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 .rendered_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 layout_engine: Option<TaffyLayoutEngine>,
213 pub(crate) root_view: Option<AnyView>,
214 pub(crate) element_id_stack: GlobalElementId,
215 pub(crate) rendered_frame: Frame,
216 pub(crate) next_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 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 fn clear(&mut self) {
267 self.element_states.clear();
268 self.mouse_listeners.values_mut().for_each(Vec::clear);
269 self.focus_listeners.clear();
270 self.dispatch_tree.clear();
271 self.depth_map.clear();
272 }
273}
274
275impl Window {
276 pub(crate) fn new(
277 handle: AnyWindowHandle,
278 options: WindowOptions,
279 cx: &mut AppContext,
280 ) -> Self {
281 let platform_window = cx.platform.open_window(handle, options);
282 let display_id = platform_window.display().id();
283 let sprite_atlas = platform_window.sprite_atlas();
284 let mouse_position = platform_window.mouse_position();
285 let content_size = platform_window.content_size();
286 let scale_factor = platform_window.scale_factor();
287 let bounds = platform_window.bounds();
288
289 platform_window.on_resize(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_moved(Box::new({
298 let mut cx = cx.to_async();
299 move || {
300 handle
301 .update(&mut cx, |_, cx| cx.window_bounds_changed())
302 .log_err();
303 }
304 }));
305 platform_window.on_active_status_change(Box::new({
306 let mut cx = cx.to_async();
307 move |active| {
308 handle
309 .update(&mut cx, |_, cx| {
310 cx.window.active = active;
311 cx.window
312 .activation_observers
313 .clone()
314 .retain(&(), |callback| callback(cx));
315 })
316 .log_err();
317 }
318 }));
319
320 platform_window.on_input({
321 let mut cx = cx.to_async();
322 Box::new(move |event| {
323 handle
324 .update(&mut cx, |_, cx| cx.dispatch_event(event))
325 .log_err()
326 .unwrap_or(false)
327 })
328 });
329
330 Window {
331 handle,
332 removed: false,
333 platform_window,
334 display_id,
335 sprite_atlas,
336 rem_size: px(16.),
337 viewport_size: content_size,
338 layout_engine: Some(TaffyLayoutEngine::new()),
339 root_view: None,
340 element_id_stack: GlobalElementId::default(),
341 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
342 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
343 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
344 focus_listeners: SubscriberSet::new(),
345 default_prevented: true,
346 mouse_position,
347 requested_cursor_style: None,
348 scale_factor,
349 bounds,
350 bounds_observers: SubscriberSet::new(),
351 active: false,
352 activation_observers: SubscriberSet::new(),
353 dirty: true,
354 last_blur: None,
355 focus: None,
356 }
357 }
358}
359
360/// Indicates which region of the window is visible. Content falling outside of this mask will not be
361/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
362/// to leave room to support more complex shapes in the future.
363#[derive(Clone, Debug, Default, PartialEq, Eq)]
364#[repr(C)]
365pub struct ContentMask<P: Clone + Default + Debug> {
366 pub bounds: Bounds<P>,
367}
368
369impl ContentMask<Pixels> {
370 /// Scale the content mask's pixel units by the given scaling factor.
371 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
372 ContentMask {
373 bounds: self.bounds.scale(factor),
374 }
375 }
376
377 /// Intersect the content mask with the given content mask.
378 pub fn intersect(&self, other: &Self) -> Self {
379 let bounds = self.bounds.intersect(&other.bounds);
380 ContentMask { bounds }
381 }
382}
383
384/// Provides access to application state in the context of a single window. Derefs
385/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
386/// an `AppContext` and call any `AppContext` methods.
387pub struct WindowContext<'a> {
388 pub(crate) app: &'a mut AppContext,
389 pub(crate) window: &'a mut Window,
390}
391
392impl<'a> WindowContext<'a> {
393 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
394 Self { app, window }
395 }
396
397 /// Obtain a handle to the window that belongs to this context.
398 pub fn window_handle(&self) -> AnyWindowHandle {
399 self.window.handle
400 }
401
402 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
403 pub fn notify(&mut self) {
404 self.window.dirty = true;
405 }
406
407 /// Close this window.
408 pub fn remove_window(&mut self) {
409 self.window.removed = true;
410 }
411
412 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
413 /// for elements rendered within this window.
414 pub fn focus_handle(&mut self) -> FocusHandle {
415 FocusHandle::new(&self.window.focus_handles)
416 }
417
418 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
419 pub fn focused(&self) -> Option<FocusHandle> {
420 self.window
421 .focus
422 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
423 }
424
425 /// Move focus to the element associated with the given `FocusHandle`.
426 pub fn focus(&mut self, handle: &FocusHandle) {
427 if self.window.focus == Some(handle.id) {
428 return;
429 }
430
431 let focus_id = handle.id;
432
433 if self.window.last_blur.is_none() {
434 self.window.last_blur = Some(self.window.focus);
435 }
436
437 self.window.focus = Some(focus_id);
438 self.window
439 .rendered_frame
440 .dispatch_tree
441 .clear_pending_keystrokes();
442 self.app.push_effect(Effect::FocusChanged {
443 window_handle: self.window.handle,
444 focused: Some(focus_id),
445 });
446 self.notify();
447 }
448
449 /// Remove focus from all elements within this context's window.
450 pub fn blur(&mut self) {
451 if self.window.last_blur.is_none() {
452 self.window.last_blur = Some(self.window.focus);
453 }
454
455 self.window.focus = None;
456 self.app.push_effect(Effect::FocusChanged {
457 window_handle: self.window.handle,
458 focused: None,
459 });
460 self.notify();
461 }
462
463 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
464 let focus_handle = self.focused();
465
466 self.defer(move |cx| {
467 let node_id = focus_handle
468 .and_then(|handle| {
469 cx.window
470 .rendered_frame
471 .dispatch_tree
472 .focusable_node_id(handle.id)
473 })
474 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
475
476 cx.propagate_event = true;
477 cx.dispatch_action_on_node(node_id, action);
478 })
479 }
480
481 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
482 /// that are currently on the stack to be returned to the app.
483 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
484 let handle = self.window.handle;
485 self.app.defer(move |cx| {
486 handle.update(cx, |_, cx| f(cx)).ok();
487 });
488 }
489
490 pub fn subscribe<Emitter, E, Evt>(
491 &mut self,
492 entity: &E,
493 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
494 ) -> Subscription
495 where
496 Emitter: EventEmitter<Evt>,
497 E: Entity<Emitter>,
498 Evt: 'static,
499 {
500 let entity_id = entity.entity_id();
501 let entity = entity.downgrade();
502 let window_handle = self.window.handle;
503 let (subscription, activate) = self.app.event_listeners.insert(
504 entity_id,
505 (
506 TypeId::of::<Evt>(),
507 Box::new(move |event, cx| {
508 window_handle
509 .update(cx, |_, cx| {
510 if let Some(handle) = E::upgrade_from(&entity) {
511 let event = event.downcast_ref().expect("invalid event type");
512 on_event(handle, event, cx);
513 true
514 } else {
515 false
516 }
517 })
518 .unwrap_or(false)
519 }),
520 ),
521 );
522 self.app.defer(move |_| activate());
523 subscription
524 }
525
526 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
527 /// await points in async code.
528 pub fn to_async(&self) -> AsyncWindowContext {
529 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
530 }
531
532 /// Schedule the given closure to be run directly after the current frame is rendered.
533 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
534 let handle = self.window.handle;
535 let display_id = self.window.display_id;
536
537 if !self.frame_consumers.contains_key(&display_id) {
538 let (tx, mut rx) = mpsc::unbounded::<()>();
539 self.platform.set_display_link_output_callback(
540 display_id,
541 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
542 );
543
544 let consumer_task = self.app.spawn(|cx| async move {
545 while rx.next().await.is_some() {
546 cx.update(|cx| {
547 for callback in cx
548 .next_frame_callbacks
549 .get_mut(&display_id)
550 .unwrap()
551 .drain(..)
552 .collect::<SmallVec<[_; 32]>>()
553 {
554 callback(cx);
555 }
556 })
557 .ok();
558
559 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
560
561 cx.update(|cx| {
562 if cx.next_frame_callbacks.is_empty() {
563 cx.platform.stop_display_link(display_id);
564 }
565 })
566 .ok();
567 }
568 });
569 self.frame_consumers.insert(display_id, consumer_task);
570 }
571
572 if self.next_frame_callbacks.is_empty() {
573 self.platform.start_display_link(display_id);
574 }
575
576 self.next_frame_callbacks
577 .entry(display_id)
578 .or_default()
579 .push(Box::new(move |cx: &mut AppContext| {
580 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
581 }));
582 }
583
584 /// Spawn the future returned by the given closure on the application thread pool.
585 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
586 /// use within your future.
587 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
588 where
589 R: 'static,
590 Fut: Future<Output = R> + 'static,
591 {
592 self.app
593 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
594 }
595
596 /// Update the global of the given type. The given closure is given simultaneous mutable
597 /// access both to the global and the context.
