1use crate::{
   2    Action, AnyDrag, AnyElement, AnyImageCache, AnyTooltip, AnyView, App, AppContext, Arena, Asset,
   3    AsyncWindowContext, AvailableSpace, Background, BorderStyle, Bounds, BoxShadow, Context,
   4    Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener, DispatchNodeId,
   5    DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, FontId,
   6    Global, GlobalElementId, GlyphId, GpuSpecs, Hsla, InputHandler, IsZero, KeyBinding, KeyContext,
   7    KeyDownEvent, KeyEvent, Keystroke, KeystrokeEvent, LayoutId, LineLayoutIndex, Modifiers,
   8    ModifiersChangedEvent, MonochromeSprite, MouseButton, MouseEvent, MouseMoveEvent, MouseUpEvent,
   9    Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput, PlatformInputHandler,
  10    PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams,
  11    RenderImage, RenderImageParams, RenderSvgParams, Replay, ResizeEdge, SMOOTH_SVG_SCALE_FACTOR,
  12    SUBPIXEL_VARIANTS, ScaledPixels, Scene, Shadow, SharedString, Size, StrikethroughStyle, Style,
  13    SubscriberSet, Subscription, TaffyLayoutEngine, Task, TextStyle, TextStyleRefinement,
  14    TransformationMatrix, Underline, UnderlineStyle, WindowAppearance, WindowBackgroundAppearance,
  15    WindowBounds, WindowControls, WindowDecorations, WindowOptions, WindowParams, WindowTextSystem,
  16    point, prelude::*, px, size, transparent_black,
  17};
  18use anyhow::{Context as _, Result, anyhow};
  19use collections::{FxHashMap, FxHashSet};
  20#[cfg(target_os = "macos")]
  21use core_video::pixel_buffer::CVPixelBuffer;
  22use derive_more::{Deref, DerefMut};
  23use futures::FutureExt;
  24use futures::channel::oneshot;
  25use parking_lot::RwLock;
  26use raw_window_handle::{HandleError, HasWindowHandle};
  27use refineable::Refineable;
  28use slotmap::SlotMap;
  29use smallvec::SmallVec;
  30use std::{
  31    any::{Any, TypeId},
  32    borrow::Cow,
  33    cell::{Cell, RefCell},
  34    cmp,
  35    fmt::{Debug, Display},
  36    hash::{Hash, Hasher},
  37    marker::PhantomData,
  38    mem,
  39    ops::{DerefMut, Range},
  40    rc::Rc,
  41    sync::{
  42        Arc, Weak,
  43        atomic::{AtomicUsize, Ordering::SeqCst},
  44    },
  45    time::{Duration, Instant},
  46};
  47use util::post_inc;
  48use util::{ResultExt, measure};
  49use uuid::Uuid;
  50
  51mod prompts;
  52
  53pub use prompts::*;
  54
  55pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1024.), px(700.));
  56
  57/// Represents the two different phases when dispatching events.
  58#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  59pub enum DispatchPhase {
  60    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  61    /// invoked front to back and keyboard event listeners are invoked from the focused element
  62    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  63    /// registering event listeners.
  64    #[default]
  65    Bubble,
  66    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  67    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  68    /// is used for special purposes such as clearing the "pressed" state for click events. If
  69    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  70    /// outside of the immediate region may rely on detecting non-local events during this phase.
  71    Capture,
  72}
  73
  74impl DispatchPhase {
  75    /// Returns true if this represents the "bubble" phase.
  76    pub fn bubble(self) -> bool {
  77        self == DispatchPhase::Bubble
  78    }
  79
  80    /// Returns true if this represents the "capture" phase.
  81    pub fn capture(self) -> bool {
  82        self == DispatchPhase::Capture
  83    }
  84}
  85
  86struct WindowInvalidatorInner {
  87    pub dirty: bool,
  88    pub draw_phase: DrawPhase,
  89    pub dirty_views: FxHashSet<EntityId>,
  90}
  91
  92#[derive(Clone)]
  93pub(crate) struct WindowInvalidator {
  94    inner: Rc<RefCell<WindowInvalidatorInner>>,
  95}
  96
  97impl WindowInvalidator {
  98    pub fn new() -> Self {
  99        WindowInvalidator {
 100            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 101                dirty: true,
 102                draw_phase: DrawPhase::None,
 103                dirty_views: FxHashSet::default(),
 104            })),
 105        }
 106    }
 107
 108    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 109        let mut inner = self.inner.borrow_mut();
 110        inner.dirty_views.insert(entity);
 111        if inner.draw_phase == DrawPhase::None {
 112            inner.dirty = true;
 113            cx.push_effect(Effect::Notify { emitter: entity });
 114            true
 115        } else {
 116            false
 117        }
 118    }
 119
 120    pub fn is_dirty(&self) -> bool {
 121        self.inner.borrow().dirty
 122    }
 123
 124    pub fn set_dirty(&self, dirty: bool) {
 125        self.inner.borrow_mut().dirty = dirty
 126    }
 127
 128    pub fn set_phase(&self, phase: DrawPhase) {
 129        self.inner.borrow_mut().draw_phase = phase
 130    }
 131
 132    pub fn take_views(&self) -> FxHashSet<EntityId> {
 133        mem::take(&mut self.inner.borrow_mut().dirty_views)
 134    }
 135
 136    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 137        self.inner.borrow_mut().dirty_views = views;
 138    }
 139
 140    pub fn not_drawing(&self) -> bool {
 141        self.inner.borrow().draw_phase == DrawPhase::None
 142    }
 143
 144    #[track_caller]
 145    pub fn debug_assert_paint(&self) {
 146        debug_assert!(
 147            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 148            "this method can only be called during paint"
 149        );
 150    }
 151
 152    #[track_caller]
 153    pub fn debug_assert_prepaint(&self) {
 154        debug_assert!(
 155            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 156            "this method can only be called during request_layout, or prepaint"
 157        );
 158    }
 159
 160    #[track_caller]
 161    pub fn debug_assert_paint_or_prepaint(&self) {
 162        debug_assert!(
 163            matches!(
 164                self.inner.borrow().draw_phase,
 165                DrawPhase::Paint | DrawPhase::Prepaint
 166            ),
 167            "this method can only be called during request_layout, prepaint, or paint"
 168        );
 169    }
 170}
 171
 172type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 173
 174pub(crate) type AnyWindowFocusListener =
 175    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 176
 177pub(crate) struct WindowFocusEvent {
 178    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 179    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 180}
 181
 182impl WindowFocusEvent {
 183    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 184        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 185    }
 186
 187    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 188        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 189    }
 190}
 191
 192/// This is provided when subscribing for `Context::on_focus_out` events.
 193pub struct FocusOutEvent {
 194    /// A weak focus handle representing what was blurred.
 195    pub blurred: WeakFocusHandle,
 196}
 197
 198slotmap::new_key_type! {
 199    /// A globally unique identifier for a focusable element.
 200    pub struct FocusId;
 201}
 202
 203thread_local! {
 204    /// 8MB wasn't quite enough...
 205    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(32 * 1024 * 1024));
 206}
 207
 208pub(crate) type FocusMap = RwLock<SlotMap<FocusId, AtomicUsize>>;
 209
 210impl FocusId {
 211    /// Obtains whether the element associated with this handle is currently focused.
 212    pub fn is_focused(&self, window: &Window) -> bool {
 213        window.focus == Some(*self)
 214    }
 215
 216    /// Obtains whether the element associated with this handle contains the focused
 217    /// element or is itself focused.
 218    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 219        window
 220            .focused(cx)
 221            .map_or(false, |focused| self.contains(focused.id, window))
 222    }
 223
 224    /// Obtains whether the element associated with this handle is contained within the
 225    /// focused element or is itself focused.
 226    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 227        let focused = window.focused(cx);
 228        focused.map_or(false, |focused| focused.id.contains(*self, window))
 229    }
 230
 231    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 232    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 233        window
 234            .rendered_frame
 235            .dispatch_tree
 236            .focus_contains(*self, other)
 237    }
 238}
 239
 240/// A handle which can be used to track and manipulate the focused element in a window.
 241pub struct FocusHandle {
 242    pub(crate) id: FocusId,
 243    handles: Arc<FocusMap>,
 244}
 245
 246impl std::fmt::Debug for FocusHandle {
 247    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 248        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 249    }
 250}
 251
 252impl FocusHandle {
 253    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 254        let id = handles.write().insert(AtomicUsize::new(1));
 255        Self {
 256            id,
 257            handles: handles.clone(),
 258        }
 259    }
 260
 261    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 262        let lock = handles.read();
 263        let ref_count = lock.get(id)?;
 264        if ref_count.load(SeqCst) == 0 {
 265            None
 266        } else {
 267            ref_count.fetch_add(1, SeqCst);
 268            Some(Self {
 269                id,
 270                handles: handles.clone(),
 271            })
 272        }
 273    }
 274
 275    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 276    pub fn downgrade(&self) -> WeakFocusHandle {
 277        WeakFocusHandle {
 278            id: self.id,
 279            handles: Arc::downgrade(&self.handles),
 280        }
 281    }
 282
 283    /// Moves the focus to the element associated with this handle.
 284    pub fn focus(&self, window: &mut Window) {
 285        window.focus(self)
 286    }
 287
 288    /// Obtains whether the element associated with this handle is currently focused.
 289    pub fn is_focused(&self, window: &Window) -> bool {
 290        self.id.is_focused(window)
 291    }
 292
 293    /// Obtains whether the element associated with this handle contains the focused
 294    /// element or is itself focused.
 295    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 296        self.id.contains_focused(window, cx)
 297    }
 298
 299    /// Obtains whether the element associated with this handle is contained within the
 300    /// focused element or is itself focused.
 301    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 302        self.id.within_focused(window, cx)
 303    }
 304
 305    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 306    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 307        self.id.contains(other.id, window)
 308    }
 309
 310    /// Dispatch an action on the element that rendered this focus handle
 311    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 312        if let Some(node_id) = window
 313            .rendered_frame
 314            .dispatch_tree
 315            .focusable_node_id(self.id)
 316        {
 317            window.dispatch_action_on_node(node_id, action, cx)
 318        }
 319    }
 320}
 321
 322impl Clone for FocusHandle {
 323    fn clone(&self) -> Self {
 324        Self::for_id(self.id, &self.handles).unwrap()
 325    }
 326}
 327
 328impl PartialEq for FocusHandle {
 329    fn eq(&self, other: &Self) -> bool {
 330        self.id == other.id
 331    }
 332}
 333
 334impl Eq for FocusHandle {}
 335
 336impl Drop for FocusHandle {
 337    fn drop(&mut self) {
 338        self.handles
 339            .read()
 340            .get(self.id)
 341            .unwrap()
 342            .fetch_sub(1, SeqCst);
 343    }
 344}
 345
 346/// A weak reference to a focus handle.
 347#[derive(Clone, Debug)]
 348pub struct WeakFocusHandle {
 349    pub(crate) id: FocusId,
 350    pub(crate) handles: Weak<FocusMap>,
 351}
 352
 353impl WeakFocusHandle {
 354    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 355    pub fn upgrade(&self) -> Option<FocusHandle> {
 356        let handles = self.handles.upgrade()?;
 357        FocusHandle::for_id(self.id, &handles)
 358    }
 359}
 360
 361impl PartialEq for WeakFocusHandle {
 362    fn eq(&self, other: &WeakFocusHandle) -> bool {
 363        self.id == other.id
 364    }
 365}
 366
 367impl Eq for WeakFocusHandle {}
 368
 369impl PartialEq<FocusHandle> for WeakFocusHandle {
 370    fn eq(&self, other: &FocusHandle) -> bool {
 371        self.id == other.id
 372    }
 373}
 374
 375impl PartialEq<WeakFocusHandle> for FocusHandle {
 376    fn eq(&self, other: &WeakFocusHandle) -> bool {
 377        self.id == other.id
 378    }
 379}
 380
 381/// Focusable allows users of your view to easily
 382/// focus it (using window.focus_view(cx, view))
 383pub trait Focusable: 'static {
 384    /// Returns the focus handle associated with this view.
 385    fn focus_handle(&self, cx: &App) -> FocusHandle;
 386}
 387
 388impl<V: Focusable> Focusable for Entity<V> {
 389    fn focus_handle(&self, cx: &App) -> FocusHandle {
 390        self.read(cx).focus_handle(cx)
 391    }
 392}
 393
 394/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 395/// where the lifecycle of the view is handled by another view.
 396pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 397
 398impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 399
 400/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 401pub struct DismissEvent;
 402
 403type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 404
 405pub(crate) type AnyMouseListener =
 406    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 407
 408#[derive(Clone)]
 409pub(crate) struct CursorStyleRequest {
 410    pub(crate) hitbox_id: Option<HitboxId>, // None represents whole window
 411    pub(crate) style: CursorStyle,
 412}
 413
 414/// An identifier for a [Hitbox].
 415#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 416pub struct HitboxId(usize);
 417
 418impl HitboxId {
 419    /// Checks if the hitbox with this id is currently hovered.
 420    pub fn is_hovered(&self, window: &Window) -> bool {
 421        window.mouse_hit_test.0.contains(self)
 422    }
 423}
 424
 425/// A rectangular region that potentially blocks hitboxes inserted prior.
 426/// See [Window::insert_hitbox] for more details.
 427#[derive(Clone, Debug, Deref)]
 428pub struct Hitbox {
 429    /// A unique identifier for the hitbox.
 430    pub id: HitboxId,
 431    /// The bounds of the hitbox.
 432    #[deref]
 433    pub bounds: Bounds<Pixels>,
 434    /// The content mask when the hitbox was inserted.
 435    pub content_mask: ContentMask<Pixels>,
 436    /// Whether the hitbox occludes other hitboxes inserted prior.
 437    pub opaque: bool,
 438}
 439
 440impl Hitbox {
 441    /// Checks if the hitbox is currently hovered.
 442    pub fn is_hovered(&self, window: &Window) -> bool {
 443        self.id.is_hovered(window)
 444    }
 445}
 446
 447#[derive(Default, Eq, PartialEq)]
 448pub(crate) struct HitTest(SmallVec<[HitboxId; 8]>);
 449
 450/// An identifier for a tooltip.
 451#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 452pub struct TooltipId(usize);
 453
 454impl TooltipId {
 455    /// Checks if the tooltip is currently hovered.
