window.rs

   1#[cfg(any(feature = "inspector", debug_assertions))]
   2use crate::Inspector;
   3use crate::{
   4    Action, AnyDrag, AnyElement, AnyImageCache, AnyTooltip, AnyView, App, AppContext, Arena, Asset,
   5    AsyncWindowContext, AvailableSpace, Background, BorderStyle, Bounds, BoxShadow, Capslock,
   6    Context, Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener,
   7    DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
   8    FileDropEvent, FontId, Global, GlobalElementId, GlyphId, GpuSpecs, Hsla, InputHandler, IsZero,
   9    KeyBinding, KeyContext, KeyDownEvent, KeyEvent, Keystroke, KeystrokeEvent, LayoutId,
  10    LineLayoutIndex, Modifiers, ModifiersChangedEvent, MonochromeSprite, MouseButton, MouseEvent,
  11    MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
  12    PlatformInputHandler, PlatformWindow, Point, PolychromeSprite, PromptButton, PromptLevel, Quad,
  13    Render, RenderGlyphParams, RenderImage, RenderImageParams, RenderSvgParams, Replay, ResizeEdge,
  14    SMOOTH_SVG_SCALE_FACTOR, SUBPIXEL_VARIANTS, ScaledPixels, Scene, Shadow, SharedString, Size,
  15    StrikethroughStyle, Style, SubscriberSet, Subscription, TaffyLayoutEngine, Task, TextStyle,
  16    TextStyleRefinement, TransformationMatrix, Underline, UnderlineStyle, WindowAppearance,
  17    WindowBackgroundAppearance, WindowBounds, WindowControls, WindowDecorations, WindowOptions,
  18    WindowParams, WindowTextSystem, point, prelude::*, px, rems, size, transparent_black,
  19};
  20use anyhow::{Context as _, Result, anyhow};
  21use collections::{FxHashMap, FxHashSet};
  22#[cfg(target_os = "macos")]
  23use core_video::pixel_buffer::CVPixelBuffer;
  24use derive_more::{Deref, DerefMut};
  25use futures::FutureExt;
  26use futures::channel::oneshot;
  27use itertools::FoldWhile::{Continue, Done};
  28use itertools::Itertools;
  29use parking_lot::RwLock;
  30use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
  31use refineable::Refineable;
  32use slotmap::SlotMap;
  33use smallvec::SmallVec;
  34use std::{
  35    any::{Any, TypeId},
  36    borrow::Cow,
  37    cell::{Cell, RefCell},
  38    cmp,
  39    fmt::{Debug, Display},
  40    hash::{Hash, Hasher},
  41    marker::PhantomData,
  42    mem,
  43    ops::{DerefMut, Range},
  44    rc::Rc,
  45    sync::{
  46        Arc, Weak,
  47        atomic::{AtomicUsize, Ordering::SeqCst},
  48    },
  49    time::{Duration, Instant},
  50};
  51use util::post_inc;
  52use util::{ResultExt, measure};
  53use uuid::Uuid;
  54
  55mod prompts;
  56
  57use crate::util::atomic_incr_if_not_zero;
  58pub use prompts::*;
  59
  60pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1024.), px(700.));
  61
  62/// Represents the two different phases when dispatching events.
  63#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  64pub enum DispatchPhase {
  65    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  66    /// invoked front to back and keyboard event listeners are invoked from the focused element
  67    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  68    /// registering event listeners.
  69    #[default]
  70    Bubble,
  71    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  72    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  73    /// is used for special purposes such as clearing the "pressed" state for click events. If
  74    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  75    /// outside of the immediate region may rely on detecting non-local events during this phase.
  76    Capture,
  77}
  78
  79impl DispatchPhase {
  80    /// Returns true if this represents the "bubble" phase.
  81    pub fn bubble(self) -> bool {
  82        self == DispatchPhase::Bubble
  83    }
  84
  85    /// Returns true if this represents the "capture" phase.
  86    pub fn capture(self) -> bool {
  87        self == DispatchPhase::Capture
  88    }
  89}
  90
  91struct WindowInvalidatorInner {
  92    pub dirty: bool,
  93    pub draw_phase: DrawPhase,
  94    pub dirty_views: FxHashSet<EntityId>,
  95}
  96
  97#[derive(Clone)]
  98pub(crate) struct WindowInvalidator {
  99    inner: Rc<RefCell<WindowInvalidatorInner>>,
 100}
 101
 102impl WindowInvalidator {
 103    pub fn new() -> Self {
 104        WindowInvalidator {
 105            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 106                dirty: true,
 107                draw_phase: DrawPhase::None,
 108                dirty_views: FxHashSet::default(),
 109            })),
 110        }
 111    }
 112
 113    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 114        let mut inner = self.inner.borrow_mut();
 115        inner.dirty_views.insert(entity);
 116        if inner.draw_phase == DrawPhase::None {
 117            inner.dirty = true;
 118            cx.push_effect(Effect::Notify { emitter: entity });
 119            true
 120        } else {
 121            false
 122        }
 123    }
 124
 125    pub fn is_dirty(&self) -> bool {
 126        self.inner.borrow().dirty
 127    }
 128
 129    pub fn set_dirty(&self, dirty: bool) {
 130        self.inner.borrow_mut().dirty = dirty
 131    }
 132
 133    pub fn set_phase(&self, phase: DrawPhase) {
 134        self.inner.borrow_mut().draw_phase = phase
 135    }
 136
 137    pub fn take_views(&self) -> FxHashSet<EntityId> {
 138        mem::take(&mut self.inner.borrow_mut().dirty_views)
 139    }
 140
 141    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 142        self.inner.borrow_mut().dirty_views = views;
 143    }
 144
 145    pub fn not_drawing(&self) -> bool {
 146        self.inner.borrow().draw_phase == DrawPhase::None
 147    }
 148
 149    #[track_caller]
 150    pub fn debug_assert_paint(&self) {
 151        debug_assert!(
 152            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 153            "this method can only be called during paint"
 154        );
 155    }
 156
 157    #[track_caller]
 158    pub fn debug_assert_prepaint(&self) {
 159        debug_assert!(
 160            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 161            "this method can only be called during request_layout, or prepaint"
 162        );
 163    }
 164
 165    #[track_caller]
 166    pub fn debug_assert_paint_or_prepaint(&self) {
 167        debug_assert!(
 168            matches!(
 169                self.inner.borrow().draw_phase,
 170                DrawPhase::Paint | DrawPhase::Prepaint
 171            ),
 172            "this method can only be called during request_layout, prepaint, or paint"
 173        );
 174    }
 175}
 176
 177type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 178
 179pub(crate) type AnyWindowFocusListener =
 180    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 181
 182pub(crate) struct WindowFocusEvent {
 183    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 184    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 185}
 186
 187impl WindowFocusEvent {
 188    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 189        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 190    }
 191
 192    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 193        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 194    }
 195}
 196
 197/// This is provided when subscribing for `Context::on_focus_out` events.
 198pub struct FocusOutEvent {
 199    /// A weak focus handle representing what was blurred.
 200    pub blurred: WeakFocusHandle,
 201}
 202
 203slotmap::new_key_type! {
 204    /// A globally unique identifier for a focusable element.
 205    pub struct FocusId;
 206}
 207
 208thread_local! {
 209    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(1024 * 1024));
 210}
 211
 212/// Returned when the element arena has been used and so must be cleared before the next draw.
 213#[must_use]
 214pub struct ArenaClearNeeded;
 215
 216impl ArenaClearNeeded {
 217    /// Clear the element arena.
 218    pub fn clear(self) {
 219        ELEMENT_ARENA.with_borrow_mut(|element_arena| {
 220            element_arena.clear();
 221        });
 222    }
 223}
 224
 225pub(crate) type FocusMap = RwLock<SlotMap<FocusId, AtomicUsize>>;
 226
 227impl FocusId {
 228    /// Obtains whether the element associated with this handle is currently focused.
 229    pub fn is_focused(&self, window: &Window) -> bool {
 230        window.focus == Some(*self)
 231    }
 232
 233    /// Obtains whether the element associated with this handle contains the focused
 234    /// element or is itself focused.
 235    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 236        window
 237            .focused(cx)
 238            .map_or(false, |focused| self.contains(focused.id, window))
 239    }
 240
 241    /// Obtains whether the element associated with this handle is contained within the
 242    /// focused element or is itself focused.
 243    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 244        let focused = window.focused(cx);
 245        focused.map_or(false, |focused| focused.id.contains(*self, window))
 246    }
 247
 248    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 249    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 250        window
 251            .rendered_frame
 252            .dispatch_tree
 253            .focus_contains(*self, other)
 254    }
 255}
 256
 257/// A handle which can be used to track and manipulate the focused element in a window.
 258pub struct FocusHandle {
 259    pub(crate) id: FocusId,
 260    handles: Arc<FocusMap>,
 261}
 262
 263impl std::fmt::Debug for FocusHandle {
 264    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 265        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 266    }
 267}
 268
 269impl FocusHandle {
 270    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 271        let id = handles.write().insert(AtomicUsize::new(1));
 272        Self {
 273            id,
 274            handles: handles.clone(),
 275        }
 276    }
 277
 278    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 279        let lock = handles.read();
 280        let ref_count = lock.get(id)?;
 281        if atomic_incr_if_not_zero(ref_count) == 0 {
 282            return None;
 283        }
 284        Some(Self {
 285            id,
 286            handles: handles.clone(),
 287        })
 288    }
 289
 290    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 291    pub fn downgrade(&self) -> WeakFocusHandle {
 292        WeakFocusHandle {
 293            id: self.id,
 294            handles: Arc::downgrade(&self.handles),
 295        }
 296    }
 297
 298    /// Moves the focus to the element associated with this handle.
 299    pub fn focus(&self, window: &mut Window) {
 300        window.focus(self)
 301    }
 302
 303    /// Obtains whether the element associated with this handle is currently focused.
 304    pub fn is_focused(&self, window: &Window) -> bool {
 305        self.id.is_focused(window)
 306    }
 307
 308    /// Obtains whether the element associated with this handle contains the focused
 309    /// element or is itself focused.
 310    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 311        self.id.contains_focused(window, cx)
 312    }
 313
 314    /// Obtains whether the element associated with this handle is contained within the
 315    /// focused element or is itself focused.
 316    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 317        self.id.within_focused(window, cx)
 318    }
 319
 320    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 321    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 322        self.id.contains(other.id, window)
 323    }
 324
 325    /// Dispatch an action on the element that rendered this focus handle
 326    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 327        if let Some(node_id) = window
 328            .rendered_frame
 329            .dispatch_tree
 330            .focusable_node_id(self.id)
 331        {
 332            window.dispatch_action_on_node(node_id, action, cx)
 333        }
 334    }
 335}
 336
 337impl Clone for FocusHandle {
 338    fn clone(&self) -> Self {
 339        Self::for_id(self.id, &self.handles).unwrap()
 340    }
 341}
 342
 343impl PartialEq for FocusHandle {
 344    fn eq(&self, other: &Self) -> bool {
 345        self.id == other.id
 346    }
 347}
 348
 349impl Eq for FocusHandle {}
 350
 351impl Drop for FocusHandle {
 352    fn drop(&mut self) {
 353        self.handles
 354            .read()
 355            .get(self.id)
 356            .unwrap()
 357            .fetch_sub(1, SeqCst);
 358    }
 359}
 360
 361/// A weak reference to a focus handle.
 362#[derive(Clone, Debug)]
 363pub struct WeakFocusHandle {
 364    pub(crate) id: FocusId,
 365    pub(crate) handles: Weak<FocusMap>,
 366}
 367
 368impl WeakFocusHandle {
 369    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 370    pub fn upgrade(&self) -> Option<FocusHandle> {
 371        let handles = self.handles.upgrade()?;
 372        FocusHandle::for_id(self.id, &handles)
 373    }
 374}
 375
 376impl PartialEq for WeakFocusHandle {
 377    fn eq(&self, other: &WeakFocusHandle) -> bool {
 378        self.id == other.id
 379    }
 380}
 381
 382impl Eq for WeakFocusHandle {}
 383
 384impl PartialEq<FocusHandle> for WeakFocusHandle {
 385    fn eq(&self, other: &FocusHandle) -> bool {
 386        self.id == other.id
 387    }
 388}
 389
 390impl PartialEq<WeakFocusHandle> for FocusHandle {
 391    fn eq(&self, other: &WeakFocusHandle) -> bool {
 392        self.id == other.id
 393    }
 394}
 395
 396/// Focusable allows users of your view to easily
 397/// focus it (using window.focus_view(cx, view))
 398pub trait Focusable: 'static {
 399    /// Returns the focus handle associated with this view.
 400    fn focus_handle(&self, cx: &App) -> FocusHandle;
 401}
 402
 403impl<V: Focusable> Focusable for Entity<V> {
 404    fn focus_handle(&self, cx: &App) -> FocusHandle {
 405        self.read(cx).focus_handle(cx)
 406    }
 407}
 408
 409/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 410/// where the lifecycle of the view is handled by another view.
 411pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 412
 413impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 414
 415/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 416pub struct DismissEvent;
 417
 418type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 419
 420pub(crate) type AnyMouseListener =
 421    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 422
 423#[derive(Clone)]
 424pub(crate) struct CursorStyleRequest {
 425    pub(crate) hitbox_id: Option<HitboxId>,
 426    pub(crate) style: CursorStyle,
 427}
 428
 429#[derive(Default, Eq, PartialEq)]
 430pub(crate) struct HitTest {
 431    pub(crate) ids: SmallVec<[HitboxId; 8]>,
 432    pub(crate) hover_hitbox_count: usize,
 433}
 434
 435/// A type of window control area that corresponds to the platform window.
 436#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 437pub enum WindowControlArea {
 438    /// An area that allows dragging of the platform window.
 439    Drag,
 440    /// An area that allows closing of the platform window.
 441    Close,
 442    /// An area that allows maximizing of the platform window.
 443    Max,
 444    /// An area that allows minimizing of the platform window.
 445    Min,
 446}
 447
 448/// An identifier for a [Hitbox] which also includes [HitboxBehavior].
 449#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 450pub struct HitboxId(u64);
 451
 452impl HitboxId {
 453    /// Checks if the hitbox with this ID is currently hovered. Except when handling
 454    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 455    /// events or paint hover styles.
 456    ///
 457    /// See [`Hitbox::is_hovered`] for details.
 458    pub fn is_hovered(self, window: &Window) -> bool {
 459        let hit_test = &window.mouse_hit_test;
 460        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 461            if self == *id {
 462                return true;
 463            }
 464        }
 465        return false;
 466    }
 467
 468    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 469    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 470    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 471    /// this distinction.
 472    pub fn should_handle_scroll(self, window: &Window) -> bool {
 473        window.mouse_hit_test.ids.contains(&self)
 474    }
 475
 476    fn next(mut self) -> HitboxId {
 477        HitboxId(self.0.wrapping_add(1))
 478    }
 479}
 480
 481/// A rectangular region that potentially blocks hitboxes inserted prior.
 482/// See [Window::insert_hitbox] for more details.
 483#[derive(Clone, Debug, Deref)]
 484pub struct Hitbox {
 485    /// A unique identifier for the hitbox.
 486    pub id: HitboxId,
 487    /// The bounds of the hitbox.
 488    #[deref]
 489    pub bounds: Bounds<Pixels>,
 490    /// The content mask when the hitbox was inserted.
 491    pub content_mask: ContentMask<Pixels>,
 492    /// Flags that specify hitbox behavior.
 493    pub behavior: HitboxBehavior,
 494}
 495
 496impl Hitbox {
 497    /// Checks if the hitbox is currently hovered. Except when handling `ScrollWheelEvent`, this is
 498    /// typically what you want when determining whether to handle mouse events or paint hover
 499    /// styles.
 500    ///
 501    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 502    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 503    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`).
 504    ///
 505    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 506    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 507    /// non-interactive while still allowing scrolling. More abstractly, this is because
 508    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 509    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 510    /// container.
 511    pub fn is_hovered(&self, window: &Window) -> bool {
 512        self.id.is_hovered(window)
 513    }
 514
 515    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 516    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 517    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 518    ///
 519    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 520    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 521    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 522        self.id.should_handle_scroll(window)
 523    }
 524}
 525
 526/// How the hitbox affects mouse behavior.
 527#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 528pub enum HitboxBehavior {
 529    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 530    #[default]
 531    Normal,
 532
 533    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 534    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 535    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 536    /// [`InteractiveElement::occlude`].
 537    ///
 538    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 539    /// bubble-phase handler for every mouse event type:
 540    ///
 541    /// ```
 542    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 543    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 544    ///         cx.stop_propagation();
 545    ///     }
 546    /// }
 547    /// ```
 548    ///
 549    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 550    /// styles and tooltops. These other behaviors are the main point of this mechanism. An
 551    /// alternative might be to not affect mouse event handling - but this would allow
 552    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 553    /// be hovered.
 554    BlockMouse,
 555
 556    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 557    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 558    /// interaction except scroll events to be ignored - see the documentation of
 559    /// [`Hitbox::is_hovered`] for details. This flag is set by
 560    /// [`InteractiveElement::block_mouse_except_scroll`].
 561    ///
 562    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 563    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 564    ///
 565    /// ```
 566    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, _cx| {
 567    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 568    ///         cx.stop_propagation();
 569    ///     }
 570    /// }
 571    /// ```
 572    ///
 573    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 574    /// handled differently than other mouse events. If also blocking these scroll events is
 575    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 576    ///
 577    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 578    /// hover styles and tooltops. These other behaviors are the main point of this mechanism.
 579    /// An alternative might be to not affect mouse event handling - but this would allow
 580    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 581    /// be hovered.
 582    BlockMouseExceptScroll,
 583}
 584
 585/// An identifier for a tooltip.
 586#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 587pub struct TooltipId(usize);
 588
 589impl TooltipId {
 590    /// Checks if the tooltip is currently hovered.