598 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
599 where
600 G: 'static,
601 {
602 let mut global = self.app.lease_global::<G>();
603 let result = f(&mut global, self);
604 self.app.end_global_lease(global);
605 result
606 }
607
608 #[must_use]
609 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
610 /// layout is being requested, along with the layout ids of any children. This method is called during
611 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
612 pub fn request_layout(
613 &mut self,
614 style: &Style,
615 children: impl IntoIterator<Item = LayoutId>,
616 ) -> LayoutId {
617 self.app.layout_id_buffer.clear();
618 self.app.layout_id_buffer.extend(children.into_iter());
619 let rem_size = self.rem_size();
620
621 self.window.layout_engine.as_mut().unwrap().request_layout(
622 style,
623 rem_size,
624 &self.app.layout_id_buffer,
625 )
626 }
627
628 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
629 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
630 /// determine the element's size. One place this is used internally is when measuring text.
631 ///
632 /// The given closure is invoked at layout time with the known dimensions and available space and
633 /// returns a `Size`.
634 pub fn request_measured_layout<
635 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
636 + 'static,
637 >(
638 &mut self,
639 style: Style,
640 measure: F,
641 ) -> LayoutId {
642 let rem_size = self.rem_size();
643 self.window
644 .layout_engine
645 .as_mut()
646 .unwrap()
647 .request_measured_layout(style, rem_size, measure)
648 }
649
650 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
651 let mut layout_engine = self.window.layout_engine.take().unwrap();
652 layout_engine.compute_layout(layout_id, available_space, self);
653 self.window.layout_engine = Some(layout_engine);
654 }
655
656 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
657 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
658 /// in order to pass your element its `Bounds` automatically.
659 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
660 let mut bounds = self
661 .window
662 .layout_engine
663 .as_mut()
664 .unwrap()
665 .layout_bounds(layout_id)
666 .map(Into::into);
667 bounds.origin += self.element_offset();
668 bounds
669 }
670
671 fn window_bounds_changed(&mut self) {
672 self.window.scale_factor = self.window.platform_window.scale_factor();
673 self.window.viewport_size = self.window.platform_window.content_size();
674 self.window.bounds = self.window.platform_window.bounds();
675 self.window.display_id = self.window.platform_window.display().id();
676 self.window.dirty = true;
677
678 self.window
679 .bounds_observers
680 .clone()
681 .retain(&(), |callback| callback(self));
682 }
683
684 pub fn window_bounds(&self) -> WindowBounds {
685 self.window.bounds
686 }
687
688 pub fn viewport_size(&self) -> Size<Pixels> {
689 self.window.viewport_size
690 }
691
692 pub fn is_window_active(&self) -> bool {
693 self.window.active
694 }
695
696 pub fn zoom_window(&self) {
697 self.window.platform_window.zoom();
698 }
699
700 pub fn set_window_title(&mut self, title: &str) {
701 self.window.platform_window.set_title(title);
702 }
703
704 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
705 self.platform
706 .displays()
707 .into_iter()
708 .find(|display| display.id() == self.window.display_id)
709 }
710
711 pub fn show_character_palette(&self) {
712 self.window.platform_window.show_character_palette();
713 }
714
715 /// The scale factor of the display associated with the window. For example, it could
716 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
717 /// be rendered as two pixels on screen.
718 pub fn scale_factor(&self) -> f32 {
719 self.window.scale_factor
720 }
721
722 /// The size of an em for the base font of the application. Adjusting this value allows the
723 /// UI to scale, just like zooming a web page.
724 pub fn rem_size(&self) -> Pixels {
725 self.window.rem_size
726 }
727
728 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
729 /// UI to scale, just like zooming a web page.
730 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
731 self.window.rem_size = rem_size.into();
732 }
733
734 /// The line height associated with the current text style.
735 pub fn line_height(&self) -> Pixels {
736 let rem_size = self.rem_size();
737 let text_style = self.text_style();
738 text_style
739 .line_height
740 .to_pixels(text_style.font_size.into(), rem_size)
741 }
742
743 /// Call to prevent the default action of an event. Currently only used to prevent
744 /// parent elements from becoming focused on mouse down.
745 pub fn prevent_default(&mut self) {
746 self.window.default_prevented = true;
747 }
748
749 /// Obtain whether default has been prevented for the event currently being dispatched.
750 pub fn default_prevented(&self) -> bool {
751 self.window.default_prevented
752 }
753
754 /// Register a mouse event listener on the window for the next frame. The type of event
755 /// is determined by the first parameter of the given listener. When the next frame is rendered
756 /// the listener will be cleared.
757 ///
758 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
759 /// a specific need to register a global listener.
760 pub fn on_mouse_event<Event: 'static>(
761 &mut self,
762 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
763 ) {
764 let order = self.window.next_frame.z_index_stack.clone();
765 self.window
766 .next_frame
767 .mouse_listeners
768 .entry(TypeId::of::<Event>())
769 .or_default()
770 .push((
771 order,
772 Box::new(move |event: &dyn Any, phase, cx| {
773 handler(event.downcast_ref().unwrap(), phase, cx)
774 }),
775 ))
776 }
777
778 /// Register a key event listener on the window for the next frame. The type of event
779 /// is determined by the first parameter of the given listener. When the next frame is rendered
780 /// the listener will be cleared.
781 ///
782 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
783 /// a specific need to register a global listener.
784 pub fn on_key_event<Event: 'static>(
785 &mut self,
786 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
787 ) {
788 self.window
789 .next_frame
790 .dispatch_tree
791 .on_key_event(Rc::new(move |event, phase, cx| {
792 if let Some(event) = event.downcast_ref::<Event>() {
793 handler(event, phase, cx)
794 }
795 }));
796 }
797
798 /// Register an action listener on the window for the next frame. The type of action
799 /// is determined by the first parameter of the given listener. When the next frame is rendered
800 /// the listener will be cleared.
801 ///
802 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
803 /// a specific need to register a global listener.
804 pub fn on_action(
805 &mut self,
806 action_type: TypeId,
807 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
808 ) {
809 self.window.next_frame.dispatch_tree.on_action(
810 action_type,
811 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
812 );
813 }
814
815 pub fn is_action_available(&self, action: &dyn Action) -> bool {
816 let target = self
817 .focused()
818 .and_then(|focused_handle| {
819 self.window
820 .rendered_frame
821 .dispatch_tree
822 .focusable_node_id(focused_handle.id)
823 })
824 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
825 self.window
826 .rendered_frame
827 .dispatch_tree
828 .is_action_available(action, target)
829 }
830
831 /// The position of the mouse relative to the window.
832 pub fn mouse_position(&self) -> Point<Pixels> {
833 self.window.mouse_position
834 }
835
836 pub fn set_cursor_style(&mut self, style: CursorStyle) {
837 self.window.requested_cursor_style = Some(style)
838 }
839
840 /// Called during painting to invoke the given closure in a new stacking context. The given
841 /// z-index is interpreted relative to the previous call to `stack`.
842 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
843 self.window.next_frame.z_index_stack.push(z_index);
844 let result = f(self);
845 self.window.next_frame.z_index_stack.pop();
846 result
847 }
848
849 /// Called during painting to track which z-index is on top at each pixel position
850 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
851 let stacking_order = self.window.next_frame.z_index_stack.clone();
852 let depth_map = &mut self.window.next_frame.depth_map;
853 match depth_map.binary_search_by(|(level, _)| stacking_order.cmp(&level)) {
854 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, bounds)),
855 }
856 }
857
858 /// Returns true if the top-most opaque layer painted over this point was part of the
859 /// same layer as the given stacking order.
860 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
861 for (stack, bounds) in self.window.rendered_frame.depth_map.iter() {
862 if bounds.contains_point(point) {
863 return level.starts_with(stack) || stack.starts_with(level);
864 }
865 }
866
867 false
868 }
869
870 /// Called during painting to get the current stacking order.
871 pub fn stacking_order(&self) -> &StackingOrder {
872 &self.window.next_frame.z_index_stack
873 }
874
875 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
876 pub fn paint_shadows(
877 &mut self,
878 bounds: Bounds<Pixels>,
879 corner_radii: Corners<Pixels>,
880 shadows: &[BoxShadow],
881 ) {
882 let scale_factor = self.scale_factor();
883 let content_mask = self.content_mask();
884 let window = &mut *self.window;
885 for shadow in shadows {
886 let mut shadow_bounds = bounds;
887 shadow_bounds.origin += shadow.offset;
888 shadow_bounds.dilate(shadow.spread_radius);
889 window.next_frame.scene_builder.insert(
890 &window.next_frame.z_index_stack,
891 Shadow {
892 order: 0,
893 bounds: shadow_bounds.scale(scale_factor),
894 content_mask: content_mask.scale(scale_factor),
895 corner_radii: corner_radii.scale(scale_factor),
896 color: shadow.color,
897 blur_radius: shadow.blur_radius.scale(scale_factor),
898 },
899 );
900 }
901 }
902
903 /// Paint one or more quads into the scene for the next frame at the current stacking context.