 456    pub fn is_hovered(&self, window: &Window) -> bool {
 457        window
 458            .tooltip_bounds
 459            .as_ref()
 460            .map_or(false, |tooltip_bounds| {
 461                tooltip_bounds.id == *self
 462                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 463            })
 464    }
 465}
 466
 467pub(crate) struct TooltipBounds {
 468    id: TooltipId,
 469    bounds: Bounds<Pixels>,
 470}
 471
 472#[derive(Clone)]
 473pub(crate) struct TooltipRequest {
 474    id: TooltipId,
 475    tooltip: AnyTooltip,
 476}
 477
 478pub(crate) struct DeferredDraw {
 479    current_view: EntityId,
 480    priority: usize,
 481    parent_node: DispatchNodeId,
 482    element_id_stack: SmallVec<[ElementId; 32]>,
 483    text_style_stack: Vec<TextStyleRefinement>,
 484    element: Option<AnyElement>,
 485    absolute_offset: Point<Pixels>,
 486    prepaint_range: Range<PrepaintStateIndex>,
 487    paint_range: Range<PaintIndex>,
 488}
 489
 490pub(crate) struct Frame {
 491    pub(crate) focus: Option<FocusId>,
 492    pub(crate) window_active: bool,
 493    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 494    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 495    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 496    pub(crate) dispatch_tree: DispatchTree,
 497    pub(crate) scene: Scene,
 498    pub(crate) hitboxes: Vec<Hitbox>,
 499    pub(crate) deferred_draws: Vec<DeferredDraw>,
 500    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 501    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 502    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 503    #[cfg(any(test, feature = "test-support"))]
 504    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 505}
 506
 507#[derive(Clone, Default)]
 508pub(crate) struct PrepaintStateIndex {
 509    hitboxes_index: usize,
 510    tooltips_index: usize,
 511    deferred_draws_index: usize,
 512    dispatch_tree_index: usize,
 513    accessed_element_states_index: usize,
 514    line_layout_index: LineLayoutIndex,
 515}
 516
 517#[derive(Clone, Default)]
 518pub(crate) struct PaintIndex {
 519    scene_index: usize,
 520    mouse_listeners_index: usize,
 521    input_handlers_index: usize,
 522    cursor_styles_index: usize,
 523    accessed_element_states_index: usize,
 524    line_layout_index: LineLayoutIndex,
 525}
 526
 527impl Frame {
 528    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 529        Frame {
 530            focus: None,
 531            window_active: false,
 532            element_states: FxHashMap::default(),
 533            accessed_element_states: Vec::new(),
 534            mouse_listeners: Vec::new(),
 535            dispatch_tree,
 536            scene: Scene::default(),
 537            hitboxes: Vec::new(),
 538            deferred_draws: Vec::new(),
 539            input_handlers: Vec::new(),
 540            tooltip_requests: Vec::new(),
 541            cursor_styles: Vec::new(),
 542
 543            #[cfg(any(test, feature = "test-support"))]
 544            debug_bounds: FxHashMap::default(),
 545        }
 546    }
 547
 548    pub(crate) fn clear(&mut self) {
 549        self.element_states.clear();
 550        self.accessed_element_states.clear();
 551        self.mouse_listeners.clear();
 552        self.dispatch_tree.clear();
 553        self.scene.clear();
 554        self.input_handlers.clear();
 555        self.tooltip_requests.clear();
 556        self.cursor_styles.clear();
 557        self.hitboxes.clear();
 558        self.deferred_draws.clear();
 559        self.focus = None;
 560    }
 561
 562    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 563        let mut hit_test = HitTest::default();
 564        for hitbox in self.hitboxes.iter().rev() {
 565            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 566            if bounds.contains(&position) {
 567                hit_test.0.push(hitbox.id);
 568                if hitbox.opaque {
 569                    break;
 570                }
 571            }
 572        }
 573        hit_test
 574    }
 575
 576    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 577        self.focus
 578            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 579            .unwrap_or_default()
 580    }
 581
 582    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 583        for element_state_key in &self.accessed_element_states {
 584            if let Some((element_state_key, element_state)) =
 585                prev_frame.element_states.remove_entry(element_state_key)
 586            {
 587                self.element_states.insert(element_state_key, element_state);
 588            }
 589        }
 590
 591        self.scene.finish();
 592    }
 593}
 594
 595/// Holds the state for a specific window.
 596pub struct Window {
 597    pub(crate) handle: AnyWindowHandle,
 598    pub(crate) invalidator: WindowInvalidator,
 599    pub(crate) removed: bool,
 600    pub(crate) platform_window: Box<dyn PlatformWindow>,
 601    display_id: Option<DisplayId>,
 602    sprite_atlas: Arc<dyn PlatformAtlas>,
 603    text_system: Arc<WindowTextSystem>,
 604    rem_size: Pixels,
 605    /// The stack of override values for the window's rem size.
 606    ///
 607    /// This is used by `with_rem_size` to allow rendering an element tree with
 608    /// a given rem size.
 609    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 610    pub(crate) viewport_size: Size<Pixels>,
 611    layout_engine: Option<TaffyLayoutEngine>,
 612    pub(crate) root: Option<AnyView>,
 613    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 614    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 615    pub(crate) rendered_entity_stack: Vec<EntityId>,
 616    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 617    pub(crate) element_opacity: Option<f32>,
 618    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 619    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 620    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 621    pub(crate) rendered_frame: Frame,
 622    pub(crate) next_frame: Frame,
 623    pub(crate) next_hitbox_id: HitboxId,
 624    pub(crate) next_tooltip_id: TooltipId,
 625    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 626    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 627    pub(crate) dirty_views: FxHashSet<EntityId>,
 628    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 629    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 630    default_prevented: bool,
 631    mouse_position: Point<Pixels>,
 632    mouse_hit_test: HitTest,
 633    modifiers: Modifiers,
 634    scale_factor: f32,
 635    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 636    appearance: WindowAppearance,
 637    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 638    active: Rc<Cell<bool>>,
 639    hovered: Rc<Cell<bool>>,
 640    pub(crate) needs_present: Rc<Cell<bool>>,
 641    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 642    pub(crate) refreshing: bool,
 643    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 644    pub(crate) focus: Option<FocusId>,
 645    focus_enabled: bool,
 646    pending_input: Option<PendingInput>,
 647    pending_modifier: ModifierState,
 648    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 649    prompt: Option<RenderablePromptHandle>,
 650    pub(crate) client_inset: Option<Pixels>,
 651}
 652
 653#[derive(Clone, Debug, Default)]
 654struct ModifierState {
 655    modifiers: Modifiers,
 656    saw_keystroke: bool,
 657}
 658
 659#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 660pub(crate) enum DrawPhase {
 661    None,
 662    Prepaint,
 663    Paint,
 664    Focus,
 665}
 666
 667#[derive(Default, Debug)]
 668struct PendingInput {
 669    keystrokes: SmallVec<[Keystroke; 1]>,
 670    focus: Option<FocusId>,
 671    timer: Option<Task<()>>,
 672}
 673
 674pub(crate) struct ElementStateBox {
 675    pub(crate) inner: Box<dyn Any>,
 676    #[cfg(debug_assertions)]
 677    pub(crate) type_name: &'static str,
 678}
 679
 680fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> Bounds<Pixels> {
 681    const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
 682
 683    // TODO, BUG: if you open a window with the currently active window
 684    // on the stack, this will erroneously select the 'unwrap_or_else'
 685    // code path
 686    cx.active_window()
 687        .and_then(|w| w.update(cx, |_, window, _| window.bounds()).ok())
 688        .map(|mut bounds| {
 689            bounds.origin += DEFAULT_WINDOW_OFFSET;
 690            bounds
 691        })
 692        .unwrap_or_else(|| {
 693            let display = display_id
 694                .map(|id| cx.find_display(id))
 695                .unwrap_or_else(|| cx.primary_display());
 696
 697            display
 698                .map(|display| display.default_bounds())
 699                .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
 700        })
 701}
 702
 703impl Window {
 704    pub(crate) fn new(
 705        handle: AnyWindowHandle,
 706        options: WindowOptions,
 707        cx: &mut App,
 708    ) -> Result<Self> {
 709        let WindowOptions {
 710            window_bounds,
 711            titlebar,
 712            focus,
 713            show,
 714            kind,
 715            is_movable,
 716            display_id,
 717            window_background,
 718            app_id,
 719            window_min_size,
 720            window_decorations,
 721        } = options;
 722
 723        let bounds = window_bounds
 724            .map(|bounds| bounds.get_bounds())
 725            .unwrap_or_else(|| default_bounds(display_id, cx));
 726        let mut platform_window = cx.platform.open_window(
 727            handle,
 728            WindowParams {
 729                bounds,
 730                titlebar,
 731                kind,
 732                is_movable,
 733                focus,
 734                show,
 735                display_id,
 736                window_min_size,
 737            },
 738        )?;
 739        let display_id = platform_window.display().map(|display| display.id());
 740        let sprite_atlas = platform_window.sprite_atlas();
 741        let mouse_position = platform_window.mouse_position();
 742        let modifiers = platform_window.modifiers();
 743        let content_size = platform_window.content_size();
 744        let scale_factor = platform_window.scale_factor();
 745        let appearance = platform_window.appearance();
 746        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
 747        let invalidator = WindowInvalidator::new();
 748        let active = Rc::new(Cell::new(platform_window.is_active()));
 749        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
 750        let needs_present = Rc::new(Cell::new(false));
 751        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
 752        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
 753
 754        platform_window
 755            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
 756        platform_window.set_background_appearance(window_background);
 757
 758        if let Some(ref window_open_state) = window_bounds {
 759            match window_open_state {
 760                WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
 761                WindowBounds::Maximized(_) => platform_window.zoom(),
 762                WindowBounds::Windowed(_) => {}
 763            }
 764        }
 765
 766        platform_window.on_close(Box::new({
 767            let mut cx = cx.to_async();
 768            move || {
 769                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
 770            }
 771        }));
 772        platform_window.on_request_frame(Box::new({
 773            let mut cx = cx.to_async();
 774            let invalidator = invalidator.clone();
 775            let active = active.clone();
 776            let needs_present = needs_present.clone();
 777            let next_frame_callbacks = next_frame_callbacks.clone();
 778            let last_input_timestamp = last_input_timestamp.clone();
 779            move |request_frame_options| {
 780                let next_frame_callbacks = next_frame_callbacks.take();
 781                if !next_frame_callbacks.is_empty() {
 782                    handle
 783                        .update(&mut cx, |_, window, cx| {
 784                            for callback in next_frame_callbacks {
 785                                callback(window, cx);
 786                            }
 787                        })
 788                        .log_err();
 789                }
 790
 791                // Keep presenting the current scene for 1 extra second since the
 792                // last input to prevent the display from underclocking the refresh rate.
 793                let needs_present = request_frame_options.require_presentation
 794                    || needs_present.get()
 795                    || (active.get()
 796                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
 797
 798                if invalidator.is_dirty() {
 799                    measure("frame duration", || {
 800                        handle
 801                            .update(&mut cx, |_, window, cx| {
 802                                window.draw(cx);
 803                                window.present();
 804                            })
 805                            .log_err();
 806                    })
 807                } else if needs_present {
 808                    handle
 809                        .update(&mut cx, |_, window, _| window.present())
 810                        .log_err();
 811                }
 812
 813                handle
 814                    .update(&mut cx, |_, window, _| {
 815                        window.complete_frame();
 816                    })
 817                    .log_err();
 818            }
 819        }));
 820        platform_window.on_resize(Box::new({
 821            let mut cx = cx.to_async();
 822            move |_, _| {
 823                handle
 824                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
 825                    .log_err();
 826            }
 827        }));
 828        platform_window.on_moved(Box::new({
 829            let mut cx = cx.to_async();
 830            move || {
 831                handle
 832                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
 833                    .log_err();
 834            }
 835        }));
 836        platform_window.on_appearance_changed(Box::new({
 837            let mut cx = cx.to_async();
 838            move || {
 839                handle
 840                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
 841                    .log_err();
 842            }
 843        }));
 844        platform_window.on_active_status_change(Box::new({
 845            let mut cx = cx.to_async();
 846            move |active| {
 847                handle
 848                    .update(&mut cx, |_, window, cx| {
 849                        window.active.set(active);
 850                        window.modifiers = window.platform_window.modifiers();
 851                        window
 852                            .activation_observers
 853                            .clone()
 854                            .retain(&(), |callback| callback(window, cx));
 855                        window.refresh();
 856                    })
 857                    .log_err();
 858            }
 859        }));
 860        platform_window.on_hover_status_change(Box::new({
 861            let mut cx = cx.to_async();
 862            move |active| {
 863                handle
 864                    .update(&mut cx, |_, window, _| {
 865                        window.hovered.set(active);
 866                        window.refresh();
 867                    })
 868                    .log_err();
 869            }
 870        }));
 871        platform_window.on_input({
 872            let mut cx = cx.to_async();
 873            Box::new(move |event| {
 874                handle
 875                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
 876                    .log_err()
 877                    .unwrap_or(DispatchEventResult::default())
 878            })
 879        });
 880
 881        if let Some(app_id) = app_id {
 882            platform_window.set_app_id(&app_id);
 883        }
 884
 885        platform_window.map_window().unwrap();
 886
 887        Ok(Window {
 888            handle,
 889            invalidator,
 890            removed: false,
 891            platform_window,
 892            display_id,
 893            sprite_atlas,
 894            text_system,
 895            rem_size: px(16.),
 896            rem_size_override_stack: SmallVec::new(),
 897            viewport_size: content_size,
 898            layout_engine: Some(TaffyLayoutEngine::new()),
 899            root: None,
 900            element_id_stack: SmallVec::default(),
 901            text_style_stack: Vec::new(),
 902            rendered_entity_stack: Vec::new(),
 903            element_offset_stack: Vec::new(),
 904            content_mask_stack: Vec::new(),
 905            element_opacity: None,
 906            requested_autoscroll: None,
 907            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
 908            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
 909            next_frame_callbacks,
 910            next_hitbox_id: HitboxId::default(),
 911            next_tooltip_id: TooltipId::default(),
 912            tooltip_bounds: None,
 913            dirty_views: FxHashSet::default(),
 914            focus_listeners: SubscriberSet::new(),
 915            focus_lost_listeners: SubscriberSet::new(),
 916            default_prevented: true,
 917            mouse_position,
 918            mouse_hit_test: HitTest::default(),
 919            modifiers,
 920            scale_factor,
 921            bounds_observers: SubscriberSet::new(),
 922            appearance,
 923            appearance_observers: SubscriberSet::new(),
 924            active,
 925            hovered,
 926            needs_present,
 927            last_input_timestamp,
 928            refreshing: false,
 929            activation_observers: SubscriberSet::new(),
 930            focus: None,
 931            focus_enabled: true,
 932            pending_input: None,
 933            pending_modifier: ModifierState::default(),
 934            pending_input_observers: SubscriberSet::new(),
 935            prompt: None,
 936            client_inset: None,
 937            image_cache_stack: Vec::new(),
 938        })
 939    }
 940
 941    pub(crate) fn new_focus_listener(
 942        &self,
 943        value: AnyWindowFocusListener,
 944    ) -> (Subscription, impl FnOnce() + use<>) {
 945        self.focus_listeners.insert((), value)
 946    }
 947}
 948
 949#[derive(Clone, Debug, Default, PartialEq, Eq)]
 950pub(crate) struct DispatchEventResult {
 951    pub propagate: bool,
 952    pub default_prevented: bool,
 953}
 954
 955/// Indicates which region of the window is visible. Content falling outside of this mask will not be
 956/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
 957/// to leave room to support more complex shapes in the future.
 958#[derive(Clone, Debug, Default, PartialEq, Eq)]
 959#[repr(C)]
 960pub struct ContentMask<P: Clone + Default + Debug> {
 961    /// The bounds
 962    pub bounds: Bounds<P>,
 963}
 964
 965impl ContentMask<Pixels> {
 966    /// Scale the content mask's pixel units by the given scaling factor.
 967    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
 968        ContentMask {
 969            bounds: self.bounds.scale(factor),
 970        }
 971    }
 972
 973    /// Intersect the content mask with the given content mask.
 974    pub fn intersect(&self, other: &Self) -> Self {
 975        let bounds = self.bounds.intersect(&other.bounds);
 976        ContentMask { bounds }
 977    }
 978}
 979
 980impl Window {
 981    fn mark_view_dirty(&mut self, view_id: EntityId) {
 982        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
 983        // should already be dirty.
 984        for view_id in self
 985            .rendered_frame
 986            .dispatch_tree
 987            .view_path(view_id)
 988            .into_iter()
 989            .rev()
 990        {
 991            if !self.dirty_views.insert(view_id) {
 992                break;
 993            }
 994        }
 995    }
 996
 997    /// Registers a callback to be invoked when the window appearance changes.
 998    pub fn observe_window_appearance(
 999        &self,
1000        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1001    ) -> Subscription {
1002        let (subscription, activate) = self.appearance_observers.insert(
1003            (),
1004            Box::new(move |window, cx| {
1005                callback(window, cx);
1006                true
1007            }),
1008        );
1009        activate();
1010        subscription
1011    }
1012
1013    /// Replaces the root entity of the window with a new one.
1014    pub fn replace_root<E>(
1015        &mut self,
1016        cx: &mut App,
1017        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1018    ) -> Entity<E>
1019    where
1020        E: 'static + Render,
1021    {
1022        let view = cx.new(|cx| build_view(self, cx));
1023        self.root = Some(view.clone().into());
1024        self.refresh();
1025        view
1026    }
1027
1028    /// Returns the root entity of the window, if it has one.
1029    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1030    where
1031        E: 'static + Render,
1032    {
1033        self.root
1034            .as_ref()
1035            .map(|view| view.clone().downcast::<E>().ok())
1036    }
1037
1038    /// Obtain a handle to the window that belongs to this context.
1039    pub fn window_handle(&self) -> AnyWindowHandle {
1040        self.handle
1041    }
1042
1043    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1044    pub fn refresh(&mut self) {
1045        if self.invalidator.not_drawing() {
1046            self.refreshing = true;
1047            self.invalidator.set_dirty(true);
1048        }
1049    }
1050
1051    /// Close this window.
1052    pub fn remove_window(&mut self) {
1053        self.removed = true;
1054    }
1055
1056    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1057    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1058        self.focus
1059            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1060    }
1061
1062    /// Move focus to the element associated with the given [`FocusHandle`].
