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, Path,
7 Pixels, Platform, PlatformAtlas, PlatformWindow, Point, PolychromeSprite, Quad, Reference,
8 RenderGlyphParams, RenderImageParams, RenderSvgParams, ScaledPixels, SceneBuilder, Shadow,
9 SharedString, Size, Style, Subscription, TaffyLayoutEngine, Task, Underline, UnderlineStyle,
10 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 // Just in case any handlers added new handlers, which is weird, but possible.
929 handlers.extend(
930 self.window
931 .mouse_listeners
932 .get_mut(&any_mouse_event.type_id())
933 .into_iter()
934 .flat_map(|handlers| handlers.drain(..)),
935 );
936 self.window
937 .mouse_listeners
938 .insert(any_mouse_event.type_id(), handlers);
939 }
940 } else if let Some(any_key_event) = event.keyboard_event() {
941 let key_dispatch_stack = mem::take(&mut self.window.key_dispatch_stack);
942 let key_event_type = any_key_event.type_id();
943 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
944
945 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
946 match frame {
947 KeyDispatchStackFrame::Listener {
948 event_type,
949 listener,
950 } => {
951 if key_event_type == *event_type {
952 if let Some(action) = listener(
953 any_key_event,
954 &context_stack,
955 DispatchPhase::Capture,
956 self,
957 ) {
958 self.dispatch_action(action, &key_dispatch_stack[..ix]);
959 }
960 if !self.app.propagate_event {
961 break;
962 }
963 }
964 }
965 KeyDispatchStackFrame::Context(context) => {
966 context_stack.push(&context);
967 }
968 }
969 }
970
971 if self.app.propagate_event {
972 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
973 match frame {
974 KeyDispatchStackFrame::Listener {
975 event_type,
976 listener,
977 } => {
978 if key_event_type == *event_type {
979 if let Some(action) = listener(
980 any_key_event,
981 &context_stack,
982 DispatchPhase::Bubble,
983 self,
984 ) {
985 self.dispatch_action(action, &key_dispatch_stack[..ix]);
986 }
987
988 if !self.app.propagate_event {
989 break;
990 }
991 }
992 }
993 KeyDispatchStackFrame::Context(_) => {
994 context_stack.pop();
995 }
996 }
997 }
998 }
999
1000 drop(context_stack);
1001 self.window.key_dispatch_stack = key_dispatch_stack;
1002 }
1003
1004 true
1005 }
1006
1007 pub fn match_keystroke(
1008 &mut self,
1009 element_id: &GlobalElementId,
1010 keystroke: &Keystroke,
1011 context_stack: &[&DispatchContext],
1012 ) -> KeyMatch {
1013 let key_match = self
1014 .window
1015 .key_matchers
1016 .get_mut(element_id)
1017 .unwrap()
1018 .match_keystroke(keystroke, context_stack);
1019
1020 if key_match.is_some() {
1021 for matcher in self.window.key_matchers.values_mut() {
1022 matcher.clear_pending();
1023 }
1024 }
1025
1026 key_match
1027 }
1028
1029 pub fn observe_global<G: 'static>(
1030 &mut self,
1031 f: impl Fn(&G, &mut WindowContext<'_, '_>) + Send + Sync + 'static,
1032 ) -> Subscription {
1033 let window_id = self.window.handle.id;
1034 self.global_observers.insert(
1035 TypeId::of::<G>(),
1036 Box::new(move |global, cx| {
1037 let global = global.downcast_ref::<G>().unwrap();
1038 cx.update_window(window_id, |cx| f(global, cx)).is_ok()
1039 }),
1040 )
1041 }
1042
1043 fn dispatch_action(
1044 &mut self,
1045 action: Box<dyn Action>,
1046 dispatch_stack: &[KeyDispatchStackFrame],
1047 ) {
1048 let action_type = action.as_any().type_id();
1049
