1use crate::{
2 px, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext, Bounds,
3 Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId, DispatchTree, DisplayId,
4 Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten, Global, GlobalElementId,
5 Hsla, KeyBinding, KeyDownEvent, KeyMatch, KeymatchResult, Keystroke, KeystrokeEvent, Model,
6 ModelContext, Modifiers, MouseButton, MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas,
7 PlatformDisplay, PlatformInput, PlatformWindow, Point, PromptLevel, Render, ScaledPixels,
8 SharedString, Size, SubscriberSet, Subscription, TaffyLayoutEngine, Task, TextStyle,
9 TextStyleRefinement, View, VisualContext, WeakView, WindowAppearance, WindowBounds,
10 WindowOptions, WindowTextSystem,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::channel::oneshot;
16use parking_lot::RwLock;
17use refineable::Refineable;
18use slotmap::SlotMap;
19use smallvec::SmallVec;
20use std::{
21 any::{Any, TypeId},
22 borrow::{Borrow, BorrowMut},
23 cell::{Cell, RefCell},
24 fmt::{Debug, Display},
25 future::Future,
26 hash::{Hash, Hasher},
27 marker::PhantomData,
28 mem,
29 rc::Rc,
30 sync::{
31 atomic::{AtomicUsize, Ordering::SeqCst},
32 Arc,
33 },
34 time::{Duration, Instant},
35};
36use util::{measure, ResultExt};
37
38mod element_cx;
39mod prompts;
40
41pub use element_cx::*;
42pub use prompts::*;
43
44/// Represents the two different phases when dispatching events.
45#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
46pub enum DispatchPhase {
47 /// After the capture phase comes the bubble phase, in which mouse event listeners are
48 /// invoked front to back and keyboard event listeners are invoked from the focused element
49 /// to the root of the element tree. This is the phase you'll most commonly want to use when
50 /// registering event listeners.
51 #[default]
52 Bubble,
53 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
54 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
55 /// is used for special purposes such as clearing the "pressed" state for click events. If
56 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
57 /// outside of the immediate region may rely on detecting non-local events during this phase.
58 Capture,
59}
60
61impl DispatchPhase {
62 /// Returns true if this represents the "bubble" phase.
63 pub fn bubble(self) -> bool {
64 self == DispatchPhase::Bubble
65 }
66
67 /// Returns true if this represents the "capture" phase.
68 pub fn capture(self) -> bool {
69 self == DispatchPhase::Capture
70 }
71}
72
73type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
74
75type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
76
77struct FocusEvent {
78 previous_focus_path: SmallVec<[FocusId; 8]>,
79 current_focus_path: SmallVec<[FocusId; 8]>,
80}
81
82slotmap::new_key_type! {
83 /// A globally unique identifier for a focusable element.
84 pub struct FocusId;
85}
86
87thread_local! {
88 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(8 * 1024 * 1024));
89}
90
91impl FocusId {
92 /// Obtains whether the element associated with this handle is currently focused.
93 pub fn is_focused(&self, cx: &WindowContext) -> bool {
94 cx.window.focus == Some(*self)
95 }
96
97 /// Obtains whether the element associated with this handle contains the focused
98 /// element or is itself focused.
99 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
100 cx.focused()
101 .map_or(false, |focused| self.contains(focused.id, cx))
102 }
103
104 /// Obtains whether the element associated with this handle is contained within the
105 /// focused element or is itself focused.
106 pub fn within_focused(&self, cx: &WindowContext) -> bool {
107 let focused = cx.focused();
108 focused.map_or(false, |focused| focused.id.contains(*self, cx))
109 }
110
111 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
112 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
113 cx.window
114 .rendered_frame
115 .dispatch_tree
116 .focus_contains(*self, other)
117 }
118}
119
120/// A handle which can be used to track and manipulate the focused element in a window.
121pub struct FocusHandle {
122 pub(crate) id: FocusId,
123 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
124}
125
126impl std::fmt::Debug for FocusHandle {
127 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
128 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
129 }
130}
131
132impl FocusHandle {
133 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
134 let id = handles.write().insert(AtomicUsize::new(1));
135 Self {
136 id,
137 handles: handles.clone(),
138 }
139 }
140
141 pub(crate) fn for_id(
142 id: FocusId,
143 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
144 ) -> Option<Self> {
145 let lock = handles.read();
146 let ref_count = lock.get(id)?;
147 if ref_count.load(SeqCst) == 0 {
148 None
149 } else {
150 ref_count.fetch_add(1, SeqCst);
151 Some(Self {
152 id,
153 handles: handles.clone(),
154 })
155 }
156 }
157
158 /// Moves the focus to the element associated with this handle.
159 pub fn focus(&self, cx: &mut WindowContext) {
160 cx.focus(self)
161 }
162
163 /// Obtains whether the element associated with this handle is currently focused.
164 pub fn is_focused(&self, cx: &WindowContext) -> bool {
165 self.id.is_focused(cx)
166 }
167
168 /// Obtains whether the element associated with this handle contains the focused
169 /// element or is itself focused.
170 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
171 self.id.contains_focused(cx)
172 }
173
174 /// Obtains whether the element associated with this handle is contained within the
175 /// focused element or is itself focused.
176 pub fn within_focused(&self, cx: &WindowContext) -> bool {
177 self.id.within_focused(cx)
178 }
179
180 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
181 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
182 self.id.contains(other.id, cx)
183 }
184}
185
186impl Clone for FocusHandle {
187 fn clone(&self) -> Self {
188 Self::for_id(self.id, &self.handles).unwrap()
189 }
190}
191
192impl PartialEq for FocusHandle {
193 fn eq(&self, other: &Self) -> bool {
194 self.id == other.id
195 }
196}
197
198impl Eq for FocusHandle {}
199
200impl Drop for FocusHandle {
201 fn drop(&mut self) {
202 self.handles
203 .read()
204 .get(self.id)
205 .unwrap()
206 .fetch_sub(1, SeqCst);
207 }
208}
209
210/// FocusableView allows users of your view to easily
211/// focus it (using cx.focus_view(view))
212pub trait FocusableView: 'static + Render {
213 /// Returns the focus handle associated with this view.
214 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
215}
216
217/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
218/// where the lifecycle of the view is handled by another view.
219pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
220
221impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
222
223/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
224pub struct DismissEvent;
225
226type FrameCallback = Box<dyn FnOnce(&mut WindowContext)>;
227
228// Holds the state for a specific window.
229#[doc(hidden)]
230pub struct Window {
231 pub(crate) handle: AnyWindowHandle,
232 pub(crate) removed: bool,
233 pub(crate) platform_window: Box<dyn PlatformWindow>,
234 display_id: DisplayId,
235 sprite_atlas: Arc<dyn PlatformAtlas>,
236 text_system: Arc<WindowTextSystem>,
237 pub(crate) rem_size: Pixels,
238 pub(crate) viewport_size: Size<Pixels>,
239 layout_engine: Option<TaffyLayoutEngine>,
240 pub(crate) root_view: Option<AnyView>,
241 pub(crate) element_id_stack: GlobalElementId,
242 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
243 pub(crate) rendered_frame: Frame,
244 pub(crate) next_frame: Frame,
245 pub(crate) next_hitbox_id: HitboxId,
246 next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
247 pub(crate) dirty_views: FxHashSet<EntityId>,
248 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
249 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
250 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
251 default_prevented: bool,
252 mouse_position: Point<Pixels>,
253 mouse_hit_test: HitTest,
254 modifiers: Modifiers,
255 scale_factor: f32,
256 bounds: WindowBounds,
257 bounds_observers: SubscriberSet<(), AnyObserver>,
258 appearance: WindowAppearance,
259 appearance_observers: SubscriberSet<(), AnyObserver>,
260 active: Rc<Cell<bool>>,
261 pub(crate) dirty: Rc<Cell<bool>>,
262 pub(crate) needs_present: Rc<Cell<bool>>,
263 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
264 pub(crate) refreshing: bool,
265 pub(crate) draw_phase: DrawPhase,
266 activation_observers: SubscriberSet<(), AnyObserver>,
267 pub(crate) focus: Option<FocusId>,
268 focus_enabled: bool,
269 pending_input: Option<PendingInput>,
270 prompt: Option<RenderablePromptHandle>,
271}
272
273#[derive(Clone, Copy, Debug, Eq, PartialEq)]
274pub(crate) enum DrawPhase {
275 None,
276 Layout,
277 Paint,
278 Focus,
279}
280
281#[derive(Default, Debug)]
282struct PendingInput {
283 keystrokes: SmallVec<[Keystroke; 1]>,
284 bindings: SmallVec<[KeyBinding; 1]>,
285 focus: Option<FocusId>,
286 timer: Option<Task<()>>,
287}
288
289impl PendingInput {
290 fn input(&self) -> String {
291 self.keystrokes
292 .iter()
293 .flat_map(|k| k.ime_key.clone())
294 .collect::<Vec<String>>()
295 .join("")
296 }
297
298 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
299 if self.keystrokes.is_empty() {
300 return true;
301 }
302 let keystroke = &self.keystrokes[0];
303 for candidate in keystroke.match_candidates() {
304 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
305 return true;
306 }
307 }
308 false
309 }
310}
311
312pub(crate) struct ElementStateBox {
313 pub(crate) inner: Box<dyn Any>,
314 #[cfg(debug_assertions)]
315 pub(crate) type_name: &'static str,
316}
317
318impl Window {
319 pub(crate) fn new(
320 handle: AnyWindowHandle,
321 options: WindowOptions,
322 cx: &mut AppContext,
323 ) -> Self {
324 let platform_window = cx.platform.open_window(handle, options);
325 let display_id = platform_window.display().id();
326 let sprite_atlas = platform_window.sprite_atlas();
327 let mouse_position = platform_window.mouse_position();
328 let modifiers = platform_window.modifiers();
329 let content_size = platform_window.content_size();
330 let scale_factor = platform_window.scale_factor();
331 let bounds = platform_window.bounds();
332 let appearance = platform_window.appearance();
333 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
334 let dirty = Rc::new(Cell::new(true));
335 let active = Rc::new(Cell::new(false));
336 let needs_present = Rc::new(Cell::new(false));
337 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
338 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
339
340 platform_window.on_close(Box::new({
341 let mut cx = cx.to_async();
342 move || {
343 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
344 }
345 }));
346 platform_window.on_request_frame(Box::new({
347 let mut cx = cx.to_async();
348 let dirty = dirty.clone();
349 let active = active.clone();
350 let needs_present = needs_present.clone();
351 let next_frame_callbacks = next_frame_callbacks.clone();
352 let last_input_timestamp = last_input_timestamp.clone();
353 move || {
354 let next_frame_callbacks = next_frame_callbacks.take();
355 if !next_frame_callbacks.is_empty() {
356 handle
357 .update(&mut cx, |_, cx| {
358 for callback in next_frame_callbacks {
359 callback(cx);
360 }
361 })
362 .log_err();
363 }
364
365 // Keep presenting the current scene for 1 extra second since the
366 // last input to prevent the display from underclocking the refresh rate.
