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(4 * 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| element_arena.clear());
1034
1035 let previous_focus_path = self.window.rendered_frame.focus_path();
1036 let previous_window_active = self.window.rendered_frame.window_active;
1037 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1038 self.window.next_frame.clear();
1039 let current_focus_path = self.window.rendered_frame.focus_path();
1040 let current_window_active = self.window.rendered_frame.window_active;
1041
1042 if previous_focus_path != current_focus_path
1043 || previous_window_active != current_window_active
1044 {
1045 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1046 self.window
1047 .focus_lost_listeners
1048 .clone()
1049 .retain(&(), |listener| listener(self));
1050 }
1051
1052 let event = FocusEvent {
1053 previous_focus_path: if previous_window_active {
1054 previous_focus_path
1055 } else {
1056 Default::default()
1057 },
1058 current_focus_path: if current_window_active {
1059 current_focus_path
1060 } else {
1061 Default::default()
1062 },
1063 };
1064 self.window
1065 .focus_listeners
1066 .clone()
1067 .retain(&(), |listener| listener(&event, self));
1068 }
1069
1070 self.window
1071 .platform_window
1072 .draw(&self.window.rendered_frame.scene);
1073 self.window.refreshing = false;
1074 self.window.drawing = false;
1075 }
1076
1077 /// Dispatch a mouse or keyboard event on the window.
1078 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1079 // Handlers may set this to false by calling `stop_propagation`.
1080 self.app.propagate_event = true;
1081 // Handlers may set this to true by calling `prevent_default`.
1082 self.window.default_prevented = false;
1083
1084 let event = match event {
1085 // Track the mouse position with our own state, since accessing the platform
1086 // API for the mouse position can only occur on the main thread.
1087 PlatformInput::MouseMove(mouse_move) => {
1088 self.window.mouse_position = mouse_move.position;
1089 self.window.modifiers = mouse_move.modifiers;
1090 PlatformInput::MouseMove(mouse_move)
1091 }
1092 PlatformInput::MouseDown(mouse_down) => {
1093 self.window.mouse_position = mouse_down.position;
1094 self.window.modifiers = mouse_down.modifiers;
1095 PlatformInput::MouseDown(mouse_down)
1096 }
1097 PlatformInput::MouseUp(mouse_up) => {
1098 self.window.mouse_position = mouse_up.position;
1099 self.window.modifiers = mouse_up.modifiers;
1100 PlatformInput::MouseUp(mouse_up)
1101 }
1102 PlatformInput::MouseExited(mouse_exited) => {
1103 self.window.modifiers = mouse_exited.modifiers;
1104 PlatformInput::MouseExited(mouse_exited)
1105 }
1106 PlatformInput::ModifiersChanged(modifiers_changed) => {
1107 self.window.modifiers = modifiers_changed.modifiers;
1108 PlatformInput::ModifiersChanged(modifiers_changed)
1109 }
1110 PlatformInput::ScrollWheel(scroll_wheel) => {
1111 self.window.mouse_position = scroll_wheel.position;
1112 self.window.modifiers = scroll_wheel.modifiers;
1113 PlatformInput::ScrollWheel(scroll_wheel)
1114 }
1115 // Translate dragging and dropping of external files from the operating system
1116 // to internal drag and drop events.
1117 PlatformInput::FileDrop(file_drop) => match file_drop {
1118 FileDropEvent::Entered { position, paths } => {
1119 self.window.mouse_position = position;
1120 if self.active_drag.is_none() {
1121 self.active_drag = Some(AnyDrag {
1122 value: Box::new(paths.clone()),
1123 view: self.new_view(|_| paths).into(),
1124 cursor_offset: position,
1125 });
1126 }
1127 PlatformInput::MouseMove(MouseMoveEvent {
1128 position,
1129 pressed_button: Some(MouseButton::Left),
1130 modifiers: Modifiers::default(),
1131 })
1132 }
1133 FileDropEvent::Pending { position } => {
1134 self.window.mouse_position = position;
1135 PlatformInput::MouseMove(MouseMoveEvent {
1136 position,
1137 pressed_button: Some(MouseButton::Left),
1138 modifiers: Modifiers::default(),
1139 })
1140 }
1141 FileDropEvent::Submit { position } => {
1142 self.activate(true);
1143 self.window.mouse_position = position;
1144 PlatformInput::MouseUp(MouseUpEvent {
1145 button: MouseButton::Left,
1146 position,
1147 modifiers: Modifiers::default(),
1148 click_count: 1,
1149 })
1150 }
1151 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1152 button: MouseButton::Left,
1153 position: Point::default(),
1154 modifiers: Modifiers::default(),
1155 click_count: 1,
1156 }),
1157 },
1158 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1159 };
1160
1161 if let Some(any_mouse_event) = event.mouse_event() {
1162 self.dispatch_mouse_event(any_mouse_event);
1163 } else if let Some(any_key_event) = event.keyboard_event() {
1164 self.dispatch_key_event(any_key_event);
1165 }
1166
1167 !self.app.propagate_event
1168 }
1169
1170 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1171 if let Some(mut handlers) = self
1172 .window
1173 .rendered_frame
1174 .mouse_listeners
1175 .remove(&event.type_id())
1176 {
1177 // Because handlers may add other handlers, we sort every time.
1178 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1179
1180 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1181 // special purposes, such as detecting events outside of a given Bounds.
1182 for (_, _, handler) in &mut handlers {
1183 self.with_element_context(|cx| {
1184 handler(event, DispatchPhase::Capture, cx);
1185 });
1186 if !self.app.propagate_event {
1187 break;
1188 }
1189 }
1190
1191 // Bubble phase, where most normal handlers do their work.
1192 if self.app.propagate_event {
1193 for (_, _, handler) in handlers.iter_mut().rev() {
1194 self.with_element_context(|cx| {
1195 handler(event, DispatchPhase::Bubble, cx);
1196 });
1197 if !self.app.propagate_event {
1198 break;
1199 }
1200 }
1201 }
1202
1203 self.window
1204 .rendered_frame
1205 .mouse_listeners
1206 .insert(event.type_id(), handlers);
1207 }
1208
1209 if self.app.propagate_event && self.has_active_drag() {
1210 if event.is::<MouseMoveEvent>() {
1211 // If this was a mouse move event, redraw the window so that the
1212 // active drag can follow the mouse cursor.
