1use crate::{
2 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
3 AvailableSpace, Bounds, Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId,
4 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
5 Global, GlobalElementId, Hsla, KeyBinding, KeyContext, KeyDownEvent, KeyMatch, KeymatchResult,
6 Keystroke, KeystrokeEvent, Model, ModelContext, Modifiers, MouseButton, MouseMoveEvent,
7 MouseUpEvent, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput, PlatformWindow, Point,
8 PromptLevel, Render, ScaledPixels, SharedString, Size, SubscriberSet, Subscription,
9 TaffyLayoutEngine, Task, View, VisualContext, WeakView, WindowAppearance, WindowBounds,
10 WindowOptions, WindowTextSystem,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::channel::oneshot;
16use parking_lot::RwLock;
17use slotmap::SlotMap;
18use smallvec::SmallVec;
19use std::{
20 any::{Any, TypeId},
21 borrow::{Borrow, BorrowMut},
22 cell::{Cell, RefCell},
23 fmt::{Debug, Display},
24 future::Future,
25 hash::{Hash, Hasher},
26 marker::PhantomData,
27 mem,
28 rc::Rc,
29 sync::{
30 atomic::{AtomicUsize, Ordering::SeqCst},
31 Arc,
32 },
33 time::{Duration, Instant},
34};
35use util::{measure, ResultExt};
36
37mod element_cx;
38pub use element_cx::*;
39
40const ACTIVE_DRAG_Z_INDEX: u16 = 1;
41
42/// A global stacking order, which is created by stacking successive z-index values.
43/// Each z-index will always be interpreted in the context of its parent z-index.
44#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
45pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
46
47/// A single entry in a primitive's z-index stacking order
48#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
49pub struct StackingContext {
50 pub(crate) z_index: u16,
51 pub(crate) id: u16,
52}
53
54impl std::fmt::Debug for StackingContext {
55 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
56 write!(f, "{{{}.{}}} ", self.z_index, self.id)
57 }
58}
59
60/// Represents the two different phases when dispatching events.
61#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
62pub enum DispatchPhase {
63 /// After the capture phase comes the bubble phase, in which mouse event listeners are
64 /// invoked front to back and keyboard event listeners are invoked from the focused element
65 /// to the root of the element tree. This is the phase you'll most commonly want to use when
66 /// registering event listeners.
67 #[default]
68 Bubble,
69 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
70 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
71 /// is used for special purposes such as clearing the "pressed" state for click events. If
72 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
73 /// outside of the immediate region may rely on detecting non-local events during this phase.
74 Capture,
75}
76
77impl DispatchPhase {
78 /// Returns true if this represents the "bubble" phase.
79 pub fn bubble(self) -> bool {
80 self == DispatchPhase::Bubble
81 }
82
83 /// Returns true if this represents the "capture" phase.
84 pub fn capture(self) -> bool {
85 self == DispatchPhase::Capture
86 }
87}
88
89type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
90
91type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
92
93struct FocusEvent {
94 previous_focus_path: SmallVec<[FocusId; 8]>,
95 current_focus_path: SmallVec<[FocusId; 8]>,
96}
97
98slotmap::new_key_type! {
99 /// A globally unique identifier for a focusable element.
100 pub struct FocusId;
101}
102
103thread_local! {
104 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(8 * 1024 * 1024));
105}
106
107impl FocusId {
108 /// Obtains whether the element associated with this handle is currently focused.
109 pub fn is_focused(&self, cx: &WindowContext) -> bool {
110 cx.window.focus == Some(*self)
111 }
112
113 /// Obtains whether the element associated with this handle contains the focused
114 /// element or is itself focused.
115 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
116 cx.focused()
117 .map_or(false, |focused| self.contains(focused.id, cx))
118 }
119
120 /// Obtains whether the element associated with this handle is contained within the
121 /// focused element or is itself focused.
122 pub fn within_focused(&self, cx: &WindowContext) -> bool {
123 let focused = cx.focused();
124 focused.map_or(false, |focused| focused.id.contains(*self, cx))
125 }
126
127 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
128 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
129 cx.window
130 .rendered_frame
131 .dispatch_tree
132 .focus_contains(*self, other)
133 }
134}
135
136/// A handle which can be used to track and manipulate the focused element in a window.
137pub struct FocusHandle {
138 pub(crate) id: FocusId,
139 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
140}
141
142impl std::fmt::Debug for FocusHandle {
143 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
144 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
145 }
146}
147
148impl FocusHandle {
149 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
150 let id = handles.write().insert(AtomicUsize::new(1));
151 Self {
152 id,
153 handles: handles.clone(),
154 }
155 }
156
157 pub(crate) fn for_id(
158 id: FocusId,
159 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
160 ) -> Option<Self> {
161 let lock = handles.read();
162 let ref_count = lock.get(id)?;
163 if ref_count.load(SeqCst) == 0 {
164 None
165 } else {
166 ref_count.fetch_add(1, SeqCst);
167 Some(Self {
168 id,
169 handles: handles.clone(),
170 })
171 }
172 }
173
174 /// Moves the focus to the element associated with this handle.
175 pub fn focus(&self, cx: &mut WindowContext) {
176 cx.focus(self)
177 }
178
179 /// Obtains whether the element associated with this handle is currently focused.
180 pub fn is_focused(&self, cx: &WindowContext) -> bool {
181 self.id.is_focused(cx)
182 }
183
184 /// Obtains whether the element associated with this handle contains the focused
185 /// element or is itself focused.
186 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
187 self.id.contains_focused(cx)
188 }
189
190 /// Obtains whether the element associated with this handle is contained within the
191 /// focused element or is itself focused.
192 pub fn within_focused(&self, cx: &WindowContext) -> bool {
193 self.id.within_focused(cx)
194 }
195
196 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
197 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
198 self.id.contains(other.id, cx)
199 }
200}
201
202impl Clone for FocusHandle {
203 fn clone(&self) -> Self {
204 Self::for_id(self.id, &self.handles).unwrap()
205 }
206}
207
208impl PartialEq for FocusHandle {
209 fn eq(&self, other: &Self) -> bool {
210 self.id == other.id
211 }
212}
213
214impl Eq for FocusHandle {}
215
216impl Drop for FocusHandle {
217 fn drop(&mut self) {
218 self.handles
219 .read()
220 .get(self.id)
221 .unwrap()
222 .fetch_sub(1, SeqCst);
223 }
224}
225
226/// FocusableView allows users of your view to easily
227/// focus it (using cx.focus_view(view))
228pub trait FocusableView: 'static + Render {
229 /// Returns the focus handle associated with this view.
230 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
231}
232
233/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
234/// where the lifecycle of the view is handled by another view.
235pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
236
237impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
238
239/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
240pub struct DismissEvent;
241
242type FrameCallback = Box<dyn FnOnce(&mut WindowContext)>;
243
244// Holds the state for a specific window.
245#[doc(hidden)]
246pub struct Window {
247 pub(crate) handle: AnyWindowHandle,
248 pub(crate) removed: bool,
249 pub(crate) platform_window: Box<dyn PlatformWindow>,
250 display_id: DisplayId,
251 sprite_atlas: Arc<dyn PlatformAtlas>,
252 text_system: Arc<WindowTextSystem>,
253 pub(crate) rem_size: Pixels,
254 pub(crate) viewport_size: Size<Pixels>,
255 layout_engine: Option<TaffyLayoutEngine>,
256 pub(crate) root_view: Option<AnyView>,
257 pub(crate) element_id_stack: GlobalElementId,
258 pub(crate) rendered_frame: Frame,
259 pub(crate) next_frame: Frame,
260 next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
261 pub(crate) dirty_views: FxHashSet<EntityId>,
262 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
263 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
264 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
265 default_prevented: bool,
266 mouse_position: Point<Pixels>,
267 modifiers: Modifiers,
268 scale_factor: f32,
269 bounds: WindowBounds,
270 bounds_observers: SubscriberSet<(), AnyObserver>,
271 appearance: WindowAppearance,
272 appearance_observers: SubscriberSet<(), AnyObserver>,
273 active: Rc<Cell<bool>>,
274 pub(crate) dirty: Rc<Cell<bool>>,
275 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
276 pub(crate) refreshing: bool,
277 pub(crate) drawing: bool,
278 activation_observers: SubscriberSet<(), AnyObserver>,
279 pub(crate) focus: Option<FocusId>,
280 focus_enabled: bool,
281 pending_input: Option<PendingInput>,
282}
283
284#[derive(Default, Debug)]
285struct PendingInput {
286 keystrokes: SmallVec<[Keystroke; 1]>,
287 bindings: SmallVec<[KeyBinding; 1]>,
288 focus: Option<FocusId>,
289 timer: Option<Task<()>>,
290}
291
292impl PendingInput {
293 fn input(&self) -> String {
294 self.keystrokes
295 .iter()
296 .flat_map(|k| k.ime_key.clone())
297 .collect::<Vec<String>>()
298 .join("")
299 }
300
301 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
302 if self.keystrokes.is_empty() {
303 return true;
304 }
305 let keystroke = &self.keystrokes[0];
306 for candidate in keystroke.match_candidates() {
307 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
308 return true;
309 }
310 }
311 false
312 }
313}
314
315pub(crate) struct ElementStateBox {
316 pub(crate) inner: Box<dyn Any>,
317 pub(crate) parent_view_id: EntityId,
318 #[cfg(debug_assertions)]
319 pub(crate) type_name: &'static str,
320}
321
322impl Window {
323 pub(crate) fn new(
324 handle: AnyWindowHandle,
325 options: WindowOptions,
326 cx: &mut AppContext,
327 ) -> Self {
328 let platform_window = cx.platform.open_window(handle, options);
329 let display_id = platform_window.display().id();
330 let sprite_atlas = platform_window.sprite_atlas();
331 let mouse_position = platform_window.mouse_position();
332 let modifiers = platform_window.modifiers();
333 let content_size = platform_window.content_size();
334 let scale_factor = platform_window.scale_factor();
335 let bounds = platform_window.bounds();
336 let appearance = platform_window.appearance();
337 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
338 let dirty = Rc::new(Cell::new(true));
339 let active = Rc::new(Cell::new(false));
340 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
341 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
342
343 platform_window.on_request_frame(Box::new({
344 let mut cx = cx.to_async();
345 let dirty = dirty.clone();
346 let active = active.clone();
347 let next_frame_callbacks = next_frame_callbacks.clone();
348 let last_input_timestamp = last_input_timestamp.clone();
349 move || {
350 let next_frame_callbacks = next_frame_callbacks.take();
351 if !next_frame_callbacks.is_empty() {
352 handle
353 .update(&mut cx, |_, cx| {
354 for callback in next_frame_callbacks {
355 callback(cx);
356 }
357 })
358 .log_err();
359 }
360
361 if dirty.get() {
362 measure("frame duration", || {
363 handle
364 .update(&mut cx, |_, cx| {
365 cx.draw();
366 cx.present();
367 })
368 .log_err();
369 })
370 }
371 // Keep presenting the current scene for 1 extra second since the
372 // last input to prevent the display from underclocking the refresh rate.
