1use crate::{
2 px, size, Action, AnyBox, AnyDrag, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
3 Bounds, BoxShadow, Context, Corners, DevicePixels, DispatchContext, DisplayId, Edges, Effect,
4 Element, EntityId, EventEmitter, ExternalPaths, FileDropEvent, FocusEvent, FontId,
5 GlobalElementId, GlyphId, Handle, Hsla, ImageData, InputEvent, IsZero, KeyListener, KeyMatch,
6 KeyMatcher, Keystroke, LayoutId, MainThread, MainThreadOnly, Modifiers, MonochromeSprite,
7 MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas,
8 PlatformWindow, Point, PolychromeSprite, Quad, Reference, RenderGlyphParams, RenderImageParams,
9 RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size, Style, Subscription,
10 TaffyLayoutEngine, Task, Underline, UnderlineStyle, WeakHandle, WindowOptions,
11 SUBPIXEL_VARIANTS,
12};
13use anyhow::Result;
14use collections::HashMap;
15use derive_more::{Deref, DerefMut};
16use parking_lot::RwLock;
17use slotmap::SlotMap;
18use smallvec::SmallVec;
19use std::{
20 any::{Any, TypeId},
21 borrow::{Borrow, BorrowMut, Cow},
22 fmt::Debug,
23 future::Future,
24 marker::PhantomData,
25 mem,
26 sync::{
27 atomic::{AtomicUsize, Ordering::SeqCst},
28 Arc,
29 },
30};
31use util::ResultExt;
32
33#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
34pub struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
35
36#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
37pub enum DispatchPhase {
38 /// After the capture phase comes the bubble phase, in which event handlers are
39 /// invoked front to back. This is the phase you'll usually want to use for event handlers.
40 #[default]
41 Bubble,
42 /// During the initial capture phase, event handlers are invoked back to front. This phase
43 /// is used for special purposes such as clearing the "pressed" state for click events. If
44 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
45 /// outside of the immediate region may rely on detecting non-local events during this phase.
46 Capture,
47}
48
49type AnyListener = Box<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + Send + 'static>;
50type AnyKeyListener = Box<
51 dyn Fn(
52 &dyn Any,
53 &[&DispatchContext],
54 DispatchPhase,
55 &mut WindowContext,
56 ) -> Option<Box<dyn Action>>
57 + Send
58 + 'static,
59>;
60type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + Send + '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,
432 {
433 let mut global = self.app.lease_global::<G>();
434 let result = f(&mut global, self);
435 self.app.end_global_lease(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 + '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 Box::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 if let Some(drag_handle_view) = &mut active_drag.drag_handle_view {
820 draw_any_view(drag_handle_view, available_space, cx);
821 }
822 cx.active_drag = Some(active_drag);
823 });
824 });
825 }
826
827 cx.window.root_view = Some(root_view);
828 let scene = cx.window.scene_builder.build();
829
830 cx.run_on_main(view, |_, cx| {
831 cx.window
832 .platform_window
833 .borrow_on_main_thread()
834 .draw(scene);
835 cx.window.dirty = false;
836 })
837 .detach();
838 });
839
840 fn draw_any_view(
841 view: &mut AnyView,
842 available_space: Size<AvailableSpace>,
843 cx: &mut ViewContext<()>,
844 ) {
845 cx.with_optional_element_state(view.id(), |element_state, cx| {
846 let mut element_state = view.initialize(&mut (), element_state, cx);
847 let layout_id = view.layout(&mut (), &mut element_state, cx);
848 cx.window
849 .layout_engine
850 .compute_layout(layout_id, available_space);
851 let bounds = cx.window.layout_engine.layout_bounds(layout_id);
852 view.paint(bounds, &mut (), &mut element_state, cx);
853 ((), element_state)
854 });
855 }
856 }
857
858 fn start_frame(&mut self) {
859 self.text_system().start_frame();
860
861 let window = &mut *self.window;
862
863 // Move the current frame element states to the previous frame.
864 // The new empty element states map will be populated for any element states we
865 // reference during the upcoming frame.
866 mem::swap(
867 &mut window.element_states,
868 &mut window.prev_frame_element_states,
869 );
870 window.element_states.clear();
871
872 // Make the current key matchers the previous, and then clear the current.
873 // An empty key matcher map will be created for every identified element in the
874 // upcoming frame.
