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 #[profiling::function]
954 pub fn draw(&mut self) {
955 self.window.dirty.set(false);
956 self.window.drawing = true;
957
958 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
959 {
960 let input_handler = self.window.platform_window.take_input_handler();
961 requested_handler.handler = input_handler;
962 }
963
964 let root_view = self.window.root_view.take().unwrap();
965 self.with_element_context(|cx| {
966 cx.with_z_index(0, |cx| {
967 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
968 // We need to use cx.cx here so we can utilize borrow splitting
969 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
970 for action_listener in action_listeners.iter().cloned() {
971 cx.cx.window.next_frame.dispatch_tree.on_action(
972 *action_type,
973 Rc::new(
974 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
975 action_listener(action, phase, cx)
976 },
977 ),
978 )
979 }
980 }
981
982 let available_space = cx.window.viewport_size.map(Into::into);
983 root_view.draw(Point::default(), available_space, cx);
984 })
985 })
986 });
987
988 if let Some(active_drag) = self.app.active_drag.take() {
989 self.with_element_context(|cx| {
990 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
991 let offset = cx.mouse_position() - active_drag.cursor_offset;
992 let available_space =
993 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
994 active_drag.view.draw(offset, available_space, cx);
995 })
996 });
997 self.active_drag = Some(active_drag);
998 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
999 self.with_element_context(|cx| {
1000 cx.with_z_index(1, |cx| {
1001 let available_space =
1002 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1003 tooltip_request.tooltip.view.draw(
1004 tooltip_request.tooltip.cursor_offset,
1005 available_space,
1006 cx,
1007 );
1008 })
1009 });
1010 self.window.next_frame.tooltip_request = Some(tooltip_request);
1011 }
1012 self.window.dirty_views.clear();
1013
1014 self.window
1015 .next_frame
1016 .dispatch_tree
1017 .preserve_pending_keystrokes(
1018 &mut self.window.rendered_frame.dispatch_tree,
1019 self.window.focus,
1020 );
1021 self.window.next_frame.focus = self.window.focus;
1022 self.window.next_frame.window_active = self.window.active.get();
1023 self.window.root_view = Some(root_view);
1024
1025 // Set the cursor only if we're the active window.
1026 let cursor_style = self
1027 .window
1028 .next_frame
1029 .requested_cursor_style
1030 .take()
1031 .unwrap_or(CursorStyle::Arrow);
1032 if self.is_window_active() {
1033 self.platform.set_cursor_style(cursor_style);
1034 }
1035
1036 // Register requested input handler with the platform window.
1037 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1038 if let Some(handler) = requested_input.handler.take() {
1039 self.window.platform_window.set_input_handler(handler);
1040 }
1041 }
1042
1043 self.window.layout_engine.as_mut().unwrap().clear();
1044 self.text_system()
1045 .finish_frame(&self.window.next_frame.reused_views);
1046 self.window
1047 .next_frame
1048 .finish(&mut self.window.rendered_frame);
1049 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1050 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1051 if percentage >= 80. {
1052 log::warn!("elevated element arena occupation: {}.", percentage);
1053 }
1054 element_arena.clear();
1055 });
1056
1057 let previous_focus_path = self.window.rendered_frame.focus_path();
1058 let previous_window_active = self.window.rendered_frame.window_active;
1059 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1060 self.window.next_frame.clear();
1061 let current_focus_path = self.window.rendered_frame.focus_path();
1062 let current_window_active = self.window.rendered_frame.window_active;
1063
1064 if previous_focus_path != current_focus_path
1065 || previous_window_active != current_window_active
1066 {
1067 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1068 self.window
1069 .focus_lost_listeners
1070 .clone()
1071 .retain(&(), |listener| listener(self));
1072 }
1073
1074 let event = FocusEvent {
1075 previous_focus_path: if previous_window_active {
1076 previous_focus_path
1077 } else {
1078 Default::default()
1079 },
1080 current_focus_path: if current_window_active {
1081 current_focus_path
1082 } else {
1083 Default::default()
1084 },
1085 };
1086 self.window
1087 .focus_listeners
1088 .clone()
1089 .retain(&(), |listener| listener(&event, self));
1090 }
1091 self.window.refreshing = false;
1092 self.window.drawing = false;
1093 self.window.needs_present.set(true);
1094 }
1095
1096 #[profiling::function]
1097 fn present(&self) {
1098 self.window
1099 .platform_window
1100 .draw(&self.window.rendered_frame.scene);
1101 self.window.needs_present.set(false);
1102 profiling::finish_frame!();
1103 }
1104
1105 /// Dispatch a given keystroke as though the user had typed it.
1106 /// You can create a keystroke with Keystroke::parse("").
1107 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
1108 let keystroke = keystroke.with_simulated_ime();
1109 if self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
1110 keystroke: keystroke.clone(),
1111 is_held: false,
1112 })) {
1113 return true;
1114 }
1115
1116 if let Some(input) = keystroke.ime_key {
1117 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1118 input_handler.dispatch_input(&input, self);
1119 self.window.platform_window.set_input_handler(input_handler);
1120 return true;
1121 }
1122 }
1123
1124 false
1125 }
1126
1127 /// Dispatch a mouse or keyboard event on the window.
1128 #[profiling::function]
1129 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1130 self.window.last_input_timestamp.set(Instant::now());
1131 // Handlers may set this to false by calling `stop_propagation`.
1132 self.app.propagate_event = true;
1133 // Handlers may set this to true by calling `prevent_default`.
1134 self.window.default_prevented = false;
1135
1136 let event = match event {
1137 // Track the mouse position with our own state, since accessing the platform
1138 // API for the mouse position can only occur on the main thread.
1139 PlatformInput::MouseMove(mouse_move) => {
1140 self.window.mouse_position = mouse_move.position;
1141 self.window.modifiers = mouse_move.modifiers;
1142 PlatformInput::MouseMove(mouse_move)
1143 }
1144 PlatformInput::MouseDown(mouse_down) => {
1145 self.window.mouse_position = mouse_down.position;
1146 self.window.modifiers = mouse_down.modifiers;
1147 PlatformInput::MouseDown(mouse_down)
1148 }
1149 PlatformInput::MouseUp(mouse_up) => {
1150 self.window.mouse_position = mouse_up.position;
1151 self.window.modifiers = mouse_up.modifiers;
1152 PlatformInput::MouseUp(mouse_up)
1153 }
1154 PlatformInput::MouseExited(mouse_exited) => {
1155 self.window.modifiers = mouse_exited.modifiers;
1156 PlatformInput::MouseExited(mouse_exited)
1157 }
1158 PlatformInput::ModifiersChanged(modifiers_changed) => {
1159 self.window.modifiers = modifiers_changed.modifiers;
1160 PlatformInput::ModifiersChanged(modifiers_changed)
1161 }
1162 PlatformInput::ScrollWheel(scroll_wheel) => {
1163 self.window.mouse_position = scroll_wheel.position;
1164 self.window.modifiers = scroll_wheel.modifiers;
1165 PlatformInput::ScrollWheel(scroll_wheel)
1166 }
1167 // Translate dragging and dropping of external files from the operating system
1168 // to internal drag and drop events.
