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 Arc::new(NullHttpClient),
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 Arc::new(NullHttpClient),
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 /// Set the http client for the application
146 pub fn with_http_client(self, http_client: Arc<dyn HttpClient>) -> Self {
147 let mut context_lock = self.0.borrow_mut();
148 context_lock.http_client = http_client;
149 drop(context_lock);
150 self
151 }
152
153 /// Start the application. The provided callback will be called once the
154 /// app is fully launched.
155 pub fn run<F>(self, on_finish_launching: F)
156 where
157 F: 'static + FnOnce(&mut AppContext),
158 {
159 let this = self.0.clone();
160 let platform = self.0.borrow().platform.clone();
161 platform.run(Box::new(move || {
162 let cx = &mut *this.borrow_mut();
163 on_finish_launching(cx);
164 }));
165 }
166
167 /// Register a handler to be invoked when the platform instructs the application
168 /// to open one or more URLs.
169 pub fn on_open_urls<F>(&self, mut callback: F) -> &Self
170 where
171 F: 'static + FnMut(Vec<String>),
172 {
173 self.0.borrow().platform.on_open_urls(Box::new(callback));
174 self
175 }
176
177 /// Invokes a handler when an already-running application is launched.
178 /// On macOS, this can occur when the application icon is double-clicked or the app is launched via the dock.
179 pub fn on_reopen<F>(&self, mut callback: F) -> &Self
180 where
181 F: 'static + FnMut(&mut AppContext),
182 {
183 let this = Rc::downgrade(&self.0);
184 self.0.borrow_mut().platform.on_reopen(Box::new(move || {
185 if let Some(app) = this.upgrade() {
186 callback(&mut app.borrow_mut());
187 }
188 }));
189 self
190 }
191
192 /// Returns a handle to the [`BackgroundExecutor`] associated with this app, which can be used to spawn futures in the background.
193 pub fn background_executor(&self) -> BackgroundExecutor {
194 self.0.borrow().background_executor.clone()
195 }
196
197 /// Returns a handle to the [`ForegroundExecutor`] associated with this app, which can be used to spawn futures in the foreground.
198 pub fn foreground_executor(&self) -> ForegroundExecutor {
199 self.0.borrow().foreground_executor.clone()
200 }
201
202 /// Returns a reference to the [`TextSystem`] associated with this app.
203 pub fn text_system(&self) -> Arc<TextSystem> {
204 self.0.borrow().text_system.clone()
205 }
206
207 /// Returns the file URL of the executable with the specified name in the application bundle
208 pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
209 self.0.borrow().path_for_auxiliary_executable(name)
210 }
211}
212
213type Handler = Box<dyn FnMut(&mut AppContext) -> bool + 'static>;
214type Listener = Box<dyn FnMut(&dyn Any, &mut AppContext) -> bool + 'static>;
215pub(crate) type KeystrokeObserver =
216 Box<dyn FnMut(&KeystrokeEvent, &mut WindowContext) -> bool + 'static>;
217type QuitHandler = Box<dyn FnOnce(&mut AppContext) -> LocalBoxFuture<'static, ()> + 'static>;
218type ReleaseListener = Box<dyn FnOnce(&mut dyn Any, &mut AppContext) + 'static>;
219type NewViewListener = Box<dyn FnMut(AnyView, &mut WindowContext) + 'static>;
220
221/// Contains the state of the full application, and passed as a reference to a variety of callbacks.
222/// Other contexts such as [ModelContext], [WindowContext], and [ViewContext] deref to this type, making it the most general context type.
223/// You need a reference to an `AppContext` to access the state of a [Model].
224pub struct AppContext {
225 pub(crate) this: Weak<AppCell>,
226 pub(crate) platform: Rc<dyn Platform>,
227 text_system: Arc<TextSystem>,
228 flushing_effects: bool,
229 pending_updates: usize,
230 pub(crate) actions: Rc<ActionRegistry>,
231 pub(crate) active_drag: Option<AnyDrag>,
232 pub(crate) background_executor: BackgroundExecutor,
233 pub(crate) foreground_executor: ForegroundExecutor,
234 pub(crate) loading_assets: FxHashMap<(TypeId, u64), Box<dyn Any>>,
235 asset_source: Arc<dyn AssetSource>,
236 pub(crate) svg_renderer: SvgRenderer,
237 http_client: Arc<dyn HttpClient>,
238 pub(crate) globals_by_type: FxHashMap<TypeId, Box<dyn Any>>,
239 pub(crate) entities: EntityMap,
240 pub(crate) new_view_observers: SubscriberSet<TypeId, NewViewListener>,
241 pub(crate) windows: SlotMap<WindowId, Option<Window>>,
242 pub(crate) window_handles: FxHashMap<WindowId, AnyWindowHandle>,
243 pub(crate) keymap: Rc<RefCell<Keymap>>,
244 pub(crate) global_action_listeners:
245 FxHashMap<TypeId, Vec<Rc<dyn Fn(&dyn Any, DispatchPhase, &mut Self)>>>,
246 pending_effects: VecDeque<Effect>,
247 pub(crate) pending_notifications: FxHashSet<EntityId>,
248 pub(crate) pending_global_notifications: FxHashSet<TypeId>,
249 pub(crate) observers: SubscriberSet<EntityId, Handler>,
250 // TypeId is the type of the event that the listener callback expects
251 pub(crate) event_listeners: SubscriberSet<EntityId, (TypeId, Listener)>,
252 pub(crate) keystroke_observers: SubscriberSet<(), KeystrokeObserver>,
253 pub(crate) release_listeners: SubscriberSet<EntityId, ReleaseListener>,
254 pub(crate) global_observers: SubscriberSet<TypeId, Handler>,
255 pub(crate) quit_observers: SubscriberSet<(), QuitHandler>,
256 pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
257 pub(crate) propagate_event: bool,
258 pub(crate) prompt_builder: Option<PromptBuilder>,
259}
260
261impl AppContext {
262 #[allow(clippy::new_ret_no_self)]
263 pub(crate) fn new(
264 platform: Rc<dyn Platform>,
265 asset_source: Arc<dyn AssetSource>,
266 http_client: Arc<dyn HttpClient>,
267 ) -> Rc<AppCell> {
268 let executor = platform.background_executor();
269 let foreground_executor = platform.foreground_executor();
270 assert!(
271 executor.is_main_thread(),
