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, 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, WindowBounds,
10 WindowOptions,
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
97#[derive(Debug)]
98struct FocusEvent {
99 previous_focus_path: SmallVec<[FocusId; 8]>,
100 current_focus_path: SmallVec<[FocusId; 8]>,
101}
102
103slotmap::new_key_type! {
104 /// A globally unique identifier for a focusable element.
105 pub struct FocusId;
106}
107
108thread_local! {
109 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(4 * 1024 * 1024));
110}
111
112impl FocusId {
113 /// Obtains whether the element associated with this handle is currently focused.
114 pub fn is_focused(&self, cx: &WindowContext) -> bool {
115 cx.window.focus == Some(*self)
116 }
117
118 /// Obtains whether the element associated with this handle contains the focused
119 /// element or is itself focused.
120 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
121 cx.focused()
122 .map_or(false, |focused| self.contains(focused.id, cx))
123 }
124
125 /// Obtains whether the element associated with this handle is contained within the
126 /// focused element or is itself focused.
127 pub fn within_focused(&self, cx: &WindowContext) -> bool {
128 let focused = cx.focused();
129 focused.map_or(false, |focused| focused.id.contains(*self, cx))
130 }
131
132 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
133 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
134 cx.window
135 .rendered_frame
136 .dispatch_tree
137 .focus_contains(*self, other)
138 }
139}
140
141/// A handle which can be used to track and manipulate the focused element in a window.
142pub struct FocusHandle {
143 pub(crate) id: FocusId,
144 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
145}
146
147impl std::fmt::Debug for FocusHandle {
148 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
149 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
150 }
151}
152
153impl FocusHandle {
154 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
155 let id = handles.write().insert(AtomicUsize::new(1));
156 Self {
157 id,
158 handles: handles.clone(),
159 }
160 }
161
162 pub(crate) fn for_id(
163 id: FocusId,
164 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
165 ) -> Option<Self> {
166 let lock = handles.read();
167 let ref_count = lock.get(id)?;
168 if ref_count.load(SeqCst) == 0 {
169 None
170 } else {
171 ref_count.fetch_add(1, SeqCst);
172 Some(Self {
173 id,
174 handles: handles.clone(),
175 })
176 }
177 }
178
179 /// Moves the focus to the element associated with this handle.
180 pub fn focus(&self, cx: &mut WindowContext) {
181 cx.focus(self)
182 }
183
184 /// Obtains whether the element associated with this handle is currently focused.
185 pub fn is_focused(&self, cx: &WindowContext) -> bool {
186 self.id.is_focused(cx)
187 }
188
189 /// Obtains whether the element associated with this handle contains the focused
190 /// element or is itself focused.
191 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
192 self.id.contains_focused(cx)
193 }
194
195 /// Obtains whether the element associated with this handle is contained within the
196 /// focused element or is itself focused.
197 pub fn within_focused(&self, cx: &WindowContext) -> bool {
198 self.id.within_focused(cx)
199 }
200
201 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
202 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
203 self.id.contains(other.id, cx)
204 }
205}
206
207impl Clone for FocusHandle {
208 fn clone(&self) -> Self {
209 Self::for_id(self.id, &self.handles).unwrap()
210 }
211}
212
213impl PartialEq for FocusHandle {
214 fn eq(&self, other: &Self) -> bool {
215 self.id == other.id
216 }
217}
218
219impl Eq for FocusHandle {}
220
221impl Drop for FocusHandle {
222 fn drop(&mut self) {
223 self.handles
224 .read()
225 .get(self.id)
226 .unwrap()
227 .fetch_sub(1, SeqCst);
228 }
229}
230
231/// FocusableView allows users of your view to easily
232/// focus it (using cx.focus_view(view))
233pub trait FocusableView: 'static + Render {
234 /// Returns the focus handle associated with this view.
235 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
236}
237
238/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
239/// where the lifecycle of the view is handled by another view.
240pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
241
242impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
243
244/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
245pub struct DismissEvent;
246
247// Holds the state for a specific window.
248#[doc(hidden)]
249pub struct Window {
250 pub(crate) handle: AnyWindowHandle,
251 pub(crate) removed: bool,
252 pub(crate) platform_window: Box<dyn PlatformWindow>,
253 display_id: DisplayId,
254 sprite_atlas: Arc<dyn PlatformAtlas>,
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 active: bool,
273 pub(crate) dirty: bool,
274 pub(crate) refreshing: bool,
275 pub(crate) drawing: bool,
276 activation_observers: SubscriberSet<(), AnyObserver>,
277 pub(crate) focus: Option<FocusId>,
278 focus_enabled: bool,
279 pending_input: Option<PendingInput>,
280
281 #[cfg(any(test, feature = "test-support"))]
282 pub(crate) focus_invalidated: bool,
283}
284
285#[derive(Default, Debug)]
286struct PendingInput {
287 keystrokes: SmallVec<[Keystroke; 1]>,
288 bindings: SmallVec<[KeyBinding; 1]>,
289 focus: Option<FocusId>,
290 timer: Option<Task<()>>,
291}
292
293impl PendingInput {
294 fn is_noop(&self) -> bool {
295 self.bindings.is_empty() && (self.keystrokes.iter().all(|k| k.ime_key.is_none()))
296 }
297
298 fn input(&self) -> String {
299 self.keystrokes
300 .iter()
301 .flat_map(|k| k.ime_key.clone())
302 .collect::<Vec<String>>()
303 .join("")
304 }
305
306 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
307 if self.keystrokes.is_empty() {
308 return true;
309 }
310 let keystroke = &self.keystrokes[0];
311 for candidate in keystroke.match_candidates() {
312 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
313 return true;
314 }
315 }
316 false
317 }
318}
319
320pub(crate) struct ElementStateBox {
321 pub(crate) inner: Box<dyn Any>,
322 pub(crate) parent_view_id: EntityId,
323 #[cfg(debug_assertions)]
324 pub(crate) type_name: &'static str,
325}
326
327impl Window {
328 pub(crate) fn new(
329 handle: AnyWindowHandle,
330 options: WindowOptions,
331 cx: &mut AppContext,
332 ) -> Self {
333 let platform_window = cx.platform.open_window(handle, options);
334 let display_id = platform_window.display().id();
335 let sprite_atlas = platform_window.sprite_atlas();
336 let mouse_position = platform_window.mouse_position();
337 let modifiers = platform_window.modifiers();
338 let content_size = platform_window.content_size();
339 let scale_factor = platform_window.scale_factor();
340 let bounds = platform_window.bounds();
341
342 platform_window.on_request_frame(Box::new({
343 let mut cx = cx.to_async();
344 move || {
345 measure("frame duration", || {
346 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
347 })
348 }
349 }));
350 platform_window.on_resize(Box::new({
351 let mut cx = cx.to_async();
352 move |_, _| {
353 handle
354 .update(&mut cx, |_, cx| cx.window_bounds_changed())
355 .log_err();
356 }
357 }));
358 platform_window.on_moved(Box::new({
359 let mut cx = cx.to_async();
360 move || {
361 handle
362 .update(&mut cx, |_, cx| cx.window_bounds_changed())
363 .log_err();
364 }
365 }));
366 platform_window.on_active_status_change(Box::new({
367 let mut cx = cx.to_async();
368 move |active| {
369 handle
370 .update(&mut cx, |_, cx| {
371 cx.window.active = active;
372 cx.window
373 .activation_observers
374 .clone()
375 .retain(&(), |callback| callback(cx));
376 })
377 .log_err();
378 }
379 }));
380
381 platform_window.on_input({
382 let mut cx = cx.to_async();
383 Box::new(move |event| {
384 handle
385 .update(&mut cx, |_, cx| cx.dispatch_event(event))
386 .log_err()
387 .unwrap_or(false)
388 })
389 });
390
391 Window {
392 handle,
393 removed: false,
394 platform_window,
395 display_id,
396 sprite_atlas,
397 rem_size: px(16.),
398 viewport_size: content_size,
399 layout_engine: Some(TaffyLayoutEngine::new()),
400 root_view: None,
401 element_id_stack: GlobalElementId::default(),
402 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
403 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
404 dirty_views: FxHashSet::default(),
405 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
406 focus_listeners: SubscriberSet::new(),
407 focus_lost_listeners: SubscriberSet::new(),
408 default_prevented: true,
409 mouse_position,
410 modifiers,
411 scale_factor,
412 bounds,
413 bounds_observers: SubscriberSet::new(),
414 active: false,
415 dirty: false,
416 refreshing: false,
417 drawing: false,
418 activation_observers: SubscriberSet::new(),
419 focus: None,
420 focus_enabled: true,
421 pending_input: None,
422
423 #[cfg(any(test, feature = "test-support"))]
424 focus_invalidated: false,
425 }
426 }
427}
428
429/// Indicates which region of the window is visible. Content falling outside of this mask will not be
430/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
431/// to leave room to support more complex shapes in the future.
432#[derive(Clone, Debug, Default, PartialEq, Eq)]
433#[repr(C)]
434pub struct ContentMask<P: Clone + Default + Debug> {
435 /// The bounds
436 pub bounds: Bounds<P>,
437}
438
439impl ContentMask<Pixels> {
440 /// Scale the content mask's pixel units by the given scaling factor.
441 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
442 ContentMask {
443 bounds: self.bounds.scale(factor),
444 }
445 }
446
447 /// Intersect the content mask with the given content mask.