367 let needs_present = needs_present.get()
368 || (active.get()
369 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
370
371 if dirty.get() {
372 measure("frame duration", || {
373 handle
374 .update(&mut cx, |_, cx| {
375 cx.draw();
376 cx.present();
377 })
378 .log_err();
379 })
380 } else if needs_present {
381 handle.update(&mut cx, |_, cx| cx.present()).log_err();
382 }
383 }
384 }));
385 platform_window.on_resize(Box::new({
386 let mut cx = cx.to_async();
387 move |_, _| {
388 handle
389 .update(&mut cx, |_, cx| cx.window_bounds_changed())
390 .log_err();
391 }
392 }));
393 platform_window.on_moved(Box::new({
394 let mut cx = cx.to_async();
395 move || {
396 handle
397 .update(&mut cx, |_, cx| cx.window_bounds_changed())
398 .log_err();
399 }
400 }));
401 platform_window.on_appearance_changed(Box::new({
402 let mut cx = cx.to_async();
403 move || {
404 handle
405 .update(&mut cx, |_, cx| cx.appearance_changed())
406 .log_err();
407 }
408 }));
409 platform_window.on_active_status_change(Box::new({
410 let mut cx = cx.to_async();
411 move |active| {
412 handle
413 .update(&mut cx, |_, cx| {
414 cx.window.active.set(active);
415 cx.window
416 .activation_observers
417 .clone()
418 .retain(&(), |callback| callback(cx));
419 })
420 .log_err();
421 }
422 }));
423
424 platform_window.on_input({
425 let mut cx = cx.to_async();
426 Box::new(move |event| {
427 handle
428 .update(&mut cx, |_, cx| cx.dispatch_event(event))
429 .log_err()
430 .unwrap_or(false)
431 })
432 });
433
434 Window {
435 handle,
436 removed: false,
437 platform_window,
438 display_id,
439 sprite_atlas,
440 text_system,
441 rem_size: px(16.),
442 viewport_size: content_size,
443 layout_engine: Some(TaffyLayoutEngine::new()),
444 root_view: None,
445 element_id_stack: GlobalElementId::default(),
446 text_style_stack: Vec::new(),
447 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
448 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
449 next_frame_callbacks,
450 next_hitbox_id: HitboxId::default(),
451 dirty_views: FxHashSet::default(),
452 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
453 focus_listeners: SubscriberSet::new(),
454 focus_lost_listeners: SubscriberSet::new(),
455 default_prevented: true,
456 mouse_position,
457 mouse_hit_test: HitTest::default(),
458 modifiers,
459 scale_factor,
460 bounds,
461 bounds_observers: SubscriberSet::new(),
462 appearance,
463 appearance_observers: SubscriberSet::new(),
464 active,
465 dirty,
466 needs_present,
467 last_input_timestamp,
468 refreshing: false,
469 draw_phase: DrawPhase::None,
470 activation_observers: SubscriberSet::new(),
471 focus: None,
472 focus_enabled: true,
473 pending_input: None,
474 prompt: None,
475 }
476 }
477 fn new_focus_listener(
478 &mut self,
479 value: AnyWindowFocusListener,
480 ) -> (Subscription, impl FnOnce()) {
481 self.focus_listeners.insert((), value)
482 }
483}
484
485/// Indicates which region of the window is visible. Content falling outside of this mask will not be
486/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
487/// to leave room to support more complex shapes in the future.
488#[derive(Clone, Debug, Default, PartialEq, Eq)]
489#[repr(C)]
490pub struct ContentMask<P: Clone + Default + Debug> {
491 /// The bounds
492 pub bounds: Bounds<P>,
493}
494
495impl ContentMask<Pixels> {
496 /// Scale the content mask's pixel units by the given scaling factor.
497 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
498 ContentMask {
499 bounds: self.bounds.scale(factor),
500 }
501 }
502
503 /// Intersect the content mask with the given content mask.
504 pub fn intersect(&self, other: &Self) -> Self {
505 let bounds = self.bounds.intersect(&other.bounds);
506 ContentMask { bounds }
507 }
508}
509
510/// Provides access to application state in the context of a single window. Derefs
511/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
512/// an [`AppContext`] and call any [`AppContext`] methods.
513pub struct WindowContext<'a> {
514 pub(crate) app: &'a mut AppContext,
515 pub(crate) window: &'a mut Window,
516}
517
518impl<'a> WindowContext<'a> {
519 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
520 Self { app, window }
521 }
522
523 /// Obtain a handle to the window that belongs to this context.
524 pub fn window_handle(&self) -> AnyWindowHandle {
525 self.window.handle
526 }
527
528 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
529 pub fn refresh(&mut self) {
530 if self.window.draw_phase == DrawPhase::None {
531 self.window.refreshing = true;
532 self.window.dirty.set(true);
533 }
534 }
535
536 /// Close this window.
537 pub fn remove_window(&mut self) {
538 self.window.removed = true;
539 }
540
541 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
542 /// for elements rendered within this window.
543 pub fn focus_handle(&mut self) -> FocusHandle {
544 FocusHandle::new(&self.window.focus_handles)
545 }
546
547 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
548 pub fn focused(&self) -> Option<FocusHandle> {
549 self.window
550 .focus
551 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
552 }
553
554 /// Move focus to the element associated with the given [`FocusHandle`].
555 pub fn focus(&mut self, handle: &FocusHandle) {
556 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
557 return;
558 }
559
560 self.window.focus = Some(handle.id);
561 self.window
562 .rendered_frame
563 .dispatch_tree
564 .clear_pending_keystrokes();
565 self.refresh();
566 }
567
568 /// Remove focus from all elements within this context's window.
569 pub fn blur(&mut self) {
570 if !self.window.focus_enabled {
571 return;
572 }
573
574 self.window.focus = None;
575 self.refresh();
576 }
577
578 /// Blur the window and don't allow anything in it to be focused again.
579 pub fn disable_focus(&mut self) {
580 self.blur();
581 self.window.focus_enabled = false;
582 }
583
584 /// Accessor for the text system.
585 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
586 &self.window.text_system
587 }
588
589 /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
590 pub fn text_style(&self) -> TextStyle {
591 let mut style = TextStyle::default();
592 for refinement in &self.window.text_style_stack {
593 style.refine(refinement);
594 }
595 style
596 }
597
598 /// Dispatch the given action on the currently focused element.
599 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
600 let focus_handle = self.focused();
601
602 let window = self.window.handle;
603 self.app.defer(move |cx| {
604 cx.propagate_event = true;
605 window
606 .update(cx, |_, cx| {
607 let node_id = focus_handle
608 .and_then(|handle| {
609 cx.window
610 .rendered_frame
611 .dispatch_tree
612 .focusable_node_id(handle.id)
613 })
614 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
615
616 cx.dispatch_action_on_node(node_id, action.as_ref());
617 })
618 .log_err();
619 if cx.propagate_event {
620 cx.dispatch_global_action(action.as_ref());
621 }
622 })
623 }
624
625 pub(crate) fn dispatch_keystroke_observers(
626 &mut self,
627 event: &dyn Any,
628 action: Option<Box<dyn Action>>,
629 ) {
630 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
631 return;
632 };
633
634 self.keystroke_observers
635 .clone()
636 .retain(&(), move |callback| {
637 (callback)(
638 &KeystrokeEvent {
639 keystroke: key_down_event.keystroke.clone(),
640 action: action.as_ref().map(|action| action.boxed_clone()),
641 },
642 self,
643 );
644 true
645 });
646 }
647
648 pub(crate) fn clear_pending_keystrokes(&mut self) {
649 self.window
650 .rendered_frame
651 .dispatch_tree
652 .clear_pending_keystrokes();
653 self.window
654 .next_frame
655 .dispatch_tree
656 .clear_pending_keystrokes();
657 }
658
659 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
660 /// that are currently on the stack to be returned to the app.
661 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
662 let handle = self.window.handle;
663 self.app.defer(move |cx| {
664 handle.update(cx, |_, cx| f(cx)).ok();
665 });
666 }
667
668 /// Subscribe to events emitted by a model or view.
669 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
670 /// 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.