 591    pub fn is_hovered(&self, window: &Window) -> bool {
 592        window
 593            .tooltip_bounds
 594            .as_ref()
 595            .map_or(false, |tooltip_bounds| {
 596                tooltip_bounds.id == *self
 597                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 598            })
 599    }
 600}
 601
 602pub(crate) struct TooltipBounds {
 603    id: TooltipId,
 604    bounds: Bounds<Pixels>,
 605}
 606
 607#[derive(Clone)]
 608pub(crate) struct TooltipRequest {
 609    id: TooltipId,
 610    tooltip: AnyTooltip,
 611}
 612
 613pub(crate) struct DeferredDraw {
 614    current_view: EntityId,
 615    priority: usize,
 616    parent_node: DispatchNodeId,
 617    element_id_stack: SmallVec<[ElementId; 32]>,
 618    text_style_stack: Vec<TextStyleRefinement>,
 619    element: Option<AnyElement>,
 620    absolute_offset: Point<Pixels>,
 621    prepaint_range: Range<PrepaintStateIndex>,
 622    paint_range: Range<PaintIndex>,
 623}
 624
 625pub(crate) struct Frame {
 626    pub(crate) focus: Option<FocusId>,
 627    pub(crate) window_active: bool,
 628    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 629    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 630    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 631    pub(crate) dispatch_tree: DispatchTree,
 632    pub(crate) scene: Scene,
 633    pub(crate) hitboxes: Vec<Hitbox>,
 634    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 635    pub(crate) deferred_draws: Vec<DeferredDraw>,
 636    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 637    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 638    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 639    #[cfg(any(test, feature = "test-support"))]
 640    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 641    #[cfg(any(feature = "inspector", debug_assertions))]
 642    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 643    #[cfg(any(feature = "inspector", debug_assertions))]
 644    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 645}
 646
 647#[derive(Clone, Default)]
 648pub(crate) struct PrepaintStateIndex {
 649    hitboxes_index: usize,
 650    tooltips_index: usize,
 651    deferred_draws_index: usize,
 652    dispatch_tree_index: usize,
 653    accessed_element_states_index: usize,
 654    line_layout_index: LineLayoutIndex,
 655}
 656
 657#[derive(Clone, Default)]
 658pub(crate) struct PaintIndex {
 659    scene_index: usize,
 660    mouse_listeners_index: usize,
 661    input_handlers_index: usize,
 662    cursor_styles_index: usize,
 663    accessed_element_states_index: usize,
 664    line_layout_index: LineLayoutIndex,
 665}
 666
 667impl Frame {
 668    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 669        Frame {
 670            focus: None,
 671            window_active: false,
 672            element_states: FxHashMap::default(),
 673            accessed_element_states: Vec::new(),
 674            mouse_listeners: Vec::new(),
 675            dispatch_tree,
 676            scene: Scene::default(),
 677            hitboxes: Vec::new(),
 678            window_control_hitboxes: Vec::new(),
 679            deferred_draws: Vec::new(),
 680            input_handlers: Vec::new(),
 681            tooltip_requests: Vec::new(),
 682            cursor_styles: Vec::new(),
 683
 684            #[cfg(any(test, feature = "test-support"))]
 685            debug_bounds: FxHashMap::default(),
 686
 687            #[cfg(any(feature = "inspector", debug_assertions))]
 688            next_inspector_instance_ids: FxHashMap::default(),
 689
 690            #[cfg(any(feature = "inspector", debug_assertions))]
 691            inspector_hitboxes: FxHashMap::default(),
 692        }
 693    }
 694
 695    pub(crate) fn clear(&mut self) {
 696        self.element_states.clear();
 697        self.accessed_element_states.clear();
 698        self.mouse_listeners.clear();
 699        self.dispatch_tree.clear();
 700        self.scene.clear();
 701        self.input_handlers.clear();
 702        self.tooltip_requests.clear();
 703        self.cursor_styles.clear();
 704        self.hitboxes.clear();
 705        self.window_control_hitboxes.clear();
 706        self.deferred_draws.clear();
 707        self.focus = None;
 708
 709        #[cfg(any(feature = "inspector", debug_assertions))]
 710        {
 711            self.next_inspector_instance_ids.clear();
 712            self.inspector_hitboxes.clear();
 713        }
 714    }
 715
 716    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 717        self.cursor_styles
 718            .iter()
 719            .rev()
 720            .fold_while(None, |style, request| match request.hitbox_id {
 721                None => Done(Some(request.style)),
 722                Some(hitbox_id) => Continue(
 723                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 724                ),
 725            })
 726            .into_inner()
 727    }
 728
 729    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 730        let mut set_hover_hitbox_count = false;
 731        let mut hit_test = HitTest::default();
 732        for hitbox in self.hitboxes.iter().rev() {
 733            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 734            if bounds.contains(&position) {
 735                hit_test.ids.push(hitbox.id);
 736                if !set_hover_hitbox_count
 737                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 738                {
 739                    hit_test.hover_hitbox_count = hit_test.ids.len();
 740                    set_hover_hitbox_count = true;
 741                }
 742                if hitbox.behavior == HitboxBehavior::BlockMouse {
 743                    break;
 744                }
 745            }
 746        }
 747        if !set_hover_hitbox_count {
 748            hit_test.hover_hitbox_count = hit_test.ids.len();
 749        }
 750        hit_test
 751    }
 752
 753    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 754        self.focus
 755            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 756            .unwrap_or_default()
 757    }
 758
 759    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 760        for element_state_key in &self.accessed_element_states {
 761            if let Some((element_state_key, element_state)) =
 762                prev_frame.element_states.remove_entry(element_state_key)
 763            {
 764                self.element_states.insert(element_state_key, element_state);
 765            }
 766        }
 767
 768        self.scene.finish();
 769    }
 770}
 771
 772/// Holds the state for a specific window.
 773pub struct Window {
 774    pub(crate) handle: AnyWindowHandle,
 775    pub(crate) invalidator: WindowInvalidator,
 776    pub(crate) removed: bool,
 777    pub(crate) platform_window: Box<dyn PlatformWindow>,
 778    display_id: Option<DisplayId>,
 779    sprite_atlas: Arc<dyn PlatformAtlas>,
 780    text_system: Arc<WindowTextSystem>,
 781    rem_size: Pixels,
 782    /// The stack of override values for the window's rem size.
 783    ///
 784    /// This is used by `with_rem_size` to allow rendering an element tree with
 785    /// a given rem size.
 786    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 787    pub(crate) viewport_size: Size<Pixels>,
 788    layout_engine: Option<TaffyLayoutEngine>,
 789    pub(crate) root: Option<AnyView>,
 790    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 791    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 792    pub(crate) rendered_entity_stack: Vec<EntityId>,
 793    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 794    pub(crate) element_opacity: Option<f32>,
 795    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 796    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 797    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 798    pub(crate) rendered_frame: Frame,
 799    pub(crate) next_frame: Frame,
 800    next_hitbox_id: HitboxId,
 801    pub(crate) next_tooltip_id: TooltipId,
 802    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 803    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 804    pub(crate) dirty_views: FxHashSet<EntityId>,
 805    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 806    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 807    default_prevented: bool,
 808    mouse_position: Point<Pixels>,
 809    mouse_hit_test: HitTest,
 810    modifiers: Modifiers,
 811    capslock: Capslock,
 812    scale_factor: f32,
 813    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 814    appearance: WindowAppearance,
 815    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 816    active: Rc<Cell<bool>>,
 817    hovered: Rc<Cell<bool>>,
 818    pub(crate) needs_present: Rc<Cell<bool>>,
 819    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 820    pub(crate) refreshing: bool,
 821    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 822    pub(crate) focus: Option<FocusId>,
 823    focus_enabled: bool,
 824    pending_input: Option<PendingInput>,
 825    pending_modifier: ModifierState,
 826    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 827    prompt: Option<RenderablePromptHandle>,
 828    pub(crate) client_inset: Option<Pixels>,
 829    #[cfg(any(feature = "inspector", debug_assertions))]
 830    inspector: Option<Entity<Inspector>>,
 831}
 832
 833#[derive(Clone, Debug, Default)]
 834struct ModifierState {
 835    modifiers: Modifiers,
 836    saw_keystroke: bool,
 837}
 838
 839#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 840pub(crate) enum DrawPhase {
 841    None,
 842    Prepaint,
 843    Paint,
 844    Focus,
 845}
 846
 847#[derive(Default, Debug)]
 848struct PendingInput {
 849    keystrokes: SmallVec<[Keystroke; 1]>,
 850    focus: Option<FocusId>,
 851    timer: Option<Task<()>>,
 852}
 853
 854pub(crate) struct ElementStateBox {
 855    pub(crate) inner: Box<dyn Any>,
 856    #[cfg(debug_assertions)]
 857    pub(crate) type_name: &'static str,
 858}
 859
 860fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> Bounds<Pixels> {
 861    const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
 862
 863    // TODO, BUG: if you open a window with the currently active window
 864    // on the stack, this will erroneously select the 'unwrap_or_else'
 865    // code path
 866    cx.active_window()
 867        .and_then(|w| w.update(cx, |_, window, _| window.bounds()).ok())
 868        .map(|mut bounds| {
 869            bounds.origin += DEFAULT_WINDOW_OFFSET;
 870            bounds
 871        })
 872        .unwrap_or_else(|| {
 873            let display = display_id
 874                .map(|id| cx.find_display(id))
 875                .unwrap_or_else(|| cx.primary_display());
 876
 877            display
 878                .map(|display| display.default_bounds())
 879                .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
 880        })
 881}
 882
 883impl Window {
 884    pub(crate) fn new(
 885        handle: AnyWindowHandle,
 886        options: WindowOptions,
 887        cx: &mut App,
 888    ) -> Result<Self> {
 889        let WindowOptions {
 890            window_bounds,
 891            titlebar,
 892            focus,
 893            show,
 894            kind,
 895            is_movable,
 896            display_id,
 897            window_background,
 898            app_id,
 899            window_min_size,
 900            window_decorations,
 901        } = options;
 902
 903        let bounds = window_bounds
 904            .map(|bounds| bounds.get_bounds())
 905            .unwrap_or_else(|| default_bounds(display_id, cx));
 906        let mut platform_window = cx.platform.open_window(
 907            handle,
 908            WindowParams {
 909                bounds,
 910                titlebar,
 911                kind,
 912                is_movable,
 913                focus,
 914                show,
 915                display_id,
 916                window_min_size,
 917            },
 918        )?;
 919        let display_id = platform_window.display().map(|display| display.id());
 920        let sprite_atlas = platform_window.sprite_atlas();
 921        let mouse_position = platform_window.mouse_position();
 922        let modifiers = platform_window.modifiers();
 923        let capslock = platform_window.capslock();
 924        let content_size = platform_window.content_size();
 925        let scale_factor = platform_window.scale_factor();
 926        let appearance = platform_window.appearance();
 927        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
 928        let invalidator = WindowInvalidator::new();
 929        let active = Rc::new(Cell::new(platform_window.is_active()));
 930        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
 931        let needs_present = Rc::new(Cell::new(false));
 932        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
 933        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
 934
 935        platform_window
 936            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
 937        platform_window.set_background_appearance(window_background);
 938
 939        if let Some(ref window_open_state) = window_bounds {
 940            match window_open_state {
 941                WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
 942                WindowBounds::Maximized(_) => platform_window.zoom(),
 943                WindowBounds::Windowed(_) => {}
 944            }
 945        }
 946
 947        platform_window.on_close(Box::new({
 948            let mut cx = cx.to_async();
 949            move || {
 950                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
 951            }
 952        }));
 953        platform_window.on_request_frame(Box::new({
 954            let mut cx = cx.to_async();
 955            let invalidator = invalidator.clone();
 956            let active = active.clone();
 957            let needs_present = needs_present.clone();
 958            let next_frame_callbacks = next_frame_callbacks.clone();
 959            let last_input_timestamp = last_input_timestamp.clone();
 960            move |request_frame_options| {
 961                let next_frame_callbacks = next_frame_callbacks.take();
 962                if !next_frame_callbacks.is_empty() {
 963                    handle
 964                        .update(&mut cx, |_, window, cx| {
 965                            for callback in next_frame_callbacks {
 966                                callback(window, cx);
 967                            }
 968                        })
 969                        .log_err();
 970                }
 971
 972                // Keep presenting the current scene for 1 extra second since the
 973                // last input to prevent the display from underclocking the refresh rate.
 974                let needs_present = request_frame_options.require_presentation
 975                    || needs_present.get()
 976                    || (active.get()
 977                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
 978
 979                if invalidator.is_dirty() {
 980                    measure("frame duration", || {
 981                        handle
 982                            .update(&mut cx, |_, window, cx| {
 983                                let arena_clear_needed = window.draw(cx);
 984                                window.present();
 985                                // drop the arena elements after present to reduce latency
 986                                arena_clear_needed.clear();
 987                            })
 988                            .log_err();
 989                    })
 990                } else if needs_present {
 991                    handle
 992                        .update(&mut cx, |_, window, _| window.present())
 993                        .log_err();
 994                }
 995
 996                handle
 997                    .update(&mut cx, |_, window, _| {
 998                        window.complete_frame();
 999                    })
1000                    .log_err();
1001            }
1002        }));
1003        platform_window.on_resize(Box::new({
1004            let mut cx = cx.to_async();
1005            move |_, _| {
1006                handle
1007                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1008                    .log_err();
1009            }
1010        }));
1011        platform_window.on_moved(Box::new({
1012            let mut cx = cx.to_async();
1013            move || {
1014                handle
1015                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1016                    .log_err();
1017            }
1018        }));
1019        platform_window.on_appearance_changed(Box::new({
1020            let mut cx = cx.to_async();
1021            move || {
1022                handle
1023                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1024                    .log_err();
1025            }
1026        }));
1027        platform_window.on_active_status_change(Box::new({
1028            let mut cx = cx.to_async();
1029            move |active| {
1030                handle
1031                    .update(&mut cx, |_, window, cx| {
1032                        window.active.set(active);
1033                        window.modifiers = window.platform_window.modifiers();
1034                        window.capslock = window.platform_window.capslock();
1035                        window
1036                            .activation_observers
1037                            .clone()
1038                            .retain(&(), |callback| callback(window, cx));
1039                        window.refresh();
1040                    })
1041                    .log_err();
1042            }
1043        }));
1044        platform_window.on_hover_status_change(Box::new({
1045            let mut cx = cx.to_async();
1046            move |active| {
1047                handle
1048                    .update(&mut cx, |_, window, _| {
1049                        window.hovered.set(active);
1050                        window.refresh();
1051                    })
1052                    .log_err();
1053            }
1054        }));
1055        platform_window.on_input({
1056            let mut cx = cx.to_async();
1057            Box::new(move |event| {
1058                handle
1059                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1060                    .log_err()
1061                    .unwrap_or(DispatchEventResult::default())
1062            })
1063        });
1064        platform_window.on_hit_test_window_control({
1065            let mut cx = cx.to_async();
1066            Box::new(move || {
1067                handle
1068                    .update(&mut cx, |_, window, _cx| {
1069                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1070                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1071                                return Some(*area);
1072                            }
1073                        }
1074                        None
1075                    })
1076                    .log_err()
1077                    .unwrap_or(None)
1078            })
1079        });
1080
1081        if let Some(app_id) = app_id {
1082            platform_window.set_app_id(&app_id);
1083        }
1084
1085        platform_window.map_window().unwrap();
1086
1087        Ok(Window {
1088            handle,
1089            invalidator,
1090            removed: false,
1091            platform_window,
1092            display_id,
1093            sprite_atlas,
1094            text_system,
1095            rem_size: px(16.),
1096            rem_size_override_stack: SmallVec::new(),
1097            viewport_size: content_size,
1098            layout_engine: Some(TaffyLayoutEngine::new()),
1099            root: None,
1100            element_id_stack: SmallVec::default(),
1101            text_style_stack: Vec::new(),
1102            rendered_entity_stack: Vec::new(),
1103            element_offset_stack: Vec::new(),
1104            content_mask_stack: Vec::new(),
1105            element_opacity: None,
1106            requested_autoscroll: None,
1107            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1108            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1109            next_frame_callbacks,
1110            next_hitbox_id: HitboxId(0),
1111            next_tooltip_id: TooltipId::default(),
1112            tooltip_bounds: None,
1113            dirty_views: FxHashSet::default(),
1114            focus_listeners: SubscriberSet::new(),
1115            focus_lost_listeners: SubscriberSet::new(),
1116            default_prevented: true,
1117            mouse_position,
1118            mouse_hit_test: HitTest::default(),
1119            modifiers,
1120            capslock,
1121            scale_factor,
1122            bounds_observers: SubscriberSet::new(),
1123            appearance,
1124            appearance_observers: SubscriberSet::new(),
1125            active,
1126            hovered,
1127            needs_present,
1128            last_input_timestamp,
1129            refreshing: false,
1130            activation_observers: SubscriberSet::new(),
1131            focus: None,
1132            focus_enabled: true,
1133            pending_input: None,
1134            pending_modifier: ModifierState::default(),
1135            pending_input_observers: SubscriberSet::new(),
1136            prompt: None,
1137            client_inset: None,
1138            image_cache_stack: Vec::new(),
1139            #[cfg(any(feature = "inspector", debug_assertions))]
1140            inspector: None,
1141        })
1142    }
1143
1144    pub(crate) fn new_focus_listener(
1145        &self,
1146        value: AnyWindowFocusListener,
1147    ) -> (Subscription, impl FnOnce() + use<>) {
1148        self.focus_listeners.insert((), value)
1149    }
1150}
1151
1152#[derive(Clone, Debug, Default, PartialEq, Eq)]
1153pub(crate) struct DispatchEventResult {
1154    pub propagate: bool,
1155    pub default_prevented: bool,
1156}
1157
1158/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1159/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1160/// to leave room to support more complex shapes in the future.
1161#[derive(Clone, Debug, Default, PartialEq, Eq)]
1162#[repr(C)]
1163pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1164    /// The bounds
1165    pub bounds: Bounds<P>,
1166}
1167
1168impl ContentMask<Pixels> {
1169    /// Scale the content mask's pixel units by the given scaling factor.
1170    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1171        ContentMask {
1172            bounds: self.bounds.scale(factor),
1173        }
1174    }
1175
1176    /// Intersect the content mask with the given content mask.
