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 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, WindowBounds,
10 WindowOptions,
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::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,
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 pub(crate) rem_size: Pixels,
255 pub(crate) viewport_size: Size<Pixels>,
256 layout_engine: Option<TaffyLayoutEngine>,
257 pub(crate) root_view: Option<AnyView>,
258 pub(crate) element_id_stack: GlobalElementId,
259 pub(crate) rendered_frame: Frame,
260 pub(crate) next_frame: Frame,
261 pub(crate) dirty_views: FxHashSet<EntityId>,
262 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
263 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
264 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
265 default_prevented: bool,
266 mouse_position: Point<Pixels>,
267 modifiers: Modifiers,
268 scale_factor: f32,
269 bounds: WindowBounds,
270 bounds_observers: SubscriberSet<(), AnyObserver>,
271 active: bool,
272 pub(crate) dirty: bool,
273 pub(crate) refreshing: bool,
274 pub(crate) drawing: bool,
275 activation_observers: SubscriberSet<(), AnyObserver>,
276 pub(crate) focus: Option<FocusId>,
277 focus_enabled: bool,
278 pending_input: Option<PendingInput>,
279
280 #[cfg(any(test, feature = "test-support"))]
281 pub(crate) focus_invalidated: bool,
282}
283
284#[derive(Default, Debug)]
285struct PendingInput {
286 keystrokes: SmallVec<[Keystroke; 1]>,
287 bindings: SmallVec<[KeyBinding; 1]>,
288 focus: Option<FocusId>,
289 timer: Option<Task<()>>,
290}
291
292impl PendingInput {
293 fn is_noop(&self) -> bool {
294 self.bindings.is_empty() && (self.keystrokes.iter().all(|k| k.ime_key.is_none()))
295 }
296
297 fn input(&self) -> String {
298 self.keystrokes
299 .iter()
300 .flat_map(|k| k.ime_key.clone())
301 .collect::<Vec<String>>()
302 .join("")
303 }
304
305 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
306 if self.keystrokes.is_empty() {
307 return true;
308 }
309 let keystroke = &self.keystrokes[0];
310 for candidate in keystroke.match_candidates() {
311 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
312 return true;
313 }
314 }
315 false
316 }
317}
318
319pub(crate) struct ElementStateBox {
320 pub(crate) inner: Box<dyn Any>,
321 pub(crate) parent_view_id: EntityId,
322 #[cfg(debug_assertions)]
323 pub(crate) type_name: &'static str,
324}
325
326impl Window {
327 pub(crate) fn new(
328 handle: AnyWindowHandle,
329 options: WindowOptions,
330 cx: &mut AppContext,
331 ) -> Self {
332 let platform_window = cx.platform.open_window(handle, options);
333 let display_id = platform_window.display().id();
334 let sprite_atlas = platform_window.sprite_atlas();
335 let mouse_position = platform_window.mouse_position();
336 let modifiers = platform_window.modifiers();
337 let content_size = platform_window.content_size();
338 let scale_factor = platform_window.scale_factor();
339 let bounds = platform_window.bounds();
340
341 platform_window.on_request_frame(Box::new({
342 let mut cx = cx.to_async();
343 move || {
344 measure("frame duration", || {
345 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
346 })
347 }
348 }));
349 platform_window.on_resize(Box::new({
350 let mut cx = cx.to_async();
351 move |_, _| {
352 handle
353 .update(&mut cx, |_, cx| cx.window_bounds_changed())
354 .log_err();
355 }
356 }));
357 platform_window.on_moved(Box::new({
358 let mut cx = cx.to_async();
359 move || {
360 handle
361 .update(&mut cx, |_, cx| cx.window_bounds_changed())
362 .log_err();
363 }
364 }));
365 platform_window.on_active_status_change(Box::new({
366 let mut cx = cx.to_async();
367 move |active| {
368 handle
369 .update(&mut cx, |_, cx| {
370 cx.window.active = active;
371 cx.window
372 .activation_observers
373 .clone()
374 .retain(&(), |callback| callback(cx));
375 })
376 .log_err();
377 }
378 }));
379
380 platform_window.on_input({
381 let mut cx = cx.to_async();
382 Box::new(move |event| {
383 handle
384 .update(&mut cx, |_, cx| cx.dispatch_event(event))
385 .log_err()
386 .unwrap_or(false)
387 })
388 });
389
390 Window {
391 handle,
392 removed: false,
393 platform_window,
394 display_id,
395 sprite_atlas,
396 rem_size: px(16.),
397 viewport_size: content_size,
398 layout_engine: Some(TaffyLayoutEngine::new()),
399 root_view: None,
400 element_id_stack: GlobalElementId::default(),
401 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
402 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
403 dirty_views: FxHashSet::default(),
404 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
405 focus_listeners: SubscriberSet::new(),
406 focus_lost_listeners: SubscriberSet::new(),
407 default_prevented: true,
408 mouse_position,
409 modifiers,
410 scale_factor,
411 bounds,
412 bounds_observers: SubscriberSet::new(),
413 active: false,
414 dirty: false,
415 refreshing: false,
416 drawing: false,
417 activation_observers: SubscriberSet::new(),
418 focus: None,
419 focus_enabled: true,
420 pending_input: None,
421
422 #[cfg(any(test, feature = "test-support"))]
423 focus_invalidated: false,
424 }
425 }
426}
427
428/// Indicates which region of the window is visible. Content falling outside of this mask will not be
429/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
430/// to leave room to support more complex shapes in the future.
431#[derive(Clone, Debug, Default, PartialEq, Eq)]
432#[repr(C)]
433pub struct ContentMask<P: Clone + Default + Debug> {
434 /// The bounds
435 pub bounds: Bounds<P>,
436}
437
438impl ContentMask<Pixels> {
439 /// Scale the content mask's pixel units by the given scaling factor.
440 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
441 ContentMask {
442 bounds: self.bounds.scale(factor),
443 }
444 }
445
446 /// Intersect the content mask with the given content mask.
447 pub fn intersect(&self, other: &Self) -> Self {
448 let bounds = self.bounds.intersect(&other.bounds);
449 ContentMask { bounds }
450 }
451}
452
453/// Provides access to application state in the context of a single window. Derefs
454/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
455/// an [`AppContext`] and call any [`AppContext`] methods.
456pub struct WindowContext<'a> {
457 pub(crate) app: &'a mut AppContext,
458 pub(crate) window: &'a mut Window,
459}
460
461impl<'a> WindowContext<'a> {
462 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
463 Self { app, window }
464 }
465
466 /// Obtain a handle to the window that belongs to this context.
467 pub fn window_handle(&self) -> AnyWindowHandle {
468 self.window.handle
469 }
470
471 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
472 pub fn refresh(&mut self) {
473 if !self.window.drawing {
474 self.window.refreshing = true;
475 self.window.dirty = true;
476 }
477 }
478
479 /// Close this window.
480 pub fn remove_window(&mut self) {
481 self.window.removed = true;
482 }
483
484 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
485 /// for elements rendered within this window.
486 pub fn focus_handle(&mut self) -> FocusHandle {
487 FocusHandle::new(&self.window.focus_handles)
488 }
489
490 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
491 pub fn focused(&self) -> Option<FocusHandle> {
492 self.window
493 .focus
494 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
495 }
496
497 /// Move focus to the element associated with the given [`FocusHandle`].
498 pub fn focus(&mut self, handle: &FocusHandle) {
499 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
500 return;
501 }
502
503 self.window.focus = Some(handle.id);
504 self.window
505 .rendered_frame
506 .dispatch_tree
507 .clear_pending_keystrokes();
508
509 #[cfg(any(test, feature = "test-support"))]
510 {
511 self.window.focus_invalidated = true;
512 }
513
514 self.refresh();
515 }
516
517 /// Remove focus from all elements within this context's window.
518 pub fn blur(&mut self) {
519 if !self.window.focus_enabled {
520 return;
521 }
522
523 self.window.focus = None;
524 self.refresh();
525 }
526
527 /// Blur the window and don't allow anything in it to be focused again.
528 pub fn disable_focus(&mut self) {
529 self.blur();
530 self.window.focus_enabled = false;
531 }
532
533 /// Dispatch the given action on the currently focused element.
