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