875 mem::swap(
876 &mut window.key_matchers,
877 &mut window.prev_frame_key_matchers,
878 );
879 window.key_matchers.clear();
880
881 // Clear mouse event listeners, because elements add new element listeners
882 // when the upcoming frame is painted.
883 window.mouse_listeners.values_mut().for_each(Vec::clear);
884
885 // Clear focus state, because we determine what is focused when the new elements
886 // in the upcoming frame are initialized.
887 window.focus_listeners.clear();
888 window.key_dispatch_stack.clear();
889 window.focus_parents_by_child.clear();
890 window.freeze_key_dispatch_stack = false;
891 }
892
893 fn dispatch_event(&mut self, event: InputEvent) -> bool {
894 let event = match event {
895 InputEvent::MouseMove(mouse_move) => {
896 self.window.mouse_position = mouse_move.position;
897 InputEvent::MouseMove(mouse_move)
898 }
899 InputEvent::FileDrop(file_drop) => match file_drop {
900 FileDropEvent::Entered { position, files } => {
901 self.window.mouse_position = position;
902 self.active_drag.get_or_insert_with(|| AnyDrag {
903 drag_handle_view: None,
904 cursor_offset: position,
905 state: Box::new(files),
906 state_type: TypeId::of::<ExternalPaths>(),
907 });
908 InputEvent::MouseDown(MouseDownEvent {
909 position,
910 button: MouseButton::Left,
911 click_count: 1,
912 modifiers: Modifiers::default(),
913 })
914 }
915 FileDropEvent::Pending { position } => {
916 self.window.mouse_position = position;
917 InputEvent::MouseMove(MouseMoveEvent {
918 position,
919 pressed_button: Some(MouseButton::Left),
920 modifiers: Modifiers::default(),
921 })
922 }
923 FileDropEvent::Submit { position } => {
924 self.window.mouse_position = position;
925 InputEvent::MouseUp(MouseUpEvent {
926 button: MouseButton::Left,
927 position,
928 modifiers: Modifiers::default(),
929 click_count: 1,
930 })
931 }
932 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
933 button: MouseButton::Left,
934 position: Point::default(),
935 modifiers: Modifiers::default(),
936 click_count: 1,
937 }),
938 },
939 _ => event,
940 };
941
942 if let Some(any_mouse_event) = event.mouse_event() {
943 // Handlers may set this to false by calling `stop_propagation`
944 self.app.propagate_event = true;
945 self.window.default_prevented = false;
946
947 if let Some(mut handlers) = self
948 .window
949 .mouse_listeners
950 .remove(&any_mouse_event.type_id())
951 {
952 // Because handlers may add other handlers, we sort every time.
953 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
954
955 // Capture phase, events bubble from back to front. Handlers for this phase are used for
956 // special purposes, such as detecting events outside of a given Bounds.
957 for (_, handler) in &handlers {
958 handler(any_mouse_event, DispatchPhase::Capture, self);
959 if !self.app.propagate_event {
960 break;
961 }
962 }
963
964 // Bubble phase, where most normal handlers do their work.
965 if self.app.propagate_event {
966 for (_, handler) in handlers.iter().rev() {
967 handler(any_mouse_event, DispatchPhase::Bubble, self);
968 if !self.app.propagate_event {
969 break;
970 }
971 }
972 }
973
974 if self.app.propagate_event
975 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
976 {
977 self.active_drag = None;
978 }
979
980 // Just in case any handlers added new handlers, which is weird, but possible.