373 else if active.get()
374 && last_input_timestamp.get().elapsed() < Duration::from_secs(1)
375 {
376 handle.update(&mut cx, |_, cx| cx.present()).log_err();
377 }
378 }
379 }));
380 platform_window.on_resize(Box::new({
381 let mut cx = cx.to_async();
382 move |_, _| {
383 handle
384 .update(&mut cx, |_, cx| cx.window_bounds_changed())
385 .log_err();
386 }
387 }));
388 platform_window.on_moved(Box::new({
389 let mut cx = cx.to_async();
390 move || {
391 handle
392 .update(&mut cx, |_, cx| cx.window_bounds_changed())
393 .log_err();
394 }
395 }));
396 platform_window.on_appearance_changed(Box::new({
397 let mut cx = cx.to_async();
398 move || {
399 handle
400 .update(&mut cx, |_, cx| cx.appearance_changed())
401 .log_err();
402 }
403 }));
404 platform_window.on_active_status_change(Box::new({
405 let mut cx = cx.to_async();
406 move |active| {
407 handle
408 .update(&mut cx, |_, cx| {
409 cx.window.active.set(active);
410 cx.window
411 .activation_observers
412 .clone()
413 .retain(&(), |callback| callback(cx));
414 })
415 .log_err();
416 }
417 }));
418
419 platform_window.on_input({
420 let mut cx = cx.to_async();
421 Box::new(move |event| {
422 handle
423 .update(&mut cx, |_, cx| cx.dispatch_event(event))
424 .log_err()
425 .unwrap_or(false)
426 })
427 });
428
429 Window {
430 handle,
431 removed: false,
432 platform_window,
433 display_id,
434 sprite_atlas,
435 text_system,
436 rem_size: px(16.),
437 viewport_size: content_size,
438 layout_engine: Some(TaffyLayoutEngine::new()),
439 root_view: None,
440 element_id_stack: GlobalElementId::default(),
441 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
442 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
443 next_frame_callbacks,
444 dirty_views: FxHashSet::default(),
445 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
446 focus_listeners: SubscriberSet::new(),
447 focus_lost_listeners: SubscriberSet::new(),
448 default_prevented: true,
449 mouse_position,
450 modifiers,
451 scale_factor,
452 bounds,
453 bounds_observers: SubscriberSet::new(),
454 appearance,
455 appearance_observers: SubscriberSet::new(),
456 active,
457 dirty,
458 last_input_timestamp,
459 refreshing: false,
460 drawing: false,
461 activation_observers: SubscriberSet::new(),
462 focus: None,
463 focus_enabled: true,
464 pending_input: None,
465 }
466 }
467 fn new_focus_listener(
468 &mut self,
469 value: AnyWindowFocusListener,
470 ) -> (Subscription, impl FnOnce()) {
471 self.focus_listeners.insert((), value)
472 }
473}
474
475/// Indicates which region of the window is visible. Content falling outside of this mask will not be
476/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
477/// to leave room to support more complex shapes in the future.
478#[derive(Clone, Debug, Default, PartialEq, Eq)]
479#[repr(C)]
480pub struct ContentMask<P: Clone + Default + Debug> {
481 /// The bounds
482 pub bounds: Bounds<P>,
483}
484
485impl ContentMask<Pixels> {
486 /// Scale the content mask's pixel units by the given scaling factor.
487 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
488 ContentMask {
489 bounds: self.bounds.scale(factor),
490 }
491 }
492
493 /// Intersect the content mask with the given content mask.
494 pub fn intersect(&self, other: &Self) -> Self {
495 let bounds = self.bounds.intersect(&other.bounds);
496 ContentMask { bounds }
497 }
498}
499
500/// Provides access to application state in the context of a single window. Derefs
501/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
502/// an [`AppContext`] and call any [`AppContext`] methods.
503pub struct WindowContext<'a> {
504 pub(crate) app: &'a mut AppContext,
505 pub(crate) window: &'a mut Window,
506}
507
508impl<'a> WindowContext<'a> {
509 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
510 Self { app, window }
511 }
512
513 /// Obtain a handle to the window that belongs to this context.
514 pub fn window_handle(&self) -> AnyWindowHandle {
515 self.window.handle
516 }
517
518 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
519 pub fn refresh(&mut self) {
520 if !self.window.drawing {
521 self.window.refreshing = true;
522 self.window.dirty.set(true);
523 }
524 }
525
526 /// Close this window.
527 pub fn remove_window(&mut self) {
528 self.window.removed = true;
529 }
530
531 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
532 /// for elements rendered within this window.
533 pub fn focus_handle(&mut self) -> FocusHandle {
534 FocusHandle::new(&self.window.focus_handles)
535 }
536
537 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
538 pub fn focused(&self) -> Option<FocusHandle> {
539 self.window
540 .focus
541 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
542 }
543
544 /// Move focus to the element associated with the given [`FocusHandle`].
545 pub fn focus(&mut self, handle: &FocusHandle) {
546 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
547 return;
548 }
549
550 self.window.focus = Some(handle.id);
551 self.window
552 .rendered_frame
553 .dispatch_tree
554 .clear_pending_keystrokes();
555 self.refresh();
556 }
557
558 /// Remove focus from all elements within this context's window.
559 pub fn blur(&mut self) {
560 if !self.window.focus_enabled {
561 return;
562 }
563
564 self.window.focus = None;
565 self.refresh();
566 }
567
568 /// Blur the window and don't allow anything in it to be focused again.
569 pub fn disable_focus(&mut self) {
570 self.blur();
571 self.window.focus_enabled = false;
572 }
573
574 /// Accessor for the text system.
575 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
576 &self.window.text_system
577 }
578
579 /// Dispatch the given action on the currently focused element.
580 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
581 let focus_handle = self.focused();
582
583 self.defer(move |cx| {
584 let node_id = focus_handle
585 .and_then(|handle| {
586 cx.window
587 .rendered_frame
588 .dispatch_tree
589 .focusable_node_id(handle.id)
590 })
591 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
592
593 cx.propagate_event = true;
594 cx.dispatch_action_on_node(node_id, action);
595 })
596 }
597
598 pub(crate) fn dispatch_keystroke_observers(
599 &mut self,
600 event: &dyn Any,
601 action: Option<Box<dyn Action>>,
602 ) {
603 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
604 return;
605 };
606
607 self.keystroke_observers
608 .clone()
609 .retain(&(), move |callback| {
610 (callback)(
611 &KeystrokeEvent {
612 keystroke: key_down_event.keystroke.clone(),
613 action: action.as_ref().map(|action| action.boxed_clone()),
614 },
615 self,
616 );
617 true
618 });
619 }
620
621 pub(crate) fn clear_pending_keystrokes(&mut self) {
622 self.window
623 .rendered_frame
624 .dispatch_tree
625 .clear_pending_keystrokes();
626 self.window
627 .next_frame
628 .dispatch_tree
629 .clear_pending_keystrokes();
630 }
631
632 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
633 /// that are currently on the stack to be returned to the app.
634 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
635 let handle = self.window.handle;
636 self.app.defer(move |cx| {
637 handle.update(cx, |_, cx| f(cx)).ok();
638 });
639 }
640
641 /// Subscribe to events emitted by a model or view.
642 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
643 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
644 pub fn subscribe<Emitter, E, Evt>(
645 &mut self,
646 entity: &E,
647 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
648 ) -> Subscription
649 where
650 Emitter: EventEmitter<Evt>,
651 E: Entity<Emitter>,
652 Evt: 'static,
653 {
654 let entity_id = entity.entity_id();
655 let entity = entity.downgrade();
656 let window_handle = self.window.handle;
657 self.app.new_subscription(
658 entity_id,
659 (
660 TypeId::of::<Evt>(),
661 Box::new(move |event, cx| {
662 window_handle
663 .update(cx, |_, cx| {
664 if let Some(handle) = E::upgrade_from(&entity) {
665 let event = event.downcast_ref().expect("invalid event type");
666 on_event(handle, event, cx);
667 true
668 } else {
669 false
670 }
671 })
672 .unwrap_or(false)
673 }),
674 ),
675 )
676 }
677
678 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
679 /// await points in async code.
680 pub fn to_async(&self) -> AsyncWindowContext {
681 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
682 }
683
684 /// Schedule the given closure to be run directly after the current frame is rendered.
685 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
686 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
687 }
688
689 /// Spawn the future returned by the given closure on the application thread pool.
690 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
691 /// use within your future.
