1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle,
4 DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId,
5 EventEmitter, FileDropEvent, Flatten, FocusEvent, FontId, GlobalElementId, GlyphId, Hsla,
6 ImageData, InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, LayoutId, Model,
7 ModelContext, Modifiers, MonochromeSprite, MouseButton, MouseDownEvent, MouseMoveEvent,
8 MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler,
9 PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams,
10 RenderImageParams, RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size,
11 Style, SubscriberSet, Subscription, Surface, TaffyLayoutEngine, Task, Underline,
12 UnderlineStyle, View, VisualContext, WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Context as _, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use media::core_video::CVImageBuffer;
22use parking_lot::RwLock;
23use slotmap::SlotMap;
24use smallvec::SmallVec;
25use std::{
26 any::{Any, TypeId},
27 borrow::{Borrow, BorrowMut, Cow},
28 fmt::Debug,
29 future::Future,
30 hash::{Hash, Hasher},
31 marker::PhantomData,
32 mem,
33 rc::Rc,
34 sync::{
35 atomic::{AtomicUsize, Ordering::SeqCst},
36 Arc,
37 },
38};
39use util::ResultExt;
40
41/// A global stacking order, which is created by stacking successive z-index values.
42/// Each z-index will always be interpreted in the context of its parent z-index.
43#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default, Debug)]
44pub struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
45
46/// Represents the two different phases when dispatching events.
47#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
48pub enum DispatchPhase {
49 /// After the capture phase comes the bubble phase, in which mouse event listeners are
50 /// invoked front to back and keyboard event listeners are invoked from the focused element
51 /// to the root of the element tree. This is the phase you'll most commonly want to use when
52 /// registering event listeners.
53 #[default]
54 Bubble,
55 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
56 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
57 /// is used for special purposes such as clearing the "pressed" state for click events. If
58 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
59 /// outside of the immediate region may rely on detecting non-local events during this phase.
60 Capture,
61}
62
63type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
64type AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
65type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
66type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
67
68slotmap::new_key_type! { pub struct FocusId; }
69
70impl FocusId {
71 /// Obtains whether the element associated with this handle is currently focused.
72 pub fn is_focused(&self, cx: &WindowContext) -> bool {
73 cx.window.focus == Some(*self)
74 }
75
76 /// Obtains whether the element associated with this handle contains the focused
77 /// element or is itself focused.
78 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
79 cx.focused()
80 .map_or(false, |focused| self.contains(focused.id, cx))
81 }
82
83 /// Obtains whether the element associated with this handle is contained within the
84 /// focused element or is itself focused.
85 pub fn within_focused(&self, cx: &WindowContext) -> bool {
86 let focused = cx.focused();
87 focused.map_or(false, |focused| focused.id.contains(*self, cx))
88 }
89
90 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
91 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
92 cx.window
93 .current_frame
94 .dispatch_tree
95 .focus_contains(*self, other)
96 }
97}
98
99/// A handle which can be used to track and manipulate the focused element in a window.
100pub struct FocusHandle {
101 pub(crate) id: FocusId,
102 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
103}
104
105impl std::fmt::Debug for FocusHandle {
106 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
107 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
108 }
109}
110
111impl FocusHandle {
112 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
113 let id = handles.write().insert(AtomicUsize::new(1));
114 Self {
115 id,
116 handles: handles.clone(),
117 }
118 }
119
120 pub(crate) fn for_id(
121 id: FocusId,
122 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
123 ) -> Option<Self> {
124 let lock = handles.read();
125 let ref_count = lock.get(id)?;
126 if ref_count.load(SeqCst) == 0 {
127 None
128 } else {
129 ref_count.fetch_add(1, SeqCst);
130 Some(Self {
131 id,
132 handles: handles.clone(),
133 })
134 }
135 }
136
137 /// Moves the focus to the element associated with this handle.
138 pub fn focus(&self, cx: &mut WindowContext) {
139 cx.focus(self)
140 }
141
142 /// Obtains whether the element associated with this handle is currently focused.
143 pub fn is_focused(&self, cx: &WindowContext) -> bool {
144 self.id.is_focused(cx)
145 }
146
147 /// Obtains whether the element associated with this handle contains the focused
148 /// element or is itself focused.
149 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
150 self.id.contains_focused(cx)
151 }
152
153 /// Obtains whether the element associated with this handle is contained within the
154 /// focused element or is itself focused.
155 pub fn within_focused(&self, cx: &WindowContext) -> bool {
156 self.id.within_focused(cx)
157 }
158
159 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
160 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
161 self.id.contains(other.id, cx)
162 }
163}
164
165impl Clone for FocusHandle {
166 fn clone(&self) -> Self {
167 Self::for_id(self.id, &self.handles).unwrap()
168 }
169}
170
171impl PartialEq for FocusHandle {
172 fn eq(&self, other: &Self) -> bool {
173 self.id == other.id
174 }
175}
176
177impl Eq for FocusHandle {}
178
179impl Drop for FocusHandle {
180 fn drop(&mut self) {
181 self.handles
182 .read()
183 .get(self.id)
184 .unwrap()
185 .fetch_sub(1, SeqCst);
186 }
187}
188
189/// FocusableView allows users of your view to easily
190/// focus it (using cx.focus_view(view))
191pub trait FocusableView: 'static + Render {
192 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
193}
194
195/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
196/// where the lifecycle of the view is handled by another view.
197pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
198
199impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
200
201pub struct DismissEvent;
202
203// Holds the state for a specific window.
204pub struct Window {
205 pub(crate) handle: AnyWindowHandle,
206 pub(crate) removed: bool,
207 pub(crate) platform_window: Box<dyn PlatformWindow>,
208 display_id: DisplayId,
209 sprite_atlas: Arc<dyn PlatformAtlas>,
210 rem_size: Pixels,
211 viewport_size: Size<Pixels>,
212 pub(crate) layout_engine: TaffyLayoutEngine,
213 pub(crate) root_view: Option<AnyView>,
214 pub(crate) element_id_stack: GlobalElementId,
215 pub(crate) previous_frame: Frame,
216 pub(crate) current_frame: Frame,
217 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
218 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
219 default_prevented: bool,
220 mouse_position: Point<Pixels>,
221 requested_cursor_style: Option<CursorStyle>,
222 scale_factor: f32,
223 bounds: WindowBounds,
224 bounds_observers: SubscriberSet<(), AnyObserver>,
225 active: bool,
226 activation_observers: SubscriberSet<(), AnyObserver>,
227 pub(crate) dirty: bool,
228 pub(crate) last_blur: Option<Option<FocusId>>,
229 pub(crate) focus: Option<FocusId>,
230}
231
232pub(crate) struct ElementStateBox {
233 inner: Box<dyn Any>,
234 #[cfg(debug_assertions)]
235 type_name: &'static str,
236}
237
238// #[derive(Default)]
239pub(crate) struct Frame {
240 pub(crate) element_states: HashMap<GlobalElementId, ElementStateBox>,
241 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
242 pub(crate) dispatch_tree: DispatchTree,
243 pub(crate) focus_listeners: Vec<AnyFocusListener>,
244 pub(crate) scene_builder: SceneBuilder,
245 pub(crate) depth_map: Vec<(StackingOrder, Bounds<Pixels>)>,
246 pub(crate) z_index_stack: StackingOrder,
247 content_mask_stack: Vec<ContentMask<Pixels>>,
248 element_offset_stack: Vec<Point<Pixels>>,
249}
250
251impl Frame {
252 pub fn new(dispatch_tree: DispatchTree) -> Self {
253 Frame {
254 element_states: HashMap::default(),
255 mouse_listeners: HashMap::default(),
256 dispatch_tree,
257 focus_listeners: Vec::new(),
258 scene_builder: SceneBuilder::default(),
259 z_index_stack: StackingOrder::default(),
260 depth_map: Default::default(),
261 content_mask_stack: Vec::new(),
262 element_offset_stack: Vec::new(),
263 }
264 }
265}
266
267impl Window {
268 pub(crate) fn new(
269 handle: AnyWindowHandle,
270 options: WindowOptions,
271 cx: &mut AppContext,
272 ) -> Self {
273 let platform_window = cx.platform.open_window(handle, options);
274 let display_id = platform_window.display().id();
275 let sprite_atlas = platform_window.sprite_atlas();
276 let mouse_position = platform_window.mouse_position();
277 let content_size = platform_window.content_size();
278 let scale_factor = platform_window.scale_factor();
279 let bounds = platform_window.bounds();
280
281 platform_window.on_resize(Box::new({
282 let mut cx = cx.to_async();
283 move |_, _| {
284 handle
285 .update(&mut cx, |_, cx| cx.window_bounds_changed())
286 .log_err();
287 }
288 }));
289 platform_window.on_moved(Box::new({
290 let mut cx = cx.to_async();
291 move || {
292 handle
293 .update(&mut cx, |_, cx| cx.window_bounds_changed())
294 .log_err();
295 }
296 }));
297 platform_window.on_active_status_change(Box::new({
298 let mut cx = cx.to_async();
299 move |active| {
300 handle
301 .update(&mut cx, |_, cx| {
302 cx.window.active = active;
303 cx.window
304 .activation_observers
305 .clone()
306 .retain(&(), |callback| callback(cx));
307 })
308 .log_err();
309 }
310 }));
311
312 platform_window.on_input({
313 let mut cx = cx.to_async();
314 Box::new(move |event| {
315 handle
316 .update(&mut cx, |_, cx| cx.dispatch_event(event))
317 .log_err()
318 .unwrap_or(false)
319 })
320 });
321
322 Window {
323 handle,
324 removed: false,
325 platform_window,
326 display_id,
327 sprite_atlas,
328 rem_size: px(16.),
329 viewport_size: content_size,
330 layout_engine: TaffyLayoutEngine::new(),
331 root_view: None,
332 element_id_stack: GlobalElementId::default(),
333 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
334 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
335 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
336 focus_listeners: SubscriberSet::new(),
337 default_prevented: true,
338 mouse_position,
339 requested_cursor_style: None,
340 scale_factor,
341 bounds,
342 bounds_observers: SubscriberSet::new(),
343 active: false,
344 activation_observers: SubscriberSet::new(),
345 dirty: true,
346 last_blur: None,
347 focus: None,
348 }
349 }
350}
351
352/// Indicates which region of the window is visible. Content falling outside of this mask will not be
353/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
354/// to leave room to support more complex shapes in the future.
