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::HashSet;
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: HashSet<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: Rc<Cell<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 input(&self) -> String {
295 self.keystrokes
296 .iter()
297 .flat_map(|k| k.ime_key.clone())
298 .collect::<Vec<String>>()
299 .join("")
300 }
301
302 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
303 if self.keystrokes.is_empty() {
304 return true;
305 }
306 let keystroke = &self.keystrokes[0];
307 for candidate in keystroke.match_candidates() {
308 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
309 return true;
310 }
311 }
312 false
313 }
314}
315
316pub(crate) struct ElementStateBox {
317 pub(crate) inner: Box<dyn Any>,
318 pub(crate) parent_view_id: EntityId,
319 #[cfg(debug_assertions)]
320 pub(crate) type_name: &'static str,
321}
322
323impl Window {
324 pub(crate) fn new(
325 handle: AnyWindowHandle,
326 options: WindowOptions,
327 cx: &mut AppContext,
328 ) -> Self {
329 let platform_window = cx.platform.open_window(handle, options);
330 let display_id = platform_window.display().id();
331 let sprite_atlas = platform_window.sprite_atlas();
332 let mouse_position = platform_window.mouse_position();
333 let modifiers = platform_window.modifiers();
334 let content_size = platform_window.content_size();
335 let scale_factor = platform_window.scale_factor();
336 let bounds = platform_window.bounds();
337 let appearance = platform_window.appearance();
338 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
339 let dirty = Rc::new(Cell::new(true));
340 let active = Rc::new(Cell::new(false));
341 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
342
343 platform_window.on_request_frame(Box::new({
344 let mut cx = cx.to_async();
345 let dirty = dirty.clone();
346 let active = active.clone();
347 let last_input_timestamp = last_input_timestamp.clone();
348 move || {
349 if dirty.get() {
350 measure("frame duration", || {
351 handle
352 .update(&mut cx, |_, cx| {
353 cx.draw();
354 cx.present();
355 })
356 .log_err();
357 })
358 }
359 // Keep presenting the current scene for 1 extra second since the
360 // last input to prevent the display from underclocking the refresh rate.
361 else if active.get()
362 && last_input_timestamp.get().elapsed() < Duration::from_secs(1)
363 {
364 handle.update(&mut cx, |_, cx| cx.present()).log_err();
365 }
366 }
367 }));
368 platform_window.on_resize(Box::new({
369 let mut cx = cx.to_async();
370 move |_, _| {
371 handle
372 .update(&mut cx, |_, cx| cx.window_bounds_changed())
373 .log_err();
374 }
375 }));
376 platform_window.on_moved(Box::new({
377 let mut cx = cx.to_async();
378 move || {
379 handle
380 .update(&mut cx, |_, cx| cx.window_bounds_changed())
381 .log_err();
382 }
383 }));
384 platform_window.on_appearance_changed(Box::new({
385 let mut cx = cx.to_async();
386 move || {
387 handle
388 .update(&mut cx, |_, cx| cx.appearance_changed())
389 .log_err();
390 }
391 }));
392 platform_window.on_active_status_change(Box::new({
393 let mut cx = cx.to_async();
394 move |active| {
395 handle
396 .update(&mut cx, |_, cx| {
397 cx.window.active.set(active);
398 cx.window
399 .activation_observers
400 .clone()
401 .retain(&(), |callback| callback(cx));
402 })
403 .log_err();
404 }
405 }));
406
407 platform_window.on_input({
408 let mut cx = cx.to_async();
409 Box::new(move |event| {
410 handle
411 .update(&mut cx, |_, cx| cx.dispatch_event(event))
412 .log_err()
413 .unwrap_or(false)
414 })
415 });
416
417 Window {
418 handle,
419 removed: false,
420 platform_window,
421 display_id,
422 sprite_atlas,
423 text_system,
424 rem_size: px(16.),
425 viewport_size: content_size,
426 layout_engine: Some(TaffyLayoutEngine::new()),
427 root_view: None,
428 element_id_stack: GlobalElementId::default(),
429 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
430 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
431 dirty_views: HashSet::default(),
432 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
433 focus_listeners: SubscriberSet::new(),
434 focus_lost_listeners: SubscriberSet::new(),
435 default_prevented: true,
436 mouse_position,
437 modifiers,
438 scale_factor,
439 bounds,
440 bounds_observers: SubscriberSet::new(),
441 appearance,
442 appearance_observers: SubscriberSet::new(),
443 active,
444 dirty,
445 last_input_timestamp,
446 refreshing: false,
447 drawing: false,
448 activation_observers: SubscriberSet::new(),
449 focus: None,
450 focus_enabled: true,
451 pending_input: None,
452 }
453 }
454 fn new_focus_listener(
455 &mut self,
456 value: AnyWindowFocusListener,
457 ) -> (Subscription, impl FnOnce()) {
458 self.focus_listeners.insert((), value)
459 }
460}
461
462/// Indicates which region of the window is visible. Content falling outside of this mask will not be
463/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
464/// to leave room to support more complex shapes in the future.
465#[derive(Clone, Debug, Default, PartialEq, Eq)]
466#[repr(C)]
467pub struct ContentMask<P: Clone + Default + Debug> {
468 /// The bounds
469 pub bounds: Bounds<P>,
470}
471
472impl ContentMask<Pixels> {
473 /// Scale the content mask's pixel units by the given scaling factor.
474 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
475 ContentMask {
476 bounds: self.bounds.scale(factor),
477 }
478 }
479
480 /// Intersect the content mask with the given content mask.
481 pub fn intersect(&self, other: &Self) -> Self {
482 let bounds = self.bounds.intersect(&other.bounds);
483 ContentMask { bounds }
484 }
485}
486
487/// Provides access to application state in the context of a single window. Derefs
488/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
489/// an [`AppContext`] and call any [`AppContext`] methods.
490pub struct WindowContext<'a> {
491 pub(crate) app: &'a mut AppContext,
492 pub(crate) window: &'a mut Window,
493}
494
495impl<'a> WindowContext<'a> {
496 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
497 Self { app, window }
498 }
499
500 /// Obtain a handle to the window that belongs to this context.
501 pub fn window_handle(&self) -> AnyWindowHandle {
502 self.window.handle
503 }
504
505 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
506 pub fn refresh(&mut self) {
507 if !self.window.drawing {
508 self.window.refreshing = true;
509 self.window.dirty.set(true);
510 }
511 }
512
513 /// Close this window.
514 pub fn remove_window(&mut self) {
515 self.window.removed = true;
516 }
517
518 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
519 /// for elements rendered within this window.
520 pub fn focus_handle(&mut self) -> FocusHandle {
521 FocusHandle::new(&self.window.focus_handles)
522 }
523
524 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
525 pub fn focused(&self) -> Option<FocusHandle> {
526 self.window
527 .focus
528 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
529 }
530
531 /// Move focus to the element associated with the given [`FocusHandle`].
532 pub fn focus(&mut self, handle: &FocusHandle) {
533 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
534 return;
535 }
536
537 self.window.focus = Some(handle.id);
538 self.window
539 .rendered_frame
540 .dispatch_tree
541 .clear_pending_keystrokes();
542 self.refresh();
543 }
544
545 /// Remove focus from all elements within this context's window.
546 pub fn blur(&mut self) {
547 if !self.window.focus_enabled {
548 return;
549 }
550
551 self.window.focus = None;
552 self.refresh();
553 }
554
555 /// Blur the window and don't allow anything in it to be focused again.
556 pub fn disable_focus(&mut self) {
557 self.blur();
558 self.window.focus_enabled = false;
559 }
560
561 /// Accessor for the text system.
562 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
563 &self.window.text_system
564 }
565
566 /// Dispatch the given action on the currently focused element.