692 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
693 where
694 R: 'static,
695 Fut: Future<Output = R> + 'static,
696 {
697 self.app
698 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
699 }
700
701 /// Updates the global of the given type. The given closure is given simultaneous mutable
702 /// access both to the global and the context.
703 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
704 where
705 G: Global,
706 {
707 let mut global = self.app.lease_global::<G>();
708 let result = f(&mut global, self);
709 self.app.end_global_lease(global);
710 result
711 }
712
713 fn window_bounds_changed(&mut self) {
714 self.window.scale_factor = self.window.platform_window.scale_factor();
715 self.window.viewport_size = self.window.platform_window.content_size();
716 self.window.bounds = self.window.platform_window.bounds();
717 self.window.display_id = self.window.platform_window.display().id();
718 self.refresh();
719
720 self.window
721 .bounds_observers
722 .clone()
723 .retain(&(), |callback| callback(self));
724 }
725
726 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
727 pub fn window_bounds(&self) -> WindowBounds {
728 self.window.bounds
729 }
730
731 fn appearance_changed(&mut self) {
732 self.window.appearance = self.window.platform_window.appearance();
733
734 self.window
735 .appearance_observers
736 .clone()
737 .retain(&(), |callback| callback(self));
738 }
739
740 /// Returns the appearance of the current window.
741 pub fn appearance(&self) -> WindowAppearance {
742 self.window.appearance
743 }
744
745 /// Returns the size of the drawable area within the window.
746 pub fn viewport_size(&self) -> Size<Pixels> {
747 self.window.viewport_size
748 }
749
750 /// Returns whether this window is focused by the operating system (receiving key events).
751 pub fn is_window_active(&self) -> bool {
752 self.window.active.get()
753 }
754
755 /// Toggle zoom on the window.
756 pub fn zoom_window(&self) {
757 self.window.platform_window.zoom();
758 }
759
760 /// Updates the window's title at the platform level.
761 pub fn set_window_title(&mut self, title: &str) {
762 self.window.platform_window.set_title(title);
763 }
764
765 /// Mark the window as dirty at the platform level.
766 pub fn set_window_edited(&mut self, edited: bool) {
767 self.window.platform_window.set_edited(edited);
768 }
769
770 /// Determine the display on which the window is visible.
771 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
772 self.platform
773 .displays()
774 .into_iter()
775 .find(|display| display.id() == self.window.display_id)
776 }
777
778 /// Show the platform character palette.
779 pub fn show_character_palette(&self) {
780 self.window.platform_window.show_character_palette();
781 }
782
783 /// The scale factor of the display associated with the window. For example, it could
784 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
785 /// be rendered as two pixels on screen.
786 pub fn scale_factor(&self) -> f32 {
787 self.window.scale_factor
788 }
789
790 /// The size of an em for the base font of the application. Adjusting this value allows the
791 /// UI to scale, just like zooming a web page.
792 pub fn rem_size(&self) -> Pixels {
793 self.window.rem_size
794 }
795
796 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
797 /// UI to scale, just like zooming a web page.
798 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
799 self.window.rem_size = rem_size.into();
800 }
801
802 /// The line height associated with the current text style.
803 pub fn line_height(&self) -> Pixels {
804 let rem_size = self.rem_size();
805 let text_style = self.text_style();
806 text_style
807 .line_height
808 .to_pixels(text_style.font_size, rem_size)
809 }
810
811 /// Call to prevent the default action of an event. Currently only used to prevent
812 /// parent elements from becoming focused on mouse down.
813 pub fn prevent_default(&mut self) {
814 self.window.default_prevented = true;
815 }
816
817 /// Obtain whether default has been prevented for the event currently being dispatched.
818 pub fn default_prevented(&self) -> bool {
819 self.window.default_prevented
820 }
821
822 /// Determine whether the given action is available along the dispatch path to the currently focused element.
823 pub fn is_action_available(&self, action: &dyn Action) -> bool {
824 let target = self
825 .focused()
826 .and_then(|focused_handle| {
827 self.window
828 .rendered_frame
829 .dispatch_tree
830 .focusable_node_id(focused_handle.id)
831 })
832 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
833 self.window
834 .rendered_frame
835 .dispatch_tree
836 .is_action_available(action, target)
837 }
838
839 /// The position of the mouse relative to the window.
840 pub fn mouse_position(&self) -> Point<Pixels> {
841 self.window.mouse_position
842 }
843
844 /// The current state of the keyboard's modifiers
845 pub fn modifiers(&self) -> Modifiers {
846 self.window.modifiers
847 }
848
849 /// Returns true if there is no opaque layer containing the given point
850 /// on top of the given level. Layers who are extensions of the queried layer
851 /// are not considered to be on top of queried layer.
852 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
853 // Precondition: the depth map is ordered from topmost to bottomost.
854
855 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
856 if layer >= opaque_layer {
857 // The queried layer is either above or is the same as the this opaque layer.
858 // Anything after this point is guaranteed to be below the queried layer.
859 return true;
860 }
861
862 if !bounds.contains(point) {
863 // This opaque layer is above the queried layer but it doesn't contain
864 // the given position, so we can ignore it even if it's above.
865 continue;
866 }
867
868 // At this point, we've established that this opaque layer is on top of the queried layer
869 // and contains the position:
870 // If neither the opaque layer or the queried layer is an extension of the other then
871 // we know they are on different stacking orders, and return false.
872 let is_on_same_layer = opaque_layer
873 .iter()
874 .zip(layer.iter())
875 .all(|(a, b)| a.z_index == b.z_index);
876
877 if !is_on_same_layer {
878 return false;
879 }
880 }
881
882 true
883 }
884
885 pub(crate) fn was_top_layer_under_active_drag(
886 &self,
887 point: &Point<Pixels>,
888 layer: &StackingOrder,
889 ) -> bool {
890 // Precondition: the depth map is ordered from topmost to bottomost.
891
892 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
893 if layer >= opaque_layer {
894 // The queried layer is either above or is the same as the this opaque layer.
895 // Anything after this point is guaranteed to be below the queried layer.
896 return true;
897 }
898
899 if !bounds.contains(point) {
900 // This opaque layer is above the queried layer but it doesn't contain
901 // the given position, so we can ignore it even if it's above.
902 continue;
903 }
904
905 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
906 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
907 // looking to see if the queried layer was the topmost underneath the drag layer.
908 if opaque_layer
909 .first()
910 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
911 .unwrap_or(false)
912 {
913 continue;
914 }
915
916 // At this point, we've established that this opaque layer is on top of the queried layer
917 // and contains the position:
918 // If neither the opaque layer or the queried layer is an extension of the other then
919 // we know they are on different stacking orders, and return false.
920 let is_on_same_layer = opaque_layer
921 .iter()
922 .zip(layer.iter())
923 .all(|(a, b)| a.z_index == b.z_index);
924
925 if !is_on_same_layer {
926 return false;
927 }
928 }
929
930 true
931 }
932
933 /// Called during painting to get the current stacking order.
934 pub fn stacking_order(&self) -> &StackingOrder {
935 &self.window.next_frame.z_index_stack
936 }
937
938 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
939 /// the contents of the new [Scene], use [present].
940 pub(crate) fn draw(&mut self) {
941 self.window.dirty.set(false);
942 self.window.drawing = true;
943
944 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
945 {
946 let input_handler = self.window.platform_window.take_input_handler();
947 requested_handler.handler = input_handler;
948 }
949
950 let root_view = self.window.root_view.take().unwrap();
951 self.with_element_context(|cx| {
952 cx.with_z_index(0, |cx| {
953 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
954 // We need to use cx.cx here so we can utilize borrow splitting
955 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
956 for action_listener in action_listeners.iter().cloned() {
957 cx.cx.window.next_frame.dispatch_tree.on_action(
958 *action_type,
959 Rc::new(
960 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
961 action_listener(action, phase, cx)
962 },
963 ),
964 )
965 }
966 }
967
968 let available_space = cx.window.viewport_size.map(Into::into);
969 root_view.draw(Point::default(), available_space, cx);
970 })
971 })
972 });
973
974 if let Some(active_drag) = self.app.active_drag.take() {
975 self.with_element_context(|cx| {
976 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
977 let offset = cx.mouse_position() - active_drag.cursor_offset;
978 let available_space =
979 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
980 active_drag.view.draw(offset, available_space, cx);
981 })
982 });
983 self.active_drag = Some(active_drag);
984 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
985 self.with_element_context(|cx| {
986 cx.with_z_index(1, |cx| {
987 let available_space =
988 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
989 tooltip_request.tooltip.view.draw(
990 tooltip_request.tooltip.cursor_offset,
991 available_space,
992 cx,
993 );
994 })
995 });
996 self.window.next_frame.tooltip_request = Some(tooltip_request);
997 }
998 self.window.dirty_views.clear();
999
1000 self.window
1001 .next_frame
1002 .dispatch_tree
1003 .preserve_pending_keystrokes(
1004 &mut self.window.rendered_frame.dispatch_tree,
1005 self.window.focus,
1006 );
1007 self.window.next_frame.focus = self.window.focus;
1008 self.window.next_frame.window_active = self.window.active.get();
1009 self.window.root_view = Some(root_view);
1010
1011 // Set the cursor only if we're the active window.
1012 let cursor_style = self
1013 .window
1014 .next_frame
1015 .requested_cursor_style
1016 .take()
1017 .unwrap_or(CursorStyle::Arrow);
1018 if self.is_window_active() {
1019 self.platform.set_cursor_style(cursor_style);
1020 }
1021
1022 // Register requested input handler with the platform window.
