1use crate::{
2 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
3 AvailableSpace, Bounds, Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId,
4 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
5 Global, GlobalElementId, Hsla, KeyBinding, KeyContext, KeyDownEvent, KeyMatch, KeymatchResult,
6 Keystroke, KeystrokeEvent, Model, ModelContext, Modifiers, MouseButton, MouseMoveEvent,
7 MouseUpEvent, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput, PlatformWindow, Point,
8 PromptLevel, Render, ScaledPixels, SharedString, Size, SubscriberSet, Subscription,
9 TaffyLayoutEngine, Task, View, VisualContext, WeakView, WindowAppearance, WindowBounds,
10 WindowOptions, WindowTextSystem,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::channel::oneshot;
16use parking_lot::RwLock;
17use slotmap::SlotMap;
18use smallvec::SmallVec;
19use std::{
20 any::{Any, TypeId},
21 borrow::{Borrow, BorrowMut},
22 cell::{Cell, RefCell},
23 fmt::{Debug, Display},
24 future::Future,
25 hash::{Hash, Hasher},
26 marker::PhantomData,
27 mem,
28 rc::Rc,
29 sync::{
30 atomic::{AtomicUsize, Ordering::SeqCst},
31 Arc,
32 },
33 time::{Duration, Instant},
34};
35use util::{measure, ResultExt};
36
37mod element_cx;
38pub use element_cx::*;
39
40const ACTIVE_DRAG_Z_INDEX: u16 = 1;
41
42/// A global stacking order, which is created by stacking successive z-index values.
43/// Each z-index will always be interpreted in the context of its parent z-index.
44#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
45pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
46
47/// A single entry in a primitive's z-index stacking order
48#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
49pub struct StackingContext {
50 pub(crate) z_index: u16,
51 pub(crate) id: u16,
52}
53
54impl std::fmt::Debug for StackingContext {
55 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
56 write!(f, "{{{}.{}}} ", self.z_index, self.id)
57 }
58}
59
60/// Represents the two different phases when dispatching events.
61#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
62pub enum DispatchPhase {
63 /// After the capture phase comes the bubble phase, in which mouse event listeners are
64 /// invoked front to back and keyboard event listeners are invoked from the focused element
65 /// to the root of the element tree. This is the phase you'll most commonly want to use when
66 /// registering event listeners.
67 #[default]
68 Bubble,
69 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
70 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
71 /// is used for special purposes such as clearing the "pressed" state for click events. If
72 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
73 /// outside of the immediate region may rely on detecting non-local events during this phase.
74 Capture,
75}
76
77impl DispatchPhase {
78 /// Returns true if this represents the "bubble" phase.
79 pub fn bubble(self) -> bool {
80 self == DispatchPhase::Bubble
81 }
82
83 /// Returns true if this represents the "capture" phase.
84 pub fn capture(self) -> bool {
85 self == DispatchPhase::Capture
86 }
87}
88
89type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
90
91type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
92
93struct FocusEvent {
94 previous_focus_path: SmallVec<[FocusId; 8]>,
95 current_focus_path: SmallVec<[FocusId; 8]>,
96}
97
98slotmap::new_key_type! {
99 /// A globally unique identifier for a focusable element.
100 pub struct FocusId;
101}
102
103thread_local! {
104 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(8 * 1024 * 1024));
105}
106
107impl FocusId {
108 /// Obtains whether the element associated with this handle is currently focused.
109 pub fn is_focused(&self, cx: &WindowContext) -> bool {
110 cx.window.focus == Some(*self)
111 }
112
113 /// Obtains whether the element associated with this handle contains the focused
114 /// element or is itself focused.
115 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
116 cx.focused()
117 .map_or(false, |focused| self.contains(focused.id, cx))
118 }
119
120 /// Obtains whether the element associated with this handle is contained within the
121 /// focused element or is itself focused.
122 pub fn within_focused(&self, cx: &WindowContext) -> bool {
123 let focused = cx.focused();
124 focused.map_or(false, |focused| focused.id.contains(*self, cx))
125 }
126
127 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
128 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
129 cx.window
130 .rendered_frame
131 .dispatch_tree
132 .focus_contains(*self, other)
133 }
134}
135
136/// A handle which can be used to track and manipulate the focused element in a window.
137pub struct FocusHandle {
138 pub(crate) id: FocusId,
139 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
140}
141
142impl std::fmt::Debug for FocusHandle {
143 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
144 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
145 }
146}
147
148impl FocusHandle {
149 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
150 let id = handles.write().insert(AtomicUsize::new(1));
151 Self {
152 id,
153 handles: handles.clone(),
154 }
155 }
156
157 pub(crate) fn for_id(
158 id: FocusId,
159 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
160 ) -> Option<Self> {
161 let lock = handles.read();
162 let ref_count = lock.get(id)?;
163 if ref_count.load(SeqCst) == 0 {
164 None
165 } else {
166 ref_count.fetch_add(1, SeqCst);
167 Some(Self {
168 id,
169 handles: handles.clone(),
170 })
171 }
172 }
173
174 /// Moves the focus to the element associated with this handle.
175 pub fn focus(&self, cx: &mut WindowContext) {
176 cx.focus(self)
177 }
178
179 /// Obtains whether the element associated with this handle is currently focused.
180 pub fn is_focused(&self, cx: &WindowContext) -> bool {
181 self.id.is_focused(cx)
182 }
183
184 /// Obtains whether the element associated with this handle contains the focused
185 /// element or is itself focused.
186 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
187 self.id.contains_focused(cx)
188 }
189
190 /// Obtains whether the element associated with this handle is contained within the
191 /// focused element or is itself focused.
192 pub fn within_focused(&self, cx: &WindowContext) -> bool {
193 self.id.within_focused(cx)
194 }
195
196 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
197 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
198 self.id.contains(other.id, cx)
199 }
200}
201
202impl Clone for FocusHandle {
203 fn clone(&self) -> Self {
204 Self::for_id(self.id, &self.handles).unwrap()
205 }
206}
207
208impl PartialEq for FocusHandle {
209 fn eq(&self, other: &Self) -> bool {
210 self.id == other.id
211 }
212}
213
214impl Eq for FocusHandle {}
215
216impl Drop for FocusHandle {
217 fn drop(&mut self) {
218 self.handles
219 .read()
220 .get(self.id)
221 .unwrap()
222 .fetch_sub(1, SeqCst);
223 }
224}
225
226/// FocusableView allows users of your view to easily
227/// focus it (using cx.focus_view(view))
228pub trait FocusableView: 'static + Render {
229 /// Returns the focus handle associated with this view.
230 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
231}
232
233/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
234/// where the lifecycle of the view is handled by another view.
235pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
236
237impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
238
239/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
240pub struct DismissEvent;
241
242type FrameCallback = Box<dyn FnOnce(&mut WindowContext)>;
243
244// Holds the state for a specific window.
245#[doc(hidden)]
246pub struct Window {
247 pub(crate) handle: AnyWindowHandle,
248 pub(crate) removed: bool,
249 pub(crate) platform_window: Box<dyn PlatformWindow>,
250 display_id: DisplayId,
251 sprite_atlas: Arc<dyn PlatformAtlas>,
252 text_system: Arc<WindowTextSystem>,
253 pub(crate) rem_size: Pixels,
254 pub(crate) viewport_size: Size<Pixels>,
255 layout_engine: Option<TaffyLayoutEngine>,
256 pub(crate) root_view: Option<AnyView>,
257 pub(crate) element_id_stack: GlobalElementId,
258 pub(crate) rendered_frame: Frame,
259 pub(crate) next_frame: Frame,
260 next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
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 appearance: WindowAppearance,
272 appearance_observers: SubscriberSet<(), AnyObserver>,
273 active: Rc<Cell<bool>>,
274 pub(crate) dirty: Rc<Cell<bool>>,
275 pub(crate) needs_present: Rc<Cell<bool>>,
276 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
277 pub(crate) refreshing: bool,
278 pub(crate) drawing: bool,
279 activation_observers: SubscriberSet<(), AnyObserver>,
280 pub(crate) focus: Option<FocusId>,
281 focus_enabled: bool,
282 pending_input: Option<PendingInput>,
283 graphics_profiler_enabled: bool,
284}
285
286#[derive(Default, Debug)]
287struct PendingInput {
288 keystrokes: SmallVec<[Keystroke; 1]>,
289 bindings: SmallVec<[KeyBinding; 1]>,
290 focus: Option<FocusId>,
291 timer: Option<Task<()>>,
292}
293
294impl PendingInput {
295 fn input(&self) -> String {
296 self.keystrokes
297 .iter()
298 .flat_map(|k| k.ime_key.clone())
299 .collect::<Vec<String>>()
300 .join("")
301 }
302
303 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
304 if self.keystrokes.is_empty() {
305 return true;
306 }
307 let keystroke = &self.keystrokes[0];
308 for candidate in keystroke.match_candidates() {
309 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
310 return true;
311 }
312 }
313 false
314 }
315}
316
317pub(crate) struct ElementStateBox {
318 pub(crate) inner: Box<dyn Any>,
319 pub(crate) parent_view_id: EntityId,
320 #[cfg(debug_assertions)]
321 pub(crate) type_name: &'static str,
322}
323
324impl Window {
325 pub(crate) fn new(
326 handle: AnyWindowHandle,
327 options: WindowOptions,
328 cx: &mut AppContext,
329 ) -> Self {
330 let platform_window = cx.platform.open_window(handle, options);
331 let display_id = platform_window.display().id();
332 let sprite_atlas = platform_window.sprite_atlas();
333 let mouse_position = platform_window.mouse_position();
334 let modifiers = platform_window.modifiers();
335 let content_size = platform_window.content_size();
336 let scale_factor = platform_window.scale_factor();
337 let bounds = platform_window.bounds();
338 let appearance = platform_window.appearance();
339 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
340 let dirty = Rc::new(Cell::new(true));
341 let active = Rc::new(Cell::new(false));
342 let needs_present = Rc::new(Cell::new(false));
343 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
344 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
345
346 platform_window.on_close(Box::new({
347 let mut cx = cx.to_async();
348 move || {
349 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
350 }
351 }));
352 platform_window.on_request_frame(Box::new({
353 let mut cx = cx.to_async();
354 let dirty = dirty.clone();
355 let active = active.clone();
356 let needs_present = needs_present.clone();
357 let next_frame_callbacks = next_frame_callbacks.clone();
358 let last_input_timestamp = last_input_timestamp.clone();
359 move || {
360 let next_frame_callbacks = next_frame_callbacks.take();
361 if !next_frame_callbacks.is_empty() {
362 handle
363 .update(&mut cx, |_, cx| {
364 for callback in next_frame_callbacks {
365 callback(cx);
366 }
367 })
368 .log_err();
369 }
370
371 // Keep presenting the current scene for 1 extra second since the
372 // last input to prevent the display from underclocking the refresh rate.