355#[derive(Clone, Debug, Default, PartialEq, Eq)]
356#[repr(C)]
357pub struct ContentMask<P: Clone + Default + Debug> {
358 pub bounds: Bounds<P>,
359}
360
361impl ContentMask<Pixels> {
362 /// Scale the content mask's pixel units by the given scaling factor.
363 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
364 ContentMask {
365 bounds: self.bounds.scale(factor),
366 }
367 }
368
369 /// Intersect the content mask with the given content mask.
370 pub fn intersect(&self, other: &Self) -> Self {
371 let bounds = self.bounds.intersect(&other.bounds);
372 ContentMask { bounds }
373 }
374}
375
376/// Provides access to application state in the context of a single window. Derefs
377/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
378/// an `AppContext` and call any `AppContext` methods.
379pub struct WindowContext<'a> {
380 pub(crate) app: &'a mut AppContext,
381 pub(crate) window: &'a mut Window,
382}
383
384impl<'a> WindowContext<'a> {
385 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
386 Self { app, window }
387 }
388
389 /// Obtain a handle to the window that belongs to this context.
390 pub fn window_handle(&self) -> AnyWindowHandle {
391 self.window.handle
392 }
393
394 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
395 pub fn notify(&mut self) {
396 self.window.dirty = true;
397 }
398
399 /// Close this window.
400 pub fn remove_window(&mut self) {
401 self.window.removed = true;
402 }
403
404 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
405 /// for elements rendered within this window.
406 pub fn focus_handle(&mut self) -> FocusHandle {
407 FocusHandle::new(&self.window.focus_handles)
408 }
409
410 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
411 pub fn focused(&self) -> Option<FocusHandle> {
412 self.window
413 .focus
414 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
415 }
416
417 /// Move focus to the element associated with the given `FocusHandle`.
418 pub fn focus(&mut self, handle: &FocusHandle) {
419 if self.window.focus == Some(handle.id) {
420 return;
421 }
422
423 let focus_id = handle.id;
424
425 if self.window.last_blur.is_none() {
426 self.window.last_blur = Some(self.window.focus);
427 }
428
429 self.window.focus = Some(focus_id);
430 self.window
431 .current_frame
432 .dispatch_tree
433 .clear_keystroke_matchers();
434 self.app.push_effect(Effect::FocusChanged {
435 window_handle: self.window.handle,
436 focused: Some(focus_id),
437 });
438 self.notify();
439 }
440
441 /// Remove focus from all elements within this context's window.
442 pub fn blur(&mut self) {
443 if self.window.last_blur.is_none() {
444 self.window.last_blur = Some(self.window.focus);
445 }
446
447 self.window.focus = None;
448 self.app.push_effect(Effect::FocusChanged {
449 window_handle: self.window.handle,
450 focused: None,
451 });
452 self.notify();
453 }
454
455 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
456 if let Some(focus_handle) = self.focused() {
457 self.defer(move |cx| {
458 if let Some(node_id) = cx
459 .window
460 .current_frame
461 .dispatch_tree
462 .focusable_node_id(focus_handle.id)
463 {
464 cx.propagate_event = true;
465 cx.dispatch_action_on_node(node_id, action);
466 }
467 })
468 }
469 }
470
471 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
472 /// that are currently on the stack to be returned to the app.
473 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
474 let handle = self.window.handle;
475 self.app.defer(move |cx| {
476 handle.update(cx, |_, cx| f(cx)).ok();
477 });
478 }
479
480 pub fn subscribe<Emitter, E, Evt>(
481 &mut self,
482 entity: &E,
483 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
484 ) -> Subscription
485 where
486 Emitter: EventEmitter<Evt>,
487 E: Entity<Emitter>,
488 Evt: 'static,
489 {
490 let entity_id = entity.entity_id();
491 let entity = entity.downgrade();
492 let window_handle = self.window.handle;
493 self.app.event_listeners.insert(
494 entity_id,
495 (
496 TypeId::of::<Evt>(),
497 Box::new(move |event, cx| {
498 window_handle
499 .update(cx, |_, cx| {
500 if let Some(handle) = E::upgrade_from(&entity) {
501 let event = event.downcast_ref().expect("invalid event type");
502 on_event(handle, event, cx);
503 true
504 } else {
505 false
506 }
507 })
508 .unwrap_or(false)
509 }),
510 ),
511 )
512 }
513
514 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
515 /// await points in async code.
516 pub fn to_async(&self) -> AsyncWindowContext {
517 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
518 }
519
520 /// Schedule the given closure to be run directly after the current frame is rendered.
521 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
522 let handle = self.window.handle;
523 let display_id = self.window.display_id;
524
525 if !self.frame_consumers.contains_key(&display_id) {
526 let (tx, mut rx) = mpsc::unbounded::<()>();
527 self.platform.set_display_link_output_callback(
528 display_id,
529 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
530 );
531
532 let consumer_task = self.app.spawn(|cx| async move {
533 while rx.next().await.is_some() {
534 cx.update(|cx| {
535 for callback in cx
536 .next_frame_callbacks
537 .get_mut(&display_id)
538 .unwrap()
539 .drain(..)
540 .collect::<SmallVec<[_; 32]>>()
541 {
542 callback(cx);
543 }
544 })
545 .ok();
546
547 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
548
549 cx.update(|cx| {
550 if cx.next_frame_callbacks.is_empty() {
551 cx.platform.stop_display_link(display_id);
552 }
553 })
554 .ok();
555 }
556 });
557 self.frame_consumers.insert(display_id, consumer_task);
558 }
559
560 if self.next_frame_callbacks.is_empty() {
561 self.platform.start_display_link(display_id);
562 }
563
564 self.next_frame_callbacks
565 .entry(display_id)
566 .or_default()
567 .push(Box::new(move |cx: &mut AppContext| {
568 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
569 }));
570 }
571
572 /// Spawn the future returned by the given closure on the application thread pool.
573 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
574 /// use within your future.
575 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
576 where
577 R: 'static,
578 Fut: Future<Output = R> + 'static,
579 {
580 self.app
581 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
582 }
583
584 /// Update the global of the given type. The given closure is given simultaneous mutable
585 /// access both to the global and the context.
586 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
587 where
588 G: 'static,
589 {
590 let mut global = self.app.lease_global::<G>();
591 let result = f(&mut global, self);
592 self.app.end_global_lease(global);
593 result
594 }
595
596 #[must_use]
597 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
598 /// layout is being requested, along with the layout ids of any children. This method is called during
599 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
600 pub fn request_layout(
601 &mut self,
602 style: &Style,
603 children: impl IntoIterator<Item = LayoutId>,
604 ) -> LayoutId {
605 self.app.layout_id_buffer.clear();
606 self.app.layout_id_buffer.extend(children.into_iter());
607 let rem_size = self.rem_size();
608
609 self.window
610 .layout_engine
611 .request_layout(style, rem_size, &self.app.layout_id_buffer)
612 }
613
614 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
615 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
616 /// determine the element's size. One place this is used internally is when measuring text.
617 ///
618 /// The given closure is invoked at layout time with the known dimensions and available space and
619 /// returns a `Size`.
620 pub fn request_measured_layout<
621 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
622 >(
623 &mut self,
624 style: Style,
625 rem_size: Pixels,
626 measure: F,
627 ) -> LayoutId {
628 self.window
629 .layout_engine
630 .request_measured_layout(style, rem_size, measure)
631 }
632
633 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
634 self.window
635 .layout_engine
636 .compute_layout(layout_id, available_space)
637 }
638
639 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
640 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
641 /// in order to pass your element its `Bounds` automatically.
642 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
643 let mut bounds = self
644 .window
645 .layout_engine
646 .layout_bounds(layout_id)
647 .map(Into::into);
648 bounds.origin += self.element_offset();
649 bounds
650 }
651
652 fn window_bounds_changed(&mut self) {
653 self.window.scale_factor = self.window.platform_window.scale_factor();
654 self.window.viewport_size = self.window.platform_window.content_size();
655 self.window.bounds = self.window.platform_window.bounds();
656 self.window.display_id = self.window.platform_window.display().id();
657 self.window.dirty = true;
658
659 self.window
660 .bounds_observers
661 .clone()
662 .retain(&(), |callback| callback(self));
663 }
664
665 pub fn window_bounds(&self) -> WindowBounds {
666 self.window.bounds
667 }
668
669 pub fn viewport_size(&self) -> Size<Pixels> {
670 self.window.viewport_size
671 }
672
673 pub fn is_window_active(&self) -> bool {
674 self.window.active
675 }
676
677 pub fn zoom_window(&self) {
678 self.window.platform_window.zoom();
679 }
680
681 pub fn set_window_title(&mut self, title: &str) {
682 self.window.platform_window.set_title(title);
683 }
684
685 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
686 self.platform
687 .displays()
688 .into_iter()
689 .find(|display| display.id() == self.window.display_id)
690 }
691
692 pub fn show_character_palette(&self) {
693 self.window.platform_window.show_character_palette();
694 }
695
696 /// The scale factor of the display associated with the window. For example, it could
697 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
698 /// be rendered as two pixels on screen.
