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 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 given keystroke as though the user had typed it.
1103 /// You can create a keystroke with Keystroke::parse("").
1104 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
1105 let keystroke = keystroke.with_simulated_ime();
1106 if self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
1107 keystroke: keystroke.clone(),
1108 is_held: false,
1109 })) {
1110 return true;
1111 }
1112
1113 if let Some(input) = keystroke.ime_key {
1114 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1115 input_handler.dispatch_input(&input, self);
1116 self.window.platform_window.set_input_handler(input_handler);
1117 return true;
1118 }
1119 }
1120
1121 false
1122 }
1123
1124 /// Dispatch a mouse or keyboard event on the window.
1125 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1126 self.window.last_input_timestamp.set(Instant::now());
1127 // Handlers may set this to false by calling `stop_propagation`.
1128 self.app.propagate_event = true;
1129 // Handlers may set this to true by calling `prevent_default`.
1130 self.window.default_prevented = false;
1131
1132 let event = match event {
1133 // Track the mouse position with our own state, since accessing the platform
1134 // API for the mouse position can only occur on the main thread.
1135 PlatformInput::MouseMove(mouse_move) => {
1136 self.window.mouse_position = mouse_move.position;
1137 self.window.modifiers = mouse_move.modifiers;
1138 PlatformInput::MouseMove(mouse_move)
1139 }
1140 PlatformInput::MouseDown(mouse_down) => {
1141 self.window.mouse_position = mouse_down.position;
1142 self.window.modifiers = mouse_down.modifiers;
1143 PlatformInput::MouseDown(mouse_down)
1144 }
1145 PlatformInput::MouseUp(mouse_up) => {
1146 self.window.mouse_position = mouse_up.position;
1147 self.window.modifiers = mouse_up.modifiers;
1148 PlatformInput::MouseUp(mouse_up)
1149 }
1150 PlatformInput::MouseExited(mouse_exited) => {
1151 self.window.modifiers = mouse_exited.modifiers;
1152 PlatformInput::MouseExited(mouse_exited)
1153 }
1154 PlatformInput::ModifiersChanged(modifiers_changed) => {
1155 self.window.modifiers = modifiers_changed.modifiers;
1156 PlatformInput::ModifiersChanged(modifiers_changed)
1157 }
1158 PlatformInput::ScrollWheel(scroll_wheel) => {
1159 self.window.mouse_position = scroll_wheel.position;
1160 self.window.modifiers = scroll_wheel.modifiers;
1161 PlatformInput::ScrollWheel(scroll_wheel)
1162 }
1163 // Translate dragging and dropping of external files from the operating system
1164 // to internal drag and drop events.
1165 PlatformInput::FileDrop(file_drop) => match file_drop {
1166 FileDropEvent::Entered { position, paths } => {
1167 self.window.mouse_position = position;
1168 if self.active_drag.is_none() {
1169 self.active_drag = Some(AnyDrag {
1170 value: Box::new(paths.clone()),
1171 view: self.new_view(|_| paths).into(),
1172 cursor_offset: position,
1173 });
1174 }
1175 PlatformInput::MouseMove(MouseMoveEvent {
1176 position,
1177 pressed_button: Some(MouseButton::Left),
1178 modifiers: Modifiers::default(),
1179 })
1180 }
1181 FileDropEvent::Pending { position } => {
1182 self.window.mouse_position = position;
1183 PlatformInput::MouseMove(MouseMoveEvent {
1184 position,
1185 pressed_button: Some(MouseButton::Left),
1186 modifiers: Modifiers::default(),
1187 })
1188 }
1189 FileDropEvent::Submit { position } => {
1190 self.activate(true);
1191 self.window.mouse_position = position;
1192 PlatformInput::MouseUp(MouseUpEvent {
1193 button: MouseButton::Left,
1194 position,
1195 modifiers: Modifiers::default(),
1196 click_count: 1,
1197 })
1198 }
1199 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1200 button: MouseButton::Left,
1201 position: Point::default(),
1202 modifiers: Modifiers::default(),
1203 click_count: 1,
1204 }),
1205 },
1206 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1207 };
1208
1209 if let Some(any_mouse_event) = event.mouse_event() {
1210 self.dispatch_mouse_event(any_mouse_event);
1211 } else if let Some(any_key_event) = event.keyboard_event() {
1212 self.dispatch_key_event(any_key_event);
1213 }
1214
1215 !self.app.propagate_event
1216 }
1217
1218 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1219 if let Some(mut handlers) = self
1220 .window
1221 .rendered_frame
1222 .mouse_listeners
1223 .remove(&event.type_id())
1224 {
1225 // Because handlers may add other handlers, we sort every time.
1226 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1227
1228 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1229 // special purposes, such as detecting events outside of a given Bounds.
1230 for (_, _, handler) in &mut handlers {
1231 self.with_element_context(|cx| {
1232 handler(event, DispatchPhase::Capture, cx);
1233 });
1234 if !self.app.propagate_event {
1235 break;
1236 }
1237 }
1238
1239 // Bubble phase, where most normal handlers do their work.
1240 if self.app.propagate_event {
1241 for (_, _, handler) in handlers.iter_mut().rev() {
1242 self.with_element_context(|cx| {
1243 handler(event, DispatchPhase::Bubble, cx);
1244 });
1245 if !self.app.propagate_event {
1246 break;
1247 }
1248 }
1249 }
1250
1251 self.window
1252 .rendered_frame
1253 .mouse_listeners
1254 .insert(event.type_id(), handlers);
1255 }
1256
1257 if self.app.propagate_event && self.has_active_drag() {
1258 if event.is::<MouseMoveEvent>() {
1259 // If this was a mouse move event, redraw the window so that the
1260 // active drag can follow the mouse cursor.
1261 self.refresh();
1262 } else if event.is::<MouseUpEvent>() {
1263 // If this was a mouse up event, cancel the active drag and redraw
1264 // the window.
