window.rs

   1#[cfg(any(feature = "inspector", debug_assertions))]
   2use crate::Inspector;
   3use crate::{
   4    Action, AnyDrag, AnyElement, AnyImageCache, AnyTooltip, AnyView, App, AppContext, Arena, Asset,
   5    AsyncWindowContext, AvailableSpace, Background, BorderStyle, Bounds, BoxShadow, Capslock,
   6    Context, Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener,
   7    DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
   8    FileDropEvent, FontId, Global, GlobalElementId, GlyphId, GpuSpecs, Hsla, InputHandler, IsZero,
   9    KeyBinding, KeyContext, KeyDownEvent, KeyEvent, Keystroke, KeystrokeEvent, LayoutId,
  10    LineLayoutIndex, Modifiers, ModifiersChangedEvent, MonochromeSprite, MouseButton, MouseEvent,
  11    MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
  12    PlatformInputHandler, PlatformWindow, Point, PolychromeSprite, PromptButton, PromptLevel, Quad,
  13    Render, RenderGlyphParams, RenderImage, RenderImageParams, RenderSvgParams, Replay, ResizeEdge,
  14    SMOOTH_SVG_SCALE_FACTOR, SUBPIXEL_VARIANTS, ScaledPixels, Scene, Shadow, SharedString, Size,
  15    StrikethroughStyle, Style, SubscriberSet, Subscription, TaffyLayoutEngine, Task, TextStyle,
  16    TextStyleRefinement, TransformationMatrix, Underline, UnderlineStyle, WindowAppearance,
  17    WindowBackgroundAppearance, WindowBounds, WindowControls, WindowDecorations, WindowOptions,
  18    WindowParams, WindowTextSystem, point, prelude::*, px, rems, size, transparent_black,
  19};
  20use anyhow::{Context as _, Result, anyhow};
  21use collections::{FxHashMap, FxHashSet};
  22#[cfg(target_os = "macos")]
  23use core_video::pixel_buffer::CVPixelBuffer;
  24use derive_more::{Deref, DerefMut};
  25use futures::FutureExt;
  26use futures::channel::oneshot;
  27use itertools::FoldWhile::{Continue, Done};
  28use itertools::Itertools;
  29use parking_lot::RwLock;
  30use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
  31use refineable::Refineable;
  32use slotmap::SlotMap;
  33use smallvec::SmallVec;
  34use std::{
  35    any::{Any, TypeId},
  36    borrow::Cow,
  37    cell::{Cell, RefCell},
  38    cmp,
  39    fmt::{Debug, Display},
  40    hash::{Hash, Hasher},
  41    marker::PhantomData,
  42    mem,
  43    ops::{DerefMut, Range},
  44    rc::Rc,
  45    sync::{
  46        Arc, Weak,
  47        atomic::{AtomicUsize, Ordering::SeqCst},
  48    },
  49    time::{Duration, Instant},
  50};
  51use util::post_inc;
  52use util::{ResultExt, measure};
  53use uuid::Uuid;
  54
  55mod prompts;
  56
  57use crate::util::atomic_incr_if_not_zero;
  58pub use prompts::*;
  59
  60pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1024.), px(700.));
  61
  62/// Represents the two different phases when dispatching events.
  63#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  64pub enum DispatchPhase {
  65    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  66    /// invoked front to back and keyboard event listeners are invoked from the focused element
  67    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  68    /// registering event listeners.
  69    #[default]
  70    Bubble,
  71    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  72    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  73    /// is used for special purposes such as clearing the "pressed" state for click events. If
  74    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  75    /// outside of the immediate region may rely on detecting non-local events during this phase.
  76    Capture,
  77}
  78
  79impl DispatchPhase {
  80    /// Returns true if this represents the "bubble" phase.
  81    pub fn bubble(self) -> bool {
  82        self == DispatchPhase::Bubble
  83    }
  84
  85    /// Returns true if this represents the "capture" phase.
  86    pub fn capture(self) -> bool {
  87        self == DispatchPhase::Capture
  88    }
  89}
  90
  91struct WindowInvalidatorInner {
  92    pub dirty: bool,
  93    pub draw_phase: DrawPhase,
  94    pub dirty_views: FxHashSet<EntityId>,
  95}
  96
  97#[derive(Clone)]
  98pub(crate) struct WindowInvalidator {
  99    inner: Rc<RefCell<WindowInvalidatorInner>>,
 100}
 101
 102impl WindowInvalidator {
 103    pub fn new() -> Self {
 104        WindowInvalidator {
 105            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 106                dirty: true,
 107                draw_phase: DrawPhase::None,
 108                dirty_views: FxHashSet::default(),
 109            })),
 110        }
 111    }
 112
 113    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 114        let mut inner = self.inner.borrow_mut();
 115        inner.dirty_views.insert(entity);
 116        if inner.draw_phase == DrawPhase::None {
 117            inner.dirty = true;
 118            cx.push_effect(Effect::Notify { emitter: entity });
 119            true
 120        } else {
 121            false
 122        }
 123    }
 124
 125    pub fn is_dirty(&self) -> bool {
 126        self.inner.borrow().dirty
 127    }
 128
 129    pub fn set_dirty(&self, dirty: bool) {
 130        self.inner.borrow_mut().dirty = dirty
 131    }
 132
 133    pub fn set_phase(&self, phase: DrawPhase) {
 134        self.inner.borrow_mut().draw_phase = phase
 135    }
 136
 137    pub fn take_views(&self) -> FxHashSet<EntityId> {
 138        mem::take(&mut self.inner.borrow_mut().dirty_views)
 139    }
 140
 141    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 142        self.inner.borrow_mut().dirty_views = views;
 143    }
 144
 145    pub fn not_drawing(&self) -> bool {
 146        self.inner.borrow().draw_phase == DrawPhase::None
 147    }
 148
 149    #[track_caller]
 150    pub fn debug_assert_paint(&self) {
 151        debug_assert!(
 152            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 153            "this method can only be called during paint"
 154        );
 155    }
 156
 157    #[track_caller]
 158    pub fn debug_assert_prepaint(&self) {
 159        debug_assert!(
 160            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 161            "this method can only be called during request_layout, or prepaint"
 162        );
 163    }
 164
 165    #[track_caller]
 166    pub fn debug_assert_paint_or_prepaint(&self) {
 167        debug_assert!(
 168            matches!(
 169                self.inner.borrow().draw_phase,
 170                DrawPhase::Paint | DrawPhase::Prepaint
 171            ),
 172            "this method can only be called during request_layout, prepaint, or paint"
 173        );
 174    }
 175}
 176
 177type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 178
 179pub(crate) type AnyWindowFocusListener =
 180    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 181
 182pub(crate) struct WindowFocusEvent {
 183    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 184    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 185}
 186
 187impl WindowFocusEvent {
 188    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 189        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 190    }
 191
 192    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 193        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 194    }
 195}
 196
 197/// This is provided when subscribing for `Context::on_focus_out` events.
 198pub struct FocusOutEvent {
 199    /// A weak focus handle representing what was blurred.
 200    pub blurred: WeakFocusHandle,
 201}
 202
 203slotmap::new_key_type! {
 204    /// A globally unique identifier for a focusable element.
 205    pub struct FocusId;
 206}
 207
 208thread_local! {
 209    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(1024 * 1024));
 210}
 211
 212/// Returned when the element arena has been used and so must be cleared before the next draw.
 213#[must_use]
 214pub struct ArenaClearNeeded;
 215
 216impl ArenaClearNeeded {
 217    /// Clear the element arena.
 218    pub fn clear(self) {
 219        ELEMENT_ARENA.with_borrow_mut(|element_arena| {
 220            element_arena.clear();
 221        });
 222    }
 223}
 224
 225pub(crate) type FocusMap = RwLock<SlotMap<FocusId, AtomicUsize>>;
 226
 227impl FocusId {
 228    /// Obtains whether the element associated with this handle is currently focused.
 229    pub fn is_focused(&self, window: &Window) -> bool {
 230        window.focus == Some(*self)
 231    }
 232
 233    /// Obtains whether the element associated with this handle contains the focused
 234    /// element or is itself focused.
 235    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 236        window
 237            .focused(cx)
 238            .map_or(false, |focused| self.contains(focused.id, window))
 239    }
 240
 241    /// Obtains whether the element associated with this handle is contained within the
 242    /// focused element or is itself focused.
 243    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 244        let focused = window.focused(cx);
 245        focused.map_or(false, |focused| focused.id.contains(*self, window))
 246    }
 247
 248    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 249    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 250        window
 251            .rendered_frame
 252            .dispatch_tree
 253            .focus_contains(*self, other)
 254    }
 255}
 256
 257/// A handle which can be used to track and manipulate the focused element in a window.
 258pub struct FocusHandle {
 259    pub(crate) id: FocusId,
 260    handles: Arc<FocusMap>,
 261}
 262
 263impl std::fmt::Debug for FocusHandle {
 264    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 265        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 266    }
 267}
 268
 269impl FocusHandle {
 270    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 271        let id = handles.write().insert(AtomicUsize::new(1));
 272        Self {
 273            id,
 274            handles: handles.clone(),
 275        }
 276    }
 277
 278    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 279        let lock = handles.read();
 280        let ref_count = lock.get(id)?;
 281        if atomic_incr_if_not_zero(ref_count) == 0 {
 282            return None;
 283        }
 284        Some(Self {
 285            id,
 286            handles: handles.clone(),
 287        })
 288    }
 289
 290    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 291    pub fn downgrade(&self) -> WeakFocusHandle {
 292        WeakFocusHandle {
 293            id: self.id,
 294            handles: Arc::downgrade(&self.handles),
 295        }
 296    }
 297
 298    /// Moves the focus to the element associated with this handle.
 299    pub fn focus(&self, window: &mut Window) {
 300        window.focus(self)
 301    }
 302
 303    /// Obtains whether the element associated with this handle is currently focused.
 304    pub fn is_focused(&self, window: &Window) -> bool {
 305        self.id.is_focused(window)
 306    }
 307
 308    /// Obtains whether the element associated with this handle contains the focused
 309    /// element or is itself focused.
 310    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 311        self.id.contains_focused(window, cx)
 312    }
 313
 314    /// Obtains whether the element associated with this handle is contained within the
 315    /// focused element or is itself focused.
 316    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 317        self.id.within_focused(window, cx)
 318    }
 319
 320    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 321    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 322        self.id.contains(other.id, window)
 323    }
 324
 325    /// Dispatch an action on the element that rendered this focus handle
 326    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 327        if let Some(node_id) = window
 328            .rendered_frame
 329            .dispatch_tree
 330            .focusable_node_id(self.id)
 331        {
 332            window.dispatch_action_on_node(node_id, action, cx)
 333        }
 334    }
 335}
 336
 337impl Clone for FocusHandle {
 338    fn clone(&self) -> Self {
 339        Self::for_id(self.id, &self.handles).unwrap()
 340    }
 341}
 342
 343impl PartialEq for FocusHandle {
 344    fn eq(&self, other: &Self) -> bool {
 345        self.id == other.id
 346    }
 347}
 348
 349impl Eq for FocusHandle {}
 350
 351impl Drop for FocusHandle {
 352    fn drop(&mut self) {
 353        self.handles
 354            .read()
 355            .get(self.id)
 356            .unwrap()
 357            .fetch_sub(1, SeqCst);
 358    }
 359}
 360
 361/// A weak reference to a focus handle.
 362#[derive(Clone, Debug)]
 363pub struct WeakFocusHandle {
 364    pub(crate) id: FocusId,
 365    pub(crate) handles: Weak<FocusMap>,
 366}
 367
 368impl WeakFocusHandle {
 369    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 370    pub fn upgrade(&self) -> Option<FocusHandle> {
 371        let handles = self.handles.upgrade()?;
 372        FocusHandle::for_id(self.id, &handles)
 373    }
 374}
 375
 376impl PartialEq for WeakFocusHandle {
 377    fn eq(&self, other: &WeakFocusHandle) -> bool {
 378        self.id == other.id
 379    }
 380}
 381
 382impl Eq for WeakFocusHandle {}
 383
 384impl PartialEq<FocusHandle> for WeakFocusHandle {
 385    fn eq(&self, other: &FocusHandle) -> bool {
 386        self.id == other.id
 387    }
 388}
 389
 390impl PartialEq<WeakFocusHandle> for FocusHandle {
 391    fn eq(&self, other: &WeakFocusHandle) -> bool {
 392        self.id == other.id
 393    }
 394}
 395
 396/// Focusable allows users of your view to easily
 397/// focus it (using window.focus_view(cx, view))
 398pub trait Focusable: 'static {
 399    /// Returns the focus handle associated with this view.
 400    fn focus_handle(&self, cx: &App) -> FocusHandle;
 401}
 402
 403impl<V: Focusable> Focusable for Entity<V> {
 404    fn focus_handle(&self, cx: &App) -> FocusHandle {
 405        self.read(cx).focus_handle(cx)
 406    }
 407}
 408
 409/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 410/// where the lifecycle of the view is handled by another view.
 411pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 412
 413impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 414
 415/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 416pub struct DismissEvent;
 417
 418type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 419
 420pub(crate) type AnyMouseListener =
 421    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 422
 423#[derive(Clone)]
 424pub(crate) struct CursorStyleRequest {
 425    pub(crate) hitbox_id: Option<HitboxId>,
 426    pub(crate) style: CursorStyle,
 427}
 428
 429#[derive(Default, Eq, PartialEq)]
 430pub(crate) struct HitTest {
 431    pub(crate) ids: SmallVec<[HitboxId; 8]>,
 432    pub(crate) hover_hitbox_count: usize,
 433}
 434
 435/// A type of window control area that corresponds to the platform window.
 436#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 437pub enum WindowControlArea {
 438    /// An area that allows dragging of the platform window.
 439    Drag,
 440    /// An area that allows closing of the platform window.
 441    Close,
 442    /// An area that allows maximizing of the platform window.
 443    Max,
 444    /// An area that allows minimizing of the platform window.
 445    Min,
 446}
 447
 448/// An identifier for a [Hitbox] which also includes [HitboxBehavior].
 449#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 450pub struct HitboxId(u64);
 451
 452impl HitboxId {
 453    /// Checks if the hitbox with this ID is currently hovered. Except when handling
 454    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 455    /// events or paint hover styles.
 456    ///
 457    /// See [`Hitbox::is_hovered`] for details.
 458    pub fn is_hovered(self, window: &Window) -> bool {
 459        let hit_test = &window.mouse_hit_test;
 460        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 461            if self == *id {
 462                return true;
 463            }
 464        }
 465        return false;
 466    }
 467
 468    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 469    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 470    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 471    /// this distinction.
 472    pub fn should_handle_scroll(self, window: &Window) -> bool {
 473        window.mouse_hit_test.ids.contains(&self)
 474    }
 475
 476    fn next(mut self) -> HitboxId {
 477        HitboxId(self.0.wrapping_add(1))
 478    }
 479}
 480
 481/// A rectangular region that potentially blocks hitboxes inserted prior.
 482/// See [Window::insert_hitbox] for more details.
 483#[derive(Clone, Debug, Deref)]
 484pub struct Hitbox {
 485    /// A unique identifier for the hitbox.
 486    pub id: HitboxId,
 487    /// The bounds of the hitbox.
 488    #[deref]
 489    pub bounds: Bounds<Pixels>,
 490    /// The content mask when the hitbox was inserted.
 491    pub content_mask: ContentMask<Pixels>,
 492    /// Flags that specify hitbox behavior.
 493    pub behavior: HitboxBehavior,
 494}
 495
 496impl Hitbox {
 497    /// Checks if the hitbox is currently hovered. Except when handling `ScrollWheelEvent`, this is
 498    /// typically what you want when determining whether to handle mouse events or paint hover
 499    /// styles.
 500    ///
 501    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 502    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 503    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`).
 504    ///
 505    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 506    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 507    /// non-interactive while still allowing scrolling. More abstractly, this is because
 508    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 509    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 510    /// container.
 511    pub fn is_hovered(&self, window: &Window) -> bool {
 512        self.id.is_hovered(window)
 513    }
 514
 515    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 516    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 517    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 518    ///
 519    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 520    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 521    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 522        self.id.should_handle_scroll(window)
 523    }
 524}
 525
 526/// How the hitbox affects mouse behavior.
 527#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 528pub enum HitboxBehavior {
 529    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 530    #[default]
 531    Normal,
 532
 533    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 534    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 535    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 536    /// [`InteractiveElement::occlude`].
 537    ///
 538    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 539    /// bubble-phase handler for every mouse event type:
 540    ///
 541    /// ```
 542    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 543    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 544    ///         cx.stop_propagation();
 545    ///     }
 546    /// }
 547    /// ```
 548    ///
 549    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 550    /// styles and tooltops. These other behaviors are the main point of this mechanism. An
 551    /// alternative might be to not affect mouse event handling - but this would allow
 552    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 553    /// be hovered.
 554    BlockMouse,
 555
 556    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 557    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 558    /// interaction except scroll events to be ignored - see the documentation of
 559    /// [`Hitbox::is_hovered`] for details. This flag is set by
 560    /// [`InteractiveElement::block_mouse_except_scroll`].
 561    ///
 562    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 563    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 564    ///
 565    /// ```
 566    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, _cx| {
 567    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 568    ///         cx.stop_propagation();
 569    ///     }
 570    /// }
 571    /// ```
 572    ///
 573    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 574    /// handled differently than other mouse events. If also blocking these scroll events is
 575    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 576    ///
 577    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 578    /// hover styles and tooltops. These other behaviors are the main point of this mechanism.
 579    /// An alternative might be to not affect mouse event handling - but this would allow
 580    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 581    /// be hovered.
 582    BlockMouseExceptScroll,
 583}
 584
 585/// An identifier for a tooltip.
 586#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 587pub struct TooltipId(usize);
 588
 589impl TooltipId {
 590    /// Checks if the tooltip is currently hovered.
