1use std::{
2 any::{type_name, TypeId},
3 cell::{Ref, RefCell, RefMut},
4 marker::PhantomData,
5 ops::{Deref, DerefMut},
6 path::{Path, PathBuf},
7 rc::{Rc, Weak},
8 sync::{atomic::Ordering::SeqCst, Arc},
9 time::Duration,
10};
11
12use anyhow::{anyhow, Result};
13use derive_more::{Deref, DerefMut};
14use futures::{
15 channel::oneshot,
16 future::{LocalBoxFuture, Shared},
17 Future, FutureExt,
18};
19use slotmap::SlotMap;
20
21pub use async_context::*;
22use collections::{FxHashMap, FxHashSet, VecDeque};
23pub use entity_map::*;
24use http_client::HttpClient;
25pub use model_context::*;
26#[cfg(any(test, feature = "test-support"))]
27pub use test_context::*;
28use util::ResultExt;
29
30use crate::{
31 current_platform, hash, init_app_menus, Action, ActionRegistry, Any, AnyView, AnyWindowHandle,
32 Asset, AssetSource, BackgroundExecutor, ClipboardItem, Context, DispatchPhase, DisplayId,
33 Entity, EventEmitter, ForegroundExecutor, Global, KeyBinding, Keymap, Keystroke, LayoutId,
34 Menu, MenuItem, OwnedMenu, PathPromptOptions, Pixels, Platform, PlatformDisplay, Point,
35 PromptBuilder, PromptHandle, PromptLevel, Render, RenderablePromptHandle, Reservation,
36 SharedString, SubscriberSet, Subscription, SvgRenderer, Task, TextSystem, View, ViewContext,
37 Window, WindowAppearance, WindowContext, WindowHandle, WindowId,
38};
39
40mod async_context;
41mod entity_map;
42mod model_context;
43#[cfg(any(test, feature = "test-support"))]
44mod test_context;
45
46/// The duration for which futures returned from [AppContext::on_app_context] or [ModelContext::on_app_quit] can run before the application fully quits.
47pub const SHUTDOWN_TIMEOUT: Duration = Duration::from_millis(100);
48
49/// Temporary(?) wrapper around [`RefCell<AppContext>`] to help us debug any double borrows.
50/// Strongly consider removing after stabilization.
51#[doc(hidden)]
52pub struct AppCell {
53 app: RefCell<AppContext>,
54}
55
56impl AppCell {
57 #[doc(hidden)]
58 #[track_caller]
59 pub fn borrow(&self) -> AppRef {
60 if option_env!("TRACK_THREAD_BORROWS").is_some() {
61 let thread_id = std::thread::current().id();
62 eprintln!("borrowed {thread_id:?}");
63 }
64 AppRef(self.app.borrow())
65 }
66
67 #[doc(hidden)]
68 #[track_caller]
69 pub fn borrow_mut(&self) -> AppRefMut {
70 if option_env!("TRACK_THREAD_BORROWS").is_some() {
71 let thread_id = std::thread::current().id();
72 eprintln!("borrowed {thread_id:?}");
73 }
74 AppRefMut(self.app.borrow_mut())
75 }
76}
77
78#[doc(hidden)]
79#[derive(Deref, DerefMut)]
80pub struct AppRef<'a>(Ref<'a, AppContext>);
81
82impl<'a> Drop for AppRef<'a> {
83 fn drop(&mut self) {
84 if option_env!("TRACK_THREAD_BORROWS").is_some() {
85 let thread_id = std::thread::current().id();
86 eprintln!("dropped borrow from {thread_id:?}");
87 }
88 }
89}
90
91#[doc(hidden)]
92#[derive(Deref, DerefMut)]
93pub struct AppRefMut<'a>(RefMut<'a, AppContext>);
94
95impl<'a> Drop for AppRefMut<'a> {
96 fn drop(&mut self) {
97 if option_env!("TRACK_THREAD_BORROWS").is_some() {
98 let thread_id = std::thread::current().id();
99 eprintln!("dropped {thread_id:?}");
100 }
101 }
102}
103
104/// A reference to a GPUI application, typically constructed in the `main` function of your app.
105/// You won't interact with this type much outside of initial configuration and startup.
106pub struct App(Rc<AppCell>);
107
108/// Represents an application before it is fully launched. Once your app is
109/// configured, you'll start the app with `App::run`.
110impl App {
111 /// Builds an app with the given asset source.
112 #[allow(clippy::new_without_default)]
113 pub fn new() -> Self {
114 #[cfg(any(test, feature = "test-support"))]
115 log::info!("GPUI was compiled in test mode");
116
117 Self(AppContext::new(
118 current_platform(false),
119 Arc::new(()),
120 http_client::client(None, None),
121 ))
122 }
123
124 /// Build an app in headless mode. This prevents opening windows,
125 /// but makes it possible to run an application in an context like
126 /// SSH, where GUI applications are not allowed.
127 pub fn headless() -> Self {
128 Self(AppContext::new(
129 current_platform(true),
130 Arc::new(()),
131 http_client::client(None, None),
132 ))
133 }
134
135 /// Assign
136 pub fn with_assets(self, asset_source: impl AssetSource) -> Self {
137 let mut context_lock = self.0.borrow_mut();
138 let asset_source = Arc::new(asset_source);
139 context_lock.asset_source = asset_source.clone();
140 context_lock.svg_renderer = SvgRenderer::new(asset_source);
141 drop(context_lock);
142 self
143 }
144
145 /// Start the application. The provided callback will be called once the
146 /// app is fully launched.
147 pub fn run<F>(self, on_finish_launching: F)
148 where
149 F: 'static + FnOnce(&mut AppContext),
150 {
151 let this = self.0.clone();
152 let platform = self.0.borrow().platform.clone();
153 platform.run(Box::new(move || {
154 let cx = &mut *this.borrow_mut();
155 on_finish_launching(cx);
156 }));
157 }
158
159 /// Register a handler to be invoked when the platform instructs the application
160 /// to open one or more URLs.
161 pub fn on_open_urls<F>(&self, mut callback: F) -> &Self
162 where
163 F: 'static + FnMut(Vec<String>),
164 {
165 self.0.borrow().platform.on_open_urls(Box::new(callback));
166 self
167 }
168
169 /// Invokes a handler when an already-running application is launched.
170 /// On macOS, this can occur when the application icon is double-clicked or the app is launched via the dock.
171 pub fn on_reopen<F>(&self, mut callback: F) -> &Self
172 where
173 F: 'static + FnMut(&mut AppContext),
174 {
175 let this = Rc::downgrade(&self.0);
176 self.0.borrow_mut().platform.on_reopen(Box::new(move || {
177 if let Some(app) = this.upgrade() {
178 callback(&mut app.borrow_mut());
179 }
180 }));
181 self
182 }
183
184 /// Returns a handle to the [`BackgroundExecutor`] associated with this app, which can be used to spawn futures in the background.
