1use crate::{
2 point, px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena,
3 AsyncWindowContext, Bounds, Context, Corners, CursorStyle, DispatchActionListener,
4 DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
5 FileDropEvent, Flatten, Global, GlobalElementId, GlobalPixels, Hsla, KeyBinding, KeyDownEvent,
6 KeyMatch, KeymatchResult, Keystroke, KeystrokeEvent, Model, ModelContext, Modifiers,
7 MouseButton, MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas, PlatformDisplay,
8 PlatformInput, PlatformWindow, Point, PromptLevel, Render, ScaledPixels, SharedString, Size,
9 SubscriberSet, Subscription, TaffyLayoutEngine, Task, TextStyle, TextStyleRefinement, View,
10 VisualContext, WeakView, WindowAppearance, WindowOptions, WindowParams, WindowTextSystem,
11};
12use anyhow::{anyhow, Context as _, Result};
13use collections::FxHashSet;
14use derive_more::{Deref, DerefMut};
15use futures::channel::oneshot;
16use parking_lot::RwLock;
17use refineable::Refineable;
18use slotmap::SlotMap;
19use smallvec::SmallVec;
20use std::{
21 any::{Any, TypeId},
22 borrow::{Borrow, BorrowMut},
23 cell::{Cell, RefCell},
24 fmt::{Debug, Display},
25 future::Future,
26 hash::{Hash, Hasher},
27 marker::PhantomData,
28 mem,
29 rc::Rc,
30 sync::{
31 atomic::{AtomicUsize, Ordering::SeqCst},
32 Arc,
33 },
34 time::{Duration, Instant},
35};
36use util::{measure, ResultExt};
37
38mod element_cx;
39mod prompts;
40
41pub use element_cx::*;
42pub use prompts::*;
43
44/// Represents the two different phases when dispatching events.
45#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
46pub enum DispatchPhase {
47 /// After the capture phase comes the bubble phase, in which mouse event listeners are
48 /// invoked front to back and keyboard event listeners are invoked from the focused element
49 /// to the root of the element tree. This is the phase you'll most commonly want to use when
50 /// registering event listeners.
51 #[default]
52 Bubble,
53 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
54 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
55 /// is used for special purposes such as clearing the "pressed" state for click events. If
56 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
57 /// outside of the immediate region may rely on detecting non-local events during this phase.
58 Capture,
59}
60
61impl DispatchPhase {
62 /// Returns true if this represents the "bubble" phase.
63 pub fn bubble(self) -> bool {
64 self == DispatchPhase::Bubble
65 }
66
67 /// Returns true if this represents the "capture" phase.
68 pub fn capture(self) -> bool {
69 self == DispatchPhase::Capture
70 }
71}
72
73type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
74
75type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
76
77struct FocusEvent {
78 previous_focus_path: SmallVec<[FocusId; 8]>,
79 current_focus_path: SmallVec<[FocusId; 8]>,
80}
81
82slotmap::new_key_type! {
83 /// A globally unique identifier for a focusable element.
84 pub struct FocusId;
85}
86
87thread_local! {
88 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(8 * 1024 * 1024));
89}
90
91impl FocusId {
92 /// Obtains whether the element associated with this handle is currently focused.
93 pub fn is_focused(&self, cx: &WindowContext) -> bool {
94 cx.window.focus == Some(*self)
95 }
96
97 /// Obtains whether the element associated with this handle contains the focused
98 /// element or is itself focused.
99 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
100 cx.focused()
101 .map_or(false, |focused| self.contains(focused.id, cx))
102 }
103
104 /// Obtains whether the element associated with this handle is contained within the
105 /// focused element or is itself focused.
106 pub fn within_focused(&self, cx: &WindowContext) -> bool {
107 let focused = cx.focused();
108 focused.map_or(false, |focused| focused.id.contains(*self, cx))
109 }
110
111 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
112 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
113 cx.window
114 .rendered_frame
115 .dispatch_tree
116 .focus_contains(*self, other)
117 }
118}
119
120/// A handle which can be used to track and manipulate the focused element in a window.
121pub struct FocusHandle {
122 pub(crate) id: FocusId,
123 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
124}
125
126impl std::fmt::Debug for FocusHandle {
127 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
128 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
129 }
130}
131
132impl FocusHandle {
133 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
134 let id = handles.write().insert(AtomicUsize::new(1));
135 Self {
136 id,
137 handles: handles.clone(),
138 }
139 }
140
141 pub(crate) fn for_id(
142 id: FocusId,
143 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
144 ) -> Option<Self> {
145 let lock = handles.read();
146 let ref_count = lock.get(id)?;
147 if ref_count.load(SeqCst) == 0 {
148 None
149 } else {
150 ref_count.fetch_add(1, SeqCst);
151 Some(Self {
152 id,
153 handles: handles.clone(),
154 })
155 }
156 }
157
158 /// Moves the focus to the element associated with this handle.
159 pub fn focus(&self, cx: &mut WindowContext) {
160 cx.focus(self)
161 }
162
163 /// Obtains whether the element associated with this handle is currently focused.
164 pub fn is_focused(&self, cx: &WindowContext) -> bool {
165 self.id.is_focused(cx)
166 }
167
168 /// Obtains whether the element associated with this handle contains the focused
169 /// element or is itself focused.
170 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
171 self.id.contains_focused(cx)
172 }
173
174 /// Obtains whether the element associated with this handle is contained within the
175 /// focused element or is itself focused.
176 pub fn within_focused(&self, cx: &WindowContext) -> bool {
177 self.id.within_focused(cx)
178 }
179
180 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
181 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
182 self.id.contains(other.id, cx)
183 }
184}
185
186impl Clone for FocusHandle {
187 fn clone(&self) -> Self {
188 Self::for_id(self.id, &self.handles).unwrap()
189 }
190}
191
192impl PartialEq for FocusHandle {
193 fn eq(&self, other: &Self) -> bool {
194 self.id == other.id
195 }
196}
197
198impl Eq for FocusHandle {}
199
200impl Drop for FocusHandle {
201 fn drop(&mut self) {
202 self.handles
203 .read()
204 .get(self.id)
205 .unwrap()
206 .fetch_sub(1, SeqCst);
207 }
208}
209
210/// FocusableView allows users of your view to easily
211/// focus it (using cx.focus_view(view))
212pub trait FocusableView: 'static + Render {
213 /// Returns the focus handle associated with this view.
214 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
215}
216
217/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
218/// where the lifecycle of the view is handled by another view.
219pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
220
221impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
222
223/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
224pub struct DismissEvent;
225
226type FrameCallback = Box<dyn FnOnce(&mut WindowContext)>;
227
228// Holds the state for a specific window.
229#[doc(hidden)]
230pub struct Window {
231 pub(crate) handle: AnyWindowHandle,
232 pub(crate) removed: bool,
233 pub(crate) platform_window: Box<dyn PlatformWindow>,
234 display_id: DisplayId,
235 sprite_atlas: Arc<dyn PlatformAtlas>,
236 text_system: Arc<WindowTextSystem>,
237 pub(crate) rem_size: Pixels,
238 pub(crate) viewport_size: Size<Pixels>,
239 layout_engine: Option<TaffyLayoutEngine>,
240 pub(crate) root_view: Option<AnyView>,
241 pub(crate) element_id_stack: GlobalElementId,
242 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
243 pub(crate) rendered_frame: Frame,
244 pub(crate) next_frame: Frame,
245 pub(crate) next_hitbox_id: HitboxId,
246 next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
247 pub(crate) dirty_views: FxHashSet<EntityId>,
248 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
249 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
250 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
251 default_prevented: bool,
252 mouse_position: Point<Pixels>,
253 mouse_hit_test: HitTest,
254 modifiers: Modifiers,
255 scale_factor: f32,
256 bounds_observers: SubscriberSet<(), AnyObserver>,
257 appearance: WindowAppearance,
258 appearance_observers: SubscriberSet<(), AnyObserver>,
259 active: Rc<Cell<bool>>,
260 pub(crate) dirty: Rc<Cell<bool>>,
261 pub(crate) needs_present: Rc<Cell<bool>>,
262 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
263 pub(crate) refreshing: bool,
264 pub(crate) draw_phase: DrawPhase,
265 activation_observers: SubscriberSet<(), AnyObserver>,
266 pub(crate) focus: Option<FocusId>,
267 focus_enabled: bool,
268 pending_input: Option<PendingInput>,
269 prompt: Option<RenderablePromptHandle>,
270}
271
272#[derive(Clone, Copy, Debug, Eq, PartialEq)]
273pub(crate) enum DrawPhase {
274 None,
275 Layout,
276 Paint,
277 Focus,
278}
279
280#[derive(Default, Debug)]
281struct PendingInput {
282 keystrokes: SmallVec<[Keystroke; 1]>,
283 bindings: SmallVec<[KeyBinding; 1]>,
284 focus: Option<FocusId>,
285 timer: Option<Task<()>>,
286}
287
288impl PendingInput {
289 fn input(&self) -> String {
290 self.keystrokes
291 .iter()
292 .flat_map(|k| k.ime_key.clone())
293 .collect::<Vec<String>>()
294 .join("")
295 }
296
297 fn used_by_binding(&self, binding: &KeyBinding) -> bool {
298 if self.keystrokes.is_empty() {
299 return true;
300 }
301 let keystroke = &self.keystrokes[0];
302 for candidate in keystroke.match_candidates() {
303 if binding.match_keystrokes(&[candidate]) == KeyMatch::Pending {
304 return true;
305 }
306 }