981 handlers.extend(
982 self.window
983 .mouse_listeners
984 .get_mut(&any_mouse_event.type_id())
985 .into_iter()
986 .flat_map(|handlers| handlers.drain(..)),
987 );
988 self.window
989 .mouse_listeners
990 .insert(any_mouse_event.type_id(), handlers);
991 }
992 } else if let Some(any_key_event) = event.keyboard_event() {
993 let key_dispatch_stack = mem::take(&mut self.window.key_dispatch_stack);
994 let key_event_type = any_key_event.type_id();
995 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
996
997 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
998 match frame {
999 KeyDispatchStackFrame::Listener {
1000 event_type,
1001 listener,
1002 } => {
1003 if key_event_type == *event_type {
1004 if let Some(action) = listener(
1005 any_key_event,
1006 &context_stack,
1007 DispatchPhase::Capture,
1008 self,
1009 ) {
1010 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1011 }
1012 if !self.app.propagate_event {
1013 break;
1014 }
1015 }
1016 }
1017 KeyDispatchStackFrame::Context(context) => {
1018 context_stack.push(&context);
1019 }
1020 }
1021 }
1022
1023 if self.app.propagate_event {
1024 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
1025 match frame {
1026 KeyDispatchStackFrame::Listener {
1027 event_type,
1028 listener,
1029 } => {
1030 if key_event_type == *event_type {
1031 if let Some(action) = listener(
1032 any_key_event,
1033 &context_stack,
1034 DispatchPhase::Bubble,
1035 self,
1036 ) {
1037 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1038 }
1039
1040 if !self.app.propagate_event {
1041 break;
1042 }
1043 }
1044 }
1045 KeyDispatchStackFrame::Context(_) => {
1046 context_stack.pop();
1047 }
1048 }
1049 }
1050 }
1051
1052 drop(context_stack);
1053 self.window.key_dispatch_stack = key_dispatch_stack;
1054 }
1055
1056 true
1057 }
1058
1059 pub fn match_keystroke(
1060 &mut self,
1061 element_id: &GlobalElementId,
1062 keystroke: &Keystroke,
1063 context_stack: &[&DispatchContext],
1064 ) -> KeyMatch {
1065 let key_match = self
1066 .window
1067 .key_matchers
1068 .get_mut(element_id)
1069 .unwrap()
1070 .match_keystroke(keystroke, context_stack);
1071
1072 if key_match.is_some() {
1073 for matcher in self.window.key_matchers.values_mut() {
1074 matcher.clear_pending();
1075 }
1076 }
1077
1078 key_match
1079 }
1080
1081 pub fn observe_global<G: 'static>(
1082 &mut self,
1083 f: impl Fn(&mut WindowContext<'_, '_>) + Send + 'static,
1084 ) -> Subscription {
1085 let window_id = self.window.handle.id;
1086 self.global_observers.insert(
1087 TypeId::of::<G>(),
1088 Box::new(move |cx| cx.update_window(window_id, |cx| f(cx)).is_ok()),
1089 )
1090 }
1091
1092 fn dispatch_action(
1093 &mut self,
1094 action: Box<dyn Action>,
1095 dispatch_stack: &[KeyDispatchStackFrame],
1096 ) {
1097 let action_type = action.as_any().type_id();
1098
1099 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1100 for listener in &global_listeners {
1101 listener(action.as_ref(), DispatchPhase::Capture, self);
1102 if !self.app.propagate_event {
1103 break;
1104 }
1105 }
1106 global_listeners.extend(
1107 self.global_action_listeners
1108 .remove(&action_type)
1109 .unwrap_or_default(),
1110 );
1111 self.global_action_listeners
1112 .insert(action_type, global_listeners);
1113 }
1114
1115 if self.app.propagate_event {
1116 for stack_frame in dispatch_stack {
1117 if let KeyDispatchStackFrame::Listener {
1118 event_type,
1119 listener,
1120 } = stack_frame
1121 {
1122 if action_type == *event_type {
1123 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1124 if !self.app.propagate_event {
1125 break;
1126 }
1127 }
1128 }
1129 }
1130 }
1131
1132 if self.app.propagate_event {
1133 for stack_frame in dispatch_stack.iter().rev() {
1134 if let KeyDispatchStackFrame::Listener {
1135 event_type,
1136 listener,
1137 } = stack_frame
1138 {
1139 if action_type == *event_type {
1140 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1141 if !self.app.propagate_event {
1142 break;
1143 }
1144 }
1145 }
1146 }
1147 }
1148
1149 if self.app.propagate_event {
1150 if let Some(mut global_listeners) =
1151 self.app.global_action_listeners.remove(&action_type)
1152 {
1153 for listener in global_listeners.iter().rev() {
1154 listener(action.as_ref(), DispatchPhase::Bubble, self);