185 pub fn background_executor(&self) -> BackgroundExecutor {
186 self.0.borrow().background_executor.clone()
187 }
188
189 /// Returns a handle to the [`ForegroundExecutor`] associated with this app, which can be used to spawn futures in the foreground.
190 pub fn foreground_executor(&self) -> ForegroundExecutor {
191 self.0.borrow().foreground_executor.clone()
192 }
193
194 /// Returns a reference to the [`TextSystem`] associated with this app.
195 pub fn text_system(&self) -> Arc<TextSystem> {
196 self.0.borrow().text_system.clone()
197 }
198
199 /// Returns the file URL of the executable with the specified name in the application bundle
200 pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
201 self.0.borrow().path_for_auxiliary_executable(name)
202 }
203}
204
205type Handler = Box<dyn FnMut(&mut AppContext) -> bool + 'static>;
206type Listener = Box<dyn FnMut(&dyn Any, &mut AppContext) -> bool + 'static>;
207pub(crate) type KeystrokeObserver =
208 Box<dyn FnMut(&KeystrokeEvent, &mut WindowContext) -> bool + 'static>;
209type QuitHandler = Box<dyn FnOnce(&mut AppContext) -> LocalBoxFuture<'static, ()> + 'static>;
210type ReleaseListener = Box<dyn FnOnce(&mut dyn Any, &mut AppContext) + 'static>;
211type NewViewListener = Box<dyn FnMut(AnyView, &mut WindowContext) + 'static>;
212
213/// Contains the state of the full application, and passed as a reference to a variety of callbacks.
214/// Other contexts such as [ModelContext], [WindowContext], and [ViewContext] deref to this type, making it the most general context type.
215/// You need a reference to an `AppContext` to access the state of a [Model].
216pub struct AppContext {
217 pub(crate) this: Weak<AppCell>,
218 pub(crate) platform: Rc<dyn Platform>,
219 text_system: Arc<TextSystem>,
220 flushing_effects: bool,
221 pending_updates: usize,
222 pub(crate) actions: Rc<ActionRegistry>,
223 pub(crate) active_drag: Option<AnyDrag>,
224 pub(crate) background_executor: BackgroundExecutor,
225 pub(crate) foreground_executor: ForegroundExecutor,
226 pub(crate) loading_assets: FxHashMap<(TypeId, u64), Box<dyn Any>>,
227 asset_source: Arc<dyn AssetSource>,
228 pub(crate) svg_renderer: SvgRenderer,
229 http_client: Arc<dyn HttpClient>,
230 pub(crate) globals_by_type: FxHashMap<TypeId, Box<dyn Any>>,
231 pub(crate) entities: EntityMap,
232 pub(crate) new_view_observers: SubscriberSet<TypeId, NewViewListener>,
233 pub(crate) windows: SlotMap<WindowId, Option<Window>>,
234 pub(crate) window_handles: FxHashMap<WindowId, AnyWindowHandle>,
235 pub(crate) keymap: Rc<RefCell<Keymap>>,
236 pub(crate) global_action_listeners:
237 FxHashMap<TypeId, Vec<Rc<dyn Fn(&dyn Any, DispatchPhase, &mut Self)>>>,
238 pending_effects: VecDeque<Effect>,
239 pub(crate) pending_notifications: FxHashSet<EntityId>,
240 pub(crate) pending_global_notifications: FxHashSet<TypeId>,
241 pub(crate) observers: SubscriberSet<EntityId, Handler>,
242 // TypeId is the type of the event that the listener callback expects
243 pub(crate) event_listeners: SubscriberSet<EntityId, (TypeId, Listener)>,
244 pub(crate) keystroke_observers: SubscriberSet<(), KeystrokeObserver>,
245 pub(crate) release_listeners: SubscriberSet<EntityId, ReleaseListener>,
246 pub(crate) global_observers: SubscriberSet<TypeId, Handler>,
247 pub(crate) quit_observers: SubscriberSet<(), QuitHandler>,
248 pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
249 pub(crate) propagate_event: bool,
250 pub(crate) prompt_builder: Option<PromptBuilder>,
251}
252
253impl AppContext {
254 #[allow(clippy::new_ret_no_self)]
255 pub(crate) fn new(
256 platform: Rc<dyn Platform>,
257 asset_source: Arc<dyn AssetSource>,
258 http_client: Arc<dyn HttpClient>,
259 ) -> Rc<AppCell> {
260 let executor = platform.background_executor();
261 let foreground_executor = platform.foreground_executor();
262 assert!(
263 executor.is_main_thread(),
264 "must construct App on main thread"
265 );
266
267 let text_system = Arc::new(TextSystem::new(platform.text_system()));
268 let entities = EntityMap::new();
269
270 let app = Rc::new_cyclic(|this| AppCell {
271 app: RefCell::new(AppContext {
272 this: this.clone(),
273 platform: platform.clone(),
274 text_system,
275 actions: Rc::new(ActionRegistry::default()),
276 flushing_effects: false,
277 pending_updates: 0,
278 active_drag: None,
279 background_executor: executor,
280 foreground_executor,
281 svg_renderer: SvgRenderer::new(asset_source.clone()),
282 loading_assets: Default::default(),
283 asset_source,
284 http_client,
285 globals_by_type: FxHashMap::default(),
286 entities,
287 new_view_observers: SubscriberSet::new(),
288 window_handles: FxHashMap::default(),
289 windows: SlotMap::with_key(),
290 keymap: Rc::new(RefCell::new(Keymap::default())),
291 global_action_listeners: FxHashMap::default(),
292 pending_effects: VecDeque::new(),
293 pending_notifications: FxHashSet::default(),
294 pending_global_notifications: FxHashSet::default(),
295 observers: SubscriberSet::new(),
296 event_listeners: SubscriberSet::new(),
297 release_listeners: SubscriberSet::new(),
298 keystroke_observers: SubscriberSet::new(),
299 global_observers: SubscriberSet::new(),
300 quit_observers: SubscriberSet::new(),
301 layout_id_buffer: Default::default(),
302 propagate_event: true,
303 prompt_builder: Some(PromptBuilder::Default),
304 }),
305 });
306
307 init_app_menus(platform.as_ref(), &mut app.borrow_mut());
308
309 platform.on_quit(Box::new({
310 let cx = app.clone();
311 move || {
312 cx.borrow_mut().shutdown();
313 }
314 }));
315
316 app
317 }
318
319 /// Quit the application gracefully. Handlers registered with [`ModelContext::on_app_quit`]
320 /// will be given 100ms to complete before exiting.
