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
341impl Window {
342 pub(crate) fn new(
343 handle: AnyWindowHandle,
344 options: WindowOptions,
345 cx: &mut AppContext,
346 ) -> Self {
347 let WindowOptions {
348 bounds,
349 titlebar,
350 focus,
351 show,
352 kind,
353 is_movable,
354 display_id,
355 fullscreen,
356 } = options;
357
358 let bounds = bounds.unwrap_or_else(|| default_bounds(cx));
359 let platform_window = cx.platform.open_window(
360 handle,
361 WindowParams {
362 bounds,
363 titlebar,
364 kind,
365 is_movable,
366 focus,
367 show,
368 display_id,
369 },
370 );
371 let display_id = platform_window.display().id();
372 let sprite_atlas = platform_window.sprite_atlas();
373 let mouse_position = platform_window.mouse_position();
374 let modifiers = platform_window.modifiers();
375 let content_size = platform_window.content_size();
376 let scale_factor = platform_window.scale_factor();
377 let appearance = platform_window.appearance();
378 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
379 let dirty = Rc::new(Cell::new(true));
380 let active = Rc::new(Cell::new(false));
381 let needs_present = Rc::new(Cell::new(false));
382 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
383 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
384
385 if fullscreen {
386 platform_window.toggle_fullscreen();
387 }
388
389 platform_window.on_close(Box::new({
390 let mut cx = cx.to_async();
391 move || {
392 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
393 }
394 }));
395 platform_window.on_request_frame(Box::new({
396 let mut cx = cx.to_async();
397 let dirty = dirty.clone();
398 let active = active.clone();
399 let needs_present = needs_present.clone();
400 let next_frame_callbacks = next_frame_callbacks.clone();
401 let last_input_timestamp = last_input_timestamp.clone();
402 move || {
403 let next_frame_callbacks = next_frame_callbacks.take();
404 if !next_frame_callbacks.is_empty() {
405 handle
406 .update(&mut cx, |_, cx| {
407 for callback in next_frame_callbacks {
408 callback(cx);
409 }
410 })
411 .log_err();
412 }
413
414 // Keep presenting the current scene for 1 extra second since the
415 // last input to prevent the display from underclocking the refresh rate.
416 let needs_present = needs_present.get()
417 || (active.get()
418 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
419
420 if dirty.get() {
421 measure("frame duration", || {
422 handle
423 .update(&mut cx, |_, cx| {
424 cx.draw();
425 cx.present();
426 })
427 .log_err();
428 })
429 } else if needs_present {
430 handle.update(&mut cx, |_, cx| cx.present()).log_err();
431 }
432 }
433 }));
434 platform_window.on_resize(Box::new({
435 let mut cx = cx.to_async();
436 move |_, _| {
437 handle
438 .update(&mut cx, |_, cx| cx.window_bounds_changed())
439 .log_err();
440 }
441 }));
442 platform_window.on_moved(Box::new({
443 let mut cx = cx.to_async();
444 move || {
445 handle
446 .update(&mut cx, |_, cx| cx.window_bounds_changed())
447 .log_err();
448 }
449 }));
450 platform_window.on_appearance_changed(Box::new({
451 let mut cx = cx.to_async();
452 move || {
453 handle
454 .update(&mut cx, |_, cx| cx.appearance_changed())
455 .log_err();
456 }
457 }));
458 platform_window.on_active_status_change(Box::new({
459 let mut cx = cx.to_async();
460 move |active| {
461 handle
462 .update(&mut cx, |_, cx| {
463 cx.window.active.set(active);
464 cx.window
465 .activation_observers
466 .clone()
467 .retain(&(), |callback| callback(cx));
468 cx.refresh();
469 })
470 .log_err();
471 }
472 }));
473
474 platform_window.on_input({
475 let mut cx = cx.to_async();
476 Box::new(move |event| {
477 handle
478 .update(&mut cx, |_, cx| cx.dispatch_event(event))
479 .log_err()
480 .unwrap_or(DispatchEventResult::default())
481 })
482 });
483
484 Window {
485 handle,
486 removed: false,
487 platform_window,
488 display_id,
489 sprite_atlas,
490 text_system,
491 rem_size: px(16.),
492 viewport_size: content_size,
493 layout_engine: Some(TaffyLayoutEngine::new()),
494 root_view: None,
495 element_id_stack: GlobalElementId::default(),
496 text_style_stack: Vec::new(),
497 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
498 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
499 next_frame_callbacks,
500 next_hitbox_id: HitboxId::default(),
501 dirty_views: FxHashSet::default(),
502 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
503 focus_listeners: SubscriberSet::new(),
504 focus_lost_listeners: SubscriberSet::new(),
505 default_prevented: true,
506 mouse_position,
507 mouse_hit_test: HitTest::default(),
508 modifiers,
509 scale_factor,
510 bounds_observers: SubscriberSet::new(),
511 appearance,
512 appearance_observers: SubscriberSet::new(),
513 active,
514 dirty,
515 needs_present,
516 last_input_timestamp,
517 refreshing: false,
518 draw_phase: DrawPhase::None,
519 activation_observers: SubscriberSet::new(),
520 focus: None,
521 focus_enabled: true,
522 pending_input: None,
523 prompt: None,
524 }
525 }
526 fn new_focus_listener(
527 &mut self,
528 value: AnyWindowFocusListener,
529 ) -> (Subscription, impl FnOnce()) {
530 self.focus_listeners.insert((), value)
531 }
532}
533
534#[derive(Clone, Debug, Default, PartialEq, Eq)]
535pub(crate) struct DispatchEventResult {
536 pub propagate: bool,
537 pub default_prevented: bool,
538}
539
540/// Indicates which region of the window is visible. Content falling outside of this mask will not be
541/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
542/// to leave room to support more complex shapes in the future.
543#[derive(Clone, Debug, Default, PartialEq, Eq)]
544#[repr(C)]
545pub struct ContentMask<P: Clone + Default + Debug> {
546 /// The bounds
547 pub bounds: Bounds<P>,
548}
549
550impl ContentMask<Pixels> {
551 /// Scale the content mask's pixel units by the given scaling factor.
552 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
553 ContentMask {
554 bounds: self.bounds.scale(factor),
555 }
556 }
557
558 /// Intersect the content mask with the given content mask.
559 pub fn intersect(&self, other: &Self) -> Self {
560 let bounds = self.bounds.intersect(&other.bounds);
561 ContentMask { bounds }
562 }
563}
564
565/// Provides access to application state in the context of a single window. Derefs
566/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
567/// an [`AppContext`] and call any [`AppContext`] methods.
568pub struct WindowContext<'a> {
569 pub(crate) app: &'a mut AppContext,
570 pub(crate) window: &'a mut Window,
571}
572
573impl<'a> WindowContext<'a> {
574 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
575 Self { app, window }
576 }
577
578 /// Obtain a handle to the window that belongs to this context.
579 pub fn window_handle(&self) -> AnyWindowHandle {
580 self.window.handle
581 }
582
583 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
584 pub fn refresh(&mut self) {
585 if self.window.draw_phase == DrawPhase::None {
586 self.window.refreshing = true;
587 self.window.dirty.set(true);
588 }
589 }
590
591 /// Close this window.
592 pub fn remove_window(&mut self) {
593 self.window.removed = true;
594 }
595
596 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
597 /// for elements rendered within this window.
598 pub fn focus_handle(&mut self) -> FocusHandle {
599 FocusHandle::new(&self.window.focus_handles)
600 }
601
602 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
603 pub fn focused(&self) -> Option<FocusHandle> {
604 self.window
605 .focus
606 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
607 }
608
609 /// Move focus to the element associated with the given [`FocusHandle`].
610 pub fn focus(&mut self, handle: &FocusHandle) {
611 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
612 return;
613 }
614
615 self.window.focus = Some(handle.id);
616 self.window
617 .rendered_frame
618 .dispatch_tree
619 .clear_pending_keystrokes();
620 self.refresh();
621 }
622
623 /// Remove focus from all elements within this context's window.
624 pub fn blur(&mut self) {
625 if !self.window.focus_enabled {
626 return;
627 }
628
629 self.window.focus = None;
630 self.refresh();
631 }
632
633 /// Blur the window and don't allow anything in it to be focused again.
634 pub fn disable_focus(&mut self) {
635 self.blur();
636 self.window.focus_enabled = false;
637 }
638
639 /// Accessor for the text system.
640 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
641 &self.window.text_system
642 }
643
644 /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
645 pub fn text_style(&self) -> TextStyle {
646 let mut style = TextStyle::default();
647 for refinement in &self.window.text_style_stack {
648 style.refine(refinement);
649 }
650 style
651 }
652
653 /// Get the platform window titlebar height
654 pub fn titlebar_height(&self) -> Pixels {
655 self.window.platform_window.titlebar_height()
656 }
657
658 /// Check if the platform window is maximized
659 /// On some platforms (namely Windows) this is different than the bounds being the size of the display
660 pub fn is_maximized(&self) -> bool {
661 self.window.platform_window.is_maximized()
662 }
663
664 /// Dispatch the given action on the currently focused element.
