens if you
2983                    // store the focus handle that registered the keypress.
2984                    window.on_key_event({
2985                        let pending_keyboard_down = pending_keyboard_down.clone();
2986                        move |event: &KeyDownEvent, phase, window, _cx| {
2987                            if phase.bubble() && !window.default_prevented() {
2988                                let stroke = &event.keystroke;
2989                                let is_activation_key = (stroke.key.eq("enter")
2990                                    || stroke.key.eq("space"))
2991                                    && !stroke.modifiers.modified();
2992                                *pending_keyboard_down.borrow_mut() =
2993                                    is_activation_key.then_some(window.focus_generation);
2994                            }
2995                        }
2996                    });
2997
2998                    // Press enter, space to trigger click, when the element is focused.
2999                    window.on_key_event({
3000                        let click_listeners = click_listeners.clone();
3001                        let hitbox = hitbox.clone();
3002                        move |event: &KeyUpEvent, phase, window, cx| {
3003                            if phase.bubble() && !window.default_prevented() {
3004                                let stroke = &event.keystroke;
3005                                let keyboard_button = if stroke.key.eq("enter") {
3006                                    Some(KeyboardButton::Enter)
3007                                } else if stroke.key.eq("space") {
3008                                    Some(KeyboardButton::Space)
3009                                } else {
3010                                    None
3011                                };
3012
3013                                if let Some(button) = keyboard_button
3014                                    && !stroke.modifiers.modified()
3015                                {
3016                                    let pending =
3017                                        std::mem::take(&mut *pending_keyboard_down.borrow_mut());
3018                                    if pending != Some(window.focus_generation) {
3019                                        return;
3020                                    }
3021
3022                                    let click_event = ClickEvent::Keyboard(KeyboardClickEvent {
3023                                        button,
3024                                        bounds: hitbox.bounds,
3025                                    });
3026
3027                                    for listener in &click_listeners {
3028                                        listener(&click_event, window, cx);
3029                                    }
3030                                } else {
3031                                    // Releasing any other key mid-press means
3032                                    // this isn't a clean activation, so cancel
3033                                    // the pending keydown.
3034                                    *pending_keyboard_down.borrow_mut() = None;
3035                                }
3036                            }
3037                        }
3038                    });
3039                }
3040
3041                window.on_mouse_event({
3042                    let mut captured_mouse_down = None;
3043                    let hitbox = hitbox.clone();
3044                    move |event: &MouseUpEvent, phase, window, cx| match phase {
3045                        // Clear the pending mouse down during the capture phase,
3046                        // so that it happens even if another event handler stops
3047                        // propagation.
3048                        DispatchPhase::Capture => {
3049                            let mut pending_mouse_down = pending_mouse_down.borrow_mut();
3050                            if pending_mouse_down.is_some() && hitbox.is_hovered(window) {
3051                                captured_mouse_down = pending_mouse_down.take();
3052                                window.refresh();
3053                            } else if pending_mouse_down.is_some() {
3054                                // Clear the pending mouse down event (without firing click handlers)
3055                                // if the hitbox is not being hovered.
3056                                // This avoids dragging elements that changed their position
3057                                // immediately after being clicked.
3058                                // See https://github.com/zed-industries/zed/issues/24600 for more details
3059                                pending_mouse_down.take();
3060                                window.refresh();
3061                            }
3062                        }
3063                        // Fire click handlers during the bubble phase.
3064                        DispatchPhase::Bubble => {
3065                            if let Some(mouse_down) = captured_mouse_down.take() {
3066                                let btn = mouse_down.button;
3067
3068                                let mouse_click = ClickEvent::Mouse(MouseClickEvent {
3069                                    down: mouse_down,
3070                                    up: event.clone(),
3071                                });
3072
3073                                match btn {
3074                                    MouseButton::Left => {
3075                                        for listener in &click_listeners {
3076                                            listener(&mouse_click, window, cx);
3077                                        }
3078                                    }
3079                                    _ => {
3080                                        for listener in &aux_click_listeners {
3081                                            listener(&mouse_click, window, cx);
3082                                        }
3083                                    }
3084                                }
3085                            }
3086                        }
3087                    }
3088                });
3089            }
3090
3091            if let Some(hover_listener) = self.hover_listener.take() {
3092                let was_hovered = element_state
3093                    .hover_listener_state
3094                    .get_or_insert_with(Default::default)
3095                    .clone();
3096                let has_mouse_down = element_state
3097                    .pending_mouse_down
3098                    .get_or_insert_with(Default::default)
3099                    .clone();
3100                let hover_listener = Rc::new(hover_listener);
3101                let update_hover = move |is_hovered: bool, window: &mut Window, cx: &mut App| {
3102                    let mut was_hovered = was_hovered.borrow_mut();
3103                    if is_hovered != *was_hovered {
3104                        *was_hovered = is_hovered;
3105                        drop(was_hovered);
3106                        hover_listener(&is_hovered, window, cx);
3107                    }
3108                };
3109
3110                window.on_mouse_event({
3111                    let update_hover = update_hover.clone();
3112                    let hitbox = hitbox.clone();
3113                    move |_: &MouseMoveEvent, phase, window, cx| {
3114                        if phase == DispatchPhase::Bubble {
3115                            let is_hovered = has_mouse_down.borrow().is_none()
3116                                && !cx.has_active_drag()
3117                                && hitbox.is_hovered(window);
3118                            update_hover(is_hovered, window, cx);
3119                        }
3120                    }
3121                });
3122
3123                // The pointer can leave the window without a final MouseMove, so also
3124                // clear hover on MouseExited.
3125                window.on_mouse_event(move |_: &MouseExitEvent, phase, window, cx| {
3126                    if phase == DispatchPhase::Bubble {
3127                        update_hover(false, window, cx);
3128                    }
3129                });
3130            }
3131
3132            if let Some(tooltip_builder) = self.tooltip_builder.take() {
3133                let active_tooltip = element_state
3134                    .active_tooltip
3135                    .get_or_insert_with(Default::default)
3136                    .clone();
3137                let pending_mouse_down = element_state
3138                    .pending_mouse_down
3139                    .get_or_insert_with(Default::default)
3140                    .clone();
3141
3142                let tooltip_is_hoverable = tooltip_builder.hoverable;
3143                let build_tooltip = Rc::new(move |window: &mut Window, cx: &mut App| {
3144                    Some(((tooltip_builder.build)(window, cx), tooltip_is_hoverable))
3145                });
3146                // Use bounds instead of testing hitbox since this is called during prepaint.
3147                let check_is_hovered_during_prepaint = Rc::new({
3148                    let pending_mouse_down = pending_mouse_down.clone();
3149                    let source_bounds = hitbox.bounds;
3150                    move |window: &Window| {
3151                        !window.last_input_was_keyboard()
3152                            && pending_mouse_down.borrow().is_none()
3153                            && source_bounds.contains(&window.mouse_position())
3154                    }
3155                });
3156                let check_is_hovered = Rc::new({
3157                    let hitbox = hitbox.clone();
3158                    move |window: &Window| {
3159                        pending_mouse_down.borrow().is_none() && hitbox.is_hovered(window)
3160                    }
3161                });
3162                register_tooltip_mouse_handlers(
3163                    &active_tooltip,
3164                    self.tooltip_id,
3165                    build_tooltip,
3166                    check_is_hovered,
3167                    check_is_hovered_during_prepaint,
3168                    self.tooltip_show_delay,
3169                    window,
3170                );
3171            }
3172
3173            // We unconditionally bind both the mouse up and mouse down active state handlers
3174            // Because we might not get a chance to render a frame before the mouse up event arrives.
3175            let active_state = element_state
3176                .clicked_state
3177                .get_or_insert_with(Default::default)
3178                .clone();
3179
3180            {
3181                let active_state = active_state.clone();
3182                window.on_mouse_event(move |_: &MouseUpEvent, phase, window, _cx| {
3183                    if phase == DispatchPhase::Capture && active_state.borrow().is_clicked() {
3184                        *active_state.borrow_mut() = ElementClickedState::default();
3185                        window.refresh();
3186                    }
3187                });
3188            }
3189
3190            {
3191                let active_group_hitbox = self
3192                    .group_active_style
3193                    .as_ref()
3194                    .and_then(|group_active| GroupHitboxes::get(&group_active.group, cx));
3195                let hitbox = hitbox.clone();
3196                window.on_mouse_event(move |_: &MouseDownEvent, phase, window, _cx| {
3197                    if phase == DispatchPhase::Bubble && !window.default_prevented() {
3198                        let group_hovered = active_group_hitbox
3199                            .is_some_and(|group_hitbox_id| group_hitbox_id.is_hovered(window));
3200                        let element_hovered = hitbox.is_hovered(window);
3201                        if group_hovered || element_hovered {
3202                            *active_state.borrow_mut() = ElementClickedState {
3203                                group: group_hovered,
3204                                element: element_hovered,
3205                            };
3206                            window.refresh();
3207                        }
3208                    }
3209                });
3210            }
3211        }
3212    }
3213
3214    fn paint_keyboard_listeners(&mut self, window: &mut Window, _cx: &mut App) {
3215        let key_down_listeners = mem::take(&mut self.key_down_listeners);
3216        let key_up_listeners = mem::take(&mut self.key_up_listeners);
3217        let modifiers_changed_listeners = mem::take(&mut self.modifiers_changed_listeners);
3218        let action_listeners = mem::take(&mut self.action_listeners);
3219        if let Some(context) = self.key_context.clone() {
3220            window.set_key_context(context);
3221        }
3222
3223        for listener in key_down_listeners {
3224            window.on_key_event(move |event: &KeyDownEvent, phase, window, cx| {
3225                listener(event, phase, window, cx);
3226            })
3227        }
3228
3229        for listener in key_up_listeners {
3230            window.on_key_event(move |event: &KeyUpEvent, phase, window, cx| {
3231                listener(event, phase, window, cx);
3232            })
3233        }
3234
3235        for listener in modifiers_changed_listeners {
3236            window.on_modifiers_changed(move |event: &ModifiersChangedEvent, window, cx| {
3237                listener(event, window, cx);
3238            })
3239        }
3240
3241        for (action_type, listener) in action_listeners {
3242            window.on_action(action_type, listener)
3243        }
3244    }
3245
3246    fn paint_hover_group_handler(&self, window: &mut Window, cx: &mut App) {
3247        let group_hitbox = self
3248            .group_hover_style
3249            .as_ref()
3250            .and_then(|group_hover| GroupHitboxes::get(&group_hover.group, cx));
3251
3252        if let Some(group_hitbox) = group_hitbox {
3253            let was_hovered = group_hitbox.is_hovered(window);
3254            let current_view = window.current_view();
3255            window.on_mouse_event(move |_: &MouseMoveEvent, phase, window, cx| {
3256                let hovered = group_hitbox.is_hovered(window);
3257                if phase == DispatchPhase::Capture && hovered != was_hovered {
3258                    cx.notify(current_view);
3259                }
3260            });
3261        }
3262    }
3263
3264    fn paint_scroll_listener(
3265        &self,
3266        hitbox: &Hitbox,
3267        style: &Style,
3268        window: &mut Window,
3269        _cx: &mut App,
3270    ) {
3271        if let Some(scroll_offset) = self.scroll_offset.clone() {
3272            let ongoing_scroll = self.ongoing_scroll.clone();
3273            let overflow = style.overflow;
3274            let allow_concurrent_scroll = style.allow_concurrent_scroll;
3275            let restrict_scroll_to_axis = style.restrict_scroll_to_axis;
3276            let line_height = window.line_height();
3277            let hitbox = hitbox.clone();
3278            let current_view = window.current_view();
3279            window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
3280                if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
3281                    let mut scroll_offset = scroll_offset.borrow_mut();
3282                    let old_scroll_offset = *scroll_offset;
3283                    let mut delta = event.delta.pixel_delta(line_height);
3284
3285                    if restrict_scroll_to_axis
3286                        && event.delta.precise()
3287                        && let Some(ongoing_scroll) = &ongoing_scroll
3288                    {
3289                        ongoing_scroll
3290                            .borrow_mut()
3291                            .filter(&mut delta, event.touch_phase);
3292                    }
3293
3294                    let mut delta_x = match overflow.x {
3295                        Overflow::Scroll if !delta.x.is_zero() => delta.x,
3296                        Overflow::Scroll
3297                            if !restrict_scroll_to_axis && overflow.y != Overflow::Scroll =>
3298                        {
3299                            delta.y
3300                        }
3301                        _ => Pixels::ZERO,
3302                    };
3303                    let mut delta_y = match overflow.y {
3304                        Overflow::Scroll if !delta.y.is_zero() => delta.y,
3305                        Overflow::Scroll
3306                            if !restrict_scroll_to_axis && overflow.x != Overflow::Scroll =>
3307                        {
3308                            delta.x
3309                        }
3310                        _ => Pixels::ZERO,
3311                    };
3312                    if !allow_concurrent_scroll && !delta_x.is_zero() && !delta_y.is_zero() {
3313                        if delta_x.abs() > delta_y.abs() {
3314                            delta_y = Pixels::ZERO;
3315                        } else {
3316                            delta_x = Pixels::ZERO;
3317                        }
3318                    }
3319                    scroll_offset.y += delta_y;
3320                    scroll_offset.x += delta_x;
3321                    if *scroll_offset != old_scroll_offset {
3322                        cx.notify(current_view);
3323                    }
3324                }
3325            });
3326        }
3327    }
3328
3329    /// Compute the visual style for this element, based on the current bounds and the element's state.
