1use crate::{
2 px, size, Action, AnyBox, AnyDrag, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
3 BorrowAppContext, Bounds, BoxShadow, Context, Corners, DevicePixels, DispatchContext,
4 DisplayId, Edges, Effect, Element, EntityId, EventEmitter, FocusEvent, FontId, GlobalElementId,
5 GlyphId, Handle, Hsla, ImageData, InputEvent, IsZero, KeyListener, KeyMatch, KeyMatcher,
6 Keystroke, LayoutId, MainThread, MainThreadOnly, MonochromeSprite, MouseMoveEvent,
7 MouseUpEvent, Path, Pixels, Platform, PlatformAtlas, PlatformWindow, Point, PolychromeSprite,
8 Quad, Reference, RenderGlyphParams, RenderImageParams, RenderSvgParams, ScaledPixels,
9 SceneBuilder, Shadow, SharedString, Size, Style, Subscription, TaffyLayoutEngine, Task,
10 Underline, UnderlineStyle, WeakHandle, WindowOptions, SUBPIXEL_VARIANTS,
11};
12use anyhow::Result;
13use collections::HashMap;
14use derive_more::{Deref, DerefMut};
15use parking_lot::RwLock;
16use slotmap::SlotMap;
17use smallvec::SmallVec;
18use std::{
19 any::{Any, TypeId},
20 borrow::Cow,
21 fmt::Debug,
22 future::Future,
23 marker::PhantomData,
24 mem,
25 sync::{
26 atomic::{AtomicUsize, Ordering::SeqCst},
27 Arc,
28 },
29};
30use util::ResultExt;
31
32#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
33pub struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
34
35#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
36pub enum DispatchPhase {
37 /// After the capture phase comes the bubble phase, in which event handlers are
38 /// invoked front to back. This is the phase you'll usually want to use for event handlers.
39 #[default]
40 Bubble,
41 /// During the initial capture phase, event handlers are invoked back to front. This phase
42 /// is used for special purposes such as clearing the "pressed" state for click events. If
43 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
44 /// outside of the immediate region may rely on detecting non-local events during this phase.
45 Capture,
46}
47
48type AnyListener = Arc<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + Send + Sync + 'static>;
49type AnyKeyListener = Arc<
50 dyn Fn(
51 &dyn Any,
52 &[&DispatchContext],
53 DispatchPhase,
54 &mut WindowContext,
55 ) -> Option<Box<dyn Action>>
56 + Send
57 + Sync
58 + 'static,
59>;
60type AnyFocusListener = Arc<dyn Fn(&FocusEvent, &mut WindowContext) + Send + Sync + 'static>;
61
62slotmap::new_key_type! { pub struct FocusId; }
63
64pub struct FocusHandle {
65 pub(crate) id: FocusId,
66 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
67}
68
69impl FocusHandle {
70 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
71 let id = handles.write().insert(AtomicUsize::new(1));
72 Self {
73 id,
74 handles: handles.clone(),
75 }
76 }
77
78 pub(crate) fn for_id(
79 id: FocusId,
80 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
81 ) -> Option<Self> {
82 let lock = handles.read();
83 let ref_count = lock.get(id)?;
84 if ref_count.load(SeqCst) == 0 {
85 None
86 } else {
87 ref_count.fetch_add(1, SeqCst);
88 Some(Self {
89 id,
90 handles: handles.clone(),
91 })
92 }
93 }
94
95 pub fn is_focused(&self, cx: &WindowContext) -> bool {
96 cx.window.focus == Some(self.id)
97 }
98
99 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
100 cx.focused()
101 .map_or(false, |focused| self.contains(&focused, cx))
102 }
103
104 pub fn within_focused(&self, cx: &WindowContext) -> bool {
105 let focused = cx.focused();
106 focused.map_or(false, |focused| focused.contains(self, cx))
107 }
108
109 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
110 let mut ancestor = Some(other.id);
111 while let Some(ancestor_id) = ancestor {
112 if self.id == ancestor_id {
113 return true;
114 } else {
115 ancestor = cx.window.focus_parents_by_child.get(&ancestor_id).copied();
116 }
117 }
118 false
119 }
120}
121
122impl Clone for FocusHandle {
123 fn clone(&self) -> Self {
124 Self::for_id(self.id, &self.handles).unwrap()
125 }
126}
127
128impl PartialEq for FocusHandle {
129 fn eq(&self, other: &Self) -> bool {
130 self.id == other.id
131 }
132}
133
134impl Eq for FocusHandle {}
135
136impl Drop for FocusHandle {
137 fn drop(&mut self) {
138 self.handles
139 .read()
140 .get(self.id)
141 .unwrap()
142 .fetch_sub(1, SeqCst);
143 }
144}
145
146pub struct Window {
147 handle: AnyWindowHandle,
148 platform_window: MainThreadOnly<Box<dyn PlatformWindow>>,
149 display_id: DisplayId,
150 sprite_atlas: Arc<dyn PlatformAtlas>,
151 rem_size: Pixels,
152 content_size: Size<Pixels>,
153 layout_engine: TaffyLayoutEngine,
154 pub(crate) root_view: Option<AnyView>,
155 pub(crate) element_id_stack: GlobalElementId,
156 prev_frame_element_states: HashMap<GlobalElementId, AnyBox>,
157 element_states: HashMap<GlobalElementId, AnyBox>,
158 prev_frame_key_matchers: HashMap<GlobalElementId, KeyMatcher>,
159 key_matchers: HashMap<GlobalElementId, KeyMatcher>,
160 z_index_stack: StackingOrder,
161 content_mask_stack: Vec<ContentMask<Pixels>>,
162 element_offset_stack: Vec<Point<Pixels>>,
163 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyListener)>>,
164 key_dispatch_stack: Vec<KeyDispatchStackFrame>,
165 freeze_key_dispatch_stack: bool,
166 focus_stack: Vec<FocusId>,
167 focus_parents_by_child: HashMap<FocusId, FocusId>,
168 pub(crate) focus_listeners: Vec<AnyFocusListener>,
169 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
170 default_prevented: bool,
171 mouse_position: Point<Pixels>,
172 scale_factor: f32,
173 pub(crate) scene_builder: SceneBuilder,
174 pub(crate) dirty: bool,
175 pub(crate) last_blur: Option<Option<FocusId>>,
176 pub(crate) focus: Option<FocusId>,
177}
178
179impl Window {
180 pub(crate) fn new(
181 handle: AnyWindowHandle,
182 options: WindowOptions,
183 cx: &mut MainThread<AppContext>,
184 ) -> Self {