1023 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1024 if let Some(handler) = requested_input.handler.take() {
1025 self.window.platform_window.set_input_handler(handler);
1026 }
1027 }
1028
1029 self.window.layout_engine.as_mut().unwrap().clear();
1030 self.text_system()
1031 .finish_frame(&self.window.next_frame.reused_views);
1032 self.window
1033 .next_frame
1034 .finish(&mut self.window.rendered_frame);
1035 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1036 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1037 if percentage >= 80. {
1038 log::warn!("elevated element arena occupation: {}.", percentage);
1039 }
1040 element_arena.clear();
1041 });
1042
1043 let previous_focus_path = self.window.rendered_frame.focus_path();
1044 let previous_window_active = self.window.rendered_frame.window_active;
1045 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1046 self.window.next_frame.clear();
1047 let current_focus_path = self.window.rendered_frame.focus_path();
1048 let current_window_active = self.window.rendered_frame.window_active;
1049
1050 if previous_focus_path != current_focus_path
1051 || previous_window_active != current_window_active
1052 {
1053 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1054 self.window
1055 .focus_lost_listeners
1056 .clone()
1057 .retain(&(), |listener| listener(self));
1058 }
1059
1060 let event = FocusEvent {
1061 previous_focus_path: if previous_window_active {
1062 previous_focus_path
1063 } else {
1064 Default::default()
1065 },
1066 current_focus_path: if current_window_active {
1067 current_focus_path
1068 } else {
1069 Default::default()
1070 },
1071 };
1072 self.window
1073 .focus_listeners
1074 .clone()
1075 .retain(&(), |listener| listener(&event, self));
1076 }
1077 self.window.refreshing = false;
1078 self.window.drawing = false;
1079 }
1080
1081 fn present(&self) {
1082 self.window
1083 .platform_window
1084 .draw(&self.window.rendered_frame.scene);
1085 }
1086
1087 /// Dispatch a mouse or keyboard event on the window.
1088 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1089 self.window.last_input_timestamp.set(Instant::now());
1090 // Handlers may set this to false by calling `stop_propagation`.
1091 self.app.propagate_event = true;
1092 // Handlers may set this to true by calling `prevent_default`.
1093 self.window.default_prevented = false;
1094
1095 let event = match event {
1096 // Track the mouse position with our own state, since accessing the platform
1097 // API for the mouse position can only occur on the main thread.
1098 PlatformInput::MouseMove(mouse_move) => {
1099 self.window.mouse_position = mouse_move.position;
1100 self.window.modifiers = mouse_move.modifiers;
1101 PlatformInput::MouseMove(mouse_move)
1102 }
1103 PlatformInput::MouseDown(mouse_down) => {
1104 self.window.mouse_position = mouse_down.position;
1105 self.window.modifiers = mouse_down.modifiers;
1106 PlatformInput::MouseDown(mouse_down)
1107 }
1108 PlatformInput::MouseUp(mouse_up) => {
1109 self.window.mouse_position = mouse_up.position;
1110 self.window.modifiers = mouse_up.modifiers;
1111 PlatformInput::MouseUp(mouse_up)
1112 }
1113 PlatformInput::MouseExited(mouse_exited) => {
1114 self.window.modifiers = mouse_exited.modifiers;
1115 PlatformInput::MouseExited(mouse_exited)
1116 }
1117 PlatformInput::ModifiersChanged(modifiers_changed) => {
1118 self.window.modifiers = modifiers_changed.modifiers;
1119 PlatformInput::ModifiersChanged(modifiers_changed)
1120 }
1121 PlatformInput::ScrollWheel(scroll_wheel) => {
1122 self.window.mouse_position = scroll_wheel.position;
1123 self.window.modifiers = scroll_wheel.modifiers;
1124 PlatformInput::ScrollWheel(scroll_wheel)
1125 }
1126 // Translate dragging and dropping of external files from the operating system
1127 // to internal drag and drop events.
1128 PlatformInput::FileDrop(file_drop) => match file_drop {
1129 FileDropEvent::Entered { position, paths } => {
1130 self.window.mouse_position = position;
1131 if self.active_drag.is_none() {
1132 self.active_drag = Some(AnyDrag {
1133 value: Box::new(paths.clone()),
1134 view: self.new_view(|_| paths).into(),
1135 cursor_offset: position,
1136 });
1137 }
1138 PlatformInput::MouseMove(MouseMoveEvent {
1139 position,
1140 pressed_button: Some(MouseButton::Left),
1141 modifiers: Modifiers::default(),
1142 })
1143 }
1144 FileDropEvent::Pending { position } => {
1145 self.window.mouse_position = position;
1146 PlatformInput::MouseMove(MouseMoveEvent {
1147 position,
1148 pressed_button: Some(MouseButton::Left),
1149 modifiers: Modifiers::default(),
1150 })
1151 }
1152 FileDropEvent::Submit { position } => {
1153 self.activate(true);
1154 self.window.mouse_position = position;
1155 PlatformInput::MouseUp(MouseUpEvent {
1156 button: MouseButton::Left,
1157 position,
1158 modifiers: Modifiers::default(),
1159 click_count: 1,
1160 })
1161 }
1162 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1163 button: MouseButton::Left,
1164 position: Point::default(),
1165 modifiers: Modifiers::default(),
1166 click_count: 1,
1167 }),
1168 },
1169 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1170 };
1171
1172 if let Some(any_mouse_event) = event.mouse_event() {
1173 self.dispatch_mouse_event(any_mouse_event);
1174 } else if let Some(any_key_event) = event.keyboard_event() {
1175 self.dispatch_key_event(any_key_event);
1176 }
1177
1178 !self.app.propagate_event
1179 }
1180
1181 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1182 if let Some(mut handlers) = self
1183 .window
1184 .rendered_frame
1185 .mouse_listeners
1186 .remove(&event.type_id())
1187 {
1188 // Because handlers may add other handlers, we sort every time.
1189 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1190
1191 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1192 // special purposes, such as detecting events outside of a given Bounds.
1193 for (_, _, handler) in &mut handlers {
1194 self.with_element_context(|cx| {
1195 handler(event, DispatchPhase::Capture, cx);
1196 });
1197 if !self.app.propagate_event {
1198 break;
1199 }
1200 }
1201
1202 // Bubble phase, where most normal handlers do their work.
1203 if self.app.propagate_event {
1204 for (_, _, handler) in handlers.iter_mut().rev() {
1205 self.with_element_context(|cx| {
1206 handler(event, DispatchPhase::Bubble, cx);
1207 });
1208 if !self.app.propagate_event {
1209 break;
1210 }
1211 }
1212 }
1213
1214 self.window
1215 .rendered_frame
1216 .mouse_listeners
1217 .insert(event.type_id(), handlers);
1218 }
1219
1220 if self.app.propagate_event && self.has_active_drag() {
1221 if event.is::<MouseMoveEvent>() {
1222 // If this was a mouse move event, redraw the window so that the
1223 // active drag can follow the mouse cursor.
1224 self.refresh();
1225 } else if event.is::<MouseUpEvent>() {
1226 // If this was a mouse up event, cancel the active drag and redraw
1227 // the window.