1177    pub fn intersect(&self, other: &Self) -> Self {
1178        let bounds = self.bounds.intersect(&other.bounds);
1179        ContentMask { bounds }
1180    }
1181}
1182
1183impl Window {
1184    fn mark_view_dirty(&mut self, view_id: EntityId) {
1185        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1186        // should already be dirty.
1187        for view_id in self
1188            .rendered_frame
1189            .dispatch_tree
1190            .view_path(view_id)
1191            .into_iter()
1192            .rev()
1193        {
1194            if !self.dirty_views.insert(view_id) {
1195                break;
1196            }
1197        }
1198    }
1199
1200    /// Registers a callback to be invoked when the window appearance changes.
1201    pub fn observe_window_appearance(
1202        &self,
1203        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1204    ) -> Subscription {
1205        let (subscription, activate) = self.appearance_observers.insert(
1206            (),
1207            Box::new(move |window, cx| {
1208                callback(window, cx);
1209                true
1210            }),
1211        );
1212        activate();
1213        subscription
1214    }
1215
1216    /// Replaces the root entity of the window with a new one.
1217    pub fn replace_root<E>(
1218        &mut self,
1219        cx: &mut App,
1220        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1221    ) -> Entity<E>
1222    where
1223        E: 'static + Render,
1224    {
1225        let view = cx.new(|cx| build_view(self, cx));
1226        self.root = Some(view.clone().into());
1227        self.refresh();
1228        view
1229    }
1230
1231    /// Returns the root entity of the window, if it has one.
1232    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1233    where
1234        E: 'static + Render,
1235    {
1236        self.root
1237            .as_ref()
1238            .map(|view| view.clone().downcast::<E>().ok())
1239    }
1240
1241    /// Obtain a handle to the window that belongs to this context.
1242    pub fn window_handle(&self) -> AnyWindowHandle {
1243        self.handle
1244    }
1245
1246    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1247    pub fn refresh(&mut self) {
1248        if self.invalidator.not_drawing() {
1249            self.refreshing = true;
1250            self.invalidator.set_dirty(true);
1251        }
1252    }
1253
1254    /// Close this window.
1255    pub fn remove_window(&mut self) {
1256        self.removed = true;
1257    }
1258
1259    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1260    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1261        self.focus
1262            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1263    }
1264
1265    /// Move focus to the element associated with the given [`FocusHandle`].
1266    pub fn focus(&mut self, handle: &FocusHandle) {
1267        if !self.focus_enabled || self.focus == Some(handle.id) {
1268            return;
1269        }
1270
1271        self.focus = Some(handle.id);
1272        self.clear_pending_keystrokes();
1273        self.refresh();
1274    }
1275
1276    /// Remove focus from all elements within this context's window.
1277    pub fn blur(&mut self) {
1278        if !self.focus_enabled {
1279            return;
1280        }
1281
1282        self.focus = None;
1283        self.refresh();
1284    }
1285
1286    /// Blur the window and don't allow anything in it to be focused again.
1287    pub fn disable_focus(&mut self) {
1288        self.blur();
1289        self.focus_enabled = false;
1290    }
1291
1292    /// Accessor for the text system.
1293    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1294        &self.text_system
1295    }
1296
1297    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1298    pub fn text_style(&self) -> TextStyle {
1299        let mut style = TextStyle::default();
1300        for refinement in &self.text_style_stack {
1301            style.refine(refinement);
1302        }
1303        style
1304    }
1305
1306    /// Check if the platform window is maximized
1307    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1308    pub fn is_maximized(&self) -> bool {
1309        self.platform_window.is_maximized()
1310    }
1311
1312    /// request a certain window decoration (Wayland)
1313    pub fn request_decorations(&self, decorations: WindowDecorations) {
1314        self.platform_window.request_decorations(decorations);
1315    }
1316
1317    /// Start a window resize operation (Wayland)
1318    pub fn start_window_resize(&self, edge: ResizeEdge) {
1319        self.platform_window.start_window_resize(edge);
1320    }
1321
1322    /// Return the `WindowBounds` to indicate that how a window should be opened
1323    /// after it has been closed
1324    pub fn window_bounds(&self) -> WindowBounds {
1325        self.platform_window.window_bounds()
1326    }
1327
1328    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1329    pub fn inner_window_bounds(&self) -> WindowBounds {
1330        self.platform_window.inner_window_bounds()
1331    }
1332
1333    /// Dispatch the given action on the currently focused element.
1334    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1335        let focus_id = self.focused(cx).map(|handle| handle.id);
1336
1337        let window = self.handle;
1338        cx.defer(move |cx| {
1339            window
1340                .update(cx, |_, window, cx| {
1341                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1342                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1343                })
1344                .log_err();
1345        })
1346    }
1347
1348    pub(crate) fn dispatch_keystroke_observers(
1349        &mut self,
1350        event: &dyn Any,
1351        action: Option<Box<dyn Action>>,
1352        context_stack: Vec<KeyContext>,
1353        cx: &mut App,
1354    ) {
1355        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1356            return;
1357        };
1358
1359        cx.keystroke_observers.clone().retain(&(), move |callback| {
1360            (callback)(
1361                &KeystrokeEvent {
1362                    keystroke: key_down_event.keystroke.clone(),
1363                    action: action.as_ref().map(|action| action.boxed_clone()),
1364                    context_stack: context_stack.clone(),
1365                },
1366                self,
1367                cx,
1368            )
1369        });
1370    }
1371
1372    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1373    /// that are currently on the stack to be returned to the app.
1374    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1375        let handle = self.handle;
1376        cx.defer(move |cx| {
1377            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1378        });
1379    }
1380
1381    /// Subscribe to events emitted by a entity.
1382    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1383    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1384    pub fn observe<T: 'static>(
1385        &mut self,
1386        observed: &Entity<T>,
1387        cx: &mut App,
1388        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1389    ) -> Subscription {
1390        let entity_id = observed.entity_id();
1391        let observed = observed.downgrade();
1392        let window_handle = self.handle;
1393        cx.new_observer(
1394            entity_id,
1395            Box::new(move |cx| {
1396                window_handle
1397                    .update(cx, |_, window, cx| {
1398                        if let Some(handle) = observed.upgrade() {
1399                            on_notify(handle, window, cx);
1400                            true
1401                        } else {
1402                            false
1403                        }
1404                    })
1405                    .unwrap_or(false)
1406            }),
1407        )
1408    }
1409
1410    /// Subscribe to events emitted by a entity.
1411    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1412    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1413    pub fn subscribe<Emitter, Evt>(
1414        &mut self,
1415        entity: &Entity<Emitter>,
1416        cx: &mut App,
1417        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1418    ) -> Subscription
1419    where
1420        Emitter: EventEmitter<Evt>,
1421        Evt: 'static,
1422    {
1423        let entity_id = entity.entity_id();
1424        let handle = entity.downgrade();
1425        let window_handle = self.handle;
1426        cx.new_subscription(
1427            entity_id,
1428            (
1429                TypeId::of::<Evt>(),
1430                Box::new(move |event, cx| {
1431                    window_handle
1432                        .update(cx, |_, window, cx| {
1433                            if let Some(entity) = handle.upgrade() {
1434                                let event = event.downcast_ref().expect("invalid event type");
1435                                on_event(entity, event, window, cx);
1436                                true
1437                            } else {
1438                                false
1439                            }
1440                        })
1441                        .unwrap_or(false)
1442                }),
1443            ),
1444        )
1445    }
1446
1447    /// Register a callback to be invoked when the given `Entity` is released.
1448    pub fn observe_release<T>(
1449        &self,
1450        entity: &Entity<T>,
1451        cx: &mut App,
1452        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1453    ) -> Subscription
1454    where
1455        T: 'static,
1456    {
1457        let entity_id = entity.entity_id();
1458        let window_handle = self.handle;
1459        let (subscription, activate) = cx.release_listeners.insert(
1460            entity_id,
1461            Box::new(move |entity, cx| {
1462                let entity = entity.downcast_mut().expect("invalid entity type");
1463                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1464            }),
1465        );
1466        activate();
1467        subscription
1468    }
1469
1470    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1471    /// await points in async code.
1472    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1473        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1474    }
1475
1476    /// Schedule the given closure to be run directly after the current frame is rendered.
1477    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1478        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1479    }
1480
1481    /// Schedule a frame to be drawn on the next animation frame.
1482    ///
1483    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1484    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1485    ///
1486    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1487    pub fn request_animation_frame(&self) {
1488        let entity = self.current_view();
1489        self.on_next_frame(move |_, cx| cx.notify(entity));
1490    }
1491
1492    /// Spawn the future returned by the given closure on the application thread pool.
1493    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1494    /// use within your future.
1495    #[track_caller]
1496    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1497    where
1498        R: 'static,
1499        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1500    {
1501        let handle = self.handle;
1502        cx.spawn(async move |app| {
1503            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1504            f(&mut async_window_cx).await
1505        })
1506    }
1507
1508    fn bounds_changed(&mut self, cx: &mut App) {
1509        self.scale_factor = self.platform_window.scale_factor();
1510        self.viewport_size = self.platform_window.content_size();
1511        self.display_id = self.platform_window.display().map(|display| display.id());
1512
1513        self.refresh();
1514
1515        self.bounds_observers
1516            .clone()
1517            .retain(&(), |callback| callback(self, cx));
1518    }
1519
1520    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1521    pub fn bounds(&self) -> Bounds<Pixels> {
1522        self.platform_window.bounds()
1523    }
1524
1525    /// Set the content size of the window.
1526    pub fn resize(&mut self, size: Size<Pixels>) {
1527        self.platform_window.resize(size);
1528    }
1529
1530    /// Returns whether or not the window is currently fullscreen
1531    pub fn is_fullscreen(&self) -> bool {
1532        self.platform_window.is_fullscreen()
1533    }
1534
1535    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1536        self.appearance = self.platform_window.appearance();
1537
1538        self.appearance_observers
1539            .clone()
1540            .retain(&(), |callback| callback(self, cx));
1541    }
1542
1543    /// Returns the appearance of the current window.
1544    pub fn appearance(&self) -> WindowAppearance {
1545        self.appearance
1546    }
1547
1548    /// Returns the size of the drawable area within the window.
1549    pub fn viewport_size(&self) -> Size<Pixels> {
1550        self.viewport_size
1551    }
1552
1553    /// Returns whether this window is focused by the operating system (receiving key events).
1554    pub fn is_window_active(&self) -> bool {
1555        self.active.get()
1556    }
1557
1558    /// Returns whether this window is considered to be the window
1559    /// that currently owns the mouse cursor.
1560    /// On mac, this is equivalent to `is_window_active`.
1561    pub fn is_window_hovered(&self) -> bool {
1562        if cfg!(any(
1563            target_os = "windows",
1564            target_os = "linux",
1565            target_os = "freebsd"
1566        )) {
1567            self.hovered.get()
1568        } else {
1569            self.is_window_active()
1570        }
1571    }
1572
1573    /// Toggle zoom on the window.
1574    pub fn zoom_window(&self) {
1575        self.platform_window.zoom();
1576    }
1577
1578    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1579    pub fn show_window_menu(&self, position: Point<Pixels>) {
1580        self.platform_window.show_window_menu(position)
1581    }
1582
1583    /// Tells the compositor to take control of window movement (Wayland and X11)
1584    ///
1585    /// Events may not be received during a move operation.
1586    pub fn start_window_move(&self) {
1587        self.platform_window.start_window_move()
1588    }
1589
1590    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1591    pub fn set_client_inset(&mut self, inset: Pixels) {
1592        self.client_inset = Some(inset);
1593        self.platform_window.set_client_inset(inset);
1594    }
1595
1596    /// Returns the client_inset value by [`Self::set_client_inset`].
1597    pub fn client_inset(&self) -> Option<Pixels> {
1598        self.client_inset
1599    }
1600
1601    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1602    pub fn window_decorations(&self) -> Decorations {
1603        self.platform_window.window_decorations()
1604    }
1605
1606    /// Returns which window controls are currently visible (Wayland)
1607    pub fn window_controls(&self) -> WindowControls {
1608        self.platform_window.window_controls()
1609    }
1610
1611    /// Updates the window's title at the platform level.
1612    pub fn set_window_title(&mut self, title: &str) {
1613        self.platform_window.set_title(title);
1614    }
1615
1616    /// Sets the application identifier.
1617    pub fn set_app_id(&mut self, app_id: &str) {
1618        self.platform_window.set_app_id(app_id);
1619    }
1620
1621    /// Sets the window background appearance.
1622    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1623        self.platform_window
1624            .set_background_appearance(background_appearance);
1625    }
1626
1627    /// Mark the window as dirty at the platform level.
1628    pub fn set_window_edited(&mut self, edited: bool) {
1629        self.platform_window.set_edited(edited);
1630    }
1631
1632    /// Determine the display on which the window is visible.
1633    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1634        cx.platform
1635            .displays()
1636            .into_iter()
1637            .find(|display| Some(display.id()) == self.display_id)
1638    }
1639
1640    /// Show the platform character palette.
1641    pub fn show_character_palette(&self) {
1642        self.platform_window.show_character_palette();
1643    }
1644
1645    /// The scale factor of the display associated with the window. For example, it could
1646    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1647    /// be rendered as two pixels on screen.
1648    pub fn scale_factor(&self) -> f32 {
1649        self.scale_factor
1650    }
1651
1652    /// The size of an em for the base font of the application. Adjusting this value allows the
1653    /// UI to scale, just like zooming a web page.
1654    pub fn rem_size(&self) -> Pixels {
1655        self.rem_size_override_stack
1656            .last()
1657            .copied()
1658            .unwrap_or(self.rem_size)
1659    }
1660
1661    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1662    /// UI to scale, just like zooming a web page.
1663    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1664        self.rem_size = rem_size.into();
1665    }
1666
1667    /// Acquire a globally unique identifier for the given ElementId.
1668    /// Only valid for the duration of the provided closure.
1669    pub fn with_global_id<R>(
1670        &mut self,
1671        element_id: ElementId,
1672        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1673    ) -> R {
1674        self.element_id_stack.push(element_id);
1675        let global_id = GlobalElementId(self.element_id_stack.clone());
1676        let result = f(&global_id, self);
1677        self.element_id_stack.pop();
1678        result
1679    }
1680
1681    /// Executes the provided function with the specified rem size.
1682    ///
1683    /// This method must only be called as part of element drawing.
1684    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1685    where
1686        F: FnOnce(&mut Self) -> R,
1687    {
1688        self.invalidator.debug_assert_paint_or_prepaint();
1689
1690        if let Some(rem_size) = rem_size {
1691            self.rem_size_override_stack.push(rem_size.into());
1692            let result = f(self);
1693            self.rem_size_override_stack.pop();
1694            result
1695        } else {
1696            f(self)
1697        }
1698    }
1699
1700    /// The line height associated with the current text style.
1701    pub fn line_height(&self) -> Pixels {
1702        self.text_style().line_height_in_pixels(self.rem_size())
1703    }
1704
1705    /// Call to prevent the default action of an event. Currently only used to prevent
1706    /// parent elements from becoming focused on mouse down.
1707    pub fn prevent_default(&mut self) {
1708        self.default_prevented = true;
1709    }
1710
1711    /// Obtain whether default has been prevented for the event currently being dispatched.
1712    pub fn default_prevented(&self) -> bool {
1713        self.default_prevented
1714    }
1715
1716    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1717    pub fn is_action_available(&self, action: &dyn Action, cx: &mut App) -> bool {
1718        let node_id =
1719            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
1720        self.rendered_frame
1721            .dispatch_tree
1722            .is_action_available(action, node_id)
1723    }
1724
1725    /// The position of the mouse relative to the window.
1726    pub fn mouse_position(&self) -> Point<Pixels> {
1727        self.mouse_position
1728    }
1729
1730    /// The current state of the keyboard's modifiers
1731    pub fn modifiers(&self) -> Modifiers {
1732        self.modifiers
1733    }
1734
1735    /// The current state of the keyboard's capslock
1736    pub fn capslock(&self) -> Capslock {
1737        self.capslock
1738    }
1739
1740    fn complete_frame(&self) {
1741        self.platform_window.completed_frame();
1742    }
1743
1744    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1745    /// the contents of the new [Scene], use [present].
1746    #[profiling::function]
1747    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
1748        self.invalidate_entities();
1749        cx.entities.clear_accessed();
1750        debug_assert!(self.rendered_entity_stack.is_empty());
1751        self.invalidator.set_dirty(false);
1752        self.requested_autoscroll = None;
1753
1754        // Restore the previously-used input handler.
1755        if let Some(input_handler) = self.platform_window.take_input_handler() {
1756            self.rendered_frame.input_handlers.push(Some(input_handler));
1757        }
1758        self.draw_roots(cx);
1759        self.dirty_views.clear();
1760        self.next_frame.window_active = self.active.get();
1761
1762        // Register requested input handler with the platform window.
