azul-layout 0.0.10

Layout solver + font and image loader the Azul GUI framework
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
//! Toast / snackbar widget — a transient notification banner. A near-clone of
//! [`crate::widgets::alert::Alert`] (a coloured message box with a "x" dismiss
//! affordance and a `visible` state) that, instead of sitting inline, floats as
//! an overlay pinned to a corner of its positioned parent
//! (`position: absolute; bottom; right`).
//!
//! Like [`crate::widgets::alert::Alert`] / [`crate::widgets::check_box::CheckBox`]
//! it is stateful: it carries a [`ToastStateWrapper`] (`{ visible } + on_dismiss`)
//! in a [`RefAny`] attached to the "x" close button. Clicking "x" flips `visible`
//! to `false`, invokes the optional user `on_dismiss`, and hides the whole toast
//! by setting `display: none` on the container via `set_css_property` (mirroring
//! alert's / check_box's live restyle).
//!
//! TODO2 — **auto-dismiss is intentionally NOT implemented (be honest, don't fake
//! it).** A real toast disappears on its own after N seconds. That requires a
//! host-driven `Timer`/`Update` loop that re-enters the event loop on a clock
//! tick and flips `visible` to `false` — a widget handler cannot *start* such a
//! timer (it only runs in response to an input event, with no access to schedule
//! a future wakeup). This is the same limitation the spinner hit with CSS
//! animation: there is no widget-local timer. So this widget ships a **manually**
//! dismissable toast (the "x"); a host that wants auto-timeout must register a
//! `Timer` itself and call `set_css_property(display: none)` (or rebuild without
//! the toast) when it fires.
//!
//! TODO2 — covering sibling widgets relies on paint order (being a later sibling)
//! because there is no real stacking-context / z-index, and a drop `box-shadow`
//! elevation is omitted (it needs a runtime-heap shadow value — see
//! `progressbar.rs`); the border + radius over the page convey the floating card.
//! The `display:none` relayout itself is not GUI-verified in this build.
//!
//! Key types: [`Toast`], [`ToastKind`], [`ToastState`], [`ToastOnDismiss`].

use azul_core::{
    callbacks::{CoreCallbackData, Update},
    dom::{Dom, IdOrClass, IdOrClass::Class, IdOrClassVec, TabIndex},
    refany::RefAny,
};
use azul_css::dynamic_selector::{CssPropertyWithConditions, CssPropertyWithConditionsVec};
use azul_css::{
    props::{
        basic::{color::ColorU, font::{StyleFontFamily, StyleFontFamilyVec}, StyleFontSize},
        layout::{LayoutDisplay, LayoutFlexDirection, LayoutAlignItems, LayoutFlexGrow, LayoutPosition, LayoutInsetBottom, LayoutRight, LayoutMaxWidth, LayoutPaddingTop, LayoutPaddingBottom, LayoutPaddingLeft, LayoutPaddingRight, LayoutMarginLeft},
        property::{CssProperty, *},
        style::{StyleBackgroundContentVec, StyleBackgroundContent, LayoutBorderTopWidth, LayoutBorderBottomWidth, LayoutBorderLeftWidth, LayoutBorderRightWidth, StyleBorderTopStyle, BorderStyle, StyleBorderBottomStyle, StyleBorderLeftStyle, StyleBorderRightStyle, StyleBorderTopColor, StyleBorderBottomColor, StyleBorderLeftColor, StyleBorderRightColor, StyleBorderTopLeftRadius, StyleBorderTopRightRadius, StyleBorderBottomLeftRadius, StyleBorderBottomRightRadius, StyleTextColor, StyleTextAlign, StyleCursor, StyleUserSelect},
    },
    impl_option_inner, AzString,
};

use crate::callbacks::{Callback, CallbackInfo};

static TOAST_CONTAINER_CLASS: &[IdOrClass] =
    &[Class(AzString::from_const_str("__azul-native-toast"))];
static TOAST_MESSAGE_CLASS: &[IdOrClass] =
    &[Class(AzString::from_const_str("__azul-native-toast-message"))];
static TOAST_CLOSE_CLASS: &[IdOrClass] =
    &[Class(AzString::from_const_str("__azul-native-toast-close"))];

const SYSTEM_UI_STR: AzString = AzString::from_const_str("system:ui");
const SYSTEM_UI_FAMILIES: &[StyleFontFamily] = &[StyleFontFamily::System(SYSTEM_UI_STR)];
const SYSTEM_UI_FAMILY: StyleFontFamilyVec =
    StyleFontFamilyVec::from_const_slice(SYSTEM_UI_FAMILIES);

