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