1265 self.active_drag = None;
1266 self.refresh();
1267 }
1268 }
1269 }
1270
1271 fn dispatch_key_event(&mut self, event: &dyn Any) {
1272 if self.window.dirty.get() {
1273 self.draw();
1274 }
1275
1276 let node_id = self
1277 .window
1278 .focus
1279 .and_then(|focus_id| {
1280 self.window
1281 .rendered_frame
1282 .dispatch_tree
1283 .focusable_node_id(focus_id)
1284 })
1285 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1286
1287 let dispatch_path = self
1288 .window
1289 .rendered_frame
1290 .dispatch_tree
1291 .dispatch_path(node_id);
1292
1293 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1294 let KeymatchResult { bindings, pending } = self
1295 .window
1296 .rendered_frame
1297 .dispatch_tree
1298 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1299
1300 if pending {
1301 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1302 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1303 {
1304 currently_pending = PendingInput::default();
1305 }
1306 currently_pending.focus = self.window.focus;
1307 currently_pending
1308 .keystrokes
1309 .push(key_down_event.keystroke.clone());
1310 for binding in bindings {
1311 currently_pending.bindings.push(binding);
1312 }
1313
1314 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1315 cx.background_executor.timer(Duration::from_secs(1)).await;
1316 cx.update(move |cx| {
1317 cx.clear_pending_keystrokes();
1318 let Some(currently_pending) = cx.window.pending_input.take() else {
1319 return;
1320 };
1321 cx.replay_pending_input(currently_pending)
1322 })
1323 .log_err();
1324 }));
1325 self.window.pending_input = Some(currently_pending);
1326
1327 self.propagate_event = false;
1328 return;
1329 } else if let Some(currently_pending) = self.window.pending_input.take() {
1330 if bindings
1331 .iter()
1332 .all(|binding| !currently_pending.used_by_binding(binding))
1333 {
1334 self.replay_pending_input(currently_pending)
1335 }
1336 }
1337
1338 if !bindings.is_empty() {
1339 self.clear_pending_keystrokes();
1340 }
1341
1342 self.propagate_event = true;
1343 for binding in bindings {
1344 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1345 if !self.propagate_event {
1346 self.dispatch_keystroke_observers(event, Some(binding.action));
1347 return;
1348 }
1349 }
1350 }
1351
1352 self.dispatch_key_down_up_event(event, &dispatch_path);
1353 if !self.propagate_event {
1354 return;
1355 }
1356
1357 self.dispatch_keystroke_observers(event, None);
1358 }
1359
1360 fn dispatch_key_down_up_event(
1361 &mut self,
1362 event: &dyn Any,
1363 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1364 ) {
1365 // Capture phase
1366 for node_id in dispatch_path {
1367 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1368
1369 for key_listener in node.key_listeners.clone() {
1370 self.with_element_context(|cx| {
1371 key_listener(event, DispatchPhase::Capture, cx);
1372 });
1373 if !self.propagate_event {
1374 return;
1375 }
1376 }
1377 }
1378
1379 // Bubble phase
1380 for node_id in dispatch_path.iter().rev() {
1381 // Handle low level key events
1382 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1383 for key_listener in node.key_listeners.clone() {
1384 self.with_element_context(|cx| {
1385 key_listener(event, DispatchPhase::Bubble, cx);
1386 });
1387 if !self.propagate_event {
1388 return;
1389 }
1390 }
1391 }
1392 }
1393
1394 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1395 pub fn has_pending_keystrokes(&self) -> bool {
1396 self.window
1397 .rendered_frame
1398 .dispatch_tree
1399 .has_pending_keystrokes()
1400 }
1401
1402 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1403 let node_id = self
1404 .window
1405 .focus
1406 .and_then(|focus_id| {
1407 self.window
1408 .rendered_frame
1409 .dispatch_tree
1410 .focusable_node_id(focus_id)
1411 })
1412 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1413
1414 if self.window.focus != currently_pending.focus {
1415 return;
1416 }
1417
1418 let input = currently_pending.input();
1419
1420 self.propagate_event = true;
1421 for binding in currently_pending.bindings {
1422 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1423 if !self.propagate_event {
1424 return;
1425 }
1426 }
1427
1428 let dispatch_path = self
1429 .window
1430 .rendered_frame
1431 .dispatch_tree
1432 .dispatch_path(node_id);
1433
1434 for keystroke in currently_pending.keystrokes {
1435 let event = KeyDownEvent {
1436 keystroke,
1437 is_held: false,
1438 };
1439
1440 self.dispatch_key_down_up_event(&event, &dispatch_path);
1441 if !self.propagate_event {
1442 return;
1443 }
1444 }
1445
1446 if !input.is_empty() {
1447 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1448 input_handler.dispatch_input(&input, self);
1449 self.window.platform_window.set_input_handler(input_handler)
1450 }
1451 }
1452 }
1453
1454 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1455 let dispatch_path = self
1456 .window
1457 .rendered_frame
1458 .dispatch_tree
1459 .dispatch_path(node_id);
1460
1461 // Capture phase
1462 for node_id in &dispatch_path {
1463 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1464 for DispatchActionListener {
1465 action_type,
1466 listener,
1467 } in node.action_listeners.clone()
1468 {
1469 let any_action = action.as_any();
1470 if action_type == any_action.type_id() {
1471 self.with_element_context(|cx| {
1472 listener(any_action, DispatchPhase::Capture, cx);
1473 });
1474
1475 if !self.propagate_event {
1476 return;
1477 }
1478 }
1479 }
1480 }
1481 // Bubble phase
1482 for node_id in dispatch_path.iter().rev() {
1483 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1484 for DispatchActionListener {
1485 action_type,
1486 listener,
1487 } in node.action_listeners.clone()
1488 {
1489 let any_action = action.as_any();
1490 if action_type == any_action.type_id() {
1491 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1492
1493 self.with_element_context(|cx| {
1494 listener(any_action, DispatchPhase::Bubble, cx);
1495 });
1496
1497 if !self.propagate_event {
1498 return;
1499 }
1500 }
1501 }
1502 }
1503 }
1504
1505 /// Toggle the graphics profiler to debug your application's rendering performance.
