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, Priority, PromptButton,
  13    PromptLevel, Quad, Render, RenderGlyphParams, RenderImage, RenderImageParams, RenderSvgParams,
  14    Replay, ResizeEdge, SMOOTH_SVG_SCALE_FACTOR, SUBPIXEL_VARIANTS_X, SUBPIXEL_VARIANTS_Y,
  15    ScaledPixels, Scene, Shadow, SharedString, Size, StrikethroughStyle, Style, SubpixelSprite,
  16    SubscriberSet, Subscription, SystemWindowTab, SystemWindowTabController, TabStopMap,
  17    TaffyLayoutEngine, Task, TextRenderingMode, TextStyle, TextStyleRefinement, ThermalState,
  18    TransformationMatrix, Underline, UnderlineStyle, WindowAppearance, WindowBackgroundAppearance,
  19    WindowBounds, WindowControls, WindowDecorations, WindowOptions, WindowParams, WindowTextSystem,
  20    point, prelude::*, px, rems, size, transparent_black,
  21};
  22use anyhow::{Context as _, Result, anyhow};
  23use collections::{FxHashMap, FxHashSet};
  24#[cfg(target_os = "macos")]
  25use core_video::pixel_buffer::CVPixelBuffer;
  26use derive_more::{Deref, DerefMut};
  27use futures::FutureExt;
  28use futures::channel::oneshot;
  29use itertools::FoldWhile::{Continue, Done};
  30use itertools::Itertools;
  31use parking_lot::RwLock;
  32use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
  33use refineable::Refineable;
  34use slotmap::SlotMap;
  35use smallvec::SmallVec;
  36use std::{
  37    any::{Any, TypeId},
  38    borrow::Cow,
  39    cell::{Cell, RefCell},
  40    cmp,
  41    fmt::{Debug, Display},
  42    hash::{Hash, Hasher},
  43    marker::PhantomData,
  44    mem,
  45    ops::{DerefMut, Range},
  46    rc::Rc,
  47    sync::{
  48        Arc, Weak,
  49        atomic::{AtomicUsize, Ordering::SeqCst},
  50    },
  51    time::{Duration, Instant},
  52};
  53use util::post_inc;
  54use util::{ResultExt, measure};
  55use uuid::Uuid;
  56
  57mod prompts;
  58
  59use crate::util::atomic_incr_if_not_zero;
  60pub use prompts::*;
  61
  62/// Default window size used when no explicit size is provided.
  63pub const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1536.), px(864.));
  64
  65/// A 6:5 aspect ratio minimum window size to be used for functional,
  66/// additional-to-main-Zed windows, like the settings and rules library windows.
  67pub const DEFAULT_ADDITIONAL_WINDOW_SIZE: Size<Pixels> = Size {
  68    width: Pixels(900.),
  69    height: Pixels(750.),
  70};
  71
  72/// Represents the two different phases when dispatching events.
  73#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  74pub enum DispatchPhase {
  75    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  76    /// invoked front to back and keyboard event listeners are invoked from the focused element
  77    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  78    /// registering event listeners.
  79    #[default]
  80    Bubble,
  81    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  82    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  83    /// is used for special purposes such as clearing the "pressed" state for click events. If
  84    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  85    /// outside of the immediate region may rely on detecting non-local events during this phase.
  86    Capture,
  87}
  88
  89impl DispatchPhase {
  90    /// Returns true if this represents the "bubble" phase.
  91    #[inline]
  92    pub fn bubble(self) -> bool {
  93        self == DispatchPhase::Bubble
  94    }
  95
  96    /// Returns true if this represents the "capture" phase.
  97    #[inline]
  98    pub fn capture(self) -> bool {
  99        self == DispatchPhase::Capture
 100    }
 101}
 102
 103struct WindowInvalidatorInner {
 104    pub dirty: bool,
 105    pub draw_phase: DrawPhase,
 106    pub dirty_views: FxHashSet<EntityId>,
 107}
 108
 109#[derive(Clone)]
 110pub(crate) struct WindowInvalidator {
 111    inner: Rc<RefCell<WindowInvalidatorInner>>,
 112}
 113
 114impl WindowInvalidator {
 115    pub fn new() -> Self {
 116        WindowInvalidator {
 117            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 118                dirty: true,
 119                draw_phase: DrawPhase::None,
 120                dirty_views: FxHashSet::default(),
 121            })),
 122        }
 123    }
 124
 125    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 126        let mut inner = self.inner.borrow_mut();
 127        inner.dirty_views.insert(entity);
 128        if inner.draw_phase == DrawPhase::None {
 129            inner.dirty = true;
 130            cx.push_effect(Effect::Notify { emitter: entity });
 131            true
 132        } else {
 133            false
 134        }
 135    }
 136
 137    pub fn is_dirty(&self) -> bool {
 138        self.inner.borrow().dirty
 139    }
 140
 141    pub fn set_dirty(&self, dirty: bool) {
 142        self.inner.borrow_mut().dirty = dirty
 143    }
 144
 145    pub fn set_phase(&self, phase: DrawPhase) {
 146        self.inner.borrow_mut().draw_phase = phase
 147    }
 148
 149    pub fn take_views(&self) -> FxHashSet<EntityId> {
 150        mem::take(&mut self.inner.borrow_mut().dirty_views)
 151    }
 152
 153    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 154        self.inner.borrow_mut().dirty_views = views;
 155    }
 156
 157    pub fn not_drawing(&self) -> bool {
 158        self.inner.borrow().draw_phase == DrawPhase::None
 159    }
 160
 161    #[track_caller]
 162    pub fn debug_assert_paint(&self) {
 163        debug_assert!(
 164            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 165            "this method can only be called during paint"
 166        );
 167    }
 168
 169    #[track_caller]
 170    pub fn debug_assert_prepaint(&self) {
 171        debug_assert!(
 172            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 173            "this method can only be called during request_layout, or prepaint"
 174        );
 175    }
 176
 177    #[track_caller]
 178    pub fn debug_assert_paint_or_prepaint(&self) {
 179        debug_assert!(
 180            matches!(
 181                self.inner.borrow().draw_phase,
 182                DrawPhase::Paint | DrawPhase::Prepaint
 183            ),
 184            "this method can only be called during request_layout, prepaint, or paint"
 185        );
 186    }
 187}
 188
 189type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 190
 191pub(crate) type AnyWindowFocusListener =
 192    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 193
 194pub(crate) struct WindowFocusEvent {
 195    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 196    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 197}
 198
 199impl WindowFocusEvent {
 200    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 201        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 202    }
 203
 204    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 205        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 206    }
 207}
 208
 209/// This is provided when subscribing for `Context::on_focus_out` events.
 210pub struct FocusOutEvent {
 211    /// A weak focus handle representing what was blurred.
 212    pub blurred: WeakFocusHandle,
 213}
 214
 215slotmap::new_key_type! {
 216    /// A globally unique identifier for a focusable element.
 217    pub struct FocusId;
 218}
 219
 220thread_local! {
 221    /// Fallback arena used when no app-specific arena is active.
 222    /// In production, each window draw sets CURRENT_ELEMENT_ARENA to the app's arena.
 223    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(1024 * 1024));
 224
 225    /// Points to the current App's element arena during draw operations.
 226    /// This allows multiple test Apps to have isolated arenas, preventing
 227    /// cross-session corruption when the scheduler interleaves their tasks.
 228    static CURRENT_ELEMENT_ARENA: Cell<Option<*const RefCell<Arena>>> = const { Cell::new(None) };
 229}
 230
 231/// Allocates an element in the current arena. Uses the app-specific arena if one
 232/// is active (during draw), otherwise falls back to the thread-local ELEMENT_ARENA.
 233pub(crate) fn with_element_arena<R>(f: impl FnOnce(&mut Arena) -> R) -> R {
 234    CURRENT_ELEMENT_ARENA.with(|current| {
 235        if let Some(arena_ptr) = current.get() {
 236            // SAFETY: The pointer is valid for the duration of the draw operation
 237            // that set it, and we're being called during that same draw.
 238            let arena_cell = unsafe { &*arena_ptr };
 239            f(&mut arena_cell.borrow_mut())
 240        } else {
 241            ELEMENT_ARENA.with_borrow_mut(f)
 242        }
 243    })
 244}
 245
 246/// RAII guard that sets CURRENT_ELEMENT_ARENA for the duration of a draw operation.
