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