534 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
535 let focus_handle = self.focused();
536
537 self.defer(move |cx| {
538 let node_id = focus_handle
539 .and_then(|handle| {
540 cx.window
541 .rendered_frame
542 .dispatch_tree
543 .focusable_node_id(handle.id)
544 })
545 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
546
547 cx.propagate_event = true;
548 cx.dispatch_action_on_node(node_id, action);
549 })
550 }
551
552 pub(crate) fn dispatch_keystroke_observers(
553 &mut self,
554 event: &dyn Any,
555 action: Option<Box<dyn Action>>,
556 ) {
557 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
558 return;
559 };
560
561 self.keystroke_observers
562 .clone()
563 .retain(&(), move |callback| {
564 (callback)(
565 &KeystrokeEvent {
566 keystroke: key_down_event.keystroke.clone(),
567 action: action.as_ref().map(|action| action.boxed_clone()),
568 },
569 self,
570 );
571 true
572 });
573 }
574
575 pub(crate) fn clear_pending_keystrokes(&mut self) {
576 self.window
577 .rendered_frame
578 .dispatch_tree
579 .clear_pending_keystrokes();
580 self.window
581 .next_frame
582 .dispatch_tree
583 .clear_pending_keystrokes();
584 }
585
586 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
587 /// that are currently on the stack to be returned to the app.
588 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
589 let handle = self.window.handle;
590 self.app.defer(move |cx| {
591 handle.update(cx, |_, cx| f(cx)).ok();
592 });
593 }
594
595 /// Subscribe to events emitted by a model or view.
596 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
597 /// 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.
598 pub fn subscribe<Emitter, E, Evt>(
599 &mut self,
600 entity: &E,
601 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
602 ) -> Subscription
603 where
604 Emitter: EventEmitter<Evt>,
605 E: Entity<Emitter>,
606 Evt: 'static,
607 {
608 let entity_id = entity.entity_id();
609 let entity = entity.downgrade();
610 let window_handle = self.window.handle;
611 let (subscription, activate) = self.app.event_listeners.insert(
612 entity_id,
613 (
614 TypeId::of::<Evt>(),
615 Box::new(move |event, cx| {
616 window_handle
617 .update(cx, |_, cx| {
618 if let Some(handle) = E::upgrade_from(&entity) {
619 let event = event.downcast_ref().expect("invalid event type");
620 on_event(handle, event, cx);
621 true
622 } else {
623 false
624 }
625 })
626 .unwrap_or(false)
627 }),
628 ),
629 );
630 self.app.defer(move |_| activate());
631 subscription
632 }
633
634 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
635 /// await points in async code.
636 pub fn to_async(&self) -> AsyncWindowContext {
637 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
638 }
639
640 /// Schedule the given closure to be run directly after the current frame is rendered.
641 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
642 let handle = self.window.handle;
643 let display_id = self.window.display_id;
644
645 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
646 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
647 let (tx, mut rx) = mpsc::unbounded::<()>();
648 self.platform.set_display_link_output_callback(
649 display_id,
650 Box::new(move || _ = tx.unbounded_send(())),
651 );
652
653 let consumer_task = self.app.spawn(|cx| async move {
654 while rx.next().await.is_some() {
655 cx.update(|cx| {
656 for callback in cx
657 .next_frame_callbacks
658 .get_mut(&display_id)
659 .unwrap()
660 .drain(..)
661 .collect::<SmallVec<[_; 32]>>()
662 {
663 callback(cx);
664 }
665 })
666 .ok();
667
668 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
669
670 cx.update(|cx| {
671 if cx.next_frame_callbacks.is_empty() {
672 cx.platform.stop_display_link(display_id);
673 }
674 })
675 .ok();
676 }
677 });
678 e.insert(consumer_task);
679 }
680 debug_assert!(self.app.frame_consumers.is_empty());
681 self.app.frame_consumers = frame_consumers;
682
683 if self.next_frame_callbacks.is_empty() {
684 self.platform.start_display_link(display_id);
685 }
686
687 self.next_frame_callbacks
688 .entry(display_id)
689 .or_default()
690 .push(Box::new(move |cx: &mut AppContext| {
691 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
692 }));
693 }
694
695 /// Spawn the future returned by the given closure on the application thread pool.
696 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
697 /// use within your future.
698 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
699 where
700 R: 'static,
701 Fut: Future<Output = R> + 'static,
702 {
703 self.app
704 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
705 }
706
707 /// Updates the global of the given type. The given closure is given simultaneous mutable
708 /// access both to the global and the context.
709 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
710 where
711 G: 'static,
712 {
713 let mut global = self.app.lease_global::<G>();
714 let result = f(&mut global, self);
715 self.app.end_global_lease(global);
716 result
717 }
718
719 fn window_bounds_changed(&mut self) {
720 self.window.scale_factor = self.window.platform_window.scale_factor();
721 self.window.viewport_size = self.window.platform_window.content_size();
722 self.window.bounds = self.window.platform_window.bounds();
723 self.window.display_id = self.window.platform_window.display().id();
724 self.refresh();
725
726 self.window
727 .bounds_observers
728 .clone()
729 .retain(&(), |callback| callback(self));
730 }
731
732 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
733 pub fn window_bounds(&self) -> WindowBounds {
734 self.window.bounds
735 }
736
737 /// Returns the size of the drawable area within the window.
738 pub fn viewport_size(&self) -> Size<Pixels> {
739 self.window.viewport_size
740 }
741
742 /// Returns whether this window is focused by the operating system (receiving key events).
743 pub fn is_window_active(&self) -> bool {
744 self.window.active
745 }
746
747 /// Toggle zoom on the window.
748 pub fn zoom_window(&self) {
749 self.window.platform_window.zoom();
750 }
751
752 /// Updates the window's title at the platform level.
753 pub fn set_window_title(&mut self, title: &str) {
754 self.window.platform_window.set_title(title);
755 }
756
757 /// Mark the window as dirty at the platform level.
758 pub fn set_window_edited(&mut self, edited: bool) {
759 self.window.platform_window.set_edited(edited);
760 }
761
762 /// Determine the display on which the window is visible.
763 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
764 self.platform
765 .displays()
766 .into_iter()
767 .find(|display| display.id() == self.window.display_id)
768 }
769
770 /// Show the platform character palette.
771 pub fn show_character_palette(&self) {
772 self.window.platform_window.show_character_palette();
773 }
774
775 /// The scale factor of the display associated with the window. For example, it could
776 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
777 /// be rendered as two pixels on screen.
778 pub fn scale_factor(&self) -> f32 {
779 self.window.scale_factor
780 }
781
782 /// The size of an em for the base font of the application. Adjusting this value allows the
783 /// UI to scale, just like zooming a web page.
784 pub fn rem_size(&self) -> Pixels {
785 self.window.rem_size
786 }
787
788 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
789 /// UI to scale, just like zooming a web page.
790 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
791 self.window.rem_size = rem_size.into();
792 }
793
794 /// The line height associated with the current text style.
795 pub fn line_height(&self) -> Pixels {
796 let rem_size = self.rem_size();
797 let text_style = self.text_style();
798 text_style
799 .line_height
800 .to_pixels(text_style.font_size, rem_size)
801 }
802
803 /// Call to prevent the default action of an event. Currently only used to prevent
804 /// parent elements from becoming focused on mouse down.
805 pub fn prevent_default(&mut self) {
806 self.window.default_prevented = true;
807 }
808
809 /// Obtain whether default has been prevented for the event currently being dispatched.
810 pub fn default_prevented(&self) -> bool {
811 self.window.default_prevented
812 }
813
814 /// Determine whether the given action is available along the dispatch path to the currently focused element.
815 pub fn is_action_available(&self, action: &dyn Action) -> bool {
816 let target = self
817 .focused()
818 .and_then(|focused_handle| {
819 self.window
820 .rendered_frame
821 .dispatch_tree
822 .focusable_node_id(focused_handle.id)
823 })
824 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
825 self.window
826 .rendered_frame
827 .dispatch_tree
828 .is_action_available(action, target)
829 }
830
831 /// The position of the mouse relative to the window.
832 pub fn mouse_position(&self) -> Point<Pixels> {
833 self.window.mouse_position
834 }
835
836 /// The current state of the keyboard's modifiers
837 pub fn modifiers(&self) -> Modifiers {
838 self.window.modifiers
839 }
840
841 /// Returns true if there is no opaque layer containing the given point
842 /// on top of the given level. Layers who are extensions of the queried layer
843 /// are not considered to be on top of queried layer.
844 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
845 // Precondition: the depth map is ordered from topmost to bottomost.
846
847 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
848 if layer >= opaque_layer {
849 // The queried layer is either above or is the same as the this opaque layer.
850 // Anything after this point is guaranteed to be below the queried layer.
851 return true;
852 }
853
854 if !bounds.contains(point) {
855 // This opaque layer is above the queried layer but it doesn't contain
856 // the given position, so we can ignore it even if it's above.
857 continue;
858 }
859
860 // At this point, we've established that this opaque layer is on top of the queried layer
861 // and contains the position:
862 // - If the opaque layer is an extension of the queried layer, we don't want
863 // to consider the opaque layer to be on top and so we ignore it.
864 // - Else, we will bail early and say that the queried layer wasn't the top one.