1169 PlatformInput::FileDrop(file_drop) => match file_drop {
1170 FileDropEvent::Entered { position, paths } => {
1171 self.window.mouse_position = position;
1172 if self.active_drag.is_none() {
1173 self.active_drag = Some(AnyDrag {
1174 value: Box::new(paths.clone()),
1175 view: self.new_view(|_| paths).into(),
1176 cursor_offset: position,
1177 });
1178 }
1179 PlatformInput::MouseMove(MouseMoveEvent {
1180 position,
1181 pressed_button: Some(MouseButton::Left),
1182 modifiers: Modifiers::default(),
1183 })
1184 }
1185 FileDropEvent::Pending { position } => {
1186 self.window.mouse_position = position;
1187 PlatformInput::MouseMove(MouseMoveEvent {
1188 position,
1189 pressed_button: Some(MouseButton::Left),
1190 modifiers: Modifiers::default(),
1191 })
1192 }
1193 FileDropEvent::Submit { position } => {
1194 self.activate(true);
1195 self.window.mouse_position = position;
1196 PlatformInput::MouseUp(MouseUpEvent {
1197 button: MouseButton::Left,
1198 position,
1199 modifiers: Modifiers::default(),
1200 click_count: 1,
1201 })
1202 }
1203 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1204 button: MouseButton::Left,
1205 position: Point::default(),
1206 modifiers: Modifiers::default(),
1207 click_count: 1,
1208 }),
1209 },
1210 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1211 };
1212
1213 if let Some(any_mouse_event) = event.mouse_event() {
1214 self.dispatch_mouse_event(any_mouse_event);
1215 } else if let Some(any_key_event) = event.keyboard_event() {
1216 self.dispatch_key_event(any_key_event);
1217 }
1218
1219 !self.app.propagate_event
1220 }
1221
1222 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1223 if let Some(mut handlers) = self
1224 .window
1225 .rendered_frame
1226 .mouse_listeners
1227 .remove(&event.type_id())
1228 {
1229 // Because handlers may add other handlers, we sort every time.
1230 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1231
1232 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1233 // special purposes, such as detecting events outside of a given Bounds.
1234 for (_, _, handler) in &mut handlers {
1235 self.with_element_context(|cx| {
1236 handler(event, DispatchPhase::Capture, cx);
1237 });
1238 if !self.app.propagate_event {
1239 break;
1240 }
1241 }
1242
1243 // Bubble phase, where most normal handlers do their work.
1244 if self.app.propagate_event {
1245 for (_, _, handler) in handlers.iter_mut().rev() {
1246 self.with_element_context(|cx| {
1247 handler(event, DispatchPhase::Bubble, cx);
1248 });
1249 if !self.app.propagate_event {
1250 break;
1251 }
1252 }
1253 }
1254
1255 self.window
1256 .rendered_frame
1257 .mouse_listeners
1258 .insert(event.type_id(), handlers);
1259 }
1260
1261 if self.app.propagate_event && self.has_active_drag() {
1262 if event.is::<MouseMoveEvent>() {
1263 // If this was a mouse move event, redraw the window so that the
1264 // active drag can follow the mouse cursor.
1265 self.refresh();
1266 } else if event.is::<MouseUpEvent>() {
1267 // If this was a mouse up event, cancel the active drag and redraw
1268 // the window.
1269 self.active_drag = None;
1270 self.refresh();
1271 }
1272 }
1273 }
1274
1275 fn dispatch_key_event(&mut self, event: &dyn Any) {
1276 if self.window.dirty.get() {
1277 self.draw();
1278 }
1279
1280 let node_id = self
1281 .window
1282 .focus
1283 .and_then(|focus_id| {
1284 self.window
1285 .rendered_frame
1286 .dispatch_tree
1287 .focusable_node_id(focus_id)
1288 })
1289 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1290
1291 let dispatch_path = self
1292 .window
1293 .rendered_frame
1294 .dispatch_tree
1295 .dispatch_path(node_id);
1296
1297 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1298 let KeymatchResult { bindings, pending } = self
1299 .window
1300 .rendered_frame
1301 .dispatch_tree
1302 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1303
1304 if pending {
1305 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1306 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1307 {
1308 currently_pending = PendingInput::default();
1309 }
1310 currently_pending.focus = self.window.focus;
1311 currently_pending
1312 .keystrokes
1313 .push(key_down_event.keystroke.clone());
1314 for binding in bindings {
1315 currently_pending.bindings.push(binding);
1316 }
1317
1318 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1319 cx.background_executor.timer(Duration::from_secs(1)).await;
1320 cx.update(move |cx| {
1321 cx.clear_pending_keystrokes();
1322 let Some(currently_pending) = cx.window.pending_input.take() else {
1323 return;
1324 };
1325 cx.replay_pending_input(currently_pending)
1326 })
1327 .log_err();
1328 }));
1329 self.window.pending_input = Some(currently_pending);
1330
1331 self.propagate_event = false;
1332 return;
1333 } else if let Some(currently_pending) = self.window.pending_input.take() {
1334 if bindings
1335 .iter()
1336 .all(|binding| !currently_pending.used_by_binding(binding))
1337 {
1338 self.replay_pending_input(currently_pending)
1339 }
1340 }
1341
1342 if !bindings.is_empty() {
1343 self.clear_pending_keystrokes();
1344 }
1345
1346 self.propagate_event = true;
1347 for binding in bindings {
1348 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1349 if !self.propagate_event {
1350 self.dispatch_keystroke_observers(event, Some(binding.action));
1351 return;
1352 }
1353 }
1354 }
1355
1356 self.dispatch_key_down_up_event(event, &dispatch_path);
1357 if !self.propagate_event {
1358 return;
1359 }
1360
1361 self.dispatch_keystroke_observers(event, None);
1362 }
1363
1364 fn dispatch_key_down_up_event(
1365 &mut self,
1366 event: &dyn Any,
1367 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1368 ) {
1369 // Capture phase
1370 for node_id in dispatch_path {
1371 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1372
1373 for key_listener in node.key_listeners.clone() {
1374 self.with_element_context(|cx| {
1375 key_listener(event, DispatchPhase::Capture, cx);
1376 });
1377 if !self.propagate_event {
1378 return;
1379 }
1380 }
1381 }
1382
1383 // Bubble phase
1384 for node_id in dispatch_path.iter().rev() {
1385 // Handle low level key events
1386 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1387 for key_listener in node.key_listeners.clone() {
1388 self.with_element_context(|cx| {
1389 key_listener(event, DispatchPhase::Bubble, cx);
1390 });
1391 if !self.propagate_event {
1392 return;
1393 }
1394 }
1395 }
1396 }
1397
1398 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1399 pub fn has_pending_keystrokes(&self) -> bool {
1400 self.window
1401 .rendered_frame
1402 .dispatch_tree
1403 .has_pending_keystrokes()