448 pub fn intersect(&self, other: &Self) -> Self {
449 let bounds = self.bounds.intersect(&other.bounds);
450 ContentMask { bounds }
451 }
452}
453
454/// Provides access to application state in the context of a single window. Derefs
455/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
456/// an [`AppContext`] and call any [`AppContext`] methods.
457pub struct WindowContext<'a> {
458 pub(crate) app: &'a mut AppContext,
459 pub(crate) window: &'a mut Window,
460}
461
462impl<'a> WindowContext<'a> {
463 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
464 Self { app, window }
465 }
466
467 /// Obtain a handle to the window that belongs to this context.
468 pub fn window_handle(&self) -> AnyWindowHandle {
469 self.window.handle
470 }
471
472 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
473 pub fn refresh(&mut self) {
474 if !self.window.drawing {
475 self.window.refreshing = true;
476 self.window.dirty = true;
477 }
478 }
479
480 /// Close this window.
481 pub fn remove_window(&mut self) {
482 self.window.removed = true;
483 }
484
485 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
486 /// for elements rendered within this window.
487 pub fn focus_handle(&mut self) -> FocusHandle {
488 FocusHandle::new(&self.window.focus_handles)
489 }
490
491 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
492 pub fn focused(&self) -> Option<FocusHandle> {
493 self.window
494 .focus
495 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
496 }
497
498 /// Move focus to the element associated with the given [`FocusHandle`].
499 pub fn focus(&mut self, handle: &FocusHandle) {
500 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
501 return;
502 }
503
504 self.window.focus = Some(handle.id);
505 self.window
506 .rendered_frame
507 .dispatch_tree
508 .clear_pending_keystrokes();
509
510 #[cfg(any(test, feature = "test-support"))]
511 {
512 self.window.focus_invalidated = true;
513 }
514
515 self.refresh();
516 }
517
518 /// Remove focus from all elements within this context's window.
519 pub fn blur(&mut self) {
520 if !self.window.focus_enabled {
521 return;
522 }
523
524 self.window.focus = None;
525 self.refresh();
526 }
527
528 /// Blur the window and don't allow anything in it to be focused again.
529 pub fn disable_focus(&mut self) {
530 self.blur();
531 self.window.focus_enabled = false;
532 }
533
534 /// Dispatch the given action on the currently focused element.
535 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
536 let focus_handle = self.focused();
537
538 self.defer(move |cx| {
539 let node_id = focus_handle
540 .and_then(|handle| {
541 cx.window
542 .rendered_frame
543 .dispatch_tree
544 .focusable_node_id(handle.id)
545 })
546 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
547
548 cx.propagate_event = true;
549 cx.dispatch_action_on_node(node_id, action);
550 })
551 }
552
553 pub(crate) fn dispatch_keystroke_observers(
554 &mut self,
555 event: &dyn Any,
556 action: Option<Box<dyn Action>>,
557 ) {
558 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
559 return;
560 };
561
562 self.keystroke_observers
563 .clone()
564 .retain(&(), move |callback| {
565 (callback)(
566 &KeystrokeEvent {
567 keystroke: key_down_event.keystroke.clone(),
568 action: action.as_ref().map(|action| action.boxed_clone()),
569 },
570 self,
571 );
572 true
573 });
574 }
575
576 pub(crate) fn clear_pending_keystrokes(&mut self) {
577 self.window
578 .rendered_frame
579 .dispatch_tree
580 .clear_pending_keystrokes();
581 self.window
582 .next_frame
583 .dispatch_tree
584 .clear_pending_keystrokes();
585 }
586
587 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
588 /// that are currently on the stack to be returned to the app.
589 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
590 let handle = self.window.handle;
591 self.app.defer(move |cx| {
592 handle.update(cx, |_, cx| f(cx)).ok();
593 });
594 }
595
596 /// Subscribe to events emitted by a model or view.
597 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
598 /// 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.
599 pub fn subscribe<Emitter, E, Evt>(
600 &mut self,
601 entity: &E,
602 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
603 ) -> Subscription
604 where
605 Emitter: EventEmitter<Evt>,
606 E: Entity<Emitter>,
607 Evt: 'static,
608 {
609 let entity_id = entity.entity_id();
610 let entity = entity.downgrade();
611 let window_handle = self.window.handle;
612 let (subscription, activate) = self.app.event_listeners.insert(
613 entity_id,
614 (
615 TypeId::of::<Evt>(),
616 Box::new(move |event, cx| {
617 window_handle
618 .update(cx, |_, cx| {
619 if let Some(handle) = E::upgrade_from(&entity) {
620 let event = event.downcast_ref().expect("invalid event type");
621 on_event(handle, event, cx);
622 true
623 } else {
624 false
625 }
626 })
627 .unwrap_or(false)
628 }),
629 ),
630 );
631 self.app.defer(move |_| activate());
632 subscription
633 }
634
635 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
636 /// await points in async code.
637 pub fn to_async(&self) -> AsyncWindowContext {
638 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
639 }
640
641 /// Schedule the given closure to be run directly after the current frame is rendered.
642 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
643 let handle = self.window.handle;
644 let display_id = self.window.display_id;
645
646 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
647 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
648 let (tx, mut rx) = mpsc::unbounded::<()>();
649 self.platform.set_display_link_output_callback(
650 display_id,
651 Box::new(move || _ = tx.unbounded_send(())),
652 );
653
654 let consumer_task = self.app.spawn(|cx| async move {
655 while rx.next().await.is_some() {
656 cx.update(|cx| {
657 for callback in cx
658 .next_frame_callbacks
659 .get_mut(&display_id)
660 .unwrap()
661 .drain(..)
662 .collect::<SmallVec<[_; 32]>>()
663 {
664 callback(cx);
665 }
666 })
667 .ok();
668
669 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
670
671 cx.update(|cx| {
672 if cx.next_frame_callbacks.is_empty() {
673 cx.platform.stop_display_link(display_id);
674 }
675 })
676 .ok();
677 }
678 });
679 e.insert(consumer_task);
680 }
681 debug_assert!(self.app.frame_consumers.is_empty());
682 self.app.frame_consumers = frame_consumers;
683
684 if self.next_frame_callbacks.is_empty() {
685 self.platform.start_display_link(display_id);
686 }
687
688 self.next_frame_callbacks
689 .entry(display_id)
690 .or_default()
691 .push(Box::new(move |cx: &mut AppContext| {
692 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
693 }));
694 }
695
696 /// Spawn the future returned by the given closure on the application thread pool.
697 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
698 /// use within your future.
699 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
700 where
701 R: 'static,
702 Fut: Future<Output = R> + 'static,
703 {
704 self.app
705 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
706 }
707
708 /// Updates the global of the given type. The given closure is given simultaneous mutable
709 /// access both to the global and the context.
710 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
711 where
712 G: 'static,
713 {
714 let mut global = self.app.lease_global::<G>();
715 let result = f(&mut global, self);
716 self.app.end_global_lease(global);
717 result
718 }
719
720 fn window_bounds_changed(&mut self) {
721 self.window.scale_factor = self.window.platform_window.scale_factor();
722 self.window.viewport_size = self.window.platform_window.content_size();
723 self.window.bounds = self.window.platform_window.bounds();
724 self.window.display_id = self.window.platform_window.display().id();
725 self.refresh();
726
727 self.window
728 .bounds_observers
729 .clone()
730 .retain(&(), |callback| callback(self));
731 }
732
733 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
734 pub fn window_bounds(&self) -> WindowBounds {
735 self.window.bounds
736 }
737
738 /// Returns the size of the drawable area within the window.
739 pub fn viewport_size(&self) -> Size<Pixels> {
740 self.window.viewport_size
741 }
742
743 /// Returns whether this window is focused by the operating system (receiving key events).
744 pub fn is_window_active(&self) -> bool {
745 self.window.active
746 }
747
748 /// Toggle zoom on the window.
749 pub fn zoom_window(&self) {
750 self.window.platform_window.zoom();
751 }
752
753 /// Updates the window's title at the platform level.
754 pub fn set_window_title(&mut self, title: &str) {
755 self.window.platform_window.set_title(title);
756 }
757
758 /// Mark the window as dirty at the platform level.
759 pub fn set_window_edited(&mut self, edited: bool) {
760 self.window.platform_window.set_edited(edited);
761 }
762
763 /// Determine the display on which the window is visible.
764 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
765 self.platform
766 .displays()
767 .into_iter()
768 .find(|display| display.id() == self.window.display_id)
769 }
770
771 /// Show the platform character palette.
772 pub fn show_character_palette(&self) {
773 self.window.platform_window.show_character_palette();
774 }
775
776 /// The scale factor of the display associated with the window. For example, it could
777 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
778 /// be rendered as two pixels on screen.
779 pub fn scale_factor(&self) -> f32 {
780 self.window.scale_factor
781 }
782
783 /// The size of an em for the base font of the application. Adjusting this value allows the
784 /// UI to scale, just like zooming a web page.
785 pub fn rem_size(&self) -> Pixels {
786 self.window.rem_size
787 }
788
789 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
790 /// UI to scale, just like zooming a web page.
791 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
792 self.window.rem_size = rem_size.into();
793 }
794
795 /// The line height associated with the current text style.
796 pub fn line_height(&self) -> Pixels {
797 let rem_size = self.rem_size();
798 let text_style = self.text_style();
799 text_style
800 .line_height
801 .to_pixels(text_style.font_size, rem_size)
802 }
803
804 /// Call to prevent the default action of an event. Currently only used to prevent
805 /// parent elements from becoming focused on mouse down.