865 let opaque_layer_is_extension_of_queried_layer = opaque_layer.len() >= layer.len()
866 && opaque_layer
867 .iter()
868 .zip(layer.iter())
869 .all(|(a, b)| a.z_index == b.z_index);
870 if !opaque_layer_is_extension_of_queried_layer {
871 return false;
872 }
873 }
874
875 true
876 }
877
878 pub(crate) fn was_top_layer_under_active_drag(
879 &self,
880 point: &Point<Pixels>,
881 layer: &StackingOrder,
882 ) -> bool {
883 // Precondition: the depth map is ordered from topmost to bottomost.
884
885 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
886 if layer >= opaque_layer {
887 // The queried layer is either above or is the same as the this opaque layer.
888 // Anything after this point is guaranteed to be below the queried layer.
889 return true;
890 }
891
892 if !bounds.contains(point) {
893 // This opaque layer is above the queried layer but it doesn't contain
894 // the given position, so we can ignore it even if it's above.
895 continue;
896 }
897
898 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
899 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
900 // looking to see if the queried layer was the topmost underneath the drag layer.
901 if opaque_layer
902 .first()
903 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
904 .unwrap_or(false)
905 {
906 continue;
907 }
908
909 // At this point, we've established that this opaque layer is on top of the queried layer
910 // and contains the position:
911 // - If the opaque layer is an extension of the queried layer, we don't want
912 // to consider the opaque layer to be on top and so we ignore it.
913 // - Else, we will bail early and say that the queried layer wasn't the top one.
914 let opaque_layer_is_extension_of_queried_layer = opaque_layer.len() >= layer.len()
915 && opaque_layer
916 .iter()
917 .zip(layer.iter())
918 .all(|(a, b)| a.z_index == b.z_index);
919 if !opaque_layer_is_extension_of_queried_layer {
920 return false;
921 }
922 }
923
924 true
925 }
926
927 /// Called during painting to get the current stacking order.
928 pub fn stacking_order(&self) -> &StackingOrder {
929 &self.window.next_frame.z_index_stack
930 }
931
932 /// Draw pixels to the display for this window based on the contents of its scene.
933 pub(crate) fn draw(&mut self) {
934 self.window.dirty = false;
935 self.window.drawing = true;
936
937 #[cfg(any(test, feature = "test-support"))]
938 {
939 self.window.focus_invalidated = false;
940 }
941
942 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
943 {
944 let input_handler = self.window.platform_window.take_input_handler();
945 requested_handler.handler = input_handler;
946 }
947
948 let root_view = self.window.root_view.take().unwrap();
949 self.with_element_context(|cx| {
950 cx.with_z_index(0, |cx| {
951 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
952 // We need to use cx.cx here so we can utilize borrow splitting
953 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
954 for action_listener in action_listeners.iter().cloned() {
955 cx.cx.window.next_frame.dispatch_tree.on_action(
956 *action_type,
957 Rc::new(
958 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
959 action_listener(action, phase, cx)
960 },
961 ),
962 )
963 }
964 }
965
966 let available_space = cx.window.viewport_size.map(Into::into);
967 root_view.draw(Point::default(), available_space, cx);
968 })
969 })
970 });
971
972 if let Some(active_drag) = self.app.active_drag.take() {
973 self.with_element_context(|cx| {
974 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
975 let offset = cx.mouse_position() - active_drag.cursor_offset;
976 let available_space =
977 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
978 active_drag.view.draw(offset, available_space, cx);
979 })
980 });
981 self.active_drag = Some(active_drag);
982 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
983 self.with_element_context(|cx| {
984 cx.with_z_index(1, |cx| {
985 let available_space =
986 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
987 tooltip_request.tooltip.view.draw(
988 tooltip_request.tooltip.cursor_offset,
989 available_space,
990 cx,
991 );
992 })
993 });
994 self.window.next_frame.tooltip_request = Some(tooltip_request);
995 }
996 self.window.dirty_views.clear();
997
998 self.window
999 .next_frame
1000 .dispatch_tree
1001 .preserve_pending_keystrokes(
1002 &mut self.window.rendered_frame.dispatch_tree,
1003 self.window.focus,
1004 );
1005 self.window.next_frame.focus = self.window.focus;
1006 self.window.next_frame.window_active = self.window.active;
1007 self.window.root_view = Some(root_view);
1008
1009 // Set the cursor only if we're the active window.
1010 let cursor_style = self
1011 .window
1012 .next_frame
1013 .requested_cursor_style
1014 .take()
1015 .unwrap_or(CursorStyle::Arrow);
1016 if self.is_window_active() {
1017 self.platform.set_cursor_style(cursor_style);
1018 }
1019
1020 // Register requested input handler with the platform window.
1021 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1022 if let Some(handler) = requested_input.handler.take() {
1023 self.window.platform_window.set_input_handler(handler);
1024 }
1025 }
1026
1027 self.window.layout_engine.as_mut().unwrap().clear();
1028 self.text_system()
1029 .finish_frame(&self.window.next_frame.reused_views);
1030 self.window
1031 .next_frame
1032 .finish(&mut self.window.rendered_frame);
1033 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1034 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1035 if percentage >= 80. {
1036 log::warn!("elevated element arena occupation: {}.", percentage);
1037 }
1038 element_arena.clear();
1039 });
1040
1041 let previous_focus_path = self.window.rendered_frame.focus_path();
1042 let previous_window_active = self.window.rendered_frame.window_active;
1043 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1044 self.window.next_frame.clear();
1045 let current_focus_path = self.window.rendered_frame.focus_path();
1046 let current_window_active = self.window.rendered_frame.window_active;
1047
1048 if previous_focus_path != current_focus_path
1049 || previous_window_active != current_window_active
1050 {
1051 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1052 self.window
1053 .focus_lost_listeners
1054 .clone()
1055 .retain(&(), |listener| listener(self));
1056 }
1057
1058 let event = FocusEvent {
1059 previous_focus_path: if previous_window_active {
1060 previous_focus_path
1061 } else {
1062 Default::default()
1063 },
1064 current_focus_path: if current_window_active {
1065 current_focus_path
1066 } else {
1067 Default::default()
1068 },
1069 };
1070 self.window
1071 .focus_listeners
1072 .clone()
1073 .retain(&(), |listener| listener(&event, self));
1074 }
1075
1076 self.window
1077 .platform_window
1078 .draw(&self.window.rendered_frame.scene);
1079 self.window.refreshing = false;
1080 self.window.drawing = false;
1081 }
1082
1083 /// Dispatch a mouse or keyboard event on the window.
1084 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1085 // Handlers may set this to false by calling `stop_propagation`.
1086 self.app.propagate_event = true;
1087 // Handlers may set this to true by calling `prevent_default`.
1088 self.window.default_prevented = false;
1089
1090 let event = match event {
1091 // Track the mouse position with our own state, since accessing the platform
1092 // API for the mouse position can only occur on the main thread.
1093 PlatformInput::MouseMove(mouse_move) => {
1094 self.window.mouse_position = mouse_move.position;
1095 self.window.modifiers = mouse_move.modifiers;
1096 PlatformInput::MouseMove(mouse_move)
1097 }
1098 PlatformInput::MouseDown(mouse_down) => {
1099 self.window.mouse_position = mouse_down.position;
1100 self.window.modifiers = mouse_down.modifiers;
1101 PlatformInput::MouseDown(mouse_down)
1102 }
1103 PlatformInput::MouseUp(mouse_up) => {
1104 self.window.mouse_position = mouse_up.position;
1105 self.window.modifiers = mouse_up.modifiers;
1106 PlatformInput::MouseUp(mouse_up)
1107 }
1108 PlatformInput::MouseExited(mouse_exited) => {
1109 self.window.modifiers = mouse_exited.modifiers;
1110 PlatformInput::MouseExited(mouse_exited)
1111 }
1112 PlatformInput::ModifiersChanged(modifiers_changed) => {
1113 self.window.modifiers = modifiers_changed.modifiers;
1114 PlatformInput::ModifiersChanged(modifiers_changed)
1115 }
1116 PlatformInput::ScrollWheel(scroll_wheel) => {
1117 self.window.mouse_position = scroll_wheel.position;
1118 self.window.modifiers = scroll_wheel.modifiers;
1119 PlatformInput::ScrollWheel(scroll_wheel)
1120 }
1121 // Translate dragging and dropping of external files from the operating system
1122 // to internal drag and drop events.
