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        dbg!(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        println!("clearing focus 1");
 709
 710        #[cfg(any(feature = "inspector", debug_assertions))]
 711        {
 712            self.next_inspector_instance_ids.clear();
 713            self.inspector_hitboxes.clear();
 714        }
 715    }
 716
 717    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 718        self.cursor_styles
 719            .iter()
 720            .rev()
 721            .fold_while(None, |style, request| match request.hitbox_id {
 722                None => Done(Some(request.style)),
 723                Some(hitbox_id) => Continue(
 724                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 725                ),
 726            })
 727            .into_inner()
 728    }
 729
 730    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 731        let mut set_hover_hitbox_count = false;
 732        let mut hit_test = HitTest::default();
 733        for hitbox in self.hitboxes.iter().rev() {
 734            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 735            if bounds.contains(&position) {
 736                hit_test.ids.push(hitbox.id);
 737                if !set_hover_hitbox_count
 738                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 739                {
 740                    hit_test.hover_hitbox_count = hit_test.ids.len();
 741                    set_hover_hitbox_count = true;
 742                }
 743                if hitbox.behavior == HitboxBehavior::BlockMouse {
 744                    break;
 745                }
 746            }
 747        }
 748        if !set_hover_hitbox_count {
 749            hit_test.hover_hitbox_count = hit_test.ids.len();
 750        }
 751        hit_test
 752    }
 753
 754    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 755        dbg!("focus path");
 756        dbg!(self.focus.is_some());
 757        self.focus
 758            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 759            .unwrap_or_default()
 760    }
 761
 762    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 763        for element_state_key in &self.accessed_element_states {
 764            if let Some((element_state_key, element_state)) =
 765                prev_frame.element_states.remove_entry(element_state_key)
 766            {
 767                self.element_states.insert(element_state_key, element_state);
 768            }
 769        }
 770
 771        self.scene.finish();
 772    }
 773}
 774
 775/// Holds the state for a specific window.
 776pub struct Window {
 777    pub(crate) handle: AnyWindowHandle,
 778    pub(crate) invalidator: WindowInvalidator,
 779    pub(crate) removed: bool,
 780    pub(crate) platform_window: Box<dyn PlatformWindow>,
 781    display_id: Option<DisplayId>,
 782    sprite_atlas: Arc<dyn PlatformAtlas>,
 783    text_system: Arc<WindowTextSystem>,
 784    rem_size: Pixels,
 785    /// The stack of override values for the window's rem size.
 786    ///
 787    /// This is used by `with_rem_size` to allow rendering an element tree with
 788    /// a given rem size.
 789    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 790    pub(crate) viewport_size: Size<Pixels>,
 791    layout_engine: Option<TaffyLayoutEngine>,
 792    pub(crate) root: Option<AnyView>,
 793    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 794    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 795    pub(crate) rendered_entity_stack: Vec<EntityId>,
 796    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 797    pub(crate) element_opacity: Option<f32>,
 798    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 799    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 800    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 801    pub(crate) rendered_frame: Frame,
 802    pub(crate) next_frame: Frame,
 803    next_hitbox_id: HitboxId,
 804    pub(crate) next_tooltip_id: TooltipId,
 805    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 806    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 807    pub(crate) dirty_views: FxHashSet<EntityId>,
 808    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 809    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 810    default_prevented: bool,
 811    mouse_position: Point<Pixels>,
 812    mouse_hit_test: HitTest,
 813    modifiers: Modifiers,
 814    capslock: Capslock,
 815    scale_factor: f32,
 816    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 817    appearance: WindowAppearance,
 818    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 819    active: Rc<Cell<bool>>,
 820    hovered: Rc<Cell<bool>>,
 821    pub(crate) needs_present: Rc<Cell<bool>>,
 822    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 823    pub(crate) refreshing: bool,
 824    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 825    pub(crate) focus: Option<FocusId>,
 826    focus_enabled: bool,
 827    pending_input: Option<PendingInput>,
 828    pending_modifier: ModifierState,
 829    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 830    prompt: Option<RenderablePromptHandle>,
 831    pub(crate) client_inset: Option<Pixels>,
 832    #[cfg(any(feature = "inspector", debug_assertions))]
 833    inspector: Option<Entity<Inspector>>,
 834}
 835
 836#[derive(Clone, Debug, Default)]
 837struct ModifierState {
 838    modifiers: Modifiers,
 839    saw_keystroke: bool,
 840}
 841
 842#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 843pub(crate) enum DrawPhase {
 844    None,
 845    Prepaint,
 846    Paint,
 847    Focus,
 848}
 849
 850#[derive(Default, Debug)]
 851struct PendingInput {
 852    keystrokes: SmallVec<[Keystroke; 1]>,
 853    focus: Option<FocusId>,
 854    timer: Option<Task<()>>,
 855}
 856
 857pub(crate) struct ElementStateBox {
 858    pub(crate) inner: Box<dyn Any>,
 859    #[cfg(debug_assertions)]
 860    pub(crate) type_name: &'static str,
 861}
 862
 863fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> Bounds<Pixels> {
 864    const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
 865
 866    // TODO, BUG: if you open a window with the currently active window
 867    // on the stack, this will erroneously select the 'unwrap_or_else'
 868    // code path
 869    cx.active_window()
 870        .and_then(|w| w.update(cx, |_, window, _| window.bounds()).ok())
 871        .map(|mut bounds| {
 872            bounds.origin += DEFAULT_WINDOW_OFFSET;
 873            bounds
 874        })
 875        .unwrap_or_else(|| {
 876            let display = display_id
 877                .map(|id| cx.find_display(id))
 878                .unwrap_or_else(|| cx.primary_display());
 879
 880            display
 881                .map(|display| display.default_bounds())
 882                .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
 883        })
 884}
 885
 886impl Window {
 887    pub(crate) fn new(
 888        handle: AnyWindowHandle,
 889        options: WindowOptions,
 890        cx: &mut App,
 891    ) -> Result<Self> {
 892        let WindowOptions {
 893            window_bounds,
 894            titlebar,
 895            focus,
 896            show,
 897            kind,
 898            is_movable,
 899            display_id,
 900            window_background,
 901            app_id,
 902            window_min_size,
 903            window_decorations,
 904        } = options;
 905
 906        let bounds = window_bounds
 907            .map(|bounds| bounds.get_bounds())
 908            .unwrap_or_else(|| default_bounds(display_id, cx));
 909        let mut platform_window = cx.platform.open_window(
 910            handle,
 911            WindowParams {
 912                bounds,
 913                titlebar,
 914                kind,
 915                is_movable,
 916                focus,
 917                show,
 918                display_id,
 919                window_min_size,
 920            },
 921        )?;
 922        let display_id = platform_window.display().map(|display| display.id());
 923        let sprite_atlas = platform_window.sprite_atlas();
 924        let mouse_position = platform_window.mouse_position();
 925        let modifiers = platform_window.modifiers();
 926        let capslock = platform_window.capslock();
 927        let content_size = platform_window.content_size();
 928        let scale_factor = platform_window.scale_factor();
 929        let appearance = platform_window.appearance();
 930        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
 931        let invalidator = WindowInvalidator::new();
 932        let active = Rc::new(Cell::new(platform_window.is_active()));
 933        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
 934        let needs_present = Rc::new(Cell::new(false));
 935        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
 936        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
 937
 938        platform_window
 939            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
 940        platform_window.set_background_appearance(window_background);
 941
 942        if let Some(ref window_open_state) = window_bounds {
 943            match window_open_state {
 944                WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
 945                WindowBounds::Maximized(_) => platform_window.zoom(),
 946                WindowBounds::Windowed(_) => {}
 947            }
 948        }
 949
 950        platform_window.on_close(Box::new({
 951            let mut cx = cx.to_async();
 952            move || {
 953                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
 954            }
 955        }));
 956        platform_window.on_request_frame(Box::new({
 957            let mut cx = cx.to_async();
 958            let invalidator = invalidator.clone();
 959            let active = active.clone();
 960            let needs_present = needs_present.clone();
 961            let next_frame_callbacks = next_frame_callbacks.clone();
 962            let last_input_timestamp = last_input_timestamp.clone();
 963            move |request_frame_options| {
 964                let next_frame_callbacks = next_frame_callbacks.take();
 965                if !next_frame_callbacks.is_empty() {
 966                    handle
 967                        .update(&mut cx, |_, window, cx| {
 968                            for callback in next_frame_callbacks {
 969                                callback(window, cx);
 970                            }
 971                        })
 972                        .log_err();
 973                }
 974
 975                // Keep presenting the current scene for 1 extra second since the
 976                // last input to prevent the display from underclocking the refresh rate.
 977                let needs_present = request_frame_options.require_presentation
 978                    || needs_present.get()
 979                    || (active.get()
 980                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
 981
 982                if invalidator.is_dirty() {
 983                    measure("frame duration", || {
 984                        handle
 985                            .update(&mut cx, |_, window, cx| {
 986                                let arena_clear_needed = window.draw(cx);
 987                                window.present();
 988                                // drop the arena elements after present to reduce latency
 989                                arena_clear_needed.clear();
 990                            })
 991                            .log_err();
 992                    })
 993                } else if needs_present {
 994                    handle
 995                        .update(&mut cx, |_, window, _| window.present())
 996                        .log_err();
 997                }
 998
 999                handle
1000                    .update(&mut cx, |_, window, _| {
1001                        window.complete_frame();
1002                    })
1003                    .log_err();
1004            }
1005        }));
1006        platform_window.on_resize(Box::new({
1007            let mut cx = cx.to_async();
1008            move |_, _| {
1009                handle
1010                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1011                    .log_err();
1012            }
1013        }));
1014        platform_window.on_moved(Box::new({
1015            let mut cx = cx.to_async();
1016            move || {
1017                handle
1018                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1019                    .log_err();
1020            }
1021        }));
1022        platform_window.on_appearance_changed(Box::new({
1023            let mut cx = cx.to_async();
1024            move || {
1025                handle
1026                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1027                    .log_err();
1028            }
1029        }));
1030        platform_window.on_active_status_change(Box::new({
1031            let mut cx = cx.to_async();
1032            move |active| {
1033                handle
1034                    .update(&mut cx, |_, window, cx| {
1035                        window.active.set(active);
1036                        window.modifiers = window.platform_window.modifiers();
1037                        window.capslock = window.platform_window.capslock();
1038                        window
1039                            .activation_observers
1040                            .clone()
1041                            .retain(&(), |callback| callback(window, cx));
1042                        window.refresh();
1043                    })
1044                    .log_err();
1045            }
1046        }));
1047        platform_window.on_hover_status_change(Box::new({
1048            let mut cx = cx.to_async();
1049            move |active| {
1050                handle
1051                    .update(&mut cx, |_, window, _| {
1052                        window.hovered.set(active);
1053                        window.refresh();
1054                    })
1055                    .log_err();
1056            }
1057        }));
1058        platform_window.on_input({
1059            let mut cx = cx.to_async();
1060            Box::new(move |event| {
1061                handle
1062                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1063                    .log_err()
1064                    .unwrap_or(DispatchEventResult::default())
1065            })
1066        });
1067        platform_window.on_hit_test_window_control({
1068            let mut cx = cx.to_async();
1069            Box::new(move || {
1070                handle
1071                    .update(&mut cx, |_, window, _cx| {
1072                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1073                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1074                                return Some(*area);
1075                            }
1076                        }
1077                        None
1078                    })
1079                    .log_err()
1080                    .unwrap_or(None)
1081            })
1082        });
1083
1084        if let Some(app_id) = app_id {
1085            platform_window.set_app_id(&app_id);
1086        }
1087
1088        platform_window.map_window().unwrap();
1089
1090        Ok(Window {
1091            handle,
1092            invalidator,
1093            removed: false,
1094            platform_window,
1095            display_id,
1096            sprite_atlas,
1097            text_system,
1098            rem_size: px(16.),
1099            rem_size_override_stack: SmallVec::new(),
1100            viewport_size: content_size,
1101            layout_engine: Some(TaffyLayoutEngine::new()),
1102            root: None,
1103            element_id_stack: SmallVec::default(),
1104            text_style_stack: Vec::new(),
1105            rendered_entity_stack: Vec::new(),
1106            element_offset_stack: Vec::new(),
1107            content_mask_stack: Vec::new(),
1108            element_opacity: None,
1109            requested_autoscroll: None,
1110            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1111            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1112            next_frame_callbacks,
1113            next_hitbox_id: HitboxId(0),
1114            next_tooltip_id: TooltipId::default(),
1115            tooltip_bounds: None,
1116            dirty_views: FxHashSet::default(),
1117            focus_listeners: SubscriberSet::new(),
1118            focus_lost_listeners: SubscriberSet::new(),
1119            default_prevented: true,
1120            mouse_position,
1121            mouse_hit_test: HitTest::default(),
1122            modifiers,
1123            capslock,
1124            scale_factor,
1125            bounds_observers: SubscriberSet::new(),
1126            appearance,
1127            appearance_observers: SubscriberSet::new(),
1128            active,
1129            hovered,
1130            needs_present,
1131            last_input_timestamp,
1132            refreshing: false,
1133            activation_observers: SubscriberSet::new(),
1134            focus: None,
1135            focus_enabled: true,
1136            pending_input: None,
1137            pending_modifier: ModifierState::default(),
1138            pending_input_observers: SubscriberSet::new(),
1139            prompt: None,
1140            client_inset: None,
1141            image_cache_stack: Vec::new(),
1142            #[cfg(any(feature = "inspector", debug_assertions))]
1143            inspector: None,
1144        })
1145    }
1146
1147    pub(crate) fn new_focus_listener(
1148        &self,
1149        value: AnyWindowFocusListener,
1150    ) -> (Subscription, impl FnOnce() + use<>) {
1151        self.focus_listeners.insert((), value)
1152    }
1153}
1154
1155#[derive(Clone, Debug, Default, PartialEq, Eq)]
1156pub(crate) struct DispatchEventResult {
1157    pub propagate: bool,
1158    pub default_prevented: bool,
1159}
1160
1161/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1162/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1163/// to leave room to support more complex shapes in the future.
1164#[derive(Clone, Debug, Default, PartialEq, Eq)]
1165#[repr(C)]
1166pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1167    /// The bounds
1168    pub bounds: Bounds<P>,
1169}
1170
1171impl ContentMask<Pixels> {
1172    /// Scale the content mask's pixel units by the given scaling factor.
1173    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1174        ContentMask {
1175            bounds: self.bounds.scale(factor),
1176        }
1177    }
1178
1179    /// Intersect the content mask with the given content mask.
1180    pub fn intersect(&self, other: &Self) -> Self {
1181        let bounds = self.bounds.intersect(&other.bounds);
1182        ContentMask { bounds }
1183    }
1184}
1185
1186impl Window {
1187    fn mark_view_dirty(&mut self, view_id: EntityId) {
1188        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1189        // should already be dirty.
1190        for view_id in self
1191            .rendered_frame
1192            .dispatch_tree
1193            .view_path(view_id)
1194            .into_iter()
1195            .rev()
1196        {
1197            if !self.dirty_views.insert(view_id) {
1198                break;
1199            }
1200        }
1201    }
1202
1203    /// Registers a callback to be invoked when the window appearance changes.
1204    pub fn observe_window_appearance(
1205        &self,
1206        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1207    ) -> Subscription {
1208        let (subscription, activate) = self.appearance_observers.insert(
1209            (),
1210            Box::new(move |window, cx| {
1211                callback(window, cx);
1212                true
1213            }),
1214        );
1215        activate();
1216        subscription
1217    }
1218
1219    /// Replaces the root entity of the window with a new one.