806 pub fn prevent_default(&mut self) {
807 self.window.default_prevented = true;
808 }
809
810 /// Obtain whether default has been prevented for the event currently being dispatched.
811 pub fn default_prevented(&self) -> bool {
812 self.window.default_prevented
813 }
814
815 /// Determine whether the given action is available along the dispatch path to the currently focused element.
816 pub fn is_action_available(&self, action: &dyn Action) -> bool {
817 let target = self
818 .focused()
819 .and_then(|focused_handle| {
820 self.window
821 .rendered_frame
822 .dispatch_tree
823 .focusable_node_id(focused_handle.id)
824 })
825 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
826 self.window
827 .rendered_frame
828 .dispatch_tree
829 .is_action_available(action, target)
830 }
831
832 /// The position of the mouse relative to the window.
833 pub fn mouse_position(&self) -> Point<Pixels> {
834 self.window.mouse_position
835 }
836
837 /// The current state of the keyboard's modifiers
838 pub fn modifiers(&self) -> Modifiers {
839 self.window.modifiers
840 }
841
842 /// Returns true if there is no opaque layer containing the given point
843 /// on top of the given level. Layers who are extensions of the queried layer
844 /// are not considered to be on top of queried layer.
845 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
846 // Precondition: the depth map is ordered from topmost to bottomost.
847
848 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
849 if layer >= opaque_layer {
850 // The queried layer is either above or is the same as the this opaque layer.
851 // Anything after this point is guaranteed to be below the queried layer.
852 return true;
853 }
854
855 if !bounds.contains(point) {
856 // This opaque layer is above the queried layer but it doesn't contain
857 // the given position, so we can ignore it even if it's above.
858 continue;
859 }
860
861 // At this point, we've established that this opaque layer is on top of the queried layer
862 // and contains the position:
863 // - If the opaque layer is an extension of the queried layer, we don't want
864 // to consider the opaque layer to be on top and so we ignore it.
865 // - Else, we will bail early and say that the queried layer wasn't the top one.
866 let opaque_layer_is_extension_of_queried_layer = opaque_layer.len() >= layer.len()
867 && opaque_layer
868 .iter()
869 .zip(layer.iter())
870 .all(|(a, b)| a.z_index == b.z_index);
871 if !opaque_layer_is_extension_of_queried_layer {
872 return false;
873 }
874 }
875
876 true
877 }
878
879 pub(crate) fn was_top_layer_under_active_drag(
880 &self,
881 point: &Point<Pixels>,
882 layer: &StackingOrder,
883 ) -> bool {
884 // Precondition: the depth map is ordered from topmost to bottomost.
885
886 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
887 if layer >= opaque_layer {
888 // The queried layer is either above or is the same as the this opaque layer.
889 // Anything after this point is guaranteed to be below the queried layer.
890 return true;
891 }
892
893 if !bounds.contains(point) {
894 // This opaque layer is above the queried layer but it doesn't contain
895 // the given position, so we can ignore it even if it's above.
896 continue;
897 }
898
899 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
900 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
901 // looking to see if the queried layer was the topmost underneath the drag layer.
902 if opaque_layer
903 .first()
904 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
905 .unwrap_or(false)
906 {
907 continue;
908 }
909
910 // At this point, we've established that this opaque layer is on top of the queried layer
911 // and contains the position:
912 // - If the opaque layer is an extension of the queried layer, we don't want
913 // to consider the opaque layer to be on top and so we ignore it.
914 // - Else, we will bail early and say that the queried layer wasn't the top one.
915 let opaque_layer_is_extension_of_queried_layer = opaque_layer.len() >= layer.len()
916 && opaque_layer
917 .iter()
918 .zip(layer.iter())
919 .all(|(a, b)| a.z_index == b.z_index);
920 if !opaque_layer_is_extension_of_queried_layer {
921 return false;
922 }
923 }
924
925 true
926 }
927
928 /// Called during painting to get the current stacking order.
929 pub fn stacking_order(&self) -> &StackingOrder {
930 &self.window.next_frame.z_index_stack
931 }
932
933 /// Draw pixels to the display for this window based on the contents of its scene.
934 pub(crate) fn draw(&mut self) {
935 self.window.dirty = false;
936 self.window.drawing = true;
937
938 #[cfg(any(test, feature = "test-support"))]
939 {
940 self.window.focus_invalidated = false;
941 }
942
943 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
944 {
945 let input_handler = self.window.platform_window.take_input_handler();
946 requested_handler.handler = input_handler;
947 }
948
949 let root_view = self.window.root_view.take().unwrap();
950 self.with_element_context(|cx| {
951 cx.with_z_index(0, |cx| {
952 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
953 // We need to use cx.cx here so we can utilize borrow splitting
954 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
955 for action_listener in action_listeners.iter().cloned() {
956 cx.cx.window.next_frame.dispatch_tree.on_action(
957 *action_type,
958 Rc::new(
959 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
960 action_listener(action, phase, cx)
961 },
962 ),
963 )
964 }
965 }
966
967 let available_space = cx.window.viewport_size.map(Into::into);
968 root_view.draw(Point::default(), available_space, cx);
969 })
970 })
971 });
972
973 if let Some(active_drag) = self.app.active_drag.take() {
974 self.with_element_context(|cx| {
975 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
976 let offset = cx.mouse_position() - active_drag.cursor_offset;
977 let available_space =
978 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
979 active_drag.view.draw(offset, available_space, cx);
980 })
981 });
982 self.active_drag = Some(active_drag);
983 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
984 self.with_element_context(|cx| {
985 cx.with_z_index(1, |cx| {
986 let available_space =
987 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
988 tooltip_request.tooltip.view.draw(
989 tooltip_request.tooltip.cursor_offset,
990 available_space,
991 cx,
992 );
993 })
994 });
995 self.window.next_frame.tooltip_request = Some(tooltip_request);
996 }
997 self.window.dirty_views.clear();
998
999 self.window
1000 .next_frame
1001 .dispatch_tree
1002 .preserve_pending_keystrokes(
1003 &mut self.window.rendered_frame.dispatch_tree,
1004 self.window.focus,
1005 );
1006 self.window.next_frame.focus = self.window.focus;
1007 self.window.next_frame.window_active = self.window.active;
1008 self.window.root_view = Some(root_view);
1009
1010 // Set the cursor only if we're the active window.
1011 let cursor_style = self
1012 .window
1013 .next_frame
1014 .requested_cursor_style
1015 .take()
1016 .unwrap_or(CursorStyle::Arrow);
1017 if self.is_window_active() {
1018 self.platform.set_cursor_style(cursor_style);
1019 }
1020
1021 // Register requested input handler with the platform window.
1022 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1023 if let Some(handler) = requested_input.handler.take() {
1024 self.window.platform_window.set_input_handler(handler);
1025 }
1026 }
1027
1028 self.window.layout_engine.as_mut().unwrap().clear();
1029 self.text_system()
1030 .finish_frame(&self.window.next_frame.reused_views);
1031 self.window
1032 .next_frame
1033 .finish(&mut self.window.rendered_frame);
1034 ELEMENT_ARENA.with_borrow_mut(|element_arena| element_arena.clear());
1035
1036 let previous_focus_path = self.window.rendered_frame.focus_path();
1037 let previous_window_active = self.window.rendered_frame.window_active;
1038 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1039 self.window.next_frame.clear();
1040 let current_focus_path = self.window.rendered_frame.focus_path();
1041 let current_window_active = self.window.rendered_frame.window_active;
1042
1043 if previous_focus_path != current_focus_path
1044 || previous_window_active != current_window_active
1045 {
1046 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1047 self.window
1048 .focus_lost_listeners
1049 .clone()
1050 .retain(&(), |listener| listener(self));
1051 }
1052
1053 let event = FocusEvent {
1054 previous_focus_path: if previous_window_active {
1055 previous_focus_path
1056 } else {
1057 Default::default()
1058 },
1059 current_focus_path: if current_window_active {
1060 current_focus_path
1061 } else {
1062 Default::default()
1063 },
1064 };
1065 self.window
1066 .focus_listeners
1067 .clone()
1068 .retain(&(), |listener| listener(&event, self));
1069 }
1070
1071 self.window
1072 .platform_window
1073 .draw(&self.window.rendered_frame.scene);
1074 self.window.refreshing = false;
1075 self.window.drawing = false;
1076 }
1077
1078 /// Dispatch a mouse or keyboard event on the window.
1079 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1080 // Handlers may set this to false by calling `stop_propagation`.
1081 self.app.propagate_event = true;
1082 // Handlers may set this to true by calling `prevent_default`.
1083 self.window.default_prevented = false;
1084
1085 let event = match event {
1086 // Track the mouse position with our own state, since accessing the platform
1087 // API for the mouse position can only occur on the main thread.
1088 PlatformInput::MouseMove(mouse_move) => {
1089 self.window.mouse_position = mouse_move.position;
1090 self.window.modifiers = mouse_move.modifiers;
1091 PlatformInput::MouseMove(mouse_move)
1092 }
1093 PlatformInput::MouseDown(mouse_down) => {
1094 self.window.mouse_position = mouse_down.position;
1095 self.window.modifiers = mouse_down.modifiers;
1096 PlatformInput::MouseDown(mouse_down)
1097 }
1098 PlatformInput::MouseUp(mouse_up) => {
1099 self.window.mouse_position = mouse_up.position;
1100 self.window.modifiers = mouse_up.modifiers;
1101 PlatformInput::MouseUp(mouse_up)
1102 }
1103 PlatformInput::MouseExited(mouse_exited) => {
1104 self.window.modifiers = mouse_exited.modifiers;
1105 PlatformInput::MouseExited(mouse_exited)
1106 }
1107 PlatformInput::ModifiersChanged(modifiers_changed) => {
1108 self.window.modifiers = modifiers_changed.modifiers;
1109 PlatformInput::ModifiersChanged(modifiers_changed)
1110 }
1111 PlatformInput::ScrollWheel(scroll_wheel) => {
1112 self.window.mouse_position = scroll_wheel.position;
1113 self.window.modifiers = scroll_wheel.modifiers;
1114 PlatformInput::ScrollWheel(scroll_wheel)
1115 }
1116 // Translate dragging and dropping of external files from the operating system
1117 // to internal drag and drop events.