567 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
568 let focus_handle = self.focused();
569
570 self.defer(move |cx| {
571 let node_id = focus_handle
572 .and_then(|handle| {
573 cx.window
574 .rendered_frame
575 .dispatch_tree
576 .focusable_node_id(handle.id)
577 })
578 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
579
580 cx.propagate_event = true;
581 cx.dispatch_action_on_node(node_id, action);
582 })
583 }
584
585 pub(crate) fn dispatch_keystroke_observers(
586 &mut self,
587 event: &dyn Any,
588 action: Option<Box<dyn Action>>,
589 ) {
590 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
591 return;
592 };
593
594 self.keystroke_observers
595 .clone()
596 .retain(&(), move |callback| {
597 (callback)(
598 &KeystrokeEvent {
599 keystroke: key_down_event.keystroke.clone(),
600 action: action.as_ref().map(|action| action.boxed_clone()),
601 },
602 self,
603 );
604 true
605 });
606 }
607
608 pub(crate) fn clear_pending_keystrokes(&mut self) {
609 self.window
610 .rendered_frame
611 .dispatch_tree
612 .clear_pending_keystrokes();
613 self.window
614 .next_frame
615 .dispatch_tree
616 .clear_pending_keystrokes();
617 }
618
619 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
620 /// that are currently on the stack to be returned to the app.
621 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
622 let handle = self.window.handle;
623 self.app.defer(move |cx| {
624 handle.update(cx, |_, cx| f(cx)).ok();
625 });
626 }
627
628 /// Subscribe to events emitted by a model or view.
629 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
630 /// 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.
631 pub fn subscribe<Emitter, E, Evt>(
632 &mut self,
633 entity: &E,
634 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
635 ) -> Subscription
636 where
637 Emitter: EventEmitter<Evt>,
638 E: Entity<Emitter>,
639 Evt: 'static,
640 {
641 let entity_id = entity.entity_id();
642 let entity = entity.downgrade();
643 let window_handle = self.window.handle;
644 self.app.new_subscription(
645 entity_id,
646 (
647 TypeId::of::<Evt>(),
648 Box::new(move |event, cx| {
649 window_handle
650 .update(cx, |_, cx| {
651 if let Some(handle) = E::upgrade_from(&entity) {
652 let event = event.downcast_ref().expect("invalid event type");
653 on_event(handle, event, cx);
654 true
655 } else {
656 false
657 }
658 })
659 .unwrap_or(false)
660 }),
661 ),
662 )
663 }
664
665 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
666 /// await points in async code.
667 pub fn to_async(&self) -> AsyncWindowContext {
668 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
669 }
670
671 /// Schedule the given closure to be run directly after the current frame is rendered.
672 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
673 let handle = self.window.handle;
674 let display_id = self.window.display_id;
675
676 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
677 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
678 let (tx, mut rx) = mpsc::unbounded::<()>();
679 self.platform.set_display_link_output_callback(
680 display_id,
681 Box::new(move || _ = tx.unbounded_send(())),
682 );
683
684 let consumer_task = self.app.spawn(|cx| async move {
685 while rx.next().await.is_some() {
686 cx.update(|cx| {
687 for callback in cx
688 .next_frame_callbacks
689 .get_mut(&display_id)
690 .unwrap()
691 .drain(..)
692 .collect::<SmallVec<[_; 32]>>()
693 {
694 callback(cx);
695 }
696 })
697 .ok();
698
699 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
700
701 cx.update(|cx| {
702 if cx.next_frame_callbacks.is_empty() {
703 cx.platform.stop_display_link(display_id);
704 }
705 })
706 .ok();
707 }
708 });
709 e.insert(consumer_task);
710 }
711 debug_assert!(self.app.frame_consumers.is_empty());
712 self.app.frame_consumers = frame_consumers;
713
714 if self.next_frame_callbacks.is_empty() {
715 self.platform.start_display_link(display_id);
716 }
717
718 self.next_frame_callbacks
719 .entry(display_id)
720 .or_default()
721 .push(Box::new(move |cx: &mut AppContext| {
722 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
723 }));
724 }
725
726 /// Spawn the future returned by the given closure on the application thread pool.
727 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
728 /// use within your future.
729 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
730 where
731 R: 'static,
732 Fut: Future<Output = R> + 'static,
733 {
734 self.app
735 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
736 }
737
738 /// Updates the global of the given type. The given closure is given simultaneous mutable
739 /// access both to the global and the context.
740 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
741 where
742 G: Global,
743 {
744 let mut global = self.app.lease_global::<G>();
745 let result = f(&mut global, self);
746 self.app.end_global_lease(global);
747 result
748 }
749
750 fn window_bounds_changed(&mut self) {
751 self.window.scale_factor = self.window.platform_window.scale_factor();
752 self.window.viewport_size = self.window.platform_window.content_size();
753 self.window.bounds = self.window.platform_window.bounds();
754 self.window.display_id = self.window.platform_window.display().id();
755 self.refresh();
756
757 self.window
758 .bounds_observers
759 .clone()
760 .retain(&(), |callback| callback(self));
761 }
762
763 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
764 pub fn window_bounds(&self) -> WindowBounds {
765 self.window.bounds
766 }
767
768 fn appearance_changed(&mut self) {
769 self.window.appearance = self.window.platform_window.appearance();
770
771 self.window
772 .appearance_observers
773 .clone()
774 .retain(&(), |callback| callback(self));
775 }
776
777 /// Returns the appearance of the current window.
778 pub fn appearance(&self) -> WindowAppearance {
779 self.window.appearance
780 }
781
782 /// Returns the size of the drawable area within the window.
783 pub fn viewport_size(&self) -> Size<Pixels> {
784 self.window.viewport_size
785 }
786
787 /// Returns whether this window is focused by the operating system (receiving key events).
788 pub fn is_window_active(&self) -> bool {
789 self.window.active.get()
790 }
791
792 /// Toggle zoom on the window.
793 pub fn zoom_window(&self) {
794 self.window.platform_window.zoom();
795 }
796
797 /// Updates the window's title at the platform level.
798 pub fn set_window_title(&mut self, title: &str) {
799 self.window.platform_window.set_title(title);
800 }
801
802 /// Mark the window as dirty at the platform level.
803 pub fn set_window_edited(&mut self, edited: bool) {
804 self.window.platform_window.set_edited(edited);
805 }
806
807 /// Determine the display on which the window is visible.
808 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
809 self.platform
810 .displays()
811 .into_iter()
812 .find(|display| display.id() == self.window.display_id)
813 }
814
815 /// Show the platform character palette.
816 pub fn show_character_palette(&self) {
817 self.window.platform_window.show_character_palette();
818 }
819
820 /// The scale factor of the display associated with the window. For example, it could
821 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
822 /// be rendered as two pixels on screen.
823 pub fn scale_factor(&self) -> f32 {
824 self.window.scale_factor
825 }
826
827 /// The size of an em for the base font of the application. Adjusting this value allows the
828 /// UI to scale, just like zooming a web page.
829 pub fn rem_size(&self) -> Pixels {
830 self.window.rem_size
831 }
832
833 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
834 /// UI to scale, just like zooming a web page.
835 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
836 self.window.rem_size = rem_size.into();
837 }
838
839 /// The line height associated with the current text style.
840 pub fn line_height(&self) -> Pixels {
841 let rem_size = self.rem_size();
842 let text_style = self.text_style();
843 text_style
844 .line_height
845 .to_pixels(text_style.font_size, rem_size)
846 }
847
848 /// Call to prevent the default action of an event. Currently only used to prevent
849 /// parent elements from becoming focused on mouse down.
850 pub fn prevent_default(&mut self) {
851 self.window.default_prevented = true;
852 }
853
854 /// Obtain whether default has been prevented for the event currently being dispatched.
855 pub fn default_prevented(&self) -> bool {
856 self.window.default_prevented
857 }
858
859 /// Determine whether the given action is available along the dispatch path to the currently focused element.
860 pub fn is_action_available(&self, action: &dyn Action) -> bool {
861 let target = self
862 .focused()
863 .and_then(|focused_handle| {
864 self.window
865 .rendered_frame
866 .dispatch_tree
867 .focusable_node_id(focused_handle.id)
868 })
869 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
870 self.window
871 .rendered_frame
872 .dispatch_tree
873 .is_action_available(action, target)
874 }
875
876 /// The position of the mouse relative to the window.