1213 self.refresh();
1214 } else if event.is::<MouseUpEvent>() {
1215 // If this was a mouse up event, cancel the active drag and redraw
1216 // the window.
1217 self.active_drag = None;
1218 self.refresh();
1219 }
1220 }
1221 }
1222
1223 fn dispatch_key_event(&mut self, event: &dyn Any) {
1224 let node_id = self
1225 .window
1226 .focus
1227 .and_then(|focus_id| {
1228 self.window
1229 .rendered_frame
1230 .dispatch_tree
1231 .focusable_node_id(focus_id)
1232 })
1233 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1234
1235 let dispatch_path = self
1236 .window
1237 .rendered_frame
1238 .dispatch_tree
1239 .dispatch_path(node_id);
1240
1241 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1242 let KeymatchResult {
1243 bindings,
1244 mut pending,
1245 } = self
1246 .window
1247 .rendered_frame
1248 .dispatch_tree
1249 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1250
1251 if self.window.rendered_frame.dispatch_tree.keymatch_mode == KeymatchMode::Immediate
1252 && !bindings.is_empty()
1253 {
1254 pending = false;
1255 }
1256
1257 if pending {
1258 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1259 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1260 {
1261 currently_pending = PendingInput::default();
1262 }
1263 currently_pending.focus = self.window.focus;
1264 currently_pending
1265 .keystrokes
1266 .push(key_down_event.keystroke.clone());
1267 for binding in bindings {
1268 currently_pending.bindings.push(binding);
1269 }
1270
1271 // for vim compatibility, we also should check "is input handler enabled"
1272 if !currently_pending.is_noop() {
1273 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1274 cx.background_executor.timer(Duration::from_secs(1)).await;
1275 cx.update(move |cx| {
1276 cx.clear_pending_keystrokes();
1277 let Some(currently_pending) = cx.window.pending_input.take() else {
1278 return;
1279 };
1280 cx.replay_pending_input(currently_pending)
1281 })
1282 .log_err();
1283 }));
1284 } else {
1285 currently_pending.timer = None;
1286 }
1287 self.window.pending_input = Some(currently_pending);
1288
1289 self.propagate_event = false;
1290 return;
1291 } else if let Some(currently_pending) = self.window.pending_input.take() {
1292 if bindings
1293 .iter()
1294 .all(|binding| !currently_pending.used_by_binding(binding))
1295 {
1296 self.replay_pending_input(currently_pending)
1297 }
1298 }
1299
1300 if !bindings.is_empty() {
1301 self.clear_pending_keystrokes();
1302 }
1303
1304 self.propagate_event = true;
1305 for binding in bindings {
1306 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1307 if !self.propagate_event {
1308 self.dispatch_keystroke_observers(event, Some(binding.action));
1309 return;
1310 }
1311 }
1312 }
1313
1314 // Capture phase
1315 for node_id in &dispatch_path {
1316 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1317
1318 for key_listener in node.key_listeners.clone() {
1319 self.with_element_context(|cx| {
1320 key_listener(event, DispatchPhase::Capture, cx);
1321 });
1322 if !self.propagate_event {
1323 return;
1324 }
1325 }
1326 }
1327
1328 // Bubble phase
1329 for node_id in dispatch_path.iter().rev() {
1330 // Handle low level key events
1331 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1332 for key_listener in node.key_listeners.clone() {
1333 self.with_element_context(|cx| {
1334 key_listener(event, DispatchPhase::Bubble, cx);
1335 });
1336 if !self.propagate_event {
1337 return;
1338 }
1339 }
1340 }
1341
1342 self.dispatch_keystroke_observers(event, None);
1343 }
1344
1345 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1346 pub fn has_pending_keystrokes(&self) -> bool {
1347 self.window
1348 .rendered_frame
1349 .dispatch_tree
1350 .has_pending_keystrokes()
1351 }
1352
1353 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1354 let node_id = self
1355 .window
1356 .focus
1357 .and_then(|focus_id| {
1358 self.window
1359 .rendered_frame
1360 .dispatch_tree
1361 .focusable_node_id(focus_id)
1362 })
1363 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1364
1365 if self.window.focus != currently_pending.focus {
1366 return;
1367 }
1368
1369 let input = currently_pending.input();
1370
1371 self.propagate_event = true;
1372 for binding in currently_pending.bindings {
1373 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1374 if !self.propagate_event {
1375 return;
1376 }
1377 }
1378
1379 if !input.is_empty() {
1380 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1381 input_handler.flush_pending_input(&input, self);
1382 self.window.platform_window.set_input_handler(input_handler)
1383 }
1384 }
1385 }
1386
1387 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1388 let dispatch_path = self
1389 .window
1390 .rendered_frame
1391 .dispatch_tree
1392 .dispatch_path(node_id);
1393
1394 // Capture phase
1395 for node_id in &dispatch_path {
1396 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1397 for DispatchActionListener {
1398 action_type,
1399 listener,
1400 } in node.action_listeners.clone()
1401 {
1402 let any_action = action.as_any();
1403 if action_type == any_action.type_id() {
1404 self.with_element_context(|cx| {
1405 listener(any_action, DispatchPhase::Capture, cx);
1406 });
1407
1408 if !self.propagate_event {
1409 return;
1410 }
1411 }
1412 }
1413 }
1414 // Bubble phase
1415 for node_id in dispatch_path.iter().rev() {
1416 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1417 for DispatchActionListener {
1418 action_type,
1419 listener,
1420 } in node.action_listeners.clone()
1421 {
1422 let any_action = action.as_any();
1423 if action_type == any_action.type_id() {
1424 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1425
1426 self.with_element_context(|cx| {
1427 listener(any_action, DispatchPhase::Bubble, cx);
1428 });
1429
1430 if !self.propagate_event {
1431 return;
1432 }
1433 }
1434 }
1435 }
1436 }
1437
1438 /// Register the given handler to be invoked whenever the global of the given type
1439 /// is updated.