1506 pub fn toggle_graphics_profiler(&mut self) {
1507 self.window.graphics_profiler_enabled = !self.window.graphics_profiler_enabled;
1508 self.window
1509 .platform_window
1510 .set_graphics_profiler_enabled(self.window.graphics_profiler_enabled);
1511 }
1512
1513 /// Register the given handler to be invoked whenever the global of the given type
1514 /// is updated.
1515 pub fn observe_global<G: Global>(
1516 &mut self,
1517 f: impl Fn(&mut WindowContext<'_>) + 'static,
1518 ) -> Subscription {
1519 let window_handle = self.window.handle;
1520 let (subscription, activate) = self.global_observers.insert(
1521 TypeId::of::<G>(),
1522 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1523 );
1524 self.app.defer(move |_| activate());
1525 subscription
1526 }
1527
1528 /// Focus the current window and bring it to the foreground at the platform level.
1529 pub fn activate_window(&self) {
1530 self.window.platform_window.activate();
1531 }
1532
1533 /// Minimize the current window at the platform level.
1534 pub fn minimize_window(&self) {
1535 self.window.platform_window.minimize();
1536 }
1537
1538 /// Toggle full screen status on the current window at the platform level.
1539 pub fn toggle_full_screen(&self) {
1540 self.window.platform_window.toggle_full_screen();
1541 }
1542
1543 /// Present a platform dialog.
1544 /// The provided message will be presented, along with buttons for each answer.
1545 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1546 pub fn prompt(
1547 &self,
1548 level: PromptLevel,
1549 message: &str,
1550 detail: Option<&str>,
1551 answers: &[&str],
1552 ) -> oneshot::Receiver<usize> {
1553 self.window
1554 .platform_window
1555 .prompt(level, message, detail, answers)
1556 }
1557
1558 /// Returns all available actions for the focused element.
1559 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1560 let node_id = self
1561 .window
1562 .focus
1563 .and_then(|focus_id| {
1564 self.window
1565 .rendered_frame
1566 .dispatch_tree
1567 .focusable_node_id(focus_id)
1568 })
1569 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1570
1571 self.window
1572 .rendered_frame
1573 .dispatch_tree
1574 .available_actions(node_id)
1575 }
1576
1577 /// Returns key bindings that invoke the given action on the currently focused element.
1578 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1579 self.window
1580 .rendered_frame
1581 .dispatch_tree
1582 .bindings_for_action(
1583 action,
1584 &self.window.rendered_frame.dispatch_tree.context_stack,
1585 )
1586 }
1587
1588 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1589 pub fn bindings_for_action_in(
1590 &self,
1591 action: &dyn Action,
1592 focus_handle: &FocusHandle,
1593 ) -> Vec<KeyBinding> {
1594 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1595
1596 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1597 return vec![];
1598 };
1599 let context_stack: Vec<_> = dispatch_tree
1600 .dispatch_path(node_id)
1601 .into_iter()
1602 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1603 .collect();
1604 dispatch_tree.bindings_for_action(action, &context_stack)
1605 }
1606
1607 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1608 pub fn listener_for<V: Render, E>(
1609 &self,
1610 view: &View<V>,
1611 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1612 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1613 let view = view.downgrade();
1614 move |e: &E, cx: &mut WindowContext| {
1615 view.update(cx, |view, cx| f(view, e, cx)).ok();
1616 }
1617 }
1618
1619 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1620 pub fn handler_for<V: Render>(
1621 &self,
1622 view: &View<V>,
1623 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1624 ) -> impl Fn(&mut WindowContext) {
1625 let view = view.downgrade();
1626 move |cx: &mut WindowContext| {
1627 view.update(cx, |view, cx| f(view, cx)).ok();
1628 }
1629 }
1630
1631 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1632 /// If the callback returns false, the window won't be closed.
1633 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1634 let mut this = self.to_async();
1635 self.window
1636 .platform_window
1637 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
1638 }
1639
1640 pub(crate) fn parent_view_id(&self) -> EntityId {
1641 *self
1642 .window
1643 .next_frame
1644 .view_stack
1645 .last()
1646 .expect("a view should always be on the stack while drawing")
1647 }
1648
1649 /// Register an action listener on the window for the next frame. The type of action
1650 /// is determined by the first parameter of the given listener. When the next frame is rendered
1651 /// the listener will be cleared.
1652 ///
1653 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1654 /// a specific need to register a global listener.