877 pub fn mouse_position(&self) -> Point<Pixels> {
878 self.window.mouse_position
879 }
880
881 /// The current state of the keyboard's modifiers
882 pub fn modifiers(&self) -> Modifiers {
883 self.window.modifiers
884 }
885
886 /// Returns true if there is no opaque layer containing the given point
887 /// on top of the given level. Layers who are extensions of the queried layer
888 /// are not considered to be on top of queried layer.
889 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
890 // Precondition: the depth map is ordered from topmost to bottomost.
891
892 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
893 if layer >= opaque_layer {
894 // The queried layer is either above or is the same as the this opaque layer.
895 // Anything after this point is guaranteed to be below the queried layer.
896 return true;
897 }
898
899 if !bounds.contains(point) {
900 // This opaque layer is above the queried layer but it doesn't contain
901 // the given position, so we can ignore it even if it's above.
902 continue;
903 }
904
905 // At this point, we've established that this opaque layer is on top of the queried layer
906 // and contains the position:
907 // If neither the opaque layer or the queried layer is an extension of the other then
908 // we know they are on different stacking orders, and return false.
909 let is_on_same_layer = opaque_layer
910 .iter()
911 .zip(layer.iter())
912 .all(|(a, b)| a.z_index == b.z_index);
913
914 if !is_on_same_layer {
915 return false;
916 }
917 }
918
919 true
920 }
921
922 pub(crate) fn was_top_layer_under_active_drag(
923 &self,
924 point: &Point<Pixels>,
925 layer: &StackingOrder,
926 ) -> bool {
927 // Precondition: the depth map is ordered from topmost to bottomost.
928
929 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
930 if layer >= opaque_layer {
931 // The queried layer is either above or is the same as the this opaque layer.
932 // Anything after this point is guaranteed to be below the queried layer.
933 return true;
934 }
935
936 if !bounds.contains(point) {
937 // This opaque layer is above the queried layer but it doesn't contain
938 // the given position, so we can ignore it even if it's above.
939 continue;
940 }
941
942 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
943 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
944 // looking to see if the queried layer was the topmost underneath the drag layer.
945 if opaque_layer
946 .first()
947 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
948 .unwrap_or(false)
949 {
950 continue;
951 }
952
953 // At this point, we've established that this opaque layer is on top of the queried layer
954 // and contains the position:
955 // If neither the opaque layer or the queried layer is an extension of the other then
956 // we know they are on different stacking orders, and return false.
957 let is_on_same_layer = opaque_layer
958 .iter()
959 .zip(layer.iter())
960 .all(|(a, b)| a.z_index == b.z_index);
961
962 if !is_on_same_layer {
963 return false;
964 }
965 }
966
967 true
968 }
969
970 /// Called during painting to get the current stacking order.
971 pub fn stacking_order(&self) -> &StackingOrder {
972 &self.window.next_frame.z_index_stack
973 }
974
975 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
976 /// the contents of the new [Scene], use [present].
977 pub(crate) fn draw(&mut self) {
978 self.window.dirty.set(false);
979 self.window.drawing = true;
980
981 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
982 {
983 let input_handler = self.window.platform_window.take_input_handler();
984 requested_handler.handler = input_handler;
985 }
986
987 let root_view = self.window.root_view.take().unwrap();
988 self.with_element_context(|cx| {
989 cx.with_z_index(0, |cx| {
990 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
991 // We need to use cx.cx here so we can utilize borrow splitting
992 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
993 for action_listener in action_listeners.iter().cloned() {
994 cx.cx.window.next_frame.dispatch_tree.on_action(
995 *action_type,
996 Rc::new(
997 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
998 action_listener(action, phase, cx)
999 },
1000 ),
1001 )
1002 }
1003 }
1004
1005 let available_space = cx.window.viewport_size.map(Into::into);
1006 root_view.draw(Point::default(), available_space, cx);
1007 })
1008 })
1009 });
1010
1011 if let Some(active_drag) = self.app.active_drag.take() {
1012 self.with_element_context(|cx| {
1013 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
1014 let offset = cx.mouse_position() - active_drag.cursor_offset;
1015 let available_space =
1016 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1017 active_drag.view.draw(offset, available_space, cx);
1018 })
1019 });
1020 self.active_drag = Some(active_drag);
1021 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
1022 self.with_element_context(|cx| {
1023 cx.with_z_index(1, |cx| {
1024 let available_space =
1025 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1026 tooltip_request.tooltip.view.draw(
1027 tooltip_request.tooltip.cursor_offset,
1028 available_space,
1029 cx,
1030 );
1031 })
1032 });
1033 self.window.next_frame.tooltip_request = Some(tooltip_request);
1034 }
1035 self.window.dirty_views.clear();
1036
1037 self.window
1038 .next_frame
1039 .dispatch_tree
1040 .preserve_pending_keystrokes(
1041 &mut self.window.rendered_frame.dispatch_tree,
1042 self.window.focus,
1043 );
1044 self.window.next_frame.focus = self.window.focus;
1045 self.window.next_frame.window_active = self.window.active.get();
1046 self.window.root_view = Some(root_view);
1047
1048 // Set the cursor only if we're the active window.
1049 let cursor_style = self
1050 .window
1051 .next_frame
1052 .requested_cursor_style
1053 .take()
1054 .unwrap_or(CursorStyle::Arrow);
1055 if self.is_window_active() {
1056 self.platform.set_cursor_style(cursor_style);
1057 }
1058
1059 // Register requested input handler with the platform window.
1060 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1061 if let Some(handler) = requested_input.handler.take() {
1062 self.window.platform_window.set_input_handler(handler);
1063 }
1064 }
1065
1066 self.window.layout_engine.as_mut().unwrap().clear();
1067 self.text_system()
1068 .finish_frame(&self.window.next_frame.reused_views);
1069 self.window
1070 .next_frame
1071 .finish(&mut self.window.rendered_frame);
1072 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1073 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1074 if percentage >= 80. {
1075 log::warn!("elevated element arena occupation: {}.", percentage);
1076 }
1077 element_arena.clear();
1078 });
1079
1080 let previous_focus_path = self.window.rendered_frame.focus_path();
1081 let previous_window_active = self.window.rendered_frame.window_active;
1082 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1083 self.window.next_frame.clear();
1084 let current_focus_path = self.window.rendered_frame.focus_path();
1085 let current_window_active = self.window.rendered_frame.window_active;
1086
1087 if previous_focus_path != current_focus_path
1088 || previous_window_active != current_window_active
1089 {
1090 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1091 self.window
1092 .focus_lost_listeners
1093 .clone()
1094 .retain(&(), |listener| listener(self));
1095 }
1096
1097 let event = FocusEvent {
1098 previous_focus_path: if previous_window_active {
1099 previous_focus_path
1100 } else {
1101 Default::default()
1102 },
1103 current_focus_path: if current_window_active {
1104 current_focus_path
1105 } else {
1106 Default::default()
1107 },
1108 };
1109 self.window
1110 .focus_listeners
1111 .clone()
1112 .retain(&(), |listener| listener(&event, self));
1113 }
1114 self.window.refreshing = false;
1115 self.window.drawing = false;
1116 }
1117
1118 fn present(&self) {
1119 self.window
1120 .platform_window
1121 .draw(&self.window.rendered_frame.scene);
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 let node_id = self
1273 .window
1274 .focus
1275 .and_then(|focus_id| {
1276 self.window
1277 .rendered_frame
1278 .dispatch_tree
1279 .focusable_node_id(focus_id)
1280 })
1281 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1282
1283 let dispatch_path = self
1284 .window
1285 .rendered_frame
1286 .dispatch_tree
1287 .dispatch_path(node_id);
1288
1289 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1290 let KeymatchResult { bindings, pending } = self
1291 .window
1292 .rendered_frame
1293 .dispatch_tree
1294 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1295
1296 if pending {
1297 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1298 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1299 {
1300 currently_pending = PendingInput::default();
1301 }
1302 currently_pending.focus = self.window.focus;