1155 if !self.app.propagate_event {
1156 break;
1157 }
1158 }
1159 global_listeners.extend(
1160 self.global_action_listeners
1161 .remove(&action_type)
1162 .unwrap_or_default(),
1163 );
1164 self.global_action_listeners
1165 .insert(action_type, global_listeners);
1166 }
1167 }
1168 }
1169}
1170
1171impl Context for WindowContext<'_, '_> {
1172 type EntityContext<'a, 'w, T> = ViewContext<'a, 'w, T>;
1173 type Result<T> = T;
1174
1175 fn entity<T>(
1176 &mut self,
1177 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
1178 ) -> Handle<T>
1179 where
1180 T: 'static + Send,
1181 {
1182 let slot = self.app.entities.reserve();
1183 let entity = build_entity(&mut ViewContext::mutable(
1184 &mut *self.app,
1185 &mut self.window,
1186 slot.downgrade(),
1187 ));
1188 self.entities.insert(slot, entity)
1189 }
1190
1191 fn update_entity<T: 'static, R>(
1192 &mut self,
1193 handle: &Handle<T>,
1194 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
1195 ) -> R {
1196 let mut entity = self.entities.lease(handle);
1197 let result = update(
1198 &mut *entity,
1199 &mut ViewContext::mutable(&mut *self.app, &mut *self.window, handle.downgrade()),
1200 );
1201 self.entities.end_lease(entity);
1202 result
1203 }
1204}
1205
1206impl<'a, 'w> std::ops::Deref for WindowContext<'a, 'w> {
1207 type Target = AppContext;
1208
1209 fn deref(&self) -> &Self::Target {
1210 &self.app
1211 }
1212}
1213
1214impl<'a, 'w> std::ops::DerefMut for WindowContext<'a, 'w> {
1215 fn deref_mut(&mut self) -> &mut Self::Target {
1216 &mut self.app
1217 }
1218}
1219
1220impl<'a, 'w> Borrow<AppContext> for WindowContext<'a, 'w> {
1221 fn borrow(&self) -> &AppContext {
1222 &self.app
1223 }
1224}
1225
1226impl<'a, 'w> BorrowMut<AppContext> for WindowContext<'a, 'w> {
1227 fn borrow_mut(&mut self) -> &mut AppContext {
1228 &mut self.app
1229 }
1230}
1231
1232pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1233 fn app_mut(&mut self) -> &mut AppContext {
1234 self.borrow_mut()
1235 }
1236
1237 fn window(&self) -> &Window {
1238 self.borrow()
1239 }
1240
1241 fn window_mut(&mut self) -> &mut Window {
1242 self.borrow_mut()
1243 }
1244
1245 fn with_element_id<R>(
1246 &mut self,
1247 id: impl Into<ElementId>,
1248 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1249 ) -> R {
1250 let keymap = self.app_mut().keymap.clone();
1251 let window = self.window_mut();
1252 window.element_id_stack.push(id.into());
1253 let global_id = window.element_id_stack.clone();
1254
1255 if window.key_matchers.get(&global_id).is_none() {
1256 window.key_matchers.insert(
1257 global_id.clone(),
1258 window
1259 .prev_frame_key_matchers
1260 .remove(&global_id)
1261 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1262 );
1263 }
1264
1265 let result = f(global_id, self);
1266 let window: &mut Window = self.borrow_mut();
1267 window.element_id_stack.pop();
1268 result
1269 }
1270
1271 fn with_content_mask<R>(
1272 &mut self,
1273 mask: ContentMask<Pixels>,
1274 f: impl FnOnce(&mut Self) -> R,
1275 ) -> R {
1276 let mask = mask.intersect(&self.content_mask());
1277 self.window_mut().content_mask_stack.push(mask);
1278 let result = f(self);
1279 self.window_mut().content_mask_stack.pop();
1280 result
1281 }
1282
1283 fn with_element_offset<R>(
1284 &mut self,
1285 offset: Option<Point<Pixels>>,
1286 f: impl FnOnce(&mut Self) -> R,
1287 ) -> R {
1288 let Some(offset) = offset else {
1289 return f(self);
1290 };
1291
1292 let offset = self.element_offset() + offset;
1293 self.window_mut().element_offset_stack.push(offset);
1294 let result = f(self);
1295 self.window_mut().element_offset_stack.pop();
1296 result
1297 }
1298
1299 fn element_offset(&self) -> Point<Pixels> {
1300 self.window()
1301 .element_offset_stack
1302 .last()
1303 .copied()
1304 .unwrap_or_default()
1305 }
1306
1307 fn with_element_state<S, R>(
1308 &mut self,
1309 id: ElementId,
1310 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1311 ) -> R
1312 where
1313 S: 'static + Send,
1314 {
1315 self.with_element_id(id, |global_id, cx| {
1316 if let Some(any) = cx
1317 .window_mut()
1318 .element_states
1319 .remove(&global_id)
1320 .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
1321 {
1322 // Using the extra inner option to avoid needing to reallocate a new box.