671 pub fn subscribe<Emitter, E, Evt>(
672 &mut self,
673 entity: &E,
674 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
675 ) -> Subscription
676 where
677 Emitter: EventEmitter<Evt>,
678 E: Entity<Emitter>,
679 Evt: 'static,
680 {
681 let entity_id = entity.entity_id();
682 let entity = entity.downgrade();
683 let window_handle = self.window.handle;
684 self.app.new_subscription(
685 entity_id,
686 (
687 TypeId::of::<Evt>(),
688 Box::new(move |event, cx| {
689 window_handle
690 .update(cx, |_, cx| {
691 if let Some(handle) = E::upgrade_from(&entity) {
692 let event = event.downcast_ref().expect("invalid event type");
693 on_event(handle, event, cx);
694 true
695 } else {
696 false
697 }
698 })
699 .unwrap_or(false)
700 }),
701 ),
702 )
703 }
704
705 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
706 /// await points in async code.
707 pub fn to_async(&self) -> AsyncWindowContext {
708 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
709 }
710
711 /// Schedule the given closure to be run directly after the current frame is rendered.
712 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
713 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
714 }
715
716 /// Spawn the future returned by the given closure on the application thread pool.
717 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
718 /// use within your future.
719 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
720 where
721 R: 'static,
722 Fut: Future<Output = R> + 'static,
723 {
724 self.app
725 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
726 }
727
728 /// Updates the global of the given type. The given closure is given simultaneous mutable
729 /// access both to the global and the context.
730 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
731 where
732 G: Global,
733 {
734 let mut global = self.app.lease_global::<G>();
735 let result = f(&mut global, self);
736 self.app.end_global_lease(global);
737 result
738 }
739
740 fn window_bounds_changed(&mut self) {
741 self.window.scale_factor = self.window.platform_window.scale_factor();
742 self.window.viewport_size = self.window.platform_window.content_size();
743 self.window.bounds = self.window.platform_window.bounds();
744 self.window.display_id = self.window.platform_window.display().id();
745 self.refresh();
746
747 self.window
748 .bounds_observers
749 .clone()
750 .retain(&(), |callback| callback(self));
751 }
752
753 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
754 pub fn window_bounds(&self) -> WindowBounds {
755 self.window.bounds
756 }
757
758 fn appearance_changed(&mut self) {
759 self.window.appearance = self.window.platform_window.appearance();
760
761 self.window
762 .appearance_observers
763 .clone()
764 .retain(&(), |callback| callback(self));
765 }
766
767 /// Returns the appearance of the current window.
768 pub fn appearance(&self) -> WindowAppearance {
769 self.window.appearance
770 }
771
772 /// Returns the size of the drawable area within the window.
773 pub fn viewport_size(&self) -> Size<Pixels> {
774 self.window.viewport_size
775 }
776
777 /// Returns whether this window is focused by the operating system (receiving key events).
778 pub fn is_window_active(&self) -> bool {
779 self.window.active.get()
780 }
781
782 /// Toggle zoom on the window.
783 pub fn zoom_window(&self) {
784 self.window.platform_window.zoom();
785 }
786
787 /// Updates the window's title at the platform level.
788 pub fn set_window_title(&mut self, title: &str) {
789 self.window.platform_window.set_title(title);
790 }
791
792 /// Mark the window as dirty at the platform level.
793 pub fn set_window_edited(&mut self, edited: bool) {
794 self.window.platform_window.set_edited(edited);
795 }
796
797 /// Determine the display on which the window is visible.
798 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
799 self.platform
800 .displays()
801 .into_iter()
802 .find(|display| display.id() == self.window.display_id)
803 }
804
805 /// Show the platform character palette.
806 pub fn show_character_palette(&self) {
807 self.window.platform_window.show_character_palette();
808 }
809
810 /// The scale factor of the display associated with the window. For example, it could
811 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
812 /// be rendered as two pixels on screen.
813 pub fn scale_factor(&self) -> f32 {
814 self.window.scale_factor
815 }
816
817 /// The size of an em for the base font of the application. Adjusting this value allows the
818 /// UI to scale, just like zooming a web page.
819 pub fn rem_size(&self) -> Pixels {
820 self.window.rem_size
821 }
822
823 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
824 /// UI to scale, just like zooming a web page.
825 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
826 self.window.rem_size = rem_size.into();
827 }
828
829 /// The line height associated with the current text style.
830 pub fn line_height(&self) -> Pixels {
831 let rem_size = self.rem_size();
832 let text_style = self.text_style();
833 text_style
834 .line_height
835 .to_pixels(text_style.font_size, rem_size)
836 }
837
838 /// Call to prevent the default action of an event. Currently only used to prevent
839 /// parent elements from becoming focused on mouse down.
840 pub fn prevent_default(&mut self) {
841 self.window.default_prevented = true;
842 }
843
844 /// Obtain whether default has been prevented for the event currently being dispatched.
845 pub fn default_prevented(&self) -> bool {
846 self.window.default_prevented
847 }
848
849 /// Determine whether the given action is available along the dispatch path to the currently focused element.
850 pub fn is_action_available(&self, action: &dyn Action) -> bool {
851 let target = self
852 .focused()
853 .and_then(|focused_handle| {
854 self.window
855 .rendered_frame
856 .dispatch_tree
857 .focusable_node_id(focused_handle.id)
858 })
859 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
860 self.window
861 .rendered_frame
862 .dispatch_tree
863 .is_action_available(action, target)
864 }
865
866 /// The position of the mouse relative to the window.
867 pub fn mouse_position(&self) -> Point<Pixels> {
868 self.window.mouse_position
869 }
870
871 /// The current state of the keyboard's modifiers
872 pub fn modifiers(&self) -> Modifiers {
873 self.window.modifiers
874 }
875
876 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
877 /// the contents of the new [Scene], use [present].
878 #[profiling::function]
879 pub fn draw(&mut self) {
880 self.window.dirty.set(false);
881
882 // Restore the previously-used input handler.
883 if let Some(input_handler) = self.window.platform_window.take_input_handler() {
884 self.window
885 .rendered_frame
886 .input_handlers
887 .push(Some(input_handler));
888 }
889
890 self.with_element_context(|cx| cx.draw_roots());
891 self.window.dirty_views.clear();
892
893 self.window
894 .next_frame
895 .dispatch_tree
896 .preserve_pending_keystrokes(
897 &mut self.window.rendered_frame.dispatch_tree,
898 self.window.focus,
899 );
900 self.window.next_frame.focus = self.window.focus;
901 self.window.next_frame.window_active = self.window.active.get();
902
903 // Set the cursor only if we're the active window.
904 if self.is_window_active() {
905 let cursor_style = self.compute_cursor_style().unwrap_or(CursorStyle::Arrow);
906 self.platform.set_cursor_style(cursor_style);
907 }
908
909 // Register requested input handler with the platform window.
910 if let Some(input_handler) = self.window.next_frame.input_handlers.pop() {
911 self.window
912 .platform_window
913 .set_input_handler(input_handler.unwrap());
914 }
915
916 self.window.layout_engine.as_mut().unwrap().clear();
917 self.text_system().finish_frame();
918 self.window
919 .next_frame
920 .finish(&mut self.window.rendered_frame);
921 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
922 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
923 if percentage >= 80. {
924 log::warn!("elevated element arena occupation: {}.", percentage);
925 }
926 element_arena.clear();
927 });
928
929 self.window.draw_phase = DrawPhase::Focus;
930 let previous_focus_path = self.window.rendered_frame.focus_path();
931 let previous_window_active = self.window.rendered_frame.window_active;
932 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
933 self.window.next_frame.clear();
934 let current_focus_path = self.window.rendered_frame.focus_path();
935 let current_window_active = self.window.rendered_frame.window_active;
936
937 if previous_focus_path != current_focus_path
938 || previous_window_active != current_window_active
939 {
940 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
941 self.window
942 .focus_lost_listeners
943 .clone()
944 .retain(&(), |listener| listener(self));
945 }
946
947 let event = FocusEvent {
948 previous_focus_path: if previous_window_active {
949 previous_focus_path
950 } else {
951 Default::default()
952 },
953 current_focus_path: if current_window_active {
954 current_focus_path
955 } else {
956 Default::default()
957 },
958 };
959 self.window
960 .focus_listeners
961 .clone()
962 .retain(&(), |listener| listener(&event, self));
963 }
964 self.window.refreshing = false;
965 self.window.draw_phase = DrawPhase::None;
966 self.window.needs_present.set(true);
967 }
968
969 #[profiling::function]
970 fn present(&self) {
971 self.window
972 .platform_window
973 .draw(&self.window.rendered_frame.scene);
974 self.window.needs_present.set(false);
975 profiling::finish_frame!();
976 }
977
978 fn compute_cursor_style(&mut self) -> Option<CursorStyle> {
979 // TODO: maybe we should have a HashMap keyed by HitboxId.
980 let request = self
981 .window
982 .next_frame
983 .cursor_styles
984 .iter()
985 .rev()
986 .find(|request| request.hitbox_id.is_hovered(self))?;
987 Some(request.style)
988 }
989
990 /// Dispatch a given keystroke as though the user had typed it.
991 /// You can create a keystroke with Keystroke::parse("").
992 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
993 let keystroke = keystroke.with_simulated_ime();
994 if self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
995 keystroke: keystroke.clone(),
996 is_held: false,
997 })) {
998 return true;
999 }
1000
1001 if let Some(input) = keystroke.ime_key {
1002 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1003 input_handler.dispatch_input(&input, self);
1004 self.window.platform_window.set_input_handler(input_handler);
1005 return true;
1006 }
1007 }
1008
1009 false
1010 }
1011
1012 /// Represent this action as a key binding string, to display in the UI.
