window.rs

   1#[cfg(any(feature = "inspector", debug_assertions))]
   2use crate::Inspector;
   3use crate::{
   4    Action, AnyDrag, AnyElement, AnyImageCache, AnyTooltip, AnyView, App, AppContext, Arena, Asset,
   5    AsyncWindowContext, AvailableSpace, Background, BorderStyle, Bounds, BoxShadow, Capslock,
   6    Context, Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener,
   7    DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
   8    FileDropEvent, FontId, Global, GlobalElementId, GlyphId, GpuSpecs, Hsla, InputHandler, IsZero,
   9    KeyBinding, KeyContext, KeyDownEvent, KeyEvent, Keystroke, KeystrokeEvent, LayoutId,
  10    LineLayoutIndex, Modifiers, ModifiersChangedEvent, MonochromeSprite, MouseButton, MouseEvent,
  11    MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
  12    PlatformInputHandler, PlatformWindow, Point, PolychromeSprite, PromptButton, PromptLevel, Quad,
  13    Render, RenderGlyphParams, RenderImage, RenderImageParams, RenderSvgParams, Replay, ResizeEdge,
  14    SMOOTH_SVG_SCALE_FACTOR, SUBPIXEL_VARIANTS, ScaledPixels, Scene, Shadow, SharedString, Size,
  15    StrikethroughStyle, Style, SubscriberSet, Subscription, TaffyLayoutEngine, Task, TextStyle,
  16    TextStyleRefinement, TransformationMatrix, Underline, UnderlineStyle, WindowAppearance,
  17    WindowBackgroundAppearance, WindowBounds, WindowControls, WindowDecorations, WindowOptions,
  18    WindowParams, WindowTextSystem, point, prelude::*, px, rems, size, transparent_black,
  19};
  20use anyhow::{Context as _, Result, anyhow};
  21use collections::{FxHashMap, FxHashSet};
  22#[cfg(target_os = "macos")]
  23use core_video::pixel_buffer::CVPixelBuffer;
  24use derive_more::{Deref, DerefMut};
  25use futures::FutureExt;
  26use futures::channel::oneshot;
  27use itertools::FoldWhile::{Continue, Done};
  28use itertools::Itertools;
  29use parking_lot::RwLock;
  30use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
  31use refineable::Refineable;
  32use slotmap::SlotMap;
  33use smallvec::SmallVec;
  34use std::{
  35    any::{Any, TypeId},
  36    borrow::Cow,
  37    cell::{Cell, RefCell},
  38    cmp,
  39    fmt::{Debug, Display},
  40    hash::{Hash, Hasher},
  41    marker::PhantomData,
  42    mem,
  43    ops::{DerefMut, Range},
  44    rc::Rc,
  45    sync::{
  46        Arc, Weak,
  47        atomic::{AtomicUsize, Ordering::SeqCst},
  48    },
  49    time::{Duration, Instant},
  50};
  51use util::post_inc;
  52use util::{ResultExt, measure};
  53use uuid::Uuid;
  54
  55mod prompts;
  56
  57use crate::util::atomic_incr_if_not_zero;
  58pub use prompts::*;
  59
  60pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1024.), px(700.));
  61
  62/// Represents the two different phases when dispatching events.
  63#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  64pub enum DispatchPhase {
  65    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  66    /// invoked front to back and keyboard event listeners are invoked from the focused element
  67    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  68    /// registering event listeners.
  69    #[default]
  70    Bubble,
  71    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  72    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  73    /// is used for special purposes such as clearing the "pressed" state for click events. If
  74    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  75    /// outside of the immediate region may rely on detecting non-local events during this phase.
  76    Capture,
  77}
  78
  79impl DispatchPhase {
  80    /// Returns true if this represents the "bubble" phase.
  81    pub fn bubble(self) -> bool {
  82        self == DispatchPhase::Bubble
  83    }
  84
  85    /// Returns true if this represents the "capture" phase.
  86    pub fn capture(self) -> bool {
  87        self == DispatchPhase::Capture
  88    }
  89}
  90
  91struct WindowInvalidatorInner {
  92    pub dirty: bool,
  93    pub draw_phase: DrawPhase,
  94    pub dirty_views: FxHashSet<EntityId>,
  95}
  96
  97#[derive(Clone)]
  98pub(crate) struct WindowInvalidator {
  99    inner: Rc<RefCell<WindowInvalidatorInner>>,
 100}
 101
 102impl WindowInvalidator {
 103    pub fn new() -> Self {
 104        WindowInvalidator {
 105            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 106                dirty: true,
 107                draw_phase: DrawPhase::None,
 108                dirty_views: FxHashSet::default(),
 109            })),
 110        }
 111    }
 112
 113    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 114        let mut inner = self.inner.borrow_mut();
 115        inner.dirty_views.insert(entity);
 116        if inner.draw_phase == DrawPhase::None {
 117            inner.dirty = true;
 118            cx.push_effect(Effect::Notify { emitter: entity });
 119            true
 120        } else {
 121            false
 122        }
 123    }
 124
 125    pub fn is_dirty(&self) -> bool {
 126        self.inner.borrow().dirty
 127    }
 128
 129    pub fn set_dirty(&self, dirty: bool) {
 130        self.inner.borrow_mut().dirty = dirty
 131    }
 132
 133    pub fn set_phase(&self, phase: DrawPhase) {
 134        self.inner.borrow_mut().draw_phase = phase
 135    }
 136
 137    pub fn take_views(&self) -> FxHashSet<EntityId> {
 138        mem::take(&mut self.inner.borrow_mut().dirty_views)
 139    }
 140
 141    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 142        self.inner.borrow_mut().dirty_views = views;
 143    }
 144
 145    pub fn not_drawing(&self) -> bool {
 146        self.inner.borrow().draw_phase == DrawPhase::None
 147    }
 148
 149    #[track_caller]
 150    pub fn debug_assert_paint(&self) {
 151        debug_assert!(
 152            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 153            "this method can only be called during paint"
 154        );
 155    }
 156
 157    #[track_caller]
 158    pub fn debug_assert_prepaint(&self) {
 159        debug_assert!(
 160            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 161            "this method can only be called during request_layout, or prepaint"
 162        );
 163    }
 164
 165    #[track_caller]
 166    pub fn debug_assert_paint_or_prepaint(&self) {
 167        debug_assert!(
 168            matches!(
 169                self.inner.borrow().draw_phase,
 170                DrawPhase::Paint | DrawPhase::Prepaint
 171            ),
 172            "this method can only be called during request_layout, prepaint, or paint"
 173        );
 174    }
 175}
 176
 177type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 178
 179pub(crate) type AnyWindowFocusListener =
 180    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 181
 182pub(crate) struct WindowFocusEvent {
 183    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 184    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 185}
 186
 187impl WindowFocusEvent {
 188    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 189        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 190    }
 191
 192    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 193        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 194    }
 195}
 196
 197/// This is provided when subscribing for `Context::on_focus_out` events.
 198pub struct FocusOutEvent {
 199    /// A weak focus handle representing what was blurred.
 200    pub blurred: WeakFocusHandle,
 201}
 202
 203slotmap::new_key_type! {
 204    /// A globally unique identifier for a focusable element.
 205    pub struct FocusId;
 206}
 207
 208thread_local! {
 209    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(1024 * 1024));
 210}
 211
 212/// Returned when the element arena has been used and so must be cleared before the next draw.
 213#[must_use]
 214pub struct ArenaClearNeeded;
 215
 216impl ArenaClearNeeded {
 217    /// Clear the element arena.
 218    pub fn clear(self) {
 219        ELEMENT_ARENA.with_borrow_mut(|element_arena| {
 220            element_arena.clear();
 221        });
 222    }
 223}
 224
 225pub(crate) type FocusMap = RwLock<SlotMap<FocusId, AtomicUsize>>;
 226
 227impl FocusId {
 228    /// Obtains whether the element associated with this handle is currently focused.
 229    pub fn is_focused(&self, window: &Window) -> bool {
 230        window.focus == Some(*self)
 231    }
 232
 233    /// Obtains whether the element associated with this handle contains the focused
 234    /// element or is itself focused.
 235    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 236        window
 237            .focused(cx)
 238            .map_or(false, |focused| self.contains(focused.id, window))
 239    }
 240
 241    /// Obtains whether the element associated with this handle is contained within the
 242    /// focused element or is itself focused.
 243    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 244        let focused = window.focused(cx);
 245        focused.map_or(false, |focused| focused.id.contains(*self, window))
 246    }
 247
 248    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 249    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 250        window
 251            .rendered_frame
 252            .dispatch_tree
 253            .focus_contains(*self, other)
 254    }
 255}
 256
 257/// A handle which can be used to track and manipulate the focused element in a window.
 258pub struct FocusHandle {
 259    pub(crate) id: FocusId,
 260    handles: Arc<FocusMap>,
 261}
 262
 263impl std::fmt::Debug for FocusHandle {
 264    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 265        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 266    }
 267}
 268
 269impl FocusHandle {
 270    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 271        let id = handles.write().insert(AtomicUsize::new(1));
 272        Self {
 273            id,
 274            handles: handles.clone(),
 275        }
 276    }
 277
 278    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 279        let lock = handles.read();
 280        let ref_count = lock.get(id)?;
 281        if atomic_incr_if_not_zero(ref_count) == 0 {
 282            return None;
 283        }
 284        Some(Self {
 285            id,
 286            handles: handles.clone(),
 287        })
 288    }
 289
 290    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 291    pub fn downgrade(&self) -> WeakFocusHandle {
 292        WeakFocusHandle {
 293            id: self.id,
 294            handles: Arc::downgrade(&self.handles),
 295        }
 296    }
 297
 298    /// Moves the focus to the element associated with this handle.
 299    pub fn focus(&self, window: &mut Window) {
 300        window.focus(self)
 301    }
 302
 303    /// Obtains whether the element associated with this handle is currently focused.
 304    pub fn is_focused(&self, window: &Window) -> bool {
 305        self.id.is_focused(window)
 306    }
 307
 308    /// Obtains whether the element associated with this handle contains the focused
 309    /// element or is itself focused.
 310    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 311        self.id.contains_focused(window, cx)
 312    }
 313
 314    /// Obtains whether the element associated with this handle is contained within the
 315    /// focused element or is itself focused.
 316    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 317        self.id.within_focused(window, cx)
 318    }
 319
 320    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 321    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 322        self.id.contains(other.id, window)
 323    }
 324
 325    /// Dispatch an action on the element that rendered this focus handle
 326    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 327        if let Some(node_id) = window
 328            .rendered_frame
 329            .dispatch_tree
 330            .focusable_node_id(self.id)
 331        {
 332            window.dispatch_action_on_node(node_id, action, cx)
 333        }
 334    }
 335}
 336
 337impl Clone for FocusHandle {
 338    fn clone(&self) -> Self {
 339        Self::for_id(self.id, &self.handles).unwrap()
 340    }
 341}
 342
 343impl PartialEq for FocusHandle {
 344    fn eq(&self, other: &Self) -> bool {
 345        self.id == other.id
 346    }
 347}
 348
 349impl Eq for FocusHandle {}
 350
 351impl Drop for FocusHandle {
 352    fn drop(&mut self) {
 353        self.handles
 354            .read()
 355            .get(self.id)
 356            .unwrap()
 357            .fetch_sub(1, SeqCst);
 358    }
 359}
 360
 361/// A weak reference to a focus handle.
 362#[derive(Clone, Debug)]
 363pub struct WeakFocusHandle {
 364    pub(crate) id: FocusId,
 365    pub(crate) handles: Weak<FocusMap>,
 366}
 367
 368impl WeakFocusHandle {
 369    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 370    pub fn upgrade(&self) -> Option<FocusHandle> {
 371        let handles = self.handles.upgrade()?;
 372        FocusHandle::for_id(self.id, &handles)
 373    }
 374}
 375
 376impl PartialEq for WeakFocusHandle {
 377    fn eq(&self, other: &WeakFocusHandle) -> bool {
 378        self.id == other.id
 379    }
 380}
 381
 382impl Eq for WeakFocusHandle {}
 383
 384impl PartialEq<FocusHandle> for WeakFocusHandle {
 385    fn eq(&self, other: &FocusHandle) -> bool {
 386        self.id == other.id
 387    }
 388}
 389
 390impl PartialEq<WeakFocusHandle> for FocusHandle {
 391    fn eq(&self, other: &WeakFocusHandle) -> bool {
 392        self.id == other.id
 393    }
 394}
 395
 396/// Focusable allows users of your view to easily
 397/// focus it (using window.focus_view(cx, view))
 398pub trait Focusable: 'static {
 399    /// Returns the focus handle associated with this view.
 400    fn focus_handle(&self, cx: &App) -> FocusHandle;
 401}
 402
 403impl<V: Focusable> Focusable for Entity<V> {
 404    fn focus_handle(&self, cx: &App) -> FocusHandle {
 405        self.read(cx).focus_handle(cx)
 406    }
 407}
 408
 409/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 410/// where the lifecycle of the view is handled by another view.
 411pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 412
 413impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 414
 415/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 416pub struct DismissEvent;
 417
 418type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 419
 420pub(crate) type AnyMouseListener =
 421    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 422
 423#[derive(Clone)]
 424pub(crate) struct CursorStyleRequest {
 425    pub(crate) hitbox_id: Option<HitboxId>,
 426    pub(crate) style: CursorStyle,
 427}
 428
 429#[derive(Default, Eq, PartialEq)]
 430pub(crate) struct HitTest {
 431    pub(crate) ids: SmallVec<[HitboxId; 8]>,
 432    pub(crate) hover_hitbox_count: usize,
 433}
 434
 435/// A type of window control area that corresponds to the platform window.
 436#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 437pub enum WindowControlArea {
 438    /// An area that allows dragging of the platform window.
 439    Drag,
 440    /// An area that allows closing of the platform window.
 441    Close,
 442    /// An area that allows maximizing of the platform window.
 443    Max,
 444    /// An area that allows minimizing of the platform window.
 445    Min,
 446}
 447
 448/// An identifier for a [Hitbox] which also includes [HitboxBehavior].
 449#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 450pub struct HitboxId(u64);
 451
 452impl HitboxId {
 453    /// Checks if the hitbox with this ID is currently hovered. Except when handling
 454    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 455    /// events or paint hover styles.
 456    ///
 457    /// See [`Hitbox::is_hovered`] for details.
 458    pub fn is_hovered(self, window: &Window) -> bool {
 459        let hit_test = &window.mouse_hit_test;
 460        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 461            if self == *id {
 462                return true;
 463            }
 464        }
 465        return false;
 466    }
 467
 468    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 469    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 470    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 471    /// this distinction.
 472    pub fn should_handle_scroll(self, window: &Window) -> bool {
 473        window.mouse_hit_test.ids.contains(&self)
 474    }
 475
 476    fn next(mut self) -> HitboxId {
 477        HitboxId(self.0.wrapping_add(1))
 478    }
 479}
 480
 481/// A rectangular region that potentially blocks hitboxes inserted prior.
 482/// See [Window::insert_hitbox] for more details.
 483#[derive(Clone, Debug, Deref)]
 484pub struct Hitbox {
 485    /// A unique identifier for the hitbox.
 486    pub id: HitboxId,
 487    /// The bounds of the hitbox.
 488    #[deref]
 489    pub bounds: Bounds<Pixels>,
 490    /// The content mask when the hitbox was inserted.
 491    pub content_mask: ContentMask<Pixels>,
 492    /// Flags that specify hitbox behavior.
 493    pub behavior: HitboxBehavior,
 494}
 495
 496impl Hitbox {
 497    /// Checks if the hitbox is currently hovered. Except when handling `ScrollWheelEvent`, this is
 498    /// typically what you want when determining whether to handle mouse events or paint hover
 499    /// styles.
 500    ///
 501    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 502    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 503    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`).
 504    ///
 505    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 506    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 507    /// non-interactive while still allowing scrolling. More abstractly, this is because
 508    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 509    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 510    /// container.
 511    pub fn is_hovered(&self, window: &Window) -> bool {
 512        self.id.is_hovered(window)
 513    }
 514
 515    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 516    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 517    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 518    ///
 519    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 520    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 521    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 522        self.id.should_handle_scroll(window)
 523    }
 524}
 525
 526/// How the hitbox affects mouse behavior.
 527#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 528pub enum HitboxBehavior {
 529    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 530    #[default]
 531    Normal,
 532
 533    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 534    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 535    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 536    /// [`InteractiveElement::occlude`].
 537    ///
 538    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 539    /// bubble-phase handler for every mouse event type:
 540    ///
 541    /// ```
 542    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 543    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 544    ///         cx.stop_propagation();
 545    ///     }
 546    /// }
 547    /// ```
 548    ///
 549    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 550    /// styles and tooltops. These other behaviors are the main point of this mechanism. An
 551    /// alternative might be to not affect mouse event handling - but this would allow
 552    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 553    /// be hovered.
 554    BlockMouse,
 555
 556    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 557    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 558    /// interaction except scroll events to be ignored - see the documentation of
 559    /// [`Hitbox::is_hovered`] for details. This flag is set by
 560    /// [`InteractiveElement::block_mouse_except_scroll`].
 561    ///
 562    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 563    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 564    ///
 565    /// ```
 566    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, _cx| {
 567    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 568    ///         cx.stop_propagation();
 569    ///     }
 570    /// }
 571    /// ```
 572    ///
 573    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 574    /// handled differently than other mouse events. If also blocking these scroll events is
 575    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 576    ///
 577    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 578    /// hover styles and tooltops. These other behaviors are the main point of this mechanism.
 579    /// An alternative might be to not affect mouse event handling - but this would allow
 580    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 581    /// be hovered.
 582    BlockMouseExceptScroll,
 583}
 584
 585/// An identifier for a tooltip.
 586#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 587pub struct TooltipId(usize);
 588
 589impl TooltipId {
 590    /// Checks if the tooltip is currently hovered.
