app.rs

   1use std::{
   2    any::{TypeId, type_name},
   3    cell::{Ref, RefCell, RefMut},
   4    marker::PhantomData,
   5    mem,
   6    ops::{Deref, DerefMut},
   7    path::{Path, PathBuf},
   8    rc::{Rc, Weak},
   9    sync::{Arc, atomic::Ordering::SeqCst},
  10    time::Duration,
  11};
  12
  13use anyhow::{Result, anyhow};
  14use derive_more::{Deref, DerefMut};
  15use futures::{
  16    Future, FutureExt,
  17    channel::oneshot,
  18    future::{LocalBoxFuture, Shared},
  19};
  20use parking_lot::RwLock;
  21use slotmap::SlotMap;
  22
  23pub use async_context::*;
  24use collections::{FxHashMap, FxHashSet, HashMap, VecDeque};
  25pub use context::*;
  26pub use entity_map::*;
  27use http_client::HttpClient;
  28#[cfg(any(test, feature = "test-support"))]
  29pub use test_context::*;
  30use util::ResultExt;
  31
  32use crate::{
  33    Action, ActionBuildError, ActionRegistry, Any, AnyView, AnyWindowHandle, AppContext, Asset,
  34    AssetSource, BackgroundExecutor, Bounds, ClipboardItem, DispatchPhase, DisplayId, EventEmitter,
  35    FocusHandle, FocusMap, ForegroundExecutor, Global, KeyBinding, Keymap, Keystroke, LayoutId,
  36    Menu, MenuItem, OwnedMenu, PathPromptOptions, Pixels, Platform, PlatformDisplay, Point,
  37    PromptBuilder, PromptHandle, PromptLevel, Render, RenderablePromptHandle, Reservation,
  38    ScreenCaptureSource, SharedString, SubscriberSet, Subscription, SvgRenderer, Task, TextSystem,
  39    Window, WindowAppearance, WindowHandle, WindowId, WindowInvalidator, current_platform, hash,
  40    init_app_menus,
  41};
  42
  43mod async_context;
  44mod context;
  45mod entity_map;
  46#[cfg(any(test, feature = "test-support"))]
  47mod test_context;
  48
  49/// The duration for which futures returned from [Context::on_app_quit] can run before the application fully quits.
  50pub const SHUTDOWN_TIMEOUT: Duration = Duration::from_millis(100);
  51
  52/// Temporary(?) wrapper around [`RefCell<App>`] to help us debug any double borrows.
  53/// Strongly consider removing after stabilization.
  54#[doc(hidden)]
  55pub struct AppCell {
  56    app: RefCell<App>,
  57}
  58
  59impl AppCell {
  60    #[doc(hidden)]
  61    #[track_caller]
  62    pub fn borrow(&self) -> AppRef {
  63        if option_env!("TRACK_THREAD_BORROWS").is_some() {
  64            let thread_id = std::thread::current().id();
  65            eprintln!("borrowed {thread_id:?}");
  66        }
  67        AppRef(self.app.borrow())
  68    }
  69
  70    #[doc(hidden)]
  71    #[track_caller]
  72    pub fn borrow_mut(&self) -> AppRefMut {
  73        if option_env!("TRACK_THREAD_BORROWS").is_some() {
  74            let thread_id = std::thread::current().id();
  75            eprintln!("borrowed {thread_id:?}");
  76        }
  77        AppRefMut(self.app.borrow_mut())
  78    }
  79}
  80
  81#[doc(hidden)]
  82#[derive(Deref, DerefMut)]
  83pub struct AppRef<'a>(Ref<'a, App>);
  84
  85impl Drop for AppRef<'_> {
  86    fn drop(&mut self) {
  87        if option_env!("TRACK_THREAD_BORROWS").is_some() {
  88            let thread_id = std::thread::current().id();
  89            eprintln!("dropped borrow from {thread_id:?}");
  90        }
  91    }
  92}
  93
  94#[doc(hidden)]
  95#[derive(Deref, DerefMut)]
  96pub struct AppRefMut<'a>(RefMut<'a, App>);
  97
  98impl Drop for AppRefMut<'_> {
  99    fn drop(&mut self) {
 100        if option_env!("TRACK_THREAD_BORROWS").is_some() {
 101            let thread_id = std::thread::current().id();
 102            eprintln!("dropped {thread_id:?}");
 103        }
 104    }
 105}
 106
 107/// A reference to a GPUI application, typically constructed in the `main` function of your app.
 108/// You won't interact with this type much outside of initial configuration and startup.
 109pub struct Application(Rc<AppCell>);
 110
 111/// Represents an application before it is fully launched. Once your app is
 112/// configured, you'll start the app with `App::run`.
 113impl Application {
 114    /// Builds an app with the given asset source.
 115    #[allow(clippy::new_without_default)]
 116    pub fn new() -> Self {
 117        #[cfg(any(test, feature = "test-support"))]
 118        log::info!("GPUI was compiled in test mode");
 119
 120        Self(App::new_app(
 121            current_platform(false),
 122            Arc::new(()),
 123            Arc::new(NullHttpClient),
 124        ))
 125    }
 126
 127    /// Build an app in headless mode. This prevents opening windows,
 128    /// but makes it possible to run an application in an context like
 129    /// SSH, where GUI applications are not allowed.
 130    pub fn headless() -> Self {
 131        Self(App::new_app(
 132            current_platform(true),
 133            Arc::new(()),
 134            Arc::new(NullHttpClient),
 135        ))
 136    }
 137
 138    /// Assign
 139    pub fn with_assets(self, asset_source: impl AssetSource) -> Self {
 140        let mut context_lock = self.0.borrow_mut();
 141        let asset_source = Arc::new(asset_source);
 142        context_lock.asset_source = asset_source.clone();
 143        context_lock.svg_renderer = SvgRenderer::new(asset_source);
 144        drop(context_lock);
 145        self
 146    }
 147
 148    /// Sets the HTTP client for the application.
 149    pub fn with_http_client(self, http_client: Arc<dyn HttpClient>) -> Self {
 150        let mut context_lock = self.0.borrow_mut();
 151        context_lock.http_client = http_client;
 152        drop(context_lock);
 153        self
 154    }
 155
 156    /// Start the application. The provided callback will be called once the
 157    /// app is fully launched.
 158    pub fn run<F>(self, on_finish_launching: F)
 159    where
 160        F: 'static + FnOnce(&mut App),
 161    {
 162        let this = self.0.clone();
 163        let platform = self.0.borrow().platform.clone();
 164        platform.run(Box::new(move || {
 165            let cx = &mut *this.borrow_mut();
 166            on_finish_launching(cx);
 167        }));
 168    }
 169
 170    /// Register a handler to be invoked when the platform instructs the application
 171    /// to open one or more URLs.
 172    pub fn on_open_urls<F>(&self, mut callback: F) -> &Self
 173    where
 174        F: 'static + FnMut(Vec<String>),
 175    {
 176        self.0.borrow().platform.on_open_urls(Box::new(callback));
 177        self
 178    }
 179
 180    /// Invokes a handler when an already-running application is launched.
 181    /// On macOS, this can occur when the application icon is double-clicked or the app is launched via the dock.
 182    pub fn on_reopen<F>(&self, mut callback: F) -> &Self
 183    where
 184        F: 'static + FnMut(&mut App),
 185    {
 186        let this = Rc::downgrade(&self.0);
 187        self.0.borrow_mut().platform.on_reopen(Box::new(move || {
 188            if let Some(app) = this.upgrade() {
 189                callback(&mut app.borrow_mut());
 190            }
 191        }));
 192        self
 193    }
 194
 195    /// Returns a handle to the [`BackgroundExecutor`] associated with this app, which can be used to spawn futures in the background.
 196    pub fn background_executor(&self) -> BackgroundExecutor {
 197        self.0.borrow().background_executor.clone()
 198    }
 199
 200    /// Returns a handle to the [`ForegroundExecutor`] associated with this app, which can be used to spawn futures in the foreground.
 201    pub fn foreground_executor(&self) -> ForegroundExecutor {
 202        self.0.borrow().foreground_executor.clone()
 203    }
 204
 205    /// Returns a reference to the [`TextSystem`] associated with this app.