1228 self.active_drag = None;
1229 self.refresh();
1230 }
1231 }
1232 }
1233
1234 fn dispatch_key_event(&mut self, event: &dyn Any) {
1235 let node_id = self
1236 .window
1237 .focus
1238 .and_then(|focus_id| {
1239 self.window
1240 .rendered_frame
1241 .dispatch_tree
1242 .focusable_node_id(focus_id)
1243 })
1244 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1245
1246 let dispatch_path = self
1247 .window
1248 .rendered_frame
1249 .dispatch_tree
1250 .dispatch_path(node_id);
1251
1252 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1253 let KeymatchResult { bindings, pending } = self
1254 .window
1255 .rendered_frame
1256 .dispatch_tree
1257 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1258
1259 if pending {
1260 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1261 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1262 {
1263 currently_pending = PendingInput::default();
1264 }
1265 currently_pending.focus = self.window.focus;
1266 currently_pending
1267 .keystrokes
1268 .push(key_down_event.keystroke.clone());
1269 for binding in bindings {
1270 currently_pending.bindings.push(binding);
1271 }
1272
1273 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1274 cx.background_executor.timer(Duration::from_secs(1)).await;
1275 cx.update(move |cx| {
1276 cx.clear_pending_keystrokes();
1277 let Some(currently_pending) = cx.window.pending_input.take() else {
1278 return;
1279 };
1280 cx.replay_pending_input(currently_pending)
1281 })
1282 .log_err();
1283 }));
1284 self.window.pending_input = Some(currently_pending);
1285
1286 self.propagate_event = false;
1287 return;
1288 } else if let Some(currently_pending) = self.window.pending_input.take() {
1289 if bindings
1290 .iter()
1291 .all(|binding| !currently_pending.used_by_binding(binding))
1292 {
1293 self.replay_pending_input(currently_pending)
1294 }
1295 }
1296
1297 if !bindings.is_empty() {
1298 self.clear_pending_keystrokes();
1299 }
1300
1301 self.propagate_event = true;
1302 for binding in bindings {
1303 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1304 if !self.propagate_event {
1305 self.dispatch_keystroke_observers(event, Some(binding.action));
1306 return;
1307 }
1308 }
1309 }
1310
1311 self.dispatch_key_down_up_event(event, &dispatch_path);
1312 if !self.propagate_event {
1313 return;
1314 }
1315
1316 self.dispatch_keystroke_observers(event, None);
1317 }
1318
1319 fn dispatch_key_down_up_event(
1320 &mut self,
1321 event: &dyn Any,
1322 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1323 ) {
1324 // Capture phase
1325 for node_id in dispatch_path {
1326 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1327
1328 for key_listener in node.key_listeners.clone() {
1329 self.with_element_context(|cx| {
1330 key_listener(event, DispatchPhase::Capture, cx);
1331 });
1332 if !self.propagate_event {
1333 return;
1334 }
1335 }
1336 }
1337
1338 // Bubble phase
1339 for node_id in dispatch_path.iter().rev() {
1340 // Handle low level key events
1341 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1342 for key_listener in node.key_listeners.clone() {
1343 self.with_element_context(|cx| {
1344 key_listener(event, DispatchPhase::Bubble, cx);
1345 });
1346 if !self.propagate_event {
1347 return;
1348 }
1349 }
1350 }
1351 }
1352
1353 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1354 pub fn has_pending_keystrokes(&self) -> bool {
1355 self.window
1356 .rendered_frame
1357 .dispatch_tree
1358 .has_pending_keystrokes()
1359 }
1360
1361 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1362 let node_id = self
1363 .window
1364 .focus
1365 .and_then(|focus_id| {
1366 self.window
1367 .rendered_frame
1368 .dispatch_tree
1369 .focusable_node_id(focus_id)
1370 })
1371 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1372
1373 if self.window.focus != currently_pending.focus {
1374 return;
1375 }
1376
1377 let input = currently_pending.input();
1378
1379 self.propagate_event = true;
1380 for binding in currently_pending.bindings {
1381 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1382 if !self.propagate_event {
1383 return;
1384 }
1385 }
1386
1387 let dispatch_path = self
1388 .window
1389 .rendered_frame
1390 .dispatch_tree
1391 .dispatch_path(node_id);
1392
1393 for keystroke in currently_pending.keystrokes {
1394 let event = KeyDownEvent {
1395 keystroke,
1396 is_held: false,
1397 };
1398
1399 self.dispatch_key_down_up_event(&event, &dispatch_path);
1400 if !self.propagate_event {
1401 return;
1402 }
1403 }
1404
1405 if !input.is_empty() {
1406 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1407 input_handler.flush_pending_input(&input, self);
1408 self.window.platform_window.set_input_handler(input_handler)
1409 }
1410 }
1411 }
1412
1413 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1414 let dispatch_path = self
1415 .window
1416 .rendered_frame
1417 .dispatch_tree
1418 .dispatch_path(node_id);
1419
1420 // Capture phase
1421 for node_id in &dispatch_path {
1422 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1423 for DispatchActionListener {
1424 action_type,
1425 listener,
1426 } in node.action_listeners.clone()
1427 {
1428 let any_action = action.as_any();
1429 if action_type == any_action.type_id() {
1430 self.with_element_context(|cx| {
1431 listener(any_action, DispatchPhase::Capture, cx);
1432 });
1433
1434 if !self.propagate_event {
1435 return;
1436 }
1437 }
1438 }
1439 }
1440 // Bubble phase
1441 for node_id in dispatch_path.iter().rev() {
1442 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1443 for DispatchActionListener {
1444 action_type,
1445 listener,
1446 } in node.action_listeners.clone()
1447 {
1448 let any_action = action.as_any();
1449 if action_type == any_action.type_id() {
1450 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1451
1452 self.with_element_context(|cx| {
1453 listener(any_action, DispatchPhase::Bubble, cx);
1454 });
1455
1456 if !self.propagate_event {
1457 return;
1458 }
1459 }
1460 }
1461 }
1462 }
1463
1464 /// Register the given handler to be invoked whenever the global of the given type
1465 /// is updated.
1466 pub fn observe_global<G: Global>(
1467 &mut self,
1468 f: impl Fn(&mut WindowContext<'_>) + 'static,
1469 ) -> Subscription {
1470 let window_handle = self.window.handle;
1471 let (subscription, activate) = self.global_observers.insert(
1472 TypeId::of::<G>(),
1473 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1474 );
1475 self.app.defer(move |_| activate());
1476 subscription
1477 }
1478
1479 /// Focus the current window and bring it to the foreground at the platform level.
1480 pub fn activate_window(&self) {
1481 self.window.platform_window.activate();
1482 }
1483
1484 /// Minimize the current window at the platform level.
1485 pub fn minimize_window(&self) {
1486 self.window.platform_window.minimize();
1487 }
1488
1489 /// Toggle full screen status on the current window at the platform level.
1490 pub fn toggle_full_screen(&self) {
1491 self.window.platform_window.toggle_full_screen();
1492 }
1493
1494 /// Present a platform dialog.
1495 /// The provided message will be presented, along with buttons for each answer.
1496 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1497 pub fn prompt(
1498 &self,
1499 level: PromptLevel,
1500 message: &str,
1501 detail: Option<&str>,
1502 answers: &[&str],
1503 ) -> oneshot::Receiver<usize> {
1504 self.window
1505 .platform_window
1506 .prompt(level, message, detail, answers)
1507 }
1508
1509 /// Returns all available actions for the focused element.
1510 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1511 let node_id = self
1512 .window
1513 .focus
1514 .and_then(|focus_id| {
1515 self.window
1516 .rendered_frame
1517 .dispatch_tree
1518 .focusable_node_id(focus_id)
1519 })
1520 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1521
1522 self.window
1523 .rendered_frame
1524 .dispatch_tree
1525 .available_actions(node_id)
1526 }
1527
1528 /// Returns key bindings that invoke the given action on the currently focused element.
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 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1540 pub fn bindings_for_action_in(
1541 &self,
1542 action: &dyn Action,
1543 focus_handle: &FocusHandle,
1544 ) -> Vec<KeyBinding> {
1545 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1546
1547 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1548 return vec![];
1549 };
1550 let context_stack = dispatch_tree
1551 .dispatch_path(node_id)
1552 .into_iter()
1553 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1554 .collect();
1555 dispatch_tree.bindings_for_action(action, &context_stack)
1556 }
1557
1558 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1559 pub fn listener_for<V: Render, E>(
1560 &self,
1561 view: &View<V>,
1562 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1563 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1564 let view = view.downgrade();
1565 move |e: &E, cx: &mut WindowContext| {
1566 view.update(cx, |view, cx| f(view, e, cx)).ok();
1567 }
1568 }
1569
1570 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1571 pub fn handler_for<V: Render>(
1572 &self,
1573 view: &View<V>,
1574 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1575 ) -> impl Fn(&mut WindowContext) {
1576 let view = view.downgrade();
1577 move |cx: &mut WindowContext| {
1578 view.update(cx, |view, cx| f(view, cx)).ok();
1579 }
1580 }
1581
1582 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1583 /// If the callback returns false, the window won't be closed.
1584 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1585 let mut this = self.to_async();
1586 self.window
1587 .platform_window
1588 .on_should_close(Box::new(move || {
1589 this.update(|cx| {
1590 // Ensure that the window is removed from the app if it's been closed
1591 // by always pre-empting the system close event.
1592 if f(cx) {
1593 cx.remove_window();
1594 }
1595 false
1596 })
1597 .unwrap_or(true)
1598 }))
1599 }
1600
1601 pub(crate) fn parent_view_id(&self) -> EntityId {
1602 *self
1603 .window
1604 .next_frame
1605 .view_stack
1606 .last()
1607 .expect("a view should always be on the stack while drawing")
1608 }
1609
1610 /// Register an action listener on the window for the next frame. The type of action
1611 /// is determined by the first parameter of the given listener. When the next frame is rendered
1612 /// the listener will be cleared.
1613 ///
1614 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1615 /// a specific need to register a global listener.