 591    pub fn is_hovered(&self, window: &Window) -> bool {
 592        window
 593            .tooltip_bounds
 594            .as_ref()
 595            .map_or(false, |tooltip_bounds| {
 596                tooltip_bounds.id == *self
 597                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 598            })
 599    }
 600}
 601
 602pub(crate) struct TooltipBounds {
 603    id: TooltipId,
 604    bounds: Bounds<Pixels>,
 605}
 606
 607#[derive(Clone)]
 608pub(crate) struct TooltipRequest {
 609    id: TooltipId,
 610    tooltip: AnyTooltip,
 611}
 612
 613pub(crate) struct DeferredDraw {
 614    current_view: EntityId,
 615    priority: usize,
 616    parent_node: DispatchNodeId,
 617    element_id_stack: SmallVec<[ElementId; 32]>,
 618    text_style_stack: Vec<TextStyleRefinement>,
 619    element: Option<AnyElement>,
 620    absolute_offset: Point<Pixels>,
 621    prepaint_range: Range<PrepaintStateIndex>,
 622    paint_range: Range<PaintIndex>,
 623}
 624
 625pub(crate) struct Frame {
 626    pub(crate) focus: Option<FocusId>,
 627    pub(crate) window_active: bool,
 628    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 629    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 630    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 631    pub(crate) dispatch_tree: DispatchTree,
 632    pub(crate) scene: Scene,
 633    pub(crate) hitboxes: Vec<Hitbox>,
 634    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 635    pub(crate) deferred_draws: Vec<DeferredDraw>,
 636    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 637    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 638    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 639    #[cfg(any(test, feature = "test-support"))]
 640    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 641    #[cfg(any(feature = "inspector", debug_assertions))]
 642    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 643    #[cfg(any(feature = "inspector", debug_assertions))]
 644    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 645}
 646
 647#[derive(Clone, Default)]
 648pub(crate) struct PrepaintStateIndex {
 649    hitboxes_index: usize,
 650    tooltips_index: usize,
 651    deferred_draws_index: usize,
 652    dispatch_tree_index: usize,
 653    accessed_element_states_index: usize,
 654    line_layout_index: LineLayoutIndex,
 655}
 656
 657#[derive(Clone, Default)]
 658pub(crate) struct PaintIndex {
 659    scene_index: usize,
 660    mouse_listeners_index: usize,
 661    input_handlers_index: usize,
 662    cursor_styles_index: usize,
 663    accessed_element_states_index: usize,
 664    line_layout_index: LineLayoutIndex,
 665}
 666
 667impl Frame {
 668    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 669        Frame {
 670            focus: None,
 671            window_active: false,
 672            element_states: FxHashMap::default(),
 673            accessed_element_states: Vec::new(),
 674            mouse_listeners: Vec::new(),
 675            dispatch_tree,
 676            scene: Scene::default(),
 677            hitboxes: Vec::new(),
 678            window_control_hitboxes: Vec::new(),
 679            deferred_draws: Vec::new(),
 680            input_handlers: Vec::new(),
 681            tooltip_requests: Vec::new(),
 682            cursor_styles: Vec::new(),
 683
 684            #[cfg(any(test, feature = "test-support"))]
 685            debug_bounds: FxHashMap::default(),
 686
 687            #[cfg(any(feature = "inspector", debug_assertions))]
 688            next_inspector_instance_ids: FxHashMap::default(),
 689
 690            #[cfg(any(feature = "inspector", debug_assertions))]
 691            inspector_hitboxes: FxHashMap::default(),
 692        }
 693    }
 694
 695    pub(crate) fn clear(&mut self) {
 696        self.element_states.clear();
 697        self.accessed_element_states.clear();
 698        self.mouse_listeners.clear();
 699        self.dispatch_tree.clear();
 700        self.scene.clear();
 701        self.input_handlers.clear();
 702        self.tooltip_requests.clear();
 703        self.cursor_styles.clear();
 704        self.hitboxes.clear();
 705        self.window_control_hitboxes.clear();
 706        self.deferred_draws.clear();
 707        self.focus = None;
 708
 709        #[cfg(any(feature = "inspector", debug_assertions))]
 710        {
 711            self.next_inspector_instance_ids.clear();
 712            self.inspector_hitboxes.clear();
 713        }
 714    }
 715
 716    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 717        self.cursor_styles
 718            .iter()
 719            .rev()
 720            .fold_while(None, |style, request| match request.hitbox_id {
 721                None => Done(Some(request.style)),
 722                Some(hitbox_id) => Continue(
 723                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 724                ),
 725            })
 726            .into_inner()
 727    }
 728
 729    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 730        let mut set_hover_hitbox_count = false;
 731        let mut hit_test = HitTest::default();
 732        for hitbox in self.hitboxes.iter().rev() {
 733            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 734            if bounds.contains(&position) {
 735                hit_test.ids.push(hitbox.id);
 736                if !set_hover_hitbox_count
 737                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 738                {
 739                    hit_test.hover_hitbox_count = hit_test.ids.len();
 740                    set_hover_hitbox_count = true;
 741                }
 742                if hitbox.behavior == HitboxBehavior::BlockMouse {
 743                    break;
 744                }
 745            }
 746        }
 747        if !set_hover_hitbox_count {
 748            hit_test.hover_hitbox_count = hit_test.ids.len();
 749        }
 750        hit_test
 751    }
 752
 753    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 754        self.focus
 755            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 756            .unwrap_or_default()
 757    }
 758
 759    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 760        for element_state_key in &self.accessed_element_states {
 761            if let Some((element_state_key, element_state)) =
 762                prev_frame.element_states.remove_entry(element_state_key)
 763            {
 764                self.element_states.insert(element_state_key, element_state);
 765            }
 766        }
 767
 768        self.scene.finish();
 769    }
 770}
 771
 772/// Holds the state for a specific window.
 773pub struct Window {
 774    pub(crate) handle: AnyWindowHandle,
 775    pub(crate) invalidator: WindowInvalidator,
 776    pub(crate) removed: bool,
 777    pub(crate) platform_window: Box<dyn PlatformWindow>,
 778    display_id: Option<DisplayId>,
 779    sprite_atlas: Arc<dyn PlatformAtlas>,
 780    text_system: Arc<WindowTextSystem>,
 781    rem_size: Pixels,
 782    /// The stack of override values for the window's rem size.
 783    ///
 784    /// This is used by `with_rem_size` to allow rendering an element tree with
 785    /// a given rem size.
 786    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 787    pub(crate) viewport_size: Size<Pixels>,
 788    layout_engine: Option<TaffyLayoutEngine>,
 789    pub(crate) root: Option<AnyView>,
 790    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 791    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 792    pub(crate) rendered_entity_stack: Vec<EntityId>,
 793    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 794    pub(crate) element_opacity: Option<f32>,
 795    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 796    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 797    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 798    pub(crate) rendered_frame: Frame,
 799    pub(crate) next_frame: Frame,
 800    next_hitbox_id: HitboxId,
 801    pub(crate) next_tooltip_id: TooltipId,
 802    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 803    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 804    pub(crate) dirty_views: FxHashSet<EntityId>,
 805    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 806    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 807    default_prevented: bool,
 808    mouse_position: Point<Pixels>,
 809    mouse_hit_test: HitTest,
 810    modifiers: Modifiers,
 811    capslock: Capslock,
 812    scale_factor: f32,
 813    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 814    appearance: WindowAppearance,
 815    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 816    active: Rc<Cell<bool>>,
 817    hovered: Rc<Cell<bool>>,
 818    pub(crate) needs_present: Rc<Cell<bool>>,
 819    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 820    pub(crate) refreshing: bool,
 821    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 822    pub(crate) focus: Option<FocusId>,
 823    focus_enabled: bool,
 824    pending_input: Option<PendingInput>,
 825    pending_modifier: ModifierState,
 826    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 827    prompt: Option<RenderablePromptHandle>,
 828    pub(crate) client_inset: Option<Pixels>,
 829    #[cfg(any(feature = "inspector", debug_assertions))]
 830    inspector: Option<Entity<Inspector>>,
 831}
 832
 833#[derive(Clone, Debug, Default)]
 834struct ModifierState {
 835    modifiers: Modifiers,
 836    saw_keystroke: bool,
 837}
 838
 839#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 840pub(crate) enum DrawPhase {
 841    None,
 842    Prepaint,
 843    Paint,
 844    Focus,
 845}
 846
 847#[derive(Default, Debug)]
 848struct PendingInput {
 849    keystrokes: SmallVec<[Keystroke; 1]>,
 850    focus: Option<FocusId>,
 851    timer: Option<Task<()>>,
 852}
 853
 854pub(crate) struct ElementStateBox {
 855    pub(crate) inner: Box<dyn Any>,
 856    #[cfg(debug_assertions)]
 857    pub(crate) type_name: &'static str,
 858}
 859
 860fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> Bounds<Pixels> {
 861    const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
 862
 863    // TODO, BUG: if you open a window with the currently active window
 864    // on the stack, this will erroneously select the 'unwrap_or_else'
 865    // code path
 866    cx.active_window()
 867        .and_then(|w| w.update(cx, |_, window, _| window.bounds()).ok())
 868        .map(|mut bounds| {
 869            bounds.origin += DEFAULT_WINDOW_OFFSET;
 870            bounds
 871        })
 872        .unwrap_or_else(|| {
 873            let display = display_id
 874                .map(|id| cx.find_display(id))
 875                .unwrap_or_else(|| cx.primary_display());
 876
 877            display
 878                .map(|display| display.default_bounds())
 879                .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
 880        })
 881}
 882
 883impl Window {
 884    pub(crate) fn new(
 885        handle: AnyWindowHandle,
 886        options: WindowOptions,
 887        cx: &mut App,
 888    ) -> Result<Self> {
 889        let WindowOptions {
 890            window_bounds,
 891            titlebar,
 892            focus,
 893            show,
 894            kind,
 895            is_movable,
 896            display_id,
 897            window_background,
 898            app_id,
 899            window_min_size,
 900            window_decorations,
 901        } = options;
 902
 903        let bounds = window_bounds
 904            .map(|bounds| bounds.get_bounds())
 905            .unwrap_or_else(|| default_bounds(display_id, cx));
 906        let mut platform_window = cx.platform.open_window(
 907            handle,
 908            WindowParams {
 909                bounds,
 910                titlebar,
 911                kind,
 912                is_movable,
 913                focus,
 914                show,
 915                display_id,
 916                window_min_size,
 917            },
 918        )?;
 919        let display_id = platform_window.display().map(|display| display.id());
 920        let sprite_atlas = platform_window.sprite_atlas();
 921        let mouse_position = platform_window.mouse_position();
 922        let modifiers = platform_window.modifiers();
 923        let capslock = platform_window.capslock();
 924        let content_size = platform_window.content_size();
 925        let scale_factor = platform_window.scale_factor();
 926        let appearance = platform_window.appearance();
 927        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
 928        let invalidator = WindowInvalidator::new();
 929        let active = Rc::new(Cell::new(platform_window.is_active()));
 930        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
 931        let needs_present = Rc::new(Cell::new(false));
 932        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
 933        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
 934
 935        platform_window
 936            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
 937        platform_window.set_background_appearance(window_background);
 938
 939        if let Some(ref window_open_state) = window_bounds {
 940            match window_open_state {
 941                WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
 942                WindowBounds::Maximized(_) => platform_window.zoom(),
 943                WindowBounds::Windowed(_) => {}
 944            }
 945        }
 946
 947        platform_window.on_close(Box::new({
 948            let mut cx = cx.to_async();
 949            move || {
 950                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
 951            }
 952        }));
 953        platform_window.on_request_frame(Box::new({
 954            let mut cx = cx.to_async();
 955            let invalidator = invalidator.clone();
 956            let active = active.clone();
 957            let needs_present = needs_present.clone();
 958            let next_frame_callbacks = next_frame_callbacks.clone();
 959            let last_input_timestamp = last_input_timestamp.clone();
 960            move |request_frame_options| {
 961                let next_frame_callbacks = next_frame_callbacks.take();
 962                if !next_frame_callbacks.is_empty() {
 963                    handle
 964                        .update(&mut cx, |_, window, cx| {
 965                            for callback in next_frame_callbacks {
 966                                callback(window, cx);
 967                            }
 968                        })
 969                        .log_err();
 970                }
 971
 972                // Keep presenting the current scene for 1 extra second since the
 973                // last input to prevent the display from underclocking the refresh rate.
 974                let needs_present = request_frame_options.require_presentation
 975                    || needs_present.get()
 976                    || (active.get()
 977                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
 978
 979                if invalidator.is_dirty() {
 980                    measure("frame duration", || {
 981                        handle
 982                            .update(&mut cx, |_, window, cx| {
 983                                let arena_clear_needed = window.draw(cx);
 984                                window.present();
 985                                // drop the arena elements after present to reduce latency
 986                                arena_clear_needed.clear();
 987                            })
 988                            .log_err();
 989                    })
 990                } else if needs_present {
 991                    handle
 992                        .update(&mut cx, |_, window, _| window.present())
 993                        .log_err();
 994                }
 995
 996                handle
 997                    .update(&mut cx, |_, window, _| {
 998                        window.complete_frame();
 999                    })
1000                    .log_err();
1001            }
1002        }));
1003        platform_window.on_resize(Box::new({
1004            let mut cx = cx.to_async();
1005            move |_, _| {
1006                handle
1007                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1008                    .log_err();
1009            }
1010        }));
1011        platform_window.on_moved(Box::new({
1012            let mut cx = cx.to_async();
1013            move || {
1014                handle
1015                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1016                    .log_err();
1017            }
1018        }));
1019        platform_window.on_appearance_changed(Box::new({
1020            let mut cx = cx.to_async();
1021            move || {
1022                handle
1023                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1024                    .log_err();
1025            }
1026        }));
1027        platform_window.on_active_status_change(Box::new({
1028            let mut cx = cx.to_async();
1029            move |active| {
1030                handle
1031                    .update(&mut cx, |_, window, cx| {
1032                        window.active.set(active);
1033                        window.modifiers = window.platform_window.modifiers();
1034                        window.capslock = window.platform_window.capslock();
1035                        window
1036                            .activation_observers
1037                            .clone()
1038                            .retain(&(), |callback| callback(window, cx));
1039                        window.refresh();
1040                    })
1041                    .log_err();
1042            }
1043        }));
1044        platform_window.on_hover_status_change(Box::new({
1045            let mut cx = cx.to_async();
1046            move |active| {
1047                handle
1048                    .update(&mut cx, |_, window, _| {
1049                        window.hovered.set(active);
1050                        window.refresh();
1051                    })
1052                    .log_err();
1053            }
1054        }));
1055        platform_window.on_input({
1056            let mut cx = cx.to_async();
1057            Box::new(move |event| {
1058                handle
1059                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1060                    .log_err()
1061                    .unwrap_or(DispatchEventResult::default())
1062            })
1063        });
1064        platform_window.on_hit_test_window_control({
1065            let mut cx = cx.to_async();
1066            Box::new(move || {
1067                handle
1068                    .update(&mut cx, |_, window, _cx| {
1069                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1070                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1071                                return Some(*area);
1072                            }
1073                        }
1074                        None
1075                    })
1076                    .log_err()
1077                    .unwrap_or(None)
1078            })
1079        });
1080
1081        if let Some(app_id) = app_id {
1082            platform_window.set_app_id(&app_id);
1083        }
1084
1085        platform_window.map_window().unwrap();
1086
1087        Ok(Window {
1088            handle,
1089            invalidator,
1090            removed: false,
1091            platform_window,
1092            display_id,
1093            sprite_atlas,
1094            text_system,
1095            rem_size: px(16.),
1096            rem_size_override_stack: SmallVec::new(),
1097            viewport_size: content_size,
1098            layout_engine: Some(TaffyLayoutEngine::new()),
1099            root: None,
1100            element_id_stack: SmallVec::default(),
1101            text_style_stack: Vec::new(),
1102            rendered_entity_stack: Vec::new(),
1103            element_offset_stack: Vec::new(),
1104            content_mask_stack: Vec::new(),
1105            element_opacity: None,
1106            requested_autoscroll: None,
1107            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1108            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1109            next_frame_callbacks,
1110            next_hitbox_id: HitboxId(0),
1111            next_tooltip_id: TooltipId::default(),
1112            tooltip_bounds: None,
1113            dirty_views: FxHashSet::default(),
1114            focus_listeners: SubscriberSet::new(),
1115            focus_lost_listeners: SubscriberSet::new(),
1116            default_prevented: true,
1117            mouse_position,
1118            mouse_hit_test: HitTest::default(),
1119            modifiers,
1120            capslock,
1121            scale_factor,
1122            bounds_observers: SubscriberSet::new(),
1123            appearance,
1124            appearance_observers: SubscriberSet::new(),
1125            active,
1126            hovered,
1127            needs_present,
1128            last_input_timestamp,
1129            refreshing: false,
1130            activation_observers: SubscriberSet::new(),
1131            focus: None,
1132            focus_enabled: true,
1133            pending_input: None,
1134            pending_modifier: ModifierState::default(),
1135            pending_input_observers: SubscriberSet::new(),
1136            prompt: None,
1137            client_inset: None,
1138            image_cache_stack: Vec::new(),
1139            #[cfg(any(feature = "inspector", debug_assertions))]
1140            inspector: None,
1141        })
1142    }
1143
1144    pub(crate) fn new_focus_listener(
1145        &self,
1146        value: AnyWindowFocusListener,
1147    ) -> (Subscription, impl FnOnce() + use<>) {
1148        self.focus_listeners.insert((), value)
1149    }
1150}
1151
1152#[derive(Clone, Debug, Default, PartialEq, Eq)]
1153pub(crate) struct DispatchEventResult {
1154    pub propagate: bool,
1155    pub default_prevented: bool,
1156}
1157
1158/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1159/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1160/// to leave room to support more complex shapes in the future.
1161#[derive(Clone, Debug, Default, PartialEq, Eq)]
1162#[repr(C)]
1163pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1164    /// The bounds
1165    pub bounds: Bounds<P>,
1166}
1167
1168impl ContentMask<Pixels> {
1169    /// Scale the content mask's pixel units by the given scaling factor.
1170    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1171        ContentMask {
1172            bounds: self.bounds.scale(factor),
1173        }
1174    }
1175
1176    /// Intersect the content mask with the given content mask.
1177    pub fn intersect(&self, other: &Self) -> Self {
1178        let bounds = self.bounds.intersect(&other.bounds);
1179        ContentMask { bounds }
1180    }
1181}
1182
1183impl Window {
1184    fn mark_view_dirty(&mut self, view_id: EntityId) {
1185        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1186        // should already be dirty.