 206    pub fn text_system(&self) -> Arc<TextSystem> {
 207        self.0.borrow().text_system.clone()
 208    }
 209
 210    /// Returns the file URL of the executable with the specified name in the application bundle
 211    pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
 212        self.0.borrow().path_for_auxiliary_executable(name)
 213    }
 214}
 215
 216type Handler = Box<dyn FnMut(&mut App) -> bool + 'static>;
 217type Listener = Box<dyn FnMut(&dyn Any, &mut App) -> bool + 'static>;
 218pub(crate) type KeystrokeObserver =
 219    Box<dyn FnMut(&KeystrokeEvent, &mut Window, &mut App) -> bool + 'static>;
 220type QuitHandler = Box<dyn FnOnce(&mut App) -> LocalBoxFuture<'static, ()> + 'static>;
 221type WindowClosedHandler = Box<dyn FnMut(&mut App)>;
 222type ReleaseListener = Box<dyn FnOnce(&mut dyn Any, &mut App) + 'static>;
 223type NewEntityListener = Box<dyn FnMut(AnyEntity, &mut Option<&mut Window>, &mut App) + 'static>;
 224
 225/// Contains the state of the full application, and passed as a reference to a variety of callbacks.
 226/// Other [Context] derefs to this type.
 227/// You need a reference to an `App` to access the state of a [Entity].
 228pub struct App {
 229    pub(crate) this: Weak<AppCell>,
 230    pub(crate) platform: Rc<dyn Platform>,
 231    text_system: Arc<TextSystem>,
 232    flushing_effects: bool,
 233    pending_updates: usize,
 234    pub(crate) actions: Rc<ActionRegistry>,
 235    pub(crate) active_drag: Option<AnyDrag>,
 236    pub(crate) background_executor: BackgroundExecutor,
 237    pub(crate) foreground_executor: ForegroundExecutor,
 238    pub(crate) loading_assets: FxHashMap<(TypeId, u64), Box<dyn Any>>,
 239    asset_source: Arc<dyn AssetSource>,
 240    pub(crate) svg_renderer: SvgRenderer,
 241    http_client: Arc<dyn HttpClient>,
 242    pub(crate) globals_by_type: FxHashMap<TypeId, Box<dyn Any>>,
 243    pub(crate) entities: EntityMap,
 244    pub(crate) window_update_stack: Vec<WindowId>,
 245    pub(crate) new_entity_observers: SubscriberSet<TypeId, NewEntityListener>,
 246    pub(crate) windows: SlotMap<WindowId, Option<Window>>,
 247    pub(crate) window_handles: FxHashMap<WindowId, AnyWindowHandle>,
 248    pub(crate) focus_handles: Arc<FocusMap>,
 249    pub(crate) keymap: Rc<RefCell<Keymap>>,
 250    pub(crate) keyboard_layout: SharedString,
 251    pub(crate) global_action_listeners:
 252        FxHashMap<TypeId, Vec<Rc<dyn Fn(&dyn Any, DispatchPhase, &mut Self)>>>,
 253    pending_effects: VecDeque<Effect>,
 254    pub(crate) pending_notifications: FxHashSet<EntityId>,
 255    pub(crate) pending_global_notifications: FxHashSet<TypeId>,
 256    pub(crate) observers: SubscriberSet<EntityId, Handler>,
 257    // TypeId is the type of the event that the listener callback expects
 258    pub(crate) event_listeners: SubscriberSet<EntityId, (TypeId, Listener)>,
 259    pub(crate) keystroke_observers: SubscriberSet<(), KeystrokeObserver>,
 260    pub(crate) keyboard_layout_observers: SubscriberSet<(), Handler>,
 261    pub(crate) release_listeners: SubscriberSet<EntityId, ReleaseListener>,
 262    pub(crate) global_observers: SubscriberSet<TypeId, Handler>,
 263    pub(crate) quit_observers: SubscriberSet<(), QuitHandler>,
 264    pub(crate) window_closed_observers: SubscriberSet<(), WindowClosedHandler>,
 265    pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
 266    pub(crate) propagate_event: bool,
 267    pub(crate) prompt_builder: Option<PromptBuilder>,
 268    pub(crate) window_invalidators_by_entity:
 269        FxHashMap<EntityId, FxHashMap<WindowId, WindowInvalidator>>,
 270    pub(crate) tracked_entities: FxHashMap<WindowId, FxHashSet<EntityId>>,
 271    #[cfg(any(test, feature = "test-support", debug_assertions))]
 272    pub(crate) name: Option<&'static str>,
 273}
 274
 275impl App {
 276    #[allow(clippy::new_ret_no_self)]
 277    pub(crate) fn new_app(
 278        platform: Rc<dyn Platform>,
 279        asset_source: Arc<dyn AssetSource>,
 280        http_client: Arc<dyn HttpClient>,
 281    ) -> Rc<AppCell> {
 282        let executor = platform.background_executor();
 283        let foreground_executor = platform.foreground_executor();
 284        assert!(
 285            executor.is_main_thread(),
 286            "must construct App on main thread"
 287        );
 288
 289        let text_system = Arc::new(TextSystem::new(platform.text_system()));
 290        let entities = EntityMap::new();
 291        let keyboard_layout = SharedString::from(platform.keyboard_layout());
 292
 293        let app = Rc::new_cyclic(|this| AppCell {
 294            app: RefCell::new(App {
 295                this: this.clone(),
 296                platform: platform.clone(),
 297                text_system,
 298                actions: Rc::new(ActionRegistry::default()),
 299                flushing_effects: false,
 300                pending_updates: 0,
 301                active_drag: None,
 302                background_executor: executor,
 303                foreground_executor,
 304                svg_renderer: SvgRenderer::new(asset_source.clone()),
 305                loading_assets: Default::default(),
 306                asset_source,
 307                http_client,
 308                globals_by_type: FxHashMap::default(),
 309                entities,
 310                new_entity_observers: SubscriberSet::new(),
 311                windows: SlotMap::with_key(),
 312                window_update_stack: Vec::new(),
 313                window_handles: FxHashMap::default(),
 314                focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
 315                keymap: Rc::new(RefCell::new(Keymap::default())),
 316                keyboard_layout,
 317                global_action_listeners: FxHashMap::default(),
 318                pending_effects: VecDeque::new(),
 319                pending_notifications: FxHashSet::default(),
 320                pending_global_notifications: FxHashSet::default(),
 321                observers: SubscriberSet::new(),
 322                tracked_entities: FxHashMap::default(),
 323                window_invalidators_by_entity: FxHashMap::default(),
 324                event_listeners: SubscriberSet::new(),
 325                release_listeners: SubscriberSet::new(),
 326                keystroke_observers: SubscriberSet::new(),
 327                keyboard_layout_observers: SubscriberSet::new(),
 328                global_observers: SubscriberSet::new(),
 329                quit_observers: SubscriberSet::new(),
 330                window_closed_observers: SubscriberSet::new(),
 331                layout_id_buffer: Default::default(),
 332                propagate_event: true,
 333                prompt_builder: Some(PromptBuilder::Default),
 334
 335                #[cfg(any(test, feature = "test-support", debug_assertions))]
 336                name: None,
 337            }),
 338        });
 339
 340        init_app_menus(platform.as_ref(), &mut app.borrow_mut());
 341
 342        platform.on_keyboard_layout_change(Box::new({
 343            let app = Rc::downgrade(&app);
 344            move || {
 345                if let Some(app) = app.upgrade() {
 346                    let cx = &mut app.borrow_mut();
 347                    cx.keyboard_layout = SharedString::from(cx.platform.keyboard_layout());
 348                    cx.keyboard_layout_observers
 349                        .clone()
 350                        .retain(&(), move |callback| (callback)(cx));
 351                }
 352            }
 353        }));
 354
 355        platform.on_quit(Box::new({
 356            let cx = app.clone();
 357            move || {
 358                cx.borrow_mut().shutdown();
 359            }
 360        }));
 361
 362        app
 363    }
 364
 365    /// Quit the application gracefully. Handlers registered with [`Context::on_app_quit`]
 366    /// will be given 100ms to complete before exiting.
 367    pub fn shutdown(&mut self) {
 368        let mut futures = Vec::new();
 369
 370        for observer in self.quit_observers.remove(&()) {
 371            futures.push(observer(self));
 372        }
 373
 374        self.windows.clear();
 375        self.window_handles.clear();
 376        self.flush_effects();
 377
 378        let futures = futures::future::join_all(futures);
 379        if self
 380            .background_executor
 381            .block_with_timeout(SHUTDOWN_TIMEOUT, futures)
 382            .is_err()
 383        {
 384            log::error!("timed out waiting on app_will_quit");
 385        }
 386    }
 387
 388    /// Get the id of the current keyboard layout
 389    pub fn keyboard_layout(&self) -> &SharedString {
 390        &self.keyboard_layout
 391    }
 392
 393    /// Invokes a handler when the current keyboard layout changes
 394    pub fn on_keyboard_layout_change<F>(&self, mut callback: F) -> Subscription
 395    where
 396        F: 'static + FnMut(&mut App),
 397    {
 398        let (subscription, activate) = self.keyboard_layout_observers.insert(
 399            (),
 400            Box::new(move |cx| {
 401                callback(cx);
 402                true
 403            }),
 404        );
 405        activate();
 406        subscription
 407    }
 408
 409    /// Gracefully quit the application via the platform's standard routine.