307 false
308 }
309}
310
311pub(crate) struct ElementStateBox {
312 pub(crate) inner: Box<dyn Any>,
313 #[cfg(debug_assertions)]
314 pub(crate) type_name: &'static str,
315}
316
317fn default_bounds(cx: &mut AppContext) -> Bounds<GlobalPixels> {
318 const DEFAULT_WINDOW_SIZE: Size<GlobalPixels> = size(GlobalPixels(1024.0), GlobalPixels(700.0));
319 const DEFAULT_WINDOW_OFFSET: Point<GlobalPixels> = point(GlobalPixels(0.0), GlobalPixels(35.0));
320
321 cx.active_window()
322 .and_then(|w| w.update(cx, |_, cx| cx.window_bounds()).ok())
323 .map(|bounds| bounds.map_origin(|origin| origin + DEFAULT_WINDOW_OFFSET))
324 .unwrap_or_else(|| {
325 cx.primary_display()
326 .map(|display| {
327 let center = display.bounds().center();
328 let offset = DEFAULT_WINDOW_SIZE / 2.0;
329 let origin = point(center.x - offset.width, center.y - offset.height);
330 Bounds::new(origin, DEFAULT_WINDOW_SIZE)
331 })
332 .unwrap_or_else(|| {
333 Bounds::new(
334 point(GlobalPixels(0.0), GlobalPixels(0.0)),
335 DEFAULT_WINDOW_SIZE,
336 )
337 })
338 })
339}
340
341// Fixed, Maximized, Fullscreen, and 'Inherent / default'
342// Platform part, you don't, you only need Fixed, Maximized, Fullscreen
343
344impl Window {
345 pub(crate) fn new(
346 handle: AnyWindowHandle,
347 options: WindowOptions,
348 cx: &mut AppContext,
349 ) -> Self {
350 let WindowOptions {
351 bounds,
352 titlebar,
353 focus,
354 show,
355 kind,
356 is_movable,
357 display_id,
358 fullscreen,
359 } = options;
360
361 let bounds = bounds.unwrap_or_else(|| default_bounds(cx));
362 let platform_window = cx.platform.open_window(
363 handle,
364 WindowParams {
365 bounds,
366 titlebar,
367 kind,
368 is_movable,
369 focus,
370 show,
371 display_id,
372 },
373 );
374 let display_id = platform_window.display().id();
375 let sprite_atlas = platform_window.sprite_atlas();
376 let mouse_position = platform_window.mouse_position();
377 let modifiers = platform_window.modifiers();
378 let content_size = platform_window.content_size();
379 let scale_factor = platform_window.scale_factor();
380 let appearance = platform_window.appearance();
381 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
382 let dirty = Rc::new(Cell::new(true));
383 let active = Rc::new(Cell::new(false));
384 let needs_present = Rc::new(Cell::new(false));
385 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
386 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
387
388 if fullscreen {
389 platform_window.toggle_full_screen();
390 }
391
392 platform_window.on_close(Box::new({
393 let mut cx = cx.to_async();
394 move || {
395 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
396 }
397 }));
398 platform_window.on_request_frame(Box::new({
399 let mut cx = cx.to_async();
400 let dirty = dirty.clone();
401 let active = active.clone();
402 let needs_present = needs_present.clone();
403 let next_frame_callbacks = next_frame_callbacks.clone();
404 let last_input_timestamp = last_input_timestamp.clone();
405 move || {
406 let next_frame_callbacks = next_frame_callbacks.take();
407 if !next_frame_callbacks.is_empty() {
408 handle
409 .update(&mut cx, |_, cx| {
410 for callback in next_frame_callbacks {
411 callback(cx);
412 }
413 })
414 .log_err();
415 }
416
417 // Keep presenting the current scene for 1 extra second since the
418 // last input to prevent the display from underclocking the refresh rate.
419 let needs_present = needs_present.get()
420 || (active.get()
421 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
422
423 if dirty.get() {
424 measure("frame duration", || {
425 handle
426 .update(&mut cx, |_, cx| {
427 cx.draw();
428 cx.present();
429 })
430 .log_err();
431 })
432 } else if needs_present {
433 handle.update(&mut cx, |_, cx| cx.present()).log_err();
434 }
435 }
436 }));
437 platform_window.on_resize(Box::new({
438 let mut cx = cx.to_async();
439 move |_, _| {
440 handle
441 .update(&mut cx, |_, cx| cx.window_bounds_changed())
442 .log_err();
443 }
444 }));
445 platform_window.on_moved(Box::new({
446 let mut cx = cx.to_async();
447 move || {
448 handle
449 .update(&mut cx, |_, cx| cx.window_bounds_changed())
450 .log_err();
451 }
452 }));
453 platform_window.on_appearance_changed(Box::new({
454 let mut cx = cx.to_async();
455 move || {
456 handle
457 .update(&mut cx, |_, cx| cx.appearance_changed())
458 .log_err();
459 }
460 }));
461 platform_window.on_active_status_change(Box::new({
462 let mut cx = cx.to_async();
463 move |active| {
464 handle
465 .update(&mut cx, |_, cx| {
466 cx.window.active.set(active);
467 cx.window
468 .activation_observers
469 .clone()
470 .retain(&(), |callback| callback(cx));
471 cx.refresh();
472 })
473 .log_err();
474 }
475 }));
476
477 platform_window.on_input({
478 let mut cx = cx.to_async();
479 Box::new(move |event| {
480 handle
481 .update(&mut cx, |_, cx| cx.dispatch_event(event))
482 .log_err()
483 .unwrap_or(false)
484 })
485 });
486
487 Window {
488 handle,
489 removed: false,
490 platform_window,
491 display_id,
492 sprite_atlas,
493 text_system,
494 rem_size: px(16.),
495 viewport_size: content_size,
496 layout_engine: Some(TaffyLayoutEngine::new()),
497 root_view: None,
498 element_id_stack: GlobalElementId::default(),
499 text_style_stack: Vec::new(),
500 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
501 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
502 next_frame_callbacks,
503 next_hitbox_id: HitboxId::default(),
504 dirty_views: FxHashSet::default(),
505 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
506 focus_listeners: SubscriberSet::new(),
507 focus_lost_listeners: SubscriberSet::new(),
508 default_prevented: true,
509 mouse_position,
510 mouse_hit_test: HitTest::default(),
511 modifiers,
512 scale_factor,
513 bounds_observers: SubscriberSet::new(),
514 appearance,
515 appearance_observers: SubscriberSet::new(),
516 active,
517 dirty,
518 needs_present,
519 last_input_timestamp,
520 refreshing: false,
521 draw_phase: DrawPhase::None,
522 activation_observers: SubscriberSet::new(),
523 focus: None,
524 focus_enabled: true,
525 pending_input: None,
526 prompt: None,
527 }
528 }
529 fn new_focus_listener(
530 &mut self,
531 value: AnyWindowFocusListener,
532 ) -> (Subscription, impl FnOnce()) {
533 self.focus_listeners.insert((), value)
534 }
535}
536
537/// Indicates which region of the window is visible. Content falling outside of this mask will not be
538/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
539/// to leave room to support more complex shapes in the future.
540#[derive(Clone, Debug, Default, PartialEq, Eq)]
541#[repr(C)]
542pub struct ContentMask<P: Clone + Default + Debug> {
543 /// The bounds
544 pub bounds: Bounds<P>,
545}
546
547impl ContentMask<Pixels> {
548 /// Scale the content mask's pixel units by the given scaling factor.
549 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
550 ContentMask {
551 bounds: self.bounds.scale(factor),
552 }
553 }
554
555 /// Intersect the content mask with the given content mask.
556 pub fn intersect(&self, other: &Self) -> Self {
557 let bounds = self.bounds.intersect(&other.bounds);
558 ContentMask { bounds }
559 }
560}
561
562/// Provides access to application state in the context of a single window. Derefs
563/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
564/// an [`AppContext`] and call any [`AppContext`] methods.
565pub struct WindowContext<'a> {
566 pub(crate) app: &'a mut AppContext,
567 pub(crate) window: &'a mut Window,
568}
569
570impl<'a> WindowContext<'a> {
571 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
572 Self { app, window }
573 }
574
575 /// Obtain a handle to the window that belongs to this context.
576 pub fn window_handle(&self) -> AnyWindowHandle {
577 self.window.handle
578 }
579
580 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
581 pub fn refresh(&mut self) {
582 if self.window.draw_phase == DrawPhase::None {
583 self.window.refreshing = true;
584 self.window.dirty.set(true);
585 }
586 }
587
588 /// Close this window.
589 pub fn remove_window(&mut self) {
590 self.window.removed = true;
591 }
592
593 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
594 /// for elements rendered within this window.
595 pub fn focus_handle(&mut self) -> FocusHandle {
596 FocusHandle::new(&self.window.focus_handles)
597 }
598
599 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
600 pub fn focused(&self) -> Option<FocusHandle> {
601 self.window
602 .focus
603 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
604 }
605
606 /// Move focus to the element associated with the given [`FocusHandle`].
607 pub fn focus(&mut self, handle: &FocusHandle) {
608 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
609 return;
610 }
611
612 self.window.focus = Some(handle.id);
613 self.window
614 .rendered_frame
615 .dispatch_tree
616 .clear_pending_keystrokes();
617 self.refresh();
618 }
619
620 /// Remove focus from all elements within this context's window.
621 pub fn blur(&mut self) {
622 if !self.window.focus_enabled {
623 return;
624 }
625
626 self.window.focus = None;
627 self.refresh();
628 }
629
630 /// Blur the window and don't allow anything in it to be focused again.
631 pub fn disable_focus(&mut self) {
632 self.blur();
633 self.window.focus_enabled = false;
634 }
635
636 /// Accessor for the text system.
637 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
638 &self.window.text_system
639 }
640
641 /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
642 pub fn text_style(&self) -> TextStyle {
643 let mut style = TextStyle::default();
644 for refinement in &self.window.text_style_stack {
645 style.refine(refinement);
646 }
647 style
648 }
649
650 /// Dispatch the given action on the currently focused element.