665 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
666 let focus_handle = self.focused();
667
668 let window = self.window.handle;
669 self.app.defer(move |cx| {
670 cx.propagate_event = true;
671 window
672 .update(cx, |_, cx| {
673 let node_id = focus_handle
674 .and_then(|handle| {
675 cx.window
676 .rendered_frame
677 .dispatch_tree
678 .focusable_node_id(handle.id)
679 })
680 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
681
682 cx.dispatch_action_on_node(node_id, action.as_ref());
683 })
684 .log_err();
685 if cx.propagate_event {
686 cx.dispatch_global_action(action.as_ref());
687 }
688 })
689 }
690
691 pub(crate) fn dispatch_keystroke_observers(
692 &mut self,
693 event: &dyn Any,
694 action: Option<Box<dyn Action>>,
695 ) {
696 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
697 return;
698 };
699
700 self.keystroke_observers
701 .clone()
702 .retain(&(), move |callback| {
703 (callback)(
704 &KeystrokeEvent {
705 keystroke: key_down_event.keystroke.clone(),
706 action: action.as_ref().map(|action| action.boxed_clone()),
707 },
708 self,
709 );
710 true
711 });
712 }
713
714 pub(crate) fn clear_pending_keystrokes(&mut self) {
715 self.window
716 .rendered_frame
717 .dispatch_tree
718 .clear_pending_keystrokes();
719 self.window
720 .next_frame
721 .dispatch_tree
722 .clear_pending_keystrokes();
723 }
724
725 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
726 /// that are currently on the stack to be returned to the app.
727 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
728 let handle = self.window.handle;
729 self.app.defer(move |cx| {
730 handle.update(cx, |_, cx| f(cx)).ok();
731 });
732 }
733
734 /// Subscribe to events emitted by a model or view.
735 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
736 /// 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.
737 pub fn subscribe<Emitter, E, Evt>(
738 &mut self,
739 entity: &E,
740 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
741 ) -> Subscription
742 where
743 Emitter: EventEmitter<Evt>,
744 E: Entity<Emitter>,
745 Evt: 'static,
746 {
747 let entity_id = entity.entity_id();
748 let entity = entity.downgrade();
749 let window_handle = self.window.handle;
750 self.app.new_subscription(
751 entity_id,
752 (
753 TypeId::of::<Evt>(),
754 Box::new(move |event, cx| {
755 window_handle
756 .update(cx, |_, cx| {
757 if let Some(handle) = E::upgrade_from(&entity) {
758 let event = event.downcast_ref().expect("invalid event type");
759 on_event(handle, event, cx);
760 true
761 } else {
762 false
763 }
764 })
765 .unwrap_or(false)
766 }),
767 ),
768 )
769 }
770
771 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
772 /// await points in async code.
773 pub fn to_async(&self) -> AsyncWindowContext {
774 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
775 }
776
777 /// Schedule the given closure to be run directly after the current frame is rendered.
778 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
779 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
780 }
781
782 /// Spawn the future returned by the given closure on the application thread pool.
783 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
784 /// use within your future.
785 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
786 where
787 R: 'static,
788 Fut: Future<Output = R> + 'static,
789 {
790 self.app
791 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
792 }
793
794 /// Updates the global of the given type. The given closure is given simultaneous mutable
795 /// access both to the global and the context.
796 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
797 where
798 G: Global,
799 {
800 let mut global = self.app.lease_global::<G>();
801 let result = f(&mut global, self);
802 self.app.end_global_lease(global);
803 result
804 }
805
806 fn window_bounds_changed(&mut self) {
807 self.window.scale_factor = self.window.platform_window.scale_factor();
808 self.window.viewport_size = self.window.platform_window.content_size();
809 self.window.display_id = self.window.platform_window.display().id();
810 self.refresh();
811
812 self.window
813 .bounds_observers
814 .clone()
815 .retain(&(), |callback| callback(self));
816 }
817
818 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
819 pub fn window_bounds(&self) -> Bounds<GlobalPixels> {
820 self.window.platform_window.bounds()
821 }
822
823 /// Retusn whether or not the window is currently fullscreen
824 pub fn is_fullscreen(&self) -> bool {
825 self.window.platform_window.is_fullscreen()
826 }
827
828 fn appearance_changed(&mut self) {
829 self.window.appearance = self.window.platform_window.appearance();
830
831 self.window
832 .appearance_observers
833 .clone()
834 .retain(&(), |callback| callback(self));
835 }
836
837 /// Returns the appearance of the current window.
838 pub fn appearance(&self) -> WindowAppearance {
839 self.window.appearance
840 }
841
842 /// Returns the size of the drawable area within the window.
843 pub fn viewport_size(&self) -> Size<Pixels> {
844 self.window.viewport_size
845 }
846
847 /// Returns whether this window is focused by the operating system (receiving key events).
848 pub fn is_window_active(&self) -> bool {
849 self.window.active.get()
850 }
851
852 /// Toggle zoom on the window.
853 pub fn zoom_window(&self) {
854 self.window.platform_window.zoom();
855 }
856
857 /// Updates the window's title at the platform level.
858 pub fn set_window_title(&mut self, title: &str) {
859 self.window.platform_window.set_title(title);
860 }
861
862 /// Mark the window as dirty at the platform level.
863 pub fn set_window_edited(&mut self, edited: bool) {
864 self.window.platform_window.set_edited(edited);
865 }
866
867 /// Determine the display on which the window is visible.
868 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
869 self.platform
870 .displays()
871 .into_iter()
872 .find(|display| display.id() == self.window.display_id)
873 }
874
875 /// Show the platform character palette.
876 pub fn show_character_palette(&self) {
877 self.window.platform_window.show_character_palette();
878 }
879
880 /// The scale factor of the display associated with the window. For example, it could
881 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
882 /// be rendered as two pixels on screen.
883 pub fn scale_factor(&self) -> f32 {
884 self.window.scale_factor
885 }
886
887 /// The size of an em for the base font of the application. Adjusting this value allows the
888 /// UI to scale, just like zooming a web page.
889 pub fn rem_size(&self) -> Pixels {
890 self.window.rem_size
891 }
892
893 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
894 /// UI to scale, just like zooming a web page.
895 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
896 self.window.rem_size = rem_size.into();
897 }
898
899 /// The line height associated with the current text style.
900 pub fn line_height(&self) -> Pixels {
901 let rem_size = self.rem_size();
902 let text_style = self.text_style();
903 text_style
904 .line_height
905 .to_pixels(text_style.font_size, rem_size)
906 }
907
908 /// Call to prevent the default action of an event. Currently only used to prevent
909 /// parent elements from becoming focused on mouse down.
910 pub fn prevent_default(&mut self) {
911 self.window.default_prevented = true;
912 }
913
914 /// Obtain whether default has been prevented for the event currently being dispatched.
915 pub fn default_prevented(&self) -> bool {
916 self.window.default_prevented
917 }
918
919 /// Determine whether the given action is available along the dispatch path to the currently focused element.
920 pub fn is_action_available(&self, action: &dyn Action) -> bool {
921 let target = self
922 .focused()
923 .and_then(|focused_handle| {
924 self.window
925 .rendered_frame
926 .dispatch_tree
927 .focusable_node_id(focused_handle.id)
928 })
929 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
930 self.window
931 .rendered_frame
932 .dispatch_tree
933 .is_action_available(action, target)
934 }
935
936 /// The position of the mouse relative to the window.
937 pub fn mouse_position(&self) -> Point<Pixels> {
938 self.window.mouse_position
939 }
940
941 /// The current state of the keyboard's modifiers
942 pub fn modifiers(&self) -> Modifiers {
943 self.window.modifiers
944 }
945
946 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
947 /// the contents of the new [Scene], use [present].
948 #[profiling::function]
949 pub fn draw(&mut self) {
950 self.window.dirty.set(false);
951
952 // Restore the previously-used input handler.
953 if let Some(input_handler) = self.window.platform_window.take_input_handler() {
954 self.window
955 .rendered_frame
956 .input_handlers
957 .push(Some(input_handler));
958 }
959
960 self.with_element_context(|cx| cx.draw_roots());
961 self.window.dirty_views.clear();
962
963 self.window
964 .next_frame
965 .dispatch_tree
966 .preserve_pending_keystrokes(
967 &mut self.window.rendered_frame.dispatch_tree,
968 self.window.focus,
969 );
970 self.window.next_frame.focus = self.window.focus;
971 self.window.next_frame.window_active = self.window.active.get();
972
973 // Register requested input handler with the platform window.