1013 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
1014 self.bindings_for_action(action)
1015 .into_iter()
1016 .next()
1017 .map(|binding| {
1018 binding
1019 .keystrokes()
1020 .iter()
1021 .map(ToString::to_string)
1022 .collect::<Vec<_>>()
1023 .join(" ")
1024 })
1025 .unwrap_or_else(|| action.name().to_string())
1026 }
1027
1028 /// Dispatch a mouse or keyboard event on the window.
1029 #[profiling::function]
1030 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1031 self.window.last_input_timestamp.set(Instant::now());
1032 // Handlers may set this to false by calling `stop_propagation`.
1033 self.app.propagate_event = true;
1034 // Handlers may set this to true by calling `prevent_default`.
1035 self.window.default_prevented = false;
1036
1037 let event = match event {
1038 // Track the mouse position with our own state, since accessing the platform
1039 // API for the mouse position can only occur on the main thread.
1040 PlatformInput::MouseMove(mouse_move) => {
1041 self.window.mouse_position = mouse_move.position;
1042 self.window.modifiers = mouse_move.modifiers;
1043 PlatformInput::MouseMove(mouse_move)
1044 }
1045 PlatformInput::MouseDown(mouse_down) => {
1046 self.window.mouse_position = mouse_down.position;
1047 self.window.modifiers = mouse_down.modifiers;
1048 PlatformInput::MouseDown(mouse_down)
1049 }
1050 PlatformInput::MouseUp(mouse_up) => {
1051 self.window.mouse_position = mouse_up.position;
1052 self.window.modifiers = mouse_up.modifiers;
1053 PlatformInput::MouseUp(mouse_up)
1054 }
1055 PlatformInput::MouseExited(mouse_exited) => {
1056 self.window.modifiers = mouse_exited.modifiers;
1057 PlatformInput::MouseExited(mouse_exited)
1058 }
1059 PlatformInput::ModifiersChanged(modifiers_changed) => {
1060 self.window.modifiers = modifiers_changed.modifiers;
1061 PlatformInput::ModifiersChanged(modifiers_changed)
1062 }
1063 PlatformInput::ScrollWheel(scroll_wheel) => {
1064 self.window.mouse_position = scroll_wheel.position;
1065 self.window.modifiers = scroll_wheel.modifiers;
1066 PlatformInput::ScrollWheel(scroll_wheel)
1067 }
1068 // Translate dragging and dropping of external files from the operating system
1069 // to internal drag and drop events.
1070 PlatformInput::FileDrop(file_drop) => match file_drop {
1071 FileDropEvent::Entered { position, paths } => {
1072 self.window.mouse_position = position;
1073 if self.active_drag.is_none() {
1074 self.active_drag = Some(AnyDrag {
1075 value: Box::new(paths.clone()),
1076 view: self.new_view(|_| paths).into(),
1077 cursor_offset: position,
1078 });
1079 }
1080 PlatformInput::MouseMove(MouseMoveEvent {
1081 position,
1082 pressed_button: Some(MouseButton::Left),
1083 modifiers: Modifiers::default(),
1084 })
1085 }
1086 FileDropEvent::Pending { position } => {
1087 self.window.mouse_position = position;
1088 PlatformInput::MouseMove(MouseMoveEvent {
1089 position,
1090 pressed_button: Some(MouseButton::Left),
1091 modifiers: Modifiers::default(),
1092 })
1093 }
1094 FileDropEvent::Submit { position } => {
1095 self.activate(true);
1096 self.window.mouse_position = position;
1097 PlatformInput::MouseUp(MouseUpEvent {
1098 button: MouseButton::Left,
1099 position,
1100 modifiers: Modifiers::default(),
1101 click_count: 1,
1102 })
1103 }
1104 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1105 button: MouseButton::Left,
1106 position: Point::default(),
1107 modifiers: Modifiers::default(),
1108 click_count: 1,
1109 }),
1110 },
1111 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1112 };
1113
1114 if let Some(any_mouse_event) = event.mouse_event() {
1115 self.dispatch_mouse_event(any_mouse_event);
1116 } else if let Some(any_key_event) = event.keyboard_event() {
1117 self.dispatch_key_event(any_key_event);
1118 }
1119
1120 !self.app.propagate_event
1121 }
1122
1123 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1124 self.window.mouse_hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
1125
1126 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
1127 self.with_element_context(|cx| {
1128 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1129 // special purposes, such as detecting events outside of a given Bounds.
1130 for listener in &mut mouse_listeners {
1131 let listener = listener.as_mut().unwrap();
1132 listener(event, DispatchPhase::Capture, cx);
1133 if !cx.app.propagate_event {
1134 break;
1135 }
1136 }
1137
1138 // Bubble phase, where most normal handlers do their work.
1139 if cx.app.propagate_event {
1140 for listener in mouse_listeners.iter_mut().rev() {
1141 let listener = listener.as_mut().unwrap();
1142 listener(event, DispatchPhase::Bubble, cx);
1143 if !cx.app.propagate_event {
1144 break;
1145 }
1146 }
1147 }
1148 });
1149 self.window.rendered_frame.mouse_listeners = mouse_listeners;
1150
1151 if self.app.propagate_event && self.has_active_drag() {
1152 if event.is::<MouseMoveEvent>() {
1153 // If this was a mouse move event, redraw the window so that the
1154 // active drag can follow the mouse cursor.
1155 self.refresh();
1156 } else if event.is::<MouseUpEvent>() {
1157 // If this was a mouse up event, cancel the active drag and redraw
1158 // the window.
1159 self.active_drag = None;
1160 self.refresh();
1161 }
1162 }
1163 }
1164
1165 fn dispatch_key_event(&mut self, event: &dyn Any) {
1166 if self.window.dirty.get() {
1167 self.draw();
1168 }
1169
1170 let node_id = self
1171 .window
1172 .focus
1173 .and_then(|focus_id| {
1174 self.window
1175 .rendered_frame
1176 .dispatch_tree
1177 .focusable_node_id(focus_id)
1178 })
1179 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1180
1181 let dispatch_path = self
1182 .window
1183 .rendered_frame
1184 .dispatch_tree
1185 .dispatch_path(node_id);
1186
1187 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1188 let KeymatchResult { bindings, pending } = self
1189 .window
1190 .rendered_frame
1191 .dispatch_tree
1192 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1193
1194 if pending {
1195 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1196 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1197 {
1198 currently_pending = PendingInput::default();
1199 }
1200 currently_pending.focus = self.window.focus;
1201 currently_pending
1202 .keystrokes
1203 .push(key_down_event.keystroke.clone());
1204 for binding in bindings {
1205 currently_pending.bindings.push(binding);
1206 }
1207
1208 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1209 cx.background_executor.timer(Duration::from_secs(1)).await;
1210 cx.update(move |cx| {
1211 cx.clear_pending_keystrokes();
1212 let Some(currently_pending) = cx.window.pending_input.take() else {
1213 return;
1214 };
1215 cx.replay_pending_input(currently_pending)
1216 })
1217 .log_err();
1218 }));
1219
1220 self.window.pending_input = Some(currently_pending);
1221
1222 self.propagate_event = false;
1223 return;
1224 } else if let Some(currently_pending) = self.window.pending_input.take() {
1225 if bindings
1226 .iter()
1227 .all(|binding| !currently_pending.used_by_binding(binding))
1228 {
1229 self.replay_pending_input(currently_pending)
1230 }
1231 }
1232
1233 if !bindings.is_empty() {
1234 self.clear_pending_keystrokes();
1235 }
1236
1237 self.propagate_event = true;
1238 for binding in bindings {
1239 self.dispatch_action_on_node(node_id, binding.action.as_ref());
1240 if !self.propagate_event {
1241 self.dispatch_keystroke_observers(event, Some(binding.action));
1242 return;
1243 }
1244 }
1245 }
1246
1247 self.dispatch_key_down_up_event(event, &dispatch_path);
1248 if !self.propagate_event {
1249 return;
1250 }
1251
1252 self.dispatch_keystroke_observers(event, None);
1253 }
1254
1255 fn dispatch_key_down_up_event(
1256 &mut self,
1257 event: &dyn Any,
1258 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1259 ) {
1260 // Capture phase
1261 for node_id in dispatch_path {
1262 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1263
1264 for key_listener in node.key_listeners.clone() {
1265 self.with_element_context(|cx| {
1266 key_listener(event, DispatchPhase::Capture, cx);
1267 });
1268 if !self.propagate_event {
1269 return;
1270 }
1271 }
1272 }
1273
1274 // Bubble phase
1275 for node_id in dispatch_path.iter().rev() {
1276 // Handle low level key events
1277 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1278 for key_listener in node.key_listeners.clone() {
1279 self.with_element_context(|cx| {
1280 key_listener(event, DispatchPhase::Bubble, cx);
1281 });
1282 if !self.propagate_event {
1283 return;
1284 }
1285 }
1286 }
1287 }
1288
1289 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1290 pub fn has_pending_keystrokes(&self) -> bool {
1291 self.window
1292 .rendered_frame
1293 .dispatch_tree
1294 .has_pending_keystrokes()
1295 }
1296
1297 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1298 let node_id = self
1299 .window
1300 .focus
1301 .and_then(|focus_id| {
1302 self.window
1303 .rendered_frame
1304 .dispatch_tree
1305 .focusable_node_id(focus_id)
1306 })
1307 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1308
1309 if self.window.focus != currently_pending.focus {
1310 return;
1311 }
1312
1313 let input = currently_pending.input();
1314
1315 self.propagate_event = true;
1316 for binding in currently_pending.bindings {
1317 self.dispatch_action_on_node(node_id, binding.action.as_ref());
1318 if !self.propagate_event {
1319 return;
1320 }
1321 }
1322
1323 let dispatch_path = self
1324 .window
1325 .rendered_frame
1326 .dispatch_tree
1327 .dispatch_path(node_id);
1328
1329 for keystroke in currently_pending.keystrokes {
1330 let event = KeyDownEvent {
1331 keystroke,
1332 is_held: false,
1333 };
1334
1335 self.dispatch_key_down_up_event(&event, &dispatch_path);
1336 if !self.propagate_event {
1337 return;
1338 }
1339 }
1340
1341 if !input.is_empty() {
1342 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1343 input_handler.dispatch_input(&input, self);
1344 self.window.platform_window.set_input_handler(input_handler)
1345 }
1346 }
1347 }
1348
1349 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
1350 let dispatch_path = self
1351 .window
1352 .rendered_frame
1353 .dispatch_tree
1354 .dispatch_path(node_id);
1355
1356 // Capture phase
1357 for node_id in &dispatch_path {
1358 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1359 for DispatchActionListener {
1360 action_type,
1361 listener,
1362 } in node.action_listeners.clone()
1363 {
1364 let any_action = action.as_any();
1365 if action_type == any_action.type_id() {
1366 self.with_element_context(|cx| {
1367 listener(any_action, DispatchPhase::Capture, cx);
1368 });
1369
1370 if !self.propagate_event {
1371 return;
1372 }
1373 }
1374 }
1375 }
1376 // Bubble phase
1377 for node_id in dispatch_path.iter().rev() {
1378 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1379 for DispatchActionListener {
1380 action_type,
1381 listener,
1382 } in node.action_listeners.clone()
1383 {
1384 let any_action = action.as_any();
1385 if action_type == any_action.type_id() {
1386 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1387
1388 self.with_element_context(|cx| {
1389 listener(any_action, DispatchPhase::Bubble, cx);
1390 });
1391
1392 if !self.propagate_event {
1393 return;
1394 }
1395 }
1396 }
1397 }
1398 }
1399
1400 /// Register the given handler to be invoked whenever the global of the given type
1401 /// is updated.