651 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
652 let focus_handle = self.focused();
653
654 let window = self.window.handle;
655 self.app.defer(move |cx| {
656 cx.propagate_event = true;
657 window
658 .update(cx, |_, cx| {
659 let node_id = focus_handle
660 .and_then(|handle| {
661 cx.window
662 .rendered_frame
663 .dispatch_tree
664 .focusable_node_id(handle.id)
665 })
666 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
667
668 cx.dispatch_action_on_node(node_id, action.as_ref());
669 })
670 .log_err();
671 if cx.propagate_event {
672 cx.dispatch_global_action(action.as_ref());
673 }
674 })
675 }
676
677 pub(crate) fn dispatch_keystroke_observers(
678 &mut self,
679 event: &dyn Any,
680 action: Option<Box<dyn Action>>,
681 ) {
682 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
683 return;
684 };
685
686 self.keystroke_observers
687 .clone()
688 .retain(&(), move |callback| {
689 (callback)(
690 &KeystrokeEvent {
691 keystroke: key_down_event.keystroke.clone(),
692 action: action.as_ref().map(|action| action.boxed_clone()),
693 },
694 self,
695 );
696 true
697 });
698 }
699
700 pub(crate) fn clear_pending_keystrokes(&mut self) {
701 self.window
702 .rendered_frame
703 .dispatch_tree
704 .clear_pending_keystrokes();
705 self.window
706 .next_frame
707 .dispatch_tree
708 .clear_pending_keystrokes();
709 }
710
711 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
712 /// that are currently on the stack to be returned to the app.
713 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
714 let handle = self.window.handle;
715 self.app.defer(move |cx| {
716 handle.update(cx, |_, cx| f(cx)).ok();
717 });
718 }
719
720 /// Subscribe to events emitted by a model or view.
721 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
722 /// 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.
723 pub fn subscribe<Emitter, E, Evt>(
724 &mut self,
725 entity: &E,
726 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
727 ) -> Subscription
728 where
729 Emitter: EventEmitter<Evt>,
730 E: Entity<Emitter>,
731 Evt: 'static,
732 {
733 let entity_id = entity.entity_id();
734 let entity = entity.downgrade();
735 let window_handle = self.window.handle;
736 self.app.new_subscription(
737 entity_id,
738 (
739 TypeId::of::<Evt>(),
740 Box::new(move |event, cx| {
741 window_handle
742 .update(cx, |_, cx| {
743 if let Some(handle) = E::upgrade_from(&entity) {
744 let event = event.downcast_ref().expect("invalid event type");
745 on_event(handle, event, cx);
746 true
747 } else {
748 false
749 }
750 })
751 .unwrap_or(false)
752 }),
753 ),
754 )
755 }
756
757 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
758 /// await points in async code.
759 pub fn to_async(&self) -> AsyncWindowContext {
760 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
761 }
762
763 /// Schedule the given closure to be run directly after the current frame is rendered.
764 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
765 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
766 }
767
768 /// Spawn the future returned by the given closure on the application thread pool.
769 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
770 /// use within your future.
771 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
772 where
773 R: 'static,
774 Fut: Future<Output = R> + 'static,
775 {
776 self.app
777 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
778 }
779
780 /// Updates the global of the given type. The given closure is given simultaneous mutable
781 /// access both to the global and the context.
782 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
783 where
784 G: Global,
785 {
786 let mut global = self.app.lease_global::<G>();
787 let result = f(&mut global, self);
788 self.app.end_global_lease(global);
789 result
790 }
791
792 fn window_bounds_changed(&mut self) {
793 self.window.scale_factor = self.window.platform_window.scale_factor();
794 self.window.viewport_size = self.window.platform_window.content_size();
795 self.window.display_id = self.window.platform_window.display().id();
796 self.refresh();
797
798 self.window
799 .bounds_observers
800 .clone()
801 .retain(&(), |callback| callback(self));
802 }
803
804 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
805 pub fn window_bounds(&self) -> Bounds<GlobalPixels> {
806 self.window.platform_window.bounds()
807 }
808
809 /// Retusn whether or not the window is currently fullscreen
810 pub fn is_full_screen(&self) -> bool {
811 self.window.platform_window.is_full_screen()
812 }
813
814 fn appearance_changed(&mut self) {
815 self.window.appearance = self.window.platform_window.appearance();
816
817 self.window
818 .appearance_observers
819 .clone()
820 .retain(&(), |callback| callback(self));
821 }
822
823 /// Returns the appearance of the current window.
824 pub fn appearance(&self) -> WindowAppearance {
825 self.window.appearance
826 }
827
828 /// Returns the size of the drawable area within the window.
829 pub fn viewport_size(&self) -> Size<Pixels> {
830 self.window.viewport_size
831 }
832
833 /// Returns whether this window is focused by the operating system (receiving key events).
834 pub fn is_window_active(&self) -> bool {
835 self.window.active.get()
836 }
837
838 /// Toggle zoom on the window.
839 pub fn zoom_window(&self) {
840 self.window.platform_window.zoom();
841 }
842
843 /// Updates the window's title at the platform level.
844 pub fn set_window_title(&mut self, title: &str) {
845 self.window.platform_window.set_title(title);
846 }
847
848 /// Mark the window as dirty at the platform level.
849 pub fn set_window_edited(&mut self, edited: bool) {
850 self.window.platform_window.set_edited(edited);
851 }
852
853 /// Determine the display on which the window is visible.
854 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
855 self.platform
856 .displays()
857 .into_iter()
858 .find(|display| display.id() == self.window.display_id)
859 }
860
861 /// Show the platform character palette.
862 pub fn show_character_palette(&self) {
863 self.window.platform_window.show_character_palette();
864 }
865
866 /// The scale factor of the display associated with the window. For example, it could
867 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
868 /// be rendered as two pixels on screen.
869 pub fn scale_factor(&self) -> f32 {
870 self.window.scale_factor
871 }
872
873 /// The size of an em for the base font of the application. Adjusting this value allows the
874 /// UI to scale, just like zooming a web page.
875 pub fn rem_size(&self) -> Pixels {
876 self.window.rem_size
877 }
878
879 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
880 /// UI to scale, just like zooming a web page.
881 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
882 self.window.rem_size = rem_size.into();
883 }
884
885 /// The line height associated with the current text style.
886 pub fn line_height(&self) -> Pixels {
887 let rem_size = self.rem_size();
888 let text_style = self.text_style();
889 text_style
890 .line_height
891 .to_pixels(text_style.font_size, rem_size)
892 }
893
894 /// Call to prevent the default action of an event. Currently only used to prevent
895 /// parent elements from becoming focused on mouse down.
896 pub fn prevent_default(&mut self) {
897 self.window.default_prevented = true;
898 }
899
900 /// Obtain whether default has been prevented for the event currently being dispatched.
901 pub fn default_prevented(&self) -> bool {
902 self.window.default_prevented
903 }
904
905 /// Determine whether the given action is available along the dispatch path to the currently focused element.
906 pub fn is_action_available(&self, action: &dyn Action) -> bool {
907 let target = self
908 .focused()
909 .and_then(|focused_handle| {
910 self.window
911 .rendered_frame
912 .dispatch_tree
913 .focusable_node_id(focused_handle.id)
914 })
915 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
916 self.window
917 .rendered_frame
918 .dispatch_tree
919 .is_action_available(action, target)
920 }
921
922 /// The position of the mouse relative to the window.
923 pub fn mouse_position(&self) -> Point<Pixels> {
924 self.window.mouse_position
925 }
926
927 /// The current state of the keyboard's modifiers
928 pub fn modifiers(&self) -> Modifiers {
929 self.window.modifiers
930 }
931
932 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
933 /// the contents of the new [Scene], use [present].
934 #[profiling::function]
935 pub fn draw(&mut self) {
936 self.window.dirty.set(false);
937
938 // Restore the previously-used input handler.
939 if let Some(input_handler) = self.window.platform_window.take_input_handler() {
940 self.window
941 .rendered_frame
942 .input_handlers
943 .push(Some(input_handler));
944 }
945
946 self.with_element_context(|cx| cx.draw_roots());
947 self.window.dirty_views.clear();
948
949 self.window
950 .next_frame
951 .dispatch_tree
952 .preserve_pending_keystrokes(
953 &mut self.window.rendered_frame.dispatch_tree,
954 self.window.focus,
955 );
956 self.window.next_frame.focus = self.window.focus;
957 self.window.next_frame.window_active = self.window.active.get();
958
959 // Set the cursor only if we're the active window.
960 if self.is_window_active() {
961 let cursor_style = self.compute_cursor_style().unwrap_or(CursorStyle::Arrow);
962 self.platform.set_cursor_style(cursor_style);
963 }
964
965 // Register requested input handler with the platform window.
966 if let Some(input_handler) = self.window.next_frame.input_handlers.pop() {
967 self.window
968 .platform_window
969 .set_input_handler(input_handler.unwrap());
970 }
971
972 self.window.layout_engine.as_mut().unwrap().clear();
973 self.text_system().finish_frame();
974 self.window
975 .next_frame
976 .finish(&mut self.window.rendered_frame);
977 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
978 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
979 if percentage >= 80. {
980 log::warn!("elevated element arena occupation: {}.", percentage);
981 }
982 element_arena.clear();
983 });
984
985 self.window.draw_phase = DrawPhase::Focus;
986 let previous_focus_path = self.window.rendered_frame.focus_path();
987 let previous_window_active = self.window.rendered_frame.window_active;
988 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
989 self.window.next_frame.clear();
990 let current_focus_path = self.window.rendered_frame.focus_path();
991 let current_window_active = self.window.rendered_frame.window_active;
992
993 if previous_focus_path != current_focus_path
994 || previous_window_active != current_window_active
995 {
996 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
997 self.window
998 .focus_lost_listeners
999 .clone()
1000 .retain(&(), |listener| listener(self));
1001 }
1002
1003 let event = FocusEvent {
1004 previous_focus_path: if previous_window_active {
1005 previous_focus_path
1006 } else {
1007 Default::default()
1008 },
1009 current_focus_path: if current_window_active {
1010 current_focus_path
1011 } else {
1012 Default::default()
1013 },
1014 };
1015 self.window
1016 .focus_listeners
1017 .clone()
1018 .retain(&(), |listener| listener(&event, self));
1019 }
1020 self.window.refreshing = false;
1021 self.window.draw_phase = DrawPhase::None;
1022 self.window.needs_present.set(true);
1023 }
1024
1025 #[profiling::function]
1026 fn present(&self) {
1027 self.window
1028 .platform_window
1029 .draw(&self.window.rendered_frame.scene);
1030 self.window.needs_present.set(false);
1031 profiling::finish_frame!();
1032 }
1033
1034 fn compute_cursor_style(&mut self) -> Option<CursorStyle> {
1035 // TODO: maybe we should have a HashMap keyed by HitboxId.