1616 pub fn on_action(
1617 &mut self,
1618 action_type: TypeId,
1619 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1620 ) {
1621 self.window
1622 .next_frame
1623 .dispatch_tree
1624 .on_action(action_type, Rc::new(listener));
1625 }
1626}
1627
1628impl Context for WindowContext<'_> {
1629 type Result<T> = T;
1630
1631 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1632 where
1633 T: 'static,
1634 {
1635 let slot = self.app.entities.reserve();
1636 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1637 self.entities.insert(slot, model)
1638 }
1639
1640 fn update_model<T: 'static, R>(
1641 &mut self,
1642 model: &Model<T>,
1643 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1644 ) -> R {
1645 let mut entity = self.entities.lease(model);
1646 let result = update(
1647 &mut *entity,
1648 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1649 );
1650 self.entities.end_lease(entity);
1651 result
1652 }
1653
1654 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1655 where
1656 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1657 {
1658 if window == self.window.handle {
1659 let root_view = self.window.root_view.clone().unwrap();
1660 Ok(update(root_view, self))
1661 } else {
1662 window.update(self.app, update)
1663 }
1664 }
1665
1666 fn read_model<T, R>(
1667 &self,
1668 handle: &Model<T>,
1669 read: impl FnOnce(&T, &AppContext) -> R,
1670 ) -> Self::Result<R>
1671 where
1672 T: 'static,
1673 {
1674 let entity = self.entities.read(handle);
1675 read(entity, &*self.app)
1676 }
1677
1678 fn read_window<T, R>(
1679 &self,
1680 window: &WindowHandle<T>,
1681 read: impl FnOnce(View<T>, &AppContext) -> R,
1682 ) -> Result<R>
1683 where
1684 T: 'static,
1685 {
1686 if window.any_handle == self.window.handle {
1687 let root_view = self
1688 .window
1689 .root_view
1690 .clone()
1691 .unwrap()
1692 .downcast::<T>()
1693 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1694 Ok(read(root_view, self))
1695 } else {
1696 self.app.read_window(window, read)
1697 }
1698 }
1699}
1700
1701impl VisualContext for WindowContext<'_> {
1702 fn new_view<V>(
1703 &mut self,
1704 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1705 ) -> Self::Result<View<V>>
1706 where
1707 V: 'static + Render,
1708 {
1709 let slot = self.app.entities.reserve();
1710 let view = View {
1711 model: slot.clone(),
1712 };
1713 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1714 let entity = build_view_state(&mut cx);
1715 cx.entities.insert(slot, entity);
1716
1717 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1718 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1719 cx.new_view_observers.clone().retain(&tid, |observer| {
1720 let any_view = view.clone();
1721 (observer)(any_view, cx);
1722 true
1723 });
1724 }
1725 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1726
1727 view
1728 }
1729
1730 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1731 fn update_view<T: 'static, R>(
1732 &mut self,
1733 view: &View<T>,
1734 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1735 ) -> Self::Result<R> {
1736 let mut lease = self.app.entities.lease(&view.model);
1737 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1738 let result = update(&mut *lease, &mut cx);
1739 cx.app.entities.end_lease(lease);
1740 result
1741 }
1742
1743 fn replace_root_view<V>(
1744 &mut self,
1745 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1746 ) -> Self::Result<View<V>>
1747 where
1748 V: 'static + Render,
1749 {
1750 let view = self.new_view(build_view);
1751 self.window.root_view = Some(view.clone().into());
1752 self.refresh();
1753 view
1754 }
1755
1756 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1757 self.update_view(view, |view, cx| {
1758 view.focus_handle(cx).clone().focus(cx);
1759 })
1760 }
1761
1762 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1763 where
1764 V: ManagedView,
1765 {
1766 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1767 }
1768}
1769
1770impl<'a> std::ops::Deref for WindowContext<'a> {
1771 type Target = AppContext;
1772
1773 fn deref(&self) -> &Self::Target {
1774 self.app
1775 }
1776}
1777
1778impl<'a> std::ops::DerefMut for WindowContext<'a> {
1779 fn deref_mut(&mut self) -> &mut Self::Target {
1780 self.app
1781 }
1782}
1783
1784impl<'a> Borrow<AppContext> for WindowContext<'a> {
1785 fn borrow(&self) -> &AppContext {
1786 self.app
1787 }
1788}
1789
1790impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1791 fn borrow_mut(&mut self) -> &mut AppContext {
1792 self.app
1793 }
1794}
1795
1796/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1797pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1798 #[doc(hidden)]
1799 fn app_mut(&mut self) -> &mut AppContext {
1800 self.borrow_mut()
1801 }
1802
1803 #[doc(hidden)]
1804 fn app(&self) -> &AppContext {
1805 self.borrow()
1806 }
1807
1808 #[doc(hidden)]
1809 fn window(&self) -> &Window {
1810 self.borrow()
1811 }
1812
1813 #[doc(hidden)]
1814 fn window_mut(&mut self) -> &mut Window {
1815 self.borrow_mut()
1816 }
1817}
1818
1819impl Borrow<Window> for WindowContext<'_> {
1820 fn borrow(&self) -> &Window {
1821 self.window
1822 }
1823}
1824
1825impl BorrowMut<Window> for WindowContext<'_> {
1826 fn borrow_mut(&mut self) -> &mut Window {
1827 self.window
1828 }
1829}
1830
1831impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1832
1833/// Provides access to application state that is specialized for a particular [`View`].
1834/// Allows you to interact with focus, emit events, etc.
1835/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1836/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1837pub struct ViewContext<'a, V> {
1838 window_cx: WindowContext<'a>,
1839 view: &'a View<V>,
1840}
1841
1842impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1843 fn borrow(&self) -> &AppContext {
1844 &*self.window_cx.app
1845 }
1846}
1847
1848impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1849 fn borrow_mut(&mut self) -> &mut AppContext {
1850 &mut *self.window_cx.app
1851 }
1852}
1853
1854impl<V> Borrow<Window> for ViewContext<'_, V> {
1855 fn borrow(&self) -> &Window {
1856 &*self.window_cx.window
1857 }
1858}
1859
1860impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1861 fn borrow_mut(&mut self) -> &mut Window {
1862 &mut *self.window_cx.window
1863 }
1864}
1865
1866impl<'a, V: 'static> ViewContext<'a, V> {
1867 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1868 Self {
1869 window_cx: WindowContext::new(app, window),
1870 view,
1871 }
1872 }
1873
1874 /// Get the entity_id of this view.
1875 pub fn entity_id(&self) -> EntityId {
1876 self.view.entity_id()
1877 }
1878
1879 /// Get the view pointer underlying this context.
1880 pub fn view(&self) -> &View<V> {
1881 self.view
1882 }
1883
1884 /// Get the model underlying this view.
1885 pub fn model(&self) -> &Model<V> {
1886 &self.view.model
1887 }
1888
1889 /// Access the underlying window context.
1890 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1891 &mut self.window_cx
1892 }
1893
1894 /// Sets a given callback to be run on the next frame.
1895 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1896 where
1897 V: 'static,
1898 {
1899 let view = self.view().clone();
1900 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1901 }
1902
1903 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1904 /// that are currently on the stack to be returned to the app.
1905 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1906 let view = self.view().downgrade();
1907 self.window_cx.defer(move |cx| {
1908 view.update(cx, f).ok();
1909 });
1910 }
1911
1912 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1913 pub fn observe<V2, E>(
1914 &mut self,
1915 entity: &E,
1916 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1917 ) -> Subscription
1918 where
1919 V2: 'static,
1920 V: 'static,
1921 E: Entity<V2>,
1922 {
1923 let view = self.view().downgrade();
1924 let entity_id = entity.entity_id();
1925 let entity = entity.downgrade();
1926 let window_handle = self.window.handle;
1927 self.app.new_observer(
1928 entity_id,
1929 Box::new(move |cx| {
1930 window_handle
1931 .update(cx, |_, cx| {
1932 if let Some(handle) = E::upgrade_from(&entity) {
1933 view.update(cx, |this, cx| on_notify(this, handle, cx))
1934 .is_ok()
1935 } else {
1936 false
1937 }
1938 })
1939 .unwrap_or(false)
1940 }),
1941 )
1942 }
1943
1944 /// Subscribe to events emitted by another model or view.
1945 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1946 /// The callback will be invoked with a reference to the current view, a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a view context for the current view.
1947 pub fn subscribe<V2, E, Evt>(
1948 &mut self,
1949 entity: &E,
1950 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1951 ) -> Subscription
1952 where
1953 V2: EventEmitter<Evt>,
1954 E: Entity<V2>,
1955 Evt: 'static,
1956 {
1957 let view = self.view().downgrade();
1958 let entity_id = entity.entity_id();
1959 let handle = entity.downgrade();
1960 let window_handle = self.window.handle;
1961 self.app.new_subscription(
1962 entity_id,
1963 (
1964 TypeId::of::<Evt>(),
1965 Box::new(move |event, cx| {
1966 window_handle
1967 .update(cx, |_, cx| {
1968 if let Some(handle) = E::upgrade_from(&handle) {
1969 let event = event.downcast_ref().expect("invalid event type");
1970 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1971 .is_ok()
1972 } else {
1973 false
1974 }
1975 })
1976 .unwrap_or(false)
1977 }),
1978 ),
1979 )
1980 }
1981
1982 /// Register a callback to be invoked when the view is released.
1983 ///
1984 /// The callback receives a handle to the view's window. This handle may be
1985 /// invalid, if the window was closed before the view was released.
1986 pub fn on_release(
1987 &mut self,
1988 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1989 ) -> Subscription {
1990 let window_handle = self.window.handle;
1991 let (subscription, activate) = self.app.release_listeners.insert(
1992 self.view.model.entity_id,
1993 Box::new(move |this, cx| {
1994 let this = this.downcast_mut().expect("invalid entity type");
1995 on_release(this, window_handle, cx)
1996 }),
1997 );
1998 activate();
1999 subscription
2000 }
2001
2002 /// Register a callback to be invoked when the given Model or View is released.
2003 pub fn observe_release<V2, E>(
2004 &mut self,
2005 entity: &E,
2006 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2007 ) -> Subscription
2008 where
2009 V: 'static,
2010 V2: 'static,
2011 E: Entity<V2>,
2012 {
2013 let view = self.view().downgrade();
2014 let entity_id = entity.entity_id();
2015 let window_handle = self.window.handle;
2016 let (subscription, activate) = self.app.release_listeners.insert(
2017 entity_id,
2018 Box::new(move |entity, cx| {
2019 let entity = entity.downcast_mut().expect("invalid entity type");
2020 let _ = window_handle.update(cx, |_, cx| {
2021 view.update(cx, |this, cx| on_release(this, entity, cx))
2022 });
2023 }),
2024 );
2025 activate();
2026 subscription
2027 }
2028
2029 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2030 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2031 pub fn notify(&mut self) {
2032 for view_id in self
2033 .window
2034 .rendered_frame
2035 .dispatch_tree
2036 .view_path(self.view.entity_id())
2037 .into_iter()
2038 .rev()
2039 {
2040 if !self.window.dirty_views.insert(view_id) {
2041 break;
2042 }
2043 }
2044
2045 if !self.window.drawing {
2046 self.window_cx.window.dirty.set(true);
2047 self.window_cx.app.push_effect(Effect::Notify {
2048 emitter: self.view.model.entity_id,
2049 });
2050 }
2051 }
2052
2053 /// Register a callback to be invoked when the window is resized.
2054 pub fn observe_window_bounds(
2055 &mut self,
2056 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2057 ) -> Subscription {
2058 let view = self.view.downgrade();
2059 let (subscription, activate) = self.window.bounds_observers.insert(
2060 (),
2061 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2062 );
2063 activate();
2064 subscription
2065 }
2066
2067 /// Register a callback to be invoked when the window is activated or deactivated.
2068 pub fn observe_window_activation(
2069 &mut self,
2070 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2071 ) -> Subscription {
2072 let view = self.view.downgrade();
2073 let (subscription, activate) = self.window.activation_observers.insert(
2074 (),
2075 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2076 );
2077 activate();
2078 subscription
2079 }
2080
2081 /// Registers a callback to be invoked when the window appearance changes.
