1use crate::{
2 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
3 AvailableSpace, Bounds, Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId,
4 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
5 GlobalElementId, Hsla, KeyBinding, KeyContext, KeyDownEvent, KeyMatch, KeymatchMode,
6 KeymatchResult, Keystroke, KeystrokeEvent, Model, ModelContext, Modifiers, MouseButton,
7 MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
8 PlatformWindow, Point, PromptLevel, Render, ScaledPixels, SharedString, Size, SubscriberSet,
9 Subscription, TaffyLayoutEngine, Task, View, VisualContext, WeakView, WindowBounds,
10 WindowOptions,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::{
16 channel::{mpsc, oneshot},
17 StreamExt,
18};
19use parking_lot::RwLock;
20use slotmap::SlotMap;
21use smallvec::SmallVec;
22use std::{
23 any::{Any, TypeId},
24 borrow::{Borrow, BorrowMut},
25 cell::RefCell,
26 collections::hash_map::Entry,
27 fmt::{Debug, Display},
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37 time::Duration,
38};
39use util::{measure, ResultExt};
40
41mod element_cx;
42pub use element_cx::*;
43
44const ACTIVE_DRAG_Z_INDEX: u16 = 1;
45
46/// A global stacking order, which is created by stacking successive z-index values.
47/// Each z-index will always be interpreted in the context of its parent z-index.
48#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
49pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
50
51/// A single entry in a primitive's z-index stacking order
52#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
53pub struct StackingContext {
54 pub(crate) z_index: u16,
55 pub(crate) id: u16,
56}
57
58impl std::fmt::Debug for StackingContext {
59 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
60 write!(f, "{{{}.{}}} ", self.z_index, self.id)
61 }
62}
63
64/// Represents the two different phases when dispatching events.
65#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
66pub enum DispatchPhase {
67 /// After the capture phase comes the bubble phase, in which mouse event listeners are
68 /// invoked front to back and keyboard event listeners are invoked from the focused element
69 /// to the root of the element tree. This is the phase you'll most commonly want to use when
70 /// registering event listeners.
71 #[default]
72 Bubble,
73 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
74 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
75 /// is used for special purposes such as clearing the "pressed" state for click events. If
76 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
77 /// outside of the immediate region may rely on detecting non-local events during this phase.
78 Capture,
79}
80
81impl DispatchPhase {
82 /// Returns true if this represents the "bubble" phase.
83 pub fn bubble(self) -> bool {
84 self == DispatchPhase::Bubble
85 }
86
87 /// Returns true if this represents the "capture" phase.
88 pub fn capture(self) -> bool {
89 self == DispatchPhase::Capture
90 }
91}
92
93type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
94
95type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
96
97struct FocusEvent {
98 previous_focus_path: SmallVec<[FocusId; 8]>,
99 current_focus_path: SmallVec<[FocusId; 8]>,
100}
101
102slotmap::new_key_type! {
103 /// A globally unique identifier for a focusable element.
104 pub struct FocusId;
105}
106
107thread_local! {
108 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(8 * 1024 * 1024));
109}
110
111impl FocusId {
112 /// Obtains whether the element associated with this handle is currently focused.
113 pub fn is_focused(&self, cx: &WindowContext) -> bool {
114 cx.window.focus == Some(*self)
115 }
116
117 /// Obtains whether the element associated with this handle contains the focused
118 /// element or is itself focused.
119 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
120 cx.focused()
121 .map_or(false, |focused| self.contains(focused.id, cx))
122 }
123
124 /// Obtains whether the element associated with this handle is contained within the
125 /// focused element or is itself focused.
126 pub fn within_focused(&self, cx: &WindowContext) -> bool {
127 let focused = cx.focused();
128 focused.map_or(false, |focused| focused.id.contains(*self, cx))
129 }
130
131 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
132 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
133 cx.window
134 .rendered_frame
135 .dispatch_tree
136 .focus_contains(*self, other)
137 }
138}
139
140/// A handle which can be used to track and manipulate the focused element in a window.
141pub struct FocusHandle {
142 pub(crate) id: FocusId,
143 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
144}
145
146impl std::fmt::Debug for FocusHandle {
147 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
148 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
149 }
150}
151
152impl FocusHandle {
153 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
154 let id = handles.write().insert(AtomicUsize::new(1));
155 Self {
156 id,
157 handles: handles.clone(),
158 }
159 }
160
161 pub(crate) fn for_id(
162 id: FocusId,
163 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
164 ) -> Option<Self> {
165 let lock = handles.read();
166 let ref_count = lock.get(id)?;
167 if ref_count.load(SeqCst) == 0 {
168 None
169 } else {
170 ref_count.fetch_add(1, SeqCst);
171 Some(Self {
172 id,
173 handles: handles.clone(),
174 })
175 }
176 }
177
178 /// Moves the focus to the element associated with this handle.
179 pub fn focus(&self, cx: &mut WindowContext) {
180 cx.focus(self)
181 }
182
183 /// Obtains whether the element associated with this handle is currently focused.
184 pub fn is_focused(&self, cx: &WindowContext) -> bool {
185 self.id.is_focused(cx)
186 }
187
188 /// Obtains whether the element associated with this handle contains the focused
189 /// element or is itself focused.
190 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
191 self.id.contains_focused(cx)
192 }
193
194 /// Obtains whether the element associated with this handle is contained within the
195 /// focused element or is itself focused.
196 pub fn within_focused(&self, cx: &WindowContext) -> bool {
197 self.id.within_focused(cx)
198 }
199
200 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
201 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
202 self.id.contains(other.id, cx)
203 }
204}
205
206impl Clone for FocusHandle {
207 fn clone(&self) -> Self {
208 Self::for_id(self.id, &self.handles).unwrap()
209 }
210}
211
212impl PartialEq for FocusHandle {
213 fn eq(&self, other: &Self) -> bool {
214 self.id == other.id
215 }
216}
217
218impl Eq for FocusHandle {}
219
220impl Drop for FocusHandle {
221 fn drop(&mut self) {
222 self.handles
223 .read()
224 .get(self.id)
225 .unwrap()
226 .fetch_sub(1, SeqCst);
227 }
228}
229
230/// FocusableView allows users of your view to easily
231/// focus it (using cx.focus_view(view))
232pub trait FocusableView: 'static + Render {
233 /// Returns the focus handle associated with this view.
234 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
235}
236
237/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
238/// where the lifecycle of the view is handled by another view.
239pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
240
241impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
242
243/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
244pub struct DismissEvent;
245
246// Holds the state for a specific window.
247#[doc(hidden)]
248pub struct Window {
249 pub(crate) handle: AnyWindowHandle,
250 pub(crate) removed: bool,
251 pub(crate) platform_window: Box<dyn PlatformWindow>,
252 display_id: DisplayId,
253 sprite_atlas: Arc<dyn PlatformAtlas>,
254 pub(crate) rem_size: Pixels,
255 pub(crate) viewport_size: Size<Pixels>,
256 layout_engine: Option<TaffyLayoutEngine>,
257 pub(crate) root_view: Option<AnyView>,
258 pub(crate) element_id_stack: GlobalElementId,
259 pub(crate) rendered_frame: Frame,
260 pub(crate) next_frame: Frame,
261 pub(crate) dirty_views: FxHashSet<EntityId>,
262 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
263 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
264 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
265 default_prevented: bool,
266 mouse_position: Point<Pixels>,
267 modifiers: Modifiers,
268 scale_factor: f32,
269 bounds: WindowBounds,
270 bounds_observers: SubscriberSet<(), AnyObserver>,
271 active: bool,
272 pub(crate) dirty: bool,
273 pub(crate) refreshing: bool,
274 pub(crate) drawing: bool,
275 activation_observers: SubscriberSet<(), AnyObserver>,
276 pub(crate) focus: Option<FocusId>,
277 focus_enabled: bool,
278 pending_input: Option<PendingInput>,
279
280 #[cfg(any(test, feature = "test-support"))]
281 pub(crate) focus_invalidated: bool,
282}
283
284#[derive(Default, Debug)]
285struct PendingInput {
286 keystrokes: SmallVec<[Keystroke; 1]>,
287 bindings: SmallVec<[KeyBinding; 1]>,
288 focus: Option<FocusId>,
289 timer: Option<Task<()>>,
290}
291
292impl PendingInput {
293 fn is_noop(&self) -> bool {
294 self.bindings.is_empty() && (self.keystrokes.iter().all(|k| k.ime_key.is_none()))
295 }
296
297 fn input(&self) -> String {
298 self.keystrokes
299 .iter()
300 .flat_map(|k| k.ime_key.clone())
301 .collect::<Vec<String>>()
302 .join("")
303 }
304
305 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
306 if self.keystrokes.is_empty() {
307 return true;
308 }
309 let keystroke = &self.keystrokes[0];
310 for candidate in keystroke.match_candidates() {
311 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
312 return true;
313 }
314 }
315 false
316 }
317}
318
319pub(crate) struct ElementStateBox {
320 pub(crate) inner: Box<dyn Any>,
321 pub(crate) parent_view_id: EntityId,
322 #[cfg(debug_assertions)]
323 pub(crate) type_name: &'static str,
324}
325
326impl Window {
327 pub(crate) fn new(
328 handle: AnyWindowHandle,
329 options: WindowOptions,
330 cx: &mut AppContext,
331 ) -> Self {
332 let platform_window = cx.platform.open_window(handle, options);
333 let display_id = platform_window.display().id();
334 let sprite_atlas = platform_window.sprite_atlas();
335 let mouse_position = platform_window.mouse_position();
336 let modifiers = platform_window.modifiers();
337 let content_size = platform_window.content_size();
338 let scale_factor = platform_window.scale_factor();
339 let bounds = platform_window.bounds();
340
341 platform_window.on_request_frame(Box::new({
342 let mut cx = cx.to_async();
343 move || {
344 measure("frame duration", || {
345 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
346 })
347 }
348 }));
349 platform_window.on_resize(Box::new({
350 let mut cx = cx.to_async();
351 move |_, _| {
352 handle
353 .update(&mut cx, |_, cx| cx.window_bounds_changed())
354 .log_err();
355 }
356 }));
357 platform_window.on_moved(Box::new({
358 let mut cx = cx.to_async();
359 move || {
360 handle
361 .update(&mut cx, |_, cx| cx.window_bounds_changed())
362 .log_err();
363 }
364 }));
365 platform_window.on_active_status_change(Box::new({
366 let mut cx = cx.to_async();
367 move |active| {
368 handle
369 .update(&mut cx, |_, cx| {
370 cx.window.active = active;
371 cx.window
372 .activation_observers
373 .clone()
374 .retain(&(), |callback| callback(cx));
375 })
376 .log_err();
377 }
378 }));
379
380 platform_window.on_input({
381 let mut cx = cx.to_async();
382 Box::new(move |event| {
383 handle
384 .update(&mut cx, |_, cx| cx.dispatch_event(event))
385 .log_err()
386 .unwrap_or(false)
387 })
388 });
389
390 Window {
391 handle,
392 removed: false,
393 platform_window,
394 display_id,
395 sprite_atlas,
396 rem_size: px(16.),
397 viewport_size: content_size,
398 layout_engine: Some(TaffyLayoutEngine::new()),
399 root_view: None,
400 element_id_stack: GlobalElementId::default(),
401 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
402 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
403 dirty_views: FxHashSet::default(),
404 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
405 focus_listeners: SubscriberSet::new(),
406 focus_lost_listeners: SubscriberSet::new(),
407 default_prevented: true,
408 mouse_position,
409 modifiers,
410 scale_factor,
411 bounds,
412 bounds_observers: SubscriberSet::new(),
413 active: false,
414 dirty: false,
415 refreshing: false,
416 drawing: false,
417 activation_observers: SubscriberSet::new(),
418 focus: None,
419 focus_enabled: true,
420 pending_input: None,
421
422 #[cfg(any(test, feature = "test-support"))]
423 focus_invalidated: false,
424 }
425 }
426}
427
428/// Indicates which region of the window is visible. Content falling outside of this mask will not be
429/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
430/// to leave room to support more complex shapes in the future.