1036 let request = self
1037 .window
1038 .next_frame
1039 .cursor_styles
1040 .iter()
1041 .rev()
1042 .find(|request| request.hitbox_id.is_hovered(self))?;
1043 Some(request.style)
1044 }
1045
1046 /// Dispatch a given keystroke as though the user had typed it.
1047 /// You can create a keystroke with Keystroke::parse("").
1048 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
1049 let keystroke = keystroke.with_simulated_ime();
1050 if self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
1051 keystroke: keystroke.clone(),
1052 is_held: false,
1053 })) {
1054 return true;
1055 }
1056
1057 if let Some(input) = keystroke.ime_key {
1058 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1059 input_handler.dispatch_input(&input, self);
1060 self.window.platform_window.set_input_handler(input_handler);
1061 return true;
1062 }
1063 }
1064
1065 false
1066 }
1067
1068 /// Represent this action as a key binding string, to display in the UI.
1069 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
1070 self.bindings_for_action(action)
1071 .into_iter()
1072 .next()
1073 .map(|binding| {
1074 binding
1075 .keystrokes()
1076 .iter()
1077 .map(ToString::to_string)
1078 .collect::<Vec<_>>()
1079 .join(" ")
1080 })
1081 .unwrap_or_else(|| action.name().to_string())
1082 }
1083
1084 /// Dispatch a mouse or keyboard event on the window.
1085 #[profiling::function]
1086 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1087 self.window.last_input_timestamp.set(Instant::now());
1088 // Handlers may set this to false by calling `stop_propagation`.
1089 self.app.propagate_event = true;
1090 // Handlers may set this to true by calling `prevent_default`.
1091 self.window.default_prevented = false;
1092
1093 let event = match event {
1094 // Track the mouse position with our own state, since accessing the platform
1095 // API for the mouse position can only occur on the main thread.
1096 PlatformInput::MouseMove(mouse_move) => {
1097 self.window.mouse_position = mouse_move.position;
1098 self.window.modifiers = mouse_move.modifiers;
1099 PlatformInput::MouseMove(mouse_move)
1100 }
1101 PlatformInput::MouseDown(mouse_down) => {
1102 self.window.mouse_position = mouse_down.position;
1103 self.window.modifiers = mouse_down.modifiers;
1104 PlatformInput::MouseDown(mouse_down)
1105 }
1106 PlatformInput::MouseUp(mouse_up) => {
1107 self.window.mouse_position = mouse_up.position;
1108 self.window.modifiers = mouse_up.modifiers;
1109 PlatformInput::MouseUp(mouse_up)
1110 }
1111 PlatformInput::MouseExited(mouse_exited) => {
1112 self.window.modifiers = mouse_exited.modifiers;
1113 PlatformInput::MouseExited(mouse_exited)
1114 }
1115 PlatformInput::ModifiersChanged(modifiers_changed) => {
1116 self.window.modifiers = modifiers_changed.modifiers;
1117 PlatformInput::ModifiersChanged(modifiers_changed)
1118 }
1119 PlatformInput::ScrollWheel(scroll_wheel) => {
1120 self.window.mouse_position = scroll_wheel.position;
1121 self.window.modifiers = scroll_wheel.modifiers;
1122 PlatformInput::ScrollWheel(scroll_wheel)
1123 }
1124 // Translate dragging and dropping of external files from the operating system
1125 // to internal drag and drop events.
1126 PlatformInput::FileDrop(file_drop) => match file_drop {
1127 FileDropEvent::Entered { position, paths } => {
1128 self.window.mouse_position = position;
1129 if self.active_drag.is_none() {
1130 self.active_drag = Some(AnyDrag {
1131 value: Box::new(paths.clone()),
1132 view: self.new_view(|_| paths).into(),
1133 cursor_offset: position,
1134 });
1135 }
1136 PlatformInput::MouseMove(MouseMoveEvent {
1137 position,
1138 pressed_button: Some(MouseButton::Left),
1139 modifiers: Modifiers::default(),
1140 })
1141 }
1142 FileDropEvent::Pending { position } => {
1143 self.window.mouse_position = position;
1144 PlatformInput::MouseMove(MouseMoveEvent {
1145 position,
1146 pressed_button: Some(MouseButton::Left),
1147 modifiers: Modifiers::default(),
1148 })
1149 }
1150 FileDropEvent::Submit { position } => {
1151 self.activate(true);
1152 self.window.mouse_position = position;
1153 PlatformInput::MouseUp(MouseUpEvent {
1154 button: MouseButton::Left,
1155 position,
1156 modifiers: Modifiers::default(),
1157 click_count: 1,
1158 })
1159 }
1160 FileDropEvent::Exited => {
1161 self.active_drag.take();
1162 PlatformInput::FileDrop(FileDropEvent::Exited)
1163 }
1164 },
1165 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1166 };
1167
1168 if let Some(any_mouse_event) = event.mouse_event() {
1169 self.dispatch_mouse_event(any_mouse_event);
1170 } else if let Some(any_key_event) = event.keyboard_event() {
1171 self.dispatch_key_event(any_key_event);
1172 }
1173
1174 !self.app.propagate_event
1175 }
1176
1177 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1178 self.window.mouse_hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
1179
1180 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
1181 self.with_element_context(|cx| {
1182 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1183 // special purposes, such as detecting events outside of a given Bounds.
1184 for listener in &mut mouse_listeners {
1185 let listener = listener.as_mut().unwrap();
1186 listener(event, DispatchPhase::Capture, cx);
1187 if !cx.app.propagate_event {
1188 break;
1189 }
1190 }
1191
1192 // Bubble phase, where most normal handlers do their work.
1193 if cx.app.propagate_event {
1194 for listener in mouse_listeners.iter_mut().rev() {
1195 let listener = listener.as_mut().unwrap();
1196 listener(event, DispatchPhase::Bubble, cx);
1197 if !cx.app.propagate_event {
1198 break;
1199 }
1200 }
1201 }
1202 });
1203 self.window.rendered_frame.mouse_listeners = mouse_listeners;
1204
1205 if self.app.propagate_event && self.has_active_drag() {
1206 if event.is::<MouseMoveEvent>() {
1207 // If this was a mouse move event, redraw the window so that the
1208 // active drag can follow the mouse cursor.
1209 self.refresh();
1210 } else if event.is::<MouseUpEvent>() {
1211 // If this was a mouse up event, cancel the active drag and redraw
1212 // the window.
1213 self.active_drag = None;
1214 self.refresh();
1215 }
1216 }
1217 }
1218
1219 fn dispatch_key_event(&mut self, event: &dyn Any) {
1220 if self.window.dirty.get() {
1221 self.draw();
1222 }
1223
1224 let node_id = self
1225 .window
1226 .focus
1227 .and_then(|focus_id| {
1228 self.window
1229 .rendered_frame
1230 .dispatch_tree
1231 .focusable_node_id(focus_id)
1232 })
1233 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1234
1235 let dispatch_path = self
1236 .window
1237 .rendered_frame
1238 .dispatch_tree
1239 .dispatch_path(node_id);
1240
1241 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1242 let KeymatchResult { bindings, pending } = self
1243 .window
1244 .rendered_frame
1245 .dispatch_tree
1246 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1247
1248 if pending {
1249 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1250 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1251 {
1252 currently_pending = PendingInput::default();
1253 }
1254 currently_pending.focus = self.window.focus;
1255 currently_pending
1256 .keystrokes
1257 .push(key_down_event.keystroke.clone());
1258 for binding in bindings {
1259 currently_pending.bindings.push(binding);
1260 }
1261
1262 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1263 cx.background_executor.timer(Duration::from_secs(1)).await;
1264 cx.update(move |cx| {
1265 cx.clear_pending_keystrokes();
1266 let Some(currently_pending) = cx.window.pending_input.take() else {
1267 return;
1268 };
1269 cx.replay_pending_input(currently_pending)
1270 })
1271 .log_err();
1272 }));
1273
1274 self.window.pending_input = Some(currently_pending);
1275
1276 self.propagate_event = false;
1277 return;
1278 } else if let Some(currently_pending) = self.window.pending_input.take() {
1279 if bindings
1280 .iter()
1281 .all(|binding| !currently_pending.used_by_binding(binding))
1282 {
1283 self.replay_pending_input(currently_pending)
1284 }
1285 }
1286
1287 if !bindings.is_empty() {
1288 self.clear_pending_keystrokes();
1289 }
1290
1291 self.propagate_event = true;
1292 for binding in bindings {
1293 self.dispatch_action_on_node(node_id, binding.action.as_ref());
1294 if !self.propagate_event {
1295 self.dispatch_keystroke_observers(event, Some(binding.action));
1296 return;
1297 }
1298 }
1299 }
1300
1301 self.dispatch_key_down_up_event(event, &dispatch_path);
1302 if !self.propagate_event {
1303 return;
1304 }
1305
1306 self.dispatch_keystroke_observers(event, None);
1307 }
1308
1309 fn dispatch_key_down_up_event(
1310 &mut self,
1311 event: &dyn Any,
1312 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1313 ) {
1314 // Capture phase
1315 for node_id in dispatch_path {
1316 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1317
1318 for key_listener in node.key_listeners.clone() {
1319 self.with_element_context(|cx| {