904 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
905 pub fn paint_quad(
906 &mut self,
907 bounds: Bounds<Pixels>,
908 corner_radii: Corners<Pixels>,
909 background: impl Into<Hsla>,
910 border_widths: Edges<Pixels>,
911 border_color: impl Into<Hsla>,
912 ) {
913 let scale_factor = self.scale_factor();
914 let content_mask = self.content_mask();
915
916 let window = &mut *self.window;
917 window.next_frame.scene_builder.insert(
918 &window.next_frame.z_index_stack,
919 Quad {
920 order: 0,
921 bounds: bounds.scale(scale_factor),
922 content_mask: content_mask.scale(scale_factor),
923 background: background.into(),
924 border_color: border_color.into(),
925 corner_radii: corner_radii.scale(scale_factor),
926 border_widths: border_widths.scale(scale_factor),
927 },
928 );
929 }
930
931 /// Paint the given `Path` into the scene for the next frame at the current z-index.
932 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
933 let scale_factor = self.scale_factor();
934 let content_mask = self.content_mask();
935 path.content_mask = content_mask;
936 path.color = color.into();
937 let window = &mut *self.window;
938 window
939 .next_frame
940 .scene_builder
941 .insert(&window.next_frame.z_index_stack, path.scale(scale_factor));
942 }
943
944 /// Paint an underline into the scene for the next frame at the current z-index.
945 pub fn paint_underline(
946 &mut self,
947 origin: Point<Pixels>,
948 width: Pixels,
949 style: &UnderlineStyle,
950 ) {
951 let scale_factor = self.scale_factor();
952 let height = if style.wavy {
953 style.thickness * 3.
954 } else {
955 style.thickness
956 };
957 let bounds = Bounds {
958 origin,
959 size: size(width, height),
960 };
961 let content_mask = self.content_mask();
962 let window = &mut *self.window;
963 window.next_frame.scene_builder.insert(
964 &window.next_frame.z_index_stack,
965 Underline {
966 order: 0,
967 bounds: bounds.scale(scale_factor),
968 content_mask: content_mask.scale(scale_factor),
969 thickness: style.thickness.scale(scale_factor),
970 color: style.color.unwrap_or_default(),
971 wavy: style.wavy,
972 },
973 );
974 }
975
976 /// Paint a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
977 /// The y component of the origin is the baseline of the glyph.
978 pub fn paint_glyph(
979 &mut self,
980 origin: Point<Pixels>,
981 font_id: FontId,
982 glyph_id: GlyphId,
983 font_size: Pixels,
984 color: Hsla,
985 ) -> Result<()> {
986 let scale_factor = self.scale_factor();
987 let glyph_origin = origin.scale(scale_factor);
988 let subpixel_variant = Point {
989 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
990 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
991 };
992 let params = RenderGlyphParams {
993 font_id,
994 glyph_id,
995 font_size,
996 subpixel_variant,
997 scale_factor,
998 is_emoji: false,
999 };
1000
1001 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1002 if !raster_bounds.is_zero() {
1003 let tile =
1004 self.window
1005 .sprite_atlas
1006 .get_or_insert_with(¶ms.clone().into(), &mut || {
1007 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1008 Ok((size, Cow::Owned(bytes)))
1009 })?;
1010 let bounds = Bounds {
1011 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1012 size: tile.bounds.size.map(Into::into),
1013 };
1014 let content_mask = self.content_mask().scale(scale_factor);
1015 let window = &mut *self.window;
1016 window.next_frame.scene_builder.insert(
1017 &window.next_frame.z_index_stack,
1018 MonochromeSprite {
1019 order: 0,
1020 bounds,
1021 content_mask,
1022 color,
1023 tile,
1024 },
1025 );
1026 }
1027 Ok(())
1028 }
1029
1030 /// Paint an emoji glyph into the scene for the next frame at the current z-index.
1031 /// The y component of the origin is the baseline of the glyph.
1032 pub fn paint_emoji(
1033 &mut self,
1034 origin: Point<Pixels>,
1035 font_id: FontId,
1036 glyph_id: GlyphId,
1037 font_size: Pixels,
1038 ) -> Result<()> {
1039 let scale_factor = self.scale_factor();
1040 let glyph_origin = origin.scale(scale_factor);
1041 let params = RenderGlyphParams {
1042 font_id,
1043 glyph_id,
1044 font_size,
1045 // We don't render emojis with subpixel variants.
1046 subpixel_variant: Default::default(),
1047 scale_factor,
1048 is_emoji: true,
1049 };
1050
1051 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1052 if !raster_bounds.is_zero() {
1053 let tile =
1054 self.window
1055 .sprite_atlas
1056 .get_or_insert_with(¶ms.clone().into(), &mut || {
1057 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1058 Ok((size, Cow::Owned(bytes)))
1059 })?;
1060 let bounds = Bounds {
1061 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1062 size: tile.bounds.size.map(Into::into),
1063 };
1064 let content_mask = self.content_mask().scale(scale_factor);
1065 let window = &mut *self.window;
1066
1067 window.next_frame.scene_builder.insert(
1068 &window.next_frame.z_index_stack,
1069 PolychromeSprite {
1070 order: 0,
1071 bounds,
1072 corner_radii: Default::default(),
1073 content_mask,
1074 tile,
1075 grayscale: false,
1076 },
1077 );
1078 }
1079 Ok(())
1080 }
1081
1082 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
1083 pub fn paint_svg(
1084 &mut self,
1085 bounds: Bounds<Pixels>,
1086 path: SharedString,
1087 color: Hsla,
1088 ) -> Result<()> {
1089 let scale_factor = self.scale_factor();
1090 let bounds = bounds.scale(scale_factor);
1091 // Render the SVG at twice the size to get a higher quality result.
1092 let params = RenderSvgParams {
1093 path,
1094 size: bounds
1095 .size
1096 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1097 };
1098
1099 let tile =
1100 self.window
1101 .sprite_atlas
1102 .get_or_insert_with(¶ms.clone().into(), &mut || {
1103 let bytes = self.svg_renderer.render(¶ms)?;
1104 Ok((params.size, Cow::Owned(bytes)))
1105 })?;
1106 let content_mask = self.content_mask().scale(scale_factor);
1107
1108 let window = &mut *self.window;
1109 window.next_frame.scene_builder.insert(
1110 &window.next_frame.z_index_stack,
1111 MonochromeSprite {
1112 order: 0,
1113 bounds,
1114 content_mask,
1115 color,
1116 tile,
1117 },
1118 );
1119
1120 Ok(())
1121 }
1122
1123 /// Paint an image into the scene for the next frame at the current z-index.
1124 pub fn paint_image(
1125 &mut self,
1126 bounds: Bounds<Pixels>,
1127 corner_radii: Corners<Pixels>,
1128 data: Arc<ImageData>,
1129 grayscale: bool,
1130 ) -> Result<()> {
1131 let scale_factor = self.scale_factor();
1132 let bounds = bounds.scale(scale_factor);
1133 let params = RenderImageParams { image_id: data.id };
1134
1135 let tile = self
1136 .window
1137 .sprite_atlas
1138 .get_or_insert_with(¶ms.clone().into(), &mut || {
1139 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1140 })?;
1141 let content_mask = self.content_mask().scale(scale_factor);
1142 let corner_radii = corner_radii.scale(scale_factor);
1143
1144 let window = &mut *self.window;
1145 window.next_frame.scene_builder.insert(
1146 &window.next_frame.z_index_stack,
1147 PolychromeSprite {
1148 order: 0,
1149 bounds,
1150 content_mask,
1151 corner_radii,
1152 tile,
1153 grayscale,
1154 },
1155 );
1156 Ok(())
1157 }
1158
1159 /// Paint a surface into the scene for the next frame at the current z-index.
1160 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
1161 let scale_factor = self.scale_factor();
1162 let bounds = bounds.scale(scale_factor);
1163 let content_mask = self.content_mask().scale(scale_factor);
1164 let window = &mut *self.window;
1165 window.next_frame.scene_builder.insert(
1166 &window.next_frame.z_index_stack,
1167 Surface {
1168 order: 0,
1169 bounds,
1170 content_mask,
1171 image_buffer,
1172 },
1173 );
1174 }
1175
1176 /// Draw pixels to the display for this window based on the contents of its scene.