431#[derive(Clone, Debug, Default, PartialEq, Eq)]
432#[repr(C)]
433pub struct ContentMask<P: Clone + Default + Debug> {
434 /// The bounds
435 pub bounds: Bounds<P>,
436}
437
438impl ContentMask<Pixels> {
439 /// Scale the content mask's pixel units by the given scaling factor.
440 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
441 ContentMask {
442 bounds: self.bounds.scale(factor),
443 }
444 }
445
446 /// Intersect the content mask with the given content mask.
447 pub fn intersect(&self, other: &Self) -> Self {
448 let bounds = self.bounds.intersect(&other.bounds);
449 ContentMask { bounds }
450 }
451}
452
453/// Provides access to application state in the context of a single window. Derefs
454/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
455/// an [`AppContext`] and call any [`AppContext`] methods.
456pub struct WindowContext<'a> {
457 pub(crate) app: &'a mut AppContext,
458 pub(crate) window: &'a mut Window,
459}
460
461impl<'a> WindowContext<'a> {
462 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
463 Self { app, window }
464 }
465
466 /// Obtain a handle to the window that belongs to this context.
467 pub fn window_handle(&self) -> AnyWindowHandle {
468 self.window.handle
469 }
470
471 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
472 pub fn refresh(&mut self) {
473 if !self.window.drawing {
474 self.window.refreshing = true;
475 self.window.dirty = true;
476 }
477 }
478
479 /// Close this window.
480 pub fn remove_window(&mut self) {
481 self.window.removed = true;
482 }
483
484 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
485 /// for elements rendered within this window.
486 pub fn focus_handle(&mut self) -> FocusHandle {
487 FocusHandle::new(&self.window.focus_handles)
488 }
489
490 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
491 pub fn focused(&self) -> Option<FocusHandle> {
492 self.window
493 .focus
494 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
495 }
496
497 /// Move focus to the element associated with the given [`FocusHandle`].
498 pub fn focus(&mut self, handle: &FocusHandle) {
499 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
500 return;
501 }
502
503 self.window.focus = Some(handle.id);
504 self.window
505 .rendered_frame
506 .dispatch_tree
507 .clear_pending_keystrokes();
508
509 #[cfg(any(test, feature = "test-support"))]
510 {
511 self.window.focus_invalidated = true;
512 }
513
514 self.refresh();
515 }
516
517 /// Remove focus from all elements within this context's window.
518 pub fn blur(&mut self) {
519 if !self.window.focus_enabled {
520 return;
521 }
522
523 self.window.focus = None;
524 self.refresh();
525 }
526
527 /// Blur the window and don't allow anything in it to be focused again.
528 pub fn disable_focus(&mut self) {
529 self.blur();
530 self.window.focus_enabled = false;
531 }
532
533 /// Dispatch the given action on the currently focused element.
534 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
535 let focus_handle = self.focused();
536
537 self.defer(move |cx| {
538 let node_id = focus_handle
539 .and_then(|handle| {
540 cx.window
541 .rendered_frame
542 .dispatch_tree
543 .focusable_node_id(handle.id)
544 })
545 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
546
547 cx.propagate_event = true;
548 cx.dispatch_action_on_node(node_id, action);
549 })
550 }
551
552 pub(crate) fn dispatch_keystroke_observers(
553 &mut self,
554 event: &dyn Any,
555 action: Option<Box<dyn Action>>,
556 ) {
557 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
558 return;
559 };
560
561 self.keystroke_observers
562 .clone()
563 .retain(&(), move |callback| {
564 (callback)(
565 &KeystrokeEvent {
566 keystroke: key_down_event.keystroke.clone(),
567 action: action.as_ref().map(|action| action.boxed_clone()),
568 },
569 self,
570 );
571 true
572 });
573 }
574
575 pub(crate) fn clear_pending_keystrokes(&mut self) {
576 self.window
577 .rendered_frame
578 .dispatch_tree
579 .clear_pending_keystrokes();
580 self.window
581 .next_frame
582 .dispatch_tree
583 .clear_pending_keystrokes();
584 }
585
586 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
587 /// that are currently on the stack to be returned to the app.
588 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
589 let handle = self.window.handle;
590 self.app.defer(move |cx| {
591 handle.update(cx, |_, cx| f(cx)).ok();
592 });
593 }
594
595 /// Subscribe to events emitted by a model or view.
596 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
597 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
598 pub fn subscribe<Emitter, E, Evt>(
599 &mut self,
600 entity: &E,
601 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
602 ) -> Subscription
603 where
604 Emitter: EventEmitter<Evt>,
605 E: Entity<Emitter>,
606 Evt: 'static,
607 {
608 let entity_id = entity.entity_id();
609 let entity = entity.downgrade();
610 let window_handle = self.window.handle;
611 let (subscription, activate) = self.app.event_listeners.insert(
612 entity_id,
613 (
614 TypeId::of::<Evt>(),
615 Box::new(move |event, cx| {
616 window_handle
617 .update(cx, |_, cx| {
618 if let Some(handle) = E::upgrade_from(&entity) {
619 let event = event.downcast_ref().expect("invalid event type");
620 on_event(handle, event, cx);
621 true
622 } else {
623 false
624 }
625 })
626 .unwrap_or(false)
627 }),
628 ),
629 );
630 self.app.defer(move |_| activate());
631 subscription
632 }
633
634 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
635 /// await points in async code.
636 pub fn to_async(&self) -> AsyncWindowContext {
637 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
638 }
639
640 /// Schedule the given closure to be run directly after the current frame is rendered.
641 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
642 let handle = self.window.handle;
643 let display_id = self.window.display_id;
644
645 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
646 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
647 let (tx, mut rx) = mpsc::unbounded::<()>();
648 self.platform.set_display_link_output_callback(
649 display_id,
650 Box::new(move || _ = tx.unbounded_send(())),
651 );
652
653 let consumer_task = self.app.spawn(|cx| async move {
654 while rx.next().await.is_some() {
655 cx.update(|cx| {
656 for callback in cx
657 .next_frame_callbacks
658 .get_mut(&display_id)
659 .unwrap()
660 .drain(..)
661 .collect::<SmallVec<[_; 32]>>()
662 {
663 callback(cx);
664 }
665 })
666 .ok();
667
668 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
669
670 cx.update(|cx| {
671 if cx.next_frame_callbacks.is_empty() {
672 cx.platform.stop_display_link(display_id);
673 }
674 })
675 .ok();
676 }
677 });
678 e.insert(consumer_task);
679 }
680 debug_assert!(self.app.frame_consumers.is_empty());
681 self.app.frame_consumers = frame_consumers;
682
683 if self.next_frame_callbacks.is_empty() {
684 self.platform.start_display_link(display_id);
685 }
686
687 self.next_frame_callbacks
688 .entry(display_id)
689 .or_default()
690 .push(Box::new(move |cx: &mut AppContext| {
691 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
692 }));
693 }
694
695 /// Spawn the future returned by the given closure on the application thread pool.
696 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
697 /// use within your future.
698 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
699 where
700 R: 'static,
701 Fut: Future<Output = R> + 'static,
702 {
703 self.app
704 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
705 }
706
707 /// Updates the global of the given type. The given closure is given simultaneous mutable
708 /// access both to the global and the context.