185 let platform_window = cx.platform().open_window(handle, options);
186 let display_id = platform_window.display().id();
187 let sprite_atlas = platform_window.sprite_atlas();
188 let mouse_position = platform_window.mouse_position();
189 let content_size = platform_window.content_size();
190 let scale_factor = platform_window.scale_factor();
191 platform_window.on_resize(Box::new({
192 let cx = cx.to_async();
193 move |content_size, scale_factor| {
194 cx.update_window(handle, |cx| {
195 cx.window.scale_factor = scale_factor;
196 cx.window.scene_builder = SceneBuilder::new();
197 cx.window.content_size = content_size;
198 cx.window.display_id = cx
199 .window
200 .platform_window
201 .borrow_on_main_thread()
202 .display()
203 .id();
204 cx.window.dirty = true;
205 })
206 .log_err();
207 }
208 }));
209
210 platform_window.on_input({
211 let cx = cx.to_async();
212 Box::new(move |event| {
213 cx.update_window(handle, |cx| cx.dispatch_event(event))
214 .log_err()
215 .unwrap_or(true)
216 })
217 });
218
219 let platform_window = MainThreadOnly::new(Arc::new(platform_window), cx.executor.clone());
220
221 Window {
222 handle,
223 platform_window,
224 display_id,
225 sprite_atlas,
226 rem_size: px(16.),
227 content_size,
228 layout_engine: TaffyLayoutEngine::new(),
229 root_view: None,
230 element_id_stack: GlobalElementId::default(),
231 prev_frame_element_states: HashMap::default(),
232 element_states: HashMap::default(),
233 prev_frame_key_matchers: HashMap::default(),
234 key_matchers: HashMap::default(),
235 z_index_stack: StackingOrder(SmallVec::new()),
236 content_mask_stack: Vec::new(),
237 element_offset_stack: Vec::new(),
238 mouse_listeners: HashMap::default(),
239 key_dispatch_stack: Vec::new(),
240 freeze_key_dispatch_stack: false,
241 focus_stack: Vec::new(),
242 focus_parents_by_child: HashMap::default(),
243 focus_listeners: Vec::new(),
244 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
245 default_prevented: true,
246 mouse_position,
247 scale_factor,
248 scene_builder: SceneBuilder::new(),
249 dirty: true,
250 last_blur: None,
251 focus: None,
252 }
253 }
254}
255
256enum KeyDispatchStackFrame {
257 Listener {
258 event_type: TypeId,
259 listener: AnyKeyListener,
260 },
261 Context(DispatchContext),
262}
263
264#[derive(Clone, Debug, Default, PartialEq, Eq)]
265#[repr(C)]
266pub struct ContentMask<P: Clone + Default + Debug> {
267 pub bounds: Bounds<P>,
268}
269
270impl ContentMask<Pixels> {
271 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
272 ContentMask {
273 bounds: self.bounds.scale(factor),
274 }
275 }
276
277 pub fn intersect(&self, other: &Self) -> Self {
278 let bounds = self.bounds.intersect(&other.bounds);
279 ContentMask { bounds }
280 }
281}
282
283pub struct WindowContext<'a, 'w> {
284 app: Reference<'a, AppContext>,
285 pub(crate) window: Reference<'w, Window>,
286}
287
288impl<'a, 'w> WindowContext<'a, 'w> {
289 pub(crate) fn immutable(app: &'a AppContext, window: &'w Window) -> Self {
290 Self {
291 app: Reference::Immutable(app),
292 window: Reference::Immutable(window),
293 }
294 }
295
296 pub(crate) fn mutable(app: &'a mut AppContext, window: &'w mut Window) -> Self {
297 Self {
298 app: Reference::Mutable(app),
299 window: Reference::Mutable(window),
300 }
301 }
302
303 pub fn window_handle(&self) -> AnyWindowHandle {
304 self.window.handle
305 }
306
307 pub fn notify(&mut self) {
308 self.window.dirty = true;
309 }
310
311 pub fn focus_handle(&mut self) -> FocusHandle {
312 FocusHandle::new(&self.window.focus_handles)
313 }
314
315 pub fn focused(&self) -> Option<FocusHandle> {
316 self.window
317 .focus
318 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
319 }
320
321 pub fn focus(&mut self, handle: &FocusHandle) {
322 if self.window.last_blur.is_none() {
323 self.window.last_blur = Some(self.window.focus);
324 }
325
326 let window_id = self.window.handle.id;
327 self.window.focus = Some(handle.id);
328 self.app.push_effect(Effect::FocusChanged {
329 window_id,
330 focused: Some(handle.id),
331 });
332 self.notify();
333 }
334
335 pub fn blur(&mut self) {
336 if self.window.last_blur.is_none() {
337 self.window.last_blur = Some(self.window.focus);
338 }
339
340 let window_id = self.window.handle.id;
341 self.window.focus = None;
342 self.app.push_effect(Effect::FocusChanged {
343 window_id,
344 focused: None,
345 });
346 self.notify();
347 }
348
349 pub fn run_on_main<R>(
350 &mut self,
351 f: impl FnOnce(&mut MainThread<WindowContext<'_, '_>>) -> R + Send + 'static,
352 ) -> Task<Result<R>>
353 where
354 R: Send + 'static,
355 {
356 if self.executor.is_main_thread() {
357 Task::ready(Ok(f(unsafe {
358 mem::transmute::<&mut Self, &mut MainThread<Self>>(self)
359 })))
360 } else {
361 let id = self.window.handle.id;
362 self.app.run_on_main(move |cx| cx.update_window(id, f))
363 }
364 }
365
366 pub fn to_async(&self) -> AsyncWindowContext {
367 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
368 }
369
370 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut WindowContext) + Send + 'static) {
371 let f = Box::new(f);
372 let display_id = self.window.display_id;
373 self.run_on_main(move |cx| {
374 if let Some(callbacks) = cx.next_frame_callbacks.get_mut(&display_id) {
375 callbacks.push(f);
376 // If there was already a callback, it means that we already scheduled a frame.
377 if callbacks.len() > 1 {
378 return;
379 }
380 } else {
381 let async_cx = cx.to_async();
382 cx.next_frame_callbacks.insert(display_id, vec![f]);
383 cx.platform().set_display_link_output_callback(
384 display_id,
385 Box::new(move |_current_time, _output_time| {
386 let _ = async_cx.update(|cx| {
387 let callbacks = cx
388 .next_frame_callbacks
389 .get_mut(&display_id)
390 .unwrap()
391 .drain(..)