1220    pub fn replace_root<E>(
1221        &mut self,
1222        cx: &mut App,
1223        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1224    ) -> Entity<E>
1225    where
1226        E: 'static + Render,
1227    {
1228        let view = cx.new(|cx| build_view(self, cx));
1229        self.root = Some(view.clone().into());
1230        self.refresh();
1231        view
1232    }
1233
1234    /// Returns the root entity of the window, if it has one.
1235    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1236    where
1237        E: 'static + Render,
1238    {
1239        self.root
1240            .as_ref()
1241            .map(|view| view.clone().downcast::<E>().ok())
1242    }
1243
1244    /// Obtain a handle to the window that belongs to this context.
1245    pub fn window_handle(&self) -> AnyWindowHandle {
1246        self.handle
1247    }
1248
1249    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1250    pub fn refresh(&mut self) {
1251        if self.invalidator.not_drawing() {
1252            self.refreshing = true;
1253            self.invalidator.set_dirty(true);
1254        }
1255    }
1256
1257    /// Close this window.
1258    pub fn remove_window(&mut self) {
1259        self.removed = true;
1260    }
1261
1262    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1263    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1264        self.focus
1265            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1266    }
1267
1268    /// Move focus to the element associated with the given [`FocusHandle`].
1269    pub fn focus(&mut self, handle: &FocusHandle) {
1270        println!(
1271            "Setting focus to {:?} on platform {:?}",
1272            handle.id,
1273            std::env::consts::OS
1274        );
1275
1276        if !self.focus_enabled || self.focus == Some(handle.id) {
1277            return;
1278        }
1279        println!("actually setting focus");
1280        self.focus = Some(handle.id);
1281        self.clear_pending_keystrokes();
1282        self.refresh();
1283    }
1284
1285    /// Remove focus from all elements within this context's window.
1286    pub fn blur(&mut self) {
1287        if !self.focus_enabled {
1288            return;
1289        }
1290
1291        self.focus = None;
1292        println!("clearing focus 2");
1293        self.refresh();
1294    }
1295
1296    /// Blur the window and don't allow anything in it to be focused again.
1297    pub fn disable_focus(&mut self) {
1298        println!("disable_focus");
1299        self.blur();
1300        self.focus_enabled = false;
1301    }
1302
1303    /// Accessor for the text system.
1304    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1305        &self.text_system
1306    }
1307
1308    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1309    pub fn text_style(&self) -> TextStyle {
1310        let mut style = TextStyle::default();
1311        for refinement in &self.text_style_stack {
1312            style.refine(refinement);
1313        }
1314        style
1315    }
1316
1317    /// Check if the platform window is maximized
1318    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1319    pub fn is_maximized(&self) -> bool {
1320        self.platform_window.is_maximized()
1321    }
1322
1323    /// request a certain window decoration (Wayland)
1324    pub fn request_decorations(&self, decorations: WindowDecorations) {
1325        self.platform_window.request_decorations(decorations);
1326    }
1327
1328    /// Start a window resize operation (Wayland)
1329    pub fn start_window_resize(&self, edge: ResizeEdge) {
1330        self.platform_window.start_window_resize(edge);
1331    }
1332
1333    /// Return the `WindowBounds` to indicate that how a window should be opened
1334    /// after it has been closed
1335    pub fn window_bounds(&self) -> WindowBounds {
1336        self.platform_window.window_bounds()
1337    }
1338
1339    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1340    pub fn inner_window_bounds(&self) -> WindowBounds {
1341        self.platform_window.inner_window_bounds()
1342    }
1343
1344    /// Dispatch the given action on the currently focused element.
1345    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1346        let focus_id = self.focused(cx).map(|handle| handle.id);
1347        dbg!(&focus_id);
1348        let window = self.handle;
1349        cx.defer(move |cx| {
1350            window
1351                .update(cx, |_, window, cx| {
1352                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1353                    dbg!(&node_id);
1354                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1355                })
1356                .log_err();
1357        })
1358    }
1359
1360    pub(crate) fn dispatch_keystroke_observers(
1361        &mut self,
1362        event: &dyn Any,
1363        action: Option<Box<dyn Action>>,
1364        context_stack: Vec<KeyContext>,
1365        cx: &mut App,
1366    ) {
1367        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1368            return;
1369        };
1370
1371        cx.keystroke_observers.clone().retain(&(), move |callback| {
1372            (callback)(
1373                &KeystrokeEvent {
1374                    keystroke: key_down_event.keystroke.clone(),
1375                    action: action.as_ref().map(|action| action.boxed_clone()),
1376                    context_stack: context_stack.clone(),
1377                },
1378                self,
1379                cx,
1380            )
1381        });
1382    }
1383
1384    pub(crate) fn dispatch_keystroke_interceptors(
1385        &mut self,
1386        event: &dyn Any,
1387        context_stack: Vec<KeyContext>,
1388        cx: &mut App,
1389    ) {
1390        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1391            return;
1392        };
1393
1394        cx.keystroke_interceptors
1395            .clone()
1396            .retain(&(), move |callback| {
1397                (callback)(
1398                    &KeystrokeEvent {
1399                        keystroke: key_down_event.keystroke.clone(),
1400                        action: None,
1401                        context_stack: context_stack.clone(),
1402                    },
1403                    self,
1404                    cx,
1405                )
1406            });
1407    }
1408
1409    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1410    /// that are currently on the stack to be returned to the app.
1411    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1412        let handle = self.handle;
1413        cx.defer(move |cx| {
1414            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1415        });
1416    }
1417
1418    /// Subscribe to events emitted by a entity.
1419    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1420    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1421    pub fn observe<T: 'static>(
1422        &mut self,
1423        observed: &Entity<T>,
1424        cx: &mut App,
1425        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1426    ) -> Subscription {
1427        let entity_id = observed.entity_id();
1428        let observed = observed.downgrade();
1429        let window_handle = self.handle;
1430        cx.new_observer(
1431            entity_id,
1432            Box::new(move |cx| {
1433                window_handle
1434                    .update(cx, |_, window, cx| {
1435                        if let Some(handle) = observed.upgrade() {
1436                            on_notify(handle, window, cx);
1437                            true
1438                        } else {
1439                            false
1440                        }
1441                    })
1442                    .unwrap_or(false)
1443            }),
1444        )
1445    }
1446
1447    /// Subscribe to events emitted by a entity.
1448    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1449    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1450    pub fn subscribe<Emitter, Evt>(
1451        &mut self,
1452        entity: &Entity<Emitter>,
1453        cx: &mut App,
1454        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1455    ) -> Subscription
1456    where
1457        Emitter: EventEmitter<Evt>,
1458        Evt: 'static,
1459    {
1460        let entity_id = entity.entity_id();
1461        let handle = entity.downgrade();
1462        let window_handle = self.handle;
1463        cx.new_subscription(
1464            entity_id,
1465            (
1466                TypeId::of::<Evt>(),
1467                Box::new(move |event, cx| {
1468                    window_handle
1469                        .update(cx, |_, window, cx| {
1470                            if let Some(entity) = handle.upgrade() {
1471                                let event = event.downcast_ref().expect("invalid event type");
1472                                on_event(entity, event, window, cx);
1473                                true
1474                            } else {
1475                                false
1476                            }
1477                        })
1478                        .unwrap_or(false)
1479                }),
1480            ),
1481        )
1482    }
1483
1484    /// Register a callback to be invoked when the given `Entity` is released.
1485    pub fn observe_release<T>(
1486        &self,
1487        entity: &Entity<T>,
1488        cx: &mut App,
1489        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1490    ) -> Subscription
1491    where
1492        T: 'static,
1493    {
1494        let entity_id = entity.entity_id();
1495        let window_handle = self.handle;
1496        let (subscription, activate) = cx.release_listeners.insert(
1497            entity_id,
1498            Box::new(move |entity, cx| {
1499                let entity = entity.downcast_mut().expect("invalid entity type");
1500                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1501            }),
1502        );
1503        activate();
1504        subscription
1505    }
1506
1507    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1508    /// await points in async code.
1509    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1510        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1511    }
1512
1513    /// Schedule the given closure to be run directly after the current frame is rendered.
1514    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1515        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1516    }
1517
1518    /// Schedule a frame to be drawn on the next animation frame.
1519    ///
1520    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1521    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1522    ///
1523    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1524    pub fn request_animation_frame(&self) {
1525        let entity = self.current_view();
1526        self.on_next_frame(move |_, cx| cx.notify(entity));
1527    }
1528
1529    /// Spawn the future returned by the given closure on the application thread pool.
1530    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1531    /// use within your future.
1532    #[track_caller]
1533    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1534    where
1535        R: 'static,
1536        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1537    {
1538        let handle = self.handle;
1539        cx.spawn(async move |app| {
1540            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1541            f(&mut async_window_cx).await
1542        })
1543    }
1544
1545    fn bounds_changed(&mut self, cx: &mut App) {
1546        self.scale_factor = self.platform_window.scale_factor();
1547        self.viewport_size = self.platform_window.content_size();
1548        self.display_id = self.platform_window.display().map(|display| display.id());
1549
1550        self.refresh();
1551
1552        self.bounds_observers
1553            .clone()
1554            .retain(&(), |callback| callback(self, cx));
1555    }
1556
1557    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1558    pub fn bounds(&self) -> Bounds<Pixels> {
1559        self.platform_window.bounds()
1560    }
1561
1562    /// Set the content size of the window.
1563    pub fn resize(&mut self, size: Size<Pixels>) {
1564        self.platform_window.resize(size);
1565    }
1566
1567    /// Returns whether or not the window is currently fullscreen
1568    pub fn is_fullscreen(&self) -> bool {
1569        self.platform_window.is_fullscreen()
1570    }
1571
1572    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1573        self.appearance = self.platform_window.appearance();
1574
1575        self.appearance_observers
1576            .clone()
1577            .retain(&(), |callback| callback(self, cx));
1578    }
1579
1580    /// Returns the appearance of the current window.
1581    pub fn appearance(&self) -> WindowAppearance {
1582        self.appearance
1583    }
1584
1585    /// Returns the size of the drawable area within the window.
1586    pub fn viewport_size(&self) -> Size<Pixels> {
1587        self.viewport_size
1588    }
1589
1590    /// Returns whether this window is focused by the operating system (receiving key events).
1591    pub fn is_window_active(&self) -> bool {
1592        self.active.get()
1593    }
1594
1595    /// Returns whether this window is considered to be the window
1596    /// that currently owns the mouse cursor.
1597    /// On mac, this is equivalent to `is_window_active`.
1598    pub fn is_window_hovered(&self) -> bool {
1599        if cfg!(any(
1600            target_os = "windows",
1601            target_os = "linux",
1602            target_os = "freebsd"
1603        )) {
1604            self.hovered.get()
1605        } else {
1606            self.is_window_active()
1607        }
1608    }
1609
1610    /// Toggle zoom on the window.
1611    pub fn zoom_window(&self) {
1612        self.platform_window.zoom();
1613    }
1614
1615    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1616    pub fn show_window_menu(&self, position: Point<Pixels>) {
1617        self.platform_window.show_window_menu(position)
1618    }
1619
1620    /// Tells the compositor to take control of window movement (Wayland and X11)
1621    ///
1622    /// Events may not be received during a move operation.
1623    pub fn start_window_move(&self) {
1624        self.platform_window.start_window_move()
1625    }
1626
1627    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1628    pub fn set_client_inset(&mut self, inset: Pixels) {
1629        self.client_inset = Some(inset);
1630        self.platform_window.set_client_inset(inset);
1631    }
1632
1633    /// Returns the client_inset value by [`Self::set_client_inset`].
1634    pub fn client_inset(&self) -> Option<Pixels> {
1635        self.client_inset
1636    }
1637
1638    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1639    pub fn window_decorations(&self) -> Decorations {
1640        self.platform_window.window_decorations()
1641    }
1642
1643    /// Returns which window controls are currently visible (Wayland)
1644    pub fn window_controls(&self) -> WindowControls {
1645        self.platform_window.window_controls()
1646    }
1647
1648    /// Updates the window's title at the platform level.
1649    pub fn set_window_title(&mut self, title: &str) {
1650        self.platform_window.set_title(title);
1651    }
1652
1653    /// Sets the application identifier.
1654    pub fn set_app_id(&mut self, app_id: &str) {
1655        self.platform_window.set_app_id(app_id);
1656    }
1657
1658    /// Sets the window background appearance.
1659    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1660        self.platform_window
1661            .set_background_appearance(background_appearance);
1662    }
1663
1664    /// Mark the window as dirty at the platform level.
1665    pub fn set_window_edited(&mut self, edited: bool) {
1666        self.platform_window.set_edited(edited);
1667    }
1668
1669    /// Determine the display on which the window is visible.
1670    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1671        cx.platform
1672            .displays()
1673            .into_iter()
1674            .find(|display| Some(display.id()) == self.display_id)
1675    }
1676
1677    /// Show the platform character palette.
1678    pub fn show_character_palette(&self) {
1679        self.platform_window.show_character_palette();
1680    }
1681
1682    /// The scale factor of the display associated with the window. For example, it could
1683    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1684    /// be rendered as two pixels on screen.
1685    pub fn scale_factor(&self) -> f32 {
1686        self.scale_factor
1687    }
1688
1689    /// The size of an em for the base font of the application. Adjusting this value allows the
1690    /// UI to scale, just like zooming a web page.
1691    pub fn rem_size(&self) -> Pixels {
1692        self.rem_size_override_stack
1693            .last()
1694            .copied()
1695            .unwrap_or(self.rem_size)
1696    }
1697
1698    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1699    /// UI to scale, just like zooming a web page.
1700    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1701        self.rem_size = rem_size.into();
1702    }
1703
1704    /// Acquire a globally unique identifier for the given ElementId.
1705    /// Only valid for the duration of the provided closure.
1706    pub fn with_global_id<R>(
1707        &mut self,
1708        element_id: ElementId,
1709        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1710    ) -> R {
1711        self.element_id_stack.push(element_id);
1712        let global_id = GlobalElementId(self.element_id_stack.clone());
1713        let result = f(&global_id, self);
1714        self.element_id_stack.pop();
1715        result
1716    }
1717
1718    /// Executes the provided function with the specified rem size.
1719    ///
1720    /// This method must only be called as part of element drawing.
1721    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1722    where
1723        F: FnOnce(&mut Self) -> R,
1724    {
1725        self.invalidator.debug_assert_paint_or_prepaint();
1726
1727        if let Some(rem_size) = rem_size {
1728            self.rem_size_override_stack.push(rem_size.into());
1729            let result = f(self);
1730            self.rem_size_override_stack.pop();
1731            result
1732        } else {
1733            f(self)
1734        }
1735    }
1736
1737    /// The line height associated with the current text style.
1738    pub fn line_height(&self) -> Pixels {
1739        self.text_style().line_height_in_pixels(self.rem_size())
1740    }
1741
1742    /// Call to prevent the default action of an event. Currently only used to prevent
1743    /// parent elements from becoming focused on mouse down.
1744    pub fn prevent_default(&mut self) {
1745        self.default_prevented = true;
1746    }
1747
1748    /// Obtain whether default has been prevented for the event currently being dispatched.
1749    pub fn default_prevented(&self) -> bool {
1750        self.default_prevented
1751    }
1752
1753    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1754    pub fn is_action_available(&self, action: &dyn Action, cx: &mut App) -> bool {
1755        let node_id =
1756            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
1757        self.rendered_frame
1758            .dispatch_tree
1759            .is_action_available(action, node_id)
1760    }
1761
1762    /// The position of the mouse relative to the window.