1303 currently_pending
1304 .keystrokes
1305 .push(key_down_event.keystroke.clone());
1306 for binding in bindings {
1307 currently_pending.bindings.push(binding);
1308 }
1309
1310 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1311 cx.background_executor.timer(Duration::from_secs(1)).await;
1312 cx.update(move |cx| {
1313 cx.clear_pending_keystrokes();
1314 let Some(currently_pending) = cx.window.pending_input.take() else {
1315 return;
1316 };
1317 cx.replay_pending_input(currently_pending)
1318 })
1319 .log_err();
1320 }));
1321 self.window.pending_input = Some(currently_pending);
1322
1323 self.propagate_event = false;
1324 return;
1325 } else if let Some(currently_pending) = self.window.pending_input.take() {
1326 if bindings
1327 .iter()
1328 .all(|binding| !currently_pending.used_by_binding(binding))
1329 {
1330 self.replay_pending_input(currently_pending)
1331 }
1332 }
1333
1334 if !bindings.is_empty() {
1335 self.clear_pending_keystrokes();
1336 }
1337
1338 self.propagate_event = true;
1339 for binding in bindings {
1340 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1341 if !self.propagate_event {
1342 self.dispatch_keystroke_observers(event, Some(binding.action));
1343 return;
1344 }
1345 }
1346 }
1347
1348 self.dispatch_key_down_up_event(event, &dispatch_path);
1349 if !self.propagate_event {
1350 return;
1351 }
1352
1353 self.dispatch_keystroke_observers(event, None);
1354 }
1355
1356 fn dispatch_key_down_up_event(
1357 &mut self,
1358 event: &dyn Any,
1359 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1360 ) {
1361 // Capture phase
1362 for node_id in dispatch_path {
1363 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1364
1365 for key_listener in node.key_listeners.clone() {
1366 self.with_element_context(|cx| {
1367 key_listener(event, DispatchPhase::Capture, cx);
1368 });
1369 if !self.propagate_event {
1370 return;
1371 }
1372 }
1373 }
1374
1375 // Bubble phase
1376 for node_id in dispatch_path.iter().rev() {
1377 // Handle low level key events
1378 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1379 for key_listener in node.key_listeners.clone() {
1380 self.with_element_context(|cx| {
1381 key_listener(event, DispatchPhase::Bubble, cx);
1382 });
1383 if !self.propagate_event {
1384 return;
1385 }
1386 }
1387 }
1388 }
1389
1390 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1391 pub fn has_pending_keystrokes(&self) -> bool {
1392 self.window
1393 .rendered_frame
1394 .dispatch_tree
1395 .has_pending_keystrokes()
1396 }
1397
1398 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1399 let node_id = self
1400 .window
1401 .focus
1402 .and_then(|focus_id| {
1403 self.window
1404 .rendered_frame
1405 .dispatch_tree
1406 .focusable_node_id(focus_id)
1407 })
1408 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1409
1410 if self.window.focus != currently_pending.focus {
1411 return;
1412 }
1413
1414 let input = currently_pending.input();
1415
1416 self.propagate_event = true;
1417 for binding in currently_pending.bindings {
1418 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1419 if !self.propagate_event {
1420 return;
1421 }
1422 }
1423
1424 let dispatch_path = self
1425 .window
1426 .rendered_frame
1427 .dispatch_tree
1428 .dispatch_path(node_id);
1429
1430 for keystroke in currently_pending.keystrokes {
1431 let event = KeyDownEvent {
1432 keystroke,
1433 is_held: false,
1434 };
1435
1436 self.dispatch_key_down_up_event(&event, &dispatch_path);
1437 if !self.propagate_event {
1438 return;
1439 }
1440 }
1441
1442 if !input.is_empty() {
1443 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1444 input_handler.flush_pending_input(&input, self);
1445 self.window.platform_window.set_input_handler(input_handler)
1446 }
1447 }
1448 }
1449
1450 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1451 let dispatch_path = self
1452 .window
1453 .rendered_frame
1454 .dispatch_tree
1455 .dispatch_path(node_id);
1456
1457 // Capture phase
1458 for node_id in &dispatch_path {
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.with_element_context(|cx| {
1468 listener(any_action, DispatchPhase::Capture, cx);
1469 });
1470
1471 if !self.propagate_event {
1472 return;
1473 }
1474 }
1475 }
1476 }
1477 // Bubble phase
1478 for node_id in dispatch_path.iter().rev() {
1479 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1480 for DispatchActionListener {
1481 action_type,
1482 listener,
1483 } in node.action_listeners.clone()
1484 {
1485 let any_action = action.as_any();
1486 if action_type == any_action.type_id() {
1487 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1488
1489 self.with_element_context(|cx| {
1490 listener(any_action, DispatchPhase::Bubble, cx);
1491 });
1492
1493 if !self.propagate_event {
1494 return;
1495 }
1496 }
1497 }
1498 }
1499 }
1500
1501 /// Register the given handler to be invoked whenever the global of the given type
1502 /// is updated.
1503 pub fn observe_global<G: Global>(
1504 &mut self,
1505 f: impl Fn(&mut WindowContext<'_>) + 'static,
1506 ) -> Subscription {
1507 let window_handle = self.window.handle;
1508 let (subscription, activate) = self.global_observers.insert(
1509 TypeId::of::<G>(),
1510 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1511 );
1512 self.app.defer(move |_| activate());
1513 subscription
1514 }
1515
1516 /// Focus the current window and bring it to the foreground at the platform level.
1517 pub fn activate_window(&self) {
1518 self.window.platform_window.activate();
1519 }
1520
1521 /// Minimize the current window at the platform level.
1522 pub fn minimize_window(&self) {
1523 self.window.platform_window.minimize();
1524 }
1525
1526 /// Toggle full screen status on the current window at the platform level.
1527 pub fn toggle_full_screen(&self) {
1528 self.window.platform_window.toggle_full_screen();
1529 }
1530
1531 /// Present a platform dialog.
1532 /// The provided message will be presented, along with buttons for each answer.
1533 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1534 pub fn prompt(
1535 &self,
1536 level: PromptLevel,
1537 message: &str,
1538 detail: Option<&str>,
1539 answers: &[&str],
1540 ) -> oneshot::Receiver<usize> {
1541 self.window
1542 .platform_window
1543 .prompt(level, message, detail, answers)
1544 }
1545
1546 /// Returns all available actions for the focused element.
1547 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1548 let node_id = self
1549 .window
1550 .focus
1551 .and_then(|focus_id| {
1552 self.window
1553 .rendered_frame
1554 .dispatch_tree
1555 .focusable_node_id(focus_id)
1556 })
1557 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1558
1559 self.window
1560 .rendered_frame
1561 .dispatch_tree
1562 .available_actions(node_id)
1563 }
1564
1565 /// Returns key bindings that invoke the given action on the currently focused element.
1566 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1567 self.window
1568 .rendered_frame
1569 .dispatch_tree
1570 .bindings_for_action(
1571 action,
1572 &self.window.rendered_frame.dispatch_tree.context_stack,
1573 )
1574 }
1575
1576 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1577 pub fn bindings_for_action_in(
1578 &self,
1579 action: &dyn Action,
1580 focus_handle: &FocusHandle,
1581 ) -> Vec<KeyBinding> {
1582 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1583
1584 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1585 return vec![];
1586 };
1587 let context_stack = dispatch_tree
1588 .dispatch_path(node_id)
1589 .into_iter()
1590 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1591 .collect();
1592 dispatch_tree.bindings_for_action(action, &context_stack)
1593 }
1594
1595 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1596 pub fn listener_for<V: Render, E>(
1597 &self,
1598 view: &View<V>,
1599 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1600 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1601 let view = view.downgrade();
1602 move |e: &E, cx: &mut WindowContext| {
1603 view.update(cx, |view, cx| f(view, e, cx)).ok();
1604 }
1605 }
1606
1607 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1608 pub fn handler_for<V: Render>(
1609 &self,
1610 view: &View<V>,
1611 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1612 ) -> impl Fn(&mut WindowContext) {
1613 let view = view.downgrade();
1614 move |cx: &mut WindowContext| {
1615 view.update(cx, |view, cx| f(view, cx)).ok();
1616 }
1617 }
1618
1619 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1620 /// If the callback returns false, the window won't be closed.
1621 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1622 let mut this = self.to_async();
1623 self.window
1624 .platform_window
1625 .on_should_close(Box::new(move || {
1626 this.update(|cx| {
1627 // Ensure that the window is removed from the app if it's been closed
1628 // by always pre-empting the system close event.