699 pub fn scale_factor(&self) -> f32 {
700 self.window.scale_factor
701 }
702
703 /// The size of an em for the base font of the application. Adjusting this value allows the
704 /// UI to scale, just like zooming a web page.
705 pub fn rem_size(&self) -> Pixels {
706 self.window.rem_size
707 }
708
709 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
710 /// UI to scale, just like zooming a web page.
711 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
712 self.window.rem_size = rem_size.into();
713 }
714
715 /// The line height associated with the current text style.
716 pub fn line_height(&self) -> Pixels {
717 let rem_size = self.rem_size();
718 let text_style = self.text_style();
719 text_style
720 .line_height
721 .to_pixels(text_style.font_size.into(), rem_size)
722 }
723
724 /// Call to prevent the default action of an event. Currently only used to prevent
725 /// parent elements from becoming focused on mouse down.
726 pub fn prevent_default(&mut self) {
727 self.window.default_prevented = true;
728 }
729
730 /// Obtain whether default has been prevented for the event currently being dispatched.
731 pub fn default_prevented(&self) -> bool {
732 self.window.default_prevented
733 }
734
735 /// Register a mouse event listener on the window for the current frame. The type of event
736 /// is determined by the first parameter of the given listener. When the next frame is rendered
737 /// the listener will be cleared.
738 ///
739 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
740 /// a specific need to register a global listener.
741 pub fn on_mouse_event<Event: 'static>(
742 &mut self,
743 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
744 ) {
745 let order = self.window.current_frame.z_index_stack.clone();
746 self.window
747 .current_frame
748 .mouse_listeners
749 .entry(TypeId::of::<Event>())
750 .or_default()
751 .push((
752 order,
753 Box::new(move |event: &dyn Any, phase, cx| {
754 handler(event.downcast_ref().unwrap(), phase, cx)
755 }),
756 ))
757 }
758
759 /// Register a key event listener on the window for the current frame. The type of event
760 /// is determined by the first parameter of the given listener. When the next frame is rendered
761 /// the listener will be cleared.
762 ///
763 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
764 /// a specific need to register a global listener.
765 pub fn on_key_event<Event: 'static>(
766 &mut self,
767 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
768 ) {
769 self.window
770 .current_frame
771 .dispatch_tree
772 .on_key_event(Rc::new(move |event, phase, cx| {
773 if let Some(event) = event.downcast_ref::<Event>() {
774 handler(event, phase, cx)
775 }
776 }));
777 }
778
779 /// Register an action listener on the window for the current frame. The type of action
780 /// is determined by the first parameter of the given listener. When the next frame is rendered
781 /// the listener will be cleared.
782 ///
783 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
784 /// a specific need to register a global listener.
785 pub fn on_action(
786 &mut self,
787 action_type: TypeId,
788 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
789 ) {
790 self.window.current_frame.dispatch_tree.on_action(
791 action_type,
792 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
793 );
794 }
795
796 /// The position of the mouse relative to the window.
797 pub fn mouse_position(&self) -> Point<Pixels> {
798 self.window.mouse_position
799 }
800
801 pub fn set_cursor_style(&mut self, style: CursorStyle) {
802 self.window.requested_cursor_style = Some(style)
803 }
804
805 /// Called during painting to invoke the given closure in a new stacking context. The given
806 /// z-index is interpreted relative to the previous call to `stack`.
807 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
808 self.window.current_frame.z_index_stack.push(z_index);
809 let result = f(self);
810 self.window.current_frame.z_index_stack.pop();
811 result
812 }
813
814 /// Called during painting to track which z-index is on top at each pixel position
815 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
816 let stacking_order = self.window.current_frame.z_index_stack.clone();
817 let depth_map = &mut self.window.current_frame.depth_map;
818 match depth_map.binary_search_by(|(level, _)| stacking_order.cmp(&level)) {
819 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, bounds)),
820 }
821 }
822
823 /// Returns true if the top-most opaque layer painted over this point was part of the
824 /// same layer as the given stacking order.
825 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
826 for (stack, bounds) in self.window.previous_frame.depth_map.iter() {
827 if bounds.contains_point(point) {
828 return level.starts_with(stack) || stack.starts_with(level);
829 }
830 }
831
832 false
833 }
834
835 /// Called during painting to get the current stacking order.
836 pub fn stacking_order(&self) -> &StackingOrder {
837 &self.window.current_frame.z_index_stack
838 }
839
840 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
841 pub fn paint_shadows(
842 &mut self,
843 bounds: Bounds<Pixels>,
844 corner_radii: Corners<Pixels>,
845 shadows: &[BoxShadow],
846 ) {
847 let scale_factor = self.scale_factor();
848 let content_mask = self.content_mask();
849 let window = &mut *self.window;
850 for shadow in shadows {
851 let mut shadow_bounds = bounds;
852 shadow_bounds.origin += shadow.offset;
853 shadow_bounds.dilate(shadow.spread_radius);
854 window.current_frame.scene_builder.insert(
855 &window.current_frame.z_index_stack,
856 Shadow {
857 order: 0,
858 bounds: shadow_bounds.scale(scale_factor),
859 content_mask: content_mask.scale(scale_factor),
860 corner_radii: corner_radii.scale(scale_factor),
861 color: shadow.color,
862 blur_radius: shadow.blur_radius.scale(scale_factor),
863 },
864 );
865 }
866 }
867
868 /// Paint one or more quads into the scene for the current frame at the current stacking context.
869 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
870 pub fn paint_quad(
871 &mut self,
872 bounds: Bounds<Pixels>,
873 corner_radii: Corners<Pixels>,
874 background: impl Into<Hsla>,
875 border_widths: Edges<Pixels>,
876 border_color: impl Into<Hsla>,
877 ) {
878 let scale_factor = self.scale_factor();
879 let content_mask = self.content_mask();
880
881 let window = &mut *self.window;
882 window.current_frame.scene_builder.insert(
883 &window.current_frame.z_index_stack,
884 Quad {
885 order: 0,
886 bounds: bounds.scale(scale_factor),
887 content_mask: content_mask.scale(scale_factor),
888 background: background.into(),
889 border_color: border_color.into(),
890 corner_radii: corner_radii.scale(scale_factor),
891 border_widths: border_widths.scale(scale_factor),
892 },
893 );
894 }
895
896 /// Paint the given `Path` into the scene for the current frame at the current z-index.
897 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
898 let scale_factor = self.scale_factor();
899 let content_mask = self.content_mask();
900 path.content_mask = content_mask;
901 path.color = color.into();
902 let window = &mut *self.window;
903 window.current_frame.scene_builder.insert(
904 &window.current_frame.z_index_stack,
905 path.scale(scale_factor),
906 );
907 }
908
909 /// Paint an underline into the scene for the current frame at the current z-index.
910 pub fn paint_underline(
911 &mut self,
912 origin: Point<Pixels>,
913 width: Pixels,
914 style: &UnderlineStyle,
915 ) {
916 let scale_factor = self.scale_factor();
917 let height = if style.wavy {
918 style.thickness * 3.
919 } else {
920 style.thickness
921 };
922 let bounds = Bounds {
923 origin,
924 size: size(width, height),
925 };
926 let content_mask = self.content_mask();
927 let window = &mut *self.window;
928 window.current_frame.scene_builder.insert(
929 &window.current_frame.z_index_stack,
930 Underline {
931 order: 0,
932 bounds: bounds.scale(scale_factor),
933 content_mask: content_mask.scale(scale_factor),
934 thickness: style.thickness.scale(scale_factor),
935 color: style.color.unwrap_or_default(),
936 wavy: style.wavy,
937 },
938 );
939 }
940
941 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
942 /// The y component of the origin is the baseline of the glyph.
943 pub fn paint_glyph(
944 &mut self,
945 origin: Point<Pixels>,
946 font_id: FontId,
947 glyph_id: GlyphId,
948 font_size: Pixels,
949 color: Hsla,
950 ) -> Result<()> {
951 let scale_factor = self.scale_factor();
952 let glyph_origin = origin.scale(scale_factor);
953 let subpixel_variant = Point {
954 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
955 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
956 };
957 let params = RenderGlyphParams {
958 font_id,
959 glyph_id,
960 font_size,
961 subpixel_variant,
962 scale_factor,
963 is_emoji: false,
964 };
965
966 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
967 if !raster_bounds.is_zero() {
968 let tile =
969 self.window
970 .sprite_atlas
971 .get_or_insert_with(¶ms.clone().into(), &mut || {
972 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
973 Ok((size, Cow::Owned(bytes)))
974 })?;
975 let bounds = Bounds {
976 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
977 size: tile.bounds.size.map(Into::into),
978 };
979 let content_mask = self.content_mask().scale(scale_factor);
980 let window = &mut *self.window;
981 window.current_frame.scene_builder.insert(
982 &window.current_frame.z_index_stack,
983 MonochromeSprite {
984 order: 0,
985 bounds,
986 content_mask,
987 color,
988 tile,
989 },
990 );
991 }
992 Ok(())
993 }
994
995 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
996 /// The y component of the origin is the baseline of the glyph.