 591    pub fn is_hovered(&self, window: &Window) -> bool {
 592        window
 593            .tooltip_bounds
 594            .as_ref()
 595            .map_or(false, |tooltip_bounds| {
 596                tooltip_bounds.id == *self
 597                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 598            })
 599    }
 600}
 601
 602pub(crate) struct TooltipBounds {
 603    id: TooltipId,
 604    bounds: Bounds<Pixels>,
 605}
 606
 607#[derive(Clone)]
 608pub(crate) struct TooltipRequest {
 609    id: TooltipId,
 610    tooltip: AnyTooltip,
 611}
 612
 613pub(crate) struct DeferredDraw {
 614    current_view: EntityId,
 615    priority: usize,
 616    parent_node: DispatchNodeId,
 617    element_id_stack: SmallVec<[ElementId; 32]>,
 618    text_style_stack: Vec<TextStyleRefinement>,
 619    element: Option<AnyElement>,
 620    absolute_offset: Point<Pixels>,
 621    prepaint_range: Range<PrepaintStateIndex>,
 622    paint_range: Range<PaintIndex>,
 623}
 624
 625pub(crate) struct Frame {
 626    pub(crate) focus: Option<FocusId>,
 627    pub(crate) window_active: bool,
 628    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 629    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 630    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 631    pub(crate) dispatch_tree: DispatchTree,
 632    pub(crate) scene: Scene,
 633    pub(crate) hitboxes: Vec<Hitbox>,
 634    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 635    pub(crate) deferred_draws: Vec<DeferredDraw>,
 636    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 637    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 638    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 639    #[cfg(any(test, feature = "test-support"))]
 640    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 641    #[cfg(any(feature = "inspector", debug_assertions))]
 642    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 643    #[cfg(any(feature = "inspector", debug_assertions))]
 644    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 645}
 646
 647#[derive(Clone, Default)]
 648pub(crate) struct PrepaintStateIndex {
 649    hitboxes_index: usize,
 650    tooltips_index: usize,
 651    deferred_draws_index: usize,
 652    dispatch_tree_index: usize,
 653    accessed_element_states_index: usize,
 654    line_layout_index: LineLayoutIndex,
 655}
 656
 657#[derive(Clone, Default)]
 658pub(crate) struct PaintIndex {
 659    scene_index: usize,
 660    mouse_listeners_index: usize,
 661    input_handlers_index: usize,
 662    cursor_styles_index: usize,
 663    accessed_element_states_index: usize,
 664    line_layout_index: LineLayoutIndex,
 665}
 666
 667impl Frame {
 668    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 669        Frame {
 670            focus: None,
 671            window_active: false,
 672            element_states: FxHashMap::default(),
 673            accessed_element_states: Vec::new(),
 674            mouse_listeners: Vec::new(),
 675            dispatch_tree,
 676            scene: Scene::default(),
 677            hitboxes: Vec::new(),
 678            window_control_hitboxes: Vec::new(),
 679            deferred_draws: Vec::new(),
 680            input_handlers: Vec::new(),
 681            tooltip_requests: Vec::new(),
 682            cursor_styles: Vec::new(),
 683
 684            #[cfg(any(test, feature = "test-support"))]
 685            debug_bounds: FxHashMap::default(),
 686
 687            #[cfg(any(feature = "inspector", debug_assertions))]
 688            next_inspector_instance_ids: FxHashMap::default(),
 689
 690            #[cfg(any(feature = "inspector", debug_assertions))]
 691            inspector_hitboxes: FxHashMap::default(),
 692        }
 693    }
 694
 695    pub(crate) fn clear(&mut self) {
 696        self.element_states.clear();
 697        self.accessed_element_states.clear();
 698        self.mouse_listeners.clear();
 699        self.dispatch_tree.clear();
 700        self.scene.clear();
 701        self.input_handlers.clear();
 702        self.tooltip_requests.clear();
 703        self.cursor_styles.clear();
 704        self.hitboxes.clear();
 705        self.window_control_hitboxes.clear();
 706        self.deferred_draws.clear();
 707        self.focus = None;
 708
 709        #[cfg(any(feature = "inspector", debug_assertions))]
 710        {
 711            self.next_inspector_instance_ids.clear();
 712            self.inspector_hitboxes.clear();
 713        }
 714    }
 715
 716    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 717        self.cursor_styles
 718            .iter()
 719            .rev()
 720            .fold_while(None, |style, request| match request.hitbox_id {
 721                None => Done(Some(request.style)),
 722                Some(hitbox_id) => Continue(
 723                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 724                ),
 725            })
 726            .into_inner()
 727    }
 728
 729    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 730        let mut set_hover_hitbox_count = false;
 731        let mut hit_test = HitTest::default();
 732        for hitbox in self.hitboxes.iter().rev() {
 733            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 734            if bounds.contains(&position) {
 735                hit_test.ids.push(hitbox.id);
 736                if !set_hover_hitbox_count
 737                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 738                {
 739                    hit_test.hover_hitbox_count = hit_test.ids.len();
 740                    set_hover_hitbox_count = true;
 741                }
 742                if hitbox.behavior == HitboxBehavior::BlockMouse {
 743                    break;
 744                }
 745            }
 746        }
 747        if !set_hover_hitbox_count {
 748            hit_test.hover_hitbox_count = hit_test.ids.len();
 749        }
 750        hit_test
 751    }
 752
 753    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 754        self.focus
 755            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 756            .unwrap_or_default()
 757    }
 758
 759    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 760        for element_state_key in &self.accessed_element_states {
 761            if let Some((element_state_key, element_state)) =
 762                prev_frame.element_states.remove_entry(element_state_key)
 763            {
 764                self.element_states.insert(element_state_key, element_state);
 765            }
 766        }
 767
 768        self.scene.finish();
 769    }
 770}
 771
 772/// Holds the state for a specific window.
 773pub struct Window {
 774    pub(crate) handle: AnyWindowHandle,
 775    pub(crate) invalidator: WindowInvalidator,
 776    pub(crate) removed: bool,
 777    pub(crate) platform_window: Box<dyn PlatformWindow>,
 778    display_id: Option<DisplayId>,
 779    sprite_atlas: Arc<dyn PlatformAtlas>,
 780    text_system: Arc<WindowTextSystem>,
 781    rem_size: Pixels,
 782    /// The stack of override values for the window's rem size.
 783    ///
 784    /// This is used by `with_rem_size` to allow rendering an element tree with
 785    /// a given rem size.
 786    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 787    pub(crate) viewport_size: Size<Pixels>,
 788    layout_engine: Option<TaffyLayoutEngine>,
 789    pub(crate) root: Option<AnyView>,
 790    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 791    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 792    pub(crate) rendered_entity_stack: Vec<EntityId>,
 793    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 794    pub(crate) element_opacity: Option<f32>,
 795    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 796    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 797    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 798    pub(crate) rendered_frame: Frame,
 799    pub(crate) next_frame: Frame,
 800    next_hitbox_id: HitboxId,
 801    pub(crate) next_tooltip_id: TooltipId,
 802    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 803    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 804    pub(crate) dirty_views: FxHashSet<EntityId>,
 805    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 806    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 807    default_prevented: bool,
 808    mouse_position: Point<Pixels>,
 809    mouse_hit_test: HitTest,
 810    modifiers: Modifiers,
 811    capslock: Capslock,
 812    scale_factor: f32,
 813    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 814    appearance: WindowAppearance,
 815    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 816    active: Rc<Cell<bool>>,
 817    hovered: Rc<Cell<bool>>,
 818    pub(crate) needs_present: Rc<Cell<bool>>,
 819    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 820    pub(crate) refreshing: bool,
 821    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 822    pub(crate) focus: Option<FocusId>,
 823    focus_enabled: bool,
 824    pending_input: Option<PendingInput>,
 825    pending_modifier: ModifierState,
 826    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 827    prompt: Option<RenderablePromptHandle>,
 828    pub(crate) client_inset: Option<Pixels>,
 829    #[cfg(any(feature = "inspector", debug_assertions))]
 830    inspector: Option<Entity<Inspector>>,
 831}
 832
 833#[derive(Clone, Debug, Default)]
 834struct ModifierState {
 835    modifiers: Modifiers,
 836    saw_keystroke: bool,
 837}
 838
 839#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 840pub(crate) enum DrawPhase {
 841    None,
 842    Prepaint,
 843    Paint,
 844    Focus,
 845}
 846
 847#[derive(Default, Debug)]
 848struct PendingInput {
 849    keystrokes: SmallVec<[Keystroke; 1]>,
 850    focus: Option<FocusId>,
 851    timer: Option<Task<()>>,
 852}
 853
 854pub(crate) struct ElementStateBox {
 855    pub(crate) inner: Box<dyn Any>,
 856    #[cfg(debug_assertions)]
 857    pub(crate) type_name: &'static str,
 858}
 859
 860fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> Bounds<Pixels> {
 861    const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
 862
 863    // TODO, BUG: if you open a window with the currently active window
 864    // on the stack, this will erroneously select the 'unwrap_or_else'
 865    // code path
 866    cx.active_window()
 867        .and_then(|w| w.update(cx, |_, window, _| window.bounds()).ok())
 868        .map(|mut bounds| {
 869            bounds.origin += DEFAULT_WINDOW_OFFSET;
 870            bounds
 871        })
 872        .unwrap_or_else(|| {
 873            let display = display_id
 874                .map(|id| cx.find_display(id))
 875                .unwrap_or_else(|| cx.primary_display());
 876
 877            display
 878                .map(|display| display.default_bounds())
 879                .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
 880        })
 881}
 882
 883impl Window {
 884    pub(crate) fn new(
 885        handle: AnyWindowHandle,
 886        options: WindowOptions,
 887        cx: &mut App,
 888    ) -> Result<Self> {
 889        let WindowOptions {
 890            window_bounds,
 891            titlebar,
 892            focus,
 893            show,
 894            kind,
 895            is_movable,
 896            display_id,
 897            window_background,
 898            app_id,
 899            window_min_size,
 900            window_decorations,
 901        } = options;
 902
 903        let bounds = window_bounds
 904            .map(|bounds| bounds.get_bounds())
 905            .unwrap_or_else(|| default_bounds(display_id, cx));
 906        let mut platform_window = cx.platform.open_window(
 907            handle,
 908            WindowParams {
 909                bounds,
 910                titlebar,
 911                kind,
 912                is_movable,
 913                focus,
 914                show,
 915                display_id,
 916                window_min_size,
 917            },
 918        )?;
 919        let display_id = platform_window.display().map(|display| display.id());
 920        let sprite_atlas = platform_window.sprite_atlas();
 921        let mouse_position = platform_window.mouse_position();
 922        let modifiers = platform_window.modifiers();
 923        let capslock = platform_window.capslock();
 924        let content_size = platform_window.content_size();
 925        let scale_factor = platform_window.scale_factor();
 926        let appearance = platform_window.appearance();
 927        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
 928        let invalidator = WindowInvalidator::new();
 929        let active = Rc::new(Cell::new(platform_window.is_active()));
 930        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
 931        let needs_present = Rc::new(Cell::new(false));
 932        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
 933        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
 934
 935        platform_window
 936            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
 937        platform_window.set_background_appearance(window_background);
 938
 939        if let Some(ref window_open_state) = window_bounds {
 940            match window_open_state {
 941                WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
 942                WindowBounds::Maximized(_) => platform_window.zoom(),
 943                WindowBounds::Windowed(_) => {}
 944            }
 945        }
 946
 947        platform_window.on_close(Box::new({
 948            let mut cx = cx.to_async();
 949            move || {
 950                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
 951            }
 952        }));
 953        platform_window.on_request_frame(Box::new({
 954            let mut cx = cx.to_async();
 955            let invalidator = invalidator.clone();
 956            let active = active.clone();
 957            let needs_present = needs_present.clone();
 958            let next_frame_callbacks = next_frame_callbacks.clone();
 959            let last_input_timestamp = last_input_timestamp.clone();
 960            move |request_frame_options| {
 961                let next_frame_callbacks = next_frame_callbacks.take();
 962                if !next_frame_callbacks.is_empty() {
 963                    handle
 964                        .update(&mut cx, |_, window, cx| {
 965                            for callback in next_frame_callbacks {
 966                                callback(window, cx);
 967                            }
 968                        })
 969                        .log_err();
 970                }
 971
 972                // Keep presenting the current scene for 1 extra second since the
 973                // last input to prevent the display from underclocking the refresh rate.
 974                let needs_present = request_frame_options.require_presentation
 975                    || needs_present.get()
 976                    || (active.get()
 977                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
 978
 979                if invalidator.is_dirty() {
 980                    measure("frame duration", || {
 981                        handle
 982                            .update(&mut cx, |_, window, cx| {
 983                                let arena_clear_needed = window.draw(cx);
 984                                window.present();
 985                                // drop the arena elements after present to reduce latency
 986                                arena_clear_needed.clear();
 987                            })
 988                            .log_err();
 989                    })
 990                } else if needs_present {
 991                    handle
 992                        .update(&mut cx, |_, window, _| window.present())
 993                        .log_err();
 994                }
 995
 996                handle
 997                    .update(&mut cx, |_, window, _| {
 998                        window.complete_frame();
 999                    })
1000                    .log_err();
1001            }
1002        }));
1003        platform_window.on_resize(Box::new({
1004            let mut cx = cx.to_async();
1005            move |_, _| {
1006                handle
1007                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1008                    .log_err();
1009            }
1010        }));
1011        platform_window.on_moved(Box::new({
1012            let mut cx = cx.to_async();
1013            move || {
1014                handle
1015                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1016                    .log_err();
1017            }
1018        }));
1019        platform_window.on_appearance_changed(Box::new({
1020            let mut cx = cx.to_async();
1021            move || {
1022                handle
1023                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1024                    .log_err();
1025            }
1026        }));
1027        platform_window.on_active_status_change(Box::new({
1028            let mut cx = cx.to_async();
1029            move |active| {
1030                handle
1031                    .update(&mut cx, |_, window, cx| {
1032                        window.active.set(active);
1033                        window.modifiers = window.platform_window.modifiers();
1034                        window.capslock = window.platform_window.capslock();
1035                        window
1036                            .activation_observers
1037                            .clone()
1038                            .retain(&(), |callback| callback(window, cx));
1039                        window.refresh();
1040                    })
1041                    .log_err();
1042            }
1043        }));
1044        platform_window.on_hover_status_change(Box::new({
1045            let mut cx = cx.to_async();
1046            move |active| {
1047                handle
1048                    .update(&mut cx, |_, window, _| {
1049                        window.hovered.set(active);
1050                        window.refresh();
1051                    })
1052                    .log_err();
1053            }
1054        }));
1055        platform_window.on_input({
1056            let mut cx = cx.to_async();
1057            Box::new(move |event| {
1058                handle
1059                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1060                    .log_err()
1061                    .unwrap_or(DispatchEventResult::default())
1062            })
1063        });
1064        platform_window.on_hit_test_window_control({
1065            let mut cx = cx.to_async();
1066            Box::new(move || {
1067                handle
1068                    .update(&mut cx, |_, window, _cx| {
1069                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1070                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1071                                return Some(*area);
1072                            }
1073                        }
1074                        None
1075                    })
1076                    .log_err()
1077                    .unwrap_or(None)
1078            })
1079        });
1080
1081        if let Some(app_id) = app_id {
1082            platform_window.set_app_id(&app_id);
1083        }
1084
1085        platform_window.map_window().unwrap();
1086
1087        Ok(Window {
1088            handle,
1089            invalidator,
1090            removed: false,
1091            platform_window,
1092            display_id,
1093            sprite_atlas,
1094            text_system,
1095            rem_size: px(16.),
1096            rem_size_override_stack: SmallVec::new(),
1097            viewport_size: content_size,
1098            layout_engine: Some(TaffyLayoutEngine::new()),
1099            root: None,
1100            element_id_stack: SmallVec::default(),
1101            text_style_stack: Vec::new(),
1102            rendered_entity_stack: Vec::new(),
1103            element_offset_stack: Vec::new(),
1104            content_mask_stack: Vec::new(),
1105            element_opacity: None,
1106            requested_autoscroll: None,
1107            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1108            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1109            next_frame_callbacks,
1110            next_hitbox_id: HitboxId(0),
1111            next_tooltip_id: TooltipId::default(),
1112            tooltip_bounds: None,
1113            dirty_views: FxHashSet::default(),
1114            focus_listeners: SubscriberSet::new(),
1115            focus_lost_listeners: SubscriberSet::new(),
1116            default_prevented: true,
1117            mouse_position,
1118            mouse_hit_test: HitTest::default(),
1119            modifiers,
1120            capslock,
1121            scale_factor,
1122            bounds_observers: SubscriberSet::new(),
1123            appearance,
1124            appearance_observers: SubscriberSet::new(),
1125            active,
1126            hovered,
1127            needs_present,
1128            last_input_timestamp,
1129            refreshing: false,
1130            activation_observers: SubscriberSet::new(),
1131            focus: None,
1132            focus_enabled: true,
1133            pending_input: None,
1134            pending_modifier: ModifierState::default(),
1135            pending_input_observers: SubscriberSet::new(),
1136            prompt: None,
1137            client_inset: None,
1138            image_cache_stack: Vec::new(),
1139            #[cfg(any(feature = "inspector", debug_assertions))]
1140            inspector: None,
1141        })
1142    }
1143
1144    pub(crate) fn new_focus_listener(
1145        &self,
1146        value: AnyWindowFocusListener,
1147    ) -> (Subscription, impl FnOnce() + use<>) {
1148        self.focus_listeners.insert((), value)
1149    }
1150}
1151
1152#[derive(Clone, Debug, Default, PartialEq, Eq)]
1153pub(crate) struct DispatchEventResult {
1154    pub propagate: bool,
1155    pub default_prevented: bool,
1156}
1157
1158/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1159/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1160/// to leave room to support more complex shapes in the future.
1161#[derive(Clone, Debug, Default, PartialEq, Eq)]
1162#[repr(C)]
1163pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1164    /// The bounds
1165    pub bounds: Bounds<P>,
1166}
1167
1168impl ContentMask<Pixels> {
1169    /// Scale the content mask's pixel units by the given scaling factor.
1170    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1171        ContentMask {
1172            bounds: self.bounds.scale(factor),
1173        }
1174    }
1175
1176    /// Intersect the content mask with the given content mask.
1177    pub fn intersect(&self, other: &Self) -> Self {
1178        let bounds = self.bounds.intersect(&other.bounds);
1179        ContentMask { bounds }
1180    }
1181}
1182
1183impl Window {
1184    fn mark_view_dirty(&mut self, view_id: EntityId) {
1185        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1186        // should already be dirty.