272 "must construct App on main thread"
273 );
274
275 let text_system = Arc::new(TextSystem::new(platform.text_system()));
276 let entities = EntityMap::new();
277
278 let app = Rc::new_cyclic(|this| AppCell {
279 app: RefCell::new(AppContext {
280 this: this.clone(),
281 platform: platform.clone(),
282 text_system,
283 actions: Rc::new(ActionRegistry::default()),
284 flushing_effects: false,
285 pending_updates: 0,
286 active_drag: None,
287 background_executor: executor,
288 foreground_executor,
289 svg_renderer: SvgRenderer::new(asset_source.clone()),
290 loading_assets: Default::default(),
291 asset_source,
292 http_client,
293 globals_by_type: FxHashMap::default(),
294 entities,
295 new_view_observers: SubscriberSet::new(),
296 window_handles: FxHashMap::default(),
297 windows: SlotMap::with_key(),
298 keymap: Rc::new(RefCell::new(Keymap::default())),
299 global_action_listeners: FxHashMap::default(),
300 pending_effects: VecDeque::new(),
301 pending_notifications: FxHashSet::default(),
302 pending_global_notifications: FxHashSet::default(),
303 observers: SubscriberSet::new(),
304 event_listeners: SubscriberSet::new(),
305 release_listeners: SubscriberSet::new(),
306 keystroke_observers: SubscriberSet::new(),
307 global_observers: SubscriberSet::new(),
308 quit_observers: SubscriberSet::new(),
309 layout_id_buffer: Default::default(),
310 propagate_event: true,
311 prompt_builder: Some(PromptBuilder::Default),
312 }),
313 });
314
315 init_app_menus(platform.as_ref(), &mut app.borrow_mut());
316
317 platform.on_quit(Box::new({
318 let cx = app.clone();
319 move || {
320 cx.borrow_mut().shutdown();
321 }
322 }));
323
324 app
325 }
326
327 /// Quit the application gracefully. Handlers registered with [`ModelContext::on_app_quit`]
328 /// will be given 100ms to complete before exiting.
329 pub fn shutdown(&mut self) {
330 let mut futures = Vec::new();
331
332 for observer in self.quit_observers.remove(&()) {
333 futures.push(observer(self));
334 }
335
336 self.windows.clear();
337 self.window_handles.clear();
338 self.flush_effects();
339
340 let futures = futures::future::join_all(futures);
341 if self
342 .background_executor
343 .block_with_timeout(SHUTDOWN_TIMEOUT, futures)
344 .is_err()
345 {
346 log::error!("timed out waiting on app_will_quit");
347 }
348 }
349
350 /// Gracefully quit the application via the platform's standard routine.
351 pub fn quit(&mut self) {
352 self.platform.quit();
353 }
354
355 /// Schedules all windows in the application to be redrawn. This can be called
356 /// multiple times in an update cycle and still result in a single redraw.
357 pub fn refresh(&mut self) {
358 self.pending_effects.push_back(Effect::Refresh);
359 }
360
361 pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
362 self.pending_updates += 1;
363 let result = update(self);
364 if !self.flushing_effects && self.pending_updates == 1 {
365 self.flushing_effects = true;
366 self.flush_effects();
367 self.flushing_effects = false;
368 }
369 self.pending_updates -= 1;
370 result
371 }
372
373 /// Arrange a callback to be invoked when the given model or view calls `notify` on its respective context.
374 pub fn observe<W, E>(
375 &mut self,
376 entity: &E,
377 mut on_notify: impl FnMut(E, &mut AppContext) + 'static,
378 ) -> Subscription
379 where
380 W: 'static,
381 E: Entity<W>,
382 {
383 self.observe_internal(entity, move |e, cx| {
384 on_notify(e, cx);
385 true
386 })
387 }
388
389 pub(crate) fn new_observer(&mut self, key: EntityId, value: Handler) -> Subscription {
390 let (subscription, activate) = self.observers.insert(key, value);
391 self.defer(move |_| activate());
392 subscription
393 }
394 pub(crate) fn observe_internal<W, E>(
395 &mut self,
396 entity: &E,
397 mut on_notify: impl FnMut(E, &mut AppContext) -> bool + 'static,
398 ) -> Subscription
399 where
400 W: 'static,
401 E: Entity<W>,
402 {
403 let entity_id = entity.entity_id();
404 let handle = entity.downgrade();
405 self.new_observer(
406 entity_id,
407 Box::new(move |cx| {
408 if let Some(handle) = E::upgrade_from(&handle) {
409 on_notify(handle, cx)
410 } else {
411 false
412 }
413 }),
414 )
415 }
416
417 /// Arrange for the given callback to be invoked whenever the given model or view emits an event of a given type.
418 /// The callback is provided a handle to the emitting entity and a reference to the emitted event.
419 pub fn subscribe<T, E, Event>(
420 &mut self,
421 entity: &E,
422 mut on_event: impl FnMut(E, &Event, &mut AppContext) + 'static,
423 ) -> Subscription
424 where
425 T: 'static + EventEmitter<Event>,
426 E: Entity<T>,
427 Event: 'static,
428 {
429 self.subscribe_internal(entity, move |entity, event, cx| {
430 on_event(entity, event, cx);
431 true
432 })
433 }
434
435 pub(crate) fn new_subscription(
436 &mut self,
437 key: EntityId,
438 value: (TypeId, Listener),
439 ) -> Subscription {
440 let (subscription, activate) = self.event_listeners.insert(key, value);
441 self.defer(move |_| activate());
442 subscription
443 }
444 pub(crate) fn subscribe_internal<T, E, Evt>(
445 &mut self,
446 entity: &E,
447 mut on_event: impl FnMut(E, &Evt, &mut AppContext) -> bool + 'static,
448 ) -> Subscription
449 where
450 T: 'static + EventEmitter<Evt>,
451 E: Entity<T>,
452 Evt: 'static,
453 {
454 let entity_id = entity.entity_id();
455 let entity = entity.downgrade();
456 self.new_subscription(
457 entity_id,
458 (
459 TypeId::of::<Evt>(),
460 Box::new(move |event, cx| {
461 let event: &Evt = event.downcast_ref().expect("invalid event type");
462 if let Some(handle) = E::upgrade_from(&entity) {
463 on_event(handle, event, cx)
464 } else {
465 false
466 }
467 }),
468 ),
469 )
470 }
471
472 /// Returns handles to all open windows in the application.