1050 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1051 for listener in &global_listeners {
1052 listener(action.as_ref(), DispatchPhase::Capture, self);
1053 if !self.app.propagate_event {
1054 break;
1055 }
1056 }
1057 global_listeners.extend(
1058 self.global_action_listeners
1059 .remove(&action_type)
1060 .unwrap_or_default(),
1061 );
1062 self.global_action_listeners
1063 .insert(action_type, global_listeners);
1064 }
1065
1066 if self.app.propagate_event {
1067 for stack_frame in dispatch_stack {
1068 if let KeyDispatchStackFrame::Listener {
1069 event_type,
1070 listener,
1071 } = stack_frame
1072 {
1073 if action_type == *event_type {
1074 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1075 if !self.app.propagate_event {
1076 break;
1077 }
1078 }
1079 }
1080 }
1081 }
1082
1083 if self.app.propagate_event {
1084 for stack_frame in dispatch_stack.iter().rev() {
1085 if let KeyDispatchStackFrame::Listener {
1086 event_type,
1087 listener,
1088 } = stack_frame
1089 {
1090 if action_type == *event_type {
1091 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1092 if !self.app.propagate_event {
1093 break;
1094 }
1095 }
1096 }
1097 }
1098 }
1099
1100 if self.app.propagate_event {
1101 if let Some(mut global_listeners) =
1102 self.app.global_action_listeners.remove(&action_type)
1103 {
1104 for listener in global_listeners.iter().rev() {
1105 listener(action.as_ref(), DispatchPhase::Bubble, self);
1106 if !self.app.propagate_event {
1107 break;
1108 }
1109 }
1110 global_listeners.extend(
1111 self.global_action_listeners
1112 .remove(&action_type)
1113 .unwrap_or_default(),
1114 );
1115 self.global_action_listeners
1116 .insert(action_type, global_listeners);
1117 }
1118 }
1119 }
1120}
1121
1122impl<'a, 'w> MainThread<WindowContext<'a, 'w>> {
1123 fn platform(&self) -> &dyn Platform {
1124 self.platform.borrow_on_main_thread()
1125 }
1126}
1127
1128impl Context for WindowContext<'_, '_> {
1129 type EntityContext<'a, 'w, T: 'static + Send + Sync> = ViewContext<'a, 'w, T>;
1130 type Result<T> = T;
1131
1132 fn entity<T: Send + Sync + 'static>(
1133 &mut self,
1134 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
1135 ) -> Handle<T> {
1136 let slot = self.app.entities.reserve();
1137 let entity = build_entity(&mut ViewContext::mutable(
1138 &mut *self.app,
1139 &mut self.window,
1140 slot.id,
1141 ));
1142 self.entities.insert(slot, entity)
1143 }
1144
1145 fn update_entity<T: Send + Sync + 'static, R>(
1146 &mut self,
1147 handle: &Handle<T>,
1148 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
1149 ) -> R {
1150 let mut entity = self.entities.lease(handle);
1151 let result = update(
1152 &mut *entity,
1153 &mut ViewContext::mutable(&mut *self.app, &mut *self.window, handle.id),
1154 );
1155 self.entities.end_lease(entity);
1156 result
1157 }
1158}
1159
1160impl<'a, 'w> std::ops::Deref for WindowContext<'a, 'w> {
1161 type Target = AppContext;
1162
1163 fn deref(&self) -> &Self::Target {
1164 &self.app
1165 }
1166}
1167
1168impl<'a, 'w> std::ops::DerefMut for WindowContext<'a, 'w> {
1169 fn deref_mut(&mut self) -> &mut Self::Target {
1170 &mut self.app
1171 }
1172}
1173
1174impl BorrowAppContext for WindowContext<'_, '_> {
1175 fn app_mut(&mut self) -> &mut AppContext {
1176 &mut *self.app
1177 }
1178}
1179
1180pub trait BorrowWindow: BorrowAppContext {
1181 fn window(&self) -> &Window;