1402 pub fn observe_global<G: Global>(
1403 &mut self,
1404 f: impl Fn(&mut WindowContext<'_>) + 'static,
1405 ) -> Subscription {
1406 let window_handle = self.window.handle;
1407 let (subscription, activate) = self.global_observers.insert(
1408 TypeId::of::<G>(),
1409 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1410 );
1411 self.app.defer(move |_| activate());
1412 subscription
1413 }
1414
1415 /// Focus the current window and bring it to the foreground at the platform level.
1416 pub fn activate_window(&self) {
1417 self.window.platform_window.activate();
1418 }
1419
1420 /// Minimize the current window at the platform level.
1421 pub fn minimize_window(&self) {
1422 self.window.platform_window.minimize();
1423 }
1424
1425 /// Toggle full screen status on the current window at the platform level.
1426 pub fn toggle_full_screen(&self) {
1427 self.window.platform_window.toggle_full_screen();
1428 }
1429
1430 /// Present a platform dialog.
1431 /// The provided message will be presented, along with buttons for each answer.
1432 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1433 pub fn prompt(
1434 &mut self,
1435 level: PromptLevel,
1436 message: &str,
1437 detail: Option<&str>,
1438 answers: &[&str],
1439 ) -> oneshot::Receiver<usize> {
1440 let prompt_builder = self.app.prompt_builder.take();
1441 let Some(prompt_builder) = prompt_builder else {
1442 unreachable!("Re-entrant window prompting is not supported by GPUI");
1443 };
1444
1445 let receiver = match &prompt_builder {
1446 PromptBuilder::Default => self
1447 .window
1448 .platform_window
1449 .prompt(level, message, detail, answers)
1450 .unwrap_or_else(|| {
1451 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
1452 }),
1453 PromptBuilder::Custom(_) => {
1454 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
1455 }
1456 };
1457
1458 self.app.prompt_builder = Some(prompt_builder);
1459
1460 receiver
1461 }
1462
1463 fn build_custom_prompt(
1464 &mut self,
1465 prompt_builder: &PromptBuilder,
1466 level: PromptLevel,
1467 message: &str,
1468 detail: Option<&str>,
1469 answers: &[&str],
1470 ) -> oneshot::Receiver<usize> {
1471 let (sender, receiver) = oneshot::channel();
1472 let handle = PromptHandle::new(sender);
1473 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
1474 self.window.prompt = Some(handle);
1475 receiver
1476 }
1477
1478 /// Returns all available actions for the focused element.
1479 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1480 let node_id = self
1481 .window
1482 .focus
1483 .and_then(|focus_id| {
1484 self.window
1485 .rendered_frame
1486 .dispatch_tree
1487 .focusable_node_id(focus_id)
1488 })
1489 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1490
1491 let mut actions = self
1492 .window
1493 .rendered_frame
1494 .dispatch_tree
1495 .available_actions(node_id);
1496 for action_type in self.global_action_listeners.keys() {
1497 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
1498 let action = self.actions.build_action_type(action_type).ok();
1499 if let Some(action) = action {
1500 actions.insert(ix, action);
1501 }
1502 }
1503 }
1504 actions
1505 }
1506
1507 /// Returns key bindings that invoke the given action on the currently focused element.
1508 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1509 self.window
1510 .rendered_frame
1511 .dispatch_tree
1512 .bindings_for_action(
1513 action,
1514 &self.window.rendered_frame.dispatch_tree.context_stack,
1515 )
1516 }
1517
1518 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1519 pub fn bindings_for_action_in(
1520 &self,
1521 action: &dyn Action,
1522 focus_handle: &FocusHandle,
1523 ) -> Vec<KeyBinding> {
1524 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1525
1526 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1527 return vec![];
1528 };
1529 let context_stack: Vec<_> = dispatch_tree
1530 .dispatch_path(node_id)
1531 .into_iter()
1532 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1533 .collect();
1534 dispatch_tree.bindings_for_action(action, &context_stack)
1535 }
1536
1537 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1538 pub fn listener_for<V: Render, E>(
1539 &self,
1540 view: &View<V>,
1541 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1542 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1543 let view = view.downgrade();
1544 move |e: &E, cx: &mut WindowContext| {
1545 view.update(cx, |view, cx| f(view, e, cx)).ok();
1546 }
1547 }
1548
1549 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1550 pub fn handler_for<V: Render>(
1551 &self,
1552 view: &View<V>,
1553 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1554 ) -> impl Fn(&mut WindowContext) {
1555 let view = view.downgrade();
1556 move |cx: &mut WindowContext| {
1557 view.update(cx, |view, cx| f(view, cx)).ok();
1558 }
1559 }
1560
1561 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1562 /// If the callback returns false, the window won't be closed.
1563 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1564 let mut this = self.to_async();
1565 self.window
1566 .platform_window
1567 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
1568 }
1569
1570 /// Register an action listener on the window for the next frame. The type of action
1571 /// is determined by the first parameter of the given listener. When the next frame is rendered
1572 /// the listener will be cleared.
1573 ///
1574 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1575 /// a specific need to register a global listener.