1118 PlatformInput::FileDrop(file_drop) => match file_drop {
1119 FileDropEvent::Entered { position, paths } => {
1120 self.window.mouse_position = position;
1121 if self.active_drag.is_none() {
1122 self.active_drag = Some(AnyDrag {
1123 value: Box::new(paths.clone()),
1124 view: self.new_view(|_| paths).into(),
1125 cursor_offset: position,
1126 });
1127 }
1128 PlatformInput::MouseMove(MouseMoveEvent {
1129 position,
1130 pressed_button: Some(MouseButton::Left),
1131 modifiers: Modifiers::default(),
1132 })
1133 }
1134 FileDropEvent::Pending { position } => {
1135 self.window.mouse_position = position;
1136 PlatformInput::MouseMove(MouseMoveEvent {
1137 position,
1138 pressed_button: Some(MouseButton::Left),
1139 modifiers: Modifiers::default(),
1140 })
1141 }
1142 FileDropEvent::Submit { position } => {
1143 self.activate(true);
1144 self.window.mouse_position = position;
1145 PlatformInput::MouseUp(MouseUpEvent {
1146 button: MouseButton::Left,
1147 position,
1148 modifiers: Modifiers::default(),
1149 click_count: 1,
1150 })
1151 }
1152 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1153 button: MouseButton::Left,
1154 position: Point::default(),
1155 modifiers: Modifiers::default(),
1156 click_count: 1,
1157 }),
1158 },
1159 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1160 };
1161
1162 if let Some(any_mouse_event) = event.mouse_event() {
1163 self.dispatch_mouse_event(any_mouse_event);
1164 } else if let Some(any_key_event) = event.keyboard_event() {
1165 self.dispatch_key_event(any_key_event);
1166 }
1167
1168 !self.app.propagate_event
1169 }
1170
1171 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1172 if let Some(mut handlers) = self
1173 .window
1174 .rendered_frame
1175 .mouse_listeners
1176 .remove(&event.type_id())
1177 {
1178 // Because handlers may add other handlers, we sort every time.
1179 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1180
1181 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1182 // special purposes, such as detecting events outside of a given Bounds.
1183 for (_, _, handler) in &mut handlers {
1184 self.with_element_context(|cx| {
1185 handler(event, DispatchPhase::Capture, cx);
1186 });
1187 if !self.app.propagate_event {
1188 break;
1189 }
1190 }
1191
1192 // Bubble phase, where most normal handlers do their work.
1193 if self.app.propagate_event {
1194 for (_, _, handler) in handlers.iter_mut().rev() {
1195 self.with_element_context(|cx| {
1196 handler(event, DispatchPhase::Bubble, cx);
1197 });
1198 if !self.app.propagate_event {
1199 break;
1200 }
1201 }
1202 }
1203
1204 self.window
1205 .rendered_frame
1206 .mouse_listeners
1207 .insert(event.type_id(), handlers);
1208 }
1209
1210 if self.app.propagate_event && self.has_active_drag() {
1211 if event.is::<MouseMoveEvent>() {
1212 // If this was a mouse move event, redraw the window so that the
1213 // active drag can follow the mouse cursor.
1214 self.refresh();
1215 } else if event.is::<MouseUpEvent>() {
1216 // If this was a mouse up event, cancel the active drag and redraw
1217 // the window.
1218 self.active_drag = None;
1219 self.refresh();
1220 }
1221 }
1222 }
1223
1224 fn dispatch_key_event(&mut self, event: &dyn Any) {
1225 let node_id = self
1226 .window
1227 .focus
1228 .and_then(|focus_id| {
1229 self.window
1230 .rendered_frame
1231 .dispatch_tree
1232 .focusable_node_id(focus_id)
1233 })
1234 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1235
1236 let dispatch_path = self
1237 .window
1238 .rendered_frame
1239 .dispatch_tree
1240 .dispatch_path(node_id);
1241
1242 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1243 let KeymatchResult {
1244 bindings,
1245 mut pending,
1246 } = self
1247 .window
1248 .rendered_frame
1249 .dispatch_tree
1250 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1251
1252 if self.window.rendered_frame.dispatch_tree.keymatch_mode == KeymatchMode::Immediate
1253 && !bindings.is_empty()
1254 {
1255 pending = false;
1256 }
1257
1258 if pending {
1259 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1260 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1261 {
1262 currently_pending = PendingInput::default();
1263 }
1264 currently_pending.focus = self.window.focus;
1265 currently_pending
1266 .keystrokes
1267 .push(key_down_event.keystroke.clone());
1268 for binding in bindings {
1269 currently_pending.bindings.push(binding);
1270 }
1271
1272 // for vim compatibility, we also should check "is input handler enabled"
1273 if !currently_pending.is_noop() {
1274 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1275 cx.background_executor.timer(Duration::from_secs(1)).await;
1276 cx.update(move |cx| {
1277 cx.clear_pending_keystrokes();
1278 let Some(currently_pending) = cx.window.pending_input.take() else {
1279 return;
1280 };
1281 cx.replay_pending_input(currently_pending)
1282 })
1283 .log_err();
1284 }));
1285 } else {
1286 currently_pending.timer = None;
1287 }
1288 self.window.pending_input = Some(currently_pending);
1289
1290 self.propagate_event = false;
1291 return;
1292 } else if let Some(currently_pending) = self.window.pending_input.take() {
1293 if bindings
1294 .iter()
1295 .all(|binding| !currently_pending.used_by_binding(binding))
1296 {
1297 self.replay_pending_input(currently_pending)
1298 }
1299 }
1300
1301 if !bindings.is_empty() {
1302 self.clear_pending_keystrokes();
1303 }
1304
1305 self.propagate_event = true;
1306 for binding in bindings {
1307 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1308 if !self.propagate_event {
1309 self.dispatch_keystroke_observers(event, Some(binding.action));
1310 return;
1311 }
1312 }
1313 }
1314
1315 // Capture phase
1316 for node_id in &dispatch_path {
1317 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1318
1319 for key_listener in node.key_listeners.clone() {
1320 self.with_element_context(|cx| {
1321 key_listener(event, DispatchPhase::Capture, cx);
1322 });
1323 if !self.propagate_event {
1324 return;
1325 }
1326 }
1327 }
1328
1329 // Bubble phase
1330 for node_id in dispatch_path.iter().rev() {
1331 // Handle low level key events
1332 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1333 for key_listener in node.key_listeners.clone() {
1334 self.with_element_context(|cx| {
1335 key_listener(event, DispatchPhase::Bubble, cx);
1336 });
1337 if !self.propagate_event {
1338 return;
1339 }
1340 }
1341 }
1342
1343 self.dispatch_keystroke_observers(event, None);
1344 }
1345
1346 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1347 pub fn has_pending_keystrokes(&self) -> bool {
1348 self.window
1349 .rendered_frame
1350 .dispatch_tree
1351 .has_pending_keystrokes()
1352 }
1353
1354 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1355 let node_id = self
1356 .window
1357 .focus
1358 .and_then(|focus_id| {
1359 self.window
1360 .rendered_frame
1361 .dispatch_tree
1362 .focusable_node_id(focus_id)
1363 })
1364 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1365
1366 if self.window.focus != currently_pending.focus {
1367 return;
1368 }
1369
1370 let input = currently_pending.input();
1371
1372 self.propagate_event = true;
1373 for binding in currently_pending.bindings {
1374 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1375 if !self.propagate_event {
1376 return;
1377 }
1378 }
1379
1380 if !input.is_empty() {
1381 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1382 input_handler.flush_pending_input(&input, self);
1383 self.window.platform_window.set_input_handler(input_handler)
1384 }
1385 }
1386 }
1387
1388 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1389 let dispatch_path = self
1390 .window
1391 .rendered_frame
1392 .dispatch_tree
1393 .dispatch_path(node_id);
1394
1395 // Capture phase
1396 for node_id in &dispatch_path {
1397 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1398 for DispatchActionListener {
1399 action_type,
1400 listener,
1401 } in node.action_listeners.clone()
1402 {
1403 let any_action = action.as_any();
1404 if action_type == any_action.type_id() {
1405 self.with_element_context(|cx| {
1406 listener(any_action, DispatchPhase::Capture, cx);
1407 });
1408
1409 if !self.propagate_event {
1410 return;
1411 }
1412 }
1413 }
1414 }
1415 // Bubble phase
1416 for node_id in dispatch_path.iter().rev() {
1417 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1418 for DispatchActionListener {
1419 action_type,
1420 listener,
1421 } in node.action_listeners.clone()
1422 {
1423 let any_action = action.as_any();
1424 if action_type == any_action.type_id() {
1425 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1426
1427 self.with_element_context(|cx| {
1428 listener(any_action, DispatchPhase::Bubble, cx);
1429 });
1430
1431 if !self.propagate_event {
1432 return;
1433 }
1434 }
1435 }
1436 }
1437 }
1438
1439 /// Register the given handler to be invoked whenever the global of the given type
1440 /// is updated.