473 /// Each handle could be downcast to a handle typed for the root view of that window.
474 /// To find all windows of a given type, you could filter on
475 pub fn windows(&self) -> Vec<AnyWindowHandle> {
476 self.windows
477 .keys()
478 .flat_map(|window_id| self.window_handles.get(&window_id).copied())
479 .collect()
480 }
481
482 /// Returns the window handles ordered by their appearance on screen, front to back.
483 ///
484 /// The first window in the returned list is the active/topmost window of the application.
485 ///
486 /// This method returns None if the platform doesn't implement the method yet.
487 pub fn window_stack(&self) -> Option<Vec<AnyWindowHandle>> {
488 self.platform.window_stack()
489 }
490
491 /// Returns a handle to the window that is currently focused at the platform level, if one exists.
492 pub fn active_window(&self) -> Option<AnyWindowHandle> {
493 self.platform.active_window()
494 }
495
496 /// Opens a new window with the given option and the root view returned by the given function.
497 /// The function is invoked with a `WindowContext`, which can be used to interact with window-specific
498 /// functionality.
499 pub fn open_window<V: 'static + Render>(
500 &mut self,
501 options: crate::WindowOptions,
502 build_root_view: impl FnOnce(&mut WindowContext) -> View<V>,
503 ) -> anyhow::Result<WindowHandle<V>> {
504 self.update(|cx| {
505 let id = cx.windows.insert(None);
506 let handle = WindowHandle::new(id);
507 match Window::new(handle.into(), options, cx) {
508 Ok(mut window) => {
509 let root_view = build_root_view(&mut WindowContext::new(cx, &mut window));
510 window.root_view.replace(root_view.into());
511 WindowContext::new(cx, &mut window).defer(|cx| cx.appearance_changed());
512 cx.window_handles.insert(id, window.handle);
513 cx.windows.get_mut(id).unwrap().replace(window);
514 Ok(handle)
515 }
516 Err(e) => {
517 cx.windows.remove(id);
518 Err(e)
519 }
520 }
521 })
522 }
523
524 /// Instructs the platform to activate the application by bringing it to the foreground.
525 pub fn activate(&self, ignoring_other_apps: bool) {
526 self.platform.activate(ignoring_other_apps);
527 }
528
529 /// Hide the application at the platform level.
530 pub fn hide(&self) {
531 self.platform.hide();
532 }
533
534 /// Hide other applications at the platform level.
535 pub fn hide_other_apps(&self) {
536 self.platform.hide_other_apps();
537 }
538
539 /// Unhide other applications at the platform level.
540 pub fn unhide_other_apps(&self) {
541 self.platform.unhide_other_apps();
542 }
543
544 /// Returns the list of currently active displays.
545 pub fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {
546 self.platform.displays()
547 }
548
549 /// Returns the primary display that will be used for new windows.
550 pub fn primary_display(&self) -> Option<Rc<dyn PlatformDisplay>> {
551 self.platform.primary_display()
552 }
553
554 /// Returns the display with the given ID, if one exists.
555 pub fn find_display(&self, id: DisplayId) -> Option<Rc<dyn PlatformDisplay>> {
556 self.displays()
557 .iter()
558 .find(|display| display.id() == id)
559 .cloned()
560 }
561
562 /// Returns the appearance of the application's windows.
563 pub fn window_appearance(&self) -> WindowAppearance {
564 self.platform.window_appearance()
565 }
566
567 /// Writes data to the primary selection buffer.
568 /// Only available on Linux.
569 #[cfg(target_os = "linux")]
570 pub fn write_to_primary(&self, item: ClipboardItem) {
571 self.platform.write_to_primary(item)
572 }
573
574 /// Writes data to the platform clipboard.
575 pub fn write_to_clipboard(&self, item: ClipboardItem) {
576 self.platform.write_to_clipboard(item)
577 }
578
579 /// Reads data from the primary selection buffer.
580 /// Only available on Linux.
581 #[cfg(target_os = "linux")]
582 pub fn read_from_primary(&self) -> Option<ClipboardItem> {
583 self.platform.read_from_primary()
584 }
585
586 /// Reads data from the platform clipboard.
587 pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
588 self.platform.read_from_clipboard()
589 }
590
591 /// Writes credentials to the platform keychain.
592 pub fn write_credentials(
593 &self,
594 url: &str,
595 username: &str,
596 password: &[u8],
597 ) -> Task<Result<()>> {
598 self.platform.write_credentials(url, username, password)
599 }
600
601 /// Reads credentials from the platform keychain.
602 pub fn read_credentials(&self, url: &str) -> Task<Result<Option<(String, Vec<u8>)>>> {
603 self.platform.read_credentials(url)
604 }
605
606 /// Deletes credentials from the platform keychain.
607 pub fn delete_credentials(&self, url: &str) -> Task<Result<()>> {
608 self.platform.delete_credentials(url)
609 }
610
611 /// Directs the platform's default browser to open the given URL.
612 pub fn open_url(&self, url: &str) {
613 self.platform.open_url(url);
614 }
615
616 /// register_url_scheme requests that the given scheme (e.g. `zed` for `zed://` urls)
617 /// is opened by the current app.
618 /// On some platforms (e.g. macOS) you may be able to register URL schemes as part of app
619 /// distribution, but this method exists to let you register schemes at runtime.
620 pub fn register_url_scheme(&self, scheme: &str) -> Task<Result<()>> {
621 self.platform.register_url_scheme(scheme)
622 }
623
624 /// Returns the full pathname of the current app bundle.
625 /// If the app is not being run from a bundle, returns an error.
626 pub fn app_path(&self) -> Result<PathBuf> {
627 self.platform.app_path()
628 }
629
630 /// On Linux, returns the name of the compositor in use.
631 /// Is blank on other platforms.
632 pub fn compositor_name(&self) -> &'static str {
633 self.platform.compositor_name()
634 }
635
636 /// Returns the file URL of the executable with the specified name in the application bundle
637 pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
638 self.platform.path_for_auxiliary_executable(name)
639 }
640
641 /// Displays a platform modal for selecting paths.