1655 pub fn on_action(
1656 &mut self,
1657 action_type: TypeId,
1658 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1659 ) {
1660 self.window
1661 .next_frame
1662 .dispatch_tree
1663 .on_action(action_type, Rc::new(listener));
1664 }
1665}
1666
1667impl Context for WindowContext<'_> {
1668 type Result<T> = T;
1669
1670 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1671 where
1672 T: 'static,
1673 {
1674 let slot = self.app.entities.reserve();
1675 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1676 self.entities.insert(slot, model)
1677 }
1678
1679 fn update_model<T: 'static, R>(
1680 &mut self,
1681 model: &Model<T>,
1682 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1683 ) -> R {
1684 let mut entity = self.entities.lease(model);
1685 let result = update(
1686 &mut *entity,
1687 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1688 );
1689 self.entities.end_lease(entity);
1690 result
1691 }
1692
1693 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1694 where
1695 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1696 {
1697 if window == self.window.handle {
1698 let root_view = self.window.root_view.clone().unwrap();
1699 Ok(update(root_view, self))
1700 } else {
1701 window.update(self.app, update)
1702 }
1703 }
1704
1705 fn read_model<T, R>(
1706 &self,
1707 handle: &Model<T>,
1708 read: impl FnOnce(&T, &AppContext) -> R,
1709 ) -> Self::Result<R>
1710 where
1711 T: 'static,
1712 {
1713 let entity = self.entities.read(handle);
1714 read(entity, &*self.app)
1715 }
1716
1717 fn read_window<T, R>(
1718 &self,
1719 window: &WindowHandle<T>,
1720 read: impl FnOnce(View<T>, &AppContext) -> R,
1721 ) -> Result<R>
1722 where
1723 T: 'static,
1724 {
1725 if window.any_handle == self.window.handle {
1726 let root_view = self
1727 .window
1728 .root_view
1729 .clone()
1730 .unwrap()
1731 .downcast::<T>()
1732 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1733 Ok(read(root_view, self))
1734 } else {
1735 self.app.read_window(window, read)
1736 }
1737 }
1738}
1739
1740impl VisualContext for WindowContext<'_> {
1741 fn new_view<V>(
1742 &mut self,
1743 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1744 ) -> Self::Result<View<V>>
1745 where
1746 V: 'static + Render,
1747 {
1748 let slot = self.app.entities.reserve();
1749 let view = View {
1750 model: slot.clone(),
1751 };
1752 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1753 let entity = build_view_state(&mut cx);
1754 cx.entities.insert(slot, entity);
1755
1756 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1757 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1758 cx.new_view_observers.clone().retain(&tid, |observer| {
1759 let any_view = view.clone();
1760 (observer)(any_view, cx);
1761 true
1762 });
1763 }
1764 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1765
1766 view
1767 }
1768
1769 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1770 fn update_view<T: 'static, R>(
1771 &mut self,
1772 view: &View<T>,
1773 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1774 ) -> Self::Result<R> {
1775 let mut lease = self.app.entities.lease(&view.model);
1776 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1777 let result = update(&mut *lease, &mut cx);
1778 cx.app.entities.end_lease(lease);
1779 result
1780 }
1781
1782 fn replace_root_view<V>(
1783 &mut self,
1784 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1785 ) -> Self::Result<View<V>>
1786 where
1787 V: 'static + Render,
1788 {
1789 let view = self.new_view(build_view);
1790 self.window.root_view = Some(view.clone().into());
1791 self.refresh();
1792 view
1793 }
1794
1795 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1796 self.update_view(view, |view, cx| {
1797 view.focus_handle(cx).clone().focus(cx);
1798 })
1799 }
1800
1801 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1802 where
1803 V: ManagedView,
1804 {
1805 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1806 }
1807}
1808
1809impl<'a> std::ops::Deref for WindowContext<'a> {
1810 type Target = AppContext;
1811
1812 fn deref(&self) -> &Self::Target {
1813 self.app
1814 }
1815}
1816
1817impl<'a> std::ops::DerefMut for WindowContext<'a> {
1818 fn deref_mut(&mut self) -> &mut Self::Target {
1819 self.app
1820 }
1821}
1822
1823impl<'a> Borrow<AppContext> for WindowContext<'a> {
1824 fn borrow(&self) -> &AppContext {
1825 self.app
1826 }
1827}
1828
1829impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1830 fn borrow_mut(&mut self) -> &mut AppContext {
1831 self.app
1832 }
1833}
1834
1835/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1836pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1837 #[doc(hidden)]
1838 fn app_mut(&mut self) -> &mut AppContext {
1839 self.borrow_mut()
1840 }
1841
1842 #[doc(hidden)]
1843 fn app(&self) -> &AppContext {
1844 self.borrow()
1845 }
1846
1847 #[doc(hidden)]
1848 fn window(&self) -> &Window {
1849 self.borrow()
1850 }
1851
1852 #[doc(hidden)]
1853 fn window_mut(&mut self) -> &mut Window {
1854 self.borrow_mut()
1855 }
1856}
1857
1858impl Borrow<Window> for WindowContext<'_> {
1859 fn borrow(&self) -> &Window {
1860 self.window
1861 }
1862}
1863
1864impl BorrowMut<Window> for WindowContext<'_> {
1865 fn borrow_mut(&mut self) -> &mut Window {
1866 self.window
1867 }
1868}
1869
1870impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1871
1872/// Provides access to application state that is specialized for a particular [`View`].
1873/// Allows you to interact with focus, emit events, etc.
1874/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1875/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1876pub struct ViewContext<'a, V> {
1877 window_cx: WindowContext<'a>,
1878 view: &'a View<V>,
1879}
1880
1881impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1882 fn borrow(&self) -> &AppContext {
1883 &*self.window_cx.app
1884 }
1885}
1886
1887impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1888 fn borrow_mut(&mut self) -> &mut AppContext {
1889 &mut *self.window_cx.app
1890 }
1891}
1892
1893impl<V> Borrow<Window> for ViewContext<'_, V> {
1894 fn borrow(&self) -> &Window {
1895 &*self.window_cx.window
1896 }
1897}
1898
1899impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1900 fn borrow_mut(&mut self) -> &mut Window {
1901 &mut *self.window_cx.window
1902 }
1903}
1904
1905impl<'a, V: 'static> ViewContext<'a, V> {
1906 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1907 Self {
1908 window_cx: WindowContext::new(app, window),
1909 view,
1910 }
1911 }
1912
1913 /// Get the entity_id of this view.
1914 pub fn entity_id(&self) -> EntityId {
1915 self.view.entity_id()
1916 }
1917
1918 /// Get the view pointer underlying this context.
1919 pub fn view(&self) -> &View<V> {
1920 self.view
1921 }
1922
1923 /// Get the model underlying this view.
1924 pub fn model(&self) -> &Model<V> {
1925 &self.view.model
1926 }
1927
1928 /// Access the underlying window context.
1929 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1930 &mut self.window_cx
1931 }
1932
1933 /// Sets a given callback to be run on the next frame.
1934 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1935 where
1936 V: 'static,
1937 {
1938 let view = self.view().clone();
1939 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1940 }
1941
1942 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1943 /// that are currently on the stack to be returned to the app.
1944 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1945 let view = self.view().downgrade();
1946 self.window_cx.defer(move |cx| {
1947 view.update(cx, f).ok();
1948 });
1949 }
1950
1951 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1952 pub fn observe<V2, E>(
1953 &mut self,
1954 entity: &E,
1955 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1956 ) -> Subscription
1957 where
1958 V2: 'static,
1959 V: 'static,
1960 E: Entity<V2>,
1961 {
1962 let view = self.view().downgrade();
1963 let entity_id = entity.entity_id();
1964 let entity = entity.downgrade();
1965 let window_handle = self.window.handle;
1966 self.app.new_observer(
1967 entity_id,
1968 Box::new(move |cx| {
1969 window_handle
1970 .update(cx, |_, cx| {
1971 if let Some(handle) = E::upgrade_from(&entity) {
1972 view.update(cx, |this, cx| on_notify(this, handle, cx))
1973 .is_ok()
1974 } else {
1975 false
1976 }
1977 })
1978 .unwrap_or(false)
1979 }),
1980 )
1981 }
1982
1983 /// Subscribe to events emitted by another model or view.
