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, KeymatchMode,
6 KeymatchResult, Keystroke, KeystrokeEvent, Model, ModelContext, Modifiers, MouseButton,
7 MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
8 PlatformWindow, Point, PromptLevel, Render, ScaledPixels, SharedString, Size, SubscriberSet,
9 Subscription, TaffyLayoutEngine, Task, View, VisualContext, WeakView, WindowAppearance,
10 WindowBounds, WindowOptions, WindowTextSystem,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::{
16 channel::{mpsc, oneshot},
17 StreamExt,
18};
19use parking_lot::RwLock;
20use slotmap::SlotMap;
21use smallvec::SmallVec;
22use std::{
23 any::{Any, TypeId},
24 borrow::{Borrow, BorrowMut},
25 cell::RefCell,
26 collections::hash_map::Entry,
27 fmt::{Debug, Display},
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37 time::Duration,
38};
39use util::{measure, ResultExt};
40
41mod element_cx;
42pub use element_cx::*;
43
44const ACTIVE_DRAG_Z_INDEX: u16 = 1;
45
46/// A global stacking order, which is created by stacking successive z-index values.
47/// Each z-index will always be interpreted in the context of its parent z-index.
48#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
49pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
50
51/// A single entry in a primitive's z-index stacking order
52#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
53pub struct StackingContext {
54 pub(crate) z_index: u16,
55 pub(crate) id: u16,
56}
57
58impl std::fmt::Debug for StackingContext {
59 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
60 write!(f, "{{{}.{}}} ", self.z_index, self.id)
61 }
62}
63
64/// Represents the two different phases when dispatching events.
65#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
66pub enum DispatchPhase {
67 /// After the capture phase comes the bubble phase, in which mouse event listeners are
68 /// invoked front to back and keyboard event listeners are invoked from the focused element
69 /// to the root of the element tree. This is the phase you'll most commonly want to use when
70 /// registering event listeners.
71 #[default]
72 Bubble,
73 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
74 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
75 /// is used for special purposes such as clearing the "pressed" state for click events. If
76 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
77 /// outside of the immediate region may rely on detecting non-local events during this phase.
78 Capture,
79}
80
81impl DispatchPhase {
82 /// Returns true if this represents the "bubble" phase.
83 pub fn bubble(self) -> bool {
84 self == DispatchPhase::Bubble
85 }
86
87 /// Returns true if this represents the "capture" phase.
88 pub fn capture(self) -> bool {
89 self == DispatchPhase::Capture
90 }
91}
92
93type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
94
95type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
96
97struct FocusEvent {
98 previous_focus_path: SmallVec<[FocusId; 8]>,
99 current_focus_path: SmallVec<[FocusId; 8]>,
100}
101
102slotmap::new_key_type! {
103 /// A globally unique identifier for a focusable element.
104 pub struct FocusId;
105}
106
107thread_local! {
108 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(8 * 1024 * 1024));
109}
110
111impl FocusId {
112 /// Obtains whether the element associated with this handle is currently focused.
113 pub fn is_focused(&self, cx: &WindowContext) -> bool {
114 cx.window.focus == Some(*self)
115 }
116
117 /// Obtains whether the element associated with this handle contains the focused
118 /// element or is itself focused.
119 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
120 cx.focused()
121 .map_or(false, |focused| self.contains(focused.id, cx))
122 }
123
124 /// Obtains whether the element associated with this handle is contained within the
125 /// focused element or is itself focused.
126 pub fn within_focused(&self, cx: &WindowContext) -> bool {
127 let focused = cx.focused();
128 focused.map_or(false, |focused| focused.id.contains(*self, cx))
129 }
130
131 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
132 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
133 cx.window
134 .rendered_frame
135 .dispatch_tree
136 .focus_contains(*self, other)
137 }
138}
139
140/// A handle which can be used to track and manipulate the focused element in a window.
141pub struct FocusHandle {
142 pub(crate) id: FocusId,
143 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
144}
145
146impl std::fmt::Debug for FocusHandle {
147 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
148 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
149 }
150}
151
152impl FocusHandle {
153 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
154 let id = handles.write().insert(AtomicUsize::new(1));
155 Self {
156 id,
157 handles: handles.clone(),
158 }
159 }
160
161 pub(crate) fn for_id(
162 id: FocusId,
163 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
164 ) -> Option<Self> {
165 let lock = handles.read();
166 let ref_count = lock.get(id)?;
167 if ref_count.load(SeqCst) == 0 {
168 None
169 } else {
170 ref_count.fetch_add(1, SeqCst);
171 Some(Self {
172 id,
173 handles: handles.clone(),
174 })
175 }
176 }
177
178 /// Moves the focus to the element associated with this handle.
179 pub fn focus(&self, cx: &mut WindowContext) {
180 cx.focus(self)
181 }
182
183 /// Obtains whether the element associated with this handle is currently focused.
184 pub fn is_focused(&self, cx: &WindowContext) -> bool {
185 self.id.is_focused(cx)
186 }
187
188 /// Obtains whether the element associated with this handle contains the focused
189 /// element or is itself focused.
190 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
191 self.id.contains_focused(cx)
192 }
193
194 /// Obtains whether the element associated with this handle is contained within the
195 /// focused element or is itself focused.
196 pub fn within_focused(&self, cx: &WindowContext) -> bool {
197 self.id.within_focused(cx)
198 }
199
200 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
201 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
202 self.id.contains(other.id, cx)
203 }
204}
205
206impl Clone for FocusHandle {
207 fn clone(&self) -> Self {
208 Self::for_id(self.id, &self.handles).unwrap()
209 }
210}
211
212impl PartialEq for FocusHandle {
213 fn eq(&self, other: &Self) -> bool {
214 self.id == other.id
215 }
216}
217
218impl Eq for FocusHandle {}
219
220impl Drop for FocusHandle {
221 fn drop(&mut self) {
222 self.handles
223 .read()
224 .get(self.id)
225 .unwrap()
226 .fetch_sub(1, SeqCst);
227 }
228}
229
230/// FocusableView allows users of your view to easily
231/// focus it (using cx.focus_view(view))
232pub trait FocusableView: 'static + Render {
233 /// Returns the focus handle associated with this view.
234 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
235}
236
237/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
238/// where the lifecycle of the view is handled by another view.
239pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
240
241impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
242
243/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
244pub struct DismissEvent;
245
246// Holds the state for a specific window.
247#[doc(hidden)]
248pub struct Window {
249 pub(crate) handle: AnyWindowHandle,
250 pub(crate) removed: bool,
251 pub(crate) platform_window: Box<dyn PlatformWindow>,
252 display_id: DisplayId,
253 sprite_atlas: Arc<dyn PlatformAtlas>,
254 text_system: Arc<WindowTextSystem>,
255 pub(crate) rem_size: Pixels,
256 pub(crate) viewport_size: Size<Pixels>,
257 layout_engine: Option<TaffyLayoutEngine>,
258 pub(crate) root_view: Option<AnyView>,
259 pub(crate) element_id_stack: GlobalElementId,
260 pub(crate) rendered_frame: Frame,
261 pub(crate) next_frame: Frame,
262 pub(crate) dirty_views: FxHashSet<EntityId>,
263 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
264 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
265 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
266 default_prevented: bool,
267 mouse_position: Point<Pixels>,
268 modifiers: Modifiers,
269 scale_factor: f32,
270 bounds: WindowBounds,
271 bounds_observers: SubscriberSet<(), AnyObserver>,
272 appearance: WindowAppearance,
273 appearance_observers: SubscriberSet<(), AnyObserver>,
274 active: bool,
275 pub(crate) dirty: bool,
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 #[cfg(any(test, feature = "test-support"))]
284 pub(crate) focus_invalidated: bool,
285}
286
287#[derive(Default, Debug)]
288struct PendingInput {
289 keystrokes: SmallVec<[Keystroke; 1]>,
290 bindings: SmallVec<[KeyBinding; 1]>,
291 focus: Option<FocusId>,
292 timer: Option<Task<()>>,
293}
294
295impl PendingInput {
296 fn is_noop(&self) -> bool {
297 self.bindings.is_empty() && (self.keystrokes.iter().all(|k| k.ime_key.is_none()))
298 }
299
300 fn input(&self) -> String {
301 self.keystrokes
302 .iter()
303 .flat_map(|k| k.ime_key.clone())
304 .collect::<Vec<String>>()
305 .join("")
306 }
307
308 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
309 if self.keystrokes.is_empty() {
310 return true;
311 }
312 let keystroke = &self.keystrokes[0];
313 for candidate in keystroke.match_candidates() {
314 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
315 return true;
316 }
317 }
318 false
319 }
320}
321
322pub(crate) struct ElementStateBox {
323 pub(crate) inner: Box<dyn Any>,
324 pub(crate) parent_view_id: EntityId,
325 #[cfg(debug_assertions)]
326 pub(crate) type_name: &'static str,
327}
328
329impl Window {
330 pub(crate) fn new(
331 handle: AnyWindowHandle,
332 options: WindowOptions,
333 cx: &mut AppContext,
334 ) -> Self {
335 let platform_window = cx.platform.open_window(handle, options);
336 let display_id = platform_window.display().id();
337 let sprite_atlas = platform_window.sprite_atlas();
338 let mouse_position = platform_window.mouse_position();
339 let modifiers = platform_window.modifiers();
340 let content_size = platform_window.content_size();
341 let scale_factor = platform_window.scale_factor();
342 let bounds = platform_window.bounds();
343 let appearance = platform_window.appearance();
344 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
345
346 platform_window.on_request_frame(Box::new({
347 let mut cx = cx.to_async();
348 move || {
349 measure("frame duration", || {
350 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
351 })
352 }
353 }));
354 platform_window.on_resize(Box::new({
355 let mut cx = cx.to_async();
356 move |_, _| {
357 handle
358 .update(&mut cx, |_, cx| cx.window_bounds_changed())
359 .log_err();
360 }
361 }));
362 platform_window.on_moved(Box::new({
363 let mut cx = cx.to_async();
364 move || {
365 handle
366 .update(&mut cx, |_, cx| cx.window_bounds_changed())
367 .log_err();
368 }
369 }));
370 platform_window.on_appearance_changed(Box::new({
371 let mut cx = cx.to_async();
372 move || {
373 handle
374 .update(&mut cx, |_, cx| cx.appearance_changed())
375 .log_err();
376 }
377 }));
378 platform_window.on_active_status_change(Box::new({
379 let mut cx = cx.to_async();
380 move |active| {
381 handle
382 .update(&mut cx, |_, cx| {
383 cx.window.active = active;
384 cx.window
385 .activation_observers
386 .clone()
387 .retain(&(), |callback| callback(cx));
388 })
389 .log_err();
390 }
391 }));
392
393 platform_window.on_input({
394 let mut cx = cx.to_async();
395 Box::new(move |event| {
396 handle
397 .update(&mut cx, |_, cx| cx.dispatch_event(event))
398 .log_err()
399 .unwrap_or(false)
400 })
401 });
402
403 Window {
404 handle,
405 removed: false,
406 platform_window,
407 display_id,
408 sprite_atlas,
409 text_system,
410 rem_size: px(16.),
411 viewport_size: content_size,
412 layout_engine: Some(TaffyLayoutEngine::new()),
413 root_view: None,
414 element_id_stack: GlobalElementId::default(),
415 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
416 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
417 dirty_views: FxHashSet::default(),
418 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
419 focus_listeners: SubscriberSet::new(),
420 focus_lost_listeners: SubscriberSet::new(),
421 default_prevented: true,
422 mouse_position,
423 modifiers,
424 scale_factor,
425 bounds,
426 bounds_observers: SubscriberSet::new(),
427 appearance,
428 appearance_observers: SubscriberSet::new(),
429 active: false,
430 dirty: false,
431 refreshing: false,
432 drawing: false,
433 activation_observers: SubscriberSet::new(),
434 focus: None,
435 focus_enabled: true,
436 pending_input: None,
437
438 #[cfg(any(test, feature = "test-support"))]
439 focus_invalidated: false,
440 }
441 }
442}
443
444/// Indicates which region of the window is visible. Content falling outside of this mask will not be
445/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
446/// to leave room to support more complex shapes in the future.
