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, WindowBounds, WindowOptions,
10 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 active: Rc<Cell<bool>>,
272 pub(crate) dirty: Rc<Cell<bool>>,
273 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
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
282#[derive(Default, Debug)]
283struct PendingInput {
284 keystrokes: SmallVec<[Keystroke; 1]>,
285 bindings: SmallVec<[KeyBinding; 1]>,
286 focus: Option<FocusId>,
287 timer: Option<Task<()>>,
288}
289
290impl PendingInput {
291 fn input(&self) -> String {
292 self.keystrokes
293 .iter()
294 .flat_map(|k| k.ime_key.clone())
295 .collect::<Vec<String>>()
296 .join("")
297 }
298
299 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
300 if self.keystrokes.is_empty() {
301 return true;
302 }
303 let keystroke = &self.keystrokes[0];
304 for candidate in keystroke.match_candidates() {
305 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
306 return true;
307 }
308 }
309 false
310 }
311}
312
313pub(crate) struct ElementStateBox {
314 pub(crate) inner: Box<dyn Any>,
315 pub(crate) parent_view_id: EntityId,
316 #[cfg(debug_assertions)]
317 pub(crate) type_name: &'static str,
318}
319
320impl Window {
321 pub(crate) fn new(
322 handle: AnyWindowHandle,
323 options: WindowOptions,
324 cx: &mut AppContext,
325 ) -> Self {
326 let platform_window = cx.platform.open_window(handle, options);
327 let display_id = platform_window.display().id();
328 let sprite_atlas = platform_window.sprite_atlas();
329 let mouse_position = platform_window.mouse_position();
330 let modifiers = platform_window.modifiers();
331 let content_size = platform_window.content_size();
332 let scale_factor = platform_window.scale_factor();
333 let bounds = platform_window.bounds();
334 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
335 let dirty = Rc::new(Cell::new(true));
336 let active = Rc::new(Cell::new(false));
337 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
338 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
339
340 platform_window.on_request_frame(Box::new({
341 let mut cx = cx.to_async();
342 let dirty = dirty.clone();
343 let active = active.clone();
344 let next_frame_callbacks = next_frame_callbacks.clone();
345 let last_input_timestamp = last_input_timestamp.clone();
346 move || {
347 let next_frame_callbacks = next_frame_callbacks.take();
348 if !next_frame_callbacks.is_empty() {
349 handle
350 .update(&mut cx, |_, cx| {
351 for callback in next_frame_callbacks {
352 callback(cx);
353 }
354 })
355 .log_err();
356 }
357
358 if dirty.get() {
359 measure("frame duration", || {
360 handle
361 .update(&mut cx, |_, cx| {
362 cx.draw();
363 cx.present();
364 })
365 .log_err();
366 })
367 }
368 // Keep presenting the current scene for 1 extra second since the
369 // last input to prevent the display from underclocking the refresh rate.
370 else if active.get()
371 && last_input_timestamp.get().elapsed() < Duration::from_secs(1)
372 {
373 handle.update(&mut cx, |_, cx| cx.present()).log_err();
374 }
375 }
376 }));
377 platform_window.on_resize(Box::new({
378 let mut cx = cx.to_async();
379 move |_, _| {
380 handle
381 .update(&mut cx, |_, cx| cx.window_bounds_changed())
382 .log_err();
383 }
384 }));
385 platform_window.on_moved(Box::new({
386 let mut cx = cx.to_async();
387 move || {
388 handle
389 .update(&mut cx, |_, cx| cx.window_bounds_changed())
390 .log_err();
391 }
392 }));
393 platform_window.on_active_status_change(Box::new({
394 let mut cx = cx.to_async();
395 move |active| {
396 handle
397 .update(&mut cx, |_, cx| {
398 cx.window.active.set(active);
399 cx.window
400 .activation_observers
401 .clone()
402 .retain(&(), |callback| callback(cx));
403 })
404 .log_err();
405 }
406 }));
407
408 platform_window.on_input({
409 let mut cx = cx.to_async();
410 Box::new(move |event| {
411 handle
412 .update(&mut cx, |_, cx| cx.dispatch_event(event))
413 .log_err()
414 .unwrap_or(false)
415 })
416 });
417
418 Window {
419 handle,
420 removed: false,
421 platform_window,
422 display_id,
423 sprite_atlas,
424 text_system,
425 rem_size: px(16.),
426 viewport_size: content_size,
427 layout_engine: Some(TaffyLayoutEngine::new()),
428 root_view: None,
429 element_id_stack: GlobalElementId::default(),
430 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
431 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
432 next_frame_callbacks,
433 dirty_views: FxHashSet::default(),
434 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
435 focus_listeners: SubscriberSet::new(),
436 focus_lost_listeners: SubscriberSet::new(),
437 default_prevented: true,
438 mouse_position,
439 modifiers,
440 scale_factor,
441 bounds,
442 bounds_observers: SubscriberSet::new(),
443 active,
444 dirty,
445 last_input_timestamp,
446 refreshing: false,
447 drawing: false,
448 activation_observers: SubscriberSet::new(),
449 focus: None,
450 focus_enabled: true,
451 pending_input: None,
452 }
453 }
454}
455
456/// Indicates which region of the window is visible. Content falling outside of this mask will not be
457/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
458/// to leave room to support more complex shapes in the future.
459#[derive(Clone, Debug, Default, PartialEq, Eq)]
460#[repr(C)]
461pub struct ContentMask<P: Clone + Default + Debug> {
462 /// The bounds
463 pub bounds: Bounds<P>,
464}
465
466impl ContentMask<Pixels> {
467 /// Scale the content mask's pixel units by the given scaling factor.
468 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
469 ContentMask {
470 bounds: self.bounds.scale(factor),
471 }
472 }
473
474 /// Intersect the content mask with the given content mask.
475 pub fn intersect(&self, other: &Self) -> Self {
476 let bounds = self.bounds.intersect(&other.bounds);
477 ContentMask { bounds }
478 }
479}
480
481/// Provides access to application state in the context of a single window. Derefs
482/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
483/// an [`AppContext`] and call any [`AppContext`] methods.
484pub struct WindowContext<'a> {
485 pub(crate) app: &'a mut AppContext,
486 pub(crate) window: &'a mut Window,
487}
488
489impl<'a> WindowContext<'a> {
490 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
491 Self { app, window }
492 }
493
494 /// Obtain a handle to the window that belongs to this context.
495 pub fn window_handle(&self) -> AnyWindowHandle {
496 self.window.handle
497 }
498
499 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
500 pub fn refresh(&mut self) {
501 if !self.window.drawing {
502 self.window.refreshing = true;
503 self.window.dirty.set(true);
504 }
505 }
506
507 /// Close this window.
508 pub fn remove_window(&mut self) {
509 self.window.removed = true;
510 }
511
512 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
513 /// for elements rendered within this window.
514 pub fn focus_handle(&mut self) -> FocusHandle {
515 FocusHandle::new(&self.window.focus_handles)
516 }
517
518 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
519 pub fn focused(&self) -> Option<FocusHandle> {
520 self.window
521 .focus
522 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
523 }
524
525 /// Move focus to the element associated with the given [`FocusHandle`].
526 pub fn focus(&mut self, handle: &FocusHandle) {
527 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
528 return;
529 }
530
531 self.window.focus = Some(handle.id);
532 self.window
533 .rendered_frame
534 .dispatch_tree
535 .clear_pending_keystrokes();
536 self.refresh();
537 }
538
539 /// Remove focus from all elements within this context's window.
540 pub fn blur(&mut self) {
541 if !self.window.focus_enabled {
542 return;
543 }
544
545 self.window.focus = None;
546 self.refresh();
547 }
548
549 /// Blur the window and don't allow anything in it to be focused again.
550 pub fn disable_focus(&mut self) {
551 self.blur();
552 self.window.focus_enabled = false;
553 }
554
555 /// Accessor for the text system.
556 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
557 &self.window.text_system
558 }
559
560 /// Dispatch the given action on the currently focused element.
561 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
562 let focus_handle = self.focused();
563
564 self.defer(move |cx| {
565 let node_id = focus_handle
566 .and_then(|handle| {
567 cx.window
568 .rendered_frame
569 .dispatch_tree
570 .focusable_node_id(handle.id)
571 })
572 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
573
574 cx.propagate_event = true;
575 cx.dispatch_action_on_node(node_id, action);
576 })
577 }
578
579 pub(crate) fn dispatch_keystroke_observers(
580 &mut self,
581 event: &dyn Any,
582 action: Option<Box<dyn Action>>,
583 ) {
584 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
585 return;
586 };
587
588 self.keystroke_observers
589 .clone()
590 .retain(&(), move |callback| {
591 (callback)(
592 &KeystrokeEvent {
593 keystroke: key_down_event.keystroke.clone(),
594 action: action.as_ref().map(|action| action.boxed_clone()),
595 },
596 self,
597 );
598 true
599 });
600 }
601
602 pub(crate) fn clear_pending_keystrokes(&mut self) {
603 self.window
604 .rendered_frame
605 .dispatch_tree
606 .clear_pending_keystrokes();
607 self.window
608 .next_frame
609 .dispatch_tree
610 .clear_pending_keystrokes();
611 }
612
613 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
614 /// that are currently on the stack to be returned to the app.