709 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
710 where
711 G: 'static,
712 {
713 let mut global = self.app.lease_global::<G>();
714 let result = f(&mut global, self);
715 self.app.end_global_lease(global);
716 result
717 }
718
719 fn window_bounds_changed(&mut self) {
720 self.window.scale_factor = self.window.platform_window.scale_factor();
721 self.window.viewport_size = self.window.platform_window.content_size();
722 self.window.bounds = self.window.platform_window.bounds();
723 self.window.display_id = self.window.platform_window.display().id();
724 self.refresh();
725
726 self.window
727 .bounds_observers
728 .clone()
729 .retain(&(), |callback| callback(self));
730 }
731
732 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
733 pub fn window_bounds(&self) -> WindowBounds {
734 self.window.bounds
735 }
736
737 /// Returns the size of the drawable area within the window.
738 pub fn viewport_size(&self) -> Size<Pixels> {
739 self.window.viewport_size
740 }
741
742 /// Returns whether this window is focused by the operating system (receiving key events).
743 pub fn is_window_active(&self) -> bool {
744 self.window.active
745 }
746
747 /// Toggle zoom on the window.
748 pub fn zoom_window(&self) {
749 self.window.platform_window.zoom();
750 }
751
752 /// Updates the window's title at the platform level.
753 pub fn set_window_title(&mut self, title: &str) {
754 self.window.platform_window.set_title(title);
755 }
756
757 /// Mark the window as dirty at the platform level.
758 pub fn set_window_edited(&mut self, edited: bool) {
759 self.window.platform_window.set_edited(edited);
760 }
761
762 /// Determine the display on which the window is visible.
763 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
764 self.platform
765 .displays()
766 .into_iter()
767 .find(|display| display.id() == self.window.display_id)
768 }
769
770 /// Show the platform character palette.
771 pub fn show_character_palette(&self) {
772 self.window.platform_window.show_character_palette();
773 }
774
775 /// The scale factor of the display associated with the window. For example, it could
776 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
777 /// be rendered as two pixels on screen.
778 pub fn scale_factor(&self) -> f32 {
779 self.window.scale_factor
780 }
781
782 /// The size of an em for the base font of the application. Adjusting this value allows the
783 /// UI to scale, just like zooming a web page.
784 pub fn rem_size(&self) -> Pixels {
785 self.window.rem_size
786 }
787
788 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
789 /// UI to scale, just like zooming a web page.
790 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
791 self.window.rem_size = rem_size.into();
792 }
793
794 /// The line height associated with the current text style.
795 pub fn line_height(&self) -> Pixels {
796 let rem_size = self.rem_size();
797 let text_style = self.text_style();
798 text_style
799 .line_height
800 .to_pixels(text_style.font_size, rem_size)
801 }
802
803 /// Call to prevent the default action of an event. Currently only used to prevent
804 /// parent elements from becoming focused on mouse down.
805 pub fn prevent_default(&mut self) {
806 self.window.default_prevented = true;
807 }
808
809 /// Obtain whether default has been prevented for the event currently being dispatched.
810 pub fn default_prevented(&self) -> bool {
811 self.window.default_prevented
812 }
813
814 /// Determine whether the given action is available along the dispatch path to the currently focused element.
815 pub fn is_action_available(&self, action: &dyn Action) -> bool {
816 let target = self
817 .focused()
818 .and_then(|focused_handle| {
819 self.window
820 .rendered_frame
821 .dispatch_tree
822 .focusable_node_id(focused_handle.id)
823 })
824 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
825 self.window
826 .rendered_frame
827 .dispatch_tree
828 .is_action_available(action, target)
829 }
830
831 /// The position of the mouse relative to the window.
832 pub fn mouse_position(&self) -> Point<Pixels> {
833 self.window.mouse_position
834 }
835
836 /// The current state of the keyboard's modifiers
837 pub fn modifiers(&self) -> Modifiers {
838 self.window.modifiers
839 }
840
841 /// Returns true if there is no opaque layer containing the given point
842 /// on top of the given level. Layers who are extensions of the queried layer
843 /// are not considered to be on top of queried layer.
844 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
845 // Precondition: the depth map is ordered from topmost to bottomost.
846
847 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
848 if layer >= opaque_layer {
849 // The queried layer is either above or is the same as the this opaque layer.
850 // Anything after this point is guaranteed to be below the queried layer.
851 return true;
852 }
853
854 if !bounds.contains(point) {
855 // This opaque layer is above the queried layer but it doesn't contain
856 // the given position, so we can ignore it even if it's above.
857 continue;
858 }
859
860 // At this point, we've established that this opaque layer is on top of the queried layer
861 // and contains the position:
862 // If neither the opaque layer or the queried layer is an extension of the other then
863 // we know they are on different stacking orders, and return false.
864 let is_on_same_layer = opaque_layer
865 .iter()
866 .zip(layer.iter())
867 .all(|(a, b)| a.z_index == b.z_index);
868
869 if !is_on_same_layer {
870 return false;
871 }
872 }
873
874 true
875 }
876
877 pub(crate) fn was_top_layer_under_active_drag(
878 &self,
879 point: &Point<Pixels>,
880 layer: &StackingOrder,
881 ) -> bool {
882 // Precondition: the depth map is ordered from topmost to bottomost.
883
884 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
885 if layer >= opaque_layer {
886 // The queried layer is either above or is the same as the this opaque layer.
887 // Anything after this point is guaranteed to be below the queried layer.
888 return true;
889 }
890
891 if !bounds.contains(point) {
892 // This opaque layer is above the queried layer but it doesn't contain
893 // the given position, so we can ignore it even if it's above.
894 continue;
895 }
896
897 // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
898 // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
899 // looking to see if the queried layer was the topmost underneath the drag layer.
900 if opaque_layer
901 .first()
902 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
903 .unwrap_or(false)
904 {
905 continue;
906 }
907
908 // At this point, we've established that this opaque layer is on top of the queried layer
909 // and contains the position:
910 // If neither the opaque layer or the queried layer is an extension of the other then
911 // we know they are on different stacking orders, and return false.
912 let is_on_same_layer = opaque_layer
913 .iter()
914 .zip(layer.iter())
915 .all(|(a, b)| a.z_index == b.z_index);
916
917 if !is_on_same_layer {
918 return false;
919 }
920 }
921
922 true
923 }
924
925 /// Called during painting to get the current stacking order.
926 pub fn stacking_order(&self) -> &StackingOrder {
927 &self.window.next_frame.z_index_stack
928 }
929
930 /// Draw pixels to the display for this window based on the contents of its scene.
931 pub(crate) fn draw(&mut self) {
932 self.window.dirty = false;
933 self.window.drawing = true;
934
935 #[cfg(any(test, feature = "test-support"))]
936 {
937 self.window.focus_invalidated = false;
938 }
939
940 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
941 {
942 let input_handler = self.window.platform_window.take_input_handler();
943 requested_handler.handler = input_handler;
944 }
945
946 let root_view = self.window.root_view.take().unwrap();
947 self.with_element_context(|cx| {
948 cx.with_z_index(0, |cx| {
949 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
950 // We need to use cx.cx here so we can utilize borrow splitting
951 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
952 for action_listener in action_listeners.iter().cloned() {
953 cx.cx.window.next_frame.dispatch_tree.on_action(
954 *action_type,
955 Rc::new(
956 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
957 action_listener(action, phase, cx)
958 },
959 ),
960 )
961 }
962 }
963
964 let available_space = cx.window.viewport_size.map(Into::into);
965 root_view.draw(Point::default(), available_space, cx);
966 })
967 })
968 });
969
970 if let Some(active_drag) = self.app.active_drag.take() {
971 self.with_element_context(|cx| {
972 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
973 let offset = cx.mouse_position() - active_drag.cursor_offset;
974 let available_space =
975 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
976 active_drag.view.draw(offset, available_space, cx);
977 })
978 });
979 self.active_drag = Some(active_drag);
980 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
981 self.with_element_context(|cx| {
982 cx.with_z_index(1, |cx| {
983 let available_space =
984 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
985 tooltip_request.tooltip.view.draw(
986 tooltip_request.tooltip.cursor_offset,
987 available_space,
988 cx,
989 );
990 })
991 });
992 self.window.next_frame.tooltip_request = Some(tooltip_request);
993 }
994 self.window.dirty_views.clear();
995
996 self.window
997 .next_frame
998 .dispatch_tree
999 .preserve_pending_keystrokes(
1000 &mut self.window.rendered_frame.dispatch_tree,
1001 self.window.focus,
1002 );
1003 self.window.next_frame.focus = self.window.focus;
1004 self.window.next_frame.window_active = self.window.active;
1005 self.window.root_view = Some(root_view);
1006
1007 // Set the cursor only if we're the active window.
1008 let cursor_style = self
1009 .window
1010 .next_frame
1011 .requested_cursor_style
1012 .take()
1013 .unwrap_or(CursorStyle::Arrow);
1014 if self.is_window_active() {
1015 self.platform.set_cursor_style(cursor_style);
1016 }
1017
1018 // Register requested input handler with the platform window.