997 pub fn paint_emoji(
998 &mut self,
999 origin: Point<Pixels>,
1000 font_id: FontId,
1001 glyph_id: GlyphId,
1002 font_size: Pixels,
1003 ) -> Result<()> {
1004 let scale_factor = self.scale_factor();
1005 let glyph_origin = origin.scale(scale_factor);
1006 let params = RenderGlyphParams {
1007 font_id,
1008 glyph_id,
1009 font_size,
1010 // We don't render emojis with subpixel variants.
1011 subpixel_variant: Default::default(),
1012 scale_factor,
1013 is_emoji: true,
1014 };
1015
1016 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1017 if !raster_bounds.is_zero() {
1018 let tile =
1019 self.window
1020 .sprite_atlas
1021 .get_or_insert_with(¶ms.clone().into(), &mut || {
1022 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1023 Ok((size, Cow::Owned(bytes)))
1024 })?;
1025 let bounds = Bounds {
1026 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1027 size: tile.bounds.size.map(Into::into),
1028 };
1029 let content_mask = self.content_mask().scale(scale_factor);
1030 let window = &mut *self.window;
1031
1032 window.current_frame.scene_builder.insert(
1033 &window.current_frame.z_index_stack,
1034 PolychromeSprite {
1035 order: 0,
1036 bounds,
1037 corner_radii: Default::default(),
1038 content_mask,
1039 tile,
1040 grayscale: false,
1041 },
1042 );
1043 }
1044 Ok(())
1045 }
1046
1047 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1048 pub fn paint_svg(
1049 &mut self,
1050 bounds: Bounds<Pixels>,
1051 path: SharedString,
1052 color: Hsla,
1053 ) -> Result<()> {
1054 let scale_factor = self.scale_factor();
1055 let bounds = bounds.scale(scale_factor);
1056 // Render the SVG at twice the size to get a higher quality result.
1057 let params = RenderSvgParams {
1058 path,
1059 size: bounds
1060 .size
1061 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1062 };
1063
1064 let tile =
1065 self.window
1066 .sprite_atlas
1067 .get_or_insert_with(¶ms.clone().into(), &mut || {
1068 let bytes = self.svg_renderer.render(¶ms)?;
1069 Ok((params.size, Cow::Owned(bytes)))
1070 })?;
1071 let content_mask = self.content_mask().scale(scale_factor);
1072
1073 let window = &mut *self.window;
1074 window.current_frame.scene_builder.insert(
1075 &window.current_frame.z_index_stack,
1076 MonochromeSprite {
1077 order: 0,
1078 bounds,
1079 content_mask,
1080 color,
1081 tile,
1082 },
1083 );
1084
1085 Ok(())
1086 }
1087
1088 /// Paint an image into the scene for the current frame at the current z-index.
1089 pub fn paint_image(
1090 &mut self,
1091 bounds: Bounds<Pixels>,
1092 corner_radii: Corners<Pixels>,
1093 data: Arc<ImageData>,
1094 grayscale: bool,
1095 ) -> Result<()> {
1096 let scale_factor = self.scale_factor();
1097 let bounds = bounds.scale(scale_factor);
1098 let params = RenderImageParams { image_id: data.id };
1099
1100 let tile = self
1101 .window
1102 .sprite_atlas
1103 .get_or_insert_with(¶ms.clone().into(), &mut || {
1104 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1105 })?;
1106 let content_mask = self.content_mask().scale(scale_factor);
1107 let corner_radii = corner_radii.scale(scale_factor);
1108
1109 let window = &mut *self.window;
1110 window.current_frame.scene_builder.insert(
1111 &window.current_frame.z_index_stack,
1112 PolychromeSprite {
1113 order: 0,
1114 bounds,
1115 content_mask,
1116 corner_radii,
1117 tile,
1118 grayscale,
1119 },
1120 );
1121 Ok(())
1122 }
1123
1124 /// Paint a surface into the scene for the current frame at the current z-index.
1125 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
1126 let scale_factor = self.scale_factor();
1127 let bounds = bounds.scale(scale_factor);
1128 let content_mask = self.content_mask().scale(scale_factor);
1129 let window = &mut *self.window;
1130 window.current_frame.scene_builder.insert(
1131 &window.current_frame.z_index_stack,
1132 Surface {
1133 order: 0,
1134 bounds,
1135 content_mask,
1136 image_buffer,
1137 },
1138 );
1139 }
1140
1141 /// Draw pixels to the display for this window based on the contents of its scene.
1142 pub(crate) fn draw(&mut self) {
1143 let root_view = self.window.root_view.take().unwrap();
1144
1145 self.start_frame();
1146
1147 self.with_z_index(0, |cx| {
1148 let available_space = cx.window.viewport_size.map(Into::into);
1149 root_view.draw(Point::zero(), available_space, cx);
1150 });
1151
1152 if let Some(active_drag) = self.app.active_drag.take() {
1153 self.with_z_index(1, |cx| {
1154 let offset = cx.mouse_position() - active_drag.cursor_offset;
1155 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1156 active_drag.view.draw(offset, available_space, cx);
1157 cx.active_drag = Some(active_drag);
1158 });
1159 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1160 self.with_z_index(1, |cx| {
1161 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1162 active_tooltip
1163 .view
1164 .draw(active_tooltip.cursor_offset, available_space, cx);
1165 });
1166 }
1167
1168 self.window
1169 .current_frame
1170 .dispatch_tree
1171 .preserve_keystroke_matchers(
1172 &mut self.window.previous_frame.dispatch_tree,
1173 self.window.focus,
1174 );
1175
1176 self.window.root_view = Some(root_view);
1177 let scene = self.window.current_frame.scene_builder.build();
1178
1179 self.window.platform_window.draw(scene);
1180 let cursor_style = self
1181 .window
1182 .requested_cursor_style
1183 .take()
1184 .unwrap_or(CursorStyle::Arrow);
1185 self.platform.set_cursor_style(cursor_style);
1186
1187 self.window.dirty = false;
1188 }
1189
1190 /// Rotate the current frame and the previous frame, then clear the current frame.
1191 /// We repopulate all state in the current frame during each paint.
1192 fn start_frame(&mut self) {
1193 self.text_system().start_frame();
1194
1195 let window = &mut *self.window;
1196 window.layout_engine.clear();
1197
1198 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1199 let frame = &mut window.current_frame;
1200 frame.element_states.clear();
1201 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1202 frame.focus_listeners.clear();
1203 frame.dispatch_tree.clear();
1204 frame.depth_map.clear();
1205 }
1206
1207 /// Dispatch a mouse or keyboard event on the window.
1208 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1209 // Handlers may set this to false by calling `stop_propagation`
1210 self.app.propagate_event = true;
1211 self.window.default_prevented = false;
1212
1213 let event = match event {
1214 // Track the mouse position with our own state, since accessing the platform
1215 // API for the mouse position can only occur on the main thread.
1216 InputEvent::MouseMove(mouse_move) => {
1217 self.window.mouse_position = mouse_move.position;
1218 InputEvent::MouseMove(mouse_move)
1219 }
1220 InputEvent::MouseDown(mouse_down) => {
1221 self.window.mouse_position = mouse_down.position;
1222 InputEvent::MouseDown(mouse_down)
1223 }
1224 InputEvent::MouseUp(mouse_up) => {
1225 self.window.mouse_position = mouse_up.position;
1226 InputEvent::MouseUp(mouse_up)
1227 }
1228 // Translate dragging and dropping of external files from the operating system
1229 // to internal drag and drop events.
1230 InputEvent::FileDrop(file_drop) => match file_drop {
1231 FileDropEvent::Entered { position, files } => {
1232 self.window.mouse_position = position;
1233 if self.active_drag.is_none() {
1234 self.active_drag = Some(AnyDrag {
1235 view: self.build_view(|_| files).into(),
1236 cursor_offset: position,
1237 });
1238 }
1239 InputEvent::MouseDown(MouseDownEvent {
1240 position,
1241 button: MouseButton::Left,
1242 click_count: 1,
1243 modifiers: Modifiers::default(),
1244 })
1245 }
1246 FileDropEvent::Pending { position } => {
1247 self.window.mouse_position = position;
1248 InputEvent::MouseMove(MouseMoveEvent {
1249 position,
1250 pressed_button: Some(MouseButton::Left),
1251 modifiers: Modifiers::default(),
1252 })
1253 }
1254 FileDropEvent::Submit { position } => {
1255 self.window.mouse_position = position;
1256 InputEvent::MouseUp(MouseUpEvent {
1257 button: MouseButton::Left,
1258 position,
1259 modifiers: Modifiers::default(),
1260 click_count: 1,
1261 })
1262 }
1263 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1264 button: MouseButton::Left,
1265 position: Point::default(),
1266 modifiers: Modifiers::default(),
1267 click_count: 1,
1268 }),
1269 },
1270 _ => event,
1271 };
1272
1273 if let Some(any_mouse_event) = event.mouse_event() {
1274 self.dispatch_mouse_event(any_mouse_event);
1275 } else if let Some(any_key_event) = event.keyboard_event() {
1276 self.dispatch_key_event(any_key_event);
1277 }
1278
1279 !self.app.propagate_event
1280 }
1281
1282 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1283 if let Some(mut handlers) = self
1284 .window
1285 .current_frame
1286 .mouse_listeners
1287 .remove(&event.type_id())
1288 {
1289 // Because handlers may add other handlers, we sort every time.
1290 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1291
1292 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1293 // special purposes, such as detecting events outside of a given Bounds.
1294 for (_, handler) in &mut handlers {
1295 handler(event, DispatchPhase::Capture, self);
1296 if !self.app.propagate_event {
1297 break;
1298 }
1299 }
1300
1301 // Bubble phase, where most normal handlers do their work.