3330    pub fn compute_style(
3331        &self,
3332        global_id: Option<&GlobalElementId>,
3333        hitbox: Option<&Hitbox>,
3334        window: &mut Window,
3335        cx: &mut App,
3336    ) -> Style {
3337        window.with_optional_element_state(global_id, |element_state, window| {
3338            let mut element_state =
3339                element_state.map(|element_state| element_state.unwrap_or_default());
3340            let style = self.compute_style_internal(hitbox, element_state.as_mut(), window, cx);
3341            (style, element_state)
3342        })
3343    }
3344
3345    /// Called from internal methods that have already called with_element_state.
3346    fn compute_style_internal(
3347        &self,
3348        hitbox: Option<&Hitbox>,
3349        element_state: Option<&mut InteractiveElementState>,
3350        window: &mut Window,
3351        cx: &mut App,
3352    ) -> Style {
3353        let mut style = Style::default();
3354        style.refine(&self.base_style);
3355
3356        if let Some(focus_handle) = self.tracked_focus_handle.as_ref() {
3357            if let Some(in_focus_style) = self.in_focus_style.as_ref()
3358                && focus_handle.within_focused(window, cx)
3359            {
3360                style.refine(in_focus_style);
3361            }
3362
3363            if let Some(focus_style) = self.focus_style.as_ref()
3364                && focus_handle.is_focused(window)
3365            {
3366                style.refine(focus_style);
3367            }
3368
3369            if let Some(focus_visible_style) = self.focus_visible_style.as_ref()
3370                && focus_handle.is_focused(window)
3371                && window.last_input_was_keyboard()
3372            {
3373                style.refine(focus_visible_style);
3374            }
3375        }
3376
3377        if !cx.has_active_drag() {
3378            if let Some(group_hover) = self.group_hover_style.as_ref() {
3379                let is_group_hovered =
3380                    if let Some(group_hitbox_id) = GroupHitboxes::get(&group_hover.group, cx) {
3381                        group_hitbox_id.is_hovered(window)
3382                    } else if let Some(element_state) = element_state.as_ref() {
3383                        element_state
3384                            .hover_state
3385                            .as_ref()
3386                            .map(|state| state.borrow().group)
3387                            .unwrap_or(false)
3388                    } else {
3389                        false
3390                    };
3391
3392                if is_group_hovered {
3393                    style.refine(&group_hover.style);
3394                }
3395            }
3396
3397            if let Some(hover_style) = self.hover_style.as_ref() {
3398                let is_hovered = if let Some(hitbox) = hitbox {
3399                    hitbox.is_hovered(window)
3400                } else if let Some(element_state) = element_state.as_ref() {
3401                    element_state
3402                        .hover_state
3403                        .as_ref()
3404                        .map(|state| state.borrow().element)
3405                        .unwrap_or(false)
3406                } else {
3407                    false
3408                };
3409
3410                if is_hovered {
3411                    style.refine(hover_style);
3412                }
3413            }
3414        }
3415
3416        if let Some(hitbox) = hitbox {
3417            if let Some(drag) = cx.active_drag.take() {
3418                let mut can_drop = true;
3419                if let Some(can_drop_predicate) = &self.can_drop_predicate {
3420                    can_drop = can_drop_predicate(drag.value.as_ref(), window, cx);
3421                }
3422
3423                if can_drop {
3424                    for (state_type, group_drag_style) in &self.group_drag_over_styles {
3425                        if let Some(group_hitbox_id) =
3426                            GroupHitboxes::get(&group_drag_style.group, cx)
3427                            && *state_type == drag.value.as_ref().type_id()
3428                            && group_hitbox_id.is_hovered(window)
3429                        {
3430                            style.refine(&group_drag_style.style);
3431                        }
3432                    }
3433
3434                    for (state_type, build_drag_over_style) in &self.drag_over_styles {
3435                        if *state_type == drag.value.as_ref().type_id() && hitbox.is_hovered(window)
3436                        {
3437                            style.refine(&build_drag_over_style(drag.value.as_ref(), window, cx));
3438                        }
3439                    }
3440                }
3441
3442                style.mouse_cursor = drag.cursor_style;
3443                cx.active_drag = Some(drag);
3444            }
3445        }
3446
3447        if let Some(element_state) = element_state {
3448            let clicked_state = element_state
3449                .clicked_state
3450                .get_or_insert_with(Default::default)
3451                .borrow();
3452            if clicked_state.group
3453                && let Some(group) = self.group_active_style.as_ref()
3454            {
3455                style.refine(&group.style)
3456            }
3457
3458            if let Some(active_style) = self.active_style.as_ref()
3459                && clicked_state.element
3460            {
3461                style.refine(active_style)
3462            }
3463        }
3464
3465        style
3466    }
3467
3468    pub(crate) fn write_a11y_info(&self, node: &mut accesskit::Node) {
3469        if let Some(label) = &self.aria.label {
3470            node.set_label(label.to_string());
3471        }
3472        if let Some(description) = &self.aria.description {
3473            node.set_description(description.to_string());
3474        }
3475        if let Some(keyshortcuts) = &self.aria.keyshortcuts {
3476            node.set_keyboard_shortcut(keyshortcuts.to_string());
3477        }
3478        if let Some(selected) = self.aria.selected {
3479            node.set_selected(selected);
3480        }
3481        if let Some(expanded) = self.aria.expanded {
3482            node.set_expanded(expanded);
3483        }
3484        if self.aria.disabled {
3485            node.set_disabled();
3486        }
3487        if self.aria.read_only {
3488            node.set_read_only();
3489        }
3490        if self.aria.modal {
3491            node.set_modal();
3492        }
3493        if self.aria.invalid {
3494            node.set_invalid(accesskit::Invalid::True);
3495        }
3496        if self.aria.required {
3497            node.set_required();
3498        }
3499        if self.aria.busy {
3500            node.set_busy();
3501        }
3502        if let Some(live) = self.aria.live {
3503            node.set_live(live);
3504        }
3505        if self.aria.live_atomic {
3506            node.set_live_atomic();
3507        }
3508        if let Some(toggled) = self.aria.toggled {
3509            node.set_toggled(toggled);
3510        }
3511        if let Some(value) = self.aria.numeric_value {
3512            node.set_numeric_value(value);
3513        }
3514        if let Some(value) = self.aria.min_numeric_value {
3515            node.set_min_numeric_value(value);
3516        }
3517        if let Some(value) = self.aria.max_numeric_value {
3518            node.set_max_numeric_value(value);
3519        }
3520        if let Some(step) = self.aria.numeric_value_step {
3521            node.set_numeric_value_step(step);
3522        }
3523        if let Some(value) = &self.aria.value {
3524            node.set_value(value.to_string());
3525        }
3526        if let Some(placeholder) = &self.aria.placeholder {
3527            node.set_placeholder(placeholder.to_string());
3528        }
3529        if let Some(orientation) = self.aria.orientation {
3530            node.set_orientation(orientation);
3531        }
3532        if let Some(level) = self.aria.level {
3533            node.set_level(level);
3534        }
3535        if let Some(position) = self.aria.position_in_set {
3536            node.set_position_in_set(position);
3537        }
3538        if let Some(size) = self.aria.size_of_set {
3539            node.set_size_of_set(size);
3540        }
3541        if let Some(index) = self.aria.row_index {
3542            node.set_row_index(index);
3543        }
3544        if let Some(index) = self.aria.column_index {
3545            node.set_column_index(index);
3546        }
3547        if let Some(count) = self.aria.row_count {
3548            node.set_row_count(count);
3549        }
3550        if let Some(count) = self.aria.column_count {
3551            node.set_column_count(count);
3552        }
3553        if !self.click_listeners.is_empty() {
3554            node.add_action(accesskit::Action::Click);
3555        }
3556        if self.tracked_focus_handle.is_some() || self.focusable {
3557            node.add_action(accesskit::Action::Focus);
3558        }
3559        for (action, _) in &self.a11y_action_listeners {
3560            node.add_action(*action);
3561        }
3562    }
3563}
3564
3565/// The per-frame state of an interactive element. Used for tracking stateful interactions like clicks
3566/// and scroll offsets.
3567#[derive(Default)]
3568pub struct InteractiveElementState {
3569    pub(crate) focus_handle: Option<FocusHandle>,
3570    pub(crate) clicked_state: Option<Rc<RefCell<ElementClickedState>>>,
3571    pub(crate) hover_state: Option<Rc<RefCell<ElementHoverState>>>,
3572    pub(crate) hover_listener_state: Option<Rc<RefCell<bool>>>,
3573    pub(crate) pending_mouse_down: Option<Rc<RefCell<Option<MouseDownEvent>>>>,
3574    /// Set to the window's [`focus_generation`](crate::Window::focus_generation)
3575    /// when an Enter/Space keydown is received while this element is focused,
3576    /// recording that we are waiting for the matching keyup to fire a keyboard
3577    /// click. On keyup the click only fires if the stored generation still
3578    /// matches the window's current one, i.e. focus never moved during the
3579    /// press (mirroring the browser clearing a control's pressed state on
3580    /// blur). `None` means no activation key is pending.