1182 fn window_mut(&mut self) -> &mut Window;
1183
1184 fn with_element_id<R>(
1185 &mut self,
1186 id: impl Into<ElementId>,
1187 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1188 ) -> R {
1189 let keymap = self.app_mut().keymap.clone();
1190 let window = self.window_mut();
1191 window.element_id_stack.push(id.into());
1192 let global_id = window.element_id_stack.clone();
1193
1194 if window.key_matchers.get(&global_id).is_none() {
1195 window.key_matchers.insert(
1196 global_id.clone(),
1197 window
1198 .prev_frame_key_matchers
1199 .remove(&global_id)
1200 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1201 );
1202 }
1203
1204 let result = f(global_id, self);
1205 self.window_mut().element_id_stack.pop();
1206 result
1207 }
1208
1209 fn with_content_mask<R>(
1210 &mut self,
1211 mask: ContentMask<Pixels>,
1212 f: impl FnOnce(&mut Self) -> R,
1213 ) -> R {
1214 let mask = mask.intersect(&self.content_mask());
1215 self.window_mut().content_mask_stack.push(mask);
1216 let result = f(self);
1217 self.window_mut().content_mask_stack.pop();
1218 result
1219 }
1220
1221 fn with_element_offset<R>(
1222 &mut self,
1223 offset: Option<Point<Pixels>>,
1224 f: impl FnOnce(&mut Self) -> R,
1225 ) -> R {
1226 let Some(offset) = offset else {
1227 return f(self);
1228 };
1229
1230 let offset = self.element_offset() + offset;
1231 self.window_mut().element_offset_stack.push(offset);
1232 let result = f(self);
1233 self.window_mut().element_offset_stack.pop();
1234 result
1235 }
1236
1237 fn element_offset(&self) -> Point<Pixels> {
1238 self.window()
1239 .element_offset_stack
1240 .last()
1241 .copied()
1242 .unwrap_or_default()
1243 }
1244
1245 fn with_element_state<S: 'static + Send + Sync, R>(
1246 &mut self,
1247 id: ElementId,
1248 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1249 ) -> R {
1250 self.with_element_id(id, |global_id, cx| {
1251 if let Some(any) = cx
1252 .window_mut()
1253 .element_states
1254 .remove(&global_id)
1255 .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
1256 {
1257 // Using the extra inner option to avoid needing to reallocate a new box.
1258 let mut state_box = any
1259 .downcast::<Option<S>>()
1260 .expect("invalid element state type for id");
1261 let state = state_box
1262 .take()
1263 .expect("element state is already on the stack");
1264 let (result, state) = f(Some(state), cx);
1265 state_box.replace(state);
1266 cx.window_mut().element_states.insert(global_id, state_box);
1267 result
1268 } else {
1269 let (result, state) = f(None, cx);
1270 cx.window_mut()
1271 .element_states
1272 .insert(global_id, Box::new(Some(state)));
1273 result
1274 }
1275 })
1276 }
1277
1278 fn with_optional_element_state<S: 'static + Send + Sync, R>(
1279 &mut self,
1280 element_id: Option<ElementId>,
1281 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1282 ) -> R {
1283 if let Some(element_id) = element_id {
1284 self.with_element_state(element_id, f)
1285 } else {
1286 f(None, self).0
1287 }
1288 }
1289
1290 fn content_mask(&self) -> ContentMask<Pixels> {
1291 self.window()
1292 .content_mask_stack
1293 .last()
1294 .cloned()
1295 .unwrap_or_else(|| ContentMask {
1296 bounds: Bounds {
1297 origin: Point::default(),
1298 size: self.window().content_size,
1299 },
1300 })
1301 }
1302
1303 fn rem_size(&self) -> Pixels {
1304 self.window().rem_size
1305 }
1306}
1307