1187        for view_id in self
1188            .rendered_frame
1189            .dispatch_tree
1190            .view_path(view_id)
1191            .into_iter()
1192            .rev()
1193        {
1194            if !self.dirty_views.insert(view_id) {
1195                break;
1196            }
1197        }
1198    }
1199
1200    /// Registers a callback to be invoked when the window appearance changes.
1201    pub fn observe_window_appearance(
1202        &self,
1203        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1204    ) -> Subscription {
1205        let (subscription, activate) = self.appearance_observers.insert(
1206            (),
1207            Box::new(move |window, cx| {
1208                callback(window, cx);
1209                true
1210            }),
1211        );
1212        activate();
1213        subscription
1214    }
1215
1216    /// Replaces the root entity of the window with a new one.
1217    pub fn replace_root<E>(
1218        &mut self,
1219        cx: &mut App,
1220        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1221    ) -> Entity<E>
1222    where
1223        E: 'static + Render,
1224    {
1225        let view = cx.new(|cx| build_view(self, cx));
1226        self.root = Some(view.clone().into());
1227        self.refresh();
1228        view
1229    }
1230
1231    /// Returns the root entity of the window, if it has one.
1232    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1233    where
1234        E: 'static + Render,
1235    {
1236        self.root
1237            .as_ref()
1238            .map(|view| view.clone().downcast::<E>().ok())
1239    }
1240
1241    /// Obtain a handle to the window that belongs to this context.
1242    pub fn window_handle(&self) -> AnyWindowHandle {
1243        self.handle
1244    }
1245
1246    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1247    pub fn refresh(&mut self) {
1248        if self.invalidator.not_drawing() {
1249            self.refreshing = true;
1250            self.invalidator.set_dirty(true);
1251        }
1252    }
1253
1254    /// Close this window.
1255    pub fn remove_window(&mut self) {
1256        self.removed = true;
1257    }
1258
1259    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1260    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1261        self.focus
1262            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1263    }
1264
1265    /// Move focus to the element associated with the given [`FocusHandle`].
1266    pub fn focus(&mut self, handle: &FocusHandle) {
1267        if !self.focus_enabled || self.focus == Some(handle.id) {
1268            return;
1269        }
1270
1271        self.focus = Some(handle.id);
1272        self.clear_pending_keystrokes();
1273        self.refresh();
1274    }
1275
1276    /// Remove focus from all elements within this context's window.
1277    pub fn blur(&mut self) {
1278        if !self.focus_enabled {
1279            return;
1280        }
1281
1282        self.focus = None;
1283        self.refresh();
1284    }
1285
1286    /// Blur the window and don't allow anything in it to be focused again.
1287    pub fn disable_focus(&mut self) {
1288        self.blur();
1289        self.focus_enabled = false;
1290    }
1291
1292    /// Accessor for the text system.
1293    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1294        &self.text_system
1295    }
1296
1297    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1298    pub fn text_style(&self) -> TextStyle {
1299        let mut style = TextStyle::default();
1300        for refinement in &self.text_style_stack {
1301            style.refine(refinement);
1302        }
1303        style
1304    }
1305
1306    /// Check if the platform window is maximized
1307    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1308    pub fn is_maximized(&self) -> bool {
1309        self.platform_window.is_maximized()
1310    }
1311
1312    /// request a certain window decoration (Wayland)
1313    pub fn request_decorations(&self, decorations: WindowDecorations) {
1314        self.platform_window.request_decorations(decorations);
1315    }
1316
1317    /// Start a window resize operation (Wayland)
1318    pub fn start_window_resize(&self, edge: ResizeEdge) {
1319        self.platform_window.start_window_resize(edge);
1320    }
1321
1322    /// Return the `WindowBounds` to indicate that how a window should be opened
1323    /// after it has been closed
1324    pub fn window_bounds(&self) -> WindowBounds {
1325        self.platform_window.window_bounds()
1326    }
1327
1328    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1329    pub fn inner_window_bounds(&self) -> WindowBounds {
1330        self.platform_window.inner_window_bounds()
1331    }
1332
1333    /// Dispatch the given action on the currently focused element.
1334    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1335        let focus_id = self.focused(cx).map(|handle| handle.id);
1336        dbg!(&focus_id);
1337        let window = self.handle;
1338        cx.defer(move |cx| {
1339            window
1340                .update(cx, |_, window, cx| {
1341                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1342                    dbg!(&node_id);
1343                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1344                })
1345                .log_err();
1346        })
1347    }
1348
1349    pub(crate) fn dispatch_keystroke_observers(
1350        &mut self,
1351        event: &dyn Any,
1352        action: Option<Box<dyn Action>>,
1353        context_stack: Vec<KeyContext>,
1354        cx: &mut App,
1355    ) {
1356        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1357            return;
1358        };
1359
1360        cx.keystroke_observers.clone().retain(&(), move |callback| {
1361            (callback)(
1362                &KeystrokeEvent {
1363                    keystroke: key_down_event.keystroke.clone(),
1364                    action: action.as_ref().map(|action| action.boxed_clone()),
1365                    context_stack: context_stack.clone(),
1366                },
1367                self,
1368                cx,
1369            )
1370        });
1371    }
1372
1373    pub(crate) fn dispatch_keystroke_interceptors(
1374        &mut self,
1375        event: &dyn Any,
1376        context_stack: Vec<KeyContext>,
1377        cx: &mut App,
1378    ) {
1379        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1380            return;
1381        };
1382
1383        cx.keystroke_interceptors
1384            .clone()
1385            .retain(&(), move |callback| {
1386                (callback)(
1387                    &KeystrokeEvent {
1388                        keystroke: key_down_event.keystroke.clone(),
1389                        action: None,
1390                        context_stack: context_stack.clone(),
1391                    },
1392                    self,
1393                    cx,
1394                )
1395            });
1396    }
1397
1398    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1399    /// that are currently on the stack to be returned to the app.
1400    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1401        let handle = self.handle;
1402        cx.defer(move |cx| {
1403            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1404        });
1405    }
1406
1407    /// Subscribe to events emitted by a entity.
1408    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1409    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1410    pub fn observe<T: 'static>(
1411        &mut self,
1412        observed: &Entity<T>,
1413        cx: &mut App,
1414        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1415    ) -> Subscription {
1416        let entity_id = observed.entity_id();
1417        let observed = observed.downgrade();
1418        let window_handle = self.handle;
1419        cx.new_observer(
1420            entity_id,
1421            Box::new(move |cx| {
1422                window_handle
1423                    .update(cx, |_, window, cx| {
1424                        if let Some(handle) = observed.upgrade() {
1425                            on_notify(handle, window, cx);
1426                            true
1427                        } else {
1428                            false
1429                        }
1430                    })
1431                    .unwrap_or(false)
1432            }),
1433        )
1434    }
1435
1436    /// Subscribe to events emitted by a entity.
1437    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1438    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1439    pub fn subscribe<Emitter, Evt>(
1440        &mut self,
1441        entity: &Entity<Emitter>,
1442        cx: &mut App,
1443        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1444    ) -> Subscription
1445    where
1446        Emitter: EventEmitter<Evt>,
1447        Evt: 'static,
1448    {
1449        let entity_id = entity.entity_id();
1450        let handle = entity.downgrade();
1451        let window_handle = self.handle;
1452        cx.new_subscription(
1453            entity_id,
1454            (
1455                TypeId::of::<Evt>(),
1456                Box::new(move |event, cx| {
1457                    window_handle
1458                        .update(cx, |_, window, cx| {
1459                            if let Some(entity) = handle.upgrade() {
1460                                let event = event.downcast_ref().expect("invalid event type");
1461                                on_event(entity, event, window, cx);
1462                                true
1463                            } else {
1464                                false
1465                            }
1466                        })
1467                        .unwrap_or(false)
1468                }),
1469            ),
1470        )
1471    }
1472
1473    /// Register a callback to be invoked when the given `Entity` is released.
1474    pub fn observe_release<T>(
1475        &self,
1476        entity: &Entity<T>,
1477        cx: &mut App,
1478        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1479    ) -> Subscription
1480    where
1481        T: 'static,
1482    {
1483        let entity_id = entity.entity_id();
1484        let window_handle = self.handle;
1485        let (subscription, activate) = cx.release_listeners.insert(
1486            entity_id,
1487            Box::new(move |entity, cx| {
1488                let entity = entity.downcast_mut().expect("invalid entity type");
1489                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1490            }),
1491        );
1492        activate();
1493        subscription
1494    }
1495
1496    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1497    /// await points in async code.
1498    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1499        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1500    }
1501
1502    /// Schedule the given closure to be run directly after the current frame is rendered.
1503    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1504        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1505    }
1506
1507    /// Schedule a frame to be drawn on the next animation frame.
1508    ///
1509    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1510    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1511    ///
1512    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1513    pub fn request_animation_frame(&self) {
1514        let entity = self.current_view();
1515        self.on_next_frame(move |_, cx| cx.notify(entity));
1516    }
1517
1518    /// Spawn the future returned by the given closure on the application thread pool.
1519    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1520    /// use within your future.
1521    #[track_caller]
1522    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1523    where
1524        R: 'static,
1525        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1526    {
1527        let handle = self.handle;
1528        cx.spawn(async move |app| {
1529            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1530            f(&mut async_window_cx).await
1531        })
1532    }
1533
1534    fn bounds_changed(&mut self, cx: &mut App) {
1535        self.scale_factor = self.platform_window.scale_factor();
1536        self.viewport_size = self.platform_window.content_size();
1537        self.display_id = self.platform_window.display().map(|display| display.id());
1538
1539        self.refresh();
1540
1541        self.bounds_observers
1542            .clone()
1543            .retain(&(), |callback| callback(self, cx));
1544    }
1545
1546    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1547    pub fn bounds(&self) -> Bounds<Pixels> {
1548        self.platform_window.bounds()
1549    }
1550
1551    /// Set the content size of the window.
1552    pub fn resize(&mut self, size: Size<Pixels>) {
1553        self.platform_window.resize(size);
1554    }
1555
1556    /// Returns whether or not the window is currently fullscreen
1557    pub fn is_fullscreen(&self) -> bool {
1558        self.platform_window.is_fullscreen()
1559    }
1560
1561    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1562        self.appearance = self.platform_window.appearance();
1563
1564        self.appearance_observers
1565            .clone()
1566            .retain(&(), |callback| callback(self, cx));
1567    }
1568
1569    /// Returns the appearance of the current window.
1570    pub fn appearance(&self) -> WindowAppearance {
1571        self.appearance
1572    }
1573
1574    /// Returns the size of the drawable area within the window.
1575    pub fn viewport_size(&self) -> Size<Pixels> {
1576        self.viewport_size
1577    }
1578
1579    /// Returns whether this window is focused by the operating system (receiving key events).
1580    pub fn is_window_active(&self) -> bool {
1581        self.active.get()
1582    }
1583
1584    /// Returns whether this window is considered to be the window
1585    /// that currently owns the mouse cursor.
1586    /// On mac, this is equivalent to `is_window_active`.
1587    pub fn is_window_hovered(&self) -> bool {
1588        if cfg!(any(
1589            target_os = "windows",
1590            target_os = "linux",
1591            target_os = "freebsd"
1592        )) {
1593            self.hovered.get()
1594        } else {
1595            self.is_window_active()
1596        }
1597    }
1598
1599    /// Toggle zoom on the window.
1600    pub fn zoom_window(&self) {
1601        self.platform_window.zoom();
1602    }
1603
1604    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1605    pub fn show_window_menu(&self, position: Point<Pixels>) {
1606        self.platform_window.show_window_menu(position)
1607    }
1608
1609    /// Tells the compositor to take control of window movement (Wayland and X11)
1610    ///
1611    /// Events may not be received during a move operation.
1612    pub fn start_window_move(&self) {
1613        self.platform_window.start_window_move()
1614    }
1615
1616    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1617    pub fn set_client_inset(&mut self, inset: Pixels) {
1618        self.client_inset = Some(inset);
1619        self.platform_window.set_client_inset(inset);
1620    }
1621
1622    /// Returns the client_inset value by [`Self::set_client_inset`].
1623    pub fn client_inset(&self) -> Option<Pixels> {
1624        self.client_inset
1625    }
1626
1627    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1628    pub fn window_decorations(&self) -> Decorations {
1629        self.platform_window.window_decorations()
1630    }
1631
1632    /// Returns which window controls are currently visible (Wayland)
1633    pub fn window_controls(&self) -> WindowControls {
1634        self.platform_window.window_controls()
1635    }
1636
1637    /// Updates the window's title at the platform level.
1638    pub fn set_window_title(&mut self, title: &str) {
1639        self.platform_window.set_title(title);
1640    }
1641
1642    /// Sets the application identifier.
1643    pub fn set_app_id(&mut self, app_id: &str) {
1644        self.platform_window.set_app_id(app_id);
1645    }
1646
1647    /// Sets the window background appearance.
1648    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1649        self.platform_window
1650            .set_background_appearance(background_appearance);
1651    }
1652
1653    /// Mark the window as dirty at the platform level.
1654    pub fn set_window_edited(&mut self, edited: bool) {
1655        self.platform_window.set_edited(edited);
1656    }
1657
1658    /// Determine the display on which the window is visible.
1659    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1660        cx.platform
1661            .displays()
1662            .into_iter()
1663            .find(|display| Some(display.id()) == self.display_id)
1664    }
1665
1666    /// Show the platform character palette.
1667    pub fn show_character_palette(&self) {
1668        self.platform_window.show_character_palette();
1669    }
1670
1671    /// The scale factor of the display associated with the window. For example, it could
1672    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1673    /// be rendered as two pixels on screen.
1674    pub fn scale_factor(&self) -> f32 {
1675        self.scale_factor
1676    }
1677
1678    /// The size of an em for the base font of the application. Adjusting this value allows the
1679    /// UI to scale, just like zooming a web page.
1680    pub fn rem_size(&self) -> Pixels {
1681        self.rem_size_override_stack
1682            .last()
1683            .copied()
1684            .unwrap_or(self.rem_size)
1685    }
1686
1687    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1688    /// UI to scale, just like zooming a web page.
1689    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1690        self.rem_size = rem_size.into();
1691    }
1692
1693    /// Acquire a globally unique identifier for the given ElementId.
1694    /// Only valid for the duration of the provided closure.
1695    pub fn with_global_id<R>(
1696        &mut self,
1697        element_id: ElementId,
1698        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1699    ) -> R {
1700        self.element_id_stack.push(element_id);
1701        let global_id = GlobalElementId(self.element_id_stack.clone());
1702        let result = f(&global_id, self);
1703        self.element_id_stack.pop();
1704        result
1705    }
1706
1707    /// Executes the provided function with the specified rem size.
1708    ///
1709    /// This method must only be called as part of element drawing.
1710    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1711    where
1712        F: FnOnce(&mut Self) -> R,
1713    {
1714        self.invalidator.debug_assert_paint_or_prepaint();
1715
1716        if let Some(rem_size) = rem_size {
1717            self.rem_size_override_stack.push(rem_size.into());
1718            let result = f(self);
1719            self.rem_size_override_stack.pop();
1720            result
1721        } else {
1722            f(self)
1723        }
1724    }
1725
1726    /// The line height associated with the current text style.
1727    pub fn line_height(&self) -> Pixels {
1728        self.text_style().line_height_in_pixels(self.rem_size())
1729    }
1730
1731    /// Call to prevent the default action of an event. Currently only used to prevent
1732    /// parent elements from becoming focused on mouse down.
1733    pub fn prevent_default(&mut self) {
1734        self.default_prevented = true;
1735    }
1736
1737    /// Obtain whether default has been prevented for the event currently being dispatched.
1738    pub fn default_prevented(&self) -> bool {
1739        self.default_prevented
1740    }
1741
1742    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1743    pub fn is_action_available(&self, action: &dyn Action, cx: &mut App) -> bool {
1744        let node_id =
1745            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
1746        self.rendered_frame
1747            .dispatch_tree
1748            .is_action_available(action, node_id)
1749    }
1750
1751    /// The position of the mouse relative to the window.
1752    pub fn mouse_position(&self) -> Point<Pixels> {
1753        self.mouse_position
1754    }
1755
1756    /// The current state of the keyboard's modifiers
1757    pub fn modifiers(&self) -> Modifiers {
1758        self.modifiers
1759    }
1760
1761    /// The current state of the keyboard's capslock
1762    pub fn capslock(&self) -> Capslock {
1763        self.capslock
1764    }
1765
1766    fn complete_frame(&self) {
1767        self.platform_window.completed_frame();
1768    }
1769
1770    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1771    /// the contents of the new [Scene], use [present].
1772    #[profiling::function]
1773    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
1774        self.invalidate_entities();
1775        cx.entities.clear_accessed();
1776        debug_assert!(self.rendered_entity_stack.is_empty());
1777        self.invalidator.set_dirty(false);
1778        self.requested_autoscroll = None;
1779
1780        // Restore the previously-used input handler.
1781        if let Some(input_handler) = self.platform_window.take_input_handler() {
1782            self.rendered_frame.input_handlers.push(Some(input_handler));
1783        }
1784        self.draw_roots(cx);
1785        self.dirty_views.clear();
1786        self.next_frame.window_active = self.active.get();
1787
1788        // Register requested input handler with the platform window.