1576 pub fn on_action(
1577 &mut self,
1578 action_type: TypeId,
1579 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1580 ) {
1581 self.window
1582 .next_frame
1583 .dispatch_tree
1584 .on_action(action_type, Rc::new(listener));
1585 }
1586}
1587
1588impl Context for WindowContext<'_> {
1589 type Result<T> = T;
1590
1591 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1592 where
1593 T: 'static,
1594 {
1595 let slot = self.app.entities.reserve();
1596 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1597 self.entities.insert(slot, model)
1598 }
1599
1600 fn update_model<T: 'static, R>(
1601 &mut self,
1602 model: &Model<T>,
1603 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1604 ) -> R {
1605 let mut entity = self.entities.lease(model);
1606 let result = update(
1607 &mut *entity,
1608 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1609 );
1610 self.entities.end_lease(entity);
1611 result
1612 }
1613
1614 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1615 where
1616 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1617 {
1618 if window == self.window.handle {
1619 let root_view = self.window.root_view.clone().unwrap();
1620 Ok(update(root_view, self))
1621 } else {
1622 window.update(self.app, update)
1623 }
1624 }
1625
1626 fn read_model<T, R>(
1627 &self,
1628 handle: &Model<T>,
1629 read: impl FnOnce(&T, &AppContext) -> R,
1630 ) -> Self::Result<R>
1631 where
1632 T: 'static,
1633 {
1634 let entity = self.entities.read(handle);
1635 read(entity, &*self.app)
1636 }
1637
1638 fn read_window<T, R>(
1639 &self,
1640 window: &WindowHandle<T>,
1641 read: impl FnOnce(View<T>, &AppContext) -> R,
1642 ) -> Result<R>
1643 where
1644 T: 'static,
1645 {
1646 if window.any_handle == self.window.handle {
1647 let root_view = self
1648 .window
1649 .root_view
1650 .clone()
1651 .unwrap()
1652 .downcast::<T>()
1653 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1654 Ok(read(root_view, self))
1655 } else {
1656 self.app.read_window(window, read)
1657 }
1658 }
1659}
1660
1661impl VisualContext for WindowContext<'_> {
1662 fn new_view<V>(
1663 &mut self,
1664 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1665 ) -> Self::Result<View<V>>
1666 where
1667 V: 'static + Render,
1668 {
1669 let slot = self.app.entities.reserve();
1670 let view = View {
1671 model: slot.clone(),
1672 };
1673 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1674 let entity = build_view_state(&mut cx);
1675 cx.entities.insert(slot, entity);
1676
1677 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1678 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1679 cx.new_view_observers.clone().retain(&tid, |observer| {
1680 let any_view = view.clone();
1681 (observer)(any_view, cx);
1682 true
1683 });
1684 }
1685 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1686
1687 view
1688 }
1689
1690 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1691 fn update_view<T: 'static, R>(
1692 &mut self,
1693 view: &View<T>,
1694 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1695 ) -> Self::Result<R> {
1696 let mut lease = self.app.entities.lease(&view.model);
1697 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1698 let result = update(&mut *lease, &mut cx);
1699 cx.app.entities.end_lease(lease);
1700 result
1701 }
1702
1703 fn replace_root_view<V>(
1704 &mut self,
1705 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1706 ) -> Self::Result<View<V>>
1707 where
1708 V: 'static + Render,
1709 {
1710 let view = self.new_view(build_view);
1711 self.window.root_view = Some(view.clone().into());
1712 self.refresh();
1713 view
1714 }
1715
1716 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1717 self.update_view(view, |view, cx| {
1718 view.focus_handle(cx).clone().focus(cx);
1719 })
1720 }
1721
1722 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1723 where
1724 V: ManagedView,
1725 {
1726 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1727 }
1728}
1729
1730impl<'a> std::ops::Deref for WindowContext<'a> {
1731 type Target = AppContext;
1732
1733 fn deref(&self) -> &Self::Target {
1734 self.app
1735 }
1736}
1737
1738impl<'a> std::ops::DerefMut for WindowContext<'a> {
1739 fn deref_mut(&mut self) -> &mut Self::Target {
1740 self.app
1741 }
1742}
1743
1744impl<'a> Borrow<AppContext> for WindowContext<'a> {
1745 fn borrow(&self) -> &AppContext {
1746 self.app
1747 }
1748}
1749
1750impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1751 fn borrow_mut(&mut self) -> &mut AppContext {
1752 self.app
1753 }
1754}
1755
1756/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1757pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1758 #[doc(hidden)]
1759 fn app_mut(&mut self) -> &mut AppContext {
1760 self.borrow_mut()
1761 }
1762
1763 #[doc(hidden)]
1764 fn app(&self) -> &AppContext {
1765 self.borrow()
1766 }
1767
1768 #[doc(hidden)]
1769 fn window(&self) -> &Window {
1770 self.borrow()
1771 }
1772
1773 #[doc(hidden)]
1774 fn window_mut(&mut self) -> &mut Window {
1775 self.borrow_mut()
1776 }
1777}
1778
1779impl Borrow<Window> for WindowContext<'_> {
1780 fn borrow(&self) -> &Window {
1781 self.window
1782 }
1783}
1784
1785impl BorrowMut<Window> for WindowContext<'_> {
1786 fn borrow_mut(&mut self) -> &mut Window {
1787 self.window
1788 }
1789}
1790
1791impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1792
1793/// Provides access to application state that is specialized for a particular [`View`].
1794/// Allows you to interact with focus, emit events, etc.
1795/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1796/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1797pub struct ViewContext<'a, V> {
1798 window_cx: WindowContext<'a>,
1799 view: &'a View<V>,
1800}
1801
1802impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1803 fn borrow(&self) -> &AppContext {
1804 &*self.window_cx.app
1805 }
1806}
1807
1808impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1809 fn borrow_mut(&mut self) -> &mut AppContext {
1810 &mut *self.window_cx.app
1811 }
1812}
1813
1814impl<V> Borrow<Window> for ViewContext<'_, V> {
1815 fn borrow(&self) -> &Window {
1816 &*self.window_cx.window
1817 }
1818}
1819
1820impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1821 fn borrow_mut(&mut self) -> &mut Window {
1822 &mut *self.window_cx.window
1823 }
1824}
1825
1826impl<'a, V: 'static> ViewContext<'a, V> {
1827 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1828 Self {
1829 window_cx: WindowContext::new(app, window),
1830 view,
1831 }
1832 }
1833
1834 /// Get the entity_id of this view.
1835 pub fn entity_id(&self) -> EntityId {
1836 self.view.entity_id()
1837 }
1838
1839 /// Get the view pointer underlying this context.
1840 pub fn view(&self) -> &View<V> {
1841 self.view
1842 }
1843
1844 /// Get the model underlying this view.
1845 pub fn model(&self) -> &Model<V> {
1846 &self.view.model
1847 }
1848
1849 /// Access the underlying window context.
1850 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1851 &mut self.window_cx
1852 }
1853
1854 /// Sets a given callback to be run on the next frame.
1855 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1856 where
1857 V: 'static,
1858 {
1859 let view = self.view().clone();
1860 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1861 }
1862
1863 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1864 /// that are currently on the stack to be returned to the app.
1865 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1866 let view = self.view().downgrade();
1867 self.window_cx.defer(move |cx| {
1868 view.update(cx, f).ok();
1869 });
1870 }
1871
1872 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1873 pub fn observe<V2, E>(
1874 &mut self,
1875 entity: &E,
1876 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1877 ) -> Subscription
1878 where
1879 V2: 'static,
1880 V: 'static,
1881 E: Entity<V2>,
1882 {
1883 let view = self.view().downgrade();
1884 let entity_id = entity.entity_id();
1885 let entity = entity.downgrade();
1886 let window_handle = self.window.handle;
1887 self.app.new_observer(
1888 entity_id,
1889 Box::new(move |cx| {
1890 window_handle
1891 .update(cx, |_, cx| {
1892 if let Some(handle) = E::upgrade_from(&entity) {
1893 view.update(cx, |this, cx| on_notify(this, handle, cx))
1894 .is_ok()
1895 } else {
1896 false
1897 }
1898 })
1899 .unwrap_or(false)
1900 }),
1901 )
1902 }
1903
1904 /// Subscribe to events emitted by another model or view.
1905 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1906 /// 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.
1907 pub fn subscribe<V2, E, Evt>(
1908 &mut self,
1909 entity: &E,
1910 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1911 ) -> Subscription
1912 where
1913 V2: EventEmitter<Evt>,
1914 E: Entity<V2>,
1915 Evt: 'static,
1916 {
1917 let view = self.view().downgrade();
1918 let entity_id = entity.entity_id();
1919 let handle = entity.downgrade();
1920 let window_handle = self.window.handle;
1921 self.app.new_subscription(
1922 entity_id,
1923 (
1924 TypeId::of::<Evt>(),
1925 Box::new(move |event, cx| {
1926 window_handle
1927 .update(cx, |_, cx| {
1928 if let Some(handle) = E::upgrade_from(&handle) {
1929 let event = event.downcast_ref().expect("invalid event type");
1930 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1931 .is_ok()
1932 } else {
1933 false
1934 }
1935 })
1936 .unwrap_or(false)
1937 }),
1938 ),
1939 )
1940 }
1941
1942 /// Register a callback to be invoked when the view is released.
1943 ///
1944 /// The callback receives a handle to the view's window. This handle may be
1945 /// invalid, if the window was closed before the view was released.
1946 pub fn on_release(
1947 &mut self,
1948 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1949 ) -> Subscription {
1950 let window_handle = self.window.handle;
1951 let (subscription, activate) = self.app.release_listeners.insert(
1952 self.view.model.entity_id,
1953 Box::new(move |this, cx| {
1954 let this = this.downcast_mut().expect("invalid entity type");
1955 on_release(this, window_handle, cx)
1956 }),
1957 );
1958 activate();
1959 subscription
1960 }
1961
1962 /// Register a callback to be invoked when the given Model or View is released.
1963 pub fn observe_release<V2, E>(
1964 &mut self,
1965 entity: &E,
1966 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1967 ) -> Subscription
1968 where
1969 V: 'static,
1970 V2: 'static,
1971 E: Entity<V2>,
1972 {
1973 let view = self.view().downgrade();
1974 let entity_id = entity.entity_id();
1975 let window_handle = self.window.handle;
1976 let (subscription, activate) = self.app.release_listeners.insert(
1977 entity_id,
1978 Box::new(move |entity, cx| {
1979 let entity = entity.downcast_mut().expect("invalid entity type");
1980 let _ = window_handle.update(cx, |_, cx| {
1981 view.update(cx, |this, cx| on_release(this, entity, cx))
1982 });
1983 }),
1984 );
1985 activate();
1986 subscription
1987 }
1988
1989 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
1990 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
1991 pub fn notify(&mut self) {
1992 for view_id in self
1993 .window
1994 .rendered_frame
1995 .dispatch_tree
1996 .view_path(self.view.entity_id())
1997 .into_iter()
1998 .rev()
1999 {
2000 if !self.window.dirty_views.insert(view_id) {
2001 break;
2002 }
2003 }
2004
2005 if self.window.draw_phase == DrawPhase::None {
2006 self.window_cx.window.dirty.set(true);
2007 self.window_cx.app.push_effect(Effect::Notify {
2008 emitter: self.view.model.entity_id,
2009 });
2010 }
2011 }
2012
2013 /// Register a callback to be invoked when the window is resized.
2014 pub fn observe_window_bounds(
2015 &mut self,
2016 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2017 ) -> Subscription {
2018 let view = self.view.downgrade();
2019 let (subscription, activate) = self.window.bounds_observers.insert(
2020 (),
2021 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2022 );
2023 activate();
2024 subscription
2025 }
2026
2027 /// Register a callback to be invoked when the window is activated or deactivated.
2028 pub fn observe_window_activation(
2029 &mut self,
2030 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2031 ) -> Subscription {
2032 let view = self.view.downgrade();
2033 let (subscription, activate) = self.window.activation_observers.insert(
2034 (),
2035 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2036 );
2037 activate();
2038 subscription
2039 }
2040
2041 /// Registers a callback to be invoked when the window appearance changes.