615 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
616 let handle = self.window.handle;
617 self.app.defer(move |cx| {
618 handle.update(cx, |_, cx| f(cx)).ok();
619 });
620 }
621
622 /// Subscribe to events emitted by a model or view.
623 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
624 /// 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.
625 pub fn subscribe<Emitter, E, Evt>(
626 &mut self,
627 entity: &E,
628 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
629 ) -> Subscription
630 where
631 Emitter: EventEmitter<Evt>,
632 E: Entity<Emitter>,
633 Evt: 'static,
634 {
635 let entity_id = entity.entity_id();
636 let entity = entity.downgrade();
637 let window_handle = self.window.handle;
638 let (subscription, activate) = self.app.event_listeners.insert(
639 entity_id,
640 (
641 TypeId::of::<Evt>(),
642 Box::new(move |event, cx| {
643 window_handle
644 .update(cx, |_, cx| {
645 if let Some(handle) = E::upgrade_from(&entity) {
646 let event = event.downcast_ref().expect("invalid event type");
647 on_event(handle, event, cx);
648 true
649 } else {
650 false
651 }
652 })
653 .unwrap_or(false)
654 }),
655 ),
656 );
657 self.app.defer(move |_| activate());
658 subscription
659 }
660
661 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
662 /// await points in async code.
663 pub fn to_async(&self) -> AsyncWindowContext {
664 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
665 }
666
667 /// Schedule the given closure to be run directly after the current frame is rendered.
668 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
669 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
670 }
671
672 /// Spawn the future returned by the given closure on the application thread pool.
673 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
674 /// use within your future.
675 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
676 where
677 R: 'static,
678 Fut: Future<Output = R> + 'static,
679 {
680 self.app
681 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
682 }
683
684 /// Updates the global of the given type. The given closure is given simultaneous mutable
685 /// access both to the global and the context.
686 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
687 where
688 G: Global,
689 {
690 let mut global = self.app.lease_global::<G>();
691 let result = f(&mut global, self);
692 self.app.end_global_lease(global);
693 result
694 }
695
696 fn window_bounds_changed(&mut self) {
697 self.window.scale_factor = self.window.platform_window.scale_factor();
698 self.window.viewport_size = self.window.platform_window.content_size();
699 self.window.bounds = self.window.platform_window.bounds();
700 self.window.display_id = self.window.platform_window.display().id();
701 self.refresh();
702
703 self.window
704 .bounds_observers
705 .clone()
706 .retain(&(), |callback| callback(self));
707 }
708
709 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
710 pub fn window_bounds(&self) -> WindowBounds {
711 self.window.bounds
712 }
713
714 /// Returns the size of the drawable area within the window.
715 pub fn viewport_size(&self) -> Size<Pixels> {
716 self.window.viewport_size
717 }
718
719 /// Returns whether this window is focused by the operating system (receiving key events).
720 pub fn is_window_active(&self) -> bool {
721 self.window.active.get()
722 }
723
724 /// Toggle zoom on the window.
725 pub fn zoom_window(&self) {
726 self.window.platform_window.zoom();
727 }
728
729 /// Updates the window's title at the platform level.
730 pub fn set_window_title(&mut self, title: &str) {
731 self.window.platform_window.set_title(title);
732 }
733
734 /// Mark the window as dirty at the platform level.
735 pub fn set_window_edited(&mut self, edited: bool) {
736 self.window.platform_window.set_edited(edited);
737 }
738
739 /// Determine the display on which the window is visible.
740 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
741 self.platform
742 .displays()
743 .into_iter()
744 .find(|display| display.id() == self.window.display_id)
745 }
746
747 /// Show the platform character palette.
748 pub fn show_character_palette(&self) {
749 self.window.platform_window.show_character_palette();
750 }
751
752 /// The scale factor of the display associated with the window. For example, it could
753 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
754 /// be rendered as two pixels on screen.
755 pub fn scale_factor(&self) -> f32 {
756 self.window.scale_factor
757 }
758
759 /// The size of an em for the base font of the application. Adjusting this value allows the
760 /// UI to scale, just like zooming a web page.
761 pub fn rem_size(&self) -> Pixels {
762 self.window.rem_size
763 }
764
765 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
766 /// UI to scale, just like zooming a web page.
767 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
768 self.window.rem_size = rem_size.into();
769 }
770
771 /// The line height associated with the current text style.
772 pub fn line_height(&self) -> Pixels {
773 let rem_size = self.rem_size();
774 let text_style = self.text_style();
775 text_style
776 .line_height
777 .to_pixels(text_style.font_size, rem_size)
778 }
779
780 /// Call to prevent the default action of an event. Currently only used to prevent
781 /// parent elements from becoming focused on mouse down.
782 pub fn prevent_default(&mut self) {
783 self.window.default_prevented = true;
784 }
785
786 /// Obtain whether default has been prevented for the event currently being dispatched.
787 pub fn default_prevented(&self) -> bool {
788 self.window.default_prevented
789 }
790
791 /// Determine whether the given action is available along the dispatch path to the currently focused element.
792 pub fn is_action_available(&self, action: &dyn Action) -> bool {
793 let target = self
794 .focused()
795 .and_then(|focused_handle| {
796 self.window
797 .rendered_frame
798 .dispatch_tree
799 .focusable_node_id(focused_handle.id)
800 })
801 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
802 self.window
803 .rendered_frame
804 .dispatch_tree
805 .is_action_available(action, target)
806 }
807
808 /// The position of the mouse relative to the window.
809 pub fn mouse_position(&self) -> Point<Pixels> {
810 self.window.mouse_position
811 }
812
813 /// The current state of the keyboard's modifiers
814 pub fn modifiers(&self) -> Modifiers {
815 self.window.modifiers
816 }
817
818 /// Returns true if there is no opaque layer containing the given point
819 /// on top of the given level. Layers who are extensions of the queried layer
820 /// are not considered to be on top of queried layer.
821 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
822 // Precondition: the depth map is ordered from topmost to bottomost.
823
824 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
825 if layer >= opaque_layer {
826 // The queried layer is either above or is the same as the this opaque layer.
827 // Anything after this point is guaranteed to be below the queried layer.
828 return true;
829 }
830
831 if !bounds.contains(point) {
832 // This opaque layer is above the queried layer but it doesn't contain
833 // the given position, so we can ignore it even if it's above.
834 continue;
835 }
836
837 // At this point, we've established that this opaque layer is on top of the queried layer
838 // and contains the position:
839 // If neither the opaque layer or the queried layer is an extension of the other then
840 // we know they are on different stacking orders, and return false.
841 let is_on_same_layer = opaque_layer
842 .iter()
843 .zip(layer.iter())
844 .all(|(a, b)| a.z_index == b.z_index);
845
846 if !is_on_same_layer {
847 return false;
848 }
849 }
850
851 true
852 }
853
854 pub(crate) fn was_top_layer_under_active_drag(
855 &self,
856 point: &Point<Pixels>,
857 layer: &StackingOrder,
858 ) -> bool {
859 // Precondition: the depth map is ordered from topmost to bottomost.
860
861 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
862 if layer >= opaque_layer {
863 // The queried layer is either above or is the same as the this opaque layer.
864 // Anything after this point is guaranteed to be below the queried layer.
865 return true;
866 }
867
868 if !bounds.contains(point) {
869 // This opaque layer is above the queried layer but it doesn't contain
870 // the given position, so we can ignore it even if it's above.
871 continue;
872 }
873
874 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
875 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
876 // looking to see if the queried layer was the topmost underneath the drag layer.
877 if opaque_layer
878 .first()
879 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
880 .unwrap_or(false)
881 {
882 continue;
883 }
884
885 // At this point, we've established that this opaque layer is on top of the queried layer
886 // and contains the position:
887 // If neither the opaque layer or the queried layer is an extension of the other then
888 // we know they are on different stacking orders, and return false.
889 let is_on_same_layer = opaque_layer
890 .iter()
891 .zip(layer.iter())
892 .all(|(a, b)| a.z_index == b.z_index);
893
894 if !is_on_same_layer {
895 return false;
896 }
897 }
898
899 true
900 }
901
902 /// Called during painting to get the current stacking order.