1323 let mut state_box = any
1324 .downcast::<Option<S>>()
1325 .expect("invalid element state type for id");
1326 let state = state_box
1327 .take()
1328 .expect("element state is already on the stack");
1329 let (result, state) = f(Some(state), cx);
1330 state_box.replace(state);
1331 cx.window_mut().element_states.insert(global_id, state_box);
1332 result
1333 } else {
1334 let (result, state) = f(None, cx);
1335 cx.window_mut()
1336 .element_states
1337 .insert(global_id, Box::new(Some(state)));
1338 result
1339 }
1340 })
1341 }
1342
1343 fn with_optional_element_state<S, R>(
1344 &mut self,
1345 element_id: Option<ElementId>,
1346 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1347 ) -> R
1348 where
1349 S: 'static + Send,
1350 {
1351 if let Some(element_id) = element_id {
1352 self.with_element_state(element_id, f)
1353 } else {
1354 f(None, self).0
1355 }
1356 }
1357
1358 fn content_mask(&self) -> ContentMask<Pixels> {
1359 self.window()
1360 .content_mask_stack
1361 .last()
1362 .cloned()
1363 .unwrap_or_else(|| ContentMask {
1364 bounds: Bounds {
1365 origin: Point::default(),
1366 size: self.window().content_size,
1367 },
1368 })
1369 }
1370
1371 fn rem_size(&self) -> Pixels {
1372 self.window().rem_size
1373 }
1374}
1375
1376impl Borrow<Window> for WindowContext<'_, '_> {
1377 fn borrow(&self) -> &Window {
1378 &self.window
1379 }
1380}
1381
1382impl BorrowMut<Window> for WindowContext<'_, '_> {
1383 fn borrow_mut(&mut self) -> &mut Window {
1384 &mut self.window
1385 }
1386}
1387
1388impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1389
1390pub struct ViewContext<'a, 'w, V> {
1391 window_cx: WindowContext<'a, 'w>,
1392 view_state: WeakHandle<V>,
1393}
1394
1395impl<V> Borrow<AppContext> for ViewContext<'_, '_, V> {
1396 fn borrow(&self) -> &AppContext {
1397 &*self.window_cx.app
1398 }
1399}
1400
1401impl<V> BorrowMut<AppContext> for ViewContext<'_, '_, V> {
1402 fn borrow_mut(&mut self) -> &mut AppContext {
1403 &mut *self.window_cx.app
1404 }
1405}
1406
1407impl<V> Borrow<Window> for ViewContext<'_, '_, V> {
1408 fn borrow(&self) -> &Window {
1409 &*self.window_cx.window
1410 }
1411}
1412
1413impl<V> BorrowMut<Window> for ViewContext<'_, '_, V> {
1414 fn borrow_mut(&mut self) -> &mut Window {
1415 &mut *self.window_cx.window
1416 }
1417}
1418
1419impl<'a, 'w, V: 'static> ViewContext<'a, 'w, V> {
1420 fn mutable(app: &'a mut AppContext, window: &'w mut Window, view_state: WeakHandle<V>) -> Self {
1421 Self {
1422 window_cx: WindowContext::mutable(app, window),
1423 view_state,
1424 }
1425 }
1426
1427 pub fn handle(&self) -> WeakHandle<V> {
1428 self.view_state.clone()
1429 }
1430
1431 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1432 self.window.z_index_stack.push(order);
1433 let result = f(self);
1434 self.window.z_index_stack.pop();
1435 result
1436 }
1437
1438 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + Send + 'static)
1439 where
1440 V: Any + Send,
1441 {
1442 let entity = self.handle();
1443 self.window_cx.on_next_frame(move |cx| {
1444 entity.update(cx, f).ok();
1445 });
1446 }
1447
1448 pub fn observe<E>(
1449 &mut self,
1450 handle: &Handle<E>,
1451 mut on_notify: impl FnMut(&mut V, Handle<E>, &mut ViewContext<'_, '_, V>) + Send + 'static,
1452 ) -> Subscription
1453 where
1454 E: 'static,
1455 V: Any + Send,
1456 {
1457 let this = self.handle();
1458 let handle = handle.downgrade();
1459 let window_handle = self.window.handle;
1460 self.app.observers.insert(