1404 }
1405
1406 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1407 let node_id = self
1408 .window
1409 .focus
1410 .and_then(|focus_id| {
1411 self.window
1412 .rendered_frame
1413 .dispatch_tree
1414 .focusable_node_id(focus_id)
1415 })
1416 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1417
1418 if self.window.focus != currently_pending.focus {
1419 return;
1420 }
1421
1422 let input = currently_pending.input();
1423
1424 self.propagate_event = true;
1425 for binding in currently_pending.bindings {
1426 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1427 if !self.propagate_event {
1428 return;
1429 }
1430 }
1431
1432 let dispatch_path = self
1433 .window
1434 .rendered_frame
1435 .dispatch_tree
1436 .dispatch_path(node_id);
1437
1438 for keystroke in currently_pending.keystrokes {
1439 let event = KeyDownEvent {
1440 keystroke,
1441 is_held: false,
1442 };
1443
1444 self.dispatch_key_down_up_event(&event, &dispatch_path);
1445 if !self.propagate_event {
1446 return;
1447 }
1448 }
1449
1450 if !input.is_empty() {
1451 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1452 input_handler.dispatch_input(&input, self);
1453 self.window.platform_window.set_input_handler(input_handler)
1454 }
1455 }
1456 }
1457
1458 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1459 let dispatch_path = self
1460 .window
1461 .rendered_frame
1462 .dispatch_tree
1463 .dispatch_path(node_id);
1464
1465 // Capture phase
1466 for node_id in &dispatch_path {
1467 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1468 for DispatchActionListener {
1469 action_type,
1470 listener,
1471 } in node.action_listeners.clone()
1472 {
1473 let any_action = action.as_any();
1474 if action_type == any_action.type_id() {
1475 self.with_element_context(|cx| {
1476 listener(any_action, DispatchPhase::Capture, cx);
1477 });
1478
1479 if !self.propagate_event {
1480 return;
1481 }
1482 }
1483 }
1484 }
1485 // Bubble phase
1486 for node_id in dispatch_path.iter().rev() {
1487 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1488 for DispatchActionListener {
1489 action_type,
1490 listener,
1491 } in node.action_listeners.clone()
1492 {
1493 let any_action = action.as_any();
1494 if action_type == any_action.type_id() {
1495 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1496
1497 self.with_element_context(|cx| {
1498 listener(any_action, DispatchPhase::Bubble, cx);
1499 });
1500
1501 if !self.propagate_event {
1502 return;
1503 }
1504 }
1505 }
1506 }
1507 }
1508
1509 /// Toggle the graphics profiler to debug your application's rendering performance.
1510 pub fn toggle_graphics_profiler(&mut self) {
1511 self.window.graphics_profiler_enabled = !self.window.graphics_profiler_enabled;
1512 self.window
1513 .platform_window
1514 .set_graphics_profiler_enabled(self.window.graphics_profiler_enabled);
1515 }
1516
1517 /// Register the given handler to be invoked whenever the global of the given type
1518 /// is updated.
1519 pub fn observe_global<G: Global>(
1520 &mut self,
1521 f: impl Fn(&mut WindowContext<'_>) + 'static,
1522 ) -> Subscription {
1523 let window_handle = self.window.handle;
1524 let (subscription, activate) = self.global_observers.insert(
1525 TypeId::of::<G>(),
1526 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1527 );
1528 self.app.defer(move |_| activate());
1529 subscription
1530 }
1531
1532 /// Focus the current window and bring it to the foreground at the platform level.
1533 pub fn activate_window(&self) {
1534 self.window.platform_window.activate();
1535 }
1536
1537 /// Minimize the current window at the platform level.
1538 pub fn minimize_window(&self) {
1539 self.window.platform_window.minimize();
1540 }
1541
1542 /// Toggle full screen status on the current window at the platform level.
1543 pub fn toggle_full_screen(&self) {
1544 self.window.platform_window.toggle_full_screen();
1545 }
1546
1547 /// Present a platform dialog.
1548 /// The provided message will be presented, along with buttons for each answer.
1549 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1550 pub fn prompt(
1551 &self,
1552 level: PromptLevel,
1553 message: &str,
1554 detail: Option<&str>,
1555 answers: &[&str],
1556 ) -> oneshot::Receiver<usize> {
1557 self.window
1558 .platform_window
1559 .prompt(level, message, detail, answers)
1560 }
1561
1562 /// Returns all available actions for the focused element.
1563 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1564 let node_id = self
1565 .window
1566 .focus
1567 .and_then(|focus_id| {
1568 self.window
1569 .rendered_frame
1570 .dispatch_tree
1571 .focusable_node_id(focus_id)
1572 })
1573 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1574
1575 self.window
1576 .rendered_frame
1577 .dispatch_tree
1578 .available_actions(node_id)
1579 }
1580
1581 /// Returns key bindings that invoke the given action on the currently focused element.
1582 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1583 self.window
1584 .rendered_frame
1585 .dispatch_tree
1586 .bindings_for_action(
1587 action,
1588 &self.window.rendered_frame.dispatch_tree.context_stack,
1589 )
1590 }
1591
1592 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1593 pub fn bindings_for_action_in(
1594 &self,
1595 action: &dyn Action,
1596 focus_handle: &FocusHandle,
1597 ) -> Vec<KeyBinding> {
1598 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1599
1600 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1601 return vec![];
1602 };
1603 let context_stack: Vec<_> = dispatch_tree
1604 .dispatch_path(node_id)
1605 .into_iter()
1606 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1607 .collect();
1608 dispatch_tree.bindings_for_action(action, &context_stack)
1609 }
1610
1611 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1612 pub fn listener_for<V: Render, E>(
1613 &self,
1614 view: &View<V>,
1615 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1616 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1617 let view = view.downgrade();
1618 move |e: &E, cx: &mut WindowContext| {
1619 view.update(cx, |view, cx| f(view, e, cx)).ok();
1620 }
1621 }
1622
1623 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1624 pub fn handler_for<V: Render>(
1625 &self,
1626 view: &View<V>,
1627 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1628 ) -> impl Fn(&mut WindowContext) {
1629 let view = view.downgrade();
1630 move |cx: &mut WindowContext| {
1631 view.update(cx, |view, cx| f(view, cx)).ok();
1632 }
1633 }
1634
1635 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1636 /// If the callback returns false, the window won't be closed.