/// Distance (logical px) of the toast from the bottom / right edges of its parent.
const TOAST_INSET: isize = 24;
/// Maximum width (logical px) of the toast card.
const TOAST_MAX_WIDTH: isize = 360;

/// Callback function type invoked when a toast's "x" close button is clicked.
pub type ToastOnDismissCallbackType = extern "C" fn(RefAny, CallbackInfo, ToastState) -> Update;
impl_widget_callback!(
    ToastOnDismiss,
    OptionToastOnDismiss,
    ToastOnDismissCallback,
    ToastOnDismissCallbackType
);

azul_core::impl_managed_callback! {
    wrapper:        ToastOnDismissCallback,
    info_ty:        CallbackInfo,
    return_ty:      Update,
    default_ret:    Update::DoNothing,
    invoker_static: TOAST_ON_DISMISS_INVOKER,
    invoker_ty:     AzToastOnDismissCallbackInvoker,
    thunk_fn:       az_toast_on_dismiss_callback_thunk,
    setter_fn:      AzApp_setToastOnDismissCallbackInvoker,
    from_handle_fn: AzToastOnDismissCallback_createFromHostHandle,
    extra_args:     [ state: ToastState ],
}

/// The semantic colour variant of a [`Toast`] (Bootstrap alert palette, mirroring
/// [`crate::widgets::alert::AlertKind`]).
#[derive(Debug, Copy, Clone, PartialEq, Eq, Default)]
#[repr(C)]
pub enum ToastKind {
    /// Blue informational toast — the default.
    #[default]
    Info,
    /// Green success toast.
    Success,
    /// Yellow warning toast.
    Warning,
    /// Red danger/error toast.
    Danger,
}

impl ToastKind {
    /// Returns the `(background, border, text)` colours for this toast kind.
    #[allow(clippy::trivially_copy_pass_by_ref)] // <=8B Copy param kept by-ref intentionally (hot pixel/coord path or to avoid churning call sites for a perf-neutral change)
    const fn colors(&self) -> (ColorU, ColorU, ColorU) {
        match self {
            Self::Info => (
                ColorU { r: 207, g: 244, b: 252, a: 255 }, // #cff4fc
                ColorU { r: 182, g: 239, b: 251, a: 255 }, // #b6effb
                ColorU { r: 5, g: 81, b: 96, a: 255 },     // #055160
            ),
            Self::Success => (
                ColorU { r: 209, g: 231, b: 221, a: 255 }, // #d1e7dd
                ColorU { r: 186, g: 219, b: 204, a: 255 }, // #badbcc
                ColorU { r: 15, g: 81, b: 50, a: 255 },    // #0f5132
            ),
            Self::Warning => (
                ColorU { r: 255, g: 243, b: 205, a: 255 }, // #fff3cd
                ColorU { r: 255, g: 236, b: 181, a: 255 }, // #ffecb5
                ColorU { r: 102, g: 77, b: 3, a: 255 },    // #664d03
            ),
            Self::Danger => (
                ColorU { r: 248, g: 215, b: 218, a: 255 }, // #f8d7da
                ColorU { r: 245, g: 194, b: 199, a: 255 }, // #f5c2c7
                ColorU { r: 132, g: 32, b: 41, a: 255 },   // #842029
            ),
        }
    }

    /// CSS class name for this toast kind (mirrors `AlertKind::class_name`).
    #[must_use] pub const fn class_name(&self) -> &'static str {
        match self {
            Self::Info => "__azul-toast-info",
            Self::Success => "__azul-toast-success",
            Self::Warning => "__azul-toast-warning",
            Self::Danger => "__azul-toast-danger",
        }
    }
}

