window.rs

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