1763        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
1764            self.platform_window
1765                .set_input_handler(input_handler.unwrap());
1766        }
1767
1768        self.layout_engine.as_mut().unwrap().clear();
1769        self.text_system().finish_frame();
1770        self.next_frame.finish(&mut self.rendered_frame);
1771
1772        self.invalidator.set_phase(DrawPhase::Focus);
1773        let previous_focus_path = self.rendered_frame.focus_path();
1774        let previous_window_active = self.rendered_frame.window_active;
1775        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
1776        self.next_frame.clear();
1777        let current_focus_path = self.rendered_frame.focus_path();
1778        let current_window_active = self.rendered_frame.window_active;
1779
1780        if previous_focus_path != current_focus_path
1781            || previous_window_active != current_window_active
1782        {
1783            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1784                self.focus_lost_listeners
1785                    .clone()
1786                    .retain(&(), |listener| listener(self, cx));
1787            }
1788
1789            let event = WindowFocusEvent {
1790                previous_focus_path: if previous_window_active {
1791                    previous_focus_path
1792                } else {
1793                    Default::default()
1794                },
1795                current_focus_path: if current_window_active {
1796                    current_focus_path
1797                } else {
1798                    Default::default()
1799                },
1800            };
1801            self.focus_listeners
1802                .clone()
1803                .retain(&(), |listener| listener(&event, self, cx));
1804        }
1805
1806        debug_assert!(self.rendered_entity_stack.is_empty());
1807        self.record_entities_accessed(cx);
1808        self.reset_cursor_style(cx);
1809        self.refreshing = false;
1810        self.invalidator.set_phase(DrawPhase::None);
1811        self.needs_present.set(true);
1812
1813        ArenaClearNeeded
1814    }
1815
1816    fn record_entities_accessed(&mut self, cx: &mut App) {
1817        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1818        let mut entities = mem::take(entities_ref.deref_mut());
1819        drop(entities_ref);
1820        let handle = self.handle;
1821        cx.record_entities_accessed(
1822            handle,
1823            // Try moving window invalidator into the Window
1824            self.invalidator.clone(),
1825            &entities,
1826        );
1827        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1828        mem::swap(&mut entities, entities_ref.deref_mut());
1829    }
1830
1831    fn invalidate_entities(&mut self) {
1832        let mut views = self.invalidator.take_views();
1833        for entity in views.drain() {
1834            self.mark_view_dirty(entity);
1835        }
1836        self.invalidator.replace_views(views);
1837    }
1838
1839    #[profiling::function]
1840    fn present(&self) {
1841        self.platform_window.draw(&self.rendered_frame.scene);
1842        self.needs_present.set(false);
1843        profiling::finish_frame!();
1844    }
1845
1846    fn draw_roots(&mut self, cx: &mut App) {
1847        self.invalidator.set_phase(DrawPhase::Prepaint);
1848        self.tooltip_bounds.take();
1849
1850        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
1851        let root_size = {
1852            #[cfg(any(feature = "inspector", debug_assertions))]
1853            {
1854                if self.inspector.is_some() {
1855                    let mut size = self.viewport_size;
1856                    size.width = (size.width - _inspector_width).max(px(0.0));
1857                    size
1858                } else {
1859                    self.viewport_size
1860                }
1861            }
1862            #[cfg(not(any(feature = "inspector", debug_assertions)))]
1863            {
1864                self.viewport_size
1865            }
1866        };
1867
1868        // Layout all root elements.
1869        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
1870        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1871
1872        #[cfg(any(feature = "inspector", debug_assertions))]
1873        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
1874
1875        let mut sorted_deferred_draws =
1876            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1877        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
1878        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
1879
1880        let mut prompt_element = None;
1881        let mut active_drag_element = None;
1882        let mut tooltip_element = None;
1883        if let Some(prompt) = self.prompt.take() {
1884            let mut element = prompt.view.any_view().into_any();
1885            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1886            prompt_element = Some(element);
1887            self.prompt = Some(prompt);
1888        } else if let Some(active_drag) = cx.active_drag.take() {
1889            let mut element = active_drag.view.clone().into_any();
1890            let offset = self.mouse_position() - active_drag.cursor_offset;
1891            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
1892            active_drag_element = Some(element);
1893            cx.active_drag = Some(active_drag);
1894        } else {
1895            tooltip_element = self.prepaint_tooltip(cx);
1896        }
1897
1898        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
1899
1900        // Now actually paint the elements.
1901        self.invalidator.set_phase(DrawPhase::Paint);
1902        root_element.paint(self, cx);
1903
1904        #[cfg(any(feature = "inspector", debug_assertions))]
1905        self.paint_inspector(inspector_element, cx);
1906
1907        self.paint_deferred_draws(&sorted_deferred_draws, cx);
1908
1909        if let Some(mut prompt_element) = prompt_element {
1910            prompt_element.paint(self, cx);
1911        } else if let Some(mut drag_element) = active_drag_element {
1912            drag_element.paint(self, cx);
1913        } else if let Some(mut tooltip_element) = tooltip_element {
1914            tooltip_element.paint(self, cx);
1915        }
1916
1917        #[cfg(any(feature = "inspector", debug_assertions))]
1918        self.paint_inspector_hitbox(cx);
1919    }
1920
1921    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
1922        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
1923        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
1924            let Some(Some(tooltip_request)) = self
1925                .next_frame
1926                .tooltip_requests
1927                .get(tooltip_request_index)
1928                .cloned()
1929            else {
1930                log::error!("Unexpectedly absent TooltipRequest");
1931                continue;
1932            };
1933            let mut element = tooltip_request.tooltip.view.clone().into_any();
1934            let mouse_position = tooltip_request.tooltip.mouse_position;
1935            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
1936
1937            let mut tooltip_bounds =
1938                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1939            let window_bounds = Bounds {
1940                origin: Point::default(),
1941                size: self.viewport_size(),
1942            };
1943
1944            if tooltip_bounds.right() > window_bounds.right() {
1945                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1946                if new_x >= Pixels::ZERO {
1947                    tooltip_bounds.origin.x = new_x;
1948                } else {
1949                    tooltip_bounds.origin.x = cmp::max(
1950                        Pixels::ZERO,
1951                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1952                    );
1953                }
1954            }
1955
1956            if tooltip_bounds.bottom() > window_bounds.bottom() {
1957                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1958                if new_y >= Pixels::ZERO {
1959                    tooltip_bounds.origin.y = new_y;
1960                } else {
1961                    tooltip_bounds.origin.y = cmp::max(
1962                        Pixels::ZERO,
1963                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1964                    );
1965                }
1966            }
1967
1968            // It's possible for an element to have an active tooltip while not being painted (e.g.
1969            // via the `visible_on_hover` method). Since mouse listeners are not active in this
1970            // case, instead update the tooltip's visibility here.
1971            let is_visible =
1972                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
1973            if !is_visible {
1974                continue;
1975            }
1976
1977            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
1978                element.prepaint(window, cx)
1979            });
1980
1981            self.tooltip_bounds = Some(TooltipBounds {
1982                id: tooltip_request.id,
1983                bounds: tooltip_bounds,
1984            });
1985            return Some(element);
1986        }
1987        None
1988    }
1989
1990    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
1991        assert_eq!(self.element_id_stack.len(), 0);
1992
1993        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
1994        for deferred_draw_ix in deferred_draw_indices {
1995            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1996            self.element_id_stack
1997                .clone_from(&deferred_draw.element_id_stack);
1998            self.text_style_stack
1999                .clone_from(&deferred_draw.text_style_stack);
2000            self.next_frame
2001                .dispatch_tree
2002                .set_active_node(deferred_draw.parent_node);
2003
2004            let prepaint_start = self.prepaint_index();
2005            if let Some(element) = deferred_draw.element.as_mut() {
2006                self.with_rendered_view(deferred_draw.current_view, |window| {
2007                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
2008                        element.prepaint(window, cx)
2009                    });
2010                })
2011            } else {
2012                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2013            }
2014            let prepaint_end = self.prepaint_index();
2015            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2016        }
2017        assert_eq!(
2018            self.next_frame.deferred_draws.len(),
2019            0,
2020            "cannot call defer_draw during deferred drawing"
2021        );
2022        self.next_frame.deferred_draws = deferred_draws;
2023        self.element_id_stack.clear();
2024        self.text_style_stack.clear();
2025    }
2026
2027    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2028        assert_eq!(self.element_id_stack.len(), 0);
2029
2030        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2031        for deferred_draw_ix in deferred_draw_indices {
2032            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2033            self.element_id_stack
2034                .clone_from(&deferred_draw.element_id_stack);
2035            self.next_frame
2036                .dispatch_tree
2037                .set_active_node(deferred_draw.parent_node);
2038
2039            let paint_start = self.paint_index();
2040            if let Some(element) = deferred_draw.element.as_mut() {
2041                self.with_rendered_view(deferred_draw.current_view, |window| {
2042                    element.paint(window, cx);
2043                })
2044            } else {
2045                self.reuse_paint(deferred_draw.paint_range.clone());
2046            }
2047            let paint_end = self.paint_index();
2048            deferred_draw.paint_range = paint_start..paint_end;
2049        }
2050        self.next_frame.deferred_draws = deferred_draws;
2051        self.element_id_stack.clear();
2052    }
2053
2054    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2055        PrepaintStateIndex {
2056            hitboxes_index: self.next_frame.hitboxes.len(),
2057            tooltips_index: self.next_frame.tooltip_requests.len(),
2058            deferred_draws_index: self.next_frame.deferred_draws.len(),
2059            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2060            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2061            line_layout_index: self.text_system.layout_index(),
2062        }
2063    }
2064
2065    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2066        self.next_frame.hitboxes.extend(
2067            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2068                .iter()
2069                .cloned(),
2070        );
2071        self.next_frame.tooltip_requests.extend(
2072            self.rendered_frame.tooltip_requests
2073                [range.start.tooltips_index..range.end.tooltips_index]
2074                .iter_mut()
2075                .map(|request| request.take()),
2076        );
2077        self.next_frame.accessed_element_states.extend(
2078            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2079                ..range.end.accessed_element_states_index]
2080                .iter()
2081                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2082        );
2083        self.text_system
2084            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2085
2086        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2087            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2088            &mut self.rendered_frame.dispatch_tree,
2089            self.focus,
2090        );
2091
2092        if reused_subtree.contains_focus() {
2093            self.next_frame.focus = self.focus;
2094        }
2095
2096        self.next_frame.deferred_draws.extend(
2097            self.rendered_frame.deferred_draws
2098                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2099                .iter()
2100                .map(|deferred_draw| DeferredDraw {
2101                    current_view: deferred_draw.current_view,
2102                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2103                    element_id_stack: deferred_draw.element_id_stack.clone(),
2104                    text_style_stack: deferred_draw.text_style_stack.clone(),
2105                    priority: deferred_draw.priority,
2106                    element: None,
2107                    absolute_offset: deferred_draw.absolute_offset,
2108                    prepaint_range: deferred_draw.prepaint_range.clone(),
2109                    paint_range: deferred_draw.paint_range.clone(),
2110                }),
2111        );
2112    }
2113
2114    pub(crate) fn paint_index(&self) -> PaintIndex {
2115        PaintIndex {
2116            scene_index: self.next_frame.scene.len(),
2117            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2118            input_handlers_index: self.next_frame.input_handlers.len(),
2119            cursor_styles_index: self.next_frame.cursor_styles.len(),
2120            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2121            line_layout_index: self.text_system.layout_index(),
2122        }
2123    }
2124
2125    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2126        self.next_frame.cursor_styles.extend(
2127            self.rendered_frame.cursor_styles
2128                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2129                .iter()
2130                .cloned(),
2131        );
2132        self.next_frame.input_handlers.extend(
2133            self.rendered_frame.input_handlers
2134                [range.start.input_handlers_index..range.end.input_handlers_index]
2135                .iter_mut()
2136                .map(|handler| handler.take()),
2137        );
2138        self.next_frame.mouse_listeners.extend(
2139            self.rendered_frame.mouse_listeners
2140                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2141                .iter_mut()
2142                .map(|listener| listener.take()),
2143        );
2144        self.next_frame.accessed_element_states.extend(
2145            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2146                ..range.end.accessed_element_states_index]
2147                .iter()
2148                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2149        );
2150
2151        self.text_system
2152            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2153        self.next_frame.scene.replay(
2154            range.start.scene_index..range.end.scene_index,
2155            &self.rendered_frame.scene,
2156        );
2157    }
2158
2159    /// Push a text style onto the stack, and call a function with that style active.
2160    /// Use [`Window::text_style`] to get the current, combined text style. This method
2161    /// should only be called as part of element drawing.
2162    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2163    where
2164        F: FnOnce(&mut Self) -> R,
2165    {
2166        self.invalidator.debug_assert_paint_or_prepaint();
2167        if let Some(style) = style {
2168            self.text_style_stack.push(style);
2169            let result = f(self);
2170            self.text_style_stack.pop();
2171            result
2172        } else {
2173            f(self)
2174        }
2175    }
2176
2177    /// Updates the cursor style at the platform level. This method should only be called
2178    /// during the prepaint phase of element drawing.
2179    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2180        self.invalidator.debug_assert_paint();
2181        self.next_frame.cursor_styles.push(CursorStyleRequest {
2182            hitbox_id: Some(hitbox.id),
2183            style,
2184        });
2185    }
2186
2187    /// Updates the cursor style for the entire window at the platform level. A cursor
2188    /// style using this method will have precedence over any cursor style set using
2189    /// `set_cursor_style`. This method should only be called during the prepaint
2190    /// phase of element drawing.
2191    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2192        self.invalidator.debug_assert_paint();
2193        self.next_frame.cursor_styles.push(CursorStyleRequest {
2194            hitbox_id: None,
2195            style,
2196        })
2197    }
2198
2199    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2200    /// during the paint phase of element drawing.
2201    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2202        self.invalidator.debug_assert_prepaint();
2203        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2204        self.next_frame
2205            .tooltip_requests
2206            .push(Some(TooltipRequest { id, tooltip }));
2207        id
2208    }
2209
2210    /// Invoke the given function with the given content mask after intersecting it
2211    /// with the current mask. This method should only be called during element drawing.
2212    pub fn with_content_mask<R>(
2213        &mut self,
2214        mask: Option<ContentMask<Pixels>>,
2215        f: impl FnOnce(&mut Self) -> R,
2216    ) -> R {
2217        self.invalidator.debug_assert_paint_or_prepaint();
2218        if let Some(mask) = mask {
2219            let mask = mask.intersect(&self.content_mask());
2220            self.content_mask_stack.push(mask);
2221            let result = f(self);
2222            self.content_mask_stack.pop();
2223            result
2224        } else {
2225            f(self)
2226        }
2227    }
2228
2229    /// Updates the global element offset relative to the current offset. This is used to implement
2230    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2231    pub fn with_element_offset<R>(
2232        &mut self,
2233        offset: Point<Pixels>,
2234        f: impl FnOnce(&mut Self) -> R,
2235    ) -> R {
2236        self.invalidator.debug_assert_prepaint();
2237
2238        if offset.is_zero() {
2239            return f(self);
2240        };
2241
2242        let abs_offset = self.element_offset() + offset;
2243        self.with_absolute_element_offset(abs_offset, f)
2244    }
2245
2246    /// Updates the global element offset based on the given offset. This is used to implement
2247    /// drag handles and other manual painting of elements. This method should only be called during
2248    /// the prepaint phase of element drawing.
2249    pub fn with_absolute_element_offset<R>(
2250        &mut self,
2251        offset: Point<Pixels>,
2252        f: impl FnOnce(&mut Self) -> R,
2253    ) -> R {
2254        self.invalidator.debug_assert_prepaint();
2255        self.element_offset_stack.push(offset);
2256        let result = f(self);
2257        self.element_offset_stack.pop();
2258        result
2259    }
2260
2261    pub(crate) fn with_element_opacity<R>(
2262        &mut self,
2263        opacity: Option<f32>,
2264        f: impl FnOnce(&mut Self) -> R,
2265    ) -> R {
2266        if opacity.is_none() {
2267            return f(self);
2268        }
2269
2270        self.invalidator.debug_assert_paint_or_prepaint();
2271        self.element_opacity = opacity;
2272        let result = f(self);
2273        self.element_opacity = None;
2274        result
2275    }
2276
2277    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2278    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2279    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2280    /// element offset and prepaint again. See [`List`] for an example. This method should only be
2281    /// called during the prepaint phase of element drawing.
2282    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2283        self.invalidator.debug_assert_prepaint();
2284        let index = self.prepaint_index();
2285        let result = f(self);
2286        if result.is_err() {
2287            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2288            self.next_frame
2289                .tooltip_requests
2290                .truncate(index.tooltips_index);
2291            self.next_frame
2292                .deferred_draws
2293                .truncate(index.deferred_draws_index);
2294            self.next_frame
2295                .dispatch_tree
2296                .truncate(index.dispatch_tree_index);
2297            self.next_frame
2298                .accessed_element_states
2299                .truncate(index.accessed_element_states_index);
2300            self.text_system.truncate_layouts(index.line_layout_index);
2301        }
2302        result
2303    }
2304
2305    /// When you call this method during [`prepaint`], containing elements will attempt to
2306    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2307    /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
2308    /// that supports this method being called on the elements it contains. This method should only be
2309    /// called during the prepaint phase of element drawing.
2310    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2311        self.invalidator.debug_assert_prepaint();
2312        self.requested_autoscroll = Some(bounds);
2313    }
2314
2315    /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
2316    /// described in [`request_autoscroll`].
2317    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2318        self.invalidator.debug_assert_prepaint();
2319        self.requested_autoscroll.take()
2320    }
2321
2322    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2323    /// Your view will be re-drawn once the asset has finished loading.
2324    ///
2325    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2326    /// time.
2327    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2328        let (task, is_first) = cx.fetch_asset::<A>(source);
2329        task.clone().now_or_never().or_else(|| {
2330            if is_first {
2331                let entity_id = self.current_view();
2332                self.spawn(cx, {
2333                    let task = task.clone();
2334                    async move |cx| {
2335                        task.await;
2336
2337                        cx.on_next_frame(move |_, cx| {
2338                            cx.notify(entity_id);
2339                        });
2340                    }
2341                })
2342                .detach();
2343            }
2344
2345            None
2346        })
2347    }
2348
2349    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2350    /// Your view will not be re-drawn once the asset has finished loading.
2351    ///
2352    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2353    /// time.
2354    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2355        let (task, _) = cx.fetch_asset::<A>(source);
2356        task.clone().now_or_never()
2357    }
2358    /// Obtain the current element offset. This method should only be called during the
2359    /// prepaint phase of element drawing.
2360    pub fn element_offset(&self) -> Point<Pixels> {
2361        self.invalidator.debug_assert_prepaint();
2362        self.element_offset_stack
2363            .last()
2364            .copied()
2365            .unwrap_or_default()
2366    }
2367
2368    /// Obtain the current element opacity. This method should only be called during the
2369    /// prepaint phase of element drawing.
2370    pub(crate) fn element_opacity(&self) -> f32 {
2371        self.invalidator.debug_assert_paint_or_prepaint();
2372        self.element_opacity.unwrap_or(1.0)
2373    }
2374
2375    /// Obtain the current content mask. This method should only be called during element drawing.