 410    pub fn quit(&self) {
 411        self.platform.quit();
 412    }
 413
 414    /// Schedules all windows in the application to be redrawn. This can be called
 415    /// multiple times in an update cycle and still result in a single redraw.
 416    pub fn refresh_windows(&mut self) {
 417        self.pending_effects.push_back(Effect::RefreshWindows);
 418    }
 419
 420    pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
 421        self.pending_updates += 1;
 422        let result = update(self);
 423        if !self.flushing_effects && self.pending_updates == 1 {
 424            self.flushing_effects = true;
 425            self.flush_effects();
 426            self.flushing_effects = false;
 427        }
 428        self.pending_updates -= 1;
 429        result
 430    }
 431
 432    /// Arrange a callback to be invoked when the given entity calls `notify` on its respective context.
 433    pub fn observe<W>(
 434        &mut self,
 435        entity: &Entity<W>,
 436        mut on_notify: impl FnMut(Entity<W>, &mut App) + 'static,
 437    ) -> Subscription
 438    where
 439        W: 'static,
 440    {
 441        self.observe_internal(entity, move |e, cx| {
 442            on_notify(e, cx);
 443            true
 444        })
 445    }
 446
 447    pub(crate) fn detect_accessed_entities<R>(
 448        &mut self,
 449        callback: impl FnOnce(&mut App) -> R,
 450    ) -> (R, FxHashSet<EntityId>) {
 451        let accessed_entities_start = self.entities.accessed_entities.borrow().clone();
 452        let result = callback(self);
 453        let accessed_entities_end = self.entities.accessed_entities.borrow().clone();
 454        let entities_accessed_in_callback = accessed_entities_end
 455            .difference(&accessed_entities_start)
 456            .copied()
 457            .collect::<FxHashSet<EntityId>>();
 458        (result, entities_accessed_in_callback)
 459    }
 460
 461    pub(crate) fn record_entities_accessed(
 462        &mut self,
 463        window_handle: AnyWindowHandle,
 464        invalidator: WindowInvalidator,
 465        entities: &FxHashSet<EntityId>,
 466    ) {
 467        let mut tracked_entities =
 468            std::mem::take(self.tracked_entities.entry(window_handle.id).or_default());
 469        for entity in tracked_entities.iter() {
 470            self.window_invalidators_by_entity
 471                .entry(*entity)
 472                .and_modify(|windows| {
 473                    windows.remove(&window_handle.id);
 474                });
 475        }
 476        for entity in entities.iter() {
 477            self.window_invalidators_by_entity
 478                .entry(*entity)
 479                .or_default()
 480                .insert(window_handle.id, invalidator.clone());
 481        }
 482        tracked_entities.clear();
 483        tracked_entities.extend(entities.iter().copied());
 484        self.tracked_entities
 485            .insert(window_handle.id, tracked_entities);
 486    }
 487
 488    pub(crate) fn new_observer(&mut self, key: EntityId, value: Handler) -> Subscription {
 489        let (subscription, activate) = self.observers.insert(key, value);
 490        self.defer(move |_| activate());
 491        subscription
 492    }
 493
 494    pub(crate) fn observe_internal<W>(
 495        &mut self,
 496        entity: &Entity<W>,
 497        mut on_notify: impl FnMut(Entity<W>, &mut App) -> bool + 'static,
 498    ) -> Subscription
 499    where
 500        W: 'static,
 501    {
 502        let entity_id = entity.entity_id();
 503        let handle = entity.downgrade();
 504        self.new_observer(
 505            entity_id,
 506            Box::new(move |cx| {
 507                if let Some(handle) = Entity::<W>::upgrade_from(&handle) {
 508                    on_notify(handle, cx)
 509                } else {
 510                    false
 511                }
 512            }),
 513        )
 514    }
 515
 516    /// Arrange for the given callback to be invoked whenever the given entity emits an event of a given type.
 517    /// The callback is provided a handle to the emitting entity and a reference to the emitted event.
 518    pub fn subscribe<T, Event>(
 519        &mut self,
 520        entity: &Entity<T>,
 521        mut on_event: impl FnMut(Entity<T>, &Event, &mut App) + 'static,
 522    ) -> Subscription
 523    where
 524        T: 'static + EventEmitter<Event>,
 525        Event: 'static,
 526    {
 527        self.subscribe_internal(entity, move |entity, event, cx| {
 528            on_event(entity, event, cx);
 529            true
 530        })
 531    }
 532
 533    pub(crate) fn new_subscription(
 534        &mut self,
 535        key: EntityId,
 536        value: (TypeId, Listener),
 537    ) -> Subscription {
 538        let (subscription, activate) = self.event_listeners.insert(key, value);
 539        self.defer(move |_| activate());
 540        subscription
 541    }
 542    pub(crate) fn subscribe_internal<T, Evt>(
 543        &mut self,
 544        entity: &Entity<T>,
 545        mut on_event: impl FnMut(Entity<T>, &Evt, &mut App) -> bool + 'static,
 546    ) -> Subscription
 547    where
 548        T: 'static + EventEmitter<Evt>,
 549        Evt: 'static,
 550    {
 551        let entity_id = entity.entity_id();
 552        let entity = entity.downgrade();
 553        self.new_subscription(
 554            entity_id,
 555            (
 556                TypeId::of::<Evt>(),
 557                Box::new(move |event, cx| {
 558                    let event: &Evt = event.downcast_ref().expect("invalid event type");
 559                    if let Some(handle) = Entity::<T>::upgrade_from(&entity) {
 560                        on_event(handle, event, cx)
 561                    } else {
 562                        false
 563                    }
 564                }),
 565            ),
 566        )
 567    }
 568
 569    /// Returns handles to all open windows in the application.
 570    /// Each handle could be downcast to a handle typed for the root view of that window.
 571    /// To find all windows of a given type, you could filter on
 572    pub fn windows(&self) -> Vec<AnyWindowHandle> {
 573        self.windows
 574            .keys()
 575            .flat_map(|window_id| self.window_handles.get(&window_id).copied())
 576            .collect()
 577    }
 578
 579    /// Returns the window handles ordered by their appearance on screen, front to back.
 580    ///
 581    /// The first window in the returned list is the active/topmost window of the application.
 582    ///
 583    /// This method returns None if the platform doesn't implement the method yet.
 584    pub fn window_stack(&self) -> Option<Vec<AnyWindowHandle>> {
 585        self.platform.window_stack()
 586    }
 587
 588    /// Returns a handle to the window that is currently focused at the platform level, if one exists.
 589    pub fn active_window(&self) -> Option<AnyWindowHandle> {
 590        self.platform.active_window()
 591    }
 592
 593    /// Opens a new window with the given option and the root view returned by the given function.
 594    /// The function is invoked with a `Window`, which can be used to interact with window-specific
 595    /// functionality.
 596    pub fn open_window<V: 'static + Render>(
 597        &mut self,
 598        options: crate::WindowOptions,
 599        build_root_view: impl FnOnce(&mut Window, &mut App) -> Entity<V>,
 600    ) -> anyhow::Result<WindowHandle<V>> {
 601        self.update(|cx| {
 602            let id = cx.windows.insert(None);
 603            let handle = WindowHandle::new(id);
 604            match Window::new(handle.into(), options, cx) {
 605                Ok(mut window) => {
 606                    cx.window_update_stack.push(id);
 607                    let root_view = build_root_view(&mut window, cx);
 608                    cx.window_update_stack.pop();
 609                    window.root.replace(root_view.into());
 610                    window.defer(cx, |window: &mut Window, cx| window.appearance_changed(cx));
 611                    cx.window_handles.insert(id, window.handle);
 612                    cx.windows.get_mut(id).unwrap().replace(window);
 613                    Ok(handle)
 614                }
 615                Err(e) => {
 616                    cx.windows.remove(id);
 617                    Err(e)
 618                }
 619            }
 620        })
 621    }
 622
 623    /// Instructs the platform to activate the application by bringing it to the foreground.
 624    pub fn activate(&self, ignoring_other_apps: bool) {
 625        self.platform.activate(ignoring_other_apps);
 626    }
 627
 628    /// Hide the application at the platform level.
 629    pub fn hide(&self) {
 630        self.platform.hide();
 631    }
 632
 633    /// Hide other applications at the platform level.
 634    pub fn hide_other_apps(&self) {
 635        self.platform.hide_other_apps();
 636    }
 637
 638    /// Unhide other applications at the platform level.
 639    pub fn unhide_other_apps(&self) {
 640        self.platform.unhide_other_apps();
 641    }
 642
 643    /// Returns the list of currently active displays.