1984 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1985 /// 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.
1986 pub fn subscribe<V2, E, Evt>(
1987 &mut self,
1988 entity: &E,
1989 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1990 ) -> Subscription
1991 where
1992 V2: EventEmitter<Evt>,
1993 E: Entity<V2>,
1994 Evt: 'static,
1995 {
1996 let view = self.view().downgrade();
1997 let entity_id = entity.entity_id();
1998 let handle = entity.downgrade();
1999 let window_handle = self.window.handle;
2000 self.app.new_subscription(
2001 entity_id,
2002 (
2003 TypeId::of::<Evt>(),
2004 Box::new(move |event, cx| {
2005 window_handle
2006 .update(cx, |_, cx| {
2007 if let Some(handle) = E::upgrade_from(&handle) {
2008 let event = event.downcast_ref().expect("invalid event type");
2009 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2010 .is_ok()
2011 } else {
2012 false
2013 }
2014 })
2015 .unwrap_or(false)
2016 }),
2017 ),
2018 )
2019 }
2020
2021 /// Register a callback to be invoked when the view is released.
2022 ///
2023 /// The callback receives a handle to the view's window. This handle may be
2024 /// invalid, if the window was closed before the view was released.
2025 pub fn on_release(
2026 &mut self,
2027 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2028 ) -> Subscription {
2029 let window_handle = self.window.handle;
2030 let (subscription, activate) = self.app.release_listeners.insert(
2031 self.view.model.entity_id,
2032 Box::new(move |this, cx| {
2033 let this = this.downcast_mut().expect("invalid entity type");
2034 on_release(this, window_handle, cx)
2035 }),
2036 );
2037 activate();
2038 subscription
2039 }
2040
2041 /// Register a callback to be invoked when the given Model or View is released.
2042 pub fn observe_release<V2, E>(
2043 &mut self,
2044 entity: &E,
2045 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2046 ) -> Subscription
2047 where
2048 V: 'static,
2049 V2: 'static,
2050 E: Entity<V2>,
2051 {
2052 let view = self.view().downgrade();
2053 let entity_id = entity.entity_id();
2054 let window_handle = self.window.handle;
2055 let (subscription, activate) = self.app.release_listeners.insert(
2056 entity_id,
2057 Box::new(move |entity, cx| {
2058 let entity = entity.downcast_mut().expect("invalid entity type");
2059 let _ = window_handle.update(cx, |_, cx| {
2060 view.update(cx, |this, cx| on_release(this, entity, cx))
2061 });
2062 }),
2063 );
2064 activate();
2065 subscription
2066 }
2067
2068 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2069 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2070 pub fn notify(&mut self) {
2071 for view_id in self
2072 .window
2073 .rendered_frame
2074 .dispatch_tree
2075 .view_path(self.view.entity_id())
2076 .into_iter()
2077 .rev()
2078 {
2079 if !self.window.dirty_views.insert(view_id) {
2080 break;
2081 }
2082 }
2083
2084 if !self.window.drawing {
2085 self.window_cx.window.dirty.set(true);
2086 self.window_cx.app.push_effect(Effect::Notify {
2087 emitter: self.view.model.entity_id,
2088 });
2089 }
2090 }
2091
2092 /// Register a callback to be invoked when the window is resized.
2093 pub fn observe_window_bounds(
2094 &mut self,
2095 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2096 ) -> Subscription {
2097 let view = self.view.downgrade();
2098 let (subscription, activate) = self.window.bounds_observers.insert(
2099 (),
2100 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2101 );
2102 activate();
2103 subscription
2104 }
2105
2106 /// Register a callback to be invoked when the window is activated or deactivated.
2107 pub fn observe_window_activation(
2108 &mut self,
2109 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2110 ) -> Subscription {
2111 let view = self.view.downgrade();
2112 let (subscription, activate) = self.window.activation_observers.insert(
2113 (),
2114 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2115 );
2116 activate();
2117 subscription
2118 }
2119
2120 /// Registers a callback to be invoked when the window appearance changes.
2121 pub fn observe_window_appearance(
2122 &mut self,
2123 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2124 ) -> Subscription {
2125 let view = self.view.downgrade();
2126 let (subscription, activate) = self.window.appearance_observers.insert(
2127 (),
2128 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2129 );
2130 activate();
2131 subscription
2132 }
2133
2134 /// Register a listener to be called when the given focus handle receives focus.
2135 /// Returns a subscription and persists until the subscription is dropped.
2136 pub fn on_focus(
2137 &mut self,
2138 handle: &FocusHandle,
2139 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2140 ) -> Subscription {
2141 let view = self.view.downgrade();
2142 let focus_id = handle.id;
2143 let (subscription, activate) =
2144 self.window.new_focus_listener(Box::new(move |event, cx| {
2145 view.update(cx, |view, cx| {
2146 if event.previous_focus_path.last() != Some(&focus_id)
2147 && event.current_focus_path.last() == Some(&focus_id)
2148 {
2149 listener(view, cx)
2150 }
2151 })
2152 .is_ok()
2153 }));
2154 self.app.defer(|_| activate());
2155 subscription
2156 }
2157
2158 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2159 /// Returns a subscription and persists until the subscription is dropped.