373 let needs_present = needs_present.get()
374 || (active.get()
375 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
376
377 if dirty.get() {
378 measure("frame duration", || {
379 handle
380 .update(&mut cx, |_, cx| {
381 cx.draw();
382 cx.present();
383 })
384 .log_err();
385 })
386 } else if needs_present {
387 handle.update(&mut cx, |_, cx| cx.present()).log_err();
388 }
389 }
390 }));
391 platform_window.on_resize(Box::new({
392 let mut cx = cx.to_async();
393 move |_, _| {
394 handle
395 .update(&mut cx, |_, cx| cx.window_bounds_changed())
396 .log_err();
397 }
398 }));
399 platform_window.on_moved(Box::new({
400 let mut cx = cx.to_async();
401 move || {
402 handle
403 .update(&mut cx, |_, cx| cx.window_bounds_changed())
404 .log_err();
405 }
406 }));
407 platform_window.on_appearance_changed(Box::new({
408 let mut cx = cx.to_async();
409 move || {
410 handle
411 .update(&mut cx, |_, cx| cx.appearance_changed())
412 .log_err();
413 }
414 }));
415 platform_window.on_active_status_change(Box::new({
416 let mut cx = cx.to_async();
417 move |active| {
418 handle
419 .update(&mut cx, |_, cx| {
420 cx.window.active.set(active);
421 cx.window
422 .activation_observers
423 .clone()
424 .retain(&(), |callback| callback(cx));
425 })
426 .log_err();
427 }
428 }));
429
430 platform_window.on_input({
431 let mut cx = cx.to_async();
432 Box::new(move |event| {
433 handle
434 .update(&mut cx, |_, cx| cx.dispatch_event(event))
435 .log_err()
436 .unwrap_or(false)
437 })
438 });
439
440 Window {
441 handle,
442 removed: false,
443 platform_window,
444 display_id,
445 sprite_atlas,
446 text_system,
447 rem_size: px(16.),
448 viewport_size: content_size,
449 layout_engine: Some(TaffyLayoutEngine::new()),
450 root_view: None,
451 element_id_stack: GlobalElementId::default(),
452 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
453 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
454 next_frame_callbacks,
455 dirty_views: FxHashSet::default(),
456 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
457 focus_listeners: SubscriberSet::new(),
458 focus_lost_listeners: SubscriberSet::new(),
459 default_prevented: true,
460 mouse_position,
461 modifiers,
462 scale_factor,
463 bounds,
464 bounds_observers: SubscriberSet::new(),
465 appearance,
466 appearance_observers: SubscriberSet::new(),
467 active,
468 dirty,
469 needs_present,
470 last_input_timestamp,
471 refreshing: false,
472 drawing: false,
473 activation_observers: SubscriberSet::new(),
474 focus: None,
475 focus_enabled: true,
476 pending_input: None,
477 graphics_profiler_enabled: false,
478 }
479 }
480 fn new_focus_listener(
481 &mut self,
482 value: AnyWindowFocusListener,
483 ) -> (Subscription, impl FnOnce()) {
484 self.focus_listeners.insert((), value)
485 }
486}
487
488/// Indicates which region of the window is visible. Content falling outside of this mask will not be
489/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
490/// to leave room to support more complex shapes in the future.
491#[derive(Clone, Debug, Default, PartialEq, Eq)]
492#[repr(C)]
493pub struct ContentMask<P: Clone + Default + Debug> {
494 /// The bounds
495 pub bounds: Bounds<P>,
496}
497
498impl ContentMask<Pixels> {
499 /// Scale the content mask's pixel units by the given scaling factor.
500 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
501 ContentMask {
502 bounds: self.bounds.scale(factor),
503 }
504 }
505
506 /// Intersect the content mask with the given content mask.
507 pub fn intersect(&self, other: &Self) -> Self {
508 let bounds = self.bounds.intersect(&other.bounds);
509 ContentMask { bounds }
510 }
511}
512
513/// Provides access to application state in the context of a single window. Derefs
514/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
515/// an [`AppContext`] and call any [`AppContext`] methods.
516pub struct WindowContext<'a> {
517 pub(crate) app: &'a mut AppContext,
518 pub(crate) window: &'a mut Window,
519}
520
521impl<'a> WindowContext<'a> {
522 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
523 Self { app, window }
524 }
525
526 /// Obtain a handle to the window that belongs to this context.
527 pub fn window_handle(&self) -> AnyWindowHandle {
528 self.window.handle
529 }
530
531 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
532 pub fn refresh(&mut self) {
533 if !self.window.drawing {
534 self.window.refreshing = true;
535 self.window.dirty.set(true);
536 }
537 }
538
539 /// Close this window.
540 pub fn remove_window(&mut self) {
541 self.window.removed = true;
542 }
543
544 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
545 /// for elements rendered within this window.
546 pub fn focus_handle(&mut self) -> FocusHandle {
547 FocusHandle::new(&self.window.focus_handles)
548 }
549
550 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
551 pub fn focused(&self) -> Option<FocusHandle> {
552 self.window
553 .focus
554 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
555 }
556
557 /// Move focus to the element associated with the given [`FocusHandle`].
558 pub fn focus(&mut self, handle: &FocusHandle) {
559 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
560 return;
561 }
562
563 self.window.focus = Some(handle.id);
564 self.window
565 .rendered_frame
566 .dispatch_tree
567 .clear_pending_keystrokes();
568 self.refresh();
569 }
570
571 /// Remove focus from all elements within this context's window.
572 pub fn blur(&mut self) {
573 if !self.window.focus_enabled {
574 return;
575 }
576
577 self.window.focus = None;
578 self.refresh();
579 }
580
581 /// Blur the window and don't allow anything in it to be focused again.
582 pub fn disable_focus(&mut self) {
583 self.blur();
584 self.window.focus_enabled = false;
585 }
586
587 /// Accessor for the text system.
588 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
589 &self.window.text_system
590 }
591
592 /// Dispatch the given action on the currently focused element.
593 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
594 let focus_handle = self.focused();
595
596 self.defer(move |cx| {
597 let node_id = focus_handle
598 .and_then(|handle| {
599 cx.window
600 .rendered_frame
601 .dispatch_tree
602 .focusable_node_id(handle.id)
603 })
604 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
605
606 cx.propagate_event = true;
607 cx.dispatch_action_on_node(node_id, action);
608 })
609 }
610
611 pub(crate) fn dispatch_keystroke_observers(
612 &mut self,
613 event: &dyn Any,
614 action: Option<Box<dyn Action>>,
615 ) {
616 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
617 return;
618 };
619
620 self.keystroke_observers
621 .clone()
622 .retain(&(), move |callback| {
623 (callback)(
624 &KeystrokeEvent {
625 keystroke: key_down_event.keystroke.clone(),
626 action: action.as_ref().map(|action| action.boxed_clone()),
627 },
628 self,
629 );
630 true
631 });
632 }
633
634 pub(crate) fn clear_pending_keystrokes(&mut self) {
635 self.window
636 .rendered_frame
637 .dispatch_tree
638 .clear_pending_keystrokes();
639 self.window
640 .next_frame
641 .dispatch_tree
642 .clear_pending_keystrokes();
643 }
644
645 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
646 /// that are currently on the stack to be returned to the app.
647 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
648 let handle = self.window.handle;
649 self.app.defer(move |cx| {
650 handle.update(cx, |_, cx| f(cx)).ok();
651 });
652 }
653
654 /// Subscribe to events emitted by a model or view.
655 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
656 /// 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.
657 pub fn subscribe<Emitter, E, Evt>(
658 &mut self,
659 entity: &E,
660 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
661 ) -> Subscription
662 where
663 Emitter: EventEmitter<Evt>,
664 E: Entity<Emitter>,
665 Evt: 'static,
666 {
667 let entity_id = entity.entity_id();
668 let entity = entity.downgrade();
669 let window_handle = self.window.handle;
670 self.app.new_subscription(
671 entity_id,
672 (
673 TypeId::of::<Evt>(),
674 Box::new(move |event, cx| {
675 window_handle
676 .update(cx, |_, cx| {
677 if let Some(handle) = E::upgrade_from(&entity) {
678 let event = event.downcast_ref().expect("invalid event type");
679 on_event(handle, event, cx);
680 true
681 } else {
682 false
683 }
684 })
685 .unwrap_or(false)
686 }),
687 ),
688 )
689 }
690
691 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
692 /// await points in async code.
693 pub fn to_async(&self) -> AsyncWindowContext {
694 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
695 }
696
697 /// Schedule the given closure to be run directly after the current frame is rendered.
698 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
699 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
700 }
701
702 /// Spawn the future returned by the given closure on the application thread pool.
703 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
704 /// use within your future.
705 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
706 where
707 R: 'static,
708 Fut: Future<Output = R> + 'static,
709 {
710 self.app
711 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
712 }
713
714 /// Updates the global of the given type. The given closure is given simultaneous mutable
715 /// access both to the global and the context.