447#[derive(Clone, Debug, Default, PartialEq, Eq)]
448#[repr(C)]
449pub struct ContentMask<P: Clone + Default + Debug> {
450 /// The bounds
451 pub bounds: Bounds<P>,
452}
453
454impl ContentMask<Pixels> {
455 /// Scale the content mask's pixel units by the given scaling factor.
456 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
457 ContentMask {
458 bounds: self.bounds.scale(factor),
459 }
460 }
461
462 /// Intersect the content mask with the given content mask.
463 pub fn intersect(&self, other: &Self) -> Self {
464 let bounds = self.bounds.intersect(&other.bounds);
465 ContentMask { bounds }
466 }
467}
468
469/// Provides access to application state in the context of a single window. Derefs
470/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
471/// an [`AppContext`] and call any [`AppContext`] methods.
472pub struct WindowContext<'a> {
473 pub(crate) app: &'a mut AppContext,
474 pub(crate) window: &'a mut Window,
475}
476
477impl<'a> WindowContext<'a> {
478 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
479 Self { app, window }
480 }
481
482 /// Obtain a handle to the window that belongs to this context.
483 pub fn window_handle(&self) -> AnyWindowHandle {
484 self.window.handle
485 }
486
487 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
488 pub fn refresh(&mut self) {
489 if !self.window.drawing {
490 self.window.refreshing = true;
491 self.window.dirty = true;
492 }
493 }
494
495 /// Close this window.
496 pub fn remove_window(&mut self) {
497 self.window.removed = true;
498 }
499
500 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
501 /// for elements rendered within this window.
502 pub fn focus_handle(&mut self) -> FocusHandle {
503 FocusHandle::new(&self.window.focus_handles)
504 }
505
506 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
507 pub fn focused(&self) -> Option<FocusHandle> {
508 self.window
509 .focus
510 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
511 }
512
513 /// Move focus to the element associated with the given [`FocusHandle`].
514 pub fn focus(&mut self, handle: &FocusHandle) {
515 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
516 return;
517 }
518
519 self.window.focus = Some(handle.id);
520 self.window
521 .rendered_frame
522 .dispatch_tree
523 .clear_pending_keystrokes();
524
525 #[cfg(any(test, feature = "test-support"))]
526 {
527 self.window.focus_invalidated = true;
528 }
529
530 self.refresh();
531 }
532
533 /// Remove focus from all elements within this context's window.
534 pub fn blur(&mut self) {
535 if !self.window.focus_enabled {
536 return;
537 }
538
539 self.window.focus = None;
540 self.refresh();
541 }
542
543 /// Blur the window and don't allow anything in it to be focused again.
544 pub fn disable_focus(&mut self) {
545 self.blur();
546 self.window.focus_enabled = false;
547 }
548
549 /// Accessor for the text system.
550 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
551 &self.window.text_system
552 }
553
554 /// Dispatch the given action on the currently focused element.
555 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
556 let focus_handle = self.focused();
557
558 self.defer(move |cx| {
559 let node_id = focus_handle
560 .and_then(|handle| {
561 cx.window
562 .rendered_frame
563 .dispatch_tree
564 .focusable_node_id(handle.id)
565 })
566 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
567
568 cx.propagate_event = true;
569 cx.dispatch_action_on_node(node_id, action);
570 })
571 }
572
573 pub(crate) fn dispatch_keystroke_observers(
574 &mut self,
575 event: &dyn Any,
576 action: Option<Box<dyn Action>>,
577 ) {
578 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
579 return;
580 };
581
582 self.keystroke_observers
583 .clone()
584 .retain(&(), move |callback| {
585 (callback)(
586 &KeystrokeEvent {
587 keystroke: key_down_event.keystroke.clone(),
588 action: action.as_ref().map(|action| action.boxed_clone()),
589 },
590 self,
591 );
592 true
593 });
594 }
595
596 pub(crate) fn clear_pending_keystrokes(&mut self) {
597 self.window
598 .rendered_frame
599 .dispatch_tree
600 .clear_pending_keystrokes();
601 self.window
602 .next_frame
603 .dispatch_tree
604 .clear_pending_keystrokes();
605 }
606
607 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
608 /// that are currently on the stack to be returned to the app.
609 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
610 let handle = self.window.handle;
611 self.app.defer(move |cx| {
612 handle.update(cx, |_, cx| f(cx)).ok();
613 });
614 }
615
616 /// Subscribe to events emitted by a model or view.
617 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
618 /// 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.
619 pub fn subscribe<Emitter, E, Evt>(
620 &mut self,
621 entity: &E,
622 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
623 ) -> Subscription
624 where
625 Emitter: EventEmitter<Evt>,
626 E: Entity<Emitter>,
627 Evt: 'static,
628 {
629 let entity_id = entity.entity_id();
630 let entity = entity.downgrade();
631 let window_handle = self.window.handle;
632 let (subscription, activate) = self.app.event_listeners.insert(
633 entity_id,
634 (
635 TypeId::of::<Evt>(),
636 Box::new(move |event, cx| {
637 window_handle
638 .update(cx, |_, cx| {
639 if let Some(handle) = E::upgrade_from(&entity) {
640 let event = event.downcast_ref().expect("invalid event type");
641 on_event(handle, event, cx);
642 true
643 } else {
644 false
645 }
646 })
647 .unwrap_or(false)
648 }),
649 ),
650 );
651 self.app.defer(move |_| activate());
652 subscription
653 }
654
655 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
656 /// await points in async code.
657 pub fn to_async(&self) -> AsyncWindowContext {
658 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
659 }
660
661 /// Schedule the given closure to be run directly after the current frame is rendered.
662 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
663 let handle = self.window.handle;
664 let display_id = self.window.display_id;
665
666 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
667 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
668 let (tx, mut rx) = mpsc::unbounded::<()>();
669 self.platform.set_display_link_output_callback(
670 display_id,
671 Box::new(move || _ = tx.unbounded_send(())),
672 );
673
674 let consumer_task = self.app.spawn(|cx| async move {
675 while rx.next().await.is_some() {
676 cx.update(|cx| {
677 for callback in cx
678 .next_frame_callbacks
679 .get_mut(&display_id)
680 .unwrap()
681 .drain(..)
682 .collect::<SmallVec<[_; 32]>>()
683 {
684 callback(cx);
685 }
686 })
687 .ok();
688
689 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
690
691 cx.update(|cx| {
692 if cx.next_frame_callbacks.is_empty() {
693 cx.platform.stop_display_link(display_id);
694 }
695 })
696 .ok();
697 }
698 });
699 e.insert(consumer_task);
700 }
701 debug_assert!(self.app.frame_consumers.is_empty());
702 self.app.frame_consumers = frame_consumers;
703
704 if self.next_frame_callbacks.is_empty() {
705 self.platform.start_display_link(display_id);
706 }
707
708 self.next_frame_callbacks
709 .entry(display_id)
710 .or_default()
711 .push(Box::new(move |cx: &mut AppContext| {
712 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
713 }));
714 }
715
716 /// Spawn the future returned by the given closure on the application thread pool.
717 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
718 /// use within your future.
719 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
720 where
721 R: 'static,
722 Fut: Future<Output = R> + 'static,
723 {
724 self.app
725 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
726 }
727
728 /// Updates the global of the given type. The given closure is given simultaneous mutable
729 /// access both to the global and the context.