 247/// When dropped, restores the previous arena (supporting nested draws).
 248pub(crate) struct ElementArenaScope {
 249    previous: Option<*const RefCell<Arena>>,
 250}
 251
 252impl ElementArenaScope {
 253    /// Enter a scope where element allocations use the given arena.
 254    pub(crate) fn enter(arena: &RefCell<Arena>) -> Self {
 255        let previous = CURRENT_ELEMENT_ARENA.with(|current| {
 256            let prev = current.get();
 257            current.set(Some(arena as *const RefCell<Arena>));
 258            prev
 259        });
 260        Self { previous }
 261    }
 262}
 263
 264impl Drop for ElementArenaScope {
 265    fn drop(&mut self) {
 266        CURRENT_ELEMENT_ARENA.with(|current| {
 267            current.set(self.previous);
 268        });
 269    }
 270}
 271
 272/// Returned when the element arena has been used and so must be cleared before the next draw.
 273#[must_use]
 274pub struct ArenaClearNeeded {
 275    arena: *const RefCell<Arena>,
 276}
 277
 278impl ArenaClearNeeded {
 279    /// Create a new ArenaClearNeeded that will clear the given arena.
 280    pub(crate) fn new(arena: &RefCell<Arena>) -> Self {
 281        Self {
 282            arena: arena as *const RefCell<Arena>,
 283        }
 284    }
 285
 286    /// Clear the element arena.
 287    pub fn clear(self) {
 288        // SAFETY: The arena pointer is valid because ArenaClearNeeded is created
 289        // at the end of draw() and must be cleared before the next draw.
 290        let arena_cell = unsafe { &*self.arena };
 291        arena_cell.borrow_mut().clear();
 292    }
 293}
 294
 295pub(crate) type FocusMap = RwLock<SlotMap<FocusId, FocusRef>>;
 296pub(crate) struct FocusRef {
 297    pub(crate) ref_count: AtomicUsize,
 298    pub(crate) tab_index: isize,
 299    pub(crate) tab_stop: bool,
 300}
 301
 302impl FocusId {
 303    /// Obtains whether the element associated with this handle is currently focused.
 304    pub fn is_focused(&self, window: &Window) -> bool {
 305        window.focus == Some(*self)
 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        window
 312            .focused(cx)
 313            .is_some_and(|focused| self.contains(focused.id, window))
 314    }
 315
 316    /// Obtains whether the element associated with this handle is contained within the
 317    /// focused element or is itself focused.
 318    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 319        let focused = window.focused(cx);
 320        focused.is_some_and(|focused| focused.id.contains(*self, window))
 321    }
 322
 323    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 324    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 325        window
 326            .rendered_frame
 327            .dispatch_tree
 328            .focus_contains(*self, other)
 329    }
 330}
 331
 332/// A handle which can be used to track and manipulate the focused element in a window.
 333pub struct FocusHandle {
 334    pub(crate) id: FocusId,
 335    handles: Arc<FocusMap>,
 336    /// The index of this element in the tab order.
 337    pub tab_index: isize,
 338    /// Whether this element can be focused by tab navigation.
 339    pub tab_stop: bool,
 340}
 341
 342impl std::fmt::Debug for FocusHandle {
 343    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 344        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 345    }
 346}
 347
 348impl FocusHandle {
 349    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 350        let id = handles.write().insert(FocusRef {
 351            ref_count: AtomicUsize::new(1),
 352            tab_index: 0,
 353            tab_stop: false,
 354        });
 355
 356        Self {
 357            id,
 358            tab_index: 0,
 359            tab_stop: false,
 360            handles: handles.clone(),
 361        }
 362    }
 363
 364    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 365        let lock = handles.read();
 366        let focus = lock.get(id)?;
 367        if atomic_incr_if_not_zero(&focus.ref_count) == 0 {
 368            return None;
 369        }
 370        Some(Self {
 371            id,
 372            tab_index: focus.tab_index,
 373            tab_stop: focus.tab_stop,
 374            handles: handles.clone(),
 375        })
 376    }
 377
 378    /// Sets the tab index of the element associated with this handle.
 379    pub fn tab_index(mut self, index: isize) -> Self {
 380        self.tab_index = index;
 381        if let Some(focus) = self.handles.write().get_mut(self.id) {
 382            focus.tab_index = index;
 383        }
 384        self
 385    }
 386
 387    /// Sets whether the element associated with this handle is a tab stop.
 388    ///
 389    /// When `false`, the element will not be included in the tab order.
 390    pub fn tab_stop(mut self, tab_stop: bool) -> Self {
 391        self.tab_stop = tab_stop;
 392        if let Some(focus) = self.handles.write().get_mut(self.id) {
 393            focus.tab_stop = tab_stop;
 394        }
 395        self
 396    }
 397
 398    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 399    pub fn downgrade(&self) -> WeakFocusHandle {
 400        WeakFocusHandle {
 401            id: self.id,
 402            handles: Arc::downgrade(&self.handles),
 403        }
 404    }
 405
 406    /// Moves the focus to the element associated with this handle.
 407    pub fn focus(&self, window: &mut Window, cx: &mut App) {
 408        window.focus(self, cx)
 409    }
 410
 411    /// Obtains whether the element associated with this handle is currently focused.
 412    pub fn is_focused(&self, window: &Window) -> bool {
 413        self.id.is_focused(window)
 414    }
 415
 416    /// Obtains whether the element associated with this handle contains the focused
 417    /// element or is itself focused.
 418    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 419        self.id.contains_focused(window, cx)
 420    }
 421
 422    /// Obtains whether the element associated with this handle is contained within the
 423    /// focused element or is itself focused.
 424    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 425        self.id.within_focused(window, cx)
 426    }
 427
 428    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 429    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 430        self.id.contains(other.id, window)
 431    }
 432
 433    /// Dispatch an action on the element that rendered this focus handle
 434    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 435        if let Some(node_id) = window
 436            .rendered_frame
 437            .dispatch_tree
 438            .focusable_node_id(self.id)
 439        {
 440            window.dispatch_action_on_node(node_id, action, cx)
 441        }
 442    }
 443}
 444
 445impl Clone for FocusHandle {
 446    fn clone(&self) -> Self {
 447        Self::for_id(self.id, &self.handles).unwrap()
 448    }
 449}
 450
 451impl PartialEq for FocusHandle {
 452    fn eq(&self, other: &Self) -> bool {
 453        self.id == other.id
 454    }
 455}
 456
 457impl Eq for FocusHandle {}
 458
 459impl Drop for FocusHandle {
 460    fn drop(&mut self) {
 461        self.handles
 462            .read()
 463            .get(self.id)
 464            .unwrap()
 465            .ref_count
 466            .fetch_sub(1, SeqCst);
 467    }
 468}
 469
 470/// A weak reference to a focus handle.
 471#[derive(Clone, Debug)]
 472pub struct WeakFocusHandle {
 473    pub(crate) id: FocusId,
 474    pub(crate) handles: Weak<FocusMap>,
 475}
 476
 477impl WeakFocusHandle {
 478    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 479    pub fn upgrade(&self) -> Option<FocusHandle> {
 480        let handles = self.handles.upgrade()?;
 481        FocusHandle::for_id(self.id, &handles)
 482    }
 483}
 484
 485impl PartialEq for WeakFocusHandle {
 486    fn eq(&self, other: &WeakFocusHandle) -> bool {
 487        self.id == other.id
 488    }
 489}
 490
 491impl Eq for WeakFocusHandle {}
 492
 493impl PartialEq<FocusHandle> for WeakFocusHandle {
 494    fn eq(&self, other: &FocusHandle) -> bool {
 495        self.id == other.id
 496    }
 497}
 498
 499impl PartialEq<WeakFocusHandle> for FocusHandle {
 500    fn eq(&self, other: &WeakFocusHandle) -> bool {
 501        self.id == other.id
 502    }
 503}
 504
 505/// Focusable allows users of your view to easily
 506/// focus it (using window.focus_view(cx, view))
 507pub trait Focusable: 'static {
 508    /// Returns the focus handle associated with this view.