321 pub fn shutdown(&mut self) {
322 let mut futures = Vec::new();
323
324 for observer in self.quit_observers.remove(&()) {
325 futures.push(observer(self));
326 }
327
328 self.windows.clear();
329 self.window_handles.clear();
330 self.flush_effects();
331
332 let futures = futures::future::join_all(futures);
333 if self
334 .background_executor
335 .block_with_timeout(SHUTDOWN_TIMEOUT, futures)
336 .is_err()
337 {
338 log::error!("timed out waiting on app_will_quit");
339 }
340 }
341
342 /// Gracefully quit the application via the platform's standard routine.
343 pub fn quit(&mut self) {
344 self.platform.quit();
345 }
346
347 /// Schedules all windows in the application to be redrawn. This can be called
348 /// multiple times in an update cycle and still result in a single redraw.
349 pub fn refresh(&mut self) {
350 self.pending_effects.push_back(Effect::Refresh);
351 }
352
353 pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
354 self.pending_updates += 1;
355 let result = update(self);
356 if !self.flushing_effects && self.pending_updates == 1 {
357 self.flushing_effects = true;
358 self.flush_effects();
359 self.flushing_effects = false;
360 }
361 self.pending_updates -= 1;
362 result
363 }
364
365 /// Arrange a callback to be invoked when the given model or view calls `notify` on its respective context.
366 pub fn observe<W, E>(
367 &mut self,
368 entity: &E,
369 mut on_notify: impl FnMut(E, &mut AppContext) + 'static,
370 ) -> Subscription
371 where
372 W: 'static,
373 E: Entity<W>,
374 {
375 self.observe_internal(entity, move |e, cx| {
376 on_notify(e, cx);
377 true
378 })
379 }
380
381 pub(crate) fn new_observer(&mut self, key: EntityId, value: Handler) -> Subscription {
382 let (subscription, activate) = self.observers.insert(key, value);
383 self.defer(move |_| activate());
384 subscription
385 }
386 pub(crate) fn observe_internal<W, E>(
387 &mut self,
388 entity: &E,
389 mut on_notify: impl FnMut(E, &mut AppContext) -> bool + 'static,
390 ) -> Subscription
391 where
392 W: 'static,
393 E: Entity<W>,
394 {
395 let entity_id = entity.entity_id();
396 let handle = entity.downgrade();
397 self.new_observer(
398 entity_id,
399 Box::new(move |cx| {
400 if let Some(handle) = E::upgrade_from(&handle) {
401 on_notify(handle, cx)
402 } else {
403 false
404 }
405 }),
406 )
407 }
408
409 /// Arrange for the given callback to be invoked whenever the given model or view emits an event of a given type.
410 /// The callback is provided a handle to the emitting entity and a reference to the emitted event.
411 pub fn subscribe<T, E, Event>(
412 &mut self,
413 entity: &E,
414 mut on_event: impl FnMut(E, &Event, &mut AppContext) + 'static,
415 ) -> Subscription
416 where
417 T: 'static + EventEmitter<Event>,
418 E: Entity<T>,
419 Event: 'static,
420 {
421 self.subscribe_internal(entity, move |entity, event, cx| {
422 on_event(entity, event, cx);
423 true
424 })
425 }
426
427 pub(crate) fn new_subscription(
428 &mut self,
429 key: EntityId,
430 value: (TypeId, Listener),
431 ) -> Subscription {
432 let (subscription, activate) = self.event_listeners.insert(key, value);
433 self.defer(move |_| activate());
434 subscription
435 }
436 pub(crate) fn subscribe_internal<T, E, Evt>(
437 &mut self,
438 entity: &E,
439 mut on_event: impl FnMut(E, &Evt, &mut AppContext) -> bool + 'static,
440 ) -> Subscription
441 where
442 T: 'static + EventEmitter<Evt>,
443 E: Entity<T>,
444 Evt: 'static,
445 {
446 let entity_id = entity.entity_id();
447 let entity = entity.downgrade();
448 self.new_subscription(
449 entity_id,
450 (
451 TypeId::of::<Evt>(),
452 Box::new(move |event, cx| {
453 let event: &Evt = event.downcast_ref().expect("invalid event type");
454 if let Some(handle) = E::upgrade_from(&entity) {
455 on_event(handle, event, cx)
456 } else {
457 false
458 }
459 }),
460 ),
461 )
462 }
463
464 /// Returns handles to all open windows in the application.
465 /// Each handle could be downcast to a handle typed for the root view of that window.
466 /// To find all windows of a given type, you could filter on
467 pub fn windows(&self) -> Vec<AnyWindowHandle> {
468 self.windows
469 .keys()
470 .flat_map(|window_id| self.window_handles.get(&window_id).copied())
471 .collect()
472 }
473
474 /// Returns the window handles ordered by their appearance on screen, front to back.
475 ///
476 /// The first window in the returned list is the active/topmost window of the application.
477 ///
478 /// This method returns None if the platform doesn't implement the method yet.
479 pub fn window_stack(&self) -> Option<Vec<AnyWindowHandle>> {
480 self.platform.window_stack()
481 }
482
483 /// Returns a handle to the window that is currently focused at the platform level, if one exists.
484 pub fn active_window(&self) -> Option<AnyWindowHandle> {
485 self.platform.active_window()
486 }
487
488 /// Opens a new window with the given option and the root view returned by the given function.
489 /// The function is invoked with a `WindowContext`, which can be used to interact with window-specific
490 /// functionality.
491 pub fn open_window<V: 'static + Render>(
492 &mut self,
493 options: crate::WindowOptions,
494 build_root_view: impl FnOnce(&mut WindowContext) -> View<V>,
495 ) -> anyhow::Result<WindowHandle<V>> {
496 self.update(|cx| {
497 let id = cx.windows.insert(None);
498 let handle = WindowHandle::new(id);
499 match Window::new(handle.into(), options, cx) {
500 Ok(mut window) => {
501 let root_view = build_root_view(&mut WindowContext::new(cx, &mut window));
502 window.root_view.replace(root_view.into());
503 WindowContext::new(cx, &mut window).defer(|cx| cx.appearance_changed());
504 cx.window_handles.insert(id, window.handle);
505 cx.windows.get_mut(id).unwrap().replace(window);
506 Ok(handle)
507 }
508 Err(e) => {
509 cx.windows.remove(id);
510 Err(e)
511 }
512 }
513 })
514 }
515
516 /// Instructs the platform to activate the application by bringing it to the foreground.
517 pub fn activate(&self, ignoring_other_apps: bool) {
518 self.platform.activate(ignoring_other_apps);
519 }
520
521 /// Hide the application at the platform level.
522 pub fn hide(&self) {
523 self.platform.hide();
524 }
525
526 /// Hide other applications at the platform level.
527 pub fn hide_other_apps(&self) {
528 self.platform.hide_other_apps();
529 }
530
531 /// Unhide other applications at the platform level.