730 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
731 where
732 G: Global,
733 {
734 let mut global = self.app.lease_global::<G>();
735 let result = f(&mut global, self);
736 self.app.end_global_lease(global);
737 result
738 }
739
740 fn window_bounds_changed(&mut self) {
741 self.window.scale_factor = self.window.platform_window.scale_factor();
742 self.window.viewport_size = self.window.platform_window.content_size();
743 self.window.bounds = self.window.platform_window.bounds();
744 self.window.display_id = self.window.platform_window.display().id();
745 self.refresh();
746
747 self.window
748 .bounds_observers
749 .clone()
750 .retain(&(), |callback| callback(self));
751 }
752
753 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
754 pub fn window_bounds(&self) -> WindowBounds {
755 self.window.bounds
756 }
757
758 fn appearance_changed(&mut self) {
759 self.window.appearance = self.window.platform_window.appearance();
760
761 self.window
762 .appearance_observers
763 .clone()
764 .retain(&(), |callback| callback(self));
765 }
766
767 /// Returns the appearance of the current window.
768 pub fn appearance(&self) -> WindowAppearance {
769 self.window.appearance
770 }
771
772 /// Returns the size of the drawable area within the window.
773 pub fn viewport_size(&self) -> Size<Pixels> {
774 self.window.viewport_size
775 }
776
777 /// Returns whether this window is focused by the operating system (receiving key events).
778 pub fn is_window_active(&self) -> bool {
779 self.window.active
780 }
781
782 /// Toggle zoom on the window.
783 pub fn zoom_window(&self) {
784 self.window.platform_window.zoom();
785 }
786
787 /// Updates the window's title at the platform level.
788 pub fn set_window_title(&mut self, title: &str) {
789 self.window.platform_window.set_title(title);
790 }
791
792 /// Mark the window as dirty at the platform level.
793 pub fn set_window_edited(&mut self, edited: bool) {
794 self.window.platform_window.set_edited(edited);
795 }
796
797 /// Determine the display on which the window is visible.
798 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
799 self.platform
800 .displays()
801 .into_iter()
802 .find(|display| display.id() == self.window.display_id)
803 }
804
805 /// Show the platform character palette.
806 pub fn show_character_palette(&self) {
807 self.window.platform_window.show_character_palette();
808 }
809
810 /// The scale factor of the display associated with the window. For example, it could
811 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
812 /// be rendered as two pixels on screen.
813 pub fn scale_factor(&self) -> f32 {
814 self.window.scale_factor
815 }
816
817 /// The size of an em for the base font of the application. Adjusting this value allows the
818 /// UI to scale, just like zooming a web page.
819 pub fn rem_size(&self) -> Pixels {
820 self.window.rem_size
821 }
822
823 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
824 /// UI to scale, just like zooming a web page.
825 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
826 self.window.rem_size = rem_size.into();
827 }
828
829 /// The line height associated with the current text style.
830 pub fn line_height(&self) -> Pixels {
831 let rem_size = self.rem_size();
832 let text_style = self.text_style();
833 text_style
834 .line_height
835 .to_pixels(text_style.font_size, rem_size)
836 }
837
838 /// Call to prevent the default action of an event. Currently only used to prevent
839 /// parent elements from becoming focused on mouse down.
840 pub fn prevent_default(&mut self) {
841 self.window.default_prevented = true;
842 }
843
844 /// Obtain whether default has been prevented for the event currently being dispatched.
845 pub fn default_prevented(&self) -> bool {
846 self.window.default_prevented
847 }
848
849 /// Determine whether the given action is available along the dispatch path to the currently focused element.
850 pub fn is_action_available(&self, action: &dyn Action) -> bool {
851 let target = self
852 .focused()
853 .and_then(|focused_handle| {
854 self.window
855 .rendered_frame
856 .dispatch_tree
857 .focusable_node_id(focused_handle.id)
858 })
859 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
860 self.window
861 .rendered_frame
862 .dispatch_tree
863 .is_action_available(action, target)
864 }
865
866 /// The position of the mouse relative to the window.
867 pub fn mouse_position(&self) -> Point<Pixels> {
868 self.window.mouse_position
869 }
870
871 /// The current state of the keyboard's modifiers
872 pub fn modifiers(&self) -> Modifiers {
873 self.window.modifiers
874 }
875
876 /// Returns true if there is no opaque layer containing the given point
877 /// on top of the given level. Layers who are extensions of the queried layer
878 /// are not considered to be on top of queried layer.
879 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
880 // Precondition: the depth map is ordered from topmost to bottomost.
881
882 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
883 if layer >= opaque_layer {
884 // The queried layer is either above or is the same as the this opaque layer.
885 // Anything after this point is guaranteed to be below the queried layer.
886 return true;
887 }
888
889 if !bounds.contains(point) {
890 // This opaque layer is above the queried layer but it doesn't contain
891 // the given position, so we can ignore it even if it's above.
892 continue;
893 }
894
895 // At this point, we've established that this opaque layer is on top of the queried layer
896 // and contains the position:
897 // If neither the opaque layer or the queried layer is an extension of the other then
898 // we know they are on different stacking orders, and return false.
899 let is_on_same_layer = opaque_layer
900 .iter()
901 .zip(layer.iter())
902 .all(|(a, b)| a.z_index == b.z_index);
903
904 if !is_on_same_layer {
905 return false;
906 }
907 }
908
909 true
910 }
911
912 pub(crate) fn was_top_layer_under_active_drag(
913 &self,
914 point: &Point<Pixels>,
915 layer: &StackingOrder,
916 ) -> bool {
917 // Precondition: the depth map is ordered from topmost to bottomost.
918
919 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
920 if layer >= opaque_layer {
921 // The queried layer is either above or is the same as the this opaque layer.
922 // Anything after this point is guaranteed to be below the queried layer.
923 return true;
924 }
925
926 if !bounds.contains(point) {
927 // This opaque layer is above the queried layer but it doesn't contain
928 // the given position, so we can ignore it even if it's above.
929 continue;
930 }
931
932 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
933 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
934 // looking to see if the queried layer was the topmost underneath the drag layer.
935 if opaque_layer
936 .first()
937 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
938 .unwrap_or(false)
939 {
940 continue;
941 }
942
943 // At this point, we've established that this opaque layer is on top of the queried layer
944 // and contains the position:
945 // If neither the opaque layer or the queried layer is an extension of the other then
946 // we know they are on different stacking orders, and return false.
947 let is_on_same_layer = opaque_layer
948 .iter()
949 .zip(layer.iter())
950 .all(|(a, b)| a.z_index == b.z_index);
951
952 if !is_on_same_layer {
953 return false;
954 }
955 }
956
957 true
958 }
959
960 /// Called during painting to get the current stacking order.
961 pub fn stacking_order(&self) -> &StackingOrder {
962 &self.window.next_frame.z_index_stack
963 }
964
965 /// Draw pixels to the display for this window based on the contents of its scene.
966 pub(crate) fn draw(&mut self) {
967 self.window.dirty = false;
968 self.window.drawing = true;
969
970 #[cfg(any(test, feature = "test-support"))]
971 {
972 self.window.focus_invalidated = false;
973 }
974
975 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
976 {
977 let input_handler = self.window.platform_window.take_input_handler();
978 requested_handler.handler = input_handler;
979 }
980
981 let root_view = self.window.root_view.take().unwrap();
982 self.with_element_context(|cx| {
983 cx.with_z_index(0, |cx| {
984 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
985 // We need to use cx.cx here so we can utilize borrow splitting
986 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
987 for action_listener in action_listeners.iter().cloned() {
988 cx.cx.window.next_frame.dispatch_tree.on_action(
989 *action_type,
990 Rc::new(
991 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
992 action_listener(action, phase, cx)
993 },
994 ),
995 )
996 }
997 }
998
999 let available_space = cx.window.viewport_size.map(Into::into);
1000 root_view.draw(Point::default(), available_space, cx);
1001 })
1002 })
1003 });
1004
1005 if let Some(active_drag) = self.app.active_drag.take() {
1006 self.with_element_context(|cx| {
1007 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
1008 let offset = cx.mouse_position() - active_drag.cursor_offset;
1009 let available_space =
1010 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1011 active_drag.view.draw(offset, available_space, cx);
1012 })
1013 });
1014 self.active_drag = Some(active_drag);
1015 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
1016 self.with_element_context(|cx| {
1017 cx.with_z_index(1, |cx| {
1018 let available_space =
1019 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1020 tooltip_request.tooltip.view.draw(
1021 tooltip_request.tooltip.cursor_offset,
1022 available_space,
1023 cx,
1024 );
1025 })
1026 });
1027 self.window.next_frame.tooltip_request = Some(tooltip_request);
1028 }
1029 self.window.dirty_views.clear();
1030
1031 self.window
1032 .next_frame
1033 .dispatch_tree
1034 .preserve_pending_keystrokes(
1035 &mut self.window.rendered_frame.dispatch_tree,
1036 self.window.focus,
1037 );
1038 self.window.next_frame.focus = self.window.focus;
1039 self.window.next_frame.window_active = self.window.active;
1040 self.window.root_view = Some(root_view);
1041
1042 // Set the cursor only if we're the active window.
1043 let cursor_style = self
1044 .window
1045 .next_frame
1046 .requested_cursor_style
1047 .take()
1048 .unwrap_or(CursorStyle::Arrow);
1049 if self.is_window_active() {
1050 self.platform.set_cursor_style(cursor_style);
1051 }
1052
1053 // Register requested input handler with the platform window.