2082 pub fn observe_window_appearance(
2083 &mut self,
2084 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2085 ) -> Subscription {
2086 let view = self.view.downgrade();
2087 let (subscription, activate) = self.window.appearance_observers.insert(
2088 (),
2089 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2090 );
2091 activate();
2092 subscription
2093 }
2094
2095 /// Register a listener to be called when the given focus handle receives focus.
2096 /// Returns a subscription and persists until the subscription is dropped.
2097 pub fn on_focus(
2098 &mut self,
2099 handle: &FocusHandle,
2100 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2101 ) -> Subscription {
2102 let view = self.view.downgrade();
2103 let focus_id = handle.id;
2104 let (subscription, activate) =
2105 self.window.new_focus_listener(Box::new(move |event, cx| {
2106 view.update(cx, |view, cx| {
2107 if event.previous_focus_path.last() != Some(&focus_id)
2108 && event.current_focus_path.last() == Some(&focus_id)
2109 {
2110 listener(view, cx)
2111 }
2112 })
2113 .is_ok()
2114 }));
2115 self.app.defer(|_| activate());
2116 subscription
2117 }
2118
2119 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2120 /// Returns a subscription and persists until the subscription is dropped.
2121 pub fn on_focus_in(
2122 &mut self,
2123 handle: &FocusHandle,
2124 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2125 ) -> Subscription {
2126 let view = self.view.downgrade();
2127 let focus_id = handle.id;
2128 let (subscription, activate) =
2129 self.window.new_focus_listener(Box::new(move |event, cx| {
2130 view.update(cx, |view, cx| {
2131 if !event.previous_focus_path.contains(&focus_id)
2132 && event.current_focus_path.contains(&focus_id)
2133 {
2134 listener(view, cx)
2135 }
2136 })
2137 .is_ok()
2138 }));
2139 self.app.defer(move |_| activate());
2140 subscription
2141 }
2142
2143 /// Register a listener to be called when the given focus handle loses focus.
2144 /// Returns a subscription and persists until the subscription is dropped.
2145 pub fn on_blur(
2146 &mut self,
2147 handle: &FocusHandle,
2148 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2149 ) -> Subscription {
2150 let view = self.view.downgrade();
2151 let focus_id = handle.id;
2152 let (subscription, activate) =
2153 self.window.new_focus_listener(Box::new(move |event, cx| {
2154 view.update(cx, |view, cx| {
2155 if event.previous_focus_path.last() == Some(&focus_id)
2156 && event.current_focus_path.last() != Some(&focus_id)
2157 {
2158 listener(view, cx)
2159 }
2160 })
2161 .is_ok()
2162 }));
2163 self.app.defer(move |_| activate());
2164 subscription
2165 }
2166
2167 /// Register a listener to be called when nothing in the window has focus.
2168 /// This typically happens when the node that was focused is removed from the tree,
2169 /// and this callback lets you chose a default place to restore the users focus.
2170 /// Returns a subscription and persists until the subscription is dropped.
2171 pub fn on_focus_lost(
2172 &mut self,
2173 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2174 ) -> Subscription {
2175 let view = self.view.downgrade();
2176 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2177 (),
2178 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2179 );
2180 activate();
2181 subscription
2182 }
2183
2184 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2185 /// Returns a subscription and persists until the subscription is dropped.
2186 pub fn on_focus_out(
2187 &mut self,
2188 handle: &FocusHandle,
2189 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2190 ) -> Subscription {
2191 let view = self.view.downgrade();
2192 let focus_id = handle.id;
2193 let (subscription, activate) =
2194 self.window.new_focus_listener(Box::new(move |event, cx| {
2195 view.update(cx, |view, cx| {
2196 if event.previous_focus_path.contains(&focus_id)
2197 && !event.current_focus_path.contains(&focus_id)
2198 {
2199 listener(view, cx)
2200 }
2201 })
2202 .is_ok()
2203 }));
2204 self.app.defer(move |_| activate());
2205 subscription
2206 }
2207
2208 /// Schedule a future to be run asynchronously.
2209 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2210 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2211 /// The returned future will be polled on the main thread.
2212 pub fn spawn<Fut, R>(
2213 &mut self,
2214 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2215 ) -> Task<R>
2216 where
2217 R: 'static,
2218 Fut: Future<Output = R> + 'static,
2219 {
2220 let view = self.view().downgrade();
2221 self.window_cx.spawn(|cx| f(view, cx))
2222 }
2223
2224 /// Updates the global state of the given type.
2225 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2226 where
2227 G: Global,
2228 {
2229 let mut global = self.app.lease_global::<G>();
2230 let result = f(&mut global, self);
2231 self.app.end_global_lease(global);
2232 result
2233 }
2234
2235 /// Register a callback to be invoked when the given global state changes.
2236 pub fn observe_global<G: Global>(
2237 &mut self,
2238 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2239 ) -> Subscription {
2240 let window_handle = self.window.handle;
2241 let view = self.view().downgrade();
2242 let (subscription, activate) = self.global_observers.insert(
2243 TypeId::of::<G>(),
2244 Box::new(move |cx| {
2245 window_handle
2246 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2247 .unwrap_or(false)
2248 }),
2249 );
2250 self.app.defer(move |_| activate());
2251 subscription
2252 }
2253
2254 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2255 pub fn on_action(
2256 &mut self,
2257 action_type: TypeId,
2258 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2259 ) {
2260 let handle = self.view().clone();
2261 self.window_cx
2262 .on_action(action_type, move |action, phase, cx| {
2263 handle.update(cx, |view, cx| {
2264 listener(view, action, phase, cx);
2265 })
2266 });
2267 }
2268
2269 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2270 pub fn emit<Evt>(&mut self, event: Evt)
2271 where
2272 Evt: 'static,
2273 V: EventEmitter<Evt>,
2274 {
2275 let emitter = self.view.model.entity_id;
2276 self.app.push_effect(Effect::Emit {
2277 emitter,
2278 event_type: TypeId::of::<Evt>(),
2279 event: Box::new(event),
2280 });
2281 }
2282
2283 /// Move focus to the current view, assuming it implements [`FocusableView`].
2284 pub fn focus_self(&mut self)
2285 where
2286 V: FocusableView,
2287 {
2288 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2289 }
2290
2291 /// Convenience method for accessing view state in an event callback.
2292 ///
2293 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2294 /// but it's often useful to be able to access view state in these
2295 /// callbacks. This method provides a convenient way to do so.
2296 pub fn listener<E>(
2297 &self,
2298 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2299 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2300 let view = self.view().downgrade();
2301 move |e: &E, cx: &mut WindowContext| {
2302 view.update(cx, |view, cx| f(view, e, cx)).ok();
2303 }
2304 }
2305}
2306
2307impl<V> Context for ViewContext<'_, V> {
2308 type Result<U> = U;
2309
2310 fn new_model<T: 'static>(
2311 &mut self,
2312 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2313 ) -> Model<T> {
2314 self.window_cx.new_model(build_model)
2315 }
2316
2317 fn update_model<T: 'static, R>(
2318 &mut self,
2319 model: &Model<T>,
2320 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2321 ) -> R {
2322 self.window_cx.update_model(model, update)
2323 }
2324
2325 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2326 where
2327 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2328 {
2329 self.window_cx.update_window(window, update)
2330 }
2331
2332 fn read_model<T, R>(
2333 &self,
2334 handle: &Model<T>,
2335 read: impl FnOnce(&T, &AppContext) -> R,
2336 ) -> Self::Result<R>
2337 where
2338 T: 'static,
2339 {
2340 self.window_cx.read_model(handle, read)
2341 }
2342
2343 fn read_window<T, R>(
2344 &self,
2345 window: &WindowHandle<T>,
2346 read: impl FnOnce(View<T>, &AppContext) -> R,
2347 ) -> Result<R>
2348 where
2349 T: 'static,
2350 {
2351 self.window_cx.read_window(window, read)
2352 }
2353}
2354
2355impl<V: 'static> VisualContext for ViewContext<'_, V> {
2356 fn new_view<W: Render + 'static>(
2357 &mut self,
2358 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2359 ) -> Self::Result<View<W>> {
2360 self.window_cx.new_view(build_view_state)
2361 }
2362
2363 fn update_view<V2: 'static, R>(
2364 &mut self,
2365 view: &View<V2>,
2366 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2367 ) -> Self::Result<R> {
2368 self.window_cx.update_view(view, update)
2369 }
2370
2371 fn replace_root_view<W>(
2372 &mut self,
2373 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2374 ) -> Self::Result<View<W>>
2375 where
2376 W: 'static + Render,
2377 {
2378 self.window_cx.replace_root_view(build_view)
2379 }
2380
2381 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2382 self.window_cx.focus_view(view)
2383 }
2384
2385 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2386 self.window_cx.dismiss_view(view)
2387 }
2388}
2389
2390impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2391 type Target = WindowContext<'a>;
2392
2393 fn deref(&self) -> &Self::Target {
2394 &self.window_cx
2395 }
2396}
2397
2398impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2399 fn deref_mut(&mut self) -> &mut Self::Target {
2400 &mut self.window_cx
2401 }
2402}
2403
2404// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2405slotmap::new_key_type! {
2406 /// A unique identifier for a window.
2407 pub struct WindowId;
2408}
2409
2410impl WindowId {
2411 /// Converts this window ID to a `u64`.
2412 pub fn as_u64(&self) -> u64 {
2413 self.0.as_ffi()
2414 }
2415}
2416
2417/// A handle to a window with a specific root view type.
2418/// Note that this does not keep the window alive on its own.
2419#[derive(Deref, DerefMut)]
2420pub struct WindowHandle<V> {
2421 #[deref]
2422 #[deref_mut]
2423 pub(crate) any_handle: AnyWindowHandle,
2424 state_type: PhantomData<V>,
2425}
2426
2427impl<V: 'static + Render> WindowHandle<V> {
2428 /// Creates a new handle from a window ID.
