app.rs

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