2376    pub fn content_mask(&self) -> ContentMask<Pixels> {
2377        self.invalidator.debug_assert_paint_or_prepaint();
2378        self.content_mask_stack
2379            .last()
2380            .cloned()
2381            .unwrap_or_else(|| ContentMask {
2382                bounds: Bounds {
2383                    origin: Point::default(),
2384                    size: self.viewport_size,
2385                },
2386            })
2387    }
2388
2389    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2390    /// This can be used within a custom element to distinguish multiple sets of child elements.
2391    pub fn with_element_namespace<R>(
2392        &mut self,
2393        element_id: impl Into<ElementId>,
2394        f: impl FnOnce(&mut Self) -> R,
2395    ) -> R {
2396        self.element_id_stack.push(element_id.into());
2397        let result = f(self);
2398        self.element_id_stack.pop();
2399        result
2400    }
2401
2402    /// Updates or initializes state for an element with the given id that lives across multiple
2403    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2404    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2405    /// when drawing the next frame. This method should only be called as part of element drawing.
2406    pub fn with_element_state<S, R>(
2407        &mut self,
2408        global_id: &GlobalElementId,
2409        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2410    ) -> R
2411    where
2412        S: 'static,
2413    {
2414        self.invalidator.debug_assert_paint_or_prepaint();
2415
2416        let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2417        self.next_frame
2418            .accessed_element_states
2419            .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2420
2421        if let Some(any) = self
2422            .next_frame
2423            .element_states
2424            .remove(&key)
2425            .or_else(|| self.rendered_frame.element_states.remove(&key))
2426        {
2427            let ElementStateBox {
2428                inner,
2429                #[cfg(debug_assertions)]
2430                type_name,
2431            } = any;
2432            // Using the extra inner option to avoid needing to reallocate a new box.
2433            let mut state_box = inner
2434                .downcast::<Option<S>>()
2435                .map_err(|_| {
2436                    #[cfg(debug_assertions)]
2437                    {
2438                        anyhow::anyhow!(
2439                            "invalid element state type for id, requested {:?}, actual: {:?}",
2440                            std::any::type_name::<S>(),
2441                            type_name
2442                        )
2443                    }
2444
2445                    #[cfg(not(debug_assertions))]
2446                    {
2447                        anyhow::anyhow!(
2448                            "invalid element state type for id, requested {:?}",
2449                            std::any::type_name::<S>(),
2450                        )
2451                    }
2452                })
2453                .unwrap();
2454
2455            let state = state_box.take().expect(
2456                "reentrant call to with_element_state for the same state type and element id",
2457            );
2458            let (result, state) = f(Some(state), self);
2459            state_box.replace(state);
2460            self.next_frame.element_states.insert(
2461                key,
2462                ElementStateBox {
2463                    inner: state_box,
2464                    #[cfg(debug_assertions)]
2465                    type_name,
2466                },
2467            );
2468            result
2469        } else {
2470            let (result, state) = f(None, self);
2471            self.next_frame.element_states.insert(
2472                key,
2473                ElementStateBox {
2474                    inner: Box::new(Some(state)),
2475                    #[cfg(debug_assertions)]
2476                    type_name: std::any::type_name::<S>(),
2477                },
2478            );
2479            result
2480        }
2481    }
2482
2483    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2484    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2485    /// when the element is guaranteed to have an id.
2486    ///
2487    /// The first option means 'no ID provided'
2488    /// The second option means 'not yet initialized'
2489    pub fn with_optional_element_state<S, R>(
2490        &mut self,
2491        global_id: Option<&GlobalElementId>,
2492        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2493    ) -> R
2494    where
2495        S: 'static,
2496    {
2497        self.invalidator.debug_assert_paint_or_prepaint();
2498
2499        if let Some(global_id) = global_id {
2500            self.with_element_state(global_id, |state, cx| {
2501                let (result, state) = f(Some(state), cx);
2502                let state =
2503                    state.expect("you must return some state when you pass some element id");
2504                (result, state)
2505            })
2506        } else {
2507            let (result, state) = f(None, self);
2508            debug_assert!(
2509                state.is_none(),
2510                "you must not return an element state when passing None for the global id"
2511            );
2512            result
2513        }
2514    }
2515
2516    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2517    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2518    /// with higher values being drawn on top.
2519    ///
2520    /// This method should only be called as part of the prepaint phase of element drawing.
2521    pub fn defer_draw(
2522        &mut self,
2523        element: AnyElement,
2524        absolute_offset: Point<Pixels>,
2525        priority: usize,
2526    ) {
2527        self.invalidator.debug_assert_prepaint();
2528        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2529        self.next_frame.deferred_draws.push(DeferredDraw {
2530            current_view: self.current_view(),
2531            parent_node,
2532            element_id_stack: self.element_id_stack.clone(),
2533            text_style_stack: self.text_style_stack.clone(),
2534            priority,
2535            element: Some(element),
2536            absolute_offset,
2537            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2538            paint_range: PaintIndex::default()..PaintIndex::default(),
2539        });
2540    }
2541
2542    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2543    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2544    /// for performance reasons.
2545    ///
2546    /// This method should only be called as part of the paint phase of element drawing.
2547    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2548        self.invalidator.debug_assert_paint();
2549
2550        let scale_factor = self.scale_factor();
2551        let content_mask = self.content_mask();
2552        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2553        if !clipped_bounds.is_empty() {
2554            self.next_frame
2555                .scene
2556                .push_layer(clipped_bounds.scale(scale_factor));
2557        }
2558
2559        let result = f(self);
2560
2561        if !clipped_bounds.is_empty() {
2562            self.next_frame.scene.pop_layer();
2563        }
2564
2565        result
2566    }
2567
2568    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2569    ///
2570    /// This method should only be called as part of the paint phase of element drawing.
2571    pub fn paint_shadows(
2572        &mut self,
2573        bounds: Bounds<Pixels>,
2574        corner_radii: Corners<Pixels>,
2575        shadows: &[BoxShadow],
2576    ) {
2577        self.invalidator.debug_assert_paint();
2578
2579        let scale_factor = self.scale_factor();
2580        let content_mask = self.content_mask();
2581        let opacity = self.element_opacity();
2582        for shadow in shadows {
2583            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2584            self.next_frame.scene.insert_primitive(Shadow {
2585                order: 0,
2586                blur_radius: shadow.blur_radius.scale(scale_factor),
2587                bounds: shadow_bounds.scale(scale_factor),
2588                content_mask: content_mask.scale(scale_factor),
2589                corner_radii: corner_radii.scale(scale_factor),
2590                color: shadow.color.opacity(opacity),
2591            });
2592        }
2593    }
2594
2595    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2596    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2597    /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2598    ///
2599    /// This method should only be called as part of the paint phase of element drawing.
2600    ///
2601    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2602    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2603    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2604    pub fn paint_quad(&mut self, quad: PaintQuad) {
2605        self.invalidator.debug_assert_paint();
2606
2607        let scale_factor = self.scale_factor();
2608        let content_mask = self.content_mask();
2609        let opacity = self.element_opacity();
2610        self.next_frame.scene.insert_primitive(Quad {
2611            order: 0,
2612            bounds: quad.bounds.scale(scale_factor),
2613            content_mask: content_mask.scale(scale_factor),
2614            background: quad.background.opacity(opacity),
2615            border_color: quad.border_color.opacity(opacity),
2616            corner_radii: quad.corner_radii.scale(scale_factor),
2617            border_widths: quad.border_widths.scale(scale_factor),
2618            border_style: quad.border_style,
2619        });
2620    }
2621
2622    /// Paint the given `Path` into the scene for the next frame at the current z-index.
2623    ///
2624    /// This method should only be called as part of the paint phase of element drawing.
2625    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2626        self.invalidator.debug_assert_paint();
2627
2628        let scale_factor = self.scale_factor();
2629        let content_mask = self.content_mask();
2630        let opacity = self.element_opacity();
2631        path.content_mask = content_mask;
2632        let color: Background = color.into();
2633        path.color = color.opacity(opacity);
2634        self.next_frame
2635            .scene
2636            .insert_primitive(path.scale(scale_factor));
2637    }
2638
2639    /// Paint an underline into the scene for the next frame at the current z-index.
2640    ///
2641    /// This method should only be called as part of the paint phase of element drawing.
2642    pub fn paint_underline(
2643        &mut self,
2644        origin: Point<Pixels>,
2645        width: Pixels,
2646        style: &UnderlineStyle,
2647    ) {
2648        self.invalidator.debug_assert_paint();
2649
2650        let scale_factor = self.scale_factor();
2651        let height = if style.wavy {
2652            style.thickness * 3.
2653        } else {
2654            style.thickness
2655        };
2656        let bounds = Bounds {
2657            origin,
2658            size: size(width, height),
2659        };
2660        let content_mask = self.content_mask();
2661        let element_opacity = self.element_opacity();
2662
2663        self.next_frame.scene.insert_primitive(Underline {
2664            order: 0,
2665            pad: 0,
2666            bounds: bounds.scale(scale_factor),
2667            content_mask: content_mask.scale(scale_factor),
2668            color: style.color.unwrap_or_default().opacity(element_opacity),
2669            thickness: style.thickness.scale(scale_factor),
2670            wavy: style.wavy,
2671        });
2672    }
2673
2674    /// Paint a strikethrough into the scene for the next frame at the current z-index.
2675    ///
2676    /// This method should only be called as part of the paint phase of element drawing.
2677    pub fn paint_strikethrough(
2678        &mut self,
2679        origin: Point<Pixels>,
2680        width: Pixels,
2681        style: &StrikethroughStyle,
2682    ) {
2683        self.invalidator.debug_assert_paint();
2684
2685        let scale_factor = self.scale_factor();
2686        let height = style.thickness;
2687        let bounds = Bounds {
2688            origin,
2689            size: size(width, height),
2690        };
2691        let content_mask = self.content_mask();
2692        let opacity = self.element_opacity();
2693
2694        self.next_frame.scene.insert_primitive(Underline {
2695            order: 0,
2696            pad: 0,
2697            bounds: bounds.scale(scale_factor),
2698            content_mask: content_mask.scale(scale_factor),
2699            thickness: style.thickness.scale(scale_factor),
2700            color: style.color.unwrap_or_default().opacity(opacity),
2701            wavy: false,
2702        });
2703    }
2704
2705    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2706    ///
2707    /// The y component of the origin is the baseline of the glyph.
2708    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2709    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2710    /// This method is only useful if you need to paint a single glyph that has already been shaped.
2711    ///
2712    /// This method should only be called as part of the paint phase of element drawing.
2713    pub fn paint_glyph(
2714        &mut self,
2715        origin: Point<Pixels>,
2716        font_id: FontId,
2717        glyph_id: GlyphId,
2718        font_size: Pixels,
2719        color: Hsla,
2720    ) -> Result<()> {
2721        self.invalidator.debug_assert_paint();
2722
2723        let element_opacity = self.element_opacity();
2724        let scale_factor = self.scale_factor();
2725        let glyph_origin = origin.scale(scale_factor);
2726        let subpixel_variant = Point {
2727            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2728            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2729        };
2730        let params = RenderGlyphParams {
2731            font_id,
2732            glyph_id,
2733            font_size,
2734            subpixel_variant,
2735            scale_factor,
2736            is_emoji: false,
2737        };
2738
2739        let raster_bounds = self.text_system().raster_bounds(&params)?;
2740        if !raster_bounds.is_zero() {
2741            let tile = self
2742                .sprite_atlas
2743                .get_or_insert_with(&params.clone().into(), &mut || {
2744                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2745                    Ok(Some((size, Cow::Owned(bytes))))
2746                })?
2747                .expect("Callback above only errors or returns Some");
2748            let bounds = Bounds {
2749                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2750                size: tile.bounds.size.map(Into::into),
2751            };
2752            let content_mask = self.content_mask().scale(scale_factor);
2753            self.next_frame.scene.insert_primitive(MonochromeSprite {
2754                order: 0,
2755                pad: 0,
2756                bounds,
2757                content_mask,
2758                color: color.opacity(element_opacity),
2759                tile,
2760                transformation: TransformationMatrix::unit(),
2761            });
2762        }
2763        Ok(())
2764    }
2765
2766    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2767    ///
2768    /// The y component of the origin is the baseline of the glyph.
2769    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2770    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2771    /// This method is only useful if you need to paint a single emoji that has already been shaped.
2772    ///
2773    /// This method should only be called as part of the paint phase of element drawing.
2774    pub fn paint_emoji(
2775        &mut self,
2776        origin: Point<Pixels>,
2777        font_id: FontId,
2778        glyph_id: GlyphId,
2779        font_size: Pixels,
2780    ) -> Result<()> {
2781        self.invalidator.debug_assert_paint();
2782
2783        let scale_factor = self.scale_factor();
2784        let glyph_origin = origin.scale(scale_factor);
2785        let params = RenderGlyphParams {
2786            font_id,
2787            glyph_id,
2788            font_size,
2789            // We don't render emojis with subpixel variants.
2790            subpixel_variant: Default::default(),
2791            scale_factor,
2792            is_emoji: true,
2793        };
2794
2795        let raster_bounds = self.text_system().raster_bounds(&params)?;
2796        if !raster_bounds.is_zero() {
2797            let tile = self
2798                .sprite_atlas
2799                .get_or_insert_with(&params.clone().into(), &mut || {
2800                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2801                    Ok(Some((size, Cow::Owned(bytes))))
2802                })?
2803                .expect("Callback above only errors or returns Some");
2804
2805            let bounds = Bounds {
2806                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2807                size: tile.bounds.size.map(Into::into),
2808            };
2809            let content_mask = self.content_mask().scale(scale_factor);
2810            let opacity = self.element_opacity();
2811
2812            self.next_frame.scene.insert_primitive(PolychromeSprite {
2813                order: 0,
2814                pad: 0,
2815                grayscale: false,
2816                bounds,
2817                corner_radii: Default::default(),
2818                content_mask,
2819                tile,
2820                opacity,
2821            });
2822        }
2823        Ok(())
2824    }
2825
2826    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2827    ///
2828    /// This method should only be called as part of the paint phase of element drawing.
2829    pub fn paint_svg(
2830        &mut self,
2831        bounds: Bounds<Pixels>,
2832        path: SharedString,
2833        transformation: TransformationMatrix,
2834        color: Hsla,
2835        cx: &App,
2836    ) -> Result<()> {
2837        self.invalidator.debug_assert_paint();
2838
2839        let element_opacity = self.element_opacity();
2840        let scale_factor = self.scale_factor();
2841        let bounds = bounds.scale(scale_factor);
2842        let params = RenderSvgParams {
2843            path,
2844            size: bounds.size.map(|pixels| {
2845                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
2846            }),
2847        };
2848
2849        let Some(tile) =
2850            self.sprite_atlas
2851                .get_or_insert_with(&params.clone().into(), &mut || {
2852                    let Some(bytes) = cx.svg_renderer.render(&params)? else {
2853                        return Ok(None);
2854                    };
2855                    Ok(Some((params.size, Cow::Owned(bytes))))
2856                })?
2857        else {
2858            return Ok(());
2859        };
2860        let content_mask = self.content_mask().scale(scale_factor);
2861
2862        self.next_frame.scene.insert_primitive(MonochromeSprite {
2863            order: 0,
2864            pad: 0,
2865            bounds: bounds
2866                .map_origin(|origin| origin.floor())
2867                .map_size(|size| size.ceil()),
2868            content_mask,
2869            color: color.opacity(element_opacity),
2870            tile,
2871            transformation,
2872        });
2873
2874        Ok(())
2875    }
2876
2877    /// Paint an image into the scene for the next frame at the current z-index.
2878    /// This method will panic if the frame_index is not valid
2879    ///
2880    /// This method should only be called as part of the paint phase of element drawing.
2881    pub fn paint_image(
2882        &mut self,
2883        bounds: Bounds<Pixels>,
2884        corner_radii: Corners<Pixels>,
2885        data: Arc<RenderImage>,
2886        frame_index: usize,
2887        grayscale: bool,
2888    ) -> Result<()> {
2889        self.invalidator.debug_assert_paint();
2890
2891        let scale_factor = self.scale_factor();
2892        let bounds = bounds.scale(scale_factor);
2893        let params = RenderImageParams {
2894            image_id: data.id,
2895            frame_index,
2896        };
2897
2898        let tile = self
2899            .sprite_atlas
2900            .get_or_insert_with(&params.clone().into(), &mut || {
2901                Ok(Some((
2902                    data.size(frame_index),
2903                    Cow::Borrowed(
2904                        data.as_bytes(frame_index)
2905                            .expect("It's the caller's job to pass a valid frame index"),
2906                    ),
2907                )))
2908            })?
2909            .expect("Callback above only returns Some");
2910        let content_mask = self.content_mask().scale(scale_factor);
2911        let corner_radii = corner_radii.scale(scale_factor);
2912        let opacity = self.element_opacity();
2913
2914        self.next_frame.scene.insert_primitive(PolychromeSprite {
2915            order: 0,
2916            pad: 0,
2917            grayscale,
2918            bounds: bounds
2919                .map_origin(|origin| origin.floor())
2920                .map_size(|size| size.ceil()),
2921            content_mask,
2922            corner_radii,
2923            tile,
2924            opacity,
2925        });
2926        Ok(())
2927    }
2928
2929    /// Paint a surface into the scene for the next frame at the current z-index.
2930    ///
2931    /// This method should only be called as part of the paint phase of element drawing.
2932    #[cfg(target_os = "macos")]
2933    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
2934        use crate::PaintSurface;
2935
2936        self.invalidator.debug_assert_paint();
2937
2938        let scale_factor = self.scale_factor();
2939        let bounds = bounds.scale(scale_factor);
2940        let content_mask = self.content_mask().scale(scale_factor);
2941        self.next_frame.scene.insert_primitive(PaintSurface {
2942            order: 0,
2943            bounds,
2944            content_mask,
2945            image_buffer,
2946        });
2947    }
2948
2949    /// Paint a custom Metal view.
2950    ///
2951    /// This method should only be called as part of the paint phase of element drawing.
