1use crate::{
2 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
3 AvailableSpace, Bounds, Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId,
4 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
5 GlobalElementId, Hsla, KeyBinding, KeyContext, KeyDownEvent, KeyMatch, KeymatchMode,
6 KeymatchResult, Keystroke, KeystrokeEvent, Model, ModelContext, Modifiers, MouseButton,
7 MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
8 PlatformWindow, Point, PromptLevel, Render, ScaledPixels, SharedString, Size, SubscriberSet,
9 Subscription, TaffyLayoutEngine, Task, View, VisualContext, WeakView, WindowBounds,
10 WindowOptions,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::{
16 channel::{mpsc, oneshot},
17 StreamExt,
18};
19use parking_lot::RwLock;
20use slotmap::SlotMap;
21use smallvec::SmallVec;
22use std::{
23 any::{Any, TypeId},
24 borrow::{Borrow, BorrowMut},
25 cell::RefCell,
26 collections::hash_map::Entry,
27 fmt::{Debug, Display},
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37 time::Duration,
38};
39use util::{measure, ResultExt};
40
41mod element_cx;
42pub use element_cx::*;
43
44const ACTIVE_DRAG_Z_INDEX: u16 = 1;
45
46/// A global stacking order, which is created by stacking successive z-index values.
47/// Each z-index will always be interpreted in the context of its parent z-index.
48#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
49pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
50
51/// A single entry in a primitive's z-index stacking order
52#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
53pub struct StackingContext {
54 pub(crate) z_index: u16,
55 pub(crate) id: u16,
56}
57
58impl std::fmt::Debug for StackingContext {
59 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
60 write!(f, "{{{}.{}}} ", self.z_index, self.id)
61 }
62}
63
64/// Represents the two different phases when dispatching events.
65#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
66pub enum DispatchPhase {
67 /// After the capture phase comes the bubble phase, in which mouse event listeners are
68 /// invoked front to back and keyboard event listeners are invoked from the focused element
69 /// to the root of the element tree. This is the phase you'll most commonly want to use when
70 /// registering event listeners.
71 #[default]
72 Bubble,
73 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
74 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
75 /// is used for special purposes such as clearing the "pressed" state for click events. If
76 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
77 /// outside of the immediate region may rely on detecting non-local events during this phase.
78 Capture,
79}
80
81impl DispatchPhase {
82 /// Returns true if this represents the "bubble" phase.
83 pub fn bubble(self) -> bool {
84 self == DispatchPhase::Bubble
85 }
86
87 /// Returns true if this represents the "capture" phase.
88 pub fn capture(self) -> bool {
89 self == DispatchPhase::Capture
90 }
91}
92
93type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
94
95type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
96
97struct FocusEvent {
98 previous_focus_path: SmallVec<[FocusId; 8]>,
99 current_focus_path: SmallVec<[FocusId; 8]>,
100}
101
102slotmap::new_key_type! {
103 /// A globally unique identifier for a focusable element.
104 pub struct FocusId;
105}
106
107thread_local! {
108 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(4 * 1024 * 1024));
109}
110
111impl FocusId {
112 /// Obtains whether the element associated with this handle is currently focused.
113 pub fn is_focused(&self, cx: &WindowContext) -> bool {
114 cx.window.focus == Some(*self)
115 }
116
117 /// Obtains whether the element associated with this handle contains the focused
118 /// element or is itself focused.
119 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
120 cx.focused()
121 .map_or(false, |focused| self.contains(focused.id, cx))
122 }
123
124 /// Obtains whether the element associated with this handle is contained within the
125 /// focused element or is itself focused.
126 pub fn within_focused(&self, cx: &WindowContext) -> bool {
127 let focused = cx.focused();
128 focused.map_or(false, |focused| focused.id.contains(*self, cx))
129 }
130
131 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
132 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
133 cx.window
134 .rendered_frame
135 .dispatch_tree
136 .focus_contains(*self, other)
137 }
138}
139
140/// A handle which can be used to track and manipulate the focused element in a window.
141pub struct FocusHandle {
142 pub(crate) id: FocusId,
143 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
144}
145
146impl std::fmt::Debug for FocusHandle {
147 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
148 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
149 }
150}
151
152impl FocusHandle {
153 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
154 let id = handles.write().insert(AtomicUsize::new(1));
155 Self {
156 id,
157 handles: handles.clone(),
158 }
159 }
160
161 pub(crate) fn for_id(
162 id: FocusId,
163 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
164 ) -> Option<Self> {
165 let lock = handles.read();
166 let ref_count = lock.get(id)?;
167 if ref_count.load(SeqCst) == 0 {
168 None
169 } else {
170 ref_count.fetch_add(1, SeqCst);
171 Some(Self {
172 id,
173 handles: handles.clone(),
174 })
175 }
176 }
177
178 /// Moves the focus to the element associated with this handle.
179 pub fn focus(&self, cx: &mut WindowContext) {
180 cx.focus(self)
181 }
182
183 /// Obtains whether the element associated with this handle is currently focused.
184 pub fn is_focused(&self, cx: &WindowContext) -> bool {
185 self.id.is_focused(cx)
186 }
187
188 /// Obtains whether the element associated with this handle contains the focused
189 /// element or is itself focused.
190 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
191 self.id.contains_focused(cx)
192 }
193
194 /// Obtains whether the element associated with this handle is contained within the
195 /// focused element or is itself focused.
196 pub fn within_focused(&self, cx: &WindowContext) -> bool {
197 self.id.within_focused(cx)
198 }
199
200 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
201 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
202 self.id.contains(other.id, cx)
203 }
204}
205
206impl Clone for FocusHandle {
207 fn clone(&self) -> Self {
208 Self::for_id(self.id, &self.handles).unwrap()
209 }
210}
211
212impl PartialEq for FocusHandle {
213 fn eq(&self, other: &Self) -> bool {
214 self.id == other.id
215 }
216}
217
218impl Eq for FocusHandle {}
219
220impl Drop for FocusHandle {
221 fn drop(&mut self) {
222 self.handles
223 .read()
224 .get(self.id)
225 .unwrap()
226 .fetch_sub(1, SeqCst);
227 }
228}
229
230/// FocusableView allows users of your view to easily
231/// focus it (using cx.focus_view(view))
232pub trait FocusableView: 'static + Render {
233 /// Returns the focus handle associated with this view.
234 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
235}
236
237/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
238/// where the lifecycle of the view is handled by another view.
239pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
240
241impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
242
243/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
244pub struct DismissEvent;
245
246// Holds the state for a specific window.
247#[doc(hidden)]
248pub struct Window {
249 pub(crate) handle: AnyWindowHandle,
250 pub(crate) removed: bool,
251 pub(crate) platform_window: Box<dyn PlatformWindow>,
252 display_id: DisplayId,
253 sprite_atlas: Arc<dyn PlatformAtlas>,
254 pub(crate) rem_size: Pixels,
255 pub(crate) viewport_size: Size<Pixels>,
256 layout_engine: Option<TaffyLayoutEngine>,
257 pub(crate) root_view: Option<AnyView>,
258 pub(crate) element_id_stack: GlobalElementId,
259 pub(crate) rendered_frame: Frame,
260 pub(crate) next_frame: Frame,
261 pub(crate) dirty_views: FxHashSet<EntityId>,
262 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
263 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
264 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
265 default_prevented: bool,
266 mouse_position: Point<Pixels>,
267 modifiers: Modifiers,
268 scale_factor: f32,
269 bounds: WindowBounds,
270 bounds_observers: SubscriberSet<(), AnyObserver>,
271 active: bool,
272 pub(crate) dirty: bool,
273 pub(crate) refreshing: bool,
274 pub(crate) drawing: bool,
275 activation_observers: SubscriberSet<(), AnyObserver>,
276 pub(crate) focus: Option<FocusId>,
277 focus_enabled: bool,
278 pending_input: Option<PendingInput>,
279
280 #[cfg(any(test, feature = "test-support"))]
281 pub(crate) focus_invalidated: bool,
282}
283
284#[derive(Default, Debug)]
285struct PendingInput {
286 keystrokes: SmallVec<[Keystroke; 1]>,
287 bindings: SmallVec<[KeyBinding; 1]>,
288 focus: Option<FocusId>,
289 timer: Option<Task<()>>,
290}
291
292impl PendingInput {
293 fn is_noop(&self) -> bool {
294 self.bindings.is_empty() && (self.keystrokes.iter().all(|k| k.ime_key.is_none()))
295 }
296
297 fn input(&self) -> String {
298 self.keystrokes
299 .iter()
300 .flat_map(|k| k.ime_key.clone())
301 .collect::<Vec<String>>()
302 .join("")
303 }
304
305 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
306 if self.keystrokes.is_empty() {
307 return true;
308 }
309 let keystroke = &self.keystrokes[0];
310 for candidate in keystroke.match_candidates() {
311 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
312 return true;
313 }
314 }
315 false
316 }
317}
318
319pub(crate) struct ElementStateBox {
320 pub(crate) inner: Box<dyn Any>,
321 pub(crate) parent_view_id: EntityId,
322 #[cfg(debug_assertions)]
323 pub(crate) type_name: &'static str,
324}
325
326impl Window {
327 pub(crate) fn new(
328 handle: AnyWindowHandle,
329 options: WindowOptions,
330 cx: &mut AppContext,
331 ) -> Self {
332 let platform_window = cx.platform.open_window(handle, options);
333 let display_id = platform_window.display().id();
334 let sprite_atlas = platform_window.sprite_atlas();
335 let mouse_position = platform_window.mouse_position();
336 let modifiers = platform_window.modifiers();
337 let content_size = platform_window.content_size();
338 let scale_factor = platform_window.scale_factor();
339 let bounds = platform_window.bounds();
340
341 platform_window.on_request_frame(Box::new({
342 let mut cx = cx.to_async();
343 move || {
344 measure("frame duration", || {
345 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
346 })
347 }
348 }));
349 platform_window.on_resize(Box::new({
350 let mut cx = cx.to_async();
351 move |_, _| {
352 handle
353 .update(&mut cx, |_, cx| cx.window_bounds_changed())
354 .log_err();
355 }
356 }));
357 platform_window.on_moved(Box::new({
358 let mut cx = cx.to_async();
359 move || {
360 handle
361 .update(&mut cx, |_, cx| cx.window_bounds_changed())
362 .log_err();
363 }
364 }));
365 platform_window.on_active_status_change(Box::new({
366 let mut cx = cx.to_async();
367 move |active| {
368 handle
369 .update(&mut cx, |_, cx| {
370 cx.window.active = active;
371 cx.window
372 .activation_observers
373 .clone()
374 .retain(&(), |callback| callback(cx));
375 })
376 .log_err();
377 }
378 }));
379
380 platform_window.on_input({
381 let mut cx = cx.to_async();
382 Box::new(move |event| {
383 handle
384 .update(&mut cx, |_, cx| cx.dispatch_event(event))
385 .log_err()
386 .unwrap_or(false)
387 })
388 });
389
390 Window {
391 handle,
392 removed: false,
393 platform_window,
394 display_id,
395 sprite_atlas,
396 rem_size: px(16.),
397 viewport_size: content_size,
398 layout_engine: Some(TaffyLayoutEngine::new()),
399 root_view: None,
400 element_id_stack: GlobalElementId::default(),
401 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
402 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
403 dirty_views: FxHashSet::default(),
404 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
405 focus_listeners: SubscriberSet::new(),
406 focus_lost_listeners: SubscriberSet::new(),
407 default_prevented: true,
408 mouse_position,
409 modifiers,
410 scale_factor,
411 bounds,
412 bounds_observers: SubscriberSet::new(),
413 active: false,
414 dirty: false,
415 refreshing: false,
416 drawing: false,
417 activation_observers: SubscriberSet::new(),
418 focus: None,
419 focus_enabled: true,
420 pending_input: None,
421
422 #[cfg(any(test, feature = "test-support"))]
423 focus_invalidated: false,
424 }
425 }
426}
427
428/// Indicates which region of the window is visible. Content falling outside of this mask will not be
429/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
430/// to leave room to support more complex shapes in the future.