1441 pub fn observe_global<G: 'static>(
1442 &mut self,
1443 f: impl Fn(&mut WindowContext<'_>) + 'static,
1444 ) -> Subscription {
1445 let window_handle = self.window.handle;
1446 let (subscription, activate) = self.global_observers.insert(
1447 TypeId::of::<G>(),
1448 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1449 );
1450 self.app.defer(move |_| activate());
1451 subscription
1452 }
1453
1454 /// Focus the current window and bring it to the foreground at the platform level.
1455 pub fn activate_window(&self) {
1456 self.window.platform_window.activate();
1457 }
1458
1459 /// Minimize the current window at the platform level.
1460 pub fn minimize_window(&self) {
1461 self.window.platform_window.minimize();
1462 }
1463
1464 /// Toggle full screen status on the current window at the platform level.
1465 pub fn toggle_full_screen(&self) {
1466 self.window.platform_window.toggle_full_screen();
1467 }
1468
1469 /// Present a platform dialog.
1470 /// The provided message will be presented, along with buttons for each answer.
1471 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1472 pub fn prompt(
1473 &self,
1474 level: PromptLevel,
1475 message: &str,
1476 answers: &[&str],
1477 ) -> oneshot::Receiver<usize> {
1478 self.window.platform_window.prompt(level, message, answers)
1479 }
1480
1481 /// Returns all available actions for the focused element.
1482 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1483 let node_id = self
1484 .window
1485 .focus
1486 .and_then(|focus_id| {
1487 self.window
1488 .rendered_frame
1489 .dispatch_tree
1490 .focusable_node_id(focus_id)
1491 })
1492 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1493
1494 self.window
1495 .rendered_frame
1496 .dispatch_tree
1497 .available_actions(node_id)
1498 }
1499
1500 /// Returns key bindings that invoke the given action on the currently focused element.
1501 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1502 self.window
1503 .rendered_frame
1504 .dispatch_tree
1505 .bindings_for_action(
1506 action,
1507 &self.window.rendered_frame.dispatch_tree.context_stack,
1508 )
1509 }
1510
1511 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1512 pub fn bindings_for_action_in(
1513 &self,
1514 action: &dyn Action,
1515 focus_handle: &FocusHandle,
1516 ) -> Vec<KeyBinding> {
1517 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1518
1519 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1520 return vec![];
1521 };
1522 let context_stack = dispatch_tree
1523 .dispatch_path(node_id)
1524 .into_iter()
1525 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1526 .collect();
1527 dispatch_tree.bindings_for_action(action, &context_stack)
1528 }
1529
1530 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1531 pub fn listener_for<V: Render, E>(
1532 &self,
1533 view: &View<V>,
1534 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1535 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1536 let view = view.downgrade();
1537 move |e: &E, cx: &mut WindowContext| {
1538 view.update(cx, |view, cx| f(view, e, cx)).ok();
1539 }
1540 }
1541
1542 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1543 pub fn handler_for<V: Render>(
1544 &self,
1545 view: &View<V>,
1546 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1547 ) -> impl Fn(&mut WindowContext) {
1548 let view = view.downgrade();
1549 move |cx: &mut WindowContext| {
1550 view.update(cx, |view, cx| f(view, cx)).ok();
1551 }
1552 }
1553
1554 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1555 /// If the callback returns false, the window won't be closed.
1556 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1557 let mut this = self.to_async();
1558 self.window
1559 .platform_window
1560 .on_should_close(Box::new(move || {
1561 this.update(|cx| {
1562 // Ensure that the window is removed from the app if it's been closed
1563 // by always pre-empting the system close event.
1564 if f(cx) {
1565 cx.remove_window();
1566 }
1567 false
1568 })
1569 .unwrap_or(true)
1570 }))
1571 }
1572
1573 pub(crate) fn parent_view_id(&self) -> EntityId {
1574 *self
1575 .window
1576 .next_frame
1577 .view_stack
1578 .last()
1579 .expect("a view should always be on the stack while drawing")
1580 }
1581
1582 /// Register an action listener on the window for the next frame. The type of action
1583 /// is determined by the first parameter of the given listener. When the next frame is rendered
1584 /// the listener will be cleared.
1585 ///
1586 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1587 /// a specific need to register a global listener.
1588 pub fn on_action(
1589 &mut self,
1590 action_type: TypeId,
1591 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1592 ) {
1593 self.window
1594 .next_frame
1595 .dispatch_tree
1596 .on_action(action_type, Rc::new(listener));
1597 }
1598}
1599
1600impl Context for WindowContext<'_> {
1601 type Result<T> = T;
1602
1603 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1604 where
1605 T: 'static,
1606 {
1607 let slot = self.app.entities.reserve();
1608 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1609 self.entities.insert(slot, model)
1610 }
1611
1612 fn update_model<T: 'static, R>(
1613 &mut self,
1614 model: &Model<T>,
1615 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1616 ) -> R {
1617 let mut entity = self.entities.lease(model);
1618 let result = update(
1619 &mut *entity,
1620 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1621 );
1622 self.entities.end_lease(entity);
1623 result
1624 }
1625
1626 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1627 where
1628 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1629 {
1630 if window == self.window.handle {
1631 let root_view = self.window.root_view.clone().unwrap();
1632 Ok(update(root_view, self))
1633 } else {
1634 window.update(self.app, update)
1635 }
1636 }
1637
1638 fn read_model<T, R>(
1639 &self,
1640 handle: &Model<T>,
1641 read: impl FnOnce(&T, &AppContext) -> R,
1642 ) -> Self::Result<R>
1643 where
1644 T: 'static,
1645 {
1646 let entity = self.entities.read(handle);
1647 read(entity, &*self.app)
1648 }
1649
1650 fn read_window<T, R>(
1651 &self,
1652 window: &WindowHandle<T>,
1653 read: impl FnOnce(View<T>, &AppContext) -> R,
1654 ) -> Result<R>
1655 where
1656 T: 'static,
1657 {
1658 if window.any_handle == self.window.handle {
1659 let root_view = self
1660 .window
1661 .root_view
1662 .clone()
1663 .unwrap()
1664 .downcast::<T>()
1665 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1666 Ok(read(root_view, self))
1667 } else {
1668 self.app.read_window(window, read)
1669 }
1670 }
1671}
1672
1673impl VisualContext for WindowContext<'_> {
1674 fn new_view<V>(
1675 &mut self,
1676 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1677 ) -> Self::Result<View<V>>
1678 where
1679 V: 'static + Render,
1680 {
1681 let slot = self.app.entities.reserve();
1682 let view = View {
1683 model: slot.clone(),
1684 };
1685 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1686 let entity = build_view_state(&mut cx);
1687 cx.entities.insert(slot, entity);
1688
1689 cx.new_view_observers
1690 .clone()
1691 .retain(&TypeId::of::<V>(), |observer| {
1692 let any_view = AnyView::from(view.clone());
1693 (observer)(any_view, self);
1694 true
1695 });
1696
1697 view
1698 }
1699
1700 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1701 fn update_view<T: 'static, R>(
1702 &mut self,
1703 view: &View<T>,
1704 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1705 ) -> Self::Result<R> {
1706 let mut lease = self.app.entities.lease(&view.model);
1707 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1708 let result = update(&mut *lease, &mut cx);
1709 cx.app.entities.end_lease(lease);
1710 result
1711 }
1712
1713 fn replace_root_view<V>(
1714 &mut self,
1715 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1716 ) -> Self::Result<View<V>>
1717 where
1718 V: 'static + Render,
1719 {
1720 let view = self.new_view(build_view);
1721 self.window.root_view = Some(view.clone().into());
1722 self.refresh();
1723 view
1724 }
1725
1726 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1727 self.update_view(view, |view, cx| {
1728 view.focus_handle(cx).clone().focus(cx);
1729 })
1730 }
1731
1732 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1733 where
1734 V: ManagedView,
1735 {
1736 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1737 }
1738}
1739
1740impl<'a> std::ops::Deref for WindowContext<'a> {
1741 type Target = AppContext;
1742
1743 fn deref(&self) -> &Self::Target {
1744 self.app
1745 }
1746}
1747
1748impl<'a> std::ops::DerefMut for WindowContext<'a> {
1749 fn deref_mut(&mut self) -> &mut Self::Target {
1750 self.app
1751 }
1752}
1753
1754impl<'a> Borrow<AppContext> for WindowContext<'a> {
1755 fn borrow(&self) -> &AppContext {
1756 self.app
1757 }
1758}
1759
1760impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1761 fn borrow_mut(&mut self) -> &mut AppContext {
1762 self.app
1763 }
1764}
1765
1766/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1767pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1768 #[doc(hidden)]
1769 fn app_mut(&mut self) -> &mut AppContext {
1770 self.borrow_mut()
1771 }
1772
1773 #[doc(hidden)]
1774 fn app(&self) -> &AppContext {
1775 self.borrow()
1776 }
1777
1778 #[doc(hidden)]
1779 fn window(&self) -> &Window {
1780 self.borrow()
1781 }
1782
1783 #[doc(hidden)]
1784 fn window_mut(&mut self) -> &mut Window {
1785 self.borrow_mut()
1786 }
1787}
1788
1789impl Borrow<Window> for WindowContext<'_> {
1790 fn borrow(&self) -> &Window {
1791 self.window
1792 }
1793}
1794
1795impl BorrowMut<Window> for WindowContext<'_> {
1796 fn borrow_mut(&mut self) -> &mut Window {
1797 self.window
1798 }
1799}
1800
1801impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1802
1803/// Provides access to application state that is specialized for a particular [`View`].