1308impl BorrowWindow for WindowContext<'_, '_> {
1309 fn window(&self) -> &Window {
1310 &*self.window
1311 }
1312
1313 fn window_mut(&mut self) -> &mut Window {
1314 &mut *self.window
1315 }
1316}
1317
1318pub struct ViewContext<'a, 'w, S> {
1319 window_cx: WindowContext<'a, 'w>,
1320 entity_type: PhantomData<S>,
1321 entity_id: EntityId,
1322}
1323
1324impl<S> BorrowAppContext for ViewContext<'_, '_, S> {
1325 fn app_mut(&mut self) -> &mut AppContext {
1326 &mut *self.window_cx.app
1327 }
1328}
1329
1330impl<S> BorrowWindow for ViewContext<'_, '_, S> {
1331 fn window(&self) -> &Window {
1332 &self.window_cx.window
1333 }
1334
1335 fn window_mut(&mut self) -> &mut Window {
1336 &mut *self.window_cx.window
1337 }
1338}
1339
1340impl<'a, 'w, V: Send + Sync + 'static> ViewContext<'a, 'w, V> {
1341 fn mutable(app: &'a mut AppContext, window: &'w mut Window, entity_id: EntityId) -> Self {
1342 Self {
1343 window_cx: WindowContext::mutable(app, window),
1344 entity_id,
1345 entity_type: PhantomData,
1346 }
1347 }
1348
1349 pub fn handle(&self) -> WeakHandle<V> {
1350 self.entities.weak_handle(self.entity_id)
1351 }
1352
1353 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1354 self.window.z_index_stack.push(order);
1355 let result = f(self);
1356 self.window.z_index_stack.pop();
1357 result
1358 }
1359
1360 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + Send + 'static) {
1361 let entity = self.handle();
1362 self.window_cx.on_next_frame(move |cx| {
1363 entity.update(cx, f).ok();
1364 });
1365 }
1366
1367 pub fn observe<E: Send + Sync + 'static>(
1368 &mut self,
1369 handle: &Handle<E>,
1370 on_notify: impl Fn(&mut V, Handle<E>, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1371 ) -> Subscription {
1372 let this = self.handle();
1373 let handle = handle.downgrade();
1374 let window_handle = self.window.handle;
1375 self.app.observers.insert(
1376 handle.id,
1377 Box::new(move |cx| {
1378 cx.update_window(window_handle.id, |cx| {
1379 if let Some(handle) = handle.upgrade() {
1380 this.update(cx, |this, cx| on_notify(this, handle, cx))
1381 .is_ok()
1382 } else {
1383 false
1384 }
1385 })
1386 .unwrap_or(false)
1387 }),
1388 )
1389 }
1390
1391 pub fn subscribe<E: EventEmitter + Send + Sync + 'static>(
1392 &mut self,
1393 handle: &Handle<E>,
1394 on_event: impl Fn(&mut V, Handle<E>, &E::Event, &mut ViewContext<'_, '_, V>)
1395 + Send
1396 + Sync
1397 + 'static,
1398 ) -> Subscription {
1399 let this = self.handle();
1400 let handle = handle.downgrade();
1401 let window_handle = self.window.handle;
1402 self.app.event_listeners.insert(
1403 handle.id,
1404 Box::new(move |event, cx| {
1405 cx.update_window(window_handle.id, |cx| {
1406 if let Some(handle) = handle.upgrade() {
1407 let event = event.downcast_ref().expect("invalid event type");
1408 this.update(cx, |this, cx| on_event(this, handle, event, cx))
1409 .is_ok()
1410 } else {
1411 false
1412 }
1413 })
1414 .unwrap_or(false)
1415 }),
1416 )
1417 }
1418
1419 pub fn on_release(
1420 &mut self,
1421 on_release: impl Fn(&mut V, &mut WindowContext) + Send + Sync + 'static,
1422 ) -> Subscription {
1423 let window_handle = self.window.handle;
1424 self.app.release_listeners.insert(
1425 self.entity_id,
1426 Box::new(move |this, cx| {
1427 let this = this.downcast_mut().expect("invalid entity type");
1428 // todo!("are we okay with silently swallowing the error?")
