1use crate::{
2 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
3 AvailableSpace, Bounds, Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId,
4 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
5 Global, GlobalElementId, Hsla, KeyBinding, KeyContext, KeyDownEvent, KeyMatch, KeymatchMode,
6 KeymatchResult, Keystroke, KeystrokeEvent, Model, ModelContext, Modifiers, MouseButton,
7 MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
8 PlatformWindow, Point, PromptLevel, Render, ScaledPixels, SharedString, Size, SubscriberSet,
9 Subscription, TaffyLayoutEngine, Task, View, VisualContext, WeakView, WindowAppearance,
10 WindowBounds, WindowOptions, WindowTextSystem,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::{
16 channel::{mpsc, oneshot},
17 StreamExt,
18};
19use parking_lot::RwLock;
20use slotmap::SlotMap;
21use smallvec::SmallVec;
22use std::{
23 any::{Any, TypeId},
24 borrow::{Borrow, BorrowMut},
25 cell::{Cell, RefCell},
26 collections::hash_map::Entry,
27 fmt::{Debug, Display},
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37 time::{Duration, Instant},
38};
39use util::{measure, ResultExt};
40
41mod element_cx;
42pub use element_cx::*;
43
44const ACTIVE_DRAG_Z_INDEX: u16 = 1;
45
46/// A global stacking order, which is created by stacking successive z-index values.
47/// Each z-index will always be interpreted in the context of its parent z-index.
48#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
49pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
50
51/// A single entry in a primitive's z-index stacking order
52#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
53pub struct StackingContext {
54 pub(crate) z_index: u16,
55 pub(crate) id: u16,
56}
57
58impl std::fmt::Debug for StackingContext {
59 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
60 write!(f, "{{{}.{}}} ", self.z_index, self.id)
61 }
62}
63
64/// Represents the two different phases when dispatching events.
65#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
66pub enum DispatchPhase {
67 /// After the capture phase comes the bubble phase, in which mouse event listeners are
68 /// invoked front to back and keyboard event listeners are invoked from the focused element
69 /// to the root of the element tree. This is the phase you'll most commonly want to use when
70 /// registering event listeners.
71 #[default]
72 Bubble,
73 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
74 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
75 /// is used for special purposes such as clearing the "pressed" state for click events. If
76 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
77 /// outside of the immediate region may rely on detecting non-local events during this phase.
78 Capture,
79}
80
81impl DispatchPhase {
82 /// Returns true if this represents the "bubble" phase.
83 pub fn bubble(self) -> bool {
84 self == DispatchPhase::Bubble
85 }
86
87 /// Returns true if this represents the "capture" phase.
88 pub fn capture(self) -> bool {
89 self == DispatchPhase::Capture
90 }
91}
92
93type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
94
95type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
96
97struct FocusEvent {
98 previous_focus_path: SmallVec<[FocusId; 8]>,
99 current_focus_path: SmallVec<[FocusId; 8]>,
100}
101
102slotmap::new_key_type! {
103 /// A globally unique identifier for a focusable element.
104 pub struct FocusId;
105}
106
107thread_local! {
108 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(8 * 1024 * 1024));
109}
110
111impl FocusId {
112 /// Obtains whether the element associated with this handle is currently focused.
113 pub fn is_focused(&self, cx: &WindowContext) -> bool {
114 cx.window.focus == Some(*self)
115 }
116
117 /// Obtains whether the element associated with this handle contains the focused
118 /// element or is itself focused.
119 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
120 cx.focused()
121 .map_or(false, |focused| self.contains(focused.id, cx))
122 }
123
124 /// Obtains whether the element associated with this handle is contained within the
125 /// focused element or is itself focused.
126 pub fn within_focused(&self, cx: &WindowContext) -> bool {
127 let focused = cx.focused();
128 focused.map_or(false, |focused| focused.id.contains(*self, cx))
129 }
130
131 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
132 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
133 cx.window
134 .rendered_frame
135 .dispatch_tree
136 .focus_contains(*self, other)
137 }
138}
139
140/// A handle which can be used to track and manipulate the focused element in a window.
141pub struct FocusHandle {
142 pub(crate) id: FocusId,
143 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
144}
145
146impl std::fmt::Debug for FocusHandle {
147 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
148 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
149 }
150}
151
152impl FocusHandle {
153 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
154 let id = handles.write().insert(AtomicUsize::new(1));
155 Self {
156 id,
157 handles: handles.clone(),
158 }
159 }
160
161 pub(crate) fn for_id(
162 id: FocusId,
163 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
164 ) -> Option<Self> {
165 let lock = handles.read();
166 let ref_count = lock.get(id)?;
167 if ref_count.load(SeqCst) == 0 {
168 None
169 } else {
170 ref_count.fetch_add(1, SeqCst);
171 Some(Self {
172 id,
173 handles: handles.clone(),
174 })
175 }
176 }
177
178 /// Moves the focus to the element associated with this handle.
179 pub fn focus(&self, cx: &mut WindowContext) {
180 cx.focus(self)
181 }
182
183 /// Obtains whether the element associated with this handle is currently focused.
184 pub fn is_focused(&self, cx: &WindowContext) -> bool {
185 self.id.is_focused(cx)
186 }
187
188 /// Obtains whether the element associated with this handle contains the focused
189 /// element or is itself focused.
190 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
191 self.id.contains_focused(cx)
192 }
193
194 /// Obtains whether the element associated with this handle is contained within the
195 /// focused element or is itself focused.
196 pub fn within_focused(&self, cx: &WindowContext) -> bool {
197 self.id.within_focused(cx)
198 }
199
200 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
201 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
202 self.id.contains(other.id, cx)
203 }
204}
205
206impl Clone for FocusHandle {
207 fn clone(&self) -> Self {
208 Self::for_id(self.id, &self.handles).unwrap()
209 }
210}
211
212impl PartialEq for FocusHandle {
213 fn eq(&self, other: &Self) -> bool {
214 self.id == other.id
215 }
216}
217
218impl Eq for FocusHandle {}
219
220impl Drop for FocusHandle {
221 fn drop(&mut self) {
222 self.handles
223 .read()
224 .get(self.id)
225 .unwrap()
226 .fetch_sub(1, SeqCst);
227 }
228}
229
230/// FocusableView allows users of your view to easily
231/// focus it (using cx.focus_view(view))
232pub trait FocusableView: 'static + Render {
233 /// Returns the focus handle associated with this view.
234 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
235}
236
237/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
238/// where the lifecycle of the view is handled by another view.
239pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
240
241impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
242
243/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
244pub struct DismissEvent;
245
246// Holds the state for a specific window.
247#[doc(hidden)]
248pub struct Window {
249 pub(crate) handle: AnyWindowHandle,
250 pub(crate) removed: bool,
251 pub(crate) platform_window: Box<dyn PlatformWindow>,
252 display_id: DisplayId,
253 sprite_atlas: Arc<dyn PlatformAtlas>,
254 text_system: Arc<WindowTextSystem>,
255 pub(crate) rem_size: Pixels,
256 pub(crate) viewport_size: Size<Pixels>,
257 layout_engine: Option<TaffyLayoutEngine>,
258 pub(crate) root_view: Option<AnyView>,
259 pub(crate) element_id_stack: GlobalElementId,
260 pub(crate) rendered_frame: Frame,
261 pub(crate) next_frame: Frame,
262 pub(crate) dirty_views: FxHashSet<EntityId>,
263 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
264 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
265 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
266 default_prevented: bool,
267 mouse_position: Point<Pixels>,
268 modifiers: Modifiers,
269 scale_factor: f32,
270 bounds: WindowBounds,
271 bounds_observers: SubscriberSet<(), AnyObserver>,
272 appearance: WindowAppearance,
273 appearance_observers: SubscriberSet<(), AnyObserver>,
274 active: bool,
275 pub(crate) dirty: 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}
284
285#[derive(Default, Debug)]
286struct PendingInput {
287 keystrokes: SmallVec<[Keystroke; 1]>,
288 bindings: SmallVec<[KeyBinding; 1]>,
289 focus: Option<FocusId>,
290 timer: Option<Task<()>>,
291}
292
293impl PendingInput {
294 fn is_noop(&self) -> bool {
295 self.bindings.is_empty() && (self.keystrokes.iter().all(|k| k.ime_key.is_none()))
296 }
297
298 fn input(&self) -> String {
299 self.keystrokes
300 .iter()
301 .flat_map(|k| k.ime_key.clone())
302 .collect::<Vec<String>>()
303 .join("")
304 }
305
306 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
307 if self.keystrokes.is_empty() {
308 return true;
309 }
310 let keystroke = &self.keystrokes[0];
311 for candidate in keystroke.match_candidates() {
312 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
313 return true;
314 }
315 }
316 false
317 }
318}
319
320pub(crate) struct ElementStateBox {
321 pub(crate) inner: Box<dyn Any>,
322 pub(crate) parent_view_id: EntityId,
323 #[cfg(debug_assertions)]
324 pub(crate) type_name: &'static str,
325}
326
327impl Window {
328 pub(crate) fn new(
329 handle: AnyWindowHandle,
330 options: WindowOptions,
331 cx: &mut AppContext,
332 ) -> Self {
333 let platform_window = cx.platform.open_window(handle, options);
334 let display_id = platform_window.display().id();
335 let sprite_atlas = platform_window.sprite_atlas();
336 let mouse_position = platform_window.mouse_position();
337 let modifiers = platform_window.modifiers();
338 let content_size = platform_window.content_size();
339 let scale_factor = platform_window.scale_factor();
340 let bounds = platform_window.bounds();
341 let appearance = platform_window.appearance();
342 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
343 let dirty = Rc::new(Cell::new(false));
344 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
345
346 platform_window.on_request_frame(Box::new({
347 let mut cx = cx.to_async();
348 let dirty = dirty.clone();
349 let last_input_timestamp = last_input_timestamp.clone();
350 move || {
351 if dirty.get() {
352 measure("frame duration", || {
353 handle
354 .update(&mut cx, |_, cx| {
355 cx.draw();
356 cx.present();
357 })
358 .log_err();
359 })
360 } else if last_input_timestamp.get().elapsed() < Duration::from_secs(1) {
361 // Keep presenting the current scene for 1 extra second since the
362 // last input to prevent the display from underclocking the refresh rate.