1804/// Allows you to interact with focus, emit events, etc.
1805/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1806/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1807pub struct ViewContext<'a, V> {
1808 window_cx: WindowContext<'a>,
1809 view: &'a View<V>,
1810}
1811
1812impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1813 fn borrow(&self) -> &AppContext {
1814 &*self.window_cx.app
1815 }
1816}
1817
1818impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1819 fn borrow_mut(&mut self) -> &mut AppContext {
1820 &mut *self.window_cx.app
1821 }
1822}
1823
1824impl<V> Borrow<Window> for ViewContext<'_, V> {
1825 fn borrow(&self) -> &Window {
1826 &*self.window_cx.window
1827 }
1828}
1829
1830impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1831 fn borrow_mut(&mut self) -> &mut Window {
1832 &mut *self.window_cx.window
1833 }
1834}
1835
1836impl<'a, V: 'static> ViewContext<'a, V> {
1837 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1838 Self {
1839 window_cx: WindowContext::new(app, window),
1840 view,
1841 }
1842 }
1843
1844 /// Get the entity_id of this view.
1845 pub fn entity_id(&self) -> EntityId {
1846 self.view.entity_id()
1847 }
1848
1849 /// Get the view pointer underlying this context.
1850 pub fn view(&self) -> &View<V> {
1851 self.view
1852 }
1853
1854 /// Get the model underlying this view.
1855 pub fn model(&self) -> &Model<V> {
1856 &self.view.model
1857 }
1858
1859 /// Access the underlying window context.
1860 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1861 &mut self.window_cx
1862 }
1863
1864 /// Sets a given callback to be run on the next frame.
1865 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1866 where
1867 V: 'static,
1868 {
1869 let view = self.view().clone();
1870 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1871 }
1872
1873 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1874 /// that are currently on the stack to be returned to the app.
1875 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1876 let view = self.view().downgrade();
1877 self.window_cx.defer(move |cx| {
1878 view.update(cx, f).ok();
1879 });
1880 }
1881
1882 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1883 pub fn observe<V2, E>(
1884 &mut self,
1885 entity: &E,
1886 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1887 ) -> Subscription
1888 where
1889 V2: 'static,
1890 V: 'static,
1891 E: Entity<V2>,
1892 {
1893 let view = self.view().downgrade();
1894 let entity_id = entity.entity_id();
1895 let entity = entity.downgrade();
1896 let window_handle = self.window.handle;
1897 let (subscription, activate) = self.app.observers.insert(
1898 entity_id,
1899 Box::new(move |cx| {
1900 window_handle
1901 .update(cx, |_, cx| {
1902 if let Some(handle) = E::upgrade_from(&entity) {
1903 view.update(cx, |this, cx| on_notify(this, handle, cx))
1904 .is_ok()
1905 } else {
1906 false
1907 }
1908 })
1909 .unwrap_or(false)
1910 }),
1911 );
1912 self.app.defer(move |_| activate());
1913 subscription
1914 }
1915
1916 /// Subscribe to events emitted by another model or view.
1917 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1918 /// 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.
1919 pub fn subscribe<V2, E, Evt>(
1920 &mut self,
1921 entity: &E,
1922 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1923 ) -> Subscription
1924 where
1925 V2: EventEmitter<Evt>,
1926 E: Entity<V2>,
1927 Evt: 'static,
1928 {
1929 let view = self.view().downgrade();
1930 let entity_id = entity.entity_id();
1931 let handle = entity.downgrade();
1932 let window_handle = self.window.handle;
1933 let (subscription, activate) = self.app.event_listeners.insert(
1934 entity_id,
1935 (
1936 TypeId::of::<Evt>(),
1937 Box::new(move |event, cx| {
1938 window_handle
1939 .update(cx, |_, cx| {
1940 if let Some(handle) = E::upgrade_from(&handle) {
1941 let event = event.downcast_ref().expect("invalid event type");
1942 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1943 .is_ok()
1944 } else {
1945 false
1946 }
1947 })
1948 .unwrap_or(false)
1949 }),
1950 ),
1951 );
1952 self.app.defer(move |_| activate());
1953 subscription
1954 }
1955
1956 /// Register a callback to be invoked when the view is released.
1957 ///
1958 /// The callback receives a handle to the view's window. This handle may be
1959 /// invalid, if the window was closed before the view was released.
1960 pub fn on_release(
1961 &mut self,
1962 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1963 ) -> Subscription {
1964 let window_handle = self.window.handle;
1965 let (subscription, activate) = self.app.release_listeners.insert(
1966 self.view.model.entity_id,
1967 Box::new(move |this, cx| {
1968 let this = this.downcast_mut().expect("invalid entity type");
1969 on_release(this, window_handle, cx)
1970 }),
1971 );
1972 activate();
1973 subscription
1974 }
1975
1976 /// Register a callback to be invoked when the given Model or View is released.
1977 pub fn observe_release<V2, E>(
1978 &mut self,
1979 entity: &E,
1980 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1981 ) -> Subscription
1982 where
1983 V: 'static,
1984 V2: 'static,
1985 E: Entity<V2>,
1986 {
1987 let view = self.view().downgrade();
1988 let entity_id = entity.entity_id();
1989 let window_handle = self.window.handle;
1990 let (subscription, activate) = self.app.release_listeners.insert(
1991 entity_id,
1992 Box::new(move |entity, cx| {
1993 let entity = entity.downcast_mut().expect("invalid entity type");
1994 let _ = window_handle.update(cx, |_, cx| {
1995 view.update(cx, |this, cx| on_release(this, entity, cx))
1996 });
1997 }),
1998 );
1999 activate();
2000 subscription
2001 }
2002
2003 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2004 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2005 pub fn notify(&mut self) {
2006 for view_id in self
2007 .window
2008 .rendered_frame
2009 .dispatch_tree
2010 .view_path(self.view.entity_id())
2011 .into_iter()
2012 .rev()
2013 {
2014 if !self.window.dirty_views.insert(view_id) {
2015 break;
2016 }
2017 }
2018
2019 // Always emit a notify effect, so that handlers fire correctly
2020 self.window_cx.app.push_effect(Effect::Notify {
2021 emitter: self.view.model.entity_id,
2022 });
2023 if !self.window.drawing {
2024 self.window_cx.window.dirty = true;
2025 }
2026 }
2027
2028 /// Register a callback to be invoked when the window is resized.
2029 pub fn observe_window_bounds(
2030 &mut self,
2031 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2032 ) -> Subscription {
2033 let view = self.view.downgrade();
2034 let (subscription, activate) = self.window.bounds_observers.insert(
2035 (),
2036 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2037 );
2038 activate();
2039 subscription
2040 }
2041
2042 /// Register a callback to be invoked when the window is activated or deactivated.
2043 pub fn observe_window_activation(
2044 &mut self,
2045 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2046 ) -> Subscription {
2047 let view = self.view.downgrade();
2048 let (subscription, activate) = self.window.activation_observers.insert(
2049 (),
2050 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2051 );
2052 activate();
2053 subscription
2054 }
2055
2056 /// Register a listener to be called when the given focus handle receives focus.
2057 /// Returns a subscription and persists until the subscription is dropped.
2058 pub fn on_focus(
2059 &mut self,
2060 handle: &FocusHandle,
2061 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2062 ) -> Subscription {
2063 let view = self.view.downgrade();
2064 let focus_id = handle.id;
2065 let (subscription, activate) = self.window.focus_listeners.insert(
2066 (),
2067 Box::new(move |event, cx| {
2068 view.update(cx, |view, cx| {
2069 if event.previous_focus_path.last() != Some(&focus_id)
2070 && event.current_focus_path.last() == Some(&focus_id)
2071 {
2072 listener(view, cx)
2073 }
2074 })
2075 .is_ok()
2076 }),
2077 );
2078 self.app.defer(move |_| activate());
2079 subscription
2080 }
2081
2082 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2083 /// Returns a subscription and persists until the subscription is dropped.
2084 pub fn on_focus_in(
2085 &mut self,
2086 handle: &FocusHandle,
2087 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2088 ) -> Subscription {
2089 let view = self.view.downgrade();
2090 let focus_id = handle.id;
2091 let (subscription, activate) = self.window.focus_listeners.insert(
2092 (),
2093 Box::new(move |event, cx| {
2094 view.update(cx, |view, cx| {
2095 if !event.previous_focus_path.contains(&focus_id)
2096 && event.current_focus_path.contains(&focus_id)
2097 {
2098 listener(view, cx)
2099 }
2100 })
2101 .is_ok()
2102 }),
2103 );
2104 self.app.defer(move |_| activate());
2105 subscription
2106 }
2107
2108 /// Register a listener to be called when the given focus handle loses focus.
2109 /// Returns a subscription and persists until the subscription is dropped.
2110 pub fn on_blur(
2111 &mut self,
2112 handle: &FocusHandle,
2113 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2114 ) -> Subscription {
2115 let view = self.view.downgrade();
2116 let focus_id = handle.id;
2117 let (subscription, activate) = self.window.focus_listeners.insert(
2118 (),
2119 Box::new(move |event, cx| {
2120 view.update(cx, |view, cx| {
2121 if event.previous_focus_path.last() == Some(&focus_id)
2122 && event.current_focus_path.last() != Some(&focus_id)
2123 {
2124 listener(view, cx)
2125 }
2126 })
2127 .is_ok()
2128 }),
2129 );
2130 self.app.defer(move |_| activate());
2131 subscription
2132 }
2133
2134 /// Register a listener to be called when nothing in the window has focus.