1187        for view_id in self
1188            .rendered_frame
1189            .dispatch_tree
1190            .view_path(view_id)
1191            .into_iter()
1192            .rev()
1193        {
1194            if !self.dirty_views.insert(view_id) {
1195                break;
1196            }
1197        }
1198    }
1199
1200    /// Registers a callback to be invoked when the window appearance changes.
1201    pub fn observe_window_appearance(
1202        &self,
1203        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1204    ) -> Subscription {
1205        let (subscription, activate) = self.appearance_observers.insert(
1206            (),
1207            Box::new(move |window, cx| {
1208                callback(window, cx);
1209                true
1210            }),
1211        );
1212        activate();
1213        subscription
1214    }
1215
1216    /// Replaces the root entity of the window with a new one.
1217    pub fn replace_root<E>(
1218        &mut self,
1219        cx: &mut App,
1220        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1221    ) -> Entity<E>
1222    where
1223        E: 'static + Render,
1224    {
1225        let view = cx.new(|cx| build_view(self, cx));
1226        self.root = Some(view.clone().into());
1227        self.refresh();
1228        view
1229    }
1230
1231    /// Returns the root entity of the window, if it has one.
1232    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1233    where
1234        E: 'static + Render,
1235    {
1236        self.root
1237            .as_ref()
1238            .map(|view| view.clone().downcast::<E>().ok())
1239    }
1240
1241    /// Obtain a handle to the window that belongs to this context.
1242    pub fn window_handle(&self) -> AnyWindowHandle {
1243        self.handle
1244    }
1245
1246    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1247    pub fn refresh(&mut self) {
1248        if self.invalidator.not_drawing() {
1249            self.refreshing = true;
1250            self.invalidator.set_dirty(true);
1251        }
1252    }
1253
1254    /// Close this window.
1255    pub fn remove_window(&mut self) {
1256        self.removed = true;
1257    }
1258
1259    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1260    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1261        self.focus
1262            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1263    }
1264
1265    /// Move focus to the element associated with the given [`FocusHandle`].
1266    pub fn focus(&mut self, handle: &FocusHandle) {
1267        println!(
1268            "Setting focus to {:?} on platform {:?}",
1269            handle.id,
1270            std::env::consts::OS
1271        );
1272
1273        if !self.focus_enabled || self.focus == Some(handle.id) {
1274            return;
1275        }
1276        println!("actually setting focus");
1277        self.focus = Some(handle.id);
1278        self.clear_pending_keystrokes();
1279        self.refresh();
1280    }
1281
1282    /// Remove focus from all elements within this context's window.
1283    pub fn blur(&mut self) {
1284        if !self.focus_enabled {
1285            return;
1286        }
1287
1288        self.focus = None;
1289        self.refresh();
1290    }
1291
1292    /// Blur the window and don't allow anything in it to be focused again.
1293    pub fn disable_focus(&mut self) {
1294        self.blur();
1295        self.focus_enabled = false;
1296    }
1297
1298    /// Accessor for the text system.
1299    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1300        &self.text_system
1301    }
1302
1303    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1304    pub fn text_style(&self) -> TextStyle {
1305        let mut style = TextStyle::default();
1306        for refinement in &self.text_style_stack {
1307            style.refine(refinement);
1308        }
1309        style
1310    }
1311
1312    /// Check if the platform window is maximized
1313    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1314    pub fn is_maximized(&self) -> bool {
1315        self.platform_window.is_maximized()
1316    }
1317
1318    /// request a certain window decoration (Wayland)
1319    pub fn request_decorations(&self, decorations: WindowDecorations) {
1320        self.platform_window.request_decorations(decorations);
1321    }
1322
1323    /// Start a window resize operation (Wayland)
1324    pub fn start_window_resize(&self, edge: ResizeEdge) {
1325        self.platform_window.start_window_resize(edge);
1326    }
1327
1328    /// Return the `WindowBounds` to indicate that how a window should be opened
1329    /// after it has been closed
1330    pub fn window_bounds(&self) -> WindowBounds {
1331        self.platform_window.window_bounds()
1332    }
1333
1334    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1335    pub fn inner_window_bounds(&self) -> WindowBounds {
1336        self.platform_window.inner_window_bounds()
1337    }
1338
1339    /// Dispatch the given action on the currently focused element.
1340    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1341        let focus_id = self.focused(cx).map(|handle| handle.id);
1342        dbg!(&focus_id);
1343        let window = self.handle;
1344        cx.defer(move |cx| {
1345            window
1346                .update(cx, |_, window, cx| {
1347                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1348                    dbg!(&node_id);
1349                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1350                })
1351                .log_err();
1352        })
1353    }
1354
1355    pub(crate) fn dispatch_keystroke_observers(
1356        &mut self,
1357        event: &dyn Any,
1358        action: Option<Box<dyn Action>>,
1359        context_stack: Vec<KeyContext>,
1360        cx: &mut App,
1361    ) {
1362        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1363            return;
1364        };
1365
1366        cx.keystroke_observers.clone().retain(&(), move |callback| {
1367            (callback)(
1368                &KeystrokeEvent {
1369                    keystroke: key_down_event.keystroke.clone(),
1370                    action: action.as_ref().map(|action| action.boxed_clone()),
1371                    context_stack: context_stack.clone(),
1372                },
1373                self,
1374                cx,
1375            )
1376        });
1377    }
1378
1379    pub(crate) fn dispatch_keystroke_interceptors(
1380        &mut self,
1381        event: &dyn Any,
1382        context_stack: Vec<KeyContext>,
1383        cx: &mut App,
1384    ) {
1385        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1386            return;
1387        };
1388
1389        cx.keystroke_interceptors
1390            .clone()
1391            .retain(&(), move |callback| {
1392                (callback)(
1393                    &KeystrokeEvent {
1394                        keystroke: key_down_event.keystroke.clone(),
1395                        action: None,
1396                        context_stack: context_stack.clone(),
1397                    },
1398                    self,
1399                    cx,
1400                )
1401            });
1402    }
1403
1404    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1405    /// that are currently on the stack to be returned to the app.
1406    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1407        let handle = self.handle;
1408        cx.defer(move |cx| {
1409            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1410        });
1411    }
1412
1413    /// Subscribe to events emitted by a entity.
1414    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1415    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1416    pub fn observe<T: 'static>(
1417        &mut self,
1418        observed: &Entity<T>,
1419        cx: &mut App,
1420        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1421    ) -> Subscription {
1422        let entity_id = observed.entity_id();
1423        let observed = observed.downgrade();
1424        let window_handle = self.handle;
1425        cx.new_observer(
1426            entity_id,
1427            Box::new(move |cx| {
1428                window_handle
1429                    .update(cx, |_, window, cx| {
1430                        if let Some(handle) = observed.upgrade() {
1431                            on_notify(handle, window, cx);
1432                            true
1433                        } else {
1434                            false
1435                        }
1436                    })
1437                    .unwrap_or(false)
1438            }),
1439        )
1440    }
1441
1442    /// Subscribe to events emitted by a entity.
1443    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1444    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1445    pub fn subscribe<Emitter, Evt>(
1446        &mut self,
1447        entity: &Entity<Emitter>,
1448        cx: &mut App,
1449        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1450    ) -> Subscription
1451    where
1452        Emitter: EventEmitter<Evt>,
1453        Evt: 'static,
1454    {
1455        let entity_id = entity.entity_id();
1456        let handle = entity.downgrade();
1457        let window_handle = self.handle;
1458        cx.new_subscription(
1459            entity_id,
1460            (
1461                TypeId::of::<Evt>(),
1462                Box::new(move |event, cx| {
1463                    window_handle
1464                        .update(cx, |_, window, cx| {
1465                            if let Some(entity) = handle.upgrade() {
1466                                let event = event.downcast_ref().expect("invalid event type");
1467                                on_event(entity, event, window, cx);
1468                                true
1469                            } else {
1470                                false
1471                            }
1472                        })
1473                        .unwrap_or(false)
1474                }),
1475            ),
1476        )
1477    }
1478
1479    /// Register a callback to be invoked when the given `Entity` is released.
1480    pub fn observe_release<T>(
1481        &self,
1482        entity: &Entity<T>,
1483        cx: &mut App,
1484        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1485    ) -> Subscription
1486    where
1487        T: 'static,
1488    {
1489        let entity_id = entity.entity_id();
1490        let window_handle = self.handle;
1491        let (subscription, activate) = cx.release_listeners.insert(
1492            entity_id,
1493            Box::new(move |entity, cx| {
1494                let entity = entity.downcast_mut().expect("invalid entity type");
1495                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1496            }),
1497        );
1498        activate();
1499        subscription
1500    }
1501
1502    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1503    /// await points in async code.
1504    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1505        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1506    }
1507
1508    /// Schedule the given closure to be run directly after the current frame is rendered.
1509    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1510        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1511    }
1512
1513    /// Schedule a frame to be drawn on the next animation frame.
1514    ///
1515    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1516    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1517    ///
1518    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1519    pub fn request_animation_frame(&self) {
1520        let entity = self.current_view();
1521        self.on_next_frame(move |_, cx| cx.notify(entity));
1522    }
1523
1524    /// Spawn the future returned by the given closure on the application thread pool.
1525    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1526    /// use within your future.
1527    #[track_caller]
1528    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1529    where
1530        R: 'static,
1531        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1532    {
1533        let handle = self.handle;
1534        cx.spawn(async move |app| {
1535            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1536            f(&mut async_window_cx).await
1537        })
1538    }
1539
1540    fn bounds_changed(&mut self, cx: &mut App) {
1541        self.scale_factor = self.platform_window.scale_factor();
1542        self.viewport_size = self.platform_window.content_size();
1543        self.display_id = self.platform_window.display().map(|display| display.id());
1544
1545        self.refresh();
1546
1547        self.bounds_observers
1548            .clone()
1549            .retain(&(), |callback| callback(self, cx));
1550    }
1551
1552    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1553    pub fn bounds(&self) -> Bounds<Pixels> {
1554        self.platform_window.bounds()
1555    }
1556
1557    /// Set the content size of the window.
1558    pub fn resize(&mut self, size: Size<Pixels>) {
1559        self.platform_window.resize(size);
1560    }
1561
1562    /// Returns whether or not the window is currently fullscreen
1563    pub fn is_fullscreen(&self) -> bool {
1564        self.platform_window.is_fullscreen()
1565    }
1566
1567    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1568        self.appearance = self.platform_window.appearance();
1569
1570        self.appearance_observers
1571            .clone()
1572            .retain(&(), |callback| callback(self, cx));
1573    }
1574
1575    /// Returns the appearance of the current window.
1576    pub fn appearance(&self) -> WindowAppearance {
1577        self.appearance
1578    }
1579
1580    /// Returns the size of the drawable area within the window.
1581    pub fn viewport_size(&self) -> Size<Pixels> {
1582        self.viewport_size
1583    }
1584
1585    /// Returns whether this window is focused by the operating system (receiving key events).
1586    pub fn is_window_active(&self) -> bool {
1587        self.active.get()
1588    }
1589
1590    /// Returns whether this window is considered to be the window
1591    /// that currently owns the mouse cursor.
1592    /// On mac, this is equivalent to `is_window_active`.
1593    pub fn is_window_hovered(&self) -> bool {
1594        if cfg!(any(
1595            target_os = "windows",
1596            target_os = "linux",
1597            target_os = "freebsd"
1598        )) {
1599            self.hovered.get()
1600        } else {
1601            self.is_window_active()
1602        }
1603    }
1604
1605    /// Toggle zoom on the window.
1606    pub fn zoom_window(&self) {
1607        self.platform_window.zoom();
1608    }
1609
1610    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1611    pub fn show_window_menu(&self, position: Point<Pixels>) {
1612        self.platform_window.show_window_menu(position)
1613    }
1614
1615    /// Tells the compositor to take control of window movement (Wayland and X11)
1616    ///
1617    /// Events may not be received during a move operation.
1618    pub fn start_window_move(&self) {
1619        self.platform_window.start_window_move()
1620    }
1621
1622    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1623    pub fn set_client_inset(&mut self, inset: Pixels) {
1624        self.client_inset = Some(inset);
1625        self.platform_window.set_client_inset(inset);
1626    }
1627
1628    /// Returns the client_inset value by [`Self::set_client_inset`].
1629    pub fn client_inset(&self) -> Option<Pixels> {
1630        self.client_inset
1631    }
1632
1633    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1634    pub fn window_decorations(&self) -> Decorations {
1635        self.platform_window.window_decorations()
1636    }
1637
1638    /// Returns which window controls are currently visible (Wayland)
1639    pub fn window_controls(&self) -> WindowControls {
1640        self.platform_window.window_controls()
1641    }
1642
1643    /// Updates the window's title at the platform level.
1644    pub fn set_window_title(&mut self, title: &str) {
1645        self.platform_window.set_title(title);
1646    }
1647
1648    /// Sets the application identifier.
1649    pub fn set_app_id(&mut self, app_id: &str) {
1650        self.platform_window.set_app_id(app_id);
1651    }
1652
1653    /// Sets the window background appearance.
1654    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1655        self.platform_window
1656            .set_background_appearance(background_appearance);
1657    }
1658
1659    /// Mark the window as dirty at the platform level.
1660    pub fn set_window_edited(&mut self, edited: bool) {
1661        self.platform_window.set_edited(edited);
1662    }
1663
1664    /// Determine the display on which the window is visible.
1665    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1666        cx.platform
1667            .displays()
1668            .into_iter()
1669            .find(|display| Some(display.id()) == self.display_id)
1670    }
1671
1672    /// Show the platform character palette.
1673    pub fn show_character_palette(&self) {
1674        self.platform_window.show_character_palette();
1675    }
1676
1677    /// The scale factor of the display associated with the window. For example, it could
1678    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1679    /// be rendered as two pixels on screen.
1680    pub fn scale_factor(&self) -> f32 {
1681        self.scale_factor
1682    }
1683
1684    /// The size of an em for the base font of the application. Adjusting this value allows the
1685    /// UI to scale, just like zooming a web page.
1686    pub fn rem_size(&self) -> Pixels {
1687        self.rem_size_override_stack
1688            .last()
1689            .copied()
1690            .unwrap_or(self.rem_size)
1691    }
1692
1693    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1694    /// UI to scale, just like zooming a web page.
1695    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1696        self.rem_size = rem_size.into();
1697    }
1698
1699    /// Acquire a globally unique identifier for the given ElementId.
1700    /// Only valid for the duration of the provided closure.
1701    pub fn with_global_id<R>(
1702        &mut self,
1703        element_id: ElementId,
1704        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1705    ) -> R {
1706        self.element_id_stack.push(element_id);
1707        let global_id = GlobalElementId(self.element_id_stack.clone());
1708        let result = f(&global_id, self);
1709        self.element_id_stack.pop();
1710        result
1711    }
1712
1713    /// Executes the provided function with the specified rem size.
1714    ///
1715    /// This method must only be called as part of element drawing.
1716    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1717    where
1718        F: FnOnce(&mut Self) -> R,
1719    {
1720        self.invalidator.debug_assert_paint_or_prepaint();
1721
1722        if let Some(rem_size) = rem_size {
1723            self.rem_size_override_stack.push(rem_size.into());
1724            let result = f(self);
1725            self.rem_size_override_stack.pop();
1726            result
1727        } else {
1728            f(self)
1729        }
1730    }
1731
1732    /// The line height associated with the current text style.
1733    pub fn line_height(&self) -> Pixels {
1734        self.text_style().line_height_in_pixels(self.rem_size())
1735    }
1736
1737    /// Call to prevent the default action of an event. Currently only used to prevent
1738    /// parent elements from becoming focused on mouse down.
1739    pub fn prevent_default(&mut self) {
1740        self.default_prevented = true;
1741    }
1742
1743    /// Obtain whether default has been prevented for the event currently being dispatched.
1744    pub fn default_prevented(&self) -> bool {
1745        self.default_prevented
1746    }
1747
1748    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1749    pub fn is_action_available(&self, action: &dyn Action, cx: &mut App) -> bool {
1750        let node_id =
1751            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
1752        self.rendered_frame
1753            .dispatch_tree
1754            .is_action_available(action, node_id)
1755    }
1756
1757    /// The position of the mouse relative to the window.
1758    pub fn mouse_position(&self) -> Point<Pixels> {
1759        self.mouse_position
1760    }
1761
1762    /// The current state of the keyboard's modifiers
1763    pub fn modifiers(&self) -> Modifiers {
1764        self.modifiers
1765    }
1766
1767    /// The current state of the keyboard's capslock
1768    pub fn capslock(&self) -> Capslock {
1769        self.capslock
1770    }
1771
1772    fn complete_frame(&self) {
1773        self.platform_window.completed_frame();
1774    }
1775
1776    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1777    /// the contents of the new [Scene], use [present].
1778    #[profiling::function]
1779    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
1780        self.invalidate_entities();
1781        cx.entities.clear_accessed();
1782        debug_assert!(self.rendered_entity_stack.is_empty());
1783        self.invalidator.set_dirty(false);
1784        self.requested_autoscroll = None;
1785
1786        // Restore the previously-used input handler.
1787        if let Some(input_handler) = self.platform_window.take_input_handler() {
1788            self.rendered_frame.input_handlers.push(Some(input_handler));
1789        }
1790        self.draw_roots(cx);
1791        self.dirty_views.clear();
1792        self.next_frame.window_active = self.active.get();
1793
1794        // Register requested input handler with the platform window.