716 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
717 where
718 G: Global,
719 {
720 let mut global = self.app.lease_global::<G>();
721 let result = f(&mut global, self);
722 self.app.end_global_lease(global);
723 result
724 }
725
726 fn window_bounds_changed(&mut self) {
727 self.window.scale_factor = self.window.platform_window.scale_factor();
728 self.window.viewport_size = self.window.platform_window.content_size();
729 self.window.bounds = self.window.platform_window.bounds();
730 self.window.display_id = self.window.platform_window.display().id();
731 self.refresh();
732
733 self.window
734 .bounds_observers
735 .clone()
736 .retain(&(), |callback| callback(self));
737 }
738
739 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
740 pub fn window_bounds(&self) -> WindowBounds {
741 self.window.bounds
742 }
743
744 fn appearance_changed(&mut self) {
745 self.window.appearance = self.window.platform_window.appearance();
746
747 self.window
748 .appearance_observers
749 .clone()
750 .retain(&(), |callback| callback(self));
751 }
752
753 /// Returns the appearance of the current window.
754 pub fn appearance(&self) -> WindowAppearance {
755 self.window.appearance
756 }
757
758 /// Returns the size of the drawable area within the window.
759 pub fn viewport_size(&self) -> Size<Pixels> {
760 self.window.viewport_size
761 }
762
763 /// Returns whether this window is focused by the operating system (receiving key events).
764 pub fn is_window_active(&self) -> bool {
765 self.window.active.get()
766 }
767
768 /// Toggle zoom on the window.
769 pub fn zoom_window(&self) {
770 self.window.platform_window.zoom();
771 }
772
773 /// Updates the window's title at the platform level.
774 pub fn set_window_title(&mut self, title: &str) {
775 self.window.platform_window.set_title(title);
776 }
777
778 /// Mark the window as dirty at the platform level.
779 pub fn set_window_edited(&mut self, edited: bool) {
780 self.window.platform_window.set_edited(edited);
781 }
782
783 /// Determine the display on which the window is visible.
784 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
785 self.platform
786 .displays()
787 .into_iter()
788 .find(|display| display.id() == self.window.display_id)
789 }
790
791 /// Show the platform character palette.
792 pub fn show_character_palette(&self) {
793 self.window.platform_window.show_character_palette();
794 }
795
796 /// The scale factor of the display associated with the window. For example, it could
797 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
798 /// be rendered as two pixels on screen.
799 pub fn scale_factor(&self) -> f32 {
800 self.window.scale_factor
801 }
802
803 /// The size of an em for the base font of the application. Adjusting this value allows the
804 /// UI to scale, just like zooming a web page.
805 pub fn rem_size(&self) -> Pixels {
806 self.window.rem_size
807 }
808
809 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
810 /// UI to scale, just like zooming a web page.
811 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
812 self.window.rem_size = rem_size.into();
813 }
814
815 /// The line height associated with the current text style.
816 pub fn line_height(&self) -> Pixels {
817 let rem_size = self.rem_size();
818 let text_style = self.text_style();
819 text_style
820 .line_height
821 .to_pixels(text_style.font_size, rem_size)
822 }
823
824 /// Call to prevent the default action of an event. Currently only used to prevent
825 /// parent elements from becoming focused on mouse down.
826 pub fn prevent_default(&mut self) {
827 self.window.default_prevented = true;
828 }
829
830 /// Obtain whether default has been prevented for the event currently being dispatched.
831 pub fn default_prevented(&self) -> bool {
832 self.window.default_prevented
833 }
834
835 /// Determine whether the given action is available along the dispatch path to the currently focused element.
836 pub fn is_action_available(&self, action: &dyn Action) -> bool {
837 let target = self
838 .focused()
839 .and_then(|focused_handle| {
840 self.window
841 .rendered_frame
842 .dispatch_tree
843 .focusable_node_id(focused_handle.id)
844 })
845 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
846 self.window
847 .rendered_frame
848 .dispatch_tree
849 .is_action_available(action, target)
850 }
851
852 /// The position of the mouse relative to the window.
853 pub fn mouse_position(&self) -> Point<Pixels> {
854 self.window.mouse_position
855 }
856
857 /// The current state of the keyboard's modifiers
858 pub fn modifiers(&self) -> Modifiers {
859 self.window.modifiers
860 }
861
862 /// Returns true if there is no opaque layer containing the given point
863 /// on top of the given level. Layers who are extensions of the queried layer
864 /// are not considered to be on top of queried layer.
865 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
866 // Precondition: the depth map is ordered from topmost to bottomost.
867
868 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
869 if layer >= opaque_layer {
870 // The queried layer is either above or is the same as the this opaque layer.
871 // Anything after this point is guaranteed to be below the queried layer.
872 return true;
873 }
874
875 if !bounds.contains(point) {
876 // This opaque layer is above the queried layer but it doesn't contain
877 // the given position, so we can ignore it even if it's above.
878 continue;
879 }
880
881 // At this point, we've established that this opaque layer is on top of the queried layer
882 // and contains the position:
883 // If neither the opaque layer or the queried layer is an extension of the other then
884 // we know they are on different stacking orders, and return false.
885 let is_on_same_layer = opaque_layer
886 .iter()
887 .zip(layer.iter())
888 .all(|(a, b)| a.z_index == b.z_index);
889
890 if !is_on_same_layer {
891 return false;
892 }
893 }
894
895 true
896 }
897
898 pub(crate) fn was_top_layer_under_active_drag(
899 &self,
900 point: &Point<Pixels>,
901 layer: &StackingOrder,
902 ) -> bool {
903 // Precondition: the depth map is ordered from topmost to bottomost.
904
905 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
906 if layer >= opaque_layer {
907 // The queried layer is either above or is the same as the this opaque layer.
908 // Anything after this point is guaranteed to be below the queried layer.
909 return true;
910 }
911
912 if !bounds.contains(point) {
913 // This opaque layer is above the queried layer but it doesn't contain
914 // the given position, so we can ignore it even if it's above.
915 continue;
916 }
917
918 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
919 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
920 // looking to see if the queried layer was the topmost underneath the drag layer.
921 if opaque_layer
922 .first()
923 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
924 .unwrap_or(false)
925 {
926 continue;
927 }
928
929 // At this point, we've established that this opaque layer is on top of the queried layer
930 // and contains the position:
931 // If neither the opaque layer or the queried layer is an extension of the other then
932 // we know they are on different stacking orders, and return false.
933 let is_on_same_layer = opaque_layer
934 .iter()
935 .zip(layer.iter())
936 .all(|(a, b)| a.z_index == b.z_index);
937
938 if !is_on_same_layer {
939 return false;
940 }
941 }
942
943 true
944 }
945
946 /// Called during painting to get the current stacking order.
947 pub fn stacking_order(&self) -> &StackingOrder {
948 &self.window.next_frame.z_index_stack
949 }
950
951 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
952 /// the contents of the new [Scene], use [present].
953 pub fn draw(&mut self) {
954 self.window.dirty.set(false);
955 self.window.drawing = true;
956
957 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
958 {
959 let input_handler = self.window.platform_window.take_input_handler();
960 requested_handler.handler = input_handler;
961 }
962
963 let root_view = self.window.root_view.take().unwrap();
964 self.with_element_context(|cx| {
965 cx.with_z_index(0, |cx| {
966 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
967 // We need to use cx.cx here so we can utilize borrow splitting
968 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
969 for action_listener in action_listeners.iter().cloned() {
970 cx.cx.window.next_frame.dispatch_tree.on_action(
971 *action_type,
972 Rc::new(
973 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
974 action_listener(action, phase, cx)
975 },
976 ),
977 )
978 }
979 }
980
981 let available_space = cx.window.viewport_size.map(Into::into);
982 root_view.draw(Point::default(), available_space, cx);
983 })
984 })
985 });
986
987 if let Some(active_drag) = self.app.active_drag.take() {
988 self.with_element_context(|cx| {
989 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
990 let offset = cx.mouse_position() - active_drag.cursor_offset;
991 let available_space =
992 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
993 active_drag.view.draw(offset, available_space, cx);
994 })
995 });
996 self.active_drag = Some(active_drag);
997 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
998 self.with_element_context(|cx| {
999 cx.with_z_index(1, |cx| {
1000 let available_space =
1001 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1002 tooltip_request.tooltip.view.draw(
1003 tooltip_request.tooltip.cursor_offset,
1004 available_space,
1005 cx,
1006 );
1007 })
1008 });
1009 self.window.next_frame.tooltip_request = Some(tooltip_request);
1010 }
1011 self.window.dirty_views.clear();
1012
1013 self.window
1014 .next_frame
1015 .dispatch_tree
1016 .preserve_pending_keystrokes(
1017 &mut self.window.rendered_frame.dispatch_tree,
1018 self.window.focus,
1019 );
1020 self.window.next_frame.focus = self.window.focus;
1021 self.window.next_frame.window_active = self.window.active.get();
1022 self.window.root_view = Some(root_view);
1023
1024 // Set the cursor only if we're the active window.
1025 let cursor_style_request = self.window.next_frame.requested_cursor_style.take();
1026 if self.is_window_active() {
1027 let cursor_style =
1028 cursor_style_request.map_or(CursorStyle::Arrow, |request| request.style);
1029 self.platform.set_cursor_style(cursor_style);
1030 }
1031
1032 // Register requested input handler with the platform window.