2135 /// This typically happens when the node that was focused is removed from the tree,
2136 /// and this callback lets you chose a default place to restore the users focus.
2137 /// Returns a subscription and persists until the subscription is dropped.
2138 pub fn on_focus_lost(
2139 &mut self,
2140 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2141 ) -> Subscription {
2142 let view = self.view.downgrade();
2143 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2144 (),
2145 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2146 );
2147 activate();
2148 subscription
2149 }
2150
2151 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2152 /// Returns a subscription and persists until the subscription is dropped.
2153 pub fn on_focus_out(
2154 &mut self,
2155 handle: &FocusHandle,
2156 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2157 ) -> Subscription {
2158 let view = self.view.downgrade();
2159 let focus_id = handle.id;
2160 let (subscription, activate) = self.window.focus_listeners.insert(
2161 (),
2162 Box::new(move |event, cx| {
2163 view.update(cx, |view, cx| {
2164 if event.previous_focus_path.contains(&focus_id)
2165 && !event.current_focus_path.contains(&focus_id)
2166 {
2167 listener(view, cx)
2168 }
2169 })
2170 .is_ok()
2171 }),
2172 );
2173 self.app.defer(move |_| activate());
2174 subscription
2175 }
2176
2177 /// Schedule a future to be run asynchronously.
2178 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2179 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2180 /// The returned future will be polled on the main thread.
2181 pub fn spawn<Fut, R>(
2182 &mut self,
2183 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2184 ) -> Task<R>
2185 where
2186 R: 'static,
2187 Fut: Future<Output = R> + 'static,
2188 {
2189 let view = self.view().downgrade();
2190 self.window_cx.spawn(|cx| f(view, cx))
2191 }
2192
2193 /// Updates the global state of the given type.
2194 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2195 where
2196 G: 'static,
2197 {
2198 let mut global = self.app.lease_global::<G>();
2199 let result = f(&mut global, self);
2200 self.app.end_global_lease(global);
2201 result
2202 }
2203
2204 /// Register a callback to be invoked when the given global state changes.
2205 pub fn observe_global<G: 'static>(
2206 &mut self,
2207 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2208 ) -> Subscription {
2209 let window_handle = self.window.handle;
2210 let view = self.view().downgrade();
2211 let (subscription, activate) = self.global_observers.insert(
2212 TypeId::of::<G>(),
2213 Box::new(move |cx| {
2214 window_handle
2215 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2216 .unwrap_or(false)
2217 }),
2218 );
2219 self.app.defer(move |_| activate());
2220 subscription
2221 }
2222
2223 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2224 pub fn on_action(
2225 &mut self,
2226 action_type: TypeId,
2227 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2228 ) {
2229 let handle = self.view().clone();
2230 self.window_cx
2231 .on_action(action_type, move |action, phase, cx| {
2232 handle.update(cx, |view, cx| {
2233 listener(view, action, phase, cx);
2234 })
2235 });
2236 }
2237
2238 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2239 pub fn emit<Evt>(&mut self, event: Evt)
2240 where
2241 Evt: 'static,
2242 V: EventEmitter<Evt>,
2243 {
2244 let emitter = self.view.model.entity_id;
2245 self.app.push_effect(Effect::Emit {
2246 emitter,
2247 event_type: TypeId::of::<Evt>(),
2248 event: Box::new(event),
2249 });
2250 }
2251
2252 /// Move focus to the current view, assuming it implements [`FocusableView`].
2253 pub fn focus_self(&mut self)
2254 where
2255 V: FocusableView,
2256 {
2257 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2258 }
2259
2260 /// Convenience method for accessing view state in an event callback.
2261 ///
2262 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2263 /// but it's often useful to be able to access view state in these
2264 /// callbacks. This method provides a convenient way to do so.
2265 pub fn listener<E>(
2266 &self,
2267 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2268 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2269 let view = self.view().downgrade();
2270 move |e: &E, cx: &mut WindowContext| {
2271 view.update(cx, |view, cx| f(view, e, cx)).ok();
2272 }
2273 }
2274}
2275
2276impl<V> Context for ViewContext<'_, V> {
2277 type Result<U> = U;
2278
2279 fn new_model<T: 'static>(
2280 &mut self,
2281 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2282 ) -> Model<T> {
2283 self.window_cx.new_model(build_model)
2284 }
2285
2286 fn update_model<T: 'static, R>(
2287 &mut self,
2288 model: &Model<T>,
2289 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2290 ) -> R {
2291 self.window_cx.update_model(model, update)
2292 }
2293
2294 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2295 where
2296 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2297 {
2298 self.window_cx.update_window(window, update)
2299 }
2300
2301 fn read_model<T, R>(
2302 &self,
2303 handle: &Model<T>,
2304 read: impl FnOnce(&T, &AppContext) -> R,
2305 ) -> Self::Result<R>
2306 where
2307 T: 'static,
2308 {
2309 self.window_cx.read_model(handle, read)
2310 }
2311
2312 fn read_window<T, R>(
2313 &self,
2314 window: &WindowHandle<T>,
2315 read: impl FnOnce(View<T>, &AppContext) -> R,
2316 ) -> Result<R>
2317 where
2318 T: 'static,
2319 {
2320 self.window_cx.read_window(window, read)
2321 }
2322}
2323
2324impl<V: 'static> VisualContext for ViewContext<'_, V> {
2325 fn new_view<W: Render + 'static>(
2326 &mut self,
2327 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2328 ) -> Self::Result<View<W>> {
2329 self.window_cx.new_view(build_view_state)
2330 }
2331
2332 fn update_view<V2: 'static, R>(
2333 &mut self,
2334 view: &View<V2>,
2335 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2336 ) -> Self::Result<R> {
2337 self.window_cx.update_view(view, update)
2338 }
2339
2340 fn replace_root_view<W>(
2341 &mut self,
2342 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2343 ) -> Self::Result<View<W>>
2344 where
2345 W: 'static + Render,
2346 {
2347 self.window_cx.replace_root_view(build_view)
2348 }
2349
2350 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2351 self.window_cx.focus_view(view)
2352 }
2353
2354 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2355 self.window_cx.dismiss_view(view)
2356 }
2357}
2358
2359impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2360 type Target = WindowContext<'a>;
2361
2362 fn deref(&self) -> &Self::Target {
2363 &self.window_cx
2364 }
2365}
2366
2367impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2368 fn deref_mut(&mut self) -> &mut Self::Target {
2369 &mut self.window_cx
2370 }
2371}
2372
2373// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2374slotmap::new_key_type! {
2375 /// A unique identifier for a window.
2376 pub struct WindowId;
2377}
2378
2379impl WindowId {
2380 /// Converts this window ID to a `u64`.
2381 pub fn as_u64(&self) -> u64 {
2382 self.0.as_ffi()
2383 }
2384}
2385
2386/// A handle to a window with a specific root view type.
2387/// Note that this does not keep the window alive on its own.
2388#[derive(Deref, DerefMut)]
2389pub struct WindowHandle<V> {
2390 #[deref]
2391 #[deref_mut]
2392 pub(crate) any_handle: AnyWindowHandle,
2393 state_type: PhantomData<V>,
2394}
2395
2396impl<V: 'static + Render> WindowHandle<V> {
2397 /// Creates a new handle from a window ID.
2398 /// This does not check if the root type of the window is `V`.
2399 pub fn new(id: WindowId) -> Self {
2400 WindowHandle {
2401 any_handle: AnyWindowHandle {
2402 id,
2403 state_type: TypeId::of::<V>(),
2404 },
2405 state_type: PhantomData,
2406 }
2407 }
2408
2409 /// Get the root view out of this window.
2410 ///
2411 /// This will fail if the window is closed or if the root view's type does not match `V`.
2412 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2413 where
2414 C: Context,
2415 {
2416 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2417 root_view
2418 .downcast::<V>()
2419 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2420 }))
2421 }
2422
2423 /// Updates the root view of this window.
2424 ///
2425 /// This will fail if the window has been closed or if the root view's type does not match
2426 pub fn update<C, R>(
2427 &self,
2428 cx: &mut C,
2429 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2430 ) -> Result<R>
2431 where
2432 C: Context,
2433 {
2434 cx.update_window(self.any_handle, |root_view, cx| {
2435 let view = root_view
2436 .downcast::<V>()
2437 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2438 Ok(cx.update_view(&view, update))
2439 })?
2440 }
2441
2442 /// Read the root view out of this window.
2443 ///
2444 /// This will fail if the window is closed or if the root view's type does not match `V`.
2445 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2446 let x = cx
2447 .windows
2448 .get(self.id)
2449 .and_then(|window| {
2450 window
2451 .as_ref()
2452 .and_then(|window| window.root_view.clone())
2453 .map(|root_view| root_view.downcast::<V>())
2454 })
2455 .ok_or_else(|| anyhow!("window not found"))?
2456 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2457
2458 Ok(x.read(cx))
2459 }
2460
2461 /// Read the root view out of this window, with a callback
2462 ///
2463 /// This will fail if the window is closed or if the root view's type does not match `V`.
2464 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2465 where
2466 C: Context,
2467 {
2468 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2469 }
2470
2471 /// Read the root view pointer off of this window.