1063    pub fn focus(&mut self, handle: &FocusHandle) {
1064        if !self.focus_enabled || self.focus == Some(handle.id) {
1065            return;
1066        }
1067
1068        self.focus = Some(handle.id);
1069        self.clear_pending_keystrokes();
1070        self.refresh();
1071    }
1072
1073    /// Remove focus from all elements within this context's window.
1074    pub fn blur(&mut self) {
1075        if !self.focus_enabled {
1076            return;
1077        }
1078
1079        self.focus = None;
1080        self.refresh();
1081    }
1082
1083    /// Blur the window and don't allow anything in it to be focused again.
1084    pub fn disable_focus(&mut self) {
1085        self.blur();
1086        self.focus_enabled = false;
1087    }
1088
1089    /// Accessor for the text system.
1090    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1091        &self.text_system
1092    }
1093
1094    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1095    pub fn text_style(&self) -> TextStyle {
1096        let mut style = TextStyle::default();
1097        for refinement in &self.text_style_stack {
1098            style.refine(refinement);
1099        }
1100        style
1101    }
1102
1103    /// Check if the platform window is maximized
1104    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1105    pub fn is_maximized(&self) -> bool {
1106        self.platform_window.is_maximized()
1107    }
1108
1109    /// request a certain window decoration (Wayland)
1110    pub fn request_decorations(&self, decorations: WindowDecorations) {
1111        self.platform_window.request_decorations(decorations);
1112    }
1113
1114    /// Start a window resize operation (Wayland)
1115    pub fn start_window_resize(&self, edge: ResizeEdge) {
1116        self.platform_window.start_window_resize(edge);
1117    }
1118
1119    /// Return the `WindowBounds` to indicate that how a window should be opened
1120    /// after it has been closed
1121    pub fn window_bounds(&self) -> WindowBounds {
1122        self.platform_window.window_bounds()
1123    }
1124
1125    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1126    pub fn inner_window_bounds(&self) -> WindowBounds {
1127        self.platform_window.inner_window_bounds()
1128    }
1129
1130    /// Dispatch the given action on the currently focused element.
1131    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1132        let focus_handle = self.focused(cx);
1133
1134        let window = self.handle;
1135        cx.defer(move |cx| {
1136            window
1137                .update(cx, |_, window, cx| {
1138                    let node_id = focus_handle
1139                        .and_then(|handle| {
1140                            window
1141                                .rendered_frame
1142                                .dispatch_tree
1143                                .focusable_node_id(handle.id)
1144                        })
1145                        .unwrap_or_else(|| window.rendered_frame.dispatch_tree.root_node_id());
1146
1147                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1148                })
1149                .log_err();
1150        })
1151    }
1152
1153    pub(crate) fn dispatch_keystroke_observers(
1154        &mut self,
1155        event: &dyn Any,
1156        action: Option<Box<dyn Action>>,
1157        context_stack: Vec<KeyContext>,
1158        cx: &mut App,
1159    ) {
1160        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1161            return;
1162        };
1163
1164        cx.keystroke_observers.clone().retain(&(), move |callback| {
1165            (callback)(
1166                &KeystrokeEvent {
1167                    keystroke: key_down_event.keystroke.clone(),
1168                    action: action.as_ref().map(|action| action.boxed_clone()),
1169                    context_stack: context_stack.clone(),
1170                },
1171                self,
1172                cx,
1173            )
1174        });
1175    }
1176
1177    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1178    /// that are currently on the stack to be returned to the app.
1179    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1180        let handle = self.handle;
1181        cx.defer(move |cx| {
1182            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1183        });
1184    }
1185
1186    /// Subscribe to events emitted by a entity.
1187    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1188    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1189    pub fn observe<T: 'static>(
1190        &mut self,
1191        observed: &Entity<T>,
1192        cx: &mut App,
1193        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1194    ) -> Subscription {
1195        let entity_id = observed.entity_id();
1196        let observed = observed.downgrade();
1197        let window_handle = self.handle;
1198        cx.new_observer(
1199            entity_id,
1200            Box::new(move |cx| {
1201                window_handle
1202                    .update(cx, |_, window, cx| {
1203                        if let Some(handle) = observed.upgrade() {
1204                            on_notify(handle, window, cx);
1205                            true
1206                        } else {
1207                            false
1208                        }
1209                    })
1210                    .unwrap_or(false)
1211            }),
1212        )
1213    }
1214
1215    /// Subscribe to events emitted by a entity.
1216    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1217    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1218    pub fn subscribe<Emitter, Evt>(
1219        &mut self,
1220        entity: &Entity<Emitter>,
1221        cx: &mut App,
1222        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1223    ) -> Subscription
1224    where
1225        Emitter: EventEmitter<Evt>,
1226        Evt: 'static,
1227    {
1228        let entity_id = entity.entity_id();
1229        let handle = entity.downgrade();
1230        let window_handle = self.handle;
1231        cx.new_subscription(
1232            entity_id,
1233            (
1234                TypeId::of::<Evt>(),
1235                Box::new(move |event, cx| {
1236                    window_handle
1237                        .update(cx, |_, window, cx| {
1238                            if let Some(entity) = handle.upgrade() {
1239                                let event = event.downcast_ref().expect("invalid event type");
1240                                on_event(entity, event, window, cx);
1241                                true
1242                            } else {
1243                                false
1244                            }
1245                        })
1246                        .unwrap_or(false)
1247                }),
1248            ),
1249        )
1250    }
1251
1252    /// Register a callback to be invoked when the given `Entity` is released.
1253    pub fn observe_release<T>(
1254        &self,
1255        entity: &Entity<T>,
1256        cx: &mut App,
1257        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1258    ) -> Subscription
1259    where
1260        T: 'static,
1261    {
1262        let entity_id = entity.entity_id();
1263        let window_handle = self.handle;
1264        let (subscription, activate) = cx.release_listeners.insert(
1265            entity_id,
1266            Box::new(move |entity, cx| {
1267                let entity = entity.downcast_mut().expect("invalid entity type");
1268                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1269            }),
1270        );
1271        activate();
1272        subscription
1273    }
1274
1275    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1276    /// await points in async code.
1277    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1278        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1279    }
1280
1281    /// Schedule the given closure to be run directly after the current frame is rendered.
1282    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1283        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1284    }
1285
1286    /// Schedule a frame to be drawn on the next animation frame.
1287    ///
1288    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1289    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1290    ///
1291    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1292    pub fn request_animation_frame(&self) {
1293        let entity = self.current_view();
1294        self.on_next_frame(move |_, cx| cx.notify(entity));
1295    }
1296
1297    /// Spawn the future returned by the given closure on the application thread pool.
1298    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1299    /// use within your future.
1300    #[track_caller]
1301    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1302    where
1303        R: 'static,
1304        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1305    {
1306        let handle = self.handle;
1307        cx.spawn(async move |app| {
1308            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1309            f(&mut async_window_cx).await
1310        })
1311    }
1312
1313    fn bounds_changed(&mut self, cx: &mut App) {
1314        self.scale_factor = self.platform_window.scale_factor();
1315        self.viewport_size = self.platform_window.content_size();
1316        self.display_id = self.platform_window.display().map(|display| display.id());
1317
1318        self.refresh();
1319
1320        self.bounds_observers
1321            .clone()
1322            .retain(&(), |callback| callback(self, cx));
1323    }
1324
1325    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1326    pub fn bounds(&self) -> Bounds<Pixels> {
1327        self.platform_window.bounds()
1328    }
1329
1330    /// Set the content size of the window.
1331    pub fn resize(&mut self, size: Size<Pixels>) {
1332        self.platform_window.resize(size);
1333    }
1334
1335    /// Returns whether or not the window is currently fullscreen
1336    pub fn is_fullscreen(&self) -> bool {
1337        self.platform_window.is_fullscreen()
1338    }
1339
1340    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1341        self.appearance = self.platform_window.appearance();
1342
1343        self.appearance_observers
1344            .clone()
1345            .retain(&(), |callback| callback(self, cx));
1346    }
1347
1348    /// Returns the appearance of the current window.
1349    pub fn appearance(&self) -> WindowAppearance {
1350        self.appearance
1351    }
1352
1353    /// Returns the size of the drawable area within the window.
1354    pub fn viewport_size(&self) -> Size<Pixels> {
1355        self.viewport_size
1356    }
1357
1358    /// Returns whether this window is focused by the operating system (receiving key events).
1359    pub fn is_window_active(&self) -> bool {
1360        self.active.get()
1361    }
1362
1363    /// Returns whether this window is considered to be the window
1364    /// that currently owns the mouse cursor.
1365    /// On mac, this is equivalent to `is_window_active`.
1366    pub fn is_window_hovered(&self) -> bool {
1367        if cfg!(any(
1368            target_os = "windows",
1369            target_os = "linux",
1370            target_os = "freebsd"
1371        )) {
1372            self.hovered.get()
1373        } else {
1374            self.is_window_active()
1375        }
1376    }
1377
1378    /// Toggle zoom on the window.
1379    pub fn zoom_window(&self) {
1380        self.platform_window.zoom();
1381    }
1382
1383    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1384    pub fn show_window_menu(&self, position: Point<Pixels>) {
1385        self.platform_window.show_window_menu(position)
1386    }
1387
1388    /// Tells the compositor to take control of window movement (Wayland and X11)
1389    ///
1390    /// Events may not be received during a move operation.
1391    pub fn start_window_move(&self) {
1392        self.platform_window.start_window_move()
1393    }
1394
1395    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1396    pub fn set_client_inset(&mut self, inset: Pixels) {
1397        self.client_inset = Some(inset);
1398        self.platform_window.set_client_inset(inset);
1399    }
1400
1401    /// Returns the client_inset value by [`Self::set_client_inset`].
1402    pub fn client_inset(&self) -> Option<Pixels> {
1403        self.client_inset
1404    }
1405
1406    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1407    pub fn window_decorations(&self) -> Decorations {
1408        self.platform_window.window_decorations()
1409    }
1410
1411    /// Returns which window controls are currently visible (Wayland)
1412    pub fn window_controls(&self) -> WindowControls {
1413        self.platform_window.window_controls()
1414    }
1415
1416    /// Updates the window's title at the platform level.
1417    pub fn set_window_title(&mut self, title: &str) {
1418        self.platform_window.set_title(title);
1419    }
1420
1421    /// Sets the application identifier.
1422    pub fn set_app_id(&mut self, app_id: &str) {
1423        self.platform_window.set_app_id(app_id);
1424    }
1425
1426    /// Sets the window background appearance.
1427    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1428        self.platform_window
1429            .set_background_appearance(background_appearance);
1430    }
1431
1432    /// Mark the window as dirty at the platform level.
1433    pub fn set_window_edited(&mut self, edited: bool) {
1434        self.platform_window.set_edited(edited);
1435    }
1436
1437    /// Determine the display on which the window is visible.
1438    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1439        cx.platform
1440            .displays()
1441            .into_iter()
1442            .find(|display| Some(display.id()) == self.display_id)
1443    }
1444
1445    /// Show the platform character palette.
1446    pub fn show_character_palette(&self) {
1447        self.platform_window.show_character_palette();
1448    }
1449
1450    /// The scale factor of the display associated with the window. For example, it could
1451    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1452    /// be rendered as two pixels on screen.
1453    pub fn scale_factor(&self) -> f32 {
1454        self.scale_factor
1455    }
1456
1457    /// The size of an em for the base font of the application. Adjusting this value allows the
1458    /// UI to scale, just like zooming a web page.
1459    pub fn rem_size(&self) -> Pixels {
1460        self.rem_size_override_stack
1461            .last()
1462            .copied()
1463            .unwrap_or(self.rem_size)
1464    }
1465
1466    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1467    /// UI to scale, just like zooming a web page.
1468    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1469        self.rem_size = rem_size.into();
1470    }
1471
1472    /// Acquire a globally unique identifier for the given ElementId.
1473    /// Only valid for the duration of the provided closure.
1474    pub fn with_global_id<R>(
1475        &mut self,
1476        element_id: ElementId,
1477        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1478    ) -> R {
1479        self.element_id_stack.push(element_id);
1480        let global_id = GlobalElementId(self.element_id_stack.clone());
1481        let result = f(&global_id, self);
1482        self.element_id_stack.pop();
1483        result
1484    }
1485
1486    /// Executes the provided function with the specified rem size.
1487    ///
1488    /// This method must only be called as part of element drawing.
1489    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1490    where
1491        F: FnOnce(&mut Self) -> R,
1492    {
1493        self.invalidator.debug_assert_paint_or_prepaint();
1494
1495        if let Some(rem_size) = rem_size {
1496            self.rem_size_override_stack.push(rem_size.into());
1497            let result = f(self);
1498            self.rem_size_override_stack.pop();
1499            result
1500        } else {
1501            f(self)
1502        }
1503    }
1504
1505    /// The line height associated with the current text style.
1506    pub fn line_height(&self) -> Pixels {
1507        self.text_style().line_height_in_pixels(self.rem_size())
1508    }
1509
1510    /// Call to prevent the default action of an event. Currently only used to prevent
1511    /// parent elements from becoming focused on mouse down.
1512    pub fn prevent_default(&mut self) {
1513        self.default_prevented = true;
1514    }
1515
1516    /// Obtain whether default has been prevented for the event currently being dispatched.
1517    pub fn default_prevented(&self) -> bool {
1518        self.default_prevented
1519    }
1520
1521    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1522    pub fn is_action_available(&self, action: &dyn Action, cx: &mut App) -> bool {
1523        let target = self
1524            .focused(cx)
1525            .and_then(|focused_handle| {
1526                self.rendered_frame
1527                    .dispatch_tree
1528                    .focusable_node_id(focused_handle.id)
1529            })
1530            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
1531        self.rendered_frame
1532            .dispatch_tree
1533            .is_action_available(action, target)
1534    }
1535
1536    /// The position of the mouse relative to the window.
1537    pub fn mouse_position(&self) -> Point<Pixels> {
1538        self.mouse_position
1539    }
1540
1541    /// The current state of the keyboard's modifiers
1542    pub fn modifiers(&self) -> Modifiers {
1543        self.modifiers
1544    }
1545
1546    fn complete_frame(&self) {
1547        self.platform_window.completed_frame();
1548    }
1549
1550    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1551    /// the contents of the new [Scene], use [present].
1552    #[profiling::function]
1553    pub fn draw(&mut self, cx: &mut App) {
1554        self.invalidate_entities();
1555        cx.entities.clear_accessed();
1556        debug_assert!(self.rendered_entity_stack.is_empty());
1557        self.invalidator.set_dirty(false);
1558        self.requested_autoscroll = None;
1559
1560        // Restore the previously-used input handler.
1561        if let Some(input_handler) = self.platform_window.take_input_handler() {
1562            self.rendered_frame.input_handlers.push(Some(input_handler));
1563        }
1564        self.draw_roots(cx);
1565        self.dirty_views.clear();
1566        self.next_frame.window_active = self.active.get();
1567
1568        // Register requested input handler with the platform window.