1789        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
1790            self.platform_window
1791                .set_input_handler(input_handler.unwrap());
1792        }
1793
1794        self.layout_engine.as_mut().unwrap().clear();
1795        self.text_system().finish_frame();
1796        self.next_frame.finish(&mut self.rendered_frame);
1797
1798        self.invalidator.set_phase(DrawPhase::Focus);
1799        let previous_focus_path = self.rendered_frame.focus_path();
1800        let previous_window_active = self.rendered_frame.window_active;
1801        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
1802        self.next_frame.clear();
1803        let current_focus_path = self.rendered_frame.focus_path();
1804        let current_window_active = self.rendered_frame.window_active;
1805
1806        if previous_focus_path != current_focus_path
1807            || previous_window_active != current_window_active
1808        {
1809            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1810                self.focus_lost_listeners
1811                    .clone()
1812                    .retain(&(), |listener| listener(self, cx));
1813            }
1814
1815            let event = WindowFocusEvent {
1816                previous_focus_path: if previous_window_active {
1817                    previous_focus_path
1818                } else {
1819                    Default::default()
1820                },
1821                current_focus_path: if current_window_active {
1822                    current_focus_path
1823                } else {
1824                    Default::default()
1825                },
1826            };
1827            self.focus_listeners
1828                .clone()
1829                .retain(&(), |listener| listener(&event, self, cx));
1830        }
1831
1832        debug_assert!(self.rendered_entity_stack.is_empty());
1833        self.record_entities_accessed(cx);
1834        self.reset_cursor_style(cx);
1835        self.refreshing = false;
1836        self.invalidator.set_phase(DrawPhase::None);
1837        self.needs_present.set(true);
1838
1839        ArenaClearNeeded
1840    }
1841
1842    fn record_entities_accessed(&mut self, cx: &mut App) {
1843        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1844        let mut entities = mem::take(entities_ref.deref_mut());
1845        drop(entities_ref);
1846        let handle = self.handle;
1847        cx.record_entities_accessed(
1848            handle,
1849            // Try moving window invalidator into the Window
1850            self.invalidator.clone(),
1851            &entities,
1852        );
1853        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1854        mem::swap(&mut entities, entities_ref.deref_mut());
1855    }
1856
1857    fn invalidate_entities(&mut self) {
1858        let mut views = self.invalidator.take_views();
1859        for entity in views.drain() {
1860            self.mark_view_dirty(entity);
1861        }
1862        self.invalidator.replace_views(views);
1863    }
1864
1865    #[profiling::function]
1866    fn present(&self) {
1867        self.platform_window.draw(&self.rendered_frame.scene);
1868        self.needs_present.set(false);
1869        profiling::finish_frame!();
1870    }
1871
1872    fn draw_roots(&mut self, cx: &mut App) {
1873        self.invalidator.set_phase(DrawPhase::Prepaint);
1874        self.tooltip_bounds.take();
1875
1876        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
1877        let root_size = {
1878            #[cfg(any(feature = "inspector", debug_assertions))]
1879            {
1880                if self.inspector.is_some() {
1881                    let mut size = self.viewport_size;
1882                    size.width = (size.width - _inspector_width).max(px(0.0));
1883                    size
1884                } else {
1885                    self.viewport_size
1886                }
1887            }
1888            #[cfg(not(any(feature = "inspector", debug_assertions)))]
1889            {
1890                self.viewport_size
1891            }
1892        };
1893
1894        // Layout all root elements.
1895        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
1896        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1897
1898        #[cfg(any(feature = "inspector", debug_assertions))]
1899        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
1900
1901        let mut sorted_deferred_draws =
1902            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1903        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
1904        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
1905
1906        let mut prompt_element = None;
1907        let mut active_drag_element = None;
1908        let mut tooltip_element = None;
1909        if let Some(prompt) = self.prompt.take() {
1910            let mut element = prompt.view.any_view().into_any();
1911            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1912            prompt_element = Some(element);
1913            self.prompt = Some(prompt);
1914        } else if let Some(active_drag) = cx.active_drag.take() {
1915            let mut element = active_drag.view.clone().into_any();
1916            let offset = self.mouse_position() - active_drag.cursor_offset;
1917            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
1918            active_drag_element = Some(element);
1919            cx.active_drag = Some(active_drag);
1920        } else {
1921            tooltip_element = self.prepaint_tooltip(cx);
1922        }
1923
1924        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
1925
1926        // Now actually paint the elements.
1927        self.invalidator.set_phase(DrawPhase::Paint);
1928        root_element.paint(self, cx);
1929
1930        #[cfg(any(feature = "inspector", debug_assertions))]
1931        self.paint_inspector(inspector_element, cx);
1932
1933        self.paint_deferred_draws(&sorted_deferred_draws, cx);
1934
1935        if let Some(mut prompt_element) = prompt_element {
1936            prompt_element.paint(self, cx);
1937        } else if let Some(mut drag_element) = active_drag_element {
1938            drag_element.paint(self, cx);
1939        } else if let Some(mut tooltip_element) = tooltip_element {
1940            tooltip_element.paint(self, cx);
1941        }
1942
1943        #[cfg(any(feature = "inspector", debug_assertions))]
1944        self.paint_inspector_hitbox(cx);
1945    }
1946
1947    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
1948        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
1949        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
1950            let Some(Some(tooltip_request)) = self
1951                .next_frame
1952                .tooltip_requests
1953                .get(tooltip_request_index)
1954                .cloned()
1955            else {
1956                log::error!("Unexpectedly absent TooltipRequest");
1957                continue;
1958            };
1959            let mut element = tooltip_request.tooltip.view.clone().into_any();
1960            let mouse_position = tooltip_request.tooltip.mouse_position;
1961            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
1962
1963            let mut tooltip_bounds =
1964                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1965            let window_bounds = Bounds {
1966                origin: Point::default(),
1967                size: self.viewport_size(),
1968            };
1969
1970            if tooltip_bounds.right() > window_bounds.right() {
1971                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1972                if new_x >= Pixels::ZERO {
1973                    tooltip_bounds.origin.x = new_x;
1974                } else {
1975                    tooltip_bounds.origin.x = cmp::max(
1976                        Pixels::ZERO,
1977                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1978                    );
1979                }
1980            }
1981
1982            if tooltip_bounds.bottom() > window_bounds.bottom() {
1983                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1984                if new_y >= Pixels::ZERO {
1985                    tooltip_bounds.origin.y = new_y;
1986                } else {
1987                    tooltip_bounds.origin.y = cmp::max(
1988                        Pixels::ZERO,
1989                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1990                    );
1991                }
1992            }
1993
1994            // It's possible for an element to have an active tooltip while not being painted (e.g.
1995            // via the `visible_on_hover` method). Since mouse listeners are not active in this
1996            // case, instead update the tooltip's visibility here.
1997            let is_visible =
1998                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
1999            if !is_visible {
2000                continue;
2001            }
2002
2003            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2004                element.prepaint(window, cx)
2005            });
2006
2007            self.tooltip_bounds = Some(TooltipBounds {
2008                id: tooltip_request.id,
2009                bounds: tooltip_bounds,
2010            });
2011            return Some(element);
2012        }
2013        None
2014    }
2015
2016    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2017        assert_eq!(self.element_id_stack.len(), 0);
2018
2019        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2020        for deferred_draw_ix in deferred_draw_indices {
2021            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2022            self.element_id_stack
2023                .clone_from(&deferred_draw.element_id_stack);
2024            self.text_style_stack
2025                .clone_from(&deferred_draw.text_style_stack);
2026            self.next_frame
2027                .dispatch_tree
2028                .set_active_node(deferred_draw.parent_node);
2029
2030            let prepaint_start = self.prepaint_index();
2031            if let Some(element) = deferred_draw.element.as_mut() {
2032                self.with_rendered_view(deferred_draw.current_view, |window| {
2033                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
2034                        element.prepaint(window, cx)
2035                    });
2036                })
2037            } else {
2038                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2039            }
2040            let prepaint_end = self.prepaint_index();
2041            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2042        }
2043        assert_eq!(
2044            self.next_frame.deferred_draws.len(),
2045            0,
2046            "cannot call defer_draw during deferred drawing"
2047        );
2048        self.next_frame.deferred_draws = deferred_draws;
2049        self.element_id_stack.clear();
2050        self.text_style_stack.clear();
2051    }
2052
2053    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2054        assert_eq!(self.element_id_stack.len(), 0);
2055
2056        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2057        for deferred_draw_ix in deferred_draw_indices {
2058            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2059            self.element_id_stack
2060                .clone_from(&deferred_draw.element_id_stack);
2061            self.next_frame
2062                .dispatch_tree
2063                .set_active_node(deferred_draw.parent_node);
2064
2065            let paint_start = self.paint_index();
2066            if let Some(element) = deferred_draw.element.as_mut() {
2067                self.with_rendered_view(deferred_draw.current_view, |window| {
2068                    element.paint(window, cx);
2069                })
2070            } else {
2071                self.reuse_paint(deferred_draw.paint_range.clone());
2072            }
2073            let paint_end = self.paint_index();
2074            deferred_draw.paint_range = paint_start..paint_end;
2075        }
2076        self.next_frame.deferred_draws = deferred_draws;
2077        self.element_id_stack.clear();
2078    }
2079
2080    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2081        PrepaintStateIndex {
2082            hitboxes_index: self.next_frame.hitboxes.len(),
2083            tooltips_index: self.next_frame.tooltip_requests.len(),
2084            deferred_draws_index: self.next_frame.deferred_draws.len(),
2085            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2086            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2087            line_layout_index: self.text_system.layout_index(),
2088        }
2089    }
2090
2091    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2092        self.next_frame.hitboxes.extend(
2093            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2094                .iter()
2095                .cloned(),
2096        );
2097        self.next_frame.tooltip_requests.extend(
2098            self.rendered_frame.tooltip_requests
2099                [range.start.tooltips_index..range.end.tooltips_index]
2100                .iter_mut()
2101                .map(|request| request.take()),
2102        );
2103        self.next_frame.accessed_element_states.extend(
2104            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2105                ..range.end.accessed_element_states_index]
2106                .iter()
2107                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2108        );
2109        self.text_system
2110            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2111
2112        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2113            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2114            &mut self.rendered_frame.dispatch_tree,
2115            self.focus,
2116        );
2117
2118        if reused_subtree.contains_focus() {
2119            self.next_frame.focus = self.focus;
2120        }
2121
2122        self.next_frame.deferred_draws.extend(
2123            self.rendered_frame.deferred_draws
2124                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2125                .iter()
2126                .map(|deferred_draw| DeferredDraw {
2127                    current_view: deferred_draw.current_view,
2128                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2129                    element_id_stack: deferred_draw.element_id_stack.clone(),
2130                    text_style_stack: deferred_draw.text_style_stack.clone(),
2131                    priority: deferred_draw.priority,
2132                    element: None,
2133                    absolute_offset: deferred_draw.absolute_offset,
2134                    prepaint_range: deferred_draw.prepaint_range.clone(),
2135                    paint_range: deferred_draw.paint_range.clone(),
2136                }),
2137        );
2138    }
2139
2140    pub(crate) fn paint_index(&self) -> PaintIndex {
2141        PaintIndex {
2142            scene_index: self.next_frame.scene.len(),
2143            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2144            input_handlers_index: self.next_frame.input_handlers.len(),
2145            cursor_styles_index: self.next_frame.cursor_styles.len(),
2146            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2147            line_layout_index: self.text_system.layout_index(),
2148        }
2149    }
2150
2151    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2152        self.next_frame.cursor_styles.extend(
2153            self.rendered_frame.cursor_styles
2154                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2155                .iter()
2156                .cloned(),
2157        );
2158        self.next_frame.input_handlers.extend(
2159            self.rendered_frame.input_handlers
2160                [range.start.input_handlers_index..range.end.input_handlers_index]
2161                .iter_mut()
2162                .map(|handler| handler.take()),
2163        );
2164        self.next_frame.mouse_listeners.extend(
2165            self.rendered_frame.mouse_listeners
2166                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2167                .iter_mut()
2168                .map(|listener| listener.take()),
2169        );
2170        self.next_frame.accessed_element_states.extend(
2171            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2172                ..range.end.accessed_element_states_index]
2173                .iter()
2174                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2175        );
2176
2177        self.text_system
2178            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2179        self.next_frame.scene.replay(
2180            range.start.scene_index..range.end.scene_index,
2181            &self.rendered_frame.scene,
2182        );
2183    }
2184
2185    /// Push a text style onto the stack, and call a function with that style active.
2186    /// Use [`Window::text_style`] to get the current, combined text style. This method
2187    /// should only be called as part of element drawing.
2188    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2189    where
2190        F: FnOnce(&mut Self) -> R,
2191    {
2192        self.invalidator.debug_assert_paint_or_prepaint();
2193        if let Some(style) = style {
2194            self.text_style_stack.push(style);
2195            let result = f(self);
2196            self.text_style_stack.pop();
2197            result
2198        } else {
2199            f(self)
2200        }
2201    }
2202
2203    /// Updates the cursor style at the platform level. This method should only be called
2204    /// during the prepaint phase of element drawing.
2205    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2206        self.invalidator.debug_assert_paint();
2207        self.next_frame.cursor_styles.push(CursorStyleRequest {
2208            hitbox_id: Some(hitbox.id),
2209            style,
2210        });
2211    }
2212
2213    /// Updates the cursor style for the entire window at the platform level. A cursor
2214    /// style using this method will have precedence over any cursor style set using
2215    /// `set_cursor_style`. This method should only be called during the prepaint
2216    /// phase of element drawing.
2217    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2218        self.invalidator.debug_assert_paint();
2219        self.next_frame.cursor_styles.push(CursorStyleRequest {
2220            hitbox_id: None,
2221            style,
2222        })
2223    }
2224
2225    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2226    /// during the paint phase of element drawing.
2227    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2228        self.invalidator.debug_assert_prepaint();
2229        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2230        self.next_frame
2231            .tooltip_requests
2232            .push(Some(TooltipRequest { id, tooltip }));
2233        id
2234    }
2235
2236    /// Invoke the given function with the given content mask after intersecting it
2237    /// with the current mask. This method should only be called during element drawing.
2238    pub fn with_content_mask<R>(
2239        &mut self,
2240        mask: Option<ContentMask<Pixels>>,
2241        f: impl FnOnce(&mut Self) -> R,
2242    ) -> R {
2243        self.invalidator.debug_assert_paint_or_prepaint();
2244        if let Some(mask) = mask {
2245            let mask = mask.intersect(&self.content_mask());
2246            self.content_mask_stack.push(mask);
2247            let result = f(self);
2248            self.content_mask_stack.pop();
2249            result
2250        } else {
2251            f(self)
2252        }
2253    }
2254
2255    /// Updates the global element offset relative to the current offset. This is used to implement
2256    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2257    pub fn with_element_offset<R>(
2258        &mut self,
2259        offset: Point<Pixels>,
2260        f: impl FnOnce(&mut Self) -> R,
2261    ) -> R {
2262        self.invalidator.debug_assert_prepaint();
2263
2264        if offset.is_zero() {
2265            return f(self);
2266        };
2267
2268        let abs_offset = self.element_offset() + offset;
2269        self.with_absolute_element_offset(abs_offset, f)
2270    }
2271
2272    /// Updates the global element offset based on the given offset. This is used to implement
2273    /// drag handles and other manual painting of elements. This method should only be called during
2274    /// the prepaint phase of element drawing.
2275    pub fn with_absolute_element_offset<R>(
2276        &mut self,
2277        offset: Point<Pixels>,
2278        f: impl FnOnce(&mut Self) -> R,
2279    ) -> R {
2280        self.invalidator.debug_assert_prepaint();
2281        self.element_offset_stack.push(offset);
2282        let result = f(self);
2283        self.element_offset_stack.pop();
2284        result
2285    }
2286
2287    pub(crate) fn with_element_opacity<R>(
2288        &mut self,
2289        opacity: Option<f32>,
2290        f: impl FnOnce(&mut Self) -> R,
2291    ) -> R {
2292        if opacity.is_none() {
2293            return f(self);
2294        }
2295
2296        self.invalidator.debug_assert_paint_or_prepaint();
2297        self.element_opacity = opacity;
2298        let result = f(self);
2299        self.element_opacity = None;
2300        result
2301    }
2302
2303    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2304    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2305    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2306    /// element offset and prepaint again. See [`List`] for an example. This method should only be
2307    /// called during the prepaint phase of element drawing.
2308    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2309        self.invalidator.debug_assert_prepaint();
2310        let index = self.prepaint_index();
2311        let result = f(self);
2312        if result.is_err() {
2313            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2314            self.next_frame
2315                .tooltip_requests
2316                .truncate(index.tooltips_index);
2317            self.next_frame
2318                .deferred_draws
2319                .truncate(index.deferred_draws_index);
2320            self.next_frame
2321                .dispatch_tree
2322                .truncate(index.dispatch_tree_index);
2323            self.next_frame
2324                .accessed_element_states
2325                .truncate(index.accessed_element_states_index);
2326            self.text_system.truncate_layouts(index.line_layout_index);
2327        }
2328        result
2329    }
2330
2331    /// When you call this method during [`prepaint`], containing elements will attempt to
2332    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2333    /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
2334    /// that supports this method being called on the elements it contains. This method should only be
2335    /// called during the prepaint phase of element drawing.
2336    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2337        self.invalidator.debug_assert_prepaint();
2338        self.requested_autoscroll = Some(bounds);
2339    }
2340
2341    /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
2342    /// described in [`request_autoscroll`].
2343    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2344        self.invalidator.debug_assert_prepaint();
2345        self.requested_autoscroll.take()
2346    }
2347
2348    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2349    /// Your view will be re-drawn once the asset has finished loading.
2350    ///
2351    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2352    /// time.
2353    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2354        let (task, is_first) = cx.fetch_asset::<A>(source);
2355        task.clone().now_or_never().or_else(|| {
2356            if is_first {
2357                let entity_id = self.current_view();
2358                self.spawn(cx, {
2359                    let task = task.clone();
2360                    async move |cx| {
2361                        task.await;
2362
2363                        cx.on_next_frame(move |_, cx| {
2364                            cx.notify(entity_id);
2365                        });
2366                    }
2367                })
2368                .detach();
2369            }
2370
2371            None
2372        })
2373    }
2374
2375    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2376    /// Your view will not be re-drawn once the asset has finished loading.
2377    ///
2378    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2379    /// time.
2380    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2381        let (task, _) = cx.fetch_asset::<A>(source);
2382        task.clone().now_or_never()
2383    }
2384    /// Obtain the current element offset. This method should only be called during the
2385    /// prepaint phase of element drawing.
2386    pub fn element_offset(&self) -> Point<Pixels> {
2387        self.invalidator.debug_assert_prepaint();
2388        self.element_offset_stack
2389            .last()
2390            .copied()
2391            .unwrap_or_default()
2392    }
2393
2394    /// Obtain the current element opacity. This method should only be called during the
2395    /// prepaint phase of element drawing.
2396    pub(crate) fn element_opacity(&self) -> f32 {
2397        self.invalidator.debug_assert_paint_or_prepaint();
2398        self.element_opacity.unwrap_or(1.0)
2399    }
2400
2401    /// Obtain the current content mask. This method should only be called during element drawing.