903 pub fn stacking_order(&self) -> &StackingOrder {
904 &self.window.next_frame.z_index_stack
905 }
906
907 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
908 /// the contents of the new [Scene], use [present].
909 pub(crate) fn draw(&mut self) {
910 self.window.dirty.set(false);
911 self.window.drawing = true;
912
913 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
914 {
915 let input_handler = self.window.platform_window.take_input_handler();
916 requested_handler.handler = input_handler;
917 }
918
919 let root_view = self.window.root_view.take().unwrap();
920 self.with_element_context(|cx| {
921 cx.with_z_index(0, |cx| {
922 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
923 // We need to use cx.cx here so we can utilize borrow splitting
924 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
925 for action_listener in action_listeners.iter().cloned() {
926 cx.cx.window.next_frame.dispatch_tree.on_action(
927 *action_type,
928 Rc::new(
929 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
930 action_listener(action, phase, cx)
931 },
932 ),
933 )
934 }
935 }
936
937 let available_space = cx.window.viewport_size.map(Into::into);
938 root_view.draw(Point::default(), available_space, cx);
939 })
940 })
941 });
942
943 if let Some(active_drag) = self.app.active_drag.take() {
944 self.with_element_context(|cx| {
945 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
946 let offset = cx.mouse_position() - active_drag.cursor_offset;
947 let available_space =
948 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
949 active_drag.view.draw(offset, available_space, cx);
950 })
951 });
952 self.active_drag = Some(active_drag);
953 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
954 self.with_element_context(|cx| {
955 cx.with_z_index(1, |cx| {
956 let available_space =
957 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
958 tooltip_request.tooltip.view.draw(
959 tooltip_request.tooltip.cursor_offset,
960 available_space,
961 cx,
962 );
963 })
964 });
965 self.window.next_frame.tooltip_request = Some(tooltip_request);
966 }
967 self.window.dirty_views.clear();
968
969 self.window
970 .next_frame
971 .dispatch_tree
972 .preserve_pending_keystrokes(
973 &mut self.window.rendered_frame.dispatch_tree,
974 self.window.focus,
975 );
976 self.window.next_frame.focus = self.window.focus;
977 self.window.next_frame.window_active = self.window.active.get();
978 self.window.root_view = Some(root_view);
979
980 // Set the cursor only if we're the active window.
981 let cursor_style = self
982 .window
983 .next_frame
984 .requested_cursor_style
985 .take()
986 .unwrap_or(CursorStyle::Arrow);
987 if self.is_window_active() {
988 self.platform.set_cursor_style(cursor_style);
989 }
990
991 // Register requested input handler with the platform window.
992 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
993 if let Some(handler) = requested_input.handler.take() {
994 self.window.platform_window.set_input_handler(handler);
995 }
996 }
997
998 self.window.layout_engine.as_mut().unwrap().clear();
999 self.text_system()
1000 .finish_frame(&self.window.next_frame.reused_views);
1001 self.window
1002 .next_frame
1003 .finish(&mut self.window.rendered_frame);
1004 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1005 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1006 if percentage >= 80. {
1007 log::warn!("elevated element arena occupation: {}.", percentage);
1008 }
1009 element_arena.clear();
1010 });
1011
1012 let previous_focus_path = self.window.rendered_frame.focus_path();
1013 let previous_window_active = self.window.rendered_frame.window_active;
1014 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1015 self.window.next_frame.clear();
1016 let current_focus_path = self.window.rendered_frame.focus_path();
1017 let current_window_active = self.window.rendered_frame.window_active;
1018
1019 if previous_focus_path != current_focus_path
1020 || previous_window_active != current_window_active
1021 {
1022 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1023 self.window
1024 .focus_lost_listeners
1025 .clone()
1026 .retain(&(), |listener| listener(self));
1027 }
1028
1029 let event = FocusEvent {
1030 previous_focus_path: if previous_window_active {
1031 previous_focus_path
1032 } else {
1033 Default::default()
1034 },
1035 current_focus_path: if current_window_active {
1036 current_focus_path
1037 } else {
1038 Default::default()
1039 },
1040 };
1041 self.window
1042 .focus_listeners
1043 .clone()
1044 .retain(&(), |listener| listener(&event, self));
1045 }
1046 self.window.refreshing = false;
1047 self.window.drawing = false;
1048 }
1049
1050 fn present(&self) {
1051 self.window
1052 .platform_window
1053 .draw(&self.window.rendered_frame.scene);
1054 }
1055
1056 /// Dispatch a mouse or keyboard event on the window.
1057 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1058 self.window.last_input_timestamp.set(Instant::now());
1059 // Handlers may set this to false by calling `stop_propagation`.
1060 self.app.propagate_event = true;
1061 // Handlers may set this to true by calling `prevent_default`.
1062 self.window.default_prevented = false;
1063
1064 let event = match event {
1065 // Track the mouse position with our own state, since accessing the platform
1066 // API for the mouse position can only occur on the main thread.
1067 PlatformInput::MouseMove(mouse_move) => {
1068 self.window.mouse_position = mouse_move.position;
1069 self.window.modifiers = mouse_move.modifiers;
1070 PlatformInput::MouseMove(mouse_move)
1071 }
1072 PlatformInput::MouseDown(mouse_down) => {
1073 self.window.mouse_position = mouse_down.position;
1074 self.window.modifiers = mouse_down.modifiers;
1075 PlatformInput::MouseDown(mouse_down)
1076 }
1077 PlatformInput::MouseUp(mouse_up) => {
1078 self.window.mouse_position = mouse_up.position;
1079 self.window.modifiers = mouse_up.modifiers;
1080 PlatformInput::MouseUp(mouse_up)
1081 }
1082 PlatformInput::MouseExited(mouse_exited) => {
1083 self.window.modifiers = mouse_exited.modifiers;
1084 PlatformInput::MouseExited(mouse_exited)
1085 }
1086 PlatformInput::ModifiersChanged(modifiers_changed) => {
1087 self.window.modifiers = modifiers_changed.modifiers;
1088 PlatformInput::ModifiersChanged(modifiers_changed)
1089 }
1090 PlatformInput::ScrollWheel(scroll_wheel) => {
1091 self.window.mouse_position = scroll_wheel.position;
1092 self.window.modifiers = scroll_wheel.modifiers;
1093 PlatformInput::ScrollWheel(scroll_wheel)
1094 }
1095 // Translate dragging and dropping of external files from the operating system
1096 // to internal drag and drop events.
1097 PlatformInput::FileDrop(file_drop) => match file_drop {
1098 FileDropEvent::Entered { position, paths } => {
1099 self.window.mouse_position = position;
1100 if self.active_drag.is_none() {
1101 self.active_drag = Some(AnyDrag {
1102 value: Box::new(paths.clone()),
1103 view: self.new_view(|_| paths).into(),
1104 cursor_offset: position,
1105 });
1106 }
1107 PlatformInput::MouseMove(MouseMoveEvent {
1108 position,
1109 pressed_button: Some(MouseButton::Left),
1110 modifiers: Modifiers::default(),
1111 })
1112 }
1113 FileDropEvent::Pending { position } => {
1114 self.window.mouse_position = position;
1115 PlatformInput::MouseMove(MouseMoveEvent {
1116 position,
1117 pressed_button: Some(MouseButton::Left),
1118 modifiers: Modifiers::default(),
1119 })
1120 }
1121 FileDropEvent::Submit { position } => {
1122 self.activate(true);
1123 self.window.mouse_position = position;
1124 PlatformInput::MouseUp(MouseUpEvent {
1125 button: MouseButton::Left,
1126 position,
1127 modifiers: Modifiers::default(),
1128 click_count: 1,
1129 })
1130 }
1131 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1132 button: MouseButton::Left,
1133 position: Point::default(),
1134 modifiers: Modifiers::default(),
1135 click_count: 1,
1136 }),
1137 },
1138 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1139 };
1140
1141 if let Some(any_mouse_event) = event.mouse_event() {
1142 self.dispatch_mouse_event(any_mouse_event);
1143 } else if let Some(any_key_event) = event.keyboard_event() {
1144 self.dispatch_key_event(any_key_event);
1145 }
1146
1147 !self.app.propagate_event
1148 }
1149
1150 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1151 if let Some(mut handlers) = self
1152 .window
1153 .rendered_frame
1154 .mouse_listeners
1155 .remove(&event.type_id())
1156 {
1157 // Because handlers may add other handlers, we sort every time.
1158 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1159
1160 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1161 // special purposes, such as detecting events outside of a given Bounds.
