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