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