2402    pub fn content_mask(&self) -> ContentMask<Pixels> {
2403        self.invalidator.debug_assert_paint_or_prepaint();
2404        self.content_mask_stack
2405            .last()
2406            .cloned()
2407            .unwrap_or_else(|| ContentMask {
2408                bounds: Bounds {
2409                    origin: Point::default(),
2410                    size: self.viewport_size,
2411                },
2412            })
2413    }
2414
2415    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2416    /// This can be used within a custom element to distinguish multiple sets of child elements.
2417    pub fn with_element_namespace<R>(
2418        &mut self,
2419        element_id: impl Into<ElementId>,
2420        f: impl FnOnce(&mut Self) -> R,
2421    ) -> R {
2422        self.element_id_stack.push(element_id.into());
2423        let result = f(self);
2424        self.element_id_stack.pop();
2425        result
2426    }
2427
2428    /// Updates or initializes state for an element with the given id that lives across multiple
2429    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2430    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2431    /// when drawing the next frame. This method should only be called as part of element drawing.
2432    pub fn with_element_state<S, R>(
2433        &mut self,
2434        global_id: &GlobalElementId,
2435        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2436    ) -> R
2437    where
2438        S: 'static,
2439    {
2440        self.invalidator.debug_assert_paint_or_prepaint();
2441
2442        let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2443        self.next_frame
2444            .accessed_element_states
2445            .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2446
2447        if let Some(any) = self
2448            .next_frame
2449            .element_states
2450            .remove(&key)
2451            .or_else(|| self.rendered_frame.element_states.remove(&key))
2452        {
2453            let ElementStateBox {
2454                inner,
2455                #[cfg(debug_assertions)]
2456                type_name,
2457            } = any;
2458            // Using the extra inner option to avoid needing to reallocate a new box.
2459            let mut state_box = inner
2460                .downcast::<Option<S>>()
2461                .map_err(|_| {
2462                    #[cfg(debug_assertions)]
2463                    {
2464                        anyhow::anyhow!(
2465                            "invalid element state type for id, requested {:?}, actual: {:?}",
2466                            std::any::type_name::<S>(),
2467                            type_name
2468                        )
2469                    }
2470
2471                    #[cfg(not(debug_assertions))]
2472                    {
2473                        anyhow::anyhow!(
2474                            "invalid element state type for id, requested {:?}",
2475                            std::any::type_name::<S>(),
2476                        )
2477                    }
2478                })
2479                .unwrap();
2480
2481            let state = state_box.take().expect(
2482                "reentrant call to with_element_state for the same state type and element id",
2483            );
2484            let (result, state) = f(Some(state), self);
2485            state_box.replace(state);
2486            self.next_frame.element_states.insert(
2487                key,
2488                ElementStateBox {
2489                    inner: state_box,
2490                    #[cfg(debug_assertions)]
2491                    type_name,
2492                },
2493            );
2494            result
2495        } else {
2496            let (result, state) = f(None, self);
2497            self.next_frame.element_states.insert(
2498                key,
2499                ElementStateBox {
2500                    inner: Box::new(Some(state)),
2501                    #[cfg(debug_assertions)]
2502                    type_name: std::any::type_name::<S>(),
2503                },
2504            );
2505            result
2506        }
2507    }
2508
2509    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2510    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2511    /// when the element is guaranteed to have an id.
2512    ///
2513    /// The first option means 'no ID provided'
2514    /// The second option means 'not yet initialized'
2515    pub fn with_optional_element_state<S, R>(
2516        &mut self,
2517        global_id: Option<&GlobalElementId>,
2518        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2519    ) -> R
2520    where
2521        S: 'static,
2522    {
2523        self.invalidator.debug_assert_paint_or_prepaint();
2524
2525        if let Some(global_id) = global_id {
2526            self.with_element_state(global_id, |state, cx| {
2527                let (result, state) = f(Some(state), cx);
2528                let state =
2529                    state.expect("you must return some state when you pass some element id");
2530                (result, state)
2531            })
2532        } else {
2533            let (result, state) = f(None, self);
2534            debug_assert!(
2535                state.is_none(),
2536                "you must not return an element state when passing None for the global id"
2537            );
2538            result
2539        }
2540    }
2541
2542    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2543    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2544    /// with higher values being drawn on top.
2545    ///
2546    /// This method should only be called as part of the prepaint phase of element drawing.
2547    pub fn defer_draw(
2548        &mut self,
2549        element: AnyElement,
2550        absolute_offset: Point<Pixels>,
2551        priority: usize,
2552    ) {
2553        self.invalidator.debug_assert_prepaint();
2554        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2555        self.next_frame.deferred_draws.push(DeferredDraw {
2556            current_view: self.current_view(),
2557            parent_node,
2558            element_id_stack: self.element_id_stack.clone(),
2559            text_style_stack: self.text_style_stack.clone(),
2560            priority,
2561            element: Some(element),
2562            absolute_offset,
2563            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2564            paint_range: PaintIndex::default()..PaintIndex::default(),
2565        });
2566    }
2567
2568    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2569    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2570    /// for performance reasons.
2571    ///
2572    /// This method should only be called as part of the paint phase of element drawing.
2573    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2574        self.invalidator.debug_assert_paint();
2575
2576        let scale_factor = self.scale_factor();
2577        let content_mask = self.content_mask();
2578        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2579        if !clipped_bounds.is_empty() {
2580            self.next_frame
2581                .scene
2582                .push_layer(clipped_bounds.scale(scale_factor));
2583        }
2584
2585        let result = f(self);
2586
2587        if !clipped_bounds.is_empty() {
2588            self.next_frame.scene.pop_layer();
2589        }
2590
2591        result
2592    }
2593
2594    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2595    ///
2596    /// This method should only be called as part of the paint phase of element drawing.
2597    pub fn paint_shadows(
2598        &mut self,
2599        bounds: Bounds<Pixels>,
2600        corner_radii: Corners<Pixels>,
2601        shadows: &[BoxShadow],
2602    ) {
2603        self.invalidator.debug_assert_paint();
2604
2605        let scale_factor = self.scale_factor();
2606        let content_mask = self.content_mask();
2607        let opacity = self.element_opacity();
2608        for shadow in shadows {
2609            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2610            self.next_frame.scene.insert_primitive(Shadow {
2611                order: 0,
2612                blur_radius: shadow.blur_radius.scale(scale_factor),
2613                bounds: shadow_bounds.scale(scale_factor),
2614                content_mask: content_mask.scale(scale_factor),
2615                corner_radii: corner_radii.scale(scale_factor),
2616                color: shadow.color.opacity(opacity),
2617            });
2618        }
2619    }
2620
2621    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2622    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2623    /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2624    ///
2625    /// This method should only be called as part of the paint phase of element drawing.
2626    ///
2627    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2628    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2629    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2630    pub fn paint_quad(&mut self, quad: PaintQuad) {
2631        self.invalidator.debug_assert_paint();
2632
2633        let scale_factor = self.scale_factor();
2634        let content_mask = self.content_mask();
2635        let opacity = self.element_opacity();
2636        self.next_frame.scene.insert_primitive(Quad {
2637            order: 0,
2638            bounds: quad.bounds.scale(scale_factor),
2639            content_mask: content_mask.scale(scale_factor),
2640            background: quad.background.opacity(opacity),
2641            border_color: quad.border_color.opacity(opacity),
2642            corner_radii: quad.corner_radii.scale(scale_factor),
2643            border_widths: quad.border_widths.scale(scale_factor),
2644            border_style: quad.border_style,
2645        });
2646    }
2647
2648    /// Paint the given `Path` into the scene for the next frame at the current z-index.
2649    ///
2650    /// This method should only be called as part of the paint phase of element drawing.
2651    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2652        self.invalidator.debug_assert_paint();
2653
2654        let scale_factor = self.scale_factor();
2655        let content_mask = self.content_mask();
2656        let opacity = self.element_opacity();
2657        path.content_mask = content_mask;
2658        let color: Background = color.into();
2659        path.color = color.opacity(opacity);
2660        self.next_frame
2661            .scene
2662            .insert_primitive(path.apply_scale(scale_factor));
2663    }
2664
2665    /// Paint an underline into the scene for the next frame at the current z-index.
2666    ///
2667    /// This method should only be called as part of the paint phase of element drawing.
2668    pub fn paint_underline(
2669        &mut self,
2670        origin: Point<Pixels>,
2671        width: Pixels,
2672        style: &UnderlineStyle,
2673    ) {
2674        self.invalidator.debug_assert_paint();
2675
2676        let scale_factor = self.scale_factor();
2677        let height = if style.wavy {
2678            style.thickness * 3.
2679        } else {
2680            style.thickness
2681        };
2682        let bounds = Bounds {
2683            origin,
2684            size: size(width, height),
2685        };
2686        let content_mask = self.content_mask();
2687        let element_opacity = self.element_opacity();
2688
2689        self.next_frame.scene.insert_primitive(Underline {
2690            order: 0,
2691            pad: 0,
2692            bounds: bounds.scale(scale_factor),
2693            content_mask: content_mask.scale(scale_factor),
2694            color: style.color.unwrap_or_default().opacity(element_opacity),
2695            thickness: style.thickness.scale(scale_factor),
2696            wavy: style.wavy,
2697        });
2698    }
2699
2700    /// Paint a strikethrough into the scene for the next frame at the current z-index.
2701    ///
2702    /// This method should only be called as part of the paint phase of element drawing.
2703    pub fn paint_strikethrough(
2704        &mut self,
2705        origin: Point<Pixels>,
2706        width: Pixels,
2707        style: &StrikethroughStyle,
2708    ) {
2709        self.invalidator.debug_assert_paint();
2710
2711        let scale_factor = self.scale_factor();
2712        let height = style.thickness;
2713        let bounds = Bounds {
2714            origin,
2715            size: size(width, height),
2716        };
2717        let content_mask = self.content_mask();
2718        let opacity = self.element_opacity();
2719
2720        self.next_frame.scene.insert_primitive(Underline {
2721            order: 0,
2722            pad: 0,
2723            bounds: bounds.scale(scale_factor),
2724            content_mask: content_mask.scale(scale_factor),
2725            thickness: style.thickness.scale(scale_factor),
2726            color: style.color.unwrap_or_default().opacity(opacity),
2727            wavy: false,
2728        });
2729    }
2730
2731    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2732    ///
2733    /// The y component of the origin is the baseline of the glyph.
2734    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2735    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2736    /// This method is only useful if you need to paint a single glyph that has already been shaped.
2737    ///
2738    /// This method should only be called as part of the paint phase of element drawing.
2739    pub fn paint_glyph(
2740        &mut self,
2741        origin: Point<Pixels>,
2742        font_id: FontId,
2743        glyph_id: GlyphId,
2744        font_size: Pixels,
2745        color: Hsla,
2746    ) -> Result<()> {
2747        self.invalidator.debug_assert_paint();
2748
2749        let element_opacity = self.element_opacity();
2750        let scale_factor = self.scale_factor();
2751        let glyph_origin = origin.scale(scale_factor);
2752        let subpixel_variant = Point {
2753            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2754            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2755        };
2756        let params = RenderGlyphParams {
2757            font_id,
2758            glyph_id,
2759            font_size,
2760            subpixel_variant,
2761            scale_factor,
2762            is_emoji: false,
2763        };
2764
2765        let raster_bounds = self.text_system().raster_bounds(&params)?;
2766        if !raster_bounds.is_zero() {
2767            let tile = self
2768                .sprite_atlas
2769                .get_or_insert_with(&params.clone().into(), &mut || {
2770                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2771                    Ok(Some((size, Cow::Owned(bytes))))
2772                })?
2773                .expect("Callback above only errors or returns Some");
2774            let bounds = Bounds {
2775                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2776                size: tile.bounds.size.map(Into::into),
2777            };
2778            let content_mask = self.content_mask().scale(scale_factor);
2779            self.next_frame.scene.insert_primitive(MonochromeSprite {
2780                order: 0,
2781                pad: 0,
2782                bounds,
2783                content_mask,
2784                color: color.opacity(element_opacity),
2785                tile,
2786                transformation: TransformationMatrix::unit(),
2787            });
2788        }
2789        Ok(())
2790    }
2791
2792    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2793    ///
2794    /// The y component of the origin is the baseline of the glyph.
2795    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2796    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2797    /// This method is only useful if you need to paint a single emoji that has already been shaped.
2798    ///
2799    /// This method should only be called as part of the paint phase of element drawing.
2800    pub fn paint_emoji(
2801        &mut self,
2802        origin: Point<Pixels>,
2803        font_id: FontId,
2804        glyph_id: GlyphId,
2805        font_size: Pixels,
2806    ) -> Result<()> {
2807        self.invalidator.debug_assert_paint();
2808
2809        let scale_factor = self.scale_factor();
2810        let glyph_origin = origin.scale(scale_factor);
2811        let params = RenderGlyphParams {
2812            font_id,
2813            glyph_id,
2814            font_size,
2815            // We don't render emojis with subpixel variants.
2816            subpixel_variant: Default::default(),
2817            scale_factor,
2818            is_emoji: true,
2819        };
2820
2821        let raster_bounds = self.text_system().raster_bounds(&params)?;
2822        if !raster_bounds.is_zero() {
2823            let tile = self
2824                .sprite_atlas
2825                .get_or_insert_with(&params.clone().into(), &mut || {
2826                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2827                    Ok(Some((size, Cow::Owned(bytes))))
2828                })?
2829                .expect("Callback above only errors or returns Some");
2830
2831            let bounds = Bounds {
2832                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2833                size: tile.bounds.size.map(Into::into),
2834            };
2835            let content_mask = self.content_mask().scale(scale_factor);
2836            let opacity = self.element_opacity();
2837
2838            self.next_frame.scene.insert_primitive(PolychromeSprite {
2839                order: 0,
2840                pad: 0,
2841                grayscale: false,
2842                bounds,
2843                corner_radii: Default::default(),
2844                content_mask,
2845                tile,
2846                opacity,
2847            });
2848        }
2849        Ok(())
2850    }
2851
2852    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2853    ///
2854    /// This method should only be called as part of the paint phase of element drawing.
2855    pub fn paint_svg(
2856        &mut self,
2857        bounds: Bounds<Pixels>,
2858        path: SharedString,
2859        transformation: TransformationMatrix,
2860        color: Hsla,
2861        cx: &App,
2862    ) -> Result<()> {
2863        self.invalidator.debug_assert_paint();
2864
2865        let element_opacity = self.element_opacity();
2866        let scale_factor = self.scale_factor();
2867        let bounds = bounds.scale(scale_factor);
2868        let params = RenderSvgParams {
2869            path,
2870            size: bounds.size.map(|pixels| {
2871                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
2872            }),
2873        };
2874
2875        let Some(tile) =
2876            self.sprite_atlas
2877                .get_or_insert_with(&params.clone().into(), &mut || {
2878                    let Some(bytes) = cx.svg_renderer.render(&params)? else {
2879                        return Ok(None);
2880                    };
2881                    Ok(Some((params.size, Cow::Owned(bytes))))
2882                })?
2883        else {
2884            return Ok(());
2885        };
2886        let content_mask = self.content_mask().scale(scale_factor);
2887
2888        self.next_frame.scene.insert_primitive(MonochromeSprite {
2889            order: 0,
2890            pad: 0,
2891            bounds: bounds
2892                .map_origin(|origin| origin.floor())
2893                .map_size(|size| size.ceil()),
2894            content_mask,
2895            color: color.opacity(element_opacity),
2896            tile,
2897            transformation,
2898        });
2899
2900        Ok(())
2901    }
2902
2903    /// Paint an image into the scene for the next frame at the current z-index.
2904    /// This method will panic if the frame_index is not valid
2905    ///
2906    /// This method should only be called as part of the paint phase of element drawing.
2907    pub fn paint_image(
2908        &mut self,
2909        bounds: Bounds<Pixels>,
2910        corner_radii: Corners<Pixels>,
2911        data: Arc<RenderImage>,
2912        frame_index: usize,
2913        grayscale: bool,
2914    ) -> Result<()> {
2915        self.invalidator.debug_assert_paint();
2916
2917        let scale_factor = self.scale_factor();
2918        let bounds = bounds.scale(scale_factor);
2919        let params = RenderImageParams {
2920            image_id: data.id,
2921            frame_index,
2922        };
2923
2924        let tile = self
2925            .sprite_atlas
2926            .get_or_insert_with(&params.clone().into(), &mut || {
2927                Ok(Some((
2928                    data.size(frame_index),
2929                    Cow::Borrowed(
2930                        data.as_bytes(frame_index)
2931                            .expect("It's the caller's job to pass a valid frame index"),
2932                    ),
2933                )))
2934            })?
2935            .expect("Callback above only returns Some");
2936        let content_mask = self.content_mask().scale(scale_factor);
2937        let corner_radii = corner_radii.scale(scale_factor);
2938        let opacity = self.element_opacity();
2939
2940        self.next_frame.scene.insert_primitive(PolychromeSprite {
2941            order: 0,
2942            pad: 0,
2943            grayscale,
2944            bounds: bounds
2945                .map_origin(|origin| origin.floor())
2946                .map_size(|size| size.ceil()),
2947            content_mask,
2948            corner_radii,
2949            tile,
2950            opacity,
2951        });
2952        Ok(())
2953    }
2954
2955    /// Paint a surface into the scene for the next frame at the current z-index.
2956    ///
2957    /// This method should only be called as part of the paint phase of element drawing.
2958    #[cfg(target_os = "macos")]
2959    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
2960        use crate::PaintSurface;
2961
2962        self.invalidator.debug_assert_paint();
2963
2964        let scale_factor = self.scale_factor();
2965        let bounds = bounds.scale(scale_factor);
2966        let content_mask = self.content_mask().scale(scale_factor);
2967        self.next_frame.scene.insert_primitive(PaintSurface {
2968            order: 0,
2969            bounds,
2970            content_mask,
2971            image_buffer,
2972        });
2973    }
2974
2975    /// Removes an image from the sprite atlas.