3581    pub(crate) pending_keyboard_down: Option<Rc<RefCell<Option<u64>>>>,
3582    pub(crate) scroll_offset: Option<Rc<RefCell<Point<Pixels>>>>,
3583    ongoing_scroll: Option<Rc<RefCell<OngoingScroll>>>,
3584    pub(crate) active_tooltip: Option<Rc<RefCell<Option<ActiveTooltip>>>>,
3585}
3586
3587/// Whether or not the element or a group that contains it is clicked by the mouse.
3588#[derive(Copy, Clone, Default, Eq, PartialEq)]
3589pub struct ElementClickedState {
3590    /// True if this element's group has been clicked, false otherwise
3591    pub group: bool,
3592
3593    /// True if this element has been clicked, false otherwise
3594    pub element: bool,
3595}
3596
3597impl ElementClickedState {
3598    fn is_clicked(&self) -> bool {
3599        self.group || self.element
3600    }
3601}
3602
3603/// Whether or not the element or a group that contains it is hovered.
3604#[derive(Copy, Clone, Default, Eq, PartialEq)]
3605pub struct ElementHoverState {
3606    /// True if this element's group is hovered, false otherwise
3607    pub group: bool,
3608
3609    /// True if this element is hovered, false otherwise
3610    pub element: bool,
3611}
3612
3613pub(crate) enum ActiveTooltip {
3614    /// Currently delaying before showing the tooltip.
3615    WaitingForShow { _task: Task<()> },
3616    /// Tooltip is visible, element was hovered or for hoverable tooltips, the tooltip was hovered.
3617    Visible {
3618        tooltip: AnyTooltip,
3619        is_hoverable: bool,
3620    },
3621    /// Tooltip is visible and hoverable, but the mouse is no longer hovering. Currently delaying
3622    /// before hiding it.
3623    WaitingForHide {
3624        tooltip: AnyTooltip,
3625        _task: Task<()>,
3626    },
3627}
3628
3629pub(crate) fn clear_active_tooltip(
3630    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3631    window: &mut Window,
3632) {
3633    match active_tooltip.borrow_mut().take() {
3634        None => {}
3635        Some(ActiveTooltip::WaitingForShow { .. }) => {}
3636        Some(ActiveTooltip::Visible { .. }) => window.refresh(),
3637        Some(ActiveTooltip::WaitingForHide { .. }) => window.refresh(),
3638    }
3639}
3640
3641pub(crate) fn clear_active_tooltip_if_not_hoverable(
3642    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3643    window: &mut Window,
3644) {
3645    let should_clear = match active_tooltip.borrow().as_ref() {
3646        None => false,
3647        Some(ActiveTooltip::WaitingForShow { .. }) => false,
3648        Some(ActiveTooltip::Visible { is_hoverable, .. }) => !is_hoverable,
3649        Some(ActiveTooltip::WaitingForHide { .. }) => false,
3650    };
3651    if should_clear {
3652        active_tooltip.borrow_mut().take();
3653        window.refresh();
3654    }
3655}
3656
3657pub(crate) fn set_tooltip_on_window(
3658    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3659    window: &mut Window,
3660) -> Option<TooltipId> {
3661    let tooltip = match active_tooltip.borrow().as_ref() {
3662        None => return None,
3663        Some(ActiveTooltip::WaitingForShow { .. }) => return None,
3664        Some(ActiveTooltip::Visible { tooltip, .. }) => tooltip.clone(),
3665        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => tooltip.clone(),
3666    };
3667    Some(window.set_tooltip(tooltip))
3668}
3669
3670pub(crate) fn register_tooltip_mouse_handlers(
3671    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3672    tooltip_id: Option<TooltipId>,
3673    build_tooltip: Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
3674    check_is_hovered: Rc<dyn Fn(&Window) -> bool>,
3675    check_is_hovered_during_prepaint: Rc<dyn Fn(&Window) -> bool>,
3676    show_delay: Option<Duration>,
3677    window: &mut Window,
3678) {
3679    let current_view = window.current_view();
3680    let show_delay = show_delay.unwrap_or(DEFAULT_TOOLTIP_SHOW_DELAY);
3681
3682    window.on_mouse_event({
3683        let active_tooltip = active_tooltip.clone();
3684        let build_tooltip = build_tooltip.clone();
3685        let check_is_hovered = check_is_hovered.clone();
3686        move |_: &MouseMoveEvent, phase, window, cx| {
3687            handle_tooltip_mouse_move(
3688                &active_tooltip,
3689                &build_tooltip,
3690                &check_is_hovered,
3691                &check_is_hovered_during_prepaint,
3692                tooltip_id,
3693                current_view,
3694                phase,
3695                show_delay,
3696                window,
3697                cx,
3698            )
3699        }
3700    });
3701
3702    window.on_mouse_event({
3703        let active_tooltip = active_tooltip.clone();
3704        move |_: &MouseExitEvent, phase, window, _cx| {
3705            if phase == DispatchPhase::Capture {
3706                clear_active_tooltip(&active_tooltip, window);
3707            }
3708        }
3709    });
3710
3711    window.on_mouse_event({
3712        let active_tooltip = active_tooltip.clone();
3713        move |_: &MouseDownEvent, _phase, window: &mut Window, _cx| {
3714            if !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)) {
3715                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
3716            }
3717        }
3718    });
3719
3720    window.on_mouse_event({
3721        let active_tooltip = active_tooltip.clone();
3722        move |_: &ScrollWheelEvent, _phase, window: &mut Window, _cx| {
3723            if !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)) {
3724                clear_active_tooltip_if_not_hoverable(&active_tooltip, window);
3725            }
3726        }
3727    });
3728}
3729
3730/// Handles displaying tooltips when an element is hovered.
3731///
3732/// The mouse hovering logic also relies on being called from window prepaint in order to handle the
3733/// case where the element the tooltip is on is not rendered - in that case its mouse listeners are
3734/// also not registered. During window prepaint, the hitbox information is not available, so
3735/// `check_is_hovered_during_prepaint` is used which bases the check off of the absolute bounds of
3736/// the element.
3737///
3738/// TODO: There's a minor bug due to the use of absolute bounds while checking during prepaint - it
3739/// does not know if the hitbox is occluded. In the case where a tooltip gets displayed and then
3740/// gets occluded after display, it will stick around until the mouse exits the hover bounds.
3741fn handle_tooltip_mouse_move(
3742    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3743    build_tooltip: &Rc<dyn Fn(&mut Window, &mut App) -> Option<(AnyView, bool)>>,
3744    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
3745    check_is_hovered_during_prepaint: &Rc<dyn Fn(&Window) -> bool>,
3746    tooltip_id: Option<TooltipId>,
3747    current_view: EntityId,
3748    phase: DispatchPhase,
3749    show_delay: Duration,
3750    window: &mut Window,
3751    cx: &mut App,
3752) {
3753    // Separates logic for what mutation should occur from applying it, to avoid overlapping
3754    // RefCell borrows.
3755    enum Action {
3756        None,
3757        CancelShow,
3758        ScheduleShow,
3759        CheckVisible,
3760    }
3761
3762    let action = match active_tooltip.borrow().as_ref() {
3763        None => {
3764            let is_hovered = check_is_hovered(window);
3765            if is_hovered && phase.bubble() {
3766                Action::ScheduleShow
3767            } else {
3768                Action::None
3769            }
3770        }
3771        Some(ActiveTooltip::WaitingForShow { .. }) => {
3772            let is_hovered = check_is_hovered(window);
3773            if is_hovered {
3774                Action::None
3775            } else {
3776                Action::CancelShow
3777            }
3778        }
3779        Some(ActiveTooltip::Visible { is_hoverable, .. }) => {
3780            if phase.capture()
3781                && !check_is_hovered(window)
3782                && (!*is_hoverable
3783                    || !tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)))
3784            {
3785                Action::CheckVisible
3786            } else {
3787                Action::None
3788            }
3789        }
3790        Some(ActiveTooltip::WaitingForHide { .. }) => {
3791            if phase.capture()
3792                && (check_is_hovered(window)
3793                    || tooltip_id.is_some_and(|tooltip_id| tooltip_id.is_hovered(window)))
3794            {
3795                Action::CheckVisible
3796            } else {
3797                Action::None
3798            }
3799        }
3800    };
3801
3802    match action {
3803        Action::None => {}
3804        Action::CancelShow => {
3805            // Cancel waiting to show tooltip when it is no longer hovered.
3806            active_tooltip.borrow_mut().take();
3807        }
3808        Action::ScheduleShow => {
3809            let delayed_show_task = window.spawn(cx, {
3810                let weak_active_tooltip = Rc::downgrade(active_tooltip);
3811                let build_tooltip = build_tooltip.clone();
3812                let check_is_hovered_during_prepaint = check_is_hovered_during_prepaint.clone();
3813                async move |cx| {
3814                    cx.background_executor().timer(show_delay).await;
3815                    let Some(active_tooltip) = weak_active_tooltip.upgrade() else {
3816                        return;
3817                    };
3818                    cx.update(|window, cx| {
3819                        let new_tooltip =
3820                            build_tooltip(window, cx).map(|(view, tooltip_is_hoverable)| {
3821                                let weak_active_tooltip = Rc::downgrade(&active_tooltip);
3822                                ActiveTooltip::Visible {
3823                                    tooltip: AnyTooltip {
3824                                        view,
3825                                        mouse_position: window.mouse_position(),
3826                                        check_visible_and_update: Rc::new(
3827                                            move |tooltip_bounds, window, cx| {
3828                                                let Some(active_tooltip) =
3829                                                    weak_active_tooltip.upgrade()
3830                                                else {
3831                                                    return false;
3832                                                };
3833                                                handle_tooltip_check_visible_and_update(
3834                                                    &active_tooltip,
3835                                                    tooltip_is_hoverable,
3836                                                    &check_is_hovered_during_prepaint,
3837                                                    tooltip_bounds,
3838                                                    window,
3839                                                    cx,
3840                                                )
3841                                            },
3842                                        ),
3843                                    },
3844                                    is_hoverable: tooltip_is_hoverable,
3845                                }
3846                            });
3847                        *active_tooltip.borrow_mut() = new_tooltip;
3848                        window.refresh();
3849                    })
3850                    .ok();
3851                }
3852            });
3853            active_tooltip
3854                .borrow_mut()
3855                .replace(ActiveTooltip::WaitingForShow {
3856                    _task: delayed_show_task,
3857                });
3858        }
3859        Action::CheckVisible => cx.notify(current_view),
3860    }
3861}
3862
3863/// Returns a callback which will be called by window prepaint to update tooltip visibility. The
3864/// purpose of doing this logic here instead of the mouse move handler is that the mouse move
3865/// handler won't get called when the element is not painted (e.g. via use of `visible_on_hover`).