1461 handle.entity_id,
1462 Box::new(move |cx| {
1463 cx.update_window(window_handle.id, |cx| {
1464 if let Some(handle) = handle.upgrade() {
1465 this.update(cx, |this, cx| on_notify(this, handle, cx))
1466 .is_ok()
1467 } else {
1468 false
1469 }
1470 })
1471 .unwrap_or(false)
1472 }),
1473 )
1474 }
1475
1476 pub fn subscribe<E: EventEmitter>(
1477 &mut self,
1478 handle: &Handle<E>,
1479 mut on_event: impl FnMut(&mut V, Handle<E>, &E::Event, &mut ViewContext<'_, '_, V>)
1480 + Send
1481 + 'static,
1482 ) -> Subscription {
1483 let this = self.handle();
1484 let handle = handle.downgrade();
1485 let window_handle = self.window.handle;
1486 self.app.event_listeners.insert(
1487 handle.entity_id,
1488 Box::new(move |event, cx| {
1489 cx.update_window(window_handle.id, |cx| {
1490 if let Some(handle) = handle.upgrade() {
1491 let event = event.downcast_ref().expect("invalid event type");
1492 this.update(cx, |this, cx| on_event(this, handle, event, cx))
1493 .is_ok()
1494 } else {
1495 false
1496 }
1497 })
1498 .unwrap_or(false)
1499 }),
1500 )
1501 }
1502
1503 pub fn on_release(
1504 &mut self,
1505 mut on_release: impl FnMut(&mut V, &mut WindowContext) + Send + 'static,
1506 ) -> Subscription {
1507 let window_handle = self.window.handle;
1508 self.app.release_listeners.insert(
1509 self.view_state.entity_id,
1510 Box::new(move |this, cx| {
1511 let this = this.downcast_mut().expect("invalid entity type");
1512 // todo!("are we okay with silently swallowing the error?")
1513 let _ = cx.update_window(window_handle.id, |cx| on_release(this, cx));
1514 }),
1515 )
1516 }
1517
1518 pub fn observe_release<T: 'static>(
1519 &mut self,
1520 handle: &Handle<T>,
1521 mut on_release: impl FnMut(&mut V, &mut T, &mut ViewContext<'_, '_, V>) + Send + 'static,
1522 ) -> Subscription
1523 where
1524 V: Any + Send,
1525 {
1526 let this = self.handle();
1527 let window_handle = self.window.handle;
1528 self.app.release_listeners.insert(
1529 handle.entity_id,
1530 Box::new(move |entity, cx| {
1531 let entity = entity.downcast_mut().expect("invalid entity type");
1532 // todo!("are we okay with silently swallowing the error?")
1533 let _ = cx.update_window(window_handle.id, |cx| {
1534 this.update(cx, |this, cx| on_release(this, entity, cx))
1535 });
1536 }),
1537 )
1538 }
1539
1540 pub fn notify(&mut self) {
1541 self.window_cx.notify();
1542 self.window_cx.app.push_effect(Effect::Notify {
1543 emitter: self.view_state.entity_id,
1544 });
1545 }
1546
1547 pub fn on_focus_changed(
1548 &mut self,
1549 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + Send + 'static,
1550 ) {
1551 let handle = self.handle();
1552 self.window.focus_listeners.push(Box::new(move |event, cx| {
1553 handle
1554 .update(cx, |view, cx| listener(view, event, cx))
1555 .log_err();
1556 }));
1557 }
1558
1559 pub fn with_key_listeners<R>(
1560 &mut self,
1561 key_listeners: impl IntoIterator<Item = (TypeId, KeyListener<V>)>,
1562 f: impl FnOnce(&mut Self) -> R,
1563 ) -> R {
1564 let old_stack_len = self.window.key_dispatch_stack.len();
1565 if !self.window.freeze_key_dispatch_stack {
1566 for (event_type, listener) in key_listeners {
1567 let handle = self.handle();
1568 let listener = Box::new(
1569 move |event: &dyn Any,
1570 context_stack: &[&DispatchContext],
1571 phase: DispatchPhase,
1572 cx: &mut WindowContext<'_, '_>| {
1573 handle
1574 .update(cx, |view, cx| {
1575 listener(view, event, context_stack, phase, cx)
1576 })
1577 .log_err()
1578 .flatten()
1579 },
1580 );