1123 PlatformInput::FileDrop(file_drop) => match file_drop {
1124 FileDropEvent::Entered { position, paths } => {
1125 self.window.mouse_position = position;
1126 if self.active_drag.is_none() {
1127 self.active_drag = Some(AnyDrag {
1128 value: Box::new(paths.clone()),
1129 view: self.new_view(|_| paths).into(),
1130 cursor_offset: position,
1131 });
1132 }
1133 PlatformInput::MouseMove(MouseMoveEvent {
1134 position,
1135 pressed_button: Some(MouseButton::Left),
1136 modifiers: Modifiers::default(),
1137 })
1138 }
1139 FileDropEvent::Pending { position } => {
1140 self.window.mouse_position = position;
1141 PlatformInput::MouseMove(MouseMoveEvent {
1142 position,
1143 pressed_button: Some(MouseButton::Left),
1144 modifiers: Modifiers::default(),
1145 })
1146 }
1147 FileDropEvent::Submit { position } => {
1148 self.activate(true);
1149 self.window.mouse_position = position;
1150 PlatformInput::MouseUp(MouseUpEvent {
1151 button: MouseButton::Left,
1152 position,
1153 modifiers: Modifiers::default(),
1154 click_count: 1,
1155 })
1156 }
1157 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1158 button: MouseButton::Left,
1159 position: Point::default(),
1160 modifiers: Modifiers::default(),
1161 click_count: 1,
1162 }),
1163 },
1164 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1165 };
1166
1167 if let Some(any_mouse_event) = event.mouse_event() {
1168 self.dispatch_mouse_event(any_mouse_event);
1169 } else if let Some(any_key_event) = event.keyboard_event() {
1170 self.dispatch_key_event(any_key_event);
1171 }
1172
1173 !self.app.propagate_event
1174 }
1175
1176 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1177 if let Some(mut handlers) = self
1178 .window
1179 .rendered_frame
1180 .mouse_listeners
1181 .remove(&event.type_id())
1182 {
1183 // Because handlers may add other handlers, we sort every time.
1184 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1185
1186 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1187 // special purposes, such as detecting events outside of a given Bounds.
1188 for (_, _, handler) in &mut handlers {
1189 self.with_element_context(|cx| {
1190 handler(event, DispatchPhase::Capture, cx);
1191 });
1192 if !self.app.propagate_event {
1193 break;
1194 }
1195 }
1196
1197 // Bubble phase, where most normal handlers do their work.
1198 if self.app.propagate_event {
1199 for (_, _, handler) in handlers.iter_mut().rev() {
1200 self.with_element_context(|cx| {
1201 handler(event, DispatchPhase::Bubble, cx);
1202 });
1203 if !self.app.propagate_event {
1204 break;
1205 }
1206 }
1207 }
1208
1209 self.window
1210 .rendered_frame
1211 .mouse_listeners
1212 .insert(event.type_id(), handlers);
1213 }
1214
1215 if self.app.propagate_event && self.has_active_drag() {
1216 if event.is::<MouseMoveEvent>() {
1217 // If this was a mouse move event, redraw the window so that the
1218 // active drag can follow the mouse cursor.
1219 self.refresh();
1220 } else if event.is::<MouseUpEvent>() {
1221 // If this was a mouse up event, cancel the active drag and redraw
1222 // the window.
1223 self.active_drag = None;
1224 self.refresh();
1225 }
1226 }
1227 }
1228
1229 fn dispatch_key_event(&mut self, event: &dyn Any) {
1230 let node_id = self
1231 .window
1232 .focus
1233 .and_then(|focus_id| {
1234 self.window
1235 .rendered_frame
1236 .dispatch_tree
1237 .focusable_node_id(focus_id)
1238 })
1239 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1240
1241 let dispatch_path = self
1242 .window
1243 .rendered_frame
1244 .dispatch_tree
1245 .dispatch_path(node_id);
1246
1247 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1248 let KeymatchResult {
1249 bindings,
1250 mut pending,
1251 } = self
1252 .window
1253 .rendered_frame
1254 .dispatch_tree
1255 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1256
1257 if self.window.rendered_frame.dispatch_tree.keymatch_mode == KeymatchMode::Immediate
1258 && !bindings.is_empty()
1259 {
1260 pending = false;
1261 }
1262
1263 if pending {
1264 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1265 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1266 {
1267 currently_pending = PendingInput::default();
1268 }
1269 currently_pending.focus = self.window.focus;
1270 currently_pending
1271 .keystrokes
1272 .push(key_down_event.keystroke.clone());
1273 for binding in bindings {
1274 currently_pending.bindings.push(binding);
1275 }
1276
1277 // for vim compatibility, we also should check "is input handler enabled"
1278 if !currently_pending.is_noop() {
1279 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1280 cx.background_executor.timer(Duration::from_secs(1)).await;
1281 cx.update(move |cx| {
1282 cx.clear_pending_keystrokes();
1283 let Some(currently_pending) = cx.window.pending_input.take() else {
1284 return;
1285 };
1286 cx.replay_pending_input(currently_pending)
1287 })
1288 .log_err();
1289 }));
1290 } else {
1291 currently_pending.timer = None;
1292 }
1293 self.window.pending_input = Some(currently_pending);
1294
1295 self.propagate_event = false;
1296 return;
1297 } else if let Some(currently_pending) = self.window.pending_input.take() {
1298 if bindings
1299 .iter()
1300 .all(|binding| !currently_pending.used_by_binding(binding))
1301 {
1302 self.replay_pending_input(currently_pending)
1303 }
1304 }
1305
1306 if !bindings.is_empty() {
1307 self.clear_pending_keystrokes();
1308 }
1309
1310 self.propagate_event = true;
1311 for binding in bindings {
1312 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1313 if !self.propagate_event {
1314 self.dispatch_keystroke_observers(event, Some(binding.action));
1315 return;
1316 }
1317 }
1318 }
1319
1320 // Capture phase
1321 for node_id in &dispatch_path {
1322 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1323
1324 for key_listener in node.key_listeners.clone() {
1325 self.with_element_context(|cx| {
1326 key_listener(event, DispatchPhase::Capture, cx);
1327 });
1328 if !self.propagate_event {
1329 return;
1330 }
1331 }
1332 }
1333
1334 // Bubble phase
1335 for node_id in dispatch_path.iter().rev() {
1336 // Handle low level key events
1337 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1338 for key_listener in node.key_listeners.clone() {
1339 self.with_element_context(|cx| {
1340 key_listener(event, DispatchPhase::Bubble, cx);
1341 });
1342 if !self.propagate_event {
1343 return;
1344 }
1345 }
1346 }
1347
1348 self.dispatch_keystroke_observers(event, None);
1349 }
1350
1351 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1352 pub fn has_pending_keystrokes(&self) -> bool {
1353 self.window
1354 .rendered_frame
1355 .dispatch_tree
1356 .has_pending_keystrokes()
1357 }
1358
1359 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1360 let node_id = self
1361 .window
1362 .focus
1363 .and_then(|focus_id| {
1364 self.window
1365 .rendered_frame
1366 .dispatch_tree
1367 .focusable_node_id(focus_id)
1368 })
1369 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1370
1371 if self.window.focus != currently_pending.focus {
1372 return;
1373 }
1374
1375 let input = currently_pending.input();
1376
1377 self.propagate_event = true;
1378 for binding in currently_pending.bindings {
1379 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1380 if !self.propagate_event {
1381 return;
1382 }
1383 }
1384
1385 if !input.is_empty() {
1386 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1387 input_handler.flush_pending_input(&input, self);
1388 self.window.platform_window.set_input_handler(input_handler)
1389 }
1390 }
1391 }
1392
1393 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1394 let dispatch_path = self
1395 .window
1396 .rendered_frame
1397 .dispatch_tree
1398 .dispatch_path(node_id);
1399
1400 // Capture phase
1401 for node_id in &dispatch_path {
1402 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1403 for DispatchActionListener {
1404 action_type,
1405 listener,
1406 } in node.action_listeners.clone()
1407 {
1408 let any_action = action.as_any();
1409 if action_type == any_action.type_id() {
1410 self.with_element_context(|cx| {
1411 listener(any_action, DispatchPhase::Capture, cx);
1412 });
1413
1414 if !self.propagate_event {
1415 return;
1416 }
1417 }
1418 }
1419 }
1420 // Bubble phase
1421 for node_id in dispatch_path.iter().rev() {
1422 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1423 for DispatchActionListener {
1424 action_type,
1425 listener,
1426 } in node.action_listeners.clone()
1427 {
1428 let any_action = action.as_any();
1429 if action_type == any_action.type_id() {
1430 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1431
1432 self.with_element_context(|cx| {
1433 listener(any_action, DispatchPhase::Bubble, cx);
1434 });
1435
1436 if !self.propagate_event {
1437 return;
1438 }
1439 }
1440 }
1441 }
1442 }
1443
1444 /// Register the given handler to be invoked whenever the global of the given type
1445 /// is updated.
1446 pub fn observe_global<G: 'static>(
1447 &mut self,
1448 f: impl Fn(&mut WindowContext<'_>) + 'static,
1449 ) -> Subscription {
1450 let window_handle = self.window.handle;
1451 let (subscription, activate) = self.global_observers.insert(
1452 TypeId::of::<G>(),
1453 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1454 );
1455 self.app.defer(move |_| activate());
1456 subscription
1457 }
1458
1459 /// Focus the current window and bring it to the foreground at the platform level.