1033 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1034 if let Some(handler) = requested_input.handler.take() {
1035 self.window.platform_window.set_input_handler(handler);
1036 }
1037 }
1038
1039 self.window.layout_engine.as_mut().unwrap().clear();
1040 self.text_system()
1041 .finish_frame(&self.window.next_frame.reused_views);
1042 self.window
1043 .next_frame
1044 .finish(&mut self.window.rendered_frame);
1045 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1046 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1047 if percentage >= 80. {
1048 log::warn!("elevated element arena occupation: {}.", percentage);
1049 }
1050 element_arena.clear();
1051 });
1052
1053 let previous_focus_path = self.window.rendered_frame.focus_path();
1054 let previous_window_active = self.window.rendered_frame.window_active;
1055 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1056 self.window.next_frame.clear();
1057 let current_focus_path = self.window.rendered_frame.focus_path();
1058 let current_window_active = self.window.rendered_frame.window_active;
1059
1060 if previous_focus_path != current_focus_path
1061 || previous_window_active != current_window_active
1062 {
1063 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1064 self.window
1065 .focus_lost_listeners
1066 .clone()
1067 .retain(&(), |listener| listener(self));
1068 }
1069
1070 let event = FocusEvent {
1071 previous_focus_path: if previous_window_active {
1072 previous_focus_path
1073 } else {
1074 Default::default()
1075 },
1076 current_focus_path: if current_window_active {
1077 current_focus_path
1078 } else {
1079 Default::default()
1080 },
1081 };
1082 self.window
1083 .focus_listeners
1084 .clone()
1085 .retain(&(), |listener| listener(&event, self));
1086 }
1087 self.window.refreshing = false;
1088 self.window.drawing = false;
1089 self.window.needs_present.set(true);
1090 }
1091
1092 fn present(&self) {
1093 self.window
1094 .platform_window
1095 .draw(&self.window.rendered_frame.scene);
1096 self.window.needs_present.set(false);
1097 }
1098
1099 /// Dispatch a given keystroke as though the user had typed it.
1100 /// You can create a keystroke with Keystroke::parse("").
1101 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
1102 let keystroke = keystroke.with_simulated_ime();
1103 if self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
1104 keystroke: keystroke.clone(),
1105 is_held: false,
1106 })) {
1107 return true;
1108 }
1109
1110 if let Some(input) = keystroke.ime_key {
1111 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1112 input_handler.dispatch_input(&input, self);
1113 self.window.platform_window.set_input_handler(input_handler);
1114 return true;
1115 }
1116 }
1117
1118 false
1119 }
1120
1121 /// Dispatch a mouse or keyboard event on the window.
1122 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1123 self.window.last_input_timestamp.set(Instant::now());
1124 // Handlers may set this to false by calling `stop_propagation`.
1125 self.app.propagate_event = true;
1126 // Handlers may set this to true by calling `prevent_default`.
1127 self.window.default_prevented = false;
1128
1129 let event = match event {
1130 // Track the mouse position with our own state, since accessing the platform
1131 // API for the mouse position can only occur on the main thread.
1132 PlatformInput::MouseMove(mouse_move) => {
1133 self.window.mouse_position = mouse_move.position;
1134 self.window.modifiers = mouse_move.modifiers;
1135 PlatformInput::MouseMove(mouse_move)
1136 }
1137 PlatformInput::MouseDown(mouse_down) => {
1138 self.window.mouse_position = mouse_down.position;
1139 self.window.modifiers = mouse_down.modifiers;
1140 PlatformInput::MouseDown(mouse_down)
1141 }
1142 PlatformInput::MouseUp(mouse_up) => {
1143 self.window.mouse_position = mouse_up.position;
1144 self.window.modifiers = mouse_up.modifiers;
1145 PlatformInput::MouseUp(mouse_up)
1146 }
1147 PlatformInput::MouseExited(mouse_exited) => {
1148 self.window.modifiers = mouse_exited.modifiers;
1149 PlatformInput::MouseExited(mouse_exited)
1150 }
1151 PlatformInput::ModifiersChanged(modifiers_changed) => {
1152 self.window.modifiers = modifiers_changed.modifiers;
1153 PlatformInput::ModifiersChanged(modifiers_changed)
1154 }
1155 PlatformInput::ScrollWheel(scroll_wheel) => {
1156 self.window.mouse_position = scroll_wheel.position;
1157 self.window.modifiers = scroll_wheel.modifiers;
1158 PlatformInput::ScrollWheel(scroll_wheel)
1159 }
1160 // Translate dragging and dropping of external files from the operating system
1161 // to internal drag and drop events.
1162 PlatformInput::FileDrop(file_drop) => match file_drop {
1163 FileDropEvent::Entered { position, paths } => {
1164 self.window.mouse_position = position;
1165 if self.active_drag.is_none() {
1166 self.active_drag = Some(AnyDrag {
1167 value: Box::new(paths.clone()),
1168 view: self.new_view(|_| paths).into(),
1169 cursor_offset: position,
1170 });
1171 }
1172 PlatformInput::MouseMove(MouseMoveEvent {
1173 position,
1174 pressed_button: Some(MouseButton::Left),
1175 modifiers: Modifiers::default(),
1176 })
1177 }
1178 FileDropEvent::Pending { position } => {
1179 self.window.mouse_position = position;
1180 PlatformInput::MouseMove(MouseMoveEvent {
1181 position,
1182 pressed_button: Some(MouseButton::Left),
1183 modifiers: Modifiers::default(),
1184 })
1185 }
1186 FileDropEvent::Submit { position } => {
1187 self.activate(true);
1188 self.window.mouse_position = position;
1189 PlatformInput::MouseUp(MouseUpEvent {
1190 button: MouseButton::Left,
1191 position,
1192 modifiers: Modifiers::default(),
1193 click_count: 1,
1194 })
1195 }
1196 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1197 button: MouseButton::Left,
1198 position: Point::default(),
1199 modifiers: Modifiers::default(),
1200 click_count: 1,
1201 }),
1202 },
1203 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1204 };
1205
1206 if let Some(any_mouse_event) = event.mouse_event() {
1207 self.dispatch_mouse_event(any_mouse_event);
1208 } else if let Some(any_key_event) = event.keyboard_event() {
1209 self.dispatch_key_event(any_key_event);
1210 }
1211
1212 !self.app.propagate_event
1213 }
1214
1215 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1216 if let Some(mut handlers) = self
1217 .window
1218 .rendered_frame
1219 .mouse_listeners
1220 .remove(&event.type_id())
1221 {
1222 // Because handlers may add other handlers, we sort every time.
1223 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1224
1225 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1226 // special purposes, such as detecting events outside of a given Bounds.
1227 for (_, _, handler) in &mut handlers {
1228 self.with_element_context(|cx| {
1229 handler(event, DispatchPhase::Capture, cx);
1230 });
1231 if !self.app.propagate_event {
1232 break;
1233 }
1234 }
1235
1236 // Bubble phase, where most normal handlers do their work.
1237 if self.app.propagate_event {
1238 for (_, _, handler) in handlers.iter_mut().rev() {
1239 self.with_element_context(|cx| {
1240 handler(event, DispatchPhase::Bubble, cx);
1241 });
1242 if !self.app.propagate_event {
1243 break;
1244 }
1245 }
1246 }
1247
1248 self.window
1249 .rendered_frame
1250 .mouse_listeners
1251 .insert(event.type_id(), handlers);
1252 }
1253
1254 if self.app.propagate_event && self.has_active_drag() {
1255 if event.is::<MouseMoveEvent>() {
1256 // If this was a mouse move event, redraw the window so that the
1257 // active drag can follow the mouse cursor.
1258 self.refresh();
1259 } else if event.is::<MouseUpEvent>() {
1260 // If this was a mouse up event, cancel the active drag and redraw
1261 // the window.