974 if let Some(input_handler) = self.window.next_frame.input_handlers.pop() {
975 self.window
976 .platform_window
977 .set_input_handler(input_handler.unwrap());
978 }
979
980 self.window.layout_engine.as_mut().unwrap().clear();
981 self.text_system().finish_frame();
982 self.window
983 .next_frame
984 .finish(&mut self.window.rendered_frame);
985 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
986 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
987 if percentage >= 80. {
988 log::warn!("elevated element arena occupation: {}.", percentage);
989 }
990 element_arena.clear();
991 });
992
993 self.window.draw_phase = DrawPhase::Focus;
994 let previous_focus_path = self.window.rendered_frame.focus_path();
995 let previous_window_active = self.window.rendered_frame.window_active;
996 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
997 self.window.next_frame.clear();
998 let current_focus_path = self.window.rendered_frame.focus_path();
999 let current_window_active = self.window.rendered_frame.window_active;
1000
1001 if previous_focus_path != current_focus_path
1002 || previous_window_active != current_window_active
1003 {
1004 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1005 self.window
1006 .focus_lost_listeners
1007 .clone()
1008 .retain(&(), |listener| listener(self));
1009 }
1010
1011 let event = FocusEvent {
1012 previous_focus_path: if previous_window_active {
1013 previous_focus_path
1014 } else {
1015 Default::default()
1016 },
1017 current_focus_path: if current_window_active {
1018 current_focus_path
1019 } else {
1020 Default::default()
1021 },
1022 };
1023 self.window
1024 .focus_listeners
1025 .clone()
1026 .retain(&(), |listener| listener(&event, self));
1027 }
1028
1029 self.reset_cursor_style();
1030 self.window.refreshing = false;
1031 self.window.draw_phase = DrawPhase::None;
1032 self.window.needs_present.set(true);
1033 }
1034
1035 #[profiling::function]
1036 fn present(&self) {
1037 self.window
1038 .platform_window
1039 .draw(&self.window.rendered_frame.scene);
1040 self.window.needs_present.set(false);
1041 profiling::finish_frame!();
1042 }
1043
1044 fn reset_cursor_style(&self) {
1045 // Set the cursor only if we're the active window.
1046 if self.is_window_active() {
1047 let style = self
1048 .window
1049 .rendered_frame
1050 .cursor_styles
1051 .iter()
1052 .rev()
1053 .find(|request| request.hitbox_id.is_hovered(self))
1054 .map(|request| request.style)
1055 .unwrap_or(CursorStyle::Arrow);
1056 self.platform.set_cursor_style(style);
1057 }
1058 }
1059
1060 /// Dispatch a given keystroke as though the user had typed it.
1061 /// You can create a keystroke with Keystroke::parse("").
1062 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
1063 let keystroke = keystroke.with_simulated_ime();
1064 let result = self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
1065 keystroke: keystroke.clone(),
1066 is_held: false,
1067 }));
1068 if !result.propagate {
1069 return true;
1070 }
1071
1072 if let Some(input) = keystroke.ime_key {
1073 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1074 input_handler.dispatch_input(&input, self);
1075 self.window.platform_window.set_input_handler(input_handler);
1076 return true;
1077 }
1078 }
1079
1080 false
1081 }
1082
1083 /// Represent this action as a key binding string, to display in the UI.
1084 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
1085 self.bindings_for_action(action)
1086 .into_iter()
1087 .next()
1088 .map(|binding| {
1089 binding
1090 .keystrokes()
1091 .iter()
1092 .map(ToString::to_string)
1093 .collect::<Vec<_>>()
1094 .join(" ")
1095 })
1096 .unwrap_or_else(|| action.name().to_string())
1097 }
1098
1099 /// Dispatch a mouse or keyboard event on the window.
1100 #[profiling::function]
1101 pub fn dispatch_event(&mut self, event: PlatformInput) -> DispatchEventResult {
1102 self.window.last_input_timestamp.set(Instant::now());
1103 // Handlers may set this to false by calling `stop_propagation`.
1104 self.app.propagate_event = true;
1105 // Handlers may set this to true by calling `prevent_default`.
1106 self.window.default_prevented = false;
1107
1108 let event = match event {
1109 // Track the mouse position with our own state, since accessing the platform
1110 // API for the mouse position can only occur on the main thread.
1111 PlatformInput::MouseMove(mouse_move) => {
1112 self.window.mouse_position = mouse_move.position;
1113 self.window.modifiers = mouse_move.modifiers;
1114 PlatformInput::MouseMove(mouse_move)
1115 }
1116 PlatformInput::MouseDown(mouse_down) => {
1117 self.window.mouse_position = mouse_down.position;
1118 self.window.modifiers = mouse_down.modifiers;
1119 PlatformInput::MouseDown(mouse_down)
1120 }
1121 PlatformInput::MouseUp(mouse_up) => {
1122 self.window.mouse_position = mouse_up.position;
1123 self.window.modifiers = mouse_up.modifiers;
1124 PlatformInput::MouseUp(mouse_up)
1125 }
1126 PlatformInput::MouseExited(mouse_exited) => {
1127 self.window.modifiers = mouse_exited.modifiers;
1128 PlatformInput::MouseExited(mouse_exited)
1129 }
1130 PlatformInput::ModifiersChanged(modifiers_changed) => {
1131 self.window.modifiers = modifiers_changed.modifiers;
1132 PlatformInput::ModifiersChanged(modifiers_changed)
1133 }
1134 PlatformInput::ScrollWheel(scroll_wheel) => {
1135 self.window.mouse_position = scroll_wheel.position;
1136 self.window.modifiers = scroll_wheel.modifiers;
1137 PlatformInput::ScrollWheel(scroll_wheel)
1138 }
1139 // Translate dragging and dropping of external files from the operating system
1140 // to internal drag and drop events.
1141 PlatformInput::FileDrop(file_drop) => match file_drop {
1142 FileDropEvent::Entered { position, paths } => {
1143 self.window.mouse_position = position;
1144 if self.active_drag.is_none() {
1145 self.active_drag = Some(AnyDrag {
1146 value: Box::new(paths.clone()),
1147 view: self.new_view(|_| paths).into(),
1148 cursor_offset: position,
1149 });
1150 }
1151 PlatformInput::MouseMove(MouseMoveEvent {
1152 position,
1153 pressed_button: Some(MouseButton::Left),
1154 modifiers: Modifiers::default(),
1155 })
1156 }
1157 FileDropEvent::Pending { position } => {
1158 self.window.mouse_position = position;
1159 PlatformInput::MouseMove(MouseMoveEvent {
1160 position,
1161 pressed_button: Some(MouseButton::Left),
1162 modifiers: Modifiers::default(),
1163 })
1164 }
1165 FileDropEvent::Submit { position } => {
1166 self.activate(true);
1167 self.window.mouse_position = position;
1168 PlatformInput::MouseUp(MouseUpEvent {
1169 button: MouseButton::Left,
1170 position,
1171 modifiers: Modifiers::default(),
1172 click_count: 1,
1173 })
1174 }
1175 FileDropEvent::Exited => {
1176 self.active_drag.take();
1177 PlatformInput::FileDrop(FileDropEvent::Exited)
1178 }
1179 },
1180 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1181 };
1182
1183 if let Some(any_mouse_event) = event.mouse_event() {
1184 self.dispatch_mouse_event(any_mouse_event);
1185 } else if let Some(any_key_event) = event.keyboard_event() {
1186 self.dispatch_key_event(any_key_event);
1187 }
1188
1189 DispatchEventResult {
1190 propagate: self.app.propagate_event,
1191 default_prevented: self.window.default_prevented,
1192 }
1193 }
1194
1195 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1196 let hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
1197 if hit_test != self.window.mouse_hit_test {
1198 self.window.mouse_hit_test = hit_test;
1199 self.reset_cursor_style();
1200 }
1201
1202 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
1203 self.with_element_context(|cx| {
1204 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1205 // special purposes, such as detecting events outside of a given Bounds.
1206 for listener in &mut mouse_listeners {
1207 let listener = listener.as_mut().unwrap();
1208 listener(event, DispatchPhase::Capture, cx);
1209 if !cx.app.propagate_event {
1210 break;
1211 }
1212 }
1213
1214 // Bubble phase, where most normal handlers do their work.
1215 if cx.app.propagate_event {
1216 for listener in mouse_listeners.iter_mut().rev() {
1217 let listener = listener.as_mut().unwrap();
1218 listener(event, DispatchPhase::Bubble, cx);
1219 if !cx.app.propagate_event {
1220 break;
1221 }
1222 }
1223 }
1224 });
1225 self.window.rendered_frame.mouse_listeners = mouse_listeners;
1226
1227 if self.app.propagate_event && self.has_active_drag() {
1228 if event.is::<MouseMoveEvent>() {
1229 // If this was a mouse move event, redraw the window so that the
1230 // active drag can follow the mouse cursor.