1795        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
1796            self.platform_window
1797                .set_input_handler(input_handler.unwrap());
1798        }
1799
1800        self.layout_engine.as_mut().unwrap().clear();
1801        self.text_system().finish_frame();
1802        self.next_frame.finish(&mut self.rendered_frame);
1803
1804        self.invalidator.set_phase(DrawPhase::Focus);
1805        let previous_focus_path = self.rendered_frame.focus_path();
1806        let previous_window_active = self.rendered_frame.window_active;
1807        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
1808        self.next_frame.clear();
1809        let current_focus_path = self.rendered_frame.focus_path();
1810        let current_window_active = self.rendered_frame.window_active;
1811
1812        dbg!(
1813            &previous_focus_path,
1814            &current_focus_path,
1815            &previous_window_active,
1816            &current_window_active
1817        );
1818
1819        if previous_focus_path != current_focus_path
1820            || previous_window_active != current_window_active
1821        {
1822            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1823                self.focus_lost_listeners
1824                    .clone()
1825                    .retain(&(), |listener| listener(self, cx));
1826            }
1827
1828            let event = WindowFocusEvent {
1829                previous_focus_path: if previous_window_active {
1830                    previous_focus_path
1831                } else {
1832                    Default::default()
1833                },
1834                current_focus_path: if current_window_active {
1835                    current_focus_path
1836                } else {
1837                    Default::default()
1838                },
1839            };
1840            self.focus_listeners
1841                .clone()
1842                .retain(&(), |listener| listener(&event, self, cx));
1843        }
1844
1845        debug_assert!(self.rendered_entity_stack.is_empty());
1846        self.record_entities_accessed(cx);
1847        self.reset_cursor_style(cx);
1848        self.refreshing = false;
1849        self.invalidator.set_phase(DrawPhase::None);
1850        self.needs_present.set(true);
1851
1852        ArenaClearNeeded
1853    }
1854
1855    fn record_entities_accessed(&mut self, cx: &mut App) {
1856        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1857        let mut entities = mem::take(entities_ref.deref_mut());
1858        drop(entities_ref);
1859        let handle = self.handle;
1860        cx.record_entities_accessed(
1861            handle,
1862            // Try moving window invalidator into the Window
1863            self.invalidator.clone(),
1864            &entities,
1865        );
1866        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
1867        mem::swap(&mut entities, entities_ref.deref_mut());
1868    }
1869
1870    fn invalidate_entities(&mut self) {
1871        let mut views = self.invalidator.take_views();
1872        for entity in views.drain() {
1873            self.mark_view_dirty(entity);
1874        }
1875        self.invalidator.replace_views(views);
1876    }
1877
1878    #[profiling::function]
1879    fn present(&self) {
1880        self.platform_window.draw(&self.rendered_frame.scene);
1881        self.needs_present.set(false);
1882        profiling::finish_frame!();
1883    }
1884
1885    fn draw_roots(&mut self, cx: &mut App) {
1886        self.invalidator.set_phase(DrawPhase::Prepaint);
1887        self.tooltip_bounds.take();
1888
1889        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
1890        let root_size = {
1891            #[cfg(any(feature = "inspector", debug_assertions))]
1892            {
1893                if self.inspector.is_some() {
1894                    let mut size = self.viewport_size;
1895                    size.width = (size.width - _inspector_width).max(px(0.0));
1896                    size
1897                } else {
1898                    self.viewport_size
1899                }
1900            }
1901            #[cfg(not(any(feature = "inspector", debug_assertions)))]
1902            {
1903                self.viewport_size
1904            }
1905        };
1906
1907        // Layout all root elements.
1908        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
1909        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1910
1911        #[cfg(any(feature = "inspector", debug_assertions))]
1912        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
1913
1914        let mut sorted_deferred_draws =
1915            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1916        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
1917        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
1918
1919        let mut prompt_element = None;
1920        let mut active_drag_element = None;
1921        let mut tooltip_element = None;
1922        if let Some(prompt) = self.prompt.take() {
1923            let mut element = prompt.view.any_view().into_any();
1924            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
1925            prompt_element = Some(element);
1926            self.prompt = Some(prompt);
1927        } else if let Some(active_drag) = cx.active_drag.take() {
1928            let mut element = active_drag.view.clone().into_any();
1929            let offset = self.mouse_position() - active_drag.cursor_offset;
1930            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
1931            active_drag_element = Some(element);
1932            cx.active_drag = Some(active_drag);
1933        } else {
1934            tooltip_element = self.prepaint_tooltip(cx);
1935        }
1936
1937        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
1938
1939        // Now actually paint the elements.
1940        self.invalidator.set_phase(DrawPhase::Paint);
1941        root_element.paint(self, cx);
1942
1943        #[cfg(any(feature = "inspector", debug_assertions))]
1944        self.paint_inspector(inspector_element, cx);
1945
1946        self.paint_deferred_draws(&sorted_deferred_draws, cx);
1947
1948        if let Some(mut prompt_element) = prompt_element {
1949            prompt_element.paint(self, cx);
1950        } else if let Some(mut drag_element) = active_drag_element {
1951            drag_element.paint(self, cx);
1952        } else if let Some(mut tooltip_element) = tooltip_element {
1953            tooltip_element.paint(self, cx);
1954        }
1955
1956        #[cfg(any(feature = "inspector", debug_assertions))]
1957        self.paint_inspector_hitbox(cx);
1958    }
1959
1960    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
1961        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
1962        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
1963            let Some(Some(tooltip_request)) = self
1964                .next_frame
1965                .tooltip_requests
1966                .get(tooltip_request_index)
1967                .cloned()
1968            else {
1969                log::error!("Unexpectedly absent TooltipRequest");
1970                continue;
1971            };
1972            let mut element = tooltip_request.tooltip.view.clone().into_any();
1973            let mouse_position = tooltip_request.tooltip.mouse_position;
1974            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
1975
1976            let mut tooltip_bounds =
1977                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1978            let window_bounds = Bounds {
1979                origin: Point::default(),
1980                size: self.viewport_size(),
1981            };
1982
1983            if tooltip_bounds.right() > window_bounds.right() {
1984                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1985                if new_x >= Pixels::ZERO {
1986                    tooltip_bounds.origin.x = new_x;
1987                } else {
1988                    tooltip_bounds.origin.x = cmp::max(
1989                        Pixels::ZERO,
1990                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1991                    );
1992                }
1993            }
1994
1995            if tooltip_bounds.bottom() > window_bounds.bottom() {
1996                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1997                if new_y >= Pixels::ZERO {
1998                    tooltip_bounds.origin.y = new_y;
1999                } else {
2000                    tooltip_bounds.origin.y = cmp::max(
2001                        Pixels::ZERO,
2002                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
2003                    );
2004                }
2005            }
2006
2007            // It's possible for an element to have an active tooltip while not being painted (e.g.
2008            // via the `visible_on_hover` method). Since mouse listeners are not active in this
2009            // case, instead update the tooltip's visibility here.
2010            let is_visible =
2011                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
2012            if !is_visible {
2013                continue;
2014            }
2015
2016            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2017                element.prepaint(window, cx)
2018            });
2019
2020            self.tooltip_bounds = Some(TooltipBounds {
2021                id: tooltip_request.id,
2022                bounds: tooltip_bounds,
2023            });
2024            return Some(element);
2025        }
2026        None
2027    }
2028
2029    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2030        assert_eq!(self.element_id_stack.len(), 0);
2031
2032        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2033        for deferred_draw_ix in deferred_draw_indices {
2034            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2035            self.element_id_stack
2036                .clone_from(&deferred_draw.element_id_stack);
2037            self.text_style_stack
2038                .clone_from(&deferred_draw.text_style_stack);
2039            self.next_frame
2040                .dispatch_tree
2041                .set_active_node(deferred_draw.parent_node);
2042
2043            let prepaint_start = self.prepaint_index();
2044            if let Some(element) = deferred_draw.element.as_mut() {
2045                self.with_rendered_view(deferred_draw.current_view, |window| {
2046                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
2047                        element.prepaint(window, cx)
2048                    });
2049                })
2050            } else {
2051                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2052            }
2053            let prepaint_end = self.prepaint_index();
2054            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2055        }
2056        assert_eq!(
2057            self.next_frame.deferred_draws.len(),
2058            0,
2059            "cannot call defer_draw during deferred drawing"
2060        );
2061        self.next_frame.deferred_draws = deferred_draws;
2062        self.element_id_stack.clear();
2063        self.text_style_stack.clear();
2064    }
2065
2066    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2067        assert_eq!(self.element_id_stack.len(), 0);
2068
2069        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2070        for deferred_draw_ix in deferred_draw_indices {
2071            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2072            self.element_id_stack
2073                .clone_from(&deferred_draw.element_id_stack);
2074            self.next_frame
2075                .dispatch_tree
2076                .set_active_node(deferred_draw.parent_node);
2077
2078            let paint_start = self.paint_index();
2079            if let Some(element) = deferred_draw.element.as_mut() {
2080                self.with_rendered_view(deferred_draw.current_view, |window| {
2081                    element.paint(window, cx);
2082                })
2083            } else {
2084                self.reuse_paint(deferred_draw.paint_range.clone());
2085            }
2086            let paint_end = self.paint_index();
2087            deferred_draw.paint_range = paint_start..paint_end;
2088        }
2089        self.next_frame.deferred_draws = deferred_draws;
2090        self.element_id_stack.clear();
2091    }
2092
2093    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2094        PrepaintStateIndex {
2095            hitboxes_index: self.next_frame.hitboxes.len(),
2096            tooltips_index: self.next_frame.tooltip_requests.len(),
2097            deferred_draws_index: self.next_frame.deferred_draws.len(),
2098            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2099            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2100            line_layout_index: self.text_system.layout_index(),
2101        }
2102    }
2103
2104    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2105        self.next_frame.hitboxes.extend(
2106            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2107                .iter()
2108                .cloned(),
2109        );
2110        self.next_frame.tooltip_requests.extend(
2111            self.rendered_frame.tooltip_requests
2112                [range.start.tooltips_index..range.end.tooltips_index]
2113                .iter_mut()
2114                .map(|request| request.take()),
2115        );
2116        self.next_frame.accessed_element_states.extend(
2117            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2118                ..range.end.accessed_element_states_index]
2119                .iter()
2120                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2121        );
2122        self.text_system
2123            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2124
2125        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2126            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2127            &mut self.rendered_frame.dispatch_tree,
2128            self.focus,
2129        );
2130
2131        if reused_subtree.contains_focus() {
2132            self.next_frame.focus = self.focus;
2133        }
2134
2135        self.next_frame.deferred_draws.extend(
2136            self.rendered_frame.deferred_draws
2137                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2138                .iter()
2139                .map(|deferred_draw| DeferredDraw {
2140                    current_view: deferred_draw.current_view,
2141                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2142                    element_id_stack: deferred_draw.element_id_stack.clone(),
2143                    text_style_stack: deferred_draw.text_style_stack.clone(),
2144                    priority: deferred_draw.priority,
2145                    element: None,
2146                    absolute_offset: deferred_draw.absolute_offset,
2147                    prepaint_range: deferred_draw.prepaint_range.clone(),
2148                    paint_range: deferred_draw.paint_range.clone(),
2149                }),
2150        );
2151    }
2152
2153    pub(crate) fn paint_index(&self) -> PaintIndex {
2154        PaintIndex {
2155            scene_index: self.next_frame.scene.len(),
2156            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2157            input_handlers_index: self.next_frame.input_handlers.len(),
2158            cursor_styles_index: self.next_frame.cursor_styles.len(),
2159            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2160            line_layout_index: self.text_system.layout_index(),
2161        }
2162    }
2163
2164    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2165        self.next_frame.cursor_styles.extend(
2166            self.rendered_frame.cursor_styles
2167                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2168                .iter()
2169                .cloned(),
2170        );
2171        self.next_frame.input_handlers.extend(
2172            self.rendered_frame.input_handlers
2173                [range.start.input_handlers_index..range.end.input_handlers_index]
2174                .iter_mut()
2175                .map(|handler| handler.take()),
2176        );
2177        self.next_frame.mouse_listeners.extend(
2178            self.rendered_frame.mouse_listeners
2179                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2180                .iter_mut()
2181                .map(|listener| listener.take()),
2182        );
2183        self.next_frame.accessed_element_states.extend(
2184            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2185                ..range.end.accessed_element_states_index]
2186                .iter()
2187                .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
2188        );
2189
2190        self.text_system
2191            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2192        self.next_frame.scene.replay(
2193            range.start.scene_index..range.end.scene_index,
2194            &self.rendered_frame.scene,
2195        );
2196    }
2197
2198    /// Push a text style onto the stack, and call a function with that style active.
2199    /// Use [`Window::text_style`] to get the current, combined text style. This method
2200    /// should only be called as part of element drawing.
2201    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2202    where
2203        F: FnOnce(&mut Self) -> R,
2204    {
2205        self.invalidator.debug_assert_paint_or_prepaint();
2206        if let Some(style) = style {
2207            self.text_style_stack.push(style);
2208            let result = f(self);
2209            self.text_style_stack.pop();
2210            result
2211        } else {
2212            f(self)
2213        }
2214    }
2215
2216    /// Updates the cursor style at the platform level. This method should only be called
2217    /// during the prepaint phase of element drawing.
2218    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2219        self.invalidator.debug_assert_paint();
2220        self.next_frame.cursor_styles.push(CursorStyleRequest {
2221            hitbox_id: Some(hitbox.id),
2222            style,
2223        });
2224    }
2225
2226    /// Updates the cursor style for the entire window at the platform level. A cursor
2227    /// style using this method will have precedence over any cursor style set using
2228    /// `set_cursor_style`. This method should only be called during the prepaint
2229    /// phase of element drawing.
2230    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2231        self.invalidator.debug_assert_paint();
2232        self.next_frame.cursor_styles.push(CursorStyleRequest {
2233            hitbox_id: None,
2234            style,
2235        })
2236    }
2237
2238    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2239    /// during the paint phase of element drawing.
2240    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2241        self.invalidator.debug_assert_prepaint();
2242        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2243        self.next_frame
2244            .tooltip_requests
2245            .push(Some(TooltipRequest { id, tooltip }));
2246        id
2247    }
2248
2249    /// Invoke the given function with the given content mask after intersecting it
2250    /// with the current mask. This method should only be called during element drawing.
2251    pub fn with_content_mask<R>(
2252        &mut self,
2253        mask: Option<ContentMask<Pixels>>,
2254        f: impl FnOnce(&mut Self) -> R,
2255    ) -> R {
2256        self.invalidator.debug_assert_paint_or_prepaint();
2257        if let Some(mask) = mask {
2258            let mask = mask.intersect(&self.content_mask());
2259            self.content_mask_stack.push(mask);
2260            let result = f(self);
2261            self.content_mask_stack.pop();
2262            result
2263        } else {
2264            f(self)
2265        }
2266    }
2267
2268    /// Updates the global element offset relative to the current offset. This is used to implement
2269    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2270    pub fn with_element_offset<R>(
2271        &mut self,
2272        offset: Point<Pixels>,
2273        f: impl FnOnce(&mut Self) -> R,
2274    ) -> R {
2275        self.invalidator.debug_assert_prepaint();
2276
2277        if offset.is_zero() {
2278            return f(self);
2279        };
2280
2281        let abs_offset = self.element_offset() + offset;
2282        self.with_absolute_element_offset(abs_offset, f)
2283    }
2284
2285    /// Updates the global element offset based on the given offset. This is used to implement
2286    /// drag handles and other manual painting of elements. This method should only be called during
2287    /// the prepaint phase of element drawing.
2288    pub fn with_absolute_element_offset<R>(
2289        &mut self,
2290        offset: Point<Pixels>,
2291        f: impl FnOnce(&mut Self) -> R,
2292    ) -> R {
2293        self.invalidator.debug_assert_prepaint();
2294        self.element_offset_stack.push(offset);
2295        let result = f(self);
2296        self.element_offset_stack.pop();
2297        result
2298    }
2299
2300    pub(crate) fn with_element_opacity<R>(
2301        &mut self,
2302        opacity: Option<f32>,
2303        f: impl FnOnce(&mut Self) -> R,
2304    ) -> R {
2305        if opacity.is_none() {
2306            return f(self);
2307        }
2308
2309        self.invalidator.debug_assert_paint_or_prepaint();
2310        self.element_opacity = opacity;
2311        let result = f(self);
2312        self.element_opacity = None;
2313        result
2314    }
2315
2316    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2317    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2318    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2319    /// element offset and prepaint again. See [`List`] for an example. This method should only be
2320    /// called during the prepaint phase of element drawing.
2321    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2322        self.invalidator.debug_assert_prepaint();
2323        let index = self.prepaint_index();
2324        let result = f(self);
2325        if result.is_err() {
2326            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2327            self.next_frame
2328                .tooltip_requests
2329                .truncate(index.tooltips_index);
2330            self.next_frame
2331                .deferred_draws
2332                .truncate(index.deferred_draws_index);
2333            self.next_frame
2334                .dispatch_tree
2335                .truncate(index.dispatch_tree_index);
2336            self.next_frame
2337                .accessed_element_states
2338                .truncate(index.accessed_element_states_index);
2339            self.text_system.truncate_layouts(index.line_layout_index);
2340        }
2341        result
2342    }
2343
2344    /// When you call this method during [`prepaint`], containing elements will attempt to
2345    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2346    /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
2347    /// that supports this method being called on the elements it contains. This method should only be
2348    /// called during the prepaint phase of element drawing.
2349    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2350        self.invalidator.debug_assert_prepaint();
2351        self.requested_autoscroll = Some(bounds);
2352    }
2353
2354    /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
2355    /// described in [`request_autoscroll`].
2356    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2357        self.invalidator.debug_assert_prepaint();
2358        self.requested_autoscroll.take()
2359    }
2360
2361    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2362    /// Your view will be re-drawn once the asset has finished loading.
2363    ///
2364    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2365    /// time.
2366    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2367        let (task, is_first) = cx.fetch_asset::<A>(source);
2368        task.clone().now_or_never().or_else(|| {
2369            if is_first {
2370                let entity_id = self.current_view();
2371                self.spawn(cx, {
2372                    let task = task.clone();
2373                    async move |cx| {
2374                        task.await;
2375
2376                        cx.on_next_frame(move |_, cx| {
2377                            cx.notify(entity_id);
2378                        });
2379                    }
2380                })
2381                .detach();
2382            }
2383
2384            None
2385        })
2386    }
2387
2388    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2389    /// Your view will not be re-drawn once the asset has finished loading.
2390    ///
2391    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2392    /// time.
2393    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2394        let (task, _) = cx.fetch_asset::<A>(source);
2395        task.clone().now_or_never()
2396    }
2397    /// Obtain the current element offset. This method should only be called during the
2398    /// prepaint phase of element drawing.
2399    pub fn element_offset(&self) -> Point<Pixels> {
2400        self.invalidator.debug_assert_prepaint();
2401        self.element_offset_stack
2402            .last()
2403            .copied()
2404            .unwrap_or_default()
2405    }
2406
2407    /// Obtain the current element opacity. This method should only be called during the
2408    /// prepaint phase of element drawing.