1262 self.active_drag = None;
1263 self.refresh();
1264 }
1265 }
1266 }
1267
1268 fn dispatch_key_event(&mut self, event: &dyn Any) {
1269 if self.window.dirty.get() {
1270 self.draw();
1271 }
1272
1273 let node_id = self
1274 .window
1275 .focus
1276 .and_then(|focus_id| {
1277 self.window
1278 .rendered_frame
1279 .dispatch_tree
1280 .focusable_node_id(focus_id)
1281 })
1282 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1283
1284 let dispatch_path = self
1285 .window
1286 .rendered_frame
1287 .dispatch_tree
1288 .dispatch_path(node_id);
1289
1290 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1291 let KeymatchResult { bindings, pending } = self
1292 .window
1293 .rendered_frame
1294 .dispatch_tree
1295 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1296
1297 if pending {
1298 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1299 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1300 {
1301 currently_pending = PendingInput::default();
1302 }
1303 currently_pending.focus = self.window.focus;
1304 currently_pending
1305 .keystrokes
1306 .push(key_down_event.keystroke.clone());
1307 for binding in bindings {
1308 currently_pending.bindings.push(binding);
1309 }
1310
1311 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1312 cx.background_executor.timer(Duration::from_secs(1)).await;
1313 cx.update(move |cx| {
1314 cx.clear_pending_keystrokes();
1315 let Some(currently_pending) = cx.window.pending_input.take() else {
1316 return;
1317 };
1318 cx.replay_pending_input(currently_pending)
1319 })
1320 .log_err();
1321 }));
1322 self.window.pending_input = Some(currently_pending);
1323
1324 self.propagate_event = false;
1325 return;
1326 } else if let Some(currently_pending) = self.window.pending_input.take() {
1327 if bindings
1328 .iter()
1329 .all(|binding| !currently_pending.used_by_binding(binding))
1330 {
1331 self.replay_pending_input(currently_pending)
1332 }
1333 }
1334
1335 if !bindings.is_empty() {
1336 self.clear_pending_keystrokes();
1337 }
1338
1339 self.propagate_event = true;
1340 for binding in bindings {
1341 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1342 if !self.propagate_event {
1343 self.dispatch_keystroke_observers(event, Some(binding.action));
1344 return;
1345 }
1346 }
1347 }
1348
1349 self.dispatch_key_down_up_event(event, &dispatch_path);
1350 if !self.propagate_event {
1351 return;
1352 }
1353
1354 self.dispatch_keystroke_observers(event, None);
1355 }
1356
1357 fn dispatch_key_down_up_event(
1358 &mut self,
1359 event: &dyn Any,
1360 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1361 ) {
1362 // Capture phase
1363 for node_id in dispatch_path {
1364 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1365
1366 for key_listener in node.key_listeners.clone() {
1367 self.with_element_context(|cx| {
1368 key_listener(event, DispatchPhase::Capture, cx);
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 // Handle low level key events
1379 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1380 for key_listener in node.key_listeners.clone() {
1381 self.with_element_context(|cx| {
1382 key_listener(event, DispatchPhase::Bubble, cx);
1383 });
1384 if !self.propagate_event {
1385 return;
1386 }
1387 }
1388 }
1389 }
1390
1391 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1392 pub fn has_pending_keystrokes(&self) -> bool {
1393 self.window
1394 .rendered_frame
1395 .dispatch_tree
1396 .has_pending_keystrokes()
1397 }
1398
1399 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1400 let node_id = self
1401 .window
1402 .focus
1403 .and_then(|focus_id| {
1404 self.window
1405 .rendered_frame
1406 .dispatch_tree
1407 .focusable_node_id(focus_id)
1408 })
1409 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1410
1411 if self.window.focus != currently_pending.focus {
1412 return;
1413 }
1414
1415 let input = currently_pending.input();
1416
1417 self.propagate_event = true;
1418 for binding in currently_pending.bindings {
1419 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1420 if !self.propagate_event {
1421 return;
1422 }
1423 }
1424
1425 let dispatch_path = self
1426 .window
1427 .rendered_frame
1428 .dispatch_tree
1429 .dispatch_path(node_id);
1430
1431 for keystroke in currently_pending.keystrokes {
1432 let event = KeyDownEvent {
1433 keystroke,
1434 is_held: false,
1435 };
1436
1437 self.dispatch_key_down_up_event(&event, &dispatch_path);
1438 if !self.propagate_event {
1439 return;
1440 }
1441 }
1442
1443 if !input.is_empty() {
1444 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1445 input_handler.dispatch_input(&input, self);
1446 self.window.platform_window.set_input_handler(input_handler)
1447 }
1448 }
1449 }
1450
1451 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1452 let dispatch_path = self
1453 .window
1454 .rendered_frame
1455 .dispatch_tree
1456 .dispatch_path(node_id);
1457
1458 // Capture phase
1459 for node_id in &dispatch_path {
1460 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1461 for DispatchActionListener {
1462 action_type,
1463 listener,
1464 } in node.action_listeners.clone()
1465 {
1466 let any_action = action.as_any();
1467 if action_type == any_action.type_id() {
1468 self.with_element_context(|cx| {
1469 listener(any_action, DispatchPhase::Capture, cx);
1470 });
1471
1472 if !self.propagate_event {
1473 return;
1474 }
1475 }
1476 }
1477 }
1478 // Bubble phase
1479 for node_id in dispatch_path.iter().rev() {
1480 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1481 for DispatchActionListener {
1482 action_type,
1483 listener,
1484 } in node.action_listeners.clone()
1485 {
1486 let any_action = action.as_any();
1487 if action_type == any_action.type_id() {
1488 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1489
1490 self.with_element_context(|cx| {
1491 listener(any_action, DispatchPhase::Bubble, cx);
1492 });
1493
1494 if !self.propagate_event {
1495 return;
1496 }
1497 }
1498 }
1499 }
1500 }
1501
1502 /// Toggle the graphics profiler to debug your application's rendering performance.
1503 pub fn toggle_graphics_profiler(&mut self) {
1504 self.window.graphics_profiler_enabled = !self.window.graphics_profiler_enabled;
1505 self.window
1506 .platform_window
1507 .set_graphics_profiler_enabled(self.window.graphics_profiler_enabled);
1508 }
1509
1510 /// Register the given handler to be invoked whenever the global of the given type
1511 /// is updated.
1512 pub fn observe_global<G: Global>(
1513 &mut self,
1514 f: impl Fn(&mut WindowContext<'_>) + 'static,
1515 ) -> Subscription {
1516 let window_handle = self.window.handle;
1517 let (subscription, activate) = self.global_observers.insert(
1518 TypeId::of::<G>(),
1519 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1520 );
1521 self.app.defer(move |_| activate());
1522 subscription
1523 }
1524
1525 /// Focus the current window and bring it to the foreground at the platform level.
1526 pub fn activate_window(&self) {
1527 self.window.platform_window.activate();
1528 }
1529
1530 /// Minimize the current window at the platform level.
1531 pub fn minimize_window(&self) {
1532 self.window.platform_window.minimize();
1533 }
1534
1535 /// Toggle full screen status on the current window at the platform level.
1536 pub fn toggle_full_screen(&self) {
1537 self.window.platform_window.toggle_full_screen();
1538 }
1539
1540 /// Present a platform dialog.
1541 /// The provided message will be presented, along with buttons for each answer.
1542 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1543 pub fn prompt(
1544 &self,
1545 level: PromptLevel,
1546 message: &str,
1547 detail: Option<&str>,
1548 answers: &[&str],
1549 ) -> oneshot::Receiver<usize> {
1550 self.window
1551 .platform_window
1552 .prompt(level, message, detail, answers)
1553 }
1554
1555 /// Returns all available actions for the focused element.
1556 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1557 let node_id = self
1558 .window
1559 .focus
1560 .and_then(|focus_id| {
1561 self.window
1562 .rendered_frame
1563 .dispatch_tree
1564 .focusable_node_id(focus_id)
1565 })
1566 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1567
1568 self.window
1569 .rendered_frame
1570 .dispatch_tree
1571 .available_actions(node_id)
1572 }
1573
1574 /// Returns key bindings that invoke the given action on the currently focused element.
1575 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1576 self.window
1577 .rendered_frame
1578 .dispatch_tree
1579 .bindings_for_action(
1580 action,
1581 &self.window.rendered_frame.dispatch_tree.context_stack,
1582 )
1583 }
1584
1585 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1586 pub fn bindings_for_action_in(
1587 &self,
1588 action: &dyn Action,
1589 focus_handle: &FocusHandle,
1590 ) -> Vec<KeyBinding> {
1591 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1592
1593 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1594 return vec![];
1595 };
1596 let context_stack: Vec<_> = dispatch_tree
1597 .dispatch_path(node_id)
1598 .into_iter()
1599 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1600 .collect();
1601 dispatch_tree.bindings_for_action(action, &context_stack)
1602 }
1603
1604 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1605 pub fn listener_for<V: Render, E>(
1606 &self,
1607 view: &View<V>,
1608 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1609 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1610 let view = view.downgrade();
1611 move |e: &E, cx: &mut WindowContext| {
1612 view.update(cx, |view, cx| f(view, e, cx)).ok();
1613 }
1614 }
1615
1616 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1617 pub fn handler_for<V: Render>(
1618 &self,
1619 view: &View<V>,
1620 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1621 ) -> impl Fn(&mut WindowContext) {
1622 let view = view.downgrade();
1623 move |cx: &mut WindowContext| {
1624 view.update(cx, |view, cx| f(view, cx)).ok();
1625 }
1626 }
1627
1628 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1629 /// If the callback returns false, the window won't be closed.
1630 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1631 let mut this = self.to_async();
1632 self.window
1633 .platform_window
1634 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
1635 }
1636
1637 pub(crate) fn parent_view_id(&self) -> EntityId {
1638 *self
1639 .window
1640 .next_frame
1641 .view_stack
1642 .last()
1643 .expect("a view should always be on the stack while drawing")
1644 }
1645
1646 /// Register an action listener on the window for the next frame. The type of action
1647 /// is determined by the first parameter of the given listener. When the next frame is rendered
1648 /// the listener will be cleared.
1649 ///
1650 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1651 /// a specific need to register a global listener.