1629 if f(cx) {
1630 cx.remove_window();
1631 }
1632 false
1633 })
1634 .unwrap_or(true)
1635 }))
1636 }
1637
1638 pub(crate) fn parent_view_id(&self) -> EntityId {
1639 *self
1640 .window
1641 .next_frame
1642 .view_stack
1643 .last()
1644 .expect("a view should always be on the stack while drawing")
1645 }
1646
1647 /// Register an action listener on the window for the next frame. The type of action
1648 /// is determined by the first parameter of the given listener. When the next frame is rendered
1649 /// the listener will be cleared.
1650 ///
1651 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1652 /// a specific need to register a global listener.
1653 pub fn on_action(
1654 &mut self,
1655 action_type: TypeId,
1656 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1657 ) {
1658 self.window
1659 .next_frame
1660 .dispatch_tree
1661 .on_action(action_type, Rc::new(listener));
1662 }
1663}
1664
1665impl Context for WindowContext<'_> {
1666 type Result<T> = T;
1667
1668 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1669 where
1670 T: 'static,
1671 {
1672 let slot = self.app.entities.reserve();
1673 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1674 self.entities.insert(slot, model)
1675 }
1676
1677 fn update_model<T: 'static, R>(
1678 &mut self,
1679 model: &Model<T>,
1680 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1681 ) -> R {
1682 let mut entity = self.entities.lease(model);
1683 let result = update(
1684 &mut *entity,
1685 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1686 );
1687 self.entities.end_lease(entity);
1688 result
1689 }
1690
1691 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1692 where
1693 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1694 {
1695 if window == self.window.handle {
1696 let root_view = self.window.root_view.clone().unwrap();
1697 Ok(update(root_view, self))
1698 } else {
1699 window.update(self.app, update)
1700 }
1701 }
1702
1703 fn read_model<T, R>(
1704 &self,
1705 handle: &Model<T>,
1706 read: impl FnOnce(&T, &AppContext) -> R,
1707 ) -> Self::Result<R>
1708 where
1709 T: 'static,
1710 {
1711 let entity = self.entities.read(handle);
1712 read(entity, &*self.app)
1713 }
1714
1715 fn read_window<T, R>(
1716 &self,
1717 window: &WindowHandle<T>,
1718 read: impl FnOnce(View<T>, &AppContext) -> R,
1719 ) -> Result<R>
1720 where
1721 T: 'static,
1722 {
1723 if window.any_handle == self.window.handle {
1724 let root_view = self
1725 .window
1726 .root_view
1727 .clone()
1728 .unwrap()
1729 .downcast::<T>()
1730 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1731 Ok(read(root_view, self))
1732 } else {
1733 self.app.read_window(window, read)
1734 }
1735 }
1736}
1737
1738impl VisualContext for WindowContext<'_> {
1739 fn new_view<V>(
1740 &mut self,
1741 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1742 ) -> Self::Result<View<V>>
1743 where
1744 V: 'static + Render,
1745 {
1746 let slot = self.app.entities.reserve();
1747 let view = View {
1748 model: slot.clone(),
1749 };
1750 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1751 let entity = build_view_state(&mut cx);
1752 cx.entities.insert(slot, entity);
1753
1754 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1755 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1756 cx.new_view_observers.clone().retain(&tid, |observer| {
1757 let any_view = view.clone();
1758 (observer)(any_view, cx);
1759 true
1760 });
1761 }
1762 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1763
1764 view
1765 }
1766
1767 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1768 fn update_view<T: 'static, R>(
1769 &mut self,
1770 view: &View<T>,
1771 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1772 ) -> Self::Result<R> {
1773 let mut lease = self.app.entities.lease(&view.model);
1774 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1775 let result = update(&mut *lease, &mut cx);
1776 cx.app.entities.end_lease(lease);
1777 result
1778 }
1779
1780 fn replace_root_view<V>(
1781 &mut self,
1782 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1783 ) -> Self::Result<View<V>>
1784 where
1785 V: 'static + Render,
1786 {
1787 let view = self.new_view(build_view);
1788 self.window.root_view = Some(view.clone().into());
1789 self.refresh();
1790 view
1791 }
1792
1793 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1794 self.update_view(view, |view, cx| {
1795 view.focus_handle(cx).clone().focus(cx);
1796 })
1797 }
1798
1799 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1800 where
1801 V: ManagedView,
1802 {
1803 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1804 }
1805}
1806
1807impl<'a> std::ops::Deref for WindowContext<'a> {
1808 type Target = AppContext;
1809
1810 fn deref(&self) -> &Self::Target {
1811 self.app
1812 }
1813}
1814
1815impl<'a> std::ops::DerefMut for WindowContext<'a> {
1816 fn deref_mut(&mut self) -> &mut Self::Target {
1817 self.app
1818 }
1819}
1820
1821impl<'a> Borrow<AppContext> for WindowContext<'a> {
1822 fn borrow(&self) -> &AppContext {
1823 self.app
1824 }
1825}
1826
1827impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1828 fn borrow_mut(&mut self) -> &mut AppContext {
1829 self.app
1830 }
1831}
1832
1833/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1834pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1835 #[doc(hidden)]
1836 fn app_mut(&mut self) -> &mut AppContext {
1837 self.borrow_mut()
1838 }
1839
1840 #[doc(hidden)]
1841 fn app(&self) -> &AppContext {
1842 self.borrow()
1843 }
1844
1845 #[doc(hidden)]
1846 fn window(&self) -> &Window {
1847 self.borrow()
1848 }
1849
1850 #[doc(hidden)]
1851 fn window_mut(&mut self) -> &mut Window {
1852 self.borrow_mut()
1853 }
1854}
1855
1856impl Borrow<Window> for WindowContext<'_> {
1857 fn borrow(&self) -> &Window {
1858 self.window
1859 }
1860}
1861
1862impl BorrowMut<Window> for WindowContext<'_> {
1863 fn borrow_mut(&mut self) -> &mut Window {
1864 self.window
1865 }
1866}
1867
1868impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1869
1870/// Provides access to application state that is specialized for a particular [`View`].
1871/// Allows you to interact with focus, emit events, etc.
1872/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1873/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1874pub struct ViewContext<'a, V> {
1875 window_cx: WindowContext<'a>,
1876 view: &'a View<V>,
1877}
1878
1879impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1880 fn borrow(&self) -> &AppContext {
1881 &*self.window_cx.app
1882 }
1883}
1884
1885impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1886 fn borrow_mut(&mut self) -> &mut AppContext {
1887 &mut *self.window_cx.app
1888 }
1889}
1890
1891impl<V> Borrow<Window> for ViewContext<'_, V> {
1892 fn borrow(&self) -> &Window {
1893 &*self.window_cx.window
1894 }
1895}
1896
1897impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1898 fn borrow_mut(&mut self) -> &mut Window {
1899 &mut *self.window_cx.window
1900 }
1901}
1902
1903impl<'a, V: 'static> ViewContext<'a, V> {
1904 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1905 Self {
1906 window_cx: WindowContext::new(app, window),
1907 view,
1908 }
1909 }
1910
1911 /// Get the entity_id of this view.
1912 pub fn entity_id(&self) -> EntityId {
1913 self.view.entity_id()
1914 }
1915
1916 /// Get the view pointer underlying this context.
1917 pub fn view(&self) -> &View<V> {
1918 self.view
1919 }
1920
1921 /// Get the model underlying this view.
1922 pub fn model(&self) -> &Model<V> {
1923 &self.view.model
1924 }
1925
1926 /// Access the underlying window context.
1927 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1928 &mut self.window_cx
1929 }
1930
1931 /// Sets a given callback to be run on the next frame.
1932 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1933 where
1934 V: 'static,
1935 {
1936 let view = self.view().clone();
1937 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1938 }
1939
1940 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1941 /// that are currently on the stack to be returned to the app.