642 /// When one or more paths are selected, they'll be relayed asynchronously via the returned oneshot channel.
643 /// If cancelled, a `None` will be relayed instead.
644 /// May return an error on Linux if the file picker couldn't be opened.
645 pub fn prompt_for_paths(
646 &self,
647 options: PathPromptOptions,
648 ) -> oneshot::Receiver<Result<Option<Vec<PathBuf>>>> {
649 self.platform.prompt_for_paths(options)
650 }
651
652 /// Displays a platform modal for selecting a new path where a file can be saved.
653 /// The provided directory will be used to set the initial location.
654 /// When a path is selected, it is relayed asynchronously via the returned oneshot channel.
655 /// If cancelled, a `None` will be relayed instead.
656 /// May return an error on Linux if the file picker couldn't be opened.
657 pub fn prompt_for_new_path(
658 &self,
659 directory: &Path,
660 ) -> oneshot::Receiver<Result<Option<PathBuf>>> {
661 self.platform.prompt_for_new_path(directory)
662 }
663
664 /// Reveals the specified path at the platform level, such as in Finder on macOS.
665 pub fn reveal_path(&self, path: &Path) {
666 self.platform.reveal_path(path)
667 }
668
669 /// Opens the specified path with the system's default application.
670 pub fn open_with_system(&self, path: &Path) {
671 self.platform.open_with_system(path)
672 }
673
674 /// Returns whether the user has configured scrollbars to auto-hide at the platform level.
675 pub fn should_auto_hide_scrollbars(&self) -> bool {
676 self.platform.should_auto_hide_scrollbars()
677 }
678
679 /// Restart the application.
680 pub fn restart(&self, binary_path: Option<PathBuf>) {
681 self.platform.restart(binary_path)
682 }
683
684 /// Updates the http client assigned to GPUI
685 pub fn set_http_client(&mut self, new_client: Arc<dyn HttpClient>) {
686 self.http_client = new_client;
687 }
688
689 /// Returns the http client assigned to GPUI
690 pub fn http_client(&self) -> Arc<dyn HttpClient> {
691 self.http_client.clone()
692 }
693
694 /// Returns the SVG renderer GPUI uses
695 pub(crate) fn svg_renderer(&self) -> SvgRenderer {
696 self.svg_renderer.clone()
697 }
698
699 pub(crate) fn push_effect(&mut self, effect: Effect) {
700 match &effect {
701 Effect::Notify { emitter } => {
702 if !self.pending_notifications.insert(*emitter) {
703 return;
704 }
705 }
706 Effect::NotifyGlobalObservers { global_type } => {
707 if !self.pending_global_notifications.insert(*global_type) {
708 return;
709 }
710 }
711 _ => {}
712 };
713
714 self.pending_effects.push_back(effect);
715 }
716
717 /// Called at the end of [`AppContext::update`] to complete any side effects
718 /// such as notifying observers, emitting events, etc. Effects can themselves
719 /// cause effects, so we continue looping until all effects are processed.
720 fn flush_effects(&mut self) {
721 loop {
722 self.release_dropped_entities();
723 self.release_dropped_focus_handles();
724
725 if let Some(effect) = self.pending_effects.pop_front() {
726 match effect {
727 Effect::Notify { emitter } => {
728 self.apply_notify_effect(emitter);
729 }
730
731 Effect::Emit {
732 emitter,
733 event_type,
734 event,
735 } => self.apply_emit_effect(emitter, event_type, event),
736
737 Effect::Refresh => {
738 self.apply_refresh_effect();
739 }
740
741 Effect::NotifyGlobalObservers { global_type } => {
742 self.apply_notify_global_observers_effect(global_type);
743 }
744
745 Effect::Defer { callback } => {
746 self.apply_defer_effect(callback);
747 }
748 }
749 } else {
750 #[cfg(any(test, feature = "test-support"))]
751 for window in self
752 .windows
753 .values()
754 .filter_map(|window| {
755 let window = window.as_ref()?;
756 window.dirty.get().then_some(window.handle)
757 })
758 .collect::<Vec<_>>()
759 {
760 self.update_window(window, |_, cx| cx.draw()).unwrap();
761 }
762
763 if self.pending_effects.is_empty() {
764 break;
765 }
766 }
767 }
768 }
769
770 /// Repeatedly called during `flush_effects` to release any entities whose
771 /// reference count has become zero. We invoke any release observers before dropping
772 /// each entity.
773 fn release_dropped_entities(&mut self) {
774 loop {
775 let dropped = self.entities.take_dropped();
776 if dropped.is_empty() {
777 break;
778 }
779
780 for (entity_id, mut entity) in dropped {
781 self.observers.remove(&entity_id);
782 self.event_listeners.remove(&entity_id);
783 for release_callback in self.release_listeners.remove(&entity_id) {
784 release_callback(entity.as_mut(), self);
785 }
786 }
787 }
788 }
789
790 /// Repeatedly called during `flush_effects` to handle a focused handle being dropped.
791 fn release_dropped_focus_handles(&mut self) {
792 for window_handle in self.windows() {
793 window_handle
794 .update(self, |_, cx| {
795 let mut blur_window = false;
796 let focus = cx.window.focus;
797 cx.window.focus_handles.write().retain(|handle_id, count| {
798 if count.load(SeqCst) == 0 {
799 if focus == Some(handle_id) {
800 blur_window = true;
801 }
802 false
803 } else {
804 true
805 }
806 });
807
808 if blur_window {
809 cx.blur();
810 }
811 })
812 .unwrap();
813 }
814 }
815
816 fn apply_notify_effect(&mut self, emitter: EntityId) {
817 self.pending_notifications.remove(&emitter);
818
819 self.observers
820 .clone()
821 .retain(&emitter, |handler| handler(self));
822 }
823
824 fn apply_emit_effect(&mut self, emitter: EntityId, event_type: TypeId, event: Box<dyn Any>) {
825 self.event_listeners
826 .clone()
827 .retain(&emitter, |(stored_type, handler)| {
828 if *stored_type == event_type {
829 handler(event.as_ref(), self)
830 } else {
831 true
832 }
833 });
834 }
835
836 fn apply_refresh_effect(&mut self) {
837 for window in self.windows.values_mut() {
838 if let Some(window) = window.as_mut() {
839 window.dirty.set(true);
840 }
841 }
842 }
843
844 fn apply_notify_global_observers_effect(&mut self, type_id: TypeId) {
845 self.pending_global_notifications.remove(&type_id);
846 self.global_observers
847 .clone()
848 .retain(&type_id, |observer| observer(self));
849 }
850
851 fn apply_defer_effect(&mut self, callback: Box<dyn FnOnce(&mut Self) + 'static>) {
852 callback(self);
853 }
854
855 /// Creates an `AsyncAppContext`, which can be cloned and has a static lifetime
856 /// so it can be held across `await` points.