1763    pub fn mouse_position(&self) -> Point<Pixels> {
1764        self.mouse_position
1765    }
1766
1767    /// The current state of the keyboard's modifiers
1768    pub fn modifiers(&self) -> Modifiers {
1769        self.modifiers
1770    }
1771
1772    /// The current state of the keyboard's capslock
1773    pub fn capslock(&self) -> Capslock {
1774        self.capslock
1775    }
1776
1777    fn complete_frame(&self) {
1778        self.platform_window.completed_frame();
1779    }
1780
1781    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1782    /// the contents of the new [Scene], use [present].
1783    #[profiling::function]
1784    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
1785        self.invalidate_entities();
1786        cx.entities.clear_accessed();
1787        debug_assert!(self.rendered_entity_stack.is_empty());
1788        self.invalidator.set_dirty(false);
1789        self.requested_autoscroll = None;
1790
1791        // Restore the previously-used input handler.
1792        if let Some(input_handler) = self.platform_window.take_input_handler() {
1793            self.rendered_frame.input_handlers.push(Some(input_handler));
1794        }
1795        self.draw_roots(cx);
1796        self.dirty_views.clear();
1797        self.next_frame.window_active = self.active.get();
1798
1799        // Register requested input handler with the platform window.
1800        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
1801            self.platform_window
1802                .set_input_handler(input_handler.unwrap());
1803        }
1804
1805        self.layout_engine.as_mut().unwrap().clear();
1806        self.text_system().finish_frame();
1807        self.next_frame.finish(&mut self.rendered_frame);
1808
1809        self.invalidator.set_phase(DrawPhase::Focus);
1810        let previous_focus_path = self.rendered_frame.focus_path();
1811        let previous_window_active = self.rendered_frame.window_active;
1812        println!(
1813            "dbg! Window::draw - pre-swap: rendered_frame.focus = {:?}, next_frame.focus = {:?}",
1814            self.rendered_frame.focus, self.next_frame.focus
1815        );
1816        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
1817        self.next_frame.clear();
1818        println!(
1819            "dbg! Window::draw - post-swap: rendered_frame.focus = {:?}, next_frame.focus = {:?}",
1820            self.rendered_frame.focus, self.next_frame.focus
1821        );
1822        let current_focus_path = self.rendered_frame.focus_path();
1823        let current_window_active = self.rendered_frame.window_active;
1824
1825        if previous_focus_path != current_focus_path
1826            || previous_window_active != current_window_active
1827        {
1828            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1829                self.focus_lost_listeners
1830                    .clone()
1831                    .retain(&(), |listener| listener(self, cx));
1832            }
1833
1834            let event = WindowFocusEvent {
1835                previous_focus_path: if previous_window_active {
1836                    previous_focus_path
1837                } else {
1838                    Default::default()
1839                },
1840                current_focus_path: if current_window_active {
1841                    current_focus_path
1842                } else {
1843                    Default::default()
1844                },
1845            };
1846            self.focus_listeners
1847                .clone()
1848                .retain(&(), |listener| listener(&event, self, cx));
1849        }
1850
1851        debug_assert!(self.rendered_entity_stack.is_empty());
1852        self.record_entities_accessed(cx);
1853        self.reset_cursor_style(cx);
1854        self.refreshing = false;
1855        self.invalidator.set_phase(DrawPhase::None);
1856        self.needs_present.set(true);
1857
1858        ArenaClearNeeded
1859    }
1860
1861    fn record_entities_accessed(&mut self, cx: &mut App) {
1862        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1863        let mut entities = mem::take(entities_ref.deref_mut());
1864        drop(entities_ref);
1865        let handle = self.handle;
1866        cx.record_entities_accessed(
1867            handle,
1868            // Try moving window invalidator into the Window
1869            self.invalidator.clone(),
1870            &entities,
1871        );
1872        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1873        mem::swap(&mut entities, entities_ref.deref_mut());
1874    }
1875
1876    fn invalidate_entities(&mut self) {
1877        let mut views = self.invalidator.take_views();
1878        for entity in views.drain() {
1879            self.mark_view_dirty(entity);
1880        }
1881        self.invalidator.replace_views(views);
1882    }
1883
1884    #[profiling::function]
1885    fn present(&self) {
1886        self.platform_window.draw(&self.rendered_frame.scene);
1887        self.needs_present.set(false);
1888        profiling::finish_frame!();
1889    }
1890
1891    fn draw_roots(&mut self, cx: &mut App) {
1892        self.invalidator.set_phase(DrawPhase::Prepaint);
1893        self.tooltip_bounds.take();
1894
1895        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
1896        let root_size = {
1897            #[cfg(any(feature = "inspector", debug_assertions))]
1898            {
1899                if self.inspector.is_some() {
1900                    let mut size = self.viewport_size;
1901                    size.width = (size.width - _inspector_width).max(px(0.0));
1902                    size
1903                } else {
1904                    self.viewport_size
1905                }
1906            }
1907            #[cfg(not(any(feature = "inspector", debug_assertions)))]
1908            {
1909                self.viewport_size
1910            }
1911        };
1912
1913        // Layout all root elements.
1914        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
1915        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1916
1917        #[cfg(any(feature = "inspector", debug_assertions))]
1918        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
1919
1920        let mut sorted_deferred_draws =
1921            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1922        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
1923        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
1924
1925        let mut prompt_element = None;
1926        let mut active_drag_element = None;
1927        let mut tooltip_element = None;
1928        if let Some(prompt) = self.prompt.take() {
1929            let mut element = prompt.view.any_view().into_any();
1930            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1931            prompt_element = Some(element);
1932            self.prompt = Some(prompt);
1933        } else if let Some(active_drag) = cx.active_drag.take() {
1934            let mut element = active_drag.view.clone().into_any();
1935            let offset = self.mouse_position() - active_drag.cursor_offset;
1936            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
1937            active_drag_element = Some(element);
1938            cx.active_drag = Some(active_drag);
1939        } else {
1940            tooltip_element = self.prepaint_tooltip(cx);
1941        }
1942
1943        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
1944
1945        // Now actually paint the elements.
1946        self.invalidator.set_phase(DrawPhase::Paint);
1947        root_element.paint(self, cx);
1948
1949        #[cfg(any(feature = "inspector", debug_assertions))]
1950        self.paint_inspector(inspector_element, cx);
1951
1952        self.paint_deferred_draws(&sorted_deferred_draws, cx);
1953
1954        if let Some(mut prompt_element) = prompt_element {
1955            prompt_element.paint(self, cx);
1956        } else if let Some(mut drag_element) = active_drag_element {
1957            drag_element.paint(self, cx);
1958        } else if let Some(mut tooltip_element) = tooltip_element {
1959            tooltip_element.paint(self, cx);
1960        }
1961
1962        #[cfg(any(feature = "inspector", debug_assertions))]
1963        self.paint_inspector_hitbox(cx);
1964    }
1965
1966    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
1967        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
1968        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
1969            let Some(Some(tooltip_request)) = self
1970                .next_frame
1971                .tooltip_requests
1972                .get(tooltip_request_index)
1973                .cloned()
1974            else {
1975                log::error!("Unexpectedly absent TooltipRequest");
1976                continue;
1977            };
1978            let mut element = tooltip_request.tooltip.view.clone().into_any();
1979            let mouse_position = tooltip_request.tooltip.mouse_position;
1980            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
1981
1982            let mut tooltip_bounds =
1983                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1984            let window_bounds = Bounds {
1985                origin: Point::default(),
1986                size: self.viewport_size(),
1987            };
1988
1989            if tooltip_bounds.right() > window_bounds.right() {
1990                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1991                if new_x >= Pixels::ZERO {
1992                    tooltip_bounds.origin.x = new_x;
1993                } else {
1994                    tooltip_bounds.origin.x = cmp::max(
1995                        Pixels::ZERO,
1996                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1997                    );
1998                }
1999            }
2000
2001            if tooltip_bounds.bottom() > window_bounds.bottom() {
2002                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
2003                if new_y >= Pixels::ZERO {
2004                    tooltip_bounds.origin.y = new_y;
2005                } else {
2006                    tooltip_bounds.origin.y = cmp::max(
2007                        Pixels::ZERO,
2008                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
2009                    );
2010                }
2011            }
2012
2013            // It's possible for an element to have an active tooltip while not being painted (e.g.
2014            // via the `visible_on_hover` method). Since mouse listeners are not active in this
2015            // case, instead update the tooltip's visibility here.
2016            let is_visible =
2017                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
2018            if !is_visible {
2019                continue;
2020            }
2021
2022            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2023                element.prepaint(window, cx)
2024            });
2025
2026            self.tooltip_bounds = Some(TooltipBounds {
2027                id: tooltip_request.id,
2028                bounds: tooltip_bounds,
2029            });
2030            return Some(element);
2031        }
2032        None
2033    }
2034
2035    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2036        assert_eq!(self.element_id_stack.len(), 0);
2037
2038        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2039        for deferred_draw_ix in deferred_draw_indices {
2040            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2041            self.element_id_stack
2042                .clone_from(&deferred_draw.element_id_stack);
2043            self.text_style_stack
2044                .clone_from(&deferred_draw.text_style_stack);
2045            self.next_frame
2046                .dispatch_tree
2047                .set_active_node(deferred_draw.parent_node);
2048
2049            let prepaint_start = self.prepaint_index();
2050            if let Some(element) = deferred_draw.element.as_mut() {
2051                self.with_rendered_view(deferred_draw.current_view, |window| {
2052                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
2053                        element.prepaint(window, cx)
2054                    });
2055                })
2056            } else {
2057                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2058            }
2059            let prepaint_end = self.prepaint_index();
2060            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2061        }
2062        assert_eq!(
2063            self.next_frame.deferred_draws.len(),
2064            0,
2065            "cannot call defer_draw during deferred drawing"
2066        );
2067        self.next_frame.deferred_draws = deferred_draws;
2068        self.element_id_stack.clear();
2069        self.text_style_stack.clear();
2070    }
2071
2072    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2073        assert_eq!(self.element_id_stack.len(), 0);
2074
2075        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2076        for deferred_draw_ix in deferred_draw_indices {
2077            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2078            self.element_id_stack
2079                .clone_from(&deferred_draw.element_id_stack);
2080            self.next_frame
2081                .dispatch_tree
2082                .set_active_node(deferred_draw.parent_node);
2083
2084            let paint_start = self.paint_index();
2085            if let Some(element) = deferred_draw.element.as_mut() {
2086                self.with_rendered_view(deferred_draw.current_view, |window| {
2087                    element.paint(window, cx);
2088                })
2089            } else {
2090                self.reuse_paint(deferred_draw.paint_range.clone());
2091            }
2092            let paint_end = self.paint_index();
2093            deferred_draw.paint_range = paint_start..paint_end;
2094        }
2095        self.next_frame.deferred_draws = deferred_draws;
2096        self.element_id_stack.clear();
2097    }
2098
2099    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2100        PrepaintStateIndex {
2101            hitboxes_index: self.next_frame.hitboxes.len(),
2102            tooltips_index: self.next_frame.tooltip_requests.len(),
2103            deferred_draws_index: self.next_frame.deferred_draws.len(),
2104            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2105            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2106            line_layout_index: self.text_system.layout_index(),
2107        }
2108    }
2109
2110    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2111        self.next_frame.hitboxes.extend(
2112            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2113                .iter()
2114                .cloned(),
2115        );
2116        self.next_frame.tooltip_requests.extend(
2117            self.rendered_frame.tooltip_requests
2118                [range.start.tooltips_index..range.end.tooltips_index]
2119                .iter_mut()
2120                .map(|request| request.take()),
2121        );
2122        self.next_frame.accessed_element_states.extend(
2123            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2124                ..range.end.accessed_element_states_index]
2125                .iter()
2126                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2127        );
2128        self.text_system
2129            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2130
2131        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2132            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2133            &mut self.rendered_frame.dispatch_tree,
2134            self.focus,
2135        );
2136
2137        if reused_subtree.contains_focus() {
2138            println!("setting focus for next frame");
2139            self.next_frame.focus = self.focus;
2140        }
2141
2142        self.next_frame.deferred_draws.extend(
2143            self.rendered_frame.deferred_draws
2144                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2145                .iter()
2146                .map(|deferred_draw| DeferredDraw {
2147                    current_view: deferred_draw.current_view,
2148                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2149                    element_id_stack: deferred_draw.element_id_stack.clone(),
2150                    text_style_stack: deferred_draw.text_style_stack.clone(),
2151                    priority: deferred_draw.priority,
2152                    element: None,
2153                    absolute_offset: deferred_draw.absolute_offset,
2154                    prepaint_range: deferred_draw.prepaint_range.clone(),
2155                    paint_range: deferred_draw.paint_range.clone(),
2156                }),
2157        );
2158    }
2159
2160    pub(crate) fn paint_index(&self) -> PaintIndex {
2161        PaintIndex {
2162            scene_index: self.next_frame.scene.len(),
2163            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2164            input_handlers_index: self.next_frame.input_handlers.len(),
2165            cursor_styles_index: self.next_frame.cursor_styles.len(),
2166            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2167            line_layout_index: self.text_system.layout_index(),
2168        }
2169    }
2170
2171    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2172        self.next_frame.cursor_styles.extend(
2173            self.rendered_frame.cursor_styles
2174                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2175                .iter()
2176                .cloned(),
2177        );
2178        self.next_frame.input_handlers.extend(
2179            self.rendered_frame.input_handlers
2180                [range.start.input_handlers_index..range.end.input_handlers_index]
2181                .iter_mut()
2182                .map(|handler| handler.take()),
2183        );
2184        self.next_frame.mouse_listeners.extend(
2185            self.rendered_frame.mouse_listeners
2186                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2187                .iter_mut()
2188                .map(|listener| listener.take()),
2189        );
2190        self.next_frame.accessed_element_states.extend(
2191            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2192                ..range.end.accessed_element_states_index]
2193                .iter()
2194                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2195        );
2196
2197        self.text_system
2198            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2199        self.next_frame.scene.replay(
2200            range.start.scene_index..range.end.scene_index,
2201            &self.rendered_frame.scene,
2202        );
2203    }
2204
2205    /// Push a text style onto the stack, and call a function with that style active.
2206    /// Use [`Window::text_style`] to get the current, combined text style. This method
2207    /// should only be called as part of element drawing.
2208    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2209    where
2210        F: FnOnce(&mut Self) -> R,
2211    {
2212        self.invalidator.debug_assert_paint_or_prepaint();
2213        if let Some(style) = style {
2214            self.text_style_stack.push(style);
2215            let result = f(self);
2216            self.text_style_stack.pop();
2217            result
2218        } else {
2219            f(self)
2220        }
2221    }
2222
2223    /// Updates the cursor style at the platform level. This method should only be called
2224    /// during the prepaint phase of element drawing.
2225    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2226        self.invalidator.debug_assert_paint();
2227        self.next_frame.cursor_styles.push(CursorStyleRequest {
2228            hitbox_id: Some(hitbox.id),
2229            style,
2230        });
2231    }
2232
2233    /// Updates the cursor style for the entire window at the platform level. A cursor
2234    /// style using this method will have precedence over any cursor style set using
2235    /// `set_cursor_style`. This method should only be called during the prepaint
2236    /// phase of element drawing.
2237    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2238        self.invalidator.debug_assert_paint();
2239        self.next_frame.cursor_styles.push(CursorStyleRequest {
2240            hitbox_id: None,
2241            style,
2242        })
2243    }
2244
2245    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2246    /// during the paint phase of element drawing.