1637 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1638 let mut this = self.to_async();
1639 self.window
1640 .platform_window
1641 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
1642 }
1643
1644 pub(crate) fn parent_view_id(&self) -> EntityId {
1645 *self
1646 .window
1647 .next_frame
1648 .view_stack
1649 .last()
1650 .expect("a view should always be on the stack while drawing")
1651 }
1652
1653 /// Register an action listener on the window for the next frame. The type of action
1654 /// is determined by the first parameter of the given listener. When the next frame is rendered
1655 /// the listener will be cleared.
1656 ///
1657 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1658 /// a specific need to register a global listener.
1659 pub fn on_action(
1660 &mut self,
1661 action_type: TypeId,
1662 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1663 ) {
1664 self.window
1665 .next_frame
1666 .dispatch_tree
1667 .on_action(action_type, Rc::new(listener));
1668 }
1669}
1670
1671impl Context for WindowContext<'_> {
1672 type Result<T> = T;
1673
1674 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1675 where
1676 T: 'static,
1677 {
1678 let slot = self.app.entities.reserve();
1679 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1680 self.entities.insert(slot, model)
1681 }
1682
1683 fn update_model<T: 'static, R>(
1684 &mut self,
1685 model: &Model<T>,
1686 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1687 ) -> R {
1688 let mut entity = self.entities.lease(model);
1689 let result = update(
1690 &mut *entity,
1691 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1692 );
1693 self.entities.end_lease(entity);
1694 result
1695 }
1696
1697 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1698 where
1699 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1700 {
1701 if window == self.window.handle {
1702 let root_view = self.window.root_view.clone().unwrap();
1703 Ok(update(root_view, self))
1704 } else {
1705 window.update(self.app, update)
1706 }
1707 }
1708
1709 fn read_model<T, R>(
1710 &self,
1711 handle: &Model<T>,
1712 read: impl FnOnce(&T, &AppContext) -> R,
1713 ) -> Self::Result<R>
1714 where
1715 T: 'static,
1716 {
1717 let entity = self.entities.read(handle);
1718 read(entity, &*self.app)
1719 }
1720
1721 fn read_window<T, R>(
1722 &self,
1723 window: &WindowHandle<T>,
1724 read: impl FnOnce(View<T>, &AppContext) -> R,
1725 ) -> Result<R>
1726 where
1727 T: 'static,
1728 {
1729 if window.any_handle == self.window.handle {
1730 let root_view = self
1731 .window
1732 .root_view
1733 .clone()
1734 .unwrap()
1735 .downcast::<T>()
1736 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1737 Ok(read(root_view, self))
1738 } else {
1739 self.app.read_window(window, read)
1740 }
1741 }
1742}
1743
1744impl VisualContext for WindowContext<'_> {
1745 fn new_view<V>(
1746 &mut self,
1747 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1748 ) -> Self::Result<View<V>>
1749 where
1750 V: 'static + Render,
1751 {
1752 let slot = self.app.entities.reserve();
1753 let view = View {
1754 model: slot.clone(),
1755 };
1756 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1757 let entity = build_view_state(&mut cx);
1758 cx.entities.insert(slot, entity);
1759
1760 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1761 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1762 cx.new_view_observers.clone().retain(&tid, |observer| {
1763 let any_view = view.clone();
1764 (observer)(any_view, cx);
1765 true
1766 });
1767 }
1768 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1769
1770 view
1771 }
1772
1773 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1774 fn update_view<T: 'static, R>(
1775 &mut self,
1776 view: &View<T>,
1777 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1778 ) -> Self::Result<R> {
1779 let mut lease = self.app.entities.lease(&view.model);
1780 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1781 let result = update(&mut *lease, &mut cx);
1782 cx.app.entities.end_lease(lease);
1783 result
1784 }
1785
1786 fn replace_root_view<V>(
1787 &mut self,
1788 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1789 ) -> Self::Result<View<V>>
1790 where
1791 V: 'static + Render,
1792 {
1793 let view = self.new_view(build_view);
1794 self.window.root_view = Some(view.clone().into());
1795 self.refresh();
1796 view
1797 }
1798
1799 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1800 self.update_view(view, |view, cx| {
1801 view.focus_handle(cx).clone().focus(cx);
1802 })
1803 }
1804
1805 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1806 where
1807 V: ManagedView,
1808 {
1809 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1810 }
1811}
1812
1813impl<'a> std::ops::Deref for WindowContext<'a> {
1814 type Target = AppContext;
1815
1816 fn deref(&self) -> &Self::Target {
1817 self.app
1818 }
1819}
1820
1821impl<'a> std::ops::DerefMut for WindowContext<'a> {
1822 fn deref_mut(&mut self) -> &mut Self::Target {
1823 self.app
1824 }
1825}
1826
1827impl<'a> Borrow<AppContext> for WindowContext<'a> {
1828 fn borrow(&self) -> &AppContext {
1829 self.app
1830 }
1831}
1832
1833impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1834 fn borrow_mut(&mut self) -> &mut AppContext {
1835 self.app
1836 }
1837}
1838
1839/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1840pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1841 #[doc(hidden)]
1842 fn app_mut(&mut self) -> &mut AppContext {
1843 self.borrow_mut()
1844 }
1845
1846 #[doc(hidden)]
1847 fn app(&self) -> &AppContext {
1848 self.borrow()
1849 }
1850
1851 #[doc(hidden)]
1852 fn window(&self) -> &Window {
1853 self.borrow()
1854 }
1855
1856 #[doc(hidden)]
1857 fn window_mut(&mut self) -> &mut Window {
1858 self.borrow_mut()
1859 }
1860}
1861
1862impl Borrow<Window> for WindowContext<'_> {
1863 fn borrow(&self) -> &Window {
1864 self.window
1865 }
1866}
1867
1868impl BorrowMut<Window> for WindowContext<'_> {
1869 fn borrow_mut(&mut self) -> &mut Window {
1870 self.window
1871 }
1872}
1873
1874impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1875
1876/// Provides access to application state that is specialized for a particular [`View`].
1877/// Allows you to interact with focus, emit events, etc.