1320 key_listener(event, DispatchPhase::Capture, cx);
1321 });
1322 if !self.propagate_event {
1323 return;
1324 }
1325 }
1326 }
1327
1328 // Bubble phase
1329 for node_id in dispatch_path.iter().rev() {
1330 // Handle low level key events
1331 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1332 for key_listener in node.key_listeners.clone() {
1333 self.with_element_context(|cx| {
1334 key_listener(event, DispatchPhase::Bubble, cx);
1335 });
1336 if !self.propagate_event {
1337 return;
1338 }
1339 }
1340 }
1341 }
1342
1343 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1344 pub fn has_pending_keystrokes(&self) -> bool {
1345 self.window
1346 .rendered_frame
1347 .dispatch_tree
1348 .has_pending_keystrokes()
1349 }
1350
1351 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1352 let node_id = self
1353 .window
1354 .focus
1355 .and_then(|focus_id| {
1356 self.window
1357 .rendered_frame
1358 .dispatch_tree
1359 .focusable_node_id(focus_id)
1360 })
1361 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1362
1363 if self.window.focus != currently_pending.focus {
1364 return;
1365 }
1366
1367 let input = currently_pending.input();
1368
1369 self.propagate_event = true;
1370 for binding in currently_pending.bindings {
1371 self.dispatch_action_on_node(node_id, binding.action.as_ref());
1372 if !self.propagate_event {
1373 return;
1374 }
1375 }
1376
1377 let dispatch_path = self
1378 .window
1379 .rendered_frame
1380 .dispatch_tree
1381 .dispatch_path(node_id);
1382
1383 for keystroke in currently_pending.keystrokes {
1384 let event = KeyDownEvent {
1385 keystroke,
1386 is_held: false,
1387 };
1388
1389 self.dispatch_key_down_up_event(&event, &dispatch_path);
1390 if !self.propagate_event {
1391 return;
1392 }
1393 }
1394
1395 if !input.is_empty() {
1396 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1397 input_handler.dispatch_input(&input, self);
1398 self.window.platform_window.set_input_handler(input_handler)
1399 }
1400 }
1401 }
1402
1403 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
1404 let dispatch_path = self
1405 .window
1406 .rendered_frame
1407 .dispatch_tree
1408 .dispatch_path(node_id);
1409
1410 // Capture phase
1411 for node_id in &dispatch_path {
1412 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1413 for DispatchActionListener {
1414 action_type,
1415 listener,
1416 } in node.action_listeners.clone()
1417 {
1418 let any_action = action.as_any();
1419 if action_type == any_action.type_id() {
1420 self.with_element_context(|cx| {
1421 listener(any_action, DispatchPhase::Capture, cx);
1422 });
1423
1424 if !self.propagate_event {
1425 return;
1426 }
1427 }
1428 }
1429 }
1430 // Bubble phase
1431 for node_id in dispatch_path.iter().rev() {
1432 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1433 for DispatchActionListener {
1434 action_type,
1435 listener,
1436 } in node.action_listeners.clone()
1437 {
1438 let any_action = action.as_any();
1439 if action_type == any_action.type_id() {
1440 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1441
1442 self.with_element_context(|cx| {
1443 listener(any_action, DispatchPhase::Bubble, cx);
1444 });
1445
1446 if !self.propagate_event {
1447 return;
1448 }
1449 }
1450 }
1451 }
1452 }
1453
1454 /// Register the given handler to be invoked whenever the global of the given type
1455 /// is updated.
1456 pub fn observe_global<G: Global>(
1457 &mut self,
1458 f: impl Fn(&mut WindowContext<'_>) + 'static,
1459 ) -> Subscription {
1460 let window_handle = self.window.handle;
1461 let (subscription, activate) = self.global_observers.insert(
1462 TypeId::of::<G>(),
1463 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1464 );
1465 self.app.defer(move |_| activate());
1466 subscription
1467 }
1468
1469 /// Focus the current window and bring it to the foreground at the platform level.
1470 pub fn activate_window(&self) {
1471 self.window.platform_window.activate();
1472 }
1473
1474 /// Minimize the current window at the platform level.
1475 pub fn minimize_window(&self) {
1476 self.window.platform_window.minimize();
1477 }
1478
1479 /// Toggle full screen status on the current window at the platform level.
1480 pub fn toggle_full_screen(&self) {
1481 self.window.platform_window.toggle_full_screen();
1482 }
1483
1484 /// Present a platform dialog.
1485 /// The provided message will be presented, along with buttons for each answer.
1486 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1487 pub fn prompt(
1488 &mut self,
1489 level: PromptLevel,
1490 message: &str,
1491 detail: Option<&str>,
1492 answers: &[&str],
1493 ) -> oneshot::Receiver<usize> {
1494 let prompt_builder = self.app.prompt_builder.take();
1495 let Some(prompt_builder) = prompt_builder else {
1496 unreachable!("Re-entrant window prompting is not supported by GPUI");
1497 };
1498
1499 let receiver = match &prompt_builder {
1500 PromptBuilder::Default => self
1501 .window
1502 .platform_window
1503 .prompt(level, message, detail, answers)
1504 .unwrap_or_else(|| {
1505 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
1506 }),
1507 PromptBuilder::Custom(_) => {
1508 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
1509 }
1510 };
1511
1512 self.app.prompt_builder = Some(prompt_builder);
1513
1514 receiver
1515 }
1516
1517 fn build_custom_prompt(
1518 &mut self,
1519 prompt_builder: &PromptBuilder,
1520 level: PromptLevel,
1521 message: &str,
1522 detail: Option<&str>,
1523 answers: &[&str],
1524 ) -> oneshot::Receiver<usize> {
1525 let (sender, receiver) = oneshot::channel();
1526 let handle = PromptHandle::new(sender);
1527 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
1528 self.window.prompt = Some(handle);
1529 receiver
1530 }
1531
1532 /// Returns all available actions for the focused element.
1533 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1534 let node_id = self
1535 .window
1536 .focus
1537 .and_then(|focus_id| {
1538 self.window
1539 .rendered_frame
1540 .dispatch_tree
1541 .focusable_node_id(focus_id)
1542 })
1543 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1544
1545 let mut actions = self
1546 .window
1547 .rendered_frame
1548 .dispatch_tree
1549 .available_actions(node_id);
1550 for action_type in self.global_action_listeners.keys() {
1551 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
1552 let action = self.actions.build_action_type(action_type).ok();
1553 if let Some(action) = action {
1554 actions.insert(ix, action);
1555 }
1556 }
1557 }
1558 actions
1559 }
1560
1561 /// Returns key bindings that invoke the given action on the currently focused element.
1562 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1563 self.window
1564 .rendered_frame
1565 .dispatch_tree
1566 .bindings_for_action(
1567 action,
1568 &self.window.rendered_frame.dispatch_tree.context_stack,
1569 )
1570 }
1571
1572 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1573 pub fn bindings_for_action_in(
1574 &self,
1575 action: &dyn Action,
1576 focus_handle: &FocusHandle,
1577 ) -> Vec<KeyBinding> {
1578 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1579
1580 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1581 return vec![];
1582 };
1583 let context_stack: Vec<_> = dispatch_tree
1584 .dispatch_path(node_id)
1585 .into_iter()
1586 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1587 .collect();
1588 dispatch_tree.bindings_for_action(action, &context_stack)
1589 }
1590
1591 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1592 pub fn listener_for<V: Render, E>(
1593 &self,
1594 view: &View<V>,
1595 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1596 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1597 let view = view.downgrade();
1598 move |e: &E, cx: &mut WindowContext| {
1599 view.update(cx, |view, cx| f(view, e, cx)).ok();
1600 }
1601 }
1602
1603 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1604 pub fn handler_for<V: Render>(
1605 &self,
1606 view: &View<V>,
1607 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1608 ) -> impl Fn(&mut WindowContext) {
1609 let view = view.downgrade();
1610 move |cx: &mut WindowContext| {
1611 view.update(cx, |view, cx| f(view, cx)).ok();
1612 }
1613 }
1614
1615 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1616 /// If the callback returns false, the window won't be closed.
1617 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1618 let mut this = self.to_async();
1619 self.window
1620 .platform_window
1621 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
1622 }
1623
1624 /// Register an action listener on the window for the next frame. The type of action
1625 /// is determined by the first parameter of the given listener. When the next frame is rendered
1626 /// the listener will be cleared.
1627 ///
1628 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1629 /// a specific need to register a global listener.
