1use scheduler::Instant;
2use std::{
3 any::{TypeId, type_name},
4 cell::{BorrowMutError, Cell, Ref, RefCell, RefMut},
5 marker::PhantomData,
6 mem,
7 ops::{Deref, DerefMut},
8 path::{Path, PathBuf},
9 rc::{Rc, Weak},
10 sync::{Arc, atomic::Ordering::SeqCst},
11 time::Duration,
12};
13
14use anyhow::{Context as _, Result, anyhow};
15use derive_more::{Deref, DerefMut};
16use futures::{
17 Future, FutureExt,
18 channel::oneshot,
19 future::{LocalBoxFuture, Shared},
20};
21use itertools::Itertools;
22use parking_lot::RwLock;
23use slotmap::SlotMap;
24
25pub use async_context::*;
26use collections::{FxHashMap, FxHashSet, HashMap, VecDeque};
27pub use context::*;
28pub use entity_map::*;
29use gpui_util::{ResultExt, debug_panic};
30#[cfg(any(test, feature = "test-support"))]
31pub use headless_app_context::*;
32use http_client::{HttpClient, Url};
33use smallvec::SmallVec;
34#[cfg(any(test, feature = "test-support"))]
35pub use test_app::*;
36#[cfg(any(test, feature = "test-support"))]
37pub use test_context::*;
38#[cfg(all(target_os = "macos", any(test, feature = "test-support")))]
39pub use visual_test_context::*;
40
41#[cfg(any(feature = "inspector", debug_assertions))]
42use crate::InspectorElementRegistry;
43use crate::{
44 Action, ActionBuildError, ActionRegistry, Any, AnyView, AnyWindowHandle, AppContext, Arena,
45 ArenaBox, Asset, AssetSource, BackgroundExecutor, Bounds, ClipboardItem, CursorStyle,
46 DispatchPhase, DisplayId, EventEmitter, FocusHandle, FocusMap, ForegroundExecutor, Global,
47 KeyBinding, KeyContext, Keymap, Keystroke, LayoutId, Menu, MenuItem, OwnedMenu,
48 PathPromptOptions, Pixels, Platform, PlatformDisplay, PlatformKeyboardLayout,
49 PlatformKeyboardMapper, Point, Priority, PromptBuilder, PromptButton, PromptHandle,
50 PromptLevel, Render, RenderImage, RenderablePromptHandle, Reservation, ScreenCaptureSource,
51 SharedString, SubscriberSet, Subscription, SvgRenderer, Task, TextRenderingMode, TextSystem,
52 ThermalState, Window, WindowAppearance, WindowButtonLayout, WindowHandle, WindowId,
53 WindowInvalidator,
54 colors::{Colors, GlobalColors},
55 hash, init_app_menus,
56};
57
58mod async_context;
59mod context;
60mod entity_map;
61#[cfg(any(test, feature = "test-support"))]
62mod headless_app_context;
63#[cfg(any(test, feature = "test-support"))]
64mod test_app;
65#[cfg(any(test, feature = "test-support"))]
66mod test_context;
67#[cfg(all(target_os = "macos", any(test, feature = "test-support")))]
68mod visual_test_context;
69
70/// The duration for which futures returned from [Context::on_app_quit] can run before the application fully quits.
71pub const SHUTDOWN_TIMEOUT: Duration = Duration::from_millis(100);
72
73/// Temporary(?) wrapper around [`RefCell<App>`] to help us debug any double borrows.
74/// Strongly consider removing after stabilization.
75#[doc(hidden)]
76pub struct AppCell {
77 app: RefCell<App>,
78}
79
80impl AppCell {
81 #[doc(hidden)]
82 #[track_caller]
83 pub fn borrow(&self) -> AppRef<'_> {
84 if option_env!("TRACK_THREAD_BORROWS").is_some() {
85 let thread_id = std::thread::current().id();
86 eprintln!("borrowed {thread_id:?}");
87 }
88 AppRef(self.app.borrow())
89 }
90
91 #[doc(hidden)]
92 #[track_caller]
93 pub fn borrow_mut(&self) -> AppRefMut<'_> {
94 if option_env!("TRACK_THREAD_BORROWS").is_some() {
95 let thread_id = std::thread::current().id();
96 eprintln!("borrowed {thread_id:?}");
97 }
98 AppRefMut(self.app.borrow_mut())
99 }
100
101 #[doc(hidden)]
102 #[track_caller]
103 pub fn try_borrow_mut(&self) -> Result<AppRefMut<'_>, BorrowMutError> {
104 if option_env!("TRACK_THREAD_BORROWS").is_some() {
105 let thread_id = std::thread::current().id();
106 eprintln!("borrowed {thread_id:?}");
107 }
108 Ok(AppRefMut(self.app.try_borrow_mut()?))
109 }
110}
111
112#[doc(hidden)]
113#[derive(Deref, DerefMut)]
114pub struct AppRef<'a>(Ref<'a, App>);
115
116impl Drop for AppRef<'_> {
117 fn drop(&mut self) {
118 if option_env!("TRACK_THREAD_BORROWS").is_some() {
119 let thread_id = std::thread::current().id();
120 eprintln!("dropped borrow from {thread_id:?}");
121 }
122 }
123}
124
125#[doc(hidden)]
126#[derive(Deref, DerefMut)]
127pub struct AppRefMut<'a>(RefMut<'a, App>);
128
129impl Drop for AppRefMut<'_> {
130 fn drop(&mut self) {
131 if option_env!("TRACK_THREAD_BORROWS").is_some() {
132 let thread_id = std::thread::current().id();
133 eprintln!("dropped {thread_id:?}");
134 }
135 }
136}
137
138/// A reference to a GPUI application, typically constructed in the `main` function of your app.
139/// You won't interact with this type much outside of initial configuration and startup.
140pub struct Application(Rc<AppCell>);
141
142/// Represents an application before it is fully launched. Once your app is
143/// configured, you'll start the app with `App::run`.
144impl Application {
145 /// Builds an app with a caller-provided platform implementation.
146 pub fn with_platform(platform: Rc<dyn Platform>) -> Self {
147 Self(App::new_app(
148 platform,
149 Arc::new(()),
150 Arc::new(NullHttpClient),
151 ))
152 }
153
154 /// Assigns the source of assets for the application.
155 pub fn with_assets(self, asset_source: impl AssetSource) -> Self {
156 let mut context_lock = self.0.borrow_mut();
157 let asset_source = Arc::new(asset_source);
158 context_lock.asset_source = asset_source.clone();
159 context_lock.svg_renderer = SvgRenderer::new(asset_source);
160 drop(context_lock);
161 self
162 }
163
164 /// Sets the HTTP client for the application.
165 pub fn with_http_client(self, http_client: Arc<dyn HttpClient>) -> Self {
166 let mut context_lock = self.0.borrow_mut();
167 context_lock.http_client = http_client;
168 drop(context_lock);
169 self
170 }
171
172 /// Configures when the application should automatically quit.
173 /// By default, [`QuitMode::Default`] is used.
174 pub fn with_quit_mode(self, mode: QuitMode) -> Self {
175 self.0.borrow_mut().quit_mode = mode;
176 self
177 }
178
179 /// Start the application. The provided callback will be called once the
180 /// app is fully launched.
181 pub fn run<F>(self, on_finish_launching: F)
182 where
183 F: 'static + FnOnce(&mut App),
184 {
185 let this = self.0.clone();
186 let platform = self.0.borrow().platform.clone();
187 platform.run(Box::new(move || {
188 let cx = &mut *this.borrow_mut();
189 on_finish_launching(cx);
190 }));
191 }
192
193 /// Register a handler to be invoked when the platform instructs the application
194 /// to open one or more URLs.
195 pub fn on_open_urls<F>(&self, mut callback: F) -> &Self
196 where
197 F: 'static + FnMut(Vec<String>),
198 {
199 self.0.borrow().platform.on_open_urls(Box::new(callback));
200 self
201 }
202
203 /// Invokes a handler when an already-running application is launched.
204 /// On macOS, this can occur when the application icon is double-clicked or the app is launched via the dock.
205 pub fn on_reopen<F>(&self, mut callback: F) -> &Self
206 where
207 F: 'static + FnMut(&mut App),
208 {
209 let this = Rc::downgrade(&self.0);
210 self.0.borrow_mut().platform.on_reopen(Box::new(move || {
211 if let Some(app) = this.upgrade() {
212 callback(&mut app.borrow_mut());
213 }
214 }));
215 self
216 }
217
218 /// Returns a handle to the [`BackgroundExecutor`] associated with this app, which can be used to spawn futures in the background.
219 pub fn background_executor(&self) -> BackgroundExecutor {
220 self.0.borrow().background_executor.clone()
221 }
222
223 /// Returns a handle to the [`ForegroundExecutor`] associated with this app, which can be used to spawn futures in the foreground.
224 pub fn foreground_executor(&self) -> ForegroundExecutor {
225 self.0.borrow().foreground_executor.clone()
226 }
227
228 /// Returns a reference to the [`TextSystem`] associated with this app.
229 pub fn text_system(&self) -> Arc<TextSystem> {
230 self.0.borrow().text_system.clone()
231 }
232
233 /// Returns the file URL of the executable with the specified name in the application bundle
234 pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
235 self.0.borrow().path_for_auxiliary_executable(name)
236 }
237}
238
239type Handler = Box<dyn FnMut(&mut App) -> bool + 'static>;
240type Listener = Box<dyn FnMut(&dyn Any, &mut App) -> bool + 'static>;
241pub(crate) type KeystrokeObserver =
242 Box<dyn FnMut(&KeystrokeEvent, &mut Window, &mut App) -> bool + 'static>;
243type QuitHandler = Box<dyn FnOnce(&mut App) -> LocalBoxFuture<'static, ()> + 'static>;
244type WindowClosedHandler = Box<dyn FnMut(&mut App, WindowId)>;
245type ReleaseListener = Box<dyn FnOnce(&mut dyn Any, &mut App) + 'static>;
246type NewEntityListener = Box<dyn FnMut(AnyEntity, &mut Option<&mut Window>, &mut App) + 'static>;
247
248/// Defines when the application should automatically quit.
249#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
250pub enum QuitMode {
251 /// Use [`QuitMode::Explicit`] on macOS and [`QuitMode::LastWindowClosed`] on other platforms.
252 #[default]
253 Default,
254 /// Quit automatically when the last window is closed.
255 LastWindowClosed,
256 /// Quit only when requested via [`App::quit`].
257 Explicit,
258}
259
260#[doc(hidden)]
261#[derive(Clone, PartialEq, Eq)]
262pub struct SystemWindowTab {
263 pub id: WindowId,
264 pub title: SharedString,
265 pub handle: AnyWindowHandle,
266 pub last_active_at: Instant,
267}
268
269impl SystemWindowTab {
270 /// Create a new instance of the window tab.
271 pub fn new(title: SharedString, handle: AnyWindowHandle) -> Self {
272 Self {
273 id: handle.id,
274 title,
275 handle,
276 last_active_at: Instant::now(),
277 }
278 }
279}
280
281/// A controller for managing window tabs.
282#[derive(Default)]
283pub struct SystemWindowTabController {
284 visible: Option<bool>,
285 tab_groups: FxHashMap<usize, Vec<SystemWindowTab>>,
286}
287
288impl Global for SystemWindowTabController {}
289
290impl SystemWindowTabController {
291 /// Create a new instance of the window tab controller.
292 pub fn new() -> Self {
293 Self {
294 visible: None,
295 tab_groups: FxHashMap::default(),
296 }
297 }
298
299 /// Initialize the global window tab controller.
300 pub fn init(cx: &mut App) {
301 cx.set_global(SystemWindowTabController::new());
302 }
303
304 /// Get all tab groups.
305 pub fn tab_groups(&self) -> &FxHashMap<usize, Vec<SystemWindowTab>> {
306 &self.tab_groups
307 }
308
309 /// Get the next tab group window handle.
310 pub fn get_next_tab_group_window(cx: &mut App, id: WindowId) -> Option<&AnyWindowHandle> {
311 let controller = cx.global::<SystemWindowTabController>();
312 let current_group = controller
313 .tab_groups
314 .iter()
315 .find_map(|(group, tabs)| tabs.iter().find(|tab| tab.id == id).map(|_| group));
316
317 let current_group = current_group?;
318 // TODO: `.keys()` returns arbitrary order, what does "next" mean?