431#[derive(Clone, Debug, Default, PartialEq, Eq)]
432#[repr(C)]
433pub struct ContentMask<P: Clone + Default + Debug> {
434 /// The bounds
435 pub bounds: Bounds<P>,
436}
437
438impl ContentMask<Pixels> {
439 /// Scale the content mask's pixel units by the given scaling factor.
440 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
441 ContentMask {
442 bounds: self.bounds.scale(factor),
443 }
444 }
445
446 /// Intersect the content mask with the given content mask.
447 pub fn intersect(&self, other: &Self) -> Self {
448 let bounds = self.bounds.intersect(&other.bounds);
449 ContentMask { bounds }
450 }
451}
452
453/// Provides access to application state in the context of a single window. Derefs
454/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
455/// an [`AppContext`] and call any [`AppContext`] methods.
456pub struct WindowContext<'a> {
457 pub(crate) app: &'a mut AppContext,
458 pub(crate) window: &'a mut Window,
459}
460
461impl<'a> WindowContext<'a> {
462 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
463 Self { app, window }
464 }
465
466 /// Obtain a handle to the window that belongs to this context.
467 pub fn window_handle(&self) -> AnyWindowHandle {
468 self.window.handle
469 }
470
471 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
472 pub fn refresh(&mut self) {
473 if !self.window.drawing {
474 self.window.refreshing = true;
475 self.window.dirty = true;
476 }
477 }
478
479 /// Close this window.
480 pub fn remove_window(&mut self) {
481 self.window.removed = true;
482 }
483
484 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
485 /// for elements rendered within this window.
486 pub fn focus_handle(&mut self) -> FocusHandle {
487 FocusHandle::new(&self.window.focus_handles)
488 }
489
490 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
491 pub fn focused(&self) -> Option<FocusHandle> {
492 self.window
493 .focus
494 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
495 }
496
497 /// Move focus to the element associated with the given [`FocusHandle`].
498 pub fn focus(&mut self, handle: &FocusHandle) {
499 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
500 return;
501 }
502
503 self.window.focus = Some(handle.id);
504 self.window
505 .rendered_frame
506 .dispatch_tree
507 .clear_pending_keystrokes();
508
509 #[cfg(any(test, feature = "test-support"))]
510 {
511 self.window.focus_invalidated = true;
512 }
513
514 self.refresh();
515 }
516
517 /// Remove focus from all elements within this context's window.
518 pub fn blur(&mut self) {
519 if !self.window.focus_enabled {
520 return;
521 }
522
523 self.window.focus = None;
524 self.refresh();
525 }
526
527 /// Blur the window and don't allow anything in it to be focused again.
528 pub fn disable_focus(&mut self) {
529 self.blur();
530 self.window.focus_enabled = false;
531 }
532
533 /// Dispatch the given action on the currently focused element.
534 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
535 let focus_handle = self.focused();
536
537 self.defer(move |cx| {
538 let node_id = focus_handle
539 .and_then(|handle| {
540 cx.window
541 .rendered_frame
542 .dispatch_tree
543 .focusable_node_id(handle.id)
544 })
545 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
546
547 cx.propagate_event = true;
548 cx.dispatch_action_on_node(node_id, action);
549 })
550 }
551
552 pub(crate) fn dispatch_keystroke_observers(
553 &mut self,
554 event: &dyn Any,
555 action: Option<Box<dyn Action>>,
556 ) {
557 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
558 return;
559 };
560
561 self.keystroke_observers
562 .clone()
563 .retain(&(), move |callback| {
564 (callback)(
565 &KeystrokeEvent {
566 keystroke: key_down_event.keystroke.clone(),
567 action: action.as_ref().map(|action| action.boxed_clone()),
568 },
569 self,
570 );
571 true
572 });
573 }
574
575 pub(crate) fn clear_pending_keystrokes(&mut self) {
576 self.window
577 .rendered_frame
578 .dispatch_tree
579 .clear_pending_keystrokes();
580 self.window
581 .next_frame
582 .dispatch_tree
583 .clear_pending_keystrokes();
584 }
585
586 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
587 /// that are currently on the stack to be returned to the app.
588 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
589 let handle = self.window.handle;
590 self.app.defer(move |cx| {
591 handle.update(cx, |_, cx| f(cx)).ok();
592 });
593 }
594
595 /// Subscribe to events emitted by a model or view.
596 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
597 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
598 pub fn subscribe<Emitter, E, Evt>(
599 &mut self,
600 entity: &E,
601 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
602 ) -> Subscription
603 where
604 Emitter: EventEmitter<Evt>,
605 E: Entity<Emitter>,
606 Evt: 'static,
607 {
608 let entity_id = entity.entity_id();
609 let entity = entity.downgrade();
610 let window_handle = self.window.handle;
611 let (subscription, activate) = self.app.event_listeners.insert(
612 entity_id,
613 (
614 TypeId::of::<Evt>(),
615 Box::new(move |event, cx| {
616 window_handle
617 .update(cx, |_, cx| {
618 if let Some(handle) = E::upgrade_from(&entity) {
619 let event = event.downcast_ref().expect("invalid event type");
620 on_event(handle, event, cx);
621 true
622 } else {
623 false
624 }
625 })
626 .unwrap_or(false)
627 }),
628 ),
629 );
630 self.app.defer(move |_| activate());
631 subscription
632 }
633
634 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
635 /// await points in async code.
636 pub fn to_async(&self) -> AsyncWindowContext {
637 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
638 }
639
640 /// Schedule the given closure to be run directly after the current frame is rendered.
641 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
642 let handle = self.window.handle;
643 let display_id = self.window.display_id;
644
645 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
646 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
647 let (tx, mut rx) = mpsc::unbounded::<()>();
648 self.platform.set_display_link_output_callback(
649 display_id,
650 Box::new(move || _ = tx.unbounded_send(())),
651 );
652
653 let consumer_task = self.app.spawn(|cx| async move {
654 while rx.next().await.is_some() {
655 cx.update(|cx| {
656 for callback in cx
657 .next_frame_callbacks
658 .get_mut(&display_id)
659 .unwrap()
660 .drain(..)
661 .collect::<SmallVec<[_; 32]>>()
662 {
663 callback(cx);
664 }
665 })
666 .ok();
667
668 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
669
670 cx.update(|cx| {
671 if cx.next_frame_callbacks.is_empty() {
672 cx.platform.stop_display_link(display_id);
673 }
674 })
675 .ok();
676 }
677 });
678 e.insert(consumer_task);
679 }
680 debug_assert!(self.app.frame_consumers.is_empty());
681 self.app.frame_consumers = frame_consumers;
682
683 if self.next_frame_callbacks.is_empty() {
684 self.platform.start_display_link(display_id);
685 }
686
687 self.next_frame_callbacks
688 .entry(display_id)
689 .or_default()
690 .push(Box::new(move |cx: &mut AppContext| {
691 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
692 }));
693 }
694
695 /// Spawn the future returned by the given closure on the application thread pool.
696 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
697 /// use within your future.