2042 pub fn observe_window_appearance(
2043 &mut self,
2044 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2045 ) -> Subscription {
2046 let view = self.view.downgrade();
2047 let (subscription, activate) = self.window.appearance_observers.insert(
2048 (),
2049 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2050 );
2051 activate();
2052 subscription
2053 }
2054
2055 /// Register a listener to be called when the given focus handle receives focus.
2056 /// Returns a subscription and persists until the subscription is dropped.
2057 pub fn on_focus(
2058 &mut self,
2059 handle: &FocusHandle,
2060 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2061 ) -> Subscription {
2062 let view = self.view.downgrade();
2063 let focus_id = handle.id;
2064 let (subscription, activate) =
2065 self.window.new_focus_listener(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 self.app.defer(|_| activate());
2076 subscription
2077 }
2078
2079 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2080 /// Returns a subscription and persists until the subscription is dropped.
2081 pub fn on_focus_in(
2082 &mut self,
2083 handle: &FocusHandle,
2084 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2085 ) -> Subscription {
2086 let view = self.view.downgrade();
2087 let focus_id = handle.id;
2088 let (subscription, activate) =
2089 self.window.new_focus_listener(Box::new(move |event, cx| {
2090 view.update(cx, |view, cx| {
2091 if !event.previous_focus_path.contains(&focus_id)
2092 && event.current_focus_path.contains(&focus_id)
2093 {
2094 listener(view, cx)
2095 }
2096 })
2097 .is_ok()
2098 }));
2099 self.app.defer(move |_| activate());
2100 subscription
2101 }
2102
2103 /// Register a listener to be called when the given focus handle loses focus.
2104 /// Returns a subscription and persists until the subscription is dropped.
2105 pub fn on_blur(
2106 &mut self,
2107 handle: &FocusHandle,
2108 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2109 ) -> Subscription {
2110 let view = self.view.downgrade();
2111 let focus_id = handle.id;
2112 let (subscription, activate) =
2113 self.window.new_focus_listener(Box::new(move |event, cx| {
2114 view.update(cx, |view, cx| {
2115 if event.previous_focus_path.last() == Some(&focus_id)
2116 && event.current_focus_path.last() != Some(&focus_id)
2117 {
2118 listener(view, cx)
2119 }
2120 })
2121 .is_ok()
2122 }));
2123 self.app.defer(move |_| activate());
2124 subscription
2125 }
2126
2127 /// Register a listener to be called when nothing in the window has focus.
2128 /// This typically happens when the node that was focused is removed from the tree,
2129 /// and this callback lets you chose a default place to restore the users focus.
2130 /// Returns a subscription and persists until the subscription is dropped.
2131 pub fn on_focus_lost(
2132 &mut self,
2133 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2134 ) -> Subscription {
2135 let view = self.view.downgrade();
2136 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2137 (),
2138 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2139 );
2140 activate();
2141 subscription
2142 }
2143
2144 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2145 /// Returns a subscription and persists until the subscription is dropped.
2146 pub fn on_focus_out(
2147 &mut self,
2148 handle: &FocusHandle,
2149 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2150 ) -> Subscription {
2151 let view = self.view.downgrade();
2152 let focus_id = handle.id;
2153 let (subscription, activate) =
2154 self.window.new_focus_listener(Box::new(move |event, cx| {
2155 view.update(cx, |view, cx| {
2156 if event.previous_focus_path.contains(&focus_id)
2157 && !event.current_focus_path.contains(&focus_id)
2158 {
2159 listener(view, cx)
2160 }
2161 })
2162 .is_ok()
2163 }));
2164 self.app.defer(move |_| activate());
2165 subscription
2166 }
2167
2168 /// Schedule a future to be run asynchronously.
2169 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2170 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2171 /// The returned future will be polled on the main thread.
2172 pub fn spawn<Fut, R>(
2173 &mut self,
2174 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2175 ) -> Task<R>
2176 where
2177 R: 'static,
2178 Fut: Future<Output = R> + 'static,
2179 {
2180 let view = self.view().downgrade();
2181 self.window_cx.spawn(|cx| f(view, cx))
2182 }
2183
2184 /// Updates the global state of the given type.
2185 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2186 where
2187 G: Global,
2188 {
2189 let mut global = self.app.lease_global::<G>();
2190 let result = f(&mut global, self);
2191 self.app.end_global_lease(global);
2192 result
2193 }
2194
2195 /// Register a callback to be invoked when the given global state changes.
2196 pub fn observe_global<G: Global>(
2197 &mut self,
2198 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2199 ) -> Subscription {
2200 let window_handle = self.window.handle;
2201 let view = self.view().downgrade();
2202 let (subscription, activate) = self.global_observers.insert(
2203 TypeId::of::<G>(),
2204 Box::new(move |cx| {
2205 window_handle
2206 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2207 .unwrap_or(false)
2208 }),
2209 );
2210 self.app.defer(move |_| activate());
2211 subscription
2212 }
2213
2214 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2215 pub fn on_action(
2216 &mut self,
2217 action_type: TypeId,
2218 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2219 ) {
2220 let handle = self.view().clone();
2221 self.window_cx
2222 .on_action(action_type, move |action, phase, cx| {
2223 handle.update(cx, |view, cx| {
2224 listener(view, action, phase, cx);
2225 })
2226 });
2227 }
2228
2229 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2230 pub fn emit<Evt>(&mut self, event: Evt)
2231 where
2232 Evt: 'static,
2233 V: EventEmitter<Evt>,
2234 {
2235 let emitter = self.view.model.entity_id;
2236 self.app.push_effect(Effect::Emit {
2237 emitter,
2238 event_type: TypeId::of::<Evt>(),
2239 event: Box::new(event),
2240 });
2241 }
2242
2243 /// Move focus to the current view, assuming it implements [`FocusableView`].
2244 pub fn focus_self(&mut self)
2245 where
2246 V: FocusableView,
2247 {
2248 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2249 }
2250
2251 /// Convenience method for accessing view state in an event callback.
2252 ///
2253 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2254 /// but it's often useful to be able to access view state in these
2255 /// callbacks. This method provides a convenient way to do so.
2256 pub fn listener<E>(
2257 &self,
2258 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2259 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2260 let view = self.view().downgrade();
2261 move |e: &E, cx: &mut WindowContext| {
2262 view.update(cx, |view, cx| f(view, e, cx)).ok();
2263 }
2264 }
2265}
2266
2267impl<V> Context for ViewContext<'_, V> {
2268 type Result<U> = U;
2269
2270 fn new_model<T: 'static>(
2271 &mut self,
2272 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2273 ) -> Model<T> {
2274 self.window_cx.new_model(build_model)
2275 }
2276
2277 fn update_model<T: 'static, R>(
2278 &mut self,
2279 model: &Model<T>,
2280 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2281 ) -> R {
2282 self.window_cx.update_model(model, update)
2283 }
2284
2285 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2286 where
2287 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2288 {
2289 self.window_cx.update_window(window, update)
2290 }
2291
2292 fn read_model<T, R>(
2293 &self,
2294 handle: &Model<T>,
2295 read: impl FnOnce(&T, &AppContext) -> R,
2296 ) -> Self::Result<R>
2297 where
2298 T: 'static,
2299 {
2300 self.window_cx.read_model(handle, read)
2301 }
2302
2303 fn read_window<T, R>(
2304 &self,
2305 window: &WindowHandle<T>,
2306 read: impl FnOnce(View<T>, &AppContext) -> R,
2307 ) -> Result<R>
2308 where
2309 T: 'static,
2310 {
2311 self.window_cx.read_window(window, read)
2312 }
2313}
2314
2315impl<V: 'static> VisualContext for ViewContext<'_, V> {
2316 fn new_view<W: Render + 'static>(
2317 &mut self,
2318 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2319 ) -> Self::Result<View<W>> {
2320 self.window_cx.new_view(build_view_state)
2321 }
2322
2323 fn update_view<V2: 'static, R>(
2324 &mut self,
2325 view: &View<V2>,
2326 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2327 ) -> Self::Result<R> {
2328 self.window_cx.update_view(view, update)
2329 }
2330
2331 fn replace_root_view<W>(
2332 &mut self,
2333 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2334 ) -> Self::Result<View<W>>
2335 where
2336 W: 'static + Render,
2337 {
2338 self.window_cx.replace_root_view(build_view)
2339 }
2340
2341 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2342 self.window_cx.focus_view(view)
2343 }
2344
2345 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2346 self.window_cx.dismiss_view(view)
2347 }
2348}
2349
2350impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2351 type Target = WindowContext<'a>;
2352
2353 fn deref(&self) -> &Self::Target {
2354 &self.window_cx
2355 }
2356}
2357
2358impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2359 fn deref_mut(&mut self) -> &mut Self::Target {
2360 &mut self.window_cx
2361 }
2362}
2363
2364// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2365slotmap::new_key_type! {
2366 /// A unique identifier for a window.
2367 pub struct WindowId;
2368}
2369
2370impl WindowId {
2371 /// Converts this window ID to a `u64`.
2372 pub fn as_u64(&self) -> u64 {
2373 self.0.as_ffi()
2374 }
2375}
2376
2377/// A handle to a window with a specific root view type.
2378/// Note that this does not keep the window alive on its own.
2379#[derive(Deref, DerefMut)]
2380pub struct WindowHandle<V> {
2381 #[deref]
2382 #[deref_mut]
2383 pub(crate) any_handle: AnyWindowHandle,
2384 state_type: PhantomData<V>,
2385}
2386
2387impl<V: 'static + Render> WindowHandle<V> {
2388 /// Creates a new handle from a window ID.