1460 pub fn activate_window(&self) {
1461 self.window.platform_window.activate();
1462 }
1463
1464 /// Minimize the current window at the platform level.
1465 pub fn minimize_window(&self) {
1466 self.window.platform_window.minimize();
1467 }
1468
1469 /// Toggle full screen status on the current window at the platform level.
1470 pub fn toggle_full_screen(&self) {
1471 self.window.platform_window.toggle_full_screen();
1472 }
1473
1474 /// Present a platform dialog.
1475 /// The provided message will be presented, along with buttons for each answer.
1476 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1477 pub fn prompt(
1478 &self,
1479 level: PromptLevel,
1480 message: &str,
1481 answers: &[&str],
1482 ) -> oneshot::Receiver<usize> {
1483 self.window.platform_window.prompt(level, message, answers)
1484 }
1485
1486 /// Returns all available actions for the focused element.
1487 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1488 let node_id = self
1489 .window
1490 .focus
1491 .and_then(|focus_id| {
1492 self.window
1493 .rendered_frame
1494 .dispatch_tree
1495 .focusable_node_id(focus_id)
1496 })
1497 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1498
1499 self.window
1500 .rendered_frame
1501 .dispatch_tree
1502 .available_actions(node_id)
1503 }
1504
1505 /// Returns key bindings that invoke the given action on the currently focused element.
1506 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1507 self.window
1508 .rendered_frame
1509 .dispatch_tree
1510 .bindings_for_action(
1511 action,
1512 &self.window.rendered_frame.dispatch_tree.context_stack,
1513 )
1514 }
1515
1516 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1517 pub fn bindings_for_action_in(
1518 &self,
1519 action: &dyn Action,
1520 focus_handle: &FocusHandle,
1521 ) -> Vec<KeyBinding> {
1522 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1523
1524 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1525 return vec![];
1526 };
1527 let context_stack = dispatch_tree
1528 .dispatch_path(node_id)
1529 .into_iter()
1530 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1531 .collect();
1532 dispatch_tree.bindings_for_action(action, &context_stack)
1533 }
1534
1535 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1536 pub fn listener_for<V: Render, E>(
1537 &self,
1538 view: &View<V>,
1539 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1540 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1541 let view = view.downgrade();
1542 move |e: &E, cx: &mut WindowContext| {
1543 view.update(cx, |view, cx| f(view, e, cx)).ok();
1544 }
1545 }
1546
1547 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1548 pub fn handler_for<V: Render>(
1549 &self,
1550 view: &View<V>,
1551 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1552 ) -> impl Fn(&mut WindowContext) {
1553 let view = view.downgrade();
1554 move |cx: &mut WindowContext| {
1555 view.update(cx, |view, cx| f(view, cx)).ok();
1556 }
1557 }
1558
1559 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1560 /// If the callback returns false, the window won't be closed.
1561 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1562 let mut this = self.to_async();
1563 self.window
1564 .platform_window
1565 .on_should_close(Box::new(move || {
1566 this.update(|cx| {
1567 // Ensure that the window is removed from the app if it's been closed
1568 // by always pre-empting the system close event.
1569 if f(cx) {
1570 cx.remove_window();
1571 }
1572 false
1573 })
1574 .unwrap_or(true)
1575 }))
1576 }
1577
1578 pub(crate) fn parent_view_id(&self) -> EntityId {
1579 *self
1580 .window
1581 .next_frame
1582 .view_stack
1583 .last()
1584 .expect("a view should always be on the stack while drawing")
1585 }
1586
1587 /// Register an action listener on the window for the next frame. The type of action
1588 /// is determined by the first parameter of the given listener. When the next frame is rendered
1589 /// the listener will be cleared.
1590 ///
1591 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1592 /// a specific need to register a global listener.
1593 pub fn on_action(
1594 &mut self,
1595 action_type: TypeId,
1596 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1597 ) {
1598 self.window
1599 .next_frame
1600 .dispatch_tree
1601 .on_action(action_type, Rc::new(listener));
1602 }
1603}
1604
1605impl Context for WindowContext<'_> {
1606 type Result<T> = T;
1607
1608 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1609 where
1610 T: 'static,
1611 {
1612 let slot = self.app.entities.reserve();
1613 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1614 self.entities.insert(slot, model)
1615 }
1616
1617 fn update_model<T: 'static, R>(
1618 &mut self,
1619 model: &Model<T>,
1620 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1621 ) -> R {
1622 let mut entity = self.entities.lease(model);
1623 let result = update(
1624 &mut *entity,
1625 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1626 );
1627 self.entities.end_lease(entity);
1628 result
1629 }
1630
1631 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1632 where
1633 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1634 {
1635 if window == self.window.handle {
1636 let root_view = self.window.root_view.clone().unwrap();
1637 Ok(update(root_view, self))
1638 } else {
1639 window.update(self.app, update)
1640 }
1641 }
1642
1643 fn read_model<T, R>(
1644 &self,
1645 handle: &Model<T>,
1646 read: impl FnOnce(&T, &AppContext) -> R,
1647 ) -> Self::Result<R>
1648 where
1649 T: 'static,
1650 {
1651 let entity = self.entities.read(handle);
1652 read(entity, &*self.app)
1653 }
1654
1655 fn read_window<T, R>(
1656 &self,
1657 window: &WindowHandle<T>,
1658 read: impl FnOnce(View<T>, &AppContext) -> R,
1659 ) -> Result<R>
1660 where
1661 T: 'static,
1662 {
1663 if window.any_handle == self.window.handle {
1664 let root_view = self
1665 .window
1666 .root_view
1667 .clone()
1668 .unwrap()
1669 .downcast::<T>()
1670 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1671 Ok(read(root_view, self))
1672 } else {
1673 self.app.read_window(window, read)
1674 }
1675 }
1676}
1677
1678impl VisualContext for WindowContext<'_> {
1679 fn new_view<V>(
1680 &mut self,
1681 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1682 ) -> Self::Result<View<V>>
1683 where
1684 V: 'static + Render,
1685 {
1686 let slot = self.app.entities.reserve();
1687 let view = View {
1688 model: slot.clone(),
1689 };
1690 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1691 let entity = build_view_state(&mut cx);
1692 cx.entities.insert(slot, entity);
1693
1694 cx.new_view_observers
1695 .clone()
1696 .retain(&TypeId::of::<V>(), |observer| {
1697 let any_view = AnyView::from(view.clone());
1698 (observer)(any_view, self);
1699 true
1700 });
1701
1702 view
1703 }
1704
1705 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1706 fn update_view<T: 'static, R>(
1707 &mut self,
1708 view: &View<T>,
1709 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1710 ) -> Self::Result<R> {
1711 let mut lease = self.app.entities.lease(&view.model);
1712 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1713 let result = update(&mut *lease, &mut cx);
1714 cx.app.entities.end_lease(lease);
1715 result
1716 }
1717
1718 fn replace_root_view<V>(
1719 &mut self,
1720 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1721 ) -> Self::Result<View<V>>
1722 where
1723 V: 'static + Render,
1724 {
1725 let view = self.new_view(build_view);
1726 self.window.root_view = Some(view.clone().into());
1727 self.refresh();
1728 view
1729 }
1730
1731 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1732 self.update_view(view, |view, cx| {
1733 view.focus_handle(cx).clone().focus(cx);
1734 })
1735 }
1736
1737 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1738 where
1739 V: ManagedView,
1740 {
1741 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1742 }
1743}
1744
1745impl<'a> std::ops::Deref for WindowContext<'a> {
1746 type Target = AppContext;
1747
1748 fn deref(&self) -> &Self::Target {
1749 self.app
1750 }
1751}
1752
1753impl<'a> std::ops::DerefMut for WindowContext<'a> {
1754 fn deref_mut(&mut self) -> &mut Self::Target {
1755 self.app
1756 }
1757}
1758
1759impl<'a> Borrow<AppContext> for WindowContext<'a> {
1760 fn borrow(&self) -> &AppContext {
1761 self.app
1762 }
1763}
1764
1765impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1766 fn borrow_mut(&mut self) -> &mut AppContext {
1767 self.app
1768 }
1769}
1770
1771/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1772pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1773 #[doc(hidden)]
1774 fn app_mut(&mut self) -> &mut AppContext {
1775 self.borrow_mut()
1776 }
1777
1778 #[doc(hidden)]
1779 fn app(&self) -> &AppContext {
1780 self.borrow()
1781 }
1782
1783 #[doc(hidden)]
1784 fn window(&self) -> &Window {
1785 self.borrow()
1786 }
1787
1788 #[doc(hidden)]
1789 fn window_mut(&mut self) -> &mut Window {
1790 self.borrow_mut()
1791 }
1792}
1793
1794impl Borrow<Window> for WindowContext<'_> {
1795 fn borrow(&self) -> &Window {
1796 self.window
1797 }
1798}
1799
1800impl BorrowMut<Window> for WindowContext<'_> {
1801 fn borrow_mut(&mut self) -> &mut Window {
1802 self.window
1803 }
1804}
1805
1806impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1807
1808/// Provides access to application state that is specialized for a particular [`View`].