857 pub fn to_async(&self) -> AsyncAppContext {
858 AsyncAppContext {
859 app: self.this.clone(),
860 background_executor: self.background_executor.clone(),
861 foreground_executor: self.foreground_executor.clone(),
862 }
863 }
864
865 /// Obtains a reference to the executor, which can be used to spawn futures.
866 pub fn background_executor(&self) -> &BackgroundExecutor {
867 &self.background_executor
868 }
869
870 /// Obtains a reference to the executor, which can be used to spawn futures.
871 pub fn foreground_executor(&self) -> &ForegroundExecutor {
872 &self.foreground_executor
873 }
874
875 /// Spawns the future returned by the given function on the thread pool. The closure will be invoked
876 /// with [AsyncAppContext], which allows the application state to be accessed across await points.
877 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut) -> Task<R>
878 where
879 Fut: Future<Output = R> + 'static,
880 R: 'static,
881 {
882 self.foreground_executor.spawn(f(self.to_async()))
883 }
884
885 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
886 /// that are currently on the stack to be returned to the app.
887 pub fn defer(&mut self, f: impl FnOnce(&mut AppContext) + 'static) {
888 self.push_effect(Effect::Defer {
889 callback: Box::new(f),
890 });
891 }
892
893 /// Accessor for the application's asset source, which is provided when constructing the `App`.
894 pub fn asset_source(&self) -> &Arc<dyn AssetSource> {
895 &self.asset_source
896 }
897
898 /// Accessor for the text system.
899 pub fn text_system(&self) -> &Arc<TextSystem> {
900 &self.text_system
901 }
902
903 /// Check whether a global of the given type has been assigned.
904 pub fn has_global<G: Global>(&self) -> bool {
905 self.globals_by_type.contains_key(&TypeId::of::<G>())
906 }
907
908 /// Access the global of the given type. Panics if a global for that type has not been assigned.
909 #[track_caller]
910 pub fn global<G: Global>(&self) -> &G {
911 self.globals_by_type
912 .get(&TypeId::of::<G>())
913 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
914 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
915 .unwrap()
916 }
917
918 /// Access the global of the given type if a value has been assigned.
919 pub fn try_global<G: Global>(&self) -> Option<&G> {
920 self.globals_by_type
921 .get(&TypeId::of::<G>())
922 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
923 }
924
925 /// Access the global of the given type mutably. Panics if a global for that type has not been assigned.
926 #[track_caller]
927 pub fn global_mut<G: Global>(&mut self) -> &mut G {
928 let global_type = TypeId::of::<G>();
929 self.push_effect(Effect::NotifyGlobalObservers { global_type });
930 self.globals_by_type
931 .get_mut(&global_type)
932 .and_then(|any_state| any_state.downcast_mut::<G>())
933 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
934 .unwrap()
935 }
936
937 /// Access the global of the given type mutably. A default value is assigned if a global of this type has not
938 /// yet been assigned.
939 pub fn default_global<G: Global + Default>(&mut self) -> &mut G {
940 let global_type = TypeId::of::<G>();
941 self.push_effect(Effect::NotifyGlobalObservers { global_type });
942 self.globals_by_type
943 .entry(global_type)
944 .or_insert_with(|| Box::<G>::default())
945 .downcast_mut::<G>()
946 .unwrap()
947 }
948
949 /// Sets the value of the global of the given type.
950 pub fn set_global<G: Global>(&mut self, global: G) {
951 let global_type = TypeId::of::<G>();
952 self.push_effect(Effect::NotifyGlobalObservers { global_type });
953 self.globals_by_type.insert(global_type, Box::new(global));
954 }
955
956 /// Clear all stored globals. Does not notify global observers.
957 #[cfg(any(test, feature = "test-support"))]
958 pub fn clear_globals(&mut self) {
959 self.globals_by_type.drain();
960 }
961
962 /// Remove the global of the given type from the app context. Does not notify global observers.
963 pub fn remove_global<G: Global>(&mut self) -> G {
964 let global_type = TypeId::of::<G>();
965 self.push_effect(Effect::NotifyGlobalObservers { global_type });
966 *self
967 .globals_by_type
968 .remove(&global_type)
969 .unwrap_or_else(|| panic!("no global added for {}", std::any::type_name::<G>()))
970 .downcast()
971 .unwrap()
972 }
973
974 /// Register a callback to be invoked when a global of the given type is updated.
975 pub fn observe_global<G: Global>(
976 &mut self,
977 mut f: impl FnMut(&mut Self) + 'static,
978 ) -> Subscription {
979 let (subscription, activate) = self.global_observers.insert(
980 TypeId::of::<G>(),
981 Box::new(move |cx| {
982 f(cx);
983 true
984 }),
985 );
986 self.defer(move |_| activate());
987 subscription
988 }
989
990 /// Move the global of the given type to the stack.
991 pub(crate) fn lease_global<G: Global>(&mut self) -> GlobalLease<G> {
992 GlobalLease::new(
993 self.globals_by_type
994 .remove(&TypeId::of::<G>())
995 .ok_or_else(|| anyhow!("no global registered of type {}", type_name::<G>()))
996 .unwrap(),
997 )
998 }
999
1000 /// Restore the global of the given type after it is moved to the stack.