1569        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
1570            self.platform_window
1571                .set_input_handler(input_handler.unwrap());
1572        }
1573
1574        self.layout_engine.as_mut().unwrap().clear();
1575        self.text_system().finish_frame();
1576        self.next_frame.finish(&mut self.rendered_frame);
1577        ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1578            let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1579            if percentage >= 80. {
1580                log::warn!("elevated element arena occupation: {}.", percentage);
1581            }
1582            element_arena.clear();
1583        });
1584
1585        self.invalidator.set_phase(DrawPhase::Focus);
1586        let previous_focus_path = self.rendered_frame.focus_path();
1587        let previous_window_active = self.rendered_frame.window_active;
1588        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
1589        self.next_frame.clear();
1590        let current_focus_path = self.rendered_frame.focus_path();
1591        let current_window_active = self.rendered_frame.window_active;
1592
1593        if previous_focus_path != current_focus_path
1594            || previous_window_active != current_window_active
1595        {
1596            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1597                self.focus_lost_listeners
1598                    .clone()
1599                    .retain(&(), |listener| listener(self, cx));
1600            }
1601
1602            let event = WindowFocusEvent {
1603                previous_focus_path: if previous_window_active {
1604                    previous_focus_path
1605                } else {
1606                    Default::default()
1607                },
1608                current_focus_path: if current_window_active {
1609                    current_focus_path
1610                } else {
1611                    Default::default()
1612                },
1613            };
1614            self.focus_listeners
1615                .clone()
1616                .retain(&(), |listener| listener(&event, self, cx));
1617        }
1618
1619        debug_assert!(self.rendered_entity_stack.is_empty());
1620        self.record_entities_accessed(cx);
1621        self.reset_cursor_style(cx);
1622        self.refreshing = false;
1623        self.invalidator.set_phase(DrawPhase::None);
1624        self.needs_present.set(true);
1625    }
1626
1627    fn record_entities_accessed(&mut self, cx: &mut App) {
1628        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1629        let mut entities = mem::take(entities_ref.deref_mut());
1630        drop(entities_ref);
1631        let handle = self.handle;
1632        cx.record_entities_accessed(
1633            handle,
1634            // Try moving window invalidator into the Window
1635            self.invalidator.clone(),
1636            &entities,
1637        );
1638        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1639        mem::swap(&mut entities, entities_ref.deref_mut());
1640    }
1641
1642    fn invalidate_entities(&mut self) {
1643        let mut views = self.invalidator.take_views();
1644        for entity in views.drain() {
1645            self.mark_view_dirty(entity);
1646        }
1647        self.invalidator.replace_views(views);
1648    }
1649
1650    #[profiling::function]
1651    fn present(&self) {
1652        self.platform_window.draw(&self.rendered_frame.scene);
1653        self.needs_present.set(false);
1654        profiling::finish_frame!();
1655    }
1656
1657    fn draw_roots(&mut self, cx: &mut App) {
1658        self.invalidator.set_phase(DrawPhase::Prepaint);
1659        self.tooltip_bounds.take();
1660
1661        // Layout all root elements.
1662        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
1663        root_element.prepaint_as_root(Point::default(), self.viewport_size.into(), self, cx);
1664
1665        let mut sorted_deferred_draws =
1666            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1667        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
1668        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
1669
1670        let mut prompt_element = None;
1671        let mut active_drag_element = None;
1672        let mut tooltip_element = None;
1673        if let Some(prompt) = self.prompt.take() {
1674            let mut element = prompt.view.any_view().into_any();
1675            element.prepaint_as_root(Point::default(), self.viewport_size.into(), self, cx);
1676            prompt_element = Some(element);
1677            self.prompt = Some(prompt);
1678        } else if let Some(active_drag) = cx.active_drag.take() {
1679            let mut element = active_drag.view.clone().into_any();
1680            let offset = self.mouse_position() - active_drag.cursor_offset;
1681            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
1682            active_drag_element = Some(element);
1683            cx.active_drag = Some(active_drag);
1684        } else {
1685            tooltip_element = self.prepaint_tooltip(cx);
1686        }
1687
1688        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
1689
1690        // Now actually paint the elements.
1691        self.invalidator.set_phase(DrawPhase::Paint);
1692        root_element.paint(self, cx);
1693
1694        self.paint_deferred_draws(&sorted_deferred_draws, cx);
1695
1696        if let Some(mut prompt_element) = prompt_element {
1697            prompt_element.paint(self, cx);
1698        } else if let Some(mut drag_element) = active_drag_element {
1699            drag_element.paint(self, cx);
1700        } else if let Some(mut tooltip_element) = tooltip_element {
1701            tooltip_element.paint(self, cx);
1702        }
1703    }
1704
1705    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
1706        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
1707        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
1708            let Some(Some(tooltip_request)) = self
1709                .next_frame
1710                .tooltip_requests
1711                .get(tooltip_request_index)
1712                .cloned()
1713            else {
1714                log::error!("Unexpectedly absent TooltipRequest");
1715                continue;
1716            };
1717            let mut element = tooltip_request.tooltip.view.clone().into_any();
1718            let mouse_position = tooltip_request.tooltip.mouse_position;
1719            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
1720
1721            let mut tooltip_bounds =
1722                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1723            let window_bounds = Bounds {
1724                origin: Point::default(),
1725                size: self.viewport_size(),
1726            };
1727
1728            if tooltip_bounds.right() > window_bounds.right() {
1729                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1730                if new_x >= Pixels::ZERO {
1731                    tooltip_bounds.origin.x = new_x;
1732                } else {
1733                    tooltip_bounds.origin.x = cmp::max(
1734                        Pixels::ZERO,
1735                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1736                    );
1737                }
1738            }
1739
1740            if tooltip_bounds.bottom() > window_bounds.bottom() {
1741                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1742                if new_y >= Pixels::ZERO {
1743                    tooltip_bounds.origin.y = new_y;
1744                } else {
1745                    tooltip_bounds.origin.y = cmp::max(
1746                        Pixels::ZERO,
1747                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1748                    );
1749                }
1750            }
1751
1752            // It's possible for an element to have an active tooltip while not being painted (e.g.
1753            // via the `visible_on_hover` method). Since mouse listeners are not active in this
1754            // case, instead update the tooltip's visibility here.
1755            let is_visible =
1756                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
1757            if !is_visible {
1758                continue;
1759            }
1760
1761            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
1762                element.prepaint(window, cx)
1763            });
1764
1765            self.tooltip_bounds = Some(TooltipBounds {
1766                id: tooltip_request.id,
1767                bounds: tooltip_bounds,
1768            });
1769            return Some(element);
1770        }
1771        None
1772    }
1773
1774    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
1775        assert_eq!(self.element_id_stack.len(), 0);
1776
1777        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
1778        for deferred_draw_ix in deferred_draw_indices {
1779            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1780            self.element_id_stack
1781                .clone_from(&deferred_draw.element_id_stack);
1782            self.text_style_stack
1783                .clone_from(&deferred_draw.text_style_stack);
1784            self.next_frame
1785                .dispatch_tree
1786                .set_active_node(deferred_draw.parent_node);
1787
1788            let prepaint_start = self.prepaint_index();
1789            if let Some(element) = deferred_draw.element.as_mut() {
1790                self.with_rendered_view(deferred_draw.current_view, |window| {
1791                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
1792                        element.prepaint(window, cx)
1793                    });
1794                })
1795            } else {
1796                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
1797            }
1798            let prepaint_end = self.prepaint_index();
1799            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
1800        }
1801        assert_eq!(
1802            self.next_frame.deferred_draws.len(),
1803            0,
1804            "cannot call defer_draw during deferred drawing"
1805        );
1806        self.next_frame.deferred_draws = deferred_draws;
1807        self.element_id_stack.clear();
1808        self.text_style_stack.clear();
1809    }
1810
1811    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
1812        assert_eq!(self.element_id_stack.len(), 0);
1813
1814        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
1815        for deferred_draw_ix in deferred_draw_indices {
1816            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1817            self.element_id_stack
1818                .clone_from(&deferred_draw.element_id_stack);
1819            self.next_frame
1820                .dispatch_tree
1821                .set_active_node(deferred_draw.parent_node);
1822
1823            let paint_start = self.paint_index();
1824            if let Some(element) = deferred_draw.element.as_mut() {
1825                self.with_rendered_view(deferred_draw.current_view, |window| {
1826                    element.paint(window, cx);
1827                })
1828            } else {
1829                self.reuse_paint(deferred_draw.paint_range.clone());
1830            }
1831            let paint_end = self.paint_index();
1832            deferred_draw.paint_range = paint_start..paint_end;
1833        }
1834        self.next_frame.deferred_draws = deferred_draws;
1835        self.element_id_stack.clear();
1836    }
1837
1838    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
1839        PrepaintStateIndex {
1840            hitboxes_index: self.next_frame.hitboxes.len(),
1841            tooltips_index: self.next_frame.tooltip_requests.len(),
1842            deferred_draws_index: self.next_frame.deferred_draws.len(),
1843            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
1844            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
1845            line_layout_index: self.text_system.layout_index(),
1846        }
1847    }
1848
1849    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
1850        self.next_frame.hitboxes.extend(
1851            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
1852                .iter()
1853                .cloned(),
1854        );
1855        self.next_frame.tooltip_requests.extend(
1856            self.rendered_frame.tooltip_requests
1857                [range.start.tooltips_index..range.end.tooltips_index]
1858                .iter_mut()
1859                .map(|request| request.take()),
1860        );
1861        self.next_frame.accessed_element_states.extend(
1862            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1863                ..range.end.accessed_element_states_index]
1864                .iter()
1865                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1866        );
1867        self.text_system
1868            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1869
1870        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
1871            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
1872            &mut self.rendered_frame.dispatch_tree,
1873            self.focus,
1874        );
1875
1876        if reused_subtree.contains_focus() {
1877            self.next_frame.focus = self.focus;
1878        }
1879
1880        self.next_frame.deferred_draws.extend(
1881            self.rendered_frame.deferred_draws
1882                [range.start.deferred_draws_index..range.end.deferred_draws_index]
1883                .iter()
1884                .map(|deferred_draw| DeferredDraw {
1885                    current_view: deferred_draw.current_view,
1886                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
1887                    element_id_stack: deferred_draw.element_id_stack.clone(),
1888                    text_style_stack: deferred_draw.text_style_stack.clone(),
1889                    priority: deferred_draw.priority,
1890                    element: None,
1891                    absolute_offset: deferred_draw.absolute_offset,
1892                    prepaint_range: deferred_draw.prepaint_range.clone(),
1893                    paint_range: deferred_draw.paint_range.clone(),
1894                }),
1895        );
1896    }
1897
1898    pub(crate) fn paint_index(&self) -> PaintIndex {
1899        PaintIndex {
1900            scene_index: self.next_frame.scene.len(),
1901            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
1902            input_handlers_index: self.next_frame.input_handlers.len(),
1903            cursor_styles_index: self.next_frame.cursor_styles.len(),
1904            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
1905            line_layout_index: self.text_system.layout_index(),
1906        }
1907    }
1908
1909    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
1910        self.next_frame.cursor_styles.extend(
1911            self.rendered_frame.cursor_styles
1912                [range.start.cursor_styles_index..range.end.cursor_styles_index]
1913                .iter()
1914                .cloned(),
1915        );
1916        self.next_frame.input_handlers.extend(
1917            self.rendered_frame.input_handlers
1918                [range.start.input_handlers_index..range.end.input_handlers_index]
1919                .iter_mut()
1920                .map(|handler| handler.take()),
1921        );
1922        self.next_frame.mouse_listeners.extend(
1923            self.rendered_frame.mouse_listeners
1924                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
1925                .iter_mut()
1926                .map(|listener| listener.take()),
1927        );
1928        self.next_frame.accessed_element_states.extend(
1929            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1930                ..range.end.accessed_element_states_index]
1931                .iter()
1932                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1933        );
1934
1935        self.text_system
1936            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1937        self.next_frame.scene.replay(
1938            range.start.scene_index..range.end.scene_index,
1939            &self.rendered_frame.scene,
1940        );
1941    }
1942
1943    /// Push a text style onto the stack, and call a function with that style active.
1944    /// Use [`Window::text_style`] to get the current, combined text style. This method
1945    /// should only be called as part of element drawing.
1946    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
1947    where
1948        F: FnOnce(&mut Self) -> R,
1949    {
1950        self.invalidator.debug_assert_paint_or_prepaint();
1951        if let Some(style) = style {
1952            self.text_style_stack.push(style);
1953            let result = f(self);
1954            self.text_style_stack.pop();
1955            result
1956        } else {
1957            f(self)
1958        }
1959    }
1960
1961    /// Updates the cursor style at the platform level. This method should only be called
1962    /// during the prepaint phase of element drawing.
1963    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: Option<&Hitbox>) {
1964        self.invalidator.debug_assert_paint();
1965        self.next_frame.cursor_styles.push(CursorStyleRequest {
1966            hitbox_id: hitbox.map(|hitbox| hitbox.id),
1967            style,
1968        });
1969    }
1970
1971    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
1972    /// during the paint phase of element drawing.
1973    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
1974        self.invalidator.debug_assert_prepaint();
1975        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
1976        self.next_frame
1977            .tooltip_requests
1978            .push(Some(TooltipRequest { id, tooltip }));
1979        id
1980    }
1981
1982    /// Invoke the given function with the given content mask after intersecting it
1983    /// with the current mask. This method should only be called during element drawing.
1984    pub fn with_content_mask<R>(
1985        &mut self,
1986        mask: Option<ContentMask<Pixels>>,
1987        f: impl FnOnce(&mut Self) -> R,
1988    ) -> R {
1989        self.invalidator.debug_assert_paint_or_prepaint();
1990        if let Some(mask) = mask {
1991            let mask = mask.intersect(&self.content_mask());
1992            self.content_mask_stack.push(mask);
1993            let result = f(self);
1994            self.content_mask_stack.pop();
1995            result
1996        } else {
1997            f(self)
1998        }
1999    }
2000
2001    /// Updates the global element offset relative to the current offset. This is used to implement
2002    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2003    pub fn with_element_offset<R>(
2004        &mut self,
2005        offset: Point<Pixels>,
2006        f: impl FnOnce(&mut Self) -> R,
2007    ) -> R {
2008        self.invalidator.debug_assert_prepaint();
2009
2010        if offset.is_zero() {
2011            return f(self);
2012        };
2013
2014        let abs_offset = self.element_offset() + offset;
2015        self.with_absolute_element_offset(abs_offset, f)
2016    }
2017
2018    /// Updates the global element offset based on the given offset. This is used to implement
2019    /// drag handles and other manual painting of elements. This method should only be called during
2020    /// the prepaint phase of element drawing.
2021    pub fn with_absolute_element_offset<R>(
2022        &mut self,
2023        offset: Point<Pixels>,
2024        f: impl FnOnce(&mut Self) -> R,
2025    ) -> R {
2026        self.invalidator.debug_assert_prepaint();
2027        self.element_offset_stack.push(offset);
2028        let result = f(self);
2029        self.element_offset_stack.pop();
2030        result
2031    }
2032
2033    pub(crate) fn with_element_opacity<R>(
2034        &mut self,
2035        opacity: Option<f32>,
2036        f: impl FnOnce(&mut Self) -> R,
2037    ) -> R {
2038        if opacity.is_none() {
2039            return f(self);
2040        }
2041
2042        self.invalidator.debug_assert_paint_or_prepaint();
2043        self.element_opacity = opacity;
2044        let result = f(self);
2045        self.element_opacity = None;
2046        result
2047    }
2048
2049    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2050    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2051    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2052    /// element offset and prepaint again. See [`List`] for an example. This method should only be
2053    /// called during the prepaint phase of element drawing.
2054    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2055        self.invalidator.debug_assert_prepaint();
2056        let index = self.prepaint_index();
2057        let result = f(self);
2058        if result.is_err() {
2059            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2060            self.next_frame
2061                .tooltip_requests
2062                .truncate(index.tooltips_index);
2063            self.next_frame
2064                .deferred_draws
2065                .truncate(index.deferred_draws_index);
2066            self.next_frame
2067                .dispatch_tree
2068                .truncate(index.dispatch_tree_index);
2069            self.next_frame
2070                .accessed_element_states
2071                .truncate(index.accessed_element_states_index);
2072            self.text_system.truncate_layouts(index.line_layout_index);
2073        }
2074        result
2075    }
2076
2077    /// When you call this method during [`prepaint`], containing elements will attempt to
2078    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2079    /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
2080    /// that supports this method being called on the elements it contains. This method should only be
2081    /// called during the prepaint phase of element drawing.
2082    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2083        self.invalidator.debug_assert_prepaint();
2084        self.requested_autoscroll = Some(bounds);
2085    }
2086
2087    /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
2088    /// described in [`request_autoscroll`].
2089    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2090        self.invalidator.debug_assert_prepaint();
2091        self.requested_autoscroll.take()
2092    }
2093
2094    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2095    /// Your view will be re-drawn once the asset has finished loading.
2096    ///
2097    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2098    /// time.
2099    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2100        let (task, is_first) = cx.fetch_asset::<A>(source);
2101        task.clone().now_or_never().or_else(|| {
2102            if is_first {
2103                let entity = self.current_view();
2104                self.spawn(cx, {
2105                    let task = task.clone();
2106                    async move |cx| {
2107                        task.await;
2108
2109                        cx.on_next_frame(move |_, cx| {
2110                            cx.notify(entity);
2111                        });
2112                    }
2113                })
2114                .detach();
2115            }
2116
2117            None
2118        })
2119    }
2120    /// Obtain the current element offset. This method should only be called during the
2121    /// prepaint phase of element drawing.