1019 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
1020 if let Some(handler) = requested_input.handler.take() {
1021 self.window.platform_window.set_input_handler(handler);
1022 }
1023 }
1024
1025 self.window.layout_engine.as_mut().unwrap().clear();
1026 self.text_system()
1027 .finish_frame(&self.window.next_frame.reused_views);
1028 self.window
1029 .next_frame
1030 .finish(&mut self.window.rendered_frame);
1031 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1032 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1033 if percentage >= 80. {
1034 log::warn!("elevated element arena occupation: {}.", percentage);
1035 }
1036 element_arena.clear();
1037 });
1038
1039 let previous_focus_path = self.window.rendered_frame.focus_path();
1040 let previous_window_active = self.window.rendered_frame.window_active;
1041 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1042 self.window.next_frame.clear();
1043 let current_focus_path = self.window.rendered_frame.focus_path();
1044 let current_window_active = self.window.rendered_frame.window_active;
1045
1046 if previous_focus_path != current_focus_path
1047 || previous_window_active != current_window_active
1048 {
1049 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1050 self.window
1051 .focus_lost_listeners
1052 .clone()
1053 .retain(&(), |listener| listener(self));
1054 }
1055
1056 let event = FocusEvent {
1057 previous_focus_path: if previous_window_active {
1058 previous_focus_path
1059 } else {
1060 Default::default()
1061 },
1062 current_focus_path: if current_window_active {
1063 current_focus_path
1064 } else {
1065 Default::default()
1066 },
1067 };
1068 self.window
1069 .focus_listeners
1070 .clone()
1071 .retain(&(), |listener| listener(&event, self));
1072 }
1073
1074 self.window
1075 .platform_window
1076 .draw(&self.window.rendered_frame.scene);
1077 self.window.refreshing = false;
1078 self.window.drawing = false;
1079 }
1080
1081 /// Dispatch a mouse or keyboard event on the window.
1082 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1083 // Handlers may set this to false by calling `stop_propagation`.
1084 self.app.propagate_event = true;
1085 // Handlers may set this to true by calling `prevent_default`.
1086 self.window.default_prevented = false;
1087
1088 let event = match event {
1089 // Track the mouse position with our own state, since accessing the platform
1090 // API for the mouse position can only occur on the main thread.
1091 PlatformInput::MouseMove(mouse_move) => {
1092 self.window.mouse_position = mouse_move.position;
1093 self.window.modifiers = mouse_move.modifiers;
1094 PlatformInput::MouseMove(mouse_move)
1095 }
1096 PlatformInput::MouseDown(mouse_down) => {
1097 self.window.mouse_position = mouse_down.position;
1098 self.window.modifiers = mouse_down.modifiers;
1099 PlatformInput::MouseDown(mouse_down)
1100 }
1101 PlatformInput::MouseUp(mouse_up) => {
1102 self.window.mouse_position = mouse_up.position;
1103 self.window.modifiers = mouse_up.modifiers;
1104 PlatformInput::MouseUp(mouse_up)
1105 }
1106 PlatformInput::MouseExited(mouse_exited) => {
1107 self.window.modifiers = mouse_exited.modifiers;
1108 PlatformInput::MouseExited(mouse_exited)
1109 }
1110 PlatformInput::ModifiersChanged(modifiers_changed) => {
1111 self.window.modifiers = modifiers_changed.modifiers;
1112 PlatformInput::ModifiersChanged(modifiers_changed)
1113 }
1114 PlatformInput::ScrollWheel(scroll_wheel) => {
1115 self.window.mouse_position = scroll_wheel.position;
1116 self.window.modifiers = scroll_wheel.modifiers;
1117 PlatformInput::ScrollWheel(scroll_wheel)
1118 }
1119 // Translate dragging and dropping of external files from the operating system
1120 // to internal drag and drop events.
1121 PlatformInput::FileDrop(file_drop) => match file_drop {
1122 FileDropEvent::Entered { position, paths } => {
1123 self.window.mouse_position = position;
1124 if self.active_drag.is_none() {
1125 self.active_drag = Some(AnyDrag {
1126 value: Box::new(paths.clone()),
1127 view: self.new_view(|_| paths).into(),
1128 cursor_offset: position,
1129 });
1130 }
1131 PlatformInput::MouseMove(MouseMoveEvent {
1132 position,
1133 pressed_button: Some(MouseButton::Left),
1134 modifiers: Modifiers::default(),
1135 })
1136 }
1137 FileDropEvent::Pending { position } => {
1138 self.window.mouse_position = position;
1139 PlatformInput::MouseMove(MouseMoveEvent {
1140 position,
1141 pressed_button: Some(MouseButton::Left),
1142 modifiers: Modifiers::default(),
1143 })
1144 }
1145 FileDropEvent::Submit { position } => {
1146 self.activate(true);
1147 self.window.mouse_position = position;
1148 PlatformInput::MouseUp(MouseUpEvent {
1149 button: MouseButton::Left,
1150 position,
1151 modifiers: Modifiers::default(),
1152 click_count: 1,
1153 })
1154 }
1155 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1156 button: MouseButton::Left,
1157 position: Point::default(),
1158 modifiers: Modifiers::default(),
1159 click_count: 1,
1160 }),
1161 },
1162 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1163 };
1164
1165 if let Some(any_mouse_event) = event.mouse_event() {
1166 self.dispatch_mouse_event(any_mouse_event);
1167 } else if let Some(any_key_event) = event.keyboard_event() {
1168 self.dispatch_key_event(any_key_event);
1169 }
1170
1171 !self.app.propagate_event
1172 }
1173
1174 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1175 if let Some(mut handlers) = self
1176 .window
1177 .rendered_frame
1178 .mouse_listeners
1179 .remove(&event.type_id())
1180 {
1181 // Because handlers may add other handlers, we sort every time.
1182 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1183
1184 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1185 // special purposes, such as detecting events outside of a given Bounds.
1186 for (_, _, handler) in &mut handlers {
1187 self.with_element_context(|cx| {
1188 handler(event, DispatchPhase::Capture, cx);
1189 });
1190 if !self.app.propagate_event {
1191 break;
1192 }
1193 }
1194
1195 // Bubble phase, where most normal handlers do their work.
1196 if self.app.propagate_event {
1197 for (_, _, handler) in handlers.iter_mut().rev() {
1198 self.with_element_context(|cx| {
1199 handler(event, DispatchPhase::Bubble, cx);
1200 });
1201 if !self.app.propagate_event {
1202 break;
1203 }
1204 }
1205 }
1206
1207 self.window
1208 .rendered_frame
1209 .mouse_listeners
1210 .insert(event.type_id(), handlers);
1211 }
1212
1213 if self.app.propagate_event && self.has_active_drag() {
1214 if event.is::<MouseMoveEvent>() {
1215 // If this was a mouse move event, redraw the window so that the
1216 // active drag can follow the mouse cursor.
1217 self.refresh();
1218 } else if event.is::<MouseUpEvent>() {
1219 // If this was a mouse up event, cancel the active drag and redraw
1220 // the window.
1221 self.active_drag = None;
1222 self.refresh();
1223 }
1224 }
1225 }
1226
1227 fn dispatch_key_event(&mut self, event: &dyn Any) {
1228 let node_id = self
1229 .window
1230 .focus
1231 .and_then(|focus_id| {
1232 self.window
1233 .rendered_frame
1234 .dispatch_tree
1235 .focusable_node_id(focus_id)
1236 })
1237 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1238
1239 let dispatch_path = self
1240 .window
1241 .rendered_frame
1242 .dispatch_tree
1243 .dispatch_path(node_id);
1244
1245 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1246 let KeymatchResult {
1247 bindings,
1248 mut pending,
1249 } = self
1250 .window
1251 .rendered_frame
1252 .dispatch_tree
1253 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1254
1255 if self.window.rendered_frame.dispatch_tree.keymatch_mode == KeymatchMode::Immediate
1256 && !bindings.is_empty()
1257 {
1258 pending = false;
1259 }
1260
1261 if pending {
1262 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1263 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1264 {
1265 currently_pending = PendingInput::default();
1266 }
1267 currently_pending.focus = self.window.focus;
1268 currently_pending
1269 .keystrokes
1270 .push(key_down_event.keystroke.clone());
1271 for binding in bindings {
1272 currently_pending.bindings.push(binding);
1273 }
1274
1275 // for vim compatibility, we also should check "is input handler enabled"
1276 if !currently_pending.is_noop() {
1277 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1278 cx.background_executor.timer(Duration::from_secs(1)).await;
1279 cx.update(move |cx| {
1280 cx.clear_pending_keystrokes();
1281 let Some(currently_pending) = cx.window.pending_input.take() else {
1282 return;
1283 };
1284 cx.replay_pending_input(currently_pending)
1285 })
1286 .log_err();
1287 }));
1288 } else {
1289 currently_pending.timer = None;
1290 }
1291 self.window.pending_input = Some(currently_pending);
1292
1293 self.propagate_event = false;
1294 return;
1295 } else if let Some(currently_pending) = self.window.pending_input.take() {
1296 if bindings
1297 .iter()
1298 .all(|binding| !currently_pending.used_by_binding(binding))
1299 {
1300 self.replay_pending_input(currently_pending)
1301 }
1302 }
1303
1304 if !bindings.is_empty() {
1305 self.clear_pending_keystrokes();
1306 }
1307
1308 self.propagate_event = true;
1309 for binding in bindings {
1310 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1311 if !self.propagate_event {
1312 self.dispatch_keystroke_observers(event, Some(binding.action));
1313 return;
1314 }
1315 }
1316 }
1317
1318 // Capture phase
1319 for node_id in &dispatch_path {
1320 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1321
1322 for key_listener in node.key_listeners.clone() {
1323 self.with_element_context(|cx| {
1324 key_listener(event, DispatchPhase::Capture, cx);
1325 });
1326 if !self.propagate_event {
1327 return;
1328 }
1329 }
1330 }
1331
1332 // Bubble phase
1333 for node_id in dispatch_path.iter().rev() {
1334 // Handle low level key events
1335 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1336 for key_listener in node.key_listeners.clone() {
1337 self.with_element_context(|cx| {
1338 key_listener(event, DispatchPhase::Bubble, cx);
1339 });
1340 if !self.propagate_event {
1341 return;
1342 }
1343 }
1344 }
1345
1346 self.dispatch_keystroke_observers(event, None);
1347 }
1348
1349 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1350 pub fn has_pending_keystrokes(&self) -> bool {
1351 self.window
1352 .rendered_frame
1353 .dispatch_tree
1354 .has_pending_keystrokes()
1355 }
1356
1357 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1358 let node_id = self
1359 .window
1360 .focus
1361 .and_then(|focus_id| {
1362 self.window
1363 .rendered_frame
1364 .dispatch_tree
1365 .focusable_node_id(focus_id)
1366 })
1367 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1368
1369 if self.window.focus != currently_pending.focus {
1370 return;
1371 }
1372
1373 let input = currently_pending.input();
1374
1375 self.propagate_event = true;
1376 for binding in currently_pending.bindings {
1377 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1378 if !self.propagate_event {
1379 return;
1380 }
1381 }
1382
1383 if !input.is_empty() {
1384 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1385 input_handler.flush_pending_input(&input, self);
1386 self.window.platform_window.set_input_handler(input_handler)
1387 }
1388 }
1389 }
1390
1391 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1392 let dispatch_path = self
1393 .window
1394 .rendered_frame
1395 .dispatch_tree
1396 .dispatch_path(node_id);
1397
1398 // Capture phase
1399 for node_id in &dispatch_path {
1400 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1401 for DispatchActionListener {
1402 action_type,
1403 listener,
1404 } in node.action_listeners.clone()
1405 {
1406 let any_action = action.as_any();
1407 if action_type == any_action.type_id() {
1408 self.with_element_context(|cx| {
1409 listener(any_action, DispatchPhase::Capture, cx);
1410 });
1411
1412 if !self.propagate_event {
1413 return;
1414 }
1415 }
1416 }
1417 }
1418 // Bubble phase
1419 for node_id in dispatch_path.iter().rev() {
1420 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1421 for DispatchActionListener {
1422 action_type,
1423 listener,
1424 } in node.action_listeners.clone()
1425 {
1426 let any_action = action.as_any();
1427 if action_type == any_action.type_id() {
1428 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1429
1430 self.with_element_context(|cx| {
1431 listener(any_action, DispatchPhase::Bubble, cx);
1432 });
1433
1434 if !self.propagate_event {
1435 return;
1436 }
1437 }
1438 }
1439 }
1440 }
1441
1442 /// Register the given handler to be invoked whenever the global of the given type
1443 /// is updated.