698 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
699 where
700 R: 'static,
701 Fut: Future<Output = R> + 'static,
702 {
703 self.app
704 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
705 }
706
707 /// Updates the global of the given type. The given closure is given simultaneous mutable
708 /// access both to the global and the context.
709 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
710 where
711 G: 'static,
712 {
713 let mut global = self.app.lease_global::<G>();
714 let result = f(&mut global, self);
715 self.app.end_global_lease(global);
716 result
717 }
718
719 fn window_bounds_changed(&mut self) {
720 self.window.scale_factor = self.window.platform_window.scale_factor();
721 self.window.viewport_size = self.window.platform_window.content_size();
722 self.window.bounds = self.window.platform_window.bounds();
723 self.window.display_id = self.window.platform_window.display().id();
724 self.refresh();
725
726 self.window
727 .bounds_observers
728 .clone()
729 .retain(&(), |callback| callback(self));
730 }
731
732 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
733 pub fn window_bounds(&self) -> WindowBounds {
734 self.window.bounds
735 }
736
737 /// Returns the size of the drawable area within the window.
738 pub fn viewport_size(&self) -> Size<Pixels> {
739 self.window.viewport_size
740 }
741
742 /// Returns whether this window is focused by the operating system (receiving key events).
743 pub fn is_window_active(&self) -> bool {
744 self.window.active
745 }
746
747 /// Toggle zoom on the window.
748 pub fn zoom_window(&self) {
749 self.window.platform_window.zoom();
750 }
751
752 /// Updates the window's title at the platform level.
753 pub fn set_window_title(&mut self, title: &str) {
754 self.window.platform_window.set_title(title);
755 }
756
757 /// Mark the window as dirty at the platform level.
758 pub fn set_window_edited(&mut self, edited: bool) {
759 self.window.platform_window.set_edited(edited);
760 }
761
762 /// Determine the display on which the window is visible.
763 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
764 self.platform
765 .displays()
766 .into_iter()
767 .find(|display| display.id() == self.window.display_id)
768 }
769
770 /// Show the platform character palette.
771 pub fn show_character_palette(&self) {
772 self.window.platform_window.show_character_palette();
773 }
774
775 /// The scale factor of the display associated with the window. For example, it could
776 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
777 /// be rendered as two pixels on screen.
778 pub fn scale_factor(&self) -> f32 {
779 self.window.scale_factor
780 }
781
782 /// The size of an em for the base font of the application. Adjusting this value allows the
783 /// UI to scale, just like zooming a web page.
784 pub fn rem_size(&self) -> Pixels {
785 self.window.rem_size
786 }
787
788 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
789 /// UI to scale, just like zooming a web page.
790 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
791 self.window.rem_size = rem_size.into();
792 }
793
794 /// The line height associated with the current text style.
795 pub fn line_height(&self) -> Pixels {
796 let rem_size = self.rem_size();
797 let text_style = self.text_style();
798 text_style
799 .line_height
800 .to_pixels(text_style.font_size, rem_size)
801 }
802
803 /// Call to prevent the default action of an event. Currently only used to prevent
804 /// parent elements from becoming focused on mouse down.
805 pub fn prevent_default(&mut self) {
806 self.window.default_prevented = true;
807 }
808
809 /// Obtain whether default has been prevented for the event currently being dispatched.
810 pub fn default_prevented(&self) -> bool {
811 self.window.default_prevented
812 }
813
814 /// Determine whether the given action is available along the dispatch path to the currently focused element.
815 pub fn is_action_available(&self, action: &dyn Action) -> bool {
816 let target = self
817 .focused()
818 .and_then(|focused_handle| {
819 self.window
820 .rendered_frame
821 .dispatch_tree
822 .focusable_node_id(focused_handle.id)
823 })
824 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
825 self.window
826 .rendered_frame
827 .dispatch_tree
828 .is_action_available(action, target)
829 }
830
831 /// The position of the mouse relative to the window.
832 pub fn mouse_position(&self) -> Point<Pixels> {
833 self.window.mouse_position
834 }
835
836 /// The current state of the keyboard's modifiers
837 pub fn modifiers(&self) -> Modifiers {
838 self.window.modifiers
839 }
840
841 /// Returns true if there is no opaque layer containing the given point
842 /// on top of the given level. Layers who are extensions of the queried layer
843 /// are not considered to be on top of queried layer.
844 pub fn was_top_layer(&self, point: &Point<Pixels>, layer: &StackingOrder) -> bool {
845 // Precondition: the depth map is ordered from topmost to bottomost.
846
847 for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
848 if layer >= opaque_layer {
849 // The queried layer is either above or is the same as the this opaque layer.
850 // Anything after this point is guaranteed to be below the queried layer.
851 return true;
852 }
853
854 if !bounds.contains(point) {
855 // This opaque layer is above the queried layer but it doesn't contain
856 // the given position, so we can ignore it even if it's above.
857 continue;
858 }
859
860 // At this point, we've established that this opaque layer is on top of the queried layer
861 // and contains the position:
862 // - If the opaque layer is an extension of the queried layer, we don't want
863 // to consider the opaque layer to be on top and so we ignore it.
864 // - Else, we will bail early and say that the queried layer wasn't the top one.
865 let opaque_layer_is_extension_of_queried_layer = opaque_layer.len() >= layer.len()
866 && opaque_layer
867 .iter()
868 .zip(layer.iter())
869 .all(|(a, b)| a.z_index == b.z_index);
870 if !opaque_layer_is_extension_of_queried_layer {
871 return false;
872 }
873 }
874
875 true
876 }
877
878 pub(crate) fn was_top_layer_under_active_drag(
879 &self,
880 point: &Point<Pixels>,
881 level: &StackingOrder,
882 ) -> bool {
883 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
884 if level >= opaque_level {
885 break;
886 }
887
888 if opaque_level
889 .first()
890 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
891 .unwrap_or(false)
892 {
893 continue;
894 }
895
896 if bounds.contains(point) {
897 return false;
898 }
899 }
900 true
901 }
902
903 /// Called during painting to get the current stacking order.
904 pub fn stacking_order(&self) -> &StackingOrder {
905 &self.window.next_frame.z_index_stack
906 }
907
908 /// Draw pixels to the display for this window based on the contents of its scene.
909 pub(crate) fn draw(&mut self) {
910 self.window.dirty = false;
911 self.window.drawing = true;
912
913 #[cfg(any(test, feature = "test-support"))]
914 {
915 self.window.focus_invalidated = false;
916 }
917
918 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
919 {
920 let input_handler = self.window.platform_window.take_input_handler();
921 requested_handler.handler = input_handler;
922 }
923
924 let root_view = self.window.root_view.take().unwrap();
925 self.with_element_context(|cx| {
926 cx.with_z_index(0, |cx| {
927 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
928 // We need to use cx.cx here so we can utilize borrow splitting
929 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
930 for action_listener in action_listeners.iter().cloned() {
931 cx.cx.window.next_frame.dispatch_tree.on_action(
932 *action_type,
933 Rc::new(
934 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
935 action_listener(action, phase, cx)
936 },
937 ),
938 )
939 }
940 }
941
942 let available_space = cx.window.viewport_size.map(Into::into);
943 root_view.draw(Point::default(), available_space, cx);
944 })
945 })
946 });
947
948 if let Some(active_drag) = self.app.active_drag.take() {
949 self.with_element_context(|cx| {
950 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
951 let offset = cx.mouse_position() - active_drag.cursor_offset;
952 let available_space =
953 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
954 active_drag.view.draw(offset, available_space, cx);
955 })
956 });
957 self.active_drag = Some(active_drag);
958 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
959 self.with_element_context(|cx| {
960 cx.with_z_index(1, |cx| {
961 let available_space =
962 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
963 tooltip_request.tooltip.view.draw(
964 tooltip_request.tooltip.cursor_offset,
965 available_space,
966 cx,
967 );
968 })
969 });
970 self.window.next_frame.tooltip_request = Some(tooltip_request);
971 }
972 self.window.dirty_views.clear();
973
974 self.window
975 .next_frame
976 .dispatch_tree
977 .preserve_pending_keystrokes(
978 &mut self.window.rendered_frame.dispatch_tree,
979 self.window.focus,
980 );
981 self.window.next_frame.focus = self.window.focus;
982 self.window.next_frame.window_active = self.window.active;
983 self.window.root_view = Some(root_view);
984
985 // Set the cursor only if we're the active window.
986 let cursor_style = self
987 .window
988 .next_frame
989 .requested_cursor_style
990 .take()
991 .unwrap_or(CursorStyle::Arrow);
992 if self.is_window_active() {
993 self.platform.set_cursor_style(cursor_style);
994 }
995
996 // Register requested input handler with the platform window.