2409    pub(crate) fn element_opacity(&self) -> f32 {
2410        self.invalidator.debug_assert_paint_or_prepaint();
2411        self.element_opacity.unwrap_or(1.0)
2412    }
2413
2414    /// Obtain the current content mask. This method should only be called during element drawing.
2415    pub fn content_mask(&self) -> ContentMask<Pixels> {
2416        self.invalidator.debug_assert_paint_or_prepaint();
2417        self.content_mask_stack
2418            .last()
2419            .cloned()
2420            .unwrap_or_else(|| ContentMask {
2421                bounds: Bounds {
2422                    origin: Point::default(),
2423                    size: self.viewport_size,
2424                },
2425            })
2426    }
2427
2428    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2429    /// This can be used within a custom element to distinguish multiple sets of child elements.
2430    pub fn with_element_namespace<R>(
2431        &mut self,
2432        element_id: impl Into<ElementId>,
2433        f: impl FnOnce(&mut Self) -> R,
2434    ) -> R {
2435        self.element_id_stack.push(element_id.into());
2436        let result = f(self);
2437        self.element_id_stack.pop();
2438        result
2439    }
2440
2441    /// Updates or initializes state for an element with the given id that lives across multiple
2442    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2443    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2444    /// when drawing the next frame. This method should only be called as part of element drawing.
2445    pub fn with_element_state<S, R>(
2446        &mut self,
2447        global_id: &GlobalElementId,
2448        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2449    ) -> R
2450    where
2451        S: 'static,
2452    {
2453        self.invalidator.debug_assert_paint_or_prepaint();
2454
2455        let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2456        self.next_frame
2457            .accessed_element_states
2458            .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2459
2460        if let Some(any) = self
2461            .next_frame
2462            .element_states
2463            .remove(&key)
2464            .or_else(|| self.rendered_frame.element_states.remove(&key))
2465        {
2466            let ElementStateBox {
2467                inner,
2468                #[cfg(debug_assertions)]
2469                type_name,
2470            } = any;
2471            // Using the extra inner option to avoid needing to reallocate a new box.
2472            let mut state_box = inner
2473                .downcast::<Option<S>>()
2474                .map_err(|_| {
2475                    #[cfg(debug_assertions)]
2476                    {
2477                        anyhow::anyhow!(
2478                            "invalid element state type for id, requested {:?}, actual: {:?}",
2479                            std::any::type_name::<S>(),
2480                            type_name
2481                        )
2482                    }
2483
2484                    #[cfg(not(debug_assertions))]
2485                    {
2486                        anyhow::anyhow!(
2487                            "invalid element state type for id, requested {:?}",
2488                            std::any::type_name::<S>(),
2489                        )
2490                    }
2491                })
2492                .unwrap();
2493
2494            let state = state_box.take().expect(
2495                "reentrant call to with_element_state for the same state type and element id",
2496            );
2497            let (result, state) = f(Some(state), self);
2498            state_box.replace(state);
2499            self.next_frame.element_states.insert(
2500                key,
2501                ElementStateBox {
2502                    inner: state_box,
2503                    #[cfg(debug_assertions)]
2504                    type_name,
2505                },
2506            );
2507            result
2508        } else {
2509            let (result, state) = f(None, self);
2510            self.next_frame.element_states.insert(
2511                key,
2512                ElementStateBox {
2513                    inner: Box::new(Some(state)),
2514                    #[cfg(debug_assertions)]
2515                    type_name: std::any::type_name::<S>(),
2516                },
2517            );
2518            result
2519        }
2520    }
2521
2522    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2523    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2524    /// when the element is guaranteed to have an id.
2525    ///
2526    /// The first option means 'no ID provided'
2527    /// The second option means 'not yet initialized'
2528    pub fn with_optional_element_state<S, R>(
2529        &mut self,
2530        global_id: Option<&GlobalElementId>,
2531        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2532    ) -> R
2533    where
2534        S: 'static,
2535    {
2536        self.invalidator.debug_assert_paint_or_prepaint();
2537
2538        if let Some(global_id) = global_id {
2539            self.with_element_state(global_id, |state, cx| {
2540                let (result, state) = f(Some(state), cx);
2541                let state =
2542                    state.expect("you must return some state when you pass some element id");
2543                (result, state)
2544            })
2545        } else {
2546            let (result, state) = f(None, self);
2547            debug_assert!(
2548                state.is_none(),
2549                "you must not return an element state when passing None for the global id"
2550            );
2551            result
2552        }
2553    }
2554
2555    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2556    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2557    /// with higher values being drawn on top.
2558    ///
2559    /// This method should only be called as part of the prepaint phase of element drawing.
2560    pub fn defer_draw(
2561        &mut self,
2562        element: AnyElement,
2563        absolute_offset: Point<Pixels>,
2564        priority: usize,
2565    ) {
2566        self.invalidator.debug_assert_prepaint();
2567        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2568        self.next_frame.deferred_draws.push(DeferredDraw {
2569            current_view: self.current_view(),
2570            parent_node,
2571            element_id_stack: self.element_id_stack.clone(),
2572            text_style_stack: self.text_style_stack.clone(),
2573            priority,
2574            element: Some(element),
2575            absolute_offset,
2576            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2577            paint_range: PaintIndex::default()..PaintIndex::default(),
2578        });
2579    }
2580
2581    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2582    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2583    /// for performance reasons.
2584    ///
2585    /// This method should only be called as part of the paint phase of element drawing.
2586    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2587        self.invalidator.debug_assert_paint();
2588
2589        let scale_factor = self.scale_factor();
2590        let content_mask = self.content_mask();
2591        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2592        if !clipped_bounds.is_empty() {
2593            self.next_frame
2594                .scene
2595                .push_layer(clipped_bounds.scale(scale_factor));
2596        }
2597
2598        let result = f(self);
2599
2600        if !clipped_bounds.is_empty() {
2601            self.next_frame.scene.pop_layer();
2602        }
2603
2604        result
2605    }
2606
2607    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2608    ///
2609    /// This method should only be called as part of the paint phase of element drawing.
2610    pub fn paint_shadows(
2611        &mut self,
2612        bounds: Bounds<Pixels>,
2613        corner_radii: Corners<Pixels>,
2614        shadows: &[BoxShadow],
2615    ) {
2616        self.invalidator.debug_assert_paint();
2617
2618        let scale_factor = self.scale_factor();
2619        let content_mask = self.content_mask();
2620        let opacity = self.element_opacity();
2621        for shadow in shadows {
2622            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2623            self.next_frame.scene.insert_primitive(Shadow {
2624                order: 0,
2625                blur_radius: shadow.blur_radius.scale(scale_factor),
2626                bounds: shadow_bounds.scale(scale_factor),
2627                content_mask: content_mask.scale(scale_factor),
2628                corner_radii: corner_radii.scale(scale_factor),
2629                color: shadow.color.opacity(opacity),
2630            });
2631        }
2632    }
2633
2634    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2635    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2636    /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2637    ///
2638    /// This method should only be called as part of the paint phase of element drawing.
2639    ///
2640    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2641    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2642    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2643    pub fn paint_quad(&mut self, quad: PaintQuad) {
2644        self.invalidator.debug_assert_paint();
2645
2646        let scale_factor = self.scale_factor();
2647        let content_mask = self.content_mask();
2648        let opacity = self.element_opacity();
2649        self.next_frame.scene.insert_primitive(Quad {
2650            order: 0,
2651            bounds: quad.bounds.scale(scale_factor),
2652            content_mask: content_mask.scale(scale_factor),
2653            background: quad.background.opacity(opacity),
2654            border_color: quad.border_color.opacity(opacity),
2655            corner_radii: quad.corner_radii.scale(scale_factor),
2656            border_widths: quad.border_widths.scale(scale_factor),
2657            border_style: quad.border_style,
2658        });
2659    }
2660
2661    /// Paint the given `Path` into the scene for the next frame at the current z-index.
2662    ///
2663    /// This method should only be called as part of the paint phase of element drawing.
2664    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2665        self.invalidator.debug_assert_paint();
2666
2667        let scale_factor = self.scale_factor();
2668        let content_mask = self.content_mask();
2669        let opacity = self.element_opacity();
2670        path.content_mask = content_mask;
2671        let color: Background = color.into();
2672        path.color = color.opacity(opacity);
2673        self.next_frame
2674            .scene
2675            .insert_primitive(path.apply_scale(scale_factor));
2676    }
2677
2678    /// Paint an underline into the scene for the next frame at the current z-index.
2679    ///
2680    /// This method should only be called as part of the paint phase of element drawing.
2681    pub fn paint_underline(
2682        &mut self,
2683        origin: Point<Pixels>,
2684        width: Pixels,
2685        style: &UnderlineStyle,
2686    ) {
2687        self.invalidator.debug_assert_paint();
2688
2689        let scale_factor = self.scale_factor();
2690        let height = if style.wavy {
2691            style.thickness * 3.
2692        } else {
2693            style.thickness
2694        };
2695        let bounds = Bounds {
2696            origin,
2697            size: size(width, height),
2698        };
2699        let content_mask = self.content_mask();
2700        let element_opacity = self.element_opacity();
2701
2702        self.next_frame.scene.insert_primitive(Underline {
2703            order: 0,
2704            pad: 0,
2705            bounds: bounds.scale(scale_factor),
2706            content_mask: content_mask.scale(scale_factor),
2707            color: style.color.unwrap_or_default().opacity(element_opacity),
2708            thickness: style.thickness.scale(scale_factor),
2709            wavy: style.wavy,
2710        });
2711    }
2712
2713    /// Paint a strikethrough into the scene for the next frame at the current z-index.
2714    ///
2715    /// This method should only be called as part of the paint phase of element drawing.
2716    pub fn paint_strikethrough(
2717        &mut self,
2718        origin: Point<Pixels>,
2719        width: Pixels,
2720        style: &StrikethroughStyle,
2721    ) {
2722        self.invalidator.debug_assert_paint();
2723
2724        let scale_factor = self.scale_factor();
2725        let height = style.thickness;
2726        let bounds = Bounds {
2727            origin,
2728            size: size(width, height),
2729        };
2730        let content_mask = self.content_mask();
2731        let opacity = self.element_opacity();
2732
2733        self.next_frame.scene.insert_primitive(Underline {
2734            order: 0,
2735            pad: 0,
2736            bounds: bounds.scale(scale_factor),
2737            content_mask: content_mask.scale(scale_factor),
2738            thickness: style.thickness.scale(scale_factor),
2739            color: style.color.unwrap_or_default().opacity(opacity),
2740            wavy: false,
2741        });
2742    }
2743
2744    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2745    ///
2746    /// The y component of the origin is the baseline of the glyph.
2747    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2748    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2749    /// This method is only useful if you need to paint a single glyph that has already been shaped.
2750    ///
2751    /// This method should only be called as part of the paint phase of element drawing.
2752    pub fn paint_glyph(
2753        &mut self,
2754        origin: Point<Pixels>,
2755        font_id: FontId,
2756        glyph_id: GlyphId,
2757        font_size: Pixels,
2758        color: Hsla,
2759    ) -> Result<()> {
2760        self.invalidator.debug_assert_paint();
2761
2762        let element_opacity = self.element_opacity();
2763        let scale_factor = self.scale_factor();
2764        let glyph_origin = origin.scale(scale_factor);
2765        let subpixel_variant = Point {
2766            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2767            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2768        };
2769        let params = RenderGlyphParams {
2770            font_id,
2771            glyph_id,
2772            font_size,
2773            subpixel_variant,
2774            scale_factor,
2775            is_emoji: false,
2776        };
2777
2778        let raster_bounds = self.text_system().raster_bounds(&params)?;
2779        if !raster_bounds.is_zero() {
2780            let tile = self
2781                .sprite_atlas
2782                .get_or_insert_with(&params.clone().into(), &mut || {
2783                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2784                    Ok(Some((size, Cow::Owned(bytes))))
2785                })?
2786                .expect("Callback above only errors or returns Some");
2787            let bounds = Bounds {
2788                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2789                size: tile.bounds.size.map(Into::into),
2790            };
2791            let content_mask = self.content_mask().scale(scale_factor);
2792            self.next_frame.scene.insert_primitive(MonochromeSprite {
2793                order: 0,
2794                pad: 0,
2795                bounds,
2796                content_mask,
2797                color: color.opacity(element_opacity),
2798                tile,
2799                transformation: TransformationMatrix::unit(),
2800            });
2801        }
2802        Ok(())
2803    }
2804
2805    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2806    ///
2807    /// The y component of the origin is the baseline of the glyph.
2808    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2809    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2810    /// This method is only useful if you need to paint a single emoji that has already been shaped.
2811    ///
2812    /// This method should only be called as part of the paint phase of element drawing.
2813    pub fn paint_emoji(
2814        &mut self,
2815        origin: Point<Pixels>,
2816        font_id: FontId,
2817        glyph_id: GlyphId,
2818        font_size: Pixels,
2819    ) -> Result<()> {
2820        self.invalidator.debug_assert_paint();
2821
2822        let scale_factor = self.scale_factor();
2823        let glyph_origin = origin.scale(scale_factor);
2824        let params = RenderGlyphParams {
2825            font_id,
2826            glyph_id,
2827            font_size,
2828            // We don't render emojis with subpixel variants.
2829            subpixel_variant: Default::default(),
2830            scale_factor,
2831            is_emoji: true,
2832        };
2833
2834        let raster_bounds = self.text_system().raster_bounds(&params)?;
2835        if !raster_bounds.is_zero() {
2836            let tile = self
2837                .sprite_atlas
2838                .get_or_insert_with(&params.clone().into(), &mut || {
2839                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2840                    Ok(Some((size, Cow::Owned(bytes))))
2841                })?
2842                .expect("Callback above only errors or returns Some");
2843
2844            let bounds = Bounds {
2845                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2846                size: tile.bounds.size.map(Into::into),
2847            };
2848            let content_mask = self.content_mask().scale(scale_factor);
2849            let opacity = self.element_opacity();
2850
2851            self.next_frame.scene.insert_primitive(PolychromeSprite {
2852                order: 0,
2853                pad: 0,
2854                grayscale: false,
2855                bounds,
2856                corner_radii: Default::default(),
2857                content_mask,
2858                tile,
2859                opacity,
2860            });
2861        }
2862        Ok(())
2863    }
2864
2865    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2866    ///
2867    /// This method should only be called as part of the paint phase of element drawing.
2868    pub fn paint_svg(
2869        &mut self,
2870        bounds: Bounds<Pixels>,
2871        path: SharedString,
2872        transformation: TransformationMatrix,
2873        color: Hsla,
2874        cx: &App,
2875    ) -> Result<()> {
2876        self.invalidator.debug_assert_paint();
2877
2878        let element_opacity = self.element_opacity();
2879        let scale_factor = self.scale_factor();
2880        let bounds = bounds.scale(scale_factor);
2881        let params = RenderSvgParams {
2882            path,
2883            size: bounds.size.map(|pixels| {
2884                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
2885            }),
2886        };
2887
2888        let Some(tile) =
2889            self.sprite_atlas
2890                .get_or_insert_with(&params.clone().into(), &mut || {
2891                    let Some(bytes) = cx.svg_renderer.render(&params)? else {
2892                        return Ok(None);
2893                    };
2894                    Ok(Some((params.size, Cow::Owned(bytes))))
2895                })?
2896        else {
2897            return Ok(());
2898        };
2899        let content_mask = self.content_mask().scale(scale_factor);
2900
2901        self.next_frame.scene.insert_primitive(MonochromeSprite {
2902            order: 0,
2903            pad: 0,
2904            bounds: bounds
2905                .map_origin(|origin| origin.floor())
2906                .map_size(|size| size.ceil()),
2907            content_mask,
2908            color: color.opacity(element_opacity),
2909            tile,
2910            transformation,
2911        });
2912
2913        Ok(())
2914    }
2915
2916    /// Paint an image into the scene for the next frame at the current z-index.
2917    /// This method will panic if the frame_index is not valid
2918    ///
2919    /// This method should only be called as part of the paint phase of element drawing.
2920    pub fn paint_image(
2921        &mut self,
2922        bounds: Bounds<Pixels>,
2923        corner_radii: Corners<Pixels>,
2924        data: Arc<RenderImage>,
2925        frame_index: usize,
2926        grayscale: bool,
2927    ) -> Result<()> {
2928        self.invalidator.debug_assert_paint();
2929
2930        let scale_factor = self.scale_factor();
2931        let bounds = bounds.scale(scale_factor);
2932        let params = RenderImageParams {
2933            image_id: data.id,
2934            frame_index,
2935        };
2936
2937        let tile = self
2938            .sprite_atlas
2939            .get_or_insert_with(&params.clone().into(), &mut || {
2940                Ok(Some((
2941                    data.size(frame_index),
2942                    Cow::Borrowed(
2943                        data.as_bytes(frame_index)
2944                            .expect("It's the caller's job to pass a valid frame index"),
2945                    ),
2946                )))
2947            })?
2948            .expect("Callback above only returns Some");
2949        let content_mask = self.content_mask().scale(scale_factor);
2950        let corner_radii = corner_radii.scale(scale_factor);
2951        let opacity = self.element_opacity();
2952
2953        self.next_frame.scene.insert_primitive(PolychromeSprite {
2954            order: 0,
2955            pad: 0,
2956            grayscale,
2957            bounds: bounds
2958                .map_origin(|origin| origin.floor())
2959                .map_size(|size| size.ceil()),
2960            content_mask,
2961            corner_radii,
2962            tile,
2963            opacity,
2964        });
2965        Ok(())
2966    }
2967
2968    /// Paint a surface into the scene for the next frame at the current z-index.
2969    ///
2970    /// This method should only be called as part of the paint phase of element drawing.
2971    #[cfg(target_os = "macos")]
2972    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
2973        use crate::PaintSurface;
2974
2975        self.invalidator.debug_assert_paint();
2976
2977        let scale_factor = self.scale_factor();
2978        let bounds = bounds.scale(scale_factor);
2979        let content_mask = self.content_mask().scale(scale_factor);
2980        self.next_frame.scene.insert_primitive(PaintSurface {
2981            order: 0,
2982            bounds,
2983            content_mask,
2984            image_buffer,
2985        });
2986    }
2987
2988    /// Removes an image from the sprite atlas.