1444 pub fn observe_global<G: 'static>(
1445 &mut self,
1446 f: impl Fn(&mut WindowContext<'_>) + 'static,
1447 ) -> Subscription {
1448 let window_handle = self.window.handle;
1449 let (subscription, activate) = self.global_observers.insert(
1450 TypeId::of::<G>(),
1451 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1452 );
1453 self.app.defer(move |_| activate());
1454 subscription
1455 }
1456
1457 /// Focus the current window and bring it to the foreground at the platform level.
1458 pub fn activate_window(&self) {
1459 self.window.platform_window.activate();
1460 }
1461
1462 /// Minimize the current window at the platform level.
1463 pub fn minimize_window(&self) {
1464 self.window.platform_window.minimize();
1465 }
1466
1467 /// Toggle full screen status on the current window at the platform level.
1468 pub fn toggle_full_screen(&self) {
1469 self.window.platform_window.toggle_full_screen();
1470 }
1471
1472 /// Present a platform dialog.
1473 /// The provided message will be presented, along with buttons for each answer.
1474 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1475 pub fn prompt(
1476 &self,
1477 level: PromptLevel,
1478 message: &str,
1479 detail: Option<&str>,
1480 answers: &[&str],
1481 ) -> oneshot::Receiver<usize> {
1482 self.window
1483 .platform_window
1484 .prompt(level, message, detail, answers)
1485 }
1486
1487 /// Returns all available actions for the focused element.
1488 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1489 let node_id = self
1490 .window
1491 .focus
1492 .and_then(|focus_id| {
1493 self.window
1494 .rendered_frame
1495 .dispatch_tree
1496 .focusable_node_id(focus_id)
1497 })
1498 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1499
1500 self.window
1501 .rendered_frame
1502 .dispatch_tree
1503 .available_actions(node_id)
1504 }
1505
1506 /// Returns key bindings that invoke the given action on the currently focused element.
1507 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1508 self.window
1509 .rendered_frame
1510 .dispatch_tree
1511 .bindings_for_action(
1512 action,
1513 &self.window.rendered_frame.dispatch_tree.context_stack,
1514 )
1515 }
1516
1517 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1518 pub fn bindings_for_action_in(
1519 &self,
1520 action: &dyn Action,
1521 focus_handle: &FocusHandle,
1522 ) -> Vec<KeyBinding> {
1523 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1524
1525 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1526 return vec![];
1527 };
1528 let context_stack = dispatch_tree
1529 .dispatch_path(node_id)
1530 .into_iter()
1531 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1532 .collect();
1533 dispatch_tree.bindings_for_action(action, &context_stack)
1534 }
1535
1536 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1537 pub fn listener_for<V: Render, E>(
1538 &self,
1539 view: &View<V>,
1540 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1541 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1542 let view = view.downgrade();
1543 move |e: &E, cx: &mut WindowContext| {
1544 view.update(cx, |view, cx| f(view, e, cx)).ok();
1545 }
1546 }
1547
1548 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1549 pub fn handler_for<V: Render>(
1550 &self,
1551 view: &View<V>,
1552 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1553 ) -> impl Fn(&mut WindowContext) {
1554 let view = view.downgrade();
1555 move |cx: &mut WindowContext| {
1556 view.update(cx, |view, cx| f(view, cx)).ok();
1557 }
1558 }
1559
1560 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1561 /// If the callback returns false, the window won't be closed.
1562 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1563 let mut this = self.to_async();
1564 self.window
1565 .platform_window
1566 .on_should_close(Box::new(move || {
1567 this.update(|cx| {
1568 // Ensure that the window is removed from the app if it's been closed
1569 // by always pre-empting the system close event.
1570 if f(cx) {
1571 cx.remove_window();
1572 }
1573 false
1574 })
1575 .unwrap_or(true)
1576 }))
1577 }
1578
1579 pub(crate) fn parent_view_id(&self) -> EntityId {
1580 *self
1581 .window
1582 .next_frame
1583 .view_stack
1584 .last()
1585 .expect("a view should always be on the stack while drawing")
1586 }
1587
1588 /// Register an action listener on the window for the next frame. The type of action
1589 /// is determined by the first parameter of the given listener. When the next frame is rendered
1590 /// the listener will be cleared.
1591 ///
1592 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1593 /// a specific need to register a global listener.
1594 pub fn on_action(
1595 &mut self,
1596 action_type: TypeId,
1597 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1598 ) {
1599 self.window
1600 .next_frame
1601 .dispatch_tree
1602 .on_action(action_type, Rc::new(listener));
1603 }
1604}
1605
1606impl Context for WindowContext<'_> {
1607 type Result<T> = T;
1608
1609 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1610 where
1611 T: 'static,
1612 {
1613 let slot = self.app.entities.reserve();
1614 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1615 self.entities.insert(slot, model)
1616 }
1617
1618 fn update_model<T: 'static, R>(
1619 &mut self,
1620 model: &Model<T>,
1621 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1622 ) -> R {
1623 let mut entity = self.entities.lease(model);
1624 let result = update(
1625 &mut *entity,
1626 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1627 );
1628 self.entities.end_lease(entity);
1629 result
1630 }
1631
1632 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1633 where
1634 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1635 {
1636 if window == self.window.handle {
1637 let root_view = self.window.root_view.clone().unwrap();
1638 Ok(update(root_view, self))
1639 } else {
1640 window.update(self.app, update)
1641 }
1642 }
1643
1644 fn read_model<T, R>(
1645 &self,
1646 handle: &Model<T>,
1647 read: impl FnOnce(&T, &AppContext) -> R,
1648 ) -> Self::Result<R>
1649 where
1650 T: 'static,
1651 {
1652 let entity = self.entities.read(handle);
1653 read(entity, &*self.app)
1654 }
1655
1656 fn read_window<T, R>(
1657 &self,
1658 window: &WindowHandle<T>,
1659 read: impl FnOnce(View<T>, &AppContext) -> R,
1660 ) -> Result<R>
1661 where
1662 T: 'static,
1663 {
1664 if window.any_handle == self.window.handle {
1665 let root_view = self
1666 .window
1667 .root_view
1668 .clone()
1669 .unwrap()
1670 .downcast::<T>()
1671 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1672 Ok(read(root_view, self))
1673 } else {
1674 self.app.read_window(window, read)
1675 }
1676 }
1677}
1678
1679impl VisualContext for WindowContext<'_> {
1680 fn new_view<V>(
1681 &mut self,
1682 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1683 ) -> Self::Result<View<V>>
1684 where
1685 V: 'static + Render,
1686 {
1687 let slot = self.app.entities.reserve();
1688 let view = View {
1689 model: slot.clone(),
1690 };
1691 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1692 let entity = build_view_state(&mut cx);
1693 cx.entities.insert(slot, entity);
1694
1695 cx.new_view_observers
1696 .clone()
1697 .retain(&TypeId::of::<V>(), |observer| {
1698 let any_view = AnyView::from(view.clone());
1699 (observer)(any_view, self);
1700 true
1701 });
1702
1703 view
1704 }
1705
1706 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1707 fn update_view<T: 'static, R>(
1708 &mut self,
1709 view: &View<T>,
1710 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1711 ) -> Self::Result<R> {
1712 let mut lease = self.app.entities.lease(&view.model);
1713 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1714 let result = update(&mut *lease, &mut cx);
1715 cx.app.entities.end_lease(lease);
1716 result
1717 }
1718
1719 fn replace_root_view<V>(
1720 &mut self,
1721 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1722 ) -> Self::Result<View<V>>
1723 where
1724 V: 'static + Render,
1725 {
1726 let view = self.new_view(build_view);
1727 self.window.root_view = Some(view.clone().into());
1728 self.refresh();
1729 view
1730 }
1731
1732 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1733 self.update_view(view, |view, cx| {
1734 view.focus_handle(cx).clone().focus(cx);
1735 })
1736 }
1737
1738 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1739 where
1740 V: ManagedView,
1741 {
1742 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1743 }
1744}
1745
1746impl<'a> std::ops::Deref for WindowContext<'a> {
1747 type Target = AppContext;
1748
1749 fn deref(&self) -> &Self::Target {
1750 self.app
1751 }
1752}
1753
1754impl<'a> std::ops::DerefMut for WindowContext<'a> {
1755 fn deref_mut(&mut self) -> &mut Self::Target {
1756 self.app
1757 }
1758}
1759
1760impl<'a> Borrow<AppContext> for WindowContext<'a> {
1761 fn borrow(&self) -> &AppContext {
1762 self.app
1763 }
1764}
1765
1766impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1767 fn borrow_mut(&mut self) -> &mut AppContext {
1768 self.app
1769 }
1770}
1771
1772/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1773pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1774 #[doc(hidden)]
1775 fn app_mut(&mut self) -> &mut AppContext {
1776 self.borrow_mut()
1777 }
1778
1779 #[doc(hidden)]
1780 fn app(&self) -> &AppContext {
1781 self.borrow()
1782 }
1783
1784 #[doc(hidden)]
1785 fn window(&self) -> &Window {
1786 self.borrow()
1787 }
1788
1789 #[doc(hidden)]
1790 fn window_mut(&mut self) -> &mut Window {
1791 self.borrow_mut()
1792 }
1793}
1794
1795impl Borrow<Window> for WindowContext<'_> {
1796 fn borrow(&self) -> &Window {
1797 self.window
1798 }
1799}
1800
1801impl BorrowMut<Window> for WindowContext<'_> {
1802 fn borrow_mut(&mut self) -> &mut Window {
1803 self.window
1804 }
1805}
1806
1807impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1808
1809/// Provides access to application state that is specialized for a particular [`View`].