1581 self.window
1582 .key_dispatch_stack
1583 .push(KeyDispatchStackFrame::Listener {
1584 event_type,
1585 listener,
1586 });
1587 }
1588 }
1589
1590 let result = f(self);
1591
1592 if !self.window.freeze_key_dispatch_stack {
1593 self.window.key_dispatch_stack.truncate(old_stack_len);
1594 }
1595
1596 result
1597 }
1598
1599 pub fn with_key_dispatch_context<R>(
1600 &mut self,
1601 context: DispatchContext,
1602 f: impl FnOnce(&mut Self) -> R,
1603 ) -> R {
1604 if context.is_empty() {
1605 return f(self);
1606 }
1607
1608 if !self.window.freeze_key_dispatch_stack {
1609 self.window
1610 .key_dispatch_stack
1611 .push(KeyDispatchStackFrame::Context(context));
1612 }
1613
1614 let result = f(self);
1615
1616 if !self.window.freeze_key_dispatch_stack {
1617 self.window.key_dispatch_stack.pop();
1618 }
1619
1620 result
1621 }
1622
1623 pub fn with_focus<R>(
1624 &mut self,
1625 focus_handle: FocusHandle,
1626 f: impl FnOnce(&mut Self) -> R,
1627 ) -> R {
1628 if let Some(parent_focus_id) = self.window.focus_stack.last().copied() {
1629 self.window
1630 .focus_parents_by_child
1631 .insert(focus_handle.id, parent_focus_id);
1632 }
1633 self.window.focus_stack.push(focus_handle.id);
1634
1635 if Some(focus_handle.id) == self.window.focus {
1636 self.window.freeze_key_dispatch_stack = true;
1637 }
1638
1639 let result = f(self);
1640
1641 self.window.focus_stack.pop();
1642 result
1643 }
1644
1645 pub fn run_on_main<R>(
1646 &mut self,
1647 view: &mut V,
1648 f: impl FnOnce(&mut V, &mut MainThread<ViewContext<'_, '_, V>>) -> R + Send + 'static,
1649 ) -> Task<Result<R>>
1650 where
1651 R: Send + 'static,
1652 {
1653 if self.executor.is_main_thread() {
1654 let cx = unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(self) };
1655 Task::ready(Ok(f(view, cx)))
1656 } else {
1657 let handle = self.handle().upgrade().unwrap();
1658 self.window_cx.run_on_main(move |cx| handle.update(cx, f))
1659 }
1660 }
1661
1662 pub fn spawn<Fut, R>(
1663 &mut self,
1664 f: impl FnOnce(WeakHandle<V>, AsyncWindowContext) -> Fut + Send + 'static,
1665 ) -> Task<R>
1666 where
1667 R: Send + 'static,
1668 Fut: Future<Output = R> + Send + 'static,
1669 {
1670 let handle = self.handle();
1671 self.window_cx.spawn(move |_, cx| {
1672 let result = f(handle, cx);
1673 async move { result.await }
1674 })
1675 }
1676
1677 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1678 where
1679 G: 'static + Send,
1680 {
1681 let mut global = self.app.lease_global::<G>();
1682 let result = f(&mut global, self);
1683 self.app.end_global_lease(global);
1684 result
1685 }
1686
1687 pub fn observe_global<G: 'static>(
1688 &mut self,
1689 f: impl Fn(&mut V, &mut ViewContext<'_, '_, V>) + Send + 'static,
1690 ) -> Subscription {
1691 let window_id = self.window.handle.id;
1692 let handle = self.handle();
1693 self.global_observers.insert(
1694 TypeId::of::<G>(),
1695 Box::new(move |cx| {
1696 cx.update_window(window_id, |cx| {
1697 handle.update(cx, |view, cx| f(view, cx)).is_ok()
1698 })
1699 .unwrap_or(false)
1700 }),
1701 )
1702 }
1703
1704 pub fn on_mouse_event<Event: 'static>(
1705 &mut self,
1706 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + Send + 'static,
1707 ) {
1708 let handle = self.handle().upgrade().unwrap();
1709 self.window_cx.on_mouse_event(move |event, phase, cx| {
1710 handle.update(cx, |view, cx| {
1711 handler(view, event, phase, cx);
1712 })
1713 });
1714 }
1715}
1716
1717impl<'a, 'w, V> ViewContext<'a, 'w, V>
1718where
1719 V: EventEmitter,