1652 pub fn on_action(
1653 &mut self,
1654 action_type: TypeId,
1655 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1656 ) {
1657 self.window
1658 .next_frame
1659 .dispatch_tree
1660 .on_action(action_type, Rc::new(listener));
1661 }
1662}
1663
1664impl Context for WindowContext<'_> {
1665 type Result<T> = T;
1666
1667 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1668 where
1669 T: 'static,
1670 {
1671 let slot = self.app.entities.reserve();
1672 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1673 self.entities.insert(slot, model)
1674 }
1675
1676 fn update_model<T: 'static, R>(
1677 &mut self,
1678 model: &Model<T>,
1679 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1680 ) -> R {
1681 let mut entity = self.entities.lease(model);
1682 let result = update(
1683 &mut *entity,
1684 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1685 );
1686 self.entities.end_lease(entity);
1687 result
1688 }
1689
1690 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1691 where
1692 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1693 {
1694 if window == self.window.handle {
1695 let root_view = self.window.root_view.clone().unwrap();
1696 Ok(update(root_view, self))
1697 } else {
1698 window.update(self.app, update)
1699 }
1700 }
1701
1702 fn read_model<T, R>(
1703 &self,
1704 handle: &Model<T>,
1705 read: impl FnOnce(&T, &AppContext) -> R,
1706 ) -> Self::Result<R>
1707 where
1708 T: 'static,
1709 {
1710 let entity = self.entities.read(handle);
1711 read(entity, &*self.app)
1712 }
1713
1714 fn read_window<T, R>(
1715 &self,
1716 window: &WindowHandle<T>,
1717 read: impl FnOnce(View<T>, &AppContext) -> R,
1718 ) -> Result<R>
1719 where
1720 T: 'static,
1721 {
1722 if window.any_handle == self.window.handle {
1723 let root_view = self
1724 .window
1725 .root_view
1726 .clone()
1727 .unwrap()
1728 .downcast::<T>()
1729 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1730 Ok(read(root_view, self))
1731 } else {
1732 self.app.read_window(window, read)
1733 }
1734 }
1735}
1736
1737impl VisualContext for WindowContext<'_> {
1738 fn new_view<V>(
1739 &mut self,
1740 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1741 ) -> Self::Result<View<V>>
1742 where
1743 V: 'static + Render,
1744 {
1745 let slot = self.app.entities.reserve();
1746 let view = View {
1747 model: slot.clone(),
1748 };
1749 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1750 let entity = build_view_state(&mut cx);
1751 cx.entities.insert(slot, entity);
1752
1753 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1754 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1755 cx.new_view_observers.clone().retain(&tid, |observer| {
1756 let any_view = view.clone();
1757 (observer)(any_view, cx);
1758 true
1759 });
1760 }
1761 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1762
1763 view
1764 }
1765
1766 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1767 fn update_view<T: 'static, R>(
1768 &mut self,
1769 view: &View<T>,
1770 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1771 ) -> Self::Result<R> {
1772 let mut lease = self.app.entities.lease(&view.model);
1773 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1774 let result = update(&mut *lease, &mut cx);
1775 cx.app.entities.end_lease(lease);
1776 result
1777 }
1778
1779 fn replace_root_view<V>(
1780 &mut self,
1781 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1782 ) -> Self::Result<View<V>>
1783 where
1784 V: 'static + Render,
1785 {
1786 let view = self.new_view(build_view);
1787 self.window.root_view = Some(view.clone().into());
1788 self.refresh();
1789 view
1790 }
1791
1792 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1793 self.update_view(view, |view, cx| {
1794 view.focus_handle(cx).clone().focus(cx);
1795 })
1796 }
1797
1798 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1799 where
1800 V: ManagedView,
1801 {
1802 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1803 }
1804}
1805
1806impl<'a> std::ops::Deref for WindowContext<'a> {
1807 type Target = AppContext;
1808
1809 fn deref(&self) -> &Self::Target {
1810 self.app
1811 }
1812}
1813
1814impl<'a> std::ops::DerefMut for WindowContext<'a> {
1815 fn deref_mut(&mut self) -> &mut Self::Target {
1816 self.app
1817 }
1818}
1819
1820impl<'a> Borrow<AppContext> for WindowContext<'a> {
1821 fn borrow(&self) -> &AppContext {
1822 self.app
1823 }
1824}
1825
1826impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1827 fn borrow_mut(&mut self) -> &mut AppContext {
1828 self.app
1829 }
1830}
1831
1832/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1833pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1834 #[doc(hidden)]
1835 fn app_mut(&mut self) -> &mut AppContext {
1836 self.borrow_mut()
1837 }
1838
1839 #[doc(hidden)]
1840 fn app(&self) -> &AppContext {
1841 self.borrow()
1842 }
1843
1844 #[doc(hidden)]
1845 fn window(&self) -> &Window {
1846 self.borrow()
1847 }
1848
1849 #[doc(hidden)]
1850 fn window_mut(&mut self) -> &mut Window {
1851 self.borrow_mut()
1852 }
1853}
1854
1855impl Borrow<Window> for WindowContext<'_> {
1856 fn borrow(&self) -> &Window {
1857 self.window
1858 }
1859}
1860
1861impl BorrowMut<Window> for WindowContext<'_> {
1862 fn borrow_mut(&mut self) -> &mut Window {
1863 self.window
1864 }
1865}
1866
1867impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1868
1869/// Provides access to application state that is specialized for a particular [`View`].
1870/// Allows you to interact with focus, emit events, etc.
1871/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1872/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1873pub struct ViewContext<'a, V> {
1874 window_cx: WindowContext<'a>,
1875 view: &'a View<V>,
1876}
1877
1878impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1879 fn borrow(&self) -> &AppContext {
1880 &*self.window_cx.app
1881 }
1882}
1883
1884impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1885 fn borrow_mut(&mut self) -> &mut AppContext {
1886 &mut *self.window_cx.app
1887 }
1888}
1889
1890impl<V> Borrow<Window> for ViewContext<'_, V> {
1891 fn borrow(&self) -> &Window {
1892 &*self.window_cx.window
1893 }
1894}
1895
1896impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1897 fn borrow_mut(&mut self) -> &mut Window {
1898 &mut *self.window_cx.window
1899 }
1900}
1901
1902impl<'a, V: 'static> ViewContext<'a, V> {
1903 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1904 Self {
1905 window_cx: WindowContext::new(app, window),
1906 view,
1907 }
1908 }
1909
1910 /// Get the entity_id of this view.
1911 pub fn entity_id(&self) -> EntityId {
1912 self.view.entity_id()
1913 }
1914
1915 /// Get the view pointer underlying this context.
1916 pub fn view(&self) -> &View<V> {
1917 self.view
1918 }
1919
1920 /// Get the model underlying this view.
1921 pub fn model(&self) -> &Model<V> {
1922 &self.view.model
1923 }
1924
1925 /// Access the underlying window context.
1926 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1927 &mut self.window_cx
1928 }
1929
1930 /// Sets a given callback to be run on the next frame.
1931 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1932 where
1933 V: 'static,
1934 {
1935 let view = self.view().clone();
1936 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1937 }
1938
1939 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1940 /// that are currently on the stack to be returned to the app.
1941 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1942 let view = self.view().downgrade();
1943 self.window_cx.defer(move |cx| {
1944 view.update(cx, f).ok();
1945 });
1946 }
1947
1948 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1949 pub fn observe<V2, E>(
1950 &mut self,
1951 entity: &E,
1952 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1953 ) -> Subscription
1954 where
1955 V2: 'static,
1956 V: 'static,
1957 E: Entity<V2>,
1958 {
1959 let view = self.view().downgrade();
1960 let entity_id = entity.entity_id();
1961 let entity = entity.downgrade();
1962 let window_handle = self.window.handle;
1963 self.app.new_observer(
1964 entity_id,
1965 Box::new(move |cx| {
1966 window_handle
1967 .update(cx, |_, cx| {
1968 if let Some(handle) = E::upgrade_from(&entity) {
1969 view.update(cx, |this, cx| on_notify(this, handle, cx))
1970 .is_ok()
1971 } else {
1972 false
1973 }
1974 })
1975 .unwrap_or(false)
1976 }),
1977 )
1978 }
1979
1980 /// Subscribe to events emitted by another model or view.
1981 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1982 /// 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.
1983 pub fn subscribe<V2, E, Evt>(
1984 &mut self,
1985 entity: &E,
1986 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1987 ) -> Subscription
1988 where
1989 V2: EventEmitter<Evt>,
1990 E: Entity<V2>,
1991 Evt: 'static,
1992 {
1993 let view = self.view().downgrade();
1994 let entity_id = entity.entity_id();
1995 let handle = entity.downgrade();
1996 let window_handle = self.window.handle;
1997 self.app.new_subscription(
1998 entity_id,
1999 (
2000 TypeId::of::<Evt>(),
2001 Box::new(move |event, cx| {
2002 window_handle
2003 .update(cx, |_, cx| {
2004 if let Some(handle) = E::upgrade_from(&handle) {
2005 let event = event.downcast_ref().expect("invalid event type");
2006 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2007 .is_ok()
2008 } else {
2009 false
2010 }
2011 })
2012 .unwrap_or(false)
2013 }),
2014 ),
2015 )
2016 }
2017
2018 /// Register a callback to be invoked when the view is released.
2019 ///
2020 /// The callback receives a handle to the view's window. This handle may be
2021 /// invalid, if the window was closed before the view was released.
2022 pub fn on_release(
2023 &mut self,
2024 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2025 ) -> Subscription {
2026 let window_handle = self.window.handle;
2027 let (subscription, activate) = self.app.release_listeners.insert(
2028 self.view.model.entity_id,
2029 Box::new(move |this, cx| {
2030 let this = this.downcast_mut().expect("invalid entity type");
2031 on_release(this, window_handle, cx)
2032 }),
2033 );
2034 activate();
2035 subscription
2036 }
2037
2038 /// Register a callback to be invoked when the given Model or View is released.
2039 pub fn observe_release<V2, E>(
2040 &mut self,
2041 entity: &E,
2042 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2043 ) -> Subscription
2044 where
2045 V: 'static,
2046 V2: 'static,
2047 E: Entity<V2>,
2048 {
2049 let view = self.view().downgrade();
2050 let entity_id = entity.entity_id();
2051 let window_handle = self.window.handle;
2052 let (subscription, activate) = self.app.release_listeners.insert(
2053 entity_id,
2054 Box::new(move |entity, cx| {
2055 let entity = entity.downcast_mut().expect("invalid entity type");
2056 let _ = window_handle.update(cx, |_, cx| {
2057 view.update(cx, |this, cx| on_release(this, entity, cx))
2058 });
2059 }),
2060 );
2061 activate();
2062 subscription
2063 }
2064
2065 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2066 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2067 pub fn notify(&mut self) {
2068 for view_id in self
2069 .window
2070 .rendered_frame
2071 .dispatch_tree
2072 .view_path(self.view.entity_id())
2073 .into_iter()
2074 .rev()
2075 {
2076 if !self.window.dirty_views.insert(view_id) {
2077 break;
2078 }
2079 }
2080
2081 if !self.window.drawing {
2082 self.window_cx.window.dirty.set(true);
2083 self.window_cx.app.push_effect(Effect::Notify {
2084 emitter: self.view.model.entity_id,
2085 });
2086 }
2087 }
2088
2089 /// Register a callback to be invoked when the window is resized.
2090 pub fn observe_window_bounds(
2091 &mut self,
2092 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2093 ) -> Subscription {
2094 let view = self.view.downgrade();
2095 let (subscription, activate) = self.window.bounds_observers.insert(
2096 (),
2097 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2098 );
2099 activate();
2100 subscription
2101 }
2102
2103 /// Register a callback to be invoked when the window is activated or deactivated.