1942 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1943 let view = self.view().downgrade();
1944 self.window_cx.defer(move |cx| {
1945 view.update(cx, f).ok();
1946 });
1947 }
1948
1949 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1950 pub fn observe<V2, E>(
1951 &mut self,
1952 entity: &E,
1953 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1954 ) -> Subscription
1955 where
1956 V2: 'static,
1957 V: 'static,
1958 E: Entity<V2>,
1959 {
1960 let view = self.view().downgrade();
1961 let entity_id = entity.entity_id();
1962 let entity = entity.downgrade();
1963 let window_handle = self.window.handle;
1964 self.app.new_observer(
1965 entity_id,
1966 Box::new(move |cx| {
1967 window_handle
1968 .update(cx, |_, cx| {
1969 if let Some(handle) = E::upgrade_from(&entity) {
1970 view.update(cx, |this, cx| on_notify(this, handle, cx))
1971 .is_ok()
1972 } else {
1973 false
1974 }
1975 })
1976 .unwrap_or(false)
1977 }),
1978 )
1979 }
1980
1981 /// Subscribe to events emitted by another model or view.
1982 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1983 /// 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.
1984 pub fn subscribe<V2, E, Evt>(
1985 &mut self,
1986 entity: &E,
1987 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1988 ) -> Subscription
1989 where
1990 V2: EventEmitter<Evt>,
1991 E: Entity<V2>,
1992 Evt: 'static,
1993 {
1994 let view = self.view().downgrade();
1995 let entity_id = entity.entity_id();
1996 let handle = entity.downgrade();
1997 let window_handle = self.window.handle;
1998 self.app.new_subscription(
1999 entity_id,
2000 (
2001 TypeId::of::<Evt>(),
2002 Box::new(move |event, cx| {
2003 window_handle
2004 .update(cx, |_, cx| {
2005 if let Some(handle) = E::upgrade_from(&handle) {
2006 let event = event.downcast_ref().expect("invalid event type");
2007 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2008 .is_ok()
2009 } else {
2010 false
2011 }
2012 })
2013 .unwrap_or(false)
2014 }),
2015 ),
2016 )
2017 }
2018
2019 /// Register a callback to be invoked when the view is released.
2020 ///
2021 /// The callback receives a handle to the view's window. This handle may be
2022 /// invalid, if the window was closed before the view was released.
2023 pub fn on_release(
2024 &mut self,
2025 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2026 ) -> Subscription {
2027 let window_handle = self.window.handle;
2028 let (subscription, activate) = self.app.release_listeners.insert(
2029 self.view.model.entity_id,
2030 Box::new(move |this, cx| {
2031 let this = this.downcast_mut().expect("invalid entity type");
2032 on_release(this, window_handle, cx)
2033 }),
2034 );
2035 activate();
2036 subscription
2037 }
2038
2039 /// Register a callback to be invoked when the given Model or View is released.
2040 pub fn observe_release<V2, E>(
2041 &mut self,
2042 entity: &E,
2043 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2044 ) -> Subscription
2045 where
2046 V: 'static,
2047 V2: 'static,
2048 E: Entity<V2>,
2049 {
2050 let view = self.view().downgrade();
2051 let entity_id = entity.entity_id();
2052 let window_handle = self.window.handle;
2053 let (subscription, activate) = self.app.release_listeners.insert(
2054 entity_id,
2055 Box::new(move |entity, cx| {
2056 let entity = entity.downcast_mut().expect("invalid entity type");
2057 let _ = window_handle.update(cx, |_, cx| {
2058 view.update(cx, |this, cx| on_release(this, entity, cx))
2059 });
2060 }),
2061 );
2062 activate();
2063 subscription
2064 }
2065
2066 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2067 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2068 pub fn notify(&mut self) {
2069 for view_id in self
2070 .window
2071 .rendered_frame
2072 .dispatch_tree
2073 .view_path(self.view.entity_id())
2074 .into_iter()
2075 .rev()
2076 {
2077 if !self.window.dirty_views.insert(view_id) {
2078 break;
2079 }
2080 }
2081
2082 if !self.window.drawing {
2083 self.window_cx.window.dirty.set(true);
2084 self.window_cx.app.push_effect(Effect::Notify {
2085 emitter: self.view.model.entity_id,
2086 });
2087 }
2088 }
2089
2090 /// Register a callback to be invoked when the window is resized.
2091 pub fn observe_window_bounds(
2092 &mut self,
2093 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2094 ) -> Subscription {
2095 let view = self.view.downgrade();
2096 let (subscription, activate) = self.window.bounds_observers.insert(
2097 (),
2098 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2099 );
2100 activate();
2101 subscription
2102 }
2103
2104 /// Register a callback to be invoked when the window is activated or deactivated.
2105 pub fn observe_window_activation(
2106 &mut self,
2107 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2108 ) -> Subscription {
2109 let view = self.view.downgrade();
2110 let (subscription, activate) = self.window.activation_observers.insert(
2111 (),
2112 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2113 );
2114 activate();
2115 subscription
2116 }
2117
2118 /// Registers a callback to be invoked when the window appearance changes.
2119 pub fn observe_window_appearance(
2120 &mut self,
2121 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2122 ) -> Subscription {
2123 let view = self.view.downgrade();
2124 let (subscription, activate) = self.window.appearance_observers.insert(
2125 (),
2126 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2127 );
2128 activate();
2129 subscription
2130 }
2131
2132 /// Register a listener to be called when the given focus handle receives focus.
2133 /// Returns a subscription and persists until the subscription is dropped.
2134 pub fn on_focus(
2135 &mut self,
2136 handle: &FocusHandle,
2137 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2138 ) -> Subscription {
2139 let view = self.view.downgrade();
2140 let focus_id = handle.id;
2141 let (subscription, activate) =
2142 self.window.new_focus_listener(Box::new(move |event, cx| {
2143 view.update(cx, |view, cx| {
2144 if event.previous_focus_path.last() != Some(&focus_id)
2145 && event.current_focus_path.last() == Some(&focus_id)
2146 {
2147 listener(view, cx)
2148 }
2149 })
2150 .is_ok()
2151 }));
2152 self.app.defer(|_| activate());
2153 subscription
2154 }
2155
2156 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2157 /// Returns a subscription and persists until the subscription is dropped.
2158 pub fn on_focus_in(
2159 &mut self,
2160 handle: &FocusHandle,
2161 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2162 ) -> Subscription {
2163 let view = self.view.downgrade();
2164 let focus_id = handle.id;
2165 let (subscription, activate) =
2166 self.window.new_focus_listener(Box::new(move |event, cx| {
2167 view.update(cx, |view, cx| {
2168 if !event.previous_focus_path.contains(&focus_id)
2169 && event.current_focus_path.contains(&focus_id)
2170 {
2171 listener(view, cx)
2172 }
2173 })
2174 .is_ok()
2175 }));
2176 self.app.defer(move |_| activate());
2177 subscription
2178 }
2179
2180 /// Register a listener to be called when the given focus handle loses focus.
2181 /// Returns a subscription and persists until the subscription is dropped.
2182 pub fn on_blur(
2183 &mut self,
2184 handle: &FocusHandle,
2185 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2186 ) -> Subscription {
2187 let view = self.view.downgrade();
2188 let focus_id = handle.id;
2189 let (subscription, activate) =
2190 self.window.new_focus_listener(Box::new(move |event, cx| {
2191 view.update(cx, |view, cx| {
2192 if event.previous_focus_path.last() == Some(&focus_id)
2193 && event.current_focus_path.last() != Some(&focus_id)
2194 {
2195 listener(view, cx)
2196 }
2197 })
2198 .is_ok()
2199 }));
2200 self.app.defer(move |_| activate());
2201 subscription
2202 }
2203
2204 /// Register a listener to be called when nothing in the window has focus.
2205 /// This typically happens when the node that was focused is removed from the tree,
2206 /// and this callback lets you chose a default place to restore the users focus.
2207 /// Returns a subscription and persists until the subscription is dropped.
2208 pub fn on_focus_lost(
2209 &mut self,
2210 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2211 ) -> Subscription {
2212 let view = self.view.downgrade();
2213 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2214 (),
2215 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2216 );
2217 activate();
2218 subscription
2219 }
2220
2221 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2222 /// Returns a subscription and persists until the subscription is dropped.