3866fn handle_tooltip_check_visible_and_update(
3867    active_tooltip: &Rc<RefCell<Option<ActiveTooltip>>>,
3868    tooltip_is_hoverable: bool,
3869    check_is_hovered: &Rc<dyn Fn(&Window) -> bool>,
3870    tooltip_bounds: Bounds<Pixels>,
3871    window: &mut Window,
3872    cx: &mut App,
3873) -> bool {
3874    // Separates logic for what mutation should occur from applying it, to avoid overlapping RefCell
3875    // borrows.
3876    enum Action {
3877        None,
3878        Hide,
3879        ScheduleHide(AnyTooltip),
3880        CancelHide(AnyTooltip),
3881    }
3882
3883    let is_hovered = check_is_hovered(window)
3884        || (tooltip_is_hoverable && tooltip_bounds.contains(&window.mouse_position()));
3885    let action = match active_tooltip.borrow().as_ref() {
3886        Some(ActiveTooltip::Visible { tooltip, .. }) => {
3887            if is_hovered {
3888                Action::None
3889            } else {
3890                if tooltip_is_hoverable {
3891                    Action::ScheduleHide(tooltip.clone())
3892                } else {
3893                    Action::Hide
3894                }
3895            }
3896        }
3897        Some(ActiveTooltip::WaitingForHide { tooltip, .. }) => {
3898            if is_hovered {
3899                Action::CancelHide(tooltip.clone())
3900            } else {
3901                Action::None
3902            }
3903        }
3904        None | Some(ActiveTooltip::WaitingForShow { .. }) => Action::None,
3905    };
3906
3907    match action {
3908        Action::None => {}
3909        Action::Hide => clear_active_tooltip(active_tooltip, window),
3910        Action::ScheduleHide(tooltip) => {
3911            let delayed_hide_task = window.spawn(cx, {
3912                let weak_active_tooltip = Rc::downgrade(active_tooltip);
3913                async move |cx| {
3914                    cx.background_executor()
3915                        .timer(HOVERABLE_TOOLTIP_HIDE_DELAY)
3916                        .await;
3917                    let Some(active_tooltip) = weak_active_tooltip.upgrade() else {
3918                        return;
3919                    };
3920                    if active_tooltip.borrow_mut().take().is_some() {
3921                        cx.update(|window, _cx| window.refresh()).ok();
3922                    }
3923                }
3924            });
3925            active_tooltip
3926                .borrow_mut()
3927                .replace(ActiveTooltip::WaitingForHide {
3928                    tooltip,
3929                    _task: delayed_hide_task,
3930                });
3931        }
3932        Action::CancelHide(tooltip) => {
3933            // Cancel waiting to hide tooltip when it becomes hovered.
3934            active_tooltip.borrow_mut().replace(ActiveTooltip::Visible {
3935                tooltip,
3936                is_hoverable: true,
3937            });
3938        }
3939    }
3940
3941    active_tooltip.borrow().is_some()
3942}
3943
3944#[derive(Default)]
3945pub(crate) struct GroupHitboxes(HashMap<SharedString, SmallVec<[HitboxId; 1]>>);
3946
3947impl Global for GroupHitboxes {}
3948
3949impl GroupHitboxes {
3950    pub fn get(name: &SharedString, cx: &mut App) -> Option<HitboxId> {
3951        cx.default_global::<Self>()
3952            .0
3953            .get(name)
3954            .and_then(|bounds_stack| bounds_stack.last())
3955            .cloned()
3956    }
3957
3958    pub fn push(name: SharedString, hitbox_id: HitboxId, cx: &mut App) {
3959        cx.default_global::<Self>()
3960            .0
3961            .entry(name)
3962            .or_default()
3963            .push(hitbox_id);
3964    }
3965
3966    pub fn pop(name: &SharedString, cx: &mut App) {
3967        cx.default_global::<Self>().0.get_mut(name).unwrap().pop();
3968    }
3969}
3970
3971/// A wrapper around an element that can store state, produced after assigning an ElementId.
3972pub struct Stateful<E> {
3973    pub(crate) element: E,
3974}
3975
3976impl<E> Styled for Stateful<E>
3977where
3978    E: Styled,
3979{
3980    fn style(&mut self) -> &mut StyleRefinement {
3981        self.element.style()
3982    }
3983}
3984
3985impl<E> StatefulInteractiveElement for Stateful<E>
3986where
3987    E: Element,
3988    Self: InteractiveElement,
3989{
3990}
3991
3992impl<E> InteractiveElement for Stateful<E>
3993where
3994    E: InteractiveElement,
3995{
3996    fn interactivity(&mut self) -> &mut Interactivity {
3997        self.element.interactivity()
3998    }
3999}
4000
4001impl<E> Element for Stateful<E>
4002where
4003    E: Element,
4004{
4005    type RequestLayoutState = E::RequestLayoutState;
4006    type PrepaintState = E::PrepaintState;
4007
4008    fn id(&self) -> Option<ElementId> {
4009        self.element.id()
4010    }
4011
4012    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
4013        self.element.source_location()
4014    }
4015
4016    fn a11y_role(&self) -> Option<accesskit::Role> {
4017        self.element.a11y_role()
4018    }
4019
4020    fn write_a11y_info(&self, node: &mut accesskit::Node) {
4021        self.element.write_a11y_info(node);
4022    }
4023
4024    fn a11y_synthetic_children(
4025        &mut self,
4026        prepaint: &mut Self::PrepaintState,
4027        builder: &mut crate::A11ySubtreeBuilder,
4028    ) {
4029        self.element.a11y_synthetic_children(prepaint, builder);
4030    }
4031
4032    fn request_layout(
4033        &mut self,
4034        id: Option<&GlobalElementId>,
4035        inspector_id: Option<&InspectorElementId>,
4036        window: &mut Window,
4037        cx: &mut App,
4038    ) -> (LayoutId, Self::RequestLayoutState) {
4039        self.element.request_layout(id, inspector_id, window, cx)
4040    }
4041
4042    fn prepaint(
4043        &mut self,
4044        id: Option<&GlobalElementId>,
4045        inspector_id: Option<&InspectorElementId>,
4046        bounds: Bounds<Pixels>,
4047        state: &mut Self::RequestLayoutState,
4048        window: &mut Window,
4049        cx: &mut App,
4050    ) -> E::PrepaintState {
4051        self.element
4052            .prepaint(id, inspector_id, bounds, state, window, cx)
4053    }
4054
4055    fn paint(
4056        &mut self,
4057        id: Option<&GlobalElementId>,
4058        inspector_id: Option<&InspectorElementId>,
4059        bounds: Bounds<Pixels>,
4060        request_layout: &mut Self::RequestLayoutState,
4061        prepaint: &mut Self::PrepaintState,
4062        window: &mut Window,
4063        cx: &mut App,
4064    ) {
4065        self.element.paint(
4066            id,
4067            inspector_id,
4068            bounds,
4069            request_layout,
4070            prepaint,
4071            window,
4072            cx,
4073        );
4074    }
4075}
4076
4077impl<E> IntoElement for Stateful<E>
4078where
4079    E: Element,
4080{
4081    type Element = Self;
4082
4083    fn into_element(self) -> Self::Element {
4084        self
4085    }
4086}
4087
4088impl<E> ParentElement for Stateful<E>
4089where
4090    E: ParentElement,
4091{
4092    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
4093        self.element.extend(elements)
4094    }
4095}
4096
4097/// Represents an element that can be scrolled *to* in its parent element.
4098/// Contrary to `ScrollHandle::scroll_to_active_item`, an anchored element does
4099/// not have to be an immediate child of the parent.
4100#[derive(Clone)]
4101pub struct ScrollAnchor {
4102    handle: ScrollHandle,
4103    last_origin: Rc<RefCell<Point<Pixels>>>,
4104}
4105
4106impl ScrollAnchor {
4107    /// Creates a [ScrollAnchor] associated with a given [ScrollHandle].
4108    pub fn for_handle(handle: ScrollHandle) -> Self {
4109        Self {
4110            handle,
4111            last_origin: Default::default(),
4112        }
4113    }
4114    /// Request scroll to this item on the next frame.
4115    pub fn scroll_to(&self, window: &mut Window, _cx: &mut App) {
4116        let this = self.clone();
4117
4118        window.on_next_frame(move |_, _| {
4119            let viewport_bounds = this.handle.bounds();
4120            let self_bounds = *this.last_origin.borrow();
4121            this.handle.set_offset(viewport_bounds.origin - self_bounds);
4122        });
4123    }
4124}
4125
4126#[derive(Default, Debug)]
4127struct ScrollHandleState {
4128    offset: Rc<RefCell<Point<Pixels>>>,
4129    ongoing_scroll: Rc<RefCell<OngoingScroll>>,
4130    bounds: Bounds<Pixels>,
4131    max_offset: Point<Pixels>,
4132    child_bounds: Vec<Bounds<Pixels>>,
4133    scroll_to_bottom: bool,
4134    overflow: Point<Overflow>,
4135    active_item: Option<ScrollActiveItem>,
4136}
4137
4138#[derive(Default, Debug, Clone, Copy)]
4139struct ScrollActiveItem {
4140    index: usize,
4141    strategy: ScrollStrategy,
4142}
4143
4144#[derive(Default, Debug, Clone, Copy)]
4145enum ScrollStrategy {
4146    #[default]
4147    FirstVisible,
4148    Top,
4149}
4150
4151/// A handle to the scrollable aspects of an element.
4152/// Used for accessing scroll state, like the current scroll offset,
4153/// and for mutating the scroll state, like scrolling to a specific child.
4154#[derive(Clone, Debug)]
4155pub struct ScrollHandle(Rc<RefCell<ScrollHandleState>>);
4156
4157impl Default for ScrollHandle {
4158    fn default() -> Self {
4159        Self::new()
4160    }
4161}
4162
4163impl ScrollHandle {
4164    /// Construct a new scroll handle.
4165    pub fn new() -> Self {
4166        Self(Rc::default())
4167    }
4168
4169    /// Get the current scroll offset.
4170    pub fn offset(&self) -> Point<Pixels> {
4171        *self.0.borrow().offset.borrow()
4172    }
4173
4174    /// Get the maximum scroll offset.
4175    pub fn max_offset(&self) -> Point<Pixels> {
4176        self.0.borrow().max_offset
4177    }
4178
4179    /// Get the top child that's scrolled into view.
4180    pub fn top_item(&self) -> usize {
4181        let state = self.0.borrow();
4182        let top = state.bounds.top() - state.offset.borrow().y;
4183
4184        match state.child_bounds.binary_search_by(|bounds| {
4185            if top < bounds.top() {
4186                Ordering::Greater
4187            } else if top > bounds.bottom() {
4188                Ordering::Less
4189            } else {
4190                Ordering::Equal
4191            }
4192        }) {
4193            Ok(ix) => ix,
4194            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
4195        }
4196    }
4197
4198    /// Get the bottom child that's scrolled into view.
4199    pub fn bottom_item(&self) -> usize {
4200        let state = self.0.borrow();
4201        let bottom = state.bounds.bottom() - state.offset.borrow().y;
4202
4203        match state.child_bounds.binary_search_by(|bounds| {
4204            if bottom < bounds.top() {
4205                Ordering::Greater
4206            } else if bottom > bounds.bottom() {
4207                Ordering::Less
4208            } else {
4209                Ordering::Equal
4210            }
4211        }) {
4212            Ok(ix) => ix,
4213            Err(ix) => ix.min(state.child_bounds.len().saturating_sub(1)),
4214        }
4215    }
4216
4217    /// Return the bounds into which this child is painted
4218    pub fn bounds(&self) -> Bounds<Pixels> {
4219        self.0.borrow().bounds
4220    }
4221
4222    /// Get the bounds for a specific child.