2247    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2248        self.invalidator.debug_assert_prepaint();
2249        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2250        self.next_frame
2251            .tooltip_requests
2252            .push(Some(TooltipRequest { id, tooltip }));
2253        id
2254    }
2255
2256    /// Invoke the given function with the given content mask after intersecting it
2257    /// with the current mask. This method should only be called during element drawing.
2258    pub fn with_content_mask<R>(
2259        &mut self,
2260        mask: Option<ContentMask<Pixels>>,
2261        f: impl FnOnce(&mut Self) -> R,
2262    ) -> R {
2263        self.invalidator.debug_assert_paint_or_prepaint();
2264        if let Some(mask) = mask {
2265            let mask = mask.intersect(&self.content_mask());
2266            self.content_mask_stack.push(mask);
2267            let result = f(self);
2268            self.content_mask_stack.pop();
2269            result
2270        } else {
2271            f(self)
2272        }
2273    }
2274
2275    /// Updates the global element offset relative to the current offset. This is used to implement
2276    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2277    pub fn with_element_offset<R>(
2278        &mut self,
2279        offset: Point<Pixels>,
2280        f: impl FnOnce(&mut Self) -> R,
2281    ) -> R {
2282        self.invalidator.debug_assert_prepaint();
2283
2284        if offset.is_zero() {
2285            return f(self);
2286        };
2287
2288        let abs_offset = self.element_offset() + offset;
2289        self.with_absolute_element_offset(abs_offset, f)
2290    }
2291
2292    /// Updates the global element offset based on the given offset. This is used to implement
2293    /// drag handles and other manual painting of elements. This method should only be called during
2294    /// the prepaint phase of element drawing.
2295    pub fn with_absolute_element_offset<R>(
2296        &mut self,
2297        offset: Point<Pixels>,
2298        f: impl FnOnce(&mut Self) -> R,
2299    ) -> R {
2300        self.invalidator.debug_assert_prepaint();
2301        self.element_offset_stack.push(offset);
2302        let result = f(self);
2303        self.element_offset_stack.pop();
2304        result
2305    }
2306
2307    pub(crate) fn with_element_opacity<R>(
2308        &mut self,
2309        opacity: Option<f32>,
2310        f: impl FnOnce(&mut Self) -> R,
2311    ) -> R {
2312        if opacity.is_none() {
2313            return f(self);
2314        }
2315
2316        self.invalidator.debug_assert_paint_or_prepaint();
2317        self.element_opacity = opacity;
2318        let result = f(self);
2319        self.element_opacity = None;
2320        result
2321    }
2322
2323    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2324    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2325    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2326    /// element offset and prepaint again. See [`List`] for an example. This method should only be
2327    /// called during the prepaint phase of element drawing.
2328    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2329        self.invalidator.debug_assert_prepaint();
2330        let index = self.prepaint_index();
2331        let result = f(self);
2332        if result.is_err() {
2333            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2334            self.next_frame
2335                .tooltip_requests
2336                .truncate(index.tooltips_index);
2337            self.next_frame
2338                .deferred_draws
2339                .truncate(index.deferred_draws_index);
2340            self.next_frame
2341                .dispatch_tree
2342                .truncate(index.dispatch_tree_index);
2343            self.next_frame
2344                .accessed_element_states
2345                .truncate(index.accessed_element_states_index);
2346            self.text_system.truncate_layouts(index.line_layout_index);
2347        }
2348        result
2349    }
2350
2351    /// When you call this method during [`prepaint`], containing elements will attempt to
2352    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2353    /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
2354    /// that supports this method being called on the elements it contains. This method should only be
2355    /// called during the prepaint phase of element drawing.
2356    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2357        self.invalidator.debug_assert_prepaint();
2358        self.requested_autoscroll = Some(bounds);
2359    }
2360
2361    /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
2362    /// described in [`request_autoscroll`].
2363    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2364        self.invalidator.debug_assert_prepaint();
2365        self.requested_autoscroll.take()
2366    }
2367
2368    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2369    /// Your view will be re-drawn once the asset has finished loading.
2370    ///
2371    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2372    /// time.
2373    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2374        let (task, is_first) = cx.fetch_asset::<A>(source);
2375        task.clone().now_or_never().or_else(|| {
2376            if is_first {
2377                let entity_id = self.current_view();
2378                self.spawn(cx, {
2379                    let task = task.clone();
2380                    async move |cx| {
2381                        task.await;
2382
2383                        cx.on_next_frame(move |_, cx| {
2384                            cx.notify(entity_id);
2385                        });
2386                    }
2387                })
2388                .detach();
2389            }
2390
2391            None
2392        })
2393    }
2394
2395    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2396    /// Your view will not be re-drawn once the asset has finished loading.
2397    ///
2398    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2399    /// time.
2400    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2401        let (task, _) = cx.fetch_asset::<A>(source);
2402        task.clone().now_or_never()
2403    }
2404    /// Obtain the current element offset. This method should only be called during the
2405    /// prepaint phase of element drawing.
2406    pub fn element_offset(&self) -> Point<Pixels> {
2407        self.invalidator.debug_assert_prepaint();
2408        self.element_offset_stack
2409            .last()
2410            .copied()
2411            .unwrap_or_default()
2412    }
2413
2414    /// Obtain the current element opacity. This method should only be called during the
2415    /// prepaint phase of element drawing.
2416    pub(crate) fn element_opacity(&self) -> f32 {
2417        self.invalidator.debug_assert_paint_or_prepaint();
2418        self.element_opacity.unwrap_or(1.0)
2419    }
2420
2421    /// Obtain the current content mask. This method should only be called during element drawing.
2422    pub fn content_mask(&self) -> ContentMask<Pixels> {
2423        self.invalidator.debug_assert_paint_or_prepaint();
2424        self.content_mask_stack
2425            .last()
2426            .cloned()
2427            .unwrap_or_else(|| ContentMask {
2428                bounds: Bounds {
2429                    origin: Point::default(),
2430                    size: self.viewport_size,
2431                },
2432            })
2433    }
2434
2435    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2436    /// This can be used within a custom element to distinguish multiple sets of child elements.
2437    pub fn with_element_namespace<R>(
2438        &mut self,
2439        element_id: impl Into<ElementId>,
2440        f: impl FnOnce(&mut Self) -> R,
2441    ) -> R {
2442        self.element_id_stack.push(element_id.into());
2443        let result = f(self);
2444        self.element_id_stack.pop();
2445        result
2446    }
2447
2448    /// Updates or initializes state for an element with the given id that lives across multiple
2449    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2450    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2451    /// when drawing the next frame. This method should only be called as part of element drawing.
2452    pub fn with_element_state<S, R>(
2453        &mut self,
2454        global_id: &GlobalElementId,
2455        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2456    ) -> R
2457    where
2458        S: 'static,
2459    {
2460        self.invalidator.debug_assert_paint_or_prepaint();
2461
2462        let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2463        self.next_frame
2464            .accessed_element_states
2465            .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2466
2467        if let Some(any) = self
2468            .next_frame
2469            .element_states
2470            .remove(&key)
2471            .or_else(|| self.rendered_frame.element_states.remove(&key))
2472        {
2473            let ElementStateBox {
2474                inner,
2475                #[cfg(debug_assertions)]
2476                type_name,
2477            } = any;
2478            // Using the extra inner option to avoid needing to reallocate a new box.
2479            let mut state_box = inner
2480                .downcast::<Option<S>>()
2481                .map_err(|_| {
2482                    #[cfg(debug_assertions)]
2483                    {
2484                        anyhow::anyhow!(
2485                            "invalid element state type for id, requested {:?}, actual: {:?}",
2486                            std::any::type_name::<S>(),
2487                            type_name
2488                        )
2489                    }
2490
2491                    #[cfg(not(debug_assertions))]
2492                    {
2493                        anyhow::anyhow!(
2494                            "invalid element state type for id, requested {:?}",
2495                            std::any::type_name::<S>(),
2496                        )
2497                    }
2498                })
2499                .unwrap();
2500
2501            let state = state_box.take().expect(
2502                "reentrant call to with_element_state for the same state type and element id",
2503            );
2504            let (result, state) = f(Some(state), self);
2505            state_box.replace(state);
2506            self.next_frame.element_states.insert(
2507                key,
2508                ElementStateBox {
2509                    inner: state_box,
2510                    #[cfg(debug_assertions)]
2511                    type_name,
2512                },
2513            );
2514            result
2515        } else {
2516            let (result, state) = f(None, self);
2517            self.next_frame.element_states.insert(
2518                key,
2519                ElementStateBox {
2520                    inner: Box::new(Some(state)),
2521                    #[cfg(debug_assertions)]
2522                    type_name: std::any::type_name::<S>(),
2523                },
2524            );
2525            result
2526        }
2527    }
2528
2529    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2530    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2531    /// when the element is guaranteed to have an id.
2532    ///
2533    /// The first option means 'no ID provided'
2534    /// The second option means 'not yet initialized'
2535    pub fn with_optional_element_state<S, R>(
2536        &mut self,
2537        global_id: Option<&GlobalElementId>,
2538        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2539    ) -> R
2540    where
2541        S: 'static,
2542    {
2543        self.invalidator.debug_assert_paint_or_prepaint();
2544
2545        if let Some(global_id) = global_id {
2546            self.with_element_state(global_id, |state, cx| {
2547                let (result, state) = f(Some(state), cx);
2548                let state =
2549                    state.expect("you must return some state when you pass some element id");
2550                (result, state)
2551            })
2552        } else {
2553            let (result, state) = f(None, self);
2554            debug_assert!(
2555                state.is_none(),
2556                "you must not return an element state when passing None for the global id"
2557            );
2558            result
2559        }
2560    }
2561
2562    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2563    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2564    /// with higher values being drawn on top.
2565    ///
2566    /// This method should only be called as part of the prepaint phase of element drawing.
2567    pub fn defer_draw(
2568        &mut self,
2569        element: AnyElement,
2570        absolute_offset: Point<Pixels>,
2571        priority: usize,
2572    ) {
2573        self.invalidator.debug_assert_prepaint();
2574        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2575        self.next_frame.deferred_draws.push(DeferredDraw {
2576            current_view: self.current_view(),
2577            parent_node,
2578            element_id_stack: self.element_id_stack.clone(),
2579            text_style_stack: self.text_style_stack.clone(),
2580            priority,
2581            element: Some(element),
2582            absolute_offset,
2583            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2584            paint_range: PaintIndex::default()..PaintIndex::default(),
2585        });
2586    }
2587
2588    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2589    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2590    /// for performance reasons.
2591    ///
2592    /// This method should only be called as part of the paint phase of element drawing.
2593    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2594        self.invalidator.debug_assert_paint();
2595
2596        let scale_factor = self.scale_factor();
2597        let content_mask = self.content_mask();
2598        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2599        if !clipped_bounds.is_empty() {
2600            self.next_frame
2601                .scene
2602                .push_layer(clipped_bounds.scale(scale_factor));
2603        }
2604
2605        let result = f(self);
2606
2607        if !clipped_bounds.is_empty() {
2608            self.next_frame.scene.pop_layer();
2609        }
2610
2611        result
2612    }
2613
2614    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2615    ///
2616    /// This method should only be called as part of the paint phase of element drawing.
2617    pub fn paint_shadows(
2618        &mut self,
2619        bounds: Bounds<Pixels>,
2620        corner_radii: Corners<Pixels>,
2621        shadows: &[BoxShadow],
2622    ) {
2623        self.invalidator.debug_assert_paint();
2624
2625        let scale_factor = self.scale_factor();
2626        let content_mask = self.content_mask();
2627        let opacity = self.element_opacity();
2628        for shadow in shadows {
2629            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2630            self.next_frame.scene.insert_primitive(Shadow {
2631                order: 0,
2632                blur_radius: shadow.blur_radius.scale(scale_factor),
2633                bounds: shadow_bounds.scale(scale_factor),
2634                content_mask: content_mask.scale(scale_factor),
2635                corner_radii: corner_radii.scale(scale_factor),
2636                color: shadow.color.opacity(opacity),
2637            });
2638        }
2639    }
2640
2641    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2642    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2643    /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2644    ///
2645    /// This method should only be called as part of the paint phase of element drawing.
2646    ///
2647    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2648    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2649    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2650    pub fn paint_quad(&mut self, quad: PaintQuad) {
2651        self.invalidator.debug_assert_paint();
2652
2653        let scale_factor = self.scale_factor();
2654        let content_mask = self.content_mask();
2655        let opacity = self.element_opacity();
2656        self.next_frame.scene.insert_primitive(Quad {
2657            order: 0,
2658            bounds: quad.bounds.scale(scale_factor),
2659            content_mask: content_mask.scale(scale_factor),
2660            background: quad.background.opacity(opacity),
2661            border_color: quad.border_color.opacity(opacity),
2662            corner_radii: quad.corner_radii.scale(scale_factor),
2663            border_widths: quad.border_widths.scale(scale_factor),
2664            border_style: quad.border_style,
2665        });
2666    }
2667
2668    /// Paint the given `Path` into the scene for the next frame at the current z-index.
2669    ///
2670    /// This method should only be called as part of the paint phase of element drawing.
2671    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2672        self.invalidator.debug_assert_paint();
2673
2674        let scale_factor = self.scale_factor();
2675        let content_mask = self.content_mask();
2676        let opacity = self.element_opacity();
2677        path.content_mask = content_mask;
2678        let color: Background = color.into();
2679        path.color = color.opacity(opacity);
2680        self.next_frame
2681            .scene
2682            .insert_primitive(path.apply_scale(scale_factor));
2683    }
2684
2685    /// Paint an underline into the scene for the next frame at the current z-index.
2686    ///
2687    /// This method should only be called as part of the paint phase of element drawing.
2688    pub fn paint_underline(
2689        &mut self,
2690        origin: Point<Pixels>,
2691        width: Pixels,
2692        style: &UnderlineStyle,
2693    ) {
2694        self.invalidator.debug_assert_paint();
2695
2696        let scale_factor = self.scale_factor();
2697        let height = if style.wavy {
2698            style.thickness * 3.
2699        } else {
2700            style.thickness
2701        };
2702        let bounds = Bounds {
2703            origin,
2704            size: size(width, height),
2705        };
2706        let content_mask = self.content_mask();
2707        let element_opacity = self.element_opacity();
2708
2709        self.next_frame.scene.insert_primitive(Underline {
2710            order: 0,
2711            pad: 0,
2712            bounds: bounds.scale(scale_factor),
2713            content_mask: content_mask.scale(scale_factor),
2714            color: style.color.unwrap_or_default().opacity(element_opacity),
2715            thickness: style.thickness.scale(scale_factor),
2716            wavy: style.wavy,
2717        });
2718    }
2719
2720    /// Paint a strikethrough into the scene for the next frame at the current z-index.
2721    ///
2722    /// This method should only be called as part of the paint phase of element drawing.
2723    pub fn paint_strikethrough(
2724        &mut self,
2725        origin: Point<Pixels>,
2726        width: Pixels,
2727        style: &StrikethroughStyle,
2728    ) {
2729        self.invalidator.debug_assert_paint();
2730
2731        let scale_factor = self.scale_factor();
2732        let height = style.thickness;
2733        let bounds = Bounds {
2734            origin,
2735            size: size(width, height),
2736        };
2737        let content_mask = self.content_mask();
2738        let opacity = self.element_opacity();
2739
2740        self.next_frame.scene.insert_primitive(Underline {
2741            order: 0,
2742            pad: 0,
2743            bounds: bounds.scale(scale_factor),
2744            content_mask: content_mask.scale(scale_factor),
2745            thickness: style.thickness.scale(scale_factor),
2746            color: style.color.unwrap_or_default().opacity(opacity),
2747            wavy: false,
2748        });
2749    }
2750
2751    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2752    ///
2753    /// The y component of the origin is the baseline of the glyph.