997 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
998 if let Some(handler) = requested_input.handler.take() {
999 self.window.platform_window.set_input_handler(handler);
1000 }
1001 }
1002
1003 self.window.layout_engine.as_mut().unwrap().clear();
1004 self.text_system()
1005 .finish_frame(&self.window.next_frame.reused_views);
1006 self.window
1007 .next_frame
1008 .finish(&mut self.window.rendered_frame);
1009 ELEMENT_ARENA.with_borrow_mut(|element_arena| element_arena.clear());
1010
1011 let previous_focus_path = self.window.rendered_frame.focus_path();
1012 let previous_window_active = self.window.rendered_frame.window_active;
1013 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1014 self.window.next_frame.clear();
1015 let current_focus_path = self.window.rendered_frame.focus_path();
1016 let current_window_active = self.window.rendered_frame.window_active;
1017
1018 if previous_focus_path != current_focus_path
1019 || previous_window_active != current_window_active
1020 {
1021 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1022 self.window
1023 .focus_lost_listeners
1024 .clone()
1025 .retain(&(), |listener| listener(self));
1026 }
1027
1028 let event = FocusEvent {
1029 previous_focus_path: if previous_window_active {
1030 previous_focus_path
1031 } else {
1032 Default::default()
1033 },
1034 current_focus_path: if current_window_active {
1035 current_focus_path
1036 } else {
1037 Default::default()
1038 },
1039 };
1040 self.window
1041 .focus_listeners
1042 .clone()
1043 .retain(&(), |listener| listener(&event, self));
1044 }
1045
1046 self.window
1047 .platform_window
1048 .draw(&self.window.rendered_frame.scene);
1049 self.window.refreshing = false;
1050 self.window.drawing = false;
1051 }
1052
1053 /// Dispatch a mouse or keyboard event on the window.
1054 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1055 // Handlers may set this to false by calling `stop_propagation`.
1056 self.app.propagate_event = true;
1057 // Handlers may set this to true by calling `prevent_default`.
1058 self.window.default_prevented = false;
1059
1060 let event = match event {
1061 // Track the mouse position with our own state, since accessing the platform
1062 // API for the mouse position can only occur on the main thread.
1063 PlatformInput::MouseMove(mouse_move) => {
1064 self.window.mouse_position = mouse_move.position;
1065 self.window.modifiers = mouse_move.modifiers;
1066 PlatformInput::MouseMove(mouse_move)
1067 }
1068 PlatformInput::MouseDown(mouse_down) => {
1069 self.window.mouse_position = mouse_down.position;
1070 self.window.modifiers = mouse_down.modifiers;
1071 PlatformInput::MouseDown(mouse_down)
1072 }
1073 PlatformInput::MouseUp(mouse_up) => {
1074 self.window.mouse_position = mouse_up.position;
1075 self.window.modifiers = mouse_up.modifiers;
1076 PlatformInput::MouseUp(mouse_up)
1077 }
1078 PlatformInput::MouseExited(mouse_exited) => {
1079 self.window.modifiers = mouse_exited.modifiers;
1080 PlatformInput::MouseExited(mouse_exited)
1081 }
1082 PlatformInput::ModifiersChanged(modifiers_changed) => {
1083 self.window.modifiers = modifiers_changed.modifiers;
1084 PlatformInput::ModifiersChanged(modifiers_changed)
1085 }
1086 PlatformInput::ScrollWheel(scroll_wheel) => {
1087 self.window.mouse_position = scroll_wheel.position;
1088 self.window.modifiers = scroll_wheel.modifiers;
1089 PlatformInput::ScrollWheel(scroll_wheel)
1090 }
1091 // Translate dragging and dropping of external files from the operating system
1092 // to internal drag and drop events.
1093 PlatformInput::FileDrop(file_drop) => match file_drop {
1094 FileDropEvent::Entered { position, paths } => {
1095 self.window.mouse_position = position;
1096 if self.active_drag.is_none() {
1097 self.active_drag = Some(AnyDrag {
1098 value: Box::new(paths.clone()),
1099 view: self.new_view(|_| paths).into(),
1100 cursor_offset: position,
1101 });
1102 }
1103 PlatformInput::MouseMove(MouseMoveEvent {
1104 position,
1105 pressed_button: Some(MouseButton::Left),
1106 modifiers: Modifiers::default(),
1107 })
1108 }
1109 FileDropEvent::Pending { position } => {
1110 self.window.mouse_position = position;
1111 PlatformInput::MouseMove(MouseMoveEvent {
1112 position,
1113 pressed_button: Some(MouseButton::Left),
1114 modifiers: Modifiers::default(),
1115 })
1116 }
1117 FileDropEvent::Submit { position } => {
1118 self.activate(true);
1119 self.window.mouse_position = position;
1120 PlatformInput::MouseUp(MouseUpEvent {
1121 button: MouseButton::Left,
1122 position,
1123 modifiers: Modifiers::default(),
1124 click_count: 1,
1125 })
1126 }
1127 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1128 button: MouseButton::Left,
1129 position: Point::default(),
1130 modifiers: Modifiers::default(),
1131 click_count: 1,
1132 }),
1133 },
1134 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1135 };
1136
1137 if let Some(any_mouse_event) = event.mouse_event() {
1138 self.dispatch_mouse_event(any_mouse_event);
1139 } else if let Some(any_key_event) = event.keyboard_event() {
1140 self.dispatch_key_event(any_key_event);
1141 }
1142
1143 !self.app.propagate_event
1144 }
1145
1146 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1147 if let Some(mut handlers) = self
1148 .window
1149 .rendered_frame
1150 .mouse_listeners
1151 .remove(&event.type_id())
1152 {
1153 // Because handlers may add other handlers, we sort every time.
1154 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1155
1156 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1157 // special purposes, such as detecting events outside of a given Bounds.
1158 for (_, _, handler) in &mut handlers {
1159 self.with_element_context(|cx| {
1160 handler(event, DispatchPhase::Capture, cx);
1161 });
1162 if !self.app.propagate_event {
1163 break;
1164 }
1165 }
1166
1167 // Bubble phase, where most normal handlers do their work.
1168 if self.app.propagate_event {
1169 for (_, _, handler) in handlers.iter_mut().rev() {
1170 self.with_element_context(|cx| {
1171 handler(event, DispatchPhase::Bubble, cx);
1172 });
1173 if !self.app.propagate_event {
1174 break;
1175 }
1176 }
1177 }
1178
1179 self.window
1180 .rendered_frame
1181 .mouse_listeners
1182 .insert(event.type_id(), handlers);
1183 }
1184
1185 if self.app.propagate_event && self.has_active_drag() {
1186 if event.is::<MouseMoveEvent>() {
1187 // If this was a mouse move event, redraw the window so that the
1188 // active drag can follow the mouse cursor.
1189 self.refresh();
1190 } else if event.is::<MouseUpEvent>() {
1191 // If this was a mouse up event, cancel the active drag and redraw
1192 // the window.
1193 self.active_drag = None;
1194 self.refresh();
1195 }
1196 }
1197 }
1198
1199 fn dispatch_key_event(&mut self, event: &dyn Any) {
1200 let node_id = self
1201 .window
1202 .focus
1203 .and_then(|focus_id| {
1204 self.window
1205 .rendered_frame
1206 .dispatch_tree
1207 .focusable_node_id(focus_id)
1208 })
1209 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1210
1211 let dispatch_path = self
1212 .window
1213 .rendered_frame
1214 .dispatch_tree
1215 .dispatch_path(node_id);
1216
1217 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1218 let KeymatchResult {
1219 bindings,
1220 mut pending,
1221 } = self
1222 .window
1223 .rendered_frame
1224 .dispatch_tree
1225 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1226
1227 if self.window.rendered_frame.dispatch_tree.keymatch_mode == KeymatchMode::Immediate
1228 && !bindings.is_empty()
1229 {
1230 pending = false;
1231 }
1232
1233 if pending {
1234 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1235 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1236 {
1237 currently_pending = PendingInput::default();
1238 }
1239 currently_pending.focus = self.window.focus;
1240 currently_pending
1241 .keystrokes
1242 .push(key_down_event.keystroke.clone());
1243 for binding in bindings {
1244 currently_pending.bindings.push(binding);
1245 }
1246
1247 // for vim compatibility, we also should check "is input handler enabled"
1248 if !currently_pending.is_noop() {
1249 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1250 cx.background_executor.timer(Duration::from_secs(1)).await;
1251 cx.update(move |cx| {
1252 cx.clear_pending_keystrokes();
1253 let Some(currently_pending) = cx.window.pending_input.take() else {
1254 return;
1255 };
1256 cx.replay_pending_input(currently_pending)
1257 })
1258 .log_err();
1259 }));
1260 } else {
1261 currently_pending.timer = None;
1262 }
1263 self.window.pending_input = Some(currently_pending);
1264
1265 self.propagate_event = false;
1266 return;
1267 } else if let Some(currently_pending) = self.window.pending_input.take() {
1268 if bindings
1269 .iter()
1270 .all(|binding| !currently_pending.used_by_binding(binding))
1271 {
1272 self.replay_pending_input(currently_pending)
1273 }
1274 }
1275
1276 if !bindings.is_empty() {
1277 self.clear_pending_keystrokes();
1278 }
1279
1280 self.propagate_event = true;
1281 for binding in bindings {
1282 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1283 if !self.propagate_event {
1284 self.dispatch_keystroke_observers(event, Some(binding.action));
1285 return;
1286 }
1287 }
1288 }
1289
1290 // Capture phase
1291 for node_id in &dispatch_path {
1292 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1293
1294 for key_listener in node.key_listeners.clone() {
1295 self.with_element_context(|cx| {
1296 key_listener(event, DispatchPhase::Capture, cx);
1297 });
1298 if !self.propagate_event {
1299 return;
1300 }
1301 }
1302 }
1303
1304 // Bubble phase
1305 for node_id in dispatch_path.iter().rev() {
1306 // Handle low level key events
1307 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1308 for key_listener in node.key_listeners.clone() {
1309 self.with_element_context(|cx| {
1310 key_listener(event, DispatchPhase::Bubble, cx);
1311 });
1312 if !self.propagate_event {
1313 return;
1314 }
1315 }
1316 }
1317
1318 self.dispatch_keystroke_observers(event, None);
1319 }
1320
1321 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1322 pub fn has_pending_keystrokes(&self) -> bool {
1323 self.window
1324 .rendered_frame
1325 .dispatch_tree
1326 .has_pending_keystrokes()
1327 }
1328
1329 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1330 let node_id = self
1331 .window
1332 .focus
1333 .and_then(|focus_id| {
1334 self.window
1335 .rendered_frame
1336 .dispatch_tree
1337 .focusable_node_id(focus_id)
1338 })
1339 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1340
1341 if self.window.focus != currently_pending.focus {
1342 return;
1343 }
1344
1345 let input = currently_pending.input();
1346
1347 self.propagate_event = true;
1348 for binding in currently_pending.bindings {
1349 self.dispatch_action_on_node(node_id, binding.action.boxed_clone());
1350 if !self.propagate_event {
1351 return;
1352 }
1353 }
1354
1355 if !input.is_empty() {
1356 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1357 input_handler.flush_pending_input(&input, self);
1358 self.window.platform_window.set_input_handler(input_handler)
1359 }
1360 }
1361 }
1362
1363 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1364 let dispatch_path = self
1365 .window
1366 .rendered_frame
1367 .dispatch_tree
1368 .dispatch_path(node_id);
1369
1370 // Capture phase
1371 for node_id in &dispatch_path {
1372 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1373 for DispatchActionListener {
1374 action_type,
1375 listener,
1376 } in node.action_listeners.clone()
1377 {
1378 let any_action = action.as_any();
1379 if action_type == any_action.type_id() {
1380 self.with_element_context(|cx| {
1381 listener(any_action, DispatchPhase::Capture, cx);
1382 });
1383
1384 if !self.propagate_event {
1385 return;
1386 }
1387 }
1388 }
1389 }
1390 // Bubble phase
1391 for node_id in dispatch_path.iter().rev() {
1392 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1393 for DispatchActionListener {
1394 action_type,
1395 listener,
1396 } in node.action_listeners.clone()
1397 {
1398 let any_action = action.as_any();
1399 if action_type == any_action.type_id() {
1400 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1401
1402 self.with_element_context(|cx| {
1403 listener(any_action, DispatchPhase::Bubble, cx);
1404 });
1405
1406 if !self.propagate_event {
1407 return;
1408 }
1409 }
1410 }
1411 }
1412 }
1413
1414 /// Register the given handler to be invoked whenever the global of the given type
1415 /// is updated.