1429 let _ = cx.update_window(window_handle.id, |cx| on_release(this, cx));
1430 }),
1431 )
1432 }
1433
1434 pub fn observe_release<E: Send + Sync + 'static>(
1435 &mut self,
1436 handle: &Handle<E>,
1437 on_release: impl Fn(&mut V, &mut E, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1438 ) -> Subscription {
1439 let this = self.handle();
1440 let window_handle = self.window.handle;
1441 self.app.release_listeners.insert(
1442 handle.id,
1443 Box::new(move |entity, cx| {
1444 let entity = entity.downcast_mut().expect("invalid entity type");
1445 // todo!("are we okay with silently swallowing the error?")
1446 let _ = cx.update_window(window_handle.id, |cx| {
1447 this.update(cx, |this, cx| on_release(this, entity, cx))
1448 });
1449 }),
1450 )
1451 }
1452
1453 pub fn notify(&mut self) {
1454 self.window_cx.notify();
1455 self.window_cx.app.push_effect(Effect::Notify {
1456 emitter: self.entity_id,
1457 });
1458 }
1459
1460 pub fn on_focus_changed(
1461 &mut self,
1462 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + Send + Sync + 'static,
1463 ) {
1464 let handle = self.handle();
1465 self.window.focus_listeners.push(Arc::new(move |event, cx| {
1466 handle
1467 .update(cx, |view, cx| listener(view, event, cx))
1468 .log_err();
1469 }));
1470 }
1471
1472 pub fn with_key_listeners<R>(
1473 &mut self,
1474 key_listeners: &[(TypeId, KeyListener<V>)],
1475 f: impl FnOnce(&mut Self) -> R,
1476 ) -> R {
1477 if !self.window.freeze_key_dispatch_stack {
1478 for (event_type, listener) in key_listeners.iter().cloned() {
1479 let handle = self.handle();
1480 let listener = Arc::new(
1481 move |event: &dyn Any,
1482 context_stack: &[&DispatchContext],
1483 phase: DispatchPhase,
1484 cx: &mut WindowContext<'_, '_>| {
1485 handle
1486 .update(cx, |view, cx| {
1487 listener(view, event, context_stack, phase, cx)
1488 })
1489 .log_err()
1490 .flatten()
1491 },
1492 );
1493 self.window
1494 .key_dispatch_stack
1495 .push(KeyDispatchStackFrame::Listener {
1496 event_type,
1497 listener,
1498 });
1499 }
1500 }
1501
1502 let result = f(self);
1503
1504 if !self.window.freeze_key_dispatch_stack {
1505 let prev_len = self.window.key_dispatch_stack.len() - key_listeners.len();
1506 self.window.key_dispatch_stack.truncate(prev_len);
1507 }
1508
1509 result
1510 }
1511
1512 pub fn with_key_dispatch_context<R>(
1513 &mut self,
1514 context: DispatchContext,
1515 f: impl FnOnce(&mut Self) -> R,
1516 ) -> R {
1517 if context.is_empty() {
1518 return f(self);
1519 }
1520
1521 if !self.window.freeze_key_dispatch_stack {
1522 self.window
1523 .key_dispatch_stack
1524 .push(KeyDispatchStackFrame::Context(context));
1525 }
1526
1527 let result = f(self);
1528
1529 if !self.window.freeze_key_dispatch_stack {
1530 self.window.key_dispatch_stack.pop();
1531 }
1532
1533 result
1534 }
1535
1536 pub fn with_focus<R>(
1537 &mut self,
1538 focus_handle: FocusHandle,
1539 f: impl FnOnce(&mut Self) -> R,
1540 ) -> R {
1541 if let Some(parent_focus_id) = self.window.focus_stack.last().copied() {
1542 self.window