2754    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2755    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2756    /// This method is only useful if you need to paint a single glyph that has already been shaped.
2757    ///
2758    /// This method should only be called as part of the paint phase of element drawing.
2759    pub fn paint_glyph(
2760        &mut self,
2761        origin: Point<Pixels>,
2762        font_id: FontId,
2763        glyph_id: GlyphId,
2764        font_size: Pixels,
2765        color: Hsla,
2766    ) -> Result<()> {
2767        self.invalidator.debug_assert_paint();
2768
2769        let element_opacity = self.element_opacity();
2770        let scale_factor = self.scale_factor();
2771        let glyph_origin = origin.scale(scale_factor);
2772        let subpixel_variant = Point {
2773            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2774            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2775        };
2776        let params = RenderGlyphParams {
2777            font_id,
2778            glyph_id,
2779            font_size,
2780            subpixel_variant,
2781            scale_factor,
2782            is_emoji: false,
2783        };
2784
2785        let raster_bounds = self.text_system().raster_bounds(&params)?;
2786        if !raster_bounds.is_zero() {
2787            let tile = self
2788                .sprite_atlas
2789                .get_or_insert_with(&params.clone().into(), &mut || {
2790                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2791                    Ok(Some((size, Cow::Owned(bytes))))
2792                })?
2793                .expect("Callback above only errors or returns Some");
2794            let bounds = Bounds {
2795                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2796                size: tile.bounds.size.map(Into::into),
2797            };
2798            let content_mask = self.content_mask().scale(scale_factor);
2799            self.next_frame.scene.insert_primitive(MonochromeSprite {
2800                order: 0,
2801                pad: 0,
2802                bounds,
2803                content_mask,
2804                color: color.opacity(element_opacity),
2805                tile,
2806                transformation: TransformationMatrix::unit(),
2807            });
2808        }
2809        Ok(())
2810    }
2811
2812    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2813    ///
2814    /// The y component of the origin is the baseline of the glyph.
2815    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2816    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2817    /// This method is only useful if you need to paint a single emoji that has already been shaped.
2818    ///
2819    /// This method should only be called as part of the paint phase of element drawing.
2820    pub fn paint_emoji(
2821        &mut self,
2822        origin: Point<Pixels>,
2823        font_id: FontId,
2824        glyph_id: GlyphId,
2825        font_size: Pixels,
2826    ) -> Result<()> {
2827        self.invalidator.debug_assert_paint();
2828
2829        let scale_factor = self.scale_factor();
2830        let glyph_origin = origin.scale(scale_factor);
2831        let params = RenderGlyphParams {
2832            font_id,
2833            glyph_id,
2834            font_size,
2835            // We don't render emojis with subpixel variants.
2836            subpixel_variant: Default::default(),
2837            scale_factor,
2838            is_emoji: true,
2839        };
2840
2841        let raster_bounds = self.text_system().raster_bounds(&params)?;
2842        if !raster_bounds.is_zero() {
2843            let tile = self
2844                .sprite_atlas
2845                .get_or_insert_with(&params.clone().into(), &mut || {
2846                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2847                    Ok(Some((size, Cow::Owned(bytes))))
2848                })?
2849                .expect("Callback above only errors or returns Some");
2850
2851            let bounds = Bounds {
2852                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2853                size: tile.bounds.size.map(Into::into),
2854            };
2855            let content_mask = self.content_mask().scale(scale_factor);
2856            let opacity = self.element_opacity();
2857
2858            self.next_frame.scene.insert_primitive(PolychromeSprite {
2859                order: 0,
2860                pad: 0,
2861                grayscale: false,
2862                bounds,
2863                corner_radii: Default::default(),
2864                content_mask,
2865                tile,
2866                opacity,
2867            });
2868        }
2869        Ok(())
2870    }
2871
2872    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2873    ///
2874    /// This method should only be called as part of the paint phase of element drawing.
2875    pub fn paint_svg(
2876        &mut self,
2877        bounds: Bounds<Pixels>,
2878        path: SharedString,
2879        transformation: TransformationMatrix,
2880        color: Hsla,
2881        cx: &App,
2882    ) -> Result<()> {
2883        self.invalidator.debug_assert_paint();
2884
2885        let element_opacity = self.element_opacity();
2886        let scale_factor = self.scale_factor();
2887        let bounds = bounds.scale(scale_factor);
2888        let params = RenderSvgParams {
2889            path,
2890            size: bounds.size.map(|pixels| {
2891                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
2892            }),
2893        };
2894
2895        let Some(tile) =
2896            self.sprite_atlas
2897                .get_or_insert_with(&params.clone().into(), &mut || {
2898                    let Some(bytes) = cx.svg_renderer.render(&params)? else {
2899                        return Ok(None);
2900                    };
2901                    Ok(Some((params.size, Cow::Owned(bytes))))
2902                })?
2903        else {
2904            return Ok(());
2905        };
2906        let content_mask = self.content_mask().scale(scale_factor);
2907
2908        self.next_frame.scene.insert_primitive(MonochromeSprite {
2909            order: 0,
2910            pad: 0,
2911            bounds: bounds
2912                .map_origin(|origin| origin.floor())
2913                .map_size(|size| size.ceil()),
2914            content_mask,
2915            color: color.opacity(element_opacity),
2916            tile,
2917            transformation,
2918        });
2919
2920        Ok(())
2921    }
2922
2923    /// Paint an image into the scene for the next frame at the current z-index.
2924    /// This method will panic if the frame_index is not valid
2925    ///
2926    /// This method should only be called as part of the paint phase of element drawing.
2927    pub fn paint_image(
2928        &mut self,
2929        bounds: Bounds<Pixels>,
2930        corner_radii: Corners<Pixels>,
2931        data: Arc<RenderImage>,
2932        frame_index: usize,
2933        grayscale: bool,
2934    ) -> Result<()> {
2935        self.invalidator.debug_assert_paint();
2936
2937        let scale_factor = self.scale_factor();
2938        let bounds = bounds.scale(scale_factor);
2939        let params = RenderImageParams {
2940            image_id: data.id,
2941            frame_index,
2942        };
2943
2944        let tile = self
2945            .sprite_atlas
2946            .get_or_insert_with(&params.clone().into(), &mut || {
2947                Ok(Some((
2948                    data.size(frame_index),
2949                    Cow::Borrowed(
2950                        data.as_bytes(frame_index)
2951                            .expect("It's the caller's job to pass a valid frame index"),
2952                    ),
2953                )))
2954            })?
2955            .expect("Callback above only returns Some");
2956        let content_mask = self.content_mask().scale(scale_factor);
2957        let corner_radii = corner_radii.scale(scale_factor);
2958        let opacity = self.element_opacity();
2959
2960        self.next_frame.scene.insert_primitive(PolychromeSprite {
2961            order: 0,
2962            pad: 0,
2963            grayscale,
2964            bounds: bounds
2965                .map_origin(|origin| origin.floor())
2966                .map_size(|size| size.ceil()),
2967            content_mask,
2968            corner_radii,
2969            tile,
2970            opacity,
2971        });
2972        Ok(())
2973    }
2974
2975    /// Paint a surface into the scene for the next frame at the current z-index.
2976    ///
2977    /// This method should only be called as part of the paint phase of element drawing.
2978    #[cfg(target_os = "macos")]
2979    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
2980        use crate::PaintSurface;
2981
2982        self.invalidator.debug_assert_paint();
2983
2984        let scale_factor = self.scale_factor();
2985        let bounds = bounds.scale(scale_factor);
2986        let content_mask = self.content_mask().scale(scale_factor);
2987        self.next_frame.scene.insert_primitive(PaintSurface {
2988            order: 0,
2989            bounds,
2990            content_mask,
2991            image_buffer,
2992        });
2993    }
2994
2995    /// Removes an image from the sprite atlas.
2996    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2997        for frame_index in 0..data.frame_count() {
2998            let params = RenderImageParams {
2999                image_id: data.id,
3000                frame_index,
3001            };
3002
3003            self.sprite_atlas.remove(&params.clone().into());
3004        }
3005
3006        Ok(())
3007    }
3008
3009    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
3010    /// layout is being requested, along with the layout ids of any children. This method is called during
3011    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
3012    ///
3013    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3014    #[must_use]
3015    pub fn request_layout(
3016        &mut self,
3017        style: Style,
3018        children: impl IntoIterator<Item = LayoutId>,
3019        cx: &mut App,
3020    ) -> LayoutId {
3021        self.invalidator.debug_assert_prepaint();
3022
3023        cx.layout_id_buffer.clear();
3024        cx.layout_id_buffer.extend(children);
3025        let rem_size = self.rem_size();
3026
3027        self.layout_engine
3028            .as_mut()
3029            .unwrap()
3030            .request_layout(style, rem_size, &cx.layout_id_buffer)
3031    }
3032
3033    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3034    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3035    /// determine the element's size. One place this is used internally is when measuring text.
3036    ///
3037    /// The given closure is invoked at layout time with the known dimensions and available space and
3038    /// returns a `Size`.
3039    ///
3040    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3041    pub fn request_measured_layout<
3042        F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3043            + 'static,
3044    >(
3045        &mut self,
3046        style: Style,
3047        measure: F,
3048    ) -> LayoutId {
3049        self.invalidator.debug_assert_prepaint();
3050
3051        let rem_size = self.rem_size();
3052        self.layout_engine
3053            .as_mut()
3054            .unwrap()
3055            .request_measured_layout(style, rem_size, measure)
3056    }
3057
3058    /// Compute the layout for the given id within the given available space.
3059    /// This method is called for its side effect, typically by the framework prior to painting.
3060    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3061    ///
3062    /// This method should only be called as part of the prepaint phase of element drawing.
3063    pub fn compute_layout(
3064        &mut self,
3065        layout_id: LayoutId,
3066        available_space: Size<AvailableSpace>,
3067        cx: &mut App,
3068    ) {
3069        self.invalidator.debug_assert_prepaint();
3070
3071        let mut layout_engine = self.layout_engine.take().unwrap();
3072        layout_engine.compute_layout(layout_id, available_space, self, cx);
3073        self.layout_engine = Some(layout_engine);
3074    }
3075
3076    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3077    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3078    ///
3079    /// This method should only be called as part of element drawing.
3080    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3081        self.invalidator.debug_assert_prepaint();
3082
3083        let mut bounds = self
3084            .layout_engine
3085            .as_mut()
3086            .unwrap()
3087            .layout_bounds(layout_id)
3088            .map(Into::into);
3089        bounds.origin += self.element_offset();
3090        bounds
3091    }
3092
3093    /// This method should be called during `prepaint`. You can use
3094    /// the returned [Hitbox] during `paint` or in an event handler
3095    /// to determine whether the inserted hitbox was the topmost.
3096    ///
3097    /// This method should only be called as part of the prepaint phase of element drawing.
3098    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3099        self.invalidator.debug_assert_prepaint();
3100
3101        let content_mask = self.content_mask();
3102        let mut id = self.next_hitbox_id;
3103        self.next_hitbox_id = self.next_hitbox_id.next();
3104        let hitbox = Hitbox {
3105            id,
3106            bounds,
3107            content_mask,
3108            behavior,
3109        };
3110        self.next_frame.hitboxes.push(hitbox.clone());
3111        hitbox
3112    }
3113
3114    /// Set a hitbox which will act as a control area of the platform window.
3115    ///
3116    /// This method should only be called as part of the paint phase of element drawing.
3117    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3118        self.invalidator.debug_assert_paint();
3119        self.next_frame.window_control_hitboxes.push((area, hitbox));
3120    }
3121
3122    /// Sets the key context for the current element. This context will be used to translate
3123    /// keybindings into actions.
3124    ///
3125    /// This method should only be called as part of the paint phase of element drawing.
3126    pub fn set_key_context(&mut self, context: KeyContext) {
3127        self.invalidator.debug_assert_paint();
3128        self.next_frame.dispatch_tree.set_key_context(context);
3129    }
3130
3131    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3132    /// and keyboard event dispatch for the element.
3133    ///
3134    /// This method should only be called as part of the prepaint phase of element drawing.
3135    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3136        self.invalidator.debug_assert_prepaint();
3137        println!("set_focus_handle called");
3138        if focus_handle.is_focused(self) {
3139            println!("setting focus for next frame");
3140            self.next_frame.focus = Some(focus_handle.id);
3141        }
3142        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3143    }
3144
3145    /// Sets the view id for the current element, which will be used to manage view caching.
3146    ///
3147    /// This method should only be called as part of element prepaint. We plan on removing this
3148    /// method eventually when we solve some issues that require us to construct editor elements
3149    /// directly instead of always using editors via views.
3150    pub fn set_view_id(&mut self, view_id: EntityId) {
3151        self.invalidator.debug_assert_prepaint();
3152        self.next_frame.dispatch_tree.set_view_id(view_id);
3153    }
3154
3155    /// Get the entity ID for the currently rendering view
3156    pub fn current_view(&self) -> EntityId {
3157        self.invalidator.debug_assert_paint_or_prepaint();
3158        self.rendered_entity_stack.last().copied().unwrap()
3159    }
3160
3161    pub(crate) fn with_rendered_view<R>(
3162        &mut self,
3163        id: EntityId,
3164        f: impl FnOnce(&mut Self) -> R,
3165    ) -> R {
3166        self.rendered_entity_stack.push(id);
3167        let result = f(self);
3168        self.rendered_entity_stack.pop();
3169        result
3170    }
3171
3172    /// Executes the provided function with the specified image cache.
3173    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3174    where
3175        F: FnOnce(&mut Self) -> R,
3176    {
3177        if let Some(image_cache) = image_cache {
3178            self.image_cache_stack.push(image_cache);
3179            let result = f(self);
3180            self.image_cache_stack.pop();
3181            result
3182        } else {
3183            f(self)
3184        }
3185    }
3186
3187    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3188    /// platform to receive textual input with proper integration with concerns such
3189    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3190    /// rendered.
3191    ///
3192    /// This method should only be called as part of the paint phase of element drawing.
3193    ///
3194    /// [element_input_handler]: crate::ElementInputHandler
3195    pub fn handle_input(
3196        &mut self,
3197        focus_handle: &FocusHandle,
3198        input_handler: impl InputHandler,
3199        cx: &App,
3200    ) {
3201        self.invalidator.debug_assert_paint();
3202
3203        if focus_handle.is_focused(self) {
3204            let cx = self.to_async(cx);
3205            self.next_frame
3206                .input_handlers
3207                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3208        }
3209    }
3210
3211    /// Register a mouse event listener on the window for the next frame. The type of event
3212    /// is determined by the first parameter of the given listener. When the next frame is rendered
3213    /// the listener will be cleared.
3214    ///
3215    /// This method should only be called as part of the paint phase of element drawing.
3216    pub fn on_mouse_event<Event: MouseEvent>(
3217        &mut self,
3218        mut handler: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3219    ) {
3220        self.invalidator.debug_assert_paint();
3221
3222        self.next_frame.mouse_listeners.push(Some(Box::new(
3223            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3224                if let Some(event) = event.downcast_ref() {
3225                    handler(event, phase, window, cx)
3226                }
3227            },
3228        )));
3229    }
3230
3231    /// Register a key event listener on the window for the next frame. The type of event
3232    /// is determined by the first parameter of the given listener. When the next frame is rendered
3233    /// the listener will be cleared.
3234    ///
3235    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3236    /// a specific need to register a global listener.