532 pub fn unhide_other_apps(&self) {
533 self.platform.unhide_other_apps();
534 }
535
536 /// Returns the list of currently active displays.
537 pub fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {
538 self.platform.displays()
539 }
540
541 /// Returns the primary display that will be used for new windows.
542 pub fn primary_display(&self) -> Option<Rc<dyn PlatformDisplay>> {
543 self.platform.primary_display()
544 }
545
546 /// Returns the display with the given ID, if one exists.
547 pub fn find_display(&self, id: DisplayId) -> Option<Rc<dyn PlatformDisplay>> {
548 self.displays()
549 .iter()
550 .find(|display| display.id() == id)
551 .cloned()
552 }
553
554 /// Returns the appearance of the application's windows.
555 pub fn window_appearance(&self) -> WindowAppearance {
556 self.platform.window_appearance()
557 }
558
559 /// Writes data to the primary selection buffer.
560 /// Only available on Linux.
561 #[cfg(target_os = "linux")]
562 pub fn write_to_primary(&self, item: ClipboardItem) {
563 self.platform.write_to_primary(item)
564 }
565
566 /// Writes data to the platform clipboard.
567 pub fn write_to_clipboard(&self, item: ClipboardItem) {
568 self.platform.write_to_clipboard(item)
569 }
570
571 /// Reads data from the primary selection buffer.
572 /// Only available on Linux.
573 #[cfg(target_os = "linux")]
574 pub fn read_from_primary(&self) -> Option<ClipboardItem> {
575 self.platform.read_from_primary()
576 }
577
578 /// Reads data from the platform clipboard.
579 pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
580 self.platform.read_from_clipboard()
581 }
582
583 /// Writes credentials to the platform keychain.
584 pub fn write_credentials(
585 &self,
586 url: &str,
587 username: &str,
588 password: &[u8],
589 ) -> Task<Result<()>> {
590 self.platform.write_credentials(url, username, password)
591 }
592
593 /// Reads credentials from the platform keychain.
594 pub fn read_credentials(&self, url: &str) -> Task<Result<Option<(String, Vec<u8>)>>> {
595 self.platform.read_credentials(url)
596 }
597
598 /// Deletes credentials from the platform keychain.
599 pub fn delete_credentials(&self, url: &str) -> Task<Result<()>> {
600 self.platform.delete_credentials(url)
601 }
602
603 /// Directs the platform's default browser to open the given URL.
604 pub fn open_url(&self, url: &str) {
605 self.platform.open_url(url);
606 }
607
608 /// register_url_scheme requests that the given scheme (e.g. `zed` for `zed://` urls)
609 /// is opened by the current app.
610 /// On some platforms (e.g. macOS) you may be able to register URL schemes as part of app
611 /// distribution, but this method exists to let you register schemes at runtime.
612 pub fn register_url_scheme(&self, scheme: &str) -> Task<Result<()>> {
613 self.platform.register_url_scheme(scheme)
614 }
615
616 /// Returns the full pathname of the current app bundle.
617 /// If the app is not being run from a bundle, returns an error.
618 pub fn app_path(&self) -> Result<PathBuf> {
619 self.platform.app_path()
620 }
621
622 /// On Linux, returns the name of the compositor in use.
623 /// Is blank on other platforms.
624 pub fn compositor_name(&self) -> &'static str {
625 self.platform.compositor_name()
626 }
627
628 /// Returns the file URL of the executable with the specified name in the application bundle
629 pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
630 self.platform.path_for_auxiliary_executable(name)
631 }
632
633 /// Displays a platform modal for selecting paths.
634 /// When one or more paths are selected, they'll be relayed asynchronously via the returned oneshot channel.
635 /// If cancelled, a `None` will be relayed instead.
636 /// May return an error on Linux if the file picker couldn't be opened.
637 pub fn prompt_for_paths(
638 &self,
639 options: PathPromptOptions,
640 ) -> oneshot::Receiver<Result<Option<Vec<PathBuf>>>> {
641 self.platform.prompt_for_paths(options)
642 }
643
644 /// Displays a platform modal for selecting a new path where a file can be saved.
645 /// The provided directory will be used to set the initial location.
646 /// When a path is selected, it is relayed asynchronously via the returned oneshot channel.
647 /// If cancelled, a `None` will be relayed instead.
648 /// May return an error on Linux if the file picker couldn't be opened.
649 pub fn prompt_for_new_path(
650 &self,
651 directory: &Path,
652 ) -> oneshot::Receiver<Result<Option<PathBuf>>> {
653 self.platform.prompt_for_new_path(directory)
654 }
655
656 /// Reveals the specified path at the platform level, such as in Finder on macOS.
657 pub fn reveal_path(&self, path: &Path) {
658 self.platform.reveal_path(path)
659 }
660
661 /// Opens the specified path with the system's default application.
662 pub fn open_with_system(&self, path: &Path) {
663 self.platform.open_with_system(path)
664 }
665
666 /// Returns whether the user has configured scrollbars to auto-hide at the platform level.
667 pub fn should_auto_hide_scrollbars(&self) -> bool {
668 self.platform.should_auto_hide_scrollbars()
669 }
670
671 /// Restart the application.
672 pub fn restart(&self, binary_path: Option<PathBuf>) {
673 self.platform.restart(binary_path)
674 }
675
676 /// Updates the http client assigned to GPUI
677 pub fn set_http_client(&mut self, new_client: Arc<dyn HttpClient>) {
678 self.http_client = new_client;
679 }
680
681 /// Returns the http client assigned to GPUI
682 pub fn http_client(&self) -> Arc<dyn HttpClient> {
683 self.http_client.clone()
684 }
685
686 /// Returns the SVG renderer GPUI uses
687 pub(crate) fn svg_renderer(&self) -> SvgRenderer {
688 self.svg_renderer.clone()
689 }
690
691 pub(crate) fn push_effect(&mut self, effect: Effect) {
692 match &effect {
693 Effect::Notify { emitter } => {
694 if !self.pending_notifications.insert(*emitter) {
695 return;
696 }
697 }
698 Effect::NotifyGlobalObservers { global_type } => {
699 if !self.pending_global_notifications.insert(*global_type) {
700 return;
701 }
702 }
703 _ => {}
704 };
705
706 self.pending_effects.push_back(effect);
707 }
708
709 /// Called at the end of [`AppContext::update`] to complete any side effects
710 /// such as notifying observers, emitting events, etc. Effects can themselves
711 /// cause effects, so we continue looping until all effects are processed.