1440 pub fn observe_global<G: 'static>(
1441 &mut self,
1442 f: impl Fn(&mut WindowContext<'_>) + 'static,
1443 ) -> Subscription {
1444 let window_handle = self.window.handle;
1445 let (subscription, activate) = self.global_observers.insert(
1446 TypeId::of::<G>(),
1447 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1448 );
1449 self.app.defer(move |_| activate());
1450 subscription
1451 }
1452
1453 /// Focus the current window and bring it to the foreground at the platform level.
1454 pub fn activate_window(&self) {
1455 self.window.platform_window.activate();
1456 }
1457
1458 /// Minimize the current window at the platform level.
1459 pub fn minimize_window(&self) {
1460 self.window.platform_window.minimize();
1461 }
1462
1463 /// Toggle full screen status on the current window at the platform level.
1464 pub fn toggle_full_screen(&self) {
1465 self.window.platform_window.toggle_full_screen();
1466 }
1467
1468 /// Present a platform dialog.
1469 /// The provided message will be presented, along with buttons for each answer.
1470 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1471 pub fn prompt(
1472 &self,
1473 level: PromptLevel,
1474 message: &str,
1475 answers: &[&str],
1476 ) -> oneshot::Receiver<usize> {
1477 self.window.platform_window.prompt(level, message, answers)
1478 }
1479
1480 /// Returns all available actions for the focused element.
1481 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1482 let node_id = self
1483 .window
1484 .focus
1485 .and_then(|focus_id| {
1486 self.window
1487 .rendered_frame
1488 .dispatch_tree
1489 .focusable_node_id(focus_id)
1490 })
1491 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1492
1493 self.window
1494 .rendered_frame
1495 .dispatch_tree
1496 .available_actions(node_id)
1497 }
1498
1499 /// Returns key bindings that invoke the given action on the currently focused element.
1500 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1501 self.window
1502 .rendered_frame
1503 .dispatch_tree
1504 .bindings_for_action(
1505 action,
1506 &self.window.rendered_frame.dispatch_tree.context_stack,
1507 )
1508 }
1509
1510 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1511 pub fn bindings_for_action_in(
1512 &self,
1513 action: &dyn Action,
1514 focus_handle: &FocusHandle,
1515 ) -> Vec<KeyBinding> {
1516 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1517
1518 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1519 return vec![];
1520 };
1521 let context_stack = dispatch_tree
1522 .dispatch_path(node_id)
1523 .into_iter()
1524 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1525 .collect();
1526 dispatch_tree.bindings_for_action(action, &context_stack)
1527 }
1528
1529 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1530 pub fn listener_for<V: Render, E>(
1531 &self,
1532 view: &View<V>,
1533 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1534 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1535 let view = view.downgrade();
1536 move |e: &E, cx: &mut WindowContext| {
1537 view.update(cx, |view, cx| f(view, e, cx)).ok();
1538 }
1539 }
1540
1541 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1542 pub fn handler_for<V: Render>(
1543 &self,
1544 view: &View<V>,
1545 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1546 ) -> impl Fn(&mut WindowContext) {
1547 let view = view.downgrade();
1548 move |cx: &mut WindowContext| {
1549 view.update(cx, |view, cx| f(view, cx)).ok();
1550 }
1551 }
1552
1553 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1554 /// If the callback returns false, the window won't be closed.
1555 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1556 let mut this = self.to_async();
1557 self.window
1558 .platform_window
1559 .on_should_close(Box::new(move || {
1560 this.update(|cx| {
1561 // Ensure that the window is removed from the app if it's been closed
1562 // by always pre-empting the system close event.
1563 if f(cx) {
1564 cx.remove_window();
1565 }
1566 false
1567 })
1568 .unwrap_or(true)
1569 }))
1570 }
1571
1572 pub(crate) fn parent_view_id(&self) -> EntityId {
1573 *self
1574 .window
1575 .next_frame
1576 .view_stack
1577 .last()
1578 .expect("a view should always be on the stack while drawing")
1579 }
1580
1581 /// Register an action listener on the window for the next frame. The type of action
1582 /// is determined by the first parameter of the given listener. When the next frame is rendered
1583 /// the listener will be cleared.
1584 ///
1585 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1586 /// a specific need to register a global listener.