2122    pub fn element_offset(&self) -> Point<Pixels> {
2123        self.invalidator.debug_assert_prepaint();
2124        self.element_offset_stack
2125            .last()
2126            .copied()
2127            .unwrap_or_default()
2128    }
2129
2130    /// Obtain the current element opacity. This method should only be called during the
2131    /// prepaint phase of element drawing.
2132    pub(crate) fn element_opacity(&self) -> f32 {
2133        self.invalidator.debug_assert_paint_or_prepaint();
2134        self.element_opacity.unwrap_or(1.0)
2135    }
2136
2137    /// Obtain the current content mask. This method should only be called during element drawing.
2138    pub fn content_mask(&self) -> ContentMask<Pixels> {
2139        self.invalidator.debug_assert_paint_or_prepaint();
2140        self.content_mask_stack
2141            .last()
2142            .cloned()
2143            .unwrap_or_else(|| ContentMask {
2144                bounds: Bounds {
2145                    origin: Point::default(),
2146                    size: self.viewport_size,
2147                },
2148            })
2149    }
2150
2151    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2152    /// This can be used within a custom element to distinguish multiple sets of child elements.
2153    pub fn with_element_namespace<R>(
2154        &mut self,
2155        element_id: impl Into<ElementId>,
2156        f: impl FnOnce(&mut Self) -> R,
2157    ) -> R {
2158        self.element_id_stack.push(element_id.into());
2159        let result = f(self);
2160        self.element_id_stack.pop();
2161        result
2162    }
2163
2164    /// Updates or initializes state for an element with the given id that lives across multiple
2165    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2166    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2167    /// when drawing the next frame. This method should only be called as part of element drawing.
2168    pub fn with_element_state<S, R>(
2169        &mut self,
2170        global_id: &GlobalElementId,
2171        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2172    ) -> R
2173    where
2174        S: 'static,
2175    {
2176        self.invalidator.debug_assert_paint_or_prepaint();
2177
2178        let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2179        self.next_frame
2180            .accessed_element_states
2181            .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2182
2183        if let Some(any) = self
2184            .next_frame
2185            .element_states
2186            .remove(&key)
2187            .or_else(|| self.rendered_frame.element_states.remove(&key))
2188        {
2189            let ElementStateBox {
2190                inner,
2191                #[cfg(debug_assertions)]
2192                type_name,
2193            } = any;
2194            // Using the extra inner option to avoid needing to reallocate a new box.
2195            let mut state_box = inner
2196                .downcast::<Option<S>>()
2197                .map_err(|_| {
2198                    #[cfg(debug_assertions)]
2199                    {
2200                        anyhow::anyhow!(
2201                            "invalid element state type for id, requested {:?}, actual: {:?}",
2202                            std::any::type_name::<S>(),
2203                            type_name
2204                        )
2205                    }
2206
2207                    #[cfg(not(debug_assertions))]
2208                    {
2209                        anyhow::anyhow!(
2210                            "invalid element state type for id, requested {:?}",
2211                            std::any::type_name::<S>(),
2212                        )
2213                    }
2214                })
2215                .unwrap();
2216
2217            let state = state_box.take().expect(
2218                "reentrant call to with_element_state for the same state type and element id",
2219            );
2220            let (result, state) = f(Some(state), self);
2221            state_box.replace(state);
2222            self.next_frame.element_states.insert(
2223                key,
2224                ElementStateBox {
2225                    inner: state_box,
2226                    #[cfg(debug_assertions)]
2227                    type_name,
2228                },
2229            );
2230            result
2231        } else {
2232            let (result, state) = f(None, self);
2233            self.next_frame.element_states.insert(
2234                key,
2235                ElementStateBox {
2236                    inner: Box::new(Some(state)),
2237                    #[cfg(debug_assertions)]
2238                    type_name: std::any::type_name::<S>(),
2239                },
2240            );
2241            result
2242        }
2243    }
2244
2245    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2246    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2247    /// when the element is guaranteed to have an id.
2248    ///
2249    /// The first option means 'no ID provided'
2250    /// The second option means 'not yet initialized'
2251    pub fn with_optional_element_state<S, R>(
2252        &mut self,
2253        global_id: Option<&GlobalElementId>,
2254        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2255    ) -> R
2256    where
2257        S: 'static,
2258    {
2259        self.invalidator.debug_assert_paint_or_prepaint();
2260
2261        if let Some(global_id) = global_id {
2262            self.with_element_state(global_id, |state, cx| {
2263                let (result, state) = f(Some(state), cx);
2264                let state =
2265                    state.expect("you must return some state when you pass some element id");
2266                (result, state)
2267            })
2268        } else {
2269            let (result, state) = f(None, self);
2270            debug_assert!(
2271                state.is_none(),
2272                "you must not return an element state when passing None for the global id"
2273            );
2274            result
2275        }
2276    }
2277
2278    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2279    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2280    /// with higher values being drawn on top.
2281    ///
2282    /// This method should only be called as part of the prepaint phase of element drawing.
2283    pub fn defer_draw(
2284        &mut self,
2285        element: AnyElement,
2286        absolute_offset: Point<Pixels>,
2287        priority: usize,
2288    ) {
2289        self.invalidator.debug_assert_prepaint();
2290        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2291        self.next_frame.deferred_draws.push(DeferredDraw {
2292            current_view: self.current_view(),
2293            parent_node,
2294            element_id_stack: self.element_id_stack.clone(),
2295            text_style_stack: self.text_style_stack.clone(),
2296            priority,
2297            element: Some(element),
2298            absolute_offset,
2299            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2300            paint_range: PaintIndex::default()..PaintIndex::default(),
2301        });
2302    }
2303
2304    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2305    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2306    /// for performance reasons.
2307    ///
2308    /// This method should only be called as part of the paint phase of element drawing.
2309    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2310        self.invalidator.debug_assert_paint();
2311
2312        let scale_factor = self.scale_factor();
2313        let content_mask = self.content_mask();
2314        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2315        if !clipped_bounds.is_empty() {
2316            self.next_frame
2317                .scene
2318                .push_layer(clipped_bounds.scale(scale_factor));
2319        }
2320
2321        let result = f(self);
2322
2323        if !clipped_bounds.is_empty() {
2324            self.next_frame.scene.pop_layer();
2325        }
2326
2327        result
2328    }
2329
2330    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2331    ///
2332    /// This method should only be called as part of the paint phase of element drawing.
2333    pub fn paint_shadows(
2334        &mut self,
2335        bounds: Bounds<Pixels>,
2336        corner_radii: Corners<Pixels>,
2337        shadows: &[BoxShadow],
2338    ) {
2339        self.invalidator.debug_assert_paint();
2340
2341        let scale_factor = self.scale_factor();
2342        let content_mask = self.content_mask();
2343        let opacity = self.element_opacity();
2344        for shadow in shadows {
2345            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2346            self.next_frame.scene.insert_primitive(Shadow {
2347                order: 0,
2348                blur_radius: shadow.blur_radius.scale(scale_factor),
2349                bounds: shadow_bounds.scale(scale_factor),
2350                content_mask: content_mask.scale(scale_factor),
2351                corner_radii: corner_radii.scale(scale_factor),
2352                color: shadow.color.opacity(opacity),
2353            });
2354        }
2355    }
2356
2357    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2358    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2359    /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2360    ///
2361    /// This method should only be called as part of the paint phase of element drawing.
2362    ///
2363    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2364    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2365    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2366    pub fn paint_quad(&mut self, quad: PaintQuad) {
2367        self.invalidator.debug_assert_paint();
2368
2369        let scale_factor = self.scale_factor();
2370        let content_mask = self.content_mask();
2371        let opacity = self.element_opacity();
2372        self.next_frame.scene.insert_primitive(Quad {
2373            order: 0,
2374            bounds: quad.bounds.scale(scale_factor),
2375            content_mask: content_mask.scale(scale_factor),
2376            background: quad.background.opacity(opacity),
2377            border_color: quad.border_color.opacity(opacity),
2378            corner_radii: quad.corner_radii.scale(scale_factor),
2379            border_widths: quad.border_widths.scale(scale_factor),
2380            border_style: quad.border_style,
2381        });
2382    }
2383
2384    /// Paint the given `Path` into the scene for the next frame at the current z-index.
2385    ///
2386    /// This method should only be called as part of the paint phase of element drawing.
2387    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2388        self.invalidator.debug_assert_paint();
2389
2390        let scale_factor = self.scale_factor();
2391        let content_mask = self.content_mask();
2392        let opacity = self.element_opacity();
2393        path.content_mask = content_mask;
2394        let color: Background = color.into();
2395        path.color = color.opacity(opacity);
2396        self.next_frame
2397            .scene
2398            .insert_primitive(path.scale(scale_factor));
2399    }
2400
2401    /// Paint an underline into the scene for the next frame at the current z-index.
2402    ///
2403    /// This method should only be called as part of the paint phase of element drawing.
2404    pub fn paint_underline(
2405        &mut self,
2406        origin: Point<Pixels>,
2407        width: Pixels,
2408        style: &UnderlineStyle,
2409    ) {
2410        self.invalidator.debug_assert_paint();
2411
2412        let scale_factor = self.scale_factor();
2413        let height = if style.wavy {
2414            style.thickness * 3.
2415        } else {
2416            style.thickness
2417        };
2418        let bounds = Bounds {
2419            origin,
2420            size: size(width, height),
2421        };
2422        let content_mask = self.content_mask();
2423        let element_opacity = self.element_opacity();
2424
2425        self.next_frame.scene.insert_primitive(Underline {
2426            order: 0,
2427            pad: 0,
2428            bounds: bounds.scale(scale_factor),
2429            content_mask: content_mask.scale(scale_factor),
2430            color: style.color.unwrap_or_default().opacity(element_opacity),
2431            thickness: style.thickness.scale(scale_factor),
2432            wavy: style.wavy,
2433        });
2434    }
2435
2436    /// Paint a strikethrough into the scene for the next frame at the current z-index.
2437    ///
2438    /// This method should only be called as part of the paint phase of element drawing.
2439    pub fn paint_strikethrough(
2440        &mut self,
2441        origin: Point<Pixels>,
2442        width: Pixels,
2443        style: &StrikethroughStyle,
2444    ) {
2445        self.invalidator.debug_assert_paint();
2446
2447        let scale_factor = self.scale_factor();
2448        let height = style.thickness;
2449        let bounds = Bounds {
2450            origin,
2451            size: size(width, height),
2452        };
2453        let content_mask = self.content_mask();
2454        let opacity = self.element_opacity();
2455
2456        self.next_frame.scene.insert_primitive(Underline {
2457            order: 0,
2458            pad: 0,
2459            bounds: bounds.scale(scale_factor),
2460            content_mask: content_mask.scale(scale_factor),
2461            thickness: style.thickness.scale(scale_factor),
2462            color: style.color.unwrap_or_default().opacity(opacity),
2463            wavy: false,
2464        });
2465    }
2466
2467    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2468    ///
2469    /// The y component of the origin is the baseline of the glyph.
2470    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2471    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2472    /// This method is only useful if you need to paint a single glyph that has already been shaped.
2473    ///
2474    /// This method should only be called as part of the paint phase of element drawing.
2475    pub fn paint_glyph(
2476        &mut self,
2477        origin: Point<Pixels>,
2478        font_id: FontId,
2479        glyph_id: GlyphId,
2480        font_size: Pixels,
2481        color: Hsla,
2482    ) -> Result<()> {
2483        self.invalidator.debug_assert_paint();
2484
2485        let element_opacity = self.element_opacity();
2486        let scale_factor = self.scale_factor();
2487        let glyph_origin = origin.scale(scale_factor);
2488        let subpixel_variant = Point {
2489            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2490            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2491        };
2492        let params = RenderGlyphParams {
2493            font_id,
2494            glyph_id,
2495            font_size,
2496            subpixel_variant,
2497            scale_factor,
2498            is_emoji: false,
2499        };
2500
2501        let raster_bounds = self.text_system().raster_bounds(&params)?;
2502        if !raster_bounds.is_zero() {
2503            let tile = self
2504                .sprite_atlas
2505                .get_or_insert_with(&params.clone().into(), &mut || {
2506                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2507                    Ok(Some((size, Cow::Owned(bytes))))
2508                })?
2509                .expect("Callback above only errors or returns Some");
2510            let bounds = Bounds {
2511                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2512                size: tile.bounds.size.map(Into::into),
2513            };
2514            let content_mask = self.content_mask().scale(scale_factor);
2515            self.next_frame.scene.insert_primitive(MonochromeSprite {
2516                order: 0,
2517                pad: 0,
2518                bounds,
2519                content_mask,
2520                color: color.opacity(element_opacity),
2521                tile,
2522                transformation: TransformationMatrix::unit(),
2523            });
2524        }
2525        Ok(())
2526    }
2527
2528    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2529    ///
2530    /// The y component of the origin is the baseline of the glyph.
2531    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2532    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2533    /// This method is only useful if you need to paint a single emoji that has already been shaped.
2534    ///
2535    /// This method should only be called as part of the paint phase of element drawing.
2536    pub fn paint_emoji(
2537        &mut self,
2538        origin: Point<Pixels>,
2539        font_id: FontId,
2540        glyph_id: GlyphId,
2541        font_size: Pixels,
2542    ) -> Result<()> {
2543        self.invalidator.debug_assert_paint();
2544
2545        let scale_factor = self.scale_factor();
2546        let glyph_origin = origin.scale(scale_factor);
2547        let params = RenderGlyphParams {
2548            font_id,
2549            glyph_id,
2550            font_size,
2551            // We don't render emojis with subpixel variants.
2552            subpixel_variant: Default::default(),
2553            scale_factor,
2554            is_emoji: true,
2555        };
2556
2557        let raster_bounds = self.text_system().raster_bounds(&params)?;
2558        if !raster_bounds.is_zero() {
2559            let tile = self
2560                .sprite_atlas
2561                .get_or_insert_with(&params.clone().into(), &mut || {
2562                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2563                    Ok(Some((size, Cow::Owned(bytes))))
2564                })?
2565                .expect("Callback above only errors or returns Some");
2566
2567            let bounds = Bounds {
2568                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2569                size: tile.bounds.size.map(Into::into),
2570            };
2571            let content_mask = self.content_mask().scale(scale_factor);
2572            let opacity = self.element_opacity();
2573
2574            self.next_frame.scene.insert_primitive(PolychromeSprite {
2575                order: 0,
2576                pad: 0,
2577                grayscale: false,
2578                bounds,
2579                corner_radii: Default::default(),
2580                content_mask,
2581                tile,
2582                opacity,
2583            });
2584        }
2585        Ok(())
2586    }
2587
2588    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2589    ///
2590    /// This method should only be called as part of the paint phase of element drawing.
2591    pub fn paint_svg(
2592        &mut self,
2593        bounds: Bounds<Pixels>,
2594        path: SharedString,
2595        transformation: TransformationMatrix,
2596        color: Hsla,
2597        cx: &App,
2598    ) -> Result<()> {
2599        self.invalidator.debug_assert_paint();
2600
2601        let element_opacity = self.element_opacity();
2602        let scale_factor = self.scale_factor();
2603        let bounds = bounds.scale(scale_factor);
2604        let params = RenderSvgParams {
2605            path,
2606            size: bounds.size.map(|pixels| {
2607                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
2608            }),
2609        };
2610
2611        let Some(tile) =
2612            self.sprite_atlas
2613                .get_or_insert_with(&params.clone().into(), &mut || {
2614                    let Some(bytes) = cx.svg_renderer.render(&params)? else {
2615                        return Ok(None);
2616                    };
2617                    Ok(Some((params.size, Cow::Owned(bytes))))
2618                })?
2619        else {
2620            return Ok(());
2621        };
2622        let content_mask = self.content_mask().scale(scale_factor);
2623
2624        self.next_frame.scene.insert_primitive(MonochromeSprite {
2625            order: 0,
2626            pad: 0,
2627            bounds: bounds
2628                .map_origin(|origin| origin.floor())
2629                .map_size(|size| size.ceil()),
2630            content_mask,
2631            color: color.opacity(element_opacity),
2632            tile,
2633            transformation,
2634        });
2635
2636        Ok(())
2637    }
2638
2639    /// Paint an image into the scene for the next frame at the current z-index.
2640    /// This method will panic if the frame_index is not valid
2641    ///
2642    /// This method should only be called as part of the paint phase of element drawing.
