1use crate::{
2 px, size, Action, AnyBox, AnyDrag, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
3 Bounds, BoxShadow, Context, Corners, DevicePixels, DispatchContext, DisplayId, Edges, Effect,
4 Element, EntityId, EventEmitter, ExternalPaths, FileDropEvent, FocusEvent, FontId,
5 GlobalElementId, GlyphId, Handle, Hsla, ImageData, InputEvent, IsZero, KeyListener, KeyMatch,
6 KeyMatcher, Keystroke, LayoutId, MainThread, MainThreadOnly, Modifiers, MonochromeSprite,
7 MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas,
8 PlatformWindow, Point, PolychromeSprite, Quad, Reference, RenderGlyphParams, RenderImageParams,
9 RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size, Style, Subscription,
10 TaffyLayoutEngine, Task, Underline, UnderlineStyle, WeakHandle, WindowOptions,
11 SUBPIXEL_VARIANTS,
12};
13use anyhow::Result;
14use collections::HashMap;
15use derive_more::{Deref, DerefMut};
16use parking_lot::RwLock;
17use slotmap::SlotMap;
18use smallvec::SmallVec;
19use std::{
20 any::{Any, TypeId},
21 borrow::{Borrow, BorrowMut, Cow},
22 fmt::Debug,
23 future::Future,
24 marker::PhantomData,
25 mem,
26 sync::{
27 atomic::{AtomicUsize, Ordering::SeqCst},
28 Arc,
29 },
30};
31use util::ResultExt;
32
33#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
34pub struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
35
36#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
37pub enum DispatchPhase {
38 /// After the capture phase comes the bubble phase, in which event handlers are
39 /// invoked front to back. This is the phase you'll usually want to use for event handlers.
40 #[default]
41 Bubble,
42 /// During the initial capture phase, event handlers are invoked back to front. This phase
43 /// is used for special purposes such as clearing the "pressed" state for click events. If
44 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
45 /// outside of the immediate region may rely on detecting non-local events during this phase.
46 Capture,
47}
48
49type AnyListener = Arc<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + Send + Sync + 'static>;
50type AnyKeyListener = Arc<
51 dyn Fn(
52 &dyn Any,
53 &[&DispatchContext],
54 DispatchPhase,
55 &mut WindowContext,
56 ) -> Option<Box<dyn Action>>
57 + Send
58 + Sync
59 + 'static,
60>;
61type AnyFocusListener = Arc<dyn Fn(&FocusEvent, &mut WindowContext) + Send + Sync + 'static>;
62
63slotmap::new_key_type! { pub struct FocusId; }
64
65pub struct FocusHandle {
66 pub(crate) id: FocusId,
67 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
68}
69
70impl FocusHandle {
71 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
72 let id = handles.write().insert(AtomicUsize::new(1));
73 Self {
74 id,
75 handles: handles.clone(),
76 }
77 }
78
79 pub(crate) fn for_id(
80 id: FocusId,
81 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
82 ) -> Option<Self> {
83 let lock = handles.read();
84 let ref_count = lock.get(id)?;
85 if ref_count.load(SeqCst) == 0 {
86 None
87 } else {
88 ref_count.fetch_add(1, SeqCst);
89 Some(Self {
90 id,
91 handles: handles.clone(),
92 })
93 }
94 }
95
96 pub fn is_focused(&self, cx: &WindowContext) -> bool {
97 cx.window.focus == Some(self.id)
98 }
99
100 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
101 cx.focused()
102 .map_or(false, |focused| self.contains(&focused, cx))
103 }
104
105 pub fn within_focused(&self, cx: &WindowContext) -> bool {
106 let focused = cx.focused();
107 focused.map_or(false, |focused| focused.contains(self, cx))
108 }
109
110 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
111 let mut ancestor = Some(other.id);
112 while let Some(ancestor_id) = ancestor {
113 if self.id == ancestor_id {
114 return true;
115 } else {
116 ancestor = cx.window.focus_parents_by_child.get(&ancestor_id).copied();
117 }
118 }
119 false
120 }
121}
122
123impl Clone for FocusHandle {
124 fn clone(&self) -> Self {
125 Self::for_id(self.id, &self.handles).unwrap()
126 }
127}
128
129impl PartialEq for FocusHandle {
130 fn eq(&self, other: &Self) -> bool {
131 self.id == other.id
132 }
133}
134
135impl Eq for FocusHandle {}
136
137impl Drop for FocusHandle {
138 fn drop(&mut self) {
139 self.handles
140 .read()
141 .get(self.id)
142 .unwrap()
143 .fetch_sub(1, SeqCst);
144 }
145}
146
147pub struct Window {
148 handle: AnyWindowHandle,
149 platform_window: MainThreadOnly<Box<dyn PlatformWindow>>,
150 display_id: DisplayId,
151 sprite_atlas: Arc<dyn PlatformAtlas>,
152 rem_size: Pixels,
153 content_size: Size<Pixels>,
154 layout_engine: TaffyLayoutEngine,
155 pub(crate) root_view: Option<AnyView>,
156 pub(crate) element_id_stack: GlobalElementId,
157 prev_frame_element_states: HashMap<GlobalElementId, AnyBox>,
158 element_states: HashMap<GlobalElementId, AnyBox>,
159 prev_frame_key_matchers: HashMap<GlobalElementId, KeyMatcher>,
160 key_matchers: HashMap<GlobalElementId, KeyMatcher>,
161 z_index_stack: StackingOrder,
162 content_mask_stack: Vec<ContentMask<Pixels>>,
163 element_offset_stack: Vec<Point<Pixels>>,
164 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyListener)>>,
165 key_dispatch_stack: Vec<KeyDispatchStackFrame>,
166 freeze_key_dispatch_stack: bool,
167 focus_stack: Vec<FocusId>,
168 focus_parents_by_child: HashMap<FocusId, FocusId>,
169 pub(crate) focus_listeners: Vec<AnyFocusListener>,
170 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
171 default_prevented: bool,
172 mouse_position: Point<Pixels>,
173 scale_factor: f32,
174 pub(crate) scene_builder: SceneBuilder,
175 pub(crate) dirty: bool,
176 pub(crate) last_blur: Option<Option<FocusId>>,
177 pub(crate) focus: Option<FocusId>,
178}
179
180impl Window {
181 pub(crate) fn new(
182 handle: AnyWindowHandle,
183 options: WindowOptions,
184 cx: &mut MainThread<AppContext>,