1177 pub(crate) fn draw(&mut self) {
1178 self.text_system().start_frame();
1179 self.window.platform_window.clear_input_handler();
1180 self.window.layout_engine.as_mut().unwrap().clear();
1181 self.window.next_frame.clear();
1182 let root_view = self.window.root_view.take().unwrap();
1183
1184 self.with_z_index(0, |cx| {
1185 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
1186 for (action_type, action_listeners) in &cx.app.global_action_listeners {
1187 for action_listener in action_listeners.iter().cloned() {
1188 cx.window.next_frame.dispatch_tree.on_action(
1189 *action_type,
1190 Rc::new(move |action, phase, cx| action_listener(action, phase, cx)),
1191 )
1192 }
1193 }
1194
1195 let available_space = cx.window.viewport_size.map(Into::into);
1196 root_view.draw(Point::default(), available_space, cx);
1197 })
1198 });
1199
1200 if let Some(active_drag) = self.app.active_drag.take() {
1201 self.with_z_index(1, |cx| {
1202 let offset = cx.mouse_position() - active_drag.cursor_offset;
1203 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1204 active_drag.view.draw(offset, available_space, cx);
1205 });
1206 self.active_drag = Some(active_drag);
1207 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1208 self.with_z_index(1, |cx| {
1209 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1210 active_tooltip
1211 .view
1212 .draw(active_tooltip.cursor_offset, available_space, cx);
1213 });
1214 }
1215
1216 self.window
1217 .next_frame
1218 .dispatch_tree
1219 .preserve_pending_keystrokes(
1220 &mut self.window.rendered_frame.dispatch_tree,
1221 self.window.focus,
1222 );
1223 self.window.root_view = Some(root_view);
1224
1225 let window = &mut self.window;
1226 mem::swap(&mut window.rendered_frame, &mut window.next_frame);
1227
1228 let scene = self.window.rendered_frame.scene_builder.build();
1229 self.window.platform_window.draw(scene);
1230 let cursor_style = self
1231 .window
1232 .requested_cursor_style
1233 .take()
1234 .unwrap_or(CursorStyle::Arrow);
1235 self.platform.set_cursor_style(cursor_style);
1236
1237 self.window.dirty = false;
1238 }
1239
1240 /// Dispatch a mouse or keyboard event on the window.
1241 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1242 // Handlers may set this to false by calling `stop_propagation`
1243 self.app.propagate_event = true;
1244 self.window.default_prevented = false;
1245
1246 let event = match event {
1247 // Track the mouse position with our own state, since accessing the platform
1248 // API for the mouse position can only occur on the main thread.
1249 InputEvent::MouseMove(mouse_move) => {
1250 self.window.mouse_position = mouse_move.position;
1251 InputEvent::MouseMove(mouse_move)
1252 }
1253 InputEvent::MouseDown(mouse_down) => {
1254 self.window.mouse_position = mouse_down.position;
1255 InputEvent::MouseDown(mouse_down)
1256 }
1257 InputEvent::MouseUp(mouse_up) => {
1258 self.window.mouse_position = mouse_up.position;
1259 InputEvent::MouseUp(mouse_up)
1260 }
1261 // Translate dragging and dropping of external files from the operating system
1262 // to internal drag and drop events.
1263 InputEvent::FileDrop(file_drop) => match file_drop {
1264 FileDropEvent::Entered { position, files } => {
1265 self.window.mouse_position = position;
1266 if self.active_drag.is_none() {
1267 self.active_drag = Some(AnyDrag {
1268 view: self.build_view(|_| files).into(),
1269 cursor_offset: position,
1270 });
1271 }
1272 InputEvent::MouseDown(MouseDownEvent {
1273 position,
1274 button: MouseButton::Left,
1275 click_count: 1,
1276 modifiers: Modifiers::default(),
1277 })
1278 }
1279 FileDropEvent::Pending { position } => {
1280 self.window.mouse_position = position;
1281 InputEvent::MouseMove(MouseMoveEvent {
1282 position,
1283 pressed_button: Some(MouseButton::Left),
1284 modifiers: Modifiers::default(),
1285 })
1286 }
1287 FileDropEvent::Submit { position } => {
1288 self.window.mouse_position = position;
1289 InputEvent::MouseUp(MouseUpEvent {
1290 button: MouseButton::Left,
1291 position,
1292 modifiers: Modifiers::default(),
1293 click_count: 1,
1294 })
1295 }
1296 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1297 button: MouseButton::Left,
1298 position: Point::default(),
1299 modifiers: Modifiers::default(),
1300 click_count: 1,
1301 }),
1302 },
1303 _ => event,
1304 };
1305
1306 if let Some(any_mouse_event) = event.mouse_event() {
1307 self.dispatch_mouse_event(any_mouse_event);
1308 } else if let Some(any_key_event) = event.keyboard_event() {
1309 self.dispatch_key_event(any_key_event);
1310 }
1311
1312 !self.app.propagate_event
1313 }
1314
1315 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1316 if let Some(mut handlers) = self
1317 .window
1318 .rendered_frame
1319 .mouse_listeners
1320 .remove(&event.type_id())
1321 {
1322 // Because handlers may add other handlers, we sort every time.
1323 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1324
1325 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1326 // special purposes, such as detecting events outside of a given Bounds.
1327 for (_, handler) in &mut handlers {
1328 handler(event, DispatchPhase::Capture, self);
1329 if !self.app.propagate_event {
1330 break;
1331 }
1332 }
1333
1334 // Bubble phase, where most normal handlers do their work.
1335 if self.app.propagate_event {
1336 for (_, handler) in handlers.iter_mut().rev() {
1337 handler(event, DispatchPhase::Bubble, self);
1338 if !self.app.propagate_event {
1339 break;
1340 }
1341 }
1342 }
1343
1344 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1345 self.active_drag = None;
1346 }
1347
1348 self.window
1349 .rendered_frame
1350 .mouse_listeners
1351 .insert(event.type_id(), handlers);
1352 }
1353 }
1354
1355 fn dispatch_key_event(&mut self, event: &dyn Any) {
1356 let node_id = self
1357 .window
1358 .focus
1359 .and_then(|focus_id| {
1360 self.window
1361 .rendered_frame
1362 .dispatch_tree
1363 .focusable_node_id(focus_id)
1364 })
1365 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1366
1367 let dispatch_path = self
1368 .window
1369 .rendered_frame
1370 .dispatch_tree
1371 .dispatch_path(node_id);
1372
1373 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1374
1375 // Capture phase
1376 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1377 self.propagate_event = true;
1378
1379 for node_id in &dispatch_path {
1380 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1381
1382 if let Some(context) = node.context.clone() {
1383 context_stack.push(context);
1384 }
1385
1386 for key_listener in node.key_listeners.clone() {
1387 key_listener(event, DispatchPhase::Capture, self);
1388 if !self.propagate_event {
1389 return;
1390 }
1391 }
1392 }
1393
1394 // Bubble phase
1395 for node_id in dispatch_path.iter().rev() {
1396 // Handle low level key events
1397 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1398 for key_listener in node.key_listeners.clone() {
1399 key_listener(event, DispatchPhase::Bubble, self);
1400 if !self.propagate_event {
1401 return;
1402 }
1403 }
1404
1405 // Match keystrokes
1406 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1407 if node.context.is_some() {
1408 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1409 if let Some(found) = self
1410 .window
1411 .rendered_frame
1412 .dispatch_tree
1413 .dispatch_key(&key_down_event.keystroke, &context_stack)
1414 {
1415 actions.push(found.boxed_clone())
1416 }
1417 }
1418
1419 context_stack.pop();
1420 }
1421 }
1422
1423 for action in actions {
1424 self.dispatch_action_on_node(node_id, action);
1425 if !self.propagate_event {
1426 return;
1427 }
1428 }
1429 }
1430
1431 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1432 let dispatch_path = self
1433 .window
1434 .rendered_frame
1435 .dispatch_tree
1436 .dispatch_path(node_id);
1437
1438 // Capture phase
1439 for node_id in &dispatch_path {
1440 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1441 for DispatchActionListener {
1442 action_type,
1443 listener,
1444 } in node.action_listeners.clone()
1445 {
1446 let any_action = action.as_any();
1447 if action_type == any_action.type_id() {
1448 listener(any_action, DispatchPhase::Capture, self);
1449 if !self.propagate_event {
1450 return;
1451 }
1452 }
1453 }
1454 }
1455 // Bubble phase
1456 for node_id in dispatch_path.iter().rev() {
1457 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1458 for DispatchActionListener {
1459 action_type,
1460 listener,
1461 } in node.action_listeners.clone()
1462 {
1463 let any_action = action.as_any();
1464 if action_type == any_action.type_id() {
1465 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1466 listener(any_action, DispatchPhase::Bubble, self);
1467 if !self.propagate_event {
1468 return;
1469 }
1470 }
1471 }
1472 }
1473 }
1474
1475 /// Register the given handler to be invoked whenever the global of the given type
1476 /// is updated.