2643    pub fn paint_image(
2644        &mut self,
2645        bounds: Bounds<Pixels>,
2646        corner_radii: Corners<Pixels>,
2647        data: Arc<RenderImage>,
2648        frame_index: usize,
2649        grayscale: bool,
2650    ) -> Result<()> {
2651        self.invalidator.debug_assert_paint();
2652
2653        let scale_factor = self.scale_factor();
2654        let bounds = bounds.scale(scale_factor);
2655        let params = RenderImageParams {
2656            image_id: data.id,
2657            frame_index,
2658        };
2659
2660        let tile = self
2661            .sprite_atlas
2662            .get_or_insert_with(&params.clone().into(), &mut || {
2663                Ok(Some((
2664                    data.size(frame_index),
2665                    Cow::Borrowed(
2666                        data.as_bytes(frame_index)
2667                            .expect("It's the caller's job to pass a valid frame index"),
2668                    ),
2669                )))
2670            })?
2671            .expect("Callback above only returns Some");
2672        let content_mask = self.content_mask().scale(scale_factor);
2673        let corner_radii = corner_radii.scale(scale_factor);
2674        let opacity = self.element_opacity();
2675
2676        self.next_frame.scene.insert_primitive(PolychromeSprite {
2677            order: 0,
2678            pad: 0,
2679            grayscale,
2680            bounds: bounds
2681                .map_origin(|origin| origin.floor())
2682                .map_size(|size| size.ceil()),
2683            content_mask,
2684            corner_radii,
2685            tile,
2686            opacity,
2687        });
2688        Ok(())
2689    }
2690
2691    /// Paint a surface into the scene for the next frame at the current z-index.
2692    ///
2693    /// This method should only be called as part of the paint phase of element drawing.
2694    #[cfg(target_os = "macos")]
2695    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
2696        use crate::PaintSurface;
2697
2698        self.invalidator.debug_assert_paint();
2699
2700        let scale_factor = self.scale_factor();
2701        let bounds = bounds.scale(scale_factor);
2702        let content_mask = self.content_mask().scale(scale_factor);
2703        self.next_frame.scene.insert_primitive(PaintSurface {
2704            order: 0,
2705            bounds,
2706            content_mask,
2707            image_buffer,
2708        });
2709    }
2710
2711    /// Removes an image from the sprite atlas.
2712    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2713        for frame_index in 0..data.frame_count() {
2714            let params = RenderImageParams {
2715                image_id: data.id,
2716                frame_index,
2717            };
2718
2719            self.sprite_atlas.remove(&params.clone().into());
2720        }
2721
2722        Ok(())
2723    }
2724
2725    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2726    /// layout is being requested, along with the layout ids of any children. This method is called during
2727    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2728    ///
2729    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2730    #[must_use]
2731    pub fn request_layout(
2732        &mut self,
2733        style: Style,
2734        children: impl IntoIterator<Item = LayoutId>,
2735        cx: &mut App,
2736    ) -> LayoutId {
2737        self.invalidator.debug_assert_prepaint();
2738
2739        cx.layout_id_buffer.clear();
2740        cx.layout_id_buffer.extend(children);
2741        let rem_size = self.rem_size();
2742
2743        self.layout_engine
2744            .as_mut()
2745            .unwrap()
2746            .request_layout(style, rem_size, &cx.layout_id_buffer)
2747    }
2748
2749    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
2750    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
2751    /// determine the element's size. One place this is used internally is when measuring text.
2752    ///
2753    /// The given closure is invoked at layout time with the known dimensions and available space and
2754    /// returns a `Size`.
2755    ///
2756    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2757    pub fn request_measured_layout<
2758        F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
2759            + 'static,
2760    >(
2761        &mut self,
2762        style: Style,
2763        measure: F,
2764    ) -> LayoutId {
2765        self.invalidator.debug_assert_prepaint();
2766
2767        let rem_size = self.rem_size();
2768        self.layout_engine
2769            .as_mut()
2770            .unwrap()
2771            .request_measured_layout(style, rem_size, measure)
2772    }
2773
2774    /// Compute the layout for the given id within the given available space.
2775    /// This method is called for its side effect, typically by the framework prior to painting.
2776    /// After calling it, you can request the bounds of the given layout node id or any descendant.
2777    ///
2778    /// This method should only be called as part of the prepaint phase of element drawing.
2779    pub fn compute_layout(
2780        &mut self,
2781        layout_id: LayoutId,
2782        available_space: Size<AvailableSpace>,
2783        cx: &mut App,
2784    ) {
2785        self.invalidator.debug_assert_prepaint();
2786
2787        let mut layout_engine = self.layout_engine.take().unwrap();
2788        layout_engine.compute_layout(layout_id, available_space, self, cx);
2789        self.layout_engine = Some(layout_engine);
2790    }
2791
2792    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
2793    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
2794    ///
2795    /// This method should only be called as part of element drawing.
2796    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
2797        self.invalidator.debug_assert_prepaint();
2798
2799        let mut bounds = self
2800            .layout_engine
2801            .as_mut()
2802            .unwrap()
2803            .layout_bounds(layout_id)
2804            .map(Into::into);
2805        bounds.origin += self.element_offset();
2806        bounds
2807    }
2808
2809    /// This method should be called during `prepaint`. You can use
2810    /// the returned [Hitbox] during `paint` or in an event handler
2811    /// to determine whether the inserted hitbox was the topmost.
2812    ///
2813    /// This method should only be called as part of the prepaint phase of element drawing.
2814    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, opaque: bool) -> Hitbox {
2815        self.invalidator.debug_assert_prepaint();
2816
2817        let content_mask = self.content_mask();
2818        let id = self.next_hitbox_id;
2819        self.next_hitbox_id.0 += 1;
2820        let hitbox = Hitbox {
2821            id,
2822            bounds,
2823            content_mask,
2824            opaque,
2825        };
2826        self.next_frame.hitboxes.push(hitbox.clone());
2827        hitbox
2828    }
2829
2830    /// Sets the key context for the current element. This context will be used to translate
2831    /// keybindings into actions.
2832    ///
2833    /// This method should only be called as part of the paint phase of element drawing.
2834    pub fn set_key_context(&mut self, context: KeyContext) {
2835        self.invalidator.debug_assert_paint();
2836        self.next_frame.dispatch_tree.set_key_context(context);
2837    }
2838
2839    /// Sets the focus handle for the current element. This handle will be used to manage focus state
2840    /// and keyboard event dispatch for the element.
2841    ///
2842    /// This method should only be called as part of the prepaint phase of element drawing.
2843    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
2844        self.invalidator.debug_assert_prepaint();
2845        if focus_handle.is_focused(self) {
2846            self.next_frame.focus = Some(focus_handle.id);
2847        }
2848        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
2849    }
2850
2851    /// Sets the view id for the current element, which will be used to manage view caching.
2852    ///
2853    /// This method should only be called as part of element prepaint. We plan on removing this
2854    /// method eventually when we solve some issues that require us to construct editor elements
2855    /// directly instead of always using editors via views.
2856    pub fn set_view_id(&mut self, view_id: EntityId) {
2857        self.invalidator.debug_assert_prepaint();
2858        self.next_frame.dispatch_tree.set_view_id(view_id);
2859    }
2860
2861    /// Get the entity ID for the currently rendering view
2862    pub fn current_view(&self) -> EntityId {
2863        self.invalidator.debug_assert_paint_or_prepaint();
2864        self.rendered_entity_stack.last().copied().unwrap()
2865    }
2866
2867    pub(crate) fn with_rendered_view<R>(
2868        &mut self,
2869        id: EntityId,
2870        f: impl FnOnce(&mut Self) -> R,
2871    ) -> R {
2872        self.rendered_entity_stack.push(id);
2873        let result = f(self);
2874        self.rendered_entity_stack.pop();
2875        result
2876    }
2877
2878    /// Executes the provided function with the specified image cache.
2879    pub(crate) fn with_image_cache<F, R>(&mut self, image_cache: AnyImageCache, f: F) -> R
2880    where
2881        F: FnOnce(&mut Self) -> R,
2882    {
2883        self.image_cache_stack.push(image_cache);
2884        let result = f(self);
2885        self.image_cache_stack.pop();
2886        result
2887    }
2888
2889    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2890    /// platform to receive textual input with proper integration with concerns such
2891    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
2892    /// rendered.
2893    ///
2894    /// This method should only be called as part of the paint phase of element drawing.
2895    ///
2896    /// [element_input_handler]: crate::ElementInputHandler
2897    pub fn handle_input(
2898        &mut self,
2899        focus_handle: &FocusHandle,
2900        input_handler: impl InputHandler,
2901        cx: &App,
2902    ) {
2903        self.invalidator.debug_assert_paint();
2904
2905        if focus_handle.is_focused(self) {
2906            let cx = self.to_async(cx);
2907            self.next_frame
2908                .input_handlers
2909                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
2910        }
2911    }
2912
2913    /// Register a mouse event listener on the window for the next frame. The type of event
2914    /// is determined by the first parameter of the given listener. When the next frame is rendered
2915    /// the listener will be cleared.
2916    ///
2917    /// This method should only be called as part of the paint phase of element drawing.
2918    pub fn on_mouse_event<Event: MouseEvent>(
2919        &mut self,
2920        mut handler: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
2921    ) {
2922        self.invalidator.debug_assert_paint();
2923
2924        self.next_frame.mouse_listeners.push(Some(Box::new(
2925            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
2926                if let Some(event) = event.downcast_ref() {
2927                    handler(event, phase, window, cx)
2928                }
2929            },
2930        )));
2931    }
2932
2933    /// Register a key event listener on the window for the next frame. The type of event
2934    /// is determined by the first parameter of the given listener. When the next frame is rendered
2935    /// the listener will be cleared.
2936    ///
2937    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2938    /// a specific need to register a global listener.
2939    ///
2940    /// This method should only be called as part of the paint phase of element drawing.
2941    pub fn on_key_event<Event: KeyEvent>(
2942        &mut self,
2943        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
2944    ) {
2945        self.invalidator.debug_assert_paint();
2946
2947        self.next_frame.dispatch_tree.on_key_event(Rc::new(
2948            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
2949                if let Some(event) = event.downcast_ref::<Event>() {
2950                    listener(event, phase, window, cx)
2951                }
2952            },
2953        ));
2954    }
2955
2956    /// Register a modifiers changed event listener on the window for the next frame.
2957    ///
2958    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2959    /// a specific need to register a global listener.
2960    ///
2961    /// This method should only be called as part of the paint phase of element drawing.
2962    pub fn on_modifiers_changed(
2963        &mut self,
2964        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
2965    ) {
2966        self.invalidator.debug_assert_paint();
2967
2968        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
2969            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
2970                listener(event, window, cx)
2971            },
2972        ));
2973    }
2974
2975    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2976    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
2977    /// Returns a subscription and persists until the subscription is dropped.
2978    pub fn on_focus_in(
2979        &mut self,
2980        handle: &FocusHandle,
2981        cx: &mut App,
2982        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
2983    ) -> Subscription {
2984        let focus_id = handle.id;
2985        let (subscription, activate) =
2986            self.new_focus_listener(Box::new(move |event, window, cx| {
2987                if event.is_focus_in(focus_id) {
2988                    listener(window, cx);
2989                }
2990                true
2991            }));
2992        cx.defer(move |_| activate());
2993        subscription
2994    }
2995
2996    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2997    /// Returns a subscription and persists until the subscription is dropped.
2998    pub fn on_focus_out(
2999        &mut self,
3000        handle: &FocusHandle,
3001        cx: &mut App,
3002        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3003    ) -> Subscription {
3004        let focus_id = handle.id;
3005        let (subscription, activate) =
3006            self.new_focus_listener(Box::new(move |event, window, cx| {
3007                if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3008                    if event.is_focus_out(focus_id) {
3009                        let event = FocusOutEvent {
3010                            blurred: WeakFocusHandle {
3011                                id: blurred_id,
3012                                handles: Arc::downgrade(&cx.focus_handles),
3013                            },
3014                        };
3015                        listener(event, window, cx)
3016                    }
3017                }
3018                true
3019            }));
3020        cx.defer(move |_| activate());
3021        subscription
3022    }
3023
3024    fn reset_cursor_style(&self, cx: &mut App) {
3025        // Set the cursor only if we're the active window.
3026        if self.is_window_hovered() {
3027            let style = self
3028                .rendered_frame
3029                .cursor_styles
3030                .iter()
3031                .rev()
3032                .find(|request| {
3033                    request
3034                        .hitbox_id
3035                        .map_or(true, |hitbox_id| hitbox_id.is_hovered(self))
3036                })
3037                .map(|request| request.style)
3038                .unwrap_or(CursorStyle::Arrow);
3039            cx.platform.set_cursor_style(style);
3040        }
3041    }
3042
3043    /// Dispatch a given keystroke as though the user had typed it.
3044    /// You can create a keystroke with Keystroke::parse("").
3045    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3046        let keystroke = keystroke.with_simulated_ime();
3047        let result = self.dispatch_event(
3048            PlatformInput::KeyDown(KeyDownEvent {
3049                keystroke: keystroke.clone(),
3050                is_held: false,
3051            }),
3052            cx,
3053        );
3054        if !result.propagate {
3055            return true;
3056        }
3057
3058        if let Some(input) = keystroke.key_char {
3059            if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3060                input_handler.dispatch_input(&input, self, cx);
3061                self.platform_window.set_input_handler(input_handler);
3062                return true;
3063            }
3064        }
3065
3066        false
3067    }
3068
3069    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3070    /// binding for the action (last binding added to the keymap).
3071    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3072        self.bindings_for_action(action)
3073            .last()
3074            .map(|binding| {
3075                binding
3076                    .keystrokes()
3077                    .iter()
3078                    .map(ToString::to_string)
3079                    .collect::<Vec<_>>()
3080                    .join(" ")
3081            })
3082            .unwrap_or_else(|| action.name().to_string())
3083    }
3084
3085    /// Dispatch a mouse or keyboard event on the window.
3086    #[profiling::function]
3087    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3088        self.last_input_timestamp.set(Instant::now());
3089        // Handlers may set this to false by calling `stop_propagation`.
3090        cx.propagate_event = true;
3091        // Handlers may set this to true by calling `prevent_default`.
3092        self.default_prevented = false;
3093
3094        let event = match event {
3095            // Track the mouse position with our own state, since accessing the platform
3096            // API for the mouse position can only occur on the main thread.
3097            PlatformInput::MouseMove(mouse_move) => {
3098                self.mouse_position = mouse_move.position;
3099                self.modifiers = mouse_move.modifiers;
3100                PlatformInput::MouseMove(mouse_move)
3101            }
3102            PlatformInput::MouseDown(mouse_down) => {
3103                self.mouse_position = mouse_down.position;
3104                self.modifiers = mouse_down.modifiers;
3105                PlatformInput::MouseDown(mouse_down)
3106            }
3107            PlatformInput::MouseUp(mouse_up) => {
3108                self.mouse_position = mouse_up.position;
3109                self.modifiers = mouse_up.modifiers;
3110                PlatformInput::MouseUp(mouse_up)
3111            }
3112            PlatformInput::MouseExited(mouse_exited) => {
3113                self.modifiers = mouse_exited.modifiers;
3114                PlatformInput::MouseExited(mouse_exited)
3115            }
3116            PlatformInput::ModifiersChanged(modifiers_changed) => {
3117                self.modifiers = modifiers_changed.modifiers;
3118                PlatformInput::ModifiersChanged(modifiers_changed)
3119            }
3120            PlatformInput::ScrollWheel(scroll_wheel) => {
3121                self.mouse_position = scroll_wheel.position;
3122                self.modifiers = scroll_wheel.modifiers;
3123                PlatformInput::ScrollWheel(scroll_wheel)
3124            }
3125            // Translate dragging and dropping of external files from the operating system
3126            // to internal drag and drop events.