 644    pub fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {
 645        self.platform.displays()
 646    }
 647
 648    /// Returns the primary display that will be used for new windows.
 649    pub fn primary_display(&self) -> Option<Rc<dyn PlatformDisplay>> {
 650        self.platform.primary_display()
 651    }
 652
 653    /// Returns whether `screen_capture_sources` may work.
 654    pub fn is_screen_capture_supported(&self) -> bool {
 655        self.platform.is_screen_capture_supported()
 656    }
 657
 658    /// Returns a list of available screen capture sources.
 659    pub fn screen_capture_sources(
 660        &self,
 661    ) -> oneshot::Receiver<Result<Vec<Box<dyn ScreenCaptureSource>>>> {
 662        self.platform.screen_capture_sources()
 663    }
 664
 665    /// Returns the display with the given ID, if one exists.
 666    pub fn find_display(&self, id: DisplayId) -> Option<Rc<dyn PlatformDisplay>> {
 667        self.displays()
 668            .iter()
 669            .find(|display| display.id() == id)
 670            .cloned()
 671    }
 672
 673    /// Returns the appearance of the application's windows.
 674    pub fn window_appearance(&self) -> WindowAppearance {
 675        self.platform.window_appearance()
 676    }
 677
 678    /// Writes data to the primary selection buffer.
 679    /// Only available on Linux.
 680    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
 681    pub fn write_to_primary(&self, item: ClipboardItem) {
 682        self.platform.write_to_primary(item)
 683    }
 684
 685    /// Writes data to the platform clipboard.
 686    pub fn write_to_clipboard(&self, item: ClipboardItem) {
 687        self.platform.write_to_clipboard(item)
 688    }
 689
 690    /// Reads data from the primary selection buffer.
 691    /// Only available on Linux.
 692    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
 693    pub fn read_from_primary(&self) -> Option<ClipboardItem> {
 694        self.platform.read_from_primary()
 695    }
 696
 697    /// Reads data from the platform clipboard.
 698    pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
 699        self.platform.read_from_clipboard()
 700    }
 701
 702    /// Writes credentials to the platform keychain.
 703    pub fn write_credentials(
 704        &self,
 705        url: &str,
 706        username: &str,
 707        password: &[u8],
 708    ) -> Task<Result<()>> {
 709        self.platform.write_credentials(url, username, password)
 710    }
 711
 712    /// Reads credentials from the platform keychain.
 713    pub fn read_credentials(&self, url: &str) -> Task<Result<Option<(String, Vec<u8>)>>> {
 714        self.platform.read_credentials(url)
 715    }
 716
 717    /// Deletes credentials from the platform keychain.
 718    pub fn delete_credentials(&self, url: &str) -> Task<Result<()>> {
 719        self.platform.delete_credentials(url)
 720    }
 721
 722    /// Directs the platform's default browser to open the given URL.
 723    pub fn open_url(&self, url: &str) {
 724        self.platform.open_url(url);
 725    }
 726
 727    /// Registers the given URL scheme (e.g. `zed` for `zed://` urls) to be
 728    /// opened by the current app.
 729    ///
 730    /// On some platforms (e.g. macOS) you may be able to register URL schemes
 731    /// as part of app distribution, but this method exists to let you register
 732    /// schemes at runtime.
 733    pub fn register_url_scheme(&self, scheme: &str) -> Task<Result<()>> {
 734        self.platform.register_url_scheme(scheme)
 735    }
 736
 737    /// Returns the full pathname of the current app bundle.
 738    ///
 739    /// Returns an error if the app is not being run from a bundle.
 740    pub fn app_path(&self) -> Result<PathBuf> {
 741        self.platform.app_path()
 742    }
 743
 744    /// On Linux, returns the name of the compositor in use.
 745    ///
 746    /// Returns an empty string on other platforms.
 747    pub fn compositor_name(&self) -> &'static str {
 748        self.platform.compositor_name()
 749    }
 750
 751    /// Returns the file URL of the executable with the specified name in the application bundle
 752    pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
 753        self.platform.path_for_auxiliary_executable(name)
 754    }
 755
 756    /// Displays a platform modal for selecting paths.
 757    ///
 758    /// When one or more paths are selected, they'll be relayed asynchronously via the returned oneshot channel.
 759    /// If cancelled, a `None` will be relayed instead.
 760    /// May return an error on Linux if the file picker couldn't be opened.
 761    pub fn prompt_for_paths(
 762        &self,
 763        options: PathPromptOptions,
 764    ) -> oneshot::Receiver<Result<Option<Vec<PathBuf>>>> {
 765        self.platform.prompt_for_paths(options)
 766    }
 767
 768    /// Displays a platform modal for selecting a new path where a file can be saved.
 769    ///
 770    /// The provided directory will be used to set the initial location.
 771    /// When a path is selected, it is relayed asynchronously via the returned oneshot channel.
 772    /// If cancelled, a `None` will be relayed instead.
 773    /// May return an error on Linux if the file picker couldn't be opened.
 774    pub fn prompt_for_new_path(
 775        &self,
 776        directory: &Path,
 777    ) -> oneshot::Receiver<Result<Option<PathBuf>>> {
 778        self.platform.prompt_for_new_path(directory)
 779    }
 780
 781    /// Reveals the specified path at the platform level, such as in Finder on macOS.
 782    pub fn reveal_path(&self, path: &Path) {
 783        self.platform.reveal_path(path)
 784    }
 785
 786    /// Opens the specified path with the system's default application.
 787    pub fn open_with_system(&self, path: &Path) {
 788        self.platform.open_with_system(path)
 789    }
 790
 791    /// Returns whether the user has configured scrollbars to auto-hide at the platform level.
 792    pub fn should_auto_hide_scrollbars(&self) -> bool {
 793        self.platform.should_auto_hide_scrollbars()
 794    }
 795
 796    /// Restarts the application.
 797    pub fn restart(&self, binary_path: Option<PathBuf>) {
 798        self.platform.restart(binary_path)
 799    }
 800
 801    /// Returns the HTTP client for the application.
 802    pub fn http_client(&self) -> Arc<dyn HttpClient> {
 803        self.http_client.clone()
 804    }
 805
 806    /// Sets the HTTP client for the application.
 807    pub fn set_http_client(&mut self, new_client: Arc<dyn HttpClient>) {
 808        self.http_client = new_client;
 809    }
 810
 811    /// Returns the SVG renderer used by the application.
 812    pub fn svg_renderer(&self) -> SvgRenderer {
 813        self.svg_renderer.clone()
 814    }
 815
 816    pub(crate) fn push_effect(&mut self, effect: Effect) {
 817        match &effect {
 818            Effect::Notify { emitter } => {
 819                if !self.pending_notifications.insert(*emitter) {
 820                    return;
 821                }
 822            }
 823            Effect::NotifyGlobalObservers { global_type } => {
 824                if !self.pending_global_notifications.insert(*global_type) {
 825                    return;
 826                }
 827            }
 828            _ => {}
 829        };
 830
 831        self.pending_effects.push_back(effect);
 832    }
 833
 834    /// Called at the end of [`App::update`] to complete any side effects
 835    /// such as notifying observers, emitting events, etc. Effects can themselves
 836    /// cause effects, so we continue looping until all effects are processed.
 837    fn flush_effects(&mut self) {
 838        loop {
 839            self.release_dropped_entities();
 840            self.release_dropped_focus_handles();
 841
 842            if let Some(effect) = self.pending_effects.pop_front() {
 843                match effect {
 844                    Effect::Notify { emitter } => {
 845                        self.apply_notify_effect(emitter);
 846                    }
 847
 848                    Effect::Emit {
 849                        emitter,
 850                        event_type,
 851                        event,
 852                    } => self.apply_emit_effect(emitter, event_type, event),
 853
 854                    Effect::RefreshWindows => {
 855                        self.apply_refresh_effect();
 856                    }
 857
 858                    Effect::NotifyGlobalObservers { global_type } => {
 859                        self.apply_notify_global_observers_effect(global_type);
 860                    }
 861
 862                    Effect::Defer { callback } => {
 863                        self.apply_defer_effect(callback);
 864                    }
 865                    Effect::EntityCreated {
 866                        entity,
 867                        tid,
 868                        window,
 869                    } => {
 870                        self.apply_entity_created_effect(entity, tid, window);
 871                    }
 872                }
 873            } else {
 874                #[cfg(any(test, feature = "test-support"))]
 875                for window in self
 876                    .windows
 877                    .values()
 878                    .filter_map(|window| {
 879                        let window = window.as_ref()?;
 880                        window.invalidator.is_dirty().then_some(window.handle)
 881                    })
 882                    .collect::<Vec<_>>()
 883                {
 884                    self.update_window(window, |_, window, cx| window.draw(cx))
 885                        .unwrap();
 886                }
 887
 888                if self.pending_effects.is_empty() {
 889                    break;
 890                }
 891            }
 892        }
 893    }
 894
 895    /// Repeatedly called during `flush_effects` to release any entities whose
 896    /// reference count has become zero. We invoke any release observers before dropping
 897    /// each entity.