/// A transient, floating notification banner with a "x" dismiss button.
#[derive(Debug, Clone, PartialEq, Eq)]
#[repr(C)]
pub struct Toast {
    /// Runtime state (`visible`) plus the optional dismiss callback.
    pub toast_state: ToastStateWrapper,
    /// The message text shown inside the toast.
    pub message: AzString,
    /// The colour variant.
    pub kind: ToastKind,
    /// Whether to render the "x" close button (default `true` — the only way to
    /// dismiss; see the module-level auto-dismiss TODO2).
    pub dismissible: bool,
    /// The computed inline style for the (absolutely-positioned) container.
    pub container_style: CssPropertyWithConditionsVec,
}

#[derive(Debug, Default, Clone, PartialEq, Eq)]
#[repr(C)]
pub struct ToastStateWrapper {
    /// Whether the toast is currently visible.
    pub inner: ToastState,
    /// Optional: function to call when the toast is dismissed.
    pub on_dismiss: OptionToastOnDismiss,
}

/// The visible/hidden state of a [`Toast`].
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[repr(C)]
pub struct ToastState {
    /// `true` (default) = shown, `false` = dismissed/hidden.
    pub visible: bool,
}

impl Default for ToastState {
    fn default() -> Self {
        Self { visible: true }
    }
}

/// Builds the container style for a given [`ToastKind`]. Mirrors
/// `alert::build_alert_style` but pins the box to the bottom-right corner of its
/// positioned parent (`position: absolute`) and caps its width instead of
/// stretching to fill a flex column.
fn build_toast_style(kind: ToastKind) -> CssPropertyWithConditionsVec {
    let (bg, border, text) = kind.colors();
    let bg_vec =
        StyleBackgroundContentVec::from_vec(alloc::vec![StyleBackgroundContent::Color(bg)]);
    CssPropertyWithConditionsVec::from_vec(alloc::vec![
        CssPropertyWithConditions::simple(CssProperty::const_display(LayoutDisplay::Flex)),
        CssPropertyWithConditions::simple(CssProperty::const_flex_direction(
            LayoutFlexDirection::Row,
        )),
        CssPropertyWithConditions::simple(CssProperty::const_align_items(LayoutAlignItems::Start)),
        CssPropertyWithConditions::simple(CssProperty::const_flex_grow(LayoutFlexGrow::const_new(
            0,
        ))),
        // Float pinned to the bottom-right corner of the positioned parent.
        CssPropertyWithConditions::simple(CssProperty::const_position(LayoutPosition::Absolute)),
        CssPropertyWithConditions::simple(CssProperty::const_bottom(LayoutInsetBottom::const_px(
            TOAST_INSET,
        ))),
        CssPropertyWithConditions::simple(CssProperty::const_right(LayoutRight::const_px(
            TOAST_INSET,
        ))),
        // Cap the width so the toast hugs its content rather than spanning the page.
        CssPropertyWithConditions::simple(CssProperty::const_max_width(LayoutMaxWidth::const_px(
            TOAST_MAX_WIDTH,
        ))),
        // padding: 12px
        CssPropertyWithConditions::simple(CssProperty::const_padding_top(LayoutPaddingTop::const_px(
            12,
        ))),
        CssPropertyWithConditions::simple(CssProperty::const_padding_bottom(
            LayoutPaddingBottom::const_px(12),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_padding_left(
            LayoutPaddingLeft::const_px(12),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_padding_right(
            LayoutPaddingRight::const_px(12),
        )),
        // border: 1px solid <border>
        CssPropertyWithConditions::simple(CssProperty::const_border_top_width(
            LayoutBorderTopWidth::const_px(1),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_bottom_width(
            LayoutBorderBottomWidth::const_px(1),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_left_width(
            LayoutBorderLeftWidth::const_px(1),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_right_width(
            LayoutBorderRightWidth::const_px(1),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_top_style(StyleBorderTopStyle {
            inner: BorderStyle::Solid,
        })),
        CssPropertyWithConditions::simple(CssProperty::const_border_bottom_style(
            StyleBorderBottomStyle {
                inner: BorderStyle::Solid,
            },
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_left_style(
            StyleBorderLeftStyle {
                inner: BorderStyle::Solid,
            },
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_right_style(
            StyleBorderRightStyle {
                inner: BorderStyle::Solid,
            },
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_top_color(StyleBorderTopColor {
            inner: border,
        })),
        CssPropertyWithConditions::simple(CssProperty::const_border_bottom_color(
            StyleBorderBottomColor { inner: border },
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_left_color(
            StyleBorderLeftColor { inner: border },
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_right_color(
            StyleBorderRightColor { inner: border },
        )),
        // border-radius: 6px
        CssPropertyWithConditions::simple(CssProperty::const_border_top_left_radius(
            StyleBorderTopLeftRadius::const_px(6),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_top_right_radius(
            StyleBorderTopRightRadius::const_px(6),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_bottom_left_radius(
            StyleBorderBottomLeftRadius::const_px(6),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_border_bottom_right_radius(
            StyleBorderBottomRightRadius::const_px(6),
        )),
        CssPropertyWithConditions::simple(CssProperty::const_font_size(StyleFontSize::const_px(14))),
        CssPropertyWithConditions::simple(CssProperty::const_font_family(SYSTEM_UI_FAMILY)),
        // Text colour is inherited by the message + close children.
        CssPropertyWithConditions::simple(CssProperty::const_text_color(StyleTextColor {
            inner: text,
        })),
        CssPropertyWithConditions::simple(CssProperty::const_background_content(bg_vec)),
    ])
}