319 let mut group_ids: Vec<_> = controller.tab_groups.keys().collect();
320 let idx = group_ids.iter().position(|g| *g == current_group)?;
321 let next_idx = (idx + 1) % group_ids.len();
322
323 controller
324 .tab_groups
325 .get(group_ids[next_idx])
326 .and_then(|tabs| {
327 tabs.iter()
328 .max_by_key(|tab| tab.last_active_at)
329 .or_else(|| tabs.first())
330 .map(|tab| &tab.handle)
331 })
332 }
333
334 /// Get the previous tab group window handle.
335 pub fn get_prev_tab_group_window(cx: &mut App, id: WindowId) -> Option<&AnyWindowHandle> {
336 let controller = cx.global::<SystemWindowTabController>();
337 let current_group = controller
338 .tab_groups
339 .iter()
340 .find_map(|(group, tabs)| tabs.iter().find(|tab| tab.id == id).map(|_| group));
341
342 let current_group = current_group?;
343 // TODO: `.keys()` returns arbitrary order, what does "previous" mean?
344 let mut group_ids: Vec<_> = controller.tab_groups.keys().collect();
345 let idx = group_ids.iter().position(|g| *g == current_group)?;
346 let prev_idx = if idx == 0 {
347 group_ids.len() - 1
348 } else {
349 idx - 1
350 };
351
352 controller
353 .tab_groups
354 .get(group_ids[prev_idx])
355 .and_then(|tabs| {
356 tabs.iter()
357 .max_by_key(|tab| tab.last_active_at)
358 .or_else(|| tabs.first())
359 .map(|tab| &tab.handle)
360 })
361 }
362
363 /// Get all tabs in the same window.
364 pub fn tabs(&self, id: WindowId) -> Option<&Vec<SystemWindowTab>> {
365 self.tab_groups
366 .values()
367 .find(|tabs| tabs.iter().any(|tab| tab.id == id))
368 }
369
370 /// Initialize the visibility of the system window tab controller.
371 pub fn init_visible(cx: &mut App, visible: bool) {
372 let mut controller = cx.global_mut::<SystemWindowTabController>();
373 if controller.visible.is_none() {
374 controller.visible = Some(visible);
375 }
376 }
377
378 /// Get the visibility of the system window tab controller.
379 pub fn is_visible(&self) -> bool {
380 self.visible.unwrap_or(false)
381 }
382
383 /// Set the visibility of the system window tab controller.
384 pub fn set_visible(cx: &mut App, visible: bool) {
385 let mut controller = cx.global_mut::<SystemWindowTabController>();
386 controller.visible = Some(visible);
387 }
388
389 /// Update the last active of a window.
390 pub fn update_last_active(cx: &mut App, id: WindowId) {
391 let mut controller = cx.global_mut::<SystemWindowTabController>();
392 for windows in controller.tab_groups.values_mut() {
393 for tab in windows.iter_mut() {
394 if tab.id == id {
395 tab.last_active_at = Instant::now();
396 }
397 }
398 }
399 }
400
401 /// Update the position of a tab within its group.
402 pub fn update_tab_position(cx: &mut App, id: WindowId, ix: usize) {
403 let mut controller = cx.global_mut::<SystemWindowTabController>();
404 for (_, windows) in controller.tab_groups.iter_mut() {
405 if let Some(current_pos) = windows.iter().position(|tab| tab.id == id) {
406 if ix < windows.len() && current_pos != ix {
407 let window_tab = windows.remove(current_pos);
408 windows.insert(ix, window_tab);
409 }
410 break;
411 }
412 }
413 }
414
415 /// Update the title of a tab.
416 pub fn update_tab_title(cx: &mut App, id: WindowId, title: SharedString) {
417 let controller = cx.global::<SystemWindowTabController>();
418 let tab = controller
419 .tab_groups
420 .values()
421 .flat_map(|windows| windows.iter())
422 .find(|tab| tab.id == id);
423
424 if tab.map_or(true, |t| t.title == title) {
425 return;
426 }
427
428 let mut controller = cx.global_mut::<SystemWindowTabController>();
429 for windows in controller.tab_groups.values_mut() {
430 for tab in windows.iter_mut() {
431 if tab.id == id {
432 tab.title = title;
433 return;
434 }
435 }
436 }
437 }
438
439 /// Insert a tab into a tab group.
440 pub fn add_tab(cx: &mut App, id: WindowId, tabs: Vec<SystemWindowTab>) {
441 let mut controller = cx.global_mut::<SystemWindowTabController>();
442 let Some(tab) = tabs.iter().find(|tab| tab.id == id).cloned() else {
443 return;
444 };
445
446 let mut expected_tab_ids: Vec<_> = tabs
447 .iter()
448 .filter(|tab| tab.id != id)
449 .map(|tab| tab.id)
450 .sorted()
451 .collect();
452
453 let mut tab_group_id = None;
454 for (group_id, group_tabs) in &controller.tab_groups {
455 let tab_ids: Vec<_> = group_tabs.iter().map(|tab| tab.id).sorted().collect();
456 if tab_ids == expected_tab_ids {
457 tab_group_id = Some(*group_id);
458 break;
459 }
460 }
461
462 if let Some(tab_group_id) = tab_group_id {
463 if let Some(tabs) = controller.tab_groups.get_mut(&tab_group_id) {
464 tabs.push(tab);
465 }
466 } else {
467 let new_group_id = controller.tab_groups.len();
468 controller.tab_groups.insert(new_group_id, tabs);
469 }
470 }
471
472 /// Remove a tab from a tab group.
473 pub fn remove_tab(cx: &mut App, id: WindowId) -> Option<SystemWindowTab> {
474 let mut controller = cx.global_mut::<SystemWindowTabController>();
475 let mut removed_tab = None;
476
477 controller.tab_groups.retain(|_, tabs| {
478 if let Some(pos) = tabs.iter().position(|tab| tab.id == id) {
479 removed_tab = Some(tabs.remove(pos));
480 }
481 !tabs.is_empty()
482 });
483
484 removed_tab
485 }
486
487 /// Move a tab to a new tab group.
488 pub fn move_tab_to_new_window(cx: &mut App, id: WindowId) {
489 let mut removed_tab = Self::remove_tab(cx, id);
490 let mut controller = cx.global_mut::<SystemWindowTabController>();
491
492 if let Some(tab) = removed_tab {
493 let new_group_id = controller.tab_groups.keys().max().map_or(0, |k| k + 1);
494 controller.tab_groups.insert(new_group_id, vec![tab]);
495 }
496 }
497
498 /// Merge all tab groups into a single group.
499 pub fn merge_all_windows(cx: &mut App, id: WindowId) {
500 let mut controller = cx.global_mut::<SystemWindowTabController>();
501 let Some(initial_tabs) = controller.tabs(id) else {
502 return;
503 };
504
505 let initial_tabs_len = initial_tabs.len();
506 let mut all_tabs = initial_tabs.clone();
507
508 for (_, mut tabs) in controller.tab_groups.drain() {
509 tabs.retain(|tab| !all_tabs[..initial_tabs_len].contains(tab));
510 all_tabs.extend(tabs);
511 }
512
513 controller.tab_groups.insert(0, all_tabs);
514 }
515
516 /// Selects the next tab in the tab group in the trailing direction.
517 pub fn select_next_tab(cx: &mut App, id: WindowId) {
518 let mut controller = cx.global_mut::<SystemWindowTabController>();
519 let Some(tabs) = controller.tabs(id) else {
520 return;
521 };
522
523 let current_index = tabs.iter().position(|tab| tab.id == id).unwrap();
524 let next_index = (current_index + 1) % tabs.len();
525
526 let _ = &tabs[next_index].handle.update(cx, |_, window, _| {
527 window.activate_window();
528 });
529 }
530
531 /// Selects the previous tab in the tab group in the leading direction.
532 pub fn select_previous_tab(cx: &mut App, id: WindowId) {
533 let mut controller = cx.global_mut::<SystemWindowTabController>();
534 let Some(tabs) = controller.tabs(id) else {
535 return;
536 };
537
538 let current_index = tabs.iter().position(|tab| tab.id == id).unwrap();
539 let previous_index = if current_index == 0 {
540 tabs.len() - 1
541 } else {
542 current_index - 1
543 };
544
545 let _ = &tabs[previous_index].handle.update(cx, |_, window, _| {
546 window.activate_window();
547 });
548 }
549}
550
551pub(crate) enum GpuiMode {
552 #[cfg(any(test, feature = "test-support"))]
553 Test {
554 skip_drawing: bool,
555 },
556 Production,
557}
558
559impl GpuiMode {
560 #[cfg(any(test, feature = "test-support"))]
561 pub fn test() -> Self {
562 GpuiMode::Test {
563 skip_drawing: false,
564 }
565 }
566
567 #[inline]
568 pub(crate) fn skip_drawing(&self) -> bool {
569 match self {
570 #[cfg(any(test, feature = "test-support"))]
571 GpuiMode::Test { skip_drawing } => *skip_drawing,
572 GpuiMode::Production => false,
573 }
574 }
575}
576
577/// Contains the state of the full application, and passed as a reference to a variety of callbacks.
578/// Other [Context] derefs to this type.
579/// You need a reference to an `App` to access the state of a [Entity].
580pub struct App {
581 pub(crate) this: Weak<AppCell>,
582 pub(crate) platform: Rc<dyn Platform>,
583 text_system: Arc<TextSystem>,
584
585 pub(crate) actions: Rc<ActionRegistry>,
586 pub(crate) active_drag: Option<AnyDrag>,
587 pub(crate) background_executor: BackgroundExecutor,
588 pub(crate) foreground_executor: ForegroundExecutor,
589 pub(crate) entities: EntityMap,
590 pub(crate) new_entity_observers: SubscriberSet<TypeId, NewEntityListener>,
591 pub(crate) windows: SlotMap<WindowId, Option<Box<Window>>>,
592 pub(crate) window_handles: FxHashMap<WindowId, AnyWindowHandle>,
593 pub(crate) focus_handles: Arc<FocusMap>,
594 pub(crate) keymap: Rc<RefCell<Keymap>>,
595 pub(crate) keyboard_layout: Box<dyn PlatformKeyboardLayout>,
596 pub(crate) keyboard_mapper: Rc<dyn PlatformKeyboardMapper>,
597 pub(crate) global_action_listeners:
598 FxHashMap<TypeId, Vec<Rc<dyn Fn(&dyn Any, DispatchPhase, &mut Self)>>>,
599 pending_effects: VecDeque<Effect>,
600
601 pub(crate) observers: SubscriberSet<EntityId, Handler>,
602 pub(crate) event_listeners: SubscriberSet<EntityId, (TypeId, Listener)>,
603 pub(crate) keystroke_observers: SubscriberSet<(), KeystrokeObserver>,
604 pub(crate) keystroke_interceptors: SubscriberSet<(), KeystrokeObserver>,
605 pub(crate) keyboard_layout_observers: SubscriberSet<(), Handler>,
606 pub(crate) thermal_state_observers: SubscriberSet<(), Handler>,
607 pub(crate) release_listeners: SubscriberSet<EntityId, ReleaseListener>,
608 pub(crate) global_observers: SubscriberSet<TypeId, Handler>,
609 pub(crate) quit_observers: SubscriberSet<(), QuitHandler>,
610 pub(crate) restart_observers: SubscriberSet<(), Handler>,
611 pub(crate) window_closed_observers: SubscriberSet<(), WindowClosedHandler>,
612
613 /// Per-App element arena. This isolates element allocations between different
614 /// App instances (important for tests where multiple Apps run concurrently).
615 pub(crate) element_arena: RefCell<Arena>,
616 /// Per-App event arena.
617 pub(crate) event_arena: Arena,
618
619 // Drop globals last. We need to ensure all tasks owned by entities and
620 // callbacks are marked cancelled at this point as this will also shutdown
621 // the tokio runtime. As any task attempting to spawn a blocking tokio task,
622 // might panic.