2160 pub fn on_focus_in(
2161 &mut self,
2162 handle: &FocusHandle,
2163 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2164 ) -> Subscription {
2165 let view = self.view.downgrade();
2166 let focus_id = handle.id;
2167 let (subscription, activate) =
2168 self.window.new_focus_listener(Box::new(move |event, cx| {
2169 view.update(cx, |view, cx| {
2170 if !event.previous_focus_path.contains(&focus_id)
2171 && event.current_focus_path.contains(&focus_id)
2172 {
2173 listener(view, cx)
2174 }
2175 })
2176 .is_ok()
2177 }));
2178 self.app.defer(move |_| activate());
2179 subscription
2180 }
2181
2182 /// Register a listener to be called when the given focus handle loses focus.
2183 /// Returns a subscription and persists until the subscription is dropped.
2184 pub fn on_blur(
2185 &mut self,
2186 handle: &FocusHandle,
2187 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2188 ) -> Subscription {
2189 let view = self.view.downgrade();
2190 let focus_id = handle.id;
2191 let (subscription, activate) =
2192 self.window.new_focus_listener(Box::new(move |event, cx| {
2193 view.update(cx, |view, cx| {
2194 if event.previous_focus_path.last() == Some(&focus_id)
2195 && event.current_focus_path.last() != Some(&focus_id)
2196 {
2197 listener(view, cx)
2198 }
2199 })
2200 .is_ok()
2201 }));
2202 self.app.defer(move |_| activate());
2203 subscription
2204 }
2205
2206 /// Register a listener to be called when nothing in the window has focus.
2207 /// This typically happens when the node that was focused is removed from the tree,
2208 /// and this callback lets you chose a default place to restore the users focus.
2209 /// Returns a subscription and persists until the subscription is dropped.
2210 pub fn on_focus_lost(
2211 &mut self,
2212 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2213 ) -> Subscription {
2214 let view = self.view.downgrade();
2215 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2216 (),
2217 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2218 );
2219 activate();
2220 subscription
2221 }
2222
2223 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2224 /// Returns a subscription and persists until the subscription is dropped.
2225 pub fn on_focus_out(
2226 &mut self,
2227 handle: &FocusHandle,
2228 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2229 ) -> Subscription {
2230 let view = self.view.downgrade();
2231 let focus_id = handle.id;
2232 let (subscription, activate) =
2233 self.window.new_focus_listener(Box::new(move |event, cx| {
2234 view.update(cx, |view, cx| {
2235 if event.previous_focus_path.contains(&focus_id)
2236 && !event.current_focus_path.contains(&focus_id)
2237 {
2238 listener(view, cx)
2239 }
2240 })
2241 .is_ok()
2242 }));
2243 self.app.defer(move |_| activate());
2244 subscription
2245 }
2246
2247 /// Schedule a future to be run asynchronously.
2248 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2249 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2250 /// The returned future will be polled on the main thread.
2251 pub fn spawn<Fut, R>(
2252 &mut self,
2253 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2254 ) -> Task<R>
2255 where
2256 R: 'static,
2257 Fut: Future<Output = R> + 'static,
2258 {
2259 let view = self.view().downgrade();
2260 self.window_cx.spawn(|cx| f(view, cx))
2261 }
2262
2263 /// Updates the global state of the given type.
2264 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2265 where
2266 G: Global,
2267 {
2268 let mut global = self.app.lease_global::<G>();
2269 let result = f(&mut global, self);
2270 self.app.end_global_lease(global);
2271 result
2272 }
2273
2274 /// Register a callback to be invoked when the given global state changes.
2275 pub fn observe_global<G: Global>(
2276 &mut self,
2277 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2278 ) -> Subscription {
2279 let window_handle = self.window.handle;
2280 let view = self.view().downgrade();
2281 let (subscription, activate) = self.global_observers.insert(
2282 TypeId::of::<G>(),
2283 Box::new(move |cx| {
2284 window_handle
2285 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2286 .unwrap_or(false)
2287 }),
2288 );
2289 self.app.defer(move |_| activate());
2290 subscription
2291 }
2292
2293 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2294 pub fn on_action(
2295 &mut self,
2296 action_type: TypeId,
2297 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2298 ) {
2299 let handle = self.view().clone();
2300 self.window_cx
2301 .on_action(action_type, move |action, phase, cx| {
2302 handle.update(cx, |view, cx| {
2303 listener(view, action, phase, cx);
2304 })
2305 });
2306 }
2307
2308 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2309 pub fn emit<Evt>(&mut self, event: Evt)
2310 where
2311 Evt: 'static,
2312 V: EventEmitter<Evt>,
2313 {
2314 let emitter = self.view.model.entity_id;
2315 self.app.push_effect(Effect::Emit {
2316 emitter,
2317 event_type: TypeId::of::<Evt>(),
2318 event: Box::new(event),
2319 });
2320 }
2321
2322 /// Move focus to the current view, assuming it implements [`FocusableView`].
2323 pub fn focus_self(&mut self)
2324 where
2325 V: FocusableView,
2326 {
2327 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2328 }
2329
2330 /// Convenience method for accessing view state in an event callback.
2331 ///
2332 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2333 /// but it's often useful to be able to access view state in these
2334 /// callbacks. This method provides a convenient way to do so.