1054 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1055 if let Some(handler) = requested_input.handler.take() {
1056 self.window.platform_window.set_input_handler(handler);
1057 }
1058 }
1059
1060 self.window.layout_engine.as_mut().unwrap().clear();
1061 self.text_system()
1062 .finish_frame(&self.window.next_frame.reused_views);
1063 self.window
1064 .next_frame
1065 .finish(&mut self.window.rendered_frame);
1066 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1067 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1068 if percentage >= 80. {
1069 log::warn!("elevated element arena occupation: {}.", percentage);
1070 }
1071 element_arena.clear();
1072 });
1073
1074 let previous_focus_path = self.window.rendered_frame.focus_path();
1075 let previous_window_active = self.window.rendered_frame.window_active;
1076 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1077 self.window.next_frame.clear();
1078 let current_focus_path = self.window.rendered_frame.focus_path();
1079 let current_window_active = self.window.rendered_frame.window_active;
1080
1081 if previous_focus_path != current_focus_path
1082 || previous_window_active != current_window_active
1083 {
1084 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1085 self.window
1086 .focus_lost_listeners
1087 .clone()
1088 .retain(&(), |listener| listener(self));
1089 }
1090
1091 let event = FocusEvent {
1092 previous_focus_path: if previous_window_active {
1093 previous_focus_path
1094 } else {
1095 Default::default()
1096 },
1097 current_focus_path: if current_window_active {
1098 current_focus_path
1099 } else {
1100 Default::default()
1101 },
1102 };
1103 self.window
1104 .focus_listeners
1105 .clone()
1106 .retain(&(), |listener| listener(&event, self));
1107 }
1108
1109 self.window
1110 .platform_window
1111 .draw(&self.window.rendered_frame.scene);
1112 self.window.refreshing = false;
1113 self.window.drawing = false;
1114 }
1115
1116 /// Dispatch a mouse or keyboard event on the window.
1117 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1118 // Handlers may set this to false by calling `stop_propagation`.
1119 self.app.propagate_event = true;
1120 // Handlers may set this to true by calling `prevent_default`.
1121 self.window.default_prevented = false;
1122
1123 let event = match event {
1124 // Track the mouse position with our own state, since accessing the platform
1125 // API for the mouse position can only occur on the main thread.
1126 PlatformInput::MouseMove(mouse_move) => {
1127 self.window.mouse_position = mouse_move.position;
1128 self.window.modifiers = mouse_move.modifiers;
1129 PlatformInput::MouseMove(mouse_move)
1130 }
1131 PlatformInput::MouseDown(mouse_down) => {
1132 self.window.mouse_position = mouse_down.position;
1133 self.window.modifiers = mouse_down.modifiers;
1134 PlatformInput::MouseDown(mouse_down)
1135 }
1136 PlatformInput::MouseUp(mouse_up) => {
1137 self.window.mouse_position = mouse_up.position;
1138 self.window.modifiers = mouse_up.modifiers;
1139 PlatformInput::MouseUp(mouse_up)
1140 }
1141 PlatformInput::MouseExited(mouse_exited) => {
1142 self.window.modifiers = mouse_exited.modifiers;
1143 PlatformInput::MouseExited(mouse_exited)
1144 }
1145 PlatformInput::ModifiersChanged(modifiers_changed) => {
1146 self.window.modifiers = modifiers_changed.modifiers;
1147 PlatformInput::ModifiersChanged(modifiers_changed)
1148 }
1149 PlatformInput::ScrollWheel(scroll_wheel) => {
1150 self.window.mouse_position = scroll_wheel.position;
1151 self.window.modifiers = scroll_wheel.modifiers;
1152 PlatformInput::ScrollWheel(scroll_wheel)
1153 }
1154 // Translate dragging and dropping of external files from the operating system
1155 // to internal drag and drop events.
1156 PlatformInput::FileDrop(file_drop) => match file_drop {
1157 FileDropEvent::Entered { position, paths } => {
1158 self.window.mouse_position = position;
1159 if self.active_drag.is_none() {
1160 self.active_drag = Some(AnyDrag {
1161 value: Box::new(paths.clone()),
1162 view: self.new_view(|_| paths).into(),
1163 cursor_offset: position,
1164 });
1165 }
1166 PlatformInput::MouseMove(MouseMoveEvent {
1167 position,
1168 pressed_button: Some(MouseButton::Left),
1169 modifiers: Modifiers::default(),
1170 })
1171 }
1172 FileDropEvent::Pending { position } => {
1173 self.window.mouse_position = position;
1174 PlatformInput::MouseMove(MouseMoveEvent {
1175 position,
1176 pressed_button: Some(MouseButton::Left),
1177 modifiers: Modifiers::default(),
1178 })
1179 }
1180 FileDropEvent::Submit { position } => {
1181 self.activate(true);
1182 self.window.mouse_position = position;
1183 PlatformInput::MouseUp(MouseUpEvent {
1184 button: MouseButton::Left,
1185 position,
1186 modifiers: Modifiers::default(),
1187 click_count: 1,
1188 })
1189 }
1190 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1191 button: MouseButton::Left,
1192 position: Point::default(),
1193 modifiers: Modifiers::default(),
1194 click_count: 1,
1195 }),
1196 },
1197 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1198 };
1199
1200 if let Some(any_mouse_event) = event.mouse_event() {
1201 self.dispatch_mouse_event(any_mouse_event);
1202 } else if let Some(any_key_event) = event.keyboard_event() {
1203 self.dispatch_key_event(any_key_event);
1204 }
1205
1206 !self.app.propagate_event
1207 }
1208
1209 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1210 if let Some(mut handlers) = self
1211 .window
1212 .rendered_frame
1213 .mouse_listeners
1214 .remove(&event.type_id())
1215 {
1216 // Because handlers may add other handlers, we sort every time.
1217 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1218
1219 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1220 // special purposes, such as detecting events outside of a given Bounds.
1221 for (_, _, handler) in &mut handlers {
1222 self.with_element_context(|cx| {
1223 handler(event, DispatchPhase::Capture, cx);
1224 });
1225 if !self.app.propagate_event {
1226 break;
1227 }
1228 }
1229
1230 // Bubble phase, where most normal handlers do their work.
1231 if self.app.propagate_event {
1232 for (_, _, handler) in handlers.iter_mut().rev() {
1233 self.with_element_context(|cx| {
1234 handler(event, DispatchPhase::Bubble, cx);
1235 });
1236 if !self.app.propagate_event {
1237 break;
1238 }
1239 }
1240 }
1241
1242 self.window
1243 .rendered_frame
1244 .mouse_listeners
1245 .insert(event.type_id(), handlers);
1246 }
1247
1248 if self.app.propagate_event && self.has_active_drag() {
1249 if event.is::<MouseMoveEvent>() {
1250 // If this was a mouse move event, redraw the window so that the
1251 // active drag can follow the mouse cursor.
1252 self.refresh();
1253 } else if event.is::<MouseUpEvent>() {
1254 // If this was a mouse up event, cancel the active drag and redraw
1255 // the window.
1256 self.active_drag = None;
1257 self.refresh();
1258 }
1259 }
1260 }
1261
1262 fn dispatch_key_event(&mut self, event: &dyn Any) {
1263 let node_id = self
1264 .window
1265 .focus
1266 .and_then(|focus_id| {
1267 self.window
1268 .rendered_frame
1269 .dispatch_tree
1270 .focusable_node_id(focus_id)
1271 })
1272 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1273
1274 let dispatch_path = self
1275 .window
1276 .rendered_frame
1277 .dispatch_tree
1278 .dispatch_path(node_id);
1279
1280 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1281 let KeymatchResult {
1282 bindings,
1283 mut pending,
1284 } = self
1285 .window
1286 .rendered_frame
1287 .dispatch_tree
1288 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1289
1290 if self.window.rendered_frame.dispatch_tree.keymatch_mode == KeymatchMode::Immediate
1291 && !bindings.is_empty()
1292 {
1293 pending = false;
1294 }
1295
1296 if pending {
1297 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1298 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1299 {
1300 currently_pending = PendingInput::default();
1301 }
1302 currently_pending.focus = self.window.focus;
1303 currently_pending
1304 .keystrokes
1305 .push(key_down_event.keystroke.clone());
1306 for binding in bindings {
1307 currently_pending.bindings.push(binding);
1308 }
1309
1310 // for vim compatibility, we also should check "is input handler enabled"
1311 if !currently_pending.is_noop() {
1312 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1313 cx.background_executor.timer(Duration::from_secs(1)).await;
1314 cx.update(move |cx| {
1315 cx.clear_pending_keystrokes();
1316 let Some(currently_pending) = cx.window.pending_input.take() else {
1317 return;
1318 };
1319 cx.replay_pending_input(currently_pending)
1320 })
1321 .log_err();
1322 }));
1323 } else {
1324 currently_pending.timer = None;
1325 }
1326 self.window.pending_input = Some(currently_pending);
1327
1328 self.propagate_event = false;
1329 return;
1330 } else if let Some(currently_pending) = self.window.pending_input.take() {
1331 if bindings
1332 .iter()
1333 .all(|binding| !currently_pending.used_by_binding(binding))
1334 {
1335 self.replay_pending_input(currently_pending)
1336 }
1337 }
1338
1339 if !bindings.is_empty() {
1340 self.clear_pending_keystrokes();
1341 }
1342
1343 self.propagate_event = true;
1344 for binding in bindings {
1345 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1346 if !self.propagate_event {
1347 self.dispatch_keystroke_observers(event, Some(binding.action));
1348 return;
1349 }
1350 }
1351 }
1352
1353 // Capture phase
1354 for node_id in &dispatch_path {
1355 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1356
1357 for key_listener in node.key_listeners.clone() {
1358 self.with_element_context(|cx| {
1359 key_listener(event, DispatchPhase::Capture, cx);
1360 });
1361 if !self.propagate_event {
1362 return;
1363 }
1364 }
1365 }
1366
1367 // Bubble phase
1368 for node_id in dispatch_path.iter().rev() {
1369 // Handle low level key events
1370 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1371 for key_listener in node.key_listeners.clone() {
1372 self.with_element_context(|cx| {
1373 key_listener(event, DispatchPhase::Bubble, cx);
1374 });
1375 if !self.propagate_event {
1376 return;
1377 }
1378 }
1379 }
1380
1381 self.dispatch_keystroke_observers(event, None);
1382 }
1383
1384 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1385 pub fn has_pending_keystrokes(&self) -> bool {
1386 self.window
1387 .rendered_frame
1388 .dispatch_tree
1389 .has_pending_keystrokes()
1390 }
1391
1392 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1393 let node_id = self
1394 .window
1395 .focus
1396 .and_then(|focus_id| {
1397 self.window
1398 .rendered_frame
1399 .dispatch_tree
1400 .focusable_node_id(focus_id)
1401 })
1402 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1403
1404 if self.window.focus != currently_pending.focus {
1405 return;
1406 }
1407
1408 let input = currently_pending.input();
1409
1410 self.propagate_event = true;
1411 for binding in currently_pending.bindings {
1412 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1413 if !self.propagate_event {
1414 return;
1415 }
1416 }
1417
1418 if !input.is_empty() {
1419 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1420 input_handler.flush_pending_input(&input, self);
1421 self.window.platform_window.set_input_handler(input_handler)
1422 }
1423 }
1424 }
1425
1426 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1427 let dispatch_path = self
1428 .window
1429 .rendered_frame
1430 .dispatch_tree
1431 .dispatch_path(node_id);
1432
1433 // Capture phase
1434 for node_id in &dispatch_path {
1435 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1436 for DispatchActionListener {
1437 action_type,
1438 listener,
1439 } in node.action_listeners.clone()
1440 {
1441 let any_action = action.as_any();
1442 if action_type == any_action.type_id() {
1443 self.with_element_context(|cx| {
1444 listener(any_action, DispatchPhase::Capture, cx);
1445 });
1446
1447 if !self.propagate_event {
1448 return;
1449 }
1450 }
1451 }
1452 }
1453 // Bubble phase
1454 for node_id in dispatch_path.iter().rev() {
1455 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1456 for DispatchActionListener {
1457 action_type,
1458 listener,
1459 } in node.action_listeners.clone()
1460 {
1461 let any_action = action.as_any();
1462 if action_type == any_action.type_id() {
1463 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1464
1465 self.with_element_context(|cx| {
1466 listener(any_action, DispatchPhase::Bubble, cx);
1467 });
1468
1469 if !self.propagate_event {
1470 return;
1471 }
1472 }
1473 }
1474 }
1475 }
1476
1477 /// Register the given handler to be invoked whenever the global of the given type
1478 /// is updated.