1302 if self.app.propagate_event {
1303 for (_, handler) in handlers.iter_mut().rev() {
1304 handler(event, DispatchPhase::Bubble, self);
1305 if !self.app.propagate_event {
1306 break;
1307 }
1308 }
1309 }
1310
1311 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1312 self.active_drag = None;
1313 }
1314
1315 // Just in case any handlers added new handlers, which is weird, but possible.
1316 handlers.extend(
1317 self.window
1318 .current_frame
1319 .mouse_listeners
1320 .get_mut(&event.type_id())
1321 .into_iter()
1322 .flat_map(|handlers| handlers.drain(..)),
1323 );
1324 self.window
1325 .current_frame
1326 .mouse_listeners
1327 .insert(event.type_id(), handlers);
1328 }
1329 }
1330
1331 fn dispatch_key_event(&mut self, event: &dyn Any) {
1332 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1333 self.window
1334 .current_frame
1335 .dispatch_tree
1336 .focusable_node_id(focus_id)
1337 }) {
1338 let dispatch_path = self
1339 .window
1340 .current_frame
1341 .dispatch_tree
1342 .dispatch_path(node_id);
1343
1344 // Capture phase
1345 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1346 self.propagate_event = true;
1347
1348 for node_id in &dispatch_path {
1349 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1350
1351 if !node.context.is_empty() {
1352 context_stack.push(node.context.clone());
1353 }
1354
1355 for key_listener in node.key_listeners.clone() {
1356 key_listener(event, DispatchPhase::Capture, self);
1357 if !self.propagate_event {
1358 return;
1359 }
1360 }
1361 }
1362
1363 // Bubble phase
1364 for node_id in dispatch_path.iter().rev() {
1365 // Handle low level key events
1366 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1367 for key_listener in node.key_listeners.clone() {
1368 key_listener(event, DispatchPhase::Bubble, self);
1369 if !self.propagate_event {
1370 return;
1371 }
1372 }
1373
1374 // Match keystrokes
1375 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1376 if !node.context.is_empty() {
1377 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1378 if let Some(action) = self
1379 .window
1380 .current_frame
1381 .dispatch_tree
1382 .dispatch_key(&key_down_event.keystroke, &context_stack)
1383 {
1384 self.dispatch_action_on_node(*node_id, action);
1385 if !self.propagate_event {
1386 return;
1387 }
1388 }
1389 }
1390
1391 context_stack.pop();
1392 }
1393 }
1394 }
1395 }
1396
1397 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1398 let dispatch_path = self
1399 .window
1400 .current_frame
1401 .dispatch_tree
1402 .dispatch_path(node_id);
1403
1404 // Capture phase
1405 for node_id in &dispatch_path {
1406 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1407 for DispatchActionListener {
1408 action_type,
1409 listener,
1410 } in node.action_listeners.clone()
1411 {
1412 let any_action = action.as_any();
1413 if action_type == any_action.type_id() {
1414 listener(any_action, DispatchPhase::Capture, self);
1415 if !self.propagate_event {
1416 return;
1417 }
1418 }
1419 }
1420 }
1421
1422 // Bubble phase
1423 for node_id in dispatch_path.iter().rev() {
1424 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1425 for DispatchActionListener {
1426 action_type,
1427 listener,
1428 } in node.action_listeners.clone()
1429 {
1430 let any_action = action.as_any();
1431 if action_type == any_action.type_id() {
1432 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1433 listener(any_action, DispatchPhase::Bubble, self);
1434 if !self.propagate_event {
1435 return;
1436 }
1437 }
1438 }
1439 }
1440 }
1441
1442 /// Register the given handler to be invoked whenever the global of the given type
1443 /// is updated.
1444 pub fn observe_global<G: 'static>(
1445 &mut self,
1446 f: impl Fn(&mut WindowContext<'_>) + 'static,
1447 ) -> Subscription {
1448 let window_handle = self.window.handle;
1449 self.global_observers.insert(
1450 TypeId::of::<G>(),
1451 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1452 )
1453 }
1454
1455 pub fn activate_window(&self) {
1456 self.window.platform_window.activate();
1457 }
1458
1459 pub fn minimize_window(&self) {
1460 self.window.platform_window.minimize();
1461 }
1462
1463 pub fn toggle_full_screen(&self) {
1464 self.window.platform_window.toggle_full_screen();
1465 }
1466
1467 pub fn prompt(
1468 &self,
1469 level: PromptLevel,
1470 msg: &str,
1471 answers: &[&str],
1472 ) -> oneshot::Receiver<usize> {
1473 self.window.platform_window.prompt(level, msg, answers)
1474 }
1475
1476 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1477 if let Some(focus_id) = self.window.focus {
1478 self.window
1479 .current_frame
1480 .dispatch_tree
1481 .available_actions(focus_id)
1482 } else {
1483 Vec::new()
1484 }
1485 }
1486
1487 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1488 self.window
1489 .current_frame
1490 .dispatch_tree
1491 .bindings_for_action(action)
1492 }
1493
1494 pub fn listener_for<V: Render, E>(
1495 &self,
1496 view: &View<V>,
1497 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1498 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1499 let view = view.downgrade();
1500 move |e: &E, cx: &mut WindowContext| {
1501 view.update(cx, |view, cx| f(view, e, cx)).ok();
1502 }
1503 }
1504
1505 pub fn handler_for<V: Render>(
1506 &self,
1507 view: &View<V>,
1508 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1509 ) -> impl Fn(&mut WindowContext) {
1510 let view = view.downgrade();
1511 move |cx: &mut WindowContext| {
1512 view.update(cx, |view, cx| f(view, cx)).ok();
1513 }
1514 }
1515
1516 //========== ELEMENT RELATED FUNCTIONS ===========
1517 pub fn with_key_dispatch<R>(
1518 &mut self,
1519 context: KeyContext,
1520 focus_handle: Option<FocusHandle>,
1521 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1522 ) -> R {
1523 let window = &mut self.window;
1524 window
1525 .current_frame
1526 .dispatch_tree
1527 .push_node(context.clone());
1528 if let Some(focus_handle) = focus_handle.as_ref() {
1529 window
1530 .current_frame
1531 .dispatch_tree
1532 .make_focusable(focus_handle.id);
1533 }
1534 let result = f(focus_handle, self);
1535
1536 self.window.current_frame.dispatch_tree.pop_node();
1537
1538 result
1539 }
1540
1541 /// Register a focus listener for the current frame only. It will be cleared
1542 /// on the next frame render. You should use this method only from within elements,
1543 /// and we may want to enforce that better via a different context type.
1544 // todo!() Move this to `FrameContext` to emphasize its individuality?
1545 pub fn on_focus_changed(
1546 &mut self,
1547 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1548 ) {
1549 self.window
1550 .current_frame
1551 .focus_listeners
1552 .push(Box::new(move |event, cx| {
1553 listener(event, cx);
1554 }));
1555 }
1556
1557 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1558 /// platform to receive textual input with proper integration with concerns such
1559 /// as IME interactions.