1810/// Allows you to interact with focus, emit events, etc.
1811/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1812/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1813pub struct ViewContext<'a, V> {
1814 window_cx: WindowContext<'a>,
1815 view: &'a View<V>,
1816}
1817
1818impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1819 fn borrow(&self) -> &AppContext {
1820 &*self.window_cx.app
1821 }
1822}
1823
1824impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1825 fn borrow_mut(&mut self) -> &mut AppContext {
1826 &mut *self.window_cx.app
1827 }
1828}
1829
1830impl<V> Borrow<Window> for ViewContext<'_, V> {
1831 fn borrow(&self) -> &Window {
1832 &*self.window_cx.window
1833 }
1834}
1835
1836impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1837 fn borrow_mut(&mut self) -> &mut Window {
1838 &mut *self.window_cx.window
1839 }
1840}
1841
1842impl<'a, V: 'static> ViewContext<'a, V> {
1843 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1844 Self {
1845 window_cx: WindowContext::new(app, window),
1846 view,
1847 }
1848 }
1849
1850 /// Get the entity_id of this view.
1851 pub fn entity_id(&self) -> EntityId {
1852 self.view.entity_id()
1853 }
1854
1855 /// Get the view pointer underlying this context.
1856 pub fn view(&self) -> &View<V> {
1857 self.view
1858 }
1859
1860 /// Get the model underlying this view.
1861 pub fn model(&self) -> &Model<V> {
1862 &self.view.model
1863 }
1864
1865 /// Access the underlying window context.
1866 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1867 &mut self.window_cx
1868 }
1869
1870 /// Sets a given callback to be run on the next frame.
1871 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1872 where
1873 V: 'static,
1874 {
1875 let view = self.view().clone();
1876 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1877 }
1878
1879 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1880 /// that are currently on the stack to be returned to the app.
1881 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1882 let view = self.view().downgrade();
1883 self.window_cx.defer(move |cx| {
1884 view.update(cx, f).ok();
1885 });
1886 }
1887
1888 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1889 pub fn observe<V2, E>(
1890 &mut self,
1891 entity: &E,
1892 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1893 ) -> Subscription
1894 where
1895 V2: 'static,
1896 V: 'static,
1897 E: Entity<V2>,
1898 {
1899 let view = self.view().downgrade();
1900 let entity_id = entity.entity_id();
1901 let entity = entity.downgrade();
1902 let window_handle = self.window.handle;
1903 let (subscription, activate) = self.app.observers.insert(
1904 entity_id,
1905 Box::new(move |cx| {
1906 window_handle
1907 .update(cx, |_, cx| {
1908 if let Some(handle) = E::upgrade_from(&entity) {
1909 view.update(cx, |this, cx| on_notify(this, handle, cx))
1910 .is_ok()
1911 } else {
1912 false
1913 }
1914 })
1915 .unwrap_or(false)
1916 }),
1917 );
1918 self.app.defer(move |_| activate());
1919 subscription
1920 }
1921
1922 /// Subscribe to events emitted by another model or view.
1923 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1924 /// 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.
1925 pub fn subscribe<V2, E, Evt>(
1926 &mut self,
1927 entity: &E,
1928 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1929 ) -> Subscription
1930 where
1931 V2: EventEmitter<Evt>,
1932 E: Entity<V2>,
1933 Evt: 'static,
1934 {
1935 let view = self.view().downgrade();
1936 let entity_id = entity.entity_id();
1937 let handle = entity.downgrade();
1938 let window_handle = self.window.handle;
1939 let (subscription, activate) = self.app.event_listeners.insert(
1940 entity_id,
1941 (
1942 TypeId::of::<Evt>(),
1943 Box::new(move |event, cx| {
1944 window_handle
1945 .update(cx, |_, cx| {
1946 if let Some(handle) = E::upgrade_from(&handle) {
1947 let event = event.downcast_ref().expect("invalid event type");
1948 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1949 .is_ok()
1950 } else {
1951 false
1952 }
1953 })
1954 .unwrap_or(false)
1955 }),
1956 ),
1957 );
1958 self.app.defer(move |_| activate());
1959 subscription
1960 }
1961
1962 /// Register a callback to be invoked when the view is released.
1963 ///
1964 /// The callback receives a handle to the view's window. This handle may be
1965 /// invalid, if the window was closed before the view was released.
1966 pub fn on_release(
1967 &mut self,
1968 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1969 ) -> Subscription {
1970 let window_handle = self.window.handle;
1971 let (subscription, activate) = self.app.release_listeners.insert(
1972 self.view.model.entity_id,
1973 Box::new(move |this, cx| {
1974 let this = this.downcast_mut().expect("invalid entity type");
1975 on_release(this, window_handle, cx)
1976 }),
1977 );
1978 activate();
1979 subscription
1980 }
1981
1982 /// Register a callback to be invoked when the given Model or View is released.
1983 pub fn observe_release<V2, E>(
1984 &mut self,
1985 entity: &E,
1986 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1987 ) -> Subscription
1988 where
1989 V: 'static,
1990 V2: 'static,
1991 E: Entity<V2>,
1992 {
1993 let view = self.view().downgrade();
1994 let entity_id = entity.entity_id();
1995 let window_handle = self.window.handle;
1996 let (subscription, activate) = self.app.release_listeners.insert(
1997 entity_id,
1998 Box::new(move |entity, cx| {
1999 let entity = entity.downcast_mut().expect("invalid entity type");
2000 let _ = window_handle.update(cx, |_, cx| {
2001 view.update(cx, |this, cx| on_release(this, entity, cx))
2002 });
2003 }),
2004 );
2005 activate();
2006 subscription
2007 }
2008
2009 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2010 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2011 pub fn notify(&mut self) {
2012 for view_id in self
2013 .window
2014 .rendered_frame
2015 .dispatch_tree
2016 .view_path(self.view.entity_id())
2017 .into_iter()
2018 .rev()
2019 {
2020 if !self.window.dirty_views.insert(view_id) {
2021 break;
2022 }
2023 }
2024
2025 if !self.window.drawing {
2026 self.window_cx.window.dirty = true;
2027 self.window_cx.app.push_effect(Effect::Notify {
2028 emitter: self.view.model.entity_id,
2029 });
2030 }
2031 }
2032
2033 /// Register a callback to be invoked when the window is resized.
2034 pub fn observe_window_bounds(
2035 &mut self,
2036 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2037 ) -> Subscription {
2038 let view = self.view.downgrade();
2039 let (subscription, activate) = self.window.bounds_observers.insert(
2040 (),
2041 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2042 );
2043 activate();
2044 subscription
2045 }
2046
2047 /// Register a callback to be invoked when the window is activated or deactivated.
2048 pub fn observe_window_activation(
2049 &mut self,
2050 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2051 ) -> Subscription {
2052 let view = self.view.downgrade();
2053 let (subscription, activate) = self.window.activation_observers.insert(
2054 (),
2055 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2056 );
2057 activate();
2058 subscription
2059 }
2060
2061 /// Register a listener to be called when the given focus handle receives focus.