3127            PlatformInput::FileDrop(file_drop) => match file_drop {
3128                FileDropEvent::Entered { position, paths } => {
3129                    self.mouse_position = position;
3130                    if cx.active_drag.is_none() {
3131                        cx.active_drag = Some(AnyDrag {
3132                            value: Arc::new(paths.clone()),
3133                            view: cx.new(|_| paths).into(),
3134                            cursor_offset: position,
3135                            cursor_style: None,
3136                        });
3137                    }
3138                    PlatformInput::MouseMove(MouseMoveEvent {
3139                        position,
3140                        pressed_button: Some(MouseButton::Left),
3141                        modifiers: Modifiers::default(),
3142                    })
3143                }
3144                FileDropEvent::Pending { position } => {
3145                    self.mouse_position = position;
3146                    PlatformInput::MouseMove(MouseMoveEvent {
3147                        position,
3148                        pressed_button: Some(MouseButton::Left),
3149                        modifiers: Modifiers::default(),
3150                    })
3151                }
3152                FileDropEvent::Submit { position } => {
3153                    cx.activate(true);
3154                    self.mouse_position = position;
3155                    PlatformInput::MouseUp(MouseUpEvent {
3156                        button: MouseButton::Left,
3157                        position,
3158                        modifiers: Modifiers::default(),
3159                        click_count: 1,
3160                    })
3161                }
3162                FileDropEvent::Exited => {
3163                    cx.active_drag.take();
3164                    PlatformInput::FileDrop(FileDropEvent::Exited)
3165                }
3166            },
3167            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3168        };
3169
3170        if let Some(any_mouse_event) = event.mouse_event() {
3171            self.dispatch_mouse_event(any_mouse_event, cx);
3172        } else if let Some(any_key_event) = event.keyboard_event() {
3173            self.dispatch_key_event(any_key_event, cx);
3174        }
3175
3176        DispatchEventResult {
3177            propagate: cx.propagate_event,
3178            default_prevented: self.default_prevented,
3179        }
3180    }
3181
3182    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3183        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3184        if hit_test != self.mouse_hit_test {
3185            self.mouse_hit_test = hit_test;
3186            self.reset_cursor_style(cx);
3187        }
3188
3189        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3190
3191        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3192        // special purposes, such as detecting events outside of a given Bounds.
3193        for listener in &mut mouse_listeners {
3194            let listener = listener.as_mut().unwrap();
3195            listener(event, DispatchPhase::Capture, self, cx);
3196            if !cx.propagate_event {
3197                break;
3198            }
3199        }
3200
3201        // Bubble phase, where most normal handlers do their work.
3202        if cx.propagate_event {
3203            for listener in mouse_listeners.iter_mut().rev() {
3204                let listener = listener.as_mut().unwrap();
3205                listener(event, DispatchPhase::Bubble, self, cx);
3206                if !cx.propagate_event {
3207                    break;
3208                }
3209            }
3210        }
3211
3212        self.rendered_frame.mouse_listeners = mouse_listeners;
3213
3214        if cx.has_active_drag() {
3215            if event.is::<MouseMoveEvent>() {
3216                // If this was a mouse move event, redraw the window so that the
3217                // active drag can follow the mouse cursor.
3218                self.refresh();
3219            } else if event.is::<MouseUpEvent>() {
3220                // If this was a mouse up event, cancel the active drag and redraw
3221                // the window.
3222                cx.active_drag = None;
3223                self.refresh();
3224            }
3225        }
3226    }
3227
3228    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3229        if self.invalidator.is_dirty() {
3230            self.draw(cx);
3231        }
3232
3233        let node_id = self
3234            .focus
3235            .and_then(|focus_id| {
3236                self.rendered_frame
3237                    .dispatch_tree
3238                    .focusable_node_id(focus_id)
3239            })
3240            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
3241
3242        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3243
3244        let mut keystroke: Option<Keystroke> = None;
3245
3246        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3247            if event.modifiers.number_of_modifiers() == 0
3248                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3249                && !self.pending_modifier.saw_keystroke
3250            {
3251                let key = match self.pending_modifier.modifiers {
3252                    modifiers if modifiers.shift => Some("shift"),
3253                    modifiers if modifiers.control => Some("control"),
3254                    modifiers if modifiers.alt => Some("alt"),
3255                    modifiers if modifiers.platform => Some("platform"),
3256                    modifiers if modifiers.function => Some("function"),
3257                    _ => None,
3258                };
3259                if let Some(key) = key {
3260                    keystroke = Some(Keystroke {
3261                        key: key.to_string(),
3262                        key_char: None,
3263                        modifiers: Modifiers::default(),
3264                    });
3265                }
3266            }
3267
3268            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3269                && event.modifiers.number_of_modifiers() == 1
3270            {
3271                self.pending_modifier.saw_keystroke = false
3272            }
3273            self.pending_modifier.modifiers = event.modifiers
3274        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3275            self.pending_modifier.saw_keystroke = true;
3276            keystroke = Some(key_down_event.keystroke.clone());
3277        }
3278
3279        let Some(keystroke) = keystroke else {
3280            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3281            return;
3282        };
3283
3284        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3285        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3286            currently_pending = PendingInput::default();
3287        }
3288
3289        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3290            currently_pending.keystrokes,
3291            keystroke,
3292            &dispatch_path,
3293        );
3294
3295        if !match_result.to_replay.is_empty() {
3296            self.replay_pending_input(match_result.to_replay, cx)
3297        }
3298
3299        if !match_result.pending.is_empty() {
3300            currently_pending.keystrokes = match_result.pending;
3301            currently_pending.focus = self.focus;
3302            currently_pending.timer = Some(self.spawn(cx, async move |cx| {
3303                cx.background_executor.timer(Duration::from_secs(1)).await;
3304                cx.update(move |window, cx| {
3305                    let Some(currently_pending) = window
3306                        .pending_input
3307                        .take()
3308                        .filter(|pending| pending.focus == window.focus)
3309                    else {
3310                        return;
3311                    };
3312
3313                    let dispatch_path = window.rendered_frame.dispatch_tree.dispatch_path(node_id);
3314
3315                    let to_replay = window
3316                        .rendered_frame
3317                        .dispatch_tree
3318                        .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3319
3320                    window.replay_pending_input(to_replay, cx)
3321                })
3322                .log_err();
3323            }));
3324            self.pending_input = Some(currently_pending);
3325            self.pending_input_changed(cx);
3326            cx.propagate_event = false;
3327            return;
3328        }
3329
3330        cx.propagate_event = true;
3331        for binding in match_result.bindings {
3332            self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3333            if !cx.propagate_event {
3334                self.dispatch_keystroke_observers(
3335                    event,
3336                    Some(binding.action),
3337                    match_result.context_stack.clone(),
3338                    cx,
3339                );
3340                self.pending_input_changed(cx);
3341                return;
3342            }
3343        }
3344
3345        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
3346        self.pending_input_changed(cx);
3347    }
3348
3349    fn finish_dispatch_key_event(
3350        &mut self,
3351        event: &dyn Any,
3352        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3353        context_stack: Vec<KeyContext>,
3354        cx: &mut App,
3355    ) {
3356        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
3357        if !cx.propagate_event {
3358            return;
3359        }
3360
3361        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
3362        if !cx.propagate_event {
3363            return;
3364        }
3365
3366        self.dispatch_keystroke_observers(event, None, context_stack, cx);
3367    }
3368
3369    fn pending_input_changed(&mut self, cx: &mut App) {
3370        self.pending_input_observers
3371            .clone()
3372            .retain(&(), |callback| callback(self, cx));
3373    }
3374
3375    fn dispatch_key_down_up_event(
3376        &mut self,
3377        event: &dyn Any,
3378        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3379        cx: &mut App,
3380    ) {
3381        // Capture phase
3382        for node_id in dispatch_path {
3383            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3384
3385            for key_listener in node.key_listeners.clone() {
3386                key_listener(event, DispatchPhase::Capture, self, cx);
3387                if !cx.propagate_event {
3388                    return;
3389                }
3390            }
3391        }
3392
3393        // Bubble phase
3394        for node_id in dispatch_path.iter().rev() {
3395            // Handle low level key events
3396            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3397            for key_listener in node.key_listeners.clone() {
3398                key_listener(event, DispatchPhase::Bubble, self, cx);
3399                if !cx.propagate_event {
3400                    return;
3401                }
3402            }
3403        }
3404    }
3405
3406    fn dispatch_modifiers_changed_event(
3407        &mut self,
3408        event: &dyn Any,
3409        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3410        cx: &mut App,
3411    ) {
3412        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3413            return;
3414        };
3415        for node_id in dispatch_path.iter().rev() {
3416            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3417            for listener in node.modifiers_changed_listeners.clone() {
3418                listener(event, self, cx);
3419                if !cx.propagate_event {
3420                    return;
3421                }
3422            }
3423        }
3424    }
3425
3426    /// Determine whether a potential multi-stroke key binding is in progress on this window.
3427    pub fn has_pending_keystrokes(&self) -> bool {
3428        self.pending_input.is_some()
3429    }
3430
3431    pub(crate) fn clear_pending_keystrokes(&mut self) {
3432        self.pending_input.take();
3433    }
3434
3435    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3436    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3437        self.pending_input
3438            .as_ref()
3439            .map(|pending_input| pending_input.keystrokes.as_slice())
3440    }
3441
3442    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
3443        let node_id = self
3444            .focus
3445            .and_then(|focus_id| {
3446                self.rendered_frame
3447                    .dispatch_tree
3448                    .focusable_node_id(focus_id)
3449            })
3450            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
3451
3452        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3453
3454        'replay: for replay in replays {
3455            let event = KeyDownEvent {
3456                keystroke: replay.keystroke.clone(),
3457                is_held: false,
3458            };
3459
3460            cx.propagate_event = true;
3461            for binding in replay.bindings {
3462                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3463                if !cx.propagate_event {
3464                    self.dispatch_keystroke_observers(
3465                        &event,
3466                        Some(binding.action),
3467                        Vec::default(),
3468                        cx,
3469                    );
3470                    continue 'replay;
3471                }
3472            }
3473
3474            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
3475            if !cx.propagate_event {
3476                continue 'replay;
3477            }
3478            if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3479                if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3480                    input_handler.dispatch_input(&input, self, cx);
3481                    self.platform_window.set_input_handler(input_handler)
3482                }
3483            }
3484        }
3485    }
3486
3487    fn dispatch_action_on_node(
3488        &mut self,
3489        node_id: DispatchNodeId,
3490        action: &dyn Action,
3491        cx: &mut App,
3492    ) {
3493        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3494
3495        // Capture phase for global actions.
3496        cx.propagate_event = true;
3497        if let Some(mut global_listeners) = cx
3498            .global_action_listeners
3499            .remove(&action.as_any().type_id())
3500        {
3501            for listener in &global_listeners {
3502                listener(action.as_any(), DispatchPhase::Capture, cx);
3503                if !cx.propagate_event {
3504                    break;
3505                }
3506            }
3507
3508            global_listeners.extend(
3509                cx.global_action_listeners
3510                    .remove(&action.as_any().type_id())
3511                    .unwrap_or_default(),
3512            );
3513
3514            cx.global_action_listeners
3515                .insert(action.as_any().type_id(), global_listeners);
3516        }
3517
3518        if !cx.propagate_event {
3519            return;
3520        }
3521
3522        // Capture phase for window actions.
3523        for node_id in &dispatch_path {
3524            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3525            for DispatchActionListener {
3526                action_type,
3527                listener,
3528            } in node.action_listeners.clone()
3529            {
3530                let any_action = action.as_any();
3531                if action_type == any_action.type_id() {
3532                    listener(any_action, DispatchPhase::Capture, self, cx);
3533
3534                    if !cx.propagate_event {
3535                        return;
3536                    }
3537                }
3538            }
3539        }
3540
3541        // Bubble phase for window actions.
3542        for node_id in dispatch_path.iter().rev() {
3543            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3544            for DispatchActionListener {
3545                action_type,
3546                listener,
3547            } in node.action_listeners.clone()
3548            {
3549                let any_action = action.as_any();
3550                if action_type == any_action.type_id() {
3551                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3552                    listener(any_action, DispatchPhase::Bubble, self, cx);
3553
3554                    if !cx.propagate_event {
3555                        return;
3556                    }
3557                }
3558            }
3559        }
3560
3561        // Bubble phase for global actions.
3562        if let Some(mut global_listeners) = cx
3563            .global_action_listeners
3564            .remove(&action.as_any().type_id())
3565        {
3566            for listener in global_listeners.iter().rev() {
3567                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3568
3569                listener(action.as_any(), DispatchPhase::Bubble, cx);
3570                if !cx.propagate_event {
3571                    break;
3572                }
3573            }
3574
3575            global_listeners.extend(
3576                cx.global_action_listeners
3577                    .remove(&action.as_any().type_id())
3578                    .unwrap_or_default(),
3579            );
3580
3581            cx.global_action_listeners
3582                .insert(action.as_any().type_id(), global_listeners);
3583        }
3584    }
3585
3586    /// Register the given handler to be invoked whenever the global of the given type
3587    /// is updated.
3588    pub fn observe_global<G: Global>(
3589        &mut self,
3590        cx: &mut App,
3591        f: impl Fn(&mut Window, &mut App) + 'static,
3592    ) -> Subscription {
3593        let window_handle = self.handle;
3594        let (subscription, activate) = cx.global_observers.insert(
3595            TypeId::of::<G>(),
3596            Box::new(move |cx| {
3597                window_handle
3598                    .update(cx, |_, window, cx| f(window, cx))
3599                    .is_ok()
3600            }),
3601        );
3602        cx.defer(move |_| activate());
3603        subscription
3604    }
3605
3606    /// Focus the current window and bring it to the foreground at the platform level.
3607    pub fn activate_window(&self) {
3608        self.platform_window.activate();
3609    }
3610
3611    /// Minimize the current window at the platform level.
3612    pub fn minimize_window(&self) {
3613        self.platform_window.minimize();
3614    }
3615
3616    /// Toggle full screen status on the current window at the platform level.
3617    pub fn toggle_fullscreen(&self) {
3618        self.platform_window.toggle_fullscreen();
3619    }
3620
3621    /// Updates the IME panel position suggestions for languages like japanese, chinese.
3622    pub fn invalidate_character_coordinates(&self) {
3623        self.on_next_frame(|window, cx| {
3624            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
3625                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
3626                    window
3627                        .platform_window
3628                        .update_ime_position(bounds.scale(window.scale_factor()));
3629                }
3630                window.platform_window.set_input_handler(input_handler);
3631            }
3632        });
3633    }
3634
3635    /// Present a platform dialog.
3636    /// The provided message will be presented, along with buttons for each answer.
3637    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3638    pub fn prompt(
3639        &mut self,
3640        level: PromptLevel,
3641        message: &str,
3642        detail: Option<&str>,
3643        answers: &[&str],
3644        cx: &mut App,
3645    ) -> oneshot::Receiver<usize> {
3646        let prompt_builder = cx.prompt_builder.take();
3647        let Some(prompt_builder) = prompt_builder else {
3648            unreachable!("Re-entrant window prompting is not supported by GPUI");
3649        };
3650
3651        let receiver = match &prompt_builder {
3652            PromptBuilder::Default => self
3653                .platform_window
3654                .prompt(level, message, detail, answers)
3655                .unwrap_or_else(|| {
3656                    self.build_custom_prompt(&prompt_builder, level, message, detail, answers, cx)
3657                }),
3658            PromptBuilder::Custom(_) => {
3659                self.build_custom_prompt(&prompt_builder, level, message, detail, answers, cx)
3660            }
3661        };
3662
3663        cx.prompt_builder = Some(prompt_builder);
3664
3665        receiver
3666    }
3667
3668    fn build_custom_prompt(
3669        &mut self,
3670        prompt_builder: &PromptBuilder,
3671        level: PromptLevel,
3672        message: &str,
3673        detail: Option<&str>,
3674        answers: &[&str],
3675        cx: &mut App,
3676    ) -> oneshot::Receiver<usize> {
3677        let (sender, receiver) = oneshot::channel();
3678        let handle = PromptHandle::new(sender);
3679        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
3680        self.prompt = Some(handle);
3681        receiver
3682    }
3683
3684    /// Returns the current context stack.
3685    pub fn context_stack(&self) -> Vec<KeyContext> {
3686        let dispatch_tree = &self.rendered_frame.dispatch_tree;
3687        let node_id = self
3688            .focus
3689            .and_then(|focus_id| dispatch_tree.focusable_node_id(focus_id))
3690            .unwrap_or_else(|| dispatch_tree.root_node_id());
3691
3692        dispatch_tree
3693            .dispatch_path(node_id)
3694            .iter()
3695            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
3696            .collect()
3697    }
3698
3699    /// Returns all available actions for the focused element.