2952    #[cfg(target_os = "macos")]
2953    pub fn paint_metal_view(
2954        &mut self,
2955        bounds: Bounds<Pixels>,
2956        render_callback: crate::MetalRenderCallback,
2957    ) {
2958        use crate::PaintMetalView;
2959
2960        self.invalidator.debug_assert_paint();
2961
2962        let scale_factor = self.scale_factor();
2963        let bounds = bounds.scale(scale_factor);
2964        let content_mask = self.content_mask().scale(scale_factor);
2965        self.next_frame.scene.insert_primitive(PaintMetalView {
2966            order: 0,
2967            bounds,
2968            content_mask,
2969            render_callback,
2970        });
2971    }
2972
2973    /// Removes an image from the sprite atlas.
2974    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2975        for frame_index in 0..data.frame_count() {
2976            let params = RenderImageParams {
2977                image_id: data.id,
2978                frame_index,
2979            };
2980
2981            self.sprite_atlas.remove(&params.clone().into());
2982        }
2983
2984        Ok(())
2985    }
2986
2987    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2988    /// layout is being requested, along with the layout ids of any children. This method is called during
2989    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2990    ///
2991    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2992    #[must_use]
2993    pub fn request_layout(
2994        &mut self,
2995        style: Style,
2996        children: impl IntoIterator<Item = LayoutId>,
2997        cx: &mut App,
2998    ) -> LayoutId {
2999        self.invalidator.debug_assert_prepaint();
3000
3001        cx.layout_id_buffer.clear();
3002        cx.layout_id_buffer.extend(children);
3003        let rem_size = self.rem_size();
3004
3005        self.layout_engine
3006            .as_mut()
3007            .unwrap()
3008            .request_layout(style, rem_size, &cx.layout_id_buffer)
3009    }
3010
3011    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3012    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3013    /// determine the element's size. One place this is used internally is when measuring text.
3014    ///
3015    /// The given closure is invoked at layout time with the known dimensions and available space and
3016    /// returns a `Size`.
3017    ///
3018    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3019    pub fn request_measured_layout<
3020        F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3021            + 'static,
3022    >(
3023        &mut self,
3024        style: Style,
3025        measure: F,
3026    ) -> LayoutId {
3027        self.invalidator.debug_assert_prepaint();
3028
3029        let rem_size = self.rem_size();
3030        self.layout_engine
3031            .as_mut()
3032            .unwrap()
3033            .request_measured_layout(style, rem_size, measure)
3034    }
3035
3036    /// Compute the layout for the given id within the given available space.
3037    /// This method is called for its side effect, typically by the framework prior to painting.
3038    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3039    ///
3040    /// This method should only be called as part of the prepaint phase of element drawing.
3041    pub fn compute_layout(
3042        &mut self,
3043        layout_id: LayoutId,
3044        available_space: Size<AvailableSpace>,
3045        cx: &mut App,
3046    ) {
3047        self.invalidator.debug_assert_prepaint();
3048
3049        let mut layout_engine = self.layout_engine.take().unwrap();
3050        layout_engine.compute_layout(layout_id, available_space, self, cx);
3051        self.layout_engine = Some(layout_engine);
3052    }
3053
3054    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3055    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3056    ///
3057    /// This method should only be called as part of element drawing.
3058    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3059        self.invalidator.debug_assert_prepaint();
3060
3061        let mut bounds = self
3062            .layout_engine
3063            .as_mut()
3064            .unwrap()
3065            .layout_bounds(layout_id)
3066            .map(Into::into);
3067        bounds.origin += self.element_offset();
3068        bounds
3069    }
3070
3071    /// This method should be called during `prepaint`. You can use
3072    /// the returned [Hitbox] during `paint` or in an event handler
3073    /// to determine whether the inserted hitbox was the topmost.
3074    ///
3075    /// This method should only be called as part of the prepaint phase of element drawing.
3076    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3077        self.invalidator.debug_assert_prepaint();
3078
3079        let content_mask = self.content_mask();
3080        let mut id = self.next_hitbox_id;
3081        self.next_hitbox_id = self.next_hitbox_id.next();
3082        let hitbox = Hitbox {
3083            id,
3084            bounds,
3085            content_mask,
3086            behavior,
3087        };
3088        self.next_frame.hitboxes.push(hitbox.clone());
3089        hitbox
3090    }
3091
3092    /// Set a hitbox which will act as a control area of the platform window.
3093    ///
3094    /// This method should only be called as part of the paint phase of element drawing.
3095    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3096        self.invalidator.debug_assert_paint();
3097        self.next_frame.window_control_hitboxes.push((area, hitbox));
3098    }
3099
3100    /// Sets the key context for the current element. This context will be used to translate
3101    /// keybindings into actions.
3102    ///
3103    /// This method should only be called as part of the paint phase of element drawing.
3104    pub fn set_key_context(&mut self, context: KeyContext) {
3105        self.invalidator.debug_assert_paint();
3106        self.next_frame.dispatch_tree.set_key_context(context);
3107    }
3108
3109    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3110    /// and keyboard event dispatch for the element.
3111    ///
3112    /// This method should only be called as part of the prepaint phase of element drawing.
3113    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3114        self.invalidator.debug_assert_prepaint();
3115        if focus_handle.is_focused(self) {
3116            self.next_frame.focus = Some(focus_handle.id);
3117        }
3118        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3119    }
3120
3121    /// Sets the view id for the current element, which will be used to manage view caching.
3122    ///
3123    /// This method should only be called as part of element prepaint. We plan on removing this
3124    /// method eventually when we solve some issues that require us to construct editor elements
3125    /// directly instead of always using editors via views.
3126    pub fn set_view_id(&mut self, view_id: EntityId) {
3127        self.invalidator.debug_assert_prepaint();
3128        self.next_frame.dispatch_tree.set_view_id(view_id);
3129    }
3130
3131    /// Get the entity ID for the currently rendering view
3132    pub fn current_view(&self) -> EntityId {
3133        self.invalidator.debug_assert_paint_or_prepaint();
3134        self.rendered_entity_stack.last().copied().unwrap()
3135    }
3136
3137    pub(crate) fn with_rendered_view<R>(
3138        &mut self,
3139        id: EntityId,
3140        f: impl FnOnce(&mut Self) -> R,
3141    ) -> R {
3142        self.rendered_entity_stack.push(id);
3143        let result = f(self);
3144        self.rendered_entity_stack.pop();
3145        result
3146    }
3147
3148    /// Executes the provided function with the specified image cache.
3149    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3150    where
3151        F: FnOnce(&mut Self) -> R,
3152    {
3153        if let Some(image_cache) = image_cache {
3154            self.image_cache_stack.push(image_cache);
3155            let result = f(self);
3156            self.image_cache_stack.pop();
3157            result
3158        } else {
3159            f(self)
3160        }
3161    }
3162
3163    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3164    /// platform to receive textual input with proper integration with concerns such
3165    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3166    /// rendered.
3167    ///
3168    /// This method should only be called as part of the paint phase of element drawing.
3169    ///
3170    /// [element_input_handler]: crate::ElementInputHandler
3171    pub fn handle_input(
3172        &mut self,
3173        focus_handle: &FocusHandle,
3174        input_handler: impl InputHandler,
3175        cx: &App,
3176    ) {
3177        self.invalidator.debug_assert_paint();
3178
3179        if focus_handle.is_focused(self) {
3180            let cx = self.to_async(cx);
3181            self.next_frame
3182                .input_handlers
3183                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3184        }
3185    }
3186
3187    /// Register a mouse event listener on the window for the next frame. The type of event
3188    /// is determined by the first parameter of the given listener. When the next frame is rendered
3189    /// the listener will be cleared.
3190    ///
3191    /// This method should only be called as part of the paint phase of element drawing.
3192    pub fn on_mouse_event<Event: MouseEvent>(
3193        &mut self,
3194        mut handler: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3195    ) {
3196        self.invalidator.debug_assert_paint();
3197
3198        self.next_frame.mouse_listeners.push(Some(Box::new(
3199            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3200                if let Some(event) = event.downcast_ref() {
3201                    handler(event, phase, window, cx)
3202                }
3203            },
3204        )));
3205    }
3206
3207    /// Register a key event listener on the window for the next frame. The type of event
3208    /// is determined by the first parameter of the given listener. When the next frame is rendered
3209    /// the listener will be cleared.
3210    ///
3211    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3212    /// a specific need to register a global listener.
3213    ///
3214    /// This method should only be called as part of the paint phase of element drawing.
3215    pub fn on_key_event<Event: KeyEvent>(
3216        &mut self,
3217        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3218    ) {
3219        self.invalidator.debug_assert_paint();
3220
3221        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3222            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3223                if let Some(event) = event.downcast_ref::<Event>() {
3224                    listener(event, phase, window, cx)
3225                }
3226            },
3227        ));
3228    }
3229
3230    /// Register a modifiers changed event listener on the window for the next frame.
3231    ///
3232    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3233    /// a specific need to register a global listener.
3234    ///
3235    /// This method should only be called as part of the paint phase of element drawing.
3236    pub fn on_modifiers_changed(
3237        &mut self,
3238        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3239    ) {
3240        self.invalidator.debug_assert_paint();
3241
3242        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3243            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3244                listener(event, window, cx)
3245            },
3246        ));
3247    }
3248
3249    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3250    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3251    /// Returns a subscription and persists until the subscription is dropped.
3252    pub fn on_focus_in(
3253        &mut self,
3254        handle: &FocusHandle,
3255        cx: &mut App,
3256        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3257    ) -> Subscription {
3258        let focus_id = handle.id;
3259        let (subscription, activate) =
3260            self.new_focus_listener(Box::new(move |event, window, cx| {
3261                if event.is_focus_in(focus_id) {
3262                    listener(window, cx);
3263                }
3264                true
3265            }));
3266        cx.defer(move |_| activate());
3267        subscription
3268    }
3269
3270    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3271    /// Returns a subscription and persists until the subscription is dropped.
3272    pub fn on_focus_out(
3273        &mut self,
3274        handle: &FocusHandle,
3275        cx: &mut App,
3276        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3277    ) -> Subscription {
3278        let focus_id = handle.id;
3279        let (subscription, activate) =
3280            self.new_focus_listener(Box::new(move |event, window, cx| {
3281                if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3282                    if event.is_focus_out(focus_id) {
3283                        let event = FocusOutEvent {
3284                            blurred: WeakFocusHandle {
3285                                id: blurred_id,
3286                                handles: Arc::downgrade(&cx.focus_handles),
3287                            },
3288                        };
3289                        listener(event, window, cx)
3290                    }
3291                }
3292                true
3293            }));
3294        cx.defer(move |_| activate());
3295        subscription
3296    }
3297
3298    fn reset_cursor_style(&self, cx: &mut App) {
3299        // Set the cursor only if we're the active window.
3300        if self.is_window_hovered() {
3301            let style = self
3302                .rendered_frame
3303                .cursor_style(self)
3304                .unwrap_or(CursorStyle::Arrow);
3305            cx.platform.set_cursor_style(style);
3306        }
3307    }
3308
3309    /// Dispatch a given keystroke as though the user had typed it.
3310    /// You can create a keystroke with Keystroke::parse("").
3311    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3312        let keystroke = keystroke.with_simulated_ime();
3313        let result = self.dispatch_event(
3314            PlatformInput::KeyDown(KeyDownEvent {
3315                keystroke: keystroke.clone(),
3316                is_held: false,
3317            }),
3318            cx,
3319        );
3320        if !result.propagate {
3321            return true;
3322        }
3323
3324        if let Some(input) = keystroke.key_char {
3325            if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3326                input_handler.dispatch_input(&input, self, cx);
3327                self.platform_window.set_input_handler(input_handler);
3328                return true;
3329            }
3330        }
3331
3332        false
3333    }
3334
3335    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3336    /// binding for the action (last binding added to the keymap).
3337    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3338        self.highest_precedence_binding_for_action(action)
3339            .map(|binding| {
3340                binding
3341                    .keystrokes()
3342                    .iter()
3343                    .map(ToString::to_string)
3344                    .collect::<Vec<_>>()
3345                    .join(" ")
3346            })
3347            .unwrap_or_else(|| action.name().to_string())
3348    }
3349
3350    /// Dispatch a mouse or keyboard event on the window.
3351    #[profiling::function]
3352    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3353        self.last_input_timestamp.set(Instant::now());
3354        // Handlers may set this to false by calling `stop_propagation`.
3355        cx.propagate_event = true;
3356        // Handlers may set this to true by calling `prevent_default`.
3357        self.default_prevented = false;
3358
3359        let event = match event {
3360            // Track the mouse position with our own state, since accessing the platform
3361            // API for the mouse position can only occur on the main thread.
3362            PlatformInput::MouseMove(mouse_move) => {
3363                self.mouse_position = mouse_move.position;
3364                self.modifiers = mouse_move.modifiers;
3365                PlatformInput::MouseMove(mouse_move)
3366            }
3367            PlatformInput::MouseDown(mouse_down) => {
3368                self.mouse_position = mouse_down.position;
3369                self.modifiers = mouse_down.modifiers;
3370                PlatformInput::MouseDown(mouse_down)
3371            }
3372            PlatformInput::MouseUp(mouse_up) => {
3373                self.mouse_position = mouse_up.position;
3374                self.modifiers = mouse_up.modifiers;
3375                PlatformInput::MouseUp(mouse_up)
3376            }
3377            PlatformInput::MouseExited(mouse_exited) => {
3378                self.modifiers = mouse_exited.modifiers;
3379                PlatformInput::MouseExited(mouse_exited)
3380            }
3381            PlatformInput::ModifiersChanged(modifiers_changed) => {
3382                self.modifiers = modifiers_changed.modifiers;
3383                self.capslock = modifiers_changed.capslock;
3384                PlatformInput::ModifiersChanged(modifiers_changed)
3385            }
3386            PlatformInput::ScrollWheel(scroll_wheel) => {
3387                self.mouse_position = scroll_wheel.position;
3388                self.modifiers = scroll_wheel.modifiers;
3389                PlatformInput::ScrollWheel(scroll_wheel)
3390            }
3391            // Translate dragging and dropping of external files from the operating system
3392            // to internal drag and drop events.
3393            PlatformInput::FileDrop(file_drop) => match file_drop {
3394                FileDropEvent::Entered { position, paths } => {
3395                    self.mouse_position = position;
3396                    if cx.active_drag.is_none() {
3397                        cx.active_drag = Some(AnyDrag {
3398                            value: Arc::new(paths.clone()),
3399                            view: cx.new(|_| paths).into(),
3400                            cursor_offset: position,
3401                            cursor_style: None,
3402                        });
3403                    }
3404                    PlatformInput::MouseMove(MouseMoveEvent {
3405                        position,
3406                        pressed_button: Some(MouseButton::Left),
3407                        modifiers: Modifiers::default(),
3408                    })
3409                }
3410                FileDropEvent::Pending { position } => {
3411                    self.mouse_position = position;
3412                    PlatformInput::MouseMove(MouseMoveEvent {
3413                        position,
3414                        pressed_button: Some(MouseButton::Left),
3415                        modifiers: Modifiers::default(),
3416                    })
3417                }
3418                FileDropEvent::Submit { position } => {
3419                    cx.activate(true);
3420                    self.mouse_position = position;
3421                    PlatformInput::MouseUp(MouseUpEvent {
3422                        button: MouseButton::Left,
3423                        position,
3424                        modifiers: Modifiers::default(),
3425                        click_count: 1,
3426                    })
3427                }
3428                FileDropEvent::Exited => {
3429                    cx.active_drag.take();
3430                    PlatformInput::FileDrop(FileDropEvent::Exited)
3431                }
3432            },
3433            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3434        };
3435
3436        if let Some(any_mouse_event) = event.mouse_event() {
3437            self.dispatch_mouse_event(any_mouse_event, cx);
3438        } else if let Some(any_key_event) = event.keyboard_event() {
3439            self.dispatch_key_event(any_key_event, cx);
3440        }
3441
3442        DispatchEventResult {
3443            propagate: cx.propagate_event,
3444            default_prevented: self.default_prevented,
3445        }
3446    }
3447
3448    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3449        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3450        if hit_test != self.mouse_hit_test {
3451            self.mouse_hit_test = hit_test;
3452            self.reset_cursor_style(cx);
3453        }
3454
3455        #[cfg(any(feature = "inspector", debug_assertions))]
3456        if self.is_inspector_picking(cx) {
3457            self.handle_inspector_mouse_event(event, cx);
3458            // When inspector is picking, all other mouse handling is skipped.
3459            return;
3460        }
3461
3462        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3463
3464        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3465        // special purposes, such as detecting events outside of a given Bounds.
3466        for listener in &mut mouse_listeners {
3467            let listener = listener.as_mut().unwrap();
3468            listener(event, DispatchPhase::Capture, self, cx);
3469            if !cx.propagate_event {
3470                break;
3471            }
3472        }
3473
3474        // Bubble phase, where most normal handlers do their work.
3475        if cx.propagate_event {
3476            for listener in mouse_listeners.iter_mut().rev() {
3477                let listener = listener.as_mut().unwrap();
3478                listener(event, DispatchPhase::Bubble, self, cx);
3479                if !cx.propagate_event {
3480                    break;
3481                }
3482            }
3483        }
3484
3485        self.rendered_frame.mouse_listeners = mouse_listeners;
3486
3487        if cx.has_active_drag() {
3488            if event.is::<MouseMoveEvent>() {
3489                // If this was a mouse move event, redraw the window so that the
3490                // active drag can follow the mouse cursor.
3491                self.refresh();
3492            } else if event.is::<MouseUpEvent>() {
3493                // If this was a mouse up event, cancel the active drag and redraw
3494                // the window.