1809/// Allows you to interact with focus, emit events, etc.
1810/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1811/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1812pub struct ViewContext<'a, V> {
1813 window_cx: WindowContext<'a>,
1814 view: &'a View<V>,
1815}
1816
1817impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1818 fn borrow(&self) -> &AppContext {
1819 &*self.window_cx.app
1820 }
1821}
1822
1823impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1824 fn borrow_mut(&mut self) -> &mut AppContext {
1825 &mut *self.window_cx.app
1826 }
1827}
1828
1829impl<V> Borrow<Window> for ViewContext<'_, V> {
1830 fn borrow(&self) -> &Window {
1831 &*self.window_cx.window
1832 }
1833}
1834
1835impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1836 fn borrow_mut(&mut self) -> &mut Window {
1837 &mut *self.window_cx.window
1838 }
1839}
1840
1841impl<'a, V: 'static> ViewContext<'a, V> {
1842 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1843 Self {
1844 window_cx: WindowContext::new(app, window),
1845 view,
1846 }
1847 }
1848
1849 /// Get the entity_id of this view.
1850 pub fn entity_id(&self) -> EntityId {
1851 self.view.entity_id()
1852 }
1853
1854 /// Get the view pointer underlying this context.
1855 pub fn view(&self) -> &View<V> {
1856 self.view
1857 }
1858
1859 /// Get the model underlying this view.
1860 pub fn model(&self) -> &Model<V> {
1861 &self.view.model
1862 }
1863
1864 /// Access the underlying window context.
1865 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1866 &mut self.window_cx
1867 }
1868
1869 /// Sets a given callback to be run on the next frame.
1870 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1871 where
1872 V: 'static,
1873 {
1874 let view = self.view().clone();
1875 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1876 }
1877
1878 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1879 /// that are currently on the stack to be returned to the app.
1880 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1881 let view = self.view().downgrade();
1882 self.window_cx.defer(move |cx| {
1883 view.update(cx, f).ok();
1884 });
1885 }
1886
1887 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1888 pub fn observe<V2, E>(
1889 &mut self,
1890 entity: &E,
1891 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1892 ) -> Subscription
1893 where
1894 V2: 'static,
1895 V: 'static,
1896 E: Entity<V2>,
1897 {
1898 let view = self.view().downgrade();
1899 let entity_id = entity.entity_id();
1900 let entity = entity.downgrade();
1901 let window_handle = self.window.handle;
1902 let (subscription, activate) = self.app.observers.insert(
1903 entity_id,
1904 Box::new(move |cx| {
1905 window_handle
1906 .update(cx, |_, cx| {
1907 if let Some(handle) = E::upgrade_from(&entity) {
1908 view.update(cx, |this, cx| on_notify(this, handle, cx))
1909 .is_ok()
1910 } else {
1911 false
1912 }
1913 })
1914 .unwrap_or(false)
1915 }),
1916 );
1917 self.app.defer(move |_| activate());
1918 subscription
1919 }
1920
1921 /// Subscribe to events emitted by another model or view.
1922 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1923 /// 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.
1924 pub fn subscribe<V2, E, Evt>(
1925 &mut self,
1926 entity: &E,
1927 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1928 ) -> Subscription
1929 where
1930 V2: EventEmitter<Evt>,
1931 E: Entity<V2>,
1932 Evt: 'static,
1933 {
1934 let view = self.view().downgrade();
1935 let entity_id = entity.entity_id();
1936 let handle = entity.downgrade();
1937 let window_handle = self.window.handle;
1938 let (subscription, activate) = self.app.event_listeners.insert(
1939 entity_id,
1940 (
1941 TypeId::of::<Evt>(),
1942 Box::new(move |event, cx| {
1943 window_handle
1944 .update(cx, |_, cx| {
1945 if let Some(handle) = E::upgrade_from(&handle) {
1946 let event = event.downcast_ref().expect("invalid event type");
1947 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1948 .is_ok()
1949 } else {
1950 false
1951 }
1952 })
1953 .unwrap_or(false)
1954 }),
1955 ),
1956 );
1957 self.app.defer(move |_| activate());
1958 subscription
1959 }
1960
1961 /// Register a callback to be invoked when the view is released.
1962 ///
1963 /// The callback receives a handle to the view's window. This handle may be
1964 /// invalid, if the window was closed before the view was released.
1965 pub fn on_release(
1966 &mut self,
1967 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1968 ) -> Subscription {
1969 let window_handle = self.window.handle;
1970 let (subscription, activate) = self.app.release_listeners.insert(
1971 self.view.model.entity_id,
1972 Box::new(move |this, cx| {
1973 let this = this.downcast_mut().expect("invalid entity type");
1974 on_release(this, window_handle, cx)
1975 }),
1976 );
1977 activate();
1978 subscription
1979 }
1980
1981 /// Register a callback to be invoked when the given Model or View is released.
1982 pub fn observe_release<V2, E>(
1983 &mut self,
1984 entity: &E,
1985 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1986 ) -> Subscription
1987 where
1988 V: 'static,
1989 V2: 'static,
1990 E: Entity<V2>,
1991 {
1992 let view = self.view().downgrade();
1993 let entity_id = entity.entity_id();
1994 let window_handle = self.window.handle;
1995 let (subscription, activate) = self.app.release_listeners.insert(
1996 entity_id,
1997 Box::new(move |entity, cx| {
1998 let entity = entity.downcast_mut().expect("invalid entity type");
1999 let _ = window_handle.update(cx, |_, cx| {
2000 view.update(cx, |this, cx| on_release(this, entity, cx))
2001 });
2002 }),
2003 );
2004 activate();
2005 subscription
2006 }
2007
2008 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2009 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2010 pub fn notify(&mut self) {
2011 for view_id in self
2012 .window
2013 .rendered_frame
2014 .dispatch_tree
2015 .view_path(self.view.entity_id())
2016 .into_iter()
2017 .rev()
2018 {
2019 if !self.window.dirty_views.insert(view_id) {
2020 break;
2021 }
2022 }
2023
2024 if !self.window.drawing {
2025 self.window_cx.window.dirty = true;
2026 self.window_cx.app.push_effect(Effect::Notify {
2027 emitter: self.view.model.entity_id,
2028 });
2029 }
2030 }
2031
2032 /// Register a callback to be invoked when the window is resized.
2033 pub fn observe_window_bounds(
2034 &mut self,
2035 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2036 ) -> Subscription {
2037 let view = self.view.downgrade();
2038 let (subscription, activate) = self.window.bounds_observers.insert(
2039 (),
2040 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2041 );
2042 activate();
2043 subscription
2044 }
2045
2046 /// Register a callback to be invoked when the window is activated or deactivated.
2047 pub fn observe_window_activation(
2048 &mut self,
2049 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2050 ) -> Subscription {
2051 let view = self.view.downgrade();
2052 let (subscription, activate) = self.window.activation_observers.insert(
2053 (),
2054 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2055 );
2056 activate();
2057 subscription
2058 }
2059
2060 /// Register a listener to be called when the given focus handle receives focus.
2061 /// Returns a subscription and persists until the subscription is dropped.
2062 pub fn on_focus(
2063 &mut self,
2064 handle: &FocusHandle,
2065 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2066 ) -> Subscription {
2067 let view = self.view.downgrade();
2068 let focus_id = handle.id;
2069 let (subscription, activate) = self.window.focus_listeners.insert(
2070 (),
2071 Box::new(move |event, cx| {
2072 view.update(cx, |view, cx| {
2073 if event.previous_focus_path.last() != Some(&focus_id)
2074 && event.current_focus_path.last() == Some(&focus_id)
2075 {
2076 listener(view, cx)
2077 }
2078 })
2079 .is_ok()
2080 }),
2081 );
2082 self.app.defer(move |_| activate());
2083 subscription
2084 }
2085
2086 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2087 /// Returns a subscription and persists until the subscription is dropped.
2088 pub fn on_focus_in(
2089 &mut self,
2090 handle: &FocusHandle,
2091 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2092 ) -> Subscription {
2093 let view = self.view.downgrade();
2094 let focus_id = handle.id;
2095 let (subscription, activate) = self.window.focus_listeners.insert(
2096 (),
2097 Box::new(move |event, cx| {
2098 view.update(cx, |view, cx| {
2099 if !event.previous_focus_path.contains(&focus_id)
2100 && event.current_focus_path.contains(&focus_id)
2101 {
2102 listener(view, cx)
2103 }
2104 })
2105 .is_ok()
2106 }),
2107 );
2108 self.app.defer(move |_| activate());
2109 subscription
2110 }
2111
2112 /// Register a listener to be called when the given focus handle loses focus.