392 .collect::<Vec<_>>();
393 for callback in callbacks {
394 callback(cx);
395 }
396
397 cx.run_on_main(move |cx| {
398 if cx.next_frame_callbacks.get(&display_id).unwrap().is_empty() {
399 cx.platform().stop_display_link(display_id);
400 }
401 })
402 .detach();
403 });
404 }),
405 );
406 }
407
408 cx.platform().start_display_link(display_id);
409 })
410 .detach();
411 }
412
413 pub fn spawn<Fut, R>(
414 &mut self,
415 f: impl FnOnce(AnyWindowHandle, AsyncWindowContext) -> Fut + Send + 'static,
416 ) -> Task<R>
417 where
418 R: Send + 'static,
419 Fut: Future<Output = R> + Send + 'static,
420 {
421 let window = self.window.handle;
422 self.app.spawn(move |app| {
423 let cx = AsyncWindowContext::new(app, window);
424 let future = f(window, cx);
425 async move { future.await }
426 })
427 }
428
429 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
430 where
431 G: 'static + Send + Sync,
432 {
433 let mut global = self.app.lease_global::<G>();
434 let result = f(global.as_mut(), self);
435 self.app.set_global(global);
436 result
437 }
438
439 pub fn request_layout(
440 &mut self,
441 style: &Style,
442 children: impl IntoIterator<Item = LayoutId>,
443 ) -> LayoutId {
444 self.app.layout_id_buffer.clear();
445 self.app.layout_id_buffer.extend(children.into_iter());
446 let rem_size = self.rem_size();
447
448 self.window
449 .layout_engine
450 .request_layout(style, rem_size, &self.app.layout_id_buffer)
451 }
452
453 pub fn request_measured_layout<
454 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
455 >(
456 &mut self,
457 style: Style,
458 rem_size: Pixels,
459 measure: F,
460 ) -> LayoutId {
461 self.window
462 .layout_engine
463 .request_measured_layout(style, rem_size, measure)
464 }
465
466 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
467 let mut bounds = self
468 .window
469 .layout_engine
470 .layout_bounds(layout_id)
471 .map(Into::into);
472 bounds.origin += self.element_offset();
473 bounds
474 }
475
476 pub fn scale_factor(&self) -> f32 {
477 self.window.scale_factor
478 }
479
480 pub fn rem_size(&self) -> Pixels {
481 self.window.rem_size
482 }
483
484 pub fn line_height(&self) -> Pixels {
485 let rem_size = self.rem_size();
486 let text_style = self.text_style();
487 text_style
488 .line_height
489 .to_pixels(text_style.font_size.into(), rem_size)
490 }
491
492 pub fn prevent_default(&mut self) {
493 self.window.default_prevented = true;
494 }
495
496 pub fn default_prevented(&self) -> bool {
497 self.window.default_prevented
498 }
499
500 pub fn on_mouse_event<Event: 'static>(
501 &mut self,
502 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + Send + Sync + 'static,
503 ) {
504 let order = self.window.z_index_stack.clone();
505 self.window
506 .mouse_listeners
507 .entry(TypeId::of::<Event>())
508 .or_default()
509 .push((
510 order,
511 Arc::new(move |event: &dyn Any, phase, cx| {
512 handler(event.downcast_ref().unwrap(), phase, cx)
513 }),
514 ))
515 }
516
517 pub fn mouse_position(&self) -> Point<Pixels> {
518 self.window.mouse_position
519 }
520
521 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
522 self.window.z_index_stack.push(order);
523 let result = f(self);
524 self.window.z_index_stack.pop();
525 result
526 }
527
528 pub fn paint_shadows(
529 &mut self,
530 bounds: Bounds<Pixels>,
531 corner_radii: Corners<Pixels>,
532 shadows: &[BoxShadow],
533 ) {
534 let scale_factor = self.scale_factor();
535 let content_mask = self.content_mask();
536 let window = &mut *self.window;
537 for shadow in shadows {
538 let mut shadow_bounds = bounds;
539 shadow_bounds.origin += shadow.offset;
540 shadow_bounds.dilate(shadow.spread_radius);
541 window.scene_builder.insert(
542 &window.z_index_stack,
543 Shadow {
544 order: 0,
545 bounds: shadow_bounds.scale(scale_factor),
546 content_mask: content_mask.scale(scale_factor),
547 corner_radii: corner_radii.scale(scale_factor),
548 color: shadow.color,
549 blur_radius: shadow.blur_radius.scale(scale_factor),
550 },
551 );
552 }
553 }
554
555 pub fn paint_quad(
556 &mut self,
557 bounds: Bounds<Pixels>,
558 corner_radii: Corners<Pixels>,
559 background: impl Into<Hsla>,
560 border_widths: Edges<Pixels>,
561 border_color: impl Into<Hsla>,
562 ) {
563 let scale_factor = self.scale_factor();
564 let content_mask = self.content_mask();
565
566 let window = &mut *self.window;
567 window.scene_builder.insert(
568 &window.z_index_stack,
569 Quad {
570 order: 0,
571 bounds: bounds.scale(scale_factor),
572 content_mask: content_mask.scale(scale_factor),
573 background: background.into(),
574 border_color: border_color.into(),
575 corner_radii: corner_radii.scale(scale_factor),
576 border_widths: border_widths.scale(scale_factor),
577 },
578 );
579 }
580
581 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
582 let scale_factor = self.scale_factor();
583 let content_mask = self.content_mask();
584 path.content_mask = content_mask;
585 path.color = color.into();
586 let window = &mut *self.window;
587 window
588 .scene_builder
589 .insert(&window.z_index_stack, path.scale(scale_factor));
590 }
591
592 pub fn paint_underline(
593 &mut self,
594 origin: Point<Pixels>,
595 width: Pixels,
596 style: &UnderlineStyle,
597 ) -> Result<()> {
598 let scale_factor = self.scale_factor();
599 let height = if style.wavy {
600 style.thickness * 3.
601 } else {
602 style.thickness
603 };
604 let bounds = Bounds {
605 origin,
606 size: size(width, height),
607 };
608 let content_mask = self.content_mask();
609 let window = &mut *self.window;
610 window.scene_builder.insert(
611 &window.z_index_stack,
612 Underline {
613 order: 0,
614 bounds: bounds.scale(scale_factor),
615 content_mask: content_mask.scale(scale_factor),
616 thickness: style.thickness.scale(scale_factor),
617 color: style.color.unwrap_or_default(),
618 wavy: style.wavy,
619 },
620 );
621 Ok(())
622 }
623
624 pub fn paint_glyph(
625 &mut self,
626 origin: Point<Pixels>,
627 font_id: FontId,
628 glyph_id: GlyphId,
629 font_size: Pixels,
630 color: Hsla,
631 ) -> Result<()> {
632 let scale_factor = self.scale_factor();
633 let glyph_origin = origin.scale(scale_factor);
634 let subpixel_variant = Point {
635 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
636 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
637 };
638 let params = RenderGlyphParams {
639 font_id,
640 glyph_id,
641 font_size,
642 subpixel_variant,
643 scale_factor,
644 is_emoji: false,
645 };
646
647 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
648 if !raster_bounds.is_zero() {
649 let tile =
650 self.window
651 .sprite_atlas
652 .get_or_insert_with(¶ms.clone().into(), &mut || {
653 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
654 Ok((size, Cow::Owned(bytes)))
655 })?;
656 let bounds = Bounds {
657 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
658 size: tile.bounds.size.map(Into::into),
659 };
660 let content_mask = self.content_mask().scale(scale_factor);
661 let window = &mut *self.window;
662 window.scene_builder.insert(
663 &window.z_index_stack,
664 MonochromeSprite {
665 order: 0,
666 bounds,
667 content_mask,
668 color,
669 tile,
670 },
671 );
672 }
673 Ok(())
674 }
675
676 pub fn paint_emoji(
677 &mut self,
678 origin: Point<Pixels>,
679 font_id: FontId,
680 glyph_id: GlyphId,
681 font_size: Pixels,
682 ) -> Result<()> {
683 let scale_factor = self.scale_factor();
684 let glyph_origin = origin.scale(scale_factor);
685 let params = RenderGlyphParams {
686 font_id,
687 glyph_id,
688 font_size,
689 // We don't render emojis with subpixel variants.