1543 .focus_parents_by_child
1544 .insert(focus_handle.id, parent_focus_id);
1545 }
1546 self.window.focus_stack.push(focus_handle.id);
1547
1548 if Some(focus_handle.id) == self.window.focus {
1549 self.window.freeze_key_dispatch_stack = true;
1550 }
1551
1552 let result = f(self);
1553
1554 self.window.focus_stack.pop();
1555 result
1556 }
1557
1558 pub fn run_on_main<R>(
1559 &mut self,
1560 view: &mut V,
1561 f: impl FnOnce(&mut V, &mut MainThread<ViewContext<'_, '_, V>>) -> R + Send + 'static,
1562 ) -> Task<Result<R>>
1563 where
1564 R: Send + 'static,
1565 {
1566 if self.executor.is_main_thread() {
1567 let cx = unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(self) };
1568 Task::ready(Ok(f(view, cx)))
1569 } else {
1570 let handle = self.handle().upgrade().unwrap();
1571 self.window_cx.run_on_main(move |cx| handle.update(cx, f))
1572 }
1573 }
1574
1575 pub fn spawn<Fut, R>(
1576 &mut self,
1577 f: impl FnOnce(WeakHandle<V>, AsyncWindowContext) -> Fut + Send + 'static,
1578 ) -> Task<R>
1579 where
1580 R: Send + 'static,
1581 Fut: Future<Output = R> + Send + 'static,
1582 {
1583 let handle = self.handle();
1584 self.window_cx.spawn(move |_, cx| {
1585 let result = f(handle, cx);
1586 async move { result.await }
1587 })
1588 }
1589
1590 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1591 where
1592 G: 'static + Send + Sync,
1593 {
1594 let mut global = self.app.lease_global::<G>();
1595 let result = f(global.as_mut(), self);
1596 self.app.restore_global(global);
1597 result
1598 }
1599
1600 pub fn observe_global<G: 'static>(
1601 &mut self,
1602 f: impl Fn(&mut V, &G, &mut ViewContext<'_, '_, V>) + Send + Sync + 'static,
1603 ) -> Subscription {
1604 let window_id = self.window.handle.id;
1605 let handle = self.handle();
1606 self.global_observers.insert(
1607 TypeId::of::<G>(),
1608 Box::new(move |global, cx| {
1609 let global = global.downcast_ref::<G>().unwrap();
1610 cx.update_window(window_id, |cx| {
1611 handle.update(cx, |view, cx| f(view, global, cx)).is_ok()
1612 })
1613 .unwrap_or(false)
1614 }),
1615 )
1616 }
1617
1618 pub fn on_mouse_event<Event: 'static>(
1619 &mut self,
1620 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + Send + Sync + 'static,
1621 ) {
1622 let handle = self.handle().upgrade().unwrap();
1623 self.window_cx.on_mouse_event(move |event, phase, cx| {
1624 handle.update(cx, |view, cx| {
1625 handler(view, event, phase, cx);
1626 })
1627 });
1628 }
1629
1630 pub(crate) fn start_drag(&mut self, drag: AnyDrag) {
1631 self.app.active_drag = Some(drag);
1632 self.notify();
1633 }
1634
1635 pub(crate) fn end_drag(&mut self) {
1636 self.app.active_drag = None;
1637 self.notify();
1638 }
1639}
1640
1641impl<'a, 'w, V: EventEmitter + Send + Sync + 'static> ViewContext<'a, 'w, V> {
1642 pub fn emit(&mut self, event: V::Event) {
1643 let emitter = self.entity_id;
1644 self.app.push_effect(Effect::Emit {
1645 emitter,
1646 event: Box::new(event),
1647 });
1648 }
1649}
1650
1651impl<'a, 'w, V> Context for ViewContext<'a, 'w, V>
1652where
1653 V: 'static + Send + Sync,