363 handle.update(&mut cx, |_, cx| cx.present()).log_err();
364 }
365 }
366 }));
367 platform_window.on_resize(Box::new({
368 let mut cx = cx.to_async();
369 move |_, _| {
370 handle
371 .update(&mut cx, |_, cx| cx.window_bounds_changed())
372 .log_err();
373 }
374 }));
375 platform_window.on_moved(Box::new({
376 let mut cx = cx.to_async();
377 move || {
378 handle
379 .update(&mut cx, |_, cx| cx.window_bounds_changed())
380 .log_err();
381 }
382 }));
383 platform_window.on_appearance_changed(Box::new({
384 let mut cx = cx.to_async();
385 move || {
386 handle
387 .update(&mut cx, |_, cx| cx.appearance_changed())
388 .log_err();
389 }
390 }));
391 platform_window.on_active_status_change(Box::new({
392 let mut cx = cx.to_async();
393 move |active| {
394 handle
395 .update(&mut cx, |_, cx| {
396 cx.window.active = active;
397 cx.window
398 .activation_observers
399 .clone()
400 .retain(&(), |callback| callback(cx));
401 })
402 .log_err();
403 }
404 }));
405
406 platform_window.on_input({
407 let mut cx = cx.to_async();
408 Box::new(move |event| {
409 handle
410 .update(&mut cx, |_, cx| cx.dispatch_event(event))
411 .log_err()
412 .unwrap_or(false)
413 })
414 });
415
416 Window {
417 handle,
418 removed: false,
419 platform_window,
420 display_id,
421 sprite_atlas,
422 text_system,
423 rem_size: px(16.),
424 viewport_size: content_size,
425 layout_engine: Some(TaffyLayoutEngine::new()),
426 root_view: None,
427 element_id_stack: GlobalElementId::default(),
428 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
429 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
430 dirty_views: FxHashSet::default(),
431 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
432 focus_listeners: SubscriberSet::new(),
433 focus_lost_listeners: SubscriberSet::new(),
434 default_prevented: true,
435 mouse_position,
436 modifiers,
437 scale_factor,
438 bounds,
439 bounds_observers: SubscriberSet::new(),
440 appearance,
441 appearance_observers: SubscriberSet::new(),
442 active: false,
443 dirty,
444 last_input_timestamp,
445 refreshing: false,
446 drawing: false,
447 activation_observers: SubscriberSet::new(),
448 focus: None,
449 focus_enabled: true,
450 pending_input: None,
451 }
452 }
453}
454
455/// Indicates which region of the window is visible. Content falling outside of this mask will not be
456/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
457/// to leave room to support more complex shapes in the future.
458#[derive(Clone, Debug, Default, PartialEq, Eq)]
459#[repr(C)]
460pub struct ContentMask<P: Clone + Default + Debug> {
461 /// The bounds
462 pub bounds: Bounds<P>,
463}
464
465impl ContentMask<Pixels> {
466 /// Scale the content mask's pixel units by the given scaling factor.
467 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
468 ContentMask {
469 bounds: self.bounds.scale(factor),
470 }
471 }
472
473 /// Intersect the content mask with the given content mask.
474 pub fn intersect(&self, other: &Self) -> Self {
475 let bounds = self.bounds.intersect(&other.bounds);
476 ContentMask { bounds }
477 }
478}
479
480/// Provides access to application state in the context of a single window. Derefs
481/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
482/// an [`AppContext`] and call any [`AppContext`] methods.
483pub struct WindowContext<'a> {
484 pub(crate) app: &'a mut AppContext,
485 pub(crate) window: &'a mut Window,
486}
487
488impl<'a> WindowContext<'a> {
489 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
490 Self { app, window }
491 }
492
493 /// Obtain a handle to the window that belongs to this context.
494 pub fn window_handle(&self) -> AnyWindowHandle {
495 self.window.handle
496 }
497
498 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
499 pub fn refresh(&mut self) {
500 if !self.window.drawing {
501 self.window.refreshing = true;
502 self.window.dirty.set(true);
503 }
504 }
505
506 /// Close this window.
507 pub fn remove_window(&mut self) {
508 self.window.removed = true;
509 }
510
511 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
512 /// for elements rendered within this window.
513 pub fn focus_handle(&mut self) -> FocusHandle {
514 FocusHandle::new(&self.window.focus_handles)
515 }
516
517 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
518 pub fn focused(&self) -> Option<FocusHandle> {
519 self.window
520 .focus
521 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
522 }
523
524 /// Move focus to the element associated with the given [`FocusHandle`].
525 pub fn focus(&mut self, handle: &FocusHandle) {
526 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
527 return;
528 }
529
530 self.window.focus = Some(handle.id);
531 self.window
532 .rendered_frame
533 .dispatch_tree
534 .clear_pending_keystrokes();
535 self.refresh();
536 }
537
538 /// Remove focus from all elements within this context's window.
539 pub fn blur(&mut self) {
540 if !self.window.focus_enabled {
541 return;
542 }
543
544 self.window.focus = None;
545 self.refresh();
546 }
547
548 /// Blur the window and don't allow anything in it to be focused again.
549 pub fn disable_focus(&mut self) {
550 self.blur();
551 self.window.focus_enabled = false;
552 }
553
554 /// Accessor for the text system.
555 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
556 &self.window.text_system
557 }
558
559 /// Dispatch the given action on the currently focused element.
560 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
561 let focus_handle = self.focused();
562
563 self.defer(move |cx| {
564 let node_id = focus_handle
565 .and_then(|handle| {
566 cx.window
567 .rendered_frame
568 .dispatch_tree
569 .focusable_node_id(handle.id)
570 })
571 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
572
573 cx.propagate_event = true;
574 cx.dispatch_action_on_node(node_id, action);
575 })
576 }
577
578 pub(crate) fn dispatch_keystroke_observers(
579 &mut self,
580 event: &dyn Any,
581 action: Option<Box<dyn Action>>,
582 ) {
583 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
584 return;
585 };
586
587 self.keystroke_observers
588 .clone()
589 .retain(&(), move |callback| {
590 (callback)(
591 &KeystrokeEvent {
592 keystroke: key_down_event.keystroke.clone(),
593 action: action.as_ref().map(|action| action.boxed_clone()),
594 },
595 self,
596 );
597 true
598 });
599 }
600
601 pub(crate) fn clear_pending_keystrokes(&mut self) {
602 self.window
603 .rendered_frame
604 .dispatch_tree
605 .clear_pending_keystrokes();
606 self.window
607 .next_frame
608 .dispatch_tree
609 .clear_pending_keystrokes();
610 }
611
612 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
613 /// that are currently on the stack to be returned to the app.
614 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
615 let handle = self.window.handle;
616 self.app.defer(move |cx| {
617 handle.update(cx, |_, cx| f(cx)).ok();
618 });
619 }
620
621 /// Subscribe to events emitted by a model or view.
622 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
623 /// 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.
624 pub fn subscribe<Emitter, E, Evt>(
625 &mut self,
626 entity: &E,
627 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
628 ) -> Subscription
629 where
630 Emitter: EventEmitter<Evt>,
631 E: Entity<Emitter>,
632 Evt: 'static,
633 {
634 let entity_id = entity.entity_id();
635 let entity = entity.downgrade();
636 let window_handle = self.window.handle;
637 let (subscription, activate) = self.app.event_listeners.insert(
638 entity_id,
639 (
640 TypeId::of::<Evt>(),
641 Box::new(move |event, cx| {
642 window_handle
643 .update(cx, |_, cx| {
644 if let Some(handle) = E::upgrade_from(&entity) {
645 let event = event.downcast_ref().expect("invalid event type");
646 on_event(handle, event, cx);
647 true
648 } else {
649 false
650 }
651 })
652 .unwrap_or(false)
653 }),
654 ),
655 );
656 self.app.defer(move |_| activate());
657 subscription
658 }
659
660 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
661 /// await points in async code.
662 pub fn to_async(&self) -> AsyncWindowContext {
663 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
664 }
665
666 /// Schedule the given closure to be run directly after the current frame is rendered.
667 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
668 let handle = self.window.handle;
669 let display_id = self.window.display_id;
670
671 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
672 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
673 let (tx, mut rx) = mpsc::unbounded::<()>();
674 self.platform.set_display_link_output_callback(
675 display_id,
676 Box::new(move || _ = tx.unbounded_send(())),
677 );
678
679 let consumer_task = self.app.spawn(|cx| async move {
680 while rx.next().await.is_some() {
681 cx.update(|cx| {
682 for callback in cx
683 .next_frame_callbacks
684 .get_mut(&display_id)
685 .unwrap()
686 .drain(..)
687 .collect::<SmallVec<[_; 32]>>()
688 {
689 callback(cx);
690 }
691 })
692 .ok();
693
694 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
695
696 cx.update(|cx| {
697 if cx.next_frame_callbacks.is_empty() {
698 cx.platform.stop_display_link(display_id);
699 }
700 })
701 .ok();
702 }
703 });
704 e.insert(consumer_task);
705 }
706 debug_assert!(self.app.frame_consumers.is_empty());
707 self.app.frame_consumers = frame_consumers;
708
709 if self.next_frame_callbacks.is_empty() {
710 self.platform.start_display_link(display_id);
711 }
712
713 self.next_frame_callbacks
714 .entry(display_id)
715 .or_default()
716 .push(Box::new(move |cx: &mut AppContext| {
717 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
718 }));
719 }
720
721 /// Spawn the future returned by the given closure on the application thread pool.