1479 pub fn observe_global<G: Global>(
1480 &mut self,
1481 f: impl Fn(&mut WindowContext<'_>) + 'static,
1482 ) -> Subscription {
1483 let window_handle = self.window.handle;
1484 let (subscription, activate) = self.global_observers.insert(
1485 TypeId::of::<G>(),
1486 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1487 );
1488 self.app.defer(move |_| activate());
1489 subscription
1490 }
1491
1492 /// Focus the current window and bring it to the foreground at the platform level.
1493 pub fn activate_window(&self) {
1494 self.window.platform_window.activate();
1495 }
1496
1497 /// Minimize the current window at the platform level.
1498 pub fn minimize_window(&self) {
1499 self.window.platform_window.minimize();
1500 }
1501
1502 /// Toggle full screen status on the current window at the platform level.
1503 pub fn toggle_full_screen(&self) {
1504 self.window.platform_window.toggle_full_screen();
1505 }
1506
1507 /// Present a platform dialog.
1508 /// The provided message will be presented, along with buttons for each answer.
1509 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1510 pub fn prompt(
1511 &self,
1512 level: PromptLevel,
1513 message: &str,
1514 detail: Option<&str>,
1515 answers: &[&str],
1516 ) -> oneshot::Receiver<usize> {
1517 self.window
1518 .platform_window
1519 .prompt(level, message, detail, answers)
1520 }
1521
1522 /// Returns all available actions for the focused element.
1523 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1524 let node_id = self
1525 .window
1526 .focus
1527 .and_then(|focus_id| {
1528 self.window
1529 .rendered_frame
1530 .dispatch_tree
1531 .focusable_node_id(focus_id)
1532 })
1533 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1534
1535 self.window
1536 .rendered_frame
1537 .dispatch_tree
1538 .available_actions(node_id)
1539 }
1540
1541 /// Returns key bindings that invoke the given action on the currently focused element.
1542 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1543 self.window
1544 .rendered_frame
1545 .dispatch_tree
1546 .bindings_for_action(
1547 action,
1548 &self.window.rendered_frame.dispatch_tree.context_stack,
1549 )
1550 }
1551
1552 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1553 pub fn bindings_for_action_in(
1554 &self,
1555 action: &dyn Action,
1556 focus_handle: &FocusHandle,
1557 ) -> Vec<KeyBinding> {
1558 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1559
1560 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1561 return vec![];
1562 };
1563 let context_stack = dispatch_tree
1564 .dispatch_path(node_id)
1565 .into_iter()
1566 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1567 .collect();
1568 dispatch_tree.bindings_for_action(action, &context_stack)
1569 }
1570
1571 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1572 pub fn listener_for<V: Render, E>(
1573 &self,
1574 view: &View<V>,
1575 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1576 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1577 let view = view.downgrade();
1578 move |e: &E, cx: &mut WindowContext| {
1579 view.update(cx, |view, cx| f(view, e, cx)).ok();
1580 }
1581 }
1582
1583 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1584 pub fn handler_for<V: Render>(
1585 &self,
1586 view: &View<V>,
1587 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1588 ) -> impl Fn(&mut WindowContext) {
1589 let view = view.downgrade();
1590 move |cx: &mut WindowContext| {
1591 view.update(cx, |view, cx| f(view, cx)).ok();
1592 }
1593 }
1594
1595 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1596 /// If the callback returns false, the window won't be closed.
1597 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1598 let mut this = self.to_async();
1599 self.window
1600 .platform_window
1601 .on_should_close(Box::new(move || {
1602 this.update(|cx| {
1603 // Ensure that the window is removed from the app if it's been closed
1604 // by always pre-empting the system close event.
1605 if f(cx) {
1606 cx.remove_window();
1607 }
1608 false
1609 })
1610 .unwrap_or(true)
1611 }))
1612 }
1613
1614 pub(crate) fn parent_view_id(&self) -> EntityId {
1615 *self
1616 .window
1617 .next_frame
1618 .view_stack
1619 .last()
1620 .expect("a view should always be on the stack while drawing")
1621 }
1622
1623 /// Register an action listener on the window for the next frame. The type of action
1624 /// is determined by the first parameter of the given listener. When the next frame is rendered
1625 /// the listener will be cleared.
1626 ///
1627 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1628 /// a specific need to register a global listener.
1629 pub fn on_action(
1630 &mut self,
1631 action_type: TypeId,
1632 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1633 ) {
1634 self.window
1635 .next_frame
1636 .dispatch_tree
1637 .on_action(action_type, Rc::new(listener));
1638 }
1639}
1640
1641impl Context for WindowContext<'_> {
1642 type Result<T> = T;
1643
1644 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1645 where
1646 T: 'static,
1647 {
1648 let slot = self.app.entities.reserve();
1649 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1650 self.entities.insert(slot, model)
1651 }
1652
1653 fn update_model<T: 'static, R>(
1654 &mut self,
1655 model: &Model<T>,
1656 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1657 ) -> R {
1658 let mut entity = self.entities.lease(model);
1659 let result = update(
1660 &mut *entity,
1661 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1662 );
1663 self.entities.end_lease(entity);
1664 result
1665 }
1666
1667 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1668 where
1669 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1670 {
1671 if window == self.window.handle {
1672 let root_view = self.window.root_view.clone().unwrap();
1673 Ok(update(root_view, self))
1674 } else {
1675 window.update(self.app, update)
1676 }
1677 }
1678
1679 fn read_model<T, R>(
1680 &self,
1681 handle: &Model<T>,
1682 read: impl FnOnce(&T, &AppContext) -> R,
1683 ) -> Self::Result<R>
1684 where
1685 T: 'static,
1686 {
1687 let entity = self.entities.read(handle);
1688 read(entity, &*self.app)
1689 }
1690
1691 fn read_window<T, R>(
1692 &self,
1693 window: &WindowHandle<T>,
1694 read: impl FnOnce(View<T>, &AppContext) -> R,
1695 ) -> Result<R>
1696 where
1697 T: 'static,
1698 {
1699 if window.any_handle == self.window.handle {
1700 let root_view = self
1701 .window
1702 .root_view
1703 .clone()
1704 .unwrap()
1705 .downcast::<T>()
1706 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1707 Ok(read(root_view, self))
1708 } else {
1709 self.app.read_window(window, read)
1710 }
1711 }
1712}
1713
1714impl VisualContext for WindowContext<'_> {
1715 fn new_view<V>(
1716 &mut self,
1717 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1718 ) -> Self::Result<View<V>>
1719 where
1720 V: 'static + Render,
1721 {
1722 let slot = self.app.entities.reserve();
1723 let view = View {
1724 model: slot.clone(),
1725 };
1726 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1727 let entity = build_view_state(&mut cx);
1728 cx.entities.insert(slot, entity);
1729
1730 cx.new_view_observers
1731 .clone()
1732 .retain(&TypeId::of::<V>(), |observer| {
1733 let any_view = AnyView::from(view.clone());
1734 (observer)(any_view, self);
1735 true
1736 });
1737
1738 view
1739 }
1740
1741 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1742 fn update_view<T: 'static, R>(
1743 &mut self,
1744 view: &View<T>,
1745 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1746 ) -> Self::Result<R> {
1747 let mut lease = self.app.entities.lease(&view.model);
1748 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1749 let result = update(&mut *lease, &mut cx);
1750 cx.app.entities.end_lease(lease);
1751 result
1752 }
1753
1754 fn replace_root_view<V>(
1755 &mut self,
1756 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1757 ) -> Self::Result<View<V>>
1758 where
1759 V: 'static + Render,
1760 {
1761 let view = self.new_view(build_view);
1762 self.window.root_view = Some(view.clone().into());
1763 self.refresh();
1764 view
1765 }
1766
1767 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1768 self.update_view(view, |view, cx| {
1769 view.focus_handle(cx).clone().focus(cx);
1770 })
1771 }
1772
1773 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1774 where
1775 V: ManagedView,
1776 {
1777 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1778 }
1779}
1780
1781impl<'a> std::ops::Deref for WindowContext<'a> {
1782 type Target = AppContext;
1783
1784 fn deref(&self) -> &Self::Target {
1785 self.app
1786 }
1787}
1788
1789impl<'a> std::ops::DerefMut for WindowContext<'a> {
1790 fn deref_mut(&mut self) -> &mut Self::Target {
1791 self.app
1792 }
1793}
1794
1795impl<'a> Borrow<AppContext> for WindowContext<'a> {
1796 fn borrow(&self) -> &AppContext {
1797 self.app
1798 }
1799}
1800
1801impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1802 fn borrow_mut(&mut self) -> &mut AppContext {
1803 self.app
1804 }
1805}
1806
1807/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1808pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1809 #[doc(hidden)]
1810 fn app_mut(&mut self) -> &mut AppContext {
1811 self.borrow_mut()
1812 }
1813
1814 #[doc(hidden)]
1815 fn app(&self) -> &AppContext {
1816 self.borrow()
1817 }
1818
1819 #[doc(hidden)]
1820 fn window(&self) -> &Window {
1821 self.borrow()
1822 }
1823
1824 #[doc(hidden)]
1825 fn window_mut(&mut self) -> &mut Window {
1826 self.borrow_mut()
1827 }
1828}
1829
1830impl Borrow<Window> for WindowContext<'_> {
1831 fn borrow(&self) -> &Window {
1832 self.window
1833 }
1834}
1835
1836impl BorrowMut<Window> for WindowContext<'_> {
1837 fn borrow_mut(&mut self) -> &mut Window {
1838 self.window
1839 }
1840}
1841
1842impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1843
1844/// Provides access to application state that is specialized for a particular [`View`].