 898    fn release_dropped_entities(&mut self) {
 899        loop {
 900            let dropped = self.entities.take_dropped();
 901            if dropped.is_empty() {
 902                break;
 903            }
 904
 905            for (entity_id, mut entity) in dropped {
 906                self.observers.remove(&entity_id);
 907                self.event_listeners.remove(&entity_id);
 908                for release_callback in self.release_listeners.remove(&entity_id) {
 909                    release_callback(entity.as_mut(), self);
 910                }
 911            }
 912        }
 913    }
 914
 915    /// Repeatedly called during `flush_effects` to handle a focused handle being dropped.
 916    fn release_dropped_focus_handles(&mut self) {
 917        self.focus_handles
 918            .clone()
 919            .write()
 920            .retain(|handle_id, count| {
 921                if count.load(SeqCst) == 0 {
 922                    for window_handle in self.windows() {
 923                        window_handle
 924                            .update(self, |_, window, _| {
 925                                if window.focus == Some(handle_id) {
 926                                    window.blur();
 927                                }
 928                            })
 929                            .unwrap();
 930                    }
 931                    false
 932                } else {
 933                    true
 934                }
 935            });
 936    }
 937
 938    fn apply_notify_effect(&mut self, emitter: EntityId) {
 939        self.pending_notifications.remove(&emitter);
 940
 941        self.observers
 942            .clone()
 943            .retain(&emitter, |handler| handler(self));
 944    }
 945
 946    fn apply_emit_effect(&mut self, emitter: EntityId, event_type: TypeId, event: Box<dyn Any>) {
 947        self.event_listeners
 948            .clone()
 949            .retain(&emitter, |(stored_type, handler)| {
 950                if *stored_type == event_type {
 951                    handler(event.as_ref(), self)
 952                } else {
 953                    true
 954                }
 955            });
 956    }
 957
 958    fn apply_refresh_effect(&mut self) {
 959        for window in self.windows.values_mut() {
 960            if let Some(window) = window.as_mut() {
 961                window.refreshing = true;
 962                window.invalidator.set_dirty(true);
 963            }
 964        }
 965    }
 966
 967    fn apply_notify_global_observers_effect(&mut self, type_id: TypeId) {
 968        self.pending_global_notifications.remove(&type_id);
 969        self.global_observers
 970            .clone()
 971            .retain(&type_id, |observer| observer(self));
 972    }
 973
 974    fn apply_defer_effect(&mut self, callback: Box<dyn FnOnce(&mut Self) + 'static>) {
 975        callback(self);
 976    }
 977
 978    fn apply_entity_created_effect(
 979        &mut self,
 980        entity: AnyEntity,
 981        tid: TypeId,
 982        window: Option<WindowId>,
 983    ) {
 984        self.new_entity_observers.clone().retain(&tid, |observer| {
 985            if let Some(id) = window {
 986                self.update_window_id(id, {
 987                    let entity = entity.clone();
 988                    |_, window, cx| (observer)(entity, &mut Some(window), cx)
 989                })
 990                .expect("All windows should be off the stack when flushing effects");
 991            } else {
 992                (observer)(entity.clone(), &mut None, self)
 993            }
 994            true
 995        });
 996    }
 997
 998    fn update_window_id<T, F>(&mut self, id: WindowId, update: F) -> Result<T>
 999    where
1000        F: FnOnce(AnyView, &mut Window, &mut App) -> T,
1001    {
1002        self.update(|cx| {
1003            let mut window = cx
1004                .windows
1005                .get_mut(id)
1006                .ok_or_else(|| anyhow!("window not found"))?
1007                .take()
1008                .ok_or_else(|| anyhow!("window not found"))?;
1009
1010            let root_view = window.root.clone().unwrap();
1011
1012            cx.window_update_stack.push(window.handle.id);
1013            let result = update(root_view, &mut window, cx);
1014            cx.window_update_stack.pop();
1015
1016            if window.removed {
1017                cx.window_handles.remove(&id);
1018                cx.windows.remove(id);
1019
1020                cx.window_closed_observers.clone().retain(&(), |callback| {
1021                    callback(cx);
1022                    true
1023                });
1024            } else {
1025                cx.windows
1026                    .get_mut(id)
1027                    .ok_or_else(|| anyhow!("window not found"))?
1028                    .replace(window);
1029            }
1030
1031            Ok(result)
1032        })
1033    }
1034    /// Creates an `AsyncApp`, which can be cloned and has a static lifetime
1035    /// so it can be held across `await` points.
1036    pub fn to_async(&self) -> AsyncApp {
1037        AsyncApp {
1038            app: self.this.clone(),
1039            background_executor: self.background_executor.clone(),
1040            foreground_executor: self.foreground_executor.clone(),
1041        }
1042    }
1043
1044    /// Obtains a reference to the executor, which can be used to spawn futures.
1045    pub fn background_executor(&self) -> &BackgroundExecutor {
1046        &self.background_executor
1047    }
1048
1049    /// Obtains a reference to the executor, which can be used to spawn futures.
1050    pub fn foreground_executor(&self) -> &ForegroundExecutor {
1051        &self.foreground_executor
1052    }
1053
1054    /// Spawns the future returned by the given function on the main thread. The closure will be invoked
1055    /// with [AsyncApp], which allows the application state to be accessed across await points.
1056    #[track_caller]
1057    pub fn spawn<AsyncFn, R>(&self, f: AsyncFn) -> Task<R>
1058    where
1059        AsyncFn: AsyncFnOnce(&mut AsyncApp) -> R + 'static,
1060        R: 'static,
1061    {
1062        let mut cx = self.to_async();
1063        self.foreground_executor
1064            .spawn(async move { f(&mut cx).await })
1065    }
1066
1067    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1068    /// that are currently on the stack to be returned to the app.
1069    pub fn defer(&mut self, f: impl FnOnce(&mut App) + 'static) {
1070        self.push_effect(Effect::Defer {
1071            callback: Box::new(f),
1072        });
1073    }
1074
1075    /// Accessor for the application's asset source, which is provided when constructing the `App`.
1076    pub fn asset_source(&self) -> &Arc<dyn AssetSource> {
1077        &self.asset_source
1078    }
1079
1080    /// Accessor for the text system.
1081    pub fn text_system(&self) -> &Arc<TextSystem> {
1082        &self.text_system
1083    }
1084
1085    /// Check whether a global of the given type has been assigned.
1086    pub fn has_global<G: Global>(&self) -> bool {
1087        self.globals_by_type.contains_key(&TypeId::of::<G>())
1088    }
1089
1090    /// Access the global of the given type. Panics if a global for that type has not been assigned.
1091    #[track_caller]
1092    pub fn global<G: Global>(&self) -> &G {
1093        self.globals_by_type
1094            .get(&TypeId::of::<G>())
1095            .map(|any_state| any_state.downcast_ref::<G>().unwrap())
1096            .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
1097            .unwrap()
1098    }
1099
1100    /// Access the global of the given type if a value has been assigned.
1101    pub fn try_global<G: Global>(&self) -> Option<&G> {
1102        self.globals_by_type
1103            .get(&TypeId::of::<G>())
1104            .map(|any_state| any_state.downcast_ref::<G>().unwrap())
1105    }
1106
1107    /// Access the global of the given type mutably. Panics if a global for that type has not been assigned.
1108    #[track_caller]
1109    pub fn global_mut<G: Global>(&mut self) -> &mut G {
1110        let global_type = TypeId::of::<G>();
1111        self.push_effect(Effect::NotifyGlobalObservers { global_type });
1112        self.globals_by_type
1113            .get_mut(&global_type)
1114            .and_then(|any_state| any_state.downcast_mut::<G>())
1115            .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
1116            .unwrap()
1117    }
1118
1119    /// Access the global of the given type mutably. A default value is assigned if a global of this type has not
1120    /// yet been assigned.
1121    pub fn default_global<G: Global + Default>(&mut self) -> &mut G {
1122        let global_type = TypeId::of::<G>();
1123        self.push_effect(Effect::NotifyGlobalObservers { global_type });
1124        self.globals_by_type
1125            .entry(global_type)
1126            .or_insert_with(|| Box::<G>::default())
1127            .downcast_mut::<G>()
1128            .unwrap()
1129    }
1130
1131    /// Sets the value of the global of the given type.
1132    pub fn set_global<G: Global>(&mut self, global: G) {
1133        let global_type = TypeId::of::<G>();
1134        self.push_effect(Effect::NotifyGlobalObservers { global_type });
1135        self.globals_by_type.insert(global_type, Box::new(global));
1136    }
1137
1138    /// Clear all stored globals. Does not notify global observers.