3495                cx.active_drag = None;
3496                self.refresh();
3497            }
3498        }
3499    }
3500
3501    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3502        if self.invalidator.is_dirty() {
3503            self.draw(cx).clear();
3504        }
3505
3506        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3507        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3508
3509        let mut keystroke: Option<Keystroke> = None;
3510
3511        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3512            if event.modifiers.number_of_modifiers() == 0
3513                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3514                && !self.pending_modifier.saw_keystroke
3515            {
3516                let key = match self.pending_modifier.modifiers {
3517                    modifiers if modifiers.shift => Some("shift"),
3518                    modifiers if modifiers.control => Some("control"),
3519                    modifiers if modifiers.alt => Some("alt"),
3520                    modifiers if modifiers.platform => Some("platform"),
3521                    modifiers if modifiers.function => Some("function"),
3522                    _ => None,
3523                };
3524                if let Some(key) = key {
3525                    keystroke = Some(Keystroke {
3526                        key: key.to_string(),
3527                        key_char: None,
3528                        modifiers: Modifiers::default(),
3529                    });
3530                }
3531            }
3532
3533            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3534                && event.modifiers.number_of_modifiers() == 1
3535            {
3536                self.pending_modifier.saw_keystroke = false
3537            }
3538            self.pending_modifier.modifiers = event.modifiers
3539        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3540            self.pending_modifier.saw_keystroke = true;
3541            keystroke = Some(key_down_event.keystroke.clone());
3542        }
3543
3544        let Some(keystroke) = keystroke else {
3545            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3546            return;
3547        };
3548
3549        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3550        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3551            currently_pending = PendingInput::default();
3552        }
3553
3554        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3555            currently_pending.keystrokes,
3556            keystroke,
3557            &dispatch_path,
3558        );
3559
3560        if !match_result.to_replay.is_empty() {
3561            self.replay_pending_input(match_result.to_replay, cx)
3562        }
3563
3564        if !match_result.pending.is_empty() {
3565            currently_pending.keystrokes = match_result.pending;
3566            currently_pending.focus = self.focus;
3567            currently_pending.timer = Some(self.spawn(cx, async move |cx| {
3568                cx.background_executor.timer(Duration::from_secs(1)).await;
3569                cx.update(move |window, cx| {
3570                    let Some(currently_pending) = window
3571                        .pending_input
3572                        .take()
3573                        .filter(|pending| pending.focus == window.focus)
3574                    else {
3575                        return;
3576                    };
3577
3578                    let node_id = window.focus_node_id_in_rendered_frame(window.focus);
3579                    let dispatch_path = window.rendered_frame.dispatch_tree.dispatch_path(node_id);
3580
3581                    let to_replay = window
3582                        .rendered_frame
3583                        .dispatch_tree
3584                        .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3585
3586                    window.pending_input_changed(cx);
3587                    window.replay_pending_input(to_replay, cx)
3588                })
3589                .log_err();
3590            }));
3591            self.pending_input = Some(currently_pending);
3592            self.pending_input_changed(cx);
3593            cx.propagate_event = false;
3594            return;
3595        }
3596
3597        cx.propagate_event = true;
3598        for binding in match_result.bindings {
3599            self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3600            if !cx.propagate_event {
3601                self.dispatch_keystroke_observers(
3602                    event,
3603                    Some(binding.action),
3604                    match_result.context_stack.clone(),
3605                    cx,
3606                );
3607                self.pending_input_changed(cx);
3608                return;
3609            }
3610        }
3611
3612        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
3613        self.pending_input_changed(cx);
3614    }
3615
3616    fn finish_dispatch_key_event(
3617        &mut self,
3618        event: &dyn Any,
3619        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3620        context_stack: Vec<KeyContext>,
3621        cx: &mut App,
3622    ) {
3623        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
3624        if !cx.propagate_event {
3625            return;
3626        }
3627
3628        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
3629        if !cx.propagate_event {
3630            return;
3631        }
3632
3633        self.dispatch_keystroke_observers(event, None, context_stack, cx);
3634    }
3635
3636    fn pending_input_changed(&mut self, cx: &mut App) {
3637        self.pending_input_observers
3638            .clone()
3639            .retain(&(), |callback| callback(self, cx));
3640    }
3641
3642    fn dispatch_key_down_up_event(
3643        &mut self,
3644        event: &dyn Any,
3645        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3646        cx: &mut App,
3647    ) {
3648        // Capture phase
3649        for node_id in dispatch_path {
3650            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3651
3652            for key_listener in node.key_listeners.clone() {
3653                key_listener(event, DispatchPhase::Capture, self, cx);
3654                if !cx.propagate_event {
3655                    return;
3656                }
3657            }
3658        }
3659
3660        // Bubble phase
3661        for node_id in dispatch_path.iter().rev() {
3662            // Handle low level key events
3663            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3664            for key_listener in node.key_listeners.clone() {
3665                key_listener(event, DispatchPhase::Bubble, self, cx);
3666                if !cx.propagate_event {
3667                    return;
3668                }
3669            }
3670        }
3671    }
3672
3673    fn dispatch_modifiers_changed_event(
3674        &mut self,
3675        event: &dyn Any,
3676        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3677        cx: &mut App,
3678    ) {
3679        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3680            return;
3681        };
3682        for node_id in dispatch_path.iter().rev() {
3683            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3684            for listener in node.modifiers_changed_listeners.clone() {
3685                listener(event, self, cx);
3686                if !cx.propagate_event {
3687                    return;
3688                }
3689            }
3690        }
3691    }
3692
3693    /// Determine whether a potential multi-stroke key binding is in progress on this window.
3694    pub fn has_pending_keystrokes(&self) -> bool {
3695        self.pending_input.is_some()
3696    }
3697
3698    pub(crate) fn clear_pending_keystrokes(&mut self) {
3699        self.pending_input.take();
3700    }
3701
3702    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3703    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3704        self.pending_input
3705            .as_ref()
3706            .map(|pending_input| pending_input.keystrokes.as_slice())
3707    }
3708
3709    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
3710        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3711        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3712
3713        'replay: for replay in replays {
3714            let event = KeyDownEvent {
3715                keystroke: replay.keystroke.clone(),
3716                is_held: false,
3717            };
3718
3719            cx.propagate_event = true;
3720            for binding in replay.bindings {
3721                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3722                if !cx.propagate_event {
3723                    self.dispatch_keystroke_observers(
3724                        &event,
3725                        Some(binding.action),
3726                        Vec::default(),
3727                        cx,
3728                    );
3729                    continue 'replay;
3730                }
3731            }
3732
3733            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
3734            if !cx.propagate_event {
3735                continue 'replay;
3736            }
3737            if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3738                if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3739                    input_handler.dispatch_input(&input, self, cx);
3740                    self.platform_window.set_input_handler(input_handler)
3741                }
3742            }
3743        }
3744    }
3745
3746    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
3747        focus_id
3748            .and_then(|focus_id| {
3749                self.rendered_frame
3750                    .dispatch_tree
3751                    .focusable_node_id(focus_id)
3752            })
3753            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id())
3754    }
3755
3756    fn dispatch_action_on_node(
3757        &mut self,
3758        node_id: DispatchNodeId,
3759        action: &dyn Action,
3760        cx: &mut App,
3761    ) {
3762        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3763
3764        // Capture phase for global actions.
3765        cx.propagate_event = true;
3766        if let Some(mut global_listeners) = cx
3767            .global_action_listeners
3768            .remove(&action.as_any().type_id())
3769        {
3770            for listener in &global_listeners {
3771                listener(action.as_any(), DispatchPhase::Capture, cx);
3772                if !cx.propagate_event {
3773                    break;
3774                }
3775            }
3776
3777            global_listeners.extend(
3778                cx.global_action_listeners
3779                    .remove(&action.as_any().type_id())
3780                    .unwrap_or_default(),
3781            );
3782
3783            cx.global_action_listeners
3784                .insert(action.as_any().type_id(), global_listeners);
3785        }
3786
3787        if !cx.propagate_event {
3788            return;
3789        }
3790
3791        // Capture phase for window actions.
3792        for node_id in &dispatch_path {
3793            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3794            for DispatchActionListener {
3795                action_type,
3796                listener,
3797            } in node.action_listeners.clone()
3798            {
3799                let any_action = action.as_any();
3800                if action_type == any_action.type_id() {
3801                    listener(any_action, DispatchPhase::Capture, self, cx);
3802
3803                    if !cx.propagate_event {
3804                        return;
3805                    }
3806                }
3807            }
3808        }
3809
3810        // Bubble phase for window actions.
3811        for node_id in dispatch_path.iter().rev() {
3812            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3813            for DispatchActionListener {
3814                action_type,
3815                listener,
3816            } in node.action_listeners.clone()
3817            {
3818                let any_action = action.as_any();
3819                if action_type == any_action.type_id() {
3820                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3821                    listener(any_action, DispatchPhase::Bubble, self, cx);
3822
3823                    if !cx.propagate_event {
3824                        return;
3825                    }
3826                }
3827            }
3828        }
3829
3830        // Bubble phase for global actions.
3831        if let Some(mut global_listeners) = cx
3832            .global_action_listeners
3833            .remove(&action.as_any().type_id())
3834        {
3835            for listener in global_listeners.iter().rev() {
3836                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3837
3838                listener(action.as_any(), DispatchPhase::Bubble, cx);
3839                if !cx.propagate_event {
3840                    break;
3841                }
3842            }
3843
3844            global_listeners.extend(
3845                cx.global_action_listeners
3846                    .remove(&action.as_any().type_id())
3847                    .unwrap_or_default(),
3848            );
3849
3850            cx.global_action_listeners
3851                .insert(action.as_any().type_id(), global_listeners);
3852        }
3853    }
3854
3855    /// Register the given handler to be invoked whenever the global of the given type
3856    /// is updated.
3857    pub fn observe_global<G: Global>(
3858        &mut self,
3859        cx: &mut App,
3860        f: impl Fn(&mut Window, &mut App) + 'static,
3861    ) -> Subscription {
3862        let window_handle = self.handle;
3863        let (subscription, activate) = cx.global_observers.insert(
3864            TypeId::of::<G>(),
3865            Box::new(move |cx| {
3866                window_handle
3867                    .update(cx, |_, window, cx| f(window, cx))
3868                    .is_ok()
3869            }),
3870        );
3871        cx.defer(move |_| activate());
3872        subscription
3873    }
3874
3875    /// Focus the current window and bring it to the foreground at the platform level.
3876    pub fn activate_window(&self) {
3877        self.platform_window.activate();
3878    }
3879
3880    /// Minimize the current window at the platform level.
3881    pub fn minimize_window(&self) {
3882        self.platform_window.minimize();
3883    }
3884
3885    /// Toggle full screen status on the current window at the platform level.
3886    pub fn toggle_fullscreen(&self) {
3887        self.platform_window.toggle_fullscreen();
3888    }
3889
3890    /// Updates the IME panel position suggestions for languages like japanese, chinese.
3891    pub fn invalidate_character_coordinates(&self) {
3892        self.on_next_frame(|window, cx| {
3893            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
3894                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
3895                    window
3896                        .platform_window
3897                        .update_ime_position(bounds.scale(window.scale_factor()));
3898                }
3899                window.platform_window.set_input_handler(input_handler);
3900            }
3901        });
3902    }
3903
3904    /// Present a platform dialog.
3905    /// The provided message will be presented, along with buttons for each answer.
3906    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3907    pub fn prompt<T>(
3908        &mut self,
3909        level: PromptLevel,
3910        message: &str,
3911        detail: Option<&str>,
3912        answers: &[T],
3913        cx: &mut App,
3914    ) -> oneshot::Receiver<usize>
3915    where
3916        T: Clone + Into<PromptButton>,
3917    {
3918        let prompt_builder = cx.prompt_builder.take();
3919        let Some(prompt_builder) = prompt_builder else {
3920            unreachable!("Re-entrant window prompting is not supported by GPUI");
3921        };
3922
3923        let answers = answers
3924            .iter()
3925            .map(|answer| answer.clone().into())
3926            .collect::<Vec<_>>();
3927
3928        let receiver = match &prompt_builder {
3929            PromptBuilder::Default => self
3930                .platform_window
3931                .prompt(level, message, detail, &answers)
3932                .unwrap_or_else(|| {
3933                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3934                }),
3935            PromptBuilder::Custom(_) => {
3936                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3937            }
3938        };
3939
3940        cx.prompt_builder = Some(prompt_builder);
3941
3942        receiver
3943    }
3944
3945    fn build_custom_prompt(
3946        &mut self,
3947        prompt_builder: &PromptBuilder,
3948        level: PromptLevel,
3949        message: &str,
3950        detail: Option<&str>,
3951        answers: &[PromptButton],
3952        cx: &mut App,
3953    ) -> oneshot::Receiver<usize> {
3954        let (sender, receiver) = oneshot::channel();
3955        let handle = PromptHandle::new(sender);
3956        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
3957        self.prompt = Some(handle);
3958        receiver
3959    }
3960
3961    /// Returns the current context stack.
3962    pub fn context_stack(&self) -> Vec<KeyContext> {
3963        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3964        let dispatch_tree = &self.rendered_frame.dispatch_tree;
3965        dispatch_tree
3966            .dispatch_path(node_id)
3967            .iter()
3968            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
3969            .collect()
3970    }
3971
3972    /// Returns all available actions for the focused element.
3973    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
3974        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3975        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
3976        for action_type in cx.global_action_listeners.keys() {
3977            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3978                let action = cx.actions.build_action_type(action_type).ok();
3979                if let Some(action) = action {
3980                    actions.insert(ix, action);
3981                }
3982            }
3983        }
3984        actions
3985    }
3986
3987    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
3988    /// returned in the order they were added. For display, the last binding should take precedence.
3989    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3990        self.rendered_frame
3991            .dispatch_tree
3992            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
3993    }
3994
3995    /// Returns the highest precedence key binding that invokes an action on the currently focused
3996    /// element. This is more efficient than getting the last result of `bindings_for_action`.
3997    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
3998        self.rendered_frame
3999            .dispatch_tree
4000            .highest_precedence_binding_for_action(
4001                action,
4002                &self.rendered_frame.dispatch_tree.context_stack,
4003            )
4004    }
4005
4006    /// Returns the key bindings for an action in a context.
4007    pub fn bindings_for_action_in_context(
4008        &self,
4009        action: &dyn Action,
4010        context: KeyContext,
4011    ) -> Vec<KeyBinding> {
4012        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4013        dispatch_tree.bindings_for_action(action, &[context])
4014    }
4015
4016    /// Returns the highest precedence key binding for an action in a context. This is more
4017    /// efficient than getting the last result of `bindings_for_action_in_context`.
4018    pub fn highest_precedence_binding_for_action_in_context(
4019        &self,
4020        action: &dyn Action,
4021        context: KeyContext,
4022    ) -> Option<KeyBinding> {
4023        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4024        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4025    }
4026
4027    /// Returns any bindings that would invoke an action on the given focus handle if it were
4028    /// focused. Bindings are returned in the order they were added. For display, the last binding
4029    /// should take precedence.
4030    pub fn bindings_for_action_in(
4031        &self,
4032        action: &dyn Action,
4033        focus_handle: &FocusHandle,
4034    ) -> Vec<KeyBinding> {
4035        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4036        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4037            return vec![];
4038        };
4039        dispatch_tree.bindings_for_action(action, &context_stack)
4040    }
4041
4042    /// Returns the highest precedence key binding that would invoke an action on the given focus
4043    /// handle if it were focused. This is more efficient than getting the last result of
4044    /// `bindings_for_action_in`.
4045    pub fn highest_precedence_binding_for_action_in(
4046        &self,
4047        action: &dyn Action,
4048        focus_handle: &FocusHandle,
4049    ) -> Option<KeyBinding> {
4050        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4051        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4052        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4053    }
4054
4055    fn context_stack_for_focus_handle(
4056        &self,
4057        focus_handle: &FocusHandle,
4058    ) -> Option<Vec<KeyContext>> {
4059        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4060        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4061        let context_stack: Vec<_> = dispatch_tree
4062            .dispatch_path(node_id)
4063            .into_iter()
4064            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4065            .collect();
4066        Some(context_stack)
4067    }
4068
4069    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4070    pub fn listener_for<V: Render, E>(
4071        &self,
4072        view: &Entity<V>,
4073        f: impl Fn(&mut V, &E, &mut Window, &mut Context<V>) + 'static,
4074    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4075        let view = view.downgrade();
4076        move |e: &E, window: &mut Window, cx: &mut App| {
4077            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4078        }
4079    }
4080
4081    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4082    pub fn handler_for<V: Render, Callback: Fn(&mut V, &mut Window, &mut Context<V>) + 'static>(
4083        &self,
4084        view: &Entity<V>,
4085        f: Callback,
4086    ) -> impl Fn(&mut Window, &mut App) + use<V, Callback> {
4087        let view = view.downgrade();
4088        move |window: &mut Window, cx: &mut App| {
4089            view.update(cx, |view, cx| f(view, window, cx)).ok();
4090        }
4091    }
4092
4093    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4094    /// If the callback returns false, the window won't be closed.
4095    pub fn on_window_should_close(
4096        &self,
4097        cx: &App,
4098        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4099    ) {
4100        let mut cx = self.to_async(cx);
4101        self.platform_window.on_should_close(Box::new(move || {
4102            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4103        }))
4104    }
4105
4106    /// Register an action listener on the window for the next frame. The type of action
4107    /// is determined by the first parameter of the given listener. When the next frame is rendered
4108    /// the listener will be cleared.
4109    ///
4110    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4111    /// a specific need to register a global listener.
4112    pub fn on_action(
4113        &mut self,
4114        action_type: TypeId,
4115        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4116    ) {
4117        self.next_frame
4118            .dispatch_tree
4119            .on_action(action_type, Rc::new(listener));
4120    }
4121
4122    /// Read information about the GPU backing this window.
4123    /// Currently returns None on Mac and Windows.
4124    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4125        self.platform_window.gpu_specs()
4126    }
4127
4128    /// Perform titlebar double-click action.
4129    /// This is MacOS specific.
4130    pub fn titlebar_double_click(&self) {
4131        self.platform_window.titlebar_double_click();
4132    }
4133
4134    /// Toggles the inspector mode on this window.
4135    #[cfg(any(feature = "inspector", debug_assertions))]
4136    pub fn toggle_inspector(&mut self, cx: &mut App) {
4137        self.inspector = match self.inspector {
4138            None => Some(cx.new(|_| Inspector::new())),
4139            Some(_) => None,
4140        };
4141        self.refresh();
4142    }
4143
4144    /// Returns true if the window is in inspector mode.
4145    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4146        #[cfg(any(feature = "inspector", debug_assertions))]
4147        {
4148            if let Some(inspector) = &self.inspector {
4149                return inspector.read(_cx).is_picking();
4150            }
4151        }
4152        false
4153    }
4154
4155    /// Executes the provided function with mutable access to an inspector state.