1560 pub fn handle_input(
1561 &mut self,
1562 focus_handle: &FocusHandle,
1563 input_handler: impl PlatformInputHandler,
1564 ) {
1565 if focus_handle.is_focused(self) {
1566 self.window
1567 .platform_window
1568 .set_input_handler(Box::new(input_handler));
1569 }
1570 }
1571
1572 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1573 let mut this = self.to_async();
1574 self.window
1575 .platform_window
1576 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1577 }
1578}
1579
1580impl Context for WindowContext<'_> {
1581 type Result<T> = T;
1582
1583 fn build_model<T>(
1584 &mut self,
1585 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1586 ) -> Model<T>
1587 where
1588 T: 'static,
1589 {
1590 let slot = self.app.entities.reserve();
1591 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1592 self.entities.insert(slot, model)
1593 }
1594
1595 fn update_model<T: 'static, R>(
1596 &mut self,
1597 model: &Model<T>,
1598 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1599 ) -> R {
1600 let mut entity = self.entities.lease(model);
1601 let result = update(
1602 &mut *entity,
1603 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1604 );
1605 self.entities.end_lease(entity);
1606 result
1607 }
1608
1609 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1610 where
1611 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1612 {
1613 if window == self.window.handle {
1614 let root_view = self.window.root_view.clone().unwrap();
1615 Ok(update(root_view, self))
1616 } else {
1617 window.update(self.app, update)
1618 }
1619 }
1620
1621 fn read_model<T, R>(
1622 &self,
1623 handle: &Model<T>,
1624 read: impl FnOnce(&T, &AppContext) -> R,
1625 ) -> Self::Result<R>
1626 where
1627 T: 'static,
1628 {
1629 let entity = self.entities.read(handle);
1630 read(&*entity, &*self.app)
1631 }
1632
1633 fn read_window<T, R>(
1634 &self,
1635 window: &WindowHandle<T>,
1636 read: impl FnOnce(View<T>, &AppContext) -> R,
1637 ) -> Result<R>
1638 where
1639 T: 'static,
1640 {
1641 if window.any_handle == self.window.handle {
1642 let root_view = self
1643 .window
1644 .root_view
1645 .clone()
1646 .unwrap()
1647 .downcast::<T>()
1648 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1649 Ok(read(root_view, self))
1650 } else {
1651 self.app.read_window(window, read)
1652 }
1653 }
1654}
1655
1656impl VisualContext for WindowContext<'_> {
1657 fn build_view<V>(
1658 &mut self,
1659 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1660 ) -> Self::Result<View<V>>
1661 where
1662 V: 'static + Render,
1663 {
1664 let slot = self.app.entities.reserve();
1665 let view = View {
1666 model: slot.clone(),
1667 };
1668 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1669 let entity = build_view_state(&mut cx);
1670 cx.entities.insert(slot, entity);
1671
1672 cx.new_view_observers
1673 .clone()
1674 .retain(&TypeId::of::<V>(), |observer| {
1675 let any_view = AnyView::from(view.clone());
1676 (observer)(any_view, self);
1677 true
1678 });
1679
1680 view
1681 }
1682
1683 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1684 fn update_view<T: 'static, R>(
1685 &mut self,
1686 view: &View<T>,
1687 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1688 ) -> Self::Result<R> {
1689 let mut lease = self.app.entities.lease(&view.model);
1690 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1691 let result = update(&mut *lease, &mut cx);
1692 cx.app.entities.end_lease(lease);
1693 result
1694 }
1695
1696 fn replace_root_view<V>(
1697 &mut self,
1698 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1699 ) -> Self::Result<View<V>>
1700 where
1701 V: 'static + Render,
1702 {
1703 let slot = self.app.entities.reserve();
1704 let view = View {
1705 model: slot.clone(),
1706 };
1707 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1708 let entity = build_view(&mut cx);
1709 self.entities.insert(slot, entity);
1710 self.window.root_view = Some(view.clone().into());
1711 view
1712 }
1713
1714 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1715 self.update_view(view, |view, cx| {
1716 view.focus_handle(cx).clone().focus(cx);
1717 })
1718 }
1719
1720 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1721 where
1722 V: ManagedView,
1723 {
1724 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1725 }
1726}
1727
1728impl<'a> std::ops::Deref for WindowContext<'a> {
1729 type Target = AppContext;
1730
1731 fn deref(&self) -> &Self::Target {
1732 &self.app
1733 }
1734}
1735
1736impl<'a> std::ops::DerefMut for WindowContext<'a> {
1737 fn deref_mut(&mut self) -> &mut Self::Target {
1738 &mut self.app
1739 }
1740}
1741
1742impl<'a> Borrow<AppContext> for WindowContext<'a> {
1743 fn borrow(&self) -> &AppContext {
1744 &self.app
1745 }
1746}
1747
1748impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1749 fn borrow_mut(&mut self) -> &mut AppContext {
1750 &mut self.app
1751 }
1752}
1753
1754pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1755 fn app_mut(&mut self) -> &mut AppContext {
1756 self.borrow_mut()
1757 }
1758
1759 fn app(&self) -> &AppContext {
1760 self.borrow()
1761 }
1762
1763 fn window(&self) -> &Window {
1764 self.borrow()
1765 }
1766
1767 fn window_mut(&mut self) -> &mut Window {
1768 self.borrow_mut()
1769 }
1770
1771 /// Pushes the given element id onto the global stack and invokes the given closure
1772 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1773 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1774 /// used to associate state with identified elements across separate frames.
1775 fn with_element_id<R>(
1776 &mut self,
1777 id: Option<impl Into<ElementId>>,
1778 f: impl FnOnce(&mut Self) -> R,
1779 ) -> R {
1780 if let Some(id) = id.map(Into::into) {
1781 let window = self.window_mut();
1782 window.element_id_stack.push(id.into());
1783 let result = f(self);
1784 let window: &mut Window = self.borrow_mut();
1785 window.element_id_stack.pop();
1786 result
1787 } else {
1788 f(self)
1789 }
1790 }
1791
1792 /// Invoke the given function with the given content mask after intersecting it
1793 /// with the current mask.
1794 fn with_content_mask<R>(
1795 &mut self,
1796 mask: Option<ContentMask<Pixels>>,
1797 f: impl FnOnce(&mut Self) -> R,
1798 ) -> R {
1799 if let Some(mask) = mask {
1800 let mask = mask.intersect(&self.content_mask());
1801 self.window_mut()
1802 .current_frame
1803 .content_mask_stack
1804 .push(mask);
1805 let result = f(self);
1806 self.window_mut().current_frame.content_mask_stack.pop();
1807 result
1808 } else {
1809 f(self)
1810 }
1811 }
1812
1813 /// Invoke the given function with the content mask reset to that
1814 /// of the window.
1815 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1816 let mask = ContentMask {
1817 bounds: Bounds {
1818 origin: Point::default(),
1819 size: self.window().viewport_size,
1820 },
1821 };
1822 self.window_mut()
1823 .current_frame
1824 .content_mask_stack
1825 .push(mask);
1826 let result = f(self);
1827 self.window_mut().current_frame.content_mask_stack.pop();
1828 result
1829 }
1830
1831 /// Update the global element offset relative to the current offset. This is used to implement
1832 /// scrolling.
1833 fn with_element_offset<R>(
1834 &mut self,
1835 offset: Point<Pixels>,
1836 f: impl FnOnce(&mut Self) -> R,
1837 ) -> R {
1838 if offset.is_zero() {
1839 return f(self);
1840 };
1841
1842 let abs_offset = self.element_offset() + offset;
1843 self.with_absolute_element_offset(abs_offset, f)
1844 }
1845
1846 /// Update the global element offset based on the given offset. This is used to implement
1847 /// drag handles and other manual painting of elements.
1848 fn with_absolute_element_offset<R>(
1849 &mut self,
1850 offset: Point<Pixels>,
1851 f: impl FnOnce(&mut Self) -> R,
1852 ) -> R {
1853 self.window_mut()
1854 .current_frame
1855 .element_offset_stack
1856 .push(offset);
1857 let result = f(self);
1858 self.window_mut().current_frame.element_offset_stack.pop();
1859 result
1860 }
1861
1862 /// Obtain the current element offset.
1863 fn element_offset(&self) -> Point<Pixels> {
1864 self.window()
1865 .current_frame
1866 .element_offset_stack
1867 .last()
1868 .copied()
1869 .unwrap_or_default()
1870 }
1871
1872 /// Update or intialize state for an element with the given id that lives across multiple
1873 /// frames. If an element with this id existed in the previous frame, its state will be passed
1874 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1875 /// when drawing the next frame.
1876 fn with_element_state<S, R>(
1877 &mut self,
1878 id: ElementId,
1879 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1880 ) -> R
1881 where
1882 S: 'static,
1883 {
1884 self.with_element_id(Some(id), |cx| {
1885 let global_id = cx.window().element_id_stack.clone();
1886
1887 if let Some(any) = cx
1888 .window_mut()
1889 .current_frame
1890 .element_states
1891 .remove(&global_id)
1892 .or_else(|| {
1893 cx.window_mut()
1894 .previous_frame
1895 .element_states
1896 .remove(&global_id)
1897 })
1898 {
1899 let ElementStateBox {
1900 inner,
1901
1902 #[cfg(debug_assertions)]
1903 type_name
1904 } = any;
1905 // Using the extra inner option to avoid needing to reallocate a new box.
1906 let mut state_box = inner
1907 .downcast::<Option<S>>()
1908 .map_err(|_| {
1909 #[cfg(debug_assertions)]
1910 {
1911 anyhow!(
1912 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1913 std::any::type_name::<S>(),
1914 type_name
1915 )
1916 }
1917
1918 #[cfg(not(debug_assertions))]
1919 {
1920 anyhow!(
1921 "invalid element state type for id, requested_type {:?}",
1922 std::any::type_name::<S>(),
1923 )
1924 }
1925 })
1926 .unwrap();
1927
1928 // Actual: Option<AnyElement> <- View
1929 // Requested: () <- AnyElemet
1930 let state = state_box
1931 .take()
1932 .expect("element state is already on the stack");
1933 let (result, state) = f(Some(state), cx);
1934 state_box.replace(state);
1935 cx.window_mut()
1936 .current_frame
1937 .element_states
1938 .insert(global_id, ElementStateBox {
1939 inner: state_box,
1940
1941 #[cfg(debug_assertions)]
1942 type_name
1943 });
1944 result
1945 } else {
1946 let (result, state) = f(None, cx);
1947 cx.window_mut()
1948 .current_frame
1949 .element_states
1950 .insert(global_id,
1951 ElementStateBox {
1952 inner: Box::new(Some(state)),
1953
1954 #[cfg(debug_assertions)]
1955 type_name: std::any::type_name::<S>()
1956 }
1957
1958 );
1959 result
1960 }
1961 })
1962 }
1963
1964 /// Obtain the current content mask.
1965 fn content_mask(&self) -> ContentMask<Pixels> {
1966 self.window()
1967 .current_frame
1968 .content_mask_stack
1969 .last()
1970 .cloned()
1971 .unwrap_or_else(|| ContentMask {
1972 bounds: Bounds {
1973 origin: Point::default(),
1974 size: self.window().viewport_size,
1975 },
1976 })
1977 }
1978
1979 /// The size of an em for the base font of the application. Adjusting this value allows the
1980 /// UI to scale, just like zooming a web page.