722 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
723 /// use within your future.
724 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
725 where
726 R: 'static,
727 Fut: Future<Output = R> + 'static,
728 {
729 self.app
730 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
731 }
732
733 /// Updates the global of the given type. The given closure is given simultaneous mutable
734 /// access both to the global and the context.
735 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
736 where
737 G: Global,
738 {
739 let mut global = self.app.lease_global::<G>();
740 let result = f(&mut global, self);
741 self.app.end_global_lease(global);
742 result
743 }
744
745 fn window_bounds_changed(&mut self) {
746 self.window.scale_factor = self.window.platform_window.scale_factor();
747 self.window.viewport_size = self.window.platform_window.content_size();
748 self.window.bounds = self.window.platform_window.bounds();
749 self.window.display_id = self.window.platform_window.display().id();
750 self.refresh();
751
752 self.window
753 .bounds_observers
754 .clone()
755 .retain(&(), |callback| callback(self));
756 }
757
758 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
759 pub fn window_bounds(&self) -> WindowBounds {
760 self.window.bounds
761 }
762
763 fn appearance_changed(&mut self) {
764 self.window.appearance = self.window.platform_window.appearance();
765
766 self.window
767 .appearance_observers
768 .clone()
769 .retain(&(), |callback| callback(self));
770 }
771
772 /// Returns the appearance of the current window.
773 pub fn appearance(&self) -> WindowAppearance {
774 self.window.appearance
775 }
776
777 /// Returns the size of the drawable area within the window.
778 pub fn viewport_size(&self) -> Size<Pixels> {
779 self.window.viewport_size
780 }
781
782 /// Returns whether this window is focused by the operating system (receiving key events).
783 pub fn is_window_active(&self) -> bool {
784 self.window.active
785 }
786
787 /// Toggle zoom on the window.
788 pub fn zoom_window(&self) {
789 self.window.platform_window.zoom();
790 }
791
792 /// Updates the window's title at the platform level.
793 pub fn set_window_title(&mut self, title: &str) {
794 self.window.platform_window.set_title(title);
795 }
796
797 /// Mark the window as dirty at the platform level.
798 pub fn set_window_edited(&mut self, edited: bool) {
799 self.window.platform_window.set_edited(edited);
800 }
801
802 /// Determine the display on which the window is visible.
803 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
804 self.platform
805 .displays()
806 .into_iter()
807 .find(|display| display.id() == self.window.display_id)
808 }
809
810 /// Show the platform character palette.
811 pub fn show_character_palette(&self) {
812 self.window.platform_window.show_character_palette();
813 }
814
815 /// The scale factor of the display associated with the window. For example, it could
816 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
817 /// be rendered as two pixels on screen.
818 pub fn scale_factor(&self) -> f32 {
819 self.window.scale_factor
820 }
821
822 /// The size of an em for the base font of the application. Adjusting this value allows the
823 /// UI to scale, just like zooming a web page.
824 pub fn rem_size(&self) -> Pixels {
825 self.window.rem_size
826 }
827
828 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
829 /// UI to scale, just like zooming a web page.
830 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
831 self.window.rem_size = rem_size.into();
832 }
833
834 /// The line height associated with the current text style.
835 pub fn line_height(&self) -> Pixels {
836 let rem_size = self.rem_size();
837 let text_style = self.text_style();
838 text_style
839 .line_height
840 .to_pixels(text_style.font_size, rem_size)
841 }
842
843 /// Call to prevent the default action of an event. Currently only used to prevent
844 /// parent elements from becoming focused on mouse down.
845 pub fn prevent_default(&mut self) {
846 self.window.default_prevented = true;
847 }
848
849 /// Obtain whether default has been prevented for the event currently being dispatched.
850 pub fn default_prevented(&self) -> bool {
851 self.window.default_prevented
852 }
853
854 /// Determine whether the given action is available along the dispatch path to the currently focused element.
855 pub fn is_action_available(&self, action: &dyn Action) -> bool {
856 let target = self
857 .focused()
858 .and_then(|focused_handle| {
859 self.window
860 .rendered_frame
861 .dispatch_tree
862 .focusable_node_id(focused_handle.id)
863 })
864 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
865 self.window
866 .rendered_frame
867 .dispatch_tree
868 .is_action_available(action, target)
869 }
870
871 /// The position of the mouse relative to the window.
872 pub fn mouse_position(&self) -> Point<Pixels> {
873 self.window.mouse_position
874 }
875
876 /// The current state of the keyboard's modifiers
877 pub fn modifiers(&self) -> Modifiers {
878 self.window.modifiers
879 }
880
881 /// Returns true if there is no opaque layer containing the given point
882 /// on top of the given level. Layers who are extensions of the queried layer
883 /// are not considered to be on top of queried layer.
884 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
885 // Precondition: the depth map is ordered from topmost to bottomost.
886
887 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
888 if layer >= opaque_layer {
889 // The queried layer is either above or is the same as the this opaque layer.
890 // Anything after this point is guaranteed to be below the queried layer.
891 return true;
892 }
893
894 if !bounds.contains(point) {
895 // This opaque layer is above the queried layer but it doesn't contain
896 // the given position, so we can ignore it even if it's above.
897 continue;
898 }
899
900 // At this point, we've established that this opaque layer is on top of the queried layer
901 // and contains the position:
902 // If neither the opaque layer or the queried layer is an extension of the other then
903 // we know they are on different stacking orders, and return false.
904 let is_on_same_layer = opaque_layer
905 .iter()
906 .zip(layer.iter())
907 .all(|(a, b)| a.z_index == b.z_index);
908
909 if !is_on_same_layer {
910 return false;
911 }
912 }
913
914 true
915 }
916
917 pub(crate) fn was_top_layer_under_active_drag(
918 &self,
919 point: &Point<Pixels>,
920 layer: &StackingOrder,
921 ) -> bool {
922 // Precondition: the depth map is ordered from topmost to bottomost.
923
924 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
925 if layer >= opaque_layer {
926 // The queried layer is either above or is the same as the this opaque layer.
927 // Anything after this point is guaranteed to be below the queried layer.
928 return true;
929 }
930
931 if !bounds.contains(point) {
932 // This opaque layer is above the queried layer but it doesn't contain
933 // the given position, so we can ignore it even if it's above.
934 continue;
935 }
936
937 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
938 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
939 // looking to see if the queried layer was the topmost underneath the drag layer.
940 if opaque_layer
941 .first()
942 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
943 .unwrap_or(false)
944 {
945 continue;
946 }
947
948 // At this point, we've established that this opaque layer is on top of the queried layer
949 // and contains the position:
950 // If neither the opaque layer or the queried layer is an extension of the other then
951 // we know they are on different stacking orders, and return false.
952 let is_on_same_layer = opaque_layer
953 .iter()
954 .zip(layer.iter())
955 .all(|(a, b)| a.z_index == b.z_index);
956
957 if !is_on_same_layer {
958 return false;
959 }
960 }
961
962 true
963 }
964
965 /// Called during painting to get the current stacking order.
966 pub fn stacking_order(&self) -> &StackingOrder {
967 &self.window.next_frame.z_index_stack
968 }
969
970 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
971 /// the contents of the new [Scene], use [present].
972 pub(crate) fn draw(&mut self) {
973 self.window.dirty.set(false);
974 self.window.drawing = true;
975
976 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
977 {
978 let input_handler = self.window.platform_window.take_input_handler();
979 requested_handler.handler = input_handler;
980 }
981
982 let root_view = self.window.root_view.take().unwrap();
983 self.with_element_context(|cx| {
984 cx.with_z_index(0, |cx| {
985 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
986 // We need to use cx.cx here so we can utilize borrow splitting
987 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
988 for action_listener in action_listeners.iter().cloned() {
989 cx.cx.window.next_frame.dispatch_tree.on_action(
990 *action_type,
991 Rc::new(
992 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
993 action_listener(action, phase, cx)
994 },
995 ),
996 )
997 }
998 }
999
1000 let available_space = cx.window.viewport_size.map(Into::into);
1001 root_view.draw(Point::default(), available_space, cx);
1002 })
1003 })
1004 });
1005
1006 if let Some(active_drag) = self.app.active_drag.take() {
1007 self.with_element_context(|cx| {
1008 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
1009 let offset = cx.mouse_position() - active_drag.cursor_offset;
1010 let available_space =
1011 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1012 active_drag.view.draw(offset, available_space, cx);
1013 })
1014 });
1015 self.active_drag = Some(active_drag);
1016 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
1017 self.with_element_context(|cx| {
1018 cx.with_z_index(1, |cx| {
1019 let available_space =
1020 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1021 tooltip_request.tooltip.view.draw(
1022 tooltip_request.tooltip.cursor_offset,
1023 available_space,
1024 cx,
1025 );
1026 })
1027 });
1028 self.window.next_frame.tooltip_request = Some(tooltip_request);
1029 }
1030 self.window.dirty_views.clear();
1031
1032 self.window
1033 .next_frame
1034 .dispatch_tree
1035 .preserve_pending_keystrokes(
1036 &mut self.window.rendered_frame.dispatch_tree,
1037 self.window.focus,
1038 );
1039 self.window.next_frame.focus = self.window.focus;
1040 self.window.next_frame.window_active = self.window.active;
1041 self.window.root_view = Some(root_view);
1042
1043 // Set the cursor only if we're the active window.
1044 let cursor_style = self
1045 .window
1046 .next_frame
1047 .requested_cursor_style
1048 .take()
1049 .unwrap_or(CursorStyle::Arrow);
1050 if self.is_window_active() {
1051 self.platform.set_cursor_style(cursor_style);
1052 }
1053
1054 // Register requested input handler with the platform window.