 509    fn focus_handle(&self, cx: &App) -> FocusHandle;
 510}
 511
 512impl<V: Focusable> Focusable for Entity<V> {
 513    fn focus_handle(&self, cx: &App) -> FocusHandle {
 514        self.read(cx).focus_handle(cx)
 515    }
 516}
 517
 518/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 519/// where the lifecycle of the view is handled by another view.
 520pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 521
 522impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 523
 524/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 525pub struct DismissEvent;
 526
 527type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 528
 529pub(crate) type AnyMouseListener =
 530    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 531
 532#[derive(Clone)]
 533pub(crate) struct CursorStyleRequest {
 534    pub(crate) hitbox_id: Option<HitboxId>,
 535    pub(crate) style: CursorStyle,
 536}
 537
 538#[derive(Default, Eq, PartialEq)]
 539pub(crate) struct HitTest {
 540    pub(crate) ids: SmallVec<[HitboxId; 8]>,
 541    pub(crate) hover_hitbox_count: usize,
 542}
 543
 544/// A type of window control area that corresponds to the platform window.
 545#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 546pub enum WindowControlArea {
 547    /// An area that allows dragging of the platform window.
 548    Drag,
 549    /// An area that allows closing of the platform window.
 550    Close,
 551    /// An area that allows maximizing of the platform window.
 552    Max,
 553    /// An area that allows minimizing of the platform window.
 554    Min,
 555}
 556
 557/// An identifier for a [Hitbox] which also includes [HitboxBehavior].
 558#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 559pub struct HitboxId(u64);
 560
 561impl HitboxId {
 562    /// Checks if the hitbox with this ID is currently hovered. Except when handling
 563    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 564    /// events or paint hover styles.
 565    ///
 566    /// See [`Hitbox::is_hovered`] for details.
 567    pub fn is_hovered(self, window: &Window) -> bool {
 568        let hit_test = &window.mouse_hit_test;
 569        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 570            if self == *id {
 571                return true;
 572            }
 573        }
 574        false
 575    }
 576
 577    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 578    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 579    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 580    /// this distinction.
 581    pub fn should_handle_scroll(self, window: &Window) -> bool {
 582        window.mouse_hit_test.ids.contains(&self)
 583    }
 584
 585    fn next(mut self) -> HitboxId {
 586        HitboxId(self.0.wrapping_add(1))
 587    }
 588}
 589
 590/// A rectangular region that potentially blocks hitboxes inserted prior.
 591/// See [Window::insert_hitbox] for more details.
 592#[derive(Clone, Debug, Deref)]
 593pub struct Hitbox {
 594    /// A unique identifier for the hitbox.
 595    pub id: HitboxId,
 596    /// The bounds of the hitbox.
 597    #[deref]
 598    pub bounds: Bounds<Pixels>,
 599    /// The content mask when the hitbox was inserted.
 600    pub content_mask: ContentMask<Pixels>,
 601    /// Flags that specify hitbox behavior.
 602    pub behavior: HitboxBehavior,
 603}
 604
 605impl Hitbox {
 606    /// Checks if the hitbox is currently hovered. Except when handling `ScrollWheelEvent`, this is
 607    /// typically what you want when determining whether to handle mouse events or paint hover
 608    /// styles.
 609    ///
 610    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 611    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 612    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`).
 613    ///
 614    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 615    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 616    /// non-interactive while still allowing scrolling. More abstractly, this is because
 617    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 618    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 619    /// container.
 620    pub fn is_hovered(&self, window: &Window) -> bool {
 621        self.id.is_hovered(window)
 622    }
 623
 624    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 625    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 626    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 627    ///
 628    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 629    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 630    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 631        self.id.should_handle_scroll(window)
 632    }
 633}
 634
 635/// How the hitbox affects mouse behavior.
 636#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 637pub enum HitboxBehavior {
 638    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 639    #[default]
 640    Normal,
 641
 642    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 643    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 644    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 645    /// [`InteractiveElement::occlude`].
 646    ///
 647    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 648    /// bubble-phase handler for every mouse event type:
 649    ///
 650    /// ```ignore
 651    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 652    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 653    ///         cx.stop_propagation();
 654    ///     }
 655    /// })
 656    /// ```
 657    ///
 658    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 659    /// styles and tooltips. These other behaviors are the main point of this mechanism. An
 660    /// alternative might be to not affect mouse event handling - but this would allow
 661    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 662    /// be hovered.
 663    BlockMouse,
 664
 665    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 666    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 667    /// interaction except scroll events to be ignored - see the documentation of
 668    /// [`Hitbox::is_hovered`] for details. This flag is set by
 669    /// [`InteractiveElement::block_mouse_except_scroll`].
 670    ///
 671    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 672    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 673    ///
 674    /// ```ignore
 675    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, cx| {
 676    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 677    ///         cx.stop_propagation();
 678    ///     }
 679    /// })
 680    /// ```
 681    ///
 682    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 683    /// handled differently than other mouse events. If also blocking these scroll events is
 684    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 685    ///
 686    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 687    /// hover styles and tooltips. These other behaviors are the main point of this mechanism.
 688    /// An alternative might be to not affect mouse event handling - but this would allow
 689    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 690    /// be hovered.
 691    BlockMouseExceptScroll,
 692}
 693
 694/// An identifier for a tooltip.
 695#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 696pub struct TooltipId(usize);
 697
 698impl TooltipId {
 699    /// Checks if the tooltip is currently hovered.
 700    pub fn is_hovered(&self, window: &Window) -> bool {
 701        window
 702            .tooltip_bounds
 703            .as_ref()
 704            .is_some_and(|tooltip_bounds| {
 705                tooltip_bounds.id == *self
 706                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 707            })
 708    }
 709}
 710
 711pub(crate) struct TooltipBounds {
 712    id: TooltipId,
 713    bounds: Bounds<Pixels>,
 714}
 715
 716#[derive(Clone)]
 717pub(crate) struct TooltipRequest {
 718    id: TooltipId,
 719    tooltip: AnyTooltip,
 720}
 721
 722pub(crate) struct DeferredDraw {
 723    current_view: EntityId,
 724    priority: usize,
 725    parent_node: DispatchNodeId,
 726    element_id_stack: SmallVec<[ElementId; 32]>,
 727    text_style_stack: Vec<TextStyleRefinement>,
 728    rem_size: Pixels,
 729    element: Option<AnyElement>,
 730    absolute_offset: Point<Pixels>,
 731    prepaint_range: Range<PrepaintStateIndex>,
 732    paint_range: Range<PaintIndex>,
 733}
 734
 735pub(crate) struct Frame {
 736    pub(crate) focus: Option<FocusId>,
 737    pub(crate) window_active: bool,
 738    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 739    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 740    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 741    pub(crate) dispatch_tree: DispatchTree,
 742    pub(crate) scene: Scene,
 743    pub(crate) hitboxes: Vec<Hitbox>,