2335 pub fn listener<E>(
2336 &self,
2337 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2338 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2339 let view = self.view().downgrade();
2340 move |e: &E, cx: &mut WindowContext| {
2341 view.update(cx, |view, cx| f(view, e, cx)).ok();
2342 }
2343 }
2344}
2345
2346impl<V> Context for ViewContext<'_, V> {
2347 type Result<U> = U;
2348
2349 fn new_model<T: 'static>(
2350 &mut self,
2351 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2352 ) -> Model<T> {
2353 self.window_cx.new_model(build_model)
2354 }
2355
2356 fn update_model<T: 'static, R>(
2357 &mut self,
2358 model: &Model<T>,
2359 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2360 ) -> R {
2361 self.window_cx.update_model(model, update)
2362 }
2363
2364 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2365 where
2366 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2367 {
2368 self.window_cx.update_window(window, update)
2369 }
2370
2371 fn read_model<T, R>(
2372 &self,
2373 handle: &Model<T>,
2374 read: impl FnOnce(&T, &AppContext) -> R,
2375 ) -> Self::Result<R>
2376 where
2377 T: 'static,
2378 {
2379 self.window_cx.read_model(handle, read)
2380 }
2381
2382 fn read_window<T, R>(
2383 &self,
2384 window: &WindowHandle<T>,
2385 read: impl FnOnce(View<T>, &AppContext) -> R,
2386 ) -> Result<R>
2387 where
2388 T: 'static,
2389 {
2390 self.window_cx.read_window(window, read)
2391 }
2392}
2393
2394impl<V: 'static> VisualContext for ViewContext<'_, V> {
2395 fn new_view<W: Render + 'static>(
2396 &mut self,
2397 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2398 ) -> Self::Result<View<W>> {
2399 self.window_cx.new_view(build_view_state)
2400 }
2401
2402 fn update_view<V2: 'static, R>(
2403 &mut self,
2404 view: &View<V2>,
2405 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2406 ) -> Self::Result<R> {
2407 self.window_cx.update_view(view, update)
2408 }
2409
2410 fn replace_root_view<W>(
2411 &mut self,
2412 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2413 ) -> Self::Result<View<W>>
2414 where
2415 W: 'static + Render,
2416 {
2417 self.window_cx.replace_root_view(build_view)
2418 }
2419
2420 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2421 self.window_cx.focus_view(view)
2422 }
2423
2424 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2425 self.window_cx.dismiss_view(view)
2426 }
2427}
2428
2429impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2430 type Target = WindowContext<'a>;
2431
2432 fn deref(&self) -> &Self::Target {
2433 &self.window_cx
2434 }
2435}
2436
2437impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2438 fn deref_mut(&mut self) -> &mut Self::Target {
2439 &mut self.window_cx
2440 }
2441}
2442
2443// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2444slotmap::new_key_type! {
2445 /// A unique identifier for a window.
2446 pub struct WindowId;
2447}
2448
2449impl WindowId {
2450 /// Converts this window ID to a `u64`.
2451 pub fn as_u64(&self) -> u64 {
2452 self.0.as_ffi()
2453 }
2454}
2455
2456/// A handle to a window with a specific root view type.
2457/// Note that this does not keep the window alive on its own.
2458#[derive(Deref, DerefMut)]
2459pub struct WindowHandle<V> {
2460 #[deref]
2461 #[deref_mut]
2462 pub(crate) any_handle: AnyWindowHandle,
2463 state_type: PhantomData<V>,
2464}
2465
2466impl<V: 'static + Render> WindowHandle<V> {
2467 /// Creates a new handle from a window ID.
2468 /// This does not check if the root type of the window is `V`.
2469 pub fn new(id: WindowId) -> Self {
2470 WindowHandle {
2471 any_handle: AnyWindowHandle {
2472 id,
2473 state_type: TypeId::of::<V>(),
2474 },
2475 state_type: PhantomData,
2476 }
2477 }
2478
2479 /// Get the root view out of this window.
2480 ///
2481 /// This will fail if the window is closed or if the root view's type does not match `V`.
2482 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2483 where
2484 C: Context,
2485 {
2486 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2487 root_view
2488 .downcast::<V>()
2489 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2490 }))
2491 }
2492
2493 /// Updates the root view of this window.
2494 ///
2495 /// This will fail if the window has been closed or if the root view's type does not match
2496 pub fn update<C, R>(
2497 &self,
2498 cx: &mut C,
2499 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2500 ) -> Result<R>
2501 where
2502 C: Context,
2503 {
2504 cx.update_window(self.any_handle, |root_view, cx| {
2505 let view = root_view
2506 .downcast::<V>()
2507 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2508 Ok(cx.update_view(&view, update))
2509 })?
2510 }
2511
2512 /// Read the root view out of this window.
2513 ///
2514 /// This will fail if the window is closed or if the root view's type does not match `V`.
2515 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2516 let x = cx
2517 .windows
2518 .get(self.id)
2519 .and_then(|window| {
2520 window
2521 .as_ref()
2522 .and_then(|window| window.root_view.clone())
2523 .map(|root_view| root_view.downcast::<V>())
2524 })
2525 .ok_or_else(|| anyhow!("window not found"))?
2526 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2527
2528 Ok(x.read(cx))
2529 }
2530
2531 /// Read the root view out of this window, with a callback
2532 ///
2533 /// This will fail if the window is closed or if the root view's type does not match `V`.
2534 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2535 where
2536 C: Context,
2537 {
2538 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2539 }
2540
2541 /// Read the root view pointer off of this window.
2542 ///
2543 /// This will fail if the window is closed or if the root view's type does not match `V`.
2544 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2545 where
2546 C: Context,
2547 {
2548 cx.read_window(self, |root_view, _cx| root_view.clone())
2549 }
2550
2551 /// Check if this window is 'active'.
2552 ///
2553 /// Will return `None` if the window is closed or currently
2554 /// borrowed.
2555 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
2556 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
2557 .ok()
2558 }
2559}
2560
2561impl<V> Copy for WindowHandle<V> {}
2562
2563impl<V> Clone for WindowHandle<V> {
2564 fn clone(&self) -> Self {
2565 *self
2566 }
2567}
2568
2569impl<V> PartialEq for WindowHandle<V> {
2570 fn eq(&self, other: &Self) -> bool {
2571 self.any_handle == other.any_handle
2572 }
2573}
2574
2575impl<V> Eq for WindowHandle<V> {}
2576
2577impl<V> Hash for WindowHandle<V> {
2578 fn hash<H: Hasher>(&self, state: &mut H) {
2579 self.any_handle.hash(state);
2580 }
2581}
2582
2583impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2584 fn from(val: WindowHandle<V>) -> Self {
2585 val.any_handle
2586 }
2587}
2588
2589/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2590#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2591pub struct AnyWindowHandle {
2592 pub(crate) id: WindowId,
2593 state_type: TypeId,
2594}
2595
2596impl AnyWindowHandle {
2597 /// Get the ID of this window.
2598 pub fn window_id(&self) -> WindowId {
2599 self.id
2600 }
2601
2602 /// Attempt to convert this handle to a window handle with a specific root view type.
2603 /// If the types do not match, this will return `None`.