4156    #[cfg(any(feature = "inspector", debug_assertions))]
4157    pub fn with_inspector_state<T: 'static, R>(
4158        &mut self,
4159        _inspector_id: Option<&crate::InspectorElementId>,
4160        cx: &mut App,
4161        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4162    ) -> R {
4163        if let Some(inspector_id) = _inspector_id {
4164            if let Some(inspector) = &self.inspector {
4165                let inspector = inspector.clone();
4166                let active_element_id = inspector.read(cx).active_element_id();
4167                if Some(inspector_id) == active_element_id {
4168                    return inspector.update(cx, |inspector, _cx| {
4169                        inspector.with_active_element_state(self, f)
4170                    });
4171                }
4172            }
4173        }
4174        f(&mut None, self)
4175    }
4176
4177    #[cfg(any(feature = "inspector", debug_assertions))]
4178    pub(crate) fn build_inspector_element_id(
4179        &mut self,
4180        path: crate::InspectorElementPath,
4181    ) -> crate::InspectorElementId {
4182        self.invalidator.debug_assert_paint_or_prepaint();
4183        let path = Rc::new(path);
4184        let next_instance_id = self
4185            .next_frame
4186            .next_inspector_instance_ids
4187            .entry(path.clone())
4188            .or_insert(0);
4189        let instance_id = *next_instance_id;
4190        *next_instance_id += 1;
4191        crate::InspectorElementId { path, instance_id }
4192    }
4193
4194    #[cfg(any(feature = "inspector", debug_assertions))]
4195    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4196        if let Some(inspector) = self.inspector.take() {
4197            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4198            inspector_element.prepaint_as_root(
4199                point(self.viewport_size.width - inspector_width, px(0.0)),
4200                size(inspector_width, self.viewport_size.height).into(),
4201                self,
4202                cx,
4203            );
4204            self.inspector = Some(inspector);
4205            Some(inspector_element)
4206        } else {
4207            None
4208        }
4209    }
4210
4211    #[cfg(any(feature = "inspector", debug_assertions))]
4212    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4213        if let Some(mut inspector_element) = inspector_element {
4214            inspector_element.paint(self, cx);
4215        };
4216    }
4217
4218    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4219    /// inspect UI elements by clicking on them.
4220    #[cfg(any(feature = "inspector", debug_assertions))]
4221    pub fn insert_inspector_hitbox(
4222        &mut self,
4223        hitbox_id: HitboxId,
4224        inspector_id: Option<&crate::InspectorElementId>,
4225        cx: &App,
4226    ) {
4227        self.invalidator.debug_assert_paint_or_prepaint();
4228        if !self.is_inspector_picking(cx) {
4229            return;
4230        }
4231        if let Some(inspector_id) = inspector_id {
4232            self.next_frame
4233                .inspector_hitboxes
4234                .insert(hitbox_id, inspector_id.clone());
4235        }
4236    }
4237
4238    #[cfg(any(feature = "inspector", debug_assertions))]
4239    fn paint_inspector_hitbox(&mut self, cx: &App) {
4240        if let Some(inspector) = self.inspector.as_ref() {
4241            let inspector = inspector.read(cx);
4242            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4243            {
4244                if let Some(hitbox) = self
4245                    .next_frame
4246                    .hitboxes
4247                    .iter()
4248                    .find(|hitbox| hitbox.id == hitbox_id)
4249                {
4250                    self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4251                }
4252            }
4253        }
4254    }
4255
4256    #[cfg(any(feature = "inspector", debug_assertions))]
4257    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4258        let Some(inspector) = self.inspector.clone() else {
4259            return;
4260        };
4261        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4262            inspector.update(cx, |inspector, _cx| {
4263                if let Some((_, inspector_id)) =
4264                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4265                {
4266                    inspector.hover(inspector_id, self);
4267                }
4268            });
4269        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4270            inspector.update(cx, |inspector, _cx| {
4271                if let Some((_, inspector_id)) =
4272                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4273                {
4274                    inspector.select(inspector_id, self);
4275                }
4276            });
4277        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4278            // This should be kept in sync with SCROLL_LINES in x11 platform.
4279            const SCROLL_LINES: f32 = 3.0;
4280            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4281            let delta_y = event
4282                .delta
4283                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4284                .y;
4285            if let Some(inspector) = self.inspector.clone() {
4286                inspector.update(cx, |inspector, _cx| {
4287                    if let Some(depth) = inspector.pick_depth.as_mut() {
4288                        *depth += delta_y.0 / SCROLL_PIXELS_PER_LAYER;
4289                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4290                        if *depth < 0.0 {
4291                            *depth = 0.0;
4292                        } else if *depth > max_depth {
4293                            *depth = max_depth;
4294                        }
4295                        if let Some((_, inspector_id)) =
4296                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4297                        {
4298                            inspector.set_active_element_id(inspector_id.clone(), self);
4299                        }
4300                    }
4301                });
4302            }
4303        }
4304    }
4305
4306    #[cfg(any(feature = "inspector", debug_assertions))]
4307    fn hovered_inspector_hitbox(
4308        &self,
4309        inspector: &Inspector,
4310        frame: &Frame,
4311    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4312        if let Some(pick_depth) = inspector.pick_depth {
4313            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4314            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4315            let skip_count = (depth as usize).min(max_skipped);
4316            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4317                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4318                    return Some((*hitbox_id, inspector_id.clone()));
4319                }
4320            }
4321        }
4322        return None;
4323    }
4324}
4325
4326// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4327slotmap::new_key_type! {
4328    /// A unique identifier for a window.
4329    pub struct WindowId;
4330}
4331
4332impl WindowId {
4333    /// Converts this window ID to a `u64`.
4334    pub fn as_u64(&self) -> u64 {
4335        self.0.as_ffi()
4336    }
4337}
4338
4339impl From<u64> for WindowId {
4340    fn from(value: u64) -> Self {
4341        WindowId(slotmap::KeyData::from_ffi(value))
4342    }
4343}
4344
4345/// A handle to a window with a specific root view type.
4346/// Note that this does not keep the window alive on its own.
4347#[derive(Deref, DerefMut)]
4348pub struct WindowHandle<V> {
4349    #[deref]
4350    #[deref_mut]
4351    pub(crate) any_handle: AnyWindowHandle,
4352    state_type: PhantomData<V>,
4353}
4354
4355impl<V: 'static + Render> WindowHandle<V> {
4356    /// Creates a new handle from a window ID.
4357    /// This does not check if the root type of the window is `V`.
4358    pub fn new(id: WindowId) -> Self {
4359        WindowHandle {
4360            any_handle: AnyWindowHandle {
4361                id,
4362                state_type: TypeId::of::<V>(),
4363            },
4364            state_type: PhantomData,
4365        }
4366    }
4367
4368    /// Get the root view out of this window.
4369    ///
4370    /// This will fail if the window is closed or if the root view's type does not match `V`.
4371    #[cfg(any(test, feature = "test-support"))]
4372    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
4373    where
4374        C: AppContext,
4375    {
4376        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
4377            root_view
4378                .downcast::<V>()
4379                .map_err(|_| anyhow!("the type of the window's root view has changed"))
4380        }))
4381    }
4382
4383    /// Updates the root view of this window.
4384    ///
4385    /// This will fail if the window has been closed or if the root view's type does not match
4386    pub fn update<C, R>(
4387        &self,
4388        cx: &mut C,
4389        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
4390    ) -> Result<R>
4391    where
4392        C: AppContext,
4393    {
4394        cx.update_window(self.any_handle, |root_view, window, cx| {
4395            let view = root_view
4396                .downcast::<V>()
4397                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4398
4399            Ok(view.update(cx, |view, cx| update(view, window, cx)))
4400        })?
4401    }
4402
4403    /// Read the root view out of this window.
4404    ///
4405    /// This will fail if the window is closed or if the root view's type does not match `V`.
4406    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
4407        let x = cx
4408            .windows
4409            .get(self.id)
4410            .and_then(|window| {
4411                window
4412                    .as_ref()
4413                    .and_then(|window| window.root.clone())
4414                    .map(|root_view| root_view.downcast::<V>())
4415            })
4416            .context("window not found")?
4417            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4418
4419        Ok(x.read(cx))
4420    }
4421
4422    /// Read the root view out of this window, with a callback
4423    ///
4424    /// This will fail if the window is closed or if the root view's type does not match `V`.
4425    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
4426    where
4427        C: AppContext,
4428    {
4429        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4430    }
4431
4432    /// Read the root view pointer off of this window.
4433    ///
4434    /// This will fail if the window is closed or if the root view's type does not match `V`.
4435    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
4436    where
4437        C: AppContext,
4438    {
4439        cx.read_window(self, |root_view, _cx| root_view.clone())
4440    }
4441
4442    /// Check if this window is 'active'.
4443    ///
4444    /// Will return `None` if the window is closed or currently
4445    /// borrowed.
4446    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
4447        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
4448            .ok()
4449    }
4450}
4451
4452impl<V> Copy for WindowHandle<V> {}
4453
4454impl<V> Clone for WindowHandle<V> {
4455    fn clone(&self) -> Self {
4456        *self
4457    }
4458}
4459
4460impl<V> PartialEq for WindowHandle<V> {
4461    fn eq(&self, other: &Self) -> bool {
4462        self.any_handle == other.any_handle
4463    }
4464}
4465
4466impl<V> Eq for WindowHandle<V> {}
4467
4468impl<V> Hash for WindowHandle<V> {
4469    fn hash<H: Hasher>(&self, state: &mut H) {
4470        self.any_handle.hash(state);
4471    }
4472}
4473
4474impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4475    fn from(val: WindowHandle<V>) -> Self {
4476        val.any_handle
4477    }
4478}
4479
4480unsafe impl<V> Send for WindowHandle<V> {}
4481unsafe impl<V> Sync for WindowHandle<V> {}
4482
4483/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4484#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4485pub struct AnyWindowHandle {
4486    pub(crate) id: WindowId,
4487    state_type: TypeId,
4488}
4489
4490impl AnyWindowHandle {
4491    /// Get the ID of this window.
4492    pub fn window_id(&self) -> WindowId {
4493        self.id
4494    }
4495
4496    /// Attempt to convert this handle to a window handle with a specific root view type.
4497    /// If the types do not match, this will return `None`.
4498    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4499        if TypeId::of::<T>() == self.state_type {
4500            Some(WindowHandle {
4501                any_handle: *self,
4502                state_type: PhantomData,
4503            })
4504        } else {
4505            None
4506        }
4507    }
4508
4509    /// Updates the state of the root view of this window.
4510    ///
4511    /// This will fail if the window has been closed.
4512    pub fn update<C, R>(
4513        self,
4514        cx: &mut C,
4515        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
4516    ) -> Result<R>
4517    where
4518        C: AppContext,
4519    {
4520        cx.update_window(self, update)
4521    }
4522
4523    /// Read the state of the root view of this window.
4524    ///
4525    /// This will fail if the window has been closed.
4526    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
4527    where
4528        C: AppContext,
4529        T: 'static,
4530    {
4531        let view = self
4532            .downcast::<T>()
4533            .context("the type of the window's root view has changed")?;
4534
4535        cx.read_window(&view, read)
4536    }
4537}
4538
4539impl HasWindowHandle for Window {
4540    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
4541        self.platform_window.window_handle()
4542    }
4543}
4544
4545impl HasDisplayHandle for Window {
4546    fn display_handle(
4547        &self,
4548    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
4549        self.platform_window.display_handle()
4550    }
4551}
4552
4553/// An identifier for an [`Element`](crate::Element).
4554///
4555/// Can be constructed with a string, a number, or both, as well
4556/// as other internal representations.
4557#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4558pub enum ElementId {
4559    /// The ID of a View element
4560    View(EntityId),
4561    /// An integer ID.
4562    Integer(u64),
4563    /// A string based ID.
4564    Name(SharedString),
4565    /// A UUID.
4566    Uuid(Uuid),
4567    /// An ID that's equated with a focus handle.
4568    FocusHandle(FocusId),
4569    /// A combination of a name and an integer.
4570    NamedInteger(SharedString, u64),
4571    /// A path.
4572    Path(Arc<std::path::Path>),
4573}
4574
4575impl ElementId {
4576    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
4577    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
4578        Self::NamedInteger(name.into(), integer as u64)
4579    }
4580}
4581
4582impl Display for ElementId {
4583    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4584        match self {
4585            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4586            ElementId::Integer(ix) => write!(f, "{}", ix)?,
4587            ElementId::Name(name) => write!(f, "{}", name)?,
4588            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4589            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4590            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4591            ElementId::Path(path) => write!(f, "{}", path.display())?,
4592        }
4593
4594        Ok(())
4595    }
4596}
4597
4598impl TryInto<SharedString> for ElementId {
4599    type Error = anyhow::Error;
4600
4601    fn try_into(self) -> anyhow::Result<SharedString> {
4602        if let ElementId::Name(name) = self {
4603            Ok(name)
4604        } else {
4605            anyhow::bail!("element id is not string")
4606        }
4607    }
4608}
4609
4610impl From<usize> for ElementId {
4611    fn from(id: usize) -> Self {
4612        ElementId::Integer(id as u64)
4613    }
4614}
4615
4616impl From<i32> for ElementId {
4617    fn from(id: i32) -> Self {
4618        Self::Integer(id as u64)
4619    }
4620}
4621
4622impl From<SharedString> for ElementId {
4623    fn from(name: SharedString) -> Self {
4624        ElementId::Name(name)
4625    }
4626}
4627
4628impl From<Arc<std::path::Path>> for ElementId {
4629    fn from(path: Arc<std::path::Path>) -> Self {
4630        ElementId::Path(path)
4631    }
4632}
4633
4634impl From<&'static str> for ElementId {
4635    fn from(name: &'static str) -> Self {
4636        ElementId::Name(name.into())
4637    }
4638}
4639
4640impl<'a> From<&'a FocusHandle> for ElementId {
4641    fn from(handle: &'a FocusHandle) -> Self {
4642        ElementId::FocusHandle(handle.id)
4643    }
4644}
4645
4646impl From<(&'static str, EntityId)> for ElementId {
4647    fn from((name, id): (&'static str, EntityId)) -> Self {
4648        ElementId::NamedInteger(name.into(), id.as_u64())
4649    }
4650}
4651
4652impl From<(&'static str, usize)> for ElementId {
4653    fn from((name, id): (&'static str, usize)) -> Self {
4654        ElementId::NamedInteger(name.into(), id as u64)
4655    }
4656}
4657
4658impl From<(SharedString, usize)> for ElementId {
4659    fn from((name, id): (SharedString, usize)) -> Self {
4660        ElementId::NamedInteger(name, id as u64)
4661    }
4662}
4663
4664impl From<(&'static str, u64)> for ElementId {
4665    fn from((name, id): (&'static str, u64)) -> Self {
4666        ElementId::NamedInteger(name.into(), id)
4667    }
4668}
4669
4670impl From<Uuid> for ElementId {
4671    fn from(value: Uuid) -> Self {
4672        Self::Uuid(value)
4673    }
4674}
4675
4676impl From<(&'static str, u32)> for ElementId {
4677    fn from((name, id): (&'static str, u32)) -> Self {
4678        ElementId::NamedInteger(name.into(), id.into())
4679    }
4680}
4681
4682/// A rectangle to be rendered in the window at the given position and size.
4683/// Passed as an argument [`Window::paint_quad`].
4684#[derive(Clone)]
4685pub struct PaintQuad {
4686    /// The bounds of the quad within the window.
4687    pub bounds: Bounds<Pixels>,
4688    /// The radii of the quad's corners.
4689    pub corner_radii: Corners<Pixels>,
4690    /// The background color of the quad.
4691    pub background: Background,
4692    /// The widths of the quad's borders.
4693    pub border_widths: Edges<Pixels>,
4694    /// The color of the quad's borders.
4695    pub border_color: Hsla,
4696    /// The style of the quad's borders.
4697    pub border_style: BorderStyle,
4698}
4699
4700impl PaintQuad {
4701    /// Sets the corner radii of the quad.
4702    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4703        PaintQuad {
4704            corner_radii: corner_radii.into(),
4705            ..self
4706        }
4707    }
4708
4709    /// Sets the border widths of the quad.
4710    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
4711        PaintQuad {
4712            border_widths: border_widths.into(),
4713            ..self
4714        }
4715    }
4716
4717    /// Sets the border color of the quad.
4718    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
4719        PaintQuad {
4720            border_color: border_color.into(),
4721            ..self
4722        }
4723    }
4724
4725    /// Sets the background color of the quad.
4726    pub fn background(self, background: impl Into<Background>) -> Self {
4727        PaintQuad {
4728            background: background.into(),
4729            ..self
4730        }
4731    }
4732}
4733
4734/// Creates a quad with the given parameters.
4735pub fn quad(
4736    bounds: Bounds<Pixels>,
4737    corner_radii: impl Into<Corners<Pixels>>,
4738    background: impl Into<Background>,
4739    border_widths: impl Into<Edges<Pixels>>,
4740    border_color: impl Into<Hsla>,
4741    border_style: BorderStyle,
4742) -> PaintQuad {
4743    PaintQuad {
4744        bounds,
4745        corner_radii: corner_radii.into(),
4746        background: background.into(),
4747        border_widths: border_widths.into(),
4748        border_color: border_color.into(),
4749        border_style,
4750    }
4751}
4752
4753/// Creates a filled quad with the given bounds and background color.
4754pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
4755    PaintQuad {
4756        bounds: bounds.into(),
4757        corner_radii: (0.).into(),
4758        background: background.into(),
4759        border_widths: (0.).into(),
4760        border_color: transparent_black(),
4761        border_style: BorderStyle::default(),
4762    }
4763}
4764
4765/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
4766pub fn outline(
4767    bounds: impl Into<Bounds<Pixels>>,
4768    border_color: impl Into<Hsla>,
4769    border_style: BorderStyle,
4770) -> PaintQuad {
4771    PaintQuad {
4772        bounds: bounds.into(),
4773        corner_radii: (0.).into(),
4774        background: transparent_black().into(),
4775        border_widths: (1.).into(),
4776        border_color: border_color.into(),
4777        border_style,
4778    }
4779}