1878/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1879/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1880pub struct ViewContext<'a, V> {
1881 window_cx: WindowContext<'a>,
1882 view: &'a View<V>,
1883}
1884
1885impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1886 fn borrow(&self) -> &AppContext {
1887 &*self.window_cx.app
1888 }
1889}
1890
1891impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1892 fn borrow_mut(&mut self) -> &mut AppContext {
1893 &mut *self.window_cx.app
1894 }
1895}
1896
1897impl<V> Borrow<Window> for ViewContext<'_, V> {
1898 fn borrow(&self) -> &Window {
1899 &*self.window_cx.window
1900 }
1901}
1902
1903impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1904 fn borrow_mut(&mut self) -> &mut Window {
1905 &mut *self.window_cx.window
1906 }
1907}
1908
1909impl<'a, V: 'static> ViewContext<'a, V> {
1910 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1911 Self {
1912 window_cx: WindowContext::new(app, window),
1913 view,
1914 }
1915 }
1916
1917 /// Get the entity_id of this view.
1918 pub fn entity_id(&self) -> EntityId {
1919 self.view.entity_id()
1920 }
1921
1922 /// Get the view pointer underlying this context.
1923 pub fn view(&self) -> &View<V> {
1924 self.view
1925 }
1926
1927 /// Get the model underlying this view.
1928 pub fn model(&self) -> &Model<V> {
1929 &self.view.model
1930 }
1931
1932 /// Access the underlying window context.
1933 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1934 &mut self.window_cx
1935 }
1936
1937 /// Sets a given callback to be run on the next frame.
1938 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1939 where
1940 V: 'static,
1941 {
1942 let view = self.view().clone();
1943 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1944 }
1945
1946 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1947 /// that are currently on the stack to be returned to the app.
1948 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1949 let view = self.view().downgrade();
1950 self.window_cx.defer(move |cx| {
1951 view.update(cx, f).ok();
1952 });
1953 }
1954
1955 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1956 pub fn observe<V2, E>(
1957 &mut self,
1958 entity: &E,
1959 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1960 ) -> Subscription
1961 where
1962 V2: 'static,
1963 V: 'static,
1964 E: Entity<V2>,
1965 {
1966 let view = self.view().downgrade();
1967 let entity_id = entity.entity_id();
1968 let entity = entity.downgrade();
1969 let window_handle = self.window.handle;
1970 self.app.new_observer(
1971 entity_id,
1972 Box::new(move |cx| {
1973 window_handle
1974 .update(cx, |_, cx| {
1975 if let Some(handle) = E::upgrade_from(&entity) {
1976 view.update(cx, |this, cx| on_notify(this, handle, cx))
1977 .is_ok()
1978 } else {
1979 false
1980 }
1981 })
1982 .unwrap_or(false)
1983 }),
1984 )
1985 }
1986
1987 /// Subscribe to events emitted by another model or view.
1988 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1989 /// 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.
1990 pub fn subscribe<V2, E, Evt>(
1991 &mut self,
1992 entity: &E,
1993 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1994 ) -> Subscription
1995 where
1996 V2: EventEmitter<Evt>,
1997 E: Entity<V2>,
1998 Evt: 'static,
1999 {
2000 let view = self.view().downgrade();
2001 let entity_id = entity.entity_id();
2002 let handle = entity.downgrade();
2003 let window_handle = self.window.handle;
2004 self.app.new_subscription(
2005 entity_id,
2006 (
2007 TypeId::of::<Evt>(),
2008 Box::new(move |event, cx| {
2009 window_handle
2010 .update(cx, |_, cx| {
2011 if let Some(handle) = E::upgrade_from(&handle) {
2012 let event = event.downcast_ref().expect("invalid event type");
2013 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2014 .is_ok()
2015 } else {
2016 false
2017 }
2018 })
2019 .unwrap_or(false)
2020 }),
2021 ),
2022 )
2023 }
2024
2025 /// Register a callback to be invoked when the view is released.
2026 ///
2027 /// The callback receives a handle to the view's window. This handle may be
2028 /// invalid, if the window was closed before the view was released.
2029 pub fn on_release(
2030 &mut self,
2031 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2032 ) -> Subscription {
2033 let window_handle = self.window.handle;
2034 let (subscription, activate) = self.app.release_listeners.insert(
2035 self.view.model.entity_id,
2036 Box::new(move |this, cx| {
2037 let this = this.downcast_mut().expect("invalid entity type");
2038 on_release(this, window_handle, cx)
2039 }),
2040 );
2041 activate();
2042 subscription
2043 }
2044
2045 /// Register a callback to be invoked when the given Model or View is released.
2046 pub fn observe_release<V2, E>(
2047 &mut self,
2048 entity: &E,
2049 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2050 ) -> Subscription
2051 where
2052 V: 'static,
2053 V2: 'static,
2054 E: Entity<V2>,
2055 {
2056 let view = self.view().downgrade();
2057 let entity_id = entity.entity_id();
2058 let window_handle = self.window.handle;
2059 let (subscription, activate) = self.app.release_listeners.insert(
2060 entity_id,
2061 Box::new(move |entity, cx| {
2062 let entity = entity.downcast_mut().expect("invalid entity type");
2063 let _ = window_handle.update(cx, |_, cx| {
2064 view.update(cx, |this, cx| on_release(this, entity, cx))
2065 });
2066 }),
2067 );
2068 activate();
2069 subscription
2070 }
2071
2072 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2073 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2074 pub fn notify(&mut self) {
2075 for view_id in self
2076 .window
2077 .rendered_frame
2078 .dispatch_tree
2079 .view_path(self.view.entity_id())
2080 .into_iter()
2081 .rev()
2082 {
2083 if !self.window.dirty_views.insert(view_id) {
2084 break;
2085 }
2086 }
2087
2088 if !self.window.drawing {
2089 self.window_cx.window.dirty.set(true);
2090 self.window_cx.app.push_effect(Effect::Notify {
2091 emitter: self.view.model.entity_id,
2092 });
2093 }
2094 }
2095
2096 /// Register a callback to be invoked when the window is resized.
2097 pub fn observe_window_bounds(
2098 &mut self,
2099 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2100 ) -> Subscription {
2101 let view = self.view.downgrade();
2102 let (subscription, activate) = self.window.bounds_observers.insert(
2103 (),
2104 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2105 );
2106 activate();
2107 subscription
2108 }
2109
2110 /// Register a callback to be invoked when the window is activated or deactivated.