690 subpixel_variant: Default::default(),
691 scale_factor,
692 is_emoji: true,
693 };
694
695 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
696 if !raster_bounds.is_zero() {
697 let tile =
698 self.window
699 .sprite_atlas
700 .get_or_insert_with(¶ms.clone().into(), &mut || {
701 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
702 Ok((size, Cow::Owned(bytes)))
703 })?;
704 let bounds = Bounds {
705 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
706 size: tile.bounds.size.map(Into::into),
707 };
708 let content_mask = self.content_mask().scale(scale_factor);
709 let window = &mut *self.window;
710
711 window.scene_builder.insert(
712 &window.z_index_stack,
713 PolychromeSprite {
714 order: 0,
715 bounds,
716 corner_radii: Default::default(),
717 content_mask,
718 tile,
719 grayscale: false,
720 },
721 );
722 }
723 Ok(())
724 }
725
726 pub fn paint_svg(
727 &mut self,
728 bounds: Bounds<Pixels>,
729 path: SharedString,
730 color: Hsla,
731 ) -> Result<()> {
732 let scale_factor = self.scale_factor();
733 let bounds = bounds.scale(scale_factor);
734 // Render the SVG at twice the size to get a higher quality result.
735 let params = RenderSvgParams {
736 path,
737 size: bounds
738 .size
739 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
740 };
741
742 let tile =
743 self.window
744 .sprite_atlas
745 .get_or_insert_with(¶ms.clone().into(), &mut || {
746 let bytes = self.svg_renderer.render(¶ms)?;
747 Ok((params.size, Cow::Owned(bytes)))
748 })?;
749 let content_mask = self.content_mask().scale(scale_factor);
750
751 let window = &mut *self.window;
752 window.scene_builder.insert(
753 &window.z_index_stack,
754 MonochromeSprite {
755 order: 0,
756 bounds,
757 content_mask,
758 color,
759 tile,
760 },
761 );
762
763 Ok(())
764 }
765
766 pub fn paint_image(
767 &mut self,
768 bounds: Bounds<Pixels>,
769 corner_radii: Corners<Pixels>,
770 data: Arc<ImageData>,
771 grayscale: bool,
772 ) -> Result<()> {
773 let scale_factor = self.scale_factor();
774 let bounds = bounds.scale(scale_factor);
775 let params = RenderImageParams { image_id: data.id };
776
777 let tile = self
778 .window
779 .sprite_atlas
780 .get_or_insert_with(¶ms.clone().into(), &mut || {
781 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
782 })?;
783 let content_mask = self.content_mask().scale(scale_factor);
784 let corner_radii = corner_radii.scale(scale_factor);
785
786 let window = &mut *self.window;
787 window.scene_builder.insert(
788 &window.z_index_stack,
789 PolychromeSprite {
790 order: 0,
791 bounds,
792 content_mask,
793 corner_radii,
794 tile,
795 grayscale,
796 },
797 );
798 Ok(())
799 }
800
801 pub(crate) fn draw(&mut self) {
802 let unit_entity = self.unit_entity.clone();
803 self.update_entity(&unit_entity, |view, cx| {
804 cx.start_frame();
805
806 let mut root_view = cx.window.root_view.take().unwrap();
807
808 cx.stack(0, |cx| {
809 let available_space = cx.window.content_size.map(Into::into);
810 draw_any_view(&mut root_view, available_space, cx);
811 });
812
813 if let Some(mut active_drag) = cx.active_drag.take() {
814 cx.stack(1, |cx| {
815 let offset = cx.mouse_position() - active_drag.cursor_offset;
816 cx.with_element_offset(Some(offset), |cx| {
817 let available_space =
818 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
819 draw_any_view(&mut active_drag.drag_handle_view, available_space, cx);
820 cx.active_drag = Some(active_drag);
821 });
822 });
823 }
824
825 cx.window.root_view = Some(root_view);
826 let scene = cx.window.scene_builder.build();
827
828 cx.run_on_main(view, |_, cx| {
829 cx.window
830 .platform_window
831 .borrow_on_main_thread()
832 .draw(scene);
833 cx.window.dirty = false;
834 })
835 .detach();
836 });
837
838 fn draw_any_view(
839 view: &mut AnyView,
840 available_space: Size<AvailableSpace>,
841 cx: &mut ViewContext<()>,
842 ) {
843 cx.with_optional_element_state(view.id(), |element_state, cx| {
844 let mut element_state = view.initialize(&mut (), element_state, cx);
845 let layout_id = view.layout(&mut (), &mut element_state, cx);
846 cx.window
847 .layout_engine
848 .compute_layout(layout_id, available_space);
849 let bounds = cx.window.layout_engine.layout_bounds(layout_id);
850 view.paint(bounds, &mut (), &mut element_state, cx);
851 ((), element_state)
852 });
853 }
854 }
855
856 fn start_frame(&mut self) {
857 self.text_system().start_frame();
858
859 let window = &mut *self.window;
860
861 // Move the current frame element states to the previous frame.
862 // The new empty element states map will be populated for any element states we
863 // reference during the upcoming frame.
864 mem::swap(
865 &mut window.element_states,
866 &mut window.prev_frame_element_states,
867 );
868 window.element_states.clear();
869
870 // Make the current key matchers the previous, and then clear the current.
871 // An empty key matcher map will be created for every identified element in the
872 // upcoming frame.
873 mem::swap(
874 &mut window.key_matchers,
875 &mut window.prev_frame_key_matchers,
876 );
877 window.key_matchers.clear();
878
879 // Clear mouse event listeners, because elements add new element listeners
880 // when the upcoming frame is painted.
881 window.mouse_listeners.values_mut().for_each(Vec::clear);
882
883 // Clear focus state, because we determine what is focused when the new elements
884 // in the upcoming frame are initialized.