4223    pub fn bounds_for_item(&self, ix: usize) -> Option<Bounds<Pixels>> {
4224        self.0.borrow().child_bounds.get(ix).cloned()
4225    }
4226
4227    /// Update the scroll handle's active item for scrolling to in prepaint.
4228    pub fn scroll_to_item(&self, ix: usize) {
4229        let mut state = self.0.borrow_mut();
4230        state.active_item = Some(ScrollActiveItem {
4231            index: ix,
4232            strategy: ScrollStrategy::default(),
4233        });
4234    }
4235
4236    /// Update the scroll handle's active item for scrolling to in prepaint.
4237    /// This scrolls the minimal amount to ensure that the child is the first visible element.
4238    pub fn scroll_to_top_of_item(&self, ix: usize) {
4239        let mut state = self.0.borrow_mut();
4240        state.active_item = Some(ScrollActiveItem {
4241            index: ix,
4242            strategy: ScrollStrategy::Top,
4243        });
4244    }
4245
4246    /// Scrolls the minimal amount to either ensure that the child is
4247    /// fully visible or the top element of the view depends on the
4248    /// scroll strategy
4249    fn scroll_to_active_item(&self) {
4250        let mut state = self.0.borrow_mut();
4251
4252        let Some(active_item) = state.active_item else {
4253            return;
4254        };
4255
4256        let active_item = match state.child_bounds.get(active_item.index) {
4257            Some(bounds) => {
4258                let mut scroll_offset = state.offset.borrow_mut();
4259
4260                match active_item.strategy {
4261                    ScrollStrategy::FirstVisible => {
4262                        if state.overflow.y == Overflow::Scroll {
4263                            let child_height = bounds.size.height;
4264                            let viewport_height = state.bounds.size.height;
4265                            if child_height > viewport_height {
4266                                scroll_offset.y = state.bounds.top() - bounds.top();
4267                            } else if bounds.top() + scroll_offset.y < state.bounds.top() {
4268                                scroll_offset.y = state.bounds.top() - bounds.top();
4269                            } else if bounds.bottom() + scroll_offset.y > state.bounds.bottom() {
4270                                scroll_offset.y = state.bounds.bottom() - bounds.bottom();
4271                            }
4272                        }
4273                    }
4274                    ScrollStrategy::Top => {
4275                        scroll_offset.y = state.bounds.top() - bounds.top();
4276                    }
4277                }
4278
4279                if state.overflow.x == Overflow::Scroll {
4280                    let child_width = bounds.size.width;
4281                    let viewport_width = state.bounds.size.width;
4282                    if child_width > viewport_width {
4283                        scroll_offset.x = state.bounds.left() - bounds.left();
4284                    } else if bounds.left() + scroll_offset.x < state.bounds.left() {
4285                        scroll_offset.x = state.bounds.left() - bounds.left();
4286                    } else if bounds.right() + scroll_offset.x > state.bounds.right() {
4287                        scroll_offset.x = state.bounds.right() - bounds.right();
4288                    }
4289                }
4290                None
4291            }
4292            None => Some(active_item),
4293        };
4294        state.active_item = active_item;
4295    }
4296
4297    /// Scrolls to the bottom.
4298    pub fn scroll_to_bottom(&self) {
4299        let mut state = self.0.borrow_mut();
4300        state.scroll_to_bottom = true;
4301    }
4302
4303    /// Set the offset explicitly. The offset is the distance from the top left of the
4304    /// parent container to the top left of the first child.
4305    /// As you scroll further down the offset becomes more negative.
4306    pub fn set_offset(&self, mut position: Point<Pixels>) {
4307        let state = self.0.borrow();
4308        *state.offset.borrow_mut() = position;
4309    }
4310
4311    /// Get the logical scroll top, based on a child index and a pixel offset.
4312    pub fn logical_scroll_top(&self) -> (usize, Pixels) {
4313        let ix = self.top_item();
4314        let state = self.0.borrow();
4315
4316        if let Some(child_bounds) = state.child_bounds.get(ix) {
4317            (
4318                ix,
4319                child_bounds.top() + state.offset.borrow().y - state.bounds.top(),
4320            )
4321        } else {
4322            (ix, px(0.))
4323        }
4324    }
4325
4326    /// Get the logical scroll bottom, based on a child index and a pixel offset.
4327    pub fn logical_scroll_bottom(&self) -> (usize, Pixels) {
4328        let ix = self.bottom_item();
4329        let state = self.0.borrow();
4330
4331        if let Some(child_bounds) = state.child_bounds.get(ix) {
4332            (
4333                ix,
4334                child_bounds.bottom() + state.offset.borrow().y - state.bounds.bottom(),
4335            )
4336        } else {
4337            (ix, px(0.))
4338        }
4339    }
4340
4341    /// Get the count of children for scrollable item.
4342    pub fn children_count(&self) -> usize {
4343        self.0.borrow().child_bounds.len()
4344    }
4345}
4346
4347#[cfg(test)]
4348mod tests {
4349    use super::*;
4350    use crate::{
4351        AnyWindowHandle, AppContext as _, Context, InputEvent, Keystroke, Modifiers,
4352        MouseDownEvent, MouseMoveEvent, MouseUpEvent, TestAppContext, canvas,
4353        util::FluentBuilder as _,
4354    };
4355    use std::{cell::Cell, rc::Weak};
4356
4357    struct PointerCaptureTestView {
4358        moves: Rc<Cell<usize>>,
4359        ups: Rc<Cell<usize>>,
4360    }
4361
4362    impl Render for PointerCaptureTestView {
4363        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4364            let moves = self.moves.clone();
4365            let ups = self.ups.clone();
4366            div().size_full().child(
4367                div()
4368                    .id("pointer-capture-target")
4369                    .size(px(50.))
4370                    .on_mouse_down_with_pointer_capture(MouseButton::Left, |_, _, _| {})
4371                    .on_mouse_move(move |_, _, _| moves.set(moves.get() + 1))
4372                    .on_mouse_up(MouseButton::Left, move |_, _, _| ups.set(ups.get() + 1)),
4373            )
4374        }
4375    }
4376
4377    #[test]
4378    fn pointer_capture_survives_a_redraw_and_delivers_events_outside_the_element() {
4379        let mut cx = TestAppContext::single();
4380        let moves = Rc::new(Cell::new(0));
4381        let ups = Rc::new(Cell::new(0));
4382        let window: AnyWindowHandle = cx
4383            .add_window({
4384                let moves = moves.clone();
4385                let ups = ups.clone();
4386                move |_, _| PointerCaptureTestView { moves, ups }
4387            })
4388            .into();
4389
4390        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
4391            .unwrap();
4392        cx.update_window(window, |_, window, cx| {
4393            window.dispatch_event(
4394                MouseDownEvent {
4395                    position: point(px(25.), px(25.)),
4396                    button: MouseButton::Left,
4397                    modifiers: Modifiers::none(),
4398                    click_count: 1,
4399                    first_mouse: false,
4400                }
4401                .to_platform_input(),
4402                cx,
4403            );
4404            let before_redraw = window.captured_hitbox().expect("captured");
4405            window.draw(cx).clear(cx);
4406            let after_redraw = window.captured_hitbox().expect("still captured");
4407            assert_ne!(
4408                before_redraw, after_redraw,
4409                "the next frame has a new hitbox"
4410            );
4411            window.dispatch_event(
4412                MouseMoveEvent {
4413                    position: point(px(75.), px(75.)),
4414                    modifiers: Modifiers::none(),
4415                    pressed_button: Some(MouseButton::Left),
4416                }
4417                .to_platform_input(),
4418                cx,
4419            );
4420            window.dispatch_event(
4421                MouseUpEvent {
4422                    position: point(px(75.), px(75.)),
4423                    button: MouseButton::Left,
4424                    modifiers: Modifiers::none(),
4425                    click_count: 1,
4426                }
4427                .to_platform_input(),
4428                cx,
4429            );
4430            assert!(window.captured_hitbox().is_none());
4431        })
4432        .unwrap();
4433
4434        assert_eq!(moves.get(), 1);
4435        assert_eq!(ups.get(), 1);
4436    }
4437
4438    struct GroupHoverTestView {
4439        render_count: Rc<Cell<usize>>,
4440        anonymous_paint_count: Rc<Cell<usize>>,
4441        stateful_width: Rc<Cell<Pixels>>,
4442    }
4443
4444    impl Render for GroupHoverTestView {
4445        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4446            self.render_count.set(self.render_count.get() + 1);
4447            let anonymous_paint_count = self.anonymous_paint_count.clone();
4448            let stateful_width = self.stateful_width.clone();
4449            div().size_full().child(
4450                div()
4451                    .ml(px(20.))
4452                    .mt(px(20.))
4453                    .size(px(50.))
4454                    .relative()
4455                    .group("hover-group")
4456                    .child(
4457                        div()
4458                            .absolute()
4459                            .size_full()
4460                            .invisible()
4461                            .group_hover("hover-group", |style| style.visible())
4462                            .child(canvas(
4463                                |_, _, _| {},
4464                                move |_, _, _, _| {
4465                                    anonymous_paint_count.set(anonymous_paint_count.get() + 1)
4466                                },
4467                            )),
4468                    )
4469                    .child(
4470                        div()
4471                            .id("stateful-group-hover-target")
4472                            .absolute()
4473                            .top_0()
4474                            .left_0()
4475                            .size(px(10.))
4476                            .group_hover("hover-group", |style| style.size(px(20.)))