1162 for (_, _, handler) in &mut handlers {
1163 self.with_element_context(|cx| {
1164 handler(event, DispatchPhase::Capture, cx);
1165 });
1166 if !self.app.propagate_event {
1167 break;
1168 }
1169 }
1170
1171 // Bubble phase, where most normal handlers do their work.
1172 if self.app.propagate_event {
1173 for (_, _, handler) in handlers.iter_mut().rev() {
1174 self.with_element_context(|cx| {
1175 handler(event, DispatchPhase::Bubble, cx);
1176 });
1177 if !self.app.propagate_event {
1178 break;
1179 }
1180 }
1181 }
1182
1183 self.window
1184 .rendered_frame
1185 .mouse_listeners
1186 .insert(event.type_id(), handlers);
1187 }
1188
1189 if self.app.propagate_event && self.has_active_drag() {
1190 if event.is::<MouseMoveEvent>() {
1191 // If this was a mouse move event, redraw the window so that the
1192 // active drag can follow the mouse cursor.
1193 self.refresh();
1194 } else if event.is::<MouseUpEvent>() {
1195 // If this was a mouse up event, cancel the active drag and redraw
1196 // the window.
1197 self.active_drag = None;
1198 self.refresh();
1199 }
1200 }
1201 }
1202
1203 fn dispatch_key_event(&mut self, event: &dyn Any) {
1204 let node_id = self
1205 .window
1206 .focus
1207 .and_then(|focus_id| {
1208 self.window
1209 .rendered_frame
1210 .dispatch_tree
1211 .focusable_node_id(focus_id)
1212 })
1213 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1214
1215 let dispatch_path = self
1216 .window
1217 .rendered_frame
1218 .dispatch_tree
1219 .dispatch_path(node_id);
1220
1221 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1222 let KeymatchResult { bindings, pending } = self
1223 .window
1224 .rendered_frame
1225 .dispatch_tree
1226 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1227
1228 if pending {
1229 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1230 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1231 {
1232 currently_pending = PendingInput::default();
1233 }
1234 currently_pending.focus = self.window.focus;
1235 currently_pending
1236 .keystrokes
1237 .push(key_down_event.keystroke.clone());
1238 for binding in bindings {
1239 currently_pending.bindings.push(binding);
1240 }
1241
1242 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1243 cx.background_executor.timer(Duration::from_secs(1)).await;
1244 cx.update(move |cx| {
1245 cx.clear_pending_keystrokes();
1246 let Some(currently_pending) = cx.window.pending_input.take() else {
1247 return;
1248 };
1249 cx.replay_pending_input(currently_pending)
1250 })
1251 .log_err();
1252 }));
1253 self.window.pending_input = Some(currently_pending);
1254
1255 self.propagate_event = false;
1256 return;
1257 } else if let Some(currently_pending) = self.window.pending_input.take() {
1258 if bindings
1259 .iter()
1260 .all(|binding| !currently_pending.used_by_binding(binding))
1261 {
1262 self.replay_pending_input(currently_pending)
1263 }
1264 }
1265
1266 if !bindings.is_empty() {
1267 self.clear_pending_keystrokes();
1268 }
1269
1270 self.propagate_event = true;
1271 for binding in bindings {
1272 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1273 if !self.propagate_event {
1274 self.dispatch_keystroke_observers(event, Some(binding.action));
1275 return;
1276 }
1277 }
1278 }
1279
1280 self.dispatch_key_down_up_event(event, &dispatch_path);
1281 if !self.propagate_event {
1282 return;
1283 }
1284
1285 self.dispatch_keystroke_observers(event, None);
1286 }
1287
1288 fn dispatch_key_down_up_event(
1289 &mut self,
1290 event: &dyn Any,
1291 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1292 ) {
1293 // Capture phase
1294 for node_id in dispatch_path {
1295 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1296
1297 for key_listener in node.key_listeners.clone() {
1298 self.with_element_context(|cx| {
1299 key_listener(event, DispatchPhase::Capture, cx);
1300 });
1301 if !self.propagate_event {
1302 return;
1303 }
1304 }
1305 }
1306
1307 // Bubble phase
1308 for node_id in dispatch_path.iter().rev() {
1309 // Handle low level key events
1310 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1311 for key_listener in node.key_listeners.clone() {
1312 self.with_element_context(|cx| {
1313 key_listener(event, DispatchPhase::Bubble, cx);
1314 });
1315 if !self.propagate_event {
1316 return;
1317 }
1318 }
1319 }
1320 }
1321
1322 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1323 pub fn has_pending_keystrokes(&self) -> bool {
1324 self.window
1325 .rendered_frame
1326 .dispatch_tree
1327 .has_pending_keystrokes()
1328 }
1329
1330 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1331 let node_id = self
1332 .window
1333 .focus
1334 .and_then(|focus_id| {
1335 self.window
1336 .rendered_frame
1337 .dispatch_tree
1338 .focusable_node_id(focus_id)
1339 })
1340 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1341
1342 if self.window.focus != currently_pending.focus {
1343 return;
1344 }
1345
1346 let input = currently_pending.input();
1347
1348 self.propagate_event = true;
1349 for binding in currently_pending.bindings {
1350 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1351 if !self.propagate_event {
1352 return;
1353 }
1354 }
1355
1356 let dispatch_path = self
1357 .window
1358 .rendered_frame
1359 .dispatch_tree
1360 .dispatch_path(node_id);
1361
1362 for keystroke in currently_pending.keystrokes {
1363 let event = KeyDownEvent {
1364 keystroke,
1365 is_held: false,
1366 };
1367
1368 self.dispatch_key_down_up_event(&event, &dispatch_path);
1369 if !self.propagate_event {
1370 return;
1371 }
1372 }
1373
1374 if !input.is_empty() {
1375 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1376 input_handler.flush_pending_input(&input, self);
1377 self.window.platform_window.set_input_handler(input_handler)
1378 }
1379 }
1380 }
1381
1382 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1383 let dispatch_path = self
1384 .window
1385 .rendered_frame
1386 .dispatch_tree
1387 .dispatch_path(node_id);
1388
1389 // Capture phase
1390 for node_id in &dispatch_path {
1391 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1392 for DispatchActionListener {
1393 action_type,
1394 listener,
1395 } in node.action_listeners.clone()
1396 {
1397 let any_action = action.as_any();
1398 if action_type == any_action.type_id() {
1399 self.with_element_context(|cx| {
1400 listener(any_action, DispatchPhase::Capture, cx);
1401 });
1402
1403 if !self.propagate_event {
1404 return;
1405 }
1406 }
1407 }
1408 }
1409 // Bubble phase
1410 for node_id in dispatch_path.iter().rev() {
1411 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1412 for DispatchActionListener {
1413 action_type,
1414 listener,
1415 } in node.action_listeners.clone()
1416 {
1417 let any_action = action.as_any();
1418 if action_type == any_action.type_id() {
1419 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1420
1421 self.with_element_context(|cx| {
1422 listener(any_action, DispatchPhase::Bubble, cx);
1423 });
1424
1425 if !self.propagate_event {
1426 return;
1427 }
1428 }
1429 }
1430 }
1431 }
1432
1433 /// Register the given handler to be invoked whenever the global of the given type
1434 /// is updated.
1435 pub fn observe_global<G: Global>(
1436 &mut self,
1437 f: impl Fn(&mut WindowContext<'_>) + 'static,
1438 ) -> Subscription {
1439 let window_handle = self.window.handle;
1440 let (subscription, activate) = self.global_observers.insert(
1441 TypeId::of::<G>(),
1442 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1443 );
1444 self.app.defer(move |_| activate());
1445 subscription
1446 }
1447
1448 /// Focus the current window and bring it to the foreground at the platform level.
1449 pub fn activate_window(&self) {
1450 self.window.platform_window.activate();
1451 }
1452
1453 /// Minimize the current window at the platform level.
1454 pub fn minimize_window(&self) {
1455 self.window.platform_window.minimize();
1456 }
1457
1458 /// Toggle full screen status on the current window at the platform level.
1459 pub fn toggle_full_screen(&self) {
1460 self.window.platform_window.toggle_full_screen();
1461 }
1462
1463 /// Present a platform dialog.
1464 /// The provided message will be presented, along with buttons for each answer.
1465 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1466 pub fn prompt(
1467 &self,
1468 level: PromptLevel,
1469 message: &str,
1470 detail: Option<&str>,
1471 answers: &[&str],
1472 ) -> oneshot::Receiver<usize> {
1473 self.window
1474 .platform_window
1475 .prompt(level, message, detail, answers)
1476 }
1477
1478 /// Returns all available actions for the focused element.