1055 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1056 if let Some(handler) = requested_input.handler.take() {
1057 self.window.platform_window.set_input_handler(handler);
1058 }
1059 }
1060
1061 self.window.layout_engine.as_mut().unwrap().clear();
1062 self.text_system()
1063 .finish_frame(&self.window.next_frame.reused_views);
1064 self.window
1065 .next_frame
1066 .finish(&mut self.window.rendered_frame);
1067 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1068 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1069 if percentage >= 80. {
1070 log::warn!("elevated element arena occupation: {}.", percentage);
1071 }
1072 element_arena.clear();
1073 });
1074
1075 let previous_focus_path = self.window.rendered_frame.focus_path();
1076 let previous_window_active = self.window.rendered_frame.window_active;
1077 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1078 self.window.next_frame.clear();
1079 let current_focus_path = self.window.rendered_frame.focus_path();
1080 let current_window_active = self.window.rendered_frame.window_active;
1081
1082 if previous_focus_path != current_focus_path
1083 || previous_window_active != current_window_active
1084 {
1085 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1086 self.window
1087 .focus_lost_listeners
1088 .clone()
1089 .retain(&(), |listener| listener(self));
1090 }
1091
1092 let event = FocusEvent {
1093 previous_focus_path: if previous_window_active {
1094 previous_focus_path
1095 } else {
1096 Default::default()
1097 },
1098 current_focus_path: if current_window_active {
1099 current_focus_path
1100 } else {
1101 Default::default()
1102 },
1103 };
1104 self.window
1105 .focus_listeners
1106 .clone()
1107 .retain(&(), |listener| listener(&event, self));
1108 }
1109 self.window.refreshing = false;
1110 self.window.drawing = false;
1111 }
1112
1113 fn present(&self) {
1114 self.window
1115 .platform_window
1116 .draw(&self.window.rendered_frame.scene);
1117 }
1118
1119 /// Dispatch a mouse or keyboard event on the window.
1120 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1121 self.window.last_input_timestamp.set(Instant::now());
1122 // Handlers may set this to false by calling `stop_propagation`.
1123 self.app.propagate_event = true;
1124 // Handlers may set this to true by calling `prevent_default`.
1125 self.window.default_prevented = false;
1126
1127 let event = match event {
1128 // Track the mouse position with our own state, since accessing the platform
1129 // API for the mouse position can only occur on the main thread.
1130 PlatformInput::MouseMove(mouse_move) => {
1131 self.window.mouse_position = mouse_move.position;
1132 self.window.modifiers = mouse_move.modifiers;
1133 PlatformInput::MouseMove(mouse_move)
1134 }
1135 PlatformInput::MouseDown(mouse_down) => {
1136 self.window.mouse_position = mouse_down.position;
1137 self.window.modifiers = mouse_down.modifiers;
1138 PlatformInput::MouseDown(mouse_down)
1139 }
1140 PlatformInput::MouseUp(mouse_up) => {
1141 self.window.mouse_position = mouse_up.position;
1142 self.window.modifiers = mouse_up.modifiers;
1143 PlatformInput::MouseUp(mouse_up)
1144 }
1145 PlatformInput::MouseExited(mouse_exited) => {
1146 self.window.modifiers = mouse_exited.modifiers;
1147 PlatformInput::MouseExited(mouse_exited)
1148 }
1149 PlatformInput::ModifiersChanged(modifiers_changed) => {
1150 self.window.modifiers = modifiers_changed.modifiers;
1151 PlatformInput::ModifiersChanged(modifiers_changed)
1152 }
1153 PlatformInput::ScrollWheel(scroll_wheel) => {
1154 self.window.mouse_position = scroll_wheel.position;
1155 self.window.modifiers = scroll_wheel.modifiers;
1156 PlatformInput::ScrollWheel(scroll_wheel)
1157 }
1158 // Translate dragging and dropping of external files from the operating system
1159 // to internal drag and drop events.
1160 PlatformInput::FileDrop(file_drop) => match file_drop {
1161 FileDropEvent::Entered { position, paths } => {
1162 self.window.mouse_position = position;
1163 if self.active_drag.is_none() {
1164 self.active_drag = Some(AnyDrag {
1165 value: Box::new(paths.clone()),
1166 view: self.new_view(|_| paths).into(),
1167 cursor_offset: position,
1168 });
1169 }
1170 PlatformInput::MouseMove(MouseMoveEvent {
1171 position,
1172 pressed_button: Some(MouseButton::Left),
1173 modifiers: Modifiers::default(),
1174 })
1175 }
1176 FileDropEvent::Pending { position } => {
1177 self.window.mouse_position = position;
1178 PlatformInput::MouseMove(MouseMoveEvent {
1179 position,
1180 pressed_button: Some(MouseButton::Left),
1181 modifiers: Modifiers::default(),
1182 })
1183 }
1184 FileDropEvent::Submit { position } => {
1185 self.activate(true);
1186 self.window.mouse_position = position;
1187 PlatformInput::MouseUp(MouseUpEvent {
1188 button: MouseButton::Left,
1189 position,
1190 modifiers: Modifiers::default(),
1191 click_count: 1,
1192 })
1193 }
1194 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1195 button: MouseButton::Left,
1196 position: Point::default(),
1197 modifiers: Modifiers::default(),
1198 click_count: 1,
1199 }),
1200 },
1201 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1202 };
1203
1204 if let Some(any_mouse_event) = event.mouse_event() {
1205 self.dispatch_mouse_event(any_mouse_event);
1206 } else if let Some(any_key_event) = event.keyboard_event() {
1207 self.dispatch_key_event(any_key_event);
1208 }
1209
1210 !self.app.propagate_event
1211 }
1212
1213 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1214 if let Some(mut handlers) = self
1215 .window
1216 .rendered_frame
1217 .mouse_listeners
1218 .remove(&event.type_id())
1219 {
1220 // Because handlers may add other handlers, we sort every time.
1221 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1222
1223 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1224 // special purposes, such as detecting events outside of a given Bounds.
1225 for (_, _, handler) in &mut handlers {
1226 self.with_element_context(|cx| {
1227 handler(event, DispatchPhase::Capture, cx);
1228 });
1229 if !self.app.propagate_event {
1230 break;
1231 }
1232 }
1233
1234 // Bubble phase, where most normal handlers do their work.
1235 if self.app.propagate_event {
1236 for (_, _, handler) in handlers.iter_mut().rev() {
1237 self.with_element_context(|cx| {
1238 handler(event, DispatchPhase::Bubble, cx);
1239 });
1240 if !self.app.propagate_event {
1241 break;
1242 }
1243 }
1244 }
1245
1246 self.window
1247 .rendered_frame
1248 .mouse_listeners
1249 .insert(event.type_id(), handlers);
1250 }
1251
1252 if self.app.propagate_event && self.has_active_drag() {
1253 if event.is::<MouseMoveEvent>() {
1254 // If this was a mouse move event, redraw the window so that the
1255 // active drag can follow the mouse cursor.
1256 self.refresh();
1257 } else if event.is::<MouseUpEvent>() {
1258 // If this was a mouse up event, cancel the active drag and redraw
1259 // the window.