2111 pub fn observe_window_activation(
2112 &mut self,
2113 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2114 ) -> Subscription {
2115 let view = self.view.downgrade();
2116 let (subscription, activate) = self.window.activation_observers.insert(
2117 (),
2118 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2119 );
2120 activate();
2121 subscription
2122 }
2123
2124 /// Registers a callback to be invoked when the window appearance changes.
2125 pub fn observe_window_appearance(
2126 &mut self,
2127 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2128 ) -> Subscription {
2129 let view = self.view.downgrade();
2130 let (subscription, activate) = self.window.appearance_observers.insert(
2131 (),
2132 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2133 );
2134 activate();
2135 subscription
2136 }
2137
2138 /// Register a listener to be called when the given focus handle receives focus.
2139 /// Returns a subscription and persists until the subscription is dropped.
2140 pub fn on_focus(
2141 &mut self,
2142 handle: &FocusHandle,
2143 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2144 ) -> Subscription {
2145 let view = self.view.downgrade();
2146 let focus_id = handle.id;
2147 let (subscription, activate) =
2148 self.window.new_focus_listener(Box::new(move |event, cx| {
2149 view.update(cx, |view, cx| {
2150 if event.previous_focus_path.last() != Some(&focus_id)
2151 && event.current_focus_path.last() == Some(&focus_id)
2152 {
2153 listener(view, cx)
2154 }
2155 })
2156 .is_ok()
2157 }));
2158 self.app.defer(|_| activate());
2159 subscription
2160 }
2161
2162 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2163 /// Returns a subscription and persists until the subscription is dropped.
2164 pub fn on_focus_in(
2165 &mut self,
2166 handle: &FocusHandle,
2167 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2168 ) -> Subscription {
2169 let view = self.view.downgrade();
2170 let focus_id = handle.id;
2171 let (subscription, activate) =
2172 self.window.new_focus_listener(Box::new(move |event, cx| {
2173 view.update(cx, |view, cx| {
2174 if !event.previous_focus_path.contains(&focus_id)
2175 && event.current_focus_path.contains(&focus_id)
2176 {
2177 listener(view, cx)
2178 }
2179 })
2180 .is_ok()
2181 }));
2182 self.app.defer(move |_| activate());
2183 subscription
2184 }
2185
2186 /// Register a listener to be called when the given focus handle loses focus.
2187 /// Returns a subscription and persists until the subscription is dropped.
2188 pub fn on_blur(
2189 &mut self,
2190 handle: &FocusHandle,
2191 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2192 ) -> Subscription {
2193 let view = self.view.downgrade();
2194 let focus_id = handle.id;
2195 let (subscription, activate) =
2196 self.window.new_focus_listener(Box::new(move |event, cx| {
2197 view.update(cx, |view, cx| {
2198 if event.previous_focus_path.last() == Some(&focus_id)
2199 && event.current_focus_path.last() != Some(&focus_id)
2200 {
2201 listener(view, cx)
2202 }
2203 })
2204 .is_ok()
2205 }));
2206 self.app.defer(move |_| activate());
2207 subscription
2208 }
2209
2210 /// Register a listener to be called when nothing in the window has focus.
2211 /// This typically happens when the node that was focused is removed from the tree,
2212 /// and this callback lets you chose a default place to restore the users focus.
2213 /// Returns a subscription and persists until the subscription is dropped.
2214 pub fn on_focus_lost(
2215 &mut self,
2216 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2217 ) -> Subscription {
2218 let view = self.view.downgrade();
2219 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2220 (),
2221 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2222 );
2223 activate();
2224 subscription
2225 }
2226
2227 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2228 /// Returns a subscription and persists until the subscription is dropped.
2229 pub fn on_focus_out(
2230 &mut self,
2231 handle: &FocusHandle,
2232 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2233 ) -> Subscription {
2234 let view = self.view.downgrade();
2235 let focus_id = handle.id;
2236 let (subscription, activate) =
2237 self.window.new_focus_listener(Box::new(move |event, cx| {
2238 view.update(cx, |view, cx| {
2239 if event.previous_focus_path.contains(&focus_id)
2240 && !event.current_focus_path.contains(&focus_id)
2241 {
2242 listener(view, cx)
2243 }
2244 })
2245 .is_ok()
2246 }));
2247 self.app.defer(move |_| activate());
2248 subscription
2249 }
2250
2251 /// Schedule a future to be run asynchronously.
2252 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2253 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2254 /// The returned future will be polled on the main thread.
2255 pub fn spawn<Fut, R>(
2256 &mut self,
2257 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2258 ) -> Task<R>
2259 where
2260 R: 'static,
2261 Fut: Future<Output = R> + 'static,
2262 {
2263 let view = self.view().downgrade();
2264 self.window_cx.spawn(|cx| f(view, cx))
2265 }
2266
2267 /// Updates the global state of the given type.
2268 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2269 where
2270 G: Global,
2271 {
2272 let mut global = self.app.lease_global::<G>();
2273 let result = f(&mut global, self);
2274 self.app.end_global_lease(global);
2275 result
2276 }
2277
2278 /// Register a callback to be invoked when the given global state changes.
2279 pub fn observe_global<G: Global>(
2280 &mut self,
2281 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2282 ) -> Subscription {
2283 let window_handle = self.window.handle;
2284 let view = self.view().downgrade();
2285 let (subscription, activate) = self.global_observers.insert(
2286 TypeId::of::<G>(),
2287 Box::new(move |cx| {
2288 window_handle
2289 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2290 .unwrap_or(false)
2291 }),
2292 );
2293 self.app.defer(move |_| activate());
2294 subscription
2295 }
2296
2297 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2298 pub fn on_action(
2299 &mut self,
2300 action_type: TypeId,
2301 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2302 ) {
2303 let handle = self.view().clone();
2304 self.window_cx
2305 .on_action(action_type, move |action, phase, cx| {
2306 handle.update(cx, |view, cx| {
2307 listener(view, action, phase, cx);
2308 })
2309 });
2310 }
2311
2312 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2313 pub fn emit<Evt>(&mut self, event: Evt)
2314 where
2315 Evt: 'static,
2316 V: EventEmitter<Evt>,
2317 {
2318 let emitter = self.view.model.entity_id;
2319 self.app.push_effect(Effect::Emit {
2320 emitter,
2321 event_type: TypeId::of::<Evt>(),
2322 event: Box::new(event),
2323 });
2324 }
2325
2326 /// Move focus to the current view, assuming it implements [`FocusableView`].
2327 pub fn focus_self(&mut self)
2328 where
2329 V: FocusableView,
2330 {
2331 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2332 }
2333
2334 /// Convenience method for accessing view state in an event callback.
2335 ///
2336 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2337 /// but it's often useful to be able to access view state in these
2338 /// callbacks. This method provides a convenient way to do so.