1630 pub fn on_action(
1631 &mut self,
1632 action_type: TypeId,
1633 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1634 ) {
1635 self.window
1636 .next_frame
1637 .dispatch_tree
1638 .on_action(action_type, Rc::new(listener));
1639 }
1640}
1641
1642impl Context for WindowContext<'_> {
1643 type Result<T> = T;
1644
1645 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1646 where
1647 T: 'static,
1648 {
1649 let slot = self.app.entities.reserve();
1650 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1651 self.entities.insert(slot, model)
1652 }
1653
1654 fn update_model<T: 'static, R>(
1655 &mut self,
1656 model: &Model<T>,
1657 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1658 ) -> R {
1659 let mut entity = self.entities.lease(model);
1660 let result = update(
1661 &mut *entity,
1662 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1663 );
1664 self.entities.end_lease(entity);
1665 result
1666 }
1667
1668 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1669 where
1670 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1671 {
1672 if window == self.window.handle {
1673 let root_view = self.window.root_view.clone().unwrap();
1674 Ok(update(root_view, self))
1675 } else {
1676 window.update(self.app, update)
1677 }
1678 }
1679
1680 fn read_model<T, R>(
1681 &self,
1682 handle: &Model<T>,
1683 read: impl FnOnce(&T, &AppContext) -> R,
1684 ) -> Self::Result<R>
1685 where
1686 T: 'static,
1687 {
1688 let entity = self.entities.read(handle);
1689 read(entity, &*self.app)
1690 }
1691
1692 fn read_window<T, R>(
1693 &self,
1694 window: &WindowHandle<T>,
1695 read: impl FnOnce(View<T>, &AppContext) -> R,
1696 ) -> Result<R>
1697 where
1698 T: 'static,
1699 {
1700 if window.any_handle == self.window.handle {
1701 let root_view = self
1702 .window
1703 .root_view
1704 .clone()
1705 .unwrap()
1706 .downcast::<T>()
1707 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1708 Ok(read(root_view, self))
1709 } else {
1710 self.app.read_window(window, read)
1711 }
1712 }
1713}
1714
1715impl VisualContext for WindowContext<'_> {
1716 fn new_view<V>(
1717 &mut self,
1718 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1719 ) -> Self::Result<View<V>>
1720 where
1721 V: 'static + Render,
1722 {
1723 let slot = self.app.entities.reserve();
1724 let view = View {
1725 model: slot.clone(),
1726 };
1727 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1728 let entity = build_view_state(&mut cx);
1729 cx.entities.insert(slot, entity);
1730
1731 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1732 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1733 cx.new_view_observers.clone().retain(&tid, |observer| {
1734 let any_view = view.clone();
1735 (observer)(any_view, cx);
1736 true
1737 });
1738 }
1739 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1740
1741 view
1742 }
1743
1744 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1745 fn update_view<T: 'static, R>(
1746 &mut self,
1747 view: &View<T>,
1748 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1749 ) -> Self::Result<R> {
1750 let mut lease = self.app.entities.lease(&view.model);
1751 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1752 let result = update(&mut *lease, &mut cx);
1753 cx.app.entities.end_lease(lease);
1754 result
1755 }
1756
1757 fn replace_root_view<V>(
1758 &mut self,
1759 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1760 ) -> Self::Result<View<V>>
1761 where
1762 V: 'static + Render,
1763 {
1764 let view = self.new_view(build_view);
1765 self.window.root_view = Some(view.clone().into());
1766 self.refresh();
1767 view
1768 }
1769
1770 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1771 self.update_view(view, |view, cx| {
1772 view.focus_handle(cx).clone().focus(cx);
1773 })
1774 }
1775
1776 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1777 where
1778 V: ManagedView,
1779 {
1780 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1781 }
1782}
1783
1784impl<'a> std::ops::Deref for WindowContext<'a> {
1785 type Target = AppContext;
1786
1787 fn deref(&self) -> &Self::Target {
1788 self.app
1789 }
1790}
1791
1792impl<'a> std::ops::DerefMut for WindowContext<'a> {
1793 fn deref_mut(&mut self) -> &mut Self::Target {
1794 self.app
1795 }
1796}
1797
1798impl<'a> Borrow<AppContext> for WindowContext<'a> {
1799 fn borrow(&self) -> &AppContext {
1800 self.app
1801 }
1802}
1803
1804impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1805 fn borrow_mut(&mut self) -> &mut AppContext {
1806 self.app
1807 }
1808}
1809
1810/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1811pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1812 #[doc(hidden)]
1813 fn app_mut(&mut self) -> &mut AppContext {
1814 self.borrow_mut()
1815 }
1816
1817 #[doc(hidden)]
1818 fn app(&self) -> &AppContext {
1819 self.borrow()
1820 }
1821
1822 #[doc(hidden)]
1823 fn window(&self) -> &Window {
1824 self.borrow()
1825 }
1826
1827 #[doc(hidden)]
1828 fn window_mut(&mut self) -> &mut Window {
1829 self.borrow_mut()
1830 }
1831}
1832
1833impl Borrow<Window> for WindowContext<'_> {
1834 fn borrow(&self) -> &Window {
1835 self.window
1836 }
1837}
1838
1839impl BorrowMut<Window> for WindowContext<'_> {
1840 fn borrow_mut(&mut self) -> &mut Window {
1841 self.window
1842 }
1843}
1844
1845impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1846
1847/// Provides access to application state that is specialized for a particular [`View`].
1848/// Allows you to interact with focus, emit events, etc.
1849/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1850/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1851pub struct ViewContext<'a, V> {
1852 window_cx: WindowContext<'a>,
1853 view: &'a View<V>,
1854}
1855
1856impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1857 fn borrow(&self) -> &AppContext {
1858 &*self.window_cx.app
1859 }
1860}
1861
1862impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1863 fn borrow_mut(&mut self) -> &mut AppContext {
1864 &mut *self.window_cx.app
1865 }
1866}
1867
1868impl<V> Borrow<Window> for ViewContext<'_, V> {
1869 fn borrow(&self) -> &Window {
1870 &*self.window_cx.window
1871 }
1872}
1873
1874impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1875 fn borrow_mut(&mut self) -> &mut Window {
1876 &mut *self.window_cx.window
1877 }
1878}
1879
1880impl<'a, V: 'static> ViewContext<'a, V> {
1881 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1882 Self {
1883 window_cx: WindowContext::new(app, window),
1884 view,
1885 }
1886 }
1887
1888 /// Get the entity_id of this view.
1889 pub fn entity_id(&self) -> EntityId {
1890 self.view.entity_id()
1891 }
1892
1893 /// Get the view pointer underlying this context.
1894 pub fn view(&self) -> &View<V> {
1895 self.view
1896 }
1897
1898 /// Get the model underlying this view.
1899 pub fn model(&self) -> &Model<V> {
1900 &self.view.model
1901 }
1902
1903 /// Access the underlying window context.
1904 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1905 &mut self.window_cx
1906 }
1907
1908 /// Sets a given callback to be run on the next frame.
1909 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1910 where
1911 V: 'static,
1912 {
1913 let view = self.view().clone();
1914 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1915 }
1916
1917 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1918 /// that are currently on the stack to be returned to the app.
1919 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1920 let view = self.view().downgrade();
1921 self.window_cx.defer(move |cx| {
1922 view.update(cx, f).ok();
1923 });
1924 }
1925
1926 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1927 pub fn observe<V2, E>(
1928 &mut self,
1929 entity: &E,
1930 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1931 ) -> Subscription
1932 where
1933 V2: 'static,
1934 V: 'static,
1935 E: Entity<V2>,
1936 {
1937 let view = self.view().downgrade();
1938 let entity_id = entity.entity_id();
1939 let entity = entity.downgrade();
1940 let window_handle = self.window.handle;
1941 self.app.new_observer(
1942 entity_id,
1943 Box::new(move |cx| {
1944 window_handle
1945 .update(cx, |_, cx| {
1946 if let Some(handle) = E::upgrade_from(&entity) {
1947 view.update(cx, |this, cx| on_notify(this, handle, cx))
1948 .is_ok()
1949 } else {
1950 false
1951 }
1952 })
1953 .unwrap_or(false)
1954 }),
1955 )
1956 }
1957
1958 /// Subscribe to events emitted by another model or view.
1959 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1960 /// 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.
1961 pub fn subscribe<V2, E, Evt>(
1962 &mut self,
1963 entity: &E,
1964 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1965 ) -> Subscription
1966 where
1967 V2: EventEmitter<Evt>,
1968 E: Entity<V2>,
1969 Evt: 'static,
1970 {
1971 let view = self.view().downgrade();
1972 let entity_id = entity.entity_id();
1973 let handle = entity.downgrade();
1974 let window_handle = self.window.handle;
1975 self.app.new_subscription(
1976 entity_id,
1977 (
1978 TypeId::of::<Evt>(),
1979 Box::new(move |event, cx| {
1980 window_handle
1981 .update(cx, |_, cx| {
1982 if let Some(handle) = E::upgrade_from(&handle) {
1983 let event = event.downcast_ref().expect("invalid event type");
1984 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1985 .is_ok()
1986 } else {
1987 false
1988 }
1989 })
1990 .unwrap_or(false)
1991 }),
1992 ),
1993 )
1994 }
1995
1996 /// Register a callback to be invoked when the view is released.
1997 ///
1998 /// The callback receives a handle to the view's window. This handle may be
1999 /// invalid, if the window was closed before the view was released.
2000 pub fn on_release(
2001 &mut self,
2002 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2003 ) -> Subscription {
2004 let window_handle = self.window.handle;
2005 let (subscription, activate) = self.app.release_listeners.insert(
2006 self.view.model.entity_id,
2007 Box::new(move |this, cx| {
2008 let this = this.downcast_mut().expect("invalid entity type");
2009 on_release(this, window_handle, cx)
2010 }),
2011 );
2012 activate();
2013 subscription
2014 }
2015
2016 /// Register a callback to be invoked when the given Model or View is released.
2017 pub fn observe_release<V2, E>(
2018 &mut self,
2019 entity: &E,
2020 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2021 ) -> Subscription
2022 where
2023 V: 'static,
2024 V2: 'static,
2025 E: Entity<V2>,
2026 {
2027 let view = self.view().downgrade();
2028 let entity_id = entity.entity_id();
2029 let window_handle = self.window.handle;
2030 let (subscription, activate) = self.app.release_listeners.insert(
2031 entity_id,
2032 Box::new(move |entity, cx| {
2033 let entity = entity.downcast_mut().expect("invalid entity type");
2034 let _ = window_handle.update(cx, |_, cx| {
2035 view.update(cx, |this, cx| on_release(this, entity, cx))
2036 });
2037 }),
2038 );
2039 activate();
2040 subscription
2041 }
2042
2043 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2044 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2045 pub fn notify(&mut self) {
2046 for view_id in self
2047 .window
2048 .rendered_frame
2049 .dispatch_tree
2050 .view_path(self.view.entity_id())
2051 .into_iter()
2052 .rev()
2053 {
2054 if !self.window.dirty_views.insert(view_id) {
2055 break;
2056 }
2057 }
2058
2059 if self.window.draw_phase == DrawPhase::None {
2060 self.window_cx.window.dirty.set(true);
2061 self.window_cx.app.push_effect(Effect::Notify {
2062 emitter: self.view.model.entity_id,
2063 });
2064 }
2065 }
2066
2067 /// Register a callback to be invoked when the window is resized.
2068 pub fn observe_window_bounds(
2069 &mut self,
2070 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2071 ) -> Subscription {
2072 let view = self.view.downgrade();
2073 let (subscription, activate) = self.window.bounds_observers.insert(
2074 (),
2075 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2076 );
2077 activate();
2078 subscription
2079 }
2080
2081 /// Register a callback to be invoked when the window is activated or deactivated.