2113 /// Returns a subscription and persists until the subscription is dropped.
2114 pub fn on_blur(
2115 &mut self,
2116 handle: &FocusHandle,
2117 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2118 ) -> Subscription {
2119 let view = self.view.downgrade();
2120 let focus_id = handle.id;
2121 let (subscription, activate) = self.window.focus_listeners.insert(
2122 (),
2123 Box::new(move |event, cx| {
2124 view.update(cx, |view, cx| {
2125 if event.previous_focus_path.last() == Some(&focus_id)
2126 && event.current_focus_path.last() != Some(&focus_id)
2127 {
2128 listener(view, cx)
2129 }
2130 })
2131 .is_ok()
2132 }),
2133 );
2134 self.app.defer(move |_| activate());
2135 subscription
2136 }
2137
2138 /// Register a listener to be called when nothing in the window has focus.
2139 /// This typically happens when the node that was focused is removed from the tree,
2140 /// and this callback lets you chose a default place to restore the users focus.
2141 /// Returns a subscription and persists until the subscription is dropped.
2142 pub fn on_focus_lost(
2143 &mut self,
2144 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2145 ) -> Subscription {
2146 let view = self.view.downgrade();
2147 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2148 (),
2149 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2150 );
2151 activate();
2152 subscription
2153 }
2154
2155 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2156 /// Returns a subscription and persists until the subscription is dropped.
2157 pub fn on_focus_out(
2158 &mut self,
2159 handle: &FocusHandle,
2160 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2161 ) -> Subscription {
2162 let view = self.view.downgrade();
2163 let focus_id = handle.id;
2164 let (subscription, activate) = self.window.focus_listeners.insert(
2165 (),
2166 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 );
2177 self.app.defer(move |_| activate());
2178 subscription
2179 }
2180
2181 /// Schedule a future to be run asynchronously.
2182 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2183 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2184 /// The returned future will be polled on the main thread.
2185 pub fn spawn<Fut, R>(
2186 &mut self,
2187 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2188 ) -> Task<R>
2189 where
2190 R: 'static,
2191 Fut: Future<Output = R> + 'static,
2192 {
2193 let view = self.view().downgrade();
2194 self.window_cx.spawn(|cx| f(view, cx))
2195 }
2196
2197 /// Updates the global state of the given type.
2198 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2199 where
2200 G: 'static,
2201 {
2202 let mut global = self.app.lease_global::<G>();
2203 let result = f(&mut global, self);
2204 self.app.end_global_lease(global);
2205 result
2206 }
2207
2208 /// Register a callback to be invoked when the given global state changes.
2209 pub fn observe_global<G: 'static>(
2210 &mut self,
2211 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2212 ) -> Subscription {
2213 let window_handle = self.window.handle;
2214 let view = self.view().downgrade();
2215 let (subscription, activate) = self.global_observers.insert(
2216 TypeId::of::<G>(),
2217 Box::new(move |cx| {
2218 window_handle
2219 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2220 .unwrap_or(false)
2221 }),
2222 );
2223 self.app.defer(move |_| activate());
2224 subscription
2225 }
2226
2227 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2228 pub fn on_action(
2229 &mut self,
2230 action_type: TypeId,
2231 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2232 ) {
2233 let handle = self.view().clone();
2234 self.window_cx
2235 .on_action(action_type, move |action, phase, cx| {
2236 handle.update(cx, |view, cx| {
2237 listener(view, action, phase, cx);
2238 })
2239 });
2240 }
2241
2242 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2243 pub fn emit<Evt>(&mut self, event: Evt)
2244 where
2245 Evt: 'static,
2246 V: EventEmitter<Evt>,
2247 {
2248 let emitter = self.view.model.entity_id;
2249 self.app.push_effect(Effect::Emit {
2250 emitter,
2251 event_type: TypeId::of::<Evt>(),
2252 event: Box::new(event),
2253 });
2254 }
2255
2256 /// Move focus to the current view, assuming it implements [`FocusableView`].
2257 pub fn focus_self(&mut self)
2258 where
2259 V: FocusableView,
2260 {
2261 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2262 }
2263
2264 /// Convenience method for accessing view state in an event callback.
2265 ///
2266 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2267 /// but it's often useful to be able to access view state in these
2268 /// callbacks. This method provides a convenient way to do so.
2269 pub fn listener<E>(
2270 &self,
2271 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2272 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2273 let view = self.view().downgrade();
2274 move |e: &E, cx: &mut WindowContext| {
2275 view.update(cx, |view, cx| f(view, e, cx)).ok();
2276 }
2277 }
2278}
2279
2280impl<V> Context for ViewContext<'_, V> {
2281 type Result<U> = U;
2282
2283 fn new_model<T: 'static>(
2284 &mut self,
2285 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2286 ) -> Model<T> {
2287 self.window_cx.new_model(build_model)
2288 }
2289
2290 fn update_model<T: 'static, R>(
2291 &mut self,
2292 model: &Model<T>,
2293 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2294 ) -> R {
2295 self.window_cx.update_model(model, update)
2296 }
2297
2298 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2299 where
2300 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2301 {
2302 self.window_cx.update_window(window, update)
2303 }
2304
2305 fn read_model<T, R>(
2306 &self,
2307 handle: &Model<T>,
2308 read: impl FnOnce(&T, &AppContext) -> R,
2309 ) -> Self::Result<R>
2310 where
2311 T: 'static,
2312 {
2313 self.window_cx.read_model(handle, read)
2314 }
2315
2316 fn read_window<T, R>(
2317 &self,
2318 window: &WindowHandle<T>,
2319 read: impl FnOnce(View<T>, &AppContext) -> R,
2320 ) -> Result<R>
2321 where
2322 T: 'static,
2323 {
2324 self.window_cx.read_window(window, read)
2325 }
2326}
2327
2328impl<V: 'static> VisualContext for ViewContext<'_, V> {
2329 fn new_view<W: Render + 'static>(
2330 &mut self,
2331 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2332 ) -> Self::Result<View<W>> {
2333 self.window_cx.new_view(build_view_state)
2334 }
2335
2336 fn update_view<V2: 'static, R>(
2337 &mut self,
2338 view: &View<V2>,
2339 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2340 ) -> Self::Result<R> {
2341 self.window_cx.update_view(view, update)
2342 }
2343
2344 fn replace_root_view<W>(
2345 &mut self,
2346 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2347 ) -> Self::Result<View<W>>
2348 where
2349 W: 'static + Render,
2350 {
2351 self.window_cx.replace_root_view(build_view)
2352 }
2353
2354 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2355 self.window_cx.focus_view(view)
2356 }
2357
2358 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2359 self.window_cx.dismiss_view(view)
2360 }
2361}
2362
2363impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2364 type Target = WindowContext<'a>;
2365
2366 fn deref(&self) -> &Self::Target {
2367 &self.window_cx
2368 }
2369}
2370
2371impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2372 fn deref_mut(&mut self) -> &mut Self::Target {
2373 &mut self.window_cx
2374 }
2375}
2376
2377// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2378slotmap::new_key_type! {
2379 /// A unique identifier for a window.
2380 pub struct WindowId;
2381}
2382
2383impl WindowId {
2384 /// Converts this window ID to a `u64`.
2385 pub fn as_u64(&self) -> u64 {
2386 self.0.as_ffi()
2387 }
2388}
2389
2390/// A handle to a window with a specific root view type.
2391/// Note that this does not keep the window alive on its own.
2392#[derive(Deref, DerefMut)]
2393pub struct WindowHandle<V> {
2394 #[deref]
2395 #[deref_mut]
2396 pub(crate) any_handle: AnyWindowHandle,
2397 state_type: PhantomData<V>,
2398}
2399
2400impl<V: 'static + Render> WindowHandle<V> {
2401 /// Creates a new handle from a window ID.
2402 /// This does not check if the root type of the window is `V`.
2403 pub fn new(id: WindowId) -> Self {
2404 WindowHandle {
2405 any_handle: AnyWindowHandle {
2406 id,
2407 state_type: TypeId::of::<V>(),
2408 },
2409 state_type: PhantomData,
2410 }
2411 }
2412
2413 /// Get the root view out of this window.
2414 ///
2415 /// This will fail if the window is closed or if the root view's type does not match `V`.
2416 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2417 where
2418 C: Context,
2419 {
2420 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2421 root_view
2422 .downcast::<V>()
2423 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2424 }))
2425 }
2426
2427 /// Updates the root view of this window.