623 pub(crate) globals_by_type: FxHashMap<TypeId, Box<dyn Any>>,
624
625 // assets
626 pub(crate) loading_assets: FxHashMap<(TypeId, u64), Box<dyn Any>>,
627 asset_source: Arc<dyn AssetSource>,
628 pub(crate) svg_renderer: SvgRenderer,
629 http_client: Arc<dyn HttpClient>,
630
631 // below is plain data, the drop order is insignificant here
632 pub(crate) pending_notifications: FxHashSet<EntityId>,
633 pub(crate) pending_global_notifications: FxHashSet<TypeId>,
634 pub(crate) restart_path: Option<PathBuf>,
635 pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
636 pub(crate) propagate_event: bool,
637 pub(crate) prompt_builder: Option<PromptBuilder>,
638 pub(crate) window_invalidators_by_entity:
639 FxHashMap<EntityId, FxHashMap<WindowId, WindowInvalidator>>,
640 pub(crate) tracked_entities: FxHashMap<WindowId, FxHashSet<EntityId>>,
641 #[cfg(any(feature = "inspector", debug_assertions))]
642 pub(crate) inspector_renderer: Option<crate::InspectorRenderer>,
643 #[cfg(any(feature = "inspector", debug_assertions))]
644 pub(crate) inspector_element_registry: InspectorElementRegistry,
645 #[cfg(any(test, feature = "test-support", debug_assertions))]
646 pub(crate) name: Option<&'static str>,
647 pub(crate) text_rendering_mode: Rc<Cell<TextRenderingMode>>,
648
649 pub(crate) window_update_stack: Vec<WindowId>,
650 pub(crate) mode: GpuiMode,
651 flushing_effects: bool,
652 pending_updates: usize,
653 quit_mode: QuitMode,
654 quitting: bool,
655
656 // We need to ensure the leak detector drops last, after all tasks, callbacks and things have been dropped.
657 // Otherwise it may report false positives.
658 #[cfg(any(test, feature = "leak-detection"))]
659 _ref_counts: Arc<RwLock<EntityRefCounts>>,
660}
661
662impl App {
663 #[allow(clippy::new_ret_no_self)]
664 pub(crate) fn new_app(
665 platform: Rc<dyn Platform>,
666 asset_source: Arc<dyn AssetSource>,
667 http_client: Arc<dyn HttpClient>,
668 ) -> Rc<AppCell> {
669 let background_executor = platform.background_executor();
670 let foreground_executor = platform.foreground_executor();
671 assert!(
672 background_executor.is_main_thread(),
673 "must construct App on main thread"
674 );
675
676 let text_system = Arc::new(TextSystem::new(platform.text_system()));
677 let entities = EntityMap::new();
678 let keyboard_layout = platform.keyboard_layout();
679 let keyboard_mapper = platform.keyboard_mapper();
680
681 #[cfg(any(test, feature = "leak-detection"))]
682 let _ref_counts = entities.ref_counts_drop_handle();
683
684 let app = Rc::new_cyclic(|this| AppCell {
685 app: RefCell::new(App {
686 this: this.clone(),
687 platform: platform.clone(),
688 text_system,
689 text_rendering_mode: Rc::new(Cell::new(TextRenderingMode::default())),
690 mode: GpuiMode::Production,
691 actions: Rc::new(ActionRegistry::default()),
692 flushing_effects: false,
693 pending_updates: 0,
694 active_drag: None,
695 background_executor,
696 foreground_executor,
697 svg_renderer: SvgRenderer::new(asset_source.clone()),
698 loading_assets: Default::default(),
699 asset_source,
700 http_client,
701 globals_by_type: FxHashMap::default(),
702 entities,
703 new_entity_observers: SubscriberSet::new(),
704 windows: SlotMap::with_key(),
705 window_update_stack: Vec::new(),
706 window_handles: FxHashMap::default(),
707 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
708 keymap: Rc::new(RefCell::new(Keymap::default())),
709 keyboard_layout,
710 keyboard_mapper,
711 global_action_listeners: FxHashMap::default(),
712 pending_effects: VecDeque::new(),
713 pending_notifications: FxHashSet::default(),
714 pending_global_notifications: FxHashSet::default(),
715 observers: SubscriberSet::new(),
716 tracked_entities: FxHashMap::default(),
717 window_invalidators_by_entity: FxHashMap::default(),
718 event_listeners: SubscriberSet::new(),
719 release_listeners: SubscriberSet::new(),
720 keystroke_observers: SubscriberSet::new(),
721 keystroke_interceptors: SubscriberSet::new(),
722 keyboard_layout_observers: SubscriberSet::new(),
723 thermal_state_observers: SubscriberSet::new(),
724 global_observers: SubscriberSet::new(),
725 quit_observers: SubscriberSet::new(),
726 restart_observers: SubscriberSet::new(),
727 restart_path: None,
728 window_closed_observers: SubscriberSet::new(),
729 layout_id_buffer: Default::default(),
730 propagate_event: true,
731 prompt_builder: Some(PromptBuilder::Default),
732 #[cfg(any(feature = "inspector", debug_assertions))]
733 inspector_renderer: None,
734 #[cfg(any(feature = "inspector", debug_assertions))]
735 inspector_element_registry: InspectorElementRegistry::default(),
736 quit_mode: QuitMode::default(),
737 quitting: false,
738
739 #[cfg(any(test, feature = "test-support", debug_assertions))]
740 name: None,
741 element_arena: RefCell::new(Arena::new(1024 * 1024)),
742 event_arena: Arena::new(1024 * 1024),
743
744 #[cfg(any(test, feature = "leak-detection"))]
745 _ref_counts,
746 }),
747 });
748
749 init_app_menus(platform.as_ref(), &app.borrow());
750 SystemWindowTabController::init(&mut app.borrow_mut());
751
752 platform.on_keyboard_layout_change(Box::new({
753 let app = Rc::downgrade(&app);
754 move || {
755 if let Some(app) = app.upgrade() {
756 let cx = &mut app.borrow_mut();
757 cx.keyboard_layout = cx.platform.keyboard_layout();
758 cx.keyboard_mapper = cx.platform.keyboard_mapper();
759 cx.keyboard_layout_observers
760 .clone()
761 .retain(&(), move |callback| (callback)(cx));
762 }
763 }
764 }));
765
766 platform.on_thermal_state_change(Box::new({
767 let app = Rc::downgrade(&app);
768 move || {
769 if let Some(app) = app.upgrade() {
770 let cx = &mut app.borrow_mut();
771 cx.thermal_state_observers
772 .clone()
773 .retain(&(), move |callback| (callback)(cx));
774 }
775 }
776 }));
777
778 platform.on_quit(Box::new({
779 let cx = Rc::downgrade(&app);
780 move || {
781 if let Some(cx) = cx.upgrade() {
782 cx.borrow_mut().shutdown();
783 }
784 }
785 }));
786
787 app
788 }
789
790 #[doc(hidden)]
791 pub fn ref_counts_drop_handle(&self) -> impl Sized + use<> {
792 self.entities.ref_counts_drop_handle()
793 }
794
795 /// Captures a snapshot of all entities that currently have alive handles.
796 ///
797 /// The returned [`LeakDetectorSnapshot`] can later be passed to
798 /// [`assert_no_new_leaks`](Self::assert_no_new_leaks) to verify that no
799 /// entities created after the snapshot are still alive.
800 #[cfg(any(test, feature = "leak-detection"))]
801 pub fn leak_detector_snapshot(&self) -> LeakDetectorSnapshot {
802 self.entities.leak_detector_snapshot()
803 }
804
805 /// Asserts that no entities created after `snapshot` still have alive handles.
806 ///
807 /// Entities that were already tracked at the time of the snapshot are ignored,
808 /// even if they still have handles. Only *new* entities (those whose
809 /// `EntityId` was not present in the snapshot) are considered leaks.
810 ///
811 /// # Panics
812 ///
813 /// Panics if any new entity handles exist. The panic message lists every
814 /// leaked entity with its type name, and includes allocation-site backtraces
815 /// when `LEAK_BACKTRACE` is set.
816 #[cfg(any(test, feature = "leak-detection"))]
817 pub fn assert_no_new_leaks(&self, snapshot: &LeakDetectorSnapshot) {
818 self.entities.assert_no_new_leaks(snapshot)
819 }
820
821 /// Quit the application gracefully. Handlers registered with [`Context::on_app_quit`]
822 /// will be given 100ms to complete before exiting.
823 pub fn shutdown(&mut self) {
824 let mut futures = Vec::new();
825
826 for observer in self.quit_observers.remove(&()) {
827 futures.push(observer(self));
828 }
829
830 self.windows.clear();
831 self.window_handles.clear();
832 self.flush_effects();
833 self.quitting = true;
834
835 let futures = futures::future::join_all(futures);
836 if self
837 .foreground_executor
838 .block_with_timeout(SHUTDOWN_TIMEOUT, futures)
839 .is_err()
840 {
841 log::error!("timed out waiting on app_will_quit");
842 }
843
844 self.quitting = false;
845 }
846
847 /// Get the id of the current keyboard layout
848 pub fn keyboard_layout(&self) -> &dyn PlatformKeyboardLayout {
849 self.keyboard_layout.as_ref()
850 }
851
852 /// Get the current keyboard mapper.
853 pub fn keyboard_mapper(&self) -> &Rc<dyn PlatformKeyboardMapper> {
854 &self.keyboard_mapper
855 }
856
857 /// Invokes a handler when the current keyboard layout changes
858 pub fn on_keyboard_layout_change<F>(&self, mut callback: F) -> Subscription
859 where
860 F: 'static + FnMut(&mut App),
861 {
862 let (subscription, activate) = self.keyboard_layout_observers.insert(
863 (),
864 Box::new(move |cx| {
865 callback(cx);
866 true
867 }),
868 );
869 activate();
870 subscription
871 }
872
873 /// Gracefully quit the application via the platform's standard routine.
874 pub fn quit(&self) {
875 self.platform.quit();
876 }
877
878 /// Schedules all windows in the application to be redrawn. This can be called
879 /// multiple times in an update cycle and still result in a single redraw.
880 pub fn refresh_windows(&mut self) {
881 self.pending_effects.push_back(Effect::RefreshWindows);
882 }
883
884 pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
885 self.start_update();
886 let result = update(self);
887 self.finish_update();
888 result
889 }
890
891 pub(crate) fn start_update(&mut self) {
892 self.pending_updates += 1;
893 }
894
895 pub(crate) fn finish_update(&mut self) {
896 if !self.flushing_effects && self.pending_updates == 1 {
897 self.flushing_effects = true;
898 self.flush_effects();
899 self.flushing_effects = false;
900 }
901 self.pending_updates -= 1;
902 }
903
904 /// Arrange a callback to be invoked when the given entity calls `notify` on its respective context.
905 pub fn observe<W>(
906 &mut self,
907 entity: &Entity<W>,
908 mut on_notify: impl FnMut(Entity<W>, &mut App) + 'static,
909 ) -> Subscription
910 where
911 W: 'static,
912 {
913 self.observe_internal(entity, move |e, cx| {
914 on_notify(e, cx);
915 true
916 })
917 }
918
919 pub(crate) fn detect_accessed_entities<R>(
920 &mut self,
921 callback: impl FnOnce(&mut App) -> R,
922 ) -> (R, FxHashSet<EntityId>) {
923 let accessed_entities_start = self.entities.accessed_entities.get_mut().clone();
924 let result = callback(self);
925 let entities_accessed_in_callback = self
926 .entities
927 .accessed_entities
928 .get_mut()
929 .difference(&accessed_entities_start)
930 .copied()
931 .collect::<FxHashSet<EntityId>>();
932 (result, entities_accessed_in_callback)
933 }
934
935 pub(crate) fn record_entities_accessed(
936 &mut self,
937 window_handle: AnyWindowHandle,
938 invalidator: WindowInvalidator,
939 entities: &FxHashSet<EntityId>,
940 ) {
941 let mut tracked_entities =
942 std::mem::take(self.tracked_entities.entry(window_handle.id).or_default());
943 for entity in tracked_entities.iter() {
944 self.window_invalidators_by_entity
945 .entry(*entity)
946 .and_modify(|windows| {
947 windows.remove(&window_handle.id);
948 });
949 }
950 for entity in entities.iter() {
951 self.window_invalidators_by_entity
952 .entry(*entity)
953 .or_default()
954 .insert(window_handle.id, invalidator.clone());
955 }
956 tracked_entities.clear();
957 tracked_entities.extend(entities.iter().copied());
958 self.tracked_entities
959 .insert(window_handle.id, tracked_entities);
960 }
961
962 pub(crate) fn new_observer(&mut self, key: EntityId, value: Handler) -> Subscription {
963 let (subscription, activate) = self.observers.insert(key, value);
964 self.defer(move |_| activate());
965 subscription
966 }
967
968 pub(crate) fn observe_internal<W>(
969 &mut self,
970 entity: &Entity<W>,
971 mut on_notify: impl FnMut(Entity<W>, &mut App) -> bool + 'static,
972 ) -> Subscription
973 where
974 W: 'static,
975 {
976 let entity_id = entity.entity_id();
977 let handle = entity.downgrade();
978 self.new_observer(
979 entity_id,
980 Box::new(move |cx| {
981 if let Some(entity) = handle.upgrade() {
982 on_notify(entity, cx)
983 } else {
984 false
985 }
986 }),
987 )
988 }
989
990 /// Arrange for the given callback to be invoked whenever the given entity emits an event of a given type.