 744    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 745    pub(crate) deferred_draws: Vec<DeferredDraw>,
 746    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 747    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 748    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 749    #[cfg(any(test, feature = "test-support"))]
 750    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 751    #[cfg(any(feature = "inspector", debug_assertions))]
 752    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 753    #[cfg(any(feature = "inspector", debug_assertions))]
 754    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 755    pub(crate) tab_stops: TabStopMap,
 756}
 757
 758#[derive(Clone, Default)]
 759pub(crate) struct PrepaintStateIndex {
 760    hitboxes_index: usize,
 761    tooltips_index: usize,
 762    deferred_draws_index: usize,
 763    dispatch_tree_index: usize,
 764    accessed_element_states_index: usize,
 765    line_layout_index: LineLayoutIndex,
 766}
 767
 768#[derive(Clone, Default)]
 769pub(crate) struct PaintIndex {
 770    scene_index: usize,
 771    mouse_listeners_index: usize,
 772    input_handlers_index: usize,
 773    cursor_styles_index: usize,
 774    accessed_element_states_index: usize,
 775    tab_handle_index: usize,
 776    line_layout_index: LineLayoutIndex,
 777}
 778
 779impl Frame {
 780    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 781        Frame {
 782            focus: None,
 783            window_active: false,
 784            element_states: FxHashMap::default(),
 785            accessed_element_states: Vec::new(),
 786            mouse_listeners: Vec::new(),
 787            dispatch_tree,
 788            scene: Scene::default(),
 789            hitboxes: Vec::new(),
 790            window_control_hitboxes: Vec::new(),
 791            deferred_draws: Vec::new(),
 792            input_handlers: Vec::new(),
 793            tooltip_requests: Vec::new(),
 794            cursor_styles: Vec::new(),
 795
 796            #[cfg(any(test, feature = "test-support"))]
 797            debug_bounds: FxHashMap::default(),
 798
 799            #[cfg(any(feature = "inspector", debug_assertions))]
 800            next_inspector_instance_ids: FxHashMap::default(),
 801
 802            #[cfg(any(feature = "inspector", debug_assertions))]
 803            inspector_hitboxes: FxHashMap::default(),
 804            tab_stops: TabStopMap::default(),
 805        }
 806    }
 807
 808    pub(crate) fn clear(&mut self) {
 809        self.element_states.clear();
 810        self.accessed_element_states.clear();
 811        self.mouse_listeners.clear();
 812        self.dispatch_tree.clear();
 813        self.scene.clear();
 814        self.input_handlers.clear();
 815        self.tooltip_requests.clear();
 816        self.cursor_styles.clear();
 817        self.hitboxes.clear();
 818        self.window_control_hitboxes.clear();
 819        self.deferred_draws.clear();
 820        self.tab_stops.clear();
 821        self.focus = None;
 822
 823        #[cfg(any(feature = "inspector", debug_assertions))]
 824        {
 825            self.next_inspector_instance_ids.clear();
 826            self.inspector_hitboxes.clear();
 827        }
 828    }
 829
 830    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 831        self.cursor_styles
 832            .iter()
 833            .rev()
 834            .fold_while(None, |style, request| match request.hitbox_id {
 835                None => Done(Some(request.style)),
 836                Some(hitbox_id) => Continue(
 837                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 838                ),
 839            })
 840            .into_inner()
 841    }
 842
 843    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 844        let mut set_hover_hitbox_count = false;
 845        let mut hit_test = HitTest::default();
 846        for hitbox in self.hitboxes.iter().rev() {
 847            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 848            if bounds.contains(&position) {
 849                hit_test.ids.push(hitbox.id);
 850                if !set_hover_hitbox_count
 851                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 852                {
 853                    hit_test.hover_hitbox_count = hit_test.ids.len();
 854                    set_hover_hitbox_count = true;
 855                }
 856                if hitbox.behavior == HitboxBehavior::BlockMouse {
 857                    break;
 858                }
 859            }
 860        }
 861        if !set_hover_hitbox_count {
 862            hit_test.hover_hitbox_count = hit_test.ids.len();
 863        }
 864        hit_test
 865    }
 866
 867    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 868        self.focus
 869            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 870            .unwrap_or_default()
 871    }
 872
 873    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 874        for element_state_key in &self.accessed_element_states {
 875            if let Some((element_state_key, element_state)) =
 876                prev_frame.element_states.remove_entry(element_state_key)
 877            {
 878                self.element_states.insert(element_state_key, element_state);
 879            }
 880        }
 881
 882        self.scene.finish();
 883    }
 884}
 885
 886#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 887enum InputModality {
 888    Mouse,
 889    Keyboard,
 890}
 891
 892/// Holds the state for a specific window.
 893pub struct Window {
 894    pub(crate) handle: AnyWindowHandle,
 895    pub(crate) invalidator: WindowInvalidator,
 896    pub(crate) removed: bool,
 897    pub(crate) platform_window: Box<dyn PlatformWindow>,
 898    display_id: Option<DisplayId>,
 899    sprite_atlas: Arc<dyn PlatformAtlas>,
 900    text_system: Arc<WindowTextSystem>,
 901    text_rendering_mode: Rc<Cell<TextRenderingMode>>,
 902    rem_size: Pixels,
 903    /// The stack of override values for the window's rem size.
 904    ///
 905    /// This is used by `with_rem_size` to allow rendering an element tree with
 906    /// a given rem size.
 907    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 908    pub(crate) viewport_size: Size<Pixels>,
 909    layout_engine: Option<TaffyLayoutEngine>,
 910    pub(crate) root: Option<AnyView>,
 911    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 912    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 913    pub(crate) rendered_entity_stack: Vec<EntityId>,
 914    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 915    pub(crate) element_opacity: f32,
 916    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 917    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 918    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 919    pub(crate) rendered_frame: Frame,
 920    pub(crate) next_frame: Frame,
 921    next_hitbox_id: HitboxId,
 922    pub(crate) next_tooltip_id: TooltipId,
 923    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 924    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 925    pub(crate) dirty_views: FxHashSet<EntityId>,
 926    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 927    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 928    default_prevented: bool,
 929    mouse_position: Point<Pixels>,
 930    mouse_hit_test: HitTest,
 931    modifiers: Modifiers,
 932    capslock: Capslock,
 933    scale_factor: f32,
 934    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 935    appearance: WindowAppearance,
 936    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 937    active: Rc<Cell<bool>>,
 938    hovered: Rc<Cell<bool>>,
 939    pub(crate) needs_present: Rc<Cell<bool>>,
 940    /// Tracks recent input event timestamps to determine if input is arriving at a high rate.
 941    /// Used to selectively enable VRR optimization only when input rate exceeds 60fps.
 942    pub(crate) input_rate_tracker: Rc<RefCell<InputRateTracker>>,
 943    last_input_modality: InputModality,
 944    pub(crate) refreshing: bool,
 945    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 946    pub(crate) focus: Option<FocusId>,
 947    focus_enabled: bool,
 948    pending_input: Option<PendingInput>,
 949    pending_modifier: ModifierState,
 950    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 951    prompt: Option<RenderablePromptHandle>,
 952    pub(crate) client_inset: Option<Pixels>,
 953    #[cfg(any(feature = "inspector", debug_assertions))]
 954    inspector: Option<Entity<Inspector>>,
 955}
 956
 957#[derive(Clone, Debug, Default)]
 958struct ModifierState {
 959    modifiers: Modifiers,
 960    saw_keystroke: bool,
 961}
 962
 963/// Tracks input event timestamps to determine if input is arriving at a high rate.
 964/// Used for selective VRR (Variable Refresh Rate) optimization.