4477                            .child(canvas(
4478                                move |bounds, _, _| stateful_width.set(bounds.size.width),
4479                                |_, _, _, _| {},
4480                            )),
4481                    ),
4482            )
4483        }
4484    }
4485
4486    #[gpui::test]
4487    fn group_hover_styles_update_only_on_transitions(cx: &mut TestAppContext) {
4488        let render_count = Rc::new(Cell::new(0));
4489        let anonymous_paint_count = Rc::new(Cell::new(0));
4490        let stateful_width = Rc::new(Cell::new(px(0.)));
4491        let window = cx.add_window({
4492            let render_count = render_count.clone();
4493            let anonymous_paint_count = anonymous_paint_count.clone();
4494            let stateful_width = stateful_width.clone();
4495            move |_, _| GroupHoverTestView {
4496                render_count,
4497                anonymous_paint_count,
4498                stateful_width,
4499            }
4500        });
4501        let window = AnyWindowHandle::from(window);
4502
4503        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
4504            .unwrap();
4505        assert_eq!(anonymous_paint_count.get(), 0);
4506        assert_eq!(stateful_width.get(), px(10.));
4507
4508        let move_mouse = |cx: &mut TestAppContext, position| {
4509            cx.update_window(window, |_, window, cx| {
4510                window.simulate_mouse_move(position, cx)
4511            })
4512            .unwrap();
4513        };
4514
4515        let initial_render_count = render_count.get();
4516        move_mouse(cx, point(px(25.), px(25.)));
4517        assert_eq!(render_count.get(), initial_render_count + 1);
4518        assert_eq!(anonymous_paint_count.get(), 1);
4519        assert_eq!(stateful_width.get(), px(20.));
4520
4521        move_mouse(cx, point(px(30.), px(30.)));
4522        assert_eq!(render_count.get(), initial_render_count + 1);
4523        assert_eq!(anonymous_paint_count.get(), 1);
4524        assert_eq!(stateful_width.get(), px(20.));
4525
4526        move_mouse(cx, point(px(5.), px(5.)));
4527        assert_eq!(render_count.get(), initial_render_count + 2);
4528        assert_eq!(anonymous_paint_count.get(), 1);
4529        assert_eq!(stateful_width.get(), px(10.));
4530
4531        move_mouse(cx, point(px(10.), px(10.)));
4532        assert_eq!(render_count.get(), initial_render_count + 2);
4533        assert_eq!(anonymous_paint_count.get(), 1);
4534        assert_eq!(stateful_width.get(), px(10.));
4535    }
4536
4537    struct TestTooltipView;
4538
4539    impl Render for TestTooltipView {
4540        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4541            div().w(px(20.)).h(px(20.)).child("tooltip")
4542        }
4543    }
4544
4545    type CapturedActiveTooltip = Rc<RefCell<Option<Weak<RefCell<Option<ActiveTooltip>>>>>>;
4546
4547    struct TooltipCaptureElement {
4548        child: AnyElement,
4549        captured_active_tooltip: CapturedActiveTooltip,
4550    }
4551
4552    impl IntoElement for TooltipCaptureElement {
4553        type Element = Self;
4554
4555        fn into_element(self) -> Self::Element {
4556            self
4557        }
4558    }
4559
4560    impl Element for TooltipCaptureElement {
4561        type RequestLayoutState = ();
4562        type PrepaintState = ();
4563
4564        fn id(&self) -> Option<ElementId> {
4565            None
4566        }
4567
4568        fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
4569            None
4570        }
4571
4572        fn request_layout(
4573            &mut self,
4574            _id: Option<&GlobalElementId>,
4575            _inspector_id: Option<&InspectorElementId>,
4576            window: &mut Window,
4577            cx: &mut App,
4578        ) -> (LayoutId, Self::RequestLayoutState) {
4579            (self.child.request_layout(window, cx), ())
4580        }
4581
4582        fn prepaint(
4583            &mut self,
4584            _id: Option<&GlobalElementId>,
4585            _inspector_id: Option<&InspectorElementId>,
4586            _bounds: Bounds<Pixels>,
4587            _request_layout: &mut Self::RequestLayoutState,
4588            window: &mut Window,
4589            cx: &mut App,
4590        ) -> Self::PrepaintState {
4591            self.child.prepaint(window, cx);
4592        }
4593
4594        fn paint(
4595            &mut self,
4596            _id: Option<&GlobalElementId>,
4597            _inspector_id: Option<&InspectorElementId>,
4598            _bounds: Bounds<Pixels>,
4599            _request_layout: &mut Self::RequestLayoutState,
4600            _prepaint: &mut Self::PrepaintState,
4601            window: &mut Window,
4602            cx: &mut App,
4603        ) {
4604            self.child.paint(window, cx);
4605            window.with_global_id("target".into(), |global_id, window| {
4606                window.with_element_state::<InteractiveElementState, _>(
4607                    global_id,
4608                    |state, _window| {
4609                        let state = state.unwrap();
4610                        *self.captured_active_tooltip.borrow_mut() =
4611                            state.active_tooltip.as_ref().map(Rc::downgrade);
4612                        ((), state)
4613                    },
4614                )
4615            });
4616        }
4617    }
4618
4619    struct TooltipOwner {
4620        captured_active_tooltip: CapturedActiveTooltip,
4621        show_delay_override: Option<Duration>,
4622    }
4623
4624    impl Render for TooltipOwner {
4625        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4626            TooltipCaptureElement {
4627                child: div()
4628                    .size_full()
4629                    .child(
4630                        div()
4631                            .id("target")
4632                            .w(px(50.))
4633                            .h(px(50.))
4634                            .tooltip(|_, cx| cx.new(|_| TestTooltipView).into())
4635                            .when_some(self.show_delay_override, |this, delay| {
4636                                this.tooltip_show_delay(delay)
4637                            }),
4638                    )
4639                    .into_any_element(),
4640                captured_active_tooltip: self.captured_active_tooltip.clone(),
4641            }
4642        }
4643    }
4644
4645    #[test]
4646    fn scroll_handle_aligns_wide_children_to_left_edge() {
4647        let handle = ScrollHandle::new();
4648        {
4649            let mut state = handle.0.borrow_mut();
4650            state.bounds = Bounds::new(point(px(0.), px(0.)), size(px(80.), px(20.)));
4651            state.child_bounds = vec![Bounds::new(point(px(25.), px(0.)), size(px(200.), px(20.)))];
4652            state.overflow.x = Overflow::Scroll;
4653            state.active_item = Some(ScrollActiveItem {
4654                index: 0,
4655                strategy: ScrollStrategy::default(),
4656            });
4657        }
4658
4659        handle.scroll_to_active_item();
4660
4661        assert_eq!(handle.offset().x, px(-25.));
4662    }
4663
4664    #[test]
4665    fn scroll_handle_aligns_tall_children_to_top_edge() {
4666        let handle = ScrollHandle::new();
4667        {
4668            let mut state = handle.0.borrow_mut();
4669            state.bounds = Bounds::new(point(px(0.), px(0.)), size(px(20.), px(80.)));
4670            state.child_bounds = vec![Bounds::new(point(px(0.), px(25.)), size(px(20.), px(200.)))];
4671            state.overflow.y = Overflow::Scroll;
4672            state.active_item = Some(ScrollActiveItem {
4673                index: 0,
4674                strategy: ScrollStrategy::default(),
4675            });
4676        }
4677
4678        handle.scroll_to_active_item();
4679
4680        assert_eq!(handle.offset().y, px(-25.));
4681    }
4682
4683    struct InitiallyScrolledVariableList {
4684        handle: ScrollHandle,
4685    }
4686
4687    impl Render for InitiallyScrolledVariableList {
4688        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4689            div()
4690                .w(px(100.))
4691                .h(px(80.))
4692                .flex()
4693                .flex_col()
4694                .id("initially-scrolled-variable-list")
4695                .overflow_y_scroll()
4696                .track_scroll(&self.handle)
4697                .children([
4698                    div().h(px(30.)).flex_none(),
4699                    div().h(px(40.)).flex_none(),
4700                    div().h(px(50.)).flex_none(),
4701                ])
4702        }
4703    }
4704
4705    #[gpui::test]
4706    fn scroll_handle_reveals_a_variable_height_child_on_first_prepaint(cx: &mut TestAppContext) {
4707        let handle = ScrollHandle::new();
4708        handle.scroll_to_item(2);
4709        let window: AnyWindowHandle = cx
4710            .add_window({
4711                let handle = handle.clone();
4712                move |_, _| InitiallyScrolledVariableList { handle }
4713            })
4714            .into();
4715
4716        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
4717            .expect("draw list");
4718
4719        assert_eq!(handle.offset().y, px(-40.));
4720    }
4721
4722    fn setup_tooltip_owner_test(
4723        show_delay_override: Option<Duration>,
4724    ) -> (
4725        TestAppContext,
4726        crate::AnyWindowHandle,
4727        CapturedActiveTooltip,
4728    ) {
4729        let mut test_app = TestAppContext::single();
4730        let captured_active_tooltip: CapturedActiveTooltip = Rc::new(RefCell::new(None));
4731        let window = test_app.add_window({
4732            let captured_active_tooltip = captured_active_tooltip.clone();
4733            move |_, _| TooltipOwner {
4734                captured_active_tooltip,
4735                show_delay_override,
4736            }
4737        });
4738        let any_window = window.into();
4739
4740        test_app
4741            .update_window(any_window, |_, window, cx| {
4742                window.draw(cx).clear(cx);
4743            })
4744            .unwrap();
4745
4746        test_app
4747            .update_window(any_window, |_, window, cx| {
4748                window.dispatch_event(
4749                    MouseMoveEvent {
4750                        position: point(px(10.), px(10.)),
4751                        modifiers: Default::default(),
4752                        pressed_button: None,
4753                    }
4754                    .to_platform_input(),
4755                    cx,
4756                );
4757            })
4758            .unwrap();
4759
4760        test_app
4761            .update_window(any_window, |_, window, cx| {
4762                window.draw(cx).clear(cx);
4763            })
4764            .unwrap();
4765
4766        (test_app, any_window, captured_active_tooltip)
4767    }
4768
4769    #[test]
4770    fn tooltip_waiting_for_show_is_released_when_its_owner_disappears() {
4771        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
4772
4773        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
4774        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
4775        assert!(matches!(
4776            active_tooltip.borrow().as_ref(),
4777            Some(ActiveTooltip::WaitingForShow { .. })
4778        ));
4779
4780        test_app
4781            .update_window(any_window, |_, window, _| {
4782                window.remove_window();
4783            })
4784            .unwrap();
4785        test_app.run_until_parked();
4786        drop(active_tooltip);
4787
4788        assert!(weak_active_tooltip.upgrade().is_none());
4789    }
4790
4791    #[test]
4792    fn tooltip_respects_custom_show_delay() {
4793        let extra_delay = Duration::from_secs(1);
4794        let show_delay_override = DEFAULT_TOOLTIP_SHOW_DELAY + extra_delay;
4795        let (mut test_app, _any_window, captured_active_tooltip) =
4796            setup_tooltip_owner_test(Some(show_delay_override));
4797
4798        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
4799        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
4800
4801        test_app
4802            .dispatcher
4803            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
4804        test_app.run_until_parked();
4805
4806        assert!(matches!(
4807            active_tooltip.borrow().as_ref(),
4808            Some(ActiveTooltip::WaitingForShow { .. })
4809        ));
4810
4811        test_app.dispatcher.advance_clock(extra_delay);
4812        test_app.run_until_parked();
4813
4814        assert!(matches!(
4815            active_tooltip.borrow().as_ref(),
