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