1260 self.active_drag = None;
1261 self.refresh();
1262 }
1263 }
1264 }
1265
1266 fn dispatch_key_event(&mut self, event: &dyn Any) {
1267 let node_id = self
1268 .window
1269 .focus
1270 .and_then(|focus_id| {
1271 self.window
1272 .rendered_frame
1273 .dispatch_tree
1274 .focusable_node_id(focus_id)
1275 })
1276 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1277
1278 let dispatch_path = self
1279 .window
1280 .rendered_frame
1281 .dispatch_tree
1282 .dispatch_path(node_id);
1283
1284 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1285 let KeymatchResult {
1286 bindings,
1287 mut pending,
1288 } = self
1289 .window
1290 .rendered_frame
1291 .dispatch_tree
1292 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1293
1294 if self.window.rendered_frame.dispatch_tree.keymatch_mode == KeymatchMode::Immediate
1295 && !bindings.is_empty()
1296 {
1297 pending = false;
1298 }
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 // for vim compatibility, we also should check "is input handler enabled"
1315 if !currently_pending.is_noop() {
1316 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1317 cx.background_executor.timer(Duration::from_secs(1)).await;
1318 cx.update(move |cx| {
1319 cx.clear_pending_keystrokes();
1320 let Some(currently_pending) = cx.window.pending_input.take() else {
1321 return;
1322 };
1323 cx.replay_pending_input(currently_pending)
1324 })
1325 .log_err();
1326 }));
1327 } else {
1328 currently_pending.timer = None;
1329 }
1330 self.window.pending_input = Some(currently_pending);
1331
1332 self.propagate_event = false;
1333 return;
1334 } else if let Some(currently_pending) = self.window.pending_input.take() {
1335 if bindings
1336 .iter()
1337 .all(|binding| !currently_pending.used_by_binding(binding))
1338 {
1339 self.replay_pending_input(currently_pending)
1340 }
1341 }
1342
1343 if !bindings.is_empty() {
1344 self.clear_pending_keystrokes();
1345 }
1346
1347 self.propagate_event = true;
1348 for binding in bindings {
1349 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1350 if !self.propagate_event {
1351 self.dispatch_keystroke_observers(event, Some(binding.action));
1352 return;
1353 }
1354 }
1355 }
1356
1357 // Capture phase
1358 for node_id in &dispatch_path {
1359 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1360
1361 for key_listener in node.key_listeners.clone() {
1362 self.with_element_context(|cx| {
1363 key_listener(event, DispatchPhase::Capture, cx);
1364 });
1365 if !self.propagate_event {
1366 return;
1367 }
1368 }
1369 }
1370
1371 // Bubble phase
1372 for node_id in dispatch_path.iter().rev() {
1373 // Handle low level key events
1374 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1375 for key_listener in node.key_listeners.clone() {
1376 self.with_element_context(|cx| {
1377 key_listener(event, DispatchPhase::Bubble, cx);
1378 });
1379 if !self.propagate_event {
1380 return;
1381 }
1382 }
1383 }
1384
1385 self.dispatch_keystroke_observers(event, None);
1386 }
1387
1388 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1389 pub fn has_pending_keystrokes(&self) -> bool {
1390 self.window
1391 .rendered_frame
1392 .dispatch_tree
1393 .has_pending_keystrokes()
1394 }
1395
1396 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1397 let node_id = self
1398 .window
1399 .focus
1400 .and_then(|focus_id| {
1401 self.window
1402 .rendered_frame
1403 .dispatch_tree
1404 .focusable_node_id(focus_id)
1405 })
1406 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1407
1408 if self.window.focus != currently_pending.focus {
1409 return;
1410 }
1411
1412 let input = currently_pending.input();
1413
1414 self.propagate_event = true;
1415 for binding in currently_pending.bindings {
1416 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1417 if !self.propagate_event {
1418 return;
1419 }
1420 }
1421
1422 if !input.is_empty() {
1423 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1424 input_handler.flush_pending_input(&input, self);
1425 self.window.platform_window.set_input_handler(input_handler)
1426 }
1427 }
1428 }
1429
1430 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1431 let dispatch_path = self
1432 .window
1433 .rendered_frame
1434 .dispatch_tree
1435 .dispatch_path(node_id);
1436
1437 // Capture phase
1438 for node_id in &dispatch_path {
1439 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1440 for DispatchActionListener {
1441 action_type,
1442 listener,
1443 } in node.action_listeners.clone()
1444 {
1445 let any_action = action.as_any();
1446 if action_type == any_action.type_id() {
1447 self.with_element_context(|cx| {
1448 listener(any_action, DispatchPhase::Capture, cx);
1449 });
1450
1451 if !self.propagate_event {
1452 return;
1453 }
1454 }
1455 }
1456 }
1457 // Bubble phase
1458 for node_id in dispatch_path.iter().rev() {
1459 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1460 for DispatchActionListener {
1461 action_type,
1462 listener,
1463 } in node.action_listeners.clone()
1464 {
1465 let any_action = action.as_any();
1466 if action_type == any_action.type_id() {
1467 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1468
1469 self.with_element_context(|cx| {
1470 listener(any_action, DispatchPhase::Bubble, cx);
1471 });
1472
1473 if !self.propagate_event {
1474 return;
1475 }
1476 }
1477 }
1478 }
1479 }
1480
1481 /// Register the given handler to be invoked whenever the global of the given type
1482 /// is updated.
1483 pub fn observe_global<G: Global>(
1484 &mut self,
1485 f: impl Fn(&mut WindowContext<'_>) + 'static,
1486 ) -> Subscription {
1487 let window_handle = self.window.handle;
1488 let (subscription, activate) = self.global_observers.insert(
1489 TypeId::of::<G>(),
1490 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1491 );
1492 self.app.defer(move |_| activate());
1493 subscription
1494 }
1495
1496 /// Focus the current window and bring it to the foreground at the platform level.
1497 pub fn activate_window(&self) {
1498 self.window.platform_window.activate();
1499 }
1500
1501 /// Minimize the current window at the platform level.
1502 pub fn minimize_window(&self) {
1503 self.window.platform_window.minimize();
1504 }
1505
1506 /// Toggle full screen status on the current window at the platform level.
1507 pub fn toggle_full_screen(&self) {
1508 self.window.platform_window.toggle_full_screen();
1509 }
1510
1511 /// Present a platform dialog.
1512 /// The provided message will be presented, along with buttons for each answer.
1513 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1514 pub fn prompt(
1515 &self,
1516 level: PromptLevel,
1517 message: &str,
1518 detail: Option<&str>,
1519 answers: &[&str],
1520 ) -> oneshot::Receiver<usize> {
1521 self.window
1522 .platform_window
1523 .prompt(level, message, detail, answers)
1524 }
1525
1526 /// Returns all available actions for the focused element.
1527 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1528 let node_id = self
1529 .window
1530 .focus
1531 .and_then(|focus_id| {
1532 self.window
1533 .rendered_frame
1534 .dispatch_tree
1535 .focusable_node_id(focus_id)
1536 })
1537 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1538
1539 self.window
1540 .rendered_frame
1541 .dispatch_tree
1542 .available_actions(node_id)
1543 }
1544
1545 /// Returns key bindings that invoke the given action on the currently focused element.
1546 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1547 self.window
1548 .rendered_frame
1549 .dispatch_tree
1550 .bindings_for_action(
1551 action,
1552 &self.window.rendered_frame.dispatch_tree.context_stack,
1553 )
1554 }
1555
1556 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1557 pub fn bindings_for_action_in(
1558 &self,
1559 action: &dyn Action,
1560 focus_handle: &FocusHandle,
1561 ) -> Vec<KeyBinding> {
1562 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1563
1564 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1565 return vec![];
1566 };
1567 let context_stack = dispatch_tree
1568 .dispatch_path(node_id)
1569 .into_iter()
1570 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1571 .collect();
1572 dispatch_tree.bindings_for_action(action, &context_stack)
1573 }
1574
1575 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1576 pub fn listener_for<V: Render, E>(
1577 &self,
1578 view: &View<V>,
1579 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1580 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1581 let view = view.downgrade();
1582 move |e: &E, cx: &mut WindowContext| {
1583 view.update(cx, |view, cx| f(view, e, cx)).ok();
1584 }
1585 }
1586
1587 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1588 pub fn handler_for<V: Render>(
1589 &self,
1590 view: &View<V>,
1591 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1592 ) -> impl Fn(&mut WindowContext) {
1593 let view = view.downgrade();
1594 move |cx: &mut WindowContext| {
1595 view.update(cx, |view, cx| f(view, cx)).ok();
1596 }
1597 }
1598
1599 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1600 /// If the callback returns false, the window won't be closed.
1601 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1602 let mut this = self.to_async();
1603 self.window
1604 .platform_window
1605 .on_should_close(Box::new(move || {
1606 this.update(|cx| {
1607 // Ensure that the window is removed from the app if it's been closed
1608 // by always pre-empting the system close event.
1609 if f(cx) {
1610 cx.remove_window();
1611 }
1612 false
1613 })
1614 .unwrap_or(true)
1615 }))
1616 }
1617
1618 pub(crate) fn parent_view_id(&self) -> EntityId {
1619 *self
1620 .window
1621 .next_frame
1622 .view_stack
1623 .last()
1624 .expect("a view should always be on the stack while drawing")
1625 }
1626
1627 /// Register an action listener on the window for the next frame. The type of action
1628 /// is determined by the first parameter of the given listener. When the next frame is rendered
1629 /// the listener will be cleared.
1630 ///
1631 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1632 /// a specific need to register a global listener.
1633 pub fn on_action(
1634 &mut self,
1635 action_type: TypeId,
1636 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1637 ) {
1638 self.window
1639 .next_frame
1640 .dispatch_tree
1641 .on_action(action_type, Rc::new(listener));
1642 }
1643}
1644
1645impl Context for WindowContext<'_> {
1646 type Result<T> = T;
1647
1648 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1649 where
1650 T: 'static,
1651 {
1652 let slot = self.app.entities.reserve();
1653 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1654 self.entities.insert(slot, model)
1655 }
1656
1657 fn update_model<T: 'static, R>(
1658 &mut self,
1659 model: &Model<T>,
1660 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1661 ) -> R {
1662 let mut entity = self.entities.lease(model);
1663 let result = update(
1664 &mut *entity,
1665 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1666 );
1667 self.entities.end_lease(entity);
1668 result
1669 }
1670
1671 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1672 where
1673 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1674 {
1675 if window == self.window.handle {
1676 let root_view = self.window.root_view.clone().unwrap();
1677 Ok(update(root_view, self))
1678 } else {
1679 window.update(self.app, update)
1680 }
1681 }
1682
1683 fn read_model<T, R>(
1684 &self,
1685 handle: &Model<T>,
1686 read: impl FnOnce(&T, &AppContext) -> R,
1687 ) -> Self::Result<R>
1688 where
1689 T: 'static,
1690 {
1691 let entity = self.entities.read(handle);
1692 read(entity, &*self.app)
1693 }
1694
1695 fn read_window<T, R>(
1696 &self,
1697 window: &WindowHandle<T>,
1698 read: impl FnOnce(View<T>, &AppContext) -> R,
1699 ) -> Result<R>
1700 where
1701 T: 'static,
1702 {
1703 if window.any_handle == self.window.handle {
1704 let root_view = self
1705 .window
1706 .root_view
1707 .clone()
1708 .unwrap()
1709 .downcast::<T>()
1710 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1711 Ok(read(root_view, self))
1712 } else {
1713 self.app.read_window(window, read)
1714 }
1715 }
1716}
1717
1718impl VisualContext for WindowContext<'_> {
1719 fn new_view<V>(
1720 &mut self,
1721 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1722 ) -> Self::Result<View<V>>
1723 where
1724 V: 'static + Render,
1725 {
1726 let slot = self.app.entities.reserve();
1727 let view = View {
1728 model: slot.clone(),
1729 };
1730 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1731 let entity = build_view_state(&mut cx);
1732 cx.entities.insert(slot, entity);
1733
1734 cx.new_view_observers
1735 .clone()
1736 .retain(&TypeId::of::<V>(), |observer| {
1737 let any_view = AnyView::from(view.clone());
1738 (observer)(any_view, self);
1739 true
1740 });
1741
1742 view
1743 }
1744
1745 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1746 fn update_view<T: 'static, R>(
1747 &mut self,
1748 view: &View<T>,
1749 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1750 ) -> Self::Result<R> {
1751 let mut lease = self.app.entities.lease(&view.model);
1752 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1753 let result = update(&mut *lease, &mut cx);
1754 cx.app.entities.end_lease(lease);
1755 result
1756 }
1757
1758 fn replace_root_view<V>(
1759 &mut self,
1760 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1761 ) -> Self::Result<View<V>>
1762 where
1763 V: 'static + Render,
1764 {
1765 let view = self.new_view(build_view);
1766 self.window.root_view = Some(view.clone().into());
1767 self.refresh();
1768 view
1769 }
1770
1771 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1772 self.update_view(view, |view, cx| {
1773 view.focus_handle(cx).clone().focus(cx);
1774 })
1775 }
1776
1777 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1778 where
1779 V: ManagedView,
1780 {
1781 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1782 }
1783}
1784
1785impl<'a> std::ops::Deref for WindowContext<'a> {
1786 type Target = AppContext;
1787
1788 fn deref(&self) -> &Self::Target {
1789 self.app
1790 }
1791}
1792
1793impl<'a> std::ops::DerefMut for WindowContext<'a> {
1794 fn deref_mut(&mut self) -> &mut Self::Target {
1795 self.app
1796 }
1797}
1798
1799impl<'a> Borrow<AppContext> for WindowContext<'a> {
1800 fn borrow(&self) -> &AppContext {
1801 self.app
1802 }
1803}
1804
1805impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1806 fn borrow_mut(&mut self) -> &mut AppContext {
1807 self.app
1808 }
1809}
1810
1811/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1812pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1813 #[doc(hidden)]
1814 fn app_mut(&mut self) -> &mut AppContext {
1815 self.borrow_mut()
1816 }
1817
1818 #[doc(hidden)]
1819 fn app(&self) -> &AppContext {
1820 self.borrow()
1821 }
1822
1823 #[doc(hidden)]
1824 fn window(&self) -> &Window {
1825 self.borrow()
1826 }
1827
1828 #[doc(hidden)]
1829 fn window_mut(&mut self) -> &mut Window {
1830 self.borrow_mut()
1831 }
1832}
1833
1834impl Borrow<Window> for WindowContext<'_> {
1835 fn borrow(&self) -> &Window {
1836 self.window
1837 }
1838}
1839
1840impl BorrowMut<Window> for WindowContext<'_> {
1841 fn borrow_mut(&mut self) -> &mut Window {
1842 self.window
1843 }
1844}
1845
1846impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1847
1848/// Provides access to application state that is specialized for a particular [`View`].