2104 pub fn observe_window_activation(
2105 &mut self,
2106 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2107 ) -> Subscription {
2108 let view = self.view.downgrade();
2109 let (subscription, activate) = self.window.activation_observers.insert(
2110 (),
2111 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2112 );
2113 activate();
2114 subscription
2115 }
2116
2117 /// Registers a callback to be invoked when the window appearance changes.
2118 pub fn observe_window_appearance(
2119 &mut self,
2120 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2121 ) -> Subscription {
2122 let view = self.view.downgrade();
2123 let (subscription, activate) = self.window.appearance_observers.insert(
2124 (),
2125 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2126 );
2127 activate();
2128 subscription
2129 }
2130
2131 /// Register a listener to be called when the given focus handle receives focus.
2132 /// Returns a subscription and persists until the subscription is dropped.
2133 pub fn on_focus(
2134 &mut self,
2135 handle: &FocusHandle,
2136 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2137 ) -> Subscription {
2138 let view = self.view.downgrade();
2139 let focus_id = handle.id;
2140 let (subscription, activate) =
2141 self.window.new_focus_listener(Box::new(move |event, cx| {
2142 view.update(cx, |view, cx| {
2143 if event.previous_focus_path.last() != Some(&focus_id)
2144 && event.current_focus_path.last() == Some(&focus_id)
2145 {
2146 listener(view, cx)
2147 }
2148 })
2149 .is_ok()
2150 }));
2151 self.app.defer(|_| activate());
2152 subscription
2153 }
2154
2155 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2156 /// Returns a subscription and persists until the subscription is dropped.
2157 pub fn on_focus_in(
2158 &mut self,
2159 handle: &FocusHandle,
2160 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2161 ) -> Subscription {
2162 let view = self.view.downgrade();
2163 let focus_id = handle.id;
2164 let (subscription, activate) =
2165 self.window.new_focus_listener(Box::new(move |event, cx| {
2166 view.update(cx, |view, cx| {
2167 if !event.previous_focus_path.contains(&focus_id)
2168 && event.current_focus_path.contains(&focus_id)
2169 {
2170 listener(view, cx)
2171 }
2172 })
2173 .is_ok()
2174 }));
2175 self.app.defer(move |_| activate());
2176 subscription
2177 }
2178
2179 /// Register a listener to be called when the given focus handle loses focus.
2180 /// Returns a subscription and persists until the subscription is dropped.
2181 pub fn on_blur(
2182 &mut self,
2183 handle: &FocusHandle,
2184 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2185 ) -> Subscription {
2186 let view = self.view.downgrade();
2187 let focus_id = handle.id;
2188 let (subscription, activate) =
2189 self.window.new_focus_listener(Box::new(move |event, cx| {
2190 view.update(cx, |view, cx| {
2191 if event.previous_focus_path.last() == Some(&focus_id)
2192 && event.current_focus_path.last() != Some(&focus_id)
2193 {
2194 listener(view, cx)
2195 }
2196 })
2197 .is_ok()
2198 }));
2199 self.app.defer(move |_| activate());
2200 subscription
2201 }
2202
2203 /// Register a listener to be called when nothing in the window has focus.
2204 /// This typically happens when the node that was focused is removed from the tree,
2205 /// and this callback lets you chose a default place to restore the users focus.
2206 /// Returns a subscription and persists until the subscription is dropped.
2207 pub fn on_focus_lost(
2208 &mut self,
2209 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2210 ) -> Subscription {
2211 let view = self.view.downgrade();
2212 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2213 (),
2214 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2215 );
2216 activate();
2217 subscription
2218 }
2219
2220 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2221 /// Returns a subscription and persists until the subscription is dropped.
2222 pub fn on_focus_out(
2223 &mut self,
2224 handle: &FocusHandle,
2225 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2226 ) -> Subscription {
2227 let view = self.view.downgrade();
2228 let focus_id = handle.id;
2229 let (subscription, activate) =
2230 self.window.new_focus_listener(Box::new(move |event, cx| {
2231 view.update(cx, |view, cx| {
2232 if event.previous_focus_path.contains(&focus_id)
2233 && !event.current_focus_path.contains(&focus_id)
2234 {
2235 listener(view, cx)
2236 }
2237 })
2238 .is_ok()
2239 }));
2240 self.app.defer(move |_| activate());
2241 subscription
2242 }
2243
2244 /// Schedule a future to be run asynchronously.
2245 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2246 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2247 /// The returned future will be polled on the main thread.
2248 pub fn spawn<Fut, R>(
2249 &mut self,
2250 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2251 ) -> Task<R>
2252 where
2253 R: 'static,
2254 Fut: Future<Output = R> + 'static,
2255 {
2256 let view = self.view().downgrade();
2257 self.window_cx.spawn(|cx| f(view, cx))
2258 }
2259
2260 /// Updates the global state of the given type.
2261 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2262 where
2263 G: Global,
2264 {
2265 let mut global = self.app.lease_global::<G>();
2266 let result = f(&mut global, self);
2267 self.app.end_global_lease(global);
2268 result
2269 }
2270
2271 /// Register a callback to be invoked when the given global state changes.
2272 pub fn observe_global<G: Global>(
2273 &mut self,
2274 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2275 ) -> Subscription {
2276 let window_handle = self.window.handle;
2277 let view = self.view().downgrade();
2278 let (subscription, activate) = self.global_observers.insert(
2279 TypeId::of::<G>(),
2280 Box::new(move |cx| {
2281 window_handle
2282 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2283 .unwrap_or(false)
2284 }),
2285 );
2286 self.app.defer(move |_| activate());
2287 subscription
2288 }
2289
2290 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2291 pub fn on_action(
2292 &mut self,
2293 action_type: TypeId,
2294 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2295 ) {
2296 let handle = self.view().clone();
2297 self.window_cx
2298 .on_action(action_type, move |action, phase, cx| {
2299 handle.update(cx, |view, cx| {
2300 listener(view, action, phase, cx);
2301 })
2302 });
2303 }
2304
2305 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2306 pub fn emit<Evt>(&mut self, event: Evt)
2307 where
2308 Evt: 'static,
2309 V: EventEmitter<Evt>,
2310 {
2311 let emitter = self.view.model.entity_id;
2312 self.app.push_effect(Effect::Emit {
2313 emitter,
2314 event_type: TypeId::of::<Evt>(),
2315 event: Box::new(event),
2316 });
2317 }
2318
2319 /// Move focus to the current view, assuming it implements [`FocusableView`].
2320 pub fn focus_self(&mut self)
2321 where
2322 V: FocusableView,
2323 {
2324 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2325 }
2326
2327 /// Convenience method for accessing view state in an event callback.
2328 ///
2329 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2330 /// but it's often useful to be able to access view state in these
2331 /// callbacks. This method provides a convenient way to do so.
2332 pub fn listener<E>(
2333 &self,
2334 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2335 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2336 let view = self.view().downgrade();
2337 move |e: &E, cx: &mut WindowContext| {
2338 view.update(cx, |view, cx| f(view, e, cx)).ok();
2339 }
2340 }
2341}
2342
2343impl<V> Context for ViewContext<'_, V> {
2344 type Result<U> = U;
2345
2346 fn new_model<T: 'static>(
2347 &mut self,
2348 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2349 ) -> Model<T> {
2350 self.window_cx.new_model(build_model)
2351 }
2352
2353 fn update_model<T: 'static, R>(
2354 &mut self,
2355 model: &Model<T>,
2356 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2357 ) -> R {
2358 self.window_cx.update_model(model, update)
2359 }
2360
2361 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2362 where
2363 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2364 {
2365 self.window_cx.update_window(window, update)
2366 }
2367
2368 fn read_model<T, R>(
2369 &self,
2370 handle: &Model<T>,
2371 read: impl FnOnce(&T, &AppContext) -> R,
2372 ) -> Self::Result<R>
2373 where
2374 T: 'static,
2375 {
2376 self.window_cx.read_model(handle, read)
2377 }
2378
2379 fn read_window<T, R>(
2380 &self,
2381 window: &WindowHandle<T>,
2382 read: impl FnOnce(View<T>, &AppContext) -> R,
2383 ) -> Result<R>
2384 where
2385 T: 'static,
2386 {
2387 self.window_cx.read_window(window, read)
2388 }
2389}
2390
2391impl<V: 'static> VisualContext for ViewContext<'_, V> {
2392 fn new_view<W: Render + 'static>(
2393 &mut self,
2394 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2395 ) -> Self::Result<View<W>> {
2396 self.window_cx.new_view(build_view_state)
2397 }
2398
2399 fn update_view<V2: 'static, R>(
2400 &mut self,
2401 view: &View<V2>,
2402 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2403 ) -> Self::Result<R> {
2404 self.window_cx.update_view(view, update)
2405 }
2406
2407 fn replace_root_view<W>(
2408 &mut self,
2409 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2410 ) -> Self::Result<View<W>>
2411 where
2412 W: 'static + Render,
2413 {
2414 self.window_cx.replace_root_view(build_view)
2415 }
2416
2417 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2418 self.window_cx.focus_view(view)
2419 }
2420
2421 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2422 self.window_cx.dismiss_view(view)
2423 }
2424}
2425
2426impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2427 type Target = WindowContext<'a>;
2428
2429 fn deref(&self) -> &Self::Target {
2430 &self.window_cx
2431 }
2432}
2433
2434impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2435 fn deref_mut(&mut self) -> &mut Self::Target {
2436 &mut self.window_cx
2437 }
2438}
2439
2440// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2441slotmap::new_key_type! {
2442 /// A unique identifier for a window.
2443 pub struct WindowId;
2444}
2445
2446impl WindowId {
2447 /// Converts this window ID to a `u64`.
2448 pub fn as_u64(&self) -> u64 {
2449 self.0.as_ffi()
2450 }
2451}
2452
2453/// A handle to a window with a specific root view type.
2454/// Note that this does not keep the window alive on its own.