185 ) -> Self {
186 let platform_window = cx.platform().open_window(handle, options);
187 let display_id = platform_window.display().id();
188 let sprite_atlas = platform_window.sprite_atlas();
189 let mouse_position = platform_window.mouse_position();
190 let content_size = platform_window.content_size();
191 let scale_factor = platform_window.scale_factor();
192 platform_window.on_resize(Box::new({
193 let cx = cx.to_async();
194 move |content_size, scale_factor| {
195 cx.update_window(handle, |cx| {
196 cx.window.scale_factor = scale_factor;
197 cx.window.scene_builder = SceneBuilder::new();
198 cx.window.content_size = content_size;
199 cx.window.display_id = cx
200 .window
201 .platform_window
202 .borrow_on_main_thread()
203 .display()
204 .id();
205 cx.window.dirty = true;
206 })
207 .log_err();
208 }
209 }));
210
211 platform_window.on_input({
212 let cx = cx.to_async();
213 Box::new(move |event| {
214 cx.update_window(handle, |cx| cx.dispatch_event(event))
215 .log_err()
216 .unwrap_or(true)
217 })
218 });
219
220 let platform_window = MainThreadOnly::new(Arc::new(platform_window), cx.executor.clone());
221
222 Window {
223 handle,
224 platform_window,
225 display_id,
226 sprite_atlas,
227 rem_size: px(16.),
228 content_size,
229 layout_engine: TaffyLayoutEngine::new(),
230 root_view: None,
231 element_id_stack: GlobalElementId::default(),
232 prev_frame_element_states: HashMap::default(),
233 element_states: HashMap::default(),
234 prev_frame_key_matchers: HashMap::default(),
235 key_matchers: HashMap::default(),
236 z_index_stack: StackingOrder(SmallVec::new()),
237 content_mask_stack: Vec::new(),
238 element_offset_stack: Vec::new(),
239 mouse_listeners: HashMap::default(),
240 key_dispatch_stack: Vec::new(),
241 freeze_key_dispatch_stack: false,
242 focus_stack: Vec::new(),
243 focus_parents_by_child: HashMap::default(),
244 focus_listeners: Vec::new(),
245 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
246 default_prevented: true,
247 mouse_position,
248 scale_factor,
249 scene_builder: SceneBuilder::new(),
250 dirty: true,
251 last_blur: None,
252 focus: None,
253 }
254 }
255}
256
257enum KeyDispatchStackFrame {
258 Listener {
259 event_type: TypeId,
260 listener: AnyKeyListener,
261 },
262 Context(DispatchContext),
263}
264
265#[derive(Clone, Debug, Default, PartialEq, Eq)]
266#[repr(C)]
267pub struct ContentMask<P: Clone + Default + Debug> {
268 pub bounds: Bounds<P>,
269}
270
271impl ContentMask<Pixels> {
272 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
273 ContentMask {
274 bounds: self.bounds.scale(factor),
275 }
276 }
277
278 pub fn intersect(&self, other: &Self) -> Self {
279 let bounds = self.bounds.intersect(&other.bounds);
280 ContentMask { bounds }
281 }
282}
283
284pub struct WindowContext<'a, 'w> {
285 app: Reference<'a, AppContext>,
286 pub(crate) window: Reference<'w, Window>,
287}
288
289impl<'a, 'w> WindowContext<'a, 'w> {
290 pub(crate) fn immutable(app: &'a AppContext, window: &'w Window) -> Self {
291 Self {
292 app: Reference::Immutable(app),
293 window: Reference::Immutable(window),
294 }
295 }
296
297 pub(crate) fn mutable(app: &'a mut AppContext, window: &'w mut Window) -> Self {
298 Self {
299 app: Reference::Mutable(app),
300 window: Reference::Mutable(window),
301 }
302 }
303
304 pub fn window_handle(&self) -> AnyWindowHandle {
305 self.window.handle
306 }
307
308 pub fn notify(&mut self) {
309 self.window.dirty = true;
310 }
311
312 pub fn focus_handle(&mut self) -> FocusHandle {
313 FocusHandle::new(&self.window.focus_handles)
314 }
315
316 pub fn focused(&self) -> Option<FocusHandle> {
317 self.window
318 .focus
319 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
320 }
321
322 pub fn focus(&mut self, handle: &FocusHandle) {
323 if self.window.last_blur.is_none() {
324 self.window.last_blur = Some(self.window.focus);
325 }
326
327 let window_id = self.window.handle.id;
328 self.window.focus = Some(handle.id);
329 self.app.push_effect(Effect::FocusChanged {
330 window_id,
331 focused: Some(handle.id),
332 });
333 self.notify();
334 }
335
336 pub fn blur(&mut self) {
337 if self.window.last_blur.is_none() {
338 self.window.last_blur = Some(self.window.focus);
339 }
340
341 let window_id = self.window.handle.id;
342 self.window.focus = None;
343 self.app.push_effect(Effect::FocusChanged {
344 window_id,
345 focused: None,
346 });
347 self.notify();
348 }
349
350 pub fn run_on_main<R>(
351 &mut self,
352 f: impl FnOnce(&mut MainThread<WindowContext<'_, '_>>) -> R + Send + 'static,
353 ) -> Task<Result<R>>
354 where
355 R: Send + 'static,
356 {
357 if self.executor.is_main_thread() {
358 Task::ready(Ok(f(unsafe {
359 mem::transmute::<&mut Self, &mut MainThread<Self>>(self)
360 })))
361 } else {
362 let id = self.window.handle.id;
363 self.app.run_on_main(move |cx| cx.update_window(id, f))
364 }
365 }
366
367 pub fn to_async(&self) -> AsyncWindowContext {
368 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
369 }
370
371 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut WindowContext) + Send + 'static) {
372 let f = Box::new(f);
373 let display_id = self.window.display_id;
374 self.run_on_main(move |cx| {
375 if let Some(callbacks) = cx.next_frame_callbacks.get_mut(&display_id) {
376 callbacks.push(f);
377 // If there was already a callback, it means that we already scheduled a frame.
378 if callbacks.len() > 1 {
379 return;
380 }
381 } else {
382 let async_cx = cx.to_async();
383 cx.next_frame_callbacks.insert(display_id, vec![f]);
384 cx.platform().set_display_link_output_callback(
385 display_id,
386 Box::new(move |_current_time, _output_time| {
387 let _ = async_cx.update(|cx| {
388 let callbacks = cx
389 .next_frame_callbacks
390 .get_mut(&display_id)
391 .unwrap()
392 .drain(..)