2082 pub fn observe_window_activation(
2083 &mut self,
2084 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2085 ) -> Subscription {
2086 let view = self.view.downgrade();
2087 let (subscription, activate) = self.window.activation_observers.insert(
2088 (),
2089 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2090 );
2091 activate();
2092 subscription
2093 }
2094
2095 /// Registers a callback to be invoked when the window appearance changes.
2096 pub fn observe_window_appearance(
2097 &mut self,
2098 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2099 ) -> Subscription {
2100 let view = self.view.downgrade();
2101 let (subscription, activate) = self.window.appearance_observers.insert(
2102 (),
2103 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2104 );
2105 activate();
2106 subscription
2107 }
2108
2109 /// Register a listener to be called when the given focus handle receives focus.
2110 /// Returns a subscription and persists until the subscription is dropped.
2111 pub fn on_focus(
2112 &mut self,
2113 handle: &FocusHandle,
2114 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2115 ) -> Subscription {
2116 let view = self.view.downgrade();
2117 let focus_id = handle.id;
2118 let (subscription, activate) =
2119 self.window.new_focus_listener(Box::new(move |event, cx| {
2120 view.update(cx, |view, cx| {
2121 if event.previous_focus_path.last() != Some(&focus_id)
2122 && event.current_focus_path.last() == Some(&focus_id)
2123 {
2124 listener(view, cx)
2125 }
2126 })
2127 .is_ok()
2128 }));
2129 self.app.defer(|_| activate());
2130 subscription
2131 }
2132
2133 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2134 /// Returns a subscription and persists until the subscription is dropped.
2135 pub fn on_focus_in(
2136 &mut self,
2137 handle: &FocusHandle,
2138 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2139 ) -> Subscription {
2140 let view = self.view.downgrade();
2141 let focus_id = handle.id;
2142 let (subscription, activate) =
2143 self.window.new_focus_listener(Box::new(move |event, cx| {
2144 view.update(cx, |view, cx| {
2145 if !event.previous_focus_path.contains(&focus_id)
2146 && event.current_focus_path.contains(&focus_id)
2147 {
2148 listener(view, cx)
2149 }
2150 })
2151 .is_ok()
2152 }));
2153 self.app.defer(move |_| activate());
2154 subscription
2155 }
2156
2157 /// Register a listener to be called when the given focus handle loses focus.
2158 /// Returns a subscription and persists until the subscription is dropped.
2159 pub fn on_blur(
2160 &mut self,
2161 handle: &FocusHandle,
2162 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2163 ) -> Subscription {
2164 let view = self.view.downgrade();
2165 let focus_id = handle.id;
2166 let (subscription, activate) =
2167 self.window.new_focus_listener(Box::new(move |event, cx| {
2168 view.update(cx, |view, cx| {
2169 if event.previous_focus_path.last() == Some(&focus_id)
2170 && event.current_focus_path.last() != Some(&focus_id)
2171 {
2172 listener(view, cx)
2173 }
2174 })
2175 .is_ok()
2176 }));
2177 self.app.defer(move |_| activate());
2178 subscription
2179 }
2180
2181 /// Register a listener to be called when nothing in the window has focus.
2182 /// This typically happens when the node that was focused is removed from the tree,
2183 /// and this callback lets you chose a default place to restore the users focus.
2184 /// Returns a subscription and persists until the subscription is dropped.
2185 pub fn on_focus_lost(
2186 &mut self,
2187 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2188 ) -> Subscription {
2189 let view = self.view.downgrade();
2190 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2191 (),
2192 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2193 );
2194 activate();
2195 subscription
2196 }
2197
2198 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2199 /// Returns a subscription and persists until the subscription is dropped.
2200 pub fn on_focus_out(
2201 &mut self,
2202 handle: &FocusHandle,
2203 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2204 ) -> Subscription {
2205 let view = self.view.downgrade();
2206 let focus_id = handle.id;
2207 let (subscription, activate) =
2208 self.window.new_focus_listener(Box::new(move |event, cx| {
2209 view.update(cx, |view, cx| {
2210 if event.previous_focus_path.contains(&focus_id)
2211 && !event.current_focus_path.contains(&focus_id)
2212 {
2213 listener(view, cx)
2214 }
2215 })
2216 .is_ok()
2217 }));
2218 self.app.defer(move |_| activate());
2219 subscription
2220 }
2221
2222 /// Schedule a future to be run asynchronously.
2223 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2224 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2225 /// The returned future will be polled on the main thread.
2226 pub fn spawn<Fut, R>(
2227 &mut self,
2228 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2229 ) -> Task<R>
2230 where
2231 R: 'static,
2232 Fut: Future<Output = R> + 'static,
2233 {
2234 let view = self.view().downgrade();
2235 self.window_cx.spawn(|cx| f(view, cx))
2236 }
2237
2238 /// Updates the global state of the given type.
2239 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2240 where
2241 G: Global,
2242 {
2243 let mut global = self.app.lease_global::<G>();
2244 let result = f(&mut global, self);
2245 self.app.end_global_lease(global);
2246 result
2247 }
2248
2249 /// Register a callback to be invoked when the given global state changes.
2250 pub fn observe_global<G: Global>(
2251 &mut self,
2252 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2253 ) -> Subscription {
2254 let window_handle = self.window.handle;
2255 let view = self.view().downgrade();
2256 let (subscription, activate) = self.global_observers.insert(
2257 TypeId::of::<G>(),
2258 Box::new(move |cx| {
2259 window_handle
2260 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2261 .unwrap_or(false)
2262 }),
2263 );
2264 self.app.defer(move |_| activate());
2265 subscription
2266 }
2267
2268 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2269 pub fn on_action(
2270 &mut self,
2271 action_type: TypeId,
2272 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2273 ) {
2274 let handle = self.view().clone();
2275 self.window_cx
2276 .on_action(action_type, move |action, phase, cx| {
2277 handle.update(cx, |view, cx| {
2278 listener(view, action, phase, cx);
2279 })
2280 });
2281 }
2282
2283 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2284 pub fn emit<Evt>(&mut self, event: Evt)
2285 where
2286 Evt: 'static,
2287 V: EventEmitter<Evt>,
2288 {
2289 let emitter = self.view.model.entity_id;
2290 self.app.push_effect(Effect::Emit {
2291 emitter,
2292 event_type: TypeId::of::<Evt>(),
2293 event: Box::new(event),
2294 });
2295 }
2296
2297 /// Move focus to the current view, assuming it implements [`FocusableView`].
2298 pub fn focus_self(&mut self)
2299 where
2300 V: FocusableView,
2301 {
2302 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2303 }
2304
2305 /// Convenience method for accessing view state in an event callback.
2306 ///
2307 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2308 /// but it's often useful to be able to access view state in these
2309 /// callbacks. This method provides a convenient way to do so.
2310 pub fn listener<E>(
2311 &self,
2312 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2313 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2314 let view = self.view().downgrade();
2315 move |e: &E, cx: &mut WindowContext| {
2316 view.update(cx, |view, cx| f(view, e, cx)).ok();
2317 }
2318 }
2319}
2320
2321impl<V> Context for ViewContext<'_, V> {
2322 type Result<U> = U;
2323
2324 fn new_model<T: 'static>(
2325 &mut self,
2326 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2327 ) -> Model<T> {
2328 self.window_cx.new_model(build_model)
2329 }
2330
2331 fn update_model<T: 'static, R>(
2332 &mut self,
2333 model: &Model<T>,
2334 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2335 ) -> R {
2336 self.window_cx.update_model(model, update)
2337 }
2338
2339 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2340 where
2341 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2342 {
2343 self.window_cx.update_window(window, update)
2344 }
2345
2346 fn read_model<T, R>(
2347 &self,
2348 handle: &Model<T>,
2349 read: impl FnOnce(&T, &AppContext) -> R,
2350 ) -> Self::Result<R>
2351 where
2352 T: 'static,
2353 {
2354 self.window_cx.read_model(handle, read)
2355 }
2356
2357 fn read_window<T, R>(
2358 &self,
2359 window: &WindowHandle<T>,
2360 read: impl FnOnce(View<T>, &AppContext) -> R,
2361 ) -> Result<R>
2362 where
2363 T: 'static,
2364 {
2365 self.window_cx.read_window(window, read)
2366 }
2367}
2368
2369impl<V: 'static> VisualContext for ViewContext<'_, V> {
2370 fn new_view<W: Render + 'static>(
2371 &mut self,
2372 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2373 ) -> Self::Result<View<W>> {
2374 self.window_cx.new_view(build_view_state)
2375 }
2376
2377 fn update_view<V2: 'static, R>(
2378 &mut self,
2379 view: &View<V2>,
2380 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2381 ) -> Self::Result<R> {
2382 self.window_cx.update_view(view, update)
2383 }
2384
2385 fn replace_root_view<W>(
2386 &mut self,
2387 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2388 ) -> Self::Result<View<W>>
2389 where
2390 W: 'static + Render,
2391 {
2392 self.window_cx.replace_root_view(build_view)
2393 }
2394
2395 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2396 self.window_cx.focus_view(view)
2397 }
2398
2399 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2400 self.window_cx.dismiss_view(view)
2401 }
2402}
2403
2404impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2405 type Target = WindowContext<'a>;
2406
2407 fn deref(&self) -> &Self::Target {
2408 &self.window_cx
2409 }
2410}
2411
2412impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2413 fn deref_mut(&mut self) -> &mut Self::Target {
2414 &mut self.window_cx
2415 }
2416}
2417
2418// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2419slotmap::new_key_type! {
2420 /// A unique identifier for a window.
2421 pub struct WindowId;
2422}
2423
2424impl WindowId {
2425 /// Converts this window ID to a `u64`.
2426 pub fn as_u64(&self) -> u64 {
2427 self.0.as_ffi()
2428 }
2429}
2430
2431/// A handle to a window with a specific root view type.