1587 pub fn on_action(
1588 &mut self,
1589 action_type: TypeId,
1590 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1591 ) {
1592 self.window
1593 .next_frame
1594 .dispatch_tree
1595 .on_action(action_type, Rc::new(listener));
1596 }
1597}
1598
1599impl Context for WindowContext<'_> {
1600 type Result<T> = T;
1601
1602 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1603 where
1604 T: 'static,
1605 {
1606 let slot = self.app.entities.reserve();
1607 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1608 self.entities.insert(slot, model)
1609 }
1610
1611 fn update_model<T: 'static, R>(
1612 &mut self,
1613 model: &Model<T>,
1614 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1615 ) -> R {
1616 let mut entity = self.entities.lease(model);
1617 let result = update(
1618 &mut *entity,
1619 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1620 );
1621 self.entities.end_lease(entity);
1622 result
1623 }
1624
1625 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1626 where
1627 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1628 {
1629 if window == self.window.handle {
1630 let root_view = self.window.root_view.clone().unwrap();
1631 Ok(update(root_view, self))
1632 } else {
1633 window.update(self.app, update)
1634 }
1635 }
1636
1637 fn read_model<T, R>(
1638 &self,
1639 handle: &Model<T>,
1640 read: impl FnOnce(&T, &AppContext) -> R,
1641 ) -> Self::Result<R>
1642 where
1643 T: 'static,
1644 {
1645 let entity = self.entities.read(handle);
1646 read(entity, &*self.app)
1647 }
1648
1649 fn read_window<T, R>(
1650 &self,
1651 window: &WindowHandle<T>,
1652 read: impl FnOnce(View<T>, &AppContext) -> R,
1653 ) -> Result<R>
1654 where
1655 T: 'static,
1656 {
1657 if window.any_handle == self.window.handle {
1658 let root_view = self
1659 .window
1660 .root_view
1661 .clone()
1662 .unwrap()
1663 .downcast::<T>()
1664 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1665 Ok(read(root_view, self))
1666 } else {
1667 self.app.read_window(window, read)
1668 }
1669 }
1670}
1671
1672impl VisualContext for WindowContext<'_> {
1673 fn new_view<V>(
1674 &mut self,
1675 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1676 ) -> Self::Result<View<V>>
1677 where
1678 V: 'static + Render,
1679 {
1680 let slot = self.app.entities.reserve();
1681 let view = View {
1682 model: slot.clone(),
1683 };
1684 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1685 let entity = build_view_state(&mut cx);
1686 cx.entities.insert(slot, entity);
1687
1688 cx.new_view_observers
1689 .clone()
1690 .retain(&TypeId::of::<V>(), |observer| {
1691 let any_view = AnyView::from(view.clone());
1692 (observer)(any_view, self);
1693 true
1694 });
1695
1696 view
1697 }
1698
1699 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1700 fn update_view<T: 'static, R>(
1701 &mut self,
1702 view: &View<T>,
1703 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1704 ) -> Self::Result<R> {
1705 let mut lease = self.app.entities.lease(&view.model);
1706 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1707 let result = update(&mut *lease, &mut cx);
1708 cx.app.entities.end_lease(lease);
1709 result
1710 }
1711
1712 fn replace_root_view<V>(
1713 &mut self,
1714 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1715 ) -> Self::Result<View<V>>
1716 where
1717 V: 'static + Render,
1718 {
1719 let view = self.new_view(build_view);
1720 self.window.root_view = Some(view.clone().into());
1721 self.refresh();
1722 view
1723 }
1724
1725 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1726 self.update_view(view, |view, cx| {
1727 view.focus_handle(cx).clone().focus(cx);
1728 })
1729 }
1730
1731 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1732 where
1733 V: ManagedView,
1734 {
1735 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1736 }
1737}
1738
1739impl<'a> std::ops::Deref for WindowContext<'a> {
1740 type Target = AppContext;
1741
1742 fn deref(&self) -> &Self::Target {
1743 self.app
1744 }
1745}
1746
1747impl<'a> std::ops::DerefMut for WindowContext<'a> {
1748 fn deref_mut(&mut self) -> &mut Self::Target {
1749 self.app
1750 }
1751}
1752
1753impl<'a> Borrow<AppContext> for WindowContext<'a> {
1754 fn borrow(&self) -> &AppContext {
1755 self.app
1756 }
1757}
1758
1759impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1760 fn borrow_mut(&mut self) -> &mut AppContext {
1761 self.app
1762 }
1763}
1764
1765/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1766pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1767 #[doc(hidden)]
1768 fn app_mut(&mut self) -> &mut AppContext {
1769 self.borrow_mut()
1770 }
1771
1772 #[doc(hidden)]
1773 fn app(&self) -> &AppContext {
1774 self.borrow()
1775 }
1776
1777 #[doc(hidden)]
1778 fn window(&self) -> &Window {
1779 self.borrow()
1780 }
1781
1782 #[doc(hidden)]
1783 fn window_mut(&mut self) -> &mut Window {
1784 self.borrow_mut()
1785 }
1786}
1787
1788impl Borrow<Window> for WindowContext<'_> {
1789 fn borrow(&self) -> &Window {
1790 self.window
1791 }
1792}
1793
1794impl BorrowMut<Window> for WindowContext<'_> {
1795 fn borrow_mut(&mut self) -> &mut Window {
1796 self.window
1797 }
1798}
1799
1800impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1801
1802/// Provides access to application state that is specialized for a particular [`View`].
1803/// Allows you to interact with focus, emit events, etc.
1804/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1805/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1806pub struct ViewContext<'a, V> {
1807 window_cx: WindowContext<'a>,
1808 view: &'a View<V>,
1809}
1810
1811impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1812 fn borrow(&self) -> &AppContext {
1813 &*self.window_cx.app
1814 }
1815}
1816
1817impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1818 fn borrow_mut(&mut self) -> &mut AppContext {
1819 &mut *self.window_cx.app
1820 }
1821}
1822
1823impl<V> Borrow<Window> for ViewContext<'_, V> {
1824 fn borrow(&self) -> &Window {
1825 &*self.window_cx.window
1826 }
1827}
1828
1829impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1830 fn borrow_mut(&mut self) -> &mut Window {
1831 &mut *self.window_cx.window
1832 }
1833}
1834
1835impl<'a, V: 'static> ViewContext<'a, V> {
1836 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1837 Self {
1838 window_cx: WindowContext::new(app, window),
1839 view,
1840 }
1841 }
1842
1843 /// Get the entity_id of this view.
1844 pub fn entity_id(&self) -> EntityId {
1845 self.view.entity_id()
1846 }
1847
1848 /// Get the view pointer underlying this context.
1849 pub fn view(&self) -> &View<V> {
1850 self.view
1851 }
1852
1853 /// Get the model underlying this view.
1854 pub fn model(&self) -> &Model<V> {
1855 &self.view.model
1856 }
1857
1858 /// Access the underlying window context.
1859 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1860 &mut self.window_cx
1861 }
1862
1863 /// Sets a given callback to be run on the next frame.
1864 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1865 where
1866 V: 'static,
1867 {
1868 let view = self.view().clone();
1869 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1870 }
1871
1872 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1873 /// that are currently on the stack to be returned to the app.