393 .collect::<Vec<_>>();
394 for callback in callbacks {
395 callback(cx);
396 }
397
398 cx.run_on_main(move |cx| {
399 if cx.next_frame_callbacks.get(&display_id).unwrap().is_empty() {
400 cx.platform().stop_display_link(display_id);
401 }
402 })
403 .detach();
404 });
405 }),
406 );
407 }
408
409 cx.platform().start_display_link(display_id);
410 })
411 .detach();
412 }
413
414 pub fn spawn<Fut, R>(
415 &mut self,
416 f: impl FnOnce(AnyWindowHandle, AsyncWindowContext) -> Fut + Send + 'static,
417 ) -> Task<R>
418 where
419 R: Send + 'static,
420 Fut: Future<Output = R> + Send + 'static,
421 {
422 let window = self.window.handle;
423 self.app.spawn(move |app| {
424 let cx = AsyncWindowContext::new(app, window);
425 let future = f(window, cx);
426 async move { future.await }
427 })
428 }
429
430 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
431 where
432 G: 'static,
433 {
434 let mut global = self.app.lease_global::<G>();
435 let result = f(&mut global, self);
436 self.app.end_global_lease(global);
437 result
438 }
439
440 pub fn request_layout(
441 &mut self,
442 style: &Style,
443 children: impl IntoIterator<Item = LayoutId>,
444 ) -> LayoutId {
445 self.app.layout_id_buffer.clear();
446 self.app.layout_id_buffer.extend(children.into_iter());
447 let rem_size = self.rem_size();
448
449 self.window
450 .layout_engine
451 .request_layout(style, rem_size, &self.app.layout_id_buffer)
452 }
453
454 pub fn request_measured_layout<
455 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
456 >(
457 &mut self,
458 style: Style,
459 rem_size: Pixels,
460 measure: F,
461 ) -> LayoutId {
462 self.window
463 .layout_engine
464 .request_measured_layout(style, rem_size, measure)
465 }
466
467 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
468 let mut bounds = self
469 .window
470 .layout_engine
471 .layout_bounds(layout_id)
472 .map(Into::into);
473 bounds.origin += self.element_offset();
474 bounds
475 }
476
477 pub fn scale_factor(&self) -> f32 {
478 self.window.scale_factor
479 }
480
481 pub fn rem_size(&self) -> Pixels {
482 self.window.rem_size
483 }
484
485 pub fn line_height(&self) -> Pixels {
486 let rem_size = self.rem_size();
487 let text_style = self.text_style();
488 text_style
489 .line_height
490 .to_pixels(text_style.font_size.into(), rem_size)
491 }
492
493 pub fn prevent_default(&mut self) {
494 self.window.default_prevented = true;
495 }
496
497 pub fn default_prevented(&self) -> bool {
498 self.window.default_prevented
499 }
500
501 pub fn on_mouse_event<Event: 'static>(
502 &mut self,
503 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + Send + Sync + 'static,
504 ) {
505 let order = self.window.z_index_stack.clone();
506 self.window
507 .mouse_listeners
508 .entry(TypeId::of::<Event>())
509 .or_default()
510 .push((
511 order,
512 Arc::new(move |event: &dyn Any, phase, cx| {
513 handler(event.downcast_ref().unwrap(), phase, cx)
514 }),
515 ))
516 }
517
518 pub fn mouse_position(&self) -> Point<Pixels> {
519 self.window.mouse_position
520 }
521
522 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
523 self.window.z_index_stack.push(order);
524 let result = f(self);
525 self.window.z_index_stack.pop();
526 result
527 }
528
529 pub fn paint_shadows(
530 &mut self,
531 bounds: Bounds<Pixels>,
532 corner_radii: Corners<Pixels>,
533 shadows: &[BoxShadow],
534 ) {
535 let scale_factor = self.scale_factor();
536 let content_mask = self.content_mask();
537 let window = &mut *self.window;
538 for shadow in shadows {
539 let mut shadow_bounds = bounds;
540 shadow_bounds.origin += shadow.offset;
541 shadow_bounds.dilate(shadow.spread_radius);
542 window.scene_builder.insert(
543 &window.z_index_stack,
544 Shadow {
545 order: 0,
546 bounds: shadow_bounds.scale(scale_factor),
547 content_mask: content_mask.scale(scale_factor),
548 corner_radii: corner_radii.scale(scale_factor),
549 color: shadow.color,
550 blur_radius: shadow.blur_radius.scale(scale_factor),
551 },
552 );
553 }
554 }
555
556 pub fn paint_quad(
557 &mut self,
558 bounds: Bounds<Pixels>,
559 corner_radii: Corners<Pixels>,
560 background: impl Into<Hsla>,
561 border_widths: Edges<Pixels>,
562 border_color: impl Into<Hsla>,
563 ) {
564 let scale_factor = self.scale_factor();
565 let content_mask = self.content_mask();
566
567 let window = &mut *self.window;
568 window.scene_builder.insert(
569 &window.z_index_stack,
570 Quad {
571 order: 0,
572 bounds: bounds.scale(scale_factor),
573 content_mask: content_mask.scale(scale_factor),
574 background: background.into(),
575 border_color: border_color.into(),
576 corner_radii: corner_radii.scale(scale_factor),
577 border_widths: border_widths.scale(scale_factor),
578 },
579 );
580 }
581
582 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
583 let scale_factor = self.scale_factor();
584 let content_mask = self.content_mask();
585 path.content_mask = content_mask;
586 path.color = color.into();
587 let window = &mut *self.window;
588 window
589 .scene_builder
590 .insert(&window.z_index_stack, path.scale(scale_factor));
591 }
592
593 pub fn paint_underline(
594 &mut self,
595 origin: Point<Pixels>,
596 width: Pixels,
597 style: &UnderlineStyle,
598 ) -> Result<()> {
599 let scale_factor = self.scale_factor();
600 let height = if style.wavy {
601 style.thickness * 3.
602 } else {
603 style.thickness
604 };
605 let bounds = Bounds {
606 origin,
607 size: size(width, height),
608 };
609 let content_mask = self.content_mask();
610 let window = &mut *self.window;
611 window.scene_builder.insert(
612 &window.z_index_stack,
613 Underline {
614 order: 0,
615 bounds: bounds.scale(scale_factor),
616 content_mask: content_mask.scale(scale_factor),
617 thickness: style.thickness.scale(scale_factor),
618 color: style.color.unwrap_or_default(),
619 wavy: style.wavy,
620 },
621 );
622 Ok(())
623 }
624
625 pub fn paint_glyph(
626 &mut self,
627 origin: Point<Pixels>,
628 font_id: FontId,
629 glyph_id: GlyphId,
630 font_size: Pixels,
631 color: Hsla,
632 ) -> Result<()> {
633 let scale_factor = self.scale_factor();
634 let glyph_origin = origin.scale(scale_factor);
635 let subpixel_variant = Point {
636 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
637 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
638 };
639 let params = RenderGlyphParams {
640 font_id,
641 glyph_id,
642 font_size,
643 subpixel_variant,
644 scale_factor,
645 is_emoji: false,
646 };
647
648 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
649 if !raster_bounds.is_zero() {
650 let tile =
651 self.window
652 .sprite_atlas
653 .get_or_insert_with(¶ms.clone().into(), &mut || {
654 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
655 Ok((size, Cow::Owned(bytes)))
656 })?;
657 let bounds = Bounds {
658 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
659 size: tile.bounds.size.map(Into::into),
660 };
661 let content_mask = self.content_mask().scale(scale_factor);
662 let window = &mut *self.window;
663 window.scene_builder.insert(
664 &window.z_index_stack,
665 MonochromeSprite {
666 order: 0,
667 bounds,
668 content_mask,
669 color,
670 tile,
671 },
672 );
673 }
674 Ok(())
675 }
676
677 pub fn paint_emoji(
678 &mut self,
679 origin: Point<Pixels>,
680 font_id: FontId,
681 glyph_id: GlyphId,
682 font_size: Pixels,
683 ) -> Result<()> {
684 let scale_factor = self.scale_factor();
685 let glyph_origin = origin.scale(scale_factor);
686 let params = RenderGlyphParams {
687 font_id,
688 glyph_id,
689 font_size,
690 // We don't render emojis with subpixel variants.