2429 /// This does not check if the root type of the window is `V`.
2430 pub fn new(id: WindowId) -> Self {
2431 WindowHandle {
2432 any_handle: AnyWindowHandle {
2433 id,
2434 state_type: TypeId::of::<V>(),
2435 },
2436 state_type: PhantomData,
2437 }
2438 }
2439
2440 /// Get the root view out of this window.
2441 ///
2442 /// This will fail if the window is closed or if the root view's type does not match `V`.
2443 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2444 where
2445 C: Context,
2446 {
2447 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2448 root_view
2449 .downcast::<V>()
2450 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2451 }))
2452 }
2453
2454 /// Updates the root view of this window.
2455 ///
2456 /// This will fail if the window has been closed or if the root view's type does not match
2457 pub fn update<C, R>(
2458 &self,
2459 cx: &mut C,
2460 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2461 ) -> Result<R>
2462 where
2463 C: Context,
2464 {
2465 cx.update_window(self.any_handle, |root_view, cx| {
2466 let view = root_view
2467 .downcast::<V>()
2468 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2469 Ok(cx.update_view(&view, update))
2470 })?
2471 }
2472
2473 /// Read the root view out of this window.
2474 ///
2475 /// This will fail if the window is closed or if the root view's type does not match `V`.
2476 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2477 let x = cx
2478 .windows
2479 .get(self.id)
2480 .and_then(|window| {
2481 window
2482 .as_ref()
2483 .and_then(|window| window.root_view.clone())
2484 .map(|root_view| root_view.downcast::<V>())
2485 })
2486 .ok_or_else(|| anyhow!("window not found"))?
2487 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2488
2489 Ok(x.read(cx))
2490 }
2491
2492 /// Read the root view out of this window, with a callback
2493 ///
2494 /// This will fail if the window is closed or if the root view's type does not match `V`.
2495 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2496 where
2497 C: Context,
2498 {
2499 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2500 }
2501
2502 /// Read the root view pointer off of this window.
2503 ///
2504 /// This will fail if the window is closed or if the root view's type does not match `V`.
2505 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2506 where
2507 C: Context,
2508 {
2509 cx.read_window(self, |root_view, _cx| root_view.clone())
2510 }
2511
2512 /// Check if this window is 'active'.
2513 ///
2514 /// Will return `None` if the window is closed.
2515 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2516 cx.windows
2517 .get(self.id)
2518 .and_then(|window| window.as_ref().map(|window| window.active.get()))
2519 }
2520}
2521
2522impl<V> Copy for WindowHandle<V> {}
2523
2524impl<V> Clone for WindowHandle<V> {
2525 fn clone(&self) -> Self {
2526 *self
2527 }
2528}
2529
2530impl<V> PartialEq for WindowHandle<V> {
2531 fn eq(&self, other: &Self) -> bool {
2532 self.any_handle == other.any_handle
2533 }
2534}
2535
2536impl<V> Eq for WindowHandle<V> {}
2537
2538impl<V> Hash for WindowHandle<V> {
2539 fn hash<H: Hasher>(&self, state: &mut H) {
2540 self.any_handle.hash(state);
2541 }
2542}
2543
2544impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2545 fn from(val: WindowHandle<V>) -> Self {
2546 val.any_handle
2547 }
2548}
2549
2550/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2551#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2552pub struct AnyWindowHandle {
2553 pub(crate) id: WindowId,
2554 state_type: TypeId,
2555}
2556
2557impl AnyWindowHandle {
2558 /// Get the ID of this window.
2559 pub fn window_id(&self) -> WindowId {
2560 self.id
2561 }
2562
2563 /// Attempt to convert this handle to a window handle with a specific root view type.
2564 /// If the types do not match, this will return `None`.
2565 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2566 if TypeId::of::<T>() == self.state_type {
2567 Some(WindowHandle {
2568 any_handle: *self,
2569 state_type: PhantomData,
2570 })
2571 } else {
2572 None
2573 }
2574 }
2575
2576 /// Updates the state of the root view of this window.
2577 ///
2578 /// This will fail if the window has been closed.
2579 pub fn update<C, R>(
2580 self,
2581 cx: &mut C,
2582 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2583 ) -> Result<R>
2584 where
2585 C: Context,
2586 {
2587 cx.update_window(self, update)
2588 }
2589
2590 /// Read the state of the root view of this window.
2591 ///
2592 /// This will fail if the window has been closed.
2593 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2594 where
2595 C: Context,
2596 T: 'static,
2597 {
2598 let view = self
2599 .downcast::<T>()
2600 .context("the type of the window's root view has changed")?;
2601
2602 cx.read_window(&view, read)
2603 }
2604}
2605
2606/// An identifier for an [`Element`](crate::Element).
2607///
2608/// Can be constructed with a string, a number, or both, as well
2609/// as other internal representations.
2610#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2611pub enum ElementId {
2612 /// The ID of a View element
2613 View(EntityId),
2614 /// An integer ID.
2615 Integer(usize),
2616 /// A string based ID.
2617 Name(SharedString),
2618 /// An ID that's equated with a focus handle.
2619 FocusHandle(FocusId),
2620 /// A combination of a name and an integer.
2621 NamedInteger(SharedString, usize),
2622}
2623
2624impl Display for ElementId {
2625 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2626 match self {
2627 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2628 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2629 ElementId::Name(name) => write!(f, "{}", name)?,
2630 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2631 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2632 }
2633
2634 Ok(())
2635 }
2636}
2637
2638impl ElementId {
2639 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2640 ElementId::View(entity_id)
2641 }
2642}
2643
2644impl TryInto<SharedString> for ElementId {
2645 type Error = anyhow::Error;
2646
2647 fn try_into(self) -> anyhow::Result<SharedString> {
2648 if let ElementId::Name(name) = self {
2649 Ok(name)
2650 } else {
2651 Err(anyhow!("element id is not string"))
2652 }
2653 }
2654}
2655
2656impl From<usize> for ElementId {
2657 fn from(id: usize) -> Self {
2658 ElementId::Integer(id)
2659 }
2660}
2661
2662impl From<i32> for ElementId {
2663 fn from(id: i32) -> Self {
2664 Self::Integer(id as usize)
2665 }
2666}
2667
2668impl From<SharedString> for ElementId {
2669 fn from(name: SharedString) -> Self {
2670 ElementId::Name(name)
2671 }
2672}
2673
2674impl From<&'static str> for ElementId {
2675 fn from(name: &'static str) -> Self {
2676 ElementId::Name(name.into())
2677 }
2678}
2679
2680impl<'a> From<&'a FocusHandle> for ElementId {
2681 fn from(handle: &'a FocusHandle) -> Self {
2682 ElementId::FocusHandle(handle.id)
2683 }
2684}
2685
2686impl From<(&'static str, EntityId)> for ElementId {
2687 fn from((name, id): (&'static str, EntityId)) -> Self {
2688 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2689 }
2690}
2691
2692impl From<(&'static str, usize)> for ElementId {
2693 fn from((name, id): (&'static str, usize)) -> Self {
2694 ElementId::NamedInteger(name.into(), id)
2695 }
2696}
2697
2698impl From<(&'static str, u64)> for ElementId {
2699 fn from((name, id): (&'static str, u64)) -> Self {
2700 ElementId::NamedInteger(name.into(), id as usize)
2701 }
2702}
2703
2704/// A rectangle to be rendered in the window at the given position and size.
2705/// Passed as an argument [`ElementContext::paint_quad`].
2706#[derive(Clone)]
2707pub struct PaintQuad {
2708 bounds: Bounds<Pixels>,
2709 corner_radii: Corners<Pixels>,
2710 background: Hsla,
2711 border_widths: Edges<Pixels>,
2712 border_color: Hsla,
2713}
2714
2715impl PaintQuad {
2716 /// Sets the corner radii of the quad.
2717 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2718 PaintQuad {
2719 corner_radii: corner_radii.into(),
2720 ..self
2721 }
2722 }
2723
2724 /// Sets the border widths of the quad.
2725 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2726 PaintQuad {
2727 border_widths: border_widths.into(),
2728 ..self
2729 }
2730 }
2731
2732 /// Sets the border color of the quad.
2733 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2734 PaintQuad {
2735 border_color: border_color.into(),
2736 ..self
2737 }
2738 }
2739
2740 /// Sets the background color of the quad.
2741 pub fn background(self, background: impl Into<Hsla>) -> Self {
2742 PaintQuad {
2743 background: background.into(),
2744 ..self
2745 }
2746 }
2747}
2748
2749/// Creates a quad with the given parameters.
2750pub fn quad(
2751 bounds: Bounds<Pixels>,
2752 corner_radii: impl Into<Corners<Pixels>>,
2753 background: impl Into<Hsla>,
2754 border_widths: impl Into<Edges<Pixels>>,
2755 border_color: impl Into<Hsla>,
2756) -> PaintQuad {
2757 PaintQuad {
2758 bounds,
2759 corner_radii: corner_radii.into(),
2760 background: background.into(),
2761 border_widths: border_widths.into(),
2762 border_color: border_color.into(),
2763 }
2764}
2765
2766/// Creates a filled quad with the given bounds and background color.
2767pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2768 PaintQuad {
2769 bounds: bounds.into(),
2770 corner_radii: (0.).into(),
2771 background: background.into(),
2772 border_widths: (0.).into(),
2773 border_color: transparent_black(),
2774 }
2775}
2776
2777/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2778pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2779 PaintQuad {
2780 bounds: bounds.into(),
2781 corner_radii: (0.).into(),
2782 background: transparent_black(),
2783 border_widths: (1.).into(),
2784 border_color: border_color.into(),
2785 }
2786}