712 fn flush_effects(&mut self) {
713 loop {
714 self.release_dropped_entities();
715 self.release_dropped_focus_handles();
716
717 if let Some(effect) = self.pending_effects.pop_front() {
718 match effect {
719 Effect::Notify { emitter } => {
720 self.apply_notify_effect(emitter);
721 }
722
723 Effect::Emit {
724 emitter,
725 event_type,
726 event,
727 } => self.apply_emit_effect(emitter, event_type, event),
728
729 Effect::Refresh => {
730 self.apply_refresh_effect();
731 }
732
733 Effect::NotifyGlobalObservers { global_type } => {
734 self.apply_notify_global_observers_effect(global_type);
735 }
736
737 Effect::Defer { callback } => {
738 self.apply_defer_effect(callback);
739 }
740 }
741 } else {
742 #[cfg(any(test, feature = "test-support"))]
743 for window in self
744 .windows
745 .values()
746 .filter_map(|window| {
747 let window = window.as_ref()?;
748 window.dirty.get().then_some(window.handle)
749 })
750 .collect::<Vec<_>>()
751 {
752 self.update_window(window, |_, cx| cx.draw()).unwrap();
753 }
754
755 if self.pending_effects.is_empty() {
756 break;
757 }
758 }
759 }
760 }
761
762 /// Repeatedly called during `flush_effects` to release any entities whose
763 /// reference count has become zero. We invoke any release observers before dropping
764 /// each entity.
765 fn release_dropped_entities(&mut self) {
766 loop {
767 let dropped = self.entities.take_dropped();
768 if dropped.is_empty() {
769 break;
770 }
771
772 for (entity_id, mut entity) in dropped {
773 self.observers.remove(&entity_id);
774 self.event_listeners.remove(&entity_id);
775 for release_callback in self.release_listeners.remove(&entity_id) {
776 release_callback(entity.as_mut(), self);
777 }
778 }
779 }
780 }
781
782 /// Repeatedly called during `flush_effects` to handle a focused handle being dropped.
783 fn release_dropped_focus_handles(&mut self) {
784 for window_handle in self.windows() {
785 window_handle
786 .update(self, |_, cx| {
787 let mut blur_window = false;
788 let focus = cx.window.focus;
789 cx.window.focus_handles.write().retain(|handle_id, count| {
790 if count.load(SeqCst) == 0 {
791 if focus == Some(handle_id) {
792 blur_window = true;
793 }
794 false
795 } else {
796 true
797 }
798 });
799
800 if blur_window {
801 cx.blur();
802 }
803 })
804 .unwrap();
805 }
806 }
807
808 fn apply_notify_effect(&mut self, emitter: EntityId) {
809 self.pending_notifications.remove(&emitter);
810
811 self.observers
812 .clone()
813 .retain(&emitter, |handler| handler(self));
814 }
815
816 fn apply_emit_effect(&mut self, emitter: EntityId, event_type: TypeId, event: Box<dyn Any>) {
817 self.event_listeners
818 .clone()
819 .retain(&emitter, |(stored_type, handler)| {
820 if *stored_type == event_type {
821 handler(event.as_ref(), self)
822 } else {
823 true
824 }
825 });
826 }
827
828 fn apply_refresh_effect(&mut self) {
829 for window in self.windows.values_mut() {
830 if let Some(window) = window.as_mut() {
831 window.dirty.set(true);
832 }
833 }
834 }
835
836 fn apply_notify_global_observers_effect(&mut self, type_id: TypeId) {
837 self.pending_global_notifications.remove(&type_id);
838 self.global_observers
839 .clone()
840 .retain(&type_id, |observer| observer(self));
841 }
842
843 fn apply_defer_effect(&mut self, callback: Box<dyn FnOnce(&mut Self) + 'static>) {
844 callback(self);
845 }
846
847 /// Creates an `AsyncAppContext`, which can be cloned and has a static lifetime
848 /// so it can be held across `await` points.
849 pub fn to_async(&self) -> AsyncAppContext {
850 AsyncAppContext {
851 app: self.this.clone(),
852 background_executor: self.background_executor.clone(),
853 foreground_executor: self.foreground_executor.clone(),
854 }
855 }
856
857 /// Obtains a reference to the executor, which can be used to spawn futures.
858 pub fn background_executor(&self) -> &BackgroundExecutor {
859 &self.background_executor
860 }
861
862 /// Obtains a reference to the executor, which can be used to spawn futures.
863 pub fn foreground_executor(&self) -> &ForegroundExecutor {
864 &self.foreground_executor
865 }
866
867 /// Spawns the future returned by the given function on the thread pool. The closure will be invoked
868 /// with [AsyncAppContext], which allows the application state to be accessed across await points.
869 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut) -> Task<R>
870 where
871 Fut: Future<Output = R> + 'static,
872 R: 'static,
873 {
874 self.foreground_executor.spawn(f(self.to_async()))
875 }
876
877 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
878 /// that are currently on the stack to be returned to the app.
879 pub fn defer(&mut self, f: impl FnOnce(&mut AppContext) + 'static) {
880 self.push_effect(Effect::Defer {
881 callback: Box::new(f),
882 });
883 }
884
885 /// Accessor for the application's asset source, which is provided when constructing the `App`.
886 pub fn asset_source(&self) -> &Arc<dyn AssetSource> {
887 &self.asset_source
888 }
889
890 /// Accessor for the text system.
891 pub fn text_system(&self) -> &Arc<TextSystem> {
892 &self.text_system
893 }
894
895 /// Check whether a global of the given type has been assigned.
896 pub fn has_global<G: Global>(&self) -> bool {
897 self.globals_by_type.contains_key(&TypeId::of::<G>())
898 }
899
900 /// Access the global of the given type. Panics if a global for that type has not been assigned.
901 #[track_caller]
902 pub fn global<G: Global>(&self) -> &G {
903 self.globals_by_type
904 .get(&TypeId::of::<G>())
905 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
906 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
907 .unwrap()
908 }
909
910 /// Access the global of the given type if a value has been assigned.
911 pub fn try_global<G: Global>(&self) -> Option<&G> {
912 self.globals_by_type
913 .get(&TypeId::of::<G>())
914 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
915 }
916
917 /// Access the global of the given type mutably. Panics if a global for that type has not been assigned.
918 #[track_caller]
919 pub fn global_mut<G: Global>(&mut self) -> &mut G {
920 let global_type = TypeId::of::<G>();
921 self.push_effect(Effect::NotifyGlobalObservers { global_type });
922 self.globals_by_type
923 .get_mut(&global_type)
924 .and_then(|any_state| any_state.downcast_mut::<G>())
925 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
926 .unwrap()
927 }
928
929 /// Access the global of the given type mutably. A default value is assigned if a global of this type has not
930 /// yet been assigned.
931 pub fn default_global<G: Global + Default>(&mut self) -> &mut G {
932 let global_type = TypeId::of::<G>();
933 self.push_effect(Effect::NotifyGlobalObservers { global_type });
934 self.globals_by_type
935 .entry(global_type)
936 .or_insert_with(|| Box::<G>::default())
937 .downcast_mut::<G>()
938 .unwrap()
939 }
940
941 /// Sets the value of the global of the given type.