1477 pub fn observe_global<G: 'static>(
1478 &mut self,
1479 f: impl Fn(&mut WindowContext<'_>) + 'static,
1480 ) -> Subscription {
1481 let window_handle = self.window.handle;
1482 let (subscription, activate) = self.global_observers.insert(
1483 TypeId::of::<G>(),
1484 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1485 );
1486 self.app.defer(move |_| activate());
1487 subscription
1488 }
1489
1490 pub fn activate_window(&self) {
1491 self.window.platform_window.activate();
1492 }
1493
1494 pub fn minimize_window(&self) {
1495 self.window.platform_window.minimize();
1496 }
1497
1498 pub fn toggle_full_screen(&self) {
1499 self.window.platform_window.toggle_full_screen();
1500 }
1501
1502 pub fn prompt(
1503 &self,
1504 level: PromptLevel,
1505 msg: &str,
1506 answers: &[&str],
1507 ) -> oneshot::Receiver<usize> {
1508 self.window.platform_window.prompt(level, msg, answers)
1509 }
1510
1511 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1512 let node_id = self
1513 .window
1514 .focus
1515 .and_then(|focus_id| {
1516 self.window
1517 .rendered_frame
1518 .dispatch_tree
1519 .focusable_node_id(focus_id)
1520 })
1521 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1522
1523 self.window
1524 .rendered_frame
1525 .dispatch_tree
1526 .available_actions(node_id)
1527 }
1528
1529 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1530 self.window
1531 .rendered_frame
1532 .dispatch_tree
1533 .bindings_for_action(
1534 action,
1535 &self.window.rendered_frame.dispatch_tree.context_stack,
1536 )
1537 }
1538
1539 pub fn bindings_for_action_in(
1540 &self,
1541 action: &dyn Action,
1542 focus_handle: &FocusHandle,
1543 ) -> Vec<KeyBinding> {
1544 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1545
1546 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1547 return vec![];
1548 };
1549 let context_stack = dispatch_tree
1550 .dispatch_path(node_id)
1551 .into_iter()
1552 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1553 .collect();
1554 dispatch_tree.bindings_for_action(action, &context_stack)
1555 }
1556
1557 pub fn listener_for<V: Render, E>(
1558 &self,
1559 view: &View<V>,
1560 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1561 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1562 let view = view.downgrade();
1563 move |e: &E, cx: &mut WindowContext| {
1564 view.update(cx, |view, cx| f(view, e, cx)).ok();
1565 }
1566 }
1567
1568 pub fn handler_for<V: Render>(
1569 &self,
1570 view: &View<V>,
1571 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1572 ) -> impl Fn(&mut WindowContext) {
1573 let view = view.downgrade();
1574 move |cx: &mut WindowContext| {
1575 view.update(cx, |view, cx| f(view, cx)).ok();
1576 }
1577 }
1578
1579 //========== ELEMENT RELATED FUNCTIONS ===========
1580 pub fn with_key_dispatch<R>(
1581 &mut self,
1582 context: Option<KeyContext>,
1583 focus_handle: Option<FocusHandle>,
1584 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1585 ) -> R {
1586 let window = &mut self.window;
1587 window.next_frame.dispatch_tree.push_node(context.clone());
1588 if let Some(focus_handle) = focus_handle.as_ref() {
1589 window
1590 .next_frame
1591 .dispatch_tree
1592 .make_focusable(focus_handle.id);
1593 }
1594 let result = f(focus_handle, self);
1595
1596 self.window.next_frame.dispatch_tree.pop_node();
1597
1598 result
1599 }
1600
1601 /// Register a focus listener for the next frame only. It will be cleared
1602 /// on the next frame render. You should use this method only from within elements,
1603 /// and we may want to enforce that better via a different context type.
1604 // todo!() Move this to `FrameContext` to emphasize its individuality?
1605 pub fn on_focus_changed(
1606 &mut self,
1607 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1608 ) {
1609 self.window
1610 .next_frame
1611 .focus_listeners
1612 .push(Box::new(move |event, cx| {
1613 listener(event, cx);
1614 }));
1615 }
1616
1617 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1618 /// platform to receive textual input with proper integration with concerns such
1619 /// as IME interactions.
1620 pub fn handle_input(
1621 &mut self,
1622 focus_handle: &FocusHandle,
1623 input_handler: impl PlatformInputHandler,
1624 ) {
1625 if focus_handle.is_focused(self) {
1626 self.window
1627 .platform_window
1628 .set_input_handler(Box::new(input_handler));
1629 }
1630 }
1631
1632 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1633 let mut this = self.to_async();
1634 self.window
1635 .platform_window
1636 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1637 }
1638}
1639
1640impl Context for WindowContext<'_> {
1641 type Result<T> = T;
1642
1643 fn build_model<T>(
1644 &mut self,
1645 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1646 ) -> Model<T>
1647 where
1648 T: 'static,
1649 {
1650 let slot = self.app.entities.reserve();
1651 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1652 self.entities.insert(slot, model)
1653 }
1654
1655 fn update_model<T: 'static, R>(
1656 &mut self,
1657 model: &Model<T>,
1658 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1659 ) -> R {
1660 let mut entity = self.entities.lease(model);
1661 let result = update(
1662 &mut *entity,
1663 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1664 );
1665 self.entities.end_lease(entity);
1666 result
1667 }
1668
1669 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1670 where
1671 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1672 {
1673 if window == self.window.handle {
1674 let root_view = self.window.root_view.clone().unwrap();
1675 Ok(update(root_view, self))
1676 } else {
1677 window.update(self.app, update)
1678 }
1679 }
1680
1681 fn read_model<T, R>(
1682 &self,
1683 handle: &Model<T>,
1684 read: impl FnOnce(&T, &AppContext) -> R,
1685 ) -> Self::Result<R>
1686 where
1687 T: 'static,
1688 {
1689 let entity = self.entities.read(handle);
1690 read(&*entity, &*self.app)
1691 }
1692
1693 fn read_window<T, R>(
1694 &self,
1695 window: &WindowHandle<T>,
1696 read: impl FnOnce(View<T>, &AppContext) -> R,
1697 ) -> Result<R>
1698 where
1699 T: 'static,
1700 {
1701 if window.any_handle == self.window.handle {
1702 let root_view = self
1703 .window
1704 .root_view
1705 .clone()
1706 .unwrap()
1707 .downcast::<T>()
1708 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1709 Ok(read(root_view, self))
1710 } else {
1711 self.app.read_window(window, read)
1712 }
1713 }
1714}
1715
1716impl VisualContext for WindowContext<'_> {
1717 fn build_view<V>(
1718 &mut self,
1719 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1720 ) -> Self::Result<View<V>>
1721 where
1722 V: 'static + Render,
1723 {
1724 let slot = self.app.entities.reserve();
1725 let view = View {
1726 model: slot.clone(),
1727 };
1728 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1729 let entity = build_view_state(&mut cx);
1730 cx.entities.insert(slot, entity);
1731
1732 cx.new_view_observers
1733 .clone()
1734 .retain(&TypeId::of::<V>(), |observer| {
1735 let any_view = AnyView::from(view.clone());
1736 (observer)(any_view, self);
1737 true
1738 });
1739
1740 view
1741 }
1742
1743 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1744 fn update_view<T: 'static, R>(
1745 &mut self,
1746 view: &View<T>,
1747 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1748 ) -> Self::Result<R> {
1749 let mut lease = self.app.entities.lease(&view.model);
1750 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1751 let result = update(&mut *lease, &mut cx);
1752 cx.app.entities.end_lease(lease);
1753 result
1754 }
1755
1756 fn replace_root_view<V>(
1757 &mut self,
1758 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1759 ) -> Self::Result<View<V>>
1760 where
1761 V: 'static + Render,
1762 {
1763 let slot = self.app.entities.reserve();
1764 let view = View {
1765 model: slot.clone(),
1766 };
1767 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1768 let entity = build_view(&mut cx);
1769 self.entities.insert(slot, entity);
1770 self.window.root_view = Some(view.clone().into());
1771 view
1772 }
1773
1774 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1775 self.update_view(view, |view, cx| {
1776 view.focus_handle(cx).clone().focus(cx);
1777 })
1778 }
1779
1780 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1781 where
1782 V: ManagedView,
1783 {
1784 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1785 }
1786}
1787
1788impl<'a> std::ops::Deref for WindowContext<'a> {
1789 type Target = AppContext;
1790
1791 fn deref(&self) -> &Self::Target {
1792 &self.app
1793 }
1794}
1795
1796impl<'a> std::ops::DerefMut for WindowContext<'a> {
1797 fn deref_mut(&mut self) -> &mut Self::Target {
1798 &mut self.app
1799 }
1800}
1801
1802impl<'a> Borrow<AppContext> for WindowContext<'a> {
1803 fn borrow(&self) -> &AppContext {
1804 &self.app
1805 }
1806}
1807
1808impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1809 fn borrow_mut(&mut self) -> &mut AppContext {
1810 &mut self.app
1811 }
1812}
1813
1814pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1815 fn app_mut(&mut self) -> &mut AppContext {
1816 self.borrow_mut()
1817 }
1818
1819 fn app(&self) -> &AppContext {
1820 self.borrow()
1821 }
1822
1823 fn window(&self) -> &Window {
1824 self.borrow()
1825 }
1826
1827 fn window_mut(&mut self) -> &mut Window {
1828 self.borrow_mut()
1829 }
1830
1831 /// Pushes the given element id onto the global stack and invokes the given closure
1832 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1833 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1834 /// used to associate state with identified elements across separate frames.