1139    #[cfg(any(test, feature = "test-support"))]
1140    pub fn clear_globals(&mut self) {
1141        self.globals_by_type.drain();
1142    }
1143
1144    /// Remove the global of the given type from the app context. Does not notify global observers.
1145    pub fn remove_global<G: Global>(&mut self) -> G {
1146        let global_type = TypeId::of::<G>();
1147        self.push_effect(Effect::NotifyGlobalObservers { global_type });
1148        *self
1149            .globals_by_type
1150            .remove(&global_type)
1151            .unwrap_or_else(|| panic!("no global added for {}", std::any::type_name::<G>()))
1152            .downcast()
1153            .unwrap()
1154    }
1155
1156    /// Register a callback to be invoked when a global of the given type is updated.
1157    pub fn observe_global<G: Global>(
1158        &mut self,
1159        mut f: impl FnMut(&mut Self) + 'static,
1160    ) -> Subscription {
1161        let (subscription, activate) = self.global_observers.insert(
1162            TypeId::of::<G>(),
1163            Box::new(move |cx| {
1164                f(cx);
1165                true
1166            }),
1167        );
1168        self.defer(move |_| activate());
1169        subscription
1170    }
1171
1172    /// Move the global of the given type to the stack.
1173    #[track_caller]
1174    pub(crate) fn lease_global<G: Global>(&mut self) -> GlobalLease<G> {
1175        GlobalLease::new(
1176            self.globals_by_type
1177                .remove(&TypeId::of::<G>())
1178                .ok_or_else(|| anyhow!("no global registered of type {}", type_name::<G>()))
1179                .unwrap(),
1180        )
1181    }
1182
1183    /// Restore the global of the given type after it is moved to the stack.
1184    pub(crate) fn end_global_lease<G: Global>(&mut self, lease: GlobalLease<G>) {
1185        let global_type = TypeId::of::<G>();
1186
1187        self.push_effect(Effect::NotifyGlobalObservers { global_type });
1188        self.globals_by_type.insert(global_type, lease.global);
1189    }
1190
1191    pub(crate) fn new_entity_observer(
1192        &self,
1193        key: TypeId,
1194        value: NewEntityListener,
1195    ) -> Subscription {
1196        let (subscription, activate) = self.new_entity_observers.insert(key, value);
1197        activate();
1198        subscription
1199    }
1200
1201    /// Arrange for the given function to be invoked whenever a view of the specified type is created.
1202    /// The function will be passed a mutable reference to the view along with an appropriate context.
1203    pub fn observe_new<T: 'static>(
1204        &self,
1205        on_new: impl 'static + Fn(&mut T, Option<&mut Window>, &mut Context<T>),
1206    ) -> Subscription {
1207        self.new_entity_observer(
1208            TypeId::of::<T>(),
1209            Box::new(
1210                move |any_entity: AnyEntity, window: &mut Option<&mut Window>, cx: &mut App| {
1211                    any_entity
1212                        .downcast::<T>()
1213                        .unwrap()
1214                        .update(cx, |entity_state, cx| {
1215                            if let Some(window) = window {
1216                                on_new(entity_state, Some(window), cx);
1217                            } else {
1218                                on_new(entity_state, None, cx);
1219                            }
1220                        })
1221                },
1222            ),
1223        )
1224    }
1225
1226    /// Observe the release of a entity. The callback is invoked after the entity
1227    /// has no more strong references but before it has been dropped.
1228    pub fn observe_release<T>(
1229        &self,
1230        handle: &Entity<T>,
1231        on_release: impl FnOnce(&mut T, &mut App) + 'static,
1232    ) -> Subscription
1233    where
1234        T: 'static,
1235    {
1236        let (subscription, activate) = self.release_listeners.insert(
1237            handle.entity_id(),
1238            Box::new(move |entity, cx| {
1239                let entity = entity.downcast_mut().expect("invalid entity type");
1240                on_release(entity, cx)
1241            }),
1242        );
1243        activate();
1244        subscription
1245    }
1246
1247    /// Observe the release of a entity. The callback is invoked after the entity
1248    /// has no more strong references but before it has been dropped.
1249    pub fn observe_release_in<T>(
1250        &self,
1251        handle: &Entity<T>,
1252        window: &Window,
1253        on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1254    ) -> Subscription
1255    where
1256        T: 'static,
1257    {
1258        let window_handle = window.handle;
1259        self.observe_release(&handle, move |entity, cx| {
1260            let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1261        })
1262    }
1263
1264    /// Register a callback to be invoked when a keystroke is received by the application
1265    /// in any window. Note that this fires after all other action and event mechanisms have resolved
1266    /// and that this API will not be invoked if the event's propagation is stopped.
1267    pub fn observe_keystrokes(
1268        &mut self,
1269        mut f: impl FnMut(&KeystrokeEvent, &mut Window, &mut App) + 'static,
1270    ) -> Subscription {
1271        fn inner(
1272            keystroke_observers: &SubscriberSet<(), KeystrokeObserver>,
1273            handler: KeystrokeObserver,
1274        ) -> Subscription {
1275            let (subscription, activate) = keystroke_observers.insert((), handler);
1276            activate();
1277            subscription
1278        }
1279
1280        inner(
1281            &mut self.keystroke_observers,
1282            Box::new(move |event, window, cx| {
1283                f(event, window, cx);
1284                true
1285            }),
1286        )
1287    }
1288
1289    /// Register key bindings.
1290    pub fn bind_keys(&mut self, bindings: impl IntoIterator<Item = KeyBinding>) {
1291        self.keymap.borrow_mut().add_bindings(bindings);
1292        self.pending_effects.push_back(Effect::RefreshWindows);
1293    }
1294
1295    /// Clear all key bindings in the app.
1296    pub fn clear_key_bindings(&mut self) {
1297        self.keymap.borrow_mut().clear();
1298        self.pending_effects.push_back(Effect::RefreshWindows);
1299    }
1300
1301    /// Register a global listener for actions invoked via the keyboard.
1302    pub fn on_action<A: Action>(&mut self, listener: impl Fn(&A, &mut Self) + 'static) {
1303        self.global_action_listeners
1304            .entry(TypeId::of::<A>())
1305            .or_default()
1306            .push(Rc::new(move |action, phase, cx| {
1307                if phase == DispatchPhase::Bubble {
1308                    let action = action.downcast_ref().unwrap();
1309                    listener(action, cx)
1310                }
1311            }));
1312    }
1313
1314    /// Event handlers propagate events by default. Call this method to stop dispatching to
1315    /// event handlers with a lower z-index (mouse) or higher in the tree (keyboard). This is
1316    /// the opposite of [`Self::propagate`]. It's also possible to cancel a call to [`Self::propagate`] by
1317    /// calling this method before effects are flushed.
1318    pub fn stop_propagation(&mut self) {
1319        self.propagate_event = false;
1320    }
1321
1322    /// Action handlers stop propagation by default during the bubble phase of action dispatch
1323    /// dispatching to action handlers higher in the element tree. This is the opposite of
1324    /// [`Self::stop_propagation`]. It's also possible to cancel a call to [`Self::stop_propagation`] by calling
1325    /// this method before effects are flushed.
1326    pub fn propagate(&mut self) {
1327        self.propagate_event = true;
1328    }
1329
1330    /// Build an action from some arbitrary data, typically a keymap entry.
1331    pub fn build_action(
1332        &self,
1333        name: &str,
1334        data: Option<serde_json::Value>,
1335    ) -> std::result::Result<Box<dyn Action>, ActionBuildError> {
1336        self.actions.build_action(name, data)
1337    }
1338
1339    /// Get all action names that have been registered. Note that registration only allows for
1340    /// actions to be built dynamically, and is unrelated to binding actions in the element tree.
1341    pub fn all_action_names(&self) -> &[SharedString] {
1342        self.actions.all_action_names()
1343    }
1344
1345    /// Returns key bindings that invoke the given action on the currently focused element, without
1346    /// checking context. Bindings are returned in the order they were added. For display, the last
1347    /// binding should take precedence.
1348    pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
1349        RefCell::borrow(&self.keymap).all_bindings_for_input(input)
1350    }
1351
1352    /// Get all non-internal actions that have been registered, along with their schemas.
1353    pub fn action_schemas(
1354        &self,
1355        generator: &mut schemars::r#gen::SchemaGenerator,
1356    ) -> Vec<(SharedString, Option<schemars::schema::Schema>)> {
1357        self.actions.action_schemas(generator)
1358    }
1359
1360    /// Get a list of all deprecated action aliases and their canonical names.