2976    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2977        for frame_index in 0..data.frame_count() {
2978            let params = RenderImageParams {
2979                image_id: data.id,
2980                frame_index,
2981            };
2982
2983            self.sprite_atlas.remove(&params.clone().into());
2984        }
2985
2986        Ok(())
2987    }
2988
2989    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2990    /// layout is being requested, along with the layout ids of any children. This method is called during
2991    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2992    ///
2993    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2994    #[must_use]
2995    pub fn request_layout(
2996        &mut self,
2997        style: Style,
2998        children: impl IntoIterator<Item = LayoutId>,
2999        cx: &mut App,
3000    ) -> LayoutId {
3001        self.invalidator.debug_assert_prepaint();
3002
3003        cx.layout_id_buffer.clear();
3004        cx.layout_id_buffer.extend(children);
3005        let rem_size = self.rem_size();
3006
3007        self.layout_engine
3008            .as_mut()
3009            .unwrap()
3010            .request_layout(style, rem_size, &cx.layout_id_buffer)
3011    }
3012
3013    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3014    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3015    /// determine the element's size. One place this is used internally is when measuring text.
3016    ///
3017    /// The given closure is invoked at layout time with the known dimensions and available space and
3018    /// returns a `Size`.
3019    ///
3020    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3021    pub fn request_measured_layout<
3022        F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3023            + 'static,
3024    >(
3025        &mut self,
3026        style: Style,
3027        measure: F,
3028    ) -> LayoutId {
3029        self.invalidator.debug_assert_prepaint();
3030
3031        let rem_size = self.rem_size();
3032        self.layout_engine
3033            .as_mut()
3034            .unwrap()
3035            .request_measured_layout(style, rem_size, measure)
3036    }
3037
3038    /// Compute the layout for the given id within the given available space.
3039    /// This method is called for its side effect, typically by the framework prior to painting.
3040    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3041    ///
3042    /// This method should only be called as part of the prepaint phase of element drawing.
3043    pub fn compute_layout(
3044        &mut self,
3045        layout_id: LayoutId,
3046        available_space: Size<AvailableSpace>,
3047        cx: &mut App,
3048    ) {
3049        self.invalidator.debug_assert_prepaint();
3050
3051        let mut layout_engine = self.layout_engine.take().unwrap();
3052        layout_engine.compute_layout(layout_id, available_space, self, cx);
3053        self.layout_engine = Some(layout_engine);
3054    }
3055
3056    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3057    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3058    ///
3059    /// This method should only be called as part of element drawing.
3060    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3061        self.invalidator.debug_assert_prepaint();
3062
3063        let mut bounds = self
3064            .layout_engine
3065            .as_mut()
3066            .unwrap()
3067            .layout_bounds(layout_id)
3068            .map(Into::into);
3069        bounds.origin += self.element_offset();
3070        bounds
3071    }
3072
3073    /// This method should be called during `prepaint`. You can use
3074    /// the returned [Hitbox] during `paint` or in an event handler
3075    /// to determine whether the inserted hitbox was the topmost.
3076    ///
3077    /// This method should only be called as part of the prepaint phase of element drawing.
3078    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3079        self.invalidator.debug_assert_prepaint();
3080
3081        let content_mask = self.content_mask();
3082        let mut id = self.next_hitbox_id;
3083        self.next_hitbox_id = self.next_hitbox_id.next();
3084        let hitbox = Hitbox {
3085            id,
3086            bounds,
3087            content_mask,
3088            behavior,
3089        };
3090        self.next_frame.hitboxes.push(hitbox.clone());
3091        hitbox
3092    }
3093
3094    /// Set a hitbox which will act as a control area of the platform window.
3095    ///
3096    /// This method should only be called as part of the paint phase of element drawing.
3097    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3098        self.invalidator.debug_assert_paint();
3099        self.next_frame.window_control_hitboxes.push((area, hitbox));
3100    }
3101
3102    /// Sets the key context for the current element. This context will be used to translate
3103    /// keybindings into actions.
3104    ///
3105    /// This method should only be called as part of the paint phase of element drawing.
3106    pub fn set_key_context(&mut self, context: KeyContext) {
3107        self.invalidator.debug_assert_paint();
3108        self.next_frame.dispatch_tree.set_key_context(context);
3109    }
3110
3111    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3112    /// and keyboard event dispatch for the element.
3113    ///
3114    /// This method should only be called as part of the prepaint phase of element drawing.
3115    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3116        self.invalidator.debug_assert_prepaint();
3117        if focus_handle.is_focused(self) {
3118            self.next_frame.focus = Some(focus_handle.id);
3119        }
3120        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3121    }
3122
3123    /// Sets the view id for the current element, which will be used to manage view caching.
3124    ///
3125    /// This method should only be called as part of element prepaint. We plan on removing this
3126    /// method eventually when we solve some issues that require us to construct editor elements
3127    /// directly instead of always using editors via views.
3128    pub fn set_view_id(&mut self, view_id: EntityId) {
3129        self.invalidator.debug_assert_prepaint();
3130        self.next_frame.dispatch_tree.set_view_id(view_id);
3131    }
3132
3133    /// Get the entity ID for the currently rendering view
3134    pub fn current_view(&self) -> EntityId {
3135        self.invalidator.debug_assert_paint_or_prepaint();
3136        self.rendered_entity_stack.last().copied().unwrap()
3137    }
3138
3139    pub(crate) fn with_rendered_view<R>(
3140        &mut self,
3141        id: EntityId,
3142        f: impl FnOnce(&mut Self) -> R,
3143    ) -> R {
3144        self.rendered_entity_stack.push(id);
3145        let result = f(self);
3146        self.rendered_entity_stack.pop();
3147        result
3148    }
3149
3150    /// Executes the provided function with the specified image cache.
3151    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3152    where
3153        F: FnOnce(&mut Self) -> R,
3154    {
3155        if let Some(image_cache) = image_cache {
3156            self.image_cache_stack.push(image_cache);
3157            let result = f(self);
3158            self.image_cache_stack.pop();
3159            result
3160        } else {
3161            f(self)
3162        }
3163    }
3164
3165    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3166    /// platform to receive textual input with proper integration with concerns such
3167    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3168    /// rendered.
3169    ///
3170    /// This method should only be called as part of the paint phase of element drawing.
3171    ///
3172    /// [element_input_handler]: crate::ElementInputHandler
3173    pub fn handle_input(
3174        &mut self,
3175        focus_handle: &FocusHandle,
3176        input_handler: impl InputHandler,
3177        cx: &App,
3178    ) {
3179        self.invalidator.debug_assert_paint();
3180
3181        if focus_handle.is_focused(self) {
3182            let cx = self.to_async(cx);
3183            self.next_frame
3184                .input_handlers
3185                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3186        }
3187    }
3188
3189    /// Register a mouse event listener on the window for the next frame. The type of event
3190    /// is determined by the first parameter of the given listener. When the next frame is rendered
3191    /// the listener will be cleared.
3192    ///
3193    /// This method should only be called as part of the paint phase of element drawing.
3194    pub fn on_mouse_event<Event: MouseEvent>(
3195        &mut self,
3196        mut handler: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3197    ) {
3198        self.invalidator.debug_assert_paint();
3199
3200        self.next_frame.mouse_listeners.push(Some(Box::new(
3201            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3202                if let Some(event) = event.downcast_ref() {
3203                    handler(event, phase, window, cx)
3204                }
3205            },
3206        )));
3207    }
3208
3209    /// Register a key event listener on the window for the next frame. The type of event
3210    /// is determined by the first parameter of the given listener. When the next frame is rendered
3211    /// the listener will be cleared.
3212    ///
3213    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3214    /// a specific need to register a global listener.
3215    ///
3216    /// This method should only be called as part of the paint phase of element drawing.
3217    pub fn on_key_event<Event: KeyEvent>(
3218        &mut self,
3219        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3220    ) {
3221        self.invalidator.debug_assert_paint();
3222
3223        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3224            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3225                if let Some(event) = event.downcast_ref::<Event>() {
3226                    listener(event, phase, window, cx)
3227                }
3228            },
3229        ));
3230    }
3231
3232    /// Register a modifiers changed event listener on the window for the next frame.
3233    ///
3234    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3235    /// a specific need to register a global listener.
3236    ///
3237    /// This method should only be called as part of the paint phase of element drawing.
3238    pub fn on_modifiers_changed(
3239        &mut self,
3240        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3241    ) {
3242        self.invalidator.debug_assert_paint();
3243
3244        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3245            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3246                listener(event, window, cx)
3247            },
3248        ));
3249    }
3250
3251    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3252    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3253    /// Returns a subscription and persists until the subscription is dropped.
3254    pub fn on_focus_in(
3255        &mut self,
3256        handle: &FocusHandle,
3257        cx: &mut App,
3258        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3259    ) -> Subscription {
3260        let focus_id = handle.id;
3261        let (subscription, activate) =
3262            self.new_focus_listener(Box::new(move |event, window, cx| {
3263                if event.is_focus_in(focus_id) {
3264                    listener(window, cx);
3265                }
3266                true
3267            }));
3268        cx.defer(move |_| activate());
3269        subscription
3270    }
3271
3272    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3273    /// Returns a subscription and persists until the subscription is dropped.
3274    pub fn on_focus_out(
3275        &mut self,
3276        handle: &FocusHandle,
3277        cx: &mut App,
3278        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3279    ) -> Subscription {
3280        let focus_id = handle.id;
3281        let (subscription, activate) =
3282            self.new_focus_listener(Box::new(move |event, window, cx| {
3283                if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3284                    if event.is_focus_out(focus_id) {
3285                        let event = FocusOutEvent {
3286                            blurred: WeakFocusHandle {
3287                                id: blurred_id,
3288                                handles: Arc::downgrade(&cx.focus_handles),
3289                            },
3290                        };
3291                        listener(event, window, cx)
3292                    }
3293                }
3294                true
3295            }));
3296        cx.defer(move |_| activate());
3297        subscription
3298    }
3299
3300    fn reset_cursor_style(&self, cx: &mut App) {
3301        // Set the cursor only if we're the active window.
3302        if self.is_window_hovered() {
3303            let style = self
3304                .rendered_frame
3305                .cursor_style(self)
3306                .unwrap_or(CursorStyle::Arrow);
3307            cx.platform.set_cursor_style(style);
3308        }
3309    }
3310
3311    /// Dispatch a given keystroke as though the user had typed it.
3312    /// You can create a keystroke with Keystroke::parse("").
3313    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3314        let keystroke = keystroke.with_simulated_ime();
3315        let result = self.dispatch_event(
3316            PlatformInput::KeyDown(KeyDownEvent {
3317                keystroke: keystroke.clone(),
3318                is_held: false,
3319            }),
3320            cx,
3321        );
3322        if !result.propagate {
3323            return true;
3324        }
3325
3326        if let Some(input) = keystroke.key_char {
3327            if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3328                input_handler.dispatch_input(&input, self, cx);
3329                self.platform_window.set_input_handler(input_handler);
3330                return true;
3331            }
3332        }
3333
3334        false
3335    }
3336
3337    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3338    /// binding for the action (last binding added to the keymap).
3339    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3340        self.highest_precedence_binding_for_action(action)
3341            .map(|binding| {
3342                binding
3343                    .keystrokes()
3344                    .iter()
3345                    .map(ToString::to_string)
3346                    .collect::<Vec<_>>()
3347                    .join(" ")
3348            })
3349            .unwrap_or_else(|| action.name().to_string())
3350    }
3351
3352    /// Dispatch a mouse or keyboard event on the window.
3353    #[profiling::function]
3354    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3355        self.last_input_timestamp.set(Instant::now());
3356        // Handlers may set this to false by calling `stop_propagation`.
3357        cx.propagate_event = true;
3358        // Handlers may set this to true by calling `prevent_default`.
3359        self.default_prevented = false;
3360
3361        let event = match event {
3362            // Track the mouse position with our own state, since accessing the platform
3363            // API for the mouse position can only occur on the main thread.
3364            PlatformInput::MouseMove(mouse_move) => {
3365                self.mouse_position = mouse_move.position;
3366                self.modifiers = mouse_move.modifiers;
3367                PlatformInput::MouseMove(mouse_move)
3368            }
3369            PlatformInput::MouseDown(mouse_down) => {
3370                self.mouse_position = mouse_down.position;
3371                self.modifiers = mouse_down.modifiers;
3372                PlatformInput::MouseDown(mouse_down)
3373            }
3374            PlatformInput::MouseUp(mouse_up) => {
3375                self.mouse_position = mouse_up.position;
3376                self.modifiers = mouse_up.modifiers;
3377                PlatformInput::MouseUp(mouse_up)
3378            }
3379            PlatformInput::MouseExited(mouse_exited) => {
3380                self.modifiers = mouse_exited.modifiers;
3381                PlatformInput::MouseExited(mouse_exited)
3382            }
3383            PlatformInput::ModifiersChanged(modifiers_changed) => {
3384                self.modifiers = modifiers_changed.modifiers;
3385                self.capslock = modifiers_changed.capslock;
3386                PlatformInput::ModifiersChanged(modifiers_changed)
3387            }
3388            PlatformInput::ScrollWheel(scroll_wheel) => {
3389                self.mouse_position = scroll_wheel.position;
3390                self.modifiers = scroll_wheel.modifiers;
3391                PlatformInput::ScrollWheel(scroll_wheel)
3392            }
3393            // Translate dragging and dropping of external files from the operating system
3394            // to internal drag and drop events.
3395            PlatformInput::FileDrop(file_drop) => match file_drop {
3396                FileDropEvent::Entered { position, paths } => {
3397                    self.mouse_position = position;
3398                    if cx.active_drag.is_none() {
3399                        cx.active_drag = Some(AnyDrag {
3400                            value: Arc::new(paths.clone()),
3401                            view: cx.new(|_| paths).into(),
3402                            cursor_offset: position,
3403                            cursor_style: None,
3404                        });
3405                    }
3406                    PlatformInput::MouseMove(MouseMoveEvent {
3407                        position,
3408                        pressed_button: Some(MouseButton::Left),
3409                        modifiers: Modifiers::default(),
3410                    })
3411                }
3412                FileDropEvent::Pending { position } => {
3413                    self.mouse_position = position;
3414                    PlatformInput::MouseMove(MouseMoveEvent {
3415                        position,
3416                        pressed_button: Some(MouseButton::Left),
3417                        modifiers: Modifiers::default(),
3418                    })
3419                }
3420                FileDropEvent::Submit { position } => {
3421                    cx.activate(true);
3422                    self.mouse_position = position;
3423                    PlatformInput::MouseUp(MouseUpEvent {
3424                        button: MouseButton::Left,
3425                        position,
3426                        modifiers: Modifiers::default(),
3427                        click_count: 1,
3428                    })
3429                }
3430                FileDropEvent::Exited => {
3431                    cx.active_drag.take();
3432                    PlatformInput::FileDrop(FileDropEvent::Exited)
3433                }
3434            },
3435            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3436        };
3437
3438        if let Some(any_mouse_event) = event.mouse_event() {
3439            self.dispatch_mouse_event(any_mouse_event, cx);
3440        } else if let Some(any_key_event) = event.keyboard_event() {
3441            self.dispatch_key_event(any_key_event, cx);
3442        }
3443
3444        DispatchEventResult {
3445            propagate: cx.propagate_event,
3446            default_prevented: self.default_prevented,
3447        }
3448    }
3449
3450    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3451        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3452        if hit_test != self.mouse_hit_test {
3453            self.mouse_hit_test = hit_test;
3454            self.reset_cursor_style(cx);
3455        }
3456
3457        #[cfg(any(feature = "inspector", debug_assertions))]
3458        if self.is_inspector_picking(cx) {
3459            self.handle_inspector_mouse_event(event, cx);
3460            // When inspector is picking, all other mouse handling is skipped.
3461            return;
3462        }
3463
3464        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3465
3466        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3467        // special purposes, such as detecting events outside of a given Bounds.
3468        for listener in &mut mouse_listeners {
3469            let listener = listener.as_mut().unwrap();
3470            listener(event, DispatchPhase::Capture, self, cx);
3471            if !cx.propagate_event {
3472                break;
3473            }
3474        }
3475
3476        // Bubble phase, where most normal handlers do their work.
3477        if cx.propagate_event {
3478            for listener in mouse_listeners.iter_mut().rev() {
3479                let listener = listener.as_mut().unwrap();
3480                listener(event, DispatchPhase::Bubble, self, cx);
3481                if !cx.propagate_event {
3482                    break;
3483                }
3484            }
3485        }
3486
3487        self.rendered_frame.mouse_listeners = mouse_listeners;
3488
3489        if cx.has_active_drag() {
3490            if event.is::<MouseMoveEvent>() {
3491                // If this was a mouse move event, redraw the window so that the
3492                // active drag can follow the mouse cursor.
3493                self.refresh();
3494            } else if event.is::<MouseUpEvent>() {
3495                // If this was a mouse up event, cancel the active drag and redraw
3496                // the window.