1849/// Allows you to interact with focus, emit events, etc.
1850/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1851/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1852pub struct ViewContext<'a, V> {
1853 window_cx: WindowContext<'a>,
1854 view: &'a View<V>,
1855}
1856
1857impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1858 fn borrow(&self) -> &AppContext {
1859 &*self.window_cx.app
1860 }
1861}
1862
1863impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1864 fn borrow_mut(&mut self) -> &mut AppContext {
1865 &mut *self.window_cx.app
1866 }
1867}
1868
1869impl<V> Borrow<Window> for ViewContext<'_, V> {
1870 fn borrow(&self) -> &Window {
1871 &*self.window_cx.window
1872 }
1873}
1874
1875impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1876 fn borrow_mut(&mut self) -> &mut Window {
1877 &mut *self.window_cx.window
1878 }
1879}
1880
1881impl<'a, V: 'static> ViewContext<'a, V> {
1882 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1883 Self {
1884 window_cx: WindowContext::new(app, window),
1885 view,
1886 }
1887 }
1888
1889 /// Get the entity_id of this view.
1890 pub fn entity_id(&self) -> EntityId {
1891 self.view.entity_id()
1892 }
1893
1894 /// Get the view pointer underlying this context.
1895 pub fn view(&self) -> &View<V> {
1896 self.view
1897 }
1898
1899 /// Get the model underlying this view.
1900 pub fn model(&self) -> &Model<V> {
1901 &self.view.model
1902 }
1903
1904 /// Access the underlying window context.
1905 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1906 &mut self.window_cx
1907 }
1908
1909 /// Sets a given callback to be run on the next frame.
1910 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1911 where
1912 V: 'static,
1913 {
1914 let view = self.view().clone();
1915 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1916 }
1917
1918 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1919 /// that are currently on the stack to be returned to the app.
1920 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1921 let view = self.view().downgrade();
1922 self.window_cx.defer(move |cx| {
1923 view.update(cx, f).ok();
1924 });
1925 }
1926
1927 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1928 pub fn observe<V2, E>(
1929 &mut self,
1930 entity: &E,
1931 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1932 ) -> Subscription
1933 where
1934 V2: 'static,
1935 V: 'static,
1936 E: Entity<V2>,
1937 {
1938 let view = self.view().downgrade();
1939 let entity_id = entity.entity_id();
1940 let entity = entity.downgrade();
1941 let window_handle = self.window.handle;
1942 let (subscription, activate) = self.app.observers.insert(
1943 entity_id,
1944 Box::new(move |cx| {
1945 window_handle
1946 .update(cx, |_, cx| {
1947 if let Some(handle) = E::upgrade_from(&entity) {
1948 view.update(cx, |this, cx| on_notify(this, handle, cx))
1949 .is_ok()
1950 } else {
1951 false
1952 }
1953 })
1954 .unwrap_or(false)
1955 }),
1956 );
1957 self.app.defer(move |_| activate());
1958 subscription
1959 }
1960
1961 /// Subscribe to events emitted by another model or view.
1962 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1963 /// The callback will be invoked with a reference to the current view, a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a view context for the current view.
1964 pub fn subscribe<V2, E, Evt>(
1965 &mut self,
1966 entity: &E,
1967 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1968 ) -> Subscription
1969 where
1970 V2: EventEmitter<Evt>,
1971 E: Entity<V2>,
1972 Evt: 'static,
1973 {
1974 let view = self.view().downgrade();
1975 let entity_id = entity.entity_id();
1976 let handle = entity.downgrade();
1977 let window_handle = self.window.handle;
1978 let (subscription, activate) = self.app.event_listeners.insert(
1979 entity_id,
1980 (
1981 TypeId::of::<Evt>(),
1982 Box::new(move |event, cx| {
1983 window_handle
1984 .update(cx, |_, cx| {
1985 if let Some(handle) = E::upgrade_from(&handle) {
1986 let event = event.downcast_ref().expect("invalid event type");
1987 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1988 .is_ok()
1989 } else {
1990 false
1991 }
1992 })
1993 .unwrap_or(false)
1994 }),
1995 ),
1996 );
1997 self.app.defer(move |_| activate());
1998 subscription
1999 }
2000
2001 /// Register a callback to be invoked when the view is released.
2002 ///
2003 /// The callback receives a handle to the view's window. This handle may be
2004 /// invalid, if the window was closed before the view was released.
2005 pub fn on_release(
2006 &mut self,
2007 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2008 ) -> Subscription {
2009 let window_handle = self.window.handle;
2010 let (subscription, activate) = self.app.release_listeners.insert(
2011 self.view.model.entity_id,
2012 Box::new(move |this, cx| {
2013 let this = this.downcast_mut().expect("invalid entity type");
2014 on_release(this, window_handle, cx)
2015 }),
2016 );
2017 activate();
2018 subscription
2019 }
2020
2021 /// Register a callback to be invoked when the given Model or View is released.
2022 pub fn observe_release<V2, E>(
2023 &mut self,
2024 entity: &E,
2025 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2026 ) -> Subscription
2027 where
2028 V: 'static,
2029 V2: 'static,
2030 E: Entity<V2>,
2031 {
2032 let view = self.view().downgrade();
2033 let entity_id = entity.entity_id();
2034 let window_handle = self.window.handle;
2035 let (subscription, activate) = self.app.release_listeners.insert(
2036 entity_id,
2037 Box::new(move |entity, cx| {
2038 let entity = entity.downcast_mut().expect("invalid entity type");
2039 let _ = window_handle.update(cx, |_, cx| {
2040 view.update(cx, |this, cx| on_release(this, entity, cx))
2041 });
2042 }),
2043 );
2044 activate();
2045 subscription
2046 }
2047
2048 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2049 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2050 pub fn notify(&mut self) {
2051 for view_id in self
2052 .window
2053 .rendered_frame
2054 .dispatch_tree
2055 .view_path(self.view.entity_id())
2056 .into_iter()
2057 .rev()
2058 {
2059 if !self.window.dirty_views.insert(view_id) {
2060 break;
2061 }
2062 }
2063
2064 if !self.window.drawing {
2065 self.window_cx.window.dirty.set(true);
2066 self.window_cx.app.push_effect(Effect::Notify {
2067 emitter: self.view.model.entity_id,
2068 });
2069 }
2070 }
2071
2072 /// Register a callback to be invoked when the window is resized.
2073 pub fn observe_window_bounds(
2074 &mut self,
2075 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2076 ) -> Subscription {
2077 let view = self.view.downgrade();
2078 let (subscription, activate) = self.window.bounds_observers.insert(
2079 (),
2080 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2081 );
2082 activate();
2083 subscription
2084 }
2085
2086 /// Register a callback to be invoked when the window is activated or deactivated.
2087 pub fn observe_window_activation(
2088 &mut self,
2089 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2090 ) -> Subscription {
2091 let view = self.view.downgrade();
2092 let (subscription, activate) = self.window.activation_observers.insert(
2093 (),
2094 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2095 );
2096 activate();
2097 subscription
2098 }
2099
2100 /// Registers a callback to be invoked when the window appearance changes.