1874 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1875 let view = self.view().downgrade();
1876 self.window_cx.defer(move |cx| {
1877 view.update(cx, f).ok();
1878 });
1879 }
1880
1881 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1882 pub fn observe<V2, E>(
1883 &mut self,
1884 entity: &E,
1885 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1886 ) -> Subscription
1887 where
1888 V2: 'static,
1889 V: 'static,
1890 E: Entity<V2>,
1891 {
1892 let view = self.view().downgrade();
1893 let entity_id = entity.entity_id();
1894 let entity = entity.downgrade();
1895 let window_handle = self.window.handle;
1896 let (subscription, activate) = self.app.observers.insert(
1897 entity_id,
1898 Box::new(move |cx| {
1899 window_handle
1900 .update(cx, |_, cx| {
1901 if let Some(handle) = E::upgrade_from(&entity) {
1902 view.update(cx, |this, cx| on_notify(this, handle, cx))
1903 .is_ok()
1904 } else {
1905 false
1906 }
1907 })
1908 .unwrap_or(false)
1909 }),
1910 );
1911 self.app.defer(move |_| activate());
1912 subscription
1913 }
1914
1915 /// Subscribe to events emitted by another model or view.
1916 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1917 /// 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.
1918 pub fn subscribe<V2, E, Evt>(
1919 &mut self,
1920 entity: &E,
1921 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1922 ) -> Subscription
1923 where
1924 V2: EventEmitter<Evt>,
1925 E: Entity<V2>,
1926 Evt: 'static,
1927 {
1928 let view = self.view().downgrade();
1929 let entity_id = entity.entity_id();
1930 let handle = entity.downgrade();
1931 let window_handle = self.window.handle;
1932 let (subscription, activate) = self.app.event_listeners.insert(
1933 entity_id,
1934 (
1935 TypeId::of::<Evt>(),
1936 Box::new(move |event, cx| {
1937 window_handle
1938 .update(cx, |_, cx| {
1939 if let Some(handle) = E::upgrade_from(&handle) {
1940 let event = event.downcast_ref().expect("invalid event type");
1941 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1942 .is_ok()
1943 } else {
1944 false
1945 }
1946 })
1947 .unwrap_or(false)
1948 }),
1949 ),
1950 );
1951 self.app.defer(move |_| activate());
1952 subscription
1953 }
1954
1955 /// Register a callback to be invoked when the view is released.
1956 ///
1957 /// The callback receives a handle to the view's window. This handle may be
1958 /// invalid, if the window was closed before the view was released.
1959 pub fn on_release(
1960 &mut self,
1961 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1962 ) -> Subscription {
1963 let window_handle = self.window.handle;
1964 let (subscription, activate) = self.app.release_listeners.insert(
1965 self.view.model.entity_id,
1966 Box::new(move |this, cx| {
1967 let this = this.downcast_mut().expect("invalid entity type");
1968 on_release(this, window_handle, cx)
1969 }),
1970 );
1971 activate();
1972 subscription
1973 }
1974
1975 /// Register a callback to be invoked when the given Model or View is released.
1976 pub fn observe_release<V2, E>(
1977 &mut self,
1978 entity: &E,
1979 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1980 ) -> Subscription
1981 where
1982 V: 'static,
1983 V2: 'static,
1984 E: Entity<V2>,
1985 {
1986 let view = self.view().downgrade();
1987 let entity_id = entity.entity_id();
1988 let window_handle = self.window.handle;
1989 let (subscription, activate) = self.app.release_listeners.insert(
1990 entity_id,
1991 Box::new(move |entity, cx| {
1992 let entity = entity.downcast_mut().expect("invalid entity type");
1993 let _ = window_handle.update(cx, |_, cx| {
1994 view.update(cx, |this, cx| on_release(this, entity, cx))
1995 });
1996 }),
1997 );
1998 activate();
1999 subscription
2000 }
2001
2002 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2003 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2004 pub fn notify(&mut self) {
2005 for view_id in self
2006 .window
2007 .rendered_frame
2008 .dispatch_tree
2009 .view_path(self.view.entity_id())
2010 .into_iter()
2011 .rev()
2012 {
2013 if !self.window.dirty_views.insert(view_id) {
2014 break;
2015 }
2016 }
2017
2018 if !self.window.drawing {
2019 self.window_cx.window.dirty = true;
2020 self.window_cx.app.push_effect(Effect::Notify {
2021 emitter: self.view.model.entity_id,
2022 });
2023 }
2024 }
2025
2026 /// Register a callback to be invoked when the window is resized.
2027 pub fn observe_window_bounds(
2028 &mut self,
2029 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2030 ) -> Subscription {
2031 let view = self.view.downgrade();
2032 let (subscription, activate) = self.window.bounds_observers.insert(
2033 (),
2034 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2035 );
2036 activate();
2037 subscription
2038 }
2039
2040 /// Register a callback to be invoked when the window is activated or deactivated.
2041 pub fn observe_window_activation(
2042 &mut self,
2043 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2044 ) -> Subscription {
2045 let view = self.view.downgrade();
2046 let (subscription, activate) = self.window.activation_observers.insert(
2047 (),
2048 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2049 );
2050 activate();
2051 subscription
2052 }
2053
2054 /// Register a listener to be called when the given focus handle receives focus.
2055 /// Returns a subscription and persists until the subscription is dropped.
2056 pub fn on_focus(
2057 &mut self,
2058 handle: &FocusHandle,
2059 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2060 ) -> Subscription {
2061 let view = self.view.downgrade();
2062 let focus_id = handle.id;
2063 let (subscription, activate) = self.window.focus_listeners.insert(
2064 (),
2065 Box::new(move |event, cx| {
2066 view.update(cx, |view, cx| {
2067 if event.previous_focus_path.last() != Some(&focus_id)
2068 && event.current_focus_path.last() == Some(&focus_id)
2069 {
2070 listener(view, cx)
2071 }
2072 })
2073 .is_ok()
2074 }),
2075 );
2076 self.app.defer(move |_| activate());
2077 subscription
2078 }
2079
2080 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2081 /// Returns a subscription and persists until the subscription is dropped.
2082 pub fn on_focus_in(
2083 &mut self,
2084 handle: &FocusHandle,
2085 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2086 ) -> Subscription {
2087 let view = self.view.downgrade();
2088 let focus_id = handle.id;
2089 let (subscription, activate) = self.window.focus_listeners.insert(
2090 (),
2091 Box::new(move |event, cx| {
2092 view.update(cx, |view, cx| {
2093 if !event.previous_focus_path.contains(&focus_id)
2094 && event.current_focus_path.contains(&focus_id)
2095 {
2096 listener(view, cx)
2097 }
2098 })
2099 .is_ok()
2100 }),
2101 );
2102 self.app.defer(move |_| activate());
2103 subscription
2104 }
2105
2106 /// Register a listener to be called when the given focus handle loses focus.