885 window.focus_listeners.clear();
886 window.key_dispatch_stack.clear();
887 window.focus_parents_by_child.clear();
888 window.freeze_key_dispatch_stack = false;
889 }
890
891 fn dispatch_event(&mut self, event: InputEvent) -> bool {
892 if let Some(any_mouse_event) = event.mouse_event() {
893 if let Some(MouseMoveEvent { position, .. }) = any_mouse_event.downcast_ref() {
894 self.window.mouse_position = *position;
895 }
896
897 // Handlers may set this to false by calling `stop_propagation`
898 self.app.propagate_event = true;
899 self.window.default_prevented = false;
900
901 if let Some(mut handlers) = self
902 .window
903 .mouse_listeners
904 .remove(&any_mouse_event.type_id())
905 {
906 // Because handlers may add other handlers, we sort every time.
907 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
908
909 // Capture phase, events bubble from back to front. Handlers for this phase are used for
910 // special purposes, such as detecting events outside of a given Bounds.
911 for (_, handler) in &handlers {
912 handler(any_mouse_event, DispatchPhase::Capture, self);
913 if !self.app.propagate_event {
914 break;
915 }
916 }
917
918 // Bubble phase, where most normal handlers do their work.
919 if self.app.propagate_event {
920 for (_, handler) in handlers.iter().rev() {
921 handler(any_mouse_event, DispatchPhase::Bubble, self);
922 if !self.app.propagate_event {
923 break;
924 }
925 }
926 }
927
928 if self.app.propagate_event
929 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
930 {
931 self.active_drag = None;
932 }
933
934 // Just in case any handlers added new handlers, which is weird, but possible.
935 handlers.extend(
936 self.window
937 .mouse_listeners
938 .get_mut(&any_mouse_event.type_id())
939 .into_iter()
940 .flat_map(|handlers| handlers.drain(..)),
941 );
942 self.window
943 .mouse_listeners
944 .insert(any_mouse_event.type_id(), handlers);
945 }
946 } else if let Some(any_key_event) = event.keyboard_event() {
947 let key_dispatch_stack = mem::take(&mut self.window.key_dispatch_stack);
948 let key_event_type = any_key_event.type_id();
949 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
950
951 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
952 match frame {
953 KeyDispatchStackFrame::Listener {
954 event_type,
955 listener,
956 } => {
957 if key_event_type == *event_type {
958 if let Some(action) = listener(
959 any_key_event,
960 &context_stack,
961 DispatchPhase::Capture,
962 self,
963 ) {
964 self.dispatch_action(action, &key_dispatch_stack[..ix]);
965 }
966 if !self.app.propagate_event {
967 break;
968 }
969 }
970 }
971 KeyDispatchStackFrame::Context(context) => {
972 context_stack.push(&context);
973 }
974 }
975 }
976
977 if self.app.propagate_event {
978 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
979 match frame {
980 KeyDispatchStackFrame::Listener {
981 event_type,
982 listener,
983 } => {
984 if key_event_type == *event_type {
985 if let Some(action) = listener(
986 any_key_event,
987 &context_stack,
988 DispatchPhase::Bubble,
989 self,
990 ) {
991 self.dispatch_action(action, &key_dispatch_stack[..ix]);
992 }
993
994 if !self.app.propagate_event {
995 break;
996 }
997 }
998 }
999 KeyDispatchStackFrame::Context(_) => {
1000 context_stack.pop();
1001 }
1002 }
1003 }
1004 }
1005
1006 drop(context_stack);
1007 self.window.key_dispatch_stack = key_dispatch_stack;
1008 }
1009
1010 true
1011 }
1012
1013 pub fn match_keystroke(
1014 &mut self,
1015 element_id: &GlobalElementId,
1016 keystroke: &Keystroke,
1017 context_stack: &[&DispatchContext],
1018 ) -> KeyMatch {
1019 let key_match = self
1020 .window
1021 .key_matchers
1022 .get_mut(element_id)
1023 .unwrap()
1024 .match_keystroke(keystroke, context_stack);
1025
1026 if key_match.is_some() {
1027 for matcher in self.window.key_matchers.values_mut() {
1028 matcher.clear_pending();
1029 }
1030 }
1031
1032 key_match
1033 }
1034
1035 pub fn observe_global<G: 'static>(
1036 &mut self,
1037 f: impl Fn(&mut WindowContext<'_, '_>) + Send + Sync + 'static,
1038 ) -> Subscription {
1039 let window_id = self.window.handle.id;
1040 self.global_observers.insert(
1041 TypeId::of::<G>(),
1042 Box::new(move |cx| cx.update_window(window_id, |cx| f(cx)).is_ok()),
1043 )
1044 }
1045
1046 fn dispatch_action(
1047 &mut self,
1048 action: Box<dyn Action>,
1049 dispatch_stack: &[KeyDispatchStackFrame],
1050 ) {
1051 let action_type = action.as_any().type_id();
1052
1053 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1054 for listener in &global_listeners {
1055 listener(action.as_ref(), DispatchPhase::Capture, self);
1056 if !self.app.propagate_event {
1057 break;
1058 }
1059 }
1060 global_listeners.extend(
1061 self.global_action_listeners
1062 .remove(&action_type)
1063 .unwrap_or_default(),
1064 );
1065 self.global_action_listeners
1066 .insert(action_type, global_listeners);
1067 }
1068
1069 if self.app.propagate_event {
1070 for stack_frame in dispatch_stack {
1071 if let KeyDispatchStackFrame::Listener {
1072 event_type,
1073 listener,
1074 } = stack_frame
1075 {
1076 if action_type == *event_type {
1077 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1078 if !self.app.propagate_event {
1079 break;
1080 }
1081 }
1082 }
1083 }
1084 }
1085
1086 if self.app.propagate_event {
1087 for stack_frame in dispatch_stack.iter().rev() {
1088 if let KeyDispatchStackFrame::Listener {
1089 event_type,
1090 listener,
1091 } = stack_frame
1092 {
1093 if action_type == *event_type {
1094 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1095 if !self.app.propagate_event {
1096 break;
1097 }
1098 }
1099 }
1100 }
1101 }
1102
1103 if self.app.propagate_event {
1104 if let Some(mut global_listeners) =
1105 self.app.global_action_listeners.remove(&action_type)
1106 {
1107 for listener in global_listeners.iter().rev() {
1108 listener(action.as_ref(), DispatchPhase::Bubble, self);