991 /// The callback is provided a handle to the emitting entity and a reference to the emitted event.
992 pub fn subscribe<T, Event>(
993 &mut self,
994 entity: &Entity<T>,
995 mut on_event: impl FnMut(Entity<T>, &Event, &mut App) + 'static,
996 ) -> Subscription
997 where
998 T: 'static + EventEmitter<Event>,
999 Event: 'static,
1000 {
1001 self.subscribe_internal(entity, move |entity, event, cx| {
1002 on_event(entity, event, cx);
1003 true
1004 })
1005 }
1006
1007 pub(crate) fn new_subscription(
1008 &mut self,
1009 key: EntityId,
1010 value: (TypeId, Listener),
1011 ) -> Subscription {
1012 let (subscription, activate) = self.event_listeners.insert(key, value);
1013 self.defer(move |_| activate());
1014 subscription
1015 }
1016 pub(crate) fn subscribe_internal<T, Evt>(
1017 &mut self,
1018 entity: &Entity<T>,
1019 mut on_event: impl FnMut(Entity<T>, &Evt, &mut App) -> bool + 'static,
1020 ) -> Subscription
1021 where
1022 T: 'static + EventEmitter<Evt>,
1023 Evt: 'static,
1024 {
1025 let entity_id = entity.entity_id();
1026 let handle = entity.downgrade();
1027 self.new_subscription(
1028 entity_id,
1029 (
1030 TypeId::of::<Evt>(),
1031 Box::new(move |event, cx| {
1032 let event: &Evt = event.downcast_ref().expect("invalid event type");
1033 if let Some(entity) = handle.upgrade() {
1034 on_event(entity, event, cx)
1035 } else {
1036 false
1037 }
1038 }),
1039 ),
1040 )
1041 }
1042
1043 /// Returns handles to all open windows in the application.
1044 /// Each handle could be downcast to a handle typed for the root view of that window.
1045 /// To find all windows of a given type, you could filter on
1046 pub fn windows(&self) -> Vec<AnyWindowHandle> {
1047 self.windows
1048 .keys()
1049 .flat_map(|window_id| self.window_handles.get(&window_id).copied())
1050 .collect()
1051 }
1052
1053 /// Returns the window handles ordered by their appearance on screen, front to back.
1054 ///
1055 /// The first window in the returned list is the active/topmost window of the application.
1056 ///
1057 /// This method returns None if the platform doesn't implement the method yet.
1058 pub fn window_stack(&self) -> Option<Vec<AnyWindowHandle>> {
1059 self.platform.window_stack()
1060 }
1061
1062 /// Returns a handle to the window that is currently focused at the platform level, if one exists.
1063 pub fn active_window(&self) -> Option<AnyWindowHandle> {
1064 self.platform.active_window()
1065 }
1066
1067 /// Opens a new window with the given option and the root view returned by the given function.
1068 /// The function is invoked with a `Window`, which can be used to interact with window-specific
1069 /// functionality.
1070 pub fn open_window<V: 'static + Render>(
1071 &mut self,
1072 options: crate::WindowOptions,
1073 build_root_view: impl FnOnce(&mut Window, &mut App) -> Entity<V>,
1074 ) -> anyhow::Result<WindowHandle<V>> {
1075 self.update(|cx| {
1076 let id = cx.windows.insert(None);
1077 let handle = WindowHandle::new(id);
1078 match Window::new(handle.into(), options, cx) {
1079 Ok(mut window) => {
1080 cx.window_update_stack.push(id);
1081 let root_view = build_root_view(&mut window, cx);
1082 cx.window_update_stack.pop();
1083 window.root.replace(root_view.into());
1084 window.defer(cx, |window: &mut Window, cx| window.appearance_changed(cx));
1085
1086 // allow a window to draw at least once before returning
1087 // this didn't cause any issues on non windows platforms as it seems we always won the race to on_request_frame
1088 // on windows we quite frequently lose the race and return a window that has never rendered, which leads to a crash
1089 // where DispatchTree::root_node_id asserts on empty nodes
1090 let clear = window.draw(cx);
1091 clear.clear();
1092
1093 cx.window_handles.insert(id, window.handle);
1094 cx.windows.get_mut(id).unwrap().replace(Box::new(window));
1095 Ok(handle)
1096 }
1097 Err(e) => {
1098 cx.windows.remove(id);
1099 Err(e)
1100 }
1101 }
1102 })
1103 }
1104
1105 /// Instructs the platform to activate the application by bringing it to the foreground.
1106 pub fn activate(&self, ignoring_other_apps: bool) {
1107 self.platform.activate(ignoring_other_apps);
1108 }
1109
1110 /// Hide the application at the platform level.
1111 pub fn hide(&self) {
1112 self.platform.hide();
1113 }
1114
1115 /// Hide other applications at the platform level.
1116 pub fn hide_other_apps(&self) {
1117 self.platform.hide_other_apps();
1118 }
1119
1120 /// Unhide other applications at the platform level.
1121 pub fn unhide_other_apps(&self) {
1122 self.platform.unhide_other_apps();
1123 }
1124
1125 /// Returns the list of currently active displays.
1126 pub fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {
1127 self.platform.displays()
1128 }
1129
1130 /// Returns the primary display that will be used for new windows.
1131 pub fn primary_display(&self) -> Option<Rc<dyn PlatformDisplay>> {
1132 self.platform.primary_display()
1133 }
1134
1135 /// Returns whether `screen_capture_sources` may work.
1136 pub fn is_screen_capture_supported(&self) -> bool {
1137 self.platform.is_screen_capture_supported()
1138 }
1139
1140 /// Returns a list of available screen capture sources.
1141 pub fn screen_capture_sources(
1142 &self,
1143 ) -> oneshot::Receiver<Result<Vec<Rc<dyn ScreenCaptureSource>>>> {
1144 self.platform.screen_capture_sources()
1145 }
1146
1147 /// Returns the display with the given ID, if one exists.
1148 pub fn find_display(&self, id: DisplayId) -> Option<Rc<dyn PlatformDisplay>> {
1149 self.displays()
1150 .iter()
1151 .find(|display| display.id() == id)
1152 .cloned()
1153 }
1154
1155 /// Returns the current thermal state of the system.
1156 pub fn thermal_state(&self) -> ThermalState {
1157 self.platform.thermal_state()
1158 }
1159
1160 /// Invokes a handler when the thermal state changes
1161 pub fn on_thermal_state_change<F>(&self, mut callback: F) -> Subscription
1162 where
1163 F: 'static + FnMut(&mut App),
1164 {
1165 let (subscription, activate) = self.thermal_state_observers.insert(
1166 (),
1167 Box::new(move |cx| {
1168 callback(cx);
1169 true
1170 }),
1171 );
1172 activate();
1173 subscription
1174 }
1175
1176 /// Returns the appearance of the application's windows.
1177 pub fn window_appearance(&self) -> WindowAppearance {
1178 self.platform.window_appearance()
1179 }
1180
1181 /// Returns the window button layout configuration when supported.
1182 pub fn button_layout(&self) -> Option<WindowButtonLayout> {
1183 self.platform.button_layout()
1184 }
1185
1186 /// Reads data from the platform clipboard.
1187 pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
1188 self.platform.read_from_clipboard()
1189 }
1190
1191 /// Sets the text rendering mode for the application.
1192 pub fn set_text_rendering_mode(&mut self, mode: TextRenderingMode) {
1193 self.text_rendering_mode.set(mode);
1194 }
1195
1196 /// Returns the current text rendering mode for the application.
1197 pub fn text_rendering_mode(&self) -> TextRenderingMode {
1198 self.text_rendering_mode.get()
1199 }
1200
1201 /// Writes data to the platform clipboard.
1202 pub fn write_to_clipboard(&self, item: ClipboardItem) {
1203 self.platform.write_to_clipboard(item)
1204 }
1205
1206 /// Reads data from the primary selection buffer.
1207 /// Only available on Linux.
1208 #[cfg(any(target_os = "linux", target_os = "freebsd"))]
1209 pub fn read_from_primary(&self) -> Option<ClipboardItem> {
1210 self.platform.read_from_primary()
1211 }
1212
1213 /// Writes data to the primary selection buffer.
1214 /// Only available on Linux.
1215 #[cfg(any(target_os = "linux", target_os = "freebsd"))]
1216 pub fn write_to_primary(&self, item: ClipboardItem) {
1217 self.platform.write_to_primary(item)
1218 }
1219
1220 /// Reads data from macOS's "Find" pasteboard.
1221 ///
1222 /// Used to share the current search string between apps.
1223 ///
1224 /// https://developer.apple.com/documentation/appkit/nspasteboard/name-swift.struct/find
1225 #[cfg(target_os = "macos")]
1226 pub fn read_from_find_pasteboard(&self) -> Option<ClipboardItem> {
1227 self.platform.read_from_find_pasteboard()
1228 }
1229
1230 /// Writes data to macOS's "Find" pasteboard.
1231 ///
1232 /// Used to share the current search string between apps.
1233 ///
1234 /// https://developer.apple.com/documentation/appkit/nspasteboard/name-swift.struct/find
1235 #[cfg(target_os = "macos")]
1236 pub fn write_to_find_pasteboard(&self, item: ClipboardItem) {
1237 self.platform.write_to_find_pasteboard(item)
1238 }
1239
1240 /// Writes credentials to the platform keychain.
1241 pub fn write_credentials(
1242 &self,
1243 url: &str,
1244 username: &str,
1245 password: &[u8],
1246 ) -> Task<Result<()>> {
1247 self.platform.write_credentials(url, username, password)
1248 }
1249
1250 /// Reads credentials from the platform keychain.
1251 pub fn read_credentials(&self, url: &str) -> Task<Result<Option<(String, Vec<u8>)>>> {
1252 self.platform.read_credentials(url)
1253 }
1254
1255 /// Deletes credentials from the platform keychain.
1256 pub fn delete_credentials(&self, url: &str) -> Task<Result<()>> {
1257 self.platform.delete_credentials(url)
1258 }
1259
1260 /// Directs the platform's default browser to open the given URL.
1261 pub fn open_url(&self, url: &str) {
1262 self.platform.open_url(url);
1263 }
1264
1265 /// Registers the given URL scheme (e.g. `zed` for `zed://` urls) to be
1266 /// opened by the current app.
1267 ///
1268 /// On some platforms (e.g. macOS) you may be able to register URL schemes
1269 /// as part of app distribution, but this method exists to let you register
1270 /// schemes at runtime.
1271 pub fn register_url_scheme(&self, scheme: &str) -> Task<Result<()>> {
1272 self.platform.register_url_scheme(scheme)
1273 }
1274
1275 /// Returns the full pathname of the current app bundle.
1276 ///
1277 /// Returns an error if the app is not being run from a bundle.
1278 pub fn app_path(&self) -> Result<PathBuf> {
1279 self.platform.app_path()
1280 }
1281
1282 /// On Linux, returns the name of the compositor in use.
1283 ///
1284 /// Returns an empty string on other platforms.
1285 pub fn compositor_name(&self) -> &'static str {
1286 self.platform.compositor_name()
1287 }
1288
1289 /// Returns the file URL of the executable with the specified name in the application bundle
1290 pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
1291 self.platform.path_for_auxiliary_executable(name)
1292 }
1293
1294 /// Displays a platform modal for selecting paths.
1295 ///
1296 /// When one or more paths are selected, they'll be relayed asynchronously via the returned oneshot channel.
1297 /// If cancelled, a `None` will be relayed instead.
1298 /// May return an error on Linux if the file picker couldn't be opened.
1299 pub fn prompt_for_paths(
1300 &self,
1301 options: PathPromptOptions,
1302 ) -> oneshot::Receiver<Result<Option<Vec<PathBuf>>>> {
1303 self.platform.prompt_for_paths(options)
1304 }
1305
1306 /// Displays a platform modal for selecting a new path where a file can be saved.
1307 ///
1308 /// The provided directory will be used to set the initial location.