1835 fn with_element_id<R>(
1836 &mut self,
1837 id: Option<impl Into<ElementId>>,
1838 f: impl FnOnce(&mut Self) -> R,
1839 ) -> R {
1840 if let Some(id) = id.map(Into::into) {
1841 let window = self.window_mut();
1842 window.element_id_stack.push(id.into());
1843 let result = f(self);
1844 let window: &mut Window = self.borrow_mut();
1845 window.element_id_stack.pop();
1846 result
1847 } else {
1848 f(self)
1849 }
1850 }
1851
1852 /// Invoke the given function with the given content mask after intersecting it
1853 /// with the current mask.
1854 fn with_content_mask<R>(
1855 &mut self,
1856 mask: Option<ContentMask<Pixels>>,
1857 f: impl FnOnce(&mut Self) -> R,
1858 ) -> R {
1859 if let Some(mask) = mask {
1860 let mask = mask.intersect(&self.content_mask());
1861 self.window_mut().next_frame.content_mask_stack.push(mask);
1862 let result = f(self);
1863 self.window_mut().next_frame.content_mask_stack.pop();
1864 result
1865 } else {
1866 f(self)
1867 }
1868 }
1869
1870 /// Invoke the given function with the content mask reset to that
1871 /// of the window.
1872 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1873 let mask = ContentMask {
1874 bounds: Bounds {
1875 origin: Point::default(),
1876 size: self.window().viewport_size,
1877 },
1878 };
1879 self.window_mut().next_frame.content_mask_stack.push(mask);
1880 let result = f(self);
1881 self.window_mut().next_frame.content_mask_stack.pop();
1882 result
1883 }
1884
1885 /// Update the global element offset relative to the current offset. This is used to implement
1886 /// scrolling.
1887 fn with_element_offset<R>(
1888 &mut self,
1889 offset: Point<Pixels>,
1890 f: impl FnOnce(&mut Self) -> R,
1891 ) -> R {
1892 if offset.is_zero() {
1893 return f(self);
1894 };
1895
1896 let abs_offset = self.element_offset() + offset;
1897 self.with_absolute_element_offset(abs_offset, f)
1898 }
1899
1900 /// Update the global element offset based on the given offset. This is used to implement
1901 /// drag handles and other manual painting of elements.
1902 fn with_absolute_element_offset<R>(
1903 &mut self,
1904 offset: Point<Pixels>,
1905 f: impl FnOnce(&mut Self) -> R,
1906 ) -> R {
1907 self.window_mut()
1908 .next_frame
1909 .element_offset_stack
1910 .push(offset);
1911 let result = f(self);
1912 self.window_mut().next_frame.element_offset_stack.pop();
1913 result
1914 }
1915
1916 /// Obtain the current element offset.
1917 fn element_offset(&self) -> Point<Pixels> {
1918 self.window()
1919 .next_frame
1920 .element_offset_stack
1921 .last()
1922 .copied()
1923 .unwrap_or_default()
1924 }
1925
1926 /// Update or initialize state for an element with the given id that lives across multiple
1927 /// frames. If an element with this id existed in the rendered frame, its state will be passed
1928 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1929 /// when drawing the next frame.
1930 fn with_element_state<S, R>(
1931 &mut self,
1932 id: ElementId,
1933 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1934 ) -> R
1935 where
1936 S: 'static,
1937 {
1938 self.with_element_id(Some(id), |cx| {
1939 let global_id = cx.window().element_id_stack.clone();
1940
1941 if let Some(any) = cx
1942 .window_mut()
1943 .next_frame
1944 .element_states
1945 .remove(&global_id)
1946 .or_else(|| {
1947 cx.window_mut()
1948 .rendered_frame
1949 .element_states
1950 .remove(&global_id)
1951 })
1952 {
1953 let ElementStateBox {
1954 inner,
1955
1956 #[cfg(debug_assertions)]
1957 type_name
1958 } = any;
1959 // Using the extra inner option to avoid needing to reallocate a new box.
1960 let mut state_box = inner
1961 .downcast::<Option<S>>()
1962 .map_err(|_| {
1963 #[cfg(debug_assertions)]
1964 {
1965 anyhow!(
1966 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1967 std::any::type_name::<S>(),
1968 type_name
1969 )
1970 }
1971
1972 #[cfg(not(debug_assertions))]
1973 {
1974 anyhow!(
1975 "invalid element state type for id, requested_type {:?}",
1976 std::any::type_name::<S>(),
1977 )
1978 }
1979 })
1980 .unwrap();
1981
1982 // Actual: Option<AnyElement> <- View
1983 // Requested: () <- AnyElemet
1984 let state = state_box
1985 .take()
1986 .expect("element state is already on the stack");
1987 let (result, state) = f(Some(state), cx);
1988 state_box.replace(state);
1989 cx.window_mut()
1990 .next_frame
1991 .element_states
1992 .insert(global_id, ElementStateBox {
1993 inner: state_box,
1994
1995 #[cfg(debug_assertions)]
1996 type_name
1997 });
1998 result
1999 } else {
2000 let (result, state) = f(None, cx);
2001 cx.window_mut()
2002 .next_frame
2003 .element_states
2004 .insert(global_id,
2005 ElementStateBox {
2006 inner: Box::new(Some(state)),
2007
2008 #[cfg(debug_assertions)]
2009 type_name: std::any::type_name::<S>()
2010 }
2011
2012 );
2013 result
2014 }
2015 })
2016 }
2017
2018 /// Obtain the current content mask.
2019 fn content_mask(&self) -> ContentMask<Pixels> {
2020 self.window()
2021 .next_frame
2022 .content_mask_stack
2023 .last()
2024 .cloned()
2025 .unwrap_or_else(|| ContentMask {
2026 bounds: Bounds {
2027 origin: Point::default(),
2028 size: self.window().viewport_size,
2029 },
2030 })
2031 }
2032
2033 /// The size of an em for the base font of the application. Adjusting this value allows the
2034 /// UI to scale, just like zooming a web page.
2035 fn rem_size(&self) -> Pixels {
2036 self.window().rem_size
2037 }
2038}
2039
2040impl Borrow<Window> for WindowContext<'_> {
2041 fn borrow(&self) -> &Window {
2042 &self.window
2043 }
2044}
2045
2046impl BorrowMut<Window> for WindowContext<'_> {
2047 fn borrow_mut(&mut self) -> &mut Window {
2048 &mut self.window
2049 }
2050}
2051
2052impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
2053
2054pub struct ViewContext<'a, V> {
2055 window_cx: WindowContext<'a>,
2056 view: &'a View<V>,
2057}
2058
2059impl<V> Borrow<AppContext> for ViewContext<'_, V> {
2060 fn borrow(&self) -> &AppContext {
2061 &*self.window_cx.app
2062 }
2063}
2064
2065impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
2066 fn borrow_mut(&mut self) -> &mut AppContext {
2067 &mut *self.window_cx.app
2068 }
2069}
2070
2071impl<V> Borrow<Window> for ViewContext<'_, V> {
2072 fn borrow(&self) -> &Window {
2073 &*self.window_cx.window
2074 }
2075}
2076
2077impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2078 fn borrow_mut(&mut self) -> &mut Window {
2079 &mut *self.window_cx.window
2080 }
2081}
2082
2083impl<'a, V: 'static> ViewContext<'a, V> {
2084 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2085 Self {
2086 window_cx: WindowContext::new(app, window),
2087 view,
2088 }
2089 }
2090
2091 pub fn entity_id(&self) -> EntityId {
2092 self.view.entity_id()
2093 }
2094
2095 pub fn view(&self) -> &View<V> {
2096 self.view
2097 }
2098
2099 pub fn model(&self) -> &Model<V> {
2100 &self.view.model
2101 }
2102
2103 /// Access the underlying window context.
2104 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2105 &mut self.window_cx
2106 }
2107
2108 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2109 self.window.next_frame.z_index_stack.push(z_index);
2110 let result = f(self);
2111 self.window.next_frame.z_index_stack.pop();
2112 result
2113 }
2114
2115 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2116 where
2117 V: 'static,
2118 {
2119 let view = self.view().clone();
2120 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2121 }
2122
2123 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2124 /// that are currently on the stack to be returned to the app.