1845/// Allows you to interact with focus, emit events, etc.
1846/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1847/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1848pub struct ViewContext<'a, V> {
1849 window_cx: WindowContext<'a>,
1850 view: &'a View<V>,
1851}
1852
1853impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1854 fn borrow(&self) -> &AppContext {
1855 &*self.window_cx.app
1856 }
1857}
1858
1859impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1860 fn borrow_mut(&mut self) -> &mut AppContext {
1861 &mut *self.window_cx.app
1862 }
1863}
1864
1865impl<V> Borrow<Window> for ViewContext<'_, V> {
1866 fn borrow(&self) -> &Window {
1867 &*self.window_cx.window
1868 }
1869}
1870
1871impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1872 fn borrow_mut(&mut self) -> &mut Window {
1873 &mut *self.window_cx.window
1874 }
1875}
1876
1877impl<'a, V: 'static> ViewContext<'a, V> {
1878 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1879 Self {
1880 window_cx: WindowContext::new(app, window),
1881 view,
1882 }
1883 }
1884
1885 /// Get the entity_id of this view.
1886 pub fn entity_id(&self) -> EntityId {
1887 self.view.entity_id()
1888 }
1889
1890 /// Get the view pointer underlying this context.
1891 pub fn view(&self) -> &View<V> {
1892 self.view
1893 }
1894
1895 /// Get the model underlying this view.
1896 pub fn model(&self) -> &Model<V> {
1897 &self.view.model
1898 }
1899
1900 /// Access the underlying window context.
1901 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1902 &mut self.window_cx
1903 }
1904
1905 /// Sets a given callback to be run on the next frame.
1906 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1907 where
1908 V: 'static,
1909 {
1910 let view = self.view().clone();
1911 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1912 }
1913
1914 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1915 /// that are currently on the stack to be returned to the app.
1916 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1917 let view = self.view().downgrade();
1918 self.window_cx.defer(move |cx| {
1919 view.update(cx, f).ok();
1920 });
1921 }
1922
1923 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1924 pub fn observe<V2, E>(
1925 &mut self,
1926 entity: &E,
1927 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1928 ) -> Subscription
1929 where
1930 V2: 'static,
1931 V: 'static,
1932 E: Entity<V2>,
1933 {
1934 let view = self.view().downgrade();
1935 let entity_id = entity.entity_id();
1936 let entity = entity.downgrade();
1937 let window_handle = self.window.handle;
1938 let (subscription, activate) = self.app.observers.insert(
1939 entity_id,
1940 Box::new(move |cx| {
1941 window_handle
1942 .update(cx, |_, cx| {
1943 if let Some(handle) = E::upgrade_from(&entity) {
1944 view.update(cx, |this, cx| on_notify(this, handle, cx))
1945 .is_ok()
1946 } else {
1947 false
1948 }
1949 })
1950 .unwrap_or(false)
1951 }),
1952 );
1953 self.app.defer(move |_| activate());
1954 subscription
1955 }
1956
1957 /// Subscribe to events emitted by another model or view.
1958 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1959 /// 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.
1960 pub fn subscribe<V2, E, Evt>(
1961 &mut self,
1962 entity: &E,
1963 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1964 ) -> Subscription
1965 where
1966 V2: EventEmitter<Evt>,
1967 E: Entity<V2>,
1968 Evt: 'static,
1969 {
1970 let view = self.view().downgrade();
1971 let entity_id = entity.entity_id();
1972 let handle = entity.downgrade();
1973 let window_handle = self.window.handle;
1974 let (subscription, activate) = self.app.event_listeners.insert(
1975 entity_id,
1976 (
1977 TypeId::of::<Evt>(),
1978 Box::new(move |event, cx| {
1979 window_handle
1980 .update(cx, |_, cx| {
1981 if let Some(handle) = E::upgrade_from(&handle) {
1982 let event = event.downcast_ref().expect("invalid event type");
1983 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1984 .is_ok()
1985 } else {
1986 false
1987 }
1988 })
1989 .unwrap_or(false)
1990 }),
1991 ),
1992 );
1993 self.app.defer(move |_| activate());
1994 subscription
1995 }
1996
1997 /// Register a callback to be invoked when the view is released.
1998 ///
1999 /// The callback receives a handle to the view's window. This handle may be
2000 /// invalid, if the window was closed before the view was released.
2001 pub fn on_release(
2002 &mut self,
2003 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2004 ) -> Subscription {
2005 let window_handle = self.window.handle;
2006 let (subscription, activate) = self.app.release_listeners.insert(
2007 self.view.model.entity_id,
2008 Box::new(move |this, cx| {
2009 let this = this.downcast_mut().expect("invalid entity type");
2010 on_release(this, window_handle, cx)
2011 }),
2012 );
2013 activate();
2014 subscription
2015 }
2016
2017 /// Register a callback to be invoked when the given Model or View is released.
2018 pub fn observe_release<V2, E>(
2019 &mut self,
2020 entity: &E,
2021 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2022 ) -> Subscription
2023 where
2024 V: 'static,
2025 V2: 'static,
2026 E: Entity<V2>,
2027 {
2028 let view = self.view().downgrade();
2029 let entity_id = entity.entity_id();
2030 let window_handle = self.window.handle;
2031 let (subscription, activate) = self.app.release_listeners.insert(
2032 entity_id,
2033 Box::new(move |entity, cx| {
2034 let entity = entity.downcast_mut().expect("invalid entity type");
2035 let _ = window_handle.update(cx, |_, cx| {
2036 view.update(cx, |this, cx| on_release(this, entity, cx))
2037 });
2038 }),
2039 );
2040 activate();
2041 subscription
2042 }
2043
2044 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2045 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2046 pub fn notify(&mut self) {
2047 for view_id in self
2048 .window
2049 .rendered_frame
2050 .dispatch_tree
2051 .view_path(self.view.entity_id())
2052 .into_iter()
2053 .rev()
2054 {
2055 if !self.window.dirty_views.insert(view_id) {
2056 break;
2057 }
2058 }
2059
2060 if !self.window.drawing {
2061 self.window_cx.window.dirty = true;
2062 self.window_cx.app.push_effect(Effect::Notify {
2063 emitter: self.view.model.entity_id,
2064 });
2065 }
2066 }
2067
2068 /// Register a callback to be invoked when the window is resized.
2069 pub fn observe_window_bounds(
2070 &mut self,
2071 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2072 ) -> Subscription {
2073 let view = self.view.downgrade();
2074 let (subscription, activate) = self.window.bounds_observers.insert(
2075 (),
2076 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2077 );
2078 activate();
2079 subscription
2080 }
2081
2082 /// Register a callback to be invoked when the window is activated or deactivated.
2083 pub fn observe_window_activation(
2084 &mut self,
2085 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2086 ) -> Subscription {
2087 let view = self.view.downgrade();
2088 let (subscription, activate) = self.window.activation_observers.insert(
2089 (),
2090 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2091 );
2092 activate();
2093 subscription
2094 }
2095
2096 /// Registers a callback to be invoked when the window appearance changes.