1309 /// When a path is selected, it is relayed asynchronously via the returned oneshot channel.
1310 /// If cancelled, a `None` will be relayed instead.
1311 /// May return an error on Linux if the file picker couldn't be opened.
1312 pub fn prompt_for_new_path(
1313 &self,
1314 directory: &Path,
1315 suggested_name: Option<&str>,
1316 ) -> oneshot::Receiver<Result<Option<PathBuf>>> {
1317 self.platform.prompt_for_new_path(directory, suggested_name)
1318 }
1319
1320 /// Reveals the specified path at the platform level, such as in Finder on macOS.
1321 pub fn reveal_path(&self, path: &Path) {
1322 self.platform.reveal_path(path)
1323 }
1324
1325 /// Opens the specified path with the system's default application.
1326 pub fn open_with_system(&self, path: &Path) {
1327 self.platform.open_with_system(path)
1328 }
1329
1330 /// Returns whether the user has configured scrollbars to auto-hide at the platform level.
1331 pub fn should_auto_hide_scrollbars(&self) -> bool {
1332 self.platform.should_auto_hide_scrollbars()
1333 }
1334
1335 /// Restarts the application.
1336 pub fn restart(&mut self) {
1337 self.restart_observers
1338 .clone()
1339 .retain(&(), |observer| observer(self));
1340 self.platform.restart(self.restart_path.take())
1341 }
1342
1343 /// Sets the path to use when restarting the application.
1344 pub fn set_restart_path(&mut self, path: PathBuf) {
1345 self.restart_path = Some(path);
1346 }
1347
1348 /// Returns the HTTP client for the application.
1349 pub fn http_client(&self) -> Arc<dyn HttpClient> {
1350 self.http_client.clone()
1351 }
1352
1353 /// Sets the HTTP client for the application.
1354 pub fn set_http_client(&mut self, new_client: Arc<dyn HttpClient>) {
1355 self.http_client = new_client;
1356 }
1357
1358 /// Configures when the application should automatically quit.
1359 /// By default, [`QuitMode::Default`] is used.
1360 pub fn set_quit_mode(&mut self, mode: QuitMode) {
1361 self.quit_mode = mode;
1362 }
1363
1364 /// Returns the SVG renderer used by the application.
1365 pub fn svg_renderer(&self) -> SvgRenderer {
1366 self.svg_renderer.clone()
1367 }
1368
1369 pub(crate) fn push_effect(&mut self, effect: Effect) {
1370 match &effect {
1371 Effect::Notify { emitter } => {
1372 if !self.pending_notifications.insert(*emitter) {
1373 return;
1374 }
1375 }
1376 Effect::NotifyGlobalObservers { global_type } => {
1377 if !self.pending_global_notifications.insert(*global_type) {
1378 return;
1379 }
1380 }
1381 _ => {}
1382 };
1383
1384 self.pending_effects.push_back(effect);
1385 }
1386
1387 /// Called at the end of [`App::update`] to complete any side effects
1388 /// such as notifying observers, emitting events, etc. Effects can themselves
1389 /// cause effects, so we continue looping until all effects are processed.
1390 fn flush_effects(&mut self) {
1391 loop {
1392 self.release_dropped_entities();
1393 self.release_dropped_focus_handles();
1394 if let Some(effect) = self.pending_effects.pop_front() {
1395 match effect {
1396 Effect::Notify { emitter } => {
1397 self.apply_notify_effect(emitter);
1398 }
1399
1400 Effect::Emit {
1401 emitter,
1402 event_type,
1403 event,
1404 } => self.apply_emit_effect(emitter, event_type, &*event),
1405
1406 Effect::RefreshWindows => {
1407 self.apply_refresh_effect();
1408 }
1409
1410 Effect::NotifyGlobalObservers { global_type } => {
1411 self.apply_notify_global_observers_effect(global_type);
1412 }
1413
1414 Effect::Defer { callback } => {
1415 self.apply_defer_effect(callback);
1416 }
1417 Effect::EntityCreated {
1418 entity,
1419 tid,
1420 window,
1421 } => {
1422 self.apply_entity_created_effect(entity, tid, window);
1423 }
1424 }
1425 } else {
1426 #[cfg(any(test, feature = "test-support"))]
1427 for window in self
1428 .windows
1429 .values()
1430 .filter_map(|window| {
1431 let window = window.as_deref()?;
1432 window.invalidator.is_dirty().then_some(window.handle)
1433 })
1434 .collect::<Vec<_>>()
1435 {
1436 self.update_window(window, |_, window, cx| window.draw(cx).clear())
1437 .unwrap();
1438 }
1439
1440 if self.pending_effects.is_empty() {
1441 self.event_arena.clear();
1442 break;
1443 }
1444 }
1445 }
1446 }
1447
1448 /// Repeatedly called during `flush_effects` to release any entities whose
1449 /// reference count has become zero. We invoke any release observers before dropping
1450 /// each entity.
1451 fn release_dropped_entities(&mut self) {
1452 loop {
1453 let dropped = self.entities.take_dropped();
1454 if dropped.is_empty() {
1455 break;
1456 }
1457
1458 for (entity_id, mut entity) in dropped {
1459 self.observers.remove(&entity_id);
1460 self.event_listeners.remove(&entity_id);
1461 for release_callback in self.release_listeners.remove(&entity_id) {
1462 release_callback(entity.as_mut(), self);
1463 }
1464 }
1465 }
1466 }
1467
1468 /// Repeatedly called during `flush_effects` to handle a focused handle being dropped.
1469 fn release_dropped_focus_handles(&mut self) {
1470 self.focus_handles
1471 .clone()
1472 .write()
1473 .retain(|handle_id, focus| {
1474 if focus.ref_count.load(SeqCst) == 0 {
1475 for window_handle in self.windows() {
1476 window_handle
1477 .update(self, |_, window, _| {
1478 if window.focus == Some(handle_id) {
1479 window.blur();
1480 }
1481 })
1482 .unwrap();
1483 }
1484 false
1485 } else {
1486 true
1487 }
1488 });
1489 }
1490
1491 fn apply_notify_effect(&mut self, emitter: EntityId) {
1492 self.pending_notifications.remove(&emitter);
1493
1494 self.observers
1495 .clone()
1496 .retain(&emitter, |handler| handler(self));
1497 }
1498
1499 fn apply_emit_effect(&mut self, emitter: EntityId, event_type: TypeId, event: &dyn Any) {
1500 self.event_listeners
1501 .clone()
1502 .retain(&emitter, |(stored_type, handler)| {
1503 if *stored_type == event_type {
1504 handler(event, self)
1505 } else {
1506 true
1507 }
1508 });
1509 }
1510
1511 fn apply_refresh_effect(&mut self) {
1512 for window in self.windows.values_mut() {
1513 if let Some(window) = window.as_deref_mut() {
1514 window.refreshing = true;
1515 window.invalidator.set_dirty(true);
1516 }
1517 }
1518 }
1519
1520 fn apply_notify_global_observers_effect(&mut self, type_id: TypeId) {
1521 self.pending_global_notifications.remove(&type_id);
1522 self.global_observers
1523 .clone()
1524 .retain(&type_id, |observer| observer(self));
1525 }
1526
1527 fn apply_defer_effect(&mut self, callback: Box<dyn FnOnce(&mut Self) + 'static>) {
1528 callback(self);
1529 }
1530
1531 fn apply_entity_created_effect(
1532 &mut self,
1533 entity: AnyEntity,
1534 tid: TypeId,
1535 window: Option<WindowId>,
1536 ) {
1537 self.new_entity_observers.clone().retain(&tid, |observer| {
1538 if let Some(id) = window {
1539 self.update_window_id(id, {
1540 let entity = entity.clone();
1541 |_, window, cx| (observer)(entity, &mut Some(window), cx)
1542 })
1543 .expect("All windows should be off the stack when flushing effects");
1544 } else {
1545 (observer)(entity.clone(), &mut None, self)
1546 }
1547 true
1548 });
1549 }
1550
1551 fn update_window_id<T, F>(&mut self, id: WindowId, update: F) -> Result<T>
1552 where
1553 F: FnOnce(AnyView, &mut Window, &mut App) -> T,
1554 {
1555 self.update(|cx| {
1556 let mut window = cx.windows.get_mut(id)?.take()?;
1557
1558 let root_view = window.root.clone().unwrap();
1559
1560 cx.window_update_stack.push(window.handle.id);
1561 let result = update(root_view, &mut window, cx);
1562 fn trail(id: WindowId, window: Box<Window>, cx: &mut App) -> Option<()> {
1563 cx.window_update_stack.pop();
1564
1565 if window.removed {
1566 cx.window_handles.remove(&id);
1567 cx.windows.remove(id);
1568
1569 cx.window_closed_observers.clone().retain(&(), |callback| {
1570 callback(cx, id);
1571 true
1572 });
1573
1574 let quit_on_empty = match cx.quit_mode {
1575 QuitMode::Explicit => false,
1576 QuitMode::LastWindowClosed => true,
1577 QuitMode::Default => cfg!(not(target_os = "macos")),
1578 };
1579
1580 if quit_on_empty && cx.windows.is_empty() {
1581 cx.quit();
1582 }
1583 } else {
1584 cx.windows.get_mut(id)?.replace(window);
1585 }
1586 Some(())
1587 }
1588 trail(id, window, cx)?;
1589
1590 Some(result)
1591 })
1592 .context("window not found")
1593 }
1594
1595 /// Creates an `AsyncApp`, which can be cloned and has a static lifetime
1596 /// so it can be held across `await` points.
1597 pub fn to_async(&self) -> AsyncApp {
1598 AsyncApp {
1599 app: self.this.clone(),
1600 background_executor: self.background_executor.clone(),
1601 foreground_executor: self.foreground_executor.clone(),
1602 }
1603 }
1604
1605 /// Obtains a reference to the executor, which can be used to spawn futures.
1606 pub fn background_executor(&self) -> &BackgroundExecutor {
1607 &self.background_executor
1608 }
1609
1610 /// Obtains a reference to the executor, which can be used to spawn futures.
1611 pub fn foreground_executor(&self) -> &ForegroundExecutor {
1612 if self.quitting {
1613 panic!("Can't spawn on main thread after on_app_quit")
1614 };
1615 &self.foreground_executor
1616 }
1617
1618 /// Spawns the future returned by the given function on the main thread. The closure will be invoked
1619 /// with [AsyncApp], which allows the application state to be accessed across await points.
1620 #[track_caller]
1621 pub fn spawn<AsyncFn, R>(&self, f: AsyncFn) -> Task<R>
1622 where
1623 AsyncFn: AsyncFnOnce(&mut AsyncApp) -> R + 'static,
1624 R: 'static,
1625 {
1626 if self.quitting {
1627 debug_panic!("Can't spawn on main thread after on_app_quit")
1628 };
1629
1630 let mut cx = self.to_async();
1631
1632 self.foreground_executor
1633 .spawn(async move { f(&mut cx).await }.boxed_local())
1634 }
1635
1636 /// Spawns the future returned by the given function on the main thread with
1637 /// the given priority. The closure will be invoked with [AsyncApp], which
1638 /// allows the application state to be accessed across await points.
1639 pub fn spawn_with_priority<AsyncFn, R>(&self, priority: Priority, f: AsyncFn) -> Task<R>
1640 where
1641 AsyncFn: AsyncFnOnce(&mut AsyncApp) -> R + 'static,
1642 R: 'static,
1643 {
1644 if self.quitting {
1645 debug_panic!("Can't spawn on main thread after on_app_quit")
1646 };
1647
1648 let mut cx = self.to_async();
1649
1650 self.foreground_executor
1651 .spawn_with_priority(priority, async move { f(&mut cx).await }.boxed_local())
1652 }
1653
1654 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1655 /// that are currently on the stack to be returned to the app.
1656 pub fn defer(&mut self, f: impl FnOnce(&mut App) + 'static) {
1657 self.push_effect(Effect::Defer {
1658 callback: Box::new(f),
1659 });
1660 }
1661
1662 /// Accessor for the application's asset source, which is provided when constructing the `App`.
1663 pub fn asset_source(&self) -> &Arc<dyn AssetSource> {
1664 &self.asset_source
1665 }
1666
1667 /// Accessor for the text system.
1668 pub fn text_system(&self) -> &Arc<TextSystem> {
1669 &self.text_system
1670 }
1671
1672 /// Check whether a global of the given type has been assigned.