3497                cx.active_drag = None;
3498                self.refresh();
3499            }
3500        }
3501    }
3502
3503    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3504        if self.invalidator.is_dirty() {
3505            self.draw(cx).clear();
3506        }
3507
3508        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3509        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3510
3511        let mut keystroke: Option<Keystroke> = None;
3512
3513        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3514            if event.modifiers.number_of_modifiers() == 0
3515                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3516                && !self.pending_modifier.saw_keystroke
3517            {
3518                let key = match self.pending_modifier.modifiers {
3519                    modifiers if modifiers.shift => Some("shift"),
3520                    modifiers if modifiers.control => Some("control"),
3521                    modifiers if modifiers.alt => Some("alt"),
3522                    modifiers if modifiers.platform => Some("platform"),
3523                    modifiers if modifiers.function => Some("function"),
3524                    _ => None,
3525                };
3526                if let Some(key) = key {
3527                    keystroke = Some(Keystroke {
3528                        key: key.to_string(),
3529                        key_char: None,
3530                        modifiers: Modifiers::default(),
3531                    });
3532                }
3533            }
3534
3535            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3536                && event.modifiers.number_of_modifiers() == 1
3537            {
3538                self.pending_modifier.saw_keystroke = false
3539            }
3540            self.pending_modifier.modifiers = event.modifiers
3541        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3542            self.pending_modifier.saw_keystroke = true;
3543            keystroke = Some(key_down_event.keystroke.clone());
3544        }
3545
3546        let Some(keystroke) = keystroke else {
3547            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3548            return;
3549        };
3550
3551        cx.propagate_event = true;
3552        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
3553        if !cx.propagate_event {
3554            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3555            return;
3556        }
3557
3558        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3559        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3560            currently_pending = PendingInput::default();
3561        }
3562
3563        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3564            currently_pending.keystrokes,
3565            keystroke,
3566            &dispatch_path,
3567        );
3568
3569        if !match_result.to_replay.is_empty() {
3570            self.replay_pending_input(match_result.to_replay, cx)
3571        }
3572
3573        if !match_result.pending.is_empty() {
3574            currently_pending.keystrokes = match_result.pending;
3575            currently_pending.focus = self.focus;
3576            currently_pending.timer = Some(self.spawn(cx, async move |cx| {
3577                cx.background_executor.timer(Duration::from_secs(1)).await;
3578                cx.update(move |window, cx| {
3579                    let Some(currently_pending) = window
3580                        .pending_input
3581                        .take()
3582                        .filter(|pending| pending.focus == window.focus)
3583                    else {
3584                        return;
3585                    };
3586
3587                    let node_id = window.focus_node_id_in_rendered_frame(window.focus);
3588                    let dispatch_path = window.rendered_frame.dispatch_tree.dispatch_path(node_id);
3589
3590                    let to_replay = window
3591                        .rendered_frame
3592                        .dispatch_tree
3593                        .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3594
3595                    window.pending_input_changed(cx);
3596                    window.replay_pending_input(to_replay, cx)
3597                })
3598                .log_err();
3599            }));
3600            self.pending_input = Some(currently_pending);
3601            self.pending_input_changed(cx);
3602            cx.propagate_event = false;
3603            return;
3604        }
3605
3606        for binding in match_result.bindings {
3607            self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3608            if !cx.propagate_event {
3609                self.dispatch_keystroke_observers(
3610                    event,
3611                    Some(binding.action),
3612                    match_result.context_stack.clone(),
3613                    cx,
3614                );
3615                self.pending_input_changed(cx);
3616                return;
3617            }
3618        }
3619
3620        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
3621        self.pending_input_changed(cx);
3622    }
3623
3624    fn finish_dispatch_key_event(
3625        &mut self,
3626        event: &dyn Any,
3627        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3628        context_stack: Vec<KeyContext>,
3629        cx: &mut App,
3630    ) {
3631        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
3632        if !cx.propagate_event {
3633            return;
3634        }
3635
3636        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
3637        if !cx.propagate_event {
3638            return;
3639        }
3640
3641        self.dispatch_keystroke_observers(event, None, context_stack, cx);
3642    }
3643
3644    fn pending_input_changed(&mut self, cx: &mut App) {
3645        self.pending_input_observers
3646            .clone()
3647            .retain(&(), |callback| callback(self, cx));
3648    }
3649
3650    fn dispatch_key_down_up_event(
3651        &mut self,
3652        event: &dyn Any,
3653        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3654        cx: &mut App,
3655    ) {
3656        // Capture phase
3657        for node_id in dispatch_path {
3658            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3659
3660            for key_listener in node.key_listeners.clone() {
3661                key_listener(event, DispatchPhase::Capture, self, cx);
3662                if !cx.propagate_event {
3663                    return;
3664                }
3665            }
3666        }
3667
3668        // Bubble phase
3669        for node_id in dispatch_path.iter().rev() {
3670            // Handle low level key events
3671            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3672            for key_listener in node.key_listeners.clone() {
3673                key_listener(event, DispatchPhase::Bubble, self, cx);
3674                if !cx.propagate_event {
3675                    return;
3676                }
3677            }
3678        }
3679    }
3680
3681    fn dispatch_modifiers_changed_event(
3682        &mut self,
3683        event: &dyn Any,
3684        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3685        cx: &mut App,
3686    ) {
3687        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3688            return;
3689        };
3690        for node_id in dispatch_path.iter().rev() {
3691            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3692            for listener in node.modifiers_changed_listeners.clone() {
3693                listener(event, self, cx);
3694                if !cx.propagate_event {
3695                    return;
3696                }
3697            }
3698        }
3699    }
3700
3701    /// Determine whether a potential multi-stroke key binding is in progress on this window.
3702    pub fn has_pending_keystrokes(&self) -> bool {
3703        self.pending_input.is_some()
3704    }
3705
3706    pub(crate) fn clear_pending_keystrokes(&mut self) {
3707        self.pending_input.take();
3708    }
3709
3710    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3711    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3712        self.pending_input
3713            .as_ref()
3714            .map(|pending_input| pending_input.keystrokes.as_slice())
3715    }
3716
3717    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
3718        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3719        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3720
3721        'replay: for replay in replays {
3722            let event = KeyDownEvent {
3723                keystroke: replay.keystroke.clone(),
3724                is_held: false,
3725            };
3726
3727            cx.propagate_event = true;
3728            for binding in replay.bindings {
3729                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3730                if !cx.propagate_event {
3731                    self.dispatch_keystroke_observers(
3732                        &event,
3733                        Some(binding.action),
3734                        Vec::default(),
3735                        cx,
3736                    );
3737                    continue 'replay;
3738                }
3739            }
3740
3741            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
3742            if !cx.propagate_event {
3743                continue 'replay;
3744            }
3745            if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3746                if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3747                    input_handler.dispatch_input(&input, self, cx);
3748                    self.platform_window.set_input_handler(input_handler)
3749                }
3750            }
3751        }
3752    }
3753
3754    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
3755        focus_id
3756            .and_then(|focus_id| {
3757                self.rendered_frame
3758                    .dispatch_tree
3759                    .focusable_node_id(focus_id)
3760            })
3761            .unwrap_or_else(|| {
3762                println!("root node id");
3763                self.rendered_frame.dispatch_tree.root_node_id()
3764            })
3765    }
3766
3767    fn dispatch_action_on_node(
3768        &mut self,
3769        node_id: DispatchNodeId,
3770        action: &dyn Action,
3771        cx: &mut App,
3772    ) {
3773        dbg!("dispatch_action_on_node");
3774        dbg!(action.name());
3775        dbg!(action.as_any().type_id());
3776        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3777        dbg!(&dispatch_path);
3778
3779        // Capture phase for global actions.
3780        cx.propagate_event = true;
3781        if let Some(mut global_listeners) = cx
3782            .global_action_listeners
3783            .remove(&action.as_any().type_id())
3784        {
3785            dbg!(
3786                "Found global listeners for capture phase",
3787                global_listeners.len()
3788            );
3789            for listener in &global_listeners {
3790                dbg!("Executing global listener in capture phase");
3791                listener(action.as_any(), DispatchPhase::Capture, cx);
3792                if !cx.propagate_event {
3793                    dbg!("Event propagation stopped in global capture phase");
3794                    break;
3795                }
3796            }
3797
3798            global_listeners.extend(
3799                cx.global_action_listeners
3800                    .remove(&action.as_any().type_id())
3801                    .unwrap_or_default(),
3802            );
3803
3804            cx.global_action_listeners
3805                .insert(action.as_any().type_id(), global_listeners);
3806        }
3807
3808        if !cx.propagate_event {
3809            return;
3810        }
3811
3812        // Capture phase for window actions.
3813        for node_id in &dispatch_path {
3814            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3815            for DispatchActionListener {
3816                action_type,
3817                listener,
3818            } in node.action_listeners.clone()
3819            {
3820                let any_action = action.as_any();
3821                if action_type == any_action.type_id() {
3822                    dbg!("Found window action listener in capture phase", node_id);
3823                    listener(any_action, DispatchPhase::Capture, self, cx);
3824
3825                    if !cx.propagate_event {
3826                        dbg!("Event propagation stopped in window capture phase");
3827                        return;
3828                    }
3829                }
3830            }
3831        }
3832
3833        // Bubble phase for window actions.
3834        for node_id in dispatch_path.iter().rev() {
3835            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3836            for DispatchActionListener {
3837                action_type,
3838                listener,
3839            } in node.action_listeners.clone()
3840            {
3841                let any_action = action.as_any();
3842                if action_type == any_action.type_id() {
3843                    dbg!("Found window action listener in bubble phase", node_id);
3844                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3845                    listener(any_action, DispatchPhase::Bubble, self, cx);
3846
3847                    if !cx.propagate_event {
3848                        dbg!("Event propagation stopped in window bubble phase");
3849                        return;
3850                    }
3851                }
3852            }
3853        }
3854
3855        // Bubble phase for global actions.
3856        if let Some(mut global_listeners) = cx
3857            .global_action_listeners
3858            .remove(&action.as_any().type_id())
3859        {
3860            dbg!(
3861                "Found global listeners for bubble phase",
3862                global_listeners.len()
3863            );
3864            for listener in global_listeners.iter().rev() {
3865                dbg!("Executing global listener in bubble phase");
3866                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3867
3868                listener(action.as_any(), DispatchPhase::Bubble, cx);
3869                if !cx.propagate_event {
3870                    dbg!("Event propagation stopped in global bubble phase");
3871                    break;
3872                }
3873            }
3874
3875            global_listeners.extend(
3876                cx.global_action_listeners
3877                    .remove(&action.as_any().type_id())
3878                    .unwrap_or_default(),
3879            );
3880
3881            cx.global_action_listeners
3882                .insert(action.as_any().type_id(), global_listeners);
3883        }
3884    }
3885
3886    /// Register the given handler to be invoked whenever the global of the given type
3887    /// is updated.
3888    pub fn observe_global<G: Global>(
3889        &mut self,
3890        cx: &mut App,
3891        f: impl Fn(&mut Window, &mut App) + 'static,
3892    ) -> Subscription {
3893        let window_handle = self.handle;
3894        let (subscription, activate) = cx.global_observers.insert(
3895            TypeId::of::<G>(),
3896            Box::new(move |cx| {
3897                window_handle
3898                    .update(cx, |_, window, cx| f(window, cx))
3899                    .is_ok()
3900            }),
3901        );
3902        cx.defer(move |_| activate());
3903        subscription
3904    }
3905
3906    /// Focus the current window and bring it to the foreground at the platform level.
3907    pub fn activate_window(&self) {
3908        self.platform_window.activate();
3909    }
3910
3911    /// Minimize the current window at the platform level.
3912    pub fn minimize_window(&self) {
3913        self.platform_window.minimize();
3914    }
3915
3916    /// Toggle full screen status on the current window at the platform level.
3917    pub fn toggle_fullscreen(&self) {
3918        self.platform_window.toggle_fullscreen();
3919    }
3920
3921    /// Updates the IME panel position suggestions for languages like japanese, chinese.
3922    pub fn invalidate_character_coordinates(&self) {
3923        self.on_next_frame(|window, cx| {
3924            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
3925                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
3926                    window
3927                        .platform_window
3928                        .update_ime_position(bounds.scale(window.scale_factor()));
3929                }
3930                window.platform_window.set_input_handler(input_handler);
3931            }
3932        });
3933    }
3934
3935    /// Present a platform dialog.
3936    /// The provided message will be presented, along with buttons for each answer.
3937    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3938    pub fn prompt<T>(
3939        &mut self,
3940        level: PromptLevel,
3941        message: &str,
3942        detail: Option<&str>,
3943        answers: &[T],
3944        cx: &mut App,
3945    ) -> oneshot::Receiver<usize>
3946    where
3947        T: Clone + Into<PromptButton>,
3948    {
3949        let prompt_builder = cx.prompt_builder.take();
3950        let Some(prompt_builder) = prompt_builder else {
3951            unreachable!("Re-entrant window prompting is not supported by GPUI");
3952        };
3953
3954        let answers = answers
3955            .iter()
3956            .map(|answer| answer.clone().into())
3957            .collect::<Vec<_>>();
3958
3959        let receiver = match &prompt_builder {
3960            PromptBuilder::Default => self
3961                .platform_window
3962                .prompt(level, message, detail, &answers)
3963                .unwrap_or_else(|| {
3964                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3965                }),
3966            PromptBuilder::Custom(_) => {
3967                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3968            }
3969        };
3970
3971        cx.prompt_builder = Some(prompt_builder);
3972
3973        receiver
3974    }
3975
3976    fn build_custom_prompt(
3977        &mut self,
3978        prompt_builder: &PromptBuilder,
3979        level: PromptLevel,
3980        message: &str,
3981        detail: Option<&str>,
3982        answers: &[PromptButton],
3983        cx: &mut App,
3984    ) -> oneshot::Receiver<usize> {
3985        let (sender, receiver) = oneshot::channel();
3986        let handle = PromptHandle::new(sender);
3987        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
3988        self.prompt = Some(handle);
3989        receiver
3990    }
3991
3992    /// Returns the current context stack.
3993    pub fn context_stack(&self) -> Vec<KeyContext> {
3994        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3995        let dispatch_tree = &self.rendered_frame.dispatch_tree;
3996        dispatch_tree
3997            .dispatch_path(node_id)
3998            .iter()
3999            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4000            .collect()
4001    }
4002
4003    /// Returns all available actions for the focused element.
4004    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4005        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4006        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4007        for action_type in cx.global_action_listeners.keys() {
4008            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4009                let action = cx.actions.build_action_type(action_type).ok();
4010                if let Some(action) = action {
4011                    actions.insert(ix, action);
4012                }
4013            }
4014        }
4015        actions
4016    }
4017
4018    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4019    /// returned in the order they were added. For display, the last binding should take precedence.
4020    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4021        self.rendered_frame
4022            .dispatch_tree
4023            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4024    }
4025
4026    /// Returns the highest precedence key binding that invokes an action on the currently focused
4027    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4028    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4029        self.rendered_frame
4030            .dispatch_tree
4031            .highest_precedence_binding_for_action(
4032                action,
4033                &self.rendered_frame.dispatch_tree.context_stack,
4034            )
4035    }
4036
4037    /// Returns the key bindings for an action in a context.
4038    pub fn bindings_for_action_in_context(
4039        &self,
4040        action: &dyn Action,
4041        context: KeyContext,
4042    ) -> Vec<KeyBinding> {
4043        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4044        dispatch_tree.bindings_for_action(action, &[context])
4045    }
4046
4047    /// Returns the highest precedence key binding for an action in a context. This is more
4048    /// efficient than getting the last result of `bindings_for_action_in_context`.
4049    pub fn highest_precedence_binding_for_action_in_context(
4050        &self,
4051        action: &dyn Action,
4052        context: KeyContext,
4053    ) -> Option<KeyBinding> {
4054        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4055        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4056    }
4057
4058    /// Returns any bindings that would invoke an action on the given focus handle if it were
4059    /// focused. Bindings are returned in the order they were added. For display, the last binding
4060    /// should take precedence.
4061    pub fn bindings_for_action_in(
4062        &self,
4063        action: &dyn Action,
4064        focus_handle: &FocusHandle,
4065    ) -> Vec<KeyBinding> {
4066        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4067        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4068            return vec![];
4069        };
4070        dispatch_tree.bindings_for_action(action, &context_stack)
4071    }
4072
4073    /// Returns the highest precedence key binding that would invoke an action on the given focus
4074    /// handle if it were focused. This is more efficient than getting the last result of
4075    /// `bindings_for_action_in`.
4076    pub fn highest_precedence_binding_for_action_in(
4077        &self,
4078        action: &dyn Action,
4079        focus_handle: &FocusHandle,
4080    ) -> Option<KeyBinding> {
4081        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4082        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4083        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4084    }
4085
4086    fn context_stack_for_focus_handle(
4087        &self,
4088        focus_handle: &FocusHandle,
4089    ) -> Option<Vec<KeyContext>> {
4090        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4091        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4092        let context_stack: Vec<_> = dispatch_tree
4093            .dispatch_path(node_id)
4094            .into_iter()
4095            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4096            .collect();
4097        Some(context_stack)
4098    }
4099
4100    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4101    pub fn listener_for<V: Render, E>(
4102        &self,
4103        view: &Entity<V>,
4104        f: impl Fn(&mut V, &E, &mut Window, &mut Context<V>) + 'static,
4105    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4106        let view = view.downgrade();
4107        move |e: &E, window: &mut Window, cx: &mut App| {
4108            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4109        }
4110    }
4111
4112    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4113    pub fn handler_for<V: Render, Callback: Fn(&mut V, &mut Window, &mut Context<V>) + 'static>(
4114        &self,
4115        view: &Entity<V>,
4116        f: Callback,
4117    ) -> impl Fn(&mut Window, &mut App) + use<V, Callback> {
4118        let view = view.downgrade();
4119        move |window: &mut Window, cx: &mut App| {
4120            view.update(cx, |view, cx| f(view, window, cx)).ok();
4121        }
4122    }
4123
4124    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4125    /// If the callback returns false, the window won't be closed.
4126    pub fn on_window_should_close(
4127        &self,
4128        cx: &App,
4129        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4130    ) {
4131        let mut cx = self.to_async(cx);
4132        self.platform_window.on_should_close(Box::new(move || {
4133            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4134        }))
4135    }
4136
4137    /// Register an action listener on the window for the next frame. The type of action
4138    /// is determined by the first parameter of the given listener. When the next frame is rendered
4139    /// the listener will be cleared.
4140    ///
4141    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4142    /// a specific need to register a global listener.
4143    pub fn on_action(
4144        &mut self,
4145        action_type: TypeId,
4146        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4147    ) {
4148        self.next_frame
4149            .dispatch_tree
4150            .on_action(action_type, Rc::new(listener));
4151    }
4152
4153    /// Read information about the GPU backing this window.
4154    /// Currently returns None on Mac and Windows.
4155    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4156        self.platform_window.gpu_specs()
4157    }
4158
4159    /// Perform titlebar double-click action.
4160    /// This is MacOS specific.
4161    pub fn titlebar_double_click(&self) {
4162        self.platform_window.titlebar_double_click();
4163    }
4164
4165    /// Toggles the inspector mode on this window.
4166    #[cfg(any(feature = "inspector", debug_assertions))]
4167    pub fn toggle_inspector(&mut self, cx: &mut App) {
4168        self.inspector = match self.inspector {
4169            None => Some(cx.new(|_| Inspector::new())),
4170            Some(_) => None,
4171        };
4172        self.refresh();
4173    }
4174
4175    /// Returns true if the window is in inspector mode.
4176    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4177        #[cfg(any(feature = "inspector", debug_assertions))]
4178        {
4179            if let Some(inspector) = &self.inspector {
4180                return inspector.read(_cx).is_picking();
4181            }
4182        }
4183        false
4184    }
4185
4186    /// Executes the provided function with mutable access to an inspector state.