691 subpixel_variant: Default::default(),
692 scale_factor,
693 is_emoji: true,
694 };
695
696 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
697 if !raster_bounds.is_zero() {
698 let tile =
699 self.window
700 .sprite_atlas
701 .get_or_insert_with(¶ms.clone().into(), &mut || {
702 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
703 Ok((size, Cow::Owned(bytes)))
704 })?;
705 let bounds = Bounds {
706 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
707 size: tile.bounds.size.map(Into::into),
708 };
709 let content_mask = self.content_mask().scale(scale_factor);
710 let window = &mut *self.window;
711
712 window.scene_builder.insert(
713 &window.z_index_stack,
714 PolychromeSprite {
715 order: 0,
716 bounds,
717 corner_radii: Default::default(),
718 content_mask,
719 tile,
720 grayscale: false,
721 },
722 );
723 }
724 Ok(())
725 }
726
727 pub fn paint_svg(
728 &mut self,
729 bounds: Bounds<Pixels>,
730 path: SharedString,
731 color: Hsla,
732 ) -> Result<()> {
733 let scale_factor = self.scale_factor();
734 let bounds = bounds.scale(scale_factor);
735 // Render the SVG at twice the size to get a higher quality result.
736 let params = RenderSvgParams {
737 path,
738 size: bounds
739 .size
740 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
741 };
742
743 let tile =
744 self.window
745 .sprite_atlas
746 .get_or_insert_with(¶ms.clone().into(), &mut || {
747 let bytes = self.svg_renderer.render(¶ms)?;
748 Ok((params.size, Cow::Owned(bytes)))
749 })?;
750 let content_mask = self.content_mask().scale(scale_factor);
751
752 let window = &mut *self.window;
753 window.scene_builder.insert(
754 &window.z_index_stack,
755 MonochromeSprite {
756 order: 0,
757 bounds,
758 content_mask,
759 color,
760 tile,
761 },
762 );
763
764 Ok(())
765 }
766
767 pub fn paint_image(
768 &mut self,
769 bounds: Bounds<Pixels>,
770 corner_radii: Corners<Pixels>,
771 data: Arc<ImageData>,
772 grayscale: bool,
773 ) -> Result<()> {
774 let scale_factor = self.scale_factor();
775 let bounds = bounds.scale(scale_factor);
776 let params = RenderImageParams { image_id: data.id };
777
778 let tile = self
779 .window
780 .sprite_atlas
781 .get_or_insert_with(¶ms.clone().into(), &mut || {
782 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
783 })?;
784 let content_mask = self.content_mask().scale(scale_factor);
785 let corner_radii = corner_radii.scale(scale_factor);
786
787 let window = &mut *self.window;
788 window.scene_builder.insert(
789 &window.z_index_stack,
790 PolychromeSprite {
791 order: 0,
792 bounds,
793 content_mask,
794 corner_radii,
795 tile,
796 grayscale,
797 },
798 );
799 Ok(())
800 }
801
802 pub(crate) fn draw(&mut self) {
803 let unit_entity = self.unit_entity.clone();
804 self.update_entity(&unit_entity, |view, cx| {
805 cx.start_frame();
806
807 let mut root_view = cx.window.root_view.take().unwrap();
808
809 cx.stack(0, |cx| {
810 let available_space = cx.window.content_size.map(Into::into);
811 draw_any_view(&mut root_view, available_space, cx);
812 });
813
814 if let Some(mut active_drag) = cx.active_drag.take() {
815 cx.stack(1, |cx| {
816 let offset = cx.mouse_position() - active_drag.cursor_offset;
817 cx.with_element_offset(Some(offset), |cx| {
818 let available_space =
819 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
820 if let Some(drag_handle_view) = &mut active_drag.drag_handle_view {
821 draw_any_view(drag_handle_view, available_space, cx);
822 }
823 cx.active_drag = Some(active_drag);
824 });
825 });
826 }
827
828 cx.window.root_view = Some(root_view);
829 let scene = cx.window.scene_builder.build();
830
831 cx.run_on_main(view, |_, cx| {
832 cx.window
833 .platform_window
834 .borrow_on_main_thread()
835 .draw(scene);
836 cx.window.dirty = false;
837 })
838 .detach();
839 });
840
841 fn draw_any_view(
842 view: &mut AnyView,
843 available_space: Size<AvailableSpace>,
844 cx: &mut ViewContext<()>,
845 ) {
846 cx.with_optional_element_state(view.id(), |element_state, cx| {
847 let mut element_state = view.initialize(&mut (), element_state, cx);
848 let layout_id = view.layout(&mut (), &mut element_state, cx);
849 cx.window
850 .layout_engine
851 .compute_layout(layout_id, available_space);
852 let bounds = cx.window.layout_engine.layout_bounds(layout_id);
853 view.paint(bounds, &mut (), &mut element_state, cx);
854 ((), element_state)
855 });
856 }
857 }
858
859 fn start_frame(&mut self) {
860 self.text_system().start_frame();
861
862 let window = &mut *self.window;
863
864 // Move the current frame element states to the previous frame.
865 // The new empty element states map will be populated for any element states we
866 // reference during the upcoming frame.
867 mem::swap(
868 &mut window.element_states,
869 &mut window.prev_frame_element_states,
870 );
871 window.element_states.clear();
872
873 // Make the current key matchers the previous, and then clear the current.
874 // An empty key matcher map will be created for every identified element in the
875 // upcoming frame.
876 mem::swap(
877 &mut window.key_matchers,
878 &mut window.prev_frame_key_matchers,
879 );
880 window.key_matchers.clear();
881
882 // Clear mouse event listeners, because elements add new element listeners
883 // when the upcoming frame is painted.
884 window.mouse_listeners.values_mut().for_each(Vec::clear);
885
886 // Clear focus state, because we determine what is focused when the new elements
887 // in the upcoming frame are initialized.
888 window.focus_listeners.clear();
889 window.key_dispatch_stack.clear();
890 window.focus_parents_by_child.clear();
891 window.freeze_key_dispatch_stack = false;
892 }
893
894 fn dispatch_event(&mut self, event: InputEvent) -> bool {
895 let event = match event {
896 InputEvent::MouseMove(mouse_move) => {
897 self.window.mouse_position = mouse_move.position;
898 InputEvent::MouseMove(mouse_move)
899 }
900 InputEvent::FileDrop(file_drop) => match file_drop {
901 FileDropEvent::Entered { position, files } => {
902 self.active_drag.get_or_insert_with(|| AnyDrag {
903 drag_handle_view: None,
904 cursor_offset: position,
905 state: Box::new(files),
906 state_type: TypeId::of::<ExternalPaths>(),
907 });
908 InputEvent::MouseDown(MouseDownEvent {
909 position,
910 button: MouseButton::Left,
911 click_count: 1,
912 modifiers: Modifiers::default(),
913 })
914 }
915 FileDropEvent::Pending { position } => InputEvent::MouseMove(MouseMoveEvent {
916 position,
917 pressed_button: Some(MouseButton::Left),
918 modifiers: Modifiers::default(),
919 }),
920 FileDropEvent::Submit { position } => InputEvent::MouseUp(MouseUpEvent {
921 button: MouseButton::Left,
922 position,
923 modifiers: Modifiers::default(),
924 click_count: 1,
925 }),
926 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
927 button: MouseButton::Left,
928 position: Point::default(),
929 modifiers: Modifiers::default(),
930 click_count: 1,
931 }),
932 },
933 _ => event,
934 };
935
936 if let Some(any_mouse_event) = event.mouse_event() {
937 // Handlers may set this to false by calling `stop_propagation`
938 self.app.propagate_event = true;
939 self.window.default_prevented = false;
940
941 if let Some(mut handlers) = self
942 .window
943 .mouse_listeners
944 .remove(&any_mouse_event.type_id())
945 {
946 // Because handlers may add other handlers, we sort every time.