942 pub fn set_global<G: Global>(&mut self, global: G) {
943 let global_type = TypeId::of::<G>();
944 self.push_effect(Effect::NotifyGlobalObservers { global_type });
945 self.globals_by_type.insert(global_type, Box::new(global));
946 }
947
948 /// Clear all stored globals. Does not notify global observers.
949 #[cfg(any(test, feature = "test-support"))]
950 pub fn clear_globals(&mut self) {
951 self.globals_by_type.drain();
952 }
953
954 /// Remove the global of the given type from the app context. Does not notify global observers.
955 pub fn remove_global<G: Global>(&mut self) -> G {
956 let global_type = TypeId::of::<G>();
957 self.push_effect(Effect::NotifyGlobalObservers { global_type });
958 *self
959 .globals_by_type
960 .remove(&global_type)
961 .unwrap_or_else(|| panic!("no global added for {}", std::any::type_name::<G>()))
962 .downcast()
963 .unwrap()
964 }
965
966 /// Register a callback to be invoked when a global of the given type is updated.
967 pub fn observe_global<G: Global>(
968 &mut self,
969 mut f: impl FnMut(&mut Self) + 'static,
970 ) -> Subscription {
971 let (subscription, activate) = self.global_observers.insert(
972 TypeId::of::<G>(),
973 Box::new(move |cx| {
974 f(cx);
975 true
976 }),
977 );
978 self.defer(move |_| activate());
979 subscription
980 }
981
982 /// Move the global of the given type to the stack.
983 pub(crate) fn lease_global<G: Global>(&mut self) -> GlobalLease<G> {
984 GlobalLease::new(
985 self.globals_by_type
986 .remove(&TypeId::of::<G>())
987 .ok_or_else(|| anyhow!("no global registered of type {}", type_name::<G>()))
988 .unwrap(),
989 )
990 }
991
992 /// Restore the global of the given type after it is moved to the stack.
993 pub(crate) fn end_global_lease<G: Global>(&mut self, lease: GlobalLease<G>) {
994 let global_type = TypeId::of::<G>();
995 self.push_effect(Effect::NotifyGlobalObservers { global_type });
996 self.globals_by_type.insert(global_type, lease.global);
997 }
998
999 pub(crate) fn new_view_observer(
1000 &mut self,
1001 key: TypeId,
1002 value: NewViewListener,
1003 ) -> Subscription {
1004 let (subscription, activate) = self.new_view_observers.insert(key, value);
1005 activate();
1006 subscription
1007 }
1008 /// Arrange for the given function to be invoked whenever a view of the specified type is created.
1009 /// The function will be passed a mutable reference to the view along with an appropriate context.
1010 pub fn observe_new_views<V: 'static>(
1011 &mut self,
1012 on_new: impl 'static + Fn(&mut V, &mut ViewContext<V>),
1013 ) -> Subscription {
1014 self.new_view_observer(
1015 TypeId::of::<V>(),
1016 Box::new(move |any_view: AnyView, cx: &mut WindowContext| {
1017 any_view
1018 .downcast::<V>()
1019 .unwrap()
1020 .update(cx, |view_state, cx| {
1021 on_new(view_state, cx);
1022 })
1023 }),
1024 )
1025 }
1026
1027 /// Observe the release of a model or view. The callback is invoked after the model or view
1028 /// has no more strong references but before it has been dropped.
1029 pub fn observe_release<E, T>(
1030 &mut self,
1031 handle: &E,
1032 on_release: impl FnOnce(&mut T, &mut AppContext) + 'static,
1033 ) -> Subscription
1034 where
1035 E: Entity<T>,
1036 T: 'static,
1037 {
1038 let (subscription, activate) = self.release_listeners.insert(
1039 handle.entity_id(),
1040 Box::new(move |entity, cx| {
1041 let entity = entity.downcast_mut().expect("invalid entity type");
1042 on_release(entity, cx)
1043 }),
1044 );
1045 activate();
1046 subscription
1047 }
1048
1049 /// Register a callback to be invoked when a keystroke is received by the application
1050 /// in any window. Note that this fires after all other action and event mechanisms have resolved
1051 /// and that this API will not be invoked if the event's propagation is stopped.
1052 pub fn observe_keystrokes(
1053 &mut self,
1054 mut f: impl FnMut(&KeystrokeEvent, &mut WindowContext) + 'static,
1055 ) -> Subscription {
1056 fn inner(
1057 keystroke_observers: &mut SubscriberSet<(), KeystrokeObserver>,
1058 handler: KeystrokeObserver,
1059 ) -> Subscription {
1060 let (subscription, activate) = keystroke_observers.insert((), handler);
1061 activate();
1062 subscription
1063 }
1064
1065 inner(
1066 &mut self.keystroke_observers,
1067 Box::new(move |event, cx| {
1068 f(event, cx);
1069 true
1070 }),
1071 )
1072 }
1073
1074 /// Register key bindings.
1075 pub fn bind_keys(&mut self, bindings: impl IntoIterator<Item = KeyBinding>) {
1076 self.keymap.borrow_mut().add_bindings(bindings);
1077 self.pending_effects.push_back(Effect::Refresh);
1078 }
1079
1080 /// Clear all key bindings in the app.
1081 pub fn clear_key_bindings(&mut self) {
1082 self.keymap.borrow_mut().clear();
1083 self.pending_effects.push_back(Effect::Refresh);
1084 }
1085
1086 /// Register a global listener for actions invoked via the keyboard.
1087 pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Self) + 'static) {
1088 self.global_action_listeners
1089 .entry(TypeId::of::<A>())
1090 .or_default()
1091 .push(Rc::new(move |action, phase, cx| {
1092 if phase == DispatchPhase::Bubble {
1093 let action = action.downcast_ref().unwrap();
1094 listener(action, cx)
1095 }
1096 }));
1097 }
1098
1099 /// Event handlers propagate events by default. Call this method to stop dispatching to
1100 /// event handlers with a lower z-index (mouse) or higher in the tree (keyboard). This is
1101 /// the opposite of [`Self::propagate`]. It's also possible to cancel a call to [`Self::propagate`] by
1102 /// calling this method before effects are flushed.
1103 pub fn stop_propagation(&mut self) {
1104 self.propagate_event = false;
1105 }
1106
1107 /// Action handlers stop propagation by default during the bubble phase of action dispatch
1108 /// dispatching to action handlers higher in the element tree. This is the opposite of
1109 /// [`Self::stop_propagation`]. It's also possible to cancel a call to [`Self::stop_propagation`] by calling
1110 /// this method before effects are flushed.
1111 pub fn propagate(&mut self) {
1112 self.propagate_event = true;
1113 }
1114
1115 /// Build an action from some arbitrary data, typically a keymap entry.