1479 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1480 let node_id = self
1481 .window
1482 .focus
1483 .and_then(|focus_id| {
1484 self.window
1485 .rendered_frame
1486 .dispatch_tree
1487 .focusable_node_id(focus_id)
1488 })
1489 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1490
1491 self.window
1492 .rendered_frame
1493 .dispatch_tree
1494 .available_actions(node_id)
1495 }
1496
1497 /// Returns key bindings that invoke the given action on the currently focused element.
1498 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1499 self.window
1500 .rendered_frame
1501 .dispatch_tree
1502 .bindings_for_action(
1503 action,
1504 &self.window.rendered_frame.dispatch_tree.context_stack,
1505 )
1506 }
1507
1508 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1509 pub fn bindings_for_action_in(
1510 &self,
1511 action: &dyn Action,
1512 focus_handle: &FocusHandle,
1513 ) -> Vec<KeyBinding> {
1514 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1515
1516 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1517 return vec![];
1518 };
1519 let context_stack = dispatch_tree
1520 .dispatch_path(node_id)
1521 .into_iter()
1522 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1523 .collect();
1524 dispatch_tree.bindings_for_action(action, &context_stack)
1525 }
1526
1527 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1528 pub fn listener_for<V: Render, E>(
1529 &self,
1530 view: &View<V>,
1531 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1532 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1533 let view = view.downgrade();
1534 move |e: &E, cx: &mut WindowContext| {
1535 view.update(cx, |view, cx| f(view, e, cx)).ok();
1536 }
1537 }
1538
1539 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1540 pub fn handler_for<V: Render>(
1541 &self,
1542 view: &View<V>,
1543 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1544 ) -> impl Fn(&mut WindowContext) {
1545 let view = view.downgrade();
1546 move |cx: &mut WindowContext| {
1547 view.update(cx, |view, cx| f(view, cx)).ok();
1548 }
1549 }
1550
1551 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1552 /// If the callback returns false, the window won't be closed.
1553 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1554 let mut this = self.to_async();
1555 self.window
1556 .platform_window
1557 .on_should_close(Box::new(move || {
1558 this.update(|cx| {
1559 // Ensure that the window is removed from the app if it's been closed
1560 // by always pre-empting the system close event.
1561 if f(cx) {
1562 cx.remove_window();
1563 }
1564 false
1565 })
1566 .unwrap_or(true)
1567 }))
1568 }
1569
1570 pub(crate) fn parent_view_id(&self) -> EntityId {
1571 *self
1572 .window
1573 .next_frame
1574 .view_stack
1575 .last()
1576 .expect("a view should always be on the stack while drawing")
1577 }
1578
1579 /// Register an action listener on the window for the next frame. The type of action
1580 /// is determined by the first parameter of the given listener. When the next frame is rendered
1581 /// the listener will be cleared.
1582 ///
1583 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1584 /// a specific need to register a global listener.
1585 pub fn on_action(
1586 &mut self,
1587 action_type: TypeId,
1588 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1589 ) {
1590 self.window
1591 .next_frame
1592 .dispatch_tree
1593 .on_action(action_type, Rc::new(listener));
1594 }
1595}
1596
1597impl Context for WindowContext<'_> {
1598 type Result<T> = T;
1599
1600 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1601 where
1602 T: 'static,
1603 {
1604 let slot = self.app.entities.reserve();
1605 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1606 self.entities.insert(slot, model)
1607 }
1608
1609 fn update_model<T: 'static, R>(
1610 &mut self,
1611 model: &Model<T>,
1612 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1613 ) -> R {
1614 let mut entity = self.entities.lease(model);
1615 let result = update(
1616 &mut *entity,
1617 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1618 );
1619 self.entities.end_lease(entity);
1620 result
1621 }
1622
1623 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1624 where
1625 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1626 {
1627 if window == self.window.handle {
1628 let root_view = self.window.root_view.clone().unwrap();
1629 Ok(update(root_view, self))
1630 } else {
1631 window.update(self.app, update)
1632 }
1633 }
1634
1635 fn read_model<T, R>(
1636 &self,
1637 handle: &Model<T>,
1638 read: impl FnOnce(&T, &AppContext) -> R,
1639 ) -> Self::Result<R>
1640 where
1641 T: 'static,
1642 {
1643 let entity = self.entities.read(handle);
1644 read(entity, &*self.app)
1645 }
1646
1647 fn read_window<T, R>(
1648 &self,
1649 window: &WindowHandle<T>,
1650 read: impl FnOnce(View<T>, &AppContext) -> R,
1651 ) -> Result<R>
1652 where
1653 T: 'static,
1654 {
1655 if window.any_handle == self.window.handle {
1656 let root_view = self
1657 .window
1658 .root_view
1659 .clone()
1660 .unwrap()
1661 .downcast::<T>()
1662 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1663 Ok(read(root_view, self))
1664 } else {
1665 self.app.read_window(window, read)
1666 }
1667 }
1668}
1669
1670impl VisualContext for WindowContext<'_> {
1671 fn new_view<V>(
1672 &mut self,
1673 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1674 ) -> Self::Result<View<V>>
1675 where
1676 V: 'static + Render,
1677 {
1678 let slot = self.app.entities.reserve();
1679 let view = View {
1680 model: slot.clone(),
1681 };
1682 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1683 let entity = build_view_state(&mut cx);
1684 cx.entities.insert(slot, entity);
1685
1686 cx.new_view_observers
1687 .clone()
1688 .retain(&TypeId::of::<V>(), |observer| {
1689 let any_view = AnyView::from(view.clone());
1690 (observer)(any_view, self);
1691 true
1692 });
1693
1694 view
1695 }
1696
1697 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1698 fn update_view<T: 'static, R>(
1699 &mut self,
1700 view: &View<T>,
1701 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1702 ) -> Self::Result<R> {
1703 let mut lease = self.app.entities.lease(&view.model);
1704 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1705 let result = update(&mut *lease, &mut cx);
1706 cx.app.entities.end_lease(lease);
1707 result
1708 }
1709
1710 fn replace_root_view<V>(
1711 &mut self,
1712 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1713 ) -> Self::Result<View<V>>
1714 where
1715 V: 'static + Render,
1716 {
1717 let view = self.new_view(build_view);
1718 self.window.root_view = Some(view.clone().into());
1719 self.refresh();
1720 view
1721 }
1722
1723 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1724 self.update_view(view, |view, cx| {
1725 view.focus_handle(cx).clone().focus(cx);
1726 })
1727 }
1728
1729 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1730 where
1731 V: ManagedView,
1732 {
1733 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1734 }
1735}
1736
1737impl<'a> std::ops::Deref for WindowContext<'a> {
1738 type Target = AppContext;
1739
1740 fn deref(&self) -> &Self::Target {
1741 self.app
1742 }
1743}
1744
1745impl<'a> std::ops::DerefMut for WindowContext<'a> {
1746 fn deref_mut(&mut self) -> &mut Self::Target {
1747 self.app
1748 }
1749}
1750
1751impl<'a> Borrow<AppContext> for WindowContext<'a> {
1752 fn borrow(&self) -> &AppContext {
1753 self.app
1754 }
1755}
1756
1757impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1758 fn borrow_mut(&mut self) -> &mut AppContext {
1759 self.app
1760 }
1761}
1762
1763/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1764pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1765 #[doc(hidden)]
1766 fn app_mut(&mut self) -> &mut AppContext {
1767 self.borrow_mut()
1768 }
1769
1770 #[doc(hidden)]
1771 fn app(&self) -> &AppContext {
1772 self.borrow()
1773 }
1774
1775 #[doc(hidden)]
1776 fn window(&self) -> &Window {
1777 self.borrow()
1778 }
1779
1780 #[doc(hidden)]
1781 fn window_mut(&mut self) -> &mut Window {
1782 self.borrow_mut()
1783 }
1784}
1785
1786impl Borrow<Window> for WindowContext<'_> {
1787 fn borrow(&self) -> &Window {
1788 self.window
1789 }
1790}
1791
1792impl BorrowMut<Window> for WindowContext<'_> {
1793 fn borrow_mut(&mut self) -> &mut Window {
1794 self.window
1795 }
1796}
1797
1798impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1799
1800/// Provides access to application state that is specialized for a particular [`View`].
1801/// Allows you to interact with focus, emit events, etc.