/// Message-text style: takes the remaining horizontal space, left-aligned.
static TOAST_MESSAGE_STYLE: &[CssPropertyWithConditions] = &[
    CssPropertyWithConditions::simple(CssProperty::const_flex_grow(LayoutFlexGrow::const_new(1))),
    CssPropertyWithConditions::simple(CssProperty::const_text_align(StyleTextAlign::Left)),
];

/// Close-button ("x") style: a small pointer-cursor box on the right.
static TOAST_CLOSE_STYLE: &[CssPropertyWithConditions] = &[
    CssPropertyWithConditions::simple(CssProperty::const_flex_grow(LayoutFlexGrow::const_new(0))),
    CssPropertyWithConditions::simple(CssProperty::const_font_size(StyleFontSize::const_px(18))),
    CssPropertyWithConditions::simple(CssProperty::const_cursor(StyleCursor::Pointer)),
    CssPropertyWithConditions::simple(CssProperty::user_select(StyleUserSelect::None)),
    CssPropertyWithConditions::simple(CssProperty::const_margin_left(LayoutMarginLeft::const_px(
        12,
    ))),
];

impl Toast {
    /// Creates a new informational (blue) toast with the given message (visible,
    /// with a "x" close button).
    #[inline]
    #[must_use] pub fn create(message: AzString) -> Self {
        Self::with_kind(message, ToastKind::Info)
    }

    /// Creates a new toast with the given message and colour variant.
    #[inline]
    #[must_use] pub fn with_kind(message: AzString, kind: ToastKind) -> Self {
        Self {
            toast_state: ToastStateWrapper::default(),
            message,
            kind,
            dismissible: true,
            container_style: build_toast_style(kind),
        }
    }

    /// Sets the colour variant, recomputing the container style.
    #[inline]
    pub fn set_kind(&mut self, kind: ToastKind) {
        self.kind = kind;
        self.container_style = build_toast_style(kind);
    }

    /// Builder-style setter for the colour variant.
    #[inline]
    #[must_use] pub fn with_toast_kind(mut self, kind: ToastKind) -> Self {
        self.set_kind(kind);
        self
    }

    /// Sets whether the toast shows a "x" close button.
    #[inline]
    pub const fn set_dismissible(&mut self, dismissible: bool) {
        self.dismissible = dismissible;
    }

    /// Builder-style setter for the dismissible flag.
    #[inline]
    #[must_use] pub const fn with_dismissible(mut self, dismissible: bool) -> Self {
        self.set_dismissible(dismissible);
        self
    }