1361    pub fn action_deprecations(&self) -> &HashMap<SharedString, SharedString> {
1362        self.actions.action_deprecations()
1363    }
1364
1365    /// Register a callback to be invoked when the application is about to quit.
1366    /// It is not possible to cancel the quit event at this point.
1367    pub fn on_app_quit<Fut>(
1368        &self,
1369        mut on_quit: impl FnMut(&mut App) -> Fut + 'static,
1370    ) -> Subscription
1371    where
1372        Fut: 'static + Future<Output = ()>,
1373    {
1374        let (subscription, activate) = self.quit_observers.insert(
1375            (),
1376            Box::new(move |cx| {
1377                let future = on_quit(cx);
1378                future.boxed_local()
1379            }),
1380        );
1381        activate();
1382        subscription
1383    }
1384
1385    /// Register a callback to be invoked when a window is closed
1386    /// The window is no longer accessible at the point this callback is invoked.
1387    pub fn on_window_closed(&self, mut on_closed: impl FnMut(&mut App) + 'static) -> Subscription {
1388        let (subscription, activate) = self.window_closed_observers.insert((), Box::new(on_closed));
1389        activate();
1390        subscription
1391    }
1392
1393    pub(crate) fn clear_pending_keystrokes(&mut self) {
1394        for window in self.windows() {
1395            window
1396                .update(self, |_, window, _| {
1397                    window.clear_pending_keystrokes();
1398                })
1399                .ok();
1400        }
1401    }
1402
1403    /// Checks if the given action is bound in the current context, as defined by the app's current focus,
1404    /// the bindings in the element tree, and any global action listeners.
1405    pub fn is_action_available(&mut self, action: &dyn Action) -> bool {
1406        let mut action_available = false;
1407        if let Some(window) = self.active_window() {
1408            if let Ok(window_action_available) =
1409                window.update(self, |_, window, cx| window.is_action_available(action, cx))
1410            {
1411                action_available = window_action_available;
1412            }
1413        }
1414
1415        action_available
1416            || self
1417                .global_action_listeners
1418                .contains_key(&action.as_any().type_id())
1419    }
1420
1421    /// Sets the menu bar for this application. This will replace any existing menu bar.
1422    pub fn set_menus(&self, menus: Vec<Menu>) {
1423        self.platform.set_menus(menus, &self.keymap.borrow());
1424    }
1425
1426    /// Gets the menu bar for this application.
1427    pub fn get_menus(&self) -> Option<Vec<OwnedMenu>> {
1428        self.platform.get_menus()
1429    }
1430
1431    /// Sets the right click menu for the app icon in the dock
1432    pub fn set_dock_menu(&self, menus: Vec<MenuItem>) {
1433        self.platform.set_dock_menu(menus, &self.keymap.borrow());
1434    }
1435
1436    /// Performs the action associated with the given dock menu item, only used on Windows for now.
1437    pub fn perform_dock_menu_action(&self, action: usize) {
1438        self.platform.perform_dock_menu_action(action);
1439    }
1440
1441    /// Adds given path to the bottom of the list of recent paths for the application.
1442    /// The list is usually shown on the application icon's context menu in the dock,
1443    /// and allows to open the recent files via that context menu.
1444    /// If the path is already in the list, it will be moved to the bottom of the list.
1445    pub fn add_recent_document(&self, path: &Path) {
1446        self.platform.add_recent_document(path);
1447    }
1448
1449    /// Dispatch an action to the currently active window or global action handler
1450    /// See [`crate::Action`] for more information on how actions work
1451    pub fn dispatch_action(&mut self, action: &dyn Action) {
1452        if let Some(active_window) = self.active_window() {
1453            active_window
1454                .update(self, |_, window, cx| {
1455                    window.dispatch_action(action.boxed_clone(), cx)
1456                })
1457                .log_err();
1458        } else {
1459            self.dispatch_global_action(action);
1460        }
1461    }
1462
1463    fn dispatch_global_action(&mut self, action: &dyn Action) {
1464        self.propagate_event = true;
1465
1466        if let Some(mut global_listeners) = self
1467            .global_action_listeners
1468            .remove(&action.as_any().type_id())
1469        {
1470            for listener in &global_listeners {
1471                listener(action.as_any(), DispatchPhase::Capture, self);
1472                if !self.propagate_event {
1473                    break;
1474                }
1475            }
1476
1477            global_listeners.extend(
1478                self.global_action_listeners
1479                    .remove(&action.as_any().type_id())
1480                    .unwrap_or_default(),
1481            );
1482
1483            self.global_action_listeners
1484                .insert(action.as_any().type_id(), global_listeners);
1485        }
1486
1487        if self.propagate_event {
1488            if let Some(mut global_listeners) = self
1489                .global_action_listeners
1490                .remove(&action.as_any().type_id())
1491            {
1492                for listener in global_listeners.iter().rev() {
1493                    listener(action.as_any(), DispatchPhase::Bubble, self);
1494                    if !self.propagate_event {
1495                        break;
1496                    }
1497                }
1498
1499                global_listeners.extend(
1500                    self.global_action_listeners
1501                        .remove(&action.as_any().type_id())
1502                        .unwrap_or_default(),
1503                );
1504
1505                self.global_action_listeners
1506                    .insert(action.as_any().type_id(), global_listeners);
1507            }
1508        }
1509    }
1510
1511    /// Is there currently something being dragged?
1512    pub fn has_active_drag(&self) -> bool {
1513        self.active_drag.is_some()
1514    }
1515
1516    /// Set the prompt renderer for GPUI. This will replace the default or platform specific
1517    /// prompts with this custom implementation.
1518    pub fn set_prompt_builder(
1519        &mut self,
1520        renderer: impl Fn(
1521            PromptLevel,
1522            &str,
1523            Option<&str>,
1524            &[&str],
1525            PromptHandle,
1526            &mut Window,
1527            &mut App,
1528        ) -> RenderablePromptHandle
1529        + 'static,
1530    ) {
1531        self.prompt_builder = Some(PromptBuilder::Custom(Box::new(renderer)))
1532    }
1533
1534    /// Reset the prompt builder to the default implementation.
1535    pub fn reset_prompt_builder(&mut self) {
1536        self.prompt_builder = Some(PromptBuilder::Default);
1537    }
1538
1539    /// Remove an asset from GPUI's cache
1540    pub fn remove_asset<A: Asset>(&mut self, source: &A::Source) {
1541        let asset_id = (TypeId::of::<A>(), hash(source));
1542        self.loading_assets.remove(&asset_id);
1543    }
1544
1545    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1546    ///
1547    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
1548    /// time, and the results of this call will be cached
1549    pub fn fetch_asset<A: Asset>(&mut self, source: &A::Source) -> (Shared<Task<A::Output>>, bool) {
1550        let asset_id = (TypeId::of::<A>(), hash(source));
1551        let mut is_first = false;
1552        let task = self
1553            .loading_assets
1554            .remove(&asset_id)
1555            .map(|boxed_task| *boxed_task.downcast::<Shared<Task<A::Output>>>().unwrap())
1556            .unwrap_or_else(|| {
1557                is_first = true;
1558                let future = A::load(source.clone(), self);
1559                let task = self.background_executor().spawn(future).shared();
1560                task
1561            });
1562
1563        self.loading_assets.insert(asset_id, Box::new(task.clone()));
1564
1565        (task, is_first)
1566    }
1567
1568    /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
1569    /// for elements rendered within this window.
1570    #[track_caller]
1571    pub fn focus_handle(&self) -> FocusHandle {
1572        FocusHandle::new(&self.focus_handles)
1573    }
1574
1575    /// Tell GPUI that an entity has changed and observers of it should be notified.
1576    pub fn notify(&mut self, entity_id: EntityId) {
1577        let window_invalidators = mem::take(
1578            self.window_invalidators_by_entity
1579                .entry(entity_id)
1580                .or_default(),
1581        );
1582
1583        if window_invalidators.is_empty() {
1584            if self.pending_notifications.insert(entity_id) {
1585                self.pending_effects
1586                    .push_back(Effect::Notify { emitter: entity_id });
1587            }
1588        } else {
1589            for invalidator in window_invalidators.values() {
1590                invalidator.invalidate_view(entity_id, self);
1591            }
1592        }
1593
1594        self.window_invalidators_by_entity
1595            .insert(entity_id, window_invalidators);
1596    }
1597
1598    /// Returns the name for this [`App`].
1599    #[cfg(any(test, feature = "test-support", debug_assertions))]
1600    pub fn get_name(&self) -> Option<&'static str> {
1601        self.name
1602    }
1603
1604    /// Returns `true` if the platform file picker supports selecting a mix of files and directories.