2097 pub fn observe_window_appearance(
2098 &mut self,
2099 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2100 ) -> Subscription {
2101 let view = self.view.downgrade();
2102 let (subscription, activate) = self.window.appearance_observers.insert(
2103 (),
2104 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2105 );
2106 activate();
2107 subscription
2108 }
2109
2110 /// Register a listener to be called when the given focus handle receives focus.
2111 /// Returns a subscription and persists until the subscription is dropped.
2112 pub fn on_focus(
2113 &mut self,
2114 handle: &FocusHandle,
2115 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2116 ) -> Subscription {
2117 let view = self.view.downgrade();
2118 let focus_id = handle.id;
2119 let (subscription, activate) = self.window.focus_listeners.insert(
2120 (),
2121 Box::new(move |event, cx| {
2122 view.update(cx, |view, cx| {
2123 if event.previous_focus_path.last() != Some(&focus_id)
2124 && event.current_focus_path.last() == Some(&focus_id)
2125 {
2126 listener(view, cx)
2127 }
2128 })
2129 .is_ok()
2130 }),
2131 );
2132 self.app.defer(move |_| activate());
2133 subscription
2134 }
2135
2136 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2137 /// Returns a subscription and persists until the subscription is dropped.
2138 pub fn on_focus_in(
2139 &mut self,
2140 handle: &FocusHandle,
2141 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2142 ) -> Subscription {
2143 let view = self.view.downgrade();
2144 let focus_id = handle.id;
2145 let (subscription, activate) = self.window.focus_listeners.insert(
2146 (),
2147 Box::new(move |event, cx| {
2148 view.update(cx, |view, cx| {
2149 if !event.previous_focus_path.contains(&focus_id)
2150 && event.current_focus_path.contains(&focus_id)
2151 {
2152 listener(view, cx)
2153 }
2154 })
2155 .is_ok()
2156 }),
2157 );
2158 self.app.defer(move |_| activate());
2159 subscription
2160 }
2161
2162 /// Register a listener to be called when the given focus handle loses focus.
2163 /// Returns a subscription and persists until the subscription is dropped.
2164 pub fn on_blur(
2165 &mut self,
2166 handle: &FocusHandle,
2167 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2168 ) -> Subscription {
2169 let view = self.view.downgrade();
2170 let focus_id = handle.id;
2171 let (subscription, activate) = self.window.focus_listeners.insert(
2172 (),
2173 Box::new(move |event, cx| {
2174 view.update(cx, |view, cx| {
2175 if event.previous_focus_path.last() == Some(&focus_id)
2176 && event.current_focus_path.last() != Some(&focus_id)
2177 {
2178 listener(view, cx)
2179 }
2180 })
2181 .is_ok()
2182 }),
2183 );
2184 self.app.defer(move |_| activate());
2185 subscription
2186 }
2187
2188 /// Register a listener to be called when nothing in the window has focus.
2189 /// This typically happens when the node that was focused is removed from the tree,
2190 /// and this callback lets you chose a default place to restore the users focus.
2191 /// Returns a subscription and persists until the subscription is dropped.
2192 pub fn on_focus_lost(
2193 &mut self,
2194 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2195 ) -> Subscription {
2196 let view = self.view.downgrade();
2197 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2198 (),
2199 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2200 );
2201 activate();
2202 subscription
2203 }
2204
2205 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2206 /// Returns a subscription and persists until the subscription is dropped.
2207 pub fn on_focus_out(
2208 &mut self,
2209 handle: &FocusHandle,
2210 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2211 ) -> Subscription {
2212 let view = self.view.downgrade();
2213 let focus_id = handle.id;
2214 let (subscription, activate) = self.window.focus_listeners.insert(
2215 (),
2216 Box::new(move |event, cx| {
2217 view.update(cx, |view, cx| {
2218 if event.previous_focus_path.contains(&focus_id)
2219 && !event.current_focus_path.contains(&focus_id)
2220 {
2221 listener(view, cx)
2222 }
2223 })
2224 .is_ok()
2225 }),
2226 );
2227 self.app.defer(move |_| activate());
2228 subscription
2229 }
2230
2231 /// Schedule a future to be run asynchronously.
2232 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2233 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2234 /// The returned future will be polled on the main thread.
2235 pub fn spawn<Fut, R>(
2236 &mut self,
2237 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2238 ) -> Task<R>
2239 where
2240 R: 'static,
2241 Fut: Future<Output = R> + 'static,
2242 {
2243 let view = self.view().downgrade();
2244 self.window_cx.spawn(|cx| f(view, cx))
2245 }
2246
2247 /// Updates the global state of the given type.
2248 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2249 where
2250 G: Global,
2251 {
2252 let mut global = self.app.lease_global::<G>();
2253 let result = f(&mut global, self);
2254 self.app.end_global_lease(global);
2255 result
2256 }
2257
2258 /// Register a callback to be invoked when the given global state changes.
2259 pub fn observe_global<G: Global>(
2260 &mut self,
2261 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2262 ) -> Subscription {
2263 let window_handle = self.window.handle;
2264 let view = self.view().downgrade();
2265 let (subscription, activate) = self.global_observers.insert(
2266 TypeId::of::<G>(),
2267 Box::new(move |cx| {
2268 window_handle
2269 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2270 .unwrap_or(false)
2271 }),
2272 );
2273 self.app.defer(move |_| activate());
2274 subscription
2275 }
2276
2277 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2278 pub fn on_action(
2279 &mut self,
2280 action_type: TypeId,
2281 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2282 ) {
2283 let handle = self.view().clone();
2284 self.window_cx
2285 .on_action(action_type, move |action, phase, cx| {
2286 handle.update(cx, |view, cx| {
2287 listener(view, action, phase, cx);
2288 })
2289 });
2290 }
2291
2292 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2293 pub fn emit<Evt>(&mut self, event: Evt)
2294 where
2295 Evt: 'static,
2296 V: EventEmitter<Evt>,
2297 {
2298 let emitter = self.view.model.entity_id;
2299 self.app.push_effect(Effect::Emit {
2300 emitter,
2301 event_type: TypeId::of::<Evt>(),
2302 event: Box::new(event),
2303 });
2304 }
2305
2306 /// Move focus to the current view, assuming it implements [`FocusableView`].
2307 pub fn focus_self(&mut self)
2308 where
2309 V: FocusableView,
2310 {
2311 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2312 }
2313
2314 /// Convenience method for accessing view state in an event callback.
2315 ///
2316 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2317 /// but it's often useful to be able to access view state in these
2318 /// callbacks. This method provides a convenient way to do so.
2319 pub fn listener<E>(
2320 &self,
2321 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2322 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2323 let view = self.view().downgrade();
2324 move |e: &E, cx: &mut WindowContext| {
2325 view.update(cx, |view, cx| f(view, e, cx)).ok();
2326 }
2327 }
2328}
2329
2330impl<V> Context for ViewContext<'_, V> {
2331 type Result<U> = U;
2332
2333 fn new_model<T: 'static>(
2334 &mut self,
2335 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2336 ) -> Model<T> {
2337 self.window_cx.new_model(build_model)
2338 }
2339
2340 fn update_model<T: 'static, R>(
2341 &mut self,
2342 model: &Model<T>,
2343 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2344 ) -> R {
2345 self.window_cx.update_model(model, update)
2346 }
2347
2348 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2349 where
2350 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2351 {
2352 self.window_cx.update_window(window, update)
2353 }
2354
2355 fn read_model<T, R>(
2356 &self,
2357 handle: &Model<T>,
2358 read: impl FnOnce(&T, &AppContext) -> R,
2359 ) -> Self::Result<R>
2360 where
2361 T: 'static,
2362 {
2363 self.window_cx.read_model(handle, read)
2364 }
2365
2366 fn read_window<T, R>(
2367 &self,
2368 window: &WindowHandle<T>,
2369 read: impl FnOnce(View<T>, &AppContext) -> R,
2370 ) -> Result<R>
2371 where
2372 T: 'static,
2373 {
2374 self.window_cx.read_window(window, read)
2375 }
2376}
2377
2378impl<V: 'static> VisualContext for ViewContext<'_, V> {
2379 fn new_view<W: Render + 'static>(
2380 &mut self,
2381 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2382 ) -> Self::Result<View<W>> {
2383 self.window_cx.new_view(build_view_state)
2384 }
2385
2386 fn update_view<V2: 'static, R>(
2387 &mut self,
2388 view: &View<V2>,
2389 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2390 ) -> Self::Result<R> {
2391 self.window_cx.update_view(view, update)
2392 }
2393
2394 fn replace_root_view<W>(
2395 &mut self,
2396 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2397 ) -> Self::Result<View<W>>
2398 where
2399 W: 'static + Render,
2400 {
2401 self.window_cx.replace_root_view(build_view)
2402 }
2403
2404 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2405 self.window_cx.focus_view(view)
2406 }
2407
2408 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2409 self.window_cx.dismiss_view(view)
2410 }
2411}
2412
2413impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2414 type Target = WindowContext<'a>;
2415
2416 fn deref(&self) -> &Self::Target {
2417 &self.window_cx
2418 }
2419}
2420
2421impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2422 fn deref_mut(&mut self) -> &mut Self::Target {
2423 &mut self.window_cx
2424 }
2425}
2426
2427// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2428slotmap::new_key_type! {
2429 /// A unique identifier for a window.
2430 pub struct WindowId;
2431}
2432
2433impl WindowId {
2434 /// Converts this window ID to a `u64`.
2435 pub fn as_u64(&self) -> u64 {
2436 self.0.as_ffi()
2437 }
2438}
2439
2440/// A handle to a window with a specific root view type.
2441/// Note that this does not keep the window alive on its own.
2442#[derive(Deref, DerefMut)]
2443pub struct WindowHandle<V> {
2444 #[deref]
2445 #[deref_mut]
2446 pub(crate) any_handle: AnyWindowHandle,
2447 state_type: PhantomData<V>,
2448}
2449
2450impl<V: 'static + Render> WindowHandle<V> {
2451 /// Creates a new handle from a window ID.