3700    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
3701        let node_id = self
3702            .focus
3703            .and_then(|focus_id| {
3704                self.rendered_frame
3705                    .dispatch_tree
3706                    .focusable_node_id(focus_id)
3707            })
3708            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id());
3709
3710        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
3711        for action_type in cx.global_action_listeners.keys() {
3712            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3713                let action = cx.actions.build_action_type(action_type).ok();
3714                if let Some(action) = action {
3715                    actions.insert(ix, action);
3716                }
3717            }
3718        }
3719        actions
3720    }
3721
3722    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
3723    /// returned in the order they were added. For display, the last binding should take precedence.
3724    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3725        self.rendered_frame
3726            .dispatch_tree
3727            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
3728    }
3729
3730    /// Returns any bindings that would invoke an action on the given focus handle if it were
3731    /// focused. Bindings are returned in the order they were added. For display, the last binding
3732    /// should take precedence.
3733    pub fn bindings_for_action_in(
3734        &self,
3735        action: &dyn Action,
3736        focus_handle: &FocusHandle,
3737    ) -> Vec<KeyBinding> {
3738        let dispatch_tree = &self.rendered_frame.dispatch_tree;
3739
3740        let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
3741            return vec![];
3742        };
3743        let context_stack: Vec<_> = dispatch_tree
3744            .dispatch_path(node_id)
3745            .into_iter()
3746            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
3747            .collect();
3748        dispatch_tree.bindings_for_action(action, &context_stack)
3749    }
3750
3751    /// Returns the key bindings for the given action in the given context.
3752    pub fn bindings_for_action_in_context(
3753        &self,
3754        action: &dyn Action,
3755        context: KeyContext,
3756    ) -> Vec<KeyBinding> {
3757        let dispatch_tree = &self.rendered_frame.dispatch_tree;
3758        dispatch_tree.bindings_for_action(action, &[context])
3759    }
3760
3761    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
3762    pub fn listener_for<V: Render, E>(
3763        &self,
3764        view: &Entity<V>,
3765        f: impl Fn(&mut V, &E, &mut Window, &mut Context<V>) + 'static,
3766    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
3767        let view = view.downgrade();
3768        move |e: &E, window: &mut Window, cx: &mut App| {
3769            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
3770        }
3771    }
3772
3773    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
3774    pub fn handler_for<V: Render, Callback: Fn(&mut V, &mut Window, &mut Context<V>) + 'static>(
3775        &self,
3776        view: &Entity<V>,
3777        f: Callback,
3778    ) -> impl Fn(&mut Window, &mut App) + use<V, Callback> {
3779        let view = view.downgrade();
3780        move |window: &mut Window, cx: &mut App| {
3781            view.update(cx, |view, cx| f(view, window, cx)).ok();
3782        }
3783    }
3784
3785    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
3786    /// If the callback returns false, the window won't be closed.
3787    pub fn on_window_should_close(
3788        &self,
3789        cx: &App,
3790        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
3791    ) {
3792        let mut cx = self.to_async(cx);
3793        self.platform_window.on_should_close(Box::new(move || {
3794            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
3795        }))
3796    }
3797
3798    /// Register an action listener on the window for the next frame. The type of action
3799    /// is determined by the first parameter of the given listener. When the next frame is rendered
3800    /// the listener will be cleared.
3801    ///
3802    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
3803    /// a specific need to register a global listener.
3804    pub fn on_action(
3805        &mut self,
3806        action_type: TypeId,
3807        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
3808    ) {
3809        self.next_frame
3810            .dispatch_tree
3811            .on_action(action_type, Rc::new(listener));
3812    }
3813
3814    /// Read information about the GPU backing this window.
3815    /// Currently returns None on Mac and Windows.
3816    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
3817        self.platform_window.gpu_specs()
3818    }
3819}
3820
3821// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
3822slotmap::new_key_type! {
3823    /// A unique identifier for a window.
3824    pub struct WindowId;
3825}
3826
3827impl WindowId {
3828    /// Converts this window ID to a `u64`.
3829    pub fn as_u64(&self) -> u64 {
3830        self.0.as_ffi()
3831    }
3832}
3833
3834impl From<u64> for WindowId {
3835    fn from(value: u64) -> Self {
3836        WindowId(slotmap::KeyData::from_ffi(value))
3837    }
3838}
3839
3840/// A handle to a window with a specific root view type.
3841/// Note that this does not keep the window alive on its own.
3842#[derive(Deref, DerefMut)]
3843pub struct WindowHandle<V> {
3844    #[deref]
3845    #[deref_mut]
3846    pub(crate) any_handle: AnyWindowHandle,
3847    state_type: PhantomData<V>,
3848}
3849
3850impl<V: 'static + Render> WindowHandle<V> {
3851    /// Creates a new handle from a window ID.
3852    /// This does not check if the root type of the window is `V`.
3853    pub fn new(id: WindowId) -> Self {
3854        WindowHandle {
3855            any_handle: AnyWindowHandle {
3856                id,
3857                state_type: TypeId::of::<V>(),
3858            },
3859            state_type: PhantomData,
3860        }
3861    }
3862
3863    /// Get the root view out of this window.
3864    ///
3865    /// This will fail if the window is closed or if the root view's type does not match `V`.
3866    #[cfg(any(test, feature = "test-support"))]
3867    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
3868    where
3869        C: AppContext,
3870    {
3871        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
3872            root_view
3873                .downcast::<V>()
3874                .map_err(|_| anyhow!("the type of the window's root view has changed"))
3875        }))
3876    }
3877
3878    /// Updates the root view of this window.
3879    ///
3880    /// This will fail if the window has been closed or if the root view's type does not match
3881    pub fn update<C, R>(
3882        &self,
3883        cx: &mut C,
3884        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
3885    ) -> Result<R>
3886    where
3887        C: AppContext,
3888    {
3889        cx.update_window(self.any_handle, |root_view, window, cx| {
3890            let view = root_view
3891                .downcast::<V>()
3892                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3893
3894            Ok(view.update(cx, |view, cx| update(view, window, cx)))
3895        })?
3896    }
3897
3898    /// Read the root view out of this window.
3899    ///
3900    /// This will fail if the window is closed or if the root view's type does not match `V`.
3901    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
3902        let x = cx
3903            .windows
3904            .get(self.id)
3905            .and_then(|window| {
3906                window
3907                    .as_ref()
3908                    .and_then(|window| window.root.clone())
3909                    .map(|root_view| root_view.downcast::<V>())
3910            })
3911            .ok_or_else(|| anyhow!("window not found"))?
3912            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3913
3914        Ok(x.read(cx))
3915    }
3916
3917    /// Read the root view out of this window, with a callback
3918    ///
3919    /// This will fail if the window is closed or if the root view's type does not match `V`.
3920    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
3921    where
3922        C: AppContext,
3923    {
3924        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
3925    }
3926
3927    /// Read the root view pointer off of this window.
3928    ///
3929    /// This will fail if the window is closed or if the root view's type does not match `V`.
3930    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
3931    where
3932        C: AppContext,
3933    {
3934        cx.read_window(self, |root_view, _cx| root_view.clone())
3935    }
3936
3937    /// Check if this window is 'active'.
3938    ///
3939    /// Will return `None` if the window is closed or currently
3940    /// borrowed.
3941    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
3942        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
3943            .ok()
3944    }
3945}
3946
3947impl<V> Copy for WindowHandle<V> {}
3948
3949impl<V> Clone for WindowHandle<V> {
3950    fn clone(&self) -> Self {
3951        *self
3952    }
3953}
3954
3955impl<V> PartialEq for WindowHandle<V> {
3956    fn eq(&self, other: &Self) -> bool {
3957        self.any_handle == other.any_handle
3958    }
3959}
3960
3961impl<V> Eq for WindowHandle<V> {}
3962
3963impl<V> Hash for WindowHandle<V> {
3964    fn hash<H: Hasher>(&self, state: &mut H) {
3965        self.any_handle.hash(state);
3966    }
3967}
3968
3969impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
3970    fn from(val: WindowHandle<V>) -> Self {
3971        val.any_handle
3972    }
3973}
3974
3975unsafe impl<V> Send for WindowHandle<V> {}
3976unsafe impl<V> Sync for WindowHandle<V> {}
3977
3978/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
3979#[derive(Copy, Clone, PartialEq, Eq, Hash)]
3980pub struct AnyWindowHandle {
3981    pub(crate) id: WindowId,
3982    state_type: TypeId,
3983}
3984
3985impl AnyWindowHandle {
3986    /// Get the ID of this window.
3987    pub fn window_id(&self) -> WindowId {
3988        self.id
3989    }
3990
3991    /// Attempt to convert this handle to a window handle with a specific root view type.
3992    /// If the types do not match, this will return `None`.
3993    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
3994        if TypeId::of::<T>() == self.state_type {
3995            Some(WindowHandle {
3996                any_handle: *self,
3997                state_type: PhantomData,
3998            })
3999        } else {
4000            None
4001        }
4002    }
4003
4004    /// Updates the state of the root view of this window.
4005    ///
4006    /// This will fail if the window has been closed.
4007    pub fn update<C, R>(
4008        self,
4009        cx: &mut C,
4010        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
4011    ) -> Result<R>
4012    where
4013        C: AppContext,
4014    {
4015        cx.update_window(self, update)
4016    }
4017
4018    /// Read the state of the root view of this window.
4019    ///
4020    /// This will fail if the window has been closed.
4021    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
4022    where
4023        C: AppContext,
4024        T: 'static,
4025    {
4026        let view = self
4027            .downcast::<T>()
4028            .context("the type of the window's root view has changed")?;
4029
4030        cx.read_window(&view, read)
4031    }
4032}
4033
4034impl HasWindowHandle for Window {
4035    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
4036        self.platform_window.window_handle()
4037    }
4038}
4039
4040/// An identifier for an [`Element`](crate::Element).
4041///
4042/// Can be constructed with a string, a number, or both, as well
4043/// as other internal representations.
4044#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4045pub enum ElementId {
4046    /// The ID of a View element
4047    View(EntityId),
4048    /// An integer ID.
4049    Integer(u64),
4050    /// A string based ID.
4051    Name(SharedString),
4052    /// A UUID.
4053    Uuid(Uuid),
4054    /// An ID that's equated with a focus handle.
4055    FocusHandle(FocusId),
4056    /// A combination of a name and an integer.
4057    NamedInteger(SharedString, u64),
4058    /// A path
4059    Path(Arc<std::path::Path>),
4060}
4061
4062impl ElementId {
4063    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
4064    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
4065        Self::NamedInteger(name.into(), integer as u64)
4066    }
4067}
4068
4069impl Display for ElementId {
4070    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4071        match self {
4072            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4073            ElementId::Integer(ix) => write!(f, "{}", ix)?,
4074            ElementId::Name(name) => write!(f, "{}", name)?,
4075            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4076            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4077            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4078            ElementId::Path(path) => write!(f, "{}", path.display())?,
4079        }
4080
4081        Ok(())
4082    }
4083}
4084
4085impl TryInto<SharedString> for ElementId {
4086    type Error = anyhow::Error;
4087
4088    fn try_into(self) -> anyhow::Result<SharedString> {
4089        if let ElementId::Name(name) = self {
4090            Ok(name)
4091        } else {
4092            Err(anyhow!("element id is not string"))
4093        }
4094    }
4095}
4096
4097impl From<usize> for ElementId {
4098    fn from(id: usize) -> Self {
4099        ElementId::Integer(id as u64)
4100    }
4101}
4102
4103impl From<i32> for ElementId {
4104    fn from(id: i32) -> Self {
4105        Self::Integer(id as u64)
4106    }
4107}
4108
4109impl From<SharedString> for ElementId {
4110    fn from(name: SharedString) -> Self {
4111        ElementId::Name(name)
4112    }
4113}
4114
4115impl From<Arc<std::path::Path>> for ElementId {
4116    fn from(path: Arc<std::path::Path>) -> Self {
4117        ElementId::Path(path)
4118    }
4119}
4120
4121impl From<&'static str> for ElementId {
4122    fn from(name: &'static str) -> Self {
4123        ElementId::Name(name.into())
4124    }
4125}
4126
4127impl<'a> From<&'a FocusHandle> for ElementId {
4128    fn from(handle: &'a FocusHandle) -> Self {
4129        ElementId::FocusHandle(handle.id)
4130    }
4131}
4132
4133impl From<(&'static str, EntityId)> for ElementId {
4134    fn from((name, id): (&'static str, EntityId)) -> Self {
4135        ElementId::NamedInteger(name.into(), id.as_u64())
4136    }
4137}
4138
4139impl From<(&'static str, usize)> for ElementId {
4140    fn from((name, id): (&'static str, usize)) -> Self {
4141        ElementId::NamedInteger(name.into(), id as u64)
4142    }
4143}
4144
4145impl From<(SharedString, usize)> for ElementId {
4146    fn from((name, id): (SharedString, usize)) -> Self {
4147        ElementId::NamedInteger(name, id as u64)
4148    }
4149}
4150
4151impl From<(&'static str, u64)> for ElementId {
4152    fn from((name, id): (&'static str, u64)) -> Self {
4153        ElementId::NamedInteger(name.into(), id)
4154    }
4155}
4156
4157impl From<Uuid> for ElementId {
4158    fn from(value: Uuid) -> Self {
4159        Self::Uuid(value)
4160    }
4161}
4162
4163impl From<(&'static str, u32)> for ElementId {
4164    fn from((name, id): (&'static str, u32)) -> Self {
4165        ElementId::NamedInteger(name.into(), id.into())
4166    }
4167}
4168
4169/// A rectangle to be rendered in the window at the given position and size.
4170/// Passed as an argument [`Window::paint_quad`].
4171#[derive(Clone)]
4172pub struct PaintQuad {
4173    /// The bounds of the quad within the window.
4174    pub bounds: Bounds<Pixels>,
4175    /// The radii of the quad's corners.
4176    pub corner_radii: Corners<Pixels>,
4177    /// The background color of the quad.
4178    pub background: Background,
4179    /// The widths of the quad's borders.
4180    pub border_widths: Edges<Pixels>,
4181    /// The color of the quad's borders.
4182    pub border_color: Hsla,
4183    /// The style of the quad's borders.
4184    pub border_style: BorderStyle,
4185}
4186
4187impl PaintQuad {
4188    /// Sets the corner radii of the quad.
4189    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4190        PaintQuad {
4191            corner_radii: corner_radii.into(),
4192            ..self
4193        }
4194    }
4195
4196    /// Sets the border widths of the quad.
4197    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
4198        PaintQuad {
4199            border_widths: border_widths.into(),
4200            ..self
4201        }
4202    }
4203
4204    /// Sets the border color of the quad.
4205    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
4206        PaintQuad {
4207            border_color: border_color.into(),
4208            ..self
4209        }
4210    }
4211
4212    /// Sets the background color of the quad.
4213    pub fn background(self, background: impl Into<Background>) -> Self {
4214        PaintQuad {
4215            background: background.into(),
4216            ..self
4217        }
4218    }
4219}
4220
4221/// Creates a quad with the given parameters.
4222pub fn quad(
4223    bounds: Bounds<Pixels>,
4224    corner_radii: impl Into<Corners<Pixels>>,
4225    background: impl Into<Background>,
4226    border_widths: impl Into<Edges<Pixels>>,
4227    border_color: impl Into<Hsla>,
4228    border_style: BorderStyle,
4229) -> PaintQuad {
4230    PaintQuad {
4231        bounds,
4232        corner_radii: corner_radii.into(),
4233        background: background.into(),
4234        border_widths: border_widths.into(),
4235        border_color: border_color.into(),
4236        border_style,
4237    }
4238}
4239
4240/// Creates a filled quad with the given bounds and background color.
4241pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
4242    PaintQuad {
4243        bounds: bounds.into(),
4244        corner_radii: (0.).into(),
4245        background: background.into(),
4246        border_widths: (0.).into(),
4247        border_color: transparent_black(),
4248        border_style: BorderStyle::default(),
4249    }
4250}
4251
4252/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
4253pub fn outline(
4254    bounds: impl Into<Bounds<Pixels>>,
4255    border_color: impl Into<Hsla>,
4256    border_style: BorderStyle,
4257) -> PaintQuad {
4258    PaintQuad {
4259        bounds: bounds.into(),
4260        corner_radii: (0.).into(),
4261        background: transparent_black().into(),
4262        border_widths: (1.).into(),
4263        border_color: border_color.into(),
4264        border_style,
4265    }
4266}