1109 if !self.app.propagate_event {
1110 break;
1111 }
1112 }
1113 global_listeners.extend(
1114 self.global_action_listeners
1115 .remove(&action_type)
1116 .unwrap_or_default(),
1117 );
1118 self.global_action_listeners
1119 .insert(action_type, global_listeners);
1120 }
1121 }
1122 }
1123}
1124
1125impl<'a, 'w> MainThread<WindowContext<'a, 'w>> {
1126 fn platform(&self) -> &dyn Platform {
1127 self.platform.borrow_on_main_thread()
1128 }
1129}
1130
1131impl Context for WindowContext<'_, '_> {
1132 type EntityContext<'a, 'w, T: 'static + Send + Sync> = ViewContext<'a, 'w, T>;
1133 type Result<T> = T;
1134
1135 fn entity<T: Send + Sync + 'static>(
1136 &mut self,
1137 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
1138 ) -> Handle<T> {
1139 let slot = self.app.entities.reserve();
1140 let entity = build_entity(&mut ViewContext::mutable(
1141 &mut *self.app,
1142 &mut self.window,
1143 slot.entity_id,
1144 ));
1145 self.entities.insert(slot, entity)
1146 }
1147
1148 fn update_entity<T: Send + Sync + 'static, R>(
1149 &mut self,
1150 handle: &Handle<T>,
1151 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
1152 ) -> R {
1153 let mut entity = self.entities.lease(handle);
1154 let result = update(
1155 &mut *entity,
1156 &mut ViewContext::mutable(&mut *self.app, &mut *self.window, handle.entity_id),
1157 );
1158 self.entities.end_lease(entity);
1159 result
1160 }
1161}
1162
1163impl<'a, 'w> std::ops::Deref for WindowContext<'a, 'w> {
1164 type Target = AppContext;
1165
1166 fn deref(&self) -> &Self::Target {
1167 &self.app
1168 }
1169}
1170
1171impl<'a, 'w> std::ops::DerefMut for WindowContext<'a, 'w> {
1172 fn deref_mut(&mut self) -> &mut Self::Target {
1173 &mut self.app
1174 }
1175}
1176
1177impl BorrowAppContext for WindowContext<'_, '_> {
1178 fn app_mut(&mut self) -> &mut AppContext {
1179 &mut *self.app
1180 }
1181}
1182
1183pub trait BorrowWindow: BorrowAppContext {
1184 fn window(&self) -> &Window;
1185 fn window_mut(&mut self) -> &mut Window;
1186
1187 fn with_element_id<R>(
1188 &mut self,
1189 id: impl Into<ElementId>,
1190 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1191 ) -> R {
1192 let keymap = self.app_mut().keymap.clone();
1193 let window = self.window_mut();
1194 window.element_id_stack.push(id.into());
1195 let global_id = window.element_id_stack.clone();
1196
1197 if window.key_matchers.get(&global_id).is_none() {
1198 window.key_matchers.insert(
1199 global_id.clone(),
1200 window
1201 .prev_frame_key_matchers
1202 .remove(&global_id)
1203 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1204 );
1205 }
1206
1207 let result = f(global_id, self);
1208 self.window_mut().element_id_stack.pop();
1209 result
1210 }
1211
1212 fn with_content_mask<R>(
1213 &mut self,
1214 mask: ContentMask<Pixels>,
1215 f: impl FnOnce(&mut Self) -> R,
1216 ) -> R {
1217 let mask = mask.intersect(&self.content_mask());
1218 self.window_mut().content_mask_stack.push(mask);
1219 let result = f(self);
1220 self.window_mut().content_mask_stack.pop();
1221 result
1222 }
1223
1224 fn with_element_offset<R>(
1225 &mut self,
1226 offset: Option<Point<Pixels>>,
1227 f: impl FnOnce(&mut Self) -> R,
1228 ) -> R {
1229 let Some(offset) = offset else {
1230 return f(self);
1231 };
1232
1233 let offset = self.element_offset() + offset;
1234 self.window_mut().element_offset_stack.push(offset);
1235 let result = f(self);
1236 self.window_mut().element_offset_stack.pop();
1237 result
1238 }
1239
1240 fn element_offset(&self) -> Point<Pixels> {
1241 self.window()
1242 .element_offset_stack
1243 .last()
1244 .copied()
1245 .unwrap_or_default()
1246 }
1247
1248 fn with_element_state<S: 'static + Send + Sync, R>(
1249 &mut self,
1250 id: ElementId,
1251 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1252 ) -> R {
1253 self.with_element_id(id, |global_id, cx| {
1254 if let Some(any) = cx
1255 .window_mut()
1256 .element_states
1257 .remove(&global_id)
1258 .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
1259 {
1260 // Using the extra inner option to avoid needing to reallocate a new box.
1261 let mut state_box = any
1262 .downcast::<Option<S>>()
1263 .expect("invalid element state type for id");
1264 let state = state_box
1265 .take()
1266 .expect("element state is already on the stack");
1267 let (result, state) = f(Some(state), cx);
1268 state_box.replace(state);
1269 cx.window_mut().element_states.insert(global_id, state_box);
1270 result
1271 } else {
1272 let (result, state) = f(None, cx);
1273 cx.window_mut()
1274 .element_states
1275 .insert(global_id, Box::new(Some(state)));
1276 result
1277 }
1278 })
1279 }
1280
1281 fn with_optional_element_state<S: 'static + Send + Sync, R>(
1282 &mut self,
1283 element_id: Option<ElementId>,
1284 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1285 ) -> R {
1286 if let Some(element_id) = element_id {
1287 self.with_element_state(element_id, f)
1288 } else {
1289 f(None, self).0
1290 }
1291 }
1292
1293 fn content_mask(&self) -> ContentMask<Pixels> {
1294 self.window()
1295 .content_mask_stack
1296 .last()
1297 .cloned()
1298 .unwrap_or_else(|| ContentMask {
1299 bounds: Bounds {
1300 origin: Point::default(),
1301 size: self.window().content_size,
1302 },
1303 })
1304 }
1305
1306 fn rem_size(&self) -> Pixels {
1307 self.window().rem_size
1308 }
1309}
1310
1311impl BorrowWindow for WindowContext<'_, '_> {
1312 fn window(&self) -> &Window {
1313 &*self.window
1314 }
1315
1316 fn window_mut(&mut self) -> &mut Window {
1317 &mut *self.window
1318 }
1319}
1320
1321pub struct ViewContext<'a, 'w, S> {
1322 window_cx: WindowContext<'a, 'w>,
1323 entity_type: PhantomData<S>,
1324 entity_id: EntityId,
1325}
1326
1327impl<S> BorrowAppContext for ViewContext<'_, '_, S> {
1328 fn app_mut(&mut self) -> &mut AppContext {
1329 &mut *self.window_cx.app
1330 }
1331}
1332