1981 fn rem_size(&self) -> Pixels {
1982 self.window().rem_size
1983 }
1984}
1985
1986impl Borrow<Window> for WindowContext<'_> {
1987 fn borrow(&self) -> &Window {
1988 &self.window
1989 }
1990}
1991
1992impl BorrowMut<Window> for WindowContext<'_> {
1993 fn borrow_mut(&mut self) -> &mut Window {
1994 &mut self.window
1995 }
1996}
1997
1998impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1999
2000pub struct ViewContext<'a, V> {
2001 window_cx: WindowContext<'a>,
2002 view: &'a View<V>,
2003}
2004
2005impl<V> Borrow<AppContext> for ViewContext<'_, V> {
2006 fn borrow(&self) -> &AppContext {
2007 &*self.window_cx.app
2008 }
2009}
2010
2011impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
2012 fn borrow_mut(&mut self) -> &mut AppContext {
2013 &mut *self.window_cx.app
2014 }
2015}
2016
2017impl<V> Borrow<Window> for ViewContext<'_, V> {
2018 fn borrow(&self) -> &Window {
2019 &*self.window_cx.window
2020 }
2021}
2022
2023impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2024 fn borrow_mut(&mut self) -> &mut Window {
2025 &mut *self.window_cx.window
2026 }
2027}
2028
2029impl<'a, V: 'static> ViewContext<'a, V> {
2030 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2031 Self {
2032 window_cx: WindowContext::new(app, window),
2033 view,
2034 }
2035 }
2036
2037 pub fn entity_id(&self) -> EntityId {
2038 self.view.entity_id()
2039 }
2040
2041 pub fn view(&self) -> &View<V> {
2042 self.view
2043 }
2044
2045 pub fn model(&self) -> &Model<V> {
2046 &self.view.model
2047 }
2048
2049 /// Access the underlying window context.
2050 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2051 &mut self.window_cx
2052 }
2053
2054 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2055 self.window.current_frame.z_index_stack.push(z_index);
2056 let result = f(self);
2057 self.window.current_frame.z_index_stack.pop();
2058 result
2059 }
2060
2061 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2062 where
2063 V: 'static,
2064 {
2065 let view = self.view().clone();
2066 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2067 }
2068
2069 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2070 /// that are currently on the stack to be returned to the app.
2071 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2072 let view = self.view().downgrade();
2073 self.window_cx.defer(move |cx| {
2074 view.update(cx, f).ok();
2075 });
2076 }
2077
2078 pub fn observe<V2, E>(
2079 &mut self,
2080 entity: &E,
2081 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2082 ) -> Subscription
2083 where
2084 V2: 'static,
2085 V: 'static,
2086 E: Entity<V2>,
2087 {
2088 let view = self.view().downgrade();
2089 let entity_id = entity.entity_id();
2090 let entity = entity.downgrade();
2091 let window_handle = self.window.handle;
2092 self.app.observers.insert(
2093 entity_id,
2094 Box::new(move |cx| {
2095 window_handle
2096 .update(cx, |_, cx| {
2097 if let Some(handle) = E::upgrade_from(&entity) {
2098 view.update(cx, |this, cx| on_notify(this, handle, cx))
2099 .is_ok()
2100 } else {
2101 false
2102 }
2103 })
2104 .unwrap_or(false)
2105 }),
2106 )
2107 }
2108
2109 pub fn subscribe<V2, E, Evt>(
2110 &mut self,
2111 entity: &E,
2112 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2113 ) -> Subscription
2114 where
2115 V2: EventEmitter<Evt>,
2116 E: Entity<V2>,
2117 Evt: 'static,
2118 {
2119 let view = self.view().downgrade();
2120 let entity_id = entity.entity_id();
2121 let handle = entity.downgrade();
2122 let window_handle = self.window.handle;
2123 self.app.event_listeners.insert(
2124 entity_id,
2125 (
2126 TypeId::of::<Evt>(),
2127 Box::new(move |event, cx| {
2128 window_handle
2129 .update(cx, |_, cx| {
2130 if let Some(handle) = E::upgrade_from(&handle) {
2131 let event = event.downcast_ref().expect("invalid event type");
2132 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2133 .is_ok()
2134 } else {
2135 false
2136 }
2137 })
2138 .unwrap_or(false)
2139 }),
2140 ),
2141 )
2142 }
2143
2144 pub fn on_release(
2145 &mut self,
2146 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2147 ) -> Subscription {
2148 let window_handle = self.window.handle;
2149 self.app.release_listeners.insert(
2150 self.view.model.entity_id,
2151 Box::new(move |this, cx| {
2152 let this = this.downcast_mut().expect("invalid entity type");
2153 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2154 }),
2155 )
2156 }
2157
2158 pub fn observe_release<V2, E>(
2159 &mut self,
2160 entity: &E,
2161 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2162 ) -> Subscription
2163 where
2164 V: 'static,
2165 V2: 'static,
2166 E: Entity<V2>,
2167 {
2168 let view = self.view().downgrade();
2169 let entity_id = entity.entity_id();
2170 let window_handle = self.window.handle;
2171 self.app.release_listeners.insert(
2172 entity_id,
2173 Box::new(move |entity, cx| {
2174 let entity = entity.downcast_mut().expect("invalid entity type");
2175 let _ = window_handle.update(cx, |_, cx| {
2176 view.update(cx, |this, cx| on_release(this, entity, cx))
2177 });
2178 }),
2179 )
2180 }
2181
2182 pub fn notify(&mut self) {
2183 self.window_cx.notify();
2184 self.window_cx.app.push_effect(Effect::Notify {
2185 emitter: self.view.model.entity_id,
2186 });
2187 }
2188
2189 pub fn observe_window_bounds(
2190 &mut self,
2191 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2192 ) -> Subscription {
2193 let view = self.view.downgrade();
2194 self.window.bounds_observers.insert(
2195 (),
2196 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2197 )
2198 }
2199
2200 pub fn observe_window_activation(
2201 &mut self,
2202 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2203 ) -> Subscription {
2204 let view = self.view.downgrade();
2205 self.window.activation_observers.insert(
2206 (),
2207 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2208 )
2209 }
2210
2211 /// Register a listener to be called when the given focus handle receives focus.
2212 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2213 /// is dropped.
2214 pub fn on_focus(
2215 &mut self,
2216 handle: &FocusHandle,
2217 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2218 ) -> Subscription {
2219 let view = self.view.downgrade();
2220 let focus_id = handle.id;
2221 self.window.focus_listeners.insert(
2222 (),
2223 Box::new(move |event, cx| {
2224 view.update(cx, |view, cx| {
2225 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2226 listener(view, cx)
2227 }
2228 })
2229 .is_ok()
2230 }),
2231 )
2232 }
2233
2234 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2235 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2236 /// is dropped.
2237 pub fn on_focus_in(
2238 &mut self,
2239 handle: &FocusHandle,
2240 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2241 ) -> Subscription {
2242 let view = self.view.downgrade();
2243 let focus_id = handle.id;
2244 self.window.focus_listeners.insert(
2245 (),
2246 Box::new(move |event, cx| {
2247 view.update(cx, |view, cx| {
2248 if event
2249 .focused
2250 .as_ref()
2251 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2252 {
2253 listener(view, cx)
2254 }
2255 })
2256 .is_ok()
2257 }),
2258 )
2259 }
2260
2261 /// Register a listener to be called when the given focus handle loses focus.
2262 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2263 /// is dropped.
2264 pub fn on_blur(
2265 &mut self,
2266 handle: &FocusHandle,
2267 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2268 ) -> Subscription {
2269 let view = self.view.downgrade();
2270 let focus_id = handle.id;
2271 self.window.focus_listeners.insert(
2272 (),
2273 Box::new(move |event, cx| {
2274 view.update(cx, |view, cx| {
2275 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2276 listener(view, cx)
2277 }
2278 })
2279 .is_ok()
2280 }),
2281 )
2282 }
2283
2284 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2285 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2286 /// is dropped.