2339 pub fn listener<E>(
2340 &self,
2341 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2342 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2343 let view = self.view().downgrade();
2344 move |e: &E, cx: &mut WindowContext| {
2345 view.update(cx, |view, cx| f(view, e, cx)).ok();
2346 }
2347 }
2348}
2349
2350impl<V> Context for ViewContext<'_, V> {
2351 type Result<U> = U;
2352
2353 fn new_model<T: 'static>(
2354 &mut self,
2355 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2356 ) -> Model<T> {
2357 self.window_cx.new_model(build_model)
2358 }
2359
2360 fn update_model<T: 'static, R>(
2361 &mut self,
2362 model: &Model<T>,
2363 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2364 ) -> R {
2365 self.window_cx.update_model(model, update)
2366 }
2367
2368 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2369 where
2370 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2371 {
2372 self.window_cx.update_window(window, update)
2373 }
2374
2375 fn read_model<T, R>(
2376 &self,
2377 handle: &Model<T>,
2378 read: impl FnOnce(&T, &AppContext) -> R,
2379 ) -> Self::Result<R>
2380 where
2381 T: 'static,
2382 {
2383 self.window_cx.read_model(handle, read)
2384 }
2385
2386 fn read_window<T, R>(
2387 &self,
2388 window: &WindowHandle<T>,
2389 read: impl FnOnce(View<T>, &AppContext) -> R,
2390 ) -> Result<R>
2391 where
2392 T: 'static,
2393 {
2394 self.window_cx.read_window(window, read)
2395 }
2396}
2397
2398impl<V: 'static> VisualContext for ViewContext<'_, V> {
2399 fn new_view<W: Render + 'static>(
2400 &mut self,
2401 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2402 ) -> Self::Result<View<W>> {
2403 self.window_cx.new_view(build_view_state)
2404 }
2405
2406 fn update_view<V2: 'static, R>(
2407 &mut self,
2408 view: &View<V2>,
2409 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2410 ) -> Self::Result<R> {
2411 self.window_cx.update_view(view, update)
2412 }
2413
2414 fn replace_root_view<W>(
2415 &mut self,
2416 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2417 ) -> Self::Result<View<W>>
2418 where
2419 W: 'static + Render,
2420 {
2421 self.window_cx.replace_root_view(build_view)
2422 }
2423
2424 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2425 self.window_cx.focus_view(view)
2426 }
2427
2428 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2429 self.window_cx.dismiss_view(view)
2430 }
2431}
2432
2433impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2434 type Target = WindowContext<'a>;
2435
2436 fn deref(&self) -> &Self::Target {
2437 &self.window_cx
2438 }
2439}
2440
2441impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2442 fn deref_mut(&mut self) -> &mut Self::Target {
2443 &mut self.window_cx
2444 }
2445}
2446
2447// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2448slotmap::new_key_type! {
2449 /// A unique identifier for a window.
2450 pub struct WindowId;
2451}
2452
2453impl WindowId {
2454 /// Converts this window ID to a `u64`.
2455 pub fn as_u64(&self) -> u64 {
2456 self.0.as_ffi()
2457 }
2458}
2459
2460/// A handle to a window with a specific root view type.
2461/// Note that this does not keep the window alive on its own.
2462#[derive(Deref, DerefMut)]
2463pub struct WindowHandle<V> {
2464 #[deref]
2465 #[deref_mut]
2466 pub(crate) any_handle: AnyWindowHandle,
2467 state_type: PhantomData<V>,
2468}
2469
2470impl<V: 'static + Render> WindowHandle<V> {
2471 /// Creates a new handle from a window ID.
2472 /// This does not check if the root type of the window is `V`.
2473 pub fn new(id: WindowId) -> Self {
2474 WindowHandle {
2475 any_handle: AnyWindowHandle {
2476 id,
2477 state_type: TypeId::of::<V>(),
2478 },
2479 state_type: PhantomData,
2480 }
2481 }
2482
2483 /// Get the root view out of this window.
2484 ///
2485 /// This will fail if the window is closed or if the root view's type does not match `V`.
2486 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2487 where
2488 C: Context,
2489 {
2490 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2491 root_view
2492 .downcast::<V>()
2493 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2494 }))
2495 }
2496
2497 /// Updates the root view of this window.
2498 ///
2499 /// This will fail if the window has been closed or if the root view's type does not match
2500 pub fn update<C, R>(
2501 &self,
2502 cx: &mut C,
2503 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2504 ) -> Result<R>
2505 where
2506 C: Context,
2507 {
2508 cx.update_window(self.any_handle, |root_view, cx| {
2509 let view = root_view
2510 .downcast::<V>()
2511 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2512 Ok(cx.update_view(&view, update))
2513 })?
2514 }
2515
2516 /// Read the root view out of this window.
2517 ///
2518 /// This will fail if the window is closed or if the root view's type does not match `V`.
2519 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2520 let x = cx
2521 .windows
2522 .get(self.id)
2523 .and_then(|window| {
2524 window
2525 .as_ref()
2526 .and_then(|window| window.root_view.clone())
2527 .map(|root_view| root_view.downcast::<V>())
2528 })
2529 .ok_or_else(|| anyhow!("window not found"))?
2530 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2531
2532 Ok(x.read(cx))
2533 }
2534
2535 /// Read the root view out of this window, with a callback
2536 ///
2537 /// This will fail if the window is closed or if the root view's type does not match `V`.
2538 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2539 where
2540 C: Context,
2541 {
2542 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2543 }
2544
2545 /// Read the root view pointer off of this window.
2546 ///
2547 /// This will fail if the window is closed or if the root view's type does not match `V`.
2548 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2549 where
2550 C: Context,
2551 {
2552 cx.read_window(self, |root_view, _cx| root_view.clone())
2553 }
2554
2555 /// Check if this window is 'active'.
2556 ///
2557 /// Will return `None` if the window is closed or currently
2558 /// borrowed.
2559 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
2560 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
2561 .ok()
2562 }
2563}
2564
2565impl<V> Copy for WindowHandle<V> {}
2566
2567impl<V> Clone for WindowHandle<V> {
2568 fn clone(&self) -> Self {
2569 *self
2570 }
2571}
2572
2573impl<V> PartialEq for WindowHandle<V> {
2574 fn eq(&self, other: &Self) -> bool {
2575 self.any_handle == other.any_handle
2576 }
2577}
2578
2579impl<V> Eq for WindowHandle<V> {}
2580
2581impl<V> Hash for WindowHandle<V> {
2582 fn hash<H: Hasher>(&self, state: &mut H) {
2583 self.any_handle.hash(state);
2584 }
2585}
2586
2587impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2588 fn from(val: WindowHandle<V>) -> Self {
2589 val.any_handle
2590 }
2591}
2592
2593/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2594#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2595pub struct AnyWindowHandle {
2596 pub(crate) id: WindowId,
2597 state_type: TypeId,
2598}
2599
2600impl AnyWindowHandle {
2601 /// Get the ID of this window.