1416 pub fn observe_global<G: 'static>(
1417 &mut self,
1418 f: impl Fn(&mut WindowContext<'_>) + 'static,
1419 ) -> Subscription {
1420 let window_handle = self.window.handle;
1421 let (subscription, activate) = self.global_observers.insert(
1422 TypeId::of::<G>(),
1423 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1424 );
1425 self.app.defer(move |_| activate());
1426 subscription
1427 }
1428
1429 /// Focus the current window and bring it to the foreground at the platform level.
1430 pub fn activate_window(&self) {
1431 self.window.platform_window.activate();
1432 }
1433
1434 /// Minimize the current window at the platform level.
1435 pub fn minimize_window(&self) {
1436 self.window.platform_window.minimize();
1437 }
1438
1439 /// Toggle full screen status on the current window at the platform level.
1440 pub fn toggle_full_screen(&self) {
1441 self.window.platform_window.toggle_full_screen();
1442 }
1443
1444 /// Present a platform dialog.
1445 /// The provided message will be presented, along with buttons for each answer.
1446 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1447 pub fn prompt(
1448 &self,
1449 level: PromptLevel,
1450 message: &str,
1451 answers: &[&str],
1452 ) -> oneshot::Receiver<usize> {
1453 self.window.platform_window.prompt(level, message, answers)
1454 }
1455
1456 /// Returns all available actions for the focused element.
1457 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1458 let node_id = self
1459 .window
1460 .focus
1461 .and_then(|focus_id| {
1462 self.window
1463 .rendered_frame
1464 .dispatch_tree
1465 .focusable_node_id(focus_id)
1466 })
1467 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1468
1469 self.window
1470 .rendered_frame
1471 .dispatch_tree
1472 .available_actions(node_id)
1473 }
1474
1475 /// Returns key bindings that invoke the given action on the currently focused element.
1476 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1477 self.window
1478 .rendered_frame
1479 .dispatch_tree
1480 .bindings_for_action(
1481 action,
1482 &self.window.rendered_frame.dispatch_tree.context_stack,
1483 )
1484 }
1485
1486 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1487 pub fn bindings_for_action_in(
1488 &self,
1489 action: &dyn Action,
1490 focus_handle: &FocusHandle,
1491 ) -> Vec<KeyBinding> {
1492 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1493
1494 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1495 return vec![];
1496 };
1497 let context_stack = dispatch_tree
1498 .dispatch_path(node_id)
1499 .into_iter()
1500 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1501 .collect();
1502 dispatch_tree.bindings_for_action(action, &context_stack)
1503 }
1504
1505 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1506 pub fn listener_for<V: Render, E>(
1507 &self,
1508 view: &View<V>,
1509 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1510 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1511 let view = view.downgrade();
1512 move |e: &E, cx: &mut WindowContext| {
1513 view.update(cx, |view, cx| f(view, e, cx)).ok();
1514 }
1515 }
1516
1517 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1518 pub fn handler_for<V: Render>(
1519 &self,
1520 view: &View<V>,
1521 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1522 ) -> impl Fn(&mut WindowContext) {
1523 let view = view.downgrade();
1524 move |cx: &mut WindowContext| {
1525 view.update(cx, |view, cx| f(view, cx)).ok();
1526 }
1527 }
1528
1529 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1530 /// If the callback returns false, the window won't be closed.
1531 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1532 let mut this = self.to_async();
1533 self.window
1534 .platform_window
1535 .on_should_close(Box::new(move || {
1536 this.update(|cx| {
1537 // Ensure that the window is removed from the app if it's been closed
1538 // by always pre-empting the system close event.
1539 if f(cx) {
1540 cx.remove_window();
1541 }
1542 false
1543 })
1544 .unwrap_or(true)
1545 }))
1546 }
1547
1548 pub(crate) fn parent_view_id(&self) -> EntityId {
1549 *self
1550 .window
1551 .next_frame
1552 .view_stack
1553 .last()
1554 .expect("a view should always be on the stack while drawing")
1555 }
1556
1557 /// Register an action listener on the window for the next frame. The type of action
1558 /// is determined by the first parameter of the given listener. When the next frame is rendered
1559 /// the listener will be cleared.
1560 ///
1561 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1562 /// a specific need to register a global listener.
1563 pub fn on_action(
1564 &mut self,
1565 action_type: TypeId,
1566 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1567 ) {
1568 self.window
1569 .next_frame
1570 .dispatch_tree
1571 .on_action(action_type, Rc::new(listener));
1572 }
1573}
1574
1575impl Context for WindowContext<'_> {
1576 type Result<T> = T;
1577
1578 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1579 where
1580 T: 'static,
1581 {
1582 let slot = self.app.entities.reserve();
1583 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1584 self.entities.insert(slot, model)
1585 }
1586
1587 fn update_model<T: 'static, R>(
1588 &mut self,
1589 model: &Model<T>,
1590 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1591 ) -> R {
1592 let mut entity = self.entities.lease(model);
1593 let result = update(
1594 &mut *entity,
1595 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1596 );
1597 self.entities.end_lease(entity);
1598 result
1599 }
1600
1601 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1602 where
1603 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1604 {
1605 if window == self.window.handle {
1606 let root_view = self.window.root_view.clone().unwrap();
1607 Ok(update(root_view, self))
1608 } else {
1609 window.update(self.app, update)
1610 }
1611 }
1612
1613 fn read_model<T, R>(
1614 &self,
1615 handle: &Model<T>,
1616 read: impl FnOnce(&T, &AppContext) -> R,
1617 ) -> Self::Result<R>
1618 where
1619 T: 'static,
1620 {
1621 let entity = self.entities.read(handle);
1622 read(entity, &*self.app)
1623 }
1624
1625 fn read_window<T, R>(
1626 &self,
1627 window: &WindowHandle<T>,
1628 read: impl FnOnce(View<T>, &AppContext) -> R,
1629 ) -> Result<R>
1630 where
1631 T: 'static,
1632 {
1633 if window.any_handle == self.window.handle {
1634 let root_view = self
1635 .window
1636 .root_view
1637 .clone()
1638 .unwrap()
1639 .downcast::<T>()
1640 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1641 Ok(read(root_view, self))
1642 } else {
1643 self.app.read_window(window, read)
1644 }
1645 }
1646}
1647
1648impl VisualContext for WindowContext<'_> {
1649 fn new_view<V>(
1650 &mut self,
1651 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1652 ) -> Self::Result<View<V>>
1653 where
1654 V: 'static + Render,
1655 {
1656 let slot = self.app.entities.reserve();
1657 let view = View {
1658 model: slot.clone(),
1659 };
1660 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1661 let entity = build_view_state(&mut cx);
1662 cx.entities.insert(slot, entity);
1663
1664 cx.new_view_observers
1665 .clone()
1666 .retain(&TypeId::of::<V>(), |observer| {
1667 let any_view = AnyView::from(view.clone());
1668 (observer)(any_view, self);
1669 true
1670 });
1671
1672 view
1673 }
1674
1675 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1676 fn update_view<T: 'static, R>(
1677 &mut self,
1678 view: &View<T>,
1679 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1680 ) -> Self::Result<R> {
1681 let mut lease = self.app.entities.lease(&view.model);
1682 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1683 let result = update(&mut *lease, &mut cx);
1684 cx.app.entities.end_lease(lease);
1685 result
1686 }
1687
1688 fn replace_root_view<V>(
1689 &mut self,
1690 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1691 ) -> Self::Result<View<V>>
1692 where
1693 V: 'static + Render,
1694 {
1695 let view = self.new_view(build_view);
1696 self.window.root_view = Some(view.clone().into());
1697 self.refresh();
1698 view
1699 }
1700
1701 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1702 self.update_view(view, |view, cx| {
1703 view.focus_handle(cx).clone().focus(cx);
1704 })
1705 }
1706
1707 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1708 where
1709 V: ManagedView,
1710 {
1711 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1712 }
1713}
1714
1715impl<'a> std::ops::Deref for WindowContext<'a> {
1716 type Target = AppContext;
1717
1718 fn deref(&self) -> &Self::Target {
1719 self.app
1720 }
1721}
1722
1723impl<'a> std::ops::DerefMut for WindowContext<'a> {
1724 fn deref_mut(&mut self) -> &mut Self::Target {
1725 self.app
1726 }
1727}
1728
1729impl<'a> Borrow<AppContext> for WindowContext<'a> {
1730 fn borrow(&self) -> &AppContext {
1731 self.app
1732 }
1733}
1734
1735impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1736 fn borrow_mut(&mut self) -> &mut AppContext {
1737 self.app
1738 }
1739}
1740
1741/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1742pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1743 #[doc(hidden)]
1744 fn app_mut(&mut self) -> &mut AppContext {
1745 self.borrow_mut()
1746 }
1747
1748 #[doc(hidden)]
1749 fn app(&self) -> &AppContext {
1750 self.borrow()
1751 }
1752
1753 #[doc(hidden)]
1754 fn window(&self) -> &Window {
1755 self.borrow()
1756 }
1757
1758 #[doc(hidden)]
1759 fn window_mut(&mut self) -> &mut Window {
1760 self.borrow_mut()
1761 }
1762}
1763
1764impl Borrow<Window> for WindowContext<'_> {
1765 fn borrow(&self) -> &Window {
1766 self.window
1767 }
1768}
1769
1770impl BorrowMut<Window> for WindowContext<'_> {
1771 fn borrow_mut(&mut self) -> &mut Window {
1772 self.window
1773 }
1774}
1775
1776impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1777
1778/// Provides access to application state that is specialized for a particular [`View`].