1333impl<S> BorrowWindow for ViewContext<'_, '_, S> {
1334 fn window(&self) -> &Window {
1335 &self.window_cx.window
1336 }
1337
1338 fn window_mut(&mut self) -> &mut Window {
1339 &mut *self.window_cx.window
1340 }
1341}
1342
1343impl<'a, 'w, V: Send + Sync + 'static> ViewContext<'a, 'w, V> {
1344 fn mutable(app: &'a mut AppContext, window: &'w mut Window, entity_id: EntityId) -> Self {
1345 Self {
1346 window_cx: WindowContext::mutable(app, window),
1347 entity_id,
1348 entity_type: PhantomData,
1349 }
1350 }
1351
1352 pub fn handle(&self) -> WeakHandle<V> {
1353 self.entities.weak_handle(self.entity_id)
1354 }
1355
1356 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1357 self.window.z_index_stack.push(order);
1358 let result = f(self);
1359 self.window.z_index_stack.pop();
1360 result
1361 }
1362
1363 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + Send + 'static) {
1364 let entity = self.handle();
1365 self.window_cx.on_next_frame(move |cx| {
1366 entity.update(cx, f).ok();
1367 });
1368 }
1369
1370 pub fn observe<E: Send + Sync + 'static>(
1371 &mut self,
1372 handle: &Handle<E>,
1373 on_notify: impl Fn(&mut V, Handle<E>, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1374 ) -> Subscription {
1375 let this = self.handle();
1376 let handle = handle.downgrade();
1377 let window_handle = self.window.handle;
1378 self.app.observers.insert(
1379 handle.entity_id,
1380 Box::new(move |cx| {
1381 cx.update_window(window_handle.id, |cx| {
1382 if let Some(handle) = handle.upgrade() {
1383 this.update(cx, |this, cx| on_notify(this, handle, cx))
1384 .is_ok()
1385 } else {
1386 false
1387 }
1388 })
1389 .unwrap_or(false)
1390 }),
1391 )
1392 }
1393
1394 pub fn subscribe<E: EventEmitter + Send + Sync + 'static>(
1395 &mut self,
1396 handle: &Handle<E>,
1397 on_event: impl Fn(&mut V, Handle<E>, &E::Event, &mut ViewContext<'_, '_, V>)
1398 + Send
1399 + Sync
1400 + 'static,
1401 ) -> Subscription {
1402 let this = self.handle();
1403 let handle = handle.downgrade();
1404 let window_handle = self.window.handle;
1405 self.app.event_listeners.insert(
1406 handle.entity_id,
1407 Box::new(move |event, cx| {
1408 cx.update_window(window_handle.id, |cx| {
1409 if let Some(handle) = handle.upgrade() {
1410 let event = event.downcast_ref().expect("invalid event type");
1411 this.update(cx, |this, cx| on_event(this, handle, event, cx))
1412 .is_ok()
1413 } else {
1414 false
1415 }
1416 })
1417 .unwrap_or(false)
1418 }),
1419 )
1420 }
1421
1422 pub fn on_release(
1423 &mut self,
1424 on_release: impl Fn(&mut V, &mut WindowContext) + Send + Sync + 'static,
1425 ) -> Subscription {
1426 let window_handle = self.window.handle;
1427 self.app.release_listeners.insert(
1428 self.entity_id,
1429 Box::new(move |this, cx| {
1430 let this = this.downcast_mut().expect("invalid entity type");
1431 // todo!("are we okay with silently swallowing the error?")
1432 let _ = cx.update_window(window_handle.id, |cx| on_release(this, cx));
1433 }),
1434 )
1435 }
1436
1437 pub fn observe_release<E: Send + Sync + 'static>(
1438 &mut self,
1439 handle: &Handle<E>,
1440 on_release: impl Fn(&mut V, &mut E, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1441 ) -> Subscription {
1442 let this = self.handle();
1443 let window_handle = self.window.handle;
1444 self.app.release_listeners.insert(
1445 handle.entity_id,
1446 Box::new(move |entity, cx| {
1447 let entity = entity.downcast_mut().expect("invalid entity type");
1448 // todo!("are we okay with silently swallowing the error?")
1449 let _ = cx.update_window(window_handle.id, |cx| {
1450 this.update(cx, |this, cx| on_release(this, entity, cx))
1451 });
1452 }),
1453 )
1454 }
1455
1456 pub fn notify(&mut self) {
1457 self.window_cx.notify();
1458 self.window_cx.app.push_effect(Effect::Notify {
1459 emitter: self.entity_id,
1460 });
1461 }
1462
1463 pub fn on_focus_changed(
1464 &mut self,
1465 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + Send + Sync + 'static,
1466 ) {
1467 let handle = self.handle();
1468 self.window.focus_listeners.push(Arc::new(move |event, cx| {
1469 handle
1470 .update(cx, |view, cx| listener(view, event, cx))
1471 .log_err();
1472 }));
1473 }
1474
1475 pub fn with_key_listeners<R>(
1476 &mut self,
1477 key_listeners: &[(TypeId, KeyListener<V>)],
1478 f: impl FnOnce(&mut Self) -> R,
1479 ) -> R {
1480 if !self.window.freeze_key_dispatch_stack {
1481 for (event_type, listener) in key_listeners.iter().cloned() {
1482 let handle = self.handle();
1483 let listener = Arc::new(
1484 move |event: &dyn Any,
1485 context_stack: &[&DispatchContext],
1486 phase: DispatchPhase,
1487 cx: &mut WindowContext<'_, '_>| {
1488 handle
1489 .update(cx, |view, cx| {
1490 listener(view, event, context_stack, phase, cx)
1491 })
1492 .log_err()
1493 .flatten()
1494 },
1495 );
1496 self.window
1497 .key_dispatch_stack
1498 .push(KeyDispatchStackFrame::Listener {
1499 event_type,
1500 listener,
1501 });
1502 }
1503 }
1504
1505 let result = f(self);
1506
1507 if !self.window.freeze_key_dispatch_stack {
1508 let prev_len = self.window.key_dispatch_stack.len() - key_listeners.len();
1509 self.window.key_dispatch_stack.truncate(prev_len);
1510 }
1511
1512 result
1513 }
1514
1515 pub fn with_key_dispatch_context<R>(
1516 &mut self,
1517 context: DispatchContext,
1518 f: impl FnOnce(&mut Self) -> R,
1519 ) -> R {
1520 if context.is_empty() {
1521 return f(self);
1522 }
1523
1524 if !self.window.freeze_key_dispatch_stack {
1525 self.window
1526 .key_dispatch_stack
1527 .push(KeyDispatchStackFrame::Context(context));
1528 }
1529
1530 let result = f(self);
1531
1532 if !self.window.freeze_key_dispatch_stack {
1533 self.window.key_dispatch_stack.pop();
1534 }
1535
1536 result
1537 }
1538
1539 pub fn with_focus<R>(
1540 &mut self,
1541 focus_handle: FocusHandle,
1542 f: impl FnOnce(&mut Self) -> R,
1543 ) -> R {