2107 /// Returns a subscription and persists until the subscription is dropped.
2108 pub fn on_blur(
2109 &mut self,
2110 handle: &FocusHandle,
2111 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2112 ) -> Subscription {
2113 let view = self.view.downgrade();
2114 let focus_id = handle.id;
2115 let (subscription, activate) = self.window.focus_listeners.insert(
2116 (),
2117 Box::new(move |event, cx| {
2118 view.update(cx, |view, cx| {
2119 if event.previous_focus_path.last() == Some(&focus_id)
2120 && event.current_focus_path.last() != Some(&focus_id)
2121 {
2122 listener(view, cx)
2123 }
2124 })
2125 .is_ok()
2126 }),
2127 );
2128 self.app.defer(move |_| activate());
2129 subscription
2130 }
2131
2132 /// Register a listener to be called when nothing in the window has focus.
2133 /// This typically happens when the node that was focused is removed from the tree,
2134 /// and this callback lets you chose a default place to restore the users focus.
2135 /// Returns a subscription and persists until the subscription is dropped.
2136 pub fn on_focus_lost(
2137 &mut self,
2138 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2139 ) -> Subscription {
2140 let view = self.view.downgrade();
2141 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2142 (),
2143 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2144 );
2145 activate();
2146 subscription
2147 }
2148
2149 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2150 /// Returns a subscription and persists until the subscription is dropped.
2151 pub fn on_focus_out(
2152 &mut self,
2153 handle: &FocusHandle,
2154 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2155 ) -> Subscription {
2156 let view = self.view.downgrade();
2157 let focus_id = handle.id;
2158 let (subscription, activate) = self.window.focus_listeners.insert(
2159 (),
2160 Box::new(move |event, cx| {
2161 view.update(cx, |view, cx| {
2162 if event.previous_focus_path.contains(&focus_id)
2163 && !event.current_focus_path.contains(&focus_id)
2164 {
2165 listener(view, cx)
2166 }
2167 })
2168 .is_ok()
2169 }),
2170 );
2171 self.app.defer(move |_| activate());
2172 subscription
2173 }
2174
2175 /// Schedule a future to be run asynchronously.
2176 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2177 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2178 /// The returned future will be polled on the main thread.
2179 pub fn spawn<Fut, R>(
2180 &mut self,
2181 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2182 ) -> Task<R>
2183 where
2184 R: 'static,
2185 Fut: Future<Output = R> + 'static,
2186 {
2187 let view = self.view().downgrade();
2188 self.window_cx.spawn(|cx| f(view, cx))
2189 }
2190
2191 /// Updates the global state of the given type.
2192 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2193 where
2194 G: 'static,
2195 {
2196 let mut global = self.app.lease_global::<G>();
2197 let result = f(&mut global, self);
2198 self.app.end_global_lease(global);
2199 result
2200 }
2201
2202 /// Register a callback to be invoked when the given global state changes.
2203 pub fn observe_global<G: 'static>(
2204 &mut self,
2205 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2206 ) -> Subscription {
2207 let window_handle = self.window.handle;
2208 let view = self.view().downgrade();
2209 let (subscription, activate) = self.global_observers.insert(
2210 TypeId::of::<G>(),
2211 Box::new(move |cx| {
2212 window_handle
2213 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2214 .unwrap_or(false)
2215 }),
2216 );
2217 self.app.defer(move |_| activate());
2218 subscription
2219 }
2220
2221 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2222 pub fn on_action(
2223 &mut self,
2224 action_type: TypeId,
2225 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2226 ) {
2227 let handle = self.view().clone();
2228 self.window_cx
2229 .on_action(action_type, move |action, phase, cx| {
2230 handle.update(cx, |view, cx| {
2231 listener(view, action, phase, cx);
2232 })
2233 });
2234 }
2235
2236 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2237 pub fn emit<Evt>(&mut self, event: Evt)
2238 where
2239 Evt: 'static,
2240 V: EventEmitter<Evt>,
2241 {
2242 let emitter = self.view.model.entity_id;
2243 self.app.push_effect(Effect::Emit {
2244 emitter,
2245 event_type: TypeId::of::<Evt>(),
2246 event: Box::new(event),
2247 });
2248 }
2249
2250 /// Move focus to the current view, assuming it implements [`FocusableView`].
2251 pub fn focus_self(&mut self)
2252 where
2253 V: FocusableView,
2254 {
2255 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2256 }
2257
2258 /// Convenience method for accessing view state in an event callback.
2259 ///
2260 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2261 /// but it's often useful to be able to access view state in these
2262 /// callbacks. This method provides a convenient way to do so.