4187    #[cfg(any(feature = "inspector", debug_assertions))]
4188    pub fn with_inspector_state<T: 'static, R>(
4189        &mut self,
4190        _inspector_id: Option<&crate::InspectorElementId>,
4191        cx: &mut App,
4192        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4193    ) -> R {
4194        if let Some(inspector_id) = _inspector_id {
4195            if let Some(inspector) = &self.inspector {
4196                let inspector = inspector.clone();
4197                let active_element_id = inspector.read(cx).active_element_id();
4198                if Some(inspector_id) == active_element_id {
4199                    return inspector.update(cx, |inspector, _cx| {
4200                        inspector.with_active_element_state(self, f)
4201                    });
4202                }
4203            }
4204        }
4205        f(&mut None, self)
4206    }
4207
4208    #[cfg(any(feature = "inspector", debug_assertions))]
4209    pub(crate) fn build_inspector_element_id(
4210        &mut self,
4211        path: crate::InspectorElementPath,
4212    ) -> crate::InspectorElementId {
4213        self.invalidator.debug_assert_paint_or_prepaint();
4214        let path = Rc::new(path);
4215        let next_instance_id = self
4216            .next_frame
4217            .next_inspector_instance_ids
4218            .entry(path.clone())
4219            .or_insert(0);
4220        let instance_id = *next_instance_id;
4221        *next_instance_id += 1;
4222        crate::InspectorElementId { path, instance_id }
4223    }
4224
4225    #[cfg(any(feature = "inspector", debug_assertions))]
4226    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4227        if let Some(inspector) = self.inspector.take() {
4228            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4229            inspector_element.prepaint_as_root(
4230                point(self.viewport_size.width - inspector_width, px(0.0)),
4231                size(inspector_width, self.viewport_size.height).into(),
4232                self,
4233                cx,
4234            );
4235            self.inspector = Some(inspector);
4236            Some(inspector_element)
4237        } else {
4238            None
4239        }
4240    }
4241
4242    #[cfg(any(feature = "inspector", debug_assertions))]
4243    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4244        if let Some(mut inspector_element) = inspector_element {
4245            inspector_element.paint(self, cx);
4246        };
4247    }
4248
4249    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4250    /// inspect UI elements by clicking on them.
4251    #[cfg(any(feature = "inspector", debug_assertions))]
4252    pub fn insert_inspector_hitbox(
4253        &mut self,
4254        hitbox_id: HitboxId,
4255        inspector_id: Option<&crate::InspectorElementId>,
4256        cx: &App,
4257    ) {
4258        self.invalidator.debug_assert_paint_or_prepaint();
4259        if !self.is_inspector_picking(cx) {
4260            return;
4261        }
4262        if let Some(inspector_id) = inspector_id {
4263            self.next_frame
4264                .inspector_hitboxes
4265                .insert(hitbox_id, inspector_id.clone());
4266        }
4267    }
4268
4269    #[cfg(any(feature = "inspector", debug_assertions))]
4270    fn paint_inspector_hitbox(&mut self, cx: &App) {
4271        if let Some(inspector) = self.inspector.as_ref() {
4272            let inspector = inspector.read(cx);
4273            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4274            {
4275                if let Some(hitbox) = self
4276                    .next_frame
4277                    .hitboxes
4278                    .iter()
4279                    .find(|hitbox| hitbox.id == hitbox_id)
4280                {
4281                    self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4282                }
4283            }
4284        }
4285    }
4286
4287    #[cfg(any(feature = "inspector", debug_assertions))]
4288    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4289        let Some(inspector) = self.inspector.clone() else {
4290            return;
4291        };
4292        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4293            inspector.update(cx, |inspector, _cx| {
4294                if let Some((_, inspector_id)) =
4295                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4296                {
4297                    inspector.hover(inspector_id, self);
4298                }
4299            });
4300        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4301            inspector.update(cx, |inspector, _cx| {
4302                if let Some((_, inspector_id)) =
4303                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4304                {
4305                    inspector.select(inspector_id, self);
4306                }
4307            });
4308        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4309            // This should be kept in sync with SCROLL_LINES in x11 platform.
4310            const SCROLL_LINES: f32 = 3.0;
4311            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4312            let delta_y = event
4313                .delta
4314                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4315                .y;
4316            if let Some(inspector) = self.inspector.clone() {
4317                inspector.update(cx, |inspector, _cx| {
4318                    if let Some(depth) = inspector.pick_depth.as_mut() {
4319                        *depth += delta_y.0 / SCROLL_PIXELS_PER_LAYER;
4320                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4321                        if *depth < 0.0 {
4322                            *depth = 0.0;
4323                        } else if *depth > max_depth {
4324                            *depth = max_depth;
4325                        }
4326                        if let Some((_, inspector_id)) =
4327                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4328                        {
4329                            inspector.set_active_element_id(inspector_id.clone(), self);
4330                        }
4331                    }
4332                });
4333            }
4334        }
4335    }
4336
4337    #[cfg(any(feature = "inspector", debug_assertions))]
4338    fn hovered_inspector_hitbox(
4339        &self,
4340        inspector: &Inspector,
4341        frame: &Frame,
4342    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4343        if let Some(pick_depth) = inspector.pick_depth {
4344            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4345            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4346            let skip_count = (depth as usize).min(max_skipped);
4347            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4348                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4349                    return Some((*hitbox_id, inspector_id.clone()));
4350                }
4351            }
4352        }
4353        return None;
4354    }
4355}
4356
4357// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4358slotmap::new_key_type! {
4359    /// A unique identifier for a window.
4360    pub struct WindowId;
4361}
4362
4363impl WindowId {
4364    /// Converts this window ID to a `u64`.
4365    pub fn as_u64(&self) -> u64 {
4366        self.0.as_ffi()
4367    }
4368}
4369
4370impl From<u64> for WindowId {
4371    fn from(value: u64) -> Self {
4372        WindowId(slotmap::KeyData::from_ffi(value))
4373    }
4374}
4375
4376/// A handle to a window with a specific root view type.
4377/// Note that this does not keep the window alive on its own.
4378#[derive(Deref, DerefMut)]
4379pub struct WindowHandle<V> {
4380    #[deref]
4381    #[deref_mut]
4382    pub(crate) any_handle: AnyWindowHandle,
4383    state_type: PhantomData<V>,
4384}
4385
4386impl<V: 'static + Render> WindowHandle<V> {
4387    /// Creates a new handle from a window ID.
4388    /// This does not check if the root type of the window is `V`.
4389    pub fn new(id: WindowId) -> Self {
4390        WindowHandle {
4391            any_handle: AnyWindowHandle {
4392                id,
4393                state_type: TypeId::of::<V>(),
4394            },
4395            state_type: PhantomData,
4396        }
4397    }
4398
4399    /// Get the root view out of this window.
4400    ///
4401    /// This will fail if the window is closed or if the root view's type does not match `V`.
4402    #[cfg(any(test, feature = "test-support"))]
4403    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
4404    where
4405        C: AppContext,
4406    {
4407        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
4408            root_view
4409                .downcast::<V>()
4410                .map_err(|_| anyhow!("the type of the window's root view has changed"))
4411        }))
4412    }
4413
4414    /// Updates the root view of this window.
4415    ///
4416    /// This will fail if the window has been closed or if the root view's type does not match
4417    pub fn update<C, R>(
4418        &self,
4419        cx: &mut C,
4420        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
4421    ) -> Result<R>
4422    where
4423        C: AppContext,
4424    {
4425        cx.update_window(self.any_handle, |root_view, window, cx| {
4426            let view = root_view
4427                .downcast::<V>()
4428                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4429
4430            Ok(view.update(cx, |view, cx| update(view, window, cx)))
4431        })?
4432    }
4433
4434    /// Read the root view out of this window.
4435    ///
4436    /// This will fail if the window is closed or if the root view's type does not match `V`.
4437    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
4438        let x = cx
4439            .windows
4440            .get(self.id)
4441            .and_then(|window| {
4442                window
4443                    .as_ref()
4444                    .and_then(|window| window.root.clone())
4445                    .map(|root_view| root_view.downcast::<V>())
4446            })
4447            .context("window not found")?
4448            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4449
4450        Ok(x.read(cx))
4451    }
4452
4453    /// Read the root view out of this window, with a callback
4454    ///
4455    /// This will fail if the window is closed or if the root view's type does not match `V`.
4456    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
4457    where
4458        C: AppContext,
4459    {
4460        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4461    }
4462
4463    /// Read the root view pointer off of this window.
4464    ///
4465    /// This will fail if the window is closed or if the root view's type does not match `V`.
4466    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
4467    where
4468        C: AppContext,
4469    {
4470        cx.read_window(self, |root_view, _cx| root_view.clone())
4471    }
4472
4473    /// Check if this window is 'active'.
4474    ///
4475    /// Will return `None` if the window is closed or currently
4476    /// borrowed.
4477    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
4478        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
4479            .ok()
4480    }
4481}
4482
4483impl<V> Copy for WindowHandle<V> {}
4484
4485impl<V> Clone for WindowHandle<V> {
4486    fn clone(&self) -> Self {
4487        *self
4488    }
4489}
4490
4491impl<V> PartialEq for WindowHandle<V> {
4492    fn eq(&self, other: &Self) -> bool {
4493        self.any_handle == other.any_handle
4494    }
4495}
4496
4497impl<V> Eq for WindowHandle<V> {}
4498
4499impl<V> Hash for WindowHandle<V> {
4500    fn hash<H: Hasher>(&self, state: &mut H) {
4501        self.any_handle.hash(state);
4502    }
4503}
4504
4505impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4506    fn from(val: WindowHandle<V>) -> Self {
4507        val.any_handle
4508    }
4509}
4510
4511unsafe impl<V> Send for WindowHandle<V> {}
4512unsafe impl<V> Sync for WindowHandle<V> {}
4513
4514/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4515#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4516pub struct AnyWindowHandle {
4517    pub(crate) id: WindowId,
4518    state_type: TypeId,
4519}
4520
4521impl AnyWindowHandle {
4522    /// Get the ID of this window.
4523    pub fn window_id(&self) -> WindowId {
4524        self.id
4525    }
4526
4527    /// Attempt to convert this handle to a window handle with a specific root view type.
4528    /// If the types do not match, this will return `None`.
4529    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4530        if TypeId::of::<T>() == self.state_type {
4531            Some(WindowHandle {
4532                any_handle: *self,
4533                state_type: PhantomData,
4534            })
4535        } else {
4536            None
4537        }
4538    }
4539
4540    /// Updates the state of the root view of this window.
4541    ///
4542    /// This will fail if the window has been closed.
4543    pub fn update<C, R>(
4544        self,
4545        cx: &mut C,
4546        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
4547    ) -> Result<R>
4548    where
4549        C: AppContext,
4550    {
4551        cx.update_window(self, update)
4552    }
4553
4554    /// Read the state of the root view of this window.
4555    ///
4556    /// This will fail if the window has been closed.
4557    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
4558    where
4559        C: AppContext,
4560        T: 'static,
4561    {
4562        let view = self
4563            .downcast::<T>()
4564            .context("the type of the window's root view has changed")?;
4565
4566        cx.read_window(&view, read)
4567    }
4568}
4569
4570impl HasWindowHandle for Window {
4571    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
4572        self.platform_window.window_handle()
4573    }
4574}
4575
4576impl HasDisplayHandle for Window {
4577    fn display_handle(
4578        &self,
4579    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
4580        self.platform_window.display_handle()
4581    }
4582}
4583
4584/// An identifier for an [`Element`](crate::Element).
4585///
4586/// Can be constructed with a string, a number, or both, as well
4587/// as other internal representations.
4588#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4589pub enum ElementId {
4590    /// The ID of a View element
4591    View(EntityId),
4592    /// An integer ID.
4593    Integer(u64),
4594    /// A string based ID.
4595    Name(SharedString),
4596    /// A UUID.
4597    Uuid(Uuid),
4598    /// An ID that's equated with a focus handle.
4599    FocusHandle(FocusId),
4600    /// A combination of a name and an integer.
4601    NamedInteger(SharedString, u64),
4602    /// A path.
4603    Path(Arc<std::path::Path>),
4604}
4605
4606impl ElementId {
4607    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
4608    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
4609        Self::NamedInteger(name.into(), integer as u64)
4610    }
4611}
4612
4613impl Display for ElementId {
4614    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4615        match self {
4616            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4617            ElementId::Integer(ix) => write!(f, "{}", ix)?,
4618            ElementId::Name(name) => write!(f, "{}", name)?,
4619            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4620            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4621            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4622            ElementId::Path(path) => write!(f, "{}", path.display())?,
4623        }
4624
4625        Ok(())
4626    }
4627}
4628
4629impl TryInto<SharedString> for ElementId {
4630    type Error = anyhow::Error;
4631
4632    fn try_into(self) -> anyhow::Result<SharedString> {
4633        if let ElementId::Name(name) = self {
4634            Ok(name)
4635        } else {
4636            anyhow::bail!("element id is not string")
4637        }
4638    }
4639}
4640
4641impl From<usize> for ElementId {
4642    fn from(id: usize) -> Self {
4643        ElementId::Integer(id as u64)
4644    }
4645}
4646
4647impl From<i32> for ElementId {
4648    fn from(id: i32) -> Self {
4649        Self::Integer(id as u64)
4650    }
4651}
4652
4653impl From<SharedString> for ElementId {
4654    fn from(name: SharedString) -> Self {
4655        ElementId::Name(name)
4656    }
4657}
4658
4659impl From<Arc<std::path::Path>> for ElementId {
4660    fn from(path: Arc<std::path::Path>) -> Self {
4661        ElementId::Path(path)
4662    }
4663}
4664
4665impl From<&'static str> for ElementId {
4666    fn from(name: &'static str) -> Self {
4667        ElementId::Name(name.into())
4668    }
4669}
4670
4671impl<'a> From<&'a FocusHandle> for ElementId {
4672    fn from(handle: &'a FocusHandle) -> Self {
4673        ElementId::FocusHandle(handle.id)
4674    }
4675}
4676
4677impl From<(&'static str, EntityId)> for ElementId {
4678    fn from((name, id): (&'static str, EntityId)) -> Self {
4679        ElementId::NamedInteger(name.into(), id.as_u64())
4680    }
4681}
4682
4683impl From<(&'static str, usize)> for ElementId {
4684    fn from((name, id): (&'static str, usize)) -> Self {
4685        ElementId::NamedInteger(name.into(), id as u64)
4686    }
4687}
4688
4689impl From<(SharedString, usize)> for ElementId {
4690    fn from((name, id): (SharedString, usize)) -> Self {
4691        ElementId::NamedInteger(name, id as u64)
4692    }
4693}
4694
4695impl From<(&'static str, u64)> for ElementId {
4696    fn from((name, id): (&'static str, u64)) -> Self {
4697        ElementId::NamedInteger(name.into(), id)
4698    }
4699}
4700
4701impl From<Uuid> for ElementId {
4702    fn from(value: Uuid) -> Self {
4703        Self::Uuid(value)
4704    }
4705}
4706
4707impl From<(&'static str, u32)> for ElementId {
4708    fn from((name, id): (&'static str, u32)) -> Self {
4709        ElementId::NamedInteger(name.into(), id.into())
4710    }
4711}
4712
4713/// A rectangle to be rendered in the window at the given position and size.
4714/// Passed as an argument [`Window::paint_quad`].
4715#[derive(Clone)]
4716pub struct PaintQuad {
4717    /// The bounds of the quad within the window.
4718    pub bounds: Bounds<Pixels>,
4719    /// The radii of the quad's corners.
4720    pub corner_radii: Corners<Pixels>,
4721    /// The background color of the quad.
4722    pub background: Background,
4723    /// The widths of the quad's borders.
4724    pub border_widths: Edges<Pixels>,
4725    /// The color of the quad's borders.
4726    pub border_color: Hsla,
4727    /// The style of the quad's borders.
4728    pub border_style: BorderStyle,
4729}
4730
4731impl PaintQuad {
4732    /// Sets the corner radii of the quad.
4733    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4734        PaintQuad {
4735            corner_radii: corner_radii.into(),
4736            ..self
4737        }
4738    }
4739
4740    /// Sets the border widths of the quad.
4741    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
4742        PaintQuad {
4743            border_widths: border_widths.into(),
4744            ..self
4745        }
4746    }
4747
4748    /// Sets the border color of the quad.
4749    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
4750        PaintQuad {
4751            border_color: border_color.into(),
4752            ..self
4753        }
4754    }
4755
4756    /// Sets the background color of the quad.
4757    pub fn background(self, background: impl Into<Background>) -> Self {
4758        PaintQuad {
4759            background: background.into(),
4760            ..self
4761        }
4762    }
4763}
4764
4765/// Creates a quad with the given parameters.
4766pub fn quad(
4767    bounds: Bounds<Pixels>,
4768    corner_radii: impl Into<Corners<Pixels>>,
4769    background: impl Into<Background>,
4770    border_widths: impl Into<Edges<Pixels>>,
4771    border_color: impl Into<Hsla>,
4772    border_style: BorderStyle,
4773) -> PaintQuad {
4774    PaintQuad {
4775        bounds,
4776        corner_radii: corner_radii.into(),
4777        background: background.into(),
4778        border_widths: border_widths.into(),
4779        border_color: border_color.into(),
4780        border_style,
4781    }
4782}
4783
4784/// Creates a filled quad with the given bounds and background color.
4785pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
4786    PaintQuad {
4787        bounds: bounds.into(),
4788        corner_radii: (0.).into(),
4789        background: background.into(),
4790        border_widths: (0.).into(),
4791        border_color: transparent_black(),
4792        border_style: BorderStyle::default(),
4793    }
4794}
4795
4796/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
4797pub fn outline(
4798    bounds: impl Into<Bounds<Pixels>>,
4799    border_color: impl Into<Hsla>,
4800    border_style: BorderStyle,
4801) -> PaintQuad {
4802    PaintQuad {
4803        bounds: bounds.into(),
4804        corner_radii: (0.).into(),
4805        background: transparent_black().into(),
4806        border_widths: (1.).into(),
4807        border_color: border_color.into(),
4808        border_style,
4809    }
4810}