2062 /// Returns a subscription and persists until the subscription is dropped.
2063 pub fn on_focus(
2064 &mut self,
2065 handle: &FocusHandle,
2066 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2067 ) -> Subscription {
2068 let view = self.view.downgrade();
2069 let focus_id = handle.id;
2070 let (subscription, activate) = self.window.focus_listeners.insert(
2071 (),
2072 Box::new(move |event, cx| {
2073 view.update(cx, |view, cx| {
2074 if event.previous_focus_path.last() != Some(&focus_id)
2075 && event.current_focus_path.last() == Some(&focus_id)
2076 {
2077 listener(view, cx)
2078 }
2079 })
2080 .is_ok()
2081 }),
2082 );
2083 self.app.defer(move |_| activate());
2084 subscription
2085 }
2086
2087 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2088 /// Returns a subscription and persists until the subscription is dropped.
2089 pub fn on_focus_in(
2090 &mut self,
2091 handle: &FocusHandle,
2092 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2093 ) -> Subscription {
2094 let view = self.view.downgrade();
2095 let focus_id = handle.id;
2096 let (subscription, activate) = self.window.focus_listeners.insert(
2097 (),
2098 Box::new(move |event, cx| {
2099 view.update(cx, |view, cx| {
2100 if !event.previous_focus_path.contains(&focus_id)
2101 && event.current_focus_path.contains(&focus_id)
2102 {
2103 listener(view, cx)
2104 }
2105 })
2106 .is_ok()
2107 }),
2108 );
2109 self.app.defer(move |_| activate());
2110 subscription
2111 }
2112
2113 /// Register a listener to be called when the given focus handle loses focus.
2114 /// Returns a subscription and persists until the subscription is dropped.
2115 pub fn on_blur(
2116 &mut self,
2117 handle: &FocusHandle,
2118 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2119 ) -> Subscription {
2120 let view = self.view.downgrade();
2121 let focus_id = handle.id;
2122 let (subscription, activate) = self.window.focus_listeners.insert(
2123 (),
2124 Box::new(move |event, cx| {
2125 view.update(cx, |view, cx| {
2126 if event.previous_focus_path.last() == Some(&focus_id)
2127 && event.current_focus_path.last() != Some(&focus_id)
2128 {
2129 listener(view, cx)
2130 }
2131 })
2132 .is_ok()
2133 }),
2134 );
2135 self.app.defer(move |_| activate());
2136 subscription
2137 }
2138
2139 /// Register a listener to be called when nothing in the window has focus.
2140 /// This typically happens when the node that was focused is removed from the tree,
2141 /// and this callback lets you chose a default place to restore the users focus.
2142 /// Returns a subscription and persists until the subscription is dropped.
2143 pub fn on_focus_lost(
2144 &mut self,
2145 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2146 ) -> Subscription {
2147 let view = self.view.downgrade();
2148 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2149 (),
2150 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2151 );
2152 activate();
2153 subscription
2154 }
2155
2156 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2157 /// Returns a subscription and persists until the subscription is dropped.
2158 pub fn on_focus_out(
2159 &mut self,
2160 handle: &FocusHandle,
2161 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2162 ) -> Subscription {
2163 let view = self.view.downgrade();
2164 let focus_id = handle.id;
2165 let (subscription, activate) = self.window.focus_listeners.insert(
2166 (),
2167 Box::new(move |event, cx| {
2168 view.update(cx, |view, cx| {
2169 if event.previous_focus_path.contains(&focus_id)
2170 && !event.current_focus_path.contains(&focus_id)
2171 {
2172 listener(view, cx)
2173 }
2174 })
2175 .is_ok()
2176 }),
2177 );
2178 self.app.defer(move |_| activate());
2179 subscription
2180 }
2181
2182 /// Schedule a future to be run asynchronously.
2183 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2184 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2185 /// The returned future will be polled on the main thread.
2186 pub fn spawn<Fut, R>(
2187 &mut self,
2188 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2189 ) -> Task<R>
2190 where
2191 R: 'static,
2192 Fut: Future<Output = R> + 'static,
2193 {
2194 let view = self.view().downgrade();
2195 self.window_cx.spawn(|cx| f(view, cx))
2196 }
2197
2198 /// Updates the global state of the given type.
2199 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2200 where
2201 G: 'static,
2202 {
2203 let mut global = self.app.lease_global::<G>();
2204 let result = f(&mut global, self);
2205 self.app.end_global_lease(global);
2206 result
2207 }
2208
2209 /// Register a callback to be invoked when the given global state changes.
2210 pub fn observe_global<G: 'static>(
2211 &mut self,
2212 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2213 ) -> Subscription {
2214 let window_handle = self.window.handle;
2215 let view = self.view().downgrade();
2216 let (subscription, activate) = self.global_observers.insert(
2217 TypeId::of::<G>(),
2218 Box::new(move |cx| {
2219 window_handle
2220 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2221 .unwrap_or(false)
2222 }),
2223 );
2224 self.app.defer(move |_| activate());
2225 subscription
2226 }
2227
2228 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2229 pub fn on_action(
2230 &mut self,
2231 action_type: TypeId,
2232 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2233 ) {
2234 let handle = self.view().clone();
2235 self.window_cx
2236 .on_action(action_type, move |action, phase, cx| {
2237 handle.update(cx, |view, cx| {
2238 listener(view, action, phase, cx);
2239 })
2240 });
2241 }
2242
2243 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2244 pub fn emit<Evt>(&mut self, event: Evt)
2245 where
2246 Evt: 'static,
2247 V: EventEmitter<Evt>,
2248 {
2249 let emitter = self.view.model.entity_id;
2250 self.app.push_effect(Effect::Emit {
2251 emitter,
2252 event_type: TypeId::of::<Evt>(),
2253 event: Box::new(event),
2254 });
2255 }
2256
2257 /// Move focus to the current view, assuming it implements [`FocusableView`].
2258 pub fn focus_self(&mut self)
2259 where
2260 V: FocusableView,
2261 {
2262 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2263 }
2264
2265 /// Convenience method for accessing view state in an event callback.
2266 ///
2267 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2268 /// but it's often useful to be able to access view state in these
2269 /// callbacks. This method provides a convenient way to do so.
2270 pub fn listener<E>(
2271 &self,
2272 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2273 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2274 let view = self.view().downgrade();
2275 move |e: &E, cx: &mut WindowContext| {
2276 view.update(cx, |view, cx| f(view, e, cx)).ok();
2277 }
2278 }
2279}
2280
2281impl<V> Context for ViewContext<'_, V> {
2282 type Result<U> = U;
2283
2284 fn new_model<T: 'static>(
2285 &mut self,
2286 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2287 ) -> Model<T> {
2288 self.window_cx.new_model(build_model)
2289 }
2290
2291 fn update_model<T: 'static, R>(
2292 &mut self,
2293 model: &Model<T>,
2294 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2295 ) -> R {
2296 self.window_cx.update_model(model, update)
2297 }
2298
2299 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2300 where
2301 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2302 {
2303 self.window_cx.update_window(window, update)
2304 }
2305
2306 fn read_model<T, R>(
2307 &self,
2308 handle: &Model<T>,
2309 read: impl FnOnce(&T, &AppContext) -> R,
2310 ) -> Self::Result<R>
2311 where
2312 T: 'static,
2313 {
2314 self.window_cx.read_model(handle, read)
2315 }
2316
2317 fn read_window<T, R>(
2318 &self,
2319 window: &WindowHandle<T>,
2320 read: impl FnOnce(View<T>, &AppContext) -> R,
2321 ) -> Result<R>
2322 where
2323 T: 'static,
2324 {
2325 self.window_cx.read_window(window, read)
2326 }
2327}
2328
2329impl<V: 'static> VisualContext for ViewContext<'_, V> {
2330 fn new_view<W: Render + 'static>(
2331 &mut self,
2332 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2333 ) -> Self::Result<View<W>> {
2334 self.window_cx.new_view(build_view_state)
2335 }
2336
2337 fn update_view<V2: 'static, R>(
2338 &mut self,
2339 view: &View<V2>,
2340 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2341 ) -> Self::Result<R> {
2342 self.window_cx.update_view(view, update)
2343 }
2344
2345 fn replace_root_view<W>(
2346 &mut self,
2347 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2348 ) -> Self::Result<View<W>>
2349 where
2350 W: 'static + Render,
2351 {
2352 self.window_cx.replace_root_view(build_view)
2353 }
2354
2355 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2356 self.window_cx.focus_view(view)
2357 }
2358
2359 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2360 self.window_cx.dismiss_view(view)
2361 }
2362}
2363
2364impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2365 type Target = WindowContext<'a>;
2366
2367 fn deref(&self) -> &Self::Target {
2368 &self.window_cx
2369 }
2370}
2371
2372impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2373 fn deref_mut(&mut self) -> &mut Self::Target {
2374 &mut self.window_cx
2375 }
2376}
2377
2378// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2379slotmap::new_key_type! {
2380 /// A unique identifier for a window.
2381 pub struct WindowId;
2382}
2383
2384impl WindowId {
2385 /// Converts this window ID to a `u64`.
2386 pub fn as_u64(&self) -> u64 {
2387 self.0.as_ffi()
2388 }
2389}
2390
2391/// A handle to a window with a specific root view type.
2392/// Note that this does not keep the window alive on its own.
2393#[derive(Deref, DerefMut)]
2394pub struct WindowHandle<V> {
2395 #[deref]
2396 #[deref_mut]
2397 pub(crate) any_handle: AnyWindowHandle,
2398 state_type: PhantomData<V>,
2399}
2400
2401impl<V: 'static + Render> WindowHandle<V> {
2402 /// Creates a new handle from a window ID.