1802/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1803/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1804pub struct ViewContext<'a, V> {
1805 window_cx: WindowContext<'a>,
1806 view: &'a View<V>,
1807}
1808
1809impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1810 fn borrow(&self) -> &AppContext {
1811 &*self.window_cx.app
1812 }
1813}
1814
1815impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1816 fn borrow_mut(&mut self) -> &mut AppContext {
1817 &mut *self.window_cx.app
1818 }
1819}
1820
1821impl<V> Borrow<Window> for ViewContext<'_, V> {
1822 fn borrow(&self) -> &Window {
1823 &*self.window_cx.window
1824 }
1825}
1826
1827impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1828 fn borrow_mut(&mut self) -> &mut Window {
1829 &mut *self.window_cx.window
1830 }
1831}
1832
1833impl<'a, V: 'static> ViewContext<'a, V> {
1834 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1835 Self {
1836 window_cx: WindowContext::new(app, window),
1837 view,
1838 }
1839 }
1840
1841 /// Get the entity_id of this view.
1842 pub fn entity_id(&self) -> EntityId {
1843 self.view.entity_id()
1844 }
1845
1846 /// Get the view pointer underlying this context.
1847 pub fn view(&self) -> &View<V> {
1848 self.view
1849 }
1850
1851 /// Get the model underlying this view.
1852 pub fn model(&self) -> &Model<V> {
1853 &self.view.model
1854 }
1855
1856 /// Access the underlying window context.
1857 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1858 &mut self.window_cx
1859 }
1860
1861 /// Sets a given callback to be run on the next frame.
1862 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1863 where
1864 V: 'static,
1865 {
1866 let view = self.view().clone();
1867 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1868 }
1869
1870 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1871 /// that are currently on the stack to be returned to the app.
1872 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1873 let view = self.view().downgrade();
1874 self.window_cx.defer(move |cx| {
1875 view.update(cx, f).ok();
1876 });
1877 }
1878
1879 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1880 pub fn observe<V2, E>(
1881 &mut self,
1882 entity: &E,
1883 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1884 ) -> Subscription
1885 where
1886 V2: 'static,
1887 V: 'static,
1888 E: Entity<V2>,
1889 {
1890 let view = self.view().downgrade();
1891 let entity_id = entity.entity_id();
1892 let entity = entity.downgrade();
1893 let window_handle = self.window.handle;
1894 let (subscription, activate) = self.app.observers.insert(
1895 entity_id,
1896 Box::new(move |cx| {
1897 window_handle
1898 .update(cx, |_, cx| {
1899 if let Some(handle) = E::upgrade_from(&entity) {
1900 view.update(cx, |this, cx| on_notify(this, handle, cx))
1901 .is_ok()
1902 } else {
1903 false
1904 }
1905 })
1906 .unwrap_or(false)
1907 }),
1908 );
1909 self.app.defer(move |_| activate());
1910 subscription
1911 }
1912
1913 /// Subscribe to events emitted by another model or view.
1914 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1915 /// 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.
1916 pub fn subscribe<V2, E, Evt>(
1917 &mut self,
1918 entity: &E,
1919 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1920 ) -> Subscription
1921 where
1922 V2: EventEmitter<Evt>,
1923 E: Entity<V2>,
1924 Evt: 'static,
1925 {
1926 let view = self.view().downgrade();
1927 let entity_id = entity.entity_id();
1928 let handle = entity.downgrade();
1929 let window_handle = self.window.handle;
1930 let (subscription, activate) = self.app.event_listeners.insert(
1931 entity_id,
1932 (
1933 TypeId::of::<Evt>(),
1934 Box::new(move |event, cx| {
1935 window_handle
1936 .update(cx, |_, cx| {
1937 if let Some(handle) = E::upgrade_from(&handle) {
1938 let event = event.downcast_ref().expect("invalid event type");
1939 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1940 .is_ok()
1941 } else {
1942 false
1943 }
1944 })
1945 .unwrap_or(false)
1946 }),
1947 ),
1948 );
1949 self.app.defer(move |_| activate());
1950 subscription
1951 }
1952
1953 /// Register a callback to be invoked when the view is released.
1954 ///
1955 /// The callback receives a handle to the view's window. This handle may be
1956 /// invalid, if the window was closed before the view was released.
1957 pub fn on_release(
1958 &mut self,
1959 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1960 ) -> Subscription {
1961 let window_handle = self.window.handle;
1962 let (subscription, activate) = self.app.release_listeners.insert(
1963 self.view.model.entity_id,
1964 Box::new(move |this, cx| {
1965 let this = this.downcast_mut().expect("invalid entity type");
1966 on_release(this, window_handle, cx)
1967 }),
1968 );
1969 activate();
1970 subscription
1971 }
1972
1973 /// Register a callback to be invoked when the given Model or View is released.
1974 pub fn observe_release<V2, E>(
1975 &mut self,
1976 entity: &E,
1977 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1978 ) -> Subscription
1979 where
1980 V: 'static,
1981 V2: 'static,
1982 E: Entity<V2>,
1983 {
1984 let view = self.view().downgrade();
1985 let entity_id = entity.entity_id();
1986 let window_handle = self.window.handle;
1987 let (subscription, activate) = self.app.release_listeners.insert(
1988 entity_id,
1989 Box::new(move |entity, cx| {
1990 let entity = entity.downcast_mut().expect("invalid entity type");
1991 let _ = window_handle.update(cx, |_, cx| {
1992 view.update(cx, |this, cx| on_release(this, entity, cx))
1993 });
1994 }),
1995 );
1996 activate();
1997 subscription
1998 }
1999
2000 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2001 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2002 pub fn notify(&mut self) {
2003 for view_id in self
2004 .window
2005 .rendered_frame
2006 .dispatch_tree
2007 .view_path(self.view.entity_id())
2008 .into_iter()
2009 .rev()
2010 {
2011 if !self.window.dirty_views.insert(view_id) {
2012 break;
2013 }
2014 }
2015
2016 if !self.window.drawing {
2017 self.window_cx.window.dirty.set(true);
2018 self.window_cx.app.push_effect(Effect::Notify {
2019 emitter: self.view.model.entity_id,
2020 });
2021 }
2022 }
2023
2024 /// Register a callback to be invoked when the window is resized.
2025 pub fn observe_window_bounds(
2026 &mut self,
2027 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2028 ) -> Subscription {
2029 let view = self.view.downgrade();
2030 let (subscription, activate) = self.window.bounds_observers.insert(
2031 (),
2032 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2033 );
2034 activate();
2035 subscription
2036 }
2037
2038 /// Register a callback to be invoked when the window is activated or deactivated.
2039 pub fn observe_window_activation(
2040 &mut self,
2041 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2042 ) -> Subscription {
2043 let view = self.view.downgrade();
2044 let (subscription, activate) = self.window.activation_observers.insert(
2045 (),
2046 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2047 );
2048 activate();
2049 subscription
2050 }
2051
2052 /// Register a listener to be called when the given focus handle receives focus.
2053 /// Returns a subscription and persists until the subscription is dropped.
2054 pub fn on_focus(
2055 &mut self,
2056 handle: &FocusHandle,
2057 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2058 ) -> Subscription {
2059 let view = self.view.downgrade();
2060 let focus_id = handle.id;
2061 let (subscription, activate) = self.window.focus_listeners.insert(
2062 (),
2063 Box::new(move |event, cx| {
2064 view.update(cx, |view, cx| {
2065 if event.previous_focus_path.last() != Some(&focus_id)
2066 && event.current_focus_path.last() == Some(&focus_id)
2067 {
2068 listener(view, cx)
2069 }
2070 })
2071 .is_ok()
2072 }),
2073 );
2074 self.app.defer(move |_| activate());
2075 subscription
2076 }
2077
2078 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2079 /// Returns a subscription and persists until the subscription is dropped.
2080 pub fn on_focus_in(
2081 &mut self,
2082 handle: &FocusHandle,
2083 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2084 ) -> Subscription {
2085 let view = self.view.downgrade();
2086 let focus_id = handle.id;
2087 let (subscription, activate) = self.window.focus_listeners.insert(
2088 (),
2089 Box::new(move |event, cx| {
2090 view.update(cx, |view, cx| {
2091 if !event.previous_focus_path.contains(&focus_id)
2092 && event.current_focus_path.contains(&focus_id)
2093 {
2094 listener(view, cx)
2095 }
2096 })
2097 .is_ok()
2098 }),
2099 );
2100 self.app.defer(move |_| activate());
2101 subscription
2102 }
2103
2104 /// Register a listener to be called when the given focus handle loses focus.
2105 /// Returns a subscription and persists until the subscription is dropped.