1779/// Allows you to interact with focus, emit events, etc.
1780/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1781/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1782pub struct ViewContext<'a, V> {
1783 window_cx: WindowContext<'a>,
1784 view: &'a View<V>,
1785}
1786
1787impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1788 fn borrow(&self) -> &AppContext {
1789 &*self.window_cx.app
1790 }
1791}
1792
1793impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1794 fn borrow_mut(&mut self) -> &mut AppContext {
1795 &mut *self.window_cx.app
1796 }
1797}
1798
1799impl<V> Borrow<Window> for ViewContext<'_, V> {
1800 fn borrow(&self) -> &Window {
1801 &*self.window_cx.window
1802 }
1803}
1804
1805impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1806 fn borrow_mut(&mut self) -> &mut Window {
1807 &mut *self.window_cx.window
1808 }
1809}
1810
1811impl<'a, V: 'static> ViewContext<'a, V> {
1812 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1813 Self {
1814 window_cx: WindowContext::new(app, window),
1815 view,
1816 }
1817 }
1818
1819 /// Get the entity_id of this view.
1820 pub fn entity_id(&self) -> EntityId {
1821 self.view.entity_id()
1822 }
1823
1824 /// Get the view pointer underlying this context.
1825 pub fn view(&self) -> &View<V> {
1826 self.view
1827 }
1828
1829 /// Get the model underlying this view.
1830 pub fn model(&self) -> &Model<V> {
1831 &self.view.model
1832 }
1833
1834 /// Access the underlying window context.
1835 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1836 &mut self.window_cx
1837 }
1838
1839 /// Sets a given callback to be run on the next frame.
1840 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1841 where
1842 V: 'static,
1843 {
1844 let view = self.view().clone();
1845 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1846 }
1847
1848 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1849 /// that are currently on the stack to be returned to the app.
1850 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1851 let view = self.view().downgrade();
1852 self.window_cx.defer(move |cx| {
1853 view.update(cx, f).ok();
1854 });
1855 }
1856
1857 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1858 pub fn observe<V2, E>(
1859 &mut self,
1860 entity: &E,
1861 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1862 ) -> Subscription
1863 where
1864 V2: 'static,
1865 V: 'static,
1866 E: Entity<V2>,
1867 {
1868 let view = self.view().downgrade();
1869 let entity_id = entity.entity_id();
1870 let entity = entity.downgrade();
1871 let window_handle = self.window.handle;
1872 let (subscription, activate) = self.app.observers.insert(
1873 entity_id,
1874 Box::new(move |cx| {
1875 window_handle
1876 .update(cx, |_, cx| {
1877 if let Some(handle) = E::upgrade_from(&entity) {
1878 view.update(cx, |this, cx| on_notify(this, handle, cx))
1879 .is_ok()
1880 } else {
1881 false
1882 }
1883 })
1884 .unwrap_or(false)
1885 }),
1886 );
1887 self.app.defer(move |_| activate());
1888 subscription
1889 }
1890
1891 /// Subscribe to events emitted by another model or view.
1892 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1893 /// 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.
1894 pub fn subscribe<V2, E, Evt>(
1895 &mut self,
1896 entity: &E,
1897 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1898 ) -> Subscription
1899 where
1900 V2: EventEmitter<Evt>,
1901 E: Entity<V2>,
1902 Evt: 'static,
1903 {
1904 let view = self.view().downgrade();
1905 let entity_id = entity.entity_id();
1906 let handle = entity.downgrade();
1907 let window_handle = self.window.handle;
1908 let (subscription, activate) = self.app.event_listeners.insert(
1909 entity_id,
1910 (
1911 TypeId::of::<Evt>(),
1912 Box::new(move |event, cx| {
1913 window_handle
1914 .update(cx, |_, cx| {
1915 if let Some(handle) = E::upgrade_from(&handle) {
1916 let event = event.downcast_ref().expect("invalid event type");
1917 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1918 .is_ok()
1919 } else {
1920 false
1921 }
1922 })
1923 .unwrap_or(false)
1924 }),
1925 ),
1926 );
1927 self.app.defer(move |_| activate());
1928 subscription
1929 }
1930
1931 /// Register a callback to be invoked when the view is released.
1932 ///
1933 /// The callback receives a handle to the view's window. This handle may be
1934 /// invalid, if the window was closed before the view was released.
1935 pub fn on_release(
1936 &mut self,
1937 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1938 ) -> Subscription {
1939 let window_handle = self.window.handle;
1940 let (subscription, activate) = self.app.release_listeners.insert(
1941 self.view.model.entity_id,
1942 Box::new(move |this, cx| {
1943 let this = this.downcast_mut().expect("invalid entity type");
1944 on_release(this, window_handle, cx)
1945 }),
1946 );
1947 activate();
1948 subscription
1949 }
1950
1951 /// Register a callback to be invoked when the given Model or View is released.
1952 pub fn observe_release<V2, E>(
1953 &mut self,
1954 entity: &E,
1955 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1956 ) -> Subscription
1957 where
1958 V: 'static,
1959 V2: 'static,
1960 E: Entity<V2>,
1961 {
1962 let view = self.view().downgrade();
1963 let entity_id = entity.entity_id();
1964 let window_handle = self.window.handle;
1965 let (subscription, activate) = self.app.release_listeners.insert(
1966 entity_id,
1967 Box::new(move |entity, cx| {
1968 let entity = entity.downcast_mut().expect("invalid entity type");
1969 let _ = window_handle.update(cx, |_, cx| {
1970 view.update(cx, |this, cx| on_release(this, entity, cx))
1971 });
1972 }),
1973 );
1974 activate();
1975 subscription
1976 }
1977
1978 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
1979 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
1980 pub fn notify(&mut self) {
1981 for view_id in self
1982 .window
1983 .rendered_frame
1984 .dispatch_tree
1985 .view_path(self.view.entity_id())
1986 .into_iter()
1987 .rev()
1988 {
1989 if !self.window.dirty_views.insert(view_id) {
1990 break;
1991 }
1992 }
1993
1994 if !self.window.drawing {
1995 self.window_cx.window.dirty = true;
1996 self.window_cx.app.push_effect(Effect::Notify {
1997 emitter: self.view.model.entity_id,
1998 });
1999 }
2000 }
2001
2002 /// Register a callback to be invoked when the window is resized.
2003 pub fn observe_window_bounds(
2004 &mut self,
2005 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2006 ) -> Subscription {
2007 let view = self.view.downgrade();
2008 let (subscription, activate) = self.window.bounds_observers.insert(
2009 (),
2010 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2011 );
2012 activate();
2013 subscription
2014 }
2015
2016 /// Register a callback to be invoked when the window is activated or deactivated.
2017 pub fn observe_window_activation(
2018 &mut self,
2019 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2020 ) -> Subscription {
2021 let view = self.view.downgrade();
2022 let (subscription, activate) = self.window.activation_observers.insert(
2023 (),
2024 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2025 );
2026 activate();
2027 subscription
2028 }
2029
2030 /// Register a listener to be called when the given focus handle receives focus.
2031 /// Returns a subscription and persists until the subscription is dropped.