947 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
948
949 // Capture phase, events bubble from back to front. Handlers for this phase are used for
950 // special purposes, such as detecting events outside of a given Bounds.
951 for (_, handler) in &handlers {
952 handler(any_mouse_event, DispatchPhase::Capture, self);
953 if !self.app.propagate_event {
954 break;
955 }
956 }
957
958 // Bubble phase, where most normal handlers do their work.
959 if self.app.propagate_event {
960 for (_, handler) in handlers.iter().rev() {
961 handler(any_mouse_event, DispatchPhase::Bubble, self);
962 if !self.app.propagate_event {
963 break;
964 }
965 }
966 }
967
968 if self.app.propagate_event
969 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
970 {
971 self.active_drag = None;
972 }
973
974 // Just in case any handlers added new handlers, which is weird, but possible.
975 handlers.extend(
976 self.window
977 .mouse_listeners
978 .get_mut(&any_mouse_event.type_id())
979 .into_iter()
980 .flat_map(|handlers| handlers.drain(..)),
981 );
982 self.window
983 .mouse_listeners
984 .insert(any_mouse_event.type_id(), handlers);
985 }
986 } else if let Some(any_key_event) = event.keyboard_event() {
987 let key_dispatch_stack = mem::take(&mut self.window.key_dispatch_stack);
988 let key_event_type = any_key_event.type_id();
989 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
990
991 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
992 match frame {
993 KeyDispatchStackFrame::Listener {
994 event_type,
995 listener,
996 } => {
997 if key_event_type == *event_type {
998 if let Some(action) = listener(
999 any_key_event,
1000 &context_stack,
1001 DispatchPhase::Capture,
1002 self,
1003 ) {
1004 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1005 }
1006 if !self.app.propagate_event {
1007 break;
1008 }
1009 }
1010 }
1011 KeyDispatchStackFrame::Context(context) => {
1012 context_stack.push(&context);
1013 }
1014 }
1015 }
1016
1017 if self.app.propagate_event {
1018 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
1019 match frame {
1020 KeyDispatchStackFrame::Listener {
1021 event_type,
1022 listener,
1023 } => {
1024 if key_event_type == *event_type {
1025 if let Some(action) = listener(
1026 any_key_event,
1027 &context_stack,
1028 DispatchPhase::Bubble,
1029 self,
1030 ) {
1031 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1032 }
1033
1034 if !self.app.propagate_event {
1035 break;
1036 }
1037 }
1038 }
1039 KeyDispatchStackFrame::Context(_) => {
1040 context_stack.pop();
1041 }
1042 }
1043 }
1044 }
1045
1046 drop(context_stack);
1047 self.window.key_dispatch_stack = key_dispatch_stack;
1048 }
1049
1050 true
1051 }
1052
1053 pub fn match_keystroke(
1054 &mut self,
1055 element_id: &GlobalElementId,
1056 keystroke: &Keystroke,
1057 context_stack: &[&DispatchContext],
1058 ) -> KeyMatch {
1059 let key_match = self
1060 .window
1061 .key_matchers
1062 .get_mut(element_id)
1063 .unwrap()
1064 .match_keystroke(keystroke, context_stack);
1065
1066 if key_match.is_some() {
1067 for matcher in self.window.key_matchers.values_mut() {
1068 matcher.clear_pending();
1069 }
1070 }
1071
1072 key_match
1073 }
1074
1075 pub fn observe_global<G: 'static>(
1076 &mut self,
1077 f: impl Fn(&mut WindowContext<'_, '_>) + Send + Sync + 'static,
1078 ) -> Subscription {
1079 let window_id = self.window.handle.id;
1080 self.global_observers.insert(
1081 TypeId::of::<G>(),
1082 Box::new(move |cx| cx.update_window(window_id, |cx| f(cx)).is_ok()),
1083 )
1084 }
1085
1086 fn dispatch_action(
1087 &mut self,
1088 action: Box<dyn Action>,
1089 dispatch_stack: &[KeyDispatchStackFrame],
1090 ) {
1091 let action_type = action.as_any().type_id();
1092
1093 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1094 for listener in &global_listeners {
1095 listener(action.as_ref(), DispatchPhase::Capture, self);
1096 if !self.app.propagate_event {
1097 break;
1098 }
1099 }
1100 global_listeners.extend(
1101 self.global_action_listeners
1102 .remove(&action_type)
1103 .unwrap_or_default(),
1104 );
1105 self.global_action_listeners
1106 .insert(action_type, global_listeners);
1107 }
1108
1109 if self.app.propagate_event {
1110 for stack_frame in dispatch_stack {
1111 if let KeyDispatchStackFrame::Listener {
1112 event_type,
1113 listener,
1114 } = stack_frame
1115 {
1116 if action_type == *event_type {
1117 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1118 if !self.app.propagate_event {
1119 break;
1120 }
1121 }
1122 }
1123 }
1124 }
1125
1126 if self.app.propagate_event {
1127 for stack_frame in dispatch_stack.iter().rev() {
1128 if let KeyDispatchStackFrame::Listener {
1129 event_type,
1130 listener,
1131 } = stack_frame
1132 {
1133 if action_type == *event_type {
1134 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1135 if !self.app.propagate_event {
1136 break;
1137 }
1138 }
1139 }
1140 }
1141 }
1142
1143 if self.app.propagate_event {
1144 if let Some(mut global_listeners) =
1145 self.app.global_action_listeners.remove(&action_type)
1146 {
1147 for listener in global_listeners.iter().rev() {
1148 listener(action.as_ref(), DispatchPhase::Bubble, self);
1149 if !self.app.propagate_event {
1150 break;
1151 }
1152 }
1153 global_listeners.extend(
1154 self.global_action_listeners
1155 .remove(&action_type)
1156 .unwrap_or_default(),
1157 );
1158 self.global_action_listeners
1159 .insert(action_type, global_listeners);
1160 }
1161 }
1162 }
1163}
1164
1165impl Context for WindowContext<'_, '_> {
1166 type EntityContext<'a, 'w, T> = ViewContext<'a, 'w, T>;
1167 type Result<T> = T;
1168
1169 fn entity<T>(
1170 &mut self,
1171 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
1172 ) -> Handle<T>
1173 where
1174 T: Any + Send + Sync,
1175 {
1176 let slot = self.app.entities.reserve();
1177 let entity = build_entity(&mut ViewContext::mutable(