2125 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2126 let view = self.view().downgrade();
2127 self.window_cx.defer(move |cx| {
2128 view.update(cx, f).ok();
2129 });
2130 }
2131
2132 pub fn observe<V2, E>(
2133 &mut self,
2134 entity: &E,
2135 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2136 ) -> Subscription
2137 where
2138 V2: 'static,
2139 V: 'static,
2140 E: Entity<V2>,
2141 {
2142 let view = self.view().downgrade();
2143 let entity_id = entity.entity_id();
2144 let entity = entity.downgrade();
2145 let window_handle = self.window.handle;
2146 let (subscription, activate) = self.app.observers.insert(
2147 entity_id,
2148 Box::new(move |cx| {
2149 window_handle
2150 .update(cx, |_, cx| {
2151 if let Some(handle) = E::upgrade_from(&entity) {
2152 view.update(cx, |this, cx| on_notify(this, handle, cx))
2153 .is_ok()
2154 } else {
2155 false
2156 }
2157 })
2158 .unwrap_or(false)
2159 }),
2160 );
2161 self.app.defer(move |_| activate());
2162 subscription
2163 }
2164
2165 pub fn subscribe<V2, E, Evt>(
2166 &mut self,
2167 entity: &E,
2168 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2169 ) -> Subscription
2170 where
2171 V2: EventEmitter<Evt>,
2172 E: Entity<V2>,
2173 Evt: 'static,
2174 {
2175 let view = self.view().downgrade();
2176 let entity_id = entity.entity_id();
2177 let handle = entity.downgrade();
2178 let window_handle = self.window.handle;
2179 let (subscription, activate) = self.app.event_listeners.insert(
2180 entity_id,
2181 (
2182 TypeId::of::<Evt>(),
2183 Box::new(move |event, cx| {
2184 window_handle
2185 .update(cx, |_, cx| {
2186 if let Some(handle) = E::upgrade_from(&handle) {
2187 let event = event.downcast_ref().expect("invalid event type");
2188 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2189 .is_ok()
2190 } else {
2191 false
2192 }
2193 })
2194 .unwrap_or(false)
2195 }),
2196 ),
2197 );
2198 self.app.defer(move |_| activate());
2199 subscription
2200 }
2201
2202 pub fn on_release(
2203 &mut self,
2204 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2205 ) -> Subscription {
2206 let window_handle = self.window.handle;
2207 let (subscription, activate) = self.app.release_listeners.insert(
2208 self.view.model.entity_id,
2209 Box::new(move |this, cx| {
2210 let this = this.downcast_mut().expect("invalid entity type");
2211 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2212 }),
2213 );
2214 activate();
2215 subscription
2216 }
2217
2218 pub fn observe_release<V2, E>(
2219 &mut self,
2220 entity: &E,
2221 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2222 ) -> Subscription
2223 where
2224 V: 'static,
2225 V2: 'static,
2226 E: Entity<V2>,
2227 {
2228 let view = self.view().downgrade();
2229 let entity_id = entity.entity_id();
2230 let window_handle = self.window.handle;
2231 let (subscription, activate) = self.app.release_listeners.insert(
2232 entity_id,
2233 Box::new(move |entity, cx| {
2234 let entity = entity.downcast_mut().expect("invalid entity type");
2235 let _ = window_handle.update(cx, |_, cx| {
2236 view.update(cx, |this, cx| on_release(this, entity, cx))
2237 });
2238 }),
2239 );
2240 activate();
2241 subscription
2242 }
2243
2244 pub fn notify(&mut self) {
2245 self.window_cx.notify();
2246 self.window_cx.app.push_effect(Effect::Notify {
2247 emitter: self.view.model.entity_id,
2248 });
2249 }
2250
2251 pub fn observe_window_bounds(
2252 &mut self,
2253 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2254 ) -> Subscription {
2255 let view = self.view.downgrade();
2256 let (subscription, activate) = self.window.bounds_observers.insert(
2257 (),
2258 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2259 );
2260 activate();
2261 subscription
2262 }
2263
2264 pub fn observe_window_activation(
2265 &mut self,
2266 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2267 ) -> Subscription {
2268 let view = self.view.downgrade();
2269 let (subscription, activate) = self.window.activation_observers.insert(
2270 (),
2271 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2272 );
2273 activate();
2274 subscription
2275 }
2276
2277 /// Register a listener to be called when the given focus handle receives focus.
2278 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2279 /// is dropped.
2280 pub fn on_focus(
2281 &mut self,
2282 handle: &FocusHandle,
2283 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2284 ) -> Subscription {
2285 let view = self.view.downgrade();
2286 let focus_id = handle.id;
2287 let (subscription, activate) = self.window.focus_listeners.insert(
2288 (),
2289 Box::new(move |event, cx| {
2290 view.update(cx, |view, cx| {
2291 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2292 listener(view, cx)
2293 }
2294 })
2295 .is_ok()
2296 }),
2297 );
2298 self.app.defer(move |_| activate());
2299 subscription
2300 }
2301
2302 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2303 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2304 /// is dropped.
2305 pub fn on_focus_in(
2306 &mut self,
2307 handle: &FocusHandle,
2308 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2309 ) -> Subscription {
2310 let view = self.view.downgrade();
2311 let focus_id = handle.id;
2312 let (subscription, activate) = self.window.focus_listeners.insert(
2313 (),
2314 Box::new(move |event, cx| {
2315 view.update(cx, |view, cx| {
2316 if event
2317 .focused
2318 .as_ref()
2319 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2320 {
2321 listener(view, cx)
2322 }
2323 })
2324 .is_ok()
2325 }),
2326 );
2327 self.app.defer(move |_| activate());
2328 subscription
2329 }
2330
2331 /// Register a listener to be called when the given focus handle loses focus.
2332 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2333 /// is dropped.
2334 pub fn on_blur(
2335 &mut self,
2336 handle: &FocusHandle,
2337 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2338 ) -> Subscription {
2339 let view = self.view.downgrade();
2340 let focus_id = handle.id;
2341 let (subscription, activate) = self.window.focus_listeners.insert(
2342 (),
2343 Box::new(move |event, cx| {
2344 view.update(cx, |view, cx| {
2345 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2346 listener(view, cx)
2347 }
2348 })
2349 .is_ok()
2350 }),
2351 );
2352 self.app.defer(move |_| activate());
2353 subscription
2354 }
2355
2356 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2357 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2358 /// is dropped.
2359 pub fn on_focus_out(
2360 &mut self,
2361 handle: &FocusHandle,
2362 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2363 ) -> Subscription {
2364 let view = self.view.downgrade();
2365 let focus_id = handle.id;
2366 let (subscription, activate) = self.window.focus_listeners.insert(
2367 (),
2368 Box::new(move |event, cx| {
2369 view.update(cx, |view, cx| {
2370 if event
2371 .blurred
2372 .as_ref()
2373 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2374 {
2375 listener(view, cx)
2376 }
2377 })
2378 .is_ok()
2379 }),
2380 );
2381 self.app.defer(move |_| activate());
2382 subscription
2383 }
2384
2385 pub fn spawn<Fut, R>(
2386 &mut self,
2387 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2388 ) -> Task<R>
2389 where
2390 R: 'static,
2391 Fut: Future<Output = R> + 'static,
2392 {
2393 let view = self.view().downgrade();
2394 self.window_cx.spawn(|cx| f(view, cx))
2395 }
2396
2397 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2398 where
2399 G: 'static,
2400 {
2401 let mut global = self.app.lease_global::<G>();
2402 let result = f(&mut global, self);
2403 self.app.end_global_lease(global);
2404 result
2405 }
2406
2407 pub fn observe_global<G: 'static>(
2408 &mut self,
2409 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2410 ) -> Subscription {
2411 let window_handle = self.window.handle;
2412 let view = self.view().downgrade();
2413 let (subscription, activate) = self.global_observers.insert(
2414 TypeId::of::<G>(),
2415 Box::new(move |cx| {
2416 window_handle
2417 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2418 .unwrap_or(false)
2419 }),
2420 );
2421 self.app.defer(move |_| activate());
2422 subscription
2423 }
2424
2425 pub fn on_mouse_event<Event: 'static>(
2426 &mut self,
2427 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2428 ) {
2429 let handle = self.view().clone();
2430 self.window_cx.on_mouse_event(move |event, phase, cx| {
2431 handle.update(cx, |view, cx| {
2432 handler(view, event, phase, cx);
2433 })
2434 });
2435 }
2436
2437 pub fn on_key_event<Event: 'static>(
2438 &mut self,
2439 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2440 ) {
2441 let handle = self.view().clone();
2442 self.window_cx.on_key_event(move |event, phase, cx| {
2443 handle.update(cx, |view, cx| {
2444 handler(view, event, phase, cx);
2445 })
2446 });
2447 }
2448
2449 pub fn on_action(
2450 &mut self,
2451 action_type: TypeId,
2452 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2453 ) {
2454 let handle = self.view().clone();
2455 self.window_cx
2456 .on_action(action_type, move |action, phase, cx| {
2457 handle.update(cx, |view, cx| {
2458 handler(view, action, phase, cx);