1231 self.refresh();
1232 } else if event.is::<MouseUpEvent>() {
1233 // If this was a mouse up event, cancel the active drag and redraw
1234 // the window.
1235 self.active_drag = None;
1236 self.refresh();
1237 }
1238 }
1239 }
1240
1241 fn dispatch_key_event(&mut self, event: &dyn Any) {
1242 if self.window.dirty.get() {
1243 self.draw();
1244 }
1245
1246 let node_id = self
1247 .window
1248 .focus
1249 .and_then(|focus_id| {
1250 self.window
1251 .rendered_frame
1252 .dispatch_tree
1253 .focusable_node_id(focus_id)
1254 })
1255 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1256
1257 let dispatch_path = self
1258 .window
1259 .rendered_frame
1260 .dispatch_tree
1261 .dispatch_path(node_id);
1262
1263 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1264 let KeymatchResult { bindings, pending } = self
1265 .window
1266 .rendered_frame
1267 .dispatch_tree
1268 .dispatch_key(&key_down_event.keystroke, &dispatch_path);
1269
1270 if pending {
1271 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
1272 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus
1273 {
1274 currently_pending = PendingInput::default();
1275 }
1276 currently_pending.focus = self.window.focus;
1277 currently_pending
1278 .keystrokes
1279 .push(key_down_event.keystroke.clone());
1280 for binding in bindings {
1281 currently_pending.bindings.push(binding);
1282 }
1283
1284 currently_pending.timer = Some(self.spawn(|mut cx| async move {
1285 cx.background_executor.timer(Duration::from_secs(1)).await;
1286 cx.update(move |cx| {
1287 cx.clear_pending_keystrokes();
1288 let Some(currently_pending) = cx.window.pending_input.take() else {
1289 return;
1290 };
1291 cx.replay_pending_input(currently_pending)
1292 })
1293 .log_err();
1294 }));
1295
1296 self.window.pending_input = Some(currently_pending);
1297
1298 self.propagate_event = false;
1299 return;
1300 } else if let Some(currently_pending) = self.window.pending_input.take() {
1301 if bindings
1302 .iter()
1303 .all(|binding| !currently_pending.used_by_binding(binding))
1304 {
1305 self.replay_pending_input(currently_pending)
1306 }
1307 }
1308
1309 if !bindings.is_empty() {
1310 self.clear_pending_keystrokes();
1311 }
1312
1313 self.propagate_event = true;
1314 for binding in bindings {
1315 self.dispatch_action_on_node(node_id, binding.action.as_ref());
1316 if !self.propagate_event {
1317 self.dispatch_keystroke_observers(event, Some(binding.action));
1318 return;
1319 }
1320 }
1321 }
1322
1323 self.dispatch_key_down_up_event(event, &dispatch_path);
1324 if !self.propagate_event {
1325 return;
1326 }
1327
1328 self.dispatch_keystroke_observers(event, None);
1329 }
1330
1331 fn dispatch_key_down_up_event(
1332 &mut self,
1333 event: &dyn Any,
1334 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
1335 ) {
1336 // Capture phase
1337 for node_id in dispatch_path {
1338 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1339
1340 for key_listener in node.key_listeners.clone() {
1341 self.with_element_context(|cx| {
1342 key_listener(event, DispatchPhase::Capture, cx);
1343 });
1344 if !self.propagate_event {
1345 return;
1346 }
1347 }
1348 }
1349
1350 // Bubble phase
1351 for node_id in dispatch_path.iter().rev() {
1352 // Handle low level key events
1353 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1354 for key_listener in node.key_listeners.clone() {
1355 self.with_element_context(|cx| {
1356 key_listener(event, DispatchPhase::Bubble, cx);
1357 });
1358 if !self.propagate_event {
1359 return;
1360 }
1361 }
1362 }
1363 }
1364
1365 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1366 pub fn has_pending_keystrokes(&self) -> bool {
1367 self.window
1368 .rendered_frame
1369 .dispatch_tree
1370 .has_pending_keystrokes()
1371 }
1372
1373 fn replay_pending_input(&mut self, currently_pending: PendingInput) {
1374 let node_id = self
1375 .window
1376 .focus
1377 .and_then(|focus_id| {
1378 self.window
1379 .rendered_frame
1380 .dispatch_tree
1381 .focusable_node_id(focus_id)
1382 })
1383 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1384
1385 if self.window.focus != currently_pending.focus {
1386 return;
1387 }
1388
1389 let input = currently_pending.input();
1390
1391 self.propagate_event = true;
1392 for binding in currently_pending.bindings {
1393 self.dispatch_action_on_node(node_id, binding.action.as_ref());
1394 if !self.propagate_event {
1395 return;
1396 }
1397 }
1398
1399 let dispatch_path = self
1400 .window
1401 .rendered_frame
1402 .dispatch_tree
1403 .dispatch_path(node_id);
1404
1405 for keystroke in currently_pending.keystrokes {
1406 let event = KeyDownEvent {
1407 keystroke,
1408 is_held: false,
1409 };
1410
1411 self.dispatch_key_down_up_event(&event, &dispatch_path);
1412 if !self.propagate_event {
1413 return;
1414 }
1415 }
1416
1417 if !input.is_empty() {
1418 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
1419 input_handler.dispatch_input(&input, self);
1420 self.window.platform_window.set_input_handler(input_handler)
1421 }
1422 }
1423 }
1424
1425 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
1426 let dispatch_path = self
1427 .window
1428 .rendered_frame
1429 .dispatch_tree
1430 .dispatch_path(node_id);
1431
1432 // Capture phase
1433 for node_id in &dispatch_path {
1434 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1435 for DispatchActionListener {
1436 action_type,
1437 listener,
1438 } in node.action_listeners.clone()
1439 {
1440 let any_action = action.as_any();
1441 if action_type == any_action.type_id() {
1442 self.with_element_context(|cx| {
1443 listener(any_action, DispatchPhase::Capture, cx);
1444 });
1445
1446 if !self.propagate_event {
1447 return;
1448 }
1449 }
1450 }
1451 }
1452 // Bubble phase
1453 for node_id in dispatch_path.iter().rev() {
1454 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1455 for DispatchActionListener {
1456 action_type,
1457 listener,
1458 } in node.action_listeners.clone()
1459 {
1460 let any_action = action.as_any();
1461 if action_type == any_action.type_id() {
1462 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1463
1464 self.with_element_context(|cx| {
1465 listener(any_action, DispatchPhase::Bubble, cx);
1466 });
1467
1468 if !self.propagate_event {
1469 return;
1470 }
1471 }
1472 }
1473 }
1474 }
1475
1476 /// Register the given handler to be invoked whenever the global of the given type
1477 /// is updated.
1478 pub fn observe_global<G: Global>(
1479 &mut self,
1480 f: impl Fn(&mut WindowContext<'_>) + 'static,
1481 ) -> Subscription {
1482 let window_handle = self.window.handle;
1483 let (subscription, activate) = self.global_observers.insert(
1484 TypeId::of::<G>(),
1485 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1486 );
1487 self.app.defer(move |_| activate());
1488 subscription
1489 }
1490
1491 /// Focus the current window and bring it to the foreground at the platform level.
1492 pub fn activate_window(&self) {
1493 self.window.platform_window.activate();
1494 }
1495
1496 /// Minimize the current window at the platform level.
1497 pub fn minimize_window(&self) {
1498 self.window.platform_window.minimize();
1499 }
1500
1501 /// Toggle full screen status on the current window at the platform level.
1502 pub fn toggle_fullscreen(&self) {
1503 self.window.platform_window.toggle_fullscreen();
1504 }
1505
1506 /// Present a platform dialog.
1507 /// The provided message will be presented, along with buttons for each answer.
1508 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1509 pub fn prompt(
1510 &mut self,
1511 level: PromptLevel,
1512 message: &str,
1513 detail: Option<&str>,
1514 answers: &[&str],
1515 ) -> oneshot::Receiver<usize> {
1516 let prompt_builder = self.app.prompt_builder.take();
1517 let Some(prompt_builder) = prompt_builder else {
1518 unreachable!("Re-entrant window prompting is not supported by GPUI");
1519 };
1520
1521 let receiver = match &prompt_builder {
1522 PromptBuilder::Default => self
1523 .window
1524 .platform_window
1525 .prompt(level, message, detail, answers)
1526 .unwrap_or_else(|| {
1527 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
1528 }),
1529 PromptBuilder::Custom(_) => {
1530 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
1531 }
1532 };
1533
1534 self.app.prompt_builder = Some(prompt_builder);
1535
1536 receiver
1537 }
1538
1539 fn build_custom_prompt(
1540 &mut self,
1541 prompt_builder: &PromptBuilder,
1542 level: PromptLevel,
1543 message: &str,
1544 detail: Option<&str>,
1545 answers: &[&str],
1546 ) -> oneshot::Receiver<usize> {
1547 let (sender, receiver) = oneshot::channel();
1548 let handle = PromptHandle::new(sender);
1549 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
1550 self.window.prompt = Some(handle);
1551 receiver
1552 }
1553
1554 /// Returns all available actions for the focused element.