2989    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2990        for frame_index in 0..data.frame_count() {
2991            let params = RenderImageParams {
2992                image_id: data.id,
2993                frame_index,
2994            };
2995
2996            self.sprite_atlas.remove(&params.clone().into());
2997        }
2998
2999        Ok(())
3000    }
3001
3002    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
3003    /// layout is being requested, along with the layout ids of any children. This method is called during
3004    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
3005    ///
3006    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3007    #[must_use]
3008    pub fn request_layout(
3009        &mut self,
3010        style: Style,
3011        children: impl IntoIterator<Item = LayoutId>,
3012        cx: &mut App,
3013    ) -> LayoutId {
3014        self.invalidator.debug_assert_prepaint();
3015
3016        cx.layout_id_buffer.clear();
3017        cx.layout_id_buffer.extend(children);
3018        let rem_size = self.rem_size();
3019
3020        self.layout_engine
3021            .as_mut()
3022            .unwrap()
3023            .request_layout(style, rem_size, &cx.layout_id_buffer)
3024    }
3025
3026    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3027    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3028    /// determine the element's size. One place this is used internally is when measuring text.
3029    ///
3030    /// The given closure is invoked at layout time with the known dimensions and available space and
3031    /// returns a `Size`.
3032    ///
3033    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3034    pub fn request_measured_layout<
3035        F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3036            + 'static,
3037    >(
3038        &mut self,
3039        style: Style,
3040        measure: F,
3041    ) -> LayoutId {
3042        self.invalidator.debug_assert_prepaint();
3043
3044        let rem_size = self.rem_size();
3045        self.layout_engine
3046            .as_mut()
3047            .unwrap()
3048            .request_measured_layout(style, rem_size, measure)
3049    }
3050
3051    /// Compute the layout for the given id within the given available space.
3052    /// This method is called for its side effect, typically by the framework prior to painting.
3053    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3054    ///
3055    /// This method should only be called as part of the prepaint phase of element drawing.
3056    pub fn compute_layout(
3057        &mut self,
3058        layout_id: LayoutId,
3059        available_space: Size<AvailableSpace>,
3060        cx: &mut App,
3061    ) {
3062        self.invalidator.debug_assert_prepaint();
3063
3064        let mut layout_engine = self.layout_engine.take().unwrap();
3065        layout_engine.compute_layout(layout_id, available_space, self, cx);
3066        self.layout_engine = Some(layout_engine);
3067    }
3068
3069    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3070    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3071    ///
3072    /// This method should only be called as part of element drawing.
3073    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3074        self.invalidator.debug_assert_prepaint();
3075
3076        let mut bounds = self
3077            .layout_engine
3078            .as_mut()
3079            .unwrap()
3080            .layout_bounds(layout_id)
3081            .map(Into::into);
3082        bounds.origin += self.element_offset();
3083        bounds
3084    }
3085
3086    /// This method should be called during `prepaint`. You can use
3087    /// the returned [Hitbox] during `paint` or in an event handler
3088    /// to determine whether the inserted hitbox was the topmost.
3089    ///
3090    /// This method should only be called as part of the prepaint phase of element drawing.
3091    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3092        self.invalidator.debug_assert_prepaint();
3093
3094        let content_mask = self.content_mask();
3095        let mut id = self.next_hitbox_id;
3096        self.next_hitbox_id = self.next_hitbox_id.next();
3097        let hitbox = Hitbox {
3098            id,
3099            bounds,
3100            content_mask,
3101            behavior,
3102        };
3103        self.next_frame.hitboxes.push(hitbox.clone());
3104        hitbox
3105    }
3106
3107    /// Set a hitbox which will act as a control area of the platform window.
3108    ///
3109    /// This method should only be called as part of the paint phase of element drawing.
3110    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3111        self.invalidator.debug_assert_paint();
3112        self.next_frame.window_control_hitboxes.push((area, hitbox));
3113    }
3114
3115    /// Sets the key context for the current element. This context will be used to translate
3116    /// keybindings into actions.
3117    ///
3118    /// This method should only be called as part of the paint phase of element drawing.
3119    pub fn set_key_context(&mut self, context: KeyContext) {
3120        self.invalidator.debug_assert_paint();
3121        self.next_frame.dispatch_tree.set_key_context(context);
3122    }
3123
3124    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3125    /// and keyboard event dispatch for the element.
3126    ///
3127    /// This method should only be called as part of the prepaint phase of element drawing.
3128    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3129        self.invalidator.debug_assert_prepaint();
3130        if focus_handle.is_focused(self) {
3131            self.next_frame.focus = Some(focus_handle.id);
3132        }
3133        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3134    }
3135
3136    /// Sets the view id for the current element, which will be used to manage view caching.
3137    ///
3138    /// This method should only be called as part of element prepaint. We plan on removing this
3139    /// method eventually when we solve some issues that require us to construct editor elements
3140    /// directly instead of always using editors via views.
3141    pub fn set_view_id(&mut self, view_id: EntityId) {
3142        self.invalidator.debug_assert_prepaint();
3143        self.next_frame.dispatch_tree.set_view_id(view_id);
3144    }
3145
3146    /// Get the entity ID for the currently rendering view
3147    pub fn current_view(&self) -> EntityId {
3148        self.invalidator.debug_assert_paint_or_prepaint();
3149        self.rendered_entity_stack.last().copied().unwrap()
3150    }
3151
3152    pub(crate) fn with_rendered_view<R>(
3153        &mut self,
3154        id: EntityId,
3155        f: impl FnOnce(&mut Self) -> R,
3156    ) -> R {
3157        self.rendered_entity_stack.push(id);
3158        let result = f(self);
3159        self.rendered_entity_stack.pop();
3160        result
3161    }
3162
3163    /// Executes the provided function with the specified image cache.
3164    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3165    where
3166        F: FnOnce(&mut Self) -> R,
3167    {
3168        if let Some(image_cache) = image_cache {
3169            self.image_cache_stack.push(image_cache);
3170            let result = f(self);
3171            self.image_cache_stack.pop();
3172            result
3173        } else {
3174            f(self)
3175        }
3176    }
3177
3178    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3179    /// platform to receive textual input with proper integration with concerns such
3180    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3181    /// rendered.
3182    ///
3183    /// This method should only be called as part of the paint phase of element drawing.
3184    ///
3185    /// [element_input_handler]: crate::ElementInputHandler
3186    pub fn handle_input(
3187        &mut self,
3188        focus_handle: &FocusHandle,
3189        input_handler: impl InputHandler,
3190        cx: &App,
3191    ) {
3192        self.invalidator.debug_assert_paint();
3193
3194        if focus_handle.is_focused(self) {
3195            let cx = self.to_async(cx);
3196            self.next_frame
3197                .input_handlers
3198                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3199        }
3200    }
3201
3202    /// Register a mouse event listener on the window for the next frame. The type of event
3203    /// is determined by the first parameter of the given listener. When the next frame is rendered
3204    /// the listener will be cleared.
3205    ///
3206    /// This method should only be called as part of the paint phase of element drawing.
3207    pub fn on_mouse_event<Event: MouseEvent>(
3208        &mut self,
3209        mut handler: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3210    ) {
3211        self.invalidator.debug_assert_paint();
3212
3213        self.next_frame.mouse_listeners.push(Some(Box::new(
3214            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3215                if let Some(event) = event.downcast_ref() {
3216                    handler(event, phase, window, cx)
3217                }
3218            },
3219        )));
3220    }
3221
3222    /// Register a key event listener on the window for the next frame. The type of event
3223    /// is determined by the first parameter of the given listener. When the next frame is rendered
3224    /// the listener will be cleared.
3225    ///
3226    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3227    /// a specific need to register a global listener.
3228    ///
3229    /// This method should only be called as part of the paint phase of element drawing.
3230    pub fn on_key_event<Event: KeyEvent>(
3231        &mut self,
3232        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3233    ) {
3234        self.invalidator.debug_assert_paint();
3235
3236        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3237            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3238                if let Some(event) = event.downcast_ref::<Event>() {
3239                    listener(event, phase, window, cx)
3240                }
3241            },
3242        ));
3243    }
3244
3245    /// Register a modifiers changed event listener on the window for the next frame.
3246    ///
3247    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3248    /// a specific need to register a global listener.
3249    ///
3250    /// This method should only be called as part of the paint phase of element drawing.
3251    pub fn on_modifiers_changed(
3252        &mut self,
3253        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3254    ) {
3255        self.invalidator.debug_assert_paint();
3256
3257        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3258            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3259                listener(event, window, cx)
3260            },
3261        ));
3262    }
3263
3264    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3265    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3266    /// Returns a subscription and persists until the subscription is dropped.
3267    pub fn on_focus_in(
3268        &mut self,
3269        handle: &FocusHandle,
3270        cx: &mut App,
3271        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3272    ) -> Subscription {
3273        let focus_id = handle.id;
3274        let (subscription, activate) =
3275            self.new_focus_listener(Box::new(move |event, window, cx| {
3276                if event.is_focus_in(focus_id) {
3277                    listener(window, cx);
3278                }
3279                true
3280            }));
3281        cx.defer(move |_| activate());
3282        subscription
3283    }
3284
3285    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3286    /// Returns a subscription and persists until the subscription is dropped.
3287    pub fn on_focus_out(
3288        &mut self,
3289        handle: &FocusHandle,
3290        cx: &mut App,
3291        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3292    ) -> Subscription {
3293        let focus_id = handle.id;
3294        let (subscription, activate) =
3295            self.new_focus_listener(Box::new(move |event, window, cx| {
3296                if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3297                    if event.is_focus_out(focus_id) {
3298                        let event = FocusOutEvent {
3299                            blurred: WeakFocusHandle {
3300                                id: blurred_id,
3301                                handles: Arc::downgrade(&cx.focus_handles),
3302                            },
3303                        };
3304                        listener(event, window, cx)
3305                    }
3306                }
3307                true
3308            }));
3309        cx.defer(move |_| activate());
3310        subscription
3311    }
3312
3313    fn reset_cursor_style(&self, cx: &mut App) {
3314        // Set the cursor only if we're the active window.
3315        if self.is_window_hovered() {
3316            let style = self
3317                .rendered_frame
3318                .cursor_style(self)
3319                .unwrap_or(CursorStyle::Arrow);
3320            cx.platform.set_cursor_style(style);
3321        }
3322    }
3323
3324    /// Dispatch a given keystroke as though the user had typed it.
3325    /// You can create a keystroke with Keystroke::parse("").
3326    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3327        let keystroke = keystroke.with_simulated_ime();
3328        let result = self.dispatch_event(
3329            PlatformInput::KeyDown(KeyDownEvent {
3330                keystroke: keystroke.clone(),
3331                is_held: false,
3332            }),
3333            cx,
3334        );
3335        if !result.propagate {
3336            return true;
3337        }
3338
3339        if let Some(input) = keystroke.key_char {
3340            if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3341                input_handler.dispatch_input(&input, self, cx);
3342                self.platform_window.set_input_handler(input_handler);
3343                return true;
3344            }
3345        }
3346
3347        false
3348    }
3349
3350    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3351    /// binding for the action (last binding added to the keymap).
3352    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3353        self.highest_precedence_binding_for_action(action)
3354            .map(|binding| {
3355                binding
3356                    .keystrokes()
3357                    .iter()
3358                    .map(ToString::to_string)
3359                    .collect::<Vec<_>>()
3360                    .join(" ")
3361            })
3362            .unwrap_or_else(|| action.name().to_string())
3363    }
3364
3365    /// Dispatch a mouse or keyboard event on the window.
3366    #[profiling::function]
3367    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3368        self.last_input_timestamp.set(Instant::now());
3369        // Handlers may set this to false by calling `stop_propagation`.
3370        cx.propagate_event = true;
3371        // Handlers may set this to true by calling `prevent_default`.
3372        self.default_prevented = false;
3373
3374        let event = match event {
3375            // Track the mouse position with our own state, since accessing the platform
3376            // API for the mouse position can only occur on the main thread.
3377            PlatformInput::MouseMove(mouse_move) => {
3378                self.mouse_position = mouse_move.position;
3379                self.modifiers = mouse_move.modifiers;
3380                PlatformInput::MouseMove(mouse_move)
3381            }
3382            PlatformInput::MouseDown(mouse_down) => {
3383                self.mouse_position = mouse_down.position;
3384                self.modifiers = mouse_down.modifiers;
3385                PlatformInput::MouseDown(mouse_down)
3386            }
3387            PlatformInput::MouseUp(mouse_up) => {
3388                self.mouse_position = mouse_up.position;
3389                self.modifiers = mouse_up.modifiers;
3390                PlatformInput::MouseUp(mouse_up)
3391            }
3392            PlatformInput::MouseExited(mouse_exited) => {
3393                self.modifiers = mouse_exited.modifiers;
3394                PlatformInput::MouseExited(mouse_exited)
3395            }
3396            PlatformInput::ModifiersChanged(modifiers_changed) => {
3397                self.modifiers = modifiers_changed.modifiers;
3398                self.capslock = modifiers_changed.capslock;
3399                PlatformInput::ModifiersChanged(modifiers_changed)
3400            }
3401            PlatformInput::ScrollWheel(scroll_wheel) => {
3402                self.mouse_position = scroll_wheel.position;
3403                self.modifiers = scroll_wheel.modifiers;
3404                PlatformInput::ScrollWheel(scroll_wheel)
3405            }
3406            // Translate dragging and dropping of external files from the operating system
3407            // to internal drag and drop events.
3408            PlatformInput::FileDrop(file_drop) => match file_drop {
3409                FileDropEvent::Entered { position, paths } => {
3410                    self.mouse_position = position;
3411                    if cx.active_drag.is_none() {
3412                        cx.active_drag = Some(AnyDrag {
3413                            value: Arc::new(paths.clone()),
3414                            view: cx.new(|_| paths).into(),
3415                            cursor_offset: position,
3416                            cursor_style: None,
3417                        });
3418                    }
3419                    PlatformInput::MouseMove(MouseMoveEvent {
3420                        position,
3421                        pressed_button: Some(MouseButton::Left),
3422                        modifiers: Modifiers::default(),
3423                    })
3424                }
3425                FileDropEvent::Pending { position } => {
3426                    self.mouse_position = position;
3427                    PlatformInput::MouseMove(MouseMoveEvent {
3428                        position,
3429                        pressed_button: Some(MouseButton::Left),
3430                        modifiers: Modifiers::default(),
3431                    })
3432                }
3433                FileDropEvent::Submit { position } => {
3434                    cx.activate(true);
3435                    self.mouse_position = position;
3436                    PlatformInput::MouseUp(MouseUpEvent {
3437                        button: MouseButton::Left,
3438                        position,
3439                        modifiers: Modifiers::default(),
3440                        click_count: 1,
3441                    })
3442                }
3443                FileDropEvent::Exited => {
3444                    cx.active_drag.take();
3445                    PlatformInput::FileDrop(FileDropEvent::Exited)
3446                }
3447            },
3448            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3449        };
3450
3451        if let Some(any_mouse_event) = event.mouse_event() {
3452            self.dispatch_mouse_event(any_mouse_event, cx);
3453        } else if let Some(any_key_event) = event.keyboard_event() {
3454            self.dispatch_key_event(any_key_event, cx);
3455        }
3456
3457        DispatchEventResult {
3458            propagate: cx.propagate_event,
3459            default_prevented: self.default_prevented,
3460        }
3461    }
3462
3463    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3464        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3465        if hit_test != self.mouse_hit_test {
3466            self.mouse_hit_test = hit_test;
3467            self.reset_cursor_style(cx);
3468        }
3469
3470        #[cfg(any(feature = "inspector", debug_assertions))]
3471        if self.is_inspector_picking(cx) {
3472            self.handle_inspector_mouse_event(event, cx);
3473            // When inspector is picking, all other mouse handling is skipped.
3474            return;
3475        }
3476
3477        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3478
3479        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3480        // special purposes, such as detecting events outside of a given Bounds.
3481        for listener in &mut mouse_listeners {
3482            let listener = listener.as_mut().unwrap();
3483            listener(event, DispatchPhase::Capture, self, cx);
3484            if !cx.propagate_event {
3485                break;
3486            }
3487        }
3488
3489        // Bubble phase, where most normal handlers do their work.
3490        if cx.propagate_event {
3491            for listener in mouse_listeners.iter_mut().rev() {
3492                let listener = listener.as_mut().unwrap();
3493                listener(event, DispatchPhase::Bubble, self, cx);
3494                if !cx.propagate_event {
3495                    break;
3496                }
3497            }
3498        }
3499
3500        self.rendered_frame.mouse_listeners = mouse_listeners;
3501
3502        if cx.has_active_drag() {
3503            if event.is::<MouseMoveEvent>() {
3504                // If this was a mouse move event, redraw the window so that the
3505                // active drag can follow the mouse cursor.
3506                self.refresh();
3507            } else if event.is::<MouseUpEvent>() {
3508                // If this was a mouse up event, cancel the active drag and redraw
3509                // the window.