2389 /// This does not check if the root type of the window is `V`.
2390 pub fn new(id: WindowId) -> Self {
2391 WindowHandle {
2392 any_handle: AnyWindowHandle {
2393 id,
2394 state_type: TypeId::of::<V>(),
2395 },
2396 state_type: PhantomData,
2397 }
2398 }
2399
2400 /// Get the root view out of this window.
2401 ///
2402 /// This will fail if the window is closed or if the root view's type does not match `V`.
2403 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2404 where
2405 C: Context,
2406 {
2407 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2408 root_view
2409 .downcast::<V>()
2410 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2411 }))
2412 }
2413
2414 /// Updates the root view of this window.
2415 ///
2416 /// This will fail if the window has been closed or if the root view's type does not match
2417 pub fn update<C, R>(
2418 &self,
2419 cx: &mut C,
2420 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2421 ) -> Result<R>
2422 where
2423 C: Context,
2424 {
2425 cx.update_window(self.any_handle, |root_view, cx| {
2426 let view = root_view
2427 .downcast::<V>()
2428 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2429 Ok(cx.update_view(&view, update))
2430 })?
2431 }
2432
2433 /// Read the root view out of this window.
2434 ///
2435 /// This will fail if the window is closed or if the root view's type does not match `V`.
2436 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2437 let x = cx
2438 .windows
2439 .get(self.id)
2440 .and_then(|window| {
2441 window
2442 .as_ref()
2443 .and_then(|window| window.root_view.clone())
2444 .map(|root_view| root_view.downcast::<V>())
2445 })
2446 .ok_or_else(|| anyhow!("window not found"))?
2447 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2448
2449 Ok(x.read(cx))
2450 }
2451
2452 /// Read the root view out of this window, with a callback
2453 ///
2454 /// This will fail if the window is closed or if the root view's type does not match `V`.
2455 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2456 where
2457 C: Context,
2458 {
2459 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2460 }
2461
2462 /// Read the root view pointer off of this window.
2463 ///
2464 /// This will fail if the window is closed or if the root view's type does not match `V`.
2465 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2466 where
2467 C: Context,
2468 {
2469 cx.read_window(self, |root_view, _cx| root_view.clone())
2470 }
2471
2472 /// Check if this window is 'active'.
2473 ///
2474 /// Will return `None` if the window is closed or currently
2475 /// borrowed.
2476 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
2477 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
2478 .ok()
2479 }
2480}
2481
2482impl<V> Copy for WindowHandle<V> {}
2483
2484impl<V> Clone for WindowHandle<V> {
2485 fn clone(&self) -> Self {
2486 *self
2487 }
2488}
2489
2490impl<V> PartialEq for WindowHandle<V> {
2491 fn eq(&self, other: &Self) -> bool {
2492 self.any_handle == other.any_handle
2493 }
2494}
2495
2496impl<V> Eq for WindowHandle<V> {}
2497
2498impl<V> Hash for WindowHandle<V> {
2499 fn hash<H: Hasher>(&self, state: &mut H) {
2500 self.any_handle.hash(state);
2501 }
2502}
2503
2504impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2505 fn from(val: WindowHandle<V>) -> Self {
2506 val.any_handle
2507 }
2508}
2509
2510/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2511#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2512pub struct AnyWindowHandle {
2513 pub(crate) id: WindowId,
2514 state_type: TypeId,
2515}
2516
2517impl AnyWindowHandle {
2518 /// Get the ID of this window.
2519 pub fn window_id(&self) -> WindowId {
2520 self.id
2521 }
2522
2523 /// Attempt to convert this handle to a window handle with a specific root view type.
2524 /// If the types do not match, this will return `None`.
2525 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2526 if TypeId::of::<T>() == self.state_type {
2527 Some(WindowHandle {
2528 any_handle: *self,
2529 state_type: PhantomData,
2530 })
2531 } else {
2532 None
2533 }
2534 }
2535
2536 /// Updates the state of the root view of this window.
2537 ///
2538 /// This will fail if the window has been closed.
2539 pub fn update<C, R>(
2540 self,
2541 cx: &mut C,
2542 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2543 ) -> Result<R>
2544 where
2545 C: Context,
2546 {
2547 cx.update_window(self, update)
2548 }
2549
2550 /// Read the state of the root view of this window.
2551 ///
2552 /// This will fail if the window has been closed.
2553 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2554 where
2555 C: Context,
2556 T: 'static,
2557 {
2558 let view = self
2559 .downcast::<T>()
2560 .context("the type of the window's root view has changed")?;
2561
2562 cx.read_window(&view, read)
2563 }
2564}
2565
2566/// An identifier for an [`Element`](crate::Element).
2567///
2568/// Can be constructed with a string, a number, or both, as well
2569/// as other internal representations.
2570#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2571pub enum ElementId {
2572 /// The ID of a View element
2573 View(EntityId),
2574 /// An integer ID.
2575 Integer(usize),
2576 /// A string based ID.
2577 Name(SharedString),
2578 /// An ID that's equated with a focus handle.
2579 FocusHandle(FocusId),
2580 /// A combination of a name and an integer.
2581 NamedInteger(SharedString, usize),
2582}
2583
2584impl Display for ElementId {
2585 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2586 match self {
2587 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2588 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2589 ElementId::Name(name) => write!(f, "{}", name)?,
2590 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2591 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2592 }
2593
2594 Ok(())
2595 }
2596}
2597
2598impl TryInto<SharedString> for ElementId {
2599 type Error = anyhow::Error;
2600
2601 fn try_into(self) -> anyhow::Result<SharedString> {
2602 if let ElementId::Name(name) = self {
2603 Ok(name)
2604 } else {
2605 Err(anyhow!("element id is not string"))
2606 }
2607 }
2608}
2609
2610impl From<usize> for ElementId {
2611 fn from(id: usize) -> Self {
2612 ElementId::Integer(id)
2613 }
2614}
2615
2616impl From<i32> for ElementId {
2617 fn from(id: i32) -> Self {
2618 Self::Integer(id as usize)
2619 }
2620}
2621
2622impl From<SharedString> for ElementId {
2623 fn from(name: SharedString) -> Self {
2624 ElementId::Name(name)
2625 }
2626}
2627
2628impl From<&'static str> for ElementId {
2629 fn from(name: &'static str) -> Self {
2630 ElementId::Name(name.into())
2631 }
2632}
2633
2634impl<'a> From<&'a FocusHandle> for ElementId {
2635 fn from(handle: &'a FocusHandle) -> Self {
2636 ElementId::FocusHandle(handle.id)
2637 }
2638}
2639
2640impl From<(&'static str, EntityId)> for ElementId {
2641 fn from((name, id): (&'static str, EntityId)) -> Self {
2642 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2643 }
2644}
2645
2646impl From<(&'static str, usize)> for ElementId {
2647 fn from((name, id): (&'static str, usize)) -> Self {
2648 ElementId::NamedInteger(name.into(), id)
2649 }
2650}
2651
2652impl From<(&'static str, u64)> for ElementId {
2653 fn from((name, id): (&'static str, u64)) -> Self {
2654 ElementId::NamedInteger(name.into(), id as usize)
2655 }
2656}
2657
2658/// A rectangle to be rendered in the window at the given position and size.
2659/// Passed as an argument [`ElementContext::paint_quad`].
2660#[derive(Clone)]
2661pub struct PaintQuad {
2662 bounds: Bounds<Pixels>,
2663 corner_radii: Corners<Pixels>,
2664 background: Hsla,
2665 border_widths: Edges<Pixels>,
2666 border_color: Hsla,
2667}
2668
2669impl PaintQuad {
2670 /// Sets the corner radii of the quad.
2671 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2672 PaintQuad {
2673 corner_radii: corner_radii.into(),
2674 ..self
2675 }
2676 }
2677
2678 /// Sets the border widths of the quad.
2679 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2680 PaintQuad {
2681 border_widths: border_widths.into(),
2682 ..self
2683 }
2684 }
2685
2686 /// Sets the border color of the quad.
2687 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2688 PaintQuad {
2689 border_color: border_color.into(),
2690 ..self
2691 }
2692 }
2693
2694 /// Sets the background color of the quad.
2695 pub fn background(self, background: impl Into<Hsla>) -> Self {
2696 PaintQuad {
2697 background: background.into(),
2698 ..self
2699 }
2700 }
2701}
2702
2703/// Creates a quad with the given parameters.
2704pub fn quad(
2705 bounds: Bounds<Pixels>,
2706 corner_radii: impl Into<Corners<Pixels>>,
2707 background: impl Into<Hsla>,
2708 border_widths: impl Into<Edges<Pixels>>,
2709 border_color: impl Into<Hsla>,
2710) -> PaintQuad {
2711 PaintQuad {
2712 bounds,
2713 corner_radii: corner_radii.into(),
2714 background: background.into(),
2715 border_widths: border_widths.into(),
2716 border_color: border_color.into(),
2717 }
2718}
2719
2720/// Creates a filled quad with the given bounds and background color.
2721pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2722 PaintQuad {
2723 bounds: bounds.into(),
2724 corner_radii: (0.).into(),
2725 background: background.into(),
2726 border_widths: (0.).into(),
2727 border_color: transparent_black(),
2728 }
2729}
2730
2731/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2732pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2733 PaintQuad {
2734 bounds: bounds.into(),
2735 corner_radii: (0.).into(),
2736 background: transparent_black(),
2737 border_widths: (1.).into(),
2738 border_color: border_color.into(),
2739 }
2740}