1605    pub fn can_select_mixed_files_and_dirs(&self) -> bool {
1606        self.platform.can_select_mixed_files_and_dirs()
1607    }
1608}
1609
1610impl AppContext for App {
1611    type Result<T> = T;
1612
1613    /// Builds an entity that is owned by the application.
1614    ///
1615    /// The given function will be invoked with a [`Context`] and must return an object representing the entity. An
1616    /// [`Entity`] handle will be returned, which can be used to access the entity in a context.
1617    fn new<T: 'static>(&mut self, build_entity: impl FnOnce(&mut Context<T>) -> T) -> Entity<T> {
1618        self.update(|cx| {
1619            let slot = cx.entities.reserve();
1620            let handle = slot.clone();
1621            let entity = build_entity(&mut Context::new_context(cx, slot.downgrade()));
1622
1623            cx.push_effect(Effect::EntityCreated {
1624                entity: handle.clone().into_any(),
1625                tid: TypeId::of::<T>(),
1626                window: cx.window_update_stack.last().cloned(),
1627            });
1628
1629            cx.entities.insert(slot, entity);
1630            handle
1631        })
1632    }
1633
1634    fn reserve_entity<T: 'static>(&mut self) -> Self::Result<Reservation<T>> {
1635        Reservation(self.entities.reserve())
1636    }
1637
1638    fn insert_entity<T: 'static>(
1639        &mut self,
1640        reservation: Reservation<T>,
1641        build_entity: impl FnOnce(&mut Context<T>) -> T,
1642    ) -> Self::Result<Entity<T>> {
1643        self.update(|cx| {
1644            let slot = reservation.0;
1645            let entity = build_entity(&mut Context::new_context(cx, slot.downgrade()));
1646            cx.entities.insert(slot, entity)
1647        })
1648    }
1649
1650    /// Updates the entity referenced by the given handle. The function is passed a mutable reference to the
1651    /// entity along with a `Context` for the entity.
1652    fn update_entity<T: 'static, R>(
1653        &mut self,
1654        handle: &Entity<T>,
1655        update: impl FnOnce(&mut T, &mut Context<T>) -> R,
1656    ) -> R {
1657        self.update(|cx| {
1658            let mut entity = cx.entities.lease(handle);
1659            let result = update(
1660                &mut entity,
1661                &mut Context::new_context(cx, handle.downgrade()),
1662            );
1663            cx.entities.end_lease(entity);
1664            result
1665        })
1666    }
1667
1668    fn read_entity<T, R>(
1669        &self,
1670        handle: &Entity<T>,
1671        read: impl FnOnce(&T, &App) -> R,
1672    ) -> Self::Result<R>
1673    where
1674        T: 'static,
1675    {
1676        let entity = self.entities.read(handle);
1677        read(entity, self)
1678    }
1679
1680    fn update_window<T, F>(&mut self, handle: AnyWindowHandle, update: F) -> Result<T>
1681    where
1682        F: FnOnce(AnyView, &mut Window, &mut App) -> T,
1683    {
1684        self.update_window_id(handle.id, update)
1685    }
1686
1687    fn read_window<T, R>(
1688        &self,
1689        window: &WindowHandle<T>,
1690        read: impl FnOnce(Entity<T>, &App) -> R,
1691    ) -> Result<R>
1692    where
1693        T: 'static,
1694    {
1695        let window = self
1696            .windows
1697            .get(window.id)
1698            .ok_or_else(|| anyhow!("window not found"))?
1699            .as_ref()
1700            .expect("attempted to read a window that is already on the stack");
1701
1702        let root_view = window.root.clone().unwrap();
1703        let view = root_view
1704            .downcast::<T>()
1705            .map_err(|_| anyhow!("root view's type has changed"))?;
1706
1707        Ok(read(view, self))
1708    }
1709
1710    fn background_spawn<R>(&self, future: impl Future<Output = R> + Send + 'static) -> Task<R>
1711    where
1712        R: Send + 'static,
1713    {
1714        self.background_executor.spawn(future)
1715    }
1716
1717    fn read_global<G, R>(&self, callback: impl FnOnce(&G, &App) -> R) -> Self::Result<R>
1718    where
1719        G: Global,
1720    {
1721        let mut g = self.global::<G>();
1722        callback(&g, self)
1723    }
1724}
1725
1726/// These effects are processed at the end of each application update cycle.
1727pub(crate) enum Effect {
1728    Notify {
1729        emitter: EntityId,
1730    },
1731    Emit {
1732        emitter: EntityId,
1733        event_type: TypeId,
1734        event: Box<dyn Any>,
1735    },
1736    RefreshWindows,
1737    NotifyGlobalObservers {
1738        global_type: TypeId,
1739    },
1740    Defer {
1741        callback: Box<dyn FnOnce(&mut App) + 'static>,
1742    },
1743    EntityCreated {
1744        entity: AnyEntity,
1745        tid: TypeId,
1746        window: Option<WindowId>,
1747    },
1748}
1749
1750impl std::fmt::Debug for Effect {
1751    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1752        match self {
1753            Effect::Notify { emitter } => write!(f, "Notify({})", emitter),
1754            Effect::Emit { emitter, .. } => write!(f, "Emit({:?})", emitter),
1755            Effect::RefreshWindows => write!(f, "RefreshWindows"),
1756            Effect::NotifyGlobalObservers { global_type } => {
1757                write!(f, "NotifyGlobalObservers({:?})", global_type)
1758            }
1759            Effect::Defer { .. } => write!(f, "Defer(..)"),
1760            Effect::EntityCreated { entity, .. } => write!(f, "EntityCreated({:?})", entity),
1761        }
1762    }
1763}
1764
1765/// Wraps a global variable value during `update_global` while the value has been moved to the stack.
1766pub(crate) struct GlobalLease<G: Global> {
1767    global: Box<dyn Any>,
1768    global_type: PhantomData<G>,
1769}
1770
1771impl<G: Global> GlobalLease<G> {
1772    fn new(global: Box<dyn Any>) -> Self {
1773        GlobalLease {
1774            global,
1775            global_type: PhantomData,
1776        }
1777    }
1778}
1779
1780impl<G: Global> Deref for GlobalLease<G> {
1781    type Target = G;
1782
1783    fn deref(&self) -> &Self::Target {
1784        self.global.downcast_ref().unwrap()
1785    }
1786}
1787
1788impl<G: Global> DerefMut for GlobalLease<G> {
1789    fn deref_mut(&mut self) -> &mut Self::Target {
1790        self.global.downcast_mut().unwrap()
1791    }
1792}
1793
1794/// Contains state associated with an active drag operation, started by dragging an element
1795/// within the window or by dragging into the app from the underlying platform.
1796pub struct AnyDrag {
1797    /// The view used to render this drag
1798    pub view: AnyView,
1799
1800    /// The value of the dragged item, to be dropped
1801    pub value: Arc<dyn Any>,
1802
1803    /// This is used to render the dragged item in the same place
1804    /// on the original element that the drag was initiated
1805    pub cursor_offset: Point<Pixels>,
1806}
1807
1808/// Contains state associated with a tooltip. You'll only need this struct if you're implementing
1809/// tooltip behavior on a custom element. Otherwise, use [Div::tooltip].
1810#[derive(Clone)]
1811pub struct AnyTooltip {
1812    /// The view used to display the tooltip
1813    pub view: AnyView,
1814
1815    /// The absolute position of the mouse when the tooltip was deployed.
1816    pub mouse_position: Point<Pixels>,
1817
1818    /// Given the bounds of the tooltip, checks whether the tooltip should still be visible and
1819    /// updates its state accordingly. This is needed atop the hovered element's mouse move handler
1820    /// to handle the case where the element is not painted (e.g. via use of `visible_on_hover`).
1821    pub check_visible_and_update: Rc<dyn Fn(Bounds<Pixels>, &mut Window, &mut App) -> bool>,
1822}
1823
1824/// A keystroke event, and potentially the associated action
1825#[derive(Debug)]
1826pub struct KeystrokeEvent {
1827    /// The keystroke that occurred
1828    pub keystroke: Keystroke,
1829
1830    /// The action that was resolved for the keystroke, if any
1831    pub action: Option<Box<dyn Action>>,
1832}
1833
1834struct NullHttpClient;
1835
1836impl HttpClient for NullHttpClient {
1837    fn send(
1838        &self,
1839        _req: http_client::Request<http_client::AsyncBody>,
1840    ) -> futures::future::BoxFuture<
1841        'static,
1842        Result<http_client::Response<http_client::AsyncBody>, anyhow::Error>,
1843    > {
1844        async move { Err(anyhow!("No HttpClient available")) }.boxed()
1845    }
1846
1847    fn proxy(&self) -> Option<&http_client::Uri> {
1848        None
1849    }
1850
1851    fn type_name(&self) -> &'static str {
1852        type_name::<Self>()
1853    }
1854}