3237    ///
3238    /// This method should only be called as part of the paint phase of element drawing.
3239    pub fn on_key_event<Event: KeyEvent>(
3240        &mut self,
3241        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3242    ) {
3243        self.invalidator.debug_assert_paint();
3244
3245        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3246            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3247                if let Some(event) = event.downcast_ref::<Event>() {
3248                    listener(event, phase, window, cx)
3249                }
3250            },
3251        ));
3252    }
3253
3254    /// Register a modifiers changed event listener on the window for the next frame.
3255    ///
3256    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3257    /// a specific need to register a global listener.
3258    ///
3259    /// This method should only be called as part of the paint phase of element drawing.
3260    pub fn on_modifiers_changed(
3261        &mut self,
3262        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3263    ) {
3264        self.invalidator.debug_assert_paint();
3265
3266        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3267            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3268                listener(event, window, cx)
3269            },
3270        ));
3271    }
3272
3273    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3274    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3275    /// Returns a subscription and persists until the subscription is dropped.
3276    pub fn on_focus_in(
3277        &mut self,
3278        handle: &FocusHandle,
3279        cx: &mut App,
3280        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3281    ) -> Subscription {
3282        let focus_id = handle.id;
3283        let (subscription, activate) =
3284            self.new_focus_listener(Box::new(move |event, window, cx| {
3285                if event.is_focus_in(focus_id) {
3286                    listener(window, cx);
3287                }
3288                true
3289            }));
3290        cx.defer(move |_| activate());
3291        subscription
3292    }
3293
3294    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3295    /// Returns a subscription and persists until the subscription is dropped.
3296    pub fn on_focus_out(
3297        &mut self,
3298        handle: &FocusHandle,
3299        cx: &mut App,
3300        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3301    ) -> Subscription {
3302        let focus_id = handle.id;
3303        let (subscription, activate) =
3304            self.new_focus_listener(Box::new(move |event, window, cx| {
3305                if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3306                    if event.is_focus_out(focus_id) {
3307                        let event = FocusOutEvent {
3308                            blurred: WeakFocusHandle {
3309                                id: blurred_id,
3310                                handles: Arc::downgrade(&cx.focus_handles),
3311                            },
3312                        };
3313                        listener(event, window, cx)
3314                    }
3315                }
3316                true
3317            }));
3318        cx.defer(move |_| activate());
3319        subscription
3320    }
3321
3322    fn reset_cursor_style(&self, cx: &mut App) {
3323        // Set the cursor only if we're the active window.
3324        if self.is_window_hovered() {
3325            let style = self
3326                .rendered_frame
3327                .cursor_style(self)
3328                .unwrap_or(CursorStyle::Arrow);
3329            cx.platform.set_cursor_style(style);
3330        }
3331    }
3332
3333    /// Dispatch a given keystroke as though the user had typed it.
3334    /// You can create a keystroke with Keystroke::parse("").
3335    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3336        let keystroke = keystroke.with_simulated_ime();
3337        let result = self.dispatch_event(
3338            PlatformInput::KeyDown(KeyDownEvent {
3339                keystroke: keystroke.clone(),
3340                is_held: false,
3341            }),
3342            cx,
3343        );
3344        if !result.propagate {
3345            return true;
3346        }
3347
3348        if let Some(input) = keystroke.key_char {
3349            if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3350                input_handler.dispatch_input(&input, self, cx);
3351                self.platform_window.set_input_handler(input_handler);
3352                return true;
3353            }
3354        }
3355
3356        false
3357    }
3358
3359    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3360    /// binding for the action (last binding added to the keymap).
3361    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3362        self.highest_precedence_binding_for_action(action)
3363            .map(|binding| {
3364                binding
3365                    .keystrokes()
3366                    .iter()
3367                    .map(ToString::to_string)
3368                    .collect::<Vec<_>>()
3369                    .join(" ")
3370            })
3371            .unwrap_or_else(|| action.name().to_string())
3372    }
3373
3374    /// Dispatch a mouse or keyboard event on the window.
3375    #[profiling::function]
3376    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3377        self.last_input_timestamp.set(Instant::now());
3378        // Handlers may set this to false by calling `stop_propagation`.
3379        cx.propagate_event = true;
3380        // Handlers may set this to true by calling `prevent_default`.
3381        self.default_prevented = false;
3382
3383        let event = match event {
3384            // Track the mouse position with our own state, since accessing the platform
3385            // API for the mouse position can only occur on the main thread.
3386            PlatformInput::MouseMove(mouse_move) => {
3387                self.mouse_position = mouse_move.position;
3388                self.modifiers = mouse_move.modifiers;
3389                PlatformInput::MouseMove(mouse_move)
3390            }
3391            PlatformInput::MouseDown(mouse_down) => {
3392                self.mouse_position = mouse_down.position;
3393                self.modifiers = mouse_down.modifiers;
3394                PlatformInput::MouseDown(mouse_down)
3395            }
3396            PlatformInput::MouseUp(mouse_up) => {
3397                self.mouse_position = mouse_up.position;
3398                self.modifiers = mouse_up.modifiers;
3399                PlatformInput::MouseUp(mouse_up)
3400            }
3401            PlatformInput::MouseExited(mouse_exited) => {
3402                self.modifiers = mouse_exited.modifiers;
3403                PlatformInput::MouseExited(mouse_exited)
3404            }
3405            PlatformInput::ModifiersChanged(modifiers_changed) => {
3406                self.modifiers = modifiers_changed.modifiers;
3407                self.capslock = modifiers_changed.capslock;
3408                PlatformInput::ModifiersChanged(modifiers_changed)
3409            }
3410            PlatformInput::ScrollWheel(scroll_wheel) => {
3411                self.mouse_position = scroll_wheel.position;
3412                self.modifiers = scroll_wheel.modifiers;
3413                PlatformInput::ScrollWheel(scroll_wheel)
3414            }
3415            // Translate dragging and dropping of external files from the operating system
3416            // to internal drag and drop events.
3417            PlatformInput::FileDrop(file_drop) => match file_drop {
3418                FileDropEvent::Entered { position, paths } => {
3419                    self.mouse_position = position;
3420                    if cx.active_drag.is_none() {
3421                        cx.active_drag = Some(AnyDrag {
3422                            value: Arc::new(paths.clone()),
3423                            view: cx.new(|_| paths).into(),
3424                            cursor_offset: position,
3425                            cursor_style: None,
3426                        });
3427                    }
3428                    PlatformInput::MouseMove(MouseMoveEvent {
3429                        position,
3430                        pressed_button: Some(MouseButton::Left),
3431                        modifiers: Modifiers::default(),
3432                    })
3433                }
3434                FileDropEvent::Pending { position } => {
3435                    self.mouse_position = position;
3436                    PlatformInput::MouseMove(MouseMoveEvent {
3437                        position,
3438                        pressed_button: Some(MouseButton::Left),
3439                        modifiers: Modifiers::default(),
3440                    })
3441                }
3442                FileDropEvent::Submit { position } => {
3443                    cx.activate(true);
3444                    self.mouse_position = position;
3445                    PlatformInput::MouseUp(MouseUpEvent {
3446                        button: MouseButton::Left,
3447                        position,
3448                        modifiers: Modifiers::default(),
3449                        click_count: 1,
3450                    })
3451                }
3452                FileDropEvent::Exited => {
3453                    cx.active_drag.take();
3454                    PlatformInput::FileDrop(FileDropEvent::Exited)
3455                }
3456            },
3457            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3458        };
3459
3460        if let Some(any_mouse_event) = event.mouse_event() {
3461            self.dispatch_mouse_event(any_mouse_event, cx);
3462        } else if let Some(any_key_event) = event.keyboard_event() {
3463            self.dispatch_key_event(any_key_event, cx);
3464        }
3465
3466        DispatchEventResult {
3467            propagate: cx.propagate_event,
3468            default_prevented: self.default_prevented,
3469        }
3470    }
3471
3472    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3473        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3474        if hit_test != self.mouse_hit_test {
3475            self.mouse_hit_test = hit_test;
3476            self.reset_cursor_style(cx);
3477        }
3478
3479        #[cfg(any(feature = "inspector", debug_assertions))]
3480        if self.is_inspector_picking(cx) {
3481            self.handle_inspector_mouse_event(event, cx);
3482            // When inspector is picking, all other mouse handling is skipped.
3483            return;
3484        }
3485
3486        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3487
3488        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3489        // special purposes, such as detecting events outside of a given Bounds.
3490        for listener in &mut mouse_listeners {
3491            let listener = listener.as_mut().unwrap();
3492            listener(event, DispatchPhase::Capture, self, cx);
3493            if !cx.propagate_event {
3494                break;
3495            }
3496        }
3497
3498        // Bubble phase, where most normal handlers do their work.
3499        if cx.propagate_event {
3500            for listener in mouse_listeners.iter_mut().rev() {
3501                let listener = listener.as_mut().unwrap();
3502                listener(event, DispatchPhase::Bubble, self, cx);
3503                if !cx.propagate_event {
3504                    break;
3505                }
3506            }
3507        }
3508
3509        self.rendered_frame.mouse_listeners = mouse_listeners;
3510
3511        if cx.has_active_drag() {
3512            if event.is::<MouseMoveEvent>() {
3513                // If this was a mouse move event, redraw the window so that the
3514                // active drag can follow the mouse cursor.
3515                self.refresh();
3516            } else if event.is::<MouseUpEvent>() {
3517                // If this was a mouse up event, cancel the active drag and redraw
3518                // the window.
3519                cx.active_drag = None;
3520                self.refresh();
3521            }
3522        }
3523    }
3524
3525    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3526        if self.invalidator.is_dirty() {
3527            self.draw(cx).clear();
3528        }
3529
3530        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3531        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3532
3533        let mut keystroke: Option<Keystroke> = None;
3534
3535        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3536            if event.modifiers.number_of_modifiers() == 0
3537                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3538                && !self.pending_modifier.saw_keystroke
3539            {
3540                let key = match self.pending_modifier.modifiers {
3541                    modifiers if modifiers.shift => Some("shift"),
3542                    modifiers if modifiers.control => Some("control"),
3543                    modifiers if modifiers.alt => Some("alt"),
3544                    modifiers if modifiers.platform => Some("platform"),
3545                    modifiers if modifiers.function => Some("function"),
3546                    _ => None,
3547                };
3548                if let Some(key) = key {
3549                    keystroke = Some(Keystroke {
3550                        key: key.to_string(),
3551                        key_char: None,
3552                        modifiers: Modifiers::default(),
3553                    });
3554                }
3555            }
3556
3557            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3558                && event.modifiers.number_of_modifiers() == 1
3559            {
3560                self.pending_modifier.saw_keystroke = false
3561            }
3562            self.pending_modifier.modifiers = event.modifiers
3563        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3564            self.pending_modifier.saw_keystroke = true;
3565            keystroke = Some(key_down_event.keystroke.clone());
3566        }
3567
3568        let Some(keystroke) = keystroke else {
3569            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3570            return;
3571        };
3572
3573        cx.propagate_event = true;
3574        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
3575        if !cx.propagate_event {
3576            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3577            return;
3578        }
3579
3580        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3581        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3582            currently_pending = PendingInput::default();
3583        }
3584
3585        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3586            currently_pending.keystrokes,
3587            keystroke,
3588            &dispatch_path,
3589        );
3590
3591        if !match_result.to_replay.is_empty() {
3592            self.replay_pending_input(match_result.to_replay, cx)
3593        }
3594
3595        if !match_result.pending.is_empty() {
3596            currently_pending.keystrokes = match_result.pending;
3597            currently_pending.focus = self.focus;
3598            currently_pending.timer = Some(self.spawn(cx, async move |cx| {
3599                cx.background_executor.timer(Duration::from_secs(1)).await;
3600                cx.update(move |window, cx| {
3601                    let Some(currently_pending) = window
3602                        .pending_input
3603                        .take()
3604                        .filter(|pending| pending.focus == window.focus)
3605                    else {
3606                        return;
3607                    };
3608
3609                    let node_id = window.focus_node_id_in_rendered_frame(window.focus);
3610                    let dispatch_path = window.rendered_frame.dispatch_tree.dispatch_path(node_id);
3611
3612                    let to_replay = window
3613                        .rendered_frame
3614                        .dispatch_tree
3615                        .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3616
3617                    window.pending_input_changed(cx);
3618                    window.replay_pending_input(to_replay, cx)
3619                })
3620                .log_err();
3621            }));
3622            self.pending_input = Some(currently_pending);
3623            self.pending_input_changed(cx);
3624            cx.propagate_event = false;
3625            return;
3626        }
3627
3628        for binding in match_result.bindings {
3629            self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3630            if !cx.propagate_event {
3631                self.dispatch_keystroke_observers(
3632                    event,
3633                    Some(binding.action),
3634                    match_result.context_stack.clone(),
3635                    cx,
3636                );
3637                self.pending_input_changed(cx);
3638                return;
3639            }
3640        }
3641
3642        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
3643        self.pending_input_changed(cx);
3644    }
3645
3646    fn finish_dispatch_key_event(
3647        &mut self,
3648        event: &dyn Any,
3649        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3650        context_stack: Vec<KeyContext>,
3651        cx: &mut App,
3652    ) {
3653        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
3654        if !cx.propagate_event {
3655            return;
3656        }
3657
3658        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
3659        if !cx.propagate_event {
3660            return;
3661        }
3662
3663        self.dispatch_keystroke_observers(event, None, context_stack, cx);
3664    }
3665
3666    fn pending_input_changed(&mut self, cx: &mut App) {
3667        self.pending_input_observers
3668            .clone()
3669            .retain(&(), |callback| callback(self, cx));
3670    }
3671
3672    fn dispatch_key_down_up_event(
3673        &mut self,
3674        event: &dyn Any,
3675        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3676        cx: &mut App,
3677    ) {
3678        // Capture phase
3679        for node_id in dispatch_path {
3680            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3681
3682            for key_listener in node.key_listeners.clone() {
3683                key_listener(event, DispatchPhase::Capture, self, cx);
3684                if !cx.propagate_event {
3685                    return;
3686                }
3687            }
3688        }
3689
3690        // Bubble phase
3691        for node_id in dispatch_path.iter().rev() {
3692            // Handle low level key events
3693            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3694            for key_listener in node.key_listeners.clone() {
3695                key_listener(event, DispatchPhase::Bubble, self, cx);
3696                if !cx.propagate_event {
3697                    return;
3698                }
3699            }
3700        }
3701    }
3702
3703    fn dispatch_modifiers_changed_event(
3704        &mut self,
3705        event: &dyn Any,
3706        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3707        cx: &mut App,
3708    ) {
3709        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3710            return;
3711        };
3712        for node_id in dispatch_path.iter().rev() {
3713            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3714            for listener in node.modifiers_changed_listeners.clone() {
3715                listener(event, self, cx);
3716                if !cx.propagate_event {
3717                    return;
3718                }
3719            }
3720        }
3721    }
3722
3723    /// Determine whether a potential multi-stroke key binding is in progress on this window.