1555 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1556 let node_id = self
1557 .window
1558 .focus
1559 .and_then(|focus_id| {
1560 self.window
1561 .rendered_frame
1562 .dispatch_tree
1563 .focusable_node_id(focus_id)
1564 })
1565 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1566
1567 let mut actions = self
1568 .window
1569 .rendered_frame
1570 .dispatch_tree
1571 .available_actions(node_id);
1572 for action_type in self.global_action_listeners.keys() {
1573 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
1574 let action = self.actions.build_action_type(action_type).ok();
1575 if let Some(action) = action {
1576 actions.insert(ix, action);
1577 }
1578 }
1579 }
1580 actions
1581 }
1582
1583 /// Returns key bindings that invoke the given action on the currently focused element.
1584 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1585 self.window
1586 .rendered_frame
1587 .dispatch_tree
1588 .bindings_for_action(
1589 action,
1590 &self.window.rendered_frame.dispatch_tree.context_stack,
1591 )
1592 }
1593
1594 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1595 pub fn bindings_for_action_in(
1596 &self,
1597 action: &dyn Action,
1598 focus_handle: &FocusHandle,
1599 ) -> Vec<KeyBinding> {
1600 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1601
1602 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1603 return vec![];
1604 };
1605 let context_stack: Vec<_> = dispatch_tree
1606 .dispatch_path(node_id)
1607 .into_iter()
1608 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1609 .collect();
1610 dispatch_tree.bindings_for_action(action, &context_stack)
1611 }
1612
1613 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1614 pub fn listener_for<V: Render, E>(
1615 &self,
1616 view: &View<V>,
1617 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1618 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1619 let view = view.downgrade();
1620 move |e: &E, cx: &mut WindowContext| {
1621 view.update(cx, |view, cx| f(view, e, cx)).ok();
1622 }
1623 }
1624
1625 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1626 pub fn handler_for<V: Render>(
1627 &self,
1628 view: &View<V>,
1629 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1630 ) -> impl Fn(&mut WindowContext) {
1631 let view = view.downgrade();
1632 move |cx: &mut WindowContext| {
1633 view.update(cx, |view, cx| f(view, cx)).ok();
1634 }
1635 }
1636
1637 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1638 /// If the callback returns false, the window won't be closed.
1639 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1640 let mut this = self.to_async();
1641 self.window
1642 .platform_window
1643 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
1644 }
1645
1646 /// Register an action listener on the window for the next frame. The type of action
1647 /// is determined by the first parameter of the given listener. When the next frame is rendered
1648 /// the listener will be cleared.
1649 ///
1650 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1651 /// a specific need to register a global listener.
1652 pub fn on_action(
1653 &mut self,
1654 action_type: TypeId,
1655 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1656 ) {
1657 self.window
1658 .next_frame
1659 .dispatch_tree
1660 .on_action(action_type, Rc::new(listener));
1661 }
1662}
1663
1664impl Context for WindowContext<'_> {
1665 type Result<T> = T;
1666
1667 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1668 where
1669 T: 'static,
1670 {
1671 let slot = self.app.entities.reserve();
1672 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1673 self.entities.insert(slot, model)
1674 }
1675
1676 fn update_model<T: 'static, R>(
1677 &mut self,
1678 model: &Model<T>,
1679 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1680 ) -> R {
1681 let mut entity = self.entities.lease(model);
1682 let result = update(
1683 &mut *entity,
1684 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1685 );
1686 self.entities.end_lease(entity);
1687 result
1688 }
1689
1690 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1691 where
1692 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1693 {
1694 if window == self.window.handle {
1695 let root_view = self.window.root_view.clone().unwrap();
1696 Ok(update(root_view, self))
1697 } else {
1698 window.update(self.app, update)
1699 }
1700 }
1701
1702 fn read_model<T, R>(
1703 &self,
1704 handle: &Model<T>,
1705 read: impl FnOnce(&T, &AppContext) -> R,
1706 ) -> Self::Result<R>
1707 where
1708 T: 'static,
1709 {
1710 let entity = self.entities.read(handle);
1711 read(entity, &*self.app)
1712 }
1713
1714 fn read_window<T, R>(
1715 &self,
1716 window: &WindowHandle<T>,
1717 read: impl FnOnce(View<T>, &AppContext) -> R,
1718 ) -> Result<R>
1719 where
1720 T: 'static,
1721 {
1722 if window.any_handle == self.window.handle {
1723 let root_view = self
1724 .window
1725 .root_view
1726 .clone()
1727 .unwrap()
1728 .downcast::<T>()
1729 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1730 Ok(read(root_view, self))
1731 } else {
1732 self.app.read_window(window, read)
1733 }
1734 }
1735}
1736
1737impl VisualContext for WindowContext<'_> {
1738 fn new_view<V>(
1739 &mut self,
1740 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1741 ) -> Self::Result<View<V>>
1742 where
1743 V: 'static + Render,
1744 {
1745 let slot = self.app.entities.reserve();
1746 let view = View {
1747 model: slot.clone(),
1748 };
1749 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1750 let entity = build_view_state(&mut cx);
1751 cx.entities.insert(slot, entity);
1752
1753 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
1754 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
1755 cx.new_view_observers.clone().retain(&tid, |observer| {
1756 let any_view = view.clone();
1757 (observer)(any_view, cx);
1758 true
1759 });
1760 }
1761 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
1762
1763 view
1764 }
1765
1766 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1767 fn update_view<T: 'static, R>(
1768 &mut self,
1769 view: &View<T>,
1770 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1771 ) -> Self::Result<R> {
1772 let mut lease = self.app.entities.lease(&view.model);
1773 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1774 let result = update(&mut *lease, &mut cx);
1775 cx.app.entities.end_lease(lease);
1776 result
1777 }
1778
1779 fn replace_root_view<V>(
1780 &mut self,
1781 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1782 ) -> Self::Result<View<V>>
1783 where
1784 V: 'static + Render,
1785 {
1786 let view = self.new_view(build_view);
1787 self.window.root_view = Some(view.clone().into());
1788 self.refresh();
1789 view
1790 }
1791
1792 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1793 self.update_view(view, |view, cx| {
1794 view.focus_handle(cx).clone().focus(cx);
1795 })
1796 }
1797
1798 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1799 where
1800 V: ManagedView,
1801 {
1802 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1803 }
1804}
1805
1806impl<'a> std::ops::Deref for WindowContext<'a> {
1807 type Target = AppContext;
1808
1809 fn deref(&self) -> &Self::Target {
1810 self.app
1811 }
1812}
1813
1814impl<'a> std::ops::DerefMut for WindowContext<'a> {
1815 fn deref_mut(&mut self) -> &mut Self::Target {
1816 self.app
1817 }
1818}
1819
1820impl<'a> Borrow<AppContext> for WindowContext<'a> {
1821 fn borrow(&self) -> &AppContext {
1822 self.app
1823 }
1824}
1825
1826impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1827 fn borrow_mut(&mut self) -> &mut AppContext {
1828 self.app
1829 }
1830}
1831
1832/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1833pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1834 #[doc(hidden)]
1835 fn app_mut(&mut self) -> &mut AppContext {
1836 self.borrow_mut()
1837 }
1838
1839 #[doc(hidden)]
1840 fn app(&self) -> &AppContext {
1841 self.borrow()
1842 }
1843
1844 #[doc(hidden)]
1845 fn window(&self) -> &Window {
1846 self.borrow()
1847 }
1848
1849 #[doc(hidden)]
1850 fn window_mut(&mut self) -> &mut Window {
1851 self.borrow_mut()
1852 }
1853}
1854
1855impl Borrow<Window> for WindowContext<'_> {
1856 fn borrow(&self) -> &Window {
1857 self.window
1858 }
1859}
1860
1861impl BorrowMut<Window> for WindowContext<'_> {
1862 fn borrow_mut(&mut self) -> &mut Window {
1863 self.window
1864 }
1865}
1866
1867impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1868
1869/// Provides access to application state that is specialized for a particular [`View`].
1870/// Allows you to interact with focus, emit events, etc.