1673 pub fn has_global<G: Global>(&self) -> bool {
1674 self.globals_by_type.contains_key(&TypeId::of::<G>())
1675 }
1676
1677 /// Access the global of the given type. Panics if a global for that type has not been assigned.
1678 #[track_caller]
1679 pub fn global<G: Global>(&self) -> &G {
1680 self.globals_by_type
1681 .get(&TypeId::of::<G>())
1682 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
1683 .with_context(|| format!("no state of type {} exists", type_name::<G>()))
1684 .unwrap()
1685 }
1686
1687 /// Access the global of the given type if a value has been assigned.
1688 pub fn try_global<G: Global>(&self) -> Option<&G> {
1689 self.globals_by_type
1690 .get(&TypeId::of::<G>())
1691 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
1692 }
1693
1694 /// Access the global of the given type mutably. Panics if a global for that type has not been assigned.
1695 #[track_caller]
1696 pub fn global_mut<G: Global>(&mut self) -> &mut G {
1697 let global_type = TypeId::of::<G>();
1698 self.push_effect(Effect::NotifyGlobalObservers { global_type });
1699 self.globals_by_type
1700 .get_mut(&global_type)
1701 .and_then(|any_state| any_state.downcast_mut::<G>())
1702 .with_context(|| format!("no state of type {} exists", type_name::<G>()))
1703 .unwrap()
1704 }
1705
1706 /// Access the global of the given type mutably. A default value is assigned if a global of this type has not
1707 /// yet been assigned.
1708 pub fn default_global<G: Global + Default>(&mut self) -> &mut G {
1709 let global_type = TypeId::of::<G>();
1710 self.push_effect(Effect::NotifyGlobalObservers { global_type });
1711 self.globals_by_type
1712 .entry(global_type)
1713 .or_insert_with(|| Box::<G>::default())
1714 .downcast_mut::<G>()
1715 .unwrap()
1716 }
1717
1718 /// Sets the value of the global of the given type.
1719 pub fn set_global<G: Global>(&mut self, global: G) {
1720 let global_type = TypeId::of::<G>();
1721 self.push_effect(Effect::NotifyGlobalObservers { global_type });
1722 self.globals_by_type.insert(global_type, Box::new(global));
1723 }
1724
1725 /// Clear all stored globals. Does not notify global observers.
1726 #[cfg(any(test, feature = "test-support"))]
1727 pub fn clear_globals(&mut self) {
1728 self.globals_by_type.drain();
1729 }
1730
1731 /// Remove the global of the given type from the app context. Does not notify global observers.
1732 pub fn remove_global<G: Global>(&mut self) -> G {
1733 let global_type = TypeId::of::<G>();
1734 self.push_effect(Effect::NotifyGlobalObservers { global_type });
1735 *self
1736 .globals_by_type
1737 .remove(&global_type)
1738 .unwrap_or_else(|| panic!("no global added for {}", std::any::type_name::<G>()))
1739 .downcast()
1740 .unwrap()
1741 }
1742
1743 /// Register a callback to be invoked when a global of the given type is updated.
1744 pub fn observe_global<G: Global>(
1745 &mut self,
1746 mut f: impl FnMut(&mut Self) + 'static,
1747 ) -> Subscription {
1748 let (subscription, activate) = self.global_observers.insert(
1749 TypeId::of::<G>(),
1750 Box::new(move |cx| {
1751 f(cx);
1752 true
1753 }),
1754 );
1755 self.defer(move |_| activate());
1756 subscription
1757 }
1758
1759 /// Move the global of the given type to the stack.
1760 #[track_caller]
1761 pub(crate) fn lease_global<G: Global>(&mut self) -> GlobalLease<G> {
1762 GlobalLease::new(
1763 self.globals_by_type
1764 .remove(&TypeId::of::<G>())
1765 .with_context(|| format!("no global registered of type {}", type_name::<G>()))
1766 .unwrap(),
1767 )
1768 }
1769
1770 /// Restore the global of the given type after it is moved to the stack.
1771 pub(crate) fn end_global_lease<G: Global>(&mut self, lease: GlobalLease<G>) {
1772 let global_type = TypeId::of::<G>();
1773
1774 self.push_effect(Effect::NotifyGlobalObservers { global_type });
1775 self.globals_by_type.insert(global_type, lease.global);
1776 }
1777
1778 pub(crate) fn new_entity_observer(
1779 &self,
1780 key: TypeId,
1781 value: NewEntityListener,
1782 ) -> Subscription {
1783 let (subscription, activate) = self.new_entity_observers.insert(key, value);
1784 activate();
1785 subscription
1786 }
1787
1788 /// Arrange for the given function to be invoked whenever a view of the specified type is created.
1789 /// The function will be passed a mutable reference to the view along with an appropriate context.
1790 pub fn observe_new<T: 'static>(
1791 &self,
1792 on_new: impl 'static + Fn(&mut T, Option<&mut Window>, &mut Context<T>),
1793 ) -> Subscription {
1794 self.new_entity_observer(
1795 TypeId::of::<T>(),
1796 Box::new(
1797 move |any_entity: AnyEntity, window: &mut Option<&mut Window>, cx: &mut App| {
1798 any_entity
1799 .downcast::<T>()
1800 .unwrap()
1801 .update(cx, |entity_state, cx| {
1802 on_new(entity_state, window.as_deref_mut(), cx)
1803 })
1804 },
1805 ),
1806 )
1807 }
1808
1809 /// Observe the release of a entity. The callback is invoked after the entity
1810 /// has no more strong references but before it has been dropped.
1811 pub fn observe_release<T>(
1812 &self,
1813 handle: &Entity<T>,
1814 on_release: impl FnOnce(&mut T, &mut App) + 'static,
1815 ) -> Subscription
1816 where
1817 T: 'static,
1818 {
1819 let (subscription, activate) = self.release_listeners.insert(
1820 handle.entity_id(),
1821 Box::new(move |entity, cx| {
1822 let entity = entity.downcast_mut().expect("invalid entity type");
1823 on_release(entity, cx)
1824 }),
1825 );
1826 activate();
1827 subscription
1828 }
1829
1830 /// Observe the release of a entity. The callback is invoked after the entity
1831 /// has no more strong references but before it has been dropped.
1832 pub fn observe_release_in<T>(
1833 &self,
1834 handle: &Entity<T>,
1835 window: &Window,
1836 on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1837 ) -> Subscription
1838 where
1839 T: 'static,
1840 {
1841 let window_handle = window.handle;
1842 self.observe_release(handle, move |entity, cx| {
1843 let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1844 })
1845 }
1846
1847 /// Register a callback to be invoked when a keystroke is received by the application
1848 /// in any window. Note that this fires after all other action and event mechanisms have resolved
1849 /// and that this API will not be invoked if the event's propagation is stopped.
1850 pub fn observe_keystrokes(
1851 &mut self,
1852 mut f: impl FnMut(&KeystrokeEvent, &mut Window, &mut App) + 'static,
1853 ) -> Subscription {
1854 fn inner(
1855 keystroke_observers: &SubscriberSet<(), KeystrokeObserver>,
1856 handler: KeystrokeObserver,
1857 ) -> Subscription {
1858 let (subscription, activate) = keystroke_observers.insert((), handler);
1859 activate();
1860 subscription
1861 }
1862
1863 inner(
1864 &self.keystroke_observers,
1865 Box::new(move |event, window, cx| {
1866 f(event, window, cx);
1867 true
1868 }),
1869 )
1870 }
1871
1872 /// Register a callback to be invoked when a keystroke is received by the application
1873 /// in any window. Note that this fires _before_ all other action and event mechanisms have resolved
1874 /// unlike [`App::observe_keystrokes`] which fires after. This means that `cx.stop_propagation` calls
1875 /// within interceptors will prevent action dispatch
1876 pub fn intercept_keystrokes(
1877 &mut self,
1878 mut f: impl FnMut(&KeystrokeEvent, &mut Window, &mut App) + 'static,
1879 ) -> Subscription {
1880 fn inner(
1881 keystroke_interceptors: &SubscriberSet<(), KeystrokeObserver>,
1882 handler: KeystrokeObserver,
1883 ) -> Subscription {
1884 let (subscription, activate) = keystroke_interceptors.insert((), handler);
1885 activate();
1886 subscription
1887 }
1888
1889 inner(
1890 &self.keystroke_interceptors,
1891 Box::new(move |event, window, cx| {
1892 f(event, window, cx);
1893 true
1894 }),
1895 )
1896 }
1897
1898 /// Register key bindings.
1899 pub fn bind_keys(&mut self, bindings: impl IntoIterator<Item = KeyBinding>) {
1900 self.keymap.borrow_mut().add_bindings(bindings);
1901 self.pending_effects.push_back(Effect::RefreshWindows);
1902 }
1903
1904 /// Clear all key bindings in the app.
1905 pub fn clear_key_bindings(&mut self) {
1906 self.keymap.borrow_mut().clear();
1907 self.pending_effects.push_back(Effect::RefreshWindows);
1908 }
1909
1910 /// Get all key bindings in the app.
1911 pub fn key_bindings(&self) -> Rc<RefCell<Keymap>> {
1912 self.keymap.clone()
1913 }
1914
1915 /// Register a global handler for actions invoked via the keyboard. These handlers are run at
1916 /// the end of the bubble phase for actions, and so will only be invoked if there are no other
1917 /// handlers or if they called `cx.propagate()`.
1918 pub fn on_action<A: Action>(
1919 &mut self,
1920 listener: impl Fn(&A, &mut Self) + 'static,
1921 ) -> &mut Self {
1922 self.global_action_listeners
1923 .entry(TypeId::of::<A>())
1924 .or_default()
1925 .push(Rc::new(move |action, phase, cx| {
1926 if phase == DispatchPhase::Bubble {
1927 let action = action.downcast_ref().unwrap();
1928 listener(action, cx)
1929 }
1930 }));
1931 self
1932 }
1933
1934 /// Event handlers propagate events by default. Call this method to stop dispatching to
1935 /// event handlers with a lower z-index (mouse) or higher in the tree (keyboard). This is
1936 /// the opposite of [`Self::propagate`]. It's also possible to cancel a call to [`Self::propagate`] by
1937 /// calling this method before effects are flushed.
1938 pub fn stop_propagation(&mut self) {
1939 self.propagate_event = false;
1940 }
1941
1942 /// Action handlers stop propagation by default during the bubble phase of action dispatch
1943 /// dispatching to action handlers higher in the element tree. This is the opposite of
1944 /// [`Self::stop_propagation`]. It's also possible to cancel a call to [`Self::stop_propagation`] by calling
1945 /// this method before effects are flushed.
1946 pub fn propagate(&mut self) {
1947 self.propagate_event = true;
1948 }
1949
1950 /// Build an action from some arbitrary data, typically a keymap entry.
1951 pub fn build_action(
1952 &self,
1953 name: &str,
1954 data: Option<serde_json::Value>,
1955 ) -> std::result::Result<Box<dyn Action>, ActionBuildError> {
1956 self.actions.build_action(name, data)
1957 }
1958
1959 /// Get all action names that have been registered. Note that registration only allows for
1960 /// actions to be built dynamically, and is unrelated to binding actions in the element tree.
1961 pub fn all_action_names(&self) -> &[&'static str] {
1962 self.actions.all_action_names()
1963 }
1964
1965 /// Returns key bindings that invoke the given action on the currently focused element, without
1966 /// checking context. Bindings are returned in the order they were added. For display, the last
1967 /// binding should take precedence.
1968 pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
1969 RefCell::borrow(&self.keymap).all_bindings_for_input(input)
1970 }
1971
1972 /// Get all non-internal actions that have been registered, along with their schemas.
1973 pub fn action_schemas(
1974 &self,
1975 generator: &mut schemars::SchemaGenerator,
1976 ) -> Vec<(&'static str, Option<schemars::Schema>)> {
1977 self.actions.action_schemas(generator)
1978 }
1979
1980 /// Get the schema for a specific action by name.
1981 /// Returns `None` if the action is not found.
1982 /// Returns `Some(None)` if the action exists but has no schema.
1983 /// Returns `Some(Some(schema))` if the action exists and has a schema.
1984 pub fn action_schema_by_name(
1985 &self,
1986 name: &str,
1987 generator: &mut schemars::SchemaGenerator,
1988 ) -> Option<Option<schemars::Schema>> {
1989 self.actions.action_schema_by_name(name, generator)
1990 }
1991
1992 /// Get a map from a deprecated action name to the canonical name.