3510                cx.active_drag = None;
3511                self.refresh();
3512            }
3513        }
3514    }
3515
3516    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3517        if self.invalidator.is_dirty() {
3518            self.draw(cx).clear();
3519        }
3520
3521        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3522        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3523
3524        let mut keystroke: Option<Keystroke> = None;
3525
3526        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3527            if event.modifiers.number_of_modifiers() == 0
3528                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3529                && !self.pending_modifier.saw_keystroke
3530            {
3531                let key = match self.pending_modifier.modifiers {
3532                    modifiers if modifiers.shift => Some("shift"),
3533                    modifiers if modifiers.control => Some("control"),
3534                    modifiers if modifiers.alt => Some("alt"),
3535                    modifiers if modifiers.platform => Some("platform"),
3536                    modifiers if modifiers.function => Some("function"),
3537                    _ => None,
3538                };
3539                if let Some(key) = key {
3540                    keystroke = Some(Keystroke {
3541                        key: key.to_string(),
3542                        key_char: None,
3543                        modifiers: Modifiers::default(),
3544                    });
3545                }
3546            }
3547
3548            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3549                && event.modifiers.number_of_modifiers() == 1
3550            {
3551                self.pending_modifier.saw_keystroke = false
3552            }
3553            self.pending_modifier.modifiers = event.modifiers
3554        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3555            self.pending_modifier.saw_keystroke = true;
3556            keystroke = Some(key_down_event.keystroke.clone());
3557        }
3558
3559        let Some(keystroke) = keystroke else {
3560            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3561            return;
3562        };
3563
3564        cx.propagate_event = true;
3565        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
3566        if !cx.propagate_event {
3567            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3568            return;
3569        }
3570
3571        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3572        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3573            currently_pending = PendingInput::default();
3574        }
3575
3576        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3577            currently_pending.keystrokes,
3578            keystroke,
3579            &dispatch_path,
3580        );
3581
3582        if !match_result.to_replay.is_empty() {
3583            self.replay_pending_input(match_result.to_replay, cx)
3584        }
3585
3586        if !match_result.pending.is_empty() {
3587            currently_pending.keystrokes = match_result.pending;
3588            currently_pending.focus = self.focus;
3589            currently_pending.timer = Some(self.spawn(cx, async move |cx| {
3590                cx.background_executor.timer(Duration::from_secs(1)).await;
3591                cx.update(move |window, cx| {
3592                    let Some(currently_pending) = window
3593                        .pending_input
3594                        .take()
3595                        .filter(|pending| pending.focus == window.focus)
3596                    else {
3597                        return;
3598                    };
3599
3600                    let node_id = window.focus_node_id_in_rendered_frame(window.focus);
3601                    let dispatch_path = window.rendered_frame.dispatch_tree.dispatch_path(node_id);
3602
3603                    let to_replay = window
3604                        .rendered_frame
3605                        .dispatch_tree
3606                        .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3607
3608                    window.pending_input_changed(cx);
3609                    window.replay_pending_input(to_replay, cx)
3610                })
3611                .log_err();
3612            }));
3613            self.pending_input = Some(currently_pending);
3614            self.pending_input_changed(cx);
3615            cx.propagate_event = false;
3616            return;
3617        }
3618
3619        for binding in match_result.bindings {
3620            self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3621            if !cx.propagate_event {
3622                self.dispatch_keystroke_observers(
3623                    event,
3624                    Some(binding.action),
3625                    match_result.context_stack.clone(),
3626                    cx,
3627                );
3628                self.pending_input_changed(cx);
3629                return;
3630            }
3631        }
3632
3633        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
3634        self.pending_input_changed(cx);
3635    }
3636
3637    fn finish_dispatch_key_event(
3638        &mut self,
3639        event: &dyn Any,
3640        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3641        context_stack: Vec<KeyContext>,
3642        cx: &mut App,
3643    ) {
3644        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
3645        if !cx.propagate_event {
3646            return;
3647        }
3648
3649        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
3650        if !cx.propagate_event {
3651            return;
3652        }
3653
3654        self.dispatch_keystroke_observers(event, None, context_stack, cx);
3655    }
3656
3657    fn pending_input_changed(&mut self, cx: &mut App) {
3658        self.pending_input_observers
3659            .clone()
3660            .retain(&(), |callback| callback(self, cx));
3661    }
3662
3663    fn dispatch_key_down_up_event(
3664        &mut self,
3665        event: &dyn Any,
3666        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3667        cx: &mut App,
3668    ) {
3669        // Capture phase
3670        for node_id in dispatch_path {
3671            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3672
3673            for key_listener in node.key_listeners.clone() {
3674                key_listener(event, DispatchPhase::Capture, self, cx);
3675                if !cx.propagate_event {
3676                    return;
3677                }
3678            }
3679        }
3680
3681        // Bubble phase
3682        for node_id in dispatch_path.iter().rev() {
3683            // Handle low level key events
3684            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3685            for key_listener in node.key_listeners.clone() {
3686                key_listener(event, DispatchPhase::Bubble, self, cx);
3687                if !cx.propagate_event {
3688                    return;
3689                }
3690            }
3691        }
3692    }
3693
3694    fn dispatch_modifiers_changed_event(
3695        &mut self,
3696        event: &dyn Any,
3697        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3698        cx: &mut App,
3699    ) {
3700        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3701            return;
3702        };
3703        for node_id in dispatch_path.iter().rev() {
3704            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3705            for listener in node.modifiers_changed_listeners.clone() {
3706                listener(event, self, cx);
3707                if !cx.propagate_event {
3708                    return;
3709                }
3710            }
3711        }
3712    }
3713
3714    /// Determine whether a potential multi-stroke key binding is in progress on this window.
3715    pub fn has_pending_keystrokes(&self) -> bool {
3716        self.pending_input.is_some()
3717    }
3718
3719    pub(crate) fn clear_pending_keystrokes(&mut self) {
3720        self.pending_input.take();
3721    }
3722
3723    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3724    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3725        self.pending_input
3726            .as_ref()
3727            .map(|pending_input| pending_input.keystrokes.as_slice())
3728    }
3729
3730    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
3731        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3732        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3733
3734        'replay: for replay in replays {
3735            let event = KeyDownEvent {
3736                keystroke: replay.keystroke.clone(),
3737                is_held: false,
3738            };
3739
3740            cx.propagate_event = true;
3741            for binding in replay.bindings {
3742                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3743                if !cx.propagate_event {
3744                    self.dispatch_keystroke_observers(
3745                        &event,
3746                        Some(binding.action),
3747                        Vec::default(),
3748                        cx,
3749                    );
3750                    continue 'replay;
3751                }
3752            }
3753
3754            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
3755            if !cx.propagate_event {
3756                continue 'replay;
3757            }
3758            if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3759                if let Some(mut input_handler) = self.platform_window.take_input_handler() {
3760                    input_handler.dispatch_input(&input, self, cx);
3761                    self.platform_window.set_input_handler(input_handler)
3762                }
3763            }
3764        }
3765    }
3766
3767    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
3768        focus_id
3769            .and_then(|focus_id| {
3770                self.rendered_frame
3771                    .dispatch_tree
3772                    .focusable_node_id(focus_id)
3773            })
3774            .unwrap_or_else(|| {
3775                println!("root node id");
3776                self.rendered_frame.dispatch_tree.root_node_id()
3777            })
3778    }
3779
3780    fn dispatch_action_on_node(
3781        &mut self,
3782        node_id: DispatchNodeId,
3783        action: &dyn Action,
3784        cx: &mut App,
3785    ) {
3786        dbg!("dispatch_action_on_node");
3787        dbg!(action.name());
3788        dbg!(action.as_any().type_id());
3789        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3790        dbg!(&dispatch_path);
3791
3792        // Capture phase for global actions.
3793        cx.propagate_event = true;
3794        if let Some(mut global_listeners) = cx
3795            .global_action_listeners
3796            .remove(&action.as_any().type_id())
3797        {
3798            dbg!(
3799                "Found global listeners for capture phase",
3800                global_listeners.len()
3801            );
3802            for listener in &global_listeners {
3803                dbg!("Executing global listener in capture phase");
3804                listener(action.as_any(), DispatchPhase::Capture, cx);
3805                if !cx.propagate_event {
3806                    dbg!("Event propagation stopped in global capture phase");
3807                    break;
3808                }
3809            }
3810
3811            global_listeners.extend(
3812                cx.global_action_listeners
3813                    .remove(&action.as_any().type_id())
3814                    .unwrap_or_default(),
3815            );
3816
3817            cx.global_action_listeners
3818                .insert(action.as_any().type_id(), global_listeners);
3819        }
3820
3821        if !cx.propagate_event {
3822            return;
3823        }
3824
3825        // Capture phase for window actions.
3826        for node_id in &dispatch_path {
3827            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3828            for DispatchActionListener {
3829                action_type,
3830                listener,
3831            } in node.action_listeners.clone()
3832            {
3833                let any_action = action.as_any();
3834                if action_type == any_action.type_id() {
3835                    dbg!("Found window action listener in capture phase", node_id);
3836                    listener(any_action, DispatchPhase::Capture, self, cx);
3837
3838                    if !cx.propagate_event {
3839                        dbg!("Event propagation stopped in window capture phase");
3840                        return;
3841                    }
3842                }
3843            }
3844        }
3845
3846        // Bubble phase for window actions.
3847        for node_id in dispatch_path.iter().rev() {
3848            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3849            for DispatchActionListener {
3850                action_type,
3851                listener,
3852            } in node.action_listeners.clone()
3853            {
3854                let any_action = action.as_any();
3855                if action_type == any_action.type_id() {
3856                    dbg!("Found window action listener in bubble phase", node_id);
3857                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3858                    listener(any_action, DispatchPhase::Bubble, self, cx);
3859
3860                    if !cx.propagate_event {
3861                        dbg!("Event propagation stopped in window bubble phase");
3862                        return;
3863                    }
3864                }
3865            }
3866        }
3867
3868        // Bubble phase for global actions.
3869        if let Some(mut global_listeners) = cx
3870            .global_action_listeners
3871            .remove(&action.as_any().type_id())
3872        {
3873            dbg!(
3874                "Found global listeners for bubble phase",
3875                global_listeners.len()
3876            );
3877            for listener in global_listeners.iter().rev() {
3878                dbg!("Executing global listener in bubble phase");
3879                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
3880
3881                listener(action.as_any(), DispatchPhase::Bubble, cx);
3882                if !cx.propagate_event {
3883                    dbg!("Event propagation stopped in global bubble phase");
3884                    break;
3885                }
3886            }
3887
3888            global_listeners.extend(
3889                cx.global_action_listeners
3890                    .remove(&action.as_any().type_id())
3891                    .unwrap_or_default(),
3892            );
3893
3894            cx.global_action_listeners
3895                .insert(action.as_any().type_id(), global_listeners);
3896        }
3897    }
3898
3899    /// Register the given handler to be invoked whenever the global of the given type
3900    /// is updated.
3901    pub fn observe_global<G: Global>(
3902        &mut self,
3903        cx: &mut App,
3904        f: impl Fn(&mut Window, &mut App) + 'static,
3905    ) -> Subscription {
3906        let window_handle = self.handle;
3907        let (subscription, activate) = cx.global_observers.insert(
3908            TypeId::of::<G>(),
3909            Box::new(move |cx| {
3910                window_handle
3911                    .update(cx, |_, window, cx| f(window, cx))
3912                    .is_ok()
3913            }),
3914        );
3915        cx.defer(move |_| activate());
3916        subscription
3917    }
3918
3919    /// Focus the current window and bring it to the foreground at the platform level.
3920    pub fn activate_window(&self) {
3921        self.platform_window.activate();
3922    }
3923
3924    /// Minimize the current window at the platform level.
3925    pub fn minimize_window(&self) {
3926        self.platform_window.minimize();
3927    }
3928
3929    /// Toggle full screen status on the current window at the platform level.
3930    pub fn toggle_fullscreen(&self) {
3931        self.platform_window.toggle_fullscreen();
3932    }
3933
3934    /// Updates the IME panel position suggestions for languages like japanese, chinese.
3935    pub fn invalidate_character_coordinates(&self) {
3936        self.on_next_frame(|window, cx| {
3937            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
3938                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
3939                    window
3940                        .platform_window
3941                        .update_ime_position(bounds.scale(window.scale_factor()));
3942                }
3943                window.platform_window.set_input_handler(input_handler);
3944            }
3945        });
3946    }
3947
3948    /// Present a platform dialog.
3949    /// The provided message will be presented, along with buttons for each answer.
3950    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3951    pub fn prompt<T>(
3952        &mut self,
3953        level: PromptLevel,
3954        message: &str,
3955        detail: Option<&str>,
3956        answers: &[T],
3957        cx: &mut App,
3958    ) -> oneshot::Receiver<usize>
3959    where
3960        T: Clone + Into<PromptButton>,
3961    {
3962        let prompt_builder = cx.prompt_builder.take();
3963        let Some(prompt_builder) = prompt_builder else {
3964            unreachable!("Re-entrant window prompting is not supported by GPUI");
3965        };
3966
3967        let answers = answers
3968            .iter()
3969            .map(|answer| answer.clone().into())
3970            .collect::<Vec<_>>();
3971
3972        let receiver = match &prompt_builder {
3973            PromptBuilder::Default => self
3974                .platform_window
3975                .prompt(level, message, detail, &answers)
3976                .unwrap_or_else(|| {
3977                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3978                }),
3979            PromptBuilder::Custom(_) => {
3980                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
3981            }
3982        };
3983
3984        cx.prompt_builder = Some(prompt_builder);
3985
3986        receiver
3987    }
3988
3989    fn build_custom_prompt(
3990        &mut self,
3991        prompt_builder: &PromptBuilder,
3992        level: PromptLevel,
3993        message: &str,
3994        detail: Option<&str>,
3995        answers: &[PromptButton],
3996        cx: &mut App,
3997    ) -> oneshot::Receiver<usize> {
3998        let (sender, receiver) = oneshot::channel();
3999        let handle = PromptHandle::new(sender);
4000        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
4001        self.prompt = Some(handle);
4002        receiver
4003    }
4004
4005    /// Returns the current context stack.
4006    pub fn context_stack(&self) -> Vec<KeyContext> {
4007        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4008        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4009        dispatch_tree
4010            .dispatch_path(node_id)
4011            .iter()
4012            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4013            .collect()
4014    }
4015
4016    /// Returns all available actions for the focused element.
4017    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4018        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4019        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4020        for action_type in cx.global_action_listeners.keys() {
4021            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4022                let action = cx.actions.build_action_type(action_type).ok();
4023                if let Some(action) = action {
4024                    actions.insert(ix, action);
4025                }
4026            }
4027        }
4028        actions
4029    }
4030
4031    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4032    /// returned in the order they were added. For display, the last binding should take precedence.
4033    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4034        self.rendered_frame
4035            .dispatch_tree
4036            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4037    }
4038
4039    /// Returns the highest precedence key binding that invokes an action on the currently focused
4040    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4041    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4042        self.rendered_frame
4043            .dispatch_tree
4044            .highest_precedence_binding_for_action(
4045                action,
4046                &self.rendered_frame.dispatch_tree.context_stack,
4047            )
4048    }
4049
4050    /// Returns the key bindings for an action in a context.
4051    pub fn bindings_for_action_in_context(
4052        &self,
4053        action: &dyn Action,
4054        context: KeyContext,
4055    ) -> Vec<KeyBinding> {
4056        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4057        dispatch_tree.bindings_for_action(action, &[context])
4058    }
4059
4060    /// Returns the highest precedence key binding for an action in a context. This is more
4061    /// efficient than getting the last result of `bindings_for_action_in_context`.
4062    pub fn highest_precedence_binding_for_action_in_context(
4063        &self,
4064        action: &dyn Action,
4065        context: KeyContext,
4066    ) -> Option<KeyBinding> {
4067        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4068        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4069    }
4070
4071    /// Returns any bindings that would invoke an action on the given focus handle if it were
4072    /// focused. Bindings are returned in the order they were added. For display, the last binding
4073    /// should take precedence.
4074    pub fn bindings_for_action_in(
4075        &self,
4076        action: &dyn Action,
4077        focus_handle: &FocusHandle,
4078    ) -> Vec<KeyBinding> {
4079        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4080        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4081            return vec![];
4082        };
4083        dispatch_tree.bindings_for_action(action, &context_stack)
4084    }
4085
4086    /// Returns the highest precedence key binding that would invoke an action on the given focus
4087    /// handle if it were focused. This is more efficient than getting the last result of
4088    /// `bindings_for_action_in`.
4089    pub fn highest_precedence_binding_for_action_in(
4090        &self,
4091        action: &dyn Action,
4092        focus_handle: &FocusHandle,
4093    ) -> Option<KeyBinding> {
4094        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4095        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4096        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4097    }
4098
4099    fn context_stack_for_focus_handle(
4100        &self,
4101        focus_handle: &FocusHandle,
4102    ) -> Option<Vec<KeyContext>> {
4103        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4104        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4105        let context_stack: Vec<_> = dispatch_tree
4106            .dispatch_path(node_id)
4107            .into_iter()
4108            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4109            .collect();
4110        Some(context_stack)
4111    }
4112
4113    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4114    pub fn listener_for<V: Render, E>(
4115        &self,
4116        view: &Entity<V>,
4117        f: impl Fn(&mut V, &E, &mut Window, &mut Context<V>) + 'static,
4118    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4119        let view = view.downgrade();
4120        move |e: &E, window: &mut Window, cx: &mut App| {
4121            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4122        }
4123    }
4124
4125    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4126    pub fn handler_for<V: Render, Callback: Fn(&mut V, &mut Window, &mut Context<V>) + 'static>(
4127        &self,
4128        view: &Entity<V>,
4129        f: Callback,
4130    ) -> impl Fn(&mut Window, &mut App) + use<V, Callback> {
4131        let view = view.downgrade();
4132        move |window: &mut Window, cx: &mut App| {
4133            view.update(cx, |view, cx| f(view, window, cx)).ok();
4134        }
4135    }
4136
4137    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4138    /// If the callback returns false, the window won't be closed.
4139    pub fn on_window_should_close(
4140        &self,
4141        cx: &App,
4142        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4143    ) {
4144        let mut cx = self.to_async(cx);
4145        self.platform_window.on_should_close(Box::new(move || {
4146            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4147        }))
4148    }
4149
4150    /// Register an action listener on the window for the next frame. The type of action
4151    /// is determined by the first parameter of the given listener. When the next frame is rendered
4152    /// the listener will be cleared.
4153    ///
4154    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4155    /// a specific need to register a global listener.
4156    pub fn on_action(
4157        &mut self,
4158        action_type: TypeId,
4159        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4160    ) {
4161        self.next_frame
4162            .dispatch_tree
4163            .on_action(action_type, Rc::new(listener));
4164    }
4165
4166    /// Read information about the GPU backing this window.
4167    /// Currently returns None on Mac and Windows.
4168    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4169        self.platform_window.gpu_specs()
4170    }
4171
4172    /// Perform titlebar double-click action.
4173    /// This is MacOS specific.
4174    pub fn titlebar_double_click(&self) {
4175        self.platform_window.titlebar_double_click();
4176    }
4177
4178    /// Toggles the inspector mode on this window.
4179    #[cfg(any(feature = "inspector", debug_assertions))]
4180    pub fn toggle_inspector(&mut self, cx: &mut App) {
4181        self.inspector = match self.inspector {
4182            None => Some(cx.new(|_| Inspector::new())),
4183            Some(_) => None,
4184        };
4185        self.refresh();
4186    }
4187
4188    /// Returns true if the window is in inspector mode.