1871/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1872/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1873pub struct ViewContext<'a, V> {
1874 window_cx: WindowContext<'a>,
1875 view: &'a View<V>,
1876}
1877
1878impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1879 fn borrow(&self) -> &AppContext {
1880 &*self.window_cx.app
1881 }
1882}
1883
1884impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1885 fn borrow_mut(&mut self) -> &mut AppContext {
1886 &mut *self.window_cx.app
1887 }
1888}
1889
1890impl<V> Borrow<Window> for ViewContext<'_, V> {
1891 fn borrow(&self) -> &Window {
1892 &*self.window_cx.window
1893 }
1894}
1895
1896impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1897 fn borrow_mut(&mut self) -> &mut Window {
1898 &mut *self.window_cx.window
1899 }
1900}
1901
1902impl<'a, V: 'static> ViewContext<'a, V> {
1903 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1904 Self {
1905 window_cx: WindowContext::new(app, window),
1906 view,
1907 }
1908 }
1909
1910 /// Get the entity_id of this view.
1911 pub fn entity_id(&self) -> EntityId {
1912 self.view.entity_id()
1913 }
1914
1915 /// Get the view pointer underlying this context.
1916 pub fn view(&self) -> &View<V> {
1917 self.view
1918 }
1919
1920 /// Get the model underlying this view.
1921 pub fn model(&self) -> &Model<V> {
1922 &self.view.model
1923 }
1924
1925 /// Access the underlying window context.
1926 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1927 &mut self.window_cx
1928 }
1929
1930 /// Sets a given callback to be run on the next frame.
1931 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1932 where
1933 V: 'static,
1934 {
1935 let view = self.view().clone();
1936 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1937 }
1938
1939 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1940 /// that are currently on the stack to be returned to the app.
1941 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1942 let view = self.view().downgrade();
1943 self.window_cx.defer(move |cx| {
1944 view.update(cx, f).ok();
1945 });
1946 }
1947
1948 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1949 pub fn observe<V2, E>(
1950 &mut self,
1951 entity: &E,
1952 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1953 ) -> Subscription
1954 where
1955 V2: 'static,
1956 V: 'static,
1957 E: Entity<V2>,
1958 {
1959 let view = self.view().downgrade();
1960 let entity_id = entity.entity_id();
1961 let entity = entity.downgrade();
1962 let window_handle = self.window.handle;
1963 self.app.new_observer(
1964 entity_id,
1965 Box::new(move |cx| {
1966 window_handle
1967 .update(cx, |_, cx| {
1968 if let Some(handle) = E::upgrade_from(&entity) {
1969 view.update(cx, |this, cx| on_notify(this, handle, cx))
1970 .is_ok()
1971 } else {
1972 false
1973 }
1974 })
1975 .unwrap_or(false)
1976 }),
1977 )
1978 }
1979
1980 /// Subscribe to events emitted by another model or view.
1981 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1982 /// The callback will be invoked with a reference to the current view, a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a view context for the current view.
1983 pub fn subscribe<V2, E, Evt>(
1984 &mut self,
1985 entity: &E,
1986 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1987 ) -> Subscription
1988 where
1989 V2: EventEmitter<Evt>,
1990 E: Entity<V2>,
1991 Evt: 'static,
1992 {
1993 let view = self.view().downgrade();
1994 let entity_id = entity.entity_id();
1995 let handle = entity.downgrade();
1996 let window_handle = self.window.handle;
1997 self.app.new_subscription(
1998 entity_id,
1999 (
2000 TypeId::of::<Evt>(),
2001 Box::new(move |event, cx| {
2002 window_handle
2003 .update(cx, |_, cx| {
2004 if let Some(handle) = E::upgrade_from(&handle) {
2005 let event = event.downcast_ref().expect("invalid event type");
2006 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2007 .is_ok()
2008 } else {
2009 false
2010 }
2011 })
2012 .unwrap_or(false)
2013 }),
2014 ),
2015 )
2016 }
2017
2018 /// Register a callback to be invoked when the view is released.
2019 ///
2020 /// The callback receives a handle to the view's window. This handle may be
2021 /// invalid, if the window was closed before the view was released.
2022 pub fn on_release(
2023 &mut self,
2024 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2025 ) -> Subscription {
2026 let window_handle = self.window.handle;
2027 let (subscription, activate) = self.app.release_listeners.insert(
2028 self.view.model.entity_id,
2029 Box::new(move |this, cx| {
2030 let this = this.downcast_mut().expect("invalid entity type");
2031 on_release(this, window_handle, cx)
2032 }),
2033 );
2034 activate();
2035 subscription
2036 }
2037
2038 /// Register a callback to be invoked when the given Model or View is released.
2039 pub fn observe_release<V2, E>(
2040 &mut self,
2041 entity: &E,
2042 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2043 ) -> Subscription
2044 where
2045 V: 'static,
2046 V2: 'static,
2047 E: Entity<V2>,
2048 {
2049 let view = self.view().downgrade();
2050 let entity_id = entity.entity_id();
2051 let window_handle = self.window.handle;
2052 let (subscription, activate) = self.app.release_listeners.insert(
2053 entity_id,
2054 Box::new(move |entity, cx| {
2055 let entity = entity.downcast_mut().expect("invalid entity type");
2056 let _ = window_handle.update(cx, |_, cx| {
2057 view.update(cx, |this, cx| on_release(this, entity, cx))
2058 });
2059 }),
2060 );
2061 activate();
2062 subscription
2063 }
2064
2065 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2066 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2067 pub fn notify(&mut self) {
2068 for view_id in self
2069 .window
2070 .rendered_frame
2071 .dispatch_tree
2072 .view_path(self.view.entity_id())
2073 .into_iter()
2074 .rev()
2075 {
2076 if !self.window.dirty_views.insert(view_id) {
2077 break;
2078 }
2079 }
2080
2081 if self.window.draw_phase == DrawPhase::None {
2082 self.window_cx.window.dirty.set(true);
2083 self.window_cx.app.push_effect(Effect::Notify {
2084 emitter: self.view.model.entity_id,
2085 });
2086 }
2087 }
2088
2089 /// Register a callback to be invoked when the window is resized.
2090 pub fn observe_window_bounds(
2091 &mut self,
2092 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2093 ) -> Subscription {
2094 let view = self.view.downgrade();
2095 let (subscription, activate) = self.window.bounds_observers.insert(
2096 (),
2097 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2098 );
2099 activate();
2100 subscription
2101 }
2102
2103 /// Register a callback to be invoked when the window is activated or deactivated.
2104 pub fn observe_window_activation(
2105 &mut self,
2106 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2107 ) -> Subscription {
2108 let view = self.view.downgrade();
2109 let (subscription, activate) = self.window.activation_observers.insert(
2110 (),
2111 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2112 );
2113 activate();
2114 subscription
2115 }
2116
2117 /// Registers a callback to be invoked when the window appearance changes.
2118 pub fn observe_window_appearance(
2119 &mut self,
2120 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2121 ) -> Subscription {
2122 let view = self.view.downgrade();
2123 let (subscription, activate) = self.window.appearance_observers.insert(
2124 (),
2125 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2126 );
2127 activate();
2128 subscription
2129 }
2130
2131 /// Register a listener to be called when the given focus handle receives focus.
2132 /// Returns a subscription and persists until the subscription is dropped.
2133 pub fn on_focus(
2134 &mut self,
2135 handle: &FocusHandle,
2136 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2137 ) -> Subscription {
2138 let view = self.view.downgrade();
2139 let focus_id = handle.id;
2140 let (subscription, activate) =
2141 self.window.new_focus_listener(Box::new(move |event, cx| {
2142 view.update(cx, |view, cx| {
2143 if event.previous_focus_path.last() != Some(&focus_id)
2144 && event.current_focus_path.last() == Some(&focus_id)
2145 {
2146 listener(view, cx)
2147 }
2148 })
2149 .is_ok()
2150 }));
2151 self.app.defer(|_| activate());
2152 subscription
2153 }
2154
2155 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2156 /// Returns a subscription and persists until the subscription is dropped.
2157 pub fn on_focus_in(
2158 &mut self,
2159 handle: &FocusHandle,
2160 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2161 ) -> Subscription {
2162 let view = self.view.downgrade();
2163 let focus_id = handle.id;
2164 let (subscription, activate) =
2165 self.window.new_focus_listener(Box::new(move |event, cx| {
2166 view.update(cx, |view, cx| {
2167 if !event.previous_focus_path.contains(&focus_id)
2168 && event.current_focus_path.contains(&focus_id)
2169 {
2170 listener(view, cx)
2171 }
2172 })
2173 .is_ok()
2174 }));
2175 self.app.defer(move |_| activate());
2176 subscription
2177 }
2178
2179 /// Register a listener to be called when the given focus handle loses focus.