2263 pub fn listener<E>(
2264 &self,
2265 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2266 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2267 let view = self.view().downgrade();
2268 move |e: &E, cx: &mut WindowContext| {
2269 view.update(cx, |view, cx| f(view, e, cx)).ok();
2270 }
2271 }
2272}
2273
2274impl<V> Context for ViewContext<'_, V> {
2275 type Result<U> = U;
2276
2277 fn new_model<T: 'static>(
2278 &mut self,
2279 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2280 ) -> Model<T> {
2281 self.window_cx.new_model(build_model)
2282 }
2283
2284 fn update_model<T: 'static, R>(
2285 &mut self,
2286 model: &Model<T>,
2287 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2288 ) -> R {
2289 self.window_cx.update_model(model, update)
2290 }
2291
2292 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2293 where
2294 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2295 {
2296 self.window_cx.update_window(window, update)
2297 }
2298
2299 fn read_model<T, R>(
2300 &self,
2301 handle: &Model<T>,
2302 read: impl FnOnce(&T, &AppContext) -> R,
2303 ) -> Self::Result<R>
2304 where
2305 T: 'static,
2306 {
2307 self.window_cx.read_model(handle, read)
2308 }
2309
2310 fn read_window<T, R>(
2311 &self,
2312 window: &WindowHandle<T>,
2313 read: impl FnOnce(View<T>, &AppContext) -> R,
2314 ) -> Result<R>
2315 where
2316 T: 'static,
2317 {
2318 self.window_cx.read_window(window, read)
2319 }
2320}
2321
2322impl<V: 'static> VisualContext for ViewContext<'_, V> {
2323 fn new_view<W: Render + 'static>(
2324 &mut self,
2325 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2326 ) -> Self::Result<View<W>> {
2327 self.window_cx.new_view(build_view_state)
2328 }
2329
2330 fn update_view<V2: 'static, R>(
2331 &mut self,
2332 view: &View<V2>,
2333 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2334 ) -> Self::Result<R> {
2335 self.window_cx.update_view(view, update)
2336 }
2337
2338 fn replace_root_view<W>(
2339 &mut self,
2340 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2341 ) -> Self::Result<View<W>>
2342 where
2343 W: 'static + Render,
2344 {
2345 self.window_cx.replace_root_view(build_view)
2346 }
2347
2348 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2349 self.window_cx.focus_view(view)
2350 }
2351
2352 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2353 self.window_cx.dismiss_view(view)
2354 }
2355}
2356
2357impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2358 type Target = WindowContext<'a>;
2359
2360 fn deref(&self) -> &Self::Target {
2361 &self.window_cx
2362 }
2363}
2364
2365impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2366 fn deref_mut(&mut self) -> &mut Self::Target {
2367 &mut self.window_cx
2368 }
2369}
2370
2371// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2372slotmap::new_key_type! {
2373 /// A unique identifier for a window.
2374 pub struct WindowId;
2375}
2376
2377impl WindowId {
2378 /// Converts this window ID to a `u64`.
2379 pub fn as_u64(&self) -> u64 {
2380 self.0.as_ffi()
2381 }
2382}
2383
2384/// A handle to a window with a specific root view type.
2385/// Note that this does not keep the window alive on its own.
2386#[derive(Deref, DerefMut)]
2387pub struct WindowHandle<V> {
2388 #[deref]
2389 #[deref_mut]
2390 pub(crate) any_handle: AnyWindowHandle,
2391 state_type: PhantomData<V>,
2392}
2393
2394impl<V: 'static + Render> WindowHandle<V> {
2395 /// Creates a new handle from a window ID.
2396 /// This does not check if the root type of the window is `V`.
2397 pub fn new(id: WindowId) -> Self {
2398 WindowHandle {
2399 any_handle: AnyWindowHandle {
2400 id,
2401 state_type: TypeId::of::<V>(),
2402 },
2403 state_type: PhantomData,
2404 }
2405 }
2406
2407 /// Get the root view out of this window.
2408 ///
2409 /// This will fail if the window is closed or if the root view's type does not match `V`.
2410 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2411 where
2412 C: Context,
2413 {
2414 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2415 root_view
2416 .downcast::<V>()
2417 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2418 }))
2419 }
2420
2421 /// Updates the root view of this window.
2422 ///
2423 /// This will fail if the window has been closed or if the root view's type does not match
2424 pub fn update<C, R>(
2425 &self,
2426 cx: &mut C,
2427 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2428 ) -> Result<R>
2429 where
2430 C: Context,
2431 {
2432 cx.update_window(self.any_handle, |root_view, cx| {
2433 let view = root_view
2434 .downcast::<V>()
2435 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2436 Ok(cx.update_view(&view, update))
2437 })?
2438 }
2439
2440 /// Read the root view out of this window.
2441 ///
2442 /// This will fail if the window is closed or if the root view's type does not match `V`.
2443 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2444 let x = cx
2445 .windows
2446 .get(self.id)
2447 .and_then(|window| {
2448 window
2449 .as_ref()
2450 .and_then(|window| window.root_view.clone())
2451 .map(|root_view| root_view.downcast::<V>())
2452 })
2453 .ok_or_else(|| anyhow!("window not found"))?
2454 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2455
2456 Ok(x.read(cx))
2457 }
2458
2459 /// Read the root view out of this window, with a callback
2460 ///
2461 /// This will fail if the window is closed or if the root view's type does not match `V`.
2462 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2463 where
2464 C: Context,
2465 {
2466 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2467 }
2468
2469 /// Read the root view pointer off of this window.
2470 ///
2471 /// This will fail if the window is closed or if the root view's type does not match `V`.
2472 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2473 where
2474 C: Context,
2475 {
2476 cx.read_window(self, |root_view, _cx| root_view.clone())
2477 }
2478
2479 /// Check if this window is 'active'.
2480 ///
2481 /// Will return `None` if the window is closed.
2482 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2483 cx.windows
2484 .get(self.id)
2485 .and_then(|window| window.as_ref().map(|window| window.active))
2486 }
2487}
2488
2489impl<V> Copy for WindowHandle<V> {}
2490
2491impl<V> Clone for WindowHandle<V> {
2492 fn clone(&self) -> Self {
2493 *self
2494 }
2495}
2496
2497impl<V> PartialEq for WindowHandle<V> {
2498 fn eq(&self, other: &Self) -> bool {
2499 self.any_handle == other.any_handle
2500 }
2501}
2502
2503impl<V> Eq for WindowHandle<V> {}
2504
2505impl<V> Hash for WindowHandle<V> {
2506 fn hash<H: Hasher>(&self, state: &mut H) {
2507 self.any_handle.hash(state);
2508 }
2509}
2510
2511impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2512 fn from(val: WindowHandle<V>) -> Self {
2513 val.any_handle
2514 }
2515}
2516
2517/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2518#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2519pub struct AnyWindowHandle {
2520 pub(crate) id: WindowId,
2521 state_type: TypeId,
2522}
2523
2524impl AnyWindowHandle {
2525 /// Get the ID of this window.
2526 pub fn window_id(&self) -> WindowId {
2527 self.id
2528 }
2529
2530 /// Attempt to convert this handle to a window handle with a specific root view type.