2432/// Note that this does not keep the window alive on its own.
2433#[derive(Deref, DerefMut)]
2434pub struct WindowHandle<V> {
2435 #[deref]
2436 #[deref_mut]
2437 pub(crate) any_handle: AnyWindowHandle,
2438 state_type: PhantomData<V>,
2439}
2440
2441impl<V: 'static + Render> WindowHandle<V> {
2442 /// Creates a new handle from a window ID.
2443 /// This does not check if the root type of the window is `V`.
2444 pub fn new(id: WindowId) -> Self {
2445 WindowHandle {
2446 any_handle: AnyWindowHandle {
2447 id,
2448 state_type: TypeId::of::<V>(),
2449 },
2450 state_type: PhantomData,
2451 }
2452 }
2453
2454 /// Get the root view out of this window.
2455 ///
2456 /// This will fail if the window is closed or if the root view's type does not match `V`.
2457 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2458 where
2459 C: Context,
2460 {
2461 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2462 root_view
2463 .downcast::<V>()
2464 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2465 }))
2466 }
2467
2468 /// Updates the root view of this window.
2469 ///
2470 /// This will fail if the window has been closed or if the root view's type does not match
2471 pub fn update<C, R>(
2472 &self,
2473 cx: &mut C,
2474 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2475 ) -> Result<R>
2476 where
2477 C: Context,
2478 {
2479 cx.update_window(self.any_handle, |root_view, cx| {
2480 let view = root_view
2481 .downcast::<V>()
2482 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2483 Ok(cx.update_view(&view, update))
2484 })?
2485 }
2486
2487 /// Read the root view out of this window.
2488 ///
2489 /// This will fail if the window is closed or if the root view's type does not match `V`.
2490 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2491 let x = cx
2492 .windows
2493 .get(self.id)
2494 .and_then(|window| {
2495 window
2496 .as_ref()
2497 .and_then(|window| window.root_view.clone())
2498 .map(|root_view| root_view.downcast::<V>())
2499 })
2500 .ok_or_else(|| anyhow!("window not found"))?
2501 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2502
2503 Ok(x.read(cx))
2504 }
2505
2506 /// Read the root view out of this window, with a callback
2507 ///
2508 /// This will fail if the window is closed or if the root view's type does not match `V`.
2509 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2510 where
2511 C: Context,
2512 {
2513 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2514 }
2515
2516 /// Read the root view pointer off of this window.
2517 ///
2518 /// This will fail if the window is closed or if the root view's type does not match `V`.
2519 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2520 where
2521 C: Context,
2522 {
2523 cx.read_window(self, |root_view, _cx| root_view.clone())
2524 }
2525
2526 /// Check if this window is 'active'.
2527 ///
2528 /// Will return `None` if the window is closed or currently
2529 /// borrowed.
2530 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
2531 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
2532 .ok()
2533 }
2534}
2535
2536impl<V> Copy for WindowHandle<V> {}
2537
2538impl<V> Clone for WindowHandle<V> {
2539 fn clone(&self) -> Self {
2540 *self
2541 }
2542}
2543
2544impl<V> PartialEq for WindowHandle<V> {
2545 fn eq(&self, other: &Self) -> bool {
2546 self.any_handle == other.any_handle
2547 }
2548}
2549
2550impl<V> Eq for WindowHandle<V> {}
2551
2552impl<V> Hash for WindowHandle<V> {
2553 fn hash<H: Hasher>(&self, state: &mut H) {
2554 self.any_handle.hash(state);
2555 }
2556}
2557
2558impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2559 fn from(val: WindowHandle<V>) -> Self {
2560 val.any_handle
2561 }
2562}
2563
2564/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2565#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2566pub struct AnyWindowHandle {
2567 pub(crate) id: WindowId,
2568 state_type: TypeId,
2569}
2570
2571impl AnyWindowHandle {
2572 /// Get the ID of this window.
2573 pub fn window_id(&self) -> WindowId {
2574 self.id
2575 }
2576
2577 /// Attempt to convert this handle to a window handle with a specific root view type.
2578 /// If the types do not match, this will return `None`.
2579 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2580 if TypeId::of::<T>() == self.state_type {
2581 Some(WindowHandle {
2582 any_handle: *self,
2583 state_type: PhantomData,
2584 })
2585 } else {
2586 None
2587 }
2588 }
2589
2590 /// Updates the state of the root view of this window.
2591 ///
2592 /// This will fail if the window has been closed.
2593 pub fn update<C, R>(
2594 self,
2595 cx: &mut C,
2596 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2597 ) -> Result<R>
2598 where
2599 C: Context,
2600 {
2601 cx.update_window(self, update)
2602 }
2603
2604 /// Read the state of the root view of this window.
2605 ///
2606 /// This will fail if the window has been closed.
2607 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2608 where
2609 C: Context,
2610 T: 'static,
2611 {
2612 let view = self
2613 .downcast::<T>()
2614 .context("the type of the window's root view has changed")?;
2615
2616 cx.read_window(&view, read)
2617 }
2618}
2619
2620/// An identifier for an [`Element`](crate::Element).
2621///
2622/// Can be constructed with a string, a number, or both, as well
2623/// as other internal representations.
2624#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2625pub enum ElementId {
2626 /// The ID of a View element
2627 View(EntityId),
2628 /// An integer ID.
2629 Integer(usize),
2630 /// A string based ID.
2631 Name(SharedString),
2632 /// An ID that's equated with a focus handle.
2633 FocusHandle(FocusId),
2634 /// A combination of a name and an integer.
2635 NamedInteger(SharedString, usize),
2636}
2637
2638impl Display for ElementId {
2639 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2640 match self {
2641 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2642 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2643 ElementId::Name(name) => write!(f, "{}", name)?,
2644 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2645 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2646 }
2647
2648 Ok(())
2649 }
2650}
2651
2652impl TryInto<SharedString> for ElementId {
2653 type Error = anyhow::Error;
2654
2655 fn try_into(self) -> anyhow::Result<SharedString> {
2656 if let ElementId::Name(name) = self {
2657 Ok(name)
2658 } else {
2659 Err(anyhow!("element id is not string"))
2660 }
2661 }
2662}
2663
2664impl From<usize> for ElementId {
2665 fn from(id: usize) -> Self {
2666 ElementId::Integer(id)
2667 }
2668}
2669
2670impl From<i32> for ElementId {
2671 fn from(id: i32) -> Self {
2672 Self::Integer(id as usize)
2673 }
2674}
2675
2676impl From<SharedString> for ElementId {
2677 fn from(name: SharedString) -> Self {
2678 ElementId::Name(name)
2679 }
2680}
2681
2682impl From<&'static str> for ElementId {
2683 fn from(name: &'static str) -> Self {
2684 ElementId::Name(name.into())
2685 }
2686}
2687
2688impl<'a> From<&'a FocusHandle> for ElementId {
2689 fn from(handle: &'a FocusHandle) -> Self {
2690 ElementId::FocusHandle(handle.id)
2691 }
2692}
2693
2694impl From<(&'static str, EntityId)> for ElementId {
2695 fn from((name, id): (&'static str, EntityId)) -> Self {
2696 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2697 }
2698}
2699
2700impl From<(&'static str, usize)> for ElementId {
2701 fn from((name, id): (&'static str, usize)) -> Self {
2702 ElementId::NamedInteger(name.into(), id)
2703 }
2704}
2705
2706impl From<(&'static str, u64)> for ElementId {
2707 fn from((name, id): (&'static str, u64)) -> Self {
2708 ElementId::NamedInteger(name.into(), id as usize)
2709 }
2710}
2711
2712/// A rectangle to be rendered in the window at the given position and size.
2713/// Passed as an argument [`ElementContext::paint_quad`].
2714#[derive(Clone)]
2715pub struct PaintQuad {
2716 bounds: Bounds<Pixels>,
2717 corner_radii: Corners<Pixels>,
2718 background: Hsla,
2719 border_widths: Edges<Pixels>,
2720 border_color: Hsla,
2721}
2722
2723impl PaintQuad {
2724 /// Sets the corner radii of the quad.
2725 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2726 PaintQuad {
2727 corner_radii: corner_radii.into(),
2728 ..self
2729 }
2730 }
2731
2732 /// Sets the border widths of the quad.
2733 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2734 PaintQuad {
2735 border_widths: border_widths.into(),
2736 ..self
2737 }
2738 }
2739
2740 /// Sets the border color of the quad.
2741 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2742 PaintQuad {
2743 border_color: border_color.into(),
2744 ..self
2745 }
2746 }
2747
2748 /// Sets the background color of the quad.
2749 pub fn background(self, background: impl Into<Hsla>) -> Self {
2750 PaintQuad {
2751 background: background.into(),
2752 ..self
2753 }
2754 }
2755}
2756
2757/// Creates a quad with the given parameters.
2758pub fn quad(
2759 bounds: Bounds<Pixels>,
2760 corner_radii: impl Into<Corners<Pixels>>,
2761 background: impl Into<Hsla>,
2762 border_widths: impl Into<Edges<Pixels>>,
2763 border_color: impl Into<Hsla>,
2764) -> PaintQuad {
2765 PaintQuad {
2766 bounds,
2767 corner_radii: corner_radii.into(),
2768 background: background.into(),
2769 border_widths: border_widths.into(),
2770 border_color: border_color.into(),
2771 }
2772}
2773
2774/// Creates a filled quad with the given bounds and background color.
2775pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2776 PaintQuad {
2777 bounds: bounds.into(),
2778 corner_radii: (0.).into(),
2779 background: background.into(),
2780 border_widths: (0.).into(),
2781 border_color: transparent_black(),
2782 }
2783}
2784
2785/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2786pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2787 PaintQuad {
2788 bounds: bounds.into(),
2789 corner_radii: (0.).into(),
2790 background: transparent_black(),
2791 border_widths: (1.).into(),
2792 border_color: border_color.into(),
2793 }
2794}