    /// Sets the dismiss callback. Implies `dismissible = true` so the close
    /// button is rendered.
    #[inline]
    pub fn set_on_dismiss<C: Into<ToastOnDismissCallback>>(&mut self, data: RefAny, on_dismiss: C) {
        self.dismissible = true;
        self.toast_state.on_dismiss = Some(ToastOnDismiss {
            callback: on_dismiss.into(),
            refany: data,
        })
        .into();
    }

    /// Builder-style setter for the dismiss callback (implies dismissible).
    #[inline]
    #[must_use] pub fn with_on_dismiss<C: Into<ToastOnDismissCallback>>(
        mut self,
        data: RefAny,
        on_dismiss: C,
    ) -> Self {
        self.set_on_dismiss(data, on_dismiss);
        self
    }

    /// Replaces `self` with a default (empty info) toast and returns the original.
    #[inline]
    #[must_use] pub fn swap_with_default(&mut self) -> Self {
        let mut s = Self::create(AzString::from_const_str(""));
        core::mem::swap(&mut s, self);
        s
    }

    /// Converts this toast into a DOM subtree with the `__azul-native-toast` class.
    #[inline]
    #[must_use] pub fn dom(self) -> Dom {
        use azul_core::{
            callbacks::CoreCallback,
            dom::{EventFilter, HoverEventFilter},
            refany::OptionRefAny,
        };

        let message = Dom::create_text(self.message)
            .with_ids_and_classes(IdOrClassVec::from_const_slice(TOAST_MESSAGE_CLASS))
            .with_css_props(CssPropertyWithConditionsVec::from_const_slice(TOAST_MESSAGE_STYLE));

        let mut children = alloc::vec![message];

        if self.dismissible {
            let close = Dom::create_text(AzString::from_const_str("\u{00D7}"))
                .with_ids_and_classes(IdOrClassVec::from_const_slice(TOAST_CLOSE_CLASS))
                .with_css_props(CssPropertyWithConditionsVec::from_const_slice(TOAST_CLOSE_STYLE))
                .with_tab_index(TabIndex::Auto)
                .with_callbacks(
                    alloc::vec![CoreCallbackData {
                        event: EventFilter::Hover(HoverEventFilter::MouseUp),
                        callback: CoreCallback {
                            cb: default_on_toast_dismiss as usize,
                            ctx: OptionRefAny::None,
                        },
                        refany: RefAny::new(self.toast_state),
                    }]
                    .into(),
                );
            children.push(close);
        }

        Dom::create_div()
            .with_ids_and_classes(IdOrClassVec::from_const_slice(TOAST_CONTAINER_CLASS))
            .with_css_props(self.container_style)
            .with_children(children.into())
    }
}

impl Default for Toast {
    fn default() -> Self {
        Self::create(AzString::from_const_str(""))
    }
}

/// Close-button click handler. The hit node is the close button (the
/// callback-bearing node, per `currentTarget` semantics — see `alert`); its
/// parent is the toast container. Flips `visible` to `false`, invokes the
/// optional user callback, then hides the whole toast via `display: none`.
extern "C" fn default_on_toast_dismiss(mut data: RefAny, mut info: CallbackInfo) -> Update {
    let close_node = info.get_hit_node();
    let Some(container) = info.get_parent(close_node) else {
        return Update::DoNothing;
    };

    let result = {
        let Some(mut toast) = data.downcast_mut::<ToastStateWrapper>() else {
            return Update::DoNothing;
        };
        toast.inner.visible = false;
        let inner = toast.inner;
        let toast = &mut *toast;
        match toast.on_dismiss.as_mut() {
            Some(ToastOnDismiss { callback, refany }) => (callback.cb)(refany.clone(), info, inner),
            None => Update::DoNothing,
        }
    };

    // TODO2: hides the toast by toggling `display: none` via set_css_property.
    // This follows the proven live-restyle pattern of alert/check_box (which
    // toggle display/opacity/background); the display:none relayout itself is not
    // GUI-verified in this build. (Auto-timeout dismissal is a host-driven Timer —
    // see the module-level TODO2 — and is intentionally not attempted here.)
    info.set_css_property(container, CssProperty::const_display(LayoutDisplay::None));

    result
}

impl From<Toast> for Dom {
    fn from(t: Toast) -> Self {
        t.dom()
    }
}