2602 pub fn window_id(&self) -> WindowId {
2603 self.id
2604 }
2605
2606 /// Attempt to convert this handle to a window handle with a specific root view type.
2607 /// If the types do not match, this will return `None`.
2608 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2609 if TypeId::of::<T>() == self.state_type {
2610 Some(WindowHandle {
2611 any_handle: *self,
2612 state_type: PhantomData,
2613 })
2614 } else {
2615 None
2616 }
2617 }
2618
2619 /// Updates the state of the root view of this window.
2620 ///
2621 /// This will fail if the window has been closed.
2622 pub fn update<C, R>(
2623 self,
2624 cx: &mut C,
2625 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2626 ) -> Result<R>
2627 where
2628 C: Context,
2629 {
2630 cx.update_window(self, update)
2631 }
2632
2633 /// Read the state of the root view of this window.
2634 ///
2635 /// This will fail if the window has been closed.
2636 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2637 where
2638 C: Context,
2639 T: 'static,
2640 {
2641 let view = self
2642 .downcast::<T>()
2643 .context("the type of the window's root view has changed")?;
2644
2645 cx.read_window(&view, read)
2646 }
2647}
2648
2649/// An identifier for an [`Element`](crate::Element).
2650///
2651/// Can be constructed with a string, a number, or both, as well
2652/// as other internal representations.
2653#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2654pub enum ElementId {
2655 /// The ID of a View element
2656 View(EntityId),
2657 /// An integer ID.
2658 Integer(usize),
2659 /// A string based ID.
2660 Name(SharedString),
2661 /// An ID that's equated with a focus handle.
2662 FocusHandle(FocusId),
2663 /// A combination of a name and an integer.
2664 NamedInteger(SharedString, usize),
2665}
2666
2667impl Display for ElementId {
2668 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2669 match self {
2670 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2671 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2672 ElementId::Name(name) => write!(f, "{}", name)?,
2673 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2674 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2675 }
2676
2677 Ok(())
2678 }
2679}
2680
2681impl ElementId {
2682 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2683 ElementId::View(entity_id)
2684 }
2685}
2686
2687impl TryInto<SharedString> for ElementId {
2688 type Error = anyhow::Error;
2689
2690 fn try_into(self) -> anyhow::Result<SharedString> {
2691 if let ElementId::Name(name) = self {
2692 Ok(name)
2693 } else {
2694 Err(anyhow!("element id is not string"))
2695 }
2696 }
2697}
2698
2699impl From<usize> for ElementId {
2700 fn from(id: usize) -> Self {
2701 ElementId::Integer(id)
2702 }
2703}
2704
2705impl From<i32> for ElementId {
2706 fn from(id: i32) -> Self {
2707 Self::Integer(id as usize)
2708 }
2709}
2710
2711impl From<SharedString> for ElementId {
2712 fn from(name: SharedString) -> Self {
2713 ElementId::Name(name)
2714 }
2715}
2716
2717impl From<&'static str> for ElementId {
2718 fn from(name: &'static str) -> Self {
2719 ElementId::Name(name.into())
2720 }
2721}
2722
2723impl<'a> From<&'a FocusHandle> for ElementId {
2724 fn from(handle: &'a FocusHandle) -> Self {
2725 ElementId::FocusHandle(handle.id)
2726 }
2727}
2728
2729impl From<(&'static str, EntityId)> for ElementId {
2730 fn from((name, id): (&'static str, EntityId)) -> Self {
2731 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2732 }
2733}
2734
2735impl From<(&'static str, usize)> for ElementId {
2736 fn from((name, id): (&'static str, usize)) -> Self {
2737 ElementId::NamedInteger(name.into(), id)
2738 }
2739}
2740
2741impl From<(&'static str, u64)> for ElementId {
2742 fn from((name, id): (&'static str, u64)) -> Self {
2743 ElementId::NamedInteger(name.into(), id as usize)
2744 }
2745}
2746
2747/// A rectangle to be rendered in the window at the given position and size.
2748/// Passed as an argument [`ElementContext::paint_quad`].
2749#[derive(Clone)]
2750pub struct PaintQuad {
2751 bounds: Bounds<Pixels>,
2752 corner_radii: Corners<Pixels>,
2753 background: Hsla,
2754 border_widths: Edges<Pixels>,
2755 border_color: Hsla,
2756}
2757
2758impl PaintQuad {
2759 /// Sets the corner radii of the quad.
2760 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2761 PaintQuad {
2762 corner_radii: corner_radii.into(),
2763 ..self
2764 }
2765 }
2766
2767 /// Sets the border widths of the quad.
2768 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2769 PaintQuad {
2770 border_widths: border_widths.into(),
2771 ..self
2772 }
2773 }
2774
2775 /// Sets the border color of the quad.
2776 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2777 PaintQuad {
2778 border_color: border_color.into(),
2779 ..self
2780 }
2781 }
2782
2783 /// Sets the background color of the quad.
2784 pub fn background(self, background: impl Into<Hsla>) -> Self {
2785 PaintQuad {
2786 background: background.into(),
2787 ..self
2788 }
2789 }
2790}
2791
2792/// Creates a quad with the given parameters.
2793pub fn quad(
2794 bounds: Bounds<Pixels>,
2795 corner_radii: impl Into<Corners<Pixels>>,
2796 background: impl Into<Hsla>,
2797 border_widths: impl Into<Edges<Pixels>>,
2798 border_color: impl Into<Hsla>,
2799) -> PaintQuad {
2800 PaintQuad {
2801 bounds,
2802 corner_radii: corner_radii.into(),
2803 background: background.into(),
2804 border_widths: border_widths.into(),
2805 border_color: border_color.into(),
2806 }
2807}
2808
2809/// Creates a filled quad with the given bounds and background color.
2810pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2811 PaintQuad {
2812 bounds: bounds.into(),
2813 corner_radii: (0.).into(),
2814 background: background.into(),
2815 border_widths: (0.).into(),
2816 border_color: transparent_black(),
2817 }
2818}
2819
2820/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2821pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2822 PaintQuad {
2823 bounds: bounds.into(),
2824 corner_radii: (0.).into(),
2825 background: transparent_black(),
2826 border_widths: (1.).into(),
2827 border_color: border_color.into(),
2828 }
2829}