4816            Some(ActiveTooltip::Visible { .. })
4817        ));
4818    }
4819
4820    #[test]
4821    fn tooltip_is_released_when_its_owner_disappears() {
4822        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
4823
4824        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
4825        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
4826
4827        test_app
4828            .dispatcher
4829            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
4830        test_app.run_until_parked();
4831
4832        assert!(matches!(
4833            active_tooltip.borrow().as_ref(),
4834            Some(ActiveTooltip::Visible { .. })
4835        ));
4836
4837        test_app
4838            .update_window(any_window, |_, window, _| {
4839                window.remove_window();
4840            })
4841            .unwrap();
4842        test_app.run_until_parked();
4843        drop(active_tooltip);
4844
4845        assert!(weak_active_tooltip.upgrade().is_none());
4846    }
4847
4848    #[test]
4849    fn tooltip_hides_after_mouse_leaves_origin() {
4850        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
4851
4852        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
4853        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
4854
4855        test_app
4856            .dispatcher
4857            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
4858        test_app.run_until_parked();
4859
4860        assert!(matches!(
4861            active_tooltip.borrow().as_ref(),
4862            Some(ActiveTooltip::Visible { .. })
4863        ));
4864
4865        test_app
4866            .update_window(any_window, |_, window, cx| {
4867                window.dispatch_event(
4868                    MouseMoveEvent {
4869                        position: point(px(75.), px(75.)),
4870                        modifiers: Default::default(),
4871                        pressed_button: None,
4872                    }
4873                    .to_platform_input(),
4874                    cx,
4875                );
4876            })
4877            .unwrap();
4878
4879        assert!(active_tooltip.borrow().is_none());
4880    }
4881
4882    #[test]
4883    fn tooltip_hides_after_mouse_exits_window() {
4884        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
4885
4886        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
4887        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
4888
4889        test_app
4890            .dispatcher
4891            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
4892        test_app.run_until_parked();
4893
4894        assert!(matches!(
4895            active_tooltip.borrow().as_ref(),
4896            Some(ActiveTooltip::Visible { .. })
4897        ));
4898
4899        test_app
4900            .update_window(any_window, |_, window, cx| {
4901                window.dispatch_event(
4902                    MouseExitEvent {
4903                        position: point(px(-1.), px(-1.)),
4904                        modifiers: Default::default(),
4905                        pressed_button: None,
4906                    }
4907                    .to_platform_input(),
4908                    cx,
4909                );
4910            })
4911            .unwrap();
4912
4913        assert!(active_tooltip.borrow().is_none());
4914    }
4915
4916    #[test]
4917    fn tooltip_does_not_show_after_mouse_exits_window() {
4918        let (mut test_app, any_window, captured_active_tooltip) = setup_tooltip_owner_test(None);
4919
4920        let weak_active_tooltip = captured_active_tooltip.borrow().clone().unwrap();
4921        let active_tooltip = weak_active_tooltip.upgrade().unwrap();
4922        assert!(matches!(
4923            active_tooltip.borrow().as_ref(),
4924            Some(ActiveTooltip::WaitingForShow { .. })
4925        ));
4926
4927        test_app
4928            .update_window(any_window, |_, window, cx| {
4929                window.dispatch_event(
4930                    MouseExitEvent {
4931                        position: point(px(-1.), px(-1.)),
4932                        modifiers: Default::default(),
4933                        pressed_button: None,
4934                    }
4935                    .to_platform_input(),
4936                    cx,
4937                );
4938            })
4939            .unwrap();
4940
4941        test_app
4942            .dispatcher
4943            .advance_clock(DEFAULT_TOOLTIP_SHOW_DELAY);
4944        test_app.run_until_parked();
4945
4946        assert!(active_tooltip.borrow().is_none());
4947    }
4948
4949    struct MouseDownOutOwner {
4950        mouse_down_out_count: Rc<RefCell<usize>>,
4951    }
4952
4953    impl Render for MouseDownOutOwner {
4954        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
4955            let mouse_down_out_count = self.mouse_down_out_count.clone();
4956            div()
4957                .size_full()
4958                .child(div().id("target").w(px(50.)).h(px(50.)).on_mouse_down_out(
4959                    move |_, _, _| {
4960                        *mouse_down_out_count.borrow_mut() += 1;
4961                    },
4962                ))
4963        }
4964    }
4965
4966    #[test]
4967    fn mouse_down_out_is_suppressed_while_window_prompt_is_active() {
4968        let mut test_app = TestAppContext::single();
4969        let mouse_down_out_count = Rc::new(RefCell::new(0));
4970        let window = test_app.add_window({
4971            let mouse_down_out_count = mouse_down_out_count.clone();
4972            move |_, _| MouseDownOutOwner {
4973                mouse_down_out_count,
4974            }
4975        });
4976        let any_window: AnyWindowHandle = window.into();
4977
4978        fn dispatch_mouse_down_outside_target(
4979            test_app: &mut TestAppContext,
4980            any_window: AnyWindowHandle,
4981        ) {
4982            test_app
4983                .update_window(any_window, |_, window, cx| {
4984                    window.dispatch_event(
4985                        MouseDownEvent {
4986                            position: point(px(75.), px(75.)),
4987                            button: MouseButton::Left,
4988                            modifiers: Default::default(),
4989                            click_count: 1,
4990                            first_mouse: false,
4991                        }
4992                        .to_platform_input(),
4993                        cx,
4994                    );
4995                })
4996                .unwrap();
4997        }
4998
4999        test_app
5000            .update_window(any_window, |_, window, cx| {
5001                window.draw(cx).clear(cx);
5002            })
5003            .unwrap();
5004
5005        dispatch_mouse_down_outside_target(&mut test_app, any_window);
5006        assert_eq!(
5007            *mouse_down_out_count.borrow(),
5008            1,
5009            "mouse down outside the element should fire mouse-down-out listeners"
5010        );
5011
5012        test_app
5013            .update_window(any_window, |_, window, cx| {
5014                cx.set_prompt_builder(crate::fallback_prompt_renderer);
5015                let _receiver =
5016                    window.prompt(crate::PromptLevel::Warning, "message", None, &["Ok"], cx);
5017                assert!(window.has_active_prompt());
5018                window.draw(cx).clear(cx);
5019            })
5020            .unwrap();
5021
5022        dispatch_mouse_down_outside_target(&mut test_app, any_window);
5023        assert_eq!(
5024            *mouse_down_out_count.borrow(),
5025            1,
5026            "mouse down over an active prompt should not fire mouse-down-out listeners"
5027        );
5028    }
5029
5030    #[test]
5031    fn test_write_a11y_info_string_and_numeric_properties() {
5032        let mut interactivity = Interactivity::default();
5033        interactivity.aria.label = Some("Buffer Font Size".into());
5034        interactivity.aria.value = Some("15".into());
5035        interactivity.aria.placeholder = Some("Search".into());
5036        interactivity.aria.numeric_value = Some(15.0);
5037        interactivity.aria.min_numeric_value = Some(6.0);
5038        interactivity.aria.max_numeric_value = Some(72.0);
5039        interactivity.aria.numeric_value_step = Some(1.0);
5040        interactivity.aria.disabled = true;
5041        interactivity.aria.read_only = true;
5042        interactivity.aria.modal = true;
5043        interactivity.aria.invalid = true;
5044        interactivity.aria.required = true;
5045        interactivity.aria.busy = true;
5046        interactivity.aria.live = Some(accesskit::Live::Polite);
5047        interactivity.aria.live_atomic = true;
5048
5049        let mut node = accesskit::Node::new(accesskit::Role::SpinButton);
5050        interactivity.write_a11y_info(&mut node);
5051
5052        assert_eq!(node.label(), Some("Buffer Font Size"));
5053        assert_eq!(node.value(), Some("15"));
5054        assert_eq!(node.placeholder(), Some("Search"));
5055        assert_eq!(node.numeric_value(), Some(15.0));
5056        assert_eq!(node.min_numeric_value(), Some(6.0));
5057        assert_eq!(node.max_numeric_value(), Some(72.0));
5058        assert_eq!(node.numeric_value_step(), Some(1.0));
5059        assert!(node.is_disabled());
5060        assert!(node.is_read_only());
5061        assert!(node.is_modal());
5062        assert_eq!(node.invalid(), Some(accesskit::Invalid::True));
5063        assert!(node.is_required());
5064        assert!(node.is_busy());
5065        assert_eq!(node.live(), Some(accesskit::Live::Polite));
5066        assert!(node.is_live_atomic());
5067    }
5068
5069    /// Two focusable, clickable elements ("a" and "b") used to exercise the
5070    /// Enter/Space -> synthesized click press/release pairing.
5071    struct KeyboardActivationTest {
5072        focus_a: FocusHandle,
5073        focus_b: FocusHandle,
5074        clicks: Rc<RefCell<Vec<&'static str>>>,
5075    }
5076
5077    impl Render for KeyboardActivationTest {
5078        fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
5079            let clicks_a = self.clicks.clone();
5080            let clicks_b = self.clicks.clone();
5081            div()
5082                .size_full()
5083                .child(
5084                    div()
5085                        .id("a")
5086                        .w(px(50.))
5087                        .h(px(50.))
5088                        .track_focus(&self.focus_a)
5089                        .role(crate::Role::Button)
5090                        .child(
5091                            div()
5092                                .id("a-child")
5093                                .track_focus(&self.focus_a)
5094                                .role(crate::Role::Label),
5095                        )
5096                        .on_click(move |_, _, _| clicks_a.borrow_mut().push("a")),
5097                )
5098                .child(
5099                    div()
5100                        .id("b")
5101                        .w(px(50.))
5102                        .h(px(50.))
5103                        .track_focus(&self.focus_b)
5104                        .role(crate::Role::Button)
5105                        .on_click(move |_, _, _| clicks_b.borrow_mut().push("b")),
5106                )
5107                .child(
5108                    div()
5109                        .id("generated")
5110                        .w(px(50.))
5111                        .h(px(50.))
5112                        .tab_index(0)
5113                        .role(crate::Role::Button),
5114                )
5115        }
5116    }
5117
5118    fn setup_keyboard_activation_test() -> (
5119        TestAppContext,
5120        AnyWindowHandle,
5121        Rc<RefCell<Vec<&'static str>>>,
5122        FocusHandle,
5123        FocusHandle,
5124    ) {
5125        let mut cx = TestAppContext::single();
5126        let (focus_a, focus_b) = cx.update(|cx| (cx.focus_handle(), cx.focus_handle()));
5127        let clicks: Rc<RefCell<Vec<&'static str>>> = Rc::new(RefCell::new(Vec::new()));
5128        let window = cx.add_window({
5129            let focus_a = focus_a.clone();
5130            let focus_b = focus_b.clone();
5131            let clicks = clicks.clone();
5132            move |_, _| KeyboardActivationTest {
5133                focus_a,
5134                focus_b,
5135                clicks,
5136            }
5137        });
5138        (cx, window.into(), clicks, focus_a, focus_b)
5139    }
5140
5141    /// Move focus to `handle`, flush effects, then paint so the newly focused
5142    /// element registers its key handlers for the next dispatched event.