1178 &mut *self.app,
1179 &mut self.window,
1180 slot.downgrade(),
1181 ));
1182 self.entities.insert(slot, entity)
1183 }
1184
1185 fn update_entity<T: 'static, R>(
1186 &mut self,
1187 handle: &Handle<T>,
1188 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
1189 ) -> R {
1190 let mut entity = self.entities.lease(handle);
1191 let result = update(
1192 &mut *entity,
1193 &mut ViewContext::mutable(&mut *self.app, &mut *self.window, handle.downgrade()),
1194 );
1195 self.entities.end_lease(entity);
1196 result
1197 }
1198}
1199
1200impl<'a, 'w> std::ops::Deref for WindowContext<'a, 'w> {
1201 type Target = AppContext;
1202
1203 fn deref(&self) -> &Self::Target {
1204 &self.app
1205 }
1206}
1207
1208impl<'a, 'w> std::ops::DerefMut for WindowContext<'a, 'w> {
1209 fn deref_mut(&mut self) -> &mut Self::Target {
1210 &mut self.app
1211 }
1212}
1213
1214impl<'a, 'w> Borrow<AppContext> for WindowContext<'a, 'w> {
1215 fn borrow(&self) -> &AppContext {
1216 &self.app
1217 }
1218}
1219
1220impl<'a, 'w> BorrowMut<AppContext> for WindowContext<'a, 'w> {
1221 fn borrow_mut(&mut self) -> &mut AppContext {
1222 &mut self.app
1223 }
1224}
1225
1226pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1227 fn app_mut(&mut self) -> &mut AppContext {
1228 self.borrow_mut()
1229 }
1230
1231 fn window(&self) -> &Window {
1232 self.borrow()
1233 }
1234
1235 fn window_mut(&mut self) -> &mut Window {
1236 self.borrow_mut()
1237 }
1238
1239 fn with_element_id<R>(
1240 &mut self,
1241 id: impl Into<ElementId>,
1242 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1243 ) -> R {
1244 let keymap = self.app_mut().keymap.clone();
1245 let window = self.window_mut();
1246 window.element_id_stack.push(id.into());
1247 let global_id = window.element_id_stack.clone();
1248
1249 if window.key_matchers.get(&global_id).is_none() {
1250 window.key_matchers.insert(
1251 global_id.clone(),
1252 window
1253 .prev_frame_key_matchers
1254 .remove(&global_id)
1255 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1256 );
1257 }
1258
1259 let result = f(global_id, self);
1260 let window: &mut Window = self.borrow_mut();
1261 window.element_id_stack.pop();
1262 result
1263 }
1264
1265 fn with_content_mask<R>(
1266 &mut self,
1267 mask: ContentMask<Pixels>,
1268 f: impl FnOnce(&mut Self) -> R,
1269 ) -> R {
1270 let mask = mask.intersect(&self.content_mask());
1271 self.window_mut().content_mask_stack.push(mask);
1272 let result = f(self);
1273 self.window_mut().content_mask_stack.pop();
1274 result
1275 }
1276
1277 fn with_element_offset<R>(
1278 &mut self,
1279 offset: Option<Point<Pixels>>,
1280 f: impl FnOnce(&mut Self) -> R,
1281 ) -> R {
1282 let Some(offset) = offset else {
1283 return f(self);
1284 };
1285
1286 let offset = self.element_offset() + offset;
1287 self.window_mut().element_offset_stack.push(offset);
1288 let result = f(self);
1289 self.window_mut().element_offset_stack.pop();
1290 result
1291 }
1292
1293 fn element_offset(&self) -> Point<Pixels> {
1294 self.window()
1295 .element_offset_stack
1296 .last()
1297 .copied()
1298 .unwrap_or_default()
1299 }
1300
1301 fn with_element_state<S, R>(
1302 &mut self,
1303 id: ElementId,
1304 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1305 ) -> R
1306 where
1307 S: Any + Send + Sync,
1308 {
1309 self.with_element_id(id, |global_id, cx| {
1310 if let Some(any) = cx
1311 .window_mut()
1312 .element_states
1313 .remove(&global_id)
1314 .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
1315 {
1316 // Using the extra inner option to avoid needing to reallocate a new box.
1317 let mut state_box = any
1318 .downcast::<Option<S>>()
1319 .expect("invalid element state type for id");
1320 let state = state_box
1321 .take()
1322 .expect("element state is already on the stack");
1323 let (result, state) = f(Some(state), cx);
1324 state_box.replace(state);
1325 cx.window_mut().element_states.insert(global_id, state_box);
1326 result
1327 } else {
1328 let (result, state) = f(None, cx);
1329 cx.window_mut()
1330 .element_states
1331 .insert(global_id, Box::new(Some(state)));
1332 result
1333 }
1334 })
1335 }
1336
1337 fn with_optional_element_state<S, R>(
1338 &mut self,
1339 element_id: Option<ElementId>,
1340 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1341 ) -> R
1342 where
1343 S: Any + Send + Sync,
1344 {
1345 if let Some(element_id) = element_id {
1346 self.with_element_state(element_id, f)
1347 } else {
1348 f(None, self).0
1349 }
1350 }
1351
1352 fn content_mask(&self) -> ContentMask<Pixels> {
1353 self.window()
1354 .content_mask_stack
1355 .last()
1356 .cloned()
1357 .unwrap_or_else(|| ContentMask {
1358 bounds: Bounds {
1359 origin: Point::default(),
1360 size: self.window().content_size,
1361 },
1362 })
1363 }
1364
1365 fn rem_size(&self) -> Pixels {
1366 self.window().rem_size
1367 }
1368}
1369
1370impl Borrow<Window> for WindowContext<'_, '_> {
1371 fn borrow(&self) -> &Window {
1372 &self.window
1373 }
1374}
1375
1376impl BorrowMut<Window> for WindowContext<'_, '_> {
1377 fn borrow_mut(&mut self) -> &mut Window {
1378 &mut self.window
1379 }
1380}
1381
1382impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1383
1384pub struct ViewContext<'a, 'w, V> {
1385 window_cx: WindowContext<'a, 'w>,
1386 view_state: WeakHandle<V>,
1387}
1388
1389impl<V> Borrow<AppContext> for ViewContext<'_, '_, V> {
1390 fn borrow(&self) -> &AppContext {
1391 &*self.window_cx.app
1392 }
1393}
1394
1395impl<V> BorrowMut<AppContext> for ViewContext<'_, '_, V> {
1396 fn borrow_mut(&mut self) -> &mut AppContext {
1397 &mut *self.window_cx.app
1398 }
1399}
1400
1401impl<V> Borrow<Window> for ViewContext<'_, '_, V> {
1402 fn borrow(&self) -> &Window {
1403 &*self.window_cx.window
1404 }
1405}
1406
1407impl<V> BorrowMut<Window> for ViewContext<'_, '_, V> {