1993 pub fn deprecated_actions_to_preferred_actions(&self) -> &HashMap<&'static str, &'static str> {
1994 self.actions.deprecated_aliases()
1995 }
1996
1997 /// Get a map from an action name to the deprecation messages.
1998 pub fn action_deprecation_messages(&self) -> &HashMap<&'static str, &'static str> {
1999 self.actions.deprecation_messages()
2000 }
2001
2002 /// Get a map from an action name to the documentation.
2003 pub fn action_documentation(&self) -> &HashMap<&'static str, &'static str> {
2004 self.actions.documentation()
2005 }
2006
2007 /// Register a callback to be invoked when the application is about to quit.
2008 /// It is not possible to cancel the quit event at this point.
2009 pub fn on_app_quit<Fut>(
2010 &self,
2011 mut on_quit: impl FnMut(&mut App) -> Fut + 'static,
2012 ) -> Subscription
2013 where
2014 Fut: 'static + Future<Output = ()>,
2015 {
2016 let (subscription, activate) = self.quit_observers.insert(
2017 (),
2018 Box::new(move |cx| {
2019 let future = on_quit(cx);
2020 future.boxed_local()
2021 }),
2022 );
2023 activate();
2024 subscription
2025 }
2026
2027 /// Register a callback to be invoked when the application is about to restart.
2028 ///
2029 /// These callbacks are called before any `on_app_quit` callbacks.
2030 pub fn on_app_restart(&self, mut on_restart: impl 'static + FnMut(&mut App)) -> Subscription {
2031 let (subscription, activate) = self.restart_observers.insert(
2032 (),
2033 Box::new(move |cx| {
2034 on_restart(cx);
2035 true
2036 }),
2037 );
2038 activate();
2039 subscription
2040 }
2041
2042 /// Register a callback to be invoked when a window is closed
2043 /// The window is no longer accessible at the point this callback is invoked.
2044 pub fn on_window_closed(
2045 &self,
2046 mut on_closed: impl FnMut(&mut App, WindowId) + 'static,
2047 ) -> Subscription {
2048 let (subscription, activate) = self.window_closed_observers.insert((), Box::new(on_closed));
2049 activate();
2050 subscription
2051 }
2052
2053 pub(crate) fn clear_pending_keystrokes(&mut self) {
2054 for window in self.windows() {
2055 window
2056 .update(self, |_, window, cx| {
2057 if window.pending_input_keystrokes().is_some() {
2058 window.clear_pending_keystrokes();
2059 window.pending_input_changed(cx);
2060 }
2061 })
2062 .ok();
2063 }
2064 }
2065
2066 /// Checks if the given action is bound in the current context, as defined by the app's current focus,
2067 /// the bindings in the element tree, and any global action listeners.
2068 pub fn is_action_available(&mut self, action: &dyn Action) -> bool {
2069 let mut action_available = false;
2070 if let Some(window) = self.active_window()
2071 && let Ok(window_action_available) =
2072 window.update(self, |_, window, cx| window.is_action_available(action, cx))
2073 {
2074 action_available = window_action_available;
2075 }
2076
2077 action_available
2078 || self
2079 .global_action_listeners
2080 .contains_key(&action.as_any().type_id())
2081 }
2082
2083 /// Sets the menu bar for this application. This will replace any existing menu bar.
2084 pub fn set_menus(&self, menus: impl IntoIterator<Item = Menu>) {
2085 let menus: Vec<Menu> = menus.into_iter().collect();
2086 self.platform.set_menus(menus, &self.keymap.borrow());
2087 }
2088
2089 /// Gets the menu bar for this application.
2090 pub fn get_menus(&self) -> Option<Vec<OwnedMenu>> {
2091 self.platform.get_menus()
2092 }
2093
2094 /// Sets the right click menu for the app icon in the dock
2095 pub fn set_dock_menu(&self, menus: Vec<MenuItem>) {
2096 self.platform.set_dock_menu(menus, &self.keymap.borrow())
2097 }
2098
2099 /// Performs the action associated with the given dock menu item, only used on Windows for now.
2100 pub fn perform_dock_menu_action(&self, action: usize) {
2101 self.platform.perform_dock_menu_action(action);
2102 }
2103
2104 /// Adds given path to the bottom of the list of recent paths for the application.
2105 /// The list is usually shown on the application icon's context menu in the dock,
2106 /// and allows to open the recent files via that context menu.
2107 /// If the path is already in the list, it will be moved to the bottom of the list.
2108 pub fn add_recent_document(&self, path: &Path) {
2109 self.platform.add_recent_document(path);
2110 }
2111
2112 /// Updates the jump list with the updated list of recent paths for the application, only used on Windows for now.
2113 /// Note that this also sets the dock menu on Windows.
2114 pub fn update_jump_list(
2115 &self,
2116 menus: Vec<MenuItem>,
2117 entries: Vec<SmallVec<[PathBuf; 2]>>,
2118 ) -> Task<Vec<SmallVec<[PathBuf; 2]>>> {
2119 self.platform.update_jump_list(menus, entries)
2120 }
2121
2122 /// Dispatch an action to the currently active window or global action handler
2123 /// See [`crate::Action`] for more information on how actions work
2124 pub fn dispatch_action(&mut self, action: &dyn Action) {
2125 if let Some(active_window) = self.active_window() {
2126 active_window
2127 .update(self, |_, window, cx| {
2128 window.dispatch_action(action.boxed_clone(), cx)
2129 })
2130 .log_err();
2131 } else {
2132 self.dispatch_global_action(action);
2133 }
2134 }
2135
2136 fn dispatch_global_action(&mut self, action: &dyn Action) {
2137 self.propagate_event = true;
2138
2139 if let Some(mut global_listeners) = self
2140 .global_action_listeners
2141 .remove(&action.as_any().type_id())
2142 {
2143 for listener in &global_listeners {
2144 listener(action.as_any(), DispatchPhase::Capture, self);
2145 if !self.propagate_event {
2146 break;
2147 }
2148 }
2149
2150 global_listeners.extend(
2151 self.global_action_listeners
2152 .remove(&action.as_any().type_id())
2153 .unwrap_or_default(),
2154 );
2155
2156 self.global_action_listeners
2157 .insert(action.as_any().type_id(), global_listeners);
2158 }
2159
2160 if self.propagate_event
2161 && let Some(mut global_listeners) = self
2162 .global_action_listeners
2163 .remove(&action.as_any().type_id())
2164 {
2165 for listener in global_listeners.iter().rev() {
2166 listener(action.as_any(), DispatchPhase::Bubble, self);
2167 if !self.propagate_event {
2168 break;
2169 }
2170 }
2171
2172 global_listeners.extend(
2173 self.global_action_listeners
2174 .remove(&action.as_any().type_id())
2175 .unwrap_or_default(),
2176 );
2177
2178 self.global_action_listeners
2179 .insert(action.as_any().type_id(), global_listeners);
2180 }
2181 }
2182
2183 /// Is there currently something being dragged?
2184 pub fn has_active_drag(&self) -> bool {
2185 self.active_drag.is_some()
2186 }
2187
2188 /// Gets the cursor style of the currently active drag operation.
2189 pub fn active_drag_cursor_style(&self) -> Option<CursorStyle> {
2190 self.active_drag.as_ref().and_then(|drag| drag.cursor_style)
2191 }
2192
2193 /// Stops active drag and clears any related effects.
2194 pub fn stop_active_drag(&mut self, window: &mut Window) -> bool {
2195 if self.active_drag.is_some() {
2196 self.active_drag = None;
2197 window.refresh();
2198 true
2199 } else {
2200 false
2201 }
2202 }
2203
2204 /// Sets the cursor style for the currently active drag operation.
2205 pub fn set_active_drag_cursor_style(
2206 &mut self,
2207 cursor_style: CursorStyle,
2208 window: &mut Window,
2209 ) -> bool {
2210 if let Some(ref mut drag) = self.active_drag {
2211 drag.cursor_style = Some(cursor_style);
2212 window.refresh();
2213 true
2214 } else {
2215 false
2216 }
2217 }
2218
2219 /// Set the prompt renderer for GPUI. This will replace the default or platform specific
2220 /// prompts with this custom implementation.
2221 pub fn set_prompt_builder(
2222 &mut self,
2223 renderer: impl Fn(
2224 PromptLevel,
2225 &str,
2226 Option<&str>,
2227 &[PromptButton],
2228 PromptHandle,
2229 &mut Window,
2230 &mut App,
2231 ) -> RenderablePromptHandle
2232 + 'static,
2233 ) {
2234 self.prompt_builder = Some(PromptBuilder::Custom(Box::new(renderer)));
2235 }
2236
2237 /// Reset the prompt builder to the default implementation.
2238 pub fn reset_prompt_builder(&mut self) {
2239 self.prompt_builder = Some(PromptBuilder::Default);
2240 }
2241
2242 /// Remove an asset from GPUI's cache
2243 pub fn remove_asset<A: Asset>(&mut self, source: &A::Source) {
2244 let asset_id = (TypeId::of::<A>(), hash(source));
2245 self.loading_assets.remove(&asset_id);
2246 }
2247
2248 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2249 ///
2250 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2251 /// time, and the results of this call will be cached
2252 pub fn fetch_asset<A: Asset>(&mut self, source: &A::Source) -> (Shared<Task<A::Output>>, bool) {
2253 let asset_id = (TypeId::of::<A>(), hash(source));
2254 let mut is_first = false;
2255 let task = self
2256 .loading_assets
2257 .remove(&asset_id)
2258 .map(|boxed_task| *boxed_task.downcast::<Shared<Task<A::Output>>>().unwrap())
2259 .unwrap_or_else(|| {
2260 is_first = true;
2261 let future = A::load(source.clone(), self);
2262
2263 self.background_executor().spawn(future).shared()
2264 });
2265
2266 self.loading_assets.insert(asset_id, Box::new(task.clone()));
2267
2268 (task, is_first)
2269 }
2270
2271 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
2272 /// for elements rendered within this window.
2273 #[track_caller]
2274 pub fn focus_handle(&self) -> FocusHandle {
2275 FocusHandle::new(&self.focus_handles)
2276 }
2277
2278 /// Tell GPUI that an entity has changed and observers of it should be notified.
2279 pub fn notify(&mut self, entity_id: EntityId) {
2280 let window_invalidators = mem::take(
2281 self.window_invalidators_by_entity
2282 .entry(entity_id)
2283 .or_default(),
2284 );
2285
2286 if window_invalidators.is_empty() {
2287 if self.pending_notifications.insert(entity_id) {
2288 self.pending_effects
2289 .push_back(Effect::Notify { emitter: entity_id });
2290 }
2291 } else {
2292 for invalidator in window_invalidators.values() {
2293 invalidator.invalidate_view(entity_id, self);
2294 }
2295 }
2296
2297 self.window_invalidators_by_entity
2298 .insert(entity_id, window_invalidators);
2299 }
2300
2301 /// Returns the name for this [`App`].
2302 #[cfg(any(test, feature = "test-support", debug_assertions))]
2303 pub fn get_name(&self) -> Option<&'static str> {
2304 self.name
2305 }
2306
2307 /// Returns `true` if the platform file picker supports selecting a mix of files and directories.
2308 pub fn can_select_mixed_files_and_dirs(&self) -> bool {
2309 self.platform.can_select_mixed_files_and_dirs()
2310 }
2311
2312 /// Removes an image from the sprite atlas on all windows.
2313 ///
2314 /// If the current window is being updated, it will be removed from `App.windows`, you can use `current_window` to specify the current window.
2315 /// This is a no-op if the image is not in the sprite atlas.
2316 pub fn drop_image(&mut self, image: Arc<RenderImage>, current_window: Option<&mut Window>) {
2317 // remove the texture from all other windows
2318 for window in self.windows.values_mut().flatten() {
2319 _ = window.drop_image(image.clone());
2320 }
2321
2322 // remove the texture from the current window
2323 if let Some(window) = current_window {
2324 _ = window.drop_image(image);
2325 }
2326 }
2327
2328 /// Sets the renderer for the inspector.
2329 #[cfg(any(feature = "inspector", debug_assertions))]
2330 pub fn set_inspector_renderer(&mut self, f: crate::InspectorRenderer) {
2331 self.inspector_renderer = Some(f);
2332 }
2333
2334 /// Registers a renderer specific to an inspector state.