1654{
1655 type EntityContext<'b, 'c, U: 'static + Send + Sync> = ViewContext<'b, 'c, U>;
1656 type Result<U> = U;
1657
1658 fn entity<T2: Send + Sync + 'static>(
1659 &mut self,
1660 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T2>) -> T2,
1661 ) -> Handle<T2> {
1662 self.window_cx.entity(build_entity)
1663 }
1664
1665 fn update_entity<U: 'static + Send + Sync, R>(
1666 &mut self,
1667 handle: &Handle<U>,
1668 update: impl FnOnce(&mut U, &mut Self::EntityContext<'_, '_, U>) -> R,
1669 ) -> R {
1670 self.window_cx.update_entity(handle, update)
1671 }
1672}
1673
1674impl<'a, 'w, S: 'static> std::ops::Deref for ViewContext<'a, 'w, S> {
1675 type Target = WindowContext<'a, 'w>;
1676
1677 fn deref(&self) -> &Self::Target {
1678 &self.window_cx
1679 }
1680}
1681
1682impl<'a, 'w, S: 'static> std::ops::DerefMut for ViewContext<'a, 'w, S> {
1683 fn deref_mut(&mut self) -> &mut Self::Target {
1684 &mut self.window_cx
1685 }
1686}
1687
1688// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
1689slotmap::new_key_type! { pub struct WindowId; }
1690
1691#[derive(PartialEq, Eq)]
1692pub struct WindowHandle<S> {
1693 id: WindowId,
1694 state_type: PhantomData<S>,
1695}
1696
1697impl<S> Copy for WindowHandle<S> {}
1698
1699impl<S> Clone for WindowHandle<S> {
1700 fn clone(&self) -> Self {
1701 WindowHandle {
1702 id: self.id,
1703 state_type: PhantomData,
1704 }
1705 }
1706}
1707
1708impl<S> WindowHandle<S> {
1709 pub fn new(id: WindowId) -> Self {
1710 WindowHandle {
1711 id,
1712 state_type: PhantomData,
1713 }
1714 }
1715}
1716
1717impl<S: 'static> Into<AnyWindowHandle> for WindowHandle<S> {
1718 fn into(self) -> AnyWindowHandle {
1719 AnyWindowHandle {
1720 id: self.id,
1721 state_type: TypeId::of::<S>(),
1722 }
1723 }
1724}
1725
1726#[derive(Copy, Clone, PartialEq, Eq)]
1727pub struct AnyWindowHandle {
1728 pub(crate) id: WindowId,
1729 state_type: TypeId,
1730}
1731
1732#[cfg(any(test, feature = "test"))]
1733impl From<SmallVec<[u32; 16]>> for StackingOrder {
1734 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
1735 StackingOrder(small_vec)
1736 }
1737}
1738
1739#[derive(Clone, Debug, Eq, PartialEq, Hash)]
1740pub enum ElementId {
1741 View(EntityId),
1742 Number(usize),
1743 Name(SharedString),
1744 FocusHandle(FocusId),
1745}
1746
1747impl From<EntityId> for ElementId {
1748 fn from(id: EntityId) -> Self {
1749 ElementId::View(id)
1750 }
1751}
1752
1753impl From<usize> for ElementId {
1754 fn from(id: usize) -> Self {
1755 ElementId::Number(id)
1756 }
1757}
1758
1759impl From<i32> for ElementId {
1760 fn from(id: i32) -> Self {
1761 Self::Number(id as usize)
1762 }
1763}
1764
1765impl From<SharedString> for ElementId {
1766 fn from(name: SharedString) -> Self {
1767 ElementId::Name(name)
1768 }
1769}
1770
1771impl From<&'static str> for ElementId {
1772 fn from(name: &'static str) -> Self {
1773 ElementId::Name(name.into())
1774 }
1775}
1776
1777impl<'a> From<&'a FocusHandle> for ElementId {
1778 fn from(handle: &'a FocusHandle) -> Self {
1779 ElementId::FocusHandle(handle.id)
1780 }
1781}