2180 /// Returns a subscription and persists until the subscription is dropped.
2181 pub fn on_blur(
2182 &mut self,
2183 handle: &FocusHandle,
2184 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2185 ) -> Subscription {
2186 let view = self.view.downgrade();
2187 let focus_id = handle.id;
2188 let (subscription, activate) =
2189 self.window.new_focus_listener(Box::new(move |event, cx| {
2190 view.update(cx, |view, cx| {
2191 if event.previous_focus_path.last() == Some(&focus_id)
2192 && event.current_focus_path.last() != Some(&focus_id)
2193 {
2194 listener(view, cx)
2195 }
2196 })
2197 .is_ok()
2198 }));
2199 self.app.defer(move |_| activate());
2200 subscription
2201 }
2202
2203 /// Register a listener to be called when nothing in the window has focus.
2204 /// This typically happens when the node that was focused is removed from the tree,
2205 /// and this callback lets you chose a default place to restore the users focus.
2206 /// Returns a subscription and persists until the subscription is dropped.
2207 pub fn on_focus_lost(
2208 &mut self,
2209 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2210 ) -> Subscription {
2211 let view = self.view.downgrade();
2212 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2213 (),
2214 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2215 );
2216 activate();
2217 subscription
2218 }
2219
2220 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2221 /// Returns a subscription and persists until the subscription is dropped.
2222 pub fn on_focus_out(
2223 &mut self,
2224 handle: &FocusHandle,
2225 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2226 ) -> Subscription {
2227 let view = self.view.downgrade();
2228 let focus_id = handle.id;
2229 let (subscription, activate) =
2230 self.window.new_focus_listener(Box::new(move |event, cx| {
2231 view.update(cx, |view, cx| {
2232 if event.previous_focus_path.contains(&focus_id)
2233 && !event.current_focus_path.contains(&focus_id)
2234 {
2235 listener(view, cx)
2236 }
2237 })
2238 .is_ok()
2239 }));
2240 self.app.defer(move |_| activate());
2241 subscription
2242 }
2243
2244 /// Schedule a future to be run asynchronously.
2245 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2246 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2247 /// The returned future will be polled on the main thread.
2248 pub fn spawn<Fut, R>(
2249 &mut self,
2250 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2251 ) -> Task<R>
2252 where
2253 R: 'static,
2254 Fut: Future<Output = R> + 'static,
2255 {
2256 let view = self.view().downgrade();
2257 self.window_cx.spawn(|cx| f(view, cx))
2258 }
2259
2260 /// Updates the global state of the given type.
2261 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2262 where
2263 G: Global,
2264 {
2265 let mut global = self.app.lease_global::<G>();
2266 let result = f(&mut global, self);
2267 self.app.end_global_lease(global);
2268 result
2269 }
2270
2271 /// Register a callback to be invoked when the given global state changes.
2272 pub fn observe_global<G: Global>(
2273 &mut self,
2274 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2275 ) -> Subscription {
2276 let window_handle = self.window.handle;
2277 let view = self.view().downgrade();
2278 let (subscription, activate) = self.global_observers.insert(
2279 TypeId::of::<G>(),
2280 Box::new(move |cx| {
2281 window_handle
2282 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2283 .unwrap_or(false)
2284 }),
2285 );
2286 self.app.defer(move |_| activate());
2287 subscription
2288 }
2289
2290 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2291 pub fn on_action(
2292 &mut self,
2293 action_type: TypeId,
2294 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2295 ) {
2296 let handle = self.view().clone();
2297 self.window_cx
2298 .on_action(action_type, move |action, phase, cx| {
2299 handle.update(cx, |view, cx| {
2300 listener(view, action, phase, cx);
2301 })
2302 });
2303 }
2304
2305 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2306 pub fn emit<Evt>(&mut self, event: Evt)
2307 where
2308 Evt: 'static,
2309 V: EventEmitter<Evt>,
2310 {
2311 let emitter = self.view.model.entity_id;
2312 self.app.push_effect(Effect::Emit {
2313 emitter,
2314 event_type: TypeId::of::<Evt>(),
2315 event: Box::new(event),
2316 });
2317 }
2318
2319 /// Move focus to the current view, assuming it implements [`FocusableView`].
2320 pub fn focus_self(&mut self)
2321 where
2322 V: FocusableView,
2323 {
2324 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2325 }
2326
2327 /// Convenience method for accessing view state in an event callback.
2328 ///
2329 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2330 /// but it's often useful to be able to access view state in these
2331 /// callbacks. This method provides a convenient way to do so.
2332 pub fn listener<E>(
2333 &self,
2334 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2335 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2336 let view = self.view().downgrade();
2337 move |e: &E, cx: &mut WindowContext| {
2338 view.update(cx, |view, cx| f(view, e, cx)).ok();
2339 }
2340 }
2341}
2342
2343impl<V> Context for ViewContext<'_, V> {
2344 type Result<U> = U;
2345
2346 fn new_model<T: 'static>(
2347 &mut self,
2348 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2349 ) -> Model<T> {
2350 self.window_cx.new_model(build_model)
2351 }
2352
2353 fn update_model<T: 'static, R>(
2354 &mut self,
2355 model: &Model<T>,
2356 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2357 ) -> R {
2358 self.window_cx.update_model(model, update)
2359 }
2360
2361 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2362 where
2363 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2364 {
2365 self.window_cx.update_window(window, update)
2366 }
2367
2368 fn read_model<T, R>(
2369 &self,
2370 handle: &Model<T>,
2371 read: impl FnOnce(&T, &AppContext) -> R,
2372 ) -> Self::Result<R>
2373 where
2374 T: 'static,
2375 {
2376 self.window_cx.read_model(handle, read)
2377 }
2378
2379 fn read_window<T, R>(
2380 &self,
2381 window: &WindowHandle<T>,
2382 read: impl FnOnce(View<T>, &AppContext) -> R,
2383 ) -> Result<R>
2384 where
2385 T: 'static,
2386 {
2387 self.window_cx.read_window(window, read)
2388 }
2389}
2390
2391impl<V: 'static> VisualContext for ViewContext<'_, V> {
2392 fn new_view<W: Render + 'static>(
2393 &mut self,
2394 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2395 ) -> Self::Result<View<W>> {
2396 self.window_cx.new_view(build_view_state)
2397 }
2398
2399 fn update_view<V2: 'static, R>(
2400 &mut self,
2401 view: &View<V2>,
2402 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2403 ) -> Self::Result<R> {
2404 self.window_cx.update_view(view, update)
2405 }
2406
2407 fn replace_root_view<W>(
2408 &mut self,
2409 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2410 ) -> Self::Result<View<W>>
2411 where
2412 W: 'static + Render,
2413 {
2414 self.window_cx.replace_root_view(build_view)
2415 }
2416
2417 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2418 self.window_cx.focus_view(view)
2419 }
2420
2421 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2422 self.window_cx.dismiss_view(view)
2423 }
2424}
2425
2426impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2427 type Target = WindowContext<'a>;
2428
2429 fn deref(&self) -> &Self::Target {
2430 &self.window_cx
2431 }
2432}
2433
2434impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2435 fn deref_mut(&mut self) -> &mut Self::Target {
2436 &mut self.window_cx
2437 }
2438}
2439
2440// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2441slotmap::new_key_type! {
2442 /// A unique identifier for a window.
2443 pub struct WindowId;
2444}
2445
2446impl WindowId {
2447 /// Converts this window ID to a `u64`.
2448 pub fn as_u64(&self) -> u64 {
2449 self.0.as_ffi()
2450 }
2451}
2452
2453/// A handle to a window with a specific root view type.
2454/// Note that this does not keep the window alive on its own.
2455#[derive(Deref, DerefMut)]
2456pub struct WindowHandle<V> {
2457 #[deref]
2458 #[deref_mut]
2459 pub(crate) any_handle: AnyWindowHandle,
2460 state_type: PhantomData<V>,
2461}
2462
2463impl<V: 'static + Render> WindowHandle<V> {
2464 /// Creates a new handle from a window ID.
2465 /// This does not check if the root type of the window is `V`.
2466 pub fn new(id: WindowId) -> Self {
2467 WindowHandle {
2468 any_handle: AnyWindowHandle {
2469 id,
2470 state_type: TypeId::of::<V>(),
2471 },
2472 state_type: PhantomData,
2473 }
2474 }
2475
2476 /// Get the root view out of this window.
2477 ///
2478 /// This will fail if the window is closed or if the root view's type does not match `V`.
2479 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2480 where
2481 C: Context,
2482 {
2483 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2484 root_view
2485 .downcast::<V>()
2486 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2487 }))
2488 }
2489
2490 /// Updates the root view of this window.