1408 fn borrow_mut(&mut self) -> &mut Window {
1409 &mut *self.window_cx.window
1410 }
1411}
1412
1413impl<'a, 'w, V: 'static> ViewContext<'a, 'w, V> {
1414 fn mutable(app: &'a mut AppContext, window: &'w mut Window, view_state: WeakHandle<V>) -> Self {
1415 Self {
1416 window_cx: WindowContext::mutable(app, window),
1417 view_state,
1418 }
1419 }
1420
1421 pub fn handle(&self) -> WeakHandle<V> {
1422 self.view_state.clone()
1423 }
1424
1425 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1426 self.window.z_index_stack.push(order);
1427 let result = f(self);
1428 self.window.z_index_stack.pop();
1429 result
1430 }
1431
1432 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + Send + 'static)
1433 where
1434 V: Any + Send + Sync,
1435 {
1436 let entity = self.handle();
1437 self.window_cx.on_next_frame(move |cx| {
1438 entity.update(cx, f).ok();
1439 });
1440 }
1441
1442 pub fn observe<E>(
1443 &mut self,
1444 handle: &Handle<E>,
1445 mut on_notify: impl FnMut(&mut V, Handle<E>, &mut ViewContext<'_, '_, V>)
1446 + Send
1447 + Sync
1448 + 'static,
1449 ) -> Subscription
1450 where
1451 E: 'static,
1452 V: Any + Send + Sync,
1453 {
1454 let this = self.handle();
1455 let handle = handle.downgrade();
1456 let window_handle = self.window.handle;
1457 self.app.observers.insert(
1458 handle.entity_id,
1459 Box::new(move |cx| {
1460 cx.update_window(window_handle.id, |cx| {
1461 if let Some(handle) = handle.upgrade() {
1462 this.update(cx, |this, cx| on_notify(this, handle, cx))
1463 .is_ok()
1464 } else {
1465 false
1466 }
1467 })
1468 .unwrap_or(false)
1469 }),
1470 )
1471 }
1472
1473 pub fn subscribe<E: EventEmitter>(
1474 &mut self,
1475 handle: &Handle<E>,
1476 mut on_event: impl FnMut(&mut V, Handle<E>, &E::Event, &mut ViewContext<'_, '_, V>)
1477 + Send
1478 + Sync
1479 + 'static,
1480 ) -> Subscription {
1481 let this = self.handle();
1482 let handle = handle.downgrade();
1483 let window_handle = self.window.handle;
1484 self.app.event_listeners.insert(
1485 handle.entity_id,
1486 Box::new(move |event, cx| {
1487 cx.update_window(window_handle.id, |cx| {
1488 if let Some(handle) = handle.upgrade() {
1489 let event = event.downcast_ref().expect("invalid event type");
1490 this.update(cx, |this, cx| on_event(this, handle, event, cx))
1491 .is_ok()
1492 } else {
1493 false
1494 }
1495 })
1496 .unwrap_or(false)
1497 }),
1498 )
1499 }
1500
1501 pub fn on_release(
1502 &mut self,
1503 mut on_release: impl FnMut(&mut V, &mut WindowContext) + Send + Sync + 'static,
1504 ) -> Subscription {
1505 let window_handle = self.window.handle;
1506 self.app.release_listeners.insert(
1507 self.view_state.entity_id,
1508 Box::new(move |this, cx| {
1509 let this = this.downcast_mut().expect("invalid entity type");
1510 // todo!("are we okay with silently swallowing the error?")
1511 let _ = cx.update_window(window_handle.id, |cx| on_release(this, cx));
1512 }),
1513 )
1514 }
1515
1516 pub fn observe_release<T: 'static>(
1517 &mut self,
1518 handle: &Handle<T>,
1519 mut on_release: impl FnMut(&mut V, &mut T, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1520 ) -> Subscription {
1521 let this = self.handle();
1522 let window_handle = self.window.handle;
1523 self.app.observe_release(handle, move |entity, cx| {
1524 let _ = cx.update_window(window_handle.id, |cx| {
1525 this.update(cx, |this, cx| on_release(this, entity, cx))
1526 });
1527 })
1528 }
1529
1530 pub fn notify(&mut self) {
1531 self.window_cx.notify();
1532 self.window_cx.app.push_effect(Effect::Notify {
1533 emitter: self.view_state.entity_id,
1534 });
1535 }
1536
1537 pub fn on_focus_changed(
1538 &mut self,
1539 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + Send + Sync + 'static,
1540 ) {
1541 let handle = self.handle();
1542 self.window.focus_listeners.push(Arc::new(move |event, cx| {
1543 handle
1544 .update(cx, |view, cx| listener(view, event, cx))
1545 .log_err();
1546 }));
1547 }
1548
1549 pub fn with_key_listeners<R>(
1550 &mut self,
1551 key_listeners: &[(TypeId, KeyListener<V>)],
1552 f: impl FnOnce(&mut Self) -> R,
1553 ) -> R {
1554 if !self.window.freeze_key_dispatch_stack {
1555 for (event_type, listener) in key_listeners.iter().cloned() {
1556 let handle = self.handle();
1557 let listener = Arc::new(
1558 move |event: &dyn Any,
1559 context_stack: &[&DispatchContext],
1560 phase: DispatchPhase,
1561 cx: &mut WindowContext<'_, '_>| {
1562 handle
1563 .update(cx, |view, cx| {
1564 listener(view, event, context_stack, phase, cx)
1565 })
1566 .log_err()
1567 .flatten()
1568 },
1569 );
1570 self.window
1571 .key_dispatch_stack
1572 .push(KeyDispatchStackFrame::Listener {
1573 event_type,
1574 listener,
1575 });
1576 }
1577 }
1578
1579 let result = f(self);
1580
1581 if !self.window.freeze_key_dispatch_stack {
1582 let prev_len = self.window.key_dispatch_stack.len() - key_listeners.len();
1583 self.window.key_dispatch_stack.truncate(prev_len);
1584 }
1585
1586 result
1587 }
1588
1589 pub fn with_key_dispatch_context<R>(
1590 &mut self,
1591 context: DispatchContext,
1592 f: impl FnOnce(&mut Self) -> R,
1593 ) -> R {
1594 if context.is_empty() {
1595 return f(self);
1596 }
1597
1598 if !self.window.freeze_key_dispatch_stack {
1599 self.window
1600 .key_dispatch_stack
1601 .push(KeyDispatchStackFrame::Context(context));
1602 }
1603
1604 let result = f(self);
1605
1606 if !self.window.freeze_key_dispatch_stack {
1607 self.window.key_dispatch_stack.pop();
1608 }
1609
1610 result
1611 }
1612
1613 pub fn with_focus<R>(
1614 &mut self,
1615 focus_handle: FocusHandle,
1616 f: impl FnOnce(&mut Self) -> R,
1617 ) -> R {
1618 if let Some(parent_focus_id) = self.window.focus_stack.last().copied() {
1619 self.window
1620 .focus_parents_by_child
1621 .insert(focus_handle.id, parent_focus_id);
1622 }
1623 self.window.focus_stack.push(focus_handle.id);