 965#[derive(Clone, Debug)]
 966pub(crate) struct InputRateTracker {
 967    timestamps: Vec<Instant>,
 968    window: Duration,
 969    inputs_per_second: u32,
 970    sustain_until: Instant,
 971    sustain_duration: Duration,
 972}
 973
 974impl Default for InputRateTracker {
 975    fn default() -> Self {
 976        Self {
 977            timestamps: Vec::new(),
 978            window: Duration::from_millis(100),
 979            inputs_per_second: 60,
 980            sustain_until: Instant::now(),
 981            sustain_duration: Duration::from_secs(1),
 982        }
 983    }
 984}
 985
 986impl InputRateTracker {
 987    pub fn record_input(&mut self) {
 988        let now = Instant::now();
 989        self.timestamps.push(now);
 990        self.prune_old_timestamps(now);
 991
 992        let min_events = self.inputs_per_second as u128 * self.window.as_millis() / 1000;
 993        if self.timestamps.len() as u128 >= min_events {
 994            self.sustain_until = now + self.sustain_duration;
 995        }
 996    }
 997
 998    pub fn is_high_rate(&self) -> bool {
 999        Instant::now() < self.sustain_until
1000    }
1001
1002    fn prune_old_timestamps(&mut self, now: Instant) {
1003        self.timestamps
1004            .retain(|&t| now.duration_since(t) <= self.window);
1005    }
1006}
1007
1008#[derive(Clone, Copy, Debug, Eq, PartialEq)]
1009pub(crate) enum DrawPhase {
1010    None,
1011    Prepaint,
1012    Paint,
1013    Focus,
1014}
1015
1016#[derive(Default, Debug)]
1017struct PendingInput {
1018    keystrokes: SmallVec<[Keystroke; 1]>,
1019    focus: Option<FocusId>,
1020    timer: Option<Task<()>>,
1021    needs_timeout: bool,
1022}
1023
1024pub(crate) struct ElementStateBox {
1025    pub(crate) inner: Box<dyn Any>,
1026    #[cfg(debug_assertions)]
1027    pub(crate) type_name: &'static str,
1028}
1029
1030fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> WindowBounds {
1031    // TODO, BUG: if you open a window with the currently active window
1032    // on the stack, this will erroneously fallback to `None`
1033    //
1034    // TODO these should be the initial window bounds not considering maximized/fullscreen
1035    let active_window_bounds = cx
1036        .active_window()
1037        .and_then(|w| w.update(cx, |_, window, _| window.window_bounds()).ok());
1038
1039    const CASCADE_OFFSET: f32 = 25.0;
1040
1041    let display = display_id
1042        .map(|id| cx.find_display(id))
1043        .unwrap_or_else(|| cx.primary_display());
1044
1045    let default_placement = || Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE);
1046
1047    // Use visible_bounds to exclude taskbar/dock areas
1048    let display_bounds = display
1049        .as_ref()
1050        .map(|d| d.visible_bounds())
1051        .unwrap_or_else(default_placement);
1052
1053    let (
1054        Bounds {
1055            origin: base_origin,
1056            size: base_size,
1057        },
1058        window_bounds_ctor,
1059    ): (_, fn(Bounds<Pixels>) -> WindowBounds) = match active_window_bounds {
1060        Some(bounds) => match bounds {
1061            WindowBounds::Windowed(bounds) => (bounds, WindowBounds::Windowed),
1062            WindowBounds::Maximized(bounds) => (bounds, WindowBounds::Maximized),
1063            WindowBounds::Fullscreen(bounds) => (bounds, WindowBounds::Fullscreen),
1064        },
1065        None => (
1066            display
1067                .as_ref()
1068                .map(|d| d.default_bounds())
1069                .unwrap_or_else(default_placement),
1070            WindowBounds::Windowed,
1071        ),
1072    };
1073
1074    let cascade_offset = point(px(CASCADE_OFFSET), px(CASCADE_OFFSET));
1075    let proposed_origin = base_origin + cascade_offset;
1076    let proposed_bounds = Bounds::new(proposed_origin, base_size);
1077
1078    let display_right = display_bounds.origin.x + display_bounds.size.width;
1079    let display_bottom = display_bounds.origin.y + display_bounds.size.height;
1080    let window_right = proposed_bounds.origin.x + proposed_bounds.size.width;
1081    let window_bottom = proposed_bounds.origin.y + proposed_bounds.size.height;
1082
1083    let fits_horizontally = window_right <= display_right;
1084    let fits_vertically = window_bottom <= display_bottom;
1085
1086    let final_origin = match (fits_horizontally, fits_vertically) {
1087        (true, true) => proposed_origin,
1088        (false, true) => point(display_bounds.origin.x, base_origin.y),
1089        (true, false) => point(base_origin.x, display_bounds.origin.y),
1090        (false, false) => display_bounds.origin,
1091    };
1092    window_bounds_ctor(Bounds::new(final_origin, base_size))
1093}
1094
1095impl Window {
1096    pub(crate) fn new(
1097        handle: AnyWindowHandle,
1098        options: WindowOptions,
1099        cx: &mut App,
1100    ) -> Result<Self> {
1101        let WindowOptions {
1102            window_bounds,
1103            titlebar,
1104            focus,
1105            show,
1106            kind,
1107            is_movable,
1108            is_resizable,
1109            is_minimizable,
1110            display_id,
1111            window_background,
1112            app_id,
1113            window_min_size,
1114            window_decorations,
1115            #[cfg_attr(not(target_os = "macos"), allow(unused_variables))]
1116            tabbing_identifier,
1117        } = options;
1118
1119        let window_bounds = window_bounds.unwrap_or_else(|| default_bounds(display_id, cx));
1120        let mut platform_window = cx.platform.open_window(
1121            handle,
1122            WindowParams {
1123                bounds: window_bounds.get_bounds(),
1124                titlebar,
1125                kind,
1126                is_movable,
1127                is_resizable,
1128                is_minimizable,
1129                focus,
1130                show,
1131                display_id,
1132                window_min_size,
1133                #[cfg(target_os = "macos")]
1134                tabbing_identifier,
1135            },
1136        )?;
1137
1138        let tab_bar_visible = platform_window.tab_bar_visible();
1139        SystemWindowTabController::init_visible(cx, tab_bar_visible);
1140        if let Some(tabs) = platform_window.tabbed_windows() {
1141            SystemWindowTabController::add_tab(cx, handle.window_id(), tabs);
1142        }
1143
1144        let display_id = platform_window.display().map(|display| display.id());
1145        let sprite_atlas = platform_window.sprite_atlas();
1146        let mouse_position = platform_window.mouse_position();
1147        let modifiers = platform_window.modifiers();
1148        let capslock = platform_window.capslock();
1149        let content_size = platform_window.content_size();
1150        let scale_factor = platform_window.scale_factor();
1151        let appearance = platform_window.appearance();
1152        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
1153        let invalidator = WindowInvalidator::new();
1154        let active = Rc::new(Cell::new(platform_window.is_active()));
1155        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
1156        let needs_present = Rc::new(Cell::new(false));
1157        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
1158        let input_rate_tracker = Rc::new(RefCell::new(InputRateTracker::default()));
1159        let last_frame_time = Rc::new(Cell::new(None));
1160
1161        platform_window
1162            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
1163        platform_window.set_background_appearance(window_background);
1164
1165        match window_bounds {
1166            WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
1167            WindowBounds::Maximized(_) => platform_window.zoom(),
1168            WindowBounds::Windowed(_) => {}
1169        }
1170
1171        platform_window.on_close(Box::new({
1172            let window_id = handle.window_id();
1173            let mut cx = cx.to_async();
1174            move || {
1175                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
1176                let _ = cx.update(|cx| {
1177                    SystemWindowTabController::remove_tab(cx, window_id);
1178                });
1179            }
1180        }));
1181        platform_window.on_request_frame(Box::new({
1182            let mut cx = cx.to_async();
1183            let invalidator = invalidator.clone();
1184            let active = active.clone();
1185            let needs_present = needs_present.clone();
1186            let next_frame_callbacks = next_frame_callbacks.clone();
1187            let input_rate_tracker = input_rate_tracker.clone();
1188            move |request_frame_options| {
1189                let thermal_state = handle
1190                    .update(&mut cx, |_, _, cx| cx.thermal_state())
1191                    .log_err();
1192
1193                if thermal_state == Some(ThermalState::Serious)
1194                    || thermal_state == Some(ThermalState::Critical)
1195                {
1196                    let now = Instant::now();
1197                    let last_frame_time = last_frame_time.replace(Some(now));
1198
1199                    if let Some(last_frame) = last_frame_time
1200                        && now.duration_since(last_frame) < Duration::from_micros(16667)
1201                    {
1202                        return;
1203                    }
1204                }
1205
1206                let next_frame_callbacks = next_frame_callbacks.take();
1207                if !next_frame_callbacks.is_empty() {
1208                    handle
1209                        .update(&mut cx, |_, window, cx| {
1210                            for callback in next_frame_callbacks {
1211                                callback(window, cx);
1212                            }
1213                        })
1214                        .log_err();
1215                }
1216
1217                // Keep presenting if input was recently arriving at a high rate (>= 60fps).
1218                // Once high-rate input is detected, we sustain presentation for 1 second
1219                // to prevent display underclocking during active input.