2491 ///
2492 /// This will fail if the window has been closed or if the root view's type does not match
2493 pub fn update<C, R>(
2494 &self,
2495 cx: &mut C,
2496 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2497 ) -> Result<R>
2498 where
2499 C: Context,
2500 {
2501 cx.update_window(self.any_handle, |root_view, cx| {
2502 let view = root_view
2503 .downcast::<V>()
2504 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2505 Ok(cx.update_view(&view, update))
2506 })?
2507 }
2508
2509 /// Read the root view out of this window.
2510 ///
2511 /// This will fail if the window is closed or if the root view's type does not match `V`.
2512 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2513 let x = cx
2514 .windows
2515 .get(self.id)
2516 .and_then(|window| {
2517 window
2518 .as_ref()
2519 .and_then(|window| window.root_view.clone())
2520 .map(|root_view| root_view.downcast::<V>())
2521 })
2522 .ok_or_else(|| anyhow!("window not found"))?
2523 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2524
2525 Ok(x.read(cx))
2526 }
2527
2528 /// Read the root view out of this window, with a callback
2529 ///
2530 /// This will fail if the window is closed or if the root view's type does not match `V`.
2531 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2532 where
2533 C: Context,
2534 {
2535 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2536 }
2537
2538 /// Read the root view pointer off of this window.
2539 ///
2540 /// This will fail if the window is closed or if the root view's type does not match `V`.
2541 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2542 where
2543 C: Context,
2544 {
2545 cx.read_window(self, |root_view, _cx| root_view.clone())
2546 }
2547
2548 /// Check if this window is 'active'.
2549 ///
2550 /// Will return `None` if the window is closed or currently
2551 /// borrowed.
2552 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
2553 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
2554 .ok()
2555 }
2556}
2557
2558impl<V> Copy for WindowHandle<V> {}
2559
2560impl<V> Clone for WindowHandle<V> {
2561 fn clone(&self) -> Self {
2562 *self
2563 }
2564}
2565
2566impl<V> PartialEq for WindowHandle<V> {
2567 fn eq(&self, other: &Self) -> bool {
2568 self.any_handle == other.any_handle
2569 }
2570}
2571
2572impl<V> Eq for WindowHandle<V> {}
2573
2574impl<V> Hash for WindowHandle<V> {
2575 fn hash<H: Hasher>(&self, state: &mut H) {
2576 self.any_handle.hash(state);
2577 }
2578}
2579
2580impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2581 fn from(val: WindowHandle<V>) -> Self {
2582 val.any_handle
2583 }
2584}
2585
2586/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2587#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2588pub struct AnyWindowHandle {
2589 pub(crate) id: WindowId,
2590 state_type: TypeId,
2591}
2592
2593impl AnyWindowHandle {
2594 /// Get the ID of this window.
2595 pub fn window_id(&self) -> WindowId {
2596 self.id
2597 }
2598
2599 /// Attempt to convert this handle to a window handle with a specific root view type.
2600 /// If the types do not match, this will return `None`.
2601 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2602 if TypeId::of::<T>() == self.state_type {
2603 Some(WindowHandle {
2604 any_handle: *self,
2605 state_type: PhantomData,
2606 })
2607 } else {
2608 None
2609 }
2610 }
2611
2612 /// Updates the state of the root view of this window.
2613 ///
2614 /// This will fail if the window has been closed.
2615 pub fn update<C, R>(
2616 self,
2617 cx: &mut C,
2618 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2619 ) -> Result<R>
2620 where
2621 C: Context,
2622 {
2623 cx.update_window(self, update)
2624 }
2625
2626 /// Read the state of the root view of this window.
2627 ///
2628 /// This will fail if the window has been closed.
2629 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2630 where
2631 C: Context,
2632 T: 'static,
2633 {
2634 let view = self
2635 .downcast::<T>()
2636 .context("the type of the window's root view has changed")?;
2637
2638 cx.read_window(&view, read)
2639 }
2640}
2641
2642/// An identifier for an [`Element`](crate::Element).
2643///
2644/// Can be constructed with a string, a number, or both, as well
2645/// as other internal representations.
2646#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2647pub enum ElementId {
2648 /// The ID of a View element
2649 View(EntityId),
2650 /// An integer ID.
2651 Integer(usize),
2652 /// A string based ID.
2653 Name(SharedString),
2654 /// An ID that's equated with a focus handle.
2655 FocusHandle(FocusId),
2656 /// A combination of a name and an integer.
2657 NamedInteger(SharedString, usize),
2658}
2659
2660impl Display for ElementId {
2661 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2662 match self {
2663 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2664 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2665 ElementId::Name(name) => write!(f, "{}", name)?,
2666 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
2667 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2668 }
2669
2670 Ok(())
2671 }
2672}
2673
2674impl TryInto<SharedString> for ElementId {
2675 type Error = anyhow::Error;
2676
2677 fn try_into(self) -> anyhow::Result<SharedString> {
2678 if let ElementId::Name(name) = self {
2679 Ok(name)
2680 } else {
2681 Err(anyhow!("element id is not string"))
2682 }
2683 }
2684}
2685
2686impl From<usize> for ElementId {
2687 fn from(id: usize) -> Self {
2688 ElementId::Integer(id)
2689 }
2690}
2691
2692impl From<i32> for ElementId {
2693 fn from(id: i32) -> Self {
2694 Self::Integer(id as usize)
2695 }
2696}
2697
2698impl From<SharedString> for ElementId {
2699 fn from(name: SharedString) -> Self {
2700 ElementId::Name(name)
2701 }
2702}
2703
2704impl From<&'static str> for ElementId {
2705 fn from(name: &'static str) -> Self {
2706 ElementId::Name(name.into())
2707 }
2708}
2709
2710impl<'a> From<&'a FocusHandle> for ElementId {
2711 fn from(handle: &'a FocusHandle) -> Self {
2712 ElementId::FocusHandle(handle.id)
2713 }
2714}
2715
2716impl From<(&'static str, EntityId)> for ElementId {
2717 fn from((name, id): (&'static str, EntityId)) -> Self {
2718 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2719 }
2720}
2721
2722impl From<(&'static str, usize)> for ElementId {
2723 fn from((name, id): (&'static str, usize)) -> Self {
2724 ElementId::NamedInteger(name.into(), id)
2725 }
2726}
2727
2728impl From<(&'static str, u64)> for ElementId {
2729 fn from((name, id): (&'static str, u64)) -> Self {
2730 ElementId::NamedInteger(name.into(), id as usize)
2731 }
2732}
2733
2734/// A rectangle to be rendered in the window at the given position and size.
2735/// Passed as an argument [`ElementContext::paint_quad`].
2736#[derive(Clone)]
2737pub struct PaintQuad {
2738 bounds: Bounds<Pixels>,
2739 corner_radii: Corners<Pixels>,
2740 background: Hsla,
2741 border_widths: Edges<Pixels>,
2742 border_color: Hsla,
2743}
2744
2745impl PaintQuad {
2746 /// Sets the corner radii of the quad.
2747 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2748 PaintQuad {
2749 corner_radii: corner_radii.into(),
2750 ..self
2751 }
2752 }
2753
2754 /// Sets the border widths of the quad.
2755 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2756 PaintQuad {
2757 border_widths: border_widths.into(),
2758 ..self
2759 }
2760 }
2761
2762 /// Sets the border color of the quad.
2763 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2764 PaintQuad {
2765 border_color: border_color.into(),
2766 ..self
2767 }
2768 }
2769
2770 /// Sets the background color of the quad.
2771 pub fn background(self, background: impl Into<Hsla>) -> Self {
2772 PaintQuad {
2773 background: background.into(),
2774 ..self
2775 }
2776 }
2777}
2778
2779/// Creates a quad with the given parameters.
2780pub fn quad(
2781 bounds: Bounds<Pixels>,
2782 corner_radii: impl Into<Corners<Pixels>>,
2783 background: impl Into<Hsla>,
2784 border_widths: impl Into<Edges<Pixels>>,
2785 border_color: impl Into<Hsla>,
2786) -> PaintQuad {
2787 PaintQuad {
2788 bounds,
2789 corner_radii: corner_radii.into(),
2790 background: background.into(),
2791 border_widths: border_widths.into(),
2792 border_color: border_color.into(),
2793 }
2794}
2795
2796/// Creates a filled quad with the given bounds and background color.
2797pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2798 PaintQuad {
2799 bounds: bounds.into(),
2800 corner_radii: (0.).into(),
2801 background: background.into(),
2802 border_widths: (0.).into(),
2803 border_color: transparent_black(),
2804 }
2805}
2806
2807/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2808pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2809 PaintQuad {
2810 bounds: bounds.into(),
2811 corner_radii: (0.).into(),
2812 background: transparent_black(),
2813 border_widths: (1.).into(),
2814 border_color: border_color.into(),
2815 }
2816}