1116 pub fn build_action(
1117 &self,
1118 name: &str,
1119 data: Option<serde_json::Value>,
1120 ) -> Result<Box<dyn Action>> {
1121 self.actions.build_action(name, data)
1122 }
1123
1124 /// Get a list of all action names that have been registered.
1125 /// in the application. Note that registration only allows for
1126 /// actions to be built dynamically, and is unrelated to binding
1127 /// actions in the element tree.
1128 pub fn all_action_names(&self) -> &[SharedString] {
1129 self.actions.all_action_names()
1130 }
1131
1132 /// Register a callback to be invoked when the application is about to quit.
1133 /// It is not possible to cancel the quit event at this point.
1134 pub fn on_app_quit<Fut>(
1135 &mut self,
1136 mut on_quit: impl FnMut(&mut AppContext) -> Fut + 'static,
1137 ) -> Subscription
1138 where
1139 Fut: 'static + Future<Output = ()>,
1140 {
1141 let (subscription, activate) = self.quit_observers.insert(
1142 (),
1143 Box::new(move |cx| {
1144 let future = on_quit(cx);
1145 future.boxed_local()
1146 }),
1147 );
1148 activate();
1149 subscription
1150 }
1151
1152 pub(crate) fn clear_pending_keystrokes(&mut self) {
1153 for window in self.windows() {
1154 window
1155 .update(self, |_, cx| {
1156 cx.clear_pending_keystrokes();
1157 })
1158 .ok();
1159 }
1160 }
1161
1162 /// Checks if the given action is bound in the current context, as defined by the app's current focus,
1163 /// the bindings in the element tree, and any global action listeners.
1164 pub fn is_action_available(&mut self, action: &dyn Action) -> bool {
1165 let mut action_available = false;
1166 if let Some(window) = self.active_window() {
1167 if let Ok(window_action_available) =
1168 window.update(self, |_, cx| cx.is_action_available(action))
1169 {
1170 action_available = window_action_available;
1171 }
1172 }
1173
1174 action_available
1175 || self
1176 .global_action_listeners
1177 .contains_key(&action.as_any().type_id())
1178 }
1179
1180 /// Sets the menu bar for this application. This will replace any existing menu bar.
1181 pub fn set_menus(&mut self, menus: Vec<Menu>) {
1182 self.platform.set_menus(menus, &self.keymap.borrow());
1183 }
1184
1185 /// Gets the menu bar for this application.
1186 pub fn get_menus(&self) -> Option<Vec<OwnedMenu>> {
1187 self.platform.get_menus()
1188 }
1189
1190 /// Sets the right click menu for the app icon in the dock
1191 pub fn set_dock_menu(&mut self, menus: Vec<MenuItem>) {
1192 self.platform.set_dock_menu(menus, &self.keymap.borrow());
1193 }
1194
1195 /// Adds given path to the bottom of the list of recent paths for the application.
1196 /// The list is usually shown on the application icon's context menu in the dock,
1197 /// and allows to open the recent files via that context menu.
1198 /// If the path is already in the list, it will be moved to the bottom of the list.
1199 pub fn add_recent_document(&mut self, path: &Path) {
1200 self.platform.add_recent_document(path);
1201 }
1202
1203 /// Dispatch an action to the currently active window or global action handler
1204 /// See [action::Action] for more information on how actions work
1205 pub fn dispatch_action(&mut self, action: &dyn Action) {
1206 if let Some(active_window) = self.active_window() {
1207 active_window
1208 .update(self, |_, cx| cx.dispatch_action(action.boxed_clone()))
1209 .log_err();
1210 } else {
1211 self.dispatch_global_action(action);
1212 }
1213 }
1214
1215 fn dispatch_global_action(&mut self, action: &dyn Action) {
1216 self.propagate_event = true;
1217
1218 if let Some(mut global_listeners) = self
1219 .global_action_listeners
1220 .remove(&action.as_any().type_id())
1221 {
1222 for listener in &global_listeners {
1223 listener(action.as_any(), DispatchPhase::Capture, self);
1224 if !self.propagate_event {
1225 break;
1226 }
1227 }
1228
1229 global_listeners.extend(
1230 self.global_action_listeners
1231 .remove(&action.as_any().type_id())
1232 .unwrap_or_default(),
1233 );
1234
1235 self.global_action_listeners
1236 .insert(action.as_any().type_id(), global_listeners);
1237 }
1238
1239 if self.propagate_event {
1240 if let Some(mut global_listeners) = self
1241 .global_action_listeners
1242 .remove(&action.as_any().type_id())
1243 {
1244 for listener in global_listeners.iter().rev() {
1245 listener(action.as_any(), DispatchPhase::Bubble, self);
1246 if !self.propagate_event {
1247 break;
1248 }
1249 }
1250
1251 global_listeners.extend(
1252 self.global_action_listeners
1253 .remove(&action.as_any().type_id())
1254 .unwrap_or_default(),
1255 );
1256
1257 self.global_action_listeners
1258 .insert(action.as_any().type_id(), global_listeners);
1259 }
1260 }
1261 }
1262
1263 /// Is there currently something being dragged?
1264 pub fn has_active_drag(&self) -> bool {
1265 self.active_drag.is_some()
1266 }
1267
1268 /// Set the prompt renderer for GPUI. This will replace the default or platform specific
1269 /// prompts with this custom implementation.
1270 pub fn set_prompt_builder(
1271 &mut self,
1272 renderer: impl Fn(
1273 PromptLevel,
1274 &str,
1275 Option<&str>,
1276 &[&str],
1277 PromptHandle,
1278 &mut WindowContext,
1279 ) -> RenderablePromptHandle
1280 + 'static,
1281 ) {
1282 self.prompt_builder = Some(PromptBuilder::Custom(Box::new(renderer)))
1283 }
1284
1285 /// Remove an asset from GPUI's cache
1286 pub fn remove_cached_asset<A: Asset + 'static>(&mut self, source: &A::Source) {
1287 let asset_id = (TypeId::of::<A>(), hash(source));
1288 self.loading_assets.remove(&asset_id);
1289 }
1290
1291 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1292 ///
1293 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
1294 /// time, and the results of this call will be cached
1295 ///
1296 /// This asset will not be cached by default, see [Self::use_cached_asset]
1297 pub fn fetch_asset<A: Asset + 'static>(
1298 &mut self,
1299 source: &A::Source,
1300 ) -> (Shared<Task<A::Output>>, bool) {
1301 let asset_id = (TypeId::of::<A>(), hash(source));
1302 let mut is_first = false;
1303 let task = self
1304 .loading_assets
1305 .remove(&asset_id)
1306 .map(|boxed_task| *boxed_task.downcast::<Shared<Task<A::Output>>>().unwrap())
1307 .unwrap_or_else(|| {
1308 is_first = true;
1309 let future = A::load(source.clone(), self);
1310 let task = self.background_executor().spawn(future).shared();
1311 task
1312 });
1313
1314 self.loading_assets.insert(asset_id, Box::new(task.clone()));
1315
1316 (task, is_first)
1317 }
1318}
1319
1320impl Context for AppContext {
1321 type Result<T> = T;
1322
1323 /// Build an entity that is owned by the application. The given function will be invoked with
1324 /// a `ModelContext` and must return an object representing the entity. A `Model` handle will be returned,
1325 /// which can be used to access the entity in a context.