2335 #[cfg(any(feature = "inspector", debug_assertions))]
2336 pub fn register_inspector_element<T: 'static, R: crate::IntoElement>(
2337 &mut self,
2338 f: impl 'static + Fn(crate::InspectorElementId, &T, &mut Window, &mut App) -> R,
2339 ) {
2340 self.inspector_element_registry.register(f);
2341 }
2342
2343 /// Initializes gpui's default colors for the application.
2344 ///
2345 /// These colors can be accessed through `cx.default_colors()`.
2346 pub fn init_colors(&mut self) {
2347 self.set_global(GlobalColors(Arc::new(Colors::default())));
2348 }
2349}
2350
2351impl AppContext for App {
2352 /// Builds an entity that is owned by the application.
2353 ///
2354 /// The given function will be invoked with a [`Context`] and must return an object representing the entity. An
2355 /// [`Entity`] handle will be returned, which can be used to access the entity in a context.
2356 fn new<T: 'static>(&mut self, build_entity: impl FnOnce(&mut Context<T>) -> T) -> Entity<T> {
2357 self.update(|cx| {
2358 let slot = cx.entities.reserve();
2359 let handle = slot.clone();
2360 let entity = build_entity(&mut Context::new_context(cx, slot.downgrade()));
2361
2362 cx.push_effect(Effect::EntityCreated {
2363 entity: handle.into_any(),
2364 tid: TypeId::of::<T>(),
2365 window: cx.window_update_stack.last().cloned(),
2366 });
2367
2368 cx.entities.insert(slot, entity)
2369 })
2370 }
2371
2372 fn reserve_entity<T: 'static>(&mut self) -> Reservation<T> {
2373 Reservation(self.entities.reserve())
2374 }
2375
2376 fn insert_entity<T: 'static>(
2377 &mut self,
2378 reservation: Reservation<T>,
2379 build_entity: impl FnOnce(&mut Context<T>) -> T,
2380 ) -> Entity<T> {
2381 self.update(|cx| {
2382 let slot = reservation.0;
2383 let entity = build_entity(&mut Context::new_context(cx, slot.downgrade()));
2384 cx.entities.insert(slot, entity)
2385 })
2386 }
2387
2388 /// Updates the entity referenced by the given handle. The function is passed a mutable reference to the
2389 /// entity along with a `Context` for the entity.
2390 fn update_entity<T: 'static, R>(
2391 &mut self,
2392 handle: &Entity<T>,
2393 update: impl FnOnce(&mut T, &mut Context<T>) -> R,
2394 ) -> R {
2395 self.update(|cx| {
2396 let mut entity = cx.entities.lease(handle);
2397 let result = update(
2398 &mut entity,
2399 &mut Context::new_context(cx, handle.downgrade()),
2400 );
2401 cx.entities.end_lease(entity);
2402 result
2403 })
2404 }
2405
2406 fn as_mut<'a, T>(&'a mut self, handle: &Entity<T>) -> GpuiBorrow<'a, T>
2407 where
2408 T: 'static,
2409 {
2410 GpuiBorrow::new(handle.clone(), self)
2411 }
2412
2413 fn read_entity<T, R>(&self, handle: &Entity<T>, read: impl FnOnce(&T, &App) -> R) -> R
2414 where
2415 T: 'static,
2416 {
2417 let entity = self.entities.read(handle);
2418 read(entity, self)
2419 }
2420
2421 fn update_window<T, F>(&mut self, handle: AnyWindowHandle, update: F) -> Result<T>
2422 where
2423 F: FnOnce(AnyView, &mut Window, &mut App) -> T,
2424 {
2425 self.update_window_id(handle.id, update)
2426 }
2427
2428 fn read_window<T, R>(
2429 &self,
2430 window: &WindowHandle<T>,
2431 read: impl FnOnce(Entity<T>, &App) -> R,
2432 ) -> Result<R>
2433 where
2434 T: 'static,
2435 {
2436 let window = self
2437 .windows
2438 .get(window.id)
2439 .context("window not found")?
2440 .as_deref()
2441 .expect("attempted to read a window that is already on the stack");
2442
2443 let root_view = window.root.clone().unwrap();
2444 let view = root_view
2445 .downcast::<T>()
2446 .map_err(|_| anyhow!("root view's type has changed"))?;
2447
2448 Ok(read(view, self))
2449 }
2450
2451 fn background_spawn<R>(&self, future: impl Future<Output = R> + Send + 'static) -> Task<R>
2452 where
2453 R: Send + 'static,
2454 {
2455 self.background_executor.spawn(future)
2456 }
2457
2458 fn read_global<G, R>(&self, callback: impl FnOnce(&G, &App) -> R) -> R
2459 where
2460 G: Global,
2461 {
2462 let mut g = self.global::<G>();
2463 callback(g, self)
2464 }
2465}
2466
2467/// These effects are processed at the end of each application update cycle.
2468pub(crate) enum Effect {
2469 Notify {
2470 emitter: EntityId,
2471 },
2472 Emit {
2473 emitter: EntityId,
2474 event_type: TypeId,
2475 event: ArenaBox<dyn Any>,
2476 },
2477 RefreshWindows,
2478 NotifyGlobalObservers {
2479 global_type: TypeId,
2480 },
2481 Defer {
2482 callback: Box<dyn FnOnce(&mut App) + 'static>,
2483 },
2484 EntityCreated {
2485 entity: AnyEntity,
2486 tid: TypeId,
2487 window: Option<WindowId>,
2488 },
2489}
2490
2491impl std::fmt::Debug for Effect {
2492 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2493 match self {
2494 Effect::Notify { emitter } => write!(f, "Notify({})", emitter),
2495 Effect::Emit { emitter, .. } => write!(f, "Emit({:?})", emitter),
2496 Effect::RefreshWindows => write!(f, "RefreshWindows"),
2497 Effect::NotifyGlobalObservers { global_type } => {
2498 write!(f, "NotifyGlobalObservers({:?})", global_type)
2499 }
2500 Effect::Defer { .. } => write!(f, "Defer(..)"),
2501 Effect::EntityCreated { entity, .. } => write!(f, "EntityCreated({:?})", entity),
2502 }
2503 }
2504}
2505
2506/// Wraps a global variable value during `update_global` while the value has been moved to the stack.
2507pub(crate) struct GlobalLease<G: Global> {
2508 global: Box<dyn Any>,
2509 global_type: PhantomData<G>,
2510}
2511
2512impl<G: Global> GlobalLease<G> {
2513 fn new(global: Box<dyn Any>) -> Self {
2514 GlobalLease {
2515 global,
2516 global_type: PhantomData,
2517 }
2518 }
2519}
2520
2521impl<G: Global> Deref for GlobalLease<G> {
2522 type Target = G;
2523
2524 fn deref(&self) -> &Self::Target {
2525 self.global.downcast_ref().unwrap()
2526 }
2527}
2528
2529impl<G: Global> DerefMut for GlobalLease<G> {
2530 fn deref_mut(&mut self) -> &mut Self::Target {
2531 self.global.downcast_mut().unwrap()
2532 }
2533}
2534
2535/// Contains state associated with an active drag operation, started by dragging an element
2536/// within the window or by dragging into the app from the underlying platform.
2537pub struct AnyDrag {
2538 /// The view used to render this drag
2539 pub view: AnyView,
2540
2541 /// The value of the dragged item, to be dropped
2542 pub value: Arc<dyn Any>,
2543
2544 /// This is used to render the dragged item in the same place
2545 /// on the original element that the drag was initiated
2546 pub cursor_offset: Point<Pixels>,
2547
2548 /// The cursor style to use while dragging
2549 pub cursor_style: Option<CursorStyle>,
2550}
2551
2552/// Contains state associated with a tooltip. You'll only need this struct if you're implementing
2553/// tooltip behavior on a custom element. Otherwise, use [Div::tooltip](crate::Interactivity::tooltip).
2554#[derive(Clone)]
2555pub struct AnyTooltip {
2556 /// The view used to display the tooltip
2557 pub view: AnyView,
2558
2559 /// The absolute position of the mouse when the tooltip was deployed.
2560 pub mouse_position: Point<Pixels>,
2561
2562 /// Given the bounds of the tooltip, checks whether the tooltip should still be visible and
2563 /// updates its state accordingly. This is needed atop the hovered element's mouse move handler
2564 /// to handle the case where the element is not painted (e.g. via use of `visible_on_hover`).
2565 pub check_visible_and_update: Rc<dyn Fn(Bounds<Pixels>, &mut Window, &mut App) -> bool>,
2566}
2567
2568/// A keystroke event, and potentially the associated action
2569#[derive(Debug)]
2570pub struct KeystrokeEvent {
2571 /// The keystroke that occurred
2572 pub keystroke: Keystroke,
2573
2574 /// The action that was resolved for the keystroke, if any
2575 pub action: Option<Box<dyn Action>>,
2576
2577 /// The context stack at the time
2578 pub context_stack: Vec<KeyContext>,
2579}
2580
2581struct NullHttpClient;
2582
2583impl HttpClient for NullHttpClient {
2584 fn send(
2585 &self,
2586 _req: http_client::Request<http_client::AsyncBody>,
2587 ) -> futures::future::BoxFuture<
2588 'static,
2589 anyhow::Result<http_client::Response<http_client::AsyncBody>>,
2590 > {
2591 async move {
2592 anyhow::bail!("No HttpClient available");
2593 }
2594 .boxed()
2595 }
2596
2597 fn user_agent(&self) -> Option<&http_client::http::HeaderValue> {
2598 None
2599 }
2600
2601 fn proxy(&self) -> Option<&Url> {
2602 None
2603 }
2604}
2605
2606/// A mutable reference to an entity owned by GPUI
2607pub struct GpuiBorrow<'a, T> {
2608 inner: Option<Lease<T>>,
2609 app: &'a mut App,
2610}
2611
2612impl<'a, T: 'static> GpuiBorrow<'a, T> {
2613 fn new(inner: Entity<T>, app: &'a mut App) -> Self {
2614 app.start_update();
2615 let lease = app.entities.lease(&inner);
2616 Self {
2617 inner: Some(lease),
2618 app,
2619 }
2620 }
2621}
2622
2623impl<'a, T: 'static> std::borrow::Borrow<T> for GpuiBorrow<'a, T> {
2624 fn borrow(&self) -> &T {
2625 self.inner.as_ref().unwrap().borrow()
2626 }
2627}
2628
2629impl<'a, T: 'static> std::borrow::BorrowMut<T> for GpuiBorrow<'a, T> {
2630 fn borrow_mut(&mut self) -> &mut T {
2631 self.inner.as_mut().unwrap().borrow_mut()
2632 }
2633}
2634
2635impl<'a, T: 'static> std::ops::Deref for GpuiBorrow<'a, T> {
2636 type Target = T;
2637
2638 fn deref(&self) -> &Self::Target {
2639 self.inner.as_ref().unwrap()
2640 }
2641}
2642
2643impl<'a, T: 'static> std::ops::DerefMut for GpuiBorrow<'a, T> {
2644 fn deref_mut(&mut self) -> &mut T {
2645 self.inner.as_mut().unwrap()
2646 }
2647}
2648
2649impl<'a, T> Drop for GpuiBorrow<'a, T> {
2650 fn drop(&mut self) {
2651 let lease = self.inner.take().unwrap();
2652 self.app.notify(lease.id);
2653 self.app.entities.end_lease(lease);
2654 self.app.finish_update();
2655 }
2656}
2657
2658#[cfg(test)]
2659mod test {
2660 use std::{cell::RefCell, rc::Rc};
2661
2662 use crate::{AppContext, TestAppContext};
2663
2664 #[test]
2665 fn test_gpui_borrow() {
2666 let cx = TestAppContext::single();
2667 let observation_count = Rc::new(RefCell::new(0));
2668
2669 let state = cx.update(|cx| {
2670 let state = cx.new(|_| false);
2671 cx.observe(&state, {
2672 let observation_count = observation_count.clone();
2673 move |_, _| {
2674 let mut count = observation_count.borrow_mut();
2675 *count += 1;
2676 }
2677 })
2678 .detach();
2679
2680 state
2681 });
2682
2683 cx.update(|cx| {
2684 // Calling this like this so that we don't clobber the borrow_mut above
2685 *std::borrow::BorrowMut::borrow_mut(&mut state.as_mut(cx)) = true;
2686 });
2687
2688 cx.update(|cx| {
2689 state.write(cx, false);
2690 });
2691
2692 assert_eq!(*observation_count.borrow(), 2);
2693 }
2694}