1220                let needs_present = request_frame_options.require_presentation
1221                    || needs_present.get()
1222                    || (active.get() && input_rate_tracker.borrow_mut().is_high_rate());
1223
1224                if invalidator.is_dirty() || request_frame_options.force_render {
1225                    measure("frame duration", || {
1226                        handle
1227                            .update(&mut cx, |_, window, cx| {
1228                                let arena_clear_needed = window.draw(cx);
1229                                window.present();
1230                                arena_clear_needed.clear();
1231                            })
1232                            .log_err();
1233                    })
1234                } else if needs_present {
1235                    handle
1236                        .update(&mut cx, |_, window, _| window.present())
1237                        .log_err();
1238                }
1239
1240                handle
1241                    .update(&mut cx, |_, window, _| {
1242                        window.complete_frame();
1243                    })
1244                    .log_err();
1245            }
1246        }));
1247        platform_window.on_resize(Box::new({
1248            let mut cx = cx.to_async();
1249            move |_, _| {
1250                handle
1251                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1252                    .log_err();
1253            }
1254        }));
1255        platform_window.on_moved(Box::new({
1256            let mut cx = cx.to_async();
1257            move || {
1258                handle
1259                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1260                    .log_err();
1261            }
1262        }));
1263        platform_window.on_appearance_changed(Box::new({
1264            let mut cx = cx.to_async();
1265            move || {
1266                handle
1267                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1268                    .log_err();
1269            }
1270        }));
1271        platform_window.on_active_status_change(Box::new({
1272            let mut cx = cx.to_async();
1273            move |active| {
1274                handle
1275                    .update(&mut cx, |_, window, cx| {
1276                        window.active.set(active);
1277                        window.modifiers = window.platform_window.modifiers();
1278                        window.capslock = window.platform_window.capslock();
1279                        window
1280                            .activation_observers
1281                            .clone()
1282                            .retain(&(), |callback| callback(window, cx));
1283
1284                        window.bounds_changed(cx);
1285                        window.refresh();
1286
1287                        SystemWindowTabController::update_last_active(cx, window.handle.id);
1288                    })
1289                    .log_err();
1290            }
1291        }));
1292        platform_window.on_hover_status_change(Box::new({
1293            let mut cx = cx.to_async();
1294            move |active| {
1295                handle
1296                    .update(&mut cx, |_, window, _| {
1297                        window.hovered.set(active);
1298                        window.refresh();
1299                    })
1300                    .log_err();
1301            }
1302        }));
1303        platform_window.on_input({
1304            let mut cx = cx.to_async();
1305            Box::new(move |event| {
1306                handle
1307                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1308                    .log_err()
1309                    .unwrap_or(DispatchEventResult::default())
1310            })
1311        });
1312        platform_window.on_hit_test_window_control({
1313            let mut cx = cx.to_async();
1314            Box::new(move || {
1315                handle
1316                    .update(&mut cx, |_, window, _cx| {
1317                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1318                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1319                                return Some(*area);
1320                            }
1321                        }
1322                        None
1323                    })
1324                    .log_err()
1325                    .unwrap_or(None)
1326            })
1327        });
1328        platform_window.on_move_tab_to_new_window({
1329            let mut cx = cx.to_async();
1330            Box::new(move || {
1331                handle
1332                    .update(&mut cx, |_, _window, cx| {
1333                        SystemWindowTabController::move_tab_to_new_window(cx, handle.window_id());
1334                    })
1335                    .log_err();
1336            })
1337        });
1338        platform_window.on_merge_all_windows({
1339            let mut cx = cx.to_async();
1340            Box::new(move || {
1341                handle
1342                    .update(&mut cx, |_, _window, cx| {
1343                        SystemWindowTabController::merge_all_windows(cx, handle.window_id());
1344                    })
1345                    .log_err();
1346            })
1347        });
1348        platform_window.on_select_next_tab({
1349            let mut cx = cx.to_async();
1350            Box::new(move || {
1351                handle
1352                    .update(&mut cx, |_, _window, cx| {
1353                        SystemWindowTabController::select_next_tab(cx, handle.window_id());
1354                    })
1355                    .log_err();
1356            })
1357        });
1358        platform_window.on_select_previous_tab({
1359            let mut cx = cx.to_async();
1360            Box::new(move || {
1361                handle
1362                    .update(&mut cx, |_, _window, cx| {
1363                        SystemWindowTabController::select_previous_tab(cx, handle.window_id())
1364                    })
1365                    .log_err();
1366            })
1367        });
1368        platform_window.on_toggle_tab_bar({
1369            let mut cx = cx.to_async();
1370            Box::new(move || {
1371                handle
1372                    .update(&mut cx, |_, window, cx| {
1373                        let tab_bar_visible = window.platform_window.tab_bar_visible();
1374                        SystemWindowTabController::set_visible(cx, tab_bar_visible);
1375                    })
1376                    .log_err();
1377            })
1378        });
1379
1380        if let Some(app_id) = app_id {
1381            platform_window.set_app_id(&app_id);
1382        }
1383
1384        platform_window.map_window().unwrap();
1385
1386        Ok(Window {
1387            handle,
1388            invalidator,
1389            removed: false,
1390            platform_window,
1391            display_id,
1392            sprite_atlas,
1393            text_system,
1394            text_rendering_mode: cx.text_rendering_mode.clone(),
1395            rem_size: px(16.),
1396            rem_size_override_stack: SmallVec::new(),
1397            viewport_size: content_size,
1398            layout_engine: Some(TaffyLayoutEngine::new()),
1399            root: None,
1400            element_id_stack: SmallVec::default(),
1401            text_style_stack: Vec::new(),
1402            rendered_entity_stack: Vec::new(),
1403            element_offset_stack: Vec::new(),
1404            content_mask_stack: Vec::new(),
1405            element_opacity: 1.0,
1406            requested_autoscroll: None,
1407            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1408            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1409            next_frame_callbacks,
1410            next_hitbox_id: HitboxId(0),
1411            next_tooltip_id: TooltipId::default(),
1412            tooltip_bounds: None,
1413            dirty_views: FxHashSet::default(),
1414            focus_listeners: SubscriberSet::new(),
1415            focus_lost_listeners: SubscriberSet::new(),
1416            default_prevented: true,
1417            mouse_position,
1418            mouse_hit_test: HitTest::default(),
1419            modifiers,
1420            capslock,
1421            scale_factor,
1422            bounds_observers: SubscriberSet::new(),
1423            appearance,
1424            appearance_observers: SubscriberSet::new(),
1425            active,
1426            hovered,
1427            needs_present,
1428            input_rate_tracker,
1429            last_input_modality: InputModality::Mouse,
1430            refreshing: false,
1431            activation_observers: SubscriberSet::new(),
1432            focus: None,
1433            focus_enabled: true,
1434            pending_input: None,
1435            pending_modifier: ModifierState::default(),
1436            pending_input_observers: SubscriberSet::new(),
1437            prompt: None,
1438            client_inset: None,
1439            image_cache_stack: Vec::new(),
1440            #[cfg(any(feature = "inspector", debug_assertions))]
1441            inspector: None,
1442        })
1443    }
1444
1445    pub(crate) fn new_focus_listener(
1446        &self,
1447        value: AnyWindowFocusListener,
1448    ) -> (Subscription, impl FnOnce() + use<>) {
1449        self.focus_listeners.insert((), value)
1450    }
1451}
1452
1453#[derive(Clone, Debug, Default, PartialEq, Eq)]
1454#[expect(missing_docs)]
1455pub struct DispatchEventResult {
1456    pub propagate: bool,
1457    pub default_prevented: bool,
1458}
1459
1460/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1461/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1462/// to leave room to support more complex shapes in the future.
1463#[derive(Clone, Debug, Default, PartialEq, Eq)]
1464#[repr(C)]
1465pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1466    /// The bounds
1467    pub bounds: Bounds<P>,
1468}
1469
1470impl ContentMask<Pixels> {
1471    /// Scale the content mask's pixel units by the given scaling factor.
1472    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1473        ContentMask {
1474            bounds: self.bounds.scale(factor),
1475        }
1476    }
1477
1478    /// Intersect the content mask with the given content mask.
1479    pub fn intersect(&self, other: &Self) -> Self {
1480        let bounds = self.bounds.intersect(&other.bounds);
1481        ContentMask { bounds }
1482    }
1483}
1484
1485impl Window {
1486    fn mark_view_dirty(&mut self, view_id: EntityId) {
1487        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1488        // should already be dirty.
1489        for view_id in self
1490            .rendered_frame
1491            .dispatch_tree
1492            .view_path_reversed(view_id)
1493        {
1494            if !self.dirty_views.insert(view_id) {
1495                break;
1496            }
1497        }
1498    }
1499
1500    /// Registers a callback to be invoked when the window appearance changes.
1501    pub fn observe_window_appearance(
1502        &self,
1503        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1504    ) -> Subscription {
1505        let (subscription, activate) = self.appearance_observers.insert(
1506            (),
1507            Box::new(move |window, cx| {
1508                callback(window, cx);
1509                true
1510            }),
1511        );
1512        activate();
1513        subscription
1514    }
1515
1516    /// Replaces the root entity of the window with a new one.
1517    pub fn replace_root<E>(
1518        &mut self,
1519        cx: &mut App,
1520        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1521    ) -> Entity<E>
1522    where
1523        E: 'static + Render,
1524    {
1525        let view = cx.new(|cx| build_view(self, cx));
1526        self.root = Some(view.clone().into());
1527        self.refresh();
1528        view
1529    }
1530
1531    /// Returns the root entity of the window, if it has one.