1001 pub(crate) fn end_global_lease<G: Global>(&mut self, lease: GlobalLease<G>) {
1002 let global_type = TypeId::of::<G>();
1003 self.push_effect(Effect::NotifyGlobalObservers { global_type });
1004 self.globals_by_type.insert(global_type, lease.global);
1005 }
1006
1007 pub(crate) fn new_view_observer(
1008 &mut self,
1009 key: TypeId,
1010 value: NewViewListener,
1011 ) -> Subscription {
1012 let (subscription, activate) = self.new_view_observers.insert(key, value);
1013 activate();
1014 subscription
1015 }
1016 /// Arrange for the given function to be invoked whenever a view of the specified type is created.
1017 /// The function will be passed a mutable reference to the view along with an appropriate context.
1018 pub fn observe_new_views<V: 'static>(
1019 &mut self,
1020 on_new: impl 'static + Fn(&mut V, &mut ViewContext<V>),
1021 ) -> Subscription {
1022 self.new_view_observer(
1023 TypeId::of::<V>(),
1024 Box::new(move |any_view: AnyView, cx: &mut WindowContext| {
1025 any_view
1026 .downcast::<V>()
1027 .unwrap()
1028 .update(cx, |view_state, cx| {
1029 on_new(view_state, cx);
1030 })
1031 }),
1032 )
1033 }
1034
1035 /// Observe the release of a model or view. The callback is invoked after the model or view
1036 /// has no more strong references but before it has been dropped.
1037 pub fn observe_release<E, T>(
1038 &mut self,
1039 handle: &E,
1040 on_release: impl FnOnce(&mut T, &mut AppContext) + 'static,
1041 ) -> Subscription
1042 where
1043 E: Entity<T>,
1044 T: 'static,
1045 {
1046 let (subscription, activate) = self.release_listeners.insert(
1047 handle.entity_id(),
1048 Box::new(move |entity, cx| {
1049 let entity = entity.downcast_mut().expect("invalid entity type");
1050 on_release(entity, cx)
1051 }),
1052 );
1053 activate();
1054 subscription
1055 }
1056
1057 /// Register a callback to be invoked when a keystroke is received by the application
1058 /// in any window. Note that this fires after all other action and event mechanisms have resolved
1059 /// and that this API will not be invoked if the event's propagation is stopped.
1060 pub fn observe_keystrokes(
1061 &mut self,
1062 mut f: impl FnMut(&KeystrokeEvent, &mut WindowContext) + 'static,
1063 ) -> Subscription {
1064 fn inner(
1065 keystroke_observers: &mut SubscriberSet<(), KeystrokeObserver>,
1066 handler: KeystrokeObserver,
1067 ) -> Subscription {
1068 let (subscription, activate) = keystroke_observers.insert((), handler);
1069 activate();
1070 subscription
1071 }
1072
1073 inner(
1074 &mut self.keystroke_observers,
1075 Box::new(move |event, cx| {
1076 f(event, cx);
1077 true
1078 }),
1079 )
1080 }
1081
1082 /// Register key bindings.
1083 pub fn bind_keys(&mut self, bindings: impl IntoIterator<Item = KeyBinding>) {
1084 self.keymap.borrow_mut().add_bindings(bindings);
1085 self.pending_effects.push_back(Effect::Refresh);
1086 }
1087
1088 /// Clear all key bindings in the app.
1089 pub fn clear_key_bindings(&mut self) {
1090 self.keymap.borrow_mut().clear();
1091 self.pending_effects.push_back(Effect::Refresh);
1092 }
1093
1094 /// Register a global listener for actions invoked via the keyboard.
1095 pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Self) + 'static) {
1096 self.global_action_listeners
1097 .entry(TypeId::of::<A>())
1098 .or_default()
1099 .push(Rc::new(move |action, phase, cx| {
1100 if phase == DispatchPhase::Bubble {
1101 let action = action.downcast_ref().unwrap();
1102 listener(action, cx)
1103 }
1104 }));
1105 }
1106
1107 /// Event handlers propagate events by default. Call this method to stop dispatching to
1108 /// event handlers with a lower z-index (mouse) or higher in the tree (keyboard). This is
1109 /// the opposite of [`Self::propagate`]. It's also possible to cancel a call to [`Self::propagate`] by
1110 /// calling this method before effects are flushed.
1111 pub fn stop_propagation(&mut self) {
1112 self.propagate_event = false;
1113 }
1114
1115 /// Action handlers stop propagation by default during the bubble phase of action dispatch
1116 /// dispatching to action handlers higher in the element tree. This is the opposite of
1117 /// [`Self::stop_propagation`]. It's also possible to cancel a call to [`Self::stop_propagation`] by calling
1118 /// this method before effects are flushed.
1119 pub fn propagate(&mut self) {
1120 self.propagate_event = true;
1121 }
1122
1123 /// Build an action from some arbitrary data, typically a keymap entry.
1124 pub fn build_action(
1125 &self,
1126 name: &str,
1127 data: Option<serde_json::Value>,
1128 ) -> Result<Box<dyn Action>> {
1129 self.actions.build_action(name, data)
1130 }
1131
1132 /// Get a list of all action names that have been registered.
1133 /// in the application. Note that registration only allows for
1134 /// actions to be built dynamically, and is unrelated to binding
1135 /// actions in the element tree.
1136 pub fn all_action_names(&self) -> &[SharedString] {
1137 self.actions.all_action_names()
1138 }
1139
1140 /// Register a callback to be invoked when the application is about to quit.
1141 /// It is not possible to cancel the quit event at this point.
1142 pub fn on_app_quit<Fut>(
1143 &mut self,
1144 mut on_quit: impl FnMut(&mut AppContext) -> Fut + 'static,
1145 ) -> Subscription
1146 where
1147 Fut: 'static + Future<Output = ()>,
1148 {
1149 let (subscription, activate) = self.quit_observers.insert(
1150 (),
1151 Box::new(move |cx| {
1152 let future = on_quit(cx);
1153 future.boxed_local()
1154 }),
1155 );
1156 activate();
1157 subscription
1158 }
1159
1160 pub(crate) fn clear_pending_keystrokes(&mut self) {
1161 for window in self.windows() {
1162 window
1163 .update(self, |_, cx| {
1164 cx.clear_pending_keystrokes();
1165 })
1166 .ok();
1167 }
1168 }
1169
1170 /// Checks if the given action is bound in the current context, as defined by the app's current focus,
1171 /// the bindings in the element tree, and any global action listeners.