2452 /// This does not check if the root type of the window is `V`.
2453 pub fn new(id: WindowId) -> Self {
2454 WindowHandle {
2455 any_handle: AnyWindowHandle {
2456 id,
2457 state_type: TypeId::of::<V>(),
2458 },
2459 state_type: PhantomData,
2460 }
2461 }
2462
2463 /// Get the root view out of this window.
2464 ///
2465 /// This will fail if the window is closed or if the root view's type does not match `V`.
2466 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2467 where
2468 C: Context,
2469 {
2470 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2471 root_view
2472 .downcast::<V>()
2473 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2474 }))
2475 }
2476
2477 /// Updates the root view of this window.
2478 ///
2479 /// This will fail if the window has been closed or if the root view's type does not match
2480 pub fn update<C, R>(
2481 &self,
2482 cx: &mut C,
2483 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2484 ) -> Result<R>
2485 where
2486 C: Context,
2487 {
2488 cx.update_window(self.any_handle, |root_view, cx| {
2489 let view = root_view
2490 .downcast::<V>()
2491 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2492 Ok(cx.update_view(&view, update))
2493 })?
2494 }
2495
2496 /// Read the root view out of this window.
2497 ///
2498 /// This will fail if the window is closed or if the root view's type does not match `V`.
2499 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2500 let x = cx
2501 .windows
2502 .get(self.id)
2503 .and_then(|window| {
2504 window
2505 .as_ref()
2506 .and_then(|window| window.root_view.clone())
2507 .map(|root_view| root_view.downcast::<V>())
2508 })
2509 .ok_or_else(|| anyhow!("window not found"))?
2510 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2511
2512 Ok(x.read(cx))
2513 }
2514
2515 /// Read the root view out of this window, with a callback
2516 ///
2517 /// This will fail if the window is closed or if the root view's type does not match `V`.
2518 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2519 where
2520 C: Context,
2521 {
2522 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2523 }
2524
2525 /// Read the root view pointer off of this window.
2526 ///
2527 /// This will fail if the window is closed or if the root view's type does not match `V`.
2528 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2529 where
2530 C: Context,
2531 {
2532 cx.read_window(self, |root_view, _cx| root_view.clone())
2533 }
2534
2535 /// Check if this window is 'active'.
2536 ///
2537 /// Will return `None` if the window is closed.
2538 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2539 cx.windows
2540 .get(self.id)
2541 .and_then(|window| window.as_ref().map(|window| window.active))
2542 }
2543}
2544
2545impl<V> Copy for WindowHandle<V> {}
2546
2547impl<V> Clone for WindowHandle<V> {
2548 fn clone(&self) -> Self {
2549 *self
2550 }
2551}
2552
2553impl<V> PartialEq for WindowHandle<V> {
2554 fn eq(&self, other: &Self) -> bool {
2555 self.any_handle == other.any_handle
2556 }
2557}
2558
2559impl<V> Eq for WindowHandle<V> {}
2560
2561impl<V> Hash for WindowHandle<V> {
2562 fn hash<H: Hasher>(&self, state: &mut H) {
2563 self.any_handle.hash(state);
2564 }
2565}
2566
2567impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2568 fn from(val: WindowHandle<V>) -> Self {
2569 val.any_handle
2570 }
2571}
2572
2573/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2574#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2575pub struct AnyWindowHandle {
2576 pub(crate) id: WindowId,
2577 state_type: TypeId,
2578}
2579
2580impl AnyWindowHandle {
2581 /// Get the ID of this window.
2582 pub fn window_id(&self) -> WindowId {
2583 self.id
2584 }
2585
2586 /// Attempt to convert this handle to a window handle with a specific root view type.
2587 /// If the types do not match, this will return `None`.
2588 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2589 if TypeId::of::<T>() == self.state_type {
2590 Some(WindowHandle {
2591 any_handle: *self,
2592 state_type: PhantomData,
2593 })
2594 } else {
2595 None
2596 }
2597 }
2598
2599 /// Updates the state of the root view of this window.
2600 ///
2601 /// This will fail if the window has been closed.
2602 pub fn update<C, R>(
2603 self,
2604 cx: &mut C,
2605 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2606 ) -> Result<R>
2607 where
2608 C: Context,
2609 {
2610 cx.update_window(self, update)
2611 }
2612
2613 /// Read the state of the root view of this window.
2614 ///
2615 /// This will fail if the window has been closed.
2616 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2617 where
2618 C: Context,
2619 T: 'static,
2620 {
2621 let view = self
2622 .downcast::<T>()
2623 .context("the type of the window's root view has changed")?;
2624
2625 cx.read_window(&view, read)
2626 }
2627}
2628
2629/// An identifier for an [`Element`](crate::Element).
2630///
2631/// Can be constructed with a string, a number, or both, as well
2632/// as other internal representations.
2633#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2634pub enum ElementId {
2635 /// The ID of a View element
2636 View(EntityId),
2637 /// An integer ID.
2638 Integer(usize),
2639 /// A string based ID.
2640 Name(SharedString),
2641 /// An ID that's equated with a focus handle.
2642 FocusHandle(FocusId),
2643 /// A combination of a name and an integer.
2644 NamedInteger(SharedString, usize),
2645}
2646
2647impl Display for ElementId {
2648 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2649 match self {
2650 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2651 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2652 ElementId::Name(name) => write!(f, "{}", name)?,
2653 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2654 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2655 }
2656
2657 Ok(())
2658 }
2659}
2660
2661impl ElementId {
2662 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2663 ElementId::View(entity_id)
2664 }
2665}
2666
2667impl TryInto<SharedString> for ElementId {
2668 type Error = anyhow::Error;
2669
2670 fn try_into(self) -> anyhow::Result<SharedString> {
2671 if let ElementId::Name(name) = self {
2672 Ok(name)
2673 } else {
2674 Err(anyhow!("element id is not string"))
2675 }
2676 }
2677}
2678
2679impl From<usize> for ElementId {
2680 fn from(id: usize) -> Self {
2681 ElementId::Integer(id)
2682 }
2683}
2684
2685impl From<i32> for ElementId {
2686 fn from(id: i32) -> Self {
2687 Self::Integer(id as usize)
2688 }
2689}
2690
2691impl From<SharedString> for ElementId {
2692 fn from(name: SharedString) -> Self {
2693 ElementId::Name(name)
2694 }
2695}
2696
2697impl From<&'static str> for ElementId {
2698 fn from(name: &'static str) -> Self {
2699 ElementId::Name(name.into())
2700 }
2701}
2702
2703impl<'a> From<&'a FocusHandle> for ElementId {
2704 fn from(handle: &'a FocusHandle) -> Self {
2705 ElementId::FocusHandle(handle.id)
2706 }
2707}
2708
2709impl From<(&'static str, EntityId)> for ElementId {
2710 fn from((name, id): (&'static str, EntityId)) -> Self {
2711 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2712 }
2713}
2714
2715impl From<(&'static str, usize)> for ElementId {
2716 fn from((name, id): (&'static str, usize)) -> Self {
2717 ElementId::NamedInteger(name.into(), id)
2718 }
2719}
2720
2721impl From<(&'static str, u64)> for ElementId {
2722 fn from((name, id): (&'static str, u64)) -> Self {
2723 ElementId::NamedInteger(name.into(), id as usize)
2724 }
2725}
2726
2727/// A rectangle to be rendered in the window at the given position and size.
2728/// Passed as an argument [`ElementContext::paint_quad`].
2729#[derive(Clone)]
2730pub struct PaintQuad {
2731 bounds: Bounds<Pixels>,
2732 corner_radii: Corners<Pixels>,
2733 background: Hsla,
2734 border_widths: Edges<Pixels>,
2735 border_color: Hsla,
2736}
2737
2738impl PaintQuad {
2739 /// Sets the corner radii of the quad.
2740 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2741 PaintQuad {
2742 corner_radii: corner_radii.into(),
2743 ..self
2744 }
2745 }
2746
2747 /// Sets the border widths of the quad.
2748 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2749 PaintQuad {
2750 border_widths: border_widths.into(),
2751 ..self
2752 }
2753 }
2754
2755 /// Sets the border color of the quad.
2756 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2757 PaintQuad {
2758 border_color: border_color.into(),
2759 ..self
2760 }
2761 }
2762
2763 /// Sets the background color of the quad.
2764 pub fn background(self, background: impl Into<Hsla>) -> Self {
2765 PaintQuad {
2766 background: background.into(),
2767 ..self
2768 }
2769 }
2770}
2771
2772/// Creates a quad with the given parameters.
2773pub fn quad(
2774 bounds: Bounds<Pixels>,
2775 corner_radii: impl Into<Corners<Pixels>>,
2776 background: impl Into<Hsla>,
2777 border_widths: impl Into<Edges<Pixels>>,
2778 border_color: impl Into<Hsla>,
2779) -> PaintQuad {
2780 PaintQuad {
2781 bounds,
2782 corner_radii: corner_radii.into(),
2783 background: background.into(),
2784 border_widths: border_widths.into(),
2785 border_color: border_color.into(),
2786 }
2787}
2788
2789/// Creates a filled quad with the given bounds and background color.
2790pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2791 PaintQuad {
2792 bounds: bounds.into(),
2793 corner_radii: (0.).into(),
2794 background: background.into(),
2795 border_widths: (0.).into(),
2796 border_color: transparent_black(),
2797 }
2798}
2799
2800/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2801pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2802 PaintQuad {
2803 bounds: bounds.into(),
2804 corner_radii: (0.).into(),
2805 background: transparent_black(),
2806 border_widths: (1.).into(),
2807 border_color: border_color.into(),
2808 }
2809}