1720 V::Event: Any + Send,
1721{
1722 pub fn emit(&mut self, event: V::Event) {
1723 let emitter = self.view_state.entity_id;
1724 self.app.push_effect(Effect::Emit {
1725 emitter,
1726 event: Box::new(event),
1727 });
1728 }
1729}
1730
1731impl<'a, 'w, V> Context for ViewContext<'a, 'w, V> {
1732 type EntityContext<'b, 'c, U> = ViewContext<'b, 'c, U>;
1733 type Result<U> = U;
1734
1735 fn entity<T>(
1736 &mut self,
1737 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
1738 ) -> Handle<T>
1739 where
1740 T: 'static + Send,
1741 {
1742 self.window_cx.entity(build_entity)
1743 }
1744
1745 fn update_entity<T: 'static, R>(
1746 &mut self,
1747 handle: &Handle<T>,
1748 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
1749 ) -> R {
1750 self.window_cx.update_entity(handle, update)
1751 }
1752}
1753
1754impl<'a, 'w, V> std::ops::Deref for ViewContext<'a, 'w, V> {
1755 type Target = WindowContext<'a, 'w>;
1756
1757 fn deref(&self) -> &Self::Target {
1758 &self.window_cx
1759 }
1760}
1761
1762impl<'a, 'w, V> std::ops::DerefMut for ViewContext<'a, 'w, V> {
1763 fn deref_mut(&mut self) -> &mut Self::Target {
1764 &mut self.window_cx
1765 }
1766}
1767
1768// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
1769slotmap::new_key_type! { pub struct WindowId; }
1770
1771impl WindowId {
1772 pub fn as_u64(&self) -> u64 {
1773 self.0.as_ffi()
1774 }
1775}
1776
1777#[derive(PartialEq, Eq)]
1778pub struct WindowHandle<V> {
1779 id: WindowId,
1780 state_type: PhantomData<V>,
1781}
1782
1783impl<S> Copy for WindowHandle<S> {}
1784
1785impl<S> Clone for WindowHandle<S> {
1786 fn clone(&self) -> Self {
1787 WindowHandle {
1788 id: self.id,
1789 state_type: PhantomData,
1790 }
1791 }
1792}
1793
1794impl<S> WindowHandle<S> {
1795 pub fn new(id: WindowId) -> Self {
1796 WindowHandle {
1797 id,
1798 state_type: PhantomData,
1799 }
1800 }
1801}
1802
1803impl<S: 'static> Into<AnyWindowHandle> for WindowHandle<S> {
1804 fn into(self) -> AnyWindowHandle {
1805 AnyWindowHandle {
1806 id: self.id,
1807 state_type: TypeId::of::<S>(),
1808 }
1809 }
1810}
1811
1812#[derive(Copy, Clone, PartialEq, Eq)]
1813pub struct AnyWindowHandle {
1814 pub(crate) id: WindowId,
1815 state_type: TypeId,
1816}
1817
1818impl AnyWindowHandle {
1819 pub fn window_id(&self) -> WindowId {
1820 self.id
1821 }
1822}
1823
1824#[cfg(any(test, feature = "test-support"))]
1825impl From<SmallVec<[u32; 16]>> for StackingOrder {
1826 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
1827 StackingOrder(small_vec)
1828 }
1829}
1830
1831#[derive(Clone, Debug, Eq, PartialEq, Hash)]
1832pub enum ElementId {
1833 View(EntityId),
1834 Number(usize),
1835 Name(SharedString),
1836 FocusHandle(FocusId),
1837}
1838
1839impl From<EntityId> for ElementId {
1840 fn from(id: EntityId) -> Self {
1841 ElementId::View(id)
1842 }
1843}
1844
1845impl From<usize> for ElementId {
1846 fn from(id: usize) -> Self {
1847 ElementId::Number(id)
1848 }
1849}
1850
1851impl From<i32> for ElementId {
1852 fn from(id: i32) -> Self {
1853 Self::Number(id as usize)
1854 }
1855}
1856
1857impl From<SharedString> for ElementId {
1858 fn from(name: SharedString) -> Self {
1859 ElementId::Name(name)
1860 }
1861}
1862
1863impl From<&'static str> for ElementId {
1864 fn from(name: &'static str) -> Self {
1865 ElementId::Name(name.into())
1866 }
1867}
1868
1869impl<'a> From<&'a FocusHandle> for ElementId {
1870 fn from(handle: &'a FocusHandle) -> Self {
1871 ElementId::FocusHandle(handle.id)
1872 }
1873}