2604 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2605 if TypeId::of::<T>() == self.state_type {
2606 Some(WindowHandle {
2607 any_handle: *self,
2608 state_type: PhantomData,
2609 })
2610 } else {
2611 None
2612 }
2613 }
2614
2615 /// Updates the state of the root view of this window.
2616 ///
2617 /// This will fail if the window has been closed.
2618 pub fn update<C, R>(
2619 self,
2620 cx: &mut C,
2621 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2622 ) -> Result<R>
2623 where
2624 C: Context,
2625 {
2626 cx.update_window(self, update)
2627 }
2628
2629 /// Read the state of the root view of this window.
2630 ///
2631 /// This will fail if the window has been closed.
2632 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2633 where
2634 C: Context,
2635 T: 'static,
2636 {
2637 let view = self
2638 .downcast::<T>()
2639 .context("the type of the window's root view has changed")?;
2640
2641 cx.read_window(&view, read)
2642 }
2643}
2644
2645/// An identifier for an [`Element`](crate::Element).
2646///
2647/// Can be constructed with a string, a number, or both, as well
2648/// as other internal representations.
2649#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2650pub enum ElementId {
2651 /// The ID of a View element
2652 View(EntityId),
2653 /// An integer ID.
2654 Integer(usize),
2655 /// A string based ID.
2656 Name(SharedString),
2657 /// An ID that's equated with a focus handle.
2658 FocusHandle(FocusId),
2659 /// A combination of a name and an integer.
2660 NamedInteger(SharedString, usize),
2661}
2662
2663impl Display for ElementId {
2664 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2665 match self {
2666 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2667 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2668 ElementId::Name(name) => write!(f, "{}", name)?,
2669 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2670 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2671 }
2672
2673 Ok(())
2674 }
2675}
2676
2677impl ElementId {
2678 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2679 ElementId::View(entity_id)
2680 }
2681}
2682
2683impl TryInto<SharedString> for ElementId {
2684 type Error = anyhow::Error;
2685
2686 fn try_into(self) -> anyhow::Result<SharedString> {
2687 if let ElementId::Name(name) = self {
2688 Ok(name)
2689 } else {
2690 Err(anyhow!("element id is not string"))
2691 }
2692 }
2693}
2694
2695impl From<usize> for ElementId {
2696 fn from(id: usize) -> Self {
2697 ElementId::Integer(id)
2698 }
2699}
2700
2701impl From<i32> for ElementId {
2702 fn from(id: i32) -> Self {
2703 Self::Integer(id as usize)
2704 }
2705}
2706
2707impl From<SharedString> for ElementId {
2708 fn from(name: SharedString) -> Self {
2709 ElementId::Name(name)
2710 }
2711}
2712
2713impl From<&'static str> for ElementId {
2714 fn from(name: &'static str) -> Self {
2715 ElementId::Name(name.into())
2716 }
2717}
2718
2719impl<'a> From<&'a FocusHandle> for ElementId {
2720 fn from(handle: &'a FocusHandle) -> Self {
2721 ElementId::FocusHandle(handle.id)
2722 }
2723}
2724
2725impl From<(&'static str, EntityId)> for ElementId {
2726 fn from((name, id): (&'static str, EntityId)) -> Self {
2727 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2728 }
2729}
2730
2731impl From<(&'static str, usize)> for ElementId {
2732 fn from((name, id): (&'static str, usize)) -> Self {
2733 ElementId::NamedInteger(name.into(), id)
2734 }
2735}
2736
2737impl From<(&'static str, u64)> for ElementId {
2738 fn from((name, id): (&'static str, u64)) -> Self {
2739 ElementId::NamedInteger(name.into(), id as usize)
2740 }
2741}
2742
2743/// A rectangle to be rendered in the window at the given position and size.
2744/// Passed as an argument [`ElementContext::paint_quad`].
2745#[derive(Clone)]
2746pub struct PaintQuad {
2747 bounds: Bounds<Pixels>,
2748 corner_radii: Corners<Pixels>,
2749 background: Hsla,
2750 border_widths: Edges<Pixels>,
2751 border_color: Hsla,
2752}
2753
2754impl PaintQuad {
2755 /// Sets the corner radii of the quad.
2756 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2757 PaintQuad {
2758 corner_radii: corner_radii.into(),
2759 ..self
2760 }
2761 }
2762
2763 /// Sets the border widths of the quad.
2764 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2765 PaintQuad {
2766 border_widths: border_widths.into(),
2767 ..self
2768 }
2769 }
2770
2771 /// Sets the border color of the quad.
2772 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2773 PaintQuad {
2774 border_color: border_color.into(),
2775 ..self
2776 }
2777 }
2778
2779 /// Sets the background color of the quad.
2780 pub fn background(self, background: impl Into<Hsla>) -> Self {
2781 PaintQuad {
2782 background: background.into(),
2783 ..self
2784 }
2785 }
2786}
2787
2788/// Creates a quad with the given parameters.
2789pub fn quad(
2790 bounds: Bounds<Pixels>,
2791 corner_radii: impl Into<Corners<Pixels>>,
2792 background: impl Into<Hsla>,
2793 border_widths: impl Into<Edges<Pixels>>,
2794 border_color: impl Into<Hsla>,
2795) -> PaintQuad {
2796 PaintQuad {
2797 bounds,
2798 corner_radii: corner_radii.into(),
2799 background: background.into(),
2800 border_widths: border_widths.into(),
2801 border_color: border_color.into(),
2802 }
2803}
2804
2805/// Creates a filled quad with the given bounds and background color.
2806pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2807 PaintQuad {
2808 bounds: bounds.into(),
2809 corner_radii: (0.).into(),
2810 background: background.into(),
2811 border_widths: (0.).into(),
2812 border_color: transparent_black(),
2813 }
2814}
2815
2816/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2817pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2818 PaintQuad {
2819 bounds: bounds.into(),
2820 corner_radii: (0.).into(),
2821 background: transparent_black(),
2822 border_widths: (1.).into(),
2823 border_color: border_color.into(),
2824 }
2825}