2101 pub fn observe_window_appearance(
2102 &mut self,
2103 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2104 ) -> Subscription {
2105 let view = self.view.downgrade();
2106 let (subscription, activate) = self.window.appearance_observers.insert(
2107 (),
2108 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2109 );
2110 activate();
2111 subscription
2112 }
2113
2114 /// Register a listener to be called when the given focus handle receives focus.
2115 /// Returns a subscription and persists until the subscription is dropped.
2116 pub fn on_focus(
2117 &mut self,
2118 handle: &FocusHandle,
2119 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2120 ) -> Subscription {
2121 let view = self.view.downgrade();
2122 let focus_id = handle.id;
2123 let (subscription, activate) = self.window.focus_listeners.insert(
2124 (),
2125 Box::new(move |event, cx| {
2126 view.update(cx, |view, cx| {
2127 if event.previous_focus_path.last() != Some(&focus_id)
2128 && event.current_focus_path.last() == Some(&focus_id)
2129 {
2130 listener(view, cx)
2131 }
2132 })
2133 .is_ok()
2134 }),
2135 );
2136 self.app.defer(move |_| activate());
2137 subscription
2138 }
2139
2140 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2141 /// Returns a subscription and persists until the subscription is dropped.
2142 pub fn on_focus_in(
2143 &mut self,
2144 handle: &FocusHandle,
2145 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2146 ) -> Subscription {
2147 let view = self.view.downgrade();
2148 let focus_id = handle.id;
2149 let (subscription, activate) = self.window.focus_listeners.insert(
2150 (),
2151 Box::new(move |event, cx| {
2152 view.update(cx, |view, cx| {
2153 if !event.previous_focus_path.contains(&focus_id)
2154 && event.current_focus_path.contains(&focus_id)
2155 {
2156 listener(view, cx)
2157 }
2158 })
2159 .is_ok()
2160 }),
2161 );
2162 self.app.defer(move |_| activate());
2163 subscription
2164 }
2165
2166 /// Register a listener to be called when the given focus handle loses focus.
2167 /// Returns a subscription and persists until the subscription is dropped.
2168 pub fn on_blur(
2169 &mut self,
2170 handle: &FocusHandle,
2171 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2172 ) -> Subscription {
2173 let view = self.view.downgrade();
2174 let focus_id = handle.id;
2175 let (subscription, activate) = self.window.focus_listeners.insert(
2176 (),
2177 Box::new(move |event, cx| {
2178 view.update(cx, |view, cx| {
2179 if event.previous_focus_path.last() == Some(&focus_id)
2180 && event.current_focus_path.last() != Some(&focus_id)
2181 {
2182 listener(view, cx)
2183 }
2184 })
2185 .is_ok()
2186 }),
2187 );
2188 self.app.defer(move |_| activate());
2189 subscription
2190 }
2191
2192 /// Register a listener to be called when nothing in the window has focus.
2193 /// This typically happens when the node that was focused is removed from the tree,
2194 /// and this callback lets you chose a default place to restore the users focus.
2195 /// Returns a subscription and persists until the subscription is dropped.
2196 pub fn on_focus_lost(
2197 &mut self,
2198 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2199 ) -> Subscription {
2200 let view = self.view.downgrade();
2201 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2202 (),
2203 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2204 );
2205 activate();
2206 subscription
2207 }
2208
2209 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2210 /// Returns a subscription and persists until the subscription is dropped.
2211 pub fn on_focus_out(
2212 &mut self,
2213 handle: &FocusHandle,
2214 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2215 ) -> Subscription {
2216 let view = self.view.downgrade();
2217 let focus_id = handle.id;
2218 let (subscription, activate) = self.window.focus_listeners.insert(
2219 (),
2220 Box::new(move |event, cx| {
2221 view.update(cx, |view, cx| {
2222 if event.previous_focus_path.contains(&focus_id)
2223 && !event.current_focus_path.contains(&focus_id)
2224 {
2225 listener(view, cx)
2226 }
2227 })
2228 .is_ok()
2229 }),
2230 );
2231 self.app.defer(move |_| activate());
2232 subscription
2233 }
2234
2235 /// Schedule a future to be run asynchronously.
2236 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2237 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2238 /// The returned future will be polled on the main thread.
2239 pub fn spawn<Fut, R>(
2240 &mut self,
2241 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2242 ) -> Task<R>
2243 where
2244 R: 'static,
2245 Fut: Future<Output = R> + 'static,
2246 {
2247 let view = self.view().downgrade();
2248 self.window_cx.spawn(|cx| f(view, cx))
2249 }
2250
2251 /// Updates the global state of the given type.
2252 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2253 where
2254 G: Global,
2255 {
2256 let mut global = self.app.lease_global::<G>();
2257 let result = f(&mut global, self);
2258 self.app.end_global_lease(global);
2259 result
2260 }
2261
2262 /// Register a callback to be invoked when the given global state changes.
2263 pub fn observe_global<G: Global>(
2264 &mut self,
2265 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2266 ) -> Subscription {
2267 let window_handle = self.window.handle;
2268 let view = self.view().downgrade();
2269 let (subscription, activate) = self.global_observers.insert(
2270 TypeId::of::<G>(),
2271 Box::new(move |cx| {
2272 window_handle
2273 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2274 .unwrap_or(false)
2275 }),
2276 );
2277 self.app.defer(move |_| activate());
2278 subscription
2279 }
2280
2281 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2282 pub fn on_action(
2283 &mut self,
2284 action_type: TypeId,
2285 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2286 ) {
2287 let handle = self.view().clone();
2288 self.window_cx
2289 .on_action(action_type, move |action, phase, cx| {
2290 handle.update(cx, |view, cx| {
2291 listener(view, action, phase, cx);
2292 })
2293 });
2294 }
2295
2296 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2297 pub fn emit<Evt>(&mut self, event: Evt)
2298 where
2299 Evt: 'static,
2300 V: EventEmitter<Evt>,
2301 {
2302 let emitter = self.view.model.entity_id;
2303 self.app.push_effect(Effect::Emit {
2304 emitter,
2305 event_type: TypeId::of::<Evt>(),
2306 event: Box::new(event),
2307 });
2308 }
2309
2310 /// Move focus to the current view, assuming it implements [`FocusableView`].
2311 pub fn focus_self(&mut self)
2312 where
2313 V: FocusableView,
2314 {
2315 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2316 }
2317
2318 /// Convenience method for accessing view state in an event callback.
2319 ///
2320 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2321 /// but it's often useful to be able to access view state in these
2322 /// callbacks. This method provides a convenient way to do so.
2323 pub fn listener<E>(
2324 &self,
2325 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2326 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2327 let view = self.view().downgrade();
2328 move |e: &E, cx: &mut WindowContext| {
2329 view.update(cx, |view, cx| f(view, e, cx)).ok();
2330 }
2331 }
2332}
2333
2334impl<V> Context for ViewContext<'_, V> {
2335 type Result<U> = U;
2336
2337 fn new_model<T: 'static>(
2338 &mut self,
2339 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2340 ) -> Model<T> {
2341 self.window_cx.new_model(build_model)
2342 }
2343
2344 fn update_model<T: 'static, R>(
2345 &mut self,
2346 model: &Model<T>,
2347 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2348 ) -> R {
2349 self.window_cx.update_model(model, update)
2350 }
2351
2352 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2353 where
2354 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2355 {
2356 self.window_cx.update_window(window, update)
2357 }
2358
2359 fn read_model<T, R>(
2360 &self,
2361 handle: &Model<T>,
2362 read: impl FnOnce(&T, &AppContext) -> R,
2363 ) -> Self::Result<R>
2364 where
2365 T: 'static,
2366 {
2367 self.window_cx.read_model(handle, read)
2368 }
2369
2370 fn read_window<T, R>(
2371 &self,
2372 window: &WindowHandle<T>,
2373 read: impl FnOnce(View<T>, &AppContext) -> R,
2374 ) -> Result<R>
2375 where
2376 T: 'static,
2377 {
2378 self.window_cx.read_window(window, read)
2379 }
2380}
2381
2382impl<V: 'static> VisualContext for ViewContext<'_, V> {
2383 fn new_view<W: Render + 'static>(
2384 &mut self,
2385 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2386 ) -> Self::Result<View<W>> {
2387 self.window_cx.new_view(build_view_state)
2388 }
2389
2390 fn update_view<V2: 'static, R>(
2391 &mut self,
2392 view: &View<V2>,
2393 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2394 ) -> Self::Result<R> {
2395 self.window_cx.update_view(view, update)
2396 }
2397
2398 fn replace_root_view<W>(
2399 &mut self,
2400 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2401 ) -> Self::Result<View<W>>
2402 where
2403 W: 'static + Render,
2404 {
2405 self.window_cx.replace_root_view(build_view)
2406 }
2407
2408 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2409 self.window_cx.focus_view(view)
2410 }
2411
2412 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2413 self.window_cx.dismiss_view(view)
2414 }
2415}
2416
2417impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2418 type Target = WindowContext<'a>;
2419
2420 fn deref(&self) -> &Self::Target {
2421 &self.window_cx
2422 }
2423}
2424
2425impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2426 fn deref_mut(&mut self) -> &mut Self::Target {
2427 &mut self.window_cx
2428 }
2429}
2430
2431// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2432slotmap::new_key_type! {
2433 /// A unique identifier for a window.
2434 pub struct WindowId;
2435}
2436
2437impl WindowId {
2438 /// Converts this window ID to a `u64`.
2439 pub fn as_u64(&self) -> u64 {
2440 self.0.as_ffi()
2441 }
2442}
2443
2444/// A handle to a window with a specific root view type.
2445/// Note that this does not keep the window alive on its own.
2446#[derive(Deref, DerefMut)]
2447pub struct WindowHandle<V> {
2448 #[deref]
2449 #[deref_mut]
2450 pub(crate) any_handle: AnyWindowHandle,
2451 state_type: PhantomData<V>,
2452}
2453
2454impl<V: 'static + Render> WindowHandle<V> {
2455 /// Creates a new handle from a window ID.