2403 /// This does not check if the root type of the window is `V`.
2404 pub fn new(id: WindowId) -> Self {
2405 WindowHandle {
2406 any_handle: AnyWindowHandle {
2407 id,
2408 state_type: TypeId::of::<V>(),
2409 },
2410 state_type: PhantomData,
2411 }
2412 }
2413
2414 /// Get the root view out of this window.
2415 ///
2416 /// This will fail if the window is closed or if the root view's type does not match `V`.
2417 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2418 where
2419 C: Context,
2420 {
2421 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2422 root_view
2423 .downcast::<V>()
2424 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2425 }))
2426 }
2427
2428 /// Updates the root view of this window.
2429 ///
2430 /// This will fail if the window has been closed or if the root view's type does not match
2431 pub fn update<C, R>(
2432 &self,
2433 cx: &mut C,
2434 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2435 ) -> Result<R>
2436 where
2437 C: Context,
2438 {
2439 cx.update_window(self.any_handle, |root_view, cx| {
2440 let view = root_view
2441 .downcast::<V>()
2442 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2443 Ok(cx.update_view(&view, update))
2444 })?
2445 }
2446
2447 /// Read the root view out of this window.
2448 ///
2449 /// This will fail if the window is closed or if the root view's type does not match `V`.
2450 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2451 let x = cx
2452 .windows
2453 .get(self.id)
2454 .and_then(|window| {
2455 window
2456 .as_ref()
2457 .and_then(|window| window.root_view.clone())
2458 .map(|root_view| root_view.downcast::<V>())
2459 })
2460 .ok_or_else(|| anyhow!("window not found"))?
2461 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2462
2463 Ok(x.read(cx))
2464 }
2465
2466 /// Read the root view out of this window, with a callback
2467 ///
2468 /// This will fail if the window is closed or if the root view's type does not match `V`.
2469 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2470 where
2471 C: Context,
2472 {
2473 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2474 }
2475
2476 /// Read the root view pointer off 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_view<C>(&self, cx: &C) -> Result<View<V>>
2480 where
2481 C: Context,
2482 {
2483 cx.read_window(self, |root_view, _cx| root_view.clone())
2484 }
2485
2486 /// Check if this window is 'active'.
2487 ///
2488 /// Will return `None` if the window is closed.
2489 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2490 cx.windows
2491 .get(self.id)
2492 .and_then(|window| window.as_ref().map(|window| window.active))
2493 }
2494}
2495
2496impl<V> Copy for WindowHandle<V> {}
2497
2498impl<V> Clone for WindowHandle<V> {
2499 fn clone(&self) -> Self {
2500 *self
2501 }
2502}
2503
2504impl<V> PartialEq for WindowHandle<V> {
2505 fn eq(&self, other: &Self) -> bool {
2506 self.any_handle == other.any_handle
2507 }
2508}
2509
2510impl<V> Eq for WindowHandle<V> {}
2511
2512impl<V> Hash for WindowHandle<V> {
2513 fn hash<H: Hasher>(&self, state: &mut H) {
2514 self.any_handle.hash(state);
2515 }
2516}
2517
2518impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2519 fn from(val: WindowHandle<V>) -> Self {
2520 val.any_handle
2521 }
2522}
2523
2524/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2525#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2526pub struct AnyWindowHandle {
2527 pub(crate) id: WindowId,
2528 state_type: TypeId,
2529}
2530
2531impl AnyWindowHandle {
2532 /// Get the ID of this window.
2533 pub fn window_id(&self) -> WindowId {
2534 self.id
2535 }
2536
2537 /// Attempt to convert this handle to a window handle with a specific root view type.
2538 /// If the types do not match, this will return `None`.
2539 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2540 if TypeId::of::<T>() == self.state_type {
2541 Some(WindowHandle {
2542 any_handle: *self,
2543 state_type: PhantomData,
2544 })
2545 } else {
2546 None
2547 }
2548 }
2549
2550 /// Updates the state of the root view of this window.
2551 ///
2552 /// This will fail if the window has been closed.
2553 pub fn update<C, R>(
2554 self,
2555 cx: &mut C,
2556 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2557 ) -> Result<R>
2558 where
2559 C: Context,
2560 {
2561 cx.update_window(self, update)
2562 }
2563
2564 /// Read the state of the root view of this window.
2565 ///
2566 /// This will fail if the window has been closed.
2567 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2568 where
2569 C: Context,
2570 T: 'static,
2571 {
2572 let view = self
2573 .downcast::<T>()
2574 .context("the type of the window's root view has changed")?;
2575
2576 cx.read_window(&view, read)
2577 }
2578}
2579
2580/// An identifier for an [`Element`](crate::Element).
2581///
2582/// Can be constructed with a string, a number, or both, as well
2583/// as other internal representations.
2584#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2585pub enum ElementId {
2586 /// The ID of a View element
2587 View(EntityId),
2588 /// An integer ID.
2589 Integer(usize),
2590 /// A string based ID.
2591 Name(SharedString),
2592 /// An ID that's equated with a focus handle.
2593 FocusHandle(FocusId),
2594 /// A combination of a name and an integer.
2595 NamedInteger(SharedString, usize),
2596}
2597
2598impl Display for ElementId {
2599 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2600 match self {
2601 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2602 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2603 ElementId::Name(name) => write!(f, "{}", name)?,
2604 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2605 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2606 }
2607
2608 Ok(())
2609 }
2610}
2611
2612impl ElementId {
2613 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2614 ElementId::View(entity_id)
2615 }
2616}
2617
2618impl TryInto<SharedString> for ElementId {
2619 type Error = anyhow::Error;
2620
2621 fn try_into(self) -> anyhow::Result<SharedString> {
2622 if let ElementId::Name(name) = self {
2623 Ok(name)
2624 } else {
2625 Err(anyhow!("element id is not string"))
2626 }
2627 }
2628}
2629
2630impl From<usize> for ElementId {
2631 fn from(id: usize) -> Self {
2632 ElementId::Integer(id)
2633 }
2634}
2635
2636impl From<i32> for ElementId {
2637 fn from(id: i32) -> Self {
2638 Self::Integer(id as usize)
2639 }
2640}
2641
2642impl From<SharedString> for ElementId {
2643 fn from(name: SharedString) -> Self {
2644 ElementId::Name(name)
2645 }
2646}
2647
2648impl From<&'static str> for ElementId {
2649 fn from(name: &'static str) -> Self {
2650 ElementId::Name(name.into())
2651 }
2652}
2653
2654impl<'a> From<&'a FocusHandle> for ElementId {
2655 fn from(handle: &'a FocusHandle) -> Self {
2656 ElementId::FocusHandle(handle.id)
2657 }
2658}
2659
2660impl From<(&'static str, EntityId)> for ElementId {
2661 fn from((name, id): (&'static str, EntityId)) -> Self {
2662 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2663 }
2664}
2665
2666impl From<(&'static str, usize)> for ElementId {
2667 fn from((name, id): (&'static str, usize)) -> Self {
2668 ElementId::NamedInteger(name.into(), id)
2669 }
2670}
2671
2672impl From<(&'static str, u64)> for ElementId {
2673 fn from((name, id): (&'static str, u64)) -> Self {
2674 ElementId::NamedInteger(name.into(), id as usize)
2675 }
2676}
2677
2678/// A rectangle to be rendered in the window at the given position and size.
2679/// Passed as an argument [`ElementContext::paint_quad`].
2680#[derive(Clone)]
2681pub struct PaintQuad {
2682 bounds: Bounds<Pixels>,
2683 corner_radii: Corners<Pixels>,
2684 background: Hsla,
2685 border_widths: Edges<Pixels>,
2686 border_color: Hsla,
2687}
2688
2689impl PaintQuad {
2690 /// Sets the corner radii of the quad.
2691 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2692 PaintQuad {
2693 corner_radii: corner_radii.into(),
2694 ..self
2695 }
2696 }
2697
2698 /// Sets the border widths of the quad.
2699 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2700 PaintQuad {
2701 border_widths: border_widths.into(),
2702 ..self
2703 }
2704 }
2705
2706 /// Sets the border color of the quad.
2707 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2708 PaintQuad {
2709 border_color: border_color.into(),
2710 ..self
2711 }
2712 }
2713
2714 /// Sets the background color of the quad.
2715 pub fn background(self, background: impl Into<Hsla>) -> Self {
2716 PaintQuad {
2717 background: background.into(),
2718 ..self
2719 }
2720 }
2721}
2722
2723/// Creates a quad with the given parameters.
2724pub fn quad(
2725 bounds: Bounds<Pixels>,
2726 corner_radii: impl Into<Corners<Pixels>>,
2727 background: impl Into<Hsla>,
2728 border_widths: impl Into<Edges<Pixels>>,
2729 border_color: impl Into<Hsla>,
2730) -> PaintQuad {
2731 PaintQuad {
2732 bounds,
2733 corner_radii: corner_radii.into(),
2734 background: background.into(),
2735 border_widths: border_widths.into(),
2736 border_color: border_color.into(),
2737 }
2738}
2739
2740/// Creates a filled quad with the given bounds and background color.
2741pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2742 PaintQuad {
2743 bounds: bounds.into(),
2744 corner_radii: (0.).into(),
2745 background: background.into(),
2746 border_widths: (0.).into(),
2747 border_color: transparent_black(),
2748 }
2749}
2750
2751/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2752pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2753 PaintQuad {
2754 bounds: bounds.into(),
2755 corner_radii: (0.).into(),
2756 background: transparent_black(),
2757 border_widths: (1.).into(),
2758 border_color: border_color.into(),
2759 }
2760}