5143    fn focus_and_draw(cx: &mut TestAppContext, window: AnyWindowHandle, handle: &FocusHandle) {
5144        cx.update_window(window, |_, window, cx| window.focus(handle, cx))
5145            .unwrap();
5146        cx.run_until_parked();
5147        cx.update_window(window, |_, window, cx| {
5148            window.draw(cx).clear(cx);
5149        })
5150        .unwrap();
5151    }
5152
5153    #[test]
5154    fn accessibility_focus_action_focuses_owning_handle() {
5155        let (mut cx, window, _clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5156        cx.activate_accessibility(window);
5157        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
5158            .unwrap();
5159        let target = cx
5160            .update_window(window, |_, window, _| {
5161                let tree: serde_json::Value = serde_json::from_str(
5162                    &window
5163                        .debug_a11y_tree_json()
5164                        .expect("accessibility adapter is active"),
5165                )
5166                .expect("valid accessibility debug tree");
5167                let node = tree["nodes"]
5168                    .as_object()
5169                    .and_then(|nodes| {
5170                        nodes
5171                            .values()
5172                            .find(|node| node["element_id"] == "Name(\"a\")")
5173                    })
5174                    .expect("focusable role-bearing node");
5175                accesskit::NodeId(
5176                    node["accesskit_id"]
5177                        .as_str()
5178                        .expect("node id")
5179                        .parse()
5180                        .expect("numeric node id"),
5181                )
5182            })
5183            .unwrap();
5184        cx.dispatch_accessibility_action(
5185            window,
5186            accesskit::ActionRequest {
5187                action: accesskit::Action::Focus,
5188                target_tree: accesskit::TreeId::ROOT,
5189                target_node: target,
5190                data: None,
5191            },
5192        );
5193
5194        cx.update_window(window, |_, window, _| {
5195            assert!(focus_a.is_focused(window));
5196        })
5197        .unwrap();
5198        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
5199            .unwrap();
5200        cx.update_window(window, |_, window, _| {
5201            let tree: serde_json::Value = serde_json::from_str(
5202                &window
5203                    .debug_a11y_tree_json()
5204                    .expect("accessibility adapter is active"),
5205            )
5206            .expect("valid accessibility debug tree");
5207            let focused = tree["gpui_focus"].as_str().expect("focused debug id");
5208            assert_eq!(tree["nodes"][focused]["element_id"], "Name(\"a-child\")");
5209        })
5210        .unwrap();
5211    }
5212
5213    #[test]
5214    fn accessibility_focus_action_focuses_generated_tab_handle() {
5215        let (mut cx, window, _clicks, _focus_a, _focus_b) = setup_keyboard_activation_test();
5216        cx.activate_accessibility(window);
5217        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
5218            .unwrap();
5219        let (target, expected_debug_focus) = cx
5220            .update_window(window, |_, window, _| {
5221                let tree: serde_json::Value = serde_json::from_str(
5222                    &window
5223                        .debug_a11y_tree_json()
5224                        .expect("accessibility adapter is active"),
5225                )
5226                .expect("valid accessibility debug tree");
5227                let (debug_id, node) = tree["nodes"]
5228                    .as_object()
5229                    .and_then(|nodes| {
5230                        nodes
5231                            .iter()
5232                            .find(|(_, node)| node["element_id"] == "Name(\"generated\")")
5233                    })
5234                    .expect("generated focusable role-bearing node");
5235                (
5236                    accesskit::NodeId(
5237                        node["accesskit_id"]
5238                            .as_str()
5239                            .expect("node id")
5240                            .parse()
5241                            .expect("numeric node id"),
5242                    ),
5243                    debug_id.clone(),
5244                )
5245            })
5246            .unwrap();
5247        cx.dispatch_accessibility_action(
5248            window,
5249            accesskit::ActionRequest {
5250                action: accesskit::Action::Focus,
5251                target_tree: accesskit::TreeId::ROOT,
5252                target_node: target,
5253                data: None,
5254            },
5255        );
5256        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
5257            .unwrap();
5258
5259        cx.update_window(window, |_, window, _| {
5260            let tree: serde_json::Value = serde_json::from_str(
5261                &window
5262                    .debug_a11y_tree_json()
5263                    .expect("accessibility adapter is active"),
5264            )
5265            .expect("valid accessibility debug tree");
5266            assert_eq!(tree["gpui_focus"], expected_debug_focus);
5267        })
5268        .unwrap();
5269    }
5270
5271    fn key_down(cx: &mut TestAppContext, window: AnyWindowHandle, key: &str) {
5272        let keystroke = Keystroke::parse(key).unwrap();
5273        cx.update_window(window, |_, window, cx| {
5274            window.dispatch_event(
5275                KeyDownEvent {
5276                    keystroke,
5277                    is_held: false,
5278                    prefer_character_input: false,
5279                }
5280                .to_platform_input(),
5281                cx,
5282            );
5283        })
5284        .unwrap();
5285    }
5286
5287    fn key_up(cx: &mut TestAppContext, window: AnyWindowHandle, key: &str) {
5288        let keystroke = Keystroke::parse(key).unwrap();
5289        cx.update_window(window, |_, window, cx| {
5290            window.dispatch_event(KeyUpEvent { keystroke }.to_platform_input(), cx);
5291        })
5292        .unwrap();
5293    }
5294
5295    /// Pressing and releasing Enter on the same focused element fires a click.
5296    #[test]
5297    fn keyboard_activation_fires_click_on_same_element() {
5298        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5299
5300        focus_and_draw(&mut cx, window, &focus_a);
5301        key_down(&mut cx, window, "enter");
5302        key_up(&mut cx, window, "enter");
5303
5304        assert_eq!(*clicks.borrow(), vec!["a"]);
5305    }
5306
5307    /// A key-down whose key-up lands on a *different* element (because focus
5308    /// moved in between) must not leak a synthesized click onto the newly
5309    /// focused element. This is the core regression: previously the key-up
5310    /// handler fired unconditionally on whatever was focused at key-up time.
5311    #[test]
5312    fn keyboard_activation_does_not_leak_across_focus_change() {
5313        let (mut cx, window, clicks, focus_a, focus_b) = setup_keyboard_activation_test();
5314
5315        // Enter pressed while "a" is focused...
5316        focus_and_draw(&mut cx, window, &focus_a);
5317        key_down(&mut cx, window, "enter");
5318
5319        // ...focus moves to "b" before the release (as a confirm action would)...
5320        focus_and_draw(&mut cx, window, &focus_b);
5321        key_up(&mut cx, window, "enter");
5322
5323        // ...so neither element is clicked: "a" never saw the up, and "b"
5324        // never saw the down.
5325        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5326    }
5327
5328    /// A keydown whose flag is left pending because focus moved away before
5329    /// the keyup must not fire a click when focus later *returns* to the same
5330    /// element (the menu trigger reopening case). The stamped focus generation
5331    /// no longer matches, so the stale pending state is ignored.
5332    #[test]
5333    fn keyboard_activation_does_not_leak_when_focus_returns() {
5334        let (mut cx, window, clicks, focus_a, focus_b) = setup_keyboard_activation_test();
5335
5336        // Enter pressed on "a"...
5337        focus_and_draw(&mut cx, window, &focus_a);
5338        key_down(&mut cx, window, "enter");
5339
5340        // ...focus leaves "a" before its keyup (so the pending state is never
5341        // consumed), then comes back to "a"...
5342        focus_and_draw(&mut cx, window, &focus_b);
5343        focus_and_draw(&mut cx, window, &focus_a);
5344        key_up(&mut cx, window, "enter");
5345
5346        // ...and the now-stale pending keydown must not fire a click.
5347        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5348    }
5349
5350    /// A non-activation key *released* during the press must cancel the pending
5351    /// activation. For the sequence escape-down, space-down, escape-up,
5352    /// space-up the space forms a clean down/up pair, but the intervening
5353    /// escape-up means this isn't a plain space activation, so no click fires.
5354    #[test]
5355    fn keyboard_activation_cleared_by_intervening_key_release() {
5356        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5357
5358        focus_and_draw(&mut cx, window, &focus_a);
5359        key_down(&mut cx, window, "escape");
5360        key_down(&mut cx, window, "space");
5361        key_up(&mut cx, window, "escape");
5362        key_up(&mut cx, window, "space");
5363
5364        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5365    }
5366
5367    /// The flag is a single activation marker, not keyed by which activation
5368    /// key was used, so a Space down paired with an Enter up on the same
5369    /// element still fires a click.
5370    #[test]
5371    fn keyboard_activation_does_not_distinguish_space_and_enter() {
5372        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5373
5374        focus_and_draw(&mut cx, window, &focus_a);
5375        key_down(&mut cx, window, "space");
5376        key_up(&mut cx, window, "enter");
5377
5378        assert_eq!(*clicks.borrow(), vec!["a"]);
5379    }
5380
5381    /// A non-activation key pressed between the activation down and up clears
5382    /// the pending flag, suppressing the click.
5383    #[test]
5384    fn keyboard_activation_cleared_by_intervening_keydown() {
5385        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5386
5387        focus_and_draw(&mut cx, window, &focus_a);
5388        key_down(&mut cx, window, "enter");
5389        key_down(&mut cx, window, "a");
5390        key_up(&mut cx, window, "enter");
5391
5392        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5393    }
5394
5395    /// A modified Enter (e.g. cmd-enter) is not treated as an activation key,
5396    /// so it neither sets the pending flag nor fires a click on release.
5397    #[test]
5398    fn keyboard_activation_ignores_modified_keys() {
5399        let (mut cx, window, clicks, focus_a, _focus_b) = setup_keyboard_activation_test();
5400
5401        focus_and_draw(&mut cx, window, &focus_a);
5402        key_down(&mut cx, window, "cmd-enter");
5403        key_up(&mut cx, window, "cmd-enter");
5404
5405        assert!(clicks.borrow().is_empty(), "clicks: {:?}", clicks.borrow());
5406    }
5407
5408    /// Two sibling tab groups, each a focusable container that is *not* itself a
5409    /// tab stop and holds a single tab stop. Mirrors how the title bar and
5410    /// status bar expose their controls as ARIA toolbars.
5411    struct TabGroupFocus {
5412        group_a: FocusHandle,
5413        item_a: FocusHandle,
5414        group_b: FocusHandle,
5415        item_b: FocusHandle,
5416    }
5417
5418    impl Render for TabGroupFocus {
5419        fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
5420            fn group(container: &FocusHandle, item: &FocusHandle) -> Div {
5421                div()
5422                    .track_focus(container)
5423                    .tab_group()
5424                    .child(div().track_focus(item))
5425            }
5426            div()
5427                .child(group(&self.group_a, &self.item_a))
5428                .child(group(&self.group_b, &self.item_b))
5429        }
5430    }
5431
5432    /// Focusing a tab-group container and pressing Tab (`focus_next`) must move
5433    /// focus to the first tab stop *inside that container*, as documented on
5434    /// [`InteractiveElement::tab_stop`].
5435    #[test]
5436    fn focus_next_from_tab_group_container_enters_that_group() {
5437        let mut cx = TestAppContext::single();
5438        let (group_a, item_a, group_b, item_b) = cx.update(|cx| {
5439            (
5440                cx.focus_handle(),
5441                cx.focus_handle().tab_stop(true),
5442                cx.focus_handle(),
5443                cx.focus_handle().tab_stop(true),
5444            )
5445        });
5446        let window: AnyWindowHandle = cx
5447            .add_window({
5448                let (group_a, item_a, group_b, item_b) =
5449                    (group_a, item_a, group_b.clone(), item_b.clone());
5450                move |_, _| TabGroupFocus {
5451                    group_a,
5452                    item_a,
5453                    group_b,
5454                    item_b,
5455                }
5456            })
5457            .into();
5458        cx.update_window(window, |_, window, cx| window.draw(cx).clear(cx))
5459            .unwrap();
5460
5461        // Focus the *second* group's container, then advance like Tab would.
5462        let focused = cx
5463            .update_window(window, |_, window, cx| {
5464                window.focus(&group_b, cx);
5465                window.focus_next(cx);
5466                window.focused(cx).map(|handle| handle.id)
5467            })
5468            .unwrap();
5469
5470        assert_eq!(focused, Some(item_b.id));
5471    }
5472}