2032 pub fn on_focus(
2033 &mut self,
2034 handle: &FocusHandle,
2035 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2036 ) -> Subscription {
2037 let view = self.view.downgrade();
2038 let focus_id = handle.id;
2039 let (subscription, activate) = self.window.focus_listeners.insert(
2040 (),
2041 Box::new(move |event, cx| {
2042 view.update(cx, |view, cx| {
2043 if event.previous_focus_path.last() != Some(&focus_id)
2044 && event.current_focus_path.last() == Some(&focus_id)
2045 {
2046 listener(view, cx)
2047 }
2048 })
2049 .is_ok()
2050 }),
2051 );
2052 self.app.defer(move |_| activate());
2053 subscription
2054 }
2055
2056 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2057 /// Returns a subscription and persists until the subscription is dropped.
2058 pub fn on_focus_in(
2059 &mut self,
2060 handle: &FocusHandle,
2061 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2062 ) -> Subscription {
2063 let view = self.view.downgrade();
2064 let focus_id = handle.id;
2065 let (subscription, activate) = self.window.focus_listeners.insert(
2066 (),
2067 Box::new(move |event, cx| {
2068 view.update(cx, |view, cx| {
2069 if !event.previous_focus_path.contains(&focus_id)
2070 && event.current_focus_path.contains(&focus_id)
2071 {
2072 listener(view, cx)
2073 }
2074 })
2075 .is_ok()
2076 }),
2077 );
2078 self.app.defer(move |_| activate());
2079 subscription
2080 }
2081
2082 /// Register a listener to be called when the given focus handle loses focus.
2083 /// Returns a subscription and persists until the subscription is dropped.
2084 pub fn on_blur(
2085 &mut self,
2086 handle: &FocusHandle,
2087 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2088 ) -> Subscription {
2089 let view = self.view.downgrade();
2090 let focus_id = handle.id;
2091 let (subscription, activate) = self.window.focus_listeners.insert(
2092 (),
2093 Box::new(move |event, cx| {
2094 view.update(cx, |view, cx| {
2095 if event.previous_focus_path.last() == Some(&focus_id)
2096 && event.current_focus_path.last() != Some(&focus_id)
2097 {
2098 listener(view, cx)
2099 }
2100 })
2101 .is_ok()
2102 }),
2103 );
2104 self.app.defer(move |_| activate());
2105 subscription
2106 }
2107
2108 /// Register a listener to be called when nothing in the window has focus.
2109 /// This typically happens when the node that was focused is removed from the tree,
2110 /// and this callback lets you chose a default place to restore the users focus.
2111 /// Returns a subscription and persists until the subscription is dropped.
2112 pub fn on_focus_lost(
2113 &mut self,
2114 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2115 ) -> Subscription {
2116 let view = self.view.downgrade();
2117 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2118 (),
2119 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2120 );
2121 activate();
2122 subscription
2123 }
2124
2125 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2126 /// Returns a subscription and persists until the subscription is dropped.
2127 pub fn on_focus_out(
2128 &mut self,
2129 handle: &FocusHandle,
2130 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2131 ) -> Subscription {
2132 let view = self.view.downgrade();
2133 let focus_id = handle.id;
2134 let (subscription, activate) = self.window.focus_listeners.insert(
2135 (),
2136 Box::new(move |event, cx| {
2137 view.update(cx, |view, cx| {
2138 if event.previous_focus_path.contains(&focus_id)
2139 && !event.current_focus_path.contains(&focus_id)
2140 {
2141 listener(view, cx)
2142 }
2143 })
2144 .is_ok()
2145 }),
2146 );
2147 self.app.defer(move |_| activate());
2148 subscription
2149 }
2150
2151 /// Schedule a future to be run asynchronously.
2152 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2153 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2154 /// The returned future will be polled on the main thread.
2155 pub fn spawn<Fut, R>(
2156 &mut self,
2157 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2158 ) -> Task<R>
2159 where
2160 R: 'static,
2161 Fut: Future<Output = R> + 'static,
2162 {
2163 let view = self.view().downgrade();
2164 self.window_cx.spawn(|cx| f(view, cx))
2165 }
2166
2167 /// Updates the global state of the given type.
2168 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2169 where
2170 G: 'static,
2171 {
2172 let mut global = self.app.lease_global::<G>();
2173 let result = f(&mut global, self);
2174 self.app.end_global_lease(global);
2175 result
2176 }
2177
2178 /// Register a callback to be invoked when the given global state changes.
2179 pub fn observe_global<G: 'static>(
2180 &mut self,
2181 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2182 ) -> Subscription {
2183 let window_handle = self.window.handle;
2184 let view = self.view().downgrade();
2185 let (subscription, activate) = self.global_observers.insert(
2186 TypeId::of::<G>(),
2187 Box::new(move |cx| {
2188 window_handle
2189 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2190 .unwrap_or(false)
2191 }),
2192 );
2193 self.app.defer(move |_| activate());
2194 subscription
2195 }
2196
2197 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2198 pub fn on_action(
2199 &mut self,
2200 action_type: TypeId,
2201 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2202 ) {
2203 let handle = self.view().clone();
2204 self.window_cx
2205 .on_action(action_type, move |action, phase, cx| {
2206 handle.update(cx, |view, cx| {
2207 listener(view, action, phase, cx);
2208 })
2209 });
2210 }
2211
2212 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2213 pub fn emit<Evt>(&mut self, event: Evt)
2214 where
2215 Evt: 'static,
2216 V: EventEmitter<Evt>,
2217 {
2218 let emitter = self.view.model.entity_id;
2219 self.app.push_effect(Effect::Emit {
2220 emitter,
2221 event_type: TypeId::of::<Evt>(),
2222 event: Box::new(event),
2223 });
2224 }
2225
2226 /// Move focus to the current view, assuming it implements [`FocusableView`].
2227 pub fn focus_self(&mut self)
2228 where
2229 V: FocusableView,
2230 {
2231 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2232 }
2233
2234 /// Convenience method for accessing view state in an event callback.
2235 ///
2236 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2237 /// but it's often useful to be able to access view state in these
2238 /// callbacks. This method provides a convenient way to do so.
2239 pub fn listener<E>(
2240 &self,
2241 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2242 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2243 let view = self.view().downgrade();
2244 move |e: &E, cx: &mut WindowContext| {
2245 view.update(cx, |view, cx| f(view, e, cx)).ok();
2246 }
2247 }
2248}
2249
2250impl<V> Context for ViewContext<'_, V> {
2251 type Result<U> = U;
2252
2253 fn new_model<T: 'static>(
2254 &mut self,
2255 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2256 ) -> Model<T> {
2257 self.window_cx.new_model(build_model)
2258 }
2259
2260 fn update_model<T: 'static, R>(
2261 &mut self,
2262 model: &Model<T>,
2263 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2264 ) -> R {
2265 self.window_cx.update_model(model, update)
2266 }
2267
2268 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2269 where
2270 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2271 {
2272 self.window_cx.update_window(window, update)
2273 }
2274
2275 fn read_model<T, R>(
2276 &self,
2277 handle: &Model<T>,
2278 read: impl FnOnce(&T, &AppContext) -> R,
2279 ) -> Self::Result<R>
2280 where
2281 T: 'static,
2282 {
2283 self.window_cx.read_model(handle, read)
2284 }
2285
2286 fn read_window<T, R>(
2287 &self,
2288 window: &WindowHandle<T>,
2289 read: impl FnOnce(View<T>, &AppContext) -> R,
2290 ) -> Result<R>
2291 where
2292 T: 'static,
2293 {
2294 self.window_cx.read_window(window, read)
2295 }
2296}
2297
2298impl<V: 'static> VisualContext for ViewContext<'_, V> {
2299 fn new_view<W: Render + 'static>(
2300 &mut self,
2301 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2302 ) -> Self::Result<View<W>> {
2303 self.window_cx.new_view(build_view_state)
2304 }
2305
2306 fn update_view<V2: 'static, R>(
2307 &mut self,
2308 view: &View<V2>,
2309 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2310 ) -> Self::Result<R> {
2311 self.window_cx.update_view(view, update)
2312 }
2313
2314 fn replace_root_view<W>(
2315 &mut self,
2316 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2317 ) -> Self::Result<View<W>>
2318 where
2319 W: 'static + Render,
2320 {
2321 self.window_cx.replace_root_view(build_view)
2322 }
2323
2324 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2325 self.window_cx.focus_view(view)
2326 }
2327
2328 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2329 self.window_cx.dismiss_view(view)
2330 }
2331}
2332
2333impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2334 type Target = WindowContext<'a>;
2335
2336 fn deref(&self) -> &Self::Target {
2337 &self.window_cx
2338 }
2339}
2340
2341impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2342 fn deref_mut(&mut self) -> &mut Self::Target {
2343 &mut self.window_cx
2344 }
2345}
2346
2347// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2348slotmap::new_key_type! {
2349 /// A unique identifier for a window.
2350 pub struct WindowId;
2351}
2352
2353impl WindowId {
2354 /// Converts this window ID to a `u64`.
2355 pub fn as_u64(&self) -> u64 {
2356 self.0.as_ffi()
2357 }
2358}
2359
2360/// A handle to a window with a specific root view type.
2361/// Note that this does not keep the window alive on its own.
2362#[derive(Deref, DerefMut)]
2363pub struct WindowHandle<V> {
2364 #[deref]
2365 #[deref_mut]
2366 pub(crate) any_handle: AnyWindowHandle,
2367 state_type: PhantomData<V>,
2368}
2369
2370impl<V: 'static + Render> WindowHandle<V> {
2371 /// Creates a new handle from a window ID.
2372 /// This does not check if the root type of the window is `V`.