1532    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1533    where
1534        E: 'static + Render,
1535    {
1536        self.root
1537            .as_ref()
1538            .map(|view| view.clone().downcast::<E>().ok())
1539    }
1540
1541    /// Obtain a handle to the window that belongs to this context.
1542    pub fn window_handle(&self) -> AnyWindowHandle {
1543        self.handle
1544    }
1545
1546    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1547    pub fn refresh(&mut self) {
1548        if self.invalidator.not_drawing() {
1549            self.refreshing = true;
1550            self.invalidator.set_dirty(true);
1551        }
1552    }
1553
1554    /// Close this window.
1555    pub fn remove_window(&mut self) {
1556        self.removed = true;
1557    }
1558
1559    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1560    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1561        self.focus
1562            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1563    }
1564
1565    /// Move focus to the element associated with the given [`FocusHandle`].
1566    pub fn focus(&mut self, handle: &FocusHandle, cx: &mut App) {
1567        if !self.focus_enabled || self.focus == Some(handle.id) {
1568            return;
1569        }
1570
1571        self.focus = Some(handle.id);
1572        self.clear_pending_keystrokes();
1573
1574        // Avoid re-entrant entity updates by deferring observer notifications to the end of the
1575        // current effect cycle, and only for this window.
1576        let window_handle = self.handle;
1577        cx.defer(move |cx| {
1578            window_handle
1579                .update(cx, |_, window, cx| {
1580                    window.pending_input_changed(cx);
1581                })
1582                .ok();
1583        });
1584
1585        self.refresh();
1586    }
1587
1588    /// Remove focus from all elements within this context's window.
1589    pub fn blur(&mut self) {
1590        if !self.focus_enabled {
1591            return;
1592        }
1593
1594        self.focus = None;
1595        self.refresh();
1596    }
1597
1598    /// Blur the window and don't allow anything in it to be focused again.
1599    pub fn disable_focus(&mut self) {
1600        self.blur();
1601        self.focus_enabled = false;
1602    }
1603
1604    /// Move focus to next tab stop.
1605    pub fn focus_next(&mut self, cx: &mut App) {
1606        if !self.focus_enabled {
1607            return;
1608        }
1609
1610        if let Some(handle) = self.rendered_frame.tab_stops.next(self.focus.as_ref()) {
1611            self.focus(&handle, cx)
1612        }
1613    }
1614
1615    /// Move focus to previous tab stop.
1616    pub fn focus_prev(&mut self, cx: &mut App) {
1617        if !self.focus_enabled {
1618            return;
1619        }
1620
1621        if let Some(handle) = self.rendered_frame.tab_stops.prev(self.focus.as_ref()) {
1622            self.focus(&handle, cx)
1623        }
1624    }
1625
1626    /// Accessor for the text system.
1627    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1628        &self.text_system
1629    }
1630
1631    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1632    pub fn text_style(&self) -> TextStyle {
1633        let mut style = TextStyle::default();
1634        for refinement in &self.text_style_stack {
1635            style.refine(refinement);
1636        }
1637        style
1638    }
1639
1640    /// Check if the platform window is maximized.
1641    ///
1642    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1643    pub fn is_maximized(&self) -> bool {
1644        self.platform_window.is_maximized()
1645    }
1646
1647    /// request a certain window decoration (Wayland)
1648    pub fn request_decorations(&self, decorations: WindowDecorations) {
1649        self.platform_window.request_decorations(decorations);
1650    }
1651
1652    /// Start a window resize operation (Wayland)
1653    pub fn start_window_resize(&self, edge: ResizeEdge) {
1654        self.platform_window.start_window_resize(edge);
1655    }
1656
1657    /// Return the `WindowBounds` to indicate that how a window should be opened
1658    /// after it has been closed
1659    pub fn window_bounds(&self) -> WindowBounds {
1660        self.platform_window.window_bounds()
1661    }
1662
1663    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1664    pub fn inner_window_bounds(&self) -> WindowBounds {
1665        self.platform_window.inner_window_bounds()
1666    }
1667
1668    /// Dispatch the given action on the currently focused element.
1669    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1670        let focus_id = self.focused(cx).map(|handle| handle.id);
1671
1672        let window = self.handle;
1673        cx.defer(move |cx| {
1674            window
1675                .update(cx, |_, window, cx| {
1676                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1677                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1678                })
1679                .log_err();
1680        })
1681    }
1682
1683    pub(crate) fn dispatch_keystroke_observers(
1684        &mut self,
1685        event: &dyn Any,
1686        action: Option<Box<dyn Action>>,
1687        context_stack: Vec<KeyContext>,
1688        cx: &mut App,
1689    ) {
1690        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1691            return;
1692        };
1693
1694        cx.keystroke_observers.clone().retain(&(), move |callback| {
1695            (callback)(
1696                &KeystrokeEvent {
1697                    keystroke: key_down_event.keystroke.clone(),
1698                    action: action.as_ref().map(|action| action.boxed_clone()),
1699                    context_stack: context_stack.clone(),
1700                },
1701                self,
1702                cx,
1703            )
1704        });
1705    }
1706
1707    pub(crate) fn dispatch_keystroke_interceptors(
1708        &mut self,
1709        event: &dyn Any,
1710        context_stack: Vec<KeyContext>,
1711        cx: &mut App,
1712    ) {
1713        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1714            return;
1715        };
1716
1717        cx.keystroke_interceptors
1718            .clone()
1719            .retain(&(), move |callback| {
1720                (callback)(
1721                    &KeystrokeEvent {
1722                        keystroke: key_down_event.keystroke.clone(),
1723                        action: None,
1724                        context_stack: context_stack.clone(),
1725                    },
1726                    self,
1727                    cx,
1728                )
1729            });
1730    }
1731
1732    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1733    /// that are currently on the stack to be returned to the app.
1734    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1735        let handle = self.handle;
1736        cx.defer(move |cx| {
1737            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1738        });
1739    }
1740
1741    /// Subscribe to events emitted by a entity.
1742    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1743    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1744    pub fn observe<T: 'static>(
1745        &mut self,
1746        observed: &Entity<T>,
1747        cx: &mut App,
1748        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1749    ) -> Subscription {
1750        let entity_id = observed.entity_id();
1751        let observed = observed.downgrade();
1752        let window_handle = self.handle;
1753        cx.new_observer(
1754            entity_id,
1755            Box::new(move |cx| {
1756                window_handle
1757                    .update(cx, |_, window, cx| {
1758                        if let Some(handle) = observed.upgrade() {
1759                            on_notify(handle, window, cx);
1760                            true
1761                        } else {
1762                            false
1763                        }
1764                    })
1765                    .unwrap_or(false)
1766            }),
1767        )
1768    }
1769
1770    /// Subscribe to events emitted by a entity.
1771    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1772    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1773    pub fn subscribe<Emitter, Evt>(
1774        &mut self,
1775        entity: &Entity<Emitter>,
1776        cx: &mut App,
1777        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1778    ) -> Subscription
1779    where
1780        Emitter: EventEmitter<Evt>,
1781        Evt: 'static,
1782    {
1783        let entity_id = entity.entity_id();
1784        let handle = entity.downgrade();
1785        let window_handle = self.handle;
1786        cx.new_subscription(
1787            entity_id,
1788            (
1789                TypeId::of::<Evt>(),
1790                Box::new(move |event, cx| {
1791                    window_handle
1792                        .update(cx, |_, window, cx| {
1793                            if let Some(entity) = handle.upgrade() {
1794                                let event = event.downcast_ref().expect("invalid event type");
1795                                on_event(entity, event, window, cx);
1796                                true
1797                            } else {
1798                                false
1799                            }
1800                        })
1801                        .unwrap_or(false)
1802                }),
1803            ),
1804        )
1805    }
1806
1807    /// Register a callback to be invoked when the given `Entity` is released.
1808    pub fn observe_release<T>(
1809        &self,
1810        entity: &Entity<T>,
1811        cx: &mut App,
1812        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1813    ) -> Subscription
1814    where
1815        T: 'static,
1816    {
1817        let entity_id = entity.entity_id();
1818        let window_handle = self.handle;
1819        let (subscription, activate) = cx.release_listeners.insert(
1820            entity_id,
1821            Box::new(move |entity, cx| {
1822                let entity = entity.downcast_mut().expect("invalid entity type");
1823                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1824            }),
1825        );
1826        activate();
1827        subscription
1828    }
1829
1830    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1831    /// await points in async code.