1624
1625 if Some(focus_handle.id) == self.window.focus {
1626 self.window.freeze_key_dispatch_stack = true;
1627 }
1628
1629 let result = f(self);
1630
1631 self.window.focus_stack.pop();
1632 result
1633 }
1634
1635 pub fn run_on_main<R>(
1636 &mut self,
1637 view: &mut V,
1638 f: impl FnOnce(&mut V, &mut MainThread<ViewContext<'_, '_, V>>) -> R + Send + 'static,
1639 ) -> Task<Result<R>>
1640 where
1641 R: Send + 'static,
1642 {
1643 if self.executor.is_main_thread() {
1644 let cx = unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(self) };
1645 Task::ready(Ok(f(view, cx)))
1646 } else {
1647 let handle = self.handle().upgrade().unwrap();
1648 self.window_cx.run_on_main(move |cx| handle.update(cx, f))
1649 }
1650 }
1651
1652 pub fn spawn<Fut, R>(
1653 &mut self,
1654 f: impl FnOnce(WeakHandle<V>, AsyncWindowContext) -> Fut + Send + 'static,
1655 ) -> Task<R>
1656 where
1657 R: Send + 'static,
1658 Fut: Future<Output = R> + Send + 'static,
1659 {
1660 let handle = self.handle();
1661 self.window_cx.spawn(move |_, cx| {
1662 let result = f(handle, cx);
1663 async move { result.await }
1664 })
1665 }
1666
1667 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1668 where
1669 G: 'static + Send + Sync,
1670 {
1671 let mut global = self.app.lease_global::<G>();
1672 let result = f(&mut global, self);
1673 self.app.end_global_lease(global);
1674 result
1675 }
1676
1677 pub fn observe_global<G: 'static>(
1678 &mut self,
1679 f: impl Fn(&mut V, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1680 ) -> Subscription {
1681 let window_id = self.window.handle.id;
1682 let handle = self.handle();
1683 self.global_observers.insert(
1684 TypeId::of::<G>(),
1685 Box::new(move |cx| {
1686 cx.update_window(window_id, |cx| {
1687 handle.update(cx, |view, cx| f(view, cx)).is_ok()
1688 })
1689 .unwrap_or(false)
1690 }),
1691 )
1692 }
1693
1694 pub fn on_mouse_event<Event: 'static>(
1695 &mut self,
1696 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + Send + Sync + 'static,
1697 ) {
1698 let handle = self.handle().upgrade().unwrap();
1699 self.window_cx.on_mouse_event(move |event, phase, cx| {
1700 handle.update(cx, |view, cx| {
1701 handler(view, event, phase, cx);
1702 })
1703 });
1704 }
1705}
1706
1707impl<'a, 'w, V> ViewContext<'a, 'w, V>
1708where
1709 V: EventEmitter,
1710 V::Event: Any + Send + Sync,
1711{
1712 pub fn emit(&mut self, event: V::Event) {
1713 let emitter = self.view_state.entity_id;
1714 self.app.push_effect(Effect::Emit {
1715 emitter,
1716 event: Box::new(event),
1717 });
1718 }
1719}
1720
1721impl<'a, 'w, V> Context for ViewContext<'a, 'w, V> {
1722 type EntityContext<'b, 'c, U> = ViewContext<'b, 'c, U>;
1723 type Result<U> = U;
1724
1725 fn entity<T>(
1726 &mut self,
1727 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
1728 ) -> Handle<T>
1729 where
1730 T: 'static + Send + Sync,
1731 {
1732 self.window_cx.entity(build_entity)
1733 }
1734
1735 fn update_entity<T: 'static, R>(
1736 &mut self,
1737 handle: &Handle<T>,
1738 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
1739 ) -> R {
1740 self.window_cx.update_entity(handle, update)
1741 }
1742}
1743
1744impl<'a, 'w, V> std::ops::Deref for ViewContext<'a, 'w, V> {
1745 type Target = WindowContext<'a, 'w>;
1746
1747 fn deref(&self) -> &Self::Target {
1748 &self.window_cx
1749 }
1750}
1751
1752impl<'a, 'w, V> std::ops::DerefMut for ViewContext<'a, 'w, V> {
1753 fn deref_mut(&mut self) -> &mut Self::Target {
1754 &mut self.window_cx
1755 }
1756}
1757
1758// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
1759slotmap::new_key_type! { pub struct WindowId; }
1760
1761impl WindowId {
1762 pub fn as_u64(&self) -> u64 {
1763 self.0.as_ffi()
1764 }
1765}
1766
1767#[derive(PartialEq, Eq)]
1768pub struct WindowHandle<V> {
1769 id: WindowId,
1770 state_type: PhantomData<V>,
1771}
1772
1773impl<S> Copy for WindowHandle<S> {}
1774
1775impl<S> Clone for WindowHandle<S> {
1776 fn clone(&self) -> Self {
1777 WindowHandle {
1778 id: self.id,
1779 state_type: PhantomData,
1780 }
1781 }
1782}
1783
1784impl<S> WindowHandle<S> {
1785 pub fn new(id: WindowId) -> Self {
1786 WindowHandle {
1787 id,
1788 state_type: PhantomData,
1789 }
1790 }
1791}
1792
1793impl<S: 'static> Into<AnyWindowHandle> for WindowHandle<S> {
1794 fn into(self) -> AnyWindowHandle {
1795 AnyWindowHandle {
1796 id: self.id,
1797 state_type: TypeId::of::<S>(),
1798 }
1799 }
1800}
1801
1802#[derive(Copy, Clone, PartialEq, Eq)]
1803pub struct AnyWindowHandle {
1804 pub(crate) id: WindowId,
1805 state_type: TypeId,
1806}
1807
1808impl AnyWindowHandle {
1809 pub fn window_id(&self) -> WindowId {
1810 self.id
1811 }
1812}
1813
1814#[cfg(any(test, feature = "test-support"))]
1815impl From<SmallVec<[u32; 16]>> for StackingOrder {
1816 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
1817 StackingOrder(small_vec)
1818 }
1819}
1820
1821#[derive(Clone, Debug, Eq, PartialEq, Hash)]
1822pub enum ElementId {
1823 View(EntityId),
1824 Number(usize),
1825 Name(SharedString),
1826 FocusHandle(FocusId),
1827}
1828
1829impl From<EntityId> for ElementId {
1830 fn from(id: EntityId) -> Self {
1831 ElementId::View(id)
1832 }
1833}
1834
1835impl From<usize> for ElementId {
1836 fn from(id: usize) -> Self {
1837 ElementId::Number(id)
1838 }
1839}
1840
1841impl From<i32> for ElementId {
1842 fn from(id: i32) -> Self {
1843 Self::Number(id as usize)
1844 }
1845}
1846
1847impl From<SharedString> for ElementId {
1848 fn from(name: SharedString) -> Self {
1849 ElementId::Name(name)
1850 }
1851}
1852
1853impl From<&'static str> for ElementId {
1854 fn from(name: &'static str) -> Self {
1855 ElementId::Name(name.into())
1856 }
1857}
1858
1859impl<'a> From<&'a FocusHandle> for ElementId {
1860 fn from(handle: &'a FocusHandle) -> Self {
1861 ElementId::FocusHandle(handle.id)
1862 }
1863}