2455#[derive(Deref, DerefMut)]
2456pub struct WindowHandle<V> {
2457 #[deref]
2458 #[deref_mut]
2459 pub(crate) any_handle: AnyWindowHandle,
2460 state_type: PhantomData<V>,
2461}
2462
2463impl<V: 'static + Render> WindowHandle<V> {
2464 /// Creates a new handle from a window ID.
2465 /// This does not check if the root type of the window is `V`.
2466 pub fn new(id: WindowId) -> Self {
2467 WindowHandle {
2468 any_handle: AnyWindowHandle {
2469 id,
2470 state_type: TypeId::of::<V>(),
2471 },
2472 state_type: PhantomData,
2473 }
2474 }
2475
2476 /// Get the root view out of this window.
2477 ///
2478 /// This will fail if the window is closed or if the root view's type does not match `V`.
2479 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2480 where
2481 C: Context,
2482 {
2483 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2484 root_view
2485 .downcast::<V>()
2486 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2487 }))
2488 }
2489
2490 /// Updates the root view of this window.
2491 ///
2492 /// This will fail if the window has been closed or if the root view's type does not match
2493 pub fn update<C, R>(
2494 &self,
2495 cx: &mut C,
2496 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2497 ) -> Result<R>
2498 where
2499 C: Context,
2500 {
2501 cx.update_window(self.any_handle, |root_view, cx| {
2502 let view = root_view
2503 .downcast::<V>()
2504 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2505 Ok(cx.update_view(&view, update))
2506 })?
2507 }
2508
2509 /// Read the root view out of this window.
2510 ///
2511 /// This will fail if the window is closed or if the root view's type does not match `V`.
2512 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2513 let x = cx
2514 .windows
2515 .get(self.id)
2516 .and_then(|window| {
2517 window
2518 .as_ref()
2519 .and_then(|window| window.root_view.clone())
2520 .map(|root_view| root_view.downcast::<V>())
2521 })
2522 .ok_or_else(|| anyhow!("window not found"))?
2523 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2524
2525 Ok(x.read(cx))
2526 }
2527
2528 /// Read the root view out of this window, with a callback
2529 ///
2530 /// This will fail if the window is closed or if the root view's type does not match `V`.
2531 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2532 where
2533 C: Context,
2534 {
2535 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2536 }
2537
2538 /// Read the root view pointer off of this window.
2539 ///
2540 /// This will fail if the window is closed or if the root view's type does not match `V`.
2541 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2542 where
2543 C: Context,
2544 {
2545 cx.read_window(self, |root_view, _cx| root_view.clone())
2546 }
2547
2548 /// Check if this window is 'active'.
2549 ///
2550 /// Will return `None` if the window is closed or currently
2551 /// borrowed.
2552 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
2553 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
2554 .ok()
2555 }
2556}
2557
2558impl<V> Copy for WindowHandle<V> {}
2559
2560impl<V> Clone for WindowHandle<V> {
2561 fn clone(&self) -> Self {
2562 *self
2563 }
2564}
2565
2566impl<V> PartialEq for WindowHandle<V> {
2567 fn eq(&self, other: &Self) -> bool {
2568 self.any_handle == other.any_handle
2569 }
2570}
2571
2572impl<V> Eq for WindowHandle<V> {}
2573
2574impl<V> Hash for WindowHandle<V> {
2575 fn hash<H: Hasher>(&self, state: &mut H) {
2576 self.any_handle.hash(state);
2577 }
2578}
2579
2580impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2581 fn from(val: WindowHandle<V>) -> Self {
2582 val.any_handle
2583 }
2584}
2585
2586/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2587#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2588pub struct AnyWindowHandle {
2589 pub(crate) id: WindowId,
2590 state_type: TypeId,
2591}
2592
2593impl AnyWindowHandle {
2594 /// Get the ID of this window.
2595 pub fn window_id(&self) -> WindowId {
2596 self.id
2597 }
2598
2599 /// Attempt to convert this handle to a window handle with a specific root view type.
2600 /// If the types do not match, this will return `None`.
2601 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2602 if TypeId::of::<T>() == self.state_type {
2603 Some(WindowHandle {
2604 any_handle: *self,
2605 state_type: PhantomData,
2606 })
2607 } else {
2608 None
2609 }
2610 }
2611
2612 /// Updates the state of the root view of this window.
2613 ///
2614 /// This will fail if the window has been closed.
2615 pub fn update<C, R>(
2616 self,
2617 cx: &mut C,
2618 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2619 ) -> Result<R>
2620 where
2621 C: Context,
2622 {
2623 cx.update_window(self, update)
2624 }
2625
2626 /// Read the state of the root view of this window.
2627 ///
2628 /// This will fail if the window has been closed.
2629 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2630 where
2631 C: Context,
2632 T: 'static,
2633 {
2634 let view = self
2635 .downcast::<T>()
2636 .context("the type of the window's root view has changed")?;
2637
2638 cx.read_window(&view, read)
2639 }
2640}
2641
2642/// An identifier for an [`Element`](crate::Element).
2643///
2644/// Can be constructed with a string, a number, or both, as well
2645/// as other internal representations.
2646#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2647pub enum ElementId {
2648 /// The ID of a View element
2649 View(EntityId),
2650 /// An integer ID.
2651 Integer(usize),
2652 /// A string based ID.
2653 Name(SharedString),
2654 /// An ID that's equated with a focus handle.
2655 FocusHandle(FocusId),
2656 /// A combination of a name and an integer.
2657 NamedInteger(SharedString, usize),
2658}
2659
2660impl Display for ElementId {
2661 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2662 match self {
2663 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2664 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2665 ElementId::Name(name) => write!(f, "{}", name)?,
2666 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2667 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2668 }
2669
2670 Ok(())
2671 }
2672}
2673
2674impl ElementId {
2675 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2676 ElementId::View(entity_id)
2677 }
2678}
2679
2680impl TryInto<SharedString> for ElementId {
2681 type Error = anyhow::Error;
2682
2683 fn try_into(self) -> anyhow::Result<SharedString> {
2684 if let ElementId::Name(name) = self {
2685 Ok(name)
2686 } else {
2687 Err(anyhow!("element id is not string"))
2688 }
2689 }
2690}
2691
2692impl From<usize> for ElementId {
2693 fn from(id: usize) -> Self {
2694 ElementId::Integer(id)
2695 }
2696}
2697
2698impl From<i32> for ElementId {
2699 fn from(id: i32) -> Self {
2700 Self::Integer(id as usize)
2701 }
2702}
2703
2704impl From<SharedString> for ElementId {
2705 fn from(name: SharedString) -> Self {
2706 ElementId::Name(name)
2707 }
2708}
2709
2710impl From<&'static str> for ElementId {
2711 fn from(name: &'static str) -> Self {
2712 ElementId::Name(name.into())
2713 }
2714}
2715
2716impl<'a> From<&'a FocusHandle> for ElementId {
2717 fn from(handle: &'a FocusHandle) -> Self {
2718 ElementId::FocusHandle(handle.id)
2719 }
2720}
2721
2722impl From<(&'static str, EntityId)> for ElementId {
2723 fn from((name, id): (&'static str, EntityId)) -> Self {
2724 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2725 }
2726}
2727
2728impl From<(&'static str, usize)> for ElementId {
2729 fn from((name, id): (&'static str, usize)) -> Self {
2730 ElementId::NamedInteger(name.into(), id)
2731 }
2732}
2733
2734impl From<(&'static str, u64)> for ElementId {
2735 fn from((name, id): (&'static str, u64)) -> Self {
2736 ElementId::NamedInteger(name.into(), id as usize)
2737 }
2738}
2739
2740/// A rectangle to be rendered in the window at the given position and size.
2741/// Passed as an argument [`ElementContext::paint_quad`].
2742#[derive(Clone)]
2743pub struct PaintQuad {
2744 bounds: Bounds<Pixels>,
2745 corner_radii: Corners<Pixels>,
2746 background: Hsla,
2747 border_widths: Edges<Pixels>,
2748 border_color: Hsla,
2749}
2750
2751impl PaintQuad {
2752 /// Sets the corner radii of the quad.
2753 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2754 PaintQuad {
2755 corner_radii: corner_radii.into(),
2756 ..self
2757 }
2758 }
2759
2760 /// Sets the border widths of the quad.
2761 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2762 PaintQuad {
2763 border_widths: border_widths.into(),
2764 ..self
2765 }
2766 }
2767
2768 /// Sets the border color of the quad.
2769 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2770 PaintQuad {
2771 border_color: border_color.into(),
2772 ..self
2773 }
2774 }
2775
2776 /// Sets the background color of the quad.
2777 pub fn background(self, background: impl Into<Hsla>) -> Self {
2778 PaintQuad {
2779 background: background.into(),
2780 ..self
2781 }
2782 }
2783}
2784
2785/// Creates a quad with the given parameters.
2786pub fn quad(
2787 bounds: Bounds<Pixels>,
2788 corner_radii: impl Into<Corners<Pixels>>,
2789 background: impl Into<Hsla>,
2790 border_widths: impl Into<Edges<Pixels>>,
2791 border_color: impl Into<Hsla>,
2792) -> PaintQuad {
2793 PaintQuad {
2794 bounds,
2795 corner_radii: corner_radii.into(),
2796 background: background.into(),
2797 border_widths: border_widths.into(),
2798 border_color: border_color.into(),
2799 }
2800}
2801
2802/// Creates a filled quad with the given bounds and background color.
2803pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2804 PaintQuad {
2805 bounds: bounds.into(),
2806 corner_radii: (0.).into(),
2807 background: background.into(),
2808 border_widths: (0.).into(),
2809 border_color: transparent_black(),
2810 }
2811}
2812
2813/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2814pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2815 PaintQuad {
2816 bounds: bounds.into(),
2817 corner_radii: (0.).into(),
2818 background: transparent_black(),
2819 border_widths: (1.).into(),
2820 border_color: border_color.into(),
2821 }
2822}