2472 ///
2473 /// This will fail if the window is closed or if the root view's type does not match `V`.
2474 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2475 where
2476 C: Context,
2477 {
2478 cx.read_window(self, |root_view, _cx| root_view.clone())
2479 }
2480
2481 /// Check if this window is 'active'.
2482 ///
2483 /// Will return `None` if the window is closed.
2484 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2485 cx.windows
2486 .get(self.id)
2487 .and_then(|window| window.as_ref().map(|window| window.active))
2488 }
2489}
2490
2491impl<V> Copy for WindowHandle<V> {}
2492
2493impl<V> Clone for WindowHandle<V> {
2494 fn clone(&self) -> Self {
2495 *self
2496 }
2497}
2498
2499impl<V> PartialEq for WindowHandle<V> {
2500 fn eq(&self, other: &Self) -> bool {
2501 self.any_handle == other.any_handle
2502 }
2503}
2504
2505impl<V> Eq for WindowHandle<V> {}
2506
2507impl<V> Hash for WindowHandle<V> {
2508 fn hash<H: Hasher>(&self, state: &mut H) {
2509 self.any_handle.hash(state);
2510 }
2511}
2512
2513impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2514 fn from(val: WindowHandle<V>) -> Self {
2515 val.any_handle
2516 }
2517}
2518
2519/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2520#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2521pub struct AnyWindowHandle {
2522 pub(crate) id: WindowId,
2523 state_type: TypeId,
2524}
2525
2526impl AnyWindowHandle {
2527 /// Get the ID of this window.
2528 pub fn window_id(&self) -> WindowId {
2529 self.id
2530 }
2531
2532 /// Attempt to convert this handle to a window handle with a specific root view type.
2533 /// If the types do not match, this will return `None`.
2534 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2535 if TypeId::of::<T>() == self.state_type {
2536 Some(WindowHandle {
2537 any_handle: *self,
2538 state_type: PhantomData,
2539 })
2540 } else {
2541 None
2542 }
2543 }
2544
2545 /// Updates the state of the root view of this window.
2546 ///
2547 /// This will fail if the window has been closed.
2548 pub fn update<C, R>(
2549 self,
2550 cx: &mut C,
2551 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2552 ) -> Result<R>
2553 where
2554 C: Context,
2555 {
2556 cx.update_window(self, update)
2557 }
2558
2559 /// Read the state of the root view of this window.
2560 ///
2561 /// This will fail if the window has been closed.
2562 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2563 where
2564 C: Context,
2565 T: 'static,
2566 {
2567 let view = self
2568 .downcast::<T>()
2569 .context("the type of the window's root view has changed")?;
2570
2571 cx.read_window(&view, read)
2572 }
2573}
2574
2575/// An identifier for an [`Element`](crate::Element).
2576///
2577/// Can be constructed with a string, a number, or both, as well
2578/// as other internal representations.
2579#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2580pub enum ElementId {
2581 /// The ID of a View element
2582 View(EntityId),
2583 /// An integer ID.
2584 Integer(usize),
2585 /// A string based ID.
2586 Name(SharedString),
2587 /// An ID that's equated with a focus handle.
2588 FocusHandle(FocusId),
2589 /// A combination of a name and an integer.
2590 NamedInteger(SharedString, usize),
2591}
2592
2593impl Display for ElementId {
2594 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2595 match self {
2596 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2597 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2598 ElementId::Name(name) => write!(f, "{}", name)?,
2599 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2600 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2601 }
2602
2603 Ok(())
2604 }
2605}
2606
2607impl ElementId {
2608 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2609 ElementId::View(entity_id)
2610 }
2611}
2612
2613impl TryInto<SharedString> for ElementId {
2614 type Error = anyhow::Error;
2615
2616 fn try_into(self) -> anyhow::Result<SharedString> {
2617 if let ElementId::Name(name) = self {
2618 Ok(name)
2619 } else {
2620 Err(anyhow!("element id is not string"))
2621 }
2622 }
2623}
2624
2625impl From<usize> for ElementId {
2626 fn from(id: usize) -> Self {
2627 ElementId::Integer(id)
2628 }
2629}
2630
2631impl From<i32> for ElementId {
2632 fn from(id: i32) -> Self {
2633 Self::Integer(id as usize)
2634 }
2635}
2636
2637impl From<SharedString> for ElementId {
2638 fn from(name: SharedString) -> Self {
2639 ElementId::Name(name)
2640 }
2641}
2642
2643impl From<&'static str> for ElementId {
2644 fn from(name: &'static str) -> Self {
2645 ElementId::Name(name.into())
2646 }
2647}
2648
2649impl<'a> From<&'a FocusHandle> for ElementId {
2650 fn from(handle: &'a FocusHandle) -> Self {
2651 ElementId::FocusHandle(handle.id)
2652 }
2653}
2654
2655impl From<(&'static str, EntityId)> for ElementId {
2656 fn from((name, id): (&'static str, EntityId)) -> Self {
2657 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2658 }
2659}
2660
2661impl From<(&'static str, usize)> for ElementId {
2662 fn from((name, id): (&'static str, usize)) -> Self {
2663 ElementId::NamedInteger(name.into(), id)
2664 }
2665}
2666
2667impl From<(&'static str, u64)> for ElementId {
2668 fn from((name, id): (&'static str, u64)) -> Self {
2669 ElementId::NamedInteger(name.into(), id as usize)
2670 }
2671}
2672
2673/// A rectangle to be rendered in the window at the given position and size.
2674/// Passed as an argument [`WindowContext::paint_quad`].
2675#[derive(Clone)]
2676pub struct PaintQuad {
2677 bounds: Bounds<Pixels>,
2678 corner_radii: Corners<Pixels>,
2679 background: Hsla,
2680 border_widths: Edges<Pixels>,
2681 border_color: Hsla,
2682}
2683
2684impl PaintQuad {
2685 /// Sets the corner radii of the quad.
2686 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2687 PaintQuad {
2688 corner_radii: corner_radii.into(),
2689 ..self
2690 }
2691 }
2692
2693 /// Sets the border widths of the quad.
2694 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2695 PaintQuad {
2696 border_widths: border_widths.into(),
2697 ..self
2698 }
2699 }
2700
2701 /// Sets the border color of the quad.
2702 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2703 PaintQuad {
2704 border_color: border_color.into(),
2705 ..self
2706 }
2707 }
2708
2709 /// Sets the background color of the quad.
2710 pub fn background(self, background: impl Into<Hsla>) -> Self {
2711 PaintQuad {
2712 background: background.into(),
2713 ..self
2714 }
2715 }
2716}
2717
2718/// Creates a quad with the given parameters.
2719pub fn quad(
2720 bounds: Bounds<Pixels>,
2721 corner_radii: impl Into<Corners<Pixels>>,
2722 background: impl Into<Hsla>,
2723 border_widths: impl Into<Edges<Pixels>>,
2724 border_color: impl Into<Hsla>,
2725) -> PaintQuad {
2726 PaintQuad {
2727 bounds,
2728 corner_radii: corner_radii.into(),
2729 background: background.into(),
2730 border_widths: border_widths.into(),
2731 border_color: border_color.into(),
2732 }
2733}
2734
2735/// Creates a filled quad with the given bounds and background color.
2736pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2737 PaintQuad {
2738 bounds: bounds.into(),
2739 corner_radii: (0.).into(),
2740 background: background.into(),
2741 border_widths: (0.).into(),
2742 border_color: transparent_black(),
2743 }
2744}
2745
2746/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2747pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2748 PaintQuad {
2749 bounds: bounds.into(),
2750 corner_radii: (0.).into(),
2751 background: transparent_black(),
2752 border_widths: (1.).into(),
2753 border_color: border_color.into(),
2754 }
2755}
2756
2757#[cfg(test)]
2758mod test {
2759
2760 use std::{cell::RefCell, rc::Rc};
2761
2762 use crate::{
2763 self as gpui, div, FocusHandle, InteractiveElement, IntoElement, Render, TestAppContext,
2764 ViewContext, VisualContext,
2765 };
2766
2767 #[gpui::test]
2768 fn test_notify_on_focus(cx: &mut TestAppContext) {
2769 struct TestFocusView {
2770 handle: FocusHandle,
2771 }
2772
2773 impl Render for TestFocusView {
2774 fn render(&mut self, _cx: &mut ViewContext<Self>) -> impl IntoElement {
2775 div().id("test").track_focus(&self.handle)
2776 }
2777 }
2778
2779 let notify_counter = Rc::new(RefCell::new(0));
2780
2781 let (notify_producer, cx) = cx.add_window_view(|cx| {
2782 cx.activate_window();
2783 let handle = cx.focus_handle();
2784
2785 cx.on_focus(&handle, |_, cx| {
2786 cx.notify();
2787 })
2788 .detach();
2789
2790 TestFocusView { handle }
2791 });
2792
2793 let focus_handle = cx.update(|cx| notify_producer.read(cx).handle.clone());
2794
2795 let _notify_consumer = cx.new_view({
2796 |cx| {
2797 let notify_counter = notify_counter.clone();
2798 cx.observe(¬ify_producer, move |_, _, _| {
2799 *notify_counter.borrow_mut() += 1;
2800 })
2801 .detach();
2802 }
2803 });
2804
2805 cx.update(|cx| {
2806 cx.focus(&focus_handle);
2807 });
2808
2809 assert_eq!(*notify_counter.borrow(), 1);
2810 }
2811}