1544 if let Some(parent_focus_id) = self.window.focus_stack.last().copied() {
1545 self.window
1546 .focus_parents_by_child
1547 .insert(focus_handle.id, parent_focus_id);
1548 }
1549 self.window.focus_stack.push(focus_handle.id);
1550
1551 if Some(focus_handle.id) == self.window.focus {
1552 self.window.freeze_key_dispatch_stack = true;
1553 }
1554
1555 let result = f(self);
1556
1557 self.window.focus_stack.pop();
1558 result
1559 }
1560
1561 pub fn run_on_main<R>(
1562 &mut self,
1563 view: &mut V,
1564 f: impl FnOnce(&mut V, &mut MainThread<ViewContext<'_, '_, V>>) -> R + Send + 'static,
1565 ) -> Task<Result<R>>
1566 where
1567 R: Send + 'static,
1568 {
1569 if self.executor.is_main_thread() {
1570 let cx = unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(self) };
1571 Task::ready(Ok(f(view, cx)))
1572 } else {
1573 let handle = self.handle().upgrade().unwrap();
1574 self.window_cx.run_on_main(move |cx| handle.update(cx, f))
1575 }
1576 }
1577
1578 pub fn spawn<Fut, R>(
1579 &mut self,
1580 f: impl FnOnce(WeakHandle<V>, AsyncWindowContext) -> Fut + Send + 'static,
1581 ) -> Task<R>
1582 where
1583 R: Send + 'static,
1584 Fut: Future<Output = R> + Send + 'static,
1585 {
1586 let handle = self.handle();
1587 self.window_cx.spawn(move |_, cx| {
1588 let result = f(handle, cx);
1589 async move { result.await }
1590 })
1591 }
1592
1593 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1594 where
1595 G: 'static + Send + Sync,
1596 {
1597 let mut global = self.app.lease_global::<G>();
1598 let result = f(global.as_mut(), self);
1599 self.app.restore_global(global);
1600 result
1601 }
1602
1603 pub fn observe_global<G: 'static>(
1604 &mut self,
1605 f: impl Fn(&mut V, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1606 ) -> Subscription {
1607 let window_id = self.window.handle.id;
1608 let handle = self.handle();
1609 self.global_observers.insert(
1610 TypeId::of::<G>(),
1611 Box::new(move |cx| {
1612 cx.update_window(window_id, |cx| {
1613 handle.update(cx, |view, cx| f(view, cx)).is_ok()
1614 })
1615 .unwrap_or(false)
1616 }),
1617 )
1618 }
1619
1620 pub fn on_mouse_event<Event: 'static>(
1621 &mut self,
1622 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + Send + Sync + 'static,
1623 ) {
1624 let handle = self.handle().upgrade().unwrap();
1625 self.window_cx.on_mouse_event(move |event, phase, cx| {
1626 handle.update(cx, |view, cx| {
1627 handler(view, event, phase, cx);
1628 })
1629 });
1630 }
1631}
1632
1633impl<'a, 'w, V: EventEmitter + Send + Sync + 'static> ViewContext<'a, 'w, V> {
1634 pub fn emit(&mut self, event: V::Event) {
1635 let emitter = self.entity_id;
1636 self.app.push_effect(Effect::Emit {
1637 emitter,
1638 event: Box::new(event),
1639 });
1640 }
1641}
1642
1643impl<'a, 'w, V> Context for ViewContext<'a, 'w, V>
1644where
1645 V: 'static + Send + Sync,
1646{
1647 type EntityContext<'b, 'c, U: 'static + Send + Sync> = ViewContext<'b, 'c, U>;
1648 type Result<U> = U;
1649
1650 fn entity<T2: Send + Sync + 'static>(
1651 &mut self,
1652 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T2>) -> T2,
1653 ) -> Handle<T2> {
1654 self.window_cx.entity(build_entity)
1655 }
1656
1657 fn update_entity<U: 'static + Send + Sync, R>(
1658 &mut self,
1659 handle: &Handle<U>,
1660 update: impl FnOnce(&mut U, &mut Self::EntityContext<'_, '_, U>) -> R,
1661 ) -> R {
1662 self.window_cx.update_entity(handle, update)
1663 }
1664}
1665
1666impl<'a, 'w, S: 'static> std::ops::Deref for ViewContext<'a, 'w, S> {
1667 type Target = WindowContext<'a, 'w>;
1668
1669 fn deref(&self) -> &Self::Target {
1670 &self.window_cx
1671 }
1672}
1673
1674impl<'a, 'w, S: 'static> std::ops::DerefMut for ViewContext<'a, 'w, S> {
1675 fn deref_mut(&mut self) -> &mut Self::Target {
1676 &mut self.window_cx
1677 }
1678}
1679
1680// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
1681slotmap::new_key_type! { pub struct WindowId; }
1682
1683#[derive(PartialEq, Eq)]
1684pub struct WindowHandle<S> {
1685 id: WindowId,
1686 state_type: PhantomData<S>,
1687}
1688
1689impl<S> Copy for WindowHandle<S> {}
1690
1691impl<S> Clone for WindowHandle<S> {
1692 fn clone(&self) -> Self {
1693 WindowHandle {
1694 id: self.id,
1695 state_type: PhantomData,
1696 }
1697 }
1698}
1699
1700impl<S> WindowHandle<S> {
1701 pub fn new(id: WindowId) -> Self {
1702 WindowHandle {
1703 id,
1704 state_type: PhantomData,
1705 }
1706 }
1707}
1708
1709impl<S: 'static> Into<AnyWindowHandle> for WindowHandle<S> {
1710 fn into(self) -> AnyWindowHandle {
1711 AnyWindowHandle {
1712 id: self.id,
1713 state_type: TypeId::of::<S>(),
1714 }
1715 }
1716}
1717
1718#[derive(Copy, Clone, PartialEq, Eq)]
1719pub struct AnyWindowHandle {
1720 pub(crate) id: WindowId,
1721 state_type: TypeId,
1722}
1723
1724#[cfg(any(test, feature = "test"))]
1725impl From<SmallVec<[u32; 16]>> for StackingOrder {
1726 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
1727 StackingOrder(small_vec)
1728 }
1729}
1730
1731#[derive(Clone, Debug, Eq, PartialEq, Hash)]
1732pub enum ElementId {
1733 View(EntityId),
1734 Number(usize),
1735 Name(SharedString),
1736 FocusHandle(FocusId),
1737}
1738
1739impl From<EntityId> for ElementId {
1740 fn from(id: EntityId) -> Self {
1741 ElementId::View(id)
1742 }
1743}
1744
1745impl From<usize> for ElementId {
1746 fn from(id: usize) -> Self {
1747 ElementId::Number(id)
1748 }
1749}
1750
1751impl From<i32> for ElementId {
1752 fn from(id: i32) -> Self {
1753 Self::Number(id as usize)
1754 }
1755}
1756
1757impl From<SharedString> for ElementId {
1758 fn from(name: SharedString) -> Self {
1759 ElementId::Name(name)
1760 }
1761}
1762
1763impl From<&'static str> for ElementId {
1764 fn from(name: &'static str) -> Self {
1765 ElementId::Name(name.into())
1766 }
1767}
1768
1769impl<'a> From<&'a FocusHandle> for ElementId {
1770 fn from(handle: &'a FocusHandle) -> Self {
1771 ElementId::FocusHandle(handle.id)
1772 }
1773}