2106 pub fn on_blur(
2107 &mut self,
2108 handle: &FocusHandle,
2109 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2110 ) -> Subscription {
2111 let view = self.view.downgrade();
2112 let focus_id = handle.id;
2113 let (subscription, activate) = self.window.focus_listeners.insert(
2114 (),
2115 Box::new(move |event, cx| {
2116 view.update(cx, |view, cx| {
2117 if event.previous_focus_path.last() == Some(&focus_id)
2118 && event.current_focus_path.last() != Some(&focus_id)
2119 {
2120 listener(view, cx)
2121 }
2122 })
2123 .is_ok()
2124 }),
2125 );
2126 self.app.defer(move |_| activate());
2127 subscription
2128 }
2129
2130 /// Register a listener to be called when nothing in the window has focus.
2131 /// This typically happens when the node that was focused is removed from the tree,
2132 /// and this callback lets you chose a default place to restore the users focus.
2133 /// Returns a subscription and persists until the subscription is dropped.
2134 pub fn on_focus_lost(
2135 &mut self,
2136 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2137 ) -> Subscription {
2138 let view = self.view.downgrade();
2139 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2140 (),
2141 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2142 );
2143 activate();
2144 subscription
2145 }
2146
2147 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2148 /// Returns a subscription and persists until the subscription is dropped.
2149 pub fn on_focus_out(
2150 &mut self,
2151 handle: &FocusHandle,
2152 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2153 ) -> Subscription {
2154 let view = self.view.downgrade();
2155 let focus_id = handle.id;
2156 let (subscription, activate) = self.window.focus_listeners.insert(
2157 (),
2158 Box::new(move |event, cx| {
2159 view.update(cx, |view, cx| {
2160 if event.previous_focus_path.contains(&focus_id)
2161 && !event.current_focus_path.contains(&focus_id)
2162 {
2163 listener(view, cx)
2164 }
2165 })
2166 .is_ok()
2167 }),
2168 );
2169 self.app.defer(move |_| activate());
2170 subscription
2171 }
2172
2173 /// Schedule a future to be run asynchronously.
2174 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2175 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2176 /// The returned future will be polled on the main thread.
2177 pub fn spawn<Fut, R>(
2178 &mut self,
2179 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2180 ) -> Task<R>
2181 where
2182 R: 'static,
2183 Fut: Future<Output = R> + 'static,
2184 {
2185 let view = self.view().downgrade();
2186 self.window_cx.spawn(|cx| f(view, cx))
2187 }
2188
2189 /// Updates the global state of the given type.
2190 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2191 where
2192 G: Global,
2193 {
2194 let mut global = self.app.lease_global::<G>();
2195 let result = f(&mut global, self);
2196 self.app.end_global_lease(global);
2197 result
2198 }
2199
2200 /// Register a callback to be invoked when the given global state changes.
2201 pub fn observe_global<G: Global>(
2202 &mut self,
2203 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2204 ) -> Subscription {
2205 let window_handle = self.window.handle;
2206 let view = self.view().downgrade();
2207 let (subscription, activate) = self.global_observers.insert(
2208 TypeId::of::<G>(),
2209 Box::new(move |cx| {
2210 window_handle
2211 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2212 .unwrap_or(false)
2213 }),
2214 );
2215 self.app.defer(move |_| activate());
2216 subscription
2217 }
2218
2219 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2220 pub fn on_action(
2221 &mut self,
2222 action_type: TypeId,
2223 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2224 ) {
2225 let handle = self.view().clone();
2226 self.window_cx
2227 .on_action(action_type, move |action, phase, cx| {
2228 handle.update(cx, |view, cx| {
2229 listener(view, action, phase, cx);
2230 })
2231 });
2232 }
2233
2234 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2235 pub fn emit<Evt>(&mut self, event: Evt)
2236 where
2237 Evt: 'static,
2238 V: EventEmitter<Evt>,
2239 {
2240 let emitter = self.view.model.entity_id;
2241 self.app.push_effect(Effect::Emit {
2242 emitter,
2243 event_type: TypeId::of::<Evt>(),
2244 event: Box::new(event),
2245 });
2246 }
2247
2248 /// Move focus to the current view, assuming it implements [`FocusableView`].
2249 pub fn focus_self(&mut self)
2250 where
2251 V: FocusableView,
2252 {
2253 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2254 }
2255
2256 /// Convenience method for accessing view state in an event callback.
2257 ///
2258 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2259 /// but it's often useful to be able to access view state in these
2260 /// callbacks. This method provides a convenient way to do so.
2261 pub fn listener<E>(
2262 &self,
2263 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2264 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2265 let view = self.view().downgrade();
2266 move |e: &E, cx: &mut WindowContext| {
2267 view.update(cx, |view, cx| f(view, e, cx)).ok();
2268 }
2269 }
2270}
2271
2272impl<V> Context for ViewContext<'_, V> {
2273 type Result<U> = U;
2274
2275 fn new_model<T: 'static>(
2276 &mut self,
2277 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2278 ) -> Model<T> {
2279 self.window_cx.new_model(build_model)
2280 }
2281
2282 fn update_model<T: 'static, R>(
2283 &mut self,
2284 model: &Model<T>,
2285 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2286 ) -> R {
2287 self.window_cx.update_model(model, update)
2288 }
2289
2290 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2291 where
2292 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2293 {
2294 self.window_cx.update_window(window, update)
2295 }
2296
2297 fn read_model<T, R>(
2298 &self,
2299 handle: &Model<T>,
2300 read: impl FnOnce(&T, &AppContext) -> R,
2301 ) -> Self::Result<R>
2302 where
2303 T: 'static,
2304 {
2305 self.window_cx.read_model(handle, read)
2306 }
2307
2308 fn read_window<T, R>(
2309 &self,
2310 window: &WindowHandle<T>,
2311 read: impl FnOnce(View<T>, &AppContext) -> R,
2312 ) -> Result<R>
2313 where
2314 T: 'static,
2315 {
2316 self.window_cx.read_window(window, read)
2317 }
2318}
2319
2320impl<V: 'static> VisualContext for ViewContext<'_, V> {
2321 fn new_view<W: Render + 'static>(
2322 &mut self,
2323 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2324 ) -> Self::Result<View<W>> {
2325 self.window_cx.new_view(build_view_state)
2326 }
2327
2328 fn update_view<V2: 'static, R>(
2329 &mut self,
2330 view: &View<V2>,
2331 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2332 ) -> Self::Result<R> {
2333 self.window_cx.update_view(view, update)
2334 }
2335
2336 fn replace_root_view<W>(
2337 &mut self,
2338 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2339 ) -> Self::Result<View<W>>
2340 where
2341 W: 'static + Render,
2342 {
2343 self.window_cx.replace_root_view(build_view)
2344 }
2345
2346 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2347 self.window_cx.focus_view(view)
2348 }
2349
2350 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2351 self.window_cx.dismiss_view(view)
2352 }
2353}
2354
2355impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2356 type Target = WindowContext<'a>;
2357
2358 fn deref(&self) -> &Self::Target {
2359 &self.window_cx
2360 }
2361}
2362
2363impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2364 fn deref_mut(&mut self) -> &mut Self::Target {
2365 &mut self.window_cx
2366 }
2367}
2368
2369// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2370slotmap::new_key_type! {
2371 /// A unique identifier for a window.
2372 pub struct WindowId;
2373}
2374
2375impl WindowId {
2376 /// Converts this window ID to a `u64`.
2377 pub fn as_u64(&self) -> u64 {
2378 self.0.as_ffi()
2379 }
2380}
2381
2382/// A handle to a window with a specific root view type.
2383/// Note that this does not keep the window alive on its own.
2384#[derive(Deref, DerefMut)]
2385pub struct WindowHandle<V> {
2386 #[deref]
2387 #[deref_mut]
2388 pub(crate) any_handle: AnyWindowHandle,
2389 state_type: PhantomData<V>,
2390}
2391
2392impl<V: 'static + Render> WindowHandle<V> {
2393 /// Creates a new handle from a window ID.
2394 /// This does not check if the root type of the window is `V`.
2395 pub fn new(id: WindowId) -> Self {
2396 WindowHandle {
2397 any_handle: AnyWindowHandle {
2398 id,
2399 state_type: TypeId::of::<V>(),
2400 },
2401 state_type: PhantomData,
2402 }
2403 }
2404
2405 /// Get the root view out of this window.
2406 ///
2407 /// This will fail if the window is closed or if the root view's type does not match `V`.
2408 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2409 where
2410 C: Context,
2411 {
2412 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2413 root_view
2414 .downcast::<V>()
2415 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2416 }))
2417 }
2418
2419 /// Updates the root view of this window.
2420 ///
2421 /// This will fail if the window has been closed or if the root view's type does not match
2422 pub fn update<C, R>(
2423 &self,
2424 cx: &mut C,
2425 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2426 ) -> Result<R>
2427 where
2428 C: Context,
2429 {
2430 cx.update_window(self.any_handle, |root_view, cx| {
2431 let view = root_view
2432 .downcast::<V>()
2433 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2434 Ok(cx.update_view(&view, update))
2435 })?