2287 pub fn on_focus_out(
2288 &mut self,
2289 handle: &FocusHandle,
2290 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2291 ) -> Subscription {
2292 let view = self.view.downgrade();
2293 let focus_id = handle.id;
2294 self.window.focus_listeners.insert(
2295 (),
2296 Box::new(move |event, cx| {
2297 view.update(cx, |view, cx| {
2298 if event
2299 .blurred
2300 .as_ref()
2301 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2302 {
2303 listener(view, cx)
2304 }
2305 })
2306 .is_ok()
2307 }),
2308 )
2309 }
2310
2311 pub fn spawn<Fut, R>(
2312 &mut self,
2313 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2314 ) -> Task<R>
2315 where
2316 R: 'static,
2317 Fut: Future<Output = R> + 'static,
2318 {
2319 let view = self.view().downgrade();
2320 self.window_cx.spawn(|cx| f(view, cx))
2321 }
2322
2323 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2324 where
2325 G: 'static,
2326 {
2327 let mut global = self.app.lease_global::<G>();
2328 let result = f(&mut global, self);
2329 self.app.end_global_lease(global);
2330 result
2331 }
2332
2333 pub fn observe_global<G: 'static>(
2334 &mut self,
2335 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2336 ) -> Subscription {
2337 let window_handle = self.window.handle;
2338 let view = self.view().downgrade();
2339 self.global_observers.insert(
2340 TypeId::of::<G>(),
2341 Box::new(move |cx| {
2342 window_handle
2343 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2344 .unwrap_or(false)
2345 }),
2346 )
2347 }
2348
2349 pub fn on_mouse_event<Event: 'static>(
2350 &mut self,
2351 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2352 ) {
2353 let handle = self.view().clone();
2354 self.window_cx.on_mouse_event(move |event, phase, cx| {
2355 handle.update(cx, |view, cx| {
2356 handler(view, event, phase, cx);
2357 })
2358 });
2359 }
2360
2361 pub fn on_key_event<Event: 'static>(
2362 &mut self,
2363 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2364 ) {
2365 let handle = self.view().clone();
2366 self.window_cx.on_key_event(move |event, phase, cx| {
2367 handle.update(cx, |view, cx| {
2368 handler(view, event, phase, cx);
2369 })
2370 });
2371 }
2372
2373 pub fn on_action(
2374 &mut self,
2375 action_type: TypeId,
2376 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2377 ) {
2378 let handle = self.view().clone();
2379 self.window_cx
2380 .on_action(action_type, move |action, phase, cx| {
2381 handle.update(cx, |view, cx| {
2382 handler(view, action, phase, cx);
2383 })
2384 });
2385 }
2386
2387 pub fn emit<Evt>(&mut self, event: Evt)
2388 where
2389 Evt: 'static,
2390 V: EventEmitter<Evt>,
2391 {
2392 let emitter = self.view.model.entity_id;
2393 self.app.push_effect(Effect::Emit {
2394 emitter,
2395 event_type: TypeId::of::<Evt>(),
2396 event: Box::new(event),
2397 });
2398 }
2399
2400 pub fn focus_self(&mut self)
2401 where
2402 V: FocusableView,
2403 {
2404 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2405 }
2406
2407 pub fn dismiss_self(&mut self)
2408 where
2409 V: ManagedView,
2410 {
2411 self.defer(|_, cx| cx.emit(DismissEvent))
2412 }
2413
2414 pub fn listener<E>(
2415 &self,
2416 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2417 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2418 let view = self.view().downgrade();
2419 move |e: &E, cx: &mut WindowContext| {
2420 view.update(cx, |view, cx| f(view, e, cx)).ok();
2421 }
2422 }
2423}
2424
2425impl<V> Context for ViewContext<'_, V> {
2426 type Result<U> = U;
2427
2428 fn build_model<T: 'static>(
2429 &mut self,
2430 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2431 ) -> Model<T> {
2432 self.window_cx.build_model(build_model)
2433 }
2434
2435 fn update_model<T: 'static, R>(
2436 &mut self,
2437 model: &Model<T>,
2438 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2439 ) -> R {
2440 self.window_cx.update_model(model, update)
2441 }
2442
2443 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2444 where
2445 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2446 {
2447 self.window_cx.update_window(window, update)
2448 }
2449
2450 fn read_model<T, R>(
2451 &self,
2452 handle: &Model<T>,
2453 read: impl FnOnce(&T, &AppContext) -> R,
2454 ) -> Self::Result<R>
2455 where
2456 T: 'static,
2457 {
2458 self.window_cx.read_model(handle, read)
2459 }
2460
2461 fn read_window<T, R>(
2462 &self,
2463 window: &WindowHandle<T>,
2464 read: impl FnOnce(View<T>, &AppContext) -> R,
2465 ) -> Result<R>
2466 where
2467 T: 'static,
2468 {
2469 self.window_cx.read_window(window, read)
2470 }
2471}
2472
2473impl<V: 'static> VisualContext for ViewContext<'_, V> {
2474 fn build_view<W: Render + 'static>(
2475 &mut self,
2476 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2477 ) -> Self::Result<View<W>> {
2478 self.window_cx.build_view(build_view_state)
2479 }
2480
2481 fn update_view<V2: 'static, R>(
2482 &mut self,
2483 view: &View<V2>,
2484 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2485 ) -> Self::Result<R> {
2486 self.window_cx.update_view(view, update)
2487 }
2488
2489 fn replace_root_view<W>(
2490 &mut self,
2491 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2492 ) -> Self::Result<View<W>>
2493 where
2494 W: 'static + Render,
2495 {
2496 self.window_cx.replace_root_view(build_view)
2497 }
2498
2499 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2500 self.window_cx.focus_view(view)
2501 }
2502
2503 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2504 self.window_cx.dismiss_view(view)
2505 }
2506}
2507
2508impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2509 type Target = WindowContext<'a>;
2510
2511 fn deref(&self) -> &Self::Target {
2512 &self.window_cx
2513 }
2514}
2515
2516impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2517 fn deref_mut(&mut self) -> &mut Self::Target {
2518 &mut self.window_cx
2519 }
2520}
2521
2522// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2523slotmap::new_key_type! { pub struct WindowId; }
2524
2525impl WindowId {
2526 pub fn as_u64(&self) -> u64 {
2527 self.0.as_ffi()
2528 }
2529}
2530
2531#[derive(Deref, DerefMut)]
2532pub struct WindowHandle<V> {
2533 #[deref]
2534 #[deref_mut]
2535 pub(crate) any_handle: AnyWindowHandle,
2536 state_type: PhantomData<V>,
2537}
2538
2539impl<V: 'static + Render> WindowHandle<V> {
2540 pub fn new(id: WindowId) -> Self {
2541 WindowHandle {
2542 any_handle: AnyWindowHandle {
2543 id,
2544 state_type: TypeId::of::<V>(),
2545 },
2546 state_type: PhantomData,
2547 }
2548 }
2549
2550 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2551 where
2552 C: Context,
2553 {
2554 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2555 root_view
2556 .downcast::<V>()
2557 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2558 }))
2559 }
2560
2561 pub fn update<C, R>(
2562 &self,
2563 cx: &mut C,
2564 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2565 ) -> Result<R>
2566 where
2567 C: Context,
2568 {
2569 cx.update_window(self.any_handle, |root_view, cx| {
2570 let view = root_view
2571 .downcast::<V>()
2572 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2573 Ok(cx.update_view(&view, update))
2574 })?
2575 }
2576
2577 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2578 let x = cx
2579 .windows
2580 .get(self.id)
2581 .and_then(|window| {
2582 window
2583 .as_ref()
2584 .and_then(|window| window.root_view.clone())
2585 .map(|root_view| root_view.downcast::<V>())
2586 })
2587 .ok_or_else(|| anyhow!("window not found"))?
2588 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2589
2590 Ok(x.read(cx))
2591 }
2592
2593 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2594 where
2595 C: Context,
2596 {
2597 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2598 }
2599
2600 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2601 where
2602 C: Context,
2603 {
2604 cx.read_window(self, |root_view, _cx| root_view.clone())
2605 }
2606
2607 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2608 cx.windows
2609 .get(self.id)
2610 .and_then(|window| window.as_ref().map(|window| window.active))
2611 }
2612}
2613
2614impl<V> Copy for WindowHandle<V> {}
2615
2616impl<V> Clone for WindowHandle<V> {
2617 fn clone(&self) -> Self {
2618 WindowHandle {
2619 any_handle: self.any_handle,
2620 state_type: PhantomData,
2621 }
2622 }
2623}
2624
2625impl<V> PartialEq for WindowHandle<V> {
2626 fn eq(&self, other: &Self) -> bool {
2627 self.any_handle == other.any_handle
2628 }
2629}
2630
2631impl<V> Eq for WindowHandle<V> {}
2632
2633impl<V> Hash for WindowHandle<V> {
2634 fn hash<H: Hasher>(&self, state: &mut H) {
2635 self.any_handle.hash(state);
2636 }
2637}
2638
2639impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2640 fn into(self) -> AnyWindowHandle {
2641 self.any_handle
2642 }
2643}
2644
2645#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2646pub struct AnyWindowHandle {
2647 pub(crate) id: WindowId,
2648 state_type: TypeId,
2649}
2650
2651impl AnyWindowHandle {
2652 pub fn window_id(&self) -> WindowId {
2653 self.id
2654 }
2655
2656 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2657 if TypeId::of::<T>() == self.state_type {
2658 Some(WindowHandle {
2659 any_handle: *self,
2660 state_type: PhantomData,
2661 })
2662 } else {
2663 None
2664 }
2665 }
2666
2667 pub fn update<C, R>(
2668 self,
2669 cx: &mut C,
2670 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2671 ) -> Result<R>
2672 where
2673 C: Context,
2674 {
2675 cx.update_window(self, update)
2676 }
2677
2678 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2679 where
2680 C: Context,
2681 T: 'static,
2682 {
2683 let view = self
2684 .downcast::<T>()
2685 .context("the type of the window's root view has changed")?;
2686
2687 cx.read_window(&view, read)
2688 }
2689}
2690
2691#[cfg(any(test, feature = "test-support"))]
2692impl From<SmallVec<[u32; 16]>> for StackingOrder {
2693 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2694 StackingOrder(small_vec)
2695 }
2696}
2697
2698#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2699pub enum ElementId {
2700 View(EntityId),
2701 Integer(usize),
2702 Name(SharedString),
2703 FocusHandle(FocusId),
2704}
2705
2706impl ElementId {
2707 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2708 ElementId::View(entity_id)
2709 }
2710}
2711
2712impl TryInto<SharedString> for ElementId {
2713 type Error = anyhow::Error;
2714
2715 fn try_into(self) -> anyhow::Result<SharedString> {
2716 if let ElementId::Name(name) = self {
2717 Ok(name)
2718 } else {
2719 Err(anyhow!("element id is not string"))
2720 }
2721 }
2722}
2723
2724impl From<usize> for ElementId {
2725 fn from(id: usize) -> Self {
2726 ElementId::Integer(id)
2727 }
2728}
2729
2730impl From<i32> for ElementId {
2731 fn from(id: i32) -> Self {
2732 Self::Integer(id as usize)
2733 }
2734}
2735
2736impl From<SharedString> for ElementId {
2737 fn from(name: SharedString) -> Self {
2738 ElementId::Name(name)
2739 }
2740}
2741
2742impl From<&'static str> for ElementId {
2743 fn from(name: &'static str) -> Self {
2744 ElementId::Name(name.into())
2745 }
2746}
2747
2748impl<'a> From<&'a FocusHandle> for ElementId {
2749 fn from(handle: &'a FocusHandle) -> Self {
2750 ElementId::FocusHandle(handle.id)
2751 }
2752}