4189    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4190        #[cfg(any(feature = "inspector", debug_assertions))]
4191        {
4192            if let Some(inspector) = &self.inspector {
4193                return inspector.read(_cx).is_picking();
4194            }
4195        }
4196        false
4197    }
4198
4199    /// Executes the provided function with mutable access to an inspector state.
4200    #[cfg(any(feature = "inspector", debug_assertions))]
4201    pub fn with_inspector_state<T: 'static, R>(
4202        &mut self,
4203        _inspector_id: Option<&crate::InspectorElementId>,
4204        cx: &mut App,
4205        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4206    ) -> R {
4207        if let Some(inspector_id) = _inspector_id {
4208            if let Some(inspector) = &self.inspector {
4209                let inspector = inspector.clone();
4210                let active_element_id = inspector.read(cx).active_element_id();
4211                if Some(inspector_id) == active_element_id {
4212                    return inspector.update(cx, |inspector, _cx| {
4213                        inspector.with_active_element_state(self, f)
4214                    });
4215                }
4216            }
4217        }
4218        f(&mut None, self)
4219    }
4220
4221    #[cfg(any(feature = "inspector", debug_assertions))]
4222    pub(crate) fn build_inspector_element_id(
4223        &mut self,
4224        path: crate::InspectorElementPath,
4225    ) -> crate::InspectorElementId {
4226        self.invalidator.debug_assert_paint_or_prepaint();
4227        let path = Rc::new(path);
4228        let next_instance_id = self
4229            .next_frame
4230            .next_inspector_instance_ids
4231            .entry(path.clone())
4232            .or_insert(0);
4233        let instance_id = *next_instance_id;
4234        *next_instance_id += 1;
4235        crate::InspectorElementId { path, instance_id }
4236    }
4237
4238    #[cfg(any(feature = "inspector", debug_assertions))]
4239    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4240        if let Some(inspector) = self.inspector.take() {
4241            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4242            inspector_element.prepaint_as_root(
4243                point(self.viewport_size.width - inspector_width, px(0.0)),
4244                size(inspector_width, self.viewport_size.height).into(),
4245                self,
4246                cx,
4247            );
4248            self.inspector = Some(inspector);
4249            Some(inspector_element)
4250        } else {
4251            None
4252        }
4253    }
4254
4255    #[cfg(any(feature = "inspector", debug_assertions))]
4256    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4257        if let Some(mut inspector_element) = inspector_element {
4258            inspector_element.paint(self, cx);
4259        };
4260    }
4261
4262    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4263    /// inspect UI elements by clicking on them.
4264    #[cfg(any(feature = "inspector", debug_assertions))]
4265    pub fn insert_inspector_hitbox(
4266        &mut self,
4267        hitbox_id: HitboxId,
4268        inspector_id: Option<&crate::InspectorElementId>,
4269        cx: &App,
4270    ) {
4271        self.invalidator.debug_assert_paint_or_prepaint();
4272        if !self.is_inspector_picking(cx) {
4273            return;
4274        }
4275        if let Some(inspector_id) = inspector_id {
4276            self.next_frame
4277                .inspector_hitboxes
4278                .insert(hitbox_id, inspector_id.clone());
4279        }
4280    }
4281
4282    #[cfg(any(feature = "inspector", debug_assertions))]
4283    fn paint_inspector_hitbox(&mut self, cx: &App) {
4284        if let Some(inspector) = self.inspector.as_ref() {
4285            let inspector = inspector.read(cx);
4286            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4287            {
4288                if let Some(hitbox) = self
4289                    .next_frame
4290                    .hitboxes
4291                    .iter()
4292                    .find(|hitbox| hitbox.id == hitbox_id)
4293                {
4294                    self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4295                }
4296            }
4297        }
4298    }
4299
4300    #[cfg(any(feature = "inspector", debug_assertions))]
4301    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4302        let Some(inspector) = self.inspector.clone() else {
4303            return;
4304        };
4305        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4306            inspector.update(cx, |inspector, _cx| {
4307                if let Some((_, inspector_id)) =
4308                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4309                {
4310                    inspector.hover(inspector_id, self);
4311                }
4312            });
4313        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4314            inspector.update(cx, |inspector, _cx| {
4315                if let Some((_, inspector_id)) =
4316                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4317                {
4318                    inspector.select(inspector_id, self);
4319                }
4320            });
4321        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4322            // This should be kept in sync with SCROLL_LINES in x11 platform.
4323            const SCROLL_LINES: f32 = 3.0;
4324            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4325            let delta_y = event
4326                .delta
4327                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4328                .y;
4329            if let Some(inspector) = self.inspector.clone() {
4330                inspector.update(cx, |inspector, _cx| {
4331                    if let Some(depth) = inspector.pick_depth.as_mut() {
4332                        *depth += delta_y.0 / SCROLL_PIXELS_PER_LAYER;
4333                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4334                        if *depth < 0.0 {
4335                            *depth = 0.0;
4336                        } else if *depth > max_depth {
4337                            *depth = max_depth;
4338                        }
4339                        if let Some((_, inspector_id)) =
4340                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4341                        {
4342                            inspector.set_active_element_id(inspector_id.clone(), self);
4343                        }
4344                    }
4345                });
4346            }
4347        }
4348    }
4349
4350    #[cfg(any(feature = "inspector", debug_assertions))]
4351    fn hovered_inspector_hitbox(
4352        &self,
4353        inspector: &Inspector,
4354        frame: &Frame,
4355    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4356        if let Some(pick_depth) = inspector.pick_depth {
4357            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4358            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4359            let skip_count = (depth as usize).min(max_skipped);
4360            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4361                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4362                    return Some((*hitbox_id, inspector_id.clone()));
4363                }
4364            }
4365        }
4366        return None;
4367    }
4368}
4369
4370// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4371slotmap::new_key_type! {
4372    /// A unique identifier for a window.
4373    pub struct WindowId;
4374}
4375
4376impl WindowId {
4377    /// Converts this window ID to a `u64`.
4378    pub fn as_u64(&self) -> u64 {
4379        self.0.as_ffi()
4380    }
4381}
4382
4383impl From<u64> for WindowId {
4384    fn from(value: u64) -> Self {
4385        WindowId(slotmap::KeyData::from_ffi(value))
4386    }
4387}
4388
4389/// A handle to a window with a specific root view type.
4390/// Note that this does not keep the window alive on its own.
4391#[derive(Deref, DerefMut)]
4392pub struct WindowHandle<V> {
4393    #[deref]
4394    #[deref_mut]
4395    pub(crate) any_handle: AnyWindowHandle,
4396    state_type: PhantomData<V>,
4397}
4398
4399impl<V: 'static + Render> WindowHandle<V> {
4400    /// Creates a new handle from a window ID.
4401    /// This does not check if the root type of the window is `V`.
4402    pub fn new(id: WindowId) -> Self {
4403        WindowHandle {
4404            any_handle: AnyWindowHandle {
4405                id,
4406                state_type: TypeId::of::<V>(),
4407            },
4408            state_type: PhantomData,
4409        }
4410    }
4411
4412    /// Get the root view out of this window.
4413    ///
4414    /// This will fail if the window is closed or if the root view's type does not match `V`.
4415    #[cfg(any(test, feature = "test-support"))]
4416    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
4417    where
4418        C: AppContext,
4419    {
4420        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
4421            root_view
4422                .downcast::<V>()
4423                .map_err(|_| anyhow!("the type of the window's root view has changed"))
4424        }))
4425    }
4426
4427    /// Updates the root view of this window.
4428    ///
4429    /// This will fail if the window has been closed or if the root view's type does not match
4430    pub fn update<C, R>(
4431        &self,
4432        cx: &mut C,
4433        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
4434    ) -> Result<R>
4435    where
4436        C: AppContext,
4437    {
4438        cx.update_window(self.any_handle, |root_view, window, cx| {
4439            let view = root_view
4440                .downcast::<V>()
4441                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4442
4443            Ok(view.update(cx, |view, cx| update(view, window, cx)))
4444        })?
4445    }
4446
4447    /// Read the root view out of this window.
4448    ///
4449    /// This will fail if the window is closed or if the root view's type does not match `V`.
4450    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
4451        let x = cx
4452            .windows
4453            .get(self.id)
4454            .and_then(|window| {
4455                window
4456                    .as_ref()
4457                    .and_then(|window| window.root.clone())
4458                    .map(|root_view| root_view.downcast::<V>())
4459            })
4460            .context("window not found")?
4461            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4462
4463        Ok(x.read(cx))
4464    }
4465
4466    /// Read the root view out of this window, with a callback
4467    ///
4468    /// This will fail if the window is closed or if the root view's type does not match `V`.
4469    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
4470    where
4471        C: AppContext,
4472    {
4473        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4474    }
4475
4476    /// Read the root view pointer off of this window.
4477    ///
4478    /// This will fail if the window is closed or if the root view's type does not match `V`.
4479    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
4480    where
4481        C: AppContext,
4482    {
4483        cx.read_window(self, |root_view, _cx| root_view.clone())
4484    }
4485
4486    /// Check if this window is 'active'.
4487    ///
4488    /// Will return `None` if the window is closed or currently
4489    /// borrowed.
4490    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
4491        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
4492            .ok()
4493    }
4494}
4495
4496impl<V> Copy for WindowHandle<V> {}
4497
4498impl<V> Clone for WindowHandle<V> {
4499    fn clone(&self) -> Self {
4500        *self
4501    }
4502}
4503
4504impl<V> PartialEq for WindowHandle<V> {
4505    fn eq(&self, other: &Self) -> bool {
4506        self.any_handle == other.any_handle
4507    }
4508}
4509
4510impl<V> Eq for WindowHandle<V> {}
4511
4512impl<V> Hash for WindowHandle<V> {
4513    fn hash<H: Hasher>(&self, state: &mut H) {
4514        self.any_handle.hash(state);
4515    }
4516}
4517
4518impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4519    fn from(val: WindowHandle<V>) -> Self {
4520        val.any_handle
4521    }
4522}
4523
4524unsafe impl<V> Send for WindowHandle<V> {}
4525unsafe impl<V> Sync for WindowHandle<V> {}
4526
4527/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4528#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4529pub struct AnyWindowHandle {
4530    pub(crate) id: WindowId,
4531    state_type: TypeId,
4532}
4533
4534impl AnyWindowHandle {
4535    /// Get the ID of this window.
4536    pub fn window_id(&self) -> WindowId {
4537        self.id
4538    }
4539
4540    /// Attempt to convert this handle to a window handle with a specific root view type.
4541    /// If the types do not match, this will return `None`.
4542    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4543        if TypeId::of::<T>() == self.state_type {
4544            Some(WindowHandle {
4545                any_handle: *self,
4546                state_type: PhantomData,
4547            })
4548        } else {
4549            None
4550        }
4551    }
4552
4553    /// Updates the state of the root view of this window.
4554    ///
4555    /// This will fail if the window has been closed.
4556    pub fn update<C, R>(
4557        self,
4558        cx: &mut C,
4559        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
4560    ) -> Result<R>
4561    where
4562        C: AppContext,
4563    {
4564        cx.update_window(self, update)
4565    }
4566
4567    /// Read the state of the root view of this window.
4568    ///
4569    /// This will fail if the window has been closed.
4570    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
4571    where
4572        C: AppContext,
4573        T: 'static,
4574    {
4575        let view = self
4576            .downcast::<T>()
4577            .context("the type of the window's root view has changed")?;
4578
4579        cx.read_window(&view, read)
4580    }
4581}
4582
4583impl HasWindowHandle for Window {
4584    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
4585        self.platform_window.window_handle()
4586    }
4587}
4588
4589impl HasDisplayHandle for Window {
4590    fn display_handle(
4591        &self,
4592    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
4593        self.platform_window.display_handle()
4594    }
4595}
4596
4597/// An identifier for an [`Element`](crate::Element).
4598///
4599/// Can be constructed with a string, a number, or both, as well
4600/// as other internal representations.
4601#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4602pub enum ElementId {
4603    /// The ID of a View element
4604    View(EntityId),
4605    /// An integer ID.
4606    Integer(u64),
4607    /// A string based ID.
4608    Name(SharedString),
4609    /// A UUID.
4610    Uuid(Uuid),
4611    /// An ID that's equated with a focus handle.
4612    FocusHandle(FocusId),
4613    /// A combination of a name and an integer.
4614    NamedInteger(SharedString, u64),
4615    /// A path.
4616    Path(Arc<std::path::Path>),
4617}
4618
4619impl ElementId {
4620    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
4621    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
4622        Self::NamedInteger(name.into(), integer as u64)
4623    }
4624}
4625
4626impl Display for ElementId {
4627    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4628        match self {
4629            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4630            ElementId::Integer(ix) => write!(f, "{}", ix)?,
4631            ElementId::Name(name) => write!(f, "{}", name)?,
4632            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4633            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4634            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4635            ElementId::Path(path) => write!(f, "{}", path.display())?,
4636        }
4637
4638        Ok(())
4639    }
4640}
4641
4642impl TryInto<SharedString> for ElementId {
4643    type Error = anyhow::Error;
4644
4645    fn try_into(self) -> anyhow::Result<SharedString> {
4646        if let ElementId::Name(name) = self {
4647            Ok(name)
4648        } else {
4649            anyhow::bail!("element id is not string")
4650        }
4651    }
4652}
4653
4654impl From<usize> for ElementId {
4655    fn from(id: usize) -> Self {
4656        ElementId::Integer(id as u64)
4657    }
4658}
4659
4660impl From<i32> for ElementId {
4661    fn from(id: i32) -> Self {
4662        Self::Integer(id as u64)
4663    }
4664}
4665
4666impl From<SharedString> for ElementId {
4667    fn from(name: SharedString) -> Self {
4668        ElementId::Name(name)
4669    }
4670}
4671
4672impl From<Arc<std::path::Path>> for ElementId {
4673    fn from(path: Arc<std::path::Path>) -> Self {
4674        ElementId::Path(path)
4675    }
4676}
4677
4678impl From<&'static str> for ElementId {
4679    fn from(name: &'static str) -> Self {
4680        ElementId::Name(name.into())
4681    }
4682}
4683
4684impl<'a> From<&'a FocusHandle> for ElementId {
4685    fn from(handle: &'a FocusHandle) -> Self {
4686        ElementId::FocusHandle(handle.id)
4687    }
4688}
4689
4690impl From<(&'static str, EntityId)> for ElementId {
4691    fn from((name, id): (&'static str, EntityId)) -> Self {
4692        ElementId::NamedInteger(name.into(), id.as_u64())
4693    }
4694}
4695
4696impl From<(&'static str, usize)> for ElementId {
4697    fn from((name, id): (&'static str, usize)) -> Self {
4698        ElementId::NamedInteger(name.into(), id as u64)
4699    }
4700}
4701
4702impl From<(SharedString, usize)> for ElementId {
4703    fn from((name, id): (SharedString, usize)) -> Self {
4704        ElementId::NamedInteger(name, id as u64)
4705    }
4706}
4707
4708impl From<(&'static str, u64)> for ElementId {
4709    fn from((name, id): (&'static str, u64)) -> Self {
4710        ElementId::NamedInteger(name.into(), id)
4711    }
4712}
4713
4714impl From<Uuid> for ElementId {
4715    fn from(value: Uuid) -> Self {
4716        Self::Uuid(value)
4717    }
4718}
4719
4720impl From<(&'static str, u32)> for ElementId {
4721    fn from((name, id): (&'static str, u32)) -> Self {
4722        ElementId::NamedInteger(name.into(), id.into())
4723    }
4724}
4725
4726/// A rectangle to be rendered in the window at the given position and size.
4727/// Passed as an argument [`Window::paint_quad`].
4728#[derive(Clone)]
4729pub struct PaintQuad {
4730    /// The bounds of the quad within the window.
4731    pub bounds: Bounds<Pixels>,
4732    /// The radii of the quad's corners.
4733    pub corner_radii: Corners<Pixels>,
4734    /// The background color of the quad.
4735    pub background: Background,
4736    /// The widths of the quad's borders.
4737    pub border_widths: Edges<Pixels>,
4738    /// The color of the quad's borders.
4739    pub border_color: Hsla,
4740    /// The style of the quad's borders.
4741    pub border_style: BorderStyle,
4742}
4743
4744impl PaintQuad {
4745    /// Sets the corner radii of the quad.
4746    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4747        PaintQuad {
4748            corner_radii: corner_radii.into(),
4749            ..self
4750        }
4751    }
4752
4753    /// Sets the border widths of the quad.
4754    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
4755        PaintQuad {
4756            border_widths: border_widths.into(),
4757            ..self
4758        }
4759    }
4760
4761    /// Sets the border color of the quad.
4762    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
4763        PaintQuad {
4764            border_color: border_color.into(),
4765            ..self
4766        }
4767    }
4768
4769    /// Sets the background color of the quad.
4770    pub fn background(self, background: impl Into<Background>) -> Self {
4771        PaintQuad {
4772            background: background.into(),
4773            ..self
4774        }
4775    }
4776}
4777
4778/// Creates a quad with the given parameters.
4779pub fn quad(
4780    bounds: Bounds<Pixels>,
4781    corner_radii: impl Into<Corners<Pixels>>,
4782    background: impl Into<Background>,
4783    border_widths: impl Into<Edges<Pixels>>,
4784    border_color: impl Into<Hsla>,
4785    border_style: BorderStyle,
4786) -> PaintQuad {
4787    PaintQuad {
4788        bounds,
4789        corner_radii: corner_radii.into(),
4790        background: background.into(),
4791        border_widths: border_widths.into(),
4792        border_color: border_color.into(),
4793        border_style,
4794    }
4795}
4796
4797/// Creates a filled quad with the given bounds and background color.
4798pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
4799    PaintQuad {
4800        bounds: bounds.into(),
4801        corner_radii: (0.).into(),
4802        background: background.into(),
4803        border_widths: (0.).into(),
4804        border_color: transparent_black(),
4805        border_style: BorderStyle::default(),
4806    }
4807}
4808
4809/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
4810pub fn outline(
4811    bounds: impl Into<Bounds<Pixels>>,
4812    border_color: impl Into<Hsla>,
4813    border_style: BorderStyle,
4814) -> PaintQuad {
4815    PaintQuad {
4816        bounds: bounds.into(),
4817        corner_radii: (0.).into(),
4818        background: transparent_black().into(),
4819        border_widths: (1.).into(),
4820        border_color: border_color.into(),
4821        border_style,
4822    }
4823}