2456 /// This does not check if the root type of the window is `V`.
2457 pub fn new(id: WindowId) -> Self {
2458 WindowHandle {
2459 any_handle: AnyWindowHandle {
2460 id,
2461 state_type: TypeId::of::<V>(),
2462 },
2463 state_type: PhantomData,
2464 }
2465 }
2466
2467 /// Get the root view out 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<C>(&self, cx: &mut C) -> Result<View<V>>
2471 where
2472 C: Context,
2473 {
2474 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2475 root_view
2476 .downcast::<V>()
2477 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2478 }))
2479 }
2480
2481 /// Updates the root view of this window.
2482 ///
2483 /// This will fail if the window has been closed or if the root view's type does not match
2484 pub fn update<C, R>(
2485 &self,
2486 cx: &mut C,
2487 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2488 ) -> Result<R>
2489 where
2490 C: Context,
2491 {
2492 cx.update_window(self.any_handle, |root_view, cx| {
2493 let view = root_view
2494 .downcast::<V>()
2495 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2496 Ok(cx.update_view(&view, update))
2497 })?
2498 }
2499
2500 /// Read the root view out of this window.
2501 ///
2502 /// This will fail if the window is closed or if the root view's type does not match `V`.
2503 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2504 let x = cx
2505 .windows
2506 .get(self.id)
2507 .and_then(|window| {
2508 window
2509 .as_ref()
2510 .and_then(|window| window.root_view.clone())
2511 .map(|root_view| root_view.downcast::<V>())
2512 })
2513 .ok_or_else(|| anyhow!("window not found"))?
2514 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2515
2516 Ok(x.read(cx))
2517 }
2518
2519 /// Read the root view out of this window, with a callback
2520 ///
2521 /// This will fail if the window is closed or if the root view's type does not match `V`.
2522 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2523 where
2524 C: Context,
2525 {
2526 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2527 }
2528
2529 /// Read the root view pointer off of this window.
2530 ///
2531 /// This will fail if the window is closed or if the root view's type does not match `V`.
2532 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2533 where
2534 C: Context,
2535 {
2536 cx.read_window(self, |root_view, _cx| root_view.clone())
2537 }
2538
2539 /// Check if this window is 'active'.
2540 ///
2541 /// Will return `None` if the window is closed.
2542 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2543 cx.windows
2544 .get(self.id)
2545 .and_then(|window| window.as_ref().map(|window| window.active))
2546 }
2547}
2548
2549impl<V> Copy for WindowHandle<V> {}
2550
2551impl<V> Clone for WindowHandle<V> {
2552 fn clone(&self) -> Self {
2553 *self
2554 }
2555}
2556
2557impl<V> PartialEq for WindowHandle<V> {
2558 fn eq(&self, other: &Self) -> bool {
2559 self.any_handle == other.any_handle
2560 }
2561}
2562
2563impl<V> Eq for WindowHandle<V> {}
2564
2565impl<V> Hash for WindowHandle<V> {
2566 fn hash<H: Hasher>(&self, state: &mut H) {
2567 self.any_handle.hash(state);
2568 }
2569}
2570
2571impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2572 fn from(val: WindowHandle<V>) -> Self {
2573 val.any_handle
2574 }
2575}
2576
2577/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2578#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2579pub struct AnyWindowHandle {
2580 pub(crate) id: WindowId,
2581 state_type: TypeId,
2582}
2583
2584impl AnyWindowHandle {
2585 /// Get the ID of this window.
2586 pub fn window_id(&self) -> WindowId {
2587 self.id
2588 }
2589
2590 /// Attempt to convert this handle to a window handle with a specific root view type.
2591 /// If the types do not match, this will return `None`.
2592 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2593 if TypeId::of::<T>() == self.state_type {
2594 Some(WindowHandle {
2595 any_handle: *self,
2596 state_type: PhantomData,
2597 })
2598 } else {
2599 None
2600 }
2601 }
2602
2603 /// Updates the state of the root view of this window.
2604 ///
2605 /// This will fail if the window has been closed.
2606 pub fn update<C, R>(
2607 self,
2608 cx: &mut C,
2609 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2610 ) -> Result<R>
2611 where
2612 C: Context,
2613 {
2614 cx.update_window(self, update)
2615 }
2616
2617 /// Read the state of the root view of this window.
2618 ///
2619 /// This will fail if the window has been closed.
2620 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2621 where
2622 C: Context,
2623 T: 'static,
2624 {
2625 let view = self
2626 .downcast::<T>()
2627 .context("the type of the window's root view has changed")?;
2628
2629 cx.read_window(&view, read)
2630 }
2631}
2632
2633/// An identifier for an [`Element`](crate::Element).
2634///
2635/// Can be constructed with a string, a number, or both, as well
2636/// as other internal representations.
2637#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2638pub enum ElementId {
2639 /// The ID of a View element
2640 View(EntityId),
2641 /// An integer ID.
2642 Integer(usize),
2643 /// A string based ID.
2644 Name(SharedString),
2645 /// An ID that's equated with a focus handle.
2646 FocusHandle(FocusId),
2647 /// A combination of a name and an integer.
2648 NamedInteger(SharedString, usize),
2649}
2650
2651impl Display for ElementId {
2652 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2653 match self {
2654 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2655 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2656 ElementId::Name(name) => write!(f, "{}", name)?,
2657 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2658 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2659 }
2660
2661 Ok(())
2662 }
2663}
2664
2665impl ElementId {
2666 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2667 ElementId::View(entity_id)
2668 }
2669}
2670
2671impl TryInto<SharedString> for ElementId {
2672 type Error = anyhow::Error;
2673
2674 fn try_into(self) -> anyhow::Result<SharedString> {
2675 if let ElementId::Name(name) = self {
2676 Ok(name)
2677 } else {
2678 Err(anyhow!("element id is not string"))
2679 }
2680 }
2681}
2682
2683impl From<usize> for ElementId {
2684 fn from(id: usize) -> Self {
2685 ElementId::Integer(id)
2686 }
2687}
2688
2689impl From<i32> for ElementId {
2690 fn from(id: i32) -> Self {
2691 Self::Integer(id as usize)
2692 }
2693}
2694
2695impl From<SharedString> for ElementId {
2696 fn from(name: SharedString) -> Self {
2697 ElementId::Name(name)
2698 }
2699}
2700
2701impl From<&'static str> for ElementId {
2702 fn from(name: &'static str) -> Self {
2703 ElementId::Name(name.into())
2704 }
2705}
2706
2707impl<'a> From<&'a FocusHandle> for ElementId {
2708 fn from(handle: &'a FocusHandle) -> Self {
2709 ElementId::FocusHandle(handle.id)
2710 }
2711}
2712
2713impl From<(&'static str, EntityId)> for ElementId {
2714 fn from((name, id): (&'static str, EntityId)) -> Self {
2715 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2716 }
2717}
2718
2719impl From<(&'static str, usize)> for ElementId {
2720 fn from((name, id): (&'static str, usize)) -> Self {
2721 ElementId::NamedInteger(name.into(), id)
2722 }
2723}
2724
2725impl From<(&'static str, u64)> for ElementId {
2726 fn from((name, id): (&'static str, u64)) -> Self {
2727 ElementId::NamedInteger(name.into(), id as usize)
2728 }
2729}
2730
2731/// A rectangle to be rendered in the window at the given position and size.
2732/// Passed as an argument [`ElementContext::paint_quad`].
2733#[derive(Clone)]
2734pub struct PaintQuad {
2735 bounds: Bounds<Pixels>,
2736 corner_radii: Corners<Pixels>,
2737 background: Hsla,
2738 border_widths: Edges<Pixels>,
2739 border_color: Hsla,
2740}
2741
2742impl PaintQuad {
2743 /// Sets the corner radii of the quad.
2744 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2745 PaintQuad {
2746 corner_radii: corner_radii.into(),
2747 ..self
2748 }
2749 }
2750
2751 /// Sets the border widths of the quad.
2752 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2753 PaintQuad {
2754 border_widths: border_widths.into(),
2755 ..self
2756 }
2757 }
2758
2759 /// Sets the border color of the quad.
2760 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2761 PaintQuad {
2762 border_color: border_color.into(),
2763 ..self
2764 }
2765 }
2766
2767 /// Sets the background color of the quad.
2768 pub fn background(self, background: impl Into<Hsla>) -> Self {
2769 PaintQuad {
2770 background: background.into(),
2771 ..self
2772 }
2773 }
2774}
2775
2776/// Creates a quad with the given parameters.
2777pub fn quad(
2778 bounds: Bounds<Pixels>,
2779 corner_radii: impl Into<Corners<Pixels>>,
2780 background: impl Into<Hsla>,
2781 border_widths: impl Into<Edges<Pixels>>,
2782 border_color: impl Into<Hsla>,
2783) -> PaintQuad {
2784 PaintQuad {
2785 bounds,
2786 corner_radii: corner_radii.into(),
2787 background: background.into(),
2788 border_widths: border_widths.into(),
2789 border_color: border_color.into(),
2790 }
2791}
2792
2793/// Creates a filled quad with the given bounds and background color.
2794pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2795 PaintQuad {
2796 bounds: bounds.into(),
2797 corner_radii: (0.).into(),
2798 background: background.into(),
2799 border_widths: (0.).into(),
2800 border_color: transparent_black(),
2801 }
2802}
2803
2804/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2805pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2806 PaintQuad {
2807 bounds: bounds.into(),
2808 corner_radii: (0.).into(),
2809 background: transparent_black(),
2810 border_widths: (1.).into(),
2811 border_color: border_color.into(),
2812 }
2813}