3724    pub fn has_pending_keystrokes(&self) -> bool {
3725        self.pending_input.is_some()
3726    }
3727
3728    pub(crate) fn clear_pending_keystrokes(&mut self) {
3729        self.pending_input.take();
3730    }
3731
3732    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3733    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3734        self.pending_input
3735            .as_ref()
3736            .map(|pending_input| pending_input.keystrokes.as_slice())
3737    }
3738
3739    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
3740        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3741        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3742
3743        'replay: for replay in replays {
3744            let event = KeyDownEvent {
3745                keystroke: replay.keystroke.clone(),
3746                is_held: false,
3747            };
3748
3749            cx.propagate_event = true;
3750            for binding in replay.bindings {
3751                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3752                if !cx.propagate_event {
3753                    self.dispatch_keystroke_observers(
3754                        &event,
3755                        Some(binding.action),
3756                        Vec::default(),
3757                        cx,
3758                    );
3759                    continue 'replay;
3760                }
3761            }
3762
3763            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
3764            if !cx.propagate_event {
3765                continue 'replay;
3766            }
3767            if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3768                if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3769                    input_handler.dispatch_input(&input, self, cx);
3770                    self.platform_window.set_input_handler(input_handler)
3771                }
3772            }
3773        }
3774    }
3775
3776    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
3777        focus_id
3778            .and_then(|focus_id| {
3779                self.rendered_frame
3780                    .dispatch_tree
3781                    .focusable_node_id(focus_id)
3782            })
3783            .unwrap_or_else(|| {
3784                println!("root node id");
3785                self.rendered_frame.dispatch_tree.root_node_id()
3786            })
3787    }
3788
3789    fn dispatch_action_on_node(
3790        &mut self,
3791        node_id: DispatchNodeId,
3792        action: &dyn Action,
3793        cx: &mut App,
3794    ) {
3795        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3796
3797        // Capture phase for global actions.
3798        cx.propagate_event = true;
3799        if let Some(mut global_listeners) = cx
3800            .global_action_listeners
3801            .remove(&action.as_any().type_id())
3802        {
3803            for listener in &global_listeners {
3804                listener(action.as_any(), DispatchPhase::Capture, cx);
3805                if !cx.propagate_event {
3806                    break;
3807                }
3808            }
3809
3810            global_listeners.extend(
3811                cx.global_action_listeners
3812                    .remove(&action.as_any().type_id())
3813                    .unwrap_or_default(),
3814            );
3815
3816            cx.global_action_listeners
3817                .insert(action.as_any().type_id(), global_listeners);
3818        }
3819
3820        if !cx.propagate_event {
3821            return;
3822        }
3823
3824        // Capture phase for window actions.
3825        for node_id in &dispatch_path {
3826            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3827            for DispatchActionListener {
3828                action_type,
3829                listener,
3830            } in node.action_listeners.clone()
3831            {
3832                let any_action = action.as_any();
3833                if action_type == any_action.type_id() {
3834                    listener(any_action, DispatchPhase::Capture, self, cx);
3835
3836                    if !cx.propagate_event {
3837                        return;
3838                    }
3839                }
3840            }
3841        }
3842
3843        // Bubble phase for window actions.
3844        for node_id in dispatch_path.iter().rev() {
3845            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3846            for DispatchActionListener {
3847                action_type,
3848                listener,
3849            } in node.action_listeners.clone()
3850            {
3851                let any_action = action.as_any();
3852                if action_type == any_action.type_id() {
3853                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3854                    listener(any_action, DispatchPhase::Bubble, self, cx);
3855
3856                    if !cx.propagate_event {
3857                        return;
3858                    }
3859                }
3860            }
3861        }
3862
3863        // Bubble phase for global actions.
3864        if let Some(mut global_listeners) = cx
3865            .global_action_listeners
3866            .remove(&action.as_any().type_id())
3867        {
3868            for listener in global_listeners.iter().rev() {
3869                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3870
3871                listener(action.as_any(), DispatchPhase::Bubble, cx);
3872                if !cx.propagate_event {
3873                    break;
3874                }
3875            }
3876
3877            global_listeners.extend(
3878                cx.global_action_listeners
3879                    .remove(&action.as_any().type_id())
3880                    .unwrap_or_default(),
3881            );
3882
3883            cx.global_action_listeners
3884                .insert(action.as_any().type_id(), global_listeners);
3885        }
3886    }
3887
3888    /// Register the given handler to be invoked whenever the global of the given type
3889    /// is updated.
3890    pub fn observe_global<G: Global>(
3891        &mut self,
3892        cx: &mut App,
3893        f: impl Fn(&mut Window, &mut App) + 'static,
3894    ) -> Subscription {
3895        let window_handle = self.handle;
3896        let (subscription, activate) = cx.global_observers.insert(
3897            TypeId::of::<G>(),
3898            Box::new(move |cx| {
3899                window_handle
3900                    .update(cx, |_, window, cx| f(window, cx))
3901                    .is_ok()
3902            }),
3903        );
3904        cx.defer(move |_| activate());
3905        subscription
3906    }
3907
3908    /// Focus the current window and bring it to the foreground at the platform level.
3909    pub fn activate_window(&self) {
3910        self.platform_window.activate();
3911    }
3912
3913    /// Minimize the current window at the platform level.
3914    pub fn minimize_window(&self) {
3915        self.platform_window.minimize();
3916    }
3917
3918    /// Toggle full screen status on the current window at the platform level.
3919    pub fn toggle_fullscreen(&self) {
3920        self.platform_window.toggle_fullscreen();
3921    }
3922
3923    /// Updates the IME panel position suggestions for languages like japanese, chinese.
3924    pub fn invalidate_character_coordinates(&self) {
3925        self.on_next_frame(|window, cx| {
3926            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
3927                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
3928                    window
3929                        .platform_window
3930                        .update_ime_position(bounds.scale(window.scale_factor()));
3931                }
3932                window.platform_window.set_input_handler(input_handler);
3933            }
3934        });
3935    }
3936
3937    /// Present a platform dialog.
3938    /// The provided message will be presented, along with buttons for each answer.
3939    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3940    pub fn prompt<T>(
3941        &mut self,
3942        level: PromptLevel,
3943        message: &str,
3944        detail: Option<&str>,
3945        answers: &[T],
3946        cx: &mut App,
3947    ) -> oneshot::Receiver<usize>
3948    where
3949        T: Clone + Into<PromptButton>,
3950    {
3951        let prompt_builder = cx.prompt_builder.take();
3952        let Some(prompt_builder) = prompt_builder else {
3953            unreachable!("Re-entrant window prompting is not supported by GPUI");
3954        };
3955
3956        let answers = answers
3957            .iter()
3958            .map(|answer| answer.clone().into())
3959            .collect::<Vec<_>>();
3960
3961        let receiver = match &prompt_builder {
3962            PromptBuilder::Default => self
3963                .platform_window
3964                .prompt(level, message, detail, &answers)
3965                .unwrap_or_else(|| {
3966                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3967                }),
3968            PromptBuilder::Custom(_) => {
3969                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3970            }
3971        };
3972
3973        cx.prompt_builder = Some(prompt_builder);
3974
3975        receiver
3976    }
3977
3978    fn build_custom_prompt(
3979        &mut self,
3980        prompt_builder: &PromptBuilder,
3981        level: PromptLevel,
3982        message: &str,
3983        detail: Option<&str>,
3984        answers: &[PromptButton],
3985        cx: &mut App,
3986    ) -> oneshot::Receiver<usize> {
3987        let (sender, receiver) = oneshot::channel();
3988        let handle = PromptHandle::new(sender);
3989        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
3990        self.prompt = Some(handle);
3991        receiver
3992    }
3993
3994    /// Returns the current context stack.
3995    pub fn context_stack(&self) -> Vec<KeyContext> {
3996        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3997        let dispatch_tree = &self.rendered_frame.dispatch_tree;
3998        dispatch_tree
3999            .dispatch_path(node_id)
4000            .iter()
4001            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4002            .collect()
4003    }
4004
4005    /// Returns all available actions for the focused element.
4006    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4007        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4008        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4009        for action_type in cx.global_action_listeners.keys() {
4010            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4011                let action = cx.actions.build_action_type(action_type).ok();
4012                if let Some(action) = action {
4013                    actions.insert(ix, action);
4014                }
4015            }
4016        }
4017        actions
4018    }
4019
4020    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4021    /// returned in the order they were added. For display, the last binding should take precedence.
4022    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4023        self.rendered_frame
4024            .dispatch_tree
4025            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4026    }
4027
4028    /// Returns the highest precedence key binding that invokes an action on the currently focused
4029    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4030    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4031        self.rendered_frame
4032            .dispatch_tree
4033            .highest_precedence_binding_for_action(
4034                action,
4035                &self.rendered_frame.dispatch_tree.context_stack,
4036            )
4037    }
4038
4039    /// Returns the key bindings for an action in a context.
4040    pub fn bindings_for_action_in_context(
4041        &self,
4042        action: &dyn Action,
4043        context: KeyContext,
4044    ) -> Vec<KeyBinding> {
4045        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4046        dispatch_tree.bindings_for_action(action, &[context])
4047    }
4048
4049    /// Returns the highest precedence key binding for an action in a context. This is more
4050    /// efficient than getting the last result of `bindings_for_action_in_context`.
4051    pub fn highest_precedence_binding_for_action_in_context(
4052        &self,
4053        action: &dyn Action,
4054        context: KeyContext,
4055    ) -> Option<KeyBinding> {
4056        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4057        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4058    }
4059
4060    /// Returns any bindings that would invoke an action on the given focus handle if it were
4061    /// focused. Bindings are returned in the order they were added. For display, the last binding
4062    /// should take precedence.
4063    pub fn bindings_for_action_in(
4064        &self,
4065        action: &dyn Action,
4066        focus_handle: &FocusHandle,
4067    ) -> Vec<KeyBinding> {
4068        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4069        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4070            return vec![];
4071        };
4072        dispatch_tree.bindings_for_action(action, &context_stack)
4073    }
4074
4075    /// Returns the highest precedence key binding that would invoke an action on the given focus
4076    /// handle if it were focused. This is more efficient than getting the last result of
4077    /// `bindings_for_action_in`.
4078    pub fn highest_precedence_binding_for_action_in(
4079        &self,
4080        action: &dyn Action,
4081        focus_handle: &FocusHandle,
4082    ) -> Option<KeyBinding> {
4083        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4084        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4085        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4086    }
4087
4088    fn context_stack_for_focus_handle(
4089        &self,
4090        focus_handle: &FocusHandle,
4091    ) -> Option<Vec<KeyContext>> {
4092        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4093        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4094        let context_stack: Vec<_> = dispatch_tree
4095            .dispatch_path(node_id)
4096            .into_iter()
4097            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4098            .collect();
4099        Some(context_stack)
4100    }
4101
4102    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4103    pub fn listener_for<V: Render, E>(
4104        &self,
4105        view: &Entity<V>,
4106        f: impl Fn(&mut V, &E, &mut Window, &mut Context<V>) + 'static,
4107    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4108        let view = view.downgrade();
4109        move |e: &E, window: &mut Window, cx: &mut App| {
4110            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4111        }
4112    }
4113
4114    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4115    pub fn handler_for<V: Render, Callback: Fn(&mut V, &mut Window, &mut Context<V>) + 'static>(
4116        &self,
4117        view: &Entity<V>,
4118        f: Callback,
4119    ) -> impl Fn(&mut Window, &mut App) + use<V, Callback> {
4120        let view = view.downgrade();
4121        move |window: &mut Window, cx: &mut App| {
4122            view.update(cx, |view, cx| f(view, window, cx)).ok();
4123        }
4124    }
4125
4126    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4127    /// If the callback returns false, the window won't be closed.
4128    pub fn on_window_should_close(
4129        &self,
4130        cx: &App,
4131        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4132    ) {
4133        let mut cx = self.to_async(cx);
4134        self.platform_window.on_should_close(Box::new(move || {
4135            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4136        }))
4137    }
4138
4139    /// Register an action listener on the window for the next frame. The type of action
4140    /// is determined by the first parameter of the given listener. When the next frame is rendered
4141    /// the listener will be cleared.
4142    ///
4143    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4144    /// a specific need to register a global listener.
4145    pub fn on_action(
4146        &mut self,
4147        action_type: TypeId,
4148        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4149    ) {
4150        self.next_frame
4151            .dispatch_tree
4152            .on_action(action_type, Rc::new(listener));
4153    }
4154
4155    /// Read information about the GPU backing this window.
4156    /// Currently returns None on Mac and Windows.
4157    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4158        self.platform_window.gpu_specs()
4159    }
4160
4161    /// Perform titlebar double-click action.
4162    /// This is MacOS specific.
4163    pub fn titlebar_double_click(&self) {
4164        self.platform_window.titlebar_double_click();
4165    }
4166
4167    /// Toggles the inspector mode on this window.
4168    #[cfg(any(feature = "inspector", debug_assertions))]
4169    pub fn toggle_inspector(&mut self, cx: &mut App) {
4170        self.inspector = match self.inspector {
4171            None => Some(cx.new(|_| Inspector::new())),
4172            Some(_) => None,
4173        };
4174        self.refresh();
4175    }
4176
4177    /// Returns true if the window is in inspector mode.
4178    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4179        #[cfg(any(feature = "inspector", debug_assertions))]
4180        {
4181            if let Some(inspector) = &self.inspector {
4182                return inspector.read(_cx).is_picking();
4183            }
4184        }
4185        false
4186    }
4187
4188    /// Executes the provided function with mutable access to an inspector state.
4189    #[cfg(any(feature = "inspector", debug_assertions))]
4190    pub fn with_inspector_state<T: 'static, R>(
4191        &mut self,
4192        _inspector_id: Option<&crate::InspectorElementId>,
4193        cx: &mut App,
4194        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4195    ) -> R {
4196        if let Some(inspector_id) = _inspector_id {
4197            if let Some(inspector) = &self.inspector {
4198                let inspector = inspector.clone();
4199                let active_element_id = inspector.read(cx).active_element_id();
4200                if Some(inspector_id) == active_element_id {
4201                    return inspector.update(cx, |inspector, _cx| {
4202                        inspector.with_active_element_state(self, f)
4203                    });
4204                }
4205            }
4206        }
4207        f(&mut None, self)
4208    }
4209
4210    #[cfg(any(feature = "inspector", debug_assertions))]
4211    pub(crate) fn build_inspector_element_id(
4212        &mut self,
4213        path: crate::InspectorElementPath,
4214    ) -> crate::InspectorElementId {
4215        self.invalidator.debug_assert_paint_or_prepaint();
4216        let path = Rc::new(path);
4217        let next_instance_id = self
4218            .next_frame
4219            .next_inspector_instance_ids
4220            .entry(path.clone())
4221            .or_insert(0);
4222        let instance_id = *next_instance_id;
4223        *next_instance_id += 1;
4224        crate::InspectorElementId { path, instance_id }
4225    }
4226
4227    #[cfg(any(feature = "inspector", debug_assertions))]
4228    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4229        if let Some(inspector) = self.inspector.take() {
4230            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4231            inspector_element.prepaint_as_root(
4232                point(self.viewport_size.width - inspector_width, px(0.0)),
4233                size(inspector_width, self.viewport_size.height).into(),
4234                self,
4235                cx,
4236            );
4237            self.inspector = Some(inspector);
4238            Some(inspector_element)
4239        } else {
4240            None
4241        }
4242    }
4243
4244    #[cfg(any(feature = "inspector", debug_assertions))]
4245    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4246        if let Some(mut inspector_element) = inspector_element {
4247            inspector_element.paint(self, cx);
4248        };
4249    }
4250
4251    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4252    /// inspect UI elements by clicking on them.