1172 pub fn is_action_available(&mut self, action: &dyn Action) -> bool {
1173 let mut action_available = false;
1174 if let Some(window) = self.active_window() {
1175 if let Ok(window_action_available) =
1176 window.update(self, |_, cx| cx.is_action_available(action))
1177 {
1178 action_available = window_action_available;
1179 }
1180 }
1181
1182 action_available
1183 || self
1184 .global_action_listeners
1185 .contains_key(&action.as_any().type_id())
1186 }
1187
1188 /// Sets the menu bar for this application. This will replace any existing menu bar.
1189 pub fn set_menus(&mut self, menus: Vec<Menu>) {
1190 self.platform.set_menus(menus, &self.keymap.borrow());
1191 }
1192
1193 /// Gets the menu bar for this application.
1194 pub fn get_menus(&self) -> Option<Vec<OwnedMenu>> {
1195 self.platform.get_menus()
1196 }
1197
1198 /// Sets the right click menu for the app icon in the dock
1199 pub fn set_dock_menu(&mut self, menus: Vec<MenuItem>) {
1200 self.platform.set_dock_menu(menus, &self.keymap.borrow());
1201 }
1202
1203 /// Adds given path to the bottom of the list of recent paths for the application.
1204 /// The list is usually shown on the application icon's context menu in the dock,
1205 /// and allows to open the recent files via that context menu.
1206 /// If the path is already in the list, it will be moved to the bottom of the list.
1207 pub fn add_recent_document(&mut self, path: &Path) {
1208 self.platform.add_recent_document(path);
1209 }
1210
1211 /// Dispatch an action to the currently active window or global action handler
1212 /// See [action::Action] for more information on how actions work
1213 pub fn dispatch_action(&mut self, action: &dyn Action) {
1214 if let Some(active_window) = self.active_window() {
1215 active_window
1216 .update(self, |_, cx| cx.dispatch_action(action.boxed_clone()))
1217 .log_err();
1218 } else {
1219 self.dispatch_global_action(action);
1220 }
1221 }
1222
1223 fn dispatch_global_action(&mut self, action: &dyn Action) {
1224 self.propagate_event = true;
1225
1226 if let Some(mut global_listeners) = self
1227 .global_action_listeners
1228 .remove(&action.as_any().type_id())
1229 {
1230 for listener in &global_listeners {
1231 listener(action.as_any(), DispatchPhase::Capture, self);
1232 if !self.propagate_event {
1233 break;
1234 }
1235 }
1236
1237 global_listeners.extend(
1238 self.global_action_listeners
1239 .remove(&action.as_any().type_id())
1240 .unwrap_or_default(),
1241 );
1242
1243 self.global_action_listeners
1244 .insert(action.as_any().type_id(), global_listeners);
1245 }
1246
1247 if self.propagate_event {
1248 if let Some(mut global_listeners) = self
1249 .global_action_listeners
1250 .remove(&action.as_any().type_id())
1251 {
1252 for listener in global_listeners.iter().rev() {
1253 listener(action.as_any(), DispatchPhase::Bubble, self);
1254 if !self.propagate_event {
1255 break;
1256 }
1257 }
1258
1259 global_listeners.extend(
1260 self.global_action_listeners
1261 .remove(&action.as_any().type_id())
1262 .unwrap_or_default(),
1263 );
1264
1265 self.global_action_listeners
1266 .insert(action.as_any().type_id(), global_listeners);
1267 }
1268 }
1269 }
1270
1271 /// Is there currently something being dragged?
1272 pub fn has_active_drag(&self) -> bool {
1273 self.active_drag.is_some()
1274 }
1275
1276 /// Set the prompt renderer for GPUI. This will replace the default or platform specific
1277 /// prompts with this custom implementation.
1278 pub fn set_prompt_builder(
1279 &mut self,
1280 renderer: impl Fn(
1281 PromptLevel,
1282 &str,
1283 Option<&str>,
1284 &[&str],
1285 PromptHandle,
1286 &mut WindowContext,
1287 ) -> RenderablePromptHandle
1288 + 'static,
1289 ) {
1290 self.prompt_builder = Some(PromptBuilder::Custom(Box::new(renderer)))
1291 }
1292
1293 /// Remove an asset from GPUI's cache
1294 pub fn remove_cached_asset<A: Asset + 'static>(&mut self, source: &A::Source) {
1295 let asset_id = (TypeId::of::<A>(), hash(source));
1296 self.loading_assets.remove(&asset_id);
1297 }
1298
1299 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1300 ///
1301 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
1302 /// time, and the results of this call will be cached
1303 ///
1304 /// This asset will not be cached by default, see [Self::use_cached_asset]
1305 pub fn fetch_asset<A: Asset + 'static>(
1306 &mut self,
1307 source: &A::Source,
1308 ) -> (Shared<Task<A::Output>>, bool) {
1309 let asset_id = (TypeId::of::<A>(), hash(source));
1310 let mut is_first = false;
1311 let task = self
1312 .loading_assets
1313 .remove(&asset_id)
1314 .map(|boxed_task| *boxed_task.downcast::<Shared<Task<A::Output>>>().unwrap())
1315 .unwrap_or_else(|| {
1316 is_first = true;
1317 let future = A::load(source.clone(), self);
1318 let task = self.background_executor().spawn(future).shared();
1319 task
1320 });
1321
1322 self.loading_assets.insert(asset_id, Box::new(task.clone()));
1323
1324 (task, is_first)
1325 }
1326}
1327
1328impl Context for AppContext {
1329 type Result<T> = T;
1330
1331 /// Build an entity that is owned by the application. The given function will be invoked with
1332 /// a `ModelContext` and must return an object representing the entity. A `Model` handle will be returned,
1333 /// which can be used to access the entity in a context.
