app.rs

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