2436 }
2437
2438 /// Read the root view out of this window.
2439 ///
2440 /// This will fail if the window is closed or if the root view's type does not match `V`.
2441 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2442 let x = cx
2443 .windows
2444 .get(self.id)
2445 .and_then(|window| {
2446 window
2447 .as_ref()
2448 .and_then(|window| window.root_view.clone())
2449 .map(|root_view| root_view.downcast::<V>())
2450 })
2451 .ok_or_else(|| anyhow!("window not found"))?
2452 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2453
2454 Ok(x.read(cx))
2455 }
2456
2457 /// Read the root view out of this window, with a callback
2458 ///
2459 /// This will fail if the window is closed or if the root view's type does not match `V`.
2460 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2461 where
2462 C: Context,
2463 {
2464 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2465 }
2466
2467 /// Read the root view pointer off of this window.
2468 ///
2469 /// This will fail if the window is closed or if the root view's type does not match `V`.
2470 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2471 where
2472 C: Context,
2473 {
2474 cx.read_window(self, |root_view, _cx| root_view.clone())
2475 }
2476
2477 /// Check if this window is 'active'.
2478 ///
2479 /// Will return `None` if the window is closed.
2480 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2481 cx.windows
2482 .get(self.id)
2483 .and_then(|window| window.as_ref().map(|window| window.active.get()))
2484 }
2485}
2486
2487impl<V> Copy for WindowHandle<V> {}
2488
2489impl<V> Clone for WindowHandle<V> {
2490 fn clone(&self) -> Self {
2491 *self
2492 }
2493}
2494
2495impl<V> PartialEq for WindowHandle<V> {
2496 fn eq(&self, other: &Self) -> bool {
2497 self.any_handle == other.any_handle
2498 }
2499}
2500
2501impl<V> Eq for WindowHandle<V> {}
2502
2503impl<V> Hash for WindowHandle<V> {
2504 fn hash<H: Hasher>(&self, state: &mut H) {
2505 self.any_handle.hash(state);
2506 }
2507}
2508
2509impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2510 fn from(val: WindowHandle<V>) -> Self {
2511 val.any_handle
2512 }
2513}
2514
2515/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2516#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2517pub struct AnyWindowHandle {
2518 pub(crate) id: WindowId,
2519 state_type: TypeId,
2520}
2521
2522impl AnyWindowHandle {
2523 /// Get the ID of this window.
2524 pub fn window_id(&self) -> WindowId {
2525 self.id
2526 }
2527
2528 /// Attempt to convert this handle to a window handle with a specific root view type.
2529 /// If the types do not match, this will return `None`.
2530 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2531 if TypeId::of::<T>() == self.state_type {
2532 Some(WindowHandle {
2533 any_handle: *self,
2534 state_type: PhantomData,
2535 })
2536 } else {
2537 None
2538 }
2539 }
2540
2541 /// Updates the state of the root view of this window.
2542 ///
2543 /// This will fail if the window has been closed.
2544 pub fn update<C, R>(
2545 self,
2546 cx: &mut C,
2547 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2548 ) -> Result<R>
2549 where
2550 C: Context,
2551 {
2552 cx.update_window(self, update)
2553 }
2554
2555 /// Read the state of the root view of this window.
2556 ///
2557 /// This will fail if the window has been closed.
2558 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2559 where
2560 C: Context,
2561 T: 'static,
2562 {
2563 let view = self
2564 .downcast::<T>()
2565 .context("the type of the window's root view has changed")?;
2566
2567 cx.read_window(&view, read)
2568 }
2569}
2570
2571/// An identifier for an [`Element`](crate::Element).
2572///
2573/// Can be constructed with a string, a number, or both, as well
2574/// as other internal representations.
2575#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2576pub enum ElementId {
2577 /// The ID of a View element
2578 View(EntityId),
2579 /// An integer ID.
2580 Integer(usize),
2581 /// A string based ID.
2582 Name(SharedString),
2583 /// An ID that's equated with a focus handle.
2584 FocusHandle(FocusId),
2585 /// A combination of a name and an integer.
2586 NamedInteger(SharedString, usize),
2587}
2588
2589impl Display for ElementId {
2590 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2591 match self {
2592 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2593 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2594 ElementId::Name(name) => write!(f, "{}", name)?,
2595 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2596 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2597 }
2598
2599 Ok(())
2600 }
2601}
2602
2603impl ElementId {
2604 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2605 ElementId::View(entity_id)
2606 }
2607}
2608
2609impl TryInto<SharedString> for ElementId {
2610 type Error = anyhow::Error;
2611
2612 fn try_into(self) -> anyhow::Result<SharedString> {
2613 if let ElementId::Name(name) = self {
2614 Ok(name)
2615 } else {
2616 Err(anyhow!("element id is not string"))
2617 }
2618 }
2619}
2620
2621impl From<usize> for ElementId {
2622 fn from(id: usize) -> Self {
2623 ElementId::Integer(id)
2624 }
2625}
2626
2627impl From<i32> for ElementId {
2628 fn from(id: i32) -> Self {
2629 Self::Integer(id as usize)
2630 }
2631}
2632
2633impl From<SharedString> for ElementId {
2634 fn from(name: SharedString) -> Self {
2635 ElementId::Name(name)
2636 }
2637}
2638
2639impl From<&'static str> for ElementId {
2640 fn from(name: &'static str) -> Self {
2641 ElementId::Name(name.into())
2642 }
2643}
2644
2645impl<'a> From<&'a FocusHandle> for ElementId {
2646 fn from(handle: &'a FocusHandle) -> Self {
2647 ElementId::FocusHandle(handle.id)
2648 }
2649}
2650
2651impl From<(&'static str, EntityId)> for ElementId {
2652 fn from((name, id): (&'static str, EntityId)) -> Self {
2653 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2654 }
2655}
2656
2657impl From<(&'static str, usize)> for ElementId {
2658 fn from((name, id): (&'static str, usize)) -> Self {
2659 ElementId::NamedInteger(name.into(), id)
2660 }
2661}
2662
2663impl From<(&'static str, u64)> for ElementId {
2664 fn from((name, id): (&'static str, u64)) -> Self {
2665 ElementId::NamedInteger(name.into(), id as usize)
2666 }
2667}
2668
2669/// A rectangle to be rendered in the window at the given position and size.
2670/// Passed as an argument [`ElementContext::paint_quad`].
2671#[derive(Clone)]
2672pub struct PaintQuad {
2673 bounds: Bounds<Pixels>,
2674 corner_radii: Corners<Pixels>,
2675 background: Hsla,
2676 border_widths: Edges<Pixels>,
2677 border_color: Hsla,
2678}
2679
2680impl PaintQuad {
2681 /// Sets the corner radii of the quad.
2682 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2683 PaintQuad {
2684 corner_radii: corner_radii.into(),
2685 ..self
2686 }
2687 }
2688
2689 /// Sets the border widths of the quad.
2690 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2691 PaintQuad {
2692 border_widths: border_widths.into(),
2693 ..self
2694 }
2695 }
2696
2697 /// Sets the border color of the quad.
2698 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2699 PaintQuad {
2700 border_color: border_color.into(),
2701 ..self
2702 }
2703 }
2704
2705 /// Sets the background color of the quad.
2706 pub fn background(self, background: impl Into<Hsla>) -> Self {
2707 PaintQuad {
2708 background: background.into(),
2709 ..self
2710 }
2711 }
2712}
2713
2714/// Creates a quad with the given parameters.
2715pub fn quad(
2716 bounds: Bounds<Pixels>,
2717 corner_radii: impl Into<Corners<Pixels>>,
2718 background: impl Into<Hsla>,
2719 border_widths: impl Into<Edges<Pixels>>,
2720 border_color: impl Into<Hsla>,
2721) -> PaintQuad {
2722 PaintQuad {
2723 bounds,
2724 corner_radii: corner_radii.into(),
2725 background: background.into(),
2726 border_widths: border_widths.into(),
2727 border_color: border_color.into(),
2728 }
2729}
2730
2731/// Creates a filled quad with the given bounds and background color.
2732pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2733 PaintQuad {
2734 bounds: bounds.into(),
2735 corner_radii: (0.).into(),
2736 background: background.into(),
2737 border_widths: (0.).into(),
2738 border_color: transparent_black(),
2739 }
2740}
2741
2742/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2743pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2744 PaintQuad {
2745 bounds: bounds.into(),
2746 corner_radii: (0.).into(),
2747 background: transparent_black(),
2748 border_widths: (1.).into(),
2749 border_color: border_color.into(),
2750 }
2751}