2223 pub fn on_focus_out(
2224 &mut self,
2225 handle: &FocusHandle,
2226 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2227 ) -> Subscription {
2228 let view = self.view.downgrade();
2229 let focus_id = handle.id;
2230 let (subscription, activate) =
2231 self.window.new_focus_listener(Box::new(move |event, cx| {
2232 view.update(cx, |view, cx| {
2233 if event.previous_focus_path.contains(&focus_id)
2234 && !event.current_focus_path.contains(&focus_id)
2235 {
2236 listener(view, cx)
2237 }
2238 })
2239 .is_ok()
2240 }));
2241 self.app.defer(move |_| activate());
2242 subscription
2243 }
2244
2245 /// Schedule a future to be run asynchronously.
2246 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2247 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2248 /// The returned future will be polled on the main thread.
2249 pub fn spawn<Fut, R>(
2250 &mut self,
2251 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2252 ) -> Task<R>
2253 where
2254 R: 'static,
2255 Fut: Future<Output = R> + 'static,
2256 {
2257 let view = self.view().downgrade();
2258 self.window_cx.spawn(|cx| f(view, cx))
2259 }
2260
2261 /// Updates the global state of the given type.
2262 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2263 where
2264 G: Global,
2265 {
2266 let mut global = self.app.lease_global::<G>();
2267 let result = f(&mut global, self);
2268 self.app.end_global_lease(global);
2269 result
2270 }
2271
2272 /// Register a callback to be invoked when the given global state changes.
2273 pub fn observe_global<G: Global>(
2274 &mut self,
2275 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2276 ) -> Subscription {
2277 let window_handle = self.window.handle;
2278 let view = self.view().downgrade();
2279 let (subscription, activate) = self.global_observers.insert(
2280 TypeId::of::<G>(),
2281 Box::new(move |cx| {
2282 window_handle
2283 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2284 .unwrap_or(false)
2285 }),
2286 );
2287 self.app.defer(move |_| activate());
2288 subscription
2289 }
2290
2291 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2292 pub fn on_action(
2293 &mut self,
2294 action_type: TypeId,
2295 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2296 ) {
2297 let handle = self.view().clone();
2298 self.window_cx
2299 .on_action(action_type, move |action, phase, cx| {
2300 handle.update(cx, |view, cx| {
2301 listener(view, action, phase, cx);
2302 })
2303 });
2304 }
2305
2306 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2307 pub fn emit<Evt>(&mut self, event: Evt)
2308 where
2309 Evt: 'static,
2310 V: EventEmitter<Evt>,
2311 {
2312 let emitter = self.view.model.entity_id;
2313 self.app.push_effect(Effect::Emit {
2314 emitter,
2315 event_type: TypeId::of::<Evt>(),
2316 event: Box::new(event),
2317 });
2318 }
2319
2320 /// Move focus to the current view, assuming it implements [`FocusableView`].
2321 pub fn focus_self(&mut self)
2322 where
2323 V: FocusableView,
2324 {
2325 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2326 }
2327
2328 /// Convenience method for accessing view state in an event callback.
2329 ///
2330 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2331 /// but it's often useful to be able to access view state in these
2332 /// callbacks. This method provides a convenient way to do so.
2333 pub fn listener<E>(
2334 &self,
2335 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2336 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2337 let view = self.view().downgrade();
2338 move |e: &E, cx: &mut WindowContext| {
2339 view.update(cx, |view, cx| f(view, e, cx)).ok();
2340 }
2341 }
2342}
2343
2344impl<V> Context for ViewContext<'_, V> {
2345 type Result<U> = U;
2346
2347 fn new_model<T: 'static>(
2348 &mut self,
2349 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2350 ) -> Model<T> {
2351 self.window_cx.new_model(build_model)
2352 }
2353
2354 fn update_model<T: 'static, R>(
2355 &mut self,
2356 model: &Model<T>,
2357 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2358 ) -> R {
2359 self.window_cx.update_model(model, update)
2360 }
2361
2362 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2363 where
2364 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2365 {
2366 self.window_cx.update_window(window, update)
2367 }
2368
2369 fn read_model<T, R>(
2370 &self,
2371 handle: &Model<T>,
2372 read: impl FnOnce(&T, &AppContext) -> R,
2373 ) -> Self::Result<R>
2374 where
2375 T: 'static,
2376 {
2377 self.window_cx.read_model(handle, read)
2378 }
2379
2380 fn read_window<T, R>(
2381 &self,
2382 window: &WindowHandle<T>,
2383 read: impl FnOnce(View<T>, &AppContext) -> R,
2384 ) -> Result<R>
2385 where
2386 T: 'static,
2387 {
2388 self.window_cx.read_window(window, read)
2389 }
2390}
2391
2392impl<V: 'static> VisualContext for ViewContext<'_, V> {
2393 fn new_view<W: Render + 'static>(
2394 &mut self,
2395 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2396 ) -> Self::Result<View<W>> {
2397 self.window_cx.new_view(build_view_state)
2398 }
2399
2400 fn update_view<V2: 'static, R>(
2401 &mut self,
2402 view: &View<V2>,
2403 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2404 ) -> Self::Result<R> {
2405 self.window_cx.update_view(view, update)
2406 }
2407
2408 fn replace_root_view<W>(
2409 &mut self,
2410 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2411 ) -> Self::Result<View<W>>
2412 where
2413 W: 'static + Render,
2414 {
2415 self.window_cx.replace_root_view(build_view)
2416 }
2417
2418 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2419 self.window_cx.focus_view(view)
2420 }
2421
2422 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2423 self.window_cx.dismiss_view(view)
2424 }
2425}
2426
2427impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2428 type Target = WindowContext<'a>;
2429
2430 fn deref(&self) -> &Self::Target {
2431 &self.window_cx
2432 }
2433}
2434
2435impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2436 fn deref_mut(&mut self) -> &mut Self::Target {
2437 &mut self.window_cx
2438 }
2439}
2440
2441// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2442slotmap::new_key_type! {
2443 /// A unique identifier for a window.
2444 pub struct WindowId;
2445}
2446
2447impl WindowId {
2448 /// Converts this window ID to a `u64`.
2449 pub fn as_u64(&self) -> u64 {
2450 self.0.as_ffi()
2451 }
2452}
2453
2454/// A handle to a window with a specific root view type.
2455/// Note that this does not keep the window alive on its own.
2456#[derive(Deref, DerefMut)]
2457pub struct WindowHandle<V> {
2458 #[deref]
2459 #[deref_mut]
2460 pub(crate) any_handle: AnyWindowHandle,
2461 state_type: PhantomData<V>,
2462}
2463
2464impl<V: 'static + Render> WindowHandle<V> {
2465 /// Creates a new handle from a window ID.
2466 /// This does not check if the root type of the window is `V`.
2467 pub fn new(id: WindowId) -> Self {
2468 WindowHandle {
2469 any_handle: AnyWindowHandle {
2470 id,
2471 state_type: TypeId::of::<V>(),
2472 },
2473 state_type: PhantomData,
2474 }
2475 }
2476
2477 /// Get the root view out of this window.
2478 ///
2479 /// This will fail if the window is closed or if the root view's type does not match `V`.
2480 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2481 where
2482 C: Context,
2483 {
2484 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2485 root_view
2486 .downcast::<V>()
2487 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2488 }))
2489 }
2490
2491 /// Updates the root view of this window.
2492 ///
2493 /// This will fail if the window has been closed or if the root view's type does not match
2494 pub fn update<C, R>(
2495 &self,
2496 cx: &mut C,
2497 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2498 ) -> Result<R>
2499 where
2500 C: Context,
2501 {
2502 cx.update_window(self.any_handle, |root_view, cx| {
2503 let view = root_view
2504 .downcast::<V>()
2505 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2506 Ok(cx.update_view(&view, update))
2507 })?
2508 }
2509
2510 /// Read the root view out of this window.
2511 ///
2512 /// This will fail if the window is closed or if the root view's type does not match `V`.
2513 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2514 let x = cx
2515 .windows
2516 .get(self.id)
2517 .and_then(|window| {
2518 window
2519 .as_ref()
2520 .and_then(|window| window.root_view.clone())
2521 .map(|root_view| root_view.downcast::<V>())
2522 })
2523 .ok_or_else(|| anyhow!("window not found"))?