2531 /// If the types do not match, this will return `None`.
2532 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2533 if TypeId::of::<T>() == self.state_type {
2534 Some(WindowHandle {
2535 any_handle: *self,
2536 state_type: PhantomData,
2537 })
2538 } else {
2539 None
2540 }
2541 }
2542
2543 /// Updates the state of the root view of this window.
2544 ///
2545 /// This will fail if the window has been closed.
2546 pub fn update<C, R>(
2547 self,
2548 cx: &mut C,
2549 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2550 ) -> Result<R>
2551 where
2552 C: Context,
2553 {
2554 cx.update_window(self, update)
2555 }
2556
2557 /// Read the state of the root view of this window.
2558 ///
2559 /// This will fail if the window has been closed.
2560 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2561 where
2562 C: Context,
2563 T: 'static,
2564 {
2565 let view = self
2566 .downcast::<T>()
2567 .context("the type of the window's root view has changed")?;
2568
2569 cx.read_window(&view, read)
2570 }
2571}
2572
2573/// An identifier for an [`Element`](crate::Element).
2574///
2575/// Can be constructed with a string, a number, or both, as well
2576/// as other internal representations.
2577#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2578pub enum ElementId {
2579 /// The ID of a View element
2580 View(EntityId),
2581 /// An integer ID.
2582 Integer(usize),
2583 /// A string based ID.
2584 Name(SharedString),
2585 /// An ID that's equated with a focus handle.
2586 FocusHandle(FocusId),
2587 /// A combination of a name and an integer.
2588 NamedInteger(SharedString, usize),
2589}
2590
2591impl Display for ElementId {
2592 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2593 match self {
2594 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2595 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2596 ElementId::Name(name) => write!(f, "{}", name)?,
2597 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2598 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2599 }
2600
2601 Ok(())
2602 }
2603}
2604
2605impl ElementId {
2606 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2607 ElementId::View(entity_id)
2608 }
2609}
2610
2611impl TryInto<SharedString> for ElementId {
2612 type Error = anyhow::Error;
2613
2614 fn try_into(self) -> anyhow::Result<SharedString> {
2615 if let ElementId::Name(name) = self {
2616 Ok(name)
2617 } else {
2618 Err(anyhow!("element id is not string"))
2619 }
2620 }
2621}
2622
2623impl From<usize> for ElementId {
2624 fn from(id: usize) -> Self {
2625 ElementId::Integer(id)
2626 }
2627}
2628
2629impl From<i32> for ElementId {
2630 fn from(id: i32) -> Self {
2631 Self::Integer(id as usize)
2632 }
2633}
2634
2635impl From<SharedString> for ElementId {
2636 fn from(name: SharedString) -> Self {
2637 ElementId::Name(name)
2638 }
2639}
2640
2641impl From<&'static str> for ElementId {
2642 fn from(name: &'static str) -> Self {
2643 ElementId::Name(name.into())
2644 }
2645}
2646
2647impl<'a> From<&'a FocusHandle> for ElementId {
2648 fn from(handle: &'a FocusHandle) -> Self {
2649 ElementId::FocusHandle(handle.id)
2650 }
2651}
2652
2653impl From<(&'static str, EntityId)> for ElementId {
2654 fn from((name, id): (&'static str, EntityId)) -> Self {
2655 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2656 }
2657}
2658
2659impl From<(&'static str, usize)> for ElementId {
2660 fn from((name, id): (&'static str, usize)) -> Self {
2661 ElementId::NamedInteger(name.into(), id)
2662 }
2663}
2664
2665impl From<(&'static str, u64)> for ElementId {
2666 fn from((name, id): (&'static str, u64)) -> Self {
2667 ElementId::NamedInteger(name.into(), id as usize)
2668 }
2669}
2670
2671/// A rectangle to be rendered in the window at the given position and size.
2672/// Passed as an argument [`WindowContext::paint_quad`].
2673#[derive(Clone)]
2674pub struct PaintQuad {
2675 bounds: Bounds<Pixels>,
2676 corner_radii: Corners<Pixels>,
2677 background: Hsla,
2678 border_widths: Edges<Pixels>,
2679 border_color: Hsla,
2680}
2681
2682impl PaintQuad {
2683 /// Sets the corner radii of the quad.
2684 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2685 PaintQuad {
2686 corner_radii: corner_radii.into(),
2687 ..self
2688 }
2689 }
2690
2691 /// Sets the border widths of the quad.
2692 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2693 PaintQuad {
2694 border_widths: border_widths.into(),
2695 ..self
2696 }
2697 }
2698
2699 /// Sets the border color of the quad.
2700 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2701 PaintQuad {
2702 border_color: border_color.into(),
2703 ..self
2704 }
2705 }
2706
2707 /// Sets the background color of the quad.
2708 pub fn background(self, background: impl Into<Hsla>) -> Self {
2709 PaintQuad {
2710 background: background.into(),
2711 ..self
2712 }
2713 }
2714}
2715
2716/// Creates a quad with the given parameters.
2717pub fn quad(
2718 bounds: Bounds<Pixels>,
2719 corner_radii: impl Into<Corners<Pixels>>,
2720 background: impl Into<Hsla>,
2721 border_widths: impl Into<Edges<Pixels>>,
2722 border_color: impl Into<Hsla>,
2723) -> PaintQuad {
2724 PaintQuad {
2725 bounds,
2726 corner_radii: corner_radii.into(),
2727 background: background.into(),
2728 border_widths: border_widths.into(),
2729 border_color: border_color.into(),
2730 }
2731}
2732
2733/// Creates a filled quad with the given bounds and background color.
2734pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2735 PaintQuad {
2736 bounds: bounds.into(),
2737 corner_radii: (0.).into(),
2738 background: background.into(),
2739 border_widths: (0.).into(),
2740 border_color: transparent_black(),
2741 }
2742}
2743
2744/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2745pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2746 PaintQuad {
2747 bounds: bounds.into(),
2748 corner_radii: (0.).into(),
2749 background: transparent_black(),
2750 border_widths: (1.).into(),
2751 border_color: border_color.into(),
2752 }
2753}