1334 fn new_model<T: 'static>(
1335 &mut self,
1336 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1337 ) -> Model<T> {
1338 self.update(|cx| {
1339 let slot = cx.entities.reserve();
1340 let entity = build_model(&mut ModelContext::new(cx, slot.downgrade()));
1341 cx.entities.insert(slot, entity)
1342 })
1343 }
1344
1345 fn reserve_model<T: 'static>(&mut self) -> Self::Result<Reservation<T>> {
1346 Reservation(self.entities.reserve())
1347 }
1348
1349 fn insert_model<T: 'static>(
1350 &mut self,
1351 reservation: Reservation<T>,
1352 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1353 ) -> Self::Result<Model<T>> {
1354 self.update(|cx| {
1355 let slot = reservation.0;
1356 let entity = build_model(&mut ModelContext::new(cx, slot.downgrade()));
1357 cx.entities.insert(slot, entity)
1358 })
1359 }
1360
1361 /// Updates the entity referenced by the given model. The function is passed a mutable reference to the
1362 /// entity along with a `ModelContext` for the entity.
1363 fn update_model<T: 'static, R>(
1364 &mut self,
1365 model: &Model<T>,
1366 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1367 ) -> R {
1368 self.update(|cx| {
1369 let mut entity = cx.entities.lease(model);
1370 let result = update(&mut entity, &mut ModelContext::new(cx, model.downgrade()));
1371 cx.entities.end_lease(entity);
1372 result
1373 })
1374 }
1375
1376 fn read_model<T, R>(
1377 &self,
1378 handle: &Model<T>,
1379 read: impl FnOnce(&T, &AppContext) -> R,
1380 ) -> Self::Result<R>
1381 where
1382 T: 'static,
1383 {
1384 let entity = self.entities.read(handle);
1385 read(entity, self)
1386 }
1387
1388 fn update_window<T, F>(&mut self, handle: AnyWindowHandle, update: F) -> Result<T>
1389 where
1390 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1391 {
1392 self.update(|cx| {
1393 let mut window = cx
1394 .windows
1395 .get_mut(handle.id)
1396 .ok_or_else(|| anyhow!("window not found"))?
1397 .take()
1398 .ok_or_else(|| anyhow!("window not found"))?;
1399
1400 let root_view = window.root_view.clone().unwrap();
1401 let result = update(root_view, &mut WindowContext::new(cx, &mut window));
1402
1403 if window.removed {
1404 cx.window_handles.remove(&handle.id);
1405 cx.windows.remove(handle.id);
1406 } else {
1407 cx.windows
1408 .get_mut(handle.id)
1409 .ok_or_else(|| anyhow!("window not found"))?
1410 .replace(window);
1411 }
1412
1413 Ok(result)
1414 })
1415 }
1416
1417 fn read_window<T, R>(
1418 &self,
1419 window: &WindowHandle<T>,
1420 read: impl FnOnce(View<T>, &AppContext) -> R,
1421 ) -> Result<R>
1422 where
1423 T: 'static,
1424 {
1425 let window = self
1426 .windows
1427 .get(window.id)
1428 .ok_or_else(|| anyhow!("window not found"))?
1429 .as_ref()
1430 .unwrap();
1431
1432 let root_view = window.root_view.clone().unwrap();
1433 let view = root_view
1434 .downcast::<T>()
1435 .map_err(|_| anyhow!("root view's type has changed"))?;
1436
1437 Ok(read(view, self))
1438 }
1439}
1440
1441/// These effects are processed at the end of each application update cycle.
1442pub(crate) enum Effect {
1443 Notify {
1444 emitter: EntityId,
1445 },
1446 Emit {
1447 emitter: EntityId,
1448 event_type: TypeId,
1449 event: Box<dyn Any>,
1450 },
1451 Refresh,
1452 NotifyGlobalObservers {
1453 global_type: TypeId,
1454 },
1455 Defer {
1456 callback: Box<dyn FnOnce(&mut AppContext) + 'static>,
1457 },
1458}
1459
1460/// Wraps a global variable value during `update_global` while the value has been moved to the stack.
1461pub(crate) struct GlobalLease<G: Global> {
1462 global: Box<dyn Any>,
1463 global_type: PhantomData<G>,
1464}
1465
1466impl<G: Global> GlobalLease<G> {
1467 fn new(global: Box<dyn Any>) -> Self {
1468 GlobalLease {
1469 global,
1470 global_type: PhantomData,
1471 }
1472 }
1473}
1474
1475impl<G: Global> Deref for GlobalLease<G> {
1476 type Target = G;
1477
1478 fn deref(&self) -> &Self::Target {
1479 self.global.downcast_ref().unwrap()
1480 }
1481}
1482
1483impl<G: Global> DerefMut for GlobalLease<G> {
1484 fn deref_mut(&mut self) -> &mut Self::Target {
1485 self.global.downcast_mut().unwrap()
1486 }
1487}
1488
1489/// Contains state associated with an active drag operation, started by dragging an element
1490/// within the window or by dragging into the app from the underlying platform.
1491pub struct AnyDrag {
1492 /// The view used to render this drag
1493 pub view: AnyView,
1494
1495 /// The value of the dragged item, to be dropped
1496 pub value: Box<dyn Any>,
1497
1498 /// This is used to render the dragged item in the same place
1499 /// on the original element that the drag was initiated
1500 pub cursor_offset: Point<Pixels>,
1501}
1502
1503/// Contains state associated with a tooltip. You'll only need this struct if you're implementing
1504/// tooltip behavior on a custom element. Otherwise, use [Div::tooltip].
1505#[derive(Clone)]
1506pub struct AnyTooltip {
1507 /// The view used to display the tooltip
1508 pub view: AnyView,
1509
1510 /// The absolute position of the mouse when the tooltip was deployed.
1511 pub mouse_position: Point<Pixels>,
1512}
1513
1514/// A keystroke event, and potentially the associated action
1515#[derive(Debug)]
1516pub struct KeystrokeEvent {
1517 /// The keystroke that occurred
1518 pub keystroke: Keystroke,
1519
1520 /// The action that was resolved for the keystroke, if any
1521 pub action: Option<Box<dyn Action>>,
1522}
1523
1524struct NullHttpClient;
1525
1526impl HttpClient for NullHttpClient {
1527 fn send(
1528 &self,
1529 _req: http_client::Request<http_client::AsyncBody>,
1530 ) -> futures::future::BoxFuture<
1531 'static,
1532 Result<http_client::Response<http_client::AsyncBody>, anyhow::Error>,
1533 > {
1534 async move { Err(anyhow!("No HttpClient available")) }.boxed()
1535 }
1536
1537 fn proxy(&self) -> Option<&http_client::Uri> {
1538 None
1539 }
1540}