2524 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2525
2526 Ok(x.read(cx))
2527 }
2528
2529 /// Read the root view out of this window, with a callback
2530 ///
2531 /// This will fail if the window is closed or if the root view's type does not match `V`.
2532 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2533 where
2534 C: Context,
2535 {
2536 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2537 }
2538
2539 /// Read the root view pointer off of this window.
2540 ///
2541 /// This will fail if the window is closed or if the root view's type does not match `V`.
2542 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2543 where
2544 C: Context,
2545 {
2546 cx.read_window(self, |root_view, _cx| root_view.clone())
2547 }
2548
2549 /// Check if this window is 'active'.
2550 ///
2551 /// Will return `None` if the window is closed.
2552 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2553 cx.windows
2554 .get(self.id)
2555 .and_then(|window| window.as_ref().map(|window| window.active.get()))
2556 }
2557}
2558
2559impl<V> Copy for WindowHandle<V> {}
2560
2561impl<V> Clone for WindowHandle<V> {
2562 fn clone(&self) -> Self {
2563 *self
2564 }
2565}
2566
2567impl<V> PartialEq for WindowHandle<V> {
2568 fn eq(&self, other: &Self) -> bool {
2569 self.any_handle == other.any_handle
2570 }
2571}
2572
2573impl<V> Eq for WindowHandle<V> {}
2574
2575impl<V> Hash for WindowHandle<V> {
2576 fn hash<H: Hasher>(&self, state: &mut H) {
2577 self.any_handle.hash(state);
2578 }
2579}
2580
2581impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2582 fn from(val: WindowHandle<V>) -> Self {
2583 val.any_handle
2584 }
2585}
2586
2587/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2588#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2589pub struct AnyWindowHandle {
2590 pub(crate) id: WindowId,
2591 state_type: TypeId,
2592}
2593
2594impl AnyWindowHandle {
2595 /// Get the ID of this window.
2596 pub fn window_id(&self) -> WindowId {
2597 self.id
2598 }
2599
2600 /// Attempt to convert this handle to a window handle with a specific root view type.
2601 /// If the types do not match, this will return `None`.
2602 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2603 if TypeId::of::<T>() == self.state_type {
2604 Some(WindowHandle {
2605 any_handle: *self,
2606 state_type: PhantomData,
2607 })
2608 } else {
2609 None
2610 }
2611 }
2612
2613 /// Updates the state of the root view of this window.
2614 ///
2615 /// This will fail if the window has been closed.
2616 pub fn update<C, R>(
2617 self,
2618 cx: &mut C,
2619 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2620 ) -> Result<R>
2621 where
2622 C: Context,
2623 {
2624 cx.update_window(self, update)
2625 }
2626
2627 /// Read the state of the root view of this window.
2628 ///
2629 /// This will fail if the window has been closed.
2630 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2631 where
2632 C: Context,
2633 T: 'static,
2634 {
2635 let view = self
2636 .downcast::<T>()
2637 .context("the type of the window's root view has changed")?;
2638
2639 cx.read_window(&view, read)
2640 }
2641}
2642
2643/// An identifier for an [`Element`](crate::Element).
2644///
2645/// Can be constructed with a string, a number, or both, as well
2646/// as other internal representations.
2647#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2648pub enum ElementId {
2649 /// The ID of a View element
2650 View(EntityId),
2651 /// An integer ID.
2652 Integer(usize),
2653 /// A string based ID.
2654 Name(SharedString),
2655 /// An ID that's equated with a focus handle.
2656 FocusHandle(FocusId),
2657 /// A combination of a name and an integer.
2658 NamedInteger(SharedString, usize),
2659}
2660
2661impl Display for ElementId {
2662 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2663 match self {
2664 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2665 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2666 ElementId::Name(name) => write!(f, "{}", name)?,
2667 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2668 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2669 }
2670
2671 Ok(())
2672 }
2673}
2674
2675impl ElementId {
2676 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2677 ElementId::View(entity_id)
2678 }
2679}
2680
2681impl TryInto<SharedString> for ElementId {
2682 type Error = anyhow::Error;
2683
2684 fn try_into(self) -> anyhow::Result<SharedString> {
2685 if let ElementId::Name(name) = self {
2686 Ok(name)
2687 } else {
2688 Err(anyhow!("element id is not string"))
2689 }
2690 }
2691}
2692
2693impl From<usize> for ElementId {
2694 fn from(id: usize) -> Self {
2695 ElementId::Integer(id)
2696 }
2697}
2698
2699impl From<i32> for ElementId {
2700 fn from(id: i32) -> Self {
2701 Self::Integer(id as usize)
2702 }
2703}
2704
2705impl From<SharedString> for ElementId {
2706 fn from(name: SharedString) -> Self {
2707 ElementId::Name(name)
2708 }
2709}
2710
2711impl From<&'static str> for ElementId {
2712 fn from(name: &'static str) -> Self {
2713 ElementId::Name(name.into())
2714 }
2715}
2716
2717impl<'a> From<&'a FocusHandle> for ElementId {
2718 fn from(handle: &'a FocusHandle) -> Self {
2719 ElementId::FocusHandle(handle.id)
2720 }
2721}
2722
2723impl From<(&'static str, EntityId)> for ElementId {
2724 fn from((name, id): (&'static str, EntityId)) -> Self {
2725 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2726 }
2727}
2728
2729impl From<(&'static str, usize)> for ElementId {
2730 fn from((name, id): (&'static str, usize)) -> Self {
2731 ElementId::NamedInteger(name.into(), id)
2732 }
2733}
2734
2735impl From<(&'static str, u64)> for ElementId {
2736 fn from((name, id): (&'static str, u64)) -> Self {
2737 ElementId::NamedInteger(name.into(), id as usize)
2738 }
2739}
2740
2741/// A rectangle to be rendered in the window at the given position and size.
2742/// Passed as an argument [`ElementContext::paint_quad`].
2743#[derive(Clone)]
2744pub struct PaintQuad {
2745 bounds: Bounds<Pixels>,
2746 corner_radii: Corners<Pixels>,
2747 background: Hsla,
2748 border_widths: Edges<Pixels>,
2749 border_color: Hsla,
2750}
2751
2752impl PaintQuad {
2753 /// Sets the corner radii of the quad.
2754 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2755 PaintQuad {
2756 corner_radii: corner_radii.into(),
2757 ..self
2758 }
2759 }
2760
2761 /// Sets the border widths of the quad.
2762 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2763 PaintQuad {
2764 border_widths: border_widths.into(),
2765 ..self
2766 }
2767 }
2768
2769 /// Sets the border color of the quad.
2770 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2771 PaintQuad {
2772 border_color: border_color.into(),
2773 ..self
2774 }
2775 }
2776
2777 /// Sets the background color of the quad.
2778 pub fn background(self, background: impl Into<Hsla>) -> Self {
2779 PaintQuad {
2780 background: background.into(),
2781 ..self
2782 }
2783 }
2784}
2785
2786/// Creates a quad with the given parameters.
2787pub fn quad(
2788 bounds: Bounds<Pixels>,
2789 corner_radii: impl Into<Corners<Pixels>>,
2790 background: impl Into<Hsla>,
2791 border_widths: impl Into<Edges<Pixels>>,
2792 border_color: impl Into<Hsla>,
2793) -> PaintQuad {
2794 PaintQuad {
2795 bounds,
2796 corner_radii: corner_radii.into(),
2797 background: background.into(),
2798 border_widths: border_widths.into(),
2799 border_color: border_color.into(),
2800 }
2801}
2802
2803/// Creates a filled quad with the given bounds and background color.
2804pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2805 PaintQuad {
2806 bounds: bounds.into(),
2807 corner_radii: (0.).into(),
2808 background: background.into(),
2809 border_widths: (0.).into(),
2810 border_color: transparent_black(),
2811 }
2812}
2813
2814/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2815pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2816 PaintQuad {
2817 bounds: bounds.into(),
2818 corner_radii: (0.).into(),
2819 background: transparent_black(),
2820 border_widths: (1.).into(),
2821 border_color: border_color.into(),
2822 }
2823}