2459 })
2460 });
2461 }
2462
2463 pub fn emit<Evt>(&mut self, event: Evt)
2464 where
2465 Evt: 'static,
2466 V: EventEmitter<Evt>,
2467 {
2468 let emitter = self.view.model.entity_id;
2469 self.app.push_effect(Effect::Emit {
2470 emitter,
2471 event_type: TypeId::of::<Evt>(),
2472 event: Box::new(event),
2473 });
2474 }
2475
2476 pub fn focus_self(&mut self)
2477 where
2478 V: FocusableView,
2479 {
2480 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2481 }
2482
2483 pub fn dismiss_self(&mut self)
2484 where
2485 V: ManagedView,
2486 {
2487 self.defer(|_, cx| cx.emit(DismissEvent))
2488 }
2489
2490 pub fn listener<E>(
2491 &self,
2492 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2493 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2494 let view = self.view().downgrade();
2495 move |e: &E, cx: &mut WindowContext| {
2496 view.update(cx, |view, cx| f(view, e, cx)).ok();
2497 }
2498 }
2499}
2500
2501impl<V> Context for ViewContext<'_, V> {
2502 type Result<U> = U;
2503
2504 fn build_model<T: 'static>(
2505 &mut self,
2506 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2507 ) -> Model<T> {
2508 self.window_cx.build_model(build_model)
2509 }
2510
2511 fn update_model<T: 'static, R>(
2512 &mut self,
2513 model: &Model<T>,
2514 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2515 ) -> R {
2516 self.window_cx.update_model(model, update)
2517 }
2518
2519 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2520 where
2521 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2522 {
2523 self.window_cx.update_window(window, update)
2524 }
2525
2526 fn read_model<T, R>(
2527 &self,
2528 handle: &Model<T>,
2529 read: impl FnOnce(&T, &AppContext) -> R,
2530 ) -> Self::Result<R>
2531 where
2532 T: 'static,
2533 {
2534 self.window_cx.read_model(handle, read)
2535 }
2536
2537 fn read_window<T, R>(
2538 &self,
2539 window: &WindowHandle<T>,
2540 read: impl FnOnce(View<T>, &AppContext) -> R,
2541 ) -> Result<R>
2542 where
2543 T: 'static,
2544 {
2545 self.window_cx.read_window(window, read)
2546 }
2547}
2548
2549impl<V: 'static> VisualContext for ViewContext<'_, V> {
2550 fn build_view<W: Render + 'static>(
2551 &mut self,
2552 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2553 ) -> Self::Result<View<W>> {
2554 self.window_cx.build_view(build_view_state)
2555 }
2556
2557 fn update_view<V2: 'static, R>(
2558 &mut self,
2559 view: &View<V2>,
2560 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2561 ) -> Self::Result<R> {
2562 self.window_cx.update_view(view, update)
2563 }
2564
2565 fn replace_root_view<W>(
2566 &mut self,
2567 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2568 ) -> Self::Result<View<W>>
2569 where
2570 W: 'static + Render,
2571 {
2572 self.window_cx.replace_root_view(build_view)
2573 }
2574
2575 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2576 self.window_cx.focus_view(view)
2577 }
2578
2579 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2580 self.window_cx.dismiss_view(view)
2581 }
2582}
2583
2584impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2585 type Target = WindowContext<'a>;
2586
2587 fn deref(&self) -> &Self::Target {
2588 &self.window_cx
2589 }
2590}
2591
2592impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2593 fn deref_mut(&mut self) -> &mut Self::Target {
2594 &mut self.window_cx
2595 }
2596}
2597
2598// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2599slotmap::new_key_type! { pub struct WindowId; }
2600
2601impl WindowId {
2602 pub fn as_u64(&self) -> u64 {
2603 self.0.as_ffi()
2604 }
2605}
2606
2607#[derive(Deref, DerefMut)]
2608pub struct WindowHandle<V> {
2609 #[deref]
2610 #[deref_mut]
2611 pub(crate) any_handle: AnyWindowHandle,
2612 state_type: PhantomData<V>,
2613}
2614
2615impl<V: 'static + Render> WindowHandle<V> {
2616 pub fn new(id: WindowId) -> Self {
2617 WindowHandle {
2618 any_handle: AnyWindowHandle {
2619 id,
2620 state_type: TypeId::of::<V>(),
2621 },
2622 state_type: PhantomData,
2623 }
2624 }
2625
2626 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2627 where
2628 C: Context,
2629 {
2630 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2631 root_view
2632 .downcast::<V>()
2633 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2634 }))
2635 }
2636
2637 pub fn update<C, R>(
2638 &self,
2639 cx: &mut C,
2640 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2641 ) -> Result<R>
2642 where
2643 C: Context,
2644 {
2645 cx.update_window(self.any_handle, |root_view, cx| {
2646 let view = root_view
2647 .downcast::<V>()
2648 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2649 Ok(cx.update_view(&view, update))
2650 })?
2651 }
2652
2653 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2654 let x = cx
2655 .windows
2656 .get(self.id)
2657 .and_then(|window| {
2658 window
2659 .as_ref()
2660 .and_then(|window| window.root_view.clone())
2661 .map(|root_view| root_view.downcast::<V>())
2662 })
2663 .ok_or_else(|| anyhow!("window not found"))?
2664 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2665
2666 Ok(x.read(cx))
2667 }
2668
2669 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2670 where
2671 C: Context,
2672 {
2673 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2674 }
2675
2676 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2677 where
2678 C: Context,
2679 {
2680 cx.read_window(self, |root_view, _cx| root_view.clone())
2681 }
2682
2683 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2684 cx.windows
2685 .get(self.id)
2686 .and_then(|window| window.as_ref().map(|window| window.active))
2687 }
2688}
2689
2690impl<V> Copy for WindowHandle<V> {}
2691
2692impl<V> Clone for WindowHandle<V> {
2693 fn clone(&self) -> Self {
2694 WindowHandle {
2695 any_handle: self.any_handle,
2696 state_type: PhantomData,
2697 }
2698 }
2699}
2700
2701impl<V> PartialEq for WindowHandle<V> {
2702 fn eq(&self, other: &Self) -> bool {
2703 self.any_handle == other.any_handle
2704 }
2705}
2706
2707impl<V> Eq for WindowHandle<V> {}
2708
2709impl<V> Hash for WindowHandle<V> {
2710 fn hash<H: Hasher>(&self, state: &mut H) {
2711 self.any_handle.hash(state);
2712 }
2713}
2714
2715impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2716 fn into(self) -> AnyWindowHandle {
2717 self.any_handle
2718 }
2719}
2720
2721#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2722pub struct AnyWindowHandle {
2723 pub(crate) id: WindowId,
2724 state_type: TypeId,
2725}
2726
2727impl AnyWindowHandle {
2728 pub fn window_id(&self) -> WindowId {
2729 self.id
2730 }
2731
2732 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2733 if TypeId::of::<T>() == self.state_type {
2734 Some(WindowHandle {
2735 any_handle: *self,
2736 state_type: PhantomData,
2737 })
2738 } else {
2739 None
2740 }
2741 }
2742
2743 pub fn update<C, R>(
2744 self,
2745 cx: &mut C,
2746 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2747 ) -> Result<R>
2748 where
2749 C: Context,
2750 {
2751 cx.update_window(self, update)
2752 }
2753
2754 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2755 where
2756 C: Context,
2757 T: 'static,
2758 {
2759 let view = self
2760 .downcast::<T>()
2761 .context("the type of the window's root view has changed")?;
2762
2763 cx.read_window(&view, read)
2764 }
2765}
2766
2767#[cfg(any(test, feature = "test-support"))]
2768impl From<SmallVec<[u32; 16]>> for StackingOrder {
2769 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2770 StackingOrder(small_vec)
2771 }
2772}
2773
2774#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2775pub enum ElementId {
2776 View(EntityId),
2777 Integer(usize),
2778 Name(SharedString),
2779 FocusHandle(FocusId),
2780 NamedInteger(SharedString, usize),
2781}
2782
2783impl ElementId {
2784 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2785 ElementId::View(entity_id)
2786 }
2787}
2788
2789impl TryInto<SharedString> for ElementId {
2790 type Error = anyhow::Error;
2791
2792 fn try_into(self) -> anyhow::Result<SharedString> {
2793 if let ElementId::Name(name) = self {
2794 Ok(name)
2795 } else {
2796 Err(anyhow!("element id is not string"))
2797 }
2798 }
2799}
2800
2801impl From<usize> for ElementId {
2802 fn from(id: usize) -> Self {
2803 ElementId::Integer(id)
2804 }
2805}
2806
2807impl From<i32> for ElementId {
2808 fn from(id: i32) -> Self {
2809 Self::Integer(id as usize)
2810 }
2811}
2812
2813impl From<SharedString> for ElementId {
2814 fn from(name: SharedString) -> Self {
2815 ElementId::Name(name)
2816 }
2817}
2818
2819impl From<&'static str> for ElementId {
2820 fn from(name: &'static str) -> Self {
2821 ElementId::Name(name.into())
2822 }
2823}
2824
2825impl<'a> From<&'a FocusHandle> for ElementId {
2826 fn from(handle: &'a FocusHandle) -> Self {
2827 ElementId::FocusHandle(handle.id)
2828 }
2829}
2830
2831impl From<(&'static str, EntityId)> for ElementId {
2832 fn from((name, id): (&'static str, EntityId)) -> Self {
2833 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2834 }
2835}
2836
2837impl From<(&'static str, usize)> for ElementId {
2838 fn from((name, id): (&'static str, usize)) -> Self {
2839 ElementId::NamedInteger(name.into(), id)
2840 }
2841}