1326 fn new_model<T: 'static>(
1327 &mut self,
1328 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1329 ) -> Model<T> {
1330 self.update(|cx| {
1331 let slot = cx.entities.reserve();
1332 let entity = build_model(&mut ModelContext::new(cx, slot.downgrade()));
1333 cx.entities.insert(slot, entity)
1334 })
1335 }
1336
1337 fn reserve_model<T: 'static>(&mut self) -> Self::Result<Reservation<T>> {
1338 Reservation(self.entities.reserve())
1339 }
1340
1341 fn insert_model<T: 'static>(
1342 &mut self,
1343 reservation: Reservation<T>,
1344 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1345 ) -> Self::Result<Model<T>> {
1346 self.update(|cx| {
1347 let slot = reservation.0;
1348 let entity = build_model(&mut ModelContext::new(cx, slot.downgrade()));
1349 cx.entities.insert(slot, entity)
1350 })
1351 }
1352
1353 /// Updates the entity referenced by the given model. The function is passed a mutable reference to the
1354 /// entity along with a `ModelContext` for the entity.
1355 fn update_model<T: 'static, R>(
1356 &mut self,
1357 model: &Model<T>,
1358 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1359 ) -> R {
1360 self.update(|cx| {
1361 let mut entity = cx.entities.lease(model);
1362 let result = update(&mut entity, &mut ModelContext::new(cx, model.downgrade()));
1363 cx.entities.end_lease(entity);
1364 result
1365 })
1366 }
1367
1368 fn read_model<T, R>(
1369 &self,
1370 handle: &Model<T>,
1371 read: impl FnOnce(&T, &AppContext) -> R,
1372 ) -> Self::Result<R>
1373 where
1374 T: 'static,
1375 {
1376 let entity = self.entities.read(handle);
1377 read(entity, self)
1378 }
1379
1380 fn update_window<T, F>(&mut self, handle: AnyWindowHandle, update: F) -> Result<T>
1381 where
1382 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1383 {
1384 self.update(|cx| {
1385 let mut window = cx
1386 .windows
1387 .get_mut(handle.id)
1388 .ok_or_else(|| anyhow!("window not found"))?
1389 .take()
1390 .ok_or_else(|| anyhow!("window not found"))?;
1391
1392 let root_view = window.root_view.clone().unwrap();
1393 let result = update(root_view, &mut WindowContext::new(cx, &mut window));
1394
1395 if window.removed {
1396 cx.window_handles.remove(&handle.id);
1397 cx.windows.remove(handle.id);
1398 } else {
1399 cx.windows
1400 .get_mut(handle.id)
1401 .ok_or_else(|| anyhow!("window not found"))?
1402 .replace(window);
1403 }
1404
1405 Ok(result)
1406 })
1407 }
1408
1409 fn read_window<T, R>(
1410 &self,
1411 window: &WindowHandle<T>,
1412 read: impl FnOnce(View<T>, &AppContext) -> R,
1413 ) -> Result<R>
1414 where
1415 T: 'static,
1416 {
1417 let window = self
1418 .windows
1419 .get(window.id)
1420 .ok_or_else(|| anyhow!("window not found"))?
1421 .as_ref()
1422 .unwrap();
1423
1424 let root_view = window.root_view.clone().unwrap();
1425 let view = root_view
1426 .downcast::<T>()
1427 .map_err(|_| anyhow!("root view's type has changed"))?;
1428
1429 Ok(read(view, self))
1430 }
1431}
1432
1433/// These effects are processed at the end of each application update cycle.
1434pub(crate) enum Effect {
1435 Notify {
1436 emitter: EntityId,
1437 },
1438 Emit {
1439 emitter: EntityId,
1440 event_type: TypeId,
1441 event: Box<dyn Any>,
1442 },
1443 Refresh,
1444 NotifyGlobalObservers {
1445 global_type: TypeId,
1446 },
1447 Defer {
1448 callback: Box<dyn FnOnce(&mut AppContext) + 'static>,
1449 },
1450}
1451
1452/// Wraps a global variable value during `update_global` while the value has been moved to the stack.
1453pub(crate) struct GlobalLease<G: Global> {
1454 global: Box<dyn Any>,
1455 global_type: PhantomData<G>,
1456}
1457
1458impl<G: Global> GlobalLease<G> {
1459 fn new(global: Box<dyn Any>) -> Self {
1460 GlobalLease {
1461 global,
1462 global_type: PhantomData,
1463 }
1464 }
1465}
1466
1467impl<G: Global> Deref for GlobalLease<G> {
1468 type Target = G;
1469
1470 fn deref(&self) -> &Self::Target {
1471 self.global.downcast_ref().unwrap()
1472 }
1473}
1474
1475impl<G: Global> DerefMut for GlobalLease<G> {
1476 fn deref_mut(&mut self) -> &mut Self::Target {
1477 self.global.downcast_mut().unwrap()
1478 }
1479}
1480
1481/// Contains state associated with an active drag operation, started by dragging an element
1482/// within the window or by dragging into the app from the underlying platform.
1483pub struct AnyDrag {
1484 /// The view used to render this drag
1485 pub view: AnyView,
1486
1487 /// The value of the dragged item, to be dropped
1488 pub value: Box<dyn Any>,
1489
1490 /// This is used to render the dragged item in the same place
1491 /// on the original element that the drag was initiated
1492 pub cursor_offset: Point<Pixels>,
1493}
1494
1495/// Contains state associated with a tooltip. You'll only need this struct if you're implementing
1496/// tooltip behavior on a custom element. Otherwise, use [Div::tooltip].
1497#[derive(Clone)]
1498pub struct AnyTooltip {
1499 /// The view used to display the tooltip
1500 pub view: AnyView,
1501
1502 /// The absolute position of the mouse when the tooltip was deployed.
1503 pub mouse_position: Point<Pixels>,
1504}
1505
1506/// A keystroke event, and potentially the associated action
1507#[derive(Debug)]
1508pub struct KeystrokeEvent {
1509 /// The keystroke that occurred
1510 pub keystroke: Keystroke,
1511
1512 /// The action that was resolved for the keystroke, if any
1513 pub action: Option<Box<dyn Action>>,
1514}