2373 pub fn new(id: WindowId) -> Self {
2374 WindowHandle {
2375 any_handle: AnyWindowHandle {
2376 id,
2377 state_type: TypeId::of::<V>(),
2378 },
2379 state_type: PhantomData,
2380 }
2381 }
2382
2383 /// Get the root view out of this window.
2384 ///
2385 /// This will fail if the window is closed or if the root view's type does not match `V`.
2386 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2387 where
2388 C: Context,
2389 {
2390 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2391 root_view
2392 .downcast::<V>()
2393 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2394 }))
2395 }
2396
2397 /// Updates the root view of this window.
2398 ///
2399 /// This will fail if the window has been closed or if the root view's type does not match
2400 pub fn update<C, R>(
2401 &self,
2402 cx: &mut C,
2403 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2404 ) -> Result<R>
2405 where
2406 C: Context,
2407 {
2408 cx.update_window(self.any_handle, |root_view, cx| {
2409 let view = root_view
2410 .downcast::<V>()
2411 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2412 Ok(cx.update_view(&view, update))
2413 })?
2414 }
2415
2416 /// Read the root view out of this window.
2417 ///
2418 /// This will fail if the window is closed or if the root view's type does not match `V`.
2419 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2420 let x = cx
2421 .windows
2422 .get(self.id)
2423 .and_then(|window| {
2424 window
2425 .as_ref()
2426 .and_then(|window| window.root_view.clone())
2427 .map(|root_view| root_view.downcast::<V>())
2428 })
2429 .ok_or_else(|| anyhow!("window not found"))?
2430 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2431
2432 Ok(x.read(cx))
2433 }
2434
2435 /// Read the root view out of this window, with a callback
2436 ///
2437 /// This will fail if the window is closed or if the root view's type does not match `V`.
2438 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2439 where
2440 C: Context,
2441 {
2442 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2443 }
2444
2445 /// Read the root view pointer off of this window.
2446 ///
2447 /// This will fail if the window is closed or if the root view's type does not match `V`.
2448 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2449 where
2450 C: Context,
2451 {
2452 cx.read_window(self, |root_view, _cx| root_view.clone())
2453 }
2454
2455 /// Check if this window is 'active'.
2456 ///
2457 /// Will return `None` if the window is closed.
2458 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2459 cx.windows
2460 .get(self.id)
2461 .and_then(|window| window.as_ref().map(|window| window.active))
2462 }
2463}
2464
2465impl<V> Copy for WindowHandle<V> {}
2466
2467impl<V> Clone for WindowHandle<V> {
2468 fn clone(&self) -> Self {
2469 *self
2470 }
2471}
2472
2473impl<V> PartialEq for WindowHandle<V> {
2474 fn eq(&self, other: &Self) -> bool {
2475 self.any_handle == other.any_handle
2476 }
2477}
2478
2479impl<V> Eq for WindowHandle<V> {}
2480
2481impl<V> Hash for WindowHandle<V> {
2482 fn hash<H: Hasher>(&self, state: &mut H) {
2483 self.any_handle.hash(state);
2484 }
2485}
2486
2487impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2488 fn from(val: WindowHandle<V>) -> Self {
2489 val.any_handle
2490 }
2491}
2492
2493/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2494#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2495pub struct AnyWindowHandle {
2496 pub(crate) id: WindowId,
2497 state_type: TypeId,
2498}
2499
2500impl AnyWindowHandle {
2501 /// Get the ID of this window.
2502 pub fn window_id(&self) -> WindowId {
2503 self.id
2504 }
2505
2506 /// Attempt to convert this handle to a window handle with a specific root view type.
2507 /// If the types do not match, this will return `None`.
2508 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2509 if TypeId::of::<T>() == self.state_type {
2510 Some(WindowHandle {
2511 any_handle: *self,
2512 state_type: PhantomData,
2513 })
2514 } else {
2515 None
2516 }
2517 }
2518
2519 /// Updates the state of the root view of this window.
2520 ///
2521 /// This will fail if the window has been closed.
2522 pub fn update<C, R>(
2523 self,
2524 cx: &mut C,
2525 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2526 ) -> Result<R>
2527 where
2528 C: Context,
2529 {
2530 cx.update_window(self, update)
2531 }
2532
2533 /// Read the state of the root view of this window.
2534 ///
2535 /// This will fail if the window has been closed.
2536 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2537 where
2538 C: Context,
2539 T: 'static,
2540 {
2541 let view = self
2542 .downcast::<T>()
2543 .context("the type of the window's root view has changed")?;
2544
2545 cx.read_window(&view, read)
2546 }
2547}
2548
2549/// An identifier for an [`Element`](crate::Element).
2550///
2551/// Can be constructed with a string, a number, or both, as well
2552/// as other internal representations.
2553#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2554pub enum ElementId {
2555 /// The ID of a View element
2556 View(EntityId),
2557 /// An integer ID.
2558 Integer(usize),
2559 /// A string based ID.
2560 Name(SharedString),
2561 /// An ID that's equated with a focus handle.
2562 FocusHandle(FocusId),
2563 /// A combination of a name and an integer.
2564 NamedInteger(SharedString, usize),
2565}
2566
2567impl Display for ElementId {
2568 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2569 match self {
2570 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2571 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2572 ElementId::Name(name) => write!(f, "{}", name)?,
2573 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2574 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2575 }
2576
2577 Ok(())
2578 }
2579}
2580
2581impl ElementId {
2582 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2583 ElementId::View(entity_id)
2584 }
2585}
2586
2587impl TryInto<SharedString> for ElementId {
2588 type Error = anyhow::Error;
2589
2590 fn try_into(self) -> anyhow::Result<SharedString> {
2591 if let ElementId::Name(name) = self {
2592 Ok(name)
2593 } else {
2594 Err(anyhow!("element id is not string"))
2595 }
2596 }
2597}
2598
2599impl From<usize> for ElementId {
2600 fn from(id: usize) -> Self {
2601 ElementId::Integer(id)
2602 }
2603}
2604
2605impl From<i32> for ElementId {
2606 fn from(id: i32) -> Self {
2607 Self::Integer(id as usize)
2608 }
2609}
2610
2611impl From<SharedString> for ElementId {
2612 fn from(name: SharedString) -> Self {
2613 ElementId::Name(name)
2614 }
2615}
2616
2617impl From<&'static str> for ElementId {
2618 fn from(name: &'static str) -> Self {
2619 ElementId::Name(name.into())
2620 }
2621}
2622
2623impl<'a> From<&'a FocusHandle> for ElementId {
2624 fn from(handle: &'a FocusHandle) -> Self {
2625 ElementId::FocusHandle(handle.id)
2626 }
2627}
2628
2629impl From<(&'static str, EntityId)> for ElementId {
2630 fn from((name, id): (&'static str, EntityId)) -> Self {
2631 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2632 }
2633}
2634
2635impl From<(&'static str, usize)> for ElementId {
2636 fn from((name, id): (&'static str, usize)) -> Self {
2637 ElementId::NamedInteger(name.into(), id)
2638 }
2639}
2640
2641impl From<(&'static str, u64)> for ElementId {
2642 fn from((name, id): (&'static str, u64)) -> Self {
2643 ElementId::NamedInteger(name.into(), id as usize)
2644 }
2645}
2646
2647/// A rectangle to be rendered in the window at the given position and size.
2648/// Passed as an argument [`WindowContext::paint_quad`].
2649#[derive(Clone)]
2650pub struct PaintQuad {
2651 bounds: Bounds<Pixels>,
2652 corner_radii: Corners<Pixels>,
2653 background: Hsla,
2654 border_widths: Edges<Pixels>,
2655 border_color: Hsla,
2656}
2657
2658impl PaintQuad {
2659 /// Sets the corner radii of the quad.
2660 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2661 PaintQuad {
2662 corner_radii: corner_radii.into(),
2663 ..self
2664 }
2665 }
2666
2667 /// Sets the border widths of the quad.
2668 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2669 PaintQuad {
2670 border_widths: border_widths.into(),
2671 ..self
2672 }
2673 }
2674
2675 /// Sets the border color of the quad.
2676 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2677 PaintQuad {
2678 border_color: border_color.into(),
2679 ..self
2680 }
2681 }
2682
2683 /// Sets the background color of the quad.
2684 pub fn background(self, background: impl Into<Hsla>) -> Self {
2685 PaintQuad {
2686 background: background.into(),
2687 ..self
2688 }
2689 }
2690}
2691
2692/// Creates a quad with the given parameters.
2693pub fn quad(
2694 bounds: Bounds<Pixels>,
2695 corner_radii: impl Into<Corners<Pixels>>,
2696 background: impl Into<Hsla>,
2697 border_widths: impl Into<Edges<Pixels>>,
2698 border_color: impl Into<Hsla>,
2699) -> PaintQuad {
2700 PaintQuad {
2701 bounds,
2702 corner_radii: corner_radii.into(),
2703 background: background.into(),
2704 border_widths: border_widths.into(),
2705 border_color: border_color.into(),
2706 }
2707}
2708
2709/// Creates a filled quad with the given bounds and background color.
2710pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2711 PaintQuad {
2712 bounds: bounds.into(),
2713 corner_radii: (0.).into(),
2714 background: background.into(),
2715 border_widths: (0.).into(),
2716 border_color: transparent_black(),
2717 }
2718}
2719
2720/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2721pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2722 PaintQuad {
2723 bounds: bounds.into(),
2724 corner_radii: (0.).into(),
2725 background: transparent_black(),
2726 border_widths: (1.).into(),
2727 border_color: border_color.into(),
2728 }
2729}