2428 ///
2429 /// This will fail if the window has been closed or if the root view's type does not match
2430 pub fn update<C, R>(
2431 &self,
2432 cx: &mut C,
2433 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2434 ) -> Result<R>
2435 where
2436 C: Context,
2437 {
2438 cx.update_window(self.any_handle, |root_view, cx| {
2439 let view = root_view
2440 .downcast::<V>()
2441 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2442 Ok(cx.update_view(&view, update))
2443 })?
2444 }
2445
2446 /// Read the root view out of this window.
2447 ///
2448 /// This will fail if the window is closed or if the root view's type does not match `V`.
2449 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2450 let x = cx
2451 .windows
2452 .get(self.id)
2453 .and_then(|window| {
2454 window
2455 .as_ref()
2456 .and_then(|window| window.root_view.clone())
2457 .map(|root_view| root_view.downcast::<V>())
2458 })
2459 .ok_or_else(|| anyhow!("window not found"))?
2460 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2461
2462 Ok(x.read(cx))
2463 }
2464
2465 /// Read the root view out of this window, with a callback
2466 ///
2467 /// This will fail if the window is closed or if the root view's type does not match `V`.
2468 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2469 where
2470 C: Context,
2471 {
2472 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2473 }
2474
2475 /// Read the root view pointer off of this window.
2476 ///
2477 /// This will fail if the window is closed or if the root view's type does not match `V`.
2478 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2479 where
2480 C: Context,
2481 {
2482 cx.read_window(self, |root_view, _cx| root_view.clone())
2483 }
2484
2485 /// Check if this window is 'active'.
2486 ///
2487 /// Will return `None` if the window is closed.
2488 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2489 cx.windows
2490 .get(self.id)
2491 .and_then(|window| window.as_ref().map(|window| window.active))
2492 }
2493}
2494
2495impl<V> Copy for WindowHandle<V> {}
2496
2497impl<V> Clone for WindowHandle<V> {
2498 fn clone(&self) -> Self {
2499 *self
2500 }
2501}
2502
2503impl<V> PartialEq for WindowHandle<V> {
2504 fn eq(&self, other: &Self) -> bool {
2505 self.any_handle == other.any_handle
2506 }
2507}
2508
2509impl<V> Eq for WindowHandle<V> {}
2510
2511impl<V> Hash for WindowHandle<V> {
2512 fn hash<H: Hasher>(&self, state: &mut H) {
2513 self.any_handle.hash(state);
2514 }
2515}
2516
2517impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2518 fn from(val: WindowHandle<V>) -> Self {
2519 val.any_handle
2520 }
2521}
2522
2523/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2524#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2525pub struct AnyWindowHandle {
2526 pub(crate) id: WindowId,
2527 state_type: TypeId,
2528}
2529
2530impl AnyWindowHandle {
2531 /// Get the ID of this window.
2532 pub fn window_id(&self) -> WindowId {
2533 self.id
2534 }
2535
2536 /// Attempt to convert this handle to a window handle with a specific root view type.
2537 /// If the types do not match, this will return `None`.
2538 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2539 if TypeId::of::<T>() == self.state_type {
2540 Some(WindowHandle {
2541 any_handle: *self,
2542 state_type: PhantomData,
2543 })
2544 } else {
2545 None
2546 }
2547 }
2548
2549 /// Updates the state of the root view of this window.
2550 ///
2551 /// This will fail if the window has been closed.
2552 pub fn update<C, R>(
2553 self,
2554 cx: &mut C,
2555 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2556 ) -> Result<R>
2557 where
2558 C: Context,
2559 {
2560 cx.update_window(self, update)
2561 }
2562
2563 /// Read the state of the root view of this window.
2564 ///
2565 /// This will fail if the window has been closed.
2566 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2567 where
2568 C: Context,
2569 T: 'static,
2570 {
2571 let view = self
2572 .downcast::<T>()
2573 .context("the type of the window's root view has changed")?;
2574
2575 cx.read_window(&view, read)
2576 }
2577}
2578
2579/// An identifier for an [`Element`](crate::Element).
2580///
2581/// Can be constructed with a string, a number, or both, as well
2582/// as other internal representations.
2583#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2584pub enum ElementId {
2585 /// The ID of a View element
2586 View(EntityId),
2587 /// An integer ID.
2588 Integer(usize),
2589 /// A string based ID.
2590 Name(SharedString),
2591 /// An ID that's equated with a focus handle.
2592 FocusHandle(FocusId),
2593 /// A combination of a name and an integer.
2594 NamedInteger(SharedString, usize),
2595}
2596
2597impl Display for ElementId {
2598 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2599 match self {
2600 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2601 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2602 ElementId::Name(name) => write!(f, "{}", name)?,
2603 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2604 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2605 }
2606
2607 Ok(())
2608 }
2609}
2610
2611impl ElementId {
2612 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2613 ElementId::View(entity_id)
2614 }
2615}
2616
2617impl TryInto<SharedString> for ElementId {
2618 type Error = anyhow::Error;
2619
2620 fn try_into(self) -> anyhow::Result<SharedString> {
2621 if let ElementId::Name(name) = self {
2622 Ok(name)
2623 } else {
2624 Err(anyhow!("element id is not string"))
2625 }
2626 }
2627}
2628
2629impl From<usize> for ElementId {
2630 fn from(id: usize) -> Self {
2631 ElementId::Integer(id)
2632 }
2633}
2634
2635impl From<i32> for ElementId {
2636 fn from(id: i32) -> Self {
2637 Self::Integer(id as usize)
2638 }
2639}
2640
2641impl From<SharedString> for ElementId {
2642 fn from(name: SharedString) -> Self {
2643 ElementId::Name(name)
2644 }
2645}
2646
2647impl From<&'static str> for ElementId {
2648 fn from(name: &'static str) -> Self {
2649 ElementId::Name(name.into())
2650 }
2651}
2652
2653impl<'a> From<&'a FocusHandle> for ElementId {
2654 fn from(handle: &'a FocusHandle) -> Self {
2655 ElementId::FocusHandle(handle.id)
2656 }
2657}
2658
2659impl From<(&'static str, EntityId)> for ElementId {
2660 fn from((name, id): (&'static str, EntityId)) -> Self {
2661 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2662 }
2663}
2664
2665impl From<(&'static str, usize)> for ElementId {
2666 fn from((name, id): (&'static str, usize)) -> Self {
2667 ElementId::NamedInteger(name.into(), id)
2668 }
2669}
2670
2671impl From<(&'static str, u64)> for ElementId {
2672 fn from((name, id): (&'static str, u64)) -> Self {
2673 ElementId::NamedInteger(name.into(), id as usize)
2674 }
2675}
2676
2677/// A rectangle to be rendered in the window at the given position and size.
2678/// Passed as an argument [`ElementContext::paint_quad`].
2679#[derive(Clone)]
2680pub struct PaintQuad {
2681 bounds: Bounds<Pixels>,
2682 corner_radii: Corners<Pixels>,
2683 background: Hsla,
2684 border_widths: Edges<Pixels>,
2685 border_color: Hsla,
2686}
2687
2688impl PaintQuad {
2689 /// Sets the corner radii of the quad.
2690 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2691 PaintQuad {
2692 corner_radii: corner_radii.into(),
2693 ..self
2694 }
2695 }
2696
2697 /// Sets the border widths of the quad.
2698 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2699 PaintQuad {
2700 border_widths: border_widths.into(),
2701 ..self
2702 }
2703 }
2704
2705 /// Sets the border color of the quad.
2706 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2707 PaintQuad {
2708 border_color: border_color.into(),
2709 ..self
2710 }
2711 }
2712
2713 /// Sets the background color of the quad.
2714 pub fn background(self, background: impl Into<Hsla>) -> Self {
2715 PaintQuad {
2716 background: background.into(),
2717 ..self
2718 }
2719 }
2720}
2721
2722/// Creates a quad with the given parameters.
2723pub fn quad(
2724 bounds: Bounds<Pixels>,
2725 corner_radii: impl Into<Corners<Pixels>>,
2726 background: impl Into<Hsla>,
2727 border_widths: impl Into<Edges<Pixels>>,
2728 border_color: impl Into<Hsla>,
2729) -> PaintQuad {
2730 PaintQuad {
2731 bounds,
2732 corner_radii: corner_radii.into(),
2733 background: background.into(),
2734 border_widths: border_widths.into(),
2735 border_color: border_color.into(),
2736 }
2737}
2738
2739/// Creates a filled quad with the given bounds and background color.
2740pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2741 PaintQuad {
2742 bounds: bounds.into(),
2743 corner_radii: (0.).into(),
2744 background: background.into(),
2745 border_widths: (0.).into(),
2746 border_color: transparent_black(),
2747 }
2748}
2749
2750/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2751pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2752 PaintQuad {
2753 bounds: bounds.into(),
2754 corner_radii: (0.).into(),
2755 background: transparent_black(),
2756 border_widths: (1.).into(),
2757 border_color: border_color.into(),
2758 }
2759}