4253    #[cfg(any(feature = "inspector", debug_assertions))]
4254    pub fn insert_inspector_hitbox(
4255        &mut self,
4256        hitbox_id: HitboxId,
4257        inspector_id: Option<&crate::InspectorElementId>,
4258        cx: &App,
4259    ) {
4260        self.invalidator.debug_assert_paint_or_prepaint();
4261        if !self.is_inspector_picking(cx) {
4262            return;
4263        }
4264        if let Some(inspector_id) = inspector_id {
4265            self.next_frame
4266                .inspector_hitboxes
4267                .insert(hitbox_id, inspector_id.clone());
4268        }
4269    }
4270
4271    #[cfg(any(feature = "inspector", debug_assertions))]
4272    fn paint_inspector_hitbox(&mut self, cx: &App) {
4273        if let Some(inspector) = self.inspector.as_ref() {
4274            let inspector = inspector.read(cx);
4275            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4276            {
4277                if let Some(hitbox) = self
4278                    .next_frame
4279                    .hitboxes
4280                    .iter()
4281                    .find(|hitbox| hitbox.id == hitbox_id)
4282                {
4283                    self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4284                }
4285            }
4286        }
4287    }
4288
4289    #[cfg(any(feature = "inspector", debug_assertions))]
4290    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4291        let Some(inspector) = self.inspector.clone() else {
4292            return;
4293        };
4294        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4295            inspector.update(cx, |inspector, _cx| {
4296                if let Some((_, inspector_id)) =
4297                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4298                {
4299                    inspector.hover(inspector_id, self);
4300                }
4301            });
4302        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4303            inspector.update(cx, |inspector, _cx| {
4304                if let Some((_, inspector_id)) =
4305                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4306                {
4307                    inspector.select(inspector_id, self);
4308                }
4309            });
4310        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4311            // This should be kept in sync with SCROLL_LINES in x11 platform.
4312            const SCROLL_LINES: f32 = 3.0;
4313            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4314            let delta_y = event
4315                .delta
4316                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4317                .y;
4318            if let Some(inspector) = self.inspector.clone() {
4319                inspector.update(cx, |inspector, _cx| {
4320                    if let Some(depth) = inspector.pick_depth.as_mut() {
4321                        *depth += delta_y.0 / SCROLL_PIXELS_PER_LAYER;
4322                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4323                        if *depth < 0.0 {
4324                            *depth = 0.0;
4325                        } else if *depth > max_depth {
4326                            *depth = max_depth;
4327                        }
4328                        if let Some((_, inspector_id)) =
4329                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4330                        {
4331                            inspector.set_active_element_id(inspector_id.clone(), self);
4332                        }
4333                    }
4334                });
4335            }
4336        }
4337    }
4338
4339    #[cfg(any(feature = "inspector", debug_assertions))]
4340    fn hovered_inspector_hitbox(
4341        &self,
4342        inspector: &Inspector,
4343        frame: &Frame,
4344    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4345        if let Some(pick_depth) = inspector.pick_depth {
4346            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4347            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4348            let skip_count = (depth as usize).min(max_skipped);
4349            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4350                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4351                    return Some((*hitbox_id, inspector_id.clone()));
4352                }
4353            }
4354        }
4355        return None;
4356    }
4357}
4358
4359// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4360slotmap::new_key_type! {
4361    /// A unique identifier for a window.
4362    pub struct WindowId;
4363}
4364
4365impl WindowId {
4366    /// Converts this window ID to a `u64`.
4367    pub fn as_u64(&self) -> u64 {
4368        self.0.as_ffi()
4369    }
4370}
4371
4372impl From<u64> for WindowId {
4373    fn from(value: u64) -> Self {
4374        WindowId(slotmap::KeyData::from_ffi(value))
4375    }
4376}
4377
4378/// A handle to a window with a specific root view type.
4379/// Note that this does not keep the window alive on its own.
4380#[derive(Deref, DerefMut)]
4381pub struct WindowHandle<V> {
4382    #[deref]
4383    #[deref_mut]
4384    pub(crate) any_handle: AnyWindowHandle,
4385    state_type: PhantomData<V>,
4386}
4387
4388impl<V: 'static + Render> WindowHandle<V> {
4389    /// Creates a new handle from a window ID.
4390    /// This does not check if the root type of the window is `V`.
4391    pub fn new(id: WindowId) -> Self {
4392        WindowHandle {
4393            any_handle: AnyWindowHandle {
4394                id,
4395                state_type: TypeId::of::<V>(),
4396            },
4397            state_type: PhantomData,
4398        }
4399    }
4400
4401    /// Get the root view out of this window.
4402    ///
4403    /// This will fail if the window is closed or if the root view's type does not match `V`.
4404    #[cfg(any(test, feature = "test-support"))]
4405    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
4406    where
4407        C: AppContext,
4408    {
4409        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
4410            root_view
4411                .downcast::<V>()
4412                .map_err(|_| anyhow!("the type of the window's root view has changed"))
4413        }))
4414    }
4415
4416    /// Updates the root view of this window.
4417    ///
4418    /// This will fail if the window has been closed or if the root view's type does not match
4419    pub fn update<C, R>(
4420        &self,
4421        cx: &mut C,
4422        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
4423    ) -> Result<R>
4424    where
4425        C: AppContext,
4426    {
4427        cx.update_window(self.any_handle, |root_view, window, cx| {
4428            let view = root_view
4429                .downcast::<V>()
4430                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4431
4432            Ok(view.update(cx, |view, cx| update(view, window, cx)))
4433        })?
4434    }
4435
4436    /// Read the root view out of this window.
4437    ///
4438    /// This will fail if the window is closed or if the root view's type does not match `V`.
4439    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
4440        let x = cx
4441            .windows
4442            .get(self.id)
4443            .and_then(|window| {
4444                window
4445                    .as_ref()
4446                    .and_then(|window| window.root.clone())
4447                    .map(|root_view| root_view.downcast::<V>())
4448            })
4449            .context("window not found")?
4450            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4451
4452        Ok(x.read(cx))
4453    }
4454
4455    /// Read the root view out of this window, with a callback
4456    ///
4457    /// This will fail if the window is closed or if the root view's type does not match `V`.
4458    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
4459    where
4460        C: AppContext,
4461    {
4462        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4463    }
4464
4465    /// Read the root view pointer off of this window.
4466    ///
4467    /// This will fail if the window is closed or if the root view's type does not match `V`.
4468    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
4469    where
4470        C: AppContext,
4471    {
4472        cx.read_window(self, |root_view, _cx| root_view.clone())
4473    }
4474
4475    /// Check if this window is 'active'.
4476    ///
4477    /// Will return `None` if the window is closed or currently
4478    /// borrowed.
4479    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
4480        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
4481            .ok()
4482    }
4483}
4484
4485impl<V> Copy for WindowHandle<V> {}
4486
4487impl<V> Clone for WindowHandle<V> {
4488    fn clone(&self) -> Self {
4489        *self
4490    }
4491}
4492
4493impl<V> PartialEq for WindowHandle<V> {
4494    fn eq(&self, other: &Self) -> bool {
4495        self.any_handle == other.any_handle
4496    }
4497}
4498
4499impl<V> Eq for WindowHandle<V> {}
4500
4501impl<V> Hash for WindowHandle<V> {
4502    fn hash<H: Hasher>(&self, state: &mut H) {
4503        self.any_handle.hash(state);
4504    }
4505}
4506
4507impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4508    fn from(val: WindowHandle<V>) -> Self {
4509        val.any_handle
4510    }
4511}
4512
4513unsafe impl<V> Send for WindowHandle<V> {}
4514unsafe impl<V> Sync for WindowHandle<V> {}
4515
4516/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4517#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4518pub struct AnyWindowHandle {
4519    pub(crate) id: WindowId,
4520    state_type: TypeId,
4521}
4522
4523impl AnyWindowHandle {
4524    /// Get the ID of this window.
4525    pub fn window_id(&self) -> WindowId {
4526        self.id
4527    }
4528
4529    /// Attempt to convert this handle to a window handle with a specific root view type.
4530    /// If the types do not match, this will return `None`.
4531    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4532        if TypeId::of::<T>() == self.state_type {
4533            Some(WindowHandle {
4534                any_handle: *self,
4535                state_type: PhantomData,
4536            })
4537        } else {
4538            None
4539        }
4540    }
4541
4542    /// Updates the state of the root view of this window.
4543    ///
4544    /// This will fail if the window has been closed.
4545    pub fn update<C, R>(
4546        self,
4547        cx: &mut C,
4548        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
4549    ) -> Result<R>
4550    where
4551        C: AppContext,
4552    {
4553        cx.update_window(self, update)
4554    }
4555
4556    /// Read the state of the root view of this window.
4557    ///
4558    /// This will fail if the window has been closed.
4559    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
4560    where
4561        C: AppContext,
4562        T: 'static,
4563    {
4564        let view = self
4565            .downcast::<T>()
4566            .context("the type of the window's root view has changed")?;
4567
4568        cx.read_window(&view, read)
4569    }
4570}
4571
4572impl HasWindowHandle for Window {
4573    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
4574        self.platform_window.window_handle()
4575    }
4576}
4577
4578impl HasDisplayHandle for Window {
4579    fn display_handle(
4580        &self,
4581    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
4582        self.platform_window.display_handle()
4583    }
4584}
4585
4586/// An identifier for an [`Element`](crate::Element).
4587///
4588/// Can be constructed with a string, a number, or both, as well
4589/// as other internal representations.
4590#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4591pub enum ElementId {
4592    /// The ID of a View element
4593    View(EntityId),
4594    /// An integer ID.
4595    Integer(u64),
4596    /// A string based ID.
4597    Name(SharedString),
4598    /// A UUID.
4599    Uuid(Uuid),
4600    /// An ID that's equated with a focus handle.
4601    FocusHandle(FocusId),
4602    /// A combination of a name and an integer.
4603    NamedInteger(SharedString, u64),
4604    /// A path.
4605    Path(Arc<std::path::Path>),
4606}
4607
4608impl ElementId {
4609    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
4610    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
4611        Self::NamedInteger(name.into(), integer as u64)
4612    }
4613}
4614
4615impl Display for ElementId {
4616    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4617        match self {
4618            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4619            ElementId::Integer(ix) => write!(f, "{}", ix)?,
4620            ElementId::Name(name) => write!(f, "{}", name)?,
4621            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4622            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4623            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4624            ElementId::Path(path) => write!(f, "{}", path.display())?,
4625        }
4626
4627        Ok(())
4628    }
4629}
4630
4631impl TryInto<SharedString> for ElementId {
4632    type Error = anyhow::Error;
4633
4634    fn try_into(self) -> anyhow::Result<SharedString> {
4635        if let ElementId::Name(name) = self {
4636            Ok(name)
4637        } else {
4638            anyhow::bail!("element id is not string")
4639        }
4640    }
4641}
4642
4643impl From<usize> for ElementId {
4644    fn from(id: usize) -> Self {
4645        ElementId::Integer(id as u64)
4646    }
4647}
4648
4649impl From<i32> for ElementId {
4650    fn from(id: i32) -> Self {
4651        Self::Integer(id as u64)
4652    }
4653}
4654
4655impl From<SharedString> for ElementId {
4656    fn from(name: SharedString) -> Self {
4657        ElementId::Name(name)
4658    }
4659}
4660
4661impl From<Arc<std::path::Path>> for ElementId {
4662    fn from(path: Arc<std::path::Path>) -> Self {
4663        ElementId::Path(path)
4664    }
4665}
4666
4667impl From<&'static str> for ElementId {
4668    fn from(name: &'static str) -> Self {
4669        ElementId::Name(name.into())
4670    }
4671}
4672
4673impl<'a> From<&'a FocusHandle> for ElementId {
4674    fn from(handle: &'a FocusHandle) -> Self {
4675        ElementId::FocusHandle(handle.id)
4676    }
4677}
4678
4679impl From<(&'static str, EntityId)> for ElementId {
4680    fn from((name, id): (&'static str, EntityId)) -> Self {
4681        ElementId::NamedInteger(name.into(), id.as_u64())
4682    }
4683}
4684
4685impl From<(&'static str, usize)> for ElementId {
4686    fn from((name, id): (&'static str, usize)) -> Self {
4687        ElementId::NamedInteger(name.into(), id as u64)
4688    }
4689}
4690
4691impl From<(SharedString, usize)> for ElementId {
4692    fn from((name, id): (SharedString, usize)) -> Self {
4693        ElementId::NamedInteger(name, id as u64)
4694    }
4695}
4696
4697impl From<(&'static str, u64)> for ElementId {
4698    fn from((name, id): (&'static str, u64)) -> Self {
4699        ElementId::NamedInteger(name.into(), id)
4700    }
4701}
4702
4703impl From<Uuid> for ElementId {
4704    fn from(value: Uuid) -> Self {
4705        Self::Uuid(value)
4706    }
4707}
4708
4709impl From<(&'static str, u32)> for ElementId {
4710    fn from((name, id): (&'static str, u32)) -> Self {
4711        ElementId::NamedInteger(name.into(), id.into())
4712    }
4713}
4714
4715/// A rectangle to be rendered in the window at the given position and size.
4716/// Passed as an argument [`Window::paint_quad`].
4717#[derive(Clone)]
4718pub struct PaintQuad {
4719    /// The bounds of the quad within the window.
4720    pub bounds: Bounds<Pixels>,
4721    /// The radii of the quad's corners.
4722    pub corner_radii: Corners<Pixels>,
4723    /// The background color of the quad.
4724    pub background: Background,
4725    /// The widths of the quad's borders.
4726    pub border_widths: Edges<Pixels>,
4727    /// The color of the quad's borders.
4728    pub border_color: Hsla,
4729    /// The style of the quad's borders.
4730    pub border_style: BorderStyle,
4731}
4732
4733impl PaintQuad {
4734    /// Sets the corner radii of the quad.
4735    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4736        PaintQuad {
4737            corner_radii: corner_radii.into(),
4738            ..self
4739        }
4740    }
4741
4742    /// Sets the border widths of the quad.
4743    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
4744        PaintQuad {
4745            border_widths: border_widths.into(),
4746            ..self
4747        }
4748    }
4749
4750    /// Sets the border color of the quad.
4751    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
4752        PaintQuad {
4753            border_color: border_color.into(),
4754            ..self
4755        }
4756    }
4757
4758    /// Sets the background color of the quad.
4759    pub fn background(self, background: impl Into<Background>) -> Self {
4760        PaintQuad {
4761            background: background.into(),
4762            ..self
4763        }
4764    }
4765}
4766
4767/// Creates a quad with the given parameters.
4768pub fn quad(
4769    bounds: Bounds<Pixels>,
4770    corner_radii: impl Into<Corners<Pixels>>,
4771    background: impl Into<Background>,
4772    border_widths: impl Into<Edges<Pixels>>,
4773    border_color: impl Into<Hsla>,
4774    border_style: BorderStyle,
4775) -> PaintQuad {
4776    PaintQuad {
4777        bounds,
4778        corner_radii: corner_radii.into(),
4779        background: background.into(),
4780        border_widths: border_widths.into(),
4781        border_color: border_color.into(),
4782        border_style,
4783    }
4784}
4785
4786/// Creates a filled quad with the given bounds and background color.
4787pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
4788    PaintQuad {
4789        bounds: bounds.into(),
4790        corner_radii: (0.).into(),
4791        background: background.into(),
4792        border_widths: (0.).into(),
4793        border_color: transparent_black(),
4794        border_style: BorderStyle::default(),
4795    }
4796}
4797
4798/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
4799pub fn outline(
4800    bounds: impl Into<Bounds<Pixels>>,
4801    border_color: impl Into<Hsla>,
4802    border_style: BorderStyle,
4803) -> PaintQuad {
4804    PaintQuad {
4805        bounds: bounds.into(),
4806        corner_radii: (0.).into(),
4807        background: transparent_black().into(),
4808        border_widths: (1.).into(),
4809        border_color: border_color.into(),
4810        border_style,
4811    }
4812}