1832    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1833        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1834    }
1835
1836    /// Schedule the given closure to be run directly after the current frame is rendered.
1837    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1838        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1839    }
1840
1841    /// Schedule a frame to be drawn on the next animation frame.
1842    ///
1843    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1844    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1845    ///
1846    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1847    pub fn request_animation_frame(&self) {
1848        let entity = self.current_view();
1849        self.on_next_frame(move |_, cx| cx.notify(entity));
1850    }
1851
1852    /// Spawn the future returned by the given closure on the application thread pool.
1853    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1854    /// use within your future.
1855    #[track_caller]
1856    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1857    where
1858        R: 'static,
1859        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1860    {
1861        let handle = self.handle;
1862        cx.spawn(async move |app| {
1863            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1864            f(&mut async_window_cx).await
1865        })
1866    }
1867
1868    /// Spawn the future returned by the given closure on the application thread
1869    /// pool, with the given priority. The closure is provided a handle to the
1870    /// current window and an `AsyncWindowContext` for use within your future.
1871    #[track_caller]
1872    pub fn spawn_with_priority<AsyncFn, R>(
1873        &self,
1874        priority: Priority,
1875        cx: &App,
1876        f: AsyncFn,
1877    ) -> Task<R>
1878    where
1879        R: 'static,
1880        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1881    {
1882        let handle = self.handle;
1883        cx.spawn_with_priority(priority, async move |app| {
1884            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1885            f(&mut async_window_cx).await
1886        })
1887    }
1888
1889    fn bounds_changed(&mut self, cx: &mut App) {
1890        self.scale_factor = self.platform_window.scale_factor();
1891        self.viewport_size = self.platform_window.content_size();
1892        self.display_id = self.platform_window.display().map(|display| display.id());
1893
1894        self.refresh();
1895
1896        self.bounds_observers
1897            .clone()
1898            .retain(&(), |callback| callback(self, cx));
1899    }
1900
1901    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1902    pub fn bounds(&self) -> Bounds<Pixels> {
1903        self.platform_window.bounds()
1904    }
1905
1906    /// Renders the current frame's scene to a texture and returns the pixel data as an RGBA image.
1907    /// This does not present the frame to screen - useful for visual testing where we want
1908    /// to capture what would be rendered without displaying it or requiring the window to be visible.
1909    #[cfg(any(test, feature = "test-support"))]
1910    pub fn render_to_image(&self) -> anyhow::Result<image::RgbaImage> {
1911        self.platform_window
1912            .render_to_image(&self.rendered_frame.scene)
1913    }
1914
1915    /// Set the content size of the window.
1916    pub fn resize(&mut self, size: Size<Pixels>) {
1917        self.platform_window.resize(size);
1918    }
1919
1920    /// Returns whether or not the window is currently fullscreen
1921    pub fn is_fullscreen(&self) -> bool {
1922        self.platform_window.is_fullscreen()
1923    }
1924
1925    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1926        self.appearance = self.platform_window.appearance();
1927
1928        self.appearance_observers
1929            .clone()
1930            .retain(&(), |callback| callback(self, cx));
1931    }
1932
1933    /// Returns the appearance of the current window.
1934    pub fn appearance(&self) -> WindowAppearance {
1935        self.appearance
1936    }
1937
1938    /// Returns the size of the drawable area within the window.
1939    pub fn viewport_size(&self) -> Size<Pixels> {
1940        self.viewport_size
1941    }
1942
1943    /// Returns whether this window is focused by the operating system (receiving key events).
1944    pub fn is_window_active(&self) -> bool {
1945        self.active.get()
1946    }
1947
1948    /// Returns whether this window is considered to be the window
1949    /// that currently owns the mouse cursor.
1950    /// On mac, this is equivalent to `is_window_active`.
1951    pub fn is_window_hovered(&self) -> bool {
1952        if cfg!(any(
1953            target_os = "windows",
1954            target_os = "linux",
1955            target_os = "freebsd"
1956        )) {
1957            self.hovered.get()
1958        } else {
1959            self.is_window_active()
1960        }
1961    }
1962
1963    /// Toggle zoom on the window.
1964    pub fn zoom_window(&self) {
1965        self.platform_window.zoom();
1966    }
1967
1968    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1969    pub fn show_window_menu(&self, position: Point<Pixels>) {
1970        self.platform_window.show_window_menu(position)
1971    }
1972
1973    /// Handle window movement for Linux and macOS.
1974    /// Tells the compositor to take control of window movement (Wayland and X11)
1975    ///
1976    /// Events may not be received during a move operation.
1977    pub fn start_window_move(&self) {
1978        self.platform_window.start_window_move()
1979    }
1980
1981    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1982    pub fn set_client_inset(&mut self, inset: Pixels) {
1983        self.client_inset = Some(inset);
1984        self.platform_window.set_client_inset(inset);
1985    }
1986
1987    /// Returns the client_inset value by [`Self::set_client_inset`].
1988    pub fn client_inset(&self) -> Option<Pixels> {
1989        self.client_inset
1990    }
1991
1992    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1993    pub fn window_decorations(&self) -> Decorations {
1994        self.platform_window.window_decorations()
1995    }
1996
1997    /// Returns which window controls are currently visible (Wayland)
1998    pub fn window_controls(&self) -> WindowControls {
1999        self.platform_window.window_controls()
2000    }
2001
2002    /// Updates the window's title at the platform level.
2003    pub fn set_window_title(&mut self, title: &str) {
2004        self.platform_window.set_title(title);
2005    }
2006
2007    /// Sets the application identifier.
2008    pub fn set_app_id(&mut self, app_id: &str) {
2009        self.platform_window.set_app_id(app_id);
2010    }
2011
2012    /// Sets the window background appearance.
2013    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
2014        self.platform_window
2015            .set_background_appearance(background_appearance);
2016    }
2017
2018    /// Mark the window as dirty at the platform level.
2019    pub fn set_window_edited(&mut self, edited: bool) {
2020        self.platform_window.set_edited(edited);
2021    }
2022
2023    /// Determine the display on which the window is visible.
2024    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
2025        cx.platform
2026            .displays()
2027            .into_iter()
2028            .find(|display| Some(display.id()) == self.display_id)
2029    }
2030
2031    /// Show the platform character palette.
2032    pub fn show_character_palette(&self) {
2033        self.platform_window.show_character_palette();
2034    }
2035
2036    /// The scale factor of the display associated with the window. For example, it could
2037    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
2038    /// be rendered as two pixels on screen.
2039    pub fn scale_factor(&self) -> f32 {
2040        self.scale_factor
2041    }
2042
2043    /// The size of an em for the base font of the application. Adjusting this value allows the
2044    /// UI to scale, just like zooming a web page.
2045    pub fn rem_size(&self) -> Pixels {
2046        self.rem_size_override_stack
2047            .last()
2048            .copied()
2049            .unwrap_or(self.rem_size)
2050    }
2051
2052    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
2053    /// UI to scale, just like zooming a web page.
2054    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
2055        self.rem_size = rem_size.into();
2056    }
2057
2058    /// Acquire a globally unique identifier for the given ElementId.
2059    /// Only valid for the duration of the provided closure.
2060    pub fn with_global_id<R>(
2061        &mut self,
2062        element_id: ElementId,
2063        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
2064    ) -> R {
2065        self.with_id(element_id, |this| {
2066            let global_id = GlobalElementId(Arc::from(&*this.element_id_stack));
2067
2068            f(&global_id, this)
2069        })
2070    }
2071
2072    /// Calls the provided closure with the element ID pushed on the stack.
2073    #[inline]
2074    pub fn with_id<R>(
2075        &mut self,
2076        element_id: impl Into<ElementId>,
2077        f: impl FnOnce(&mut Self) -> R,
2078    ) -> R {
2079        self.element_id_stack.push(element_id.into());
2080        let result = f(self);
2081        self.element_id_stack.pop();
2082        result
2083    }
2084
2085    /// Executes the provided function with the specified rem size.
2086    ///
2087    /// This method must only be called as part of element drawing.
2088    // This function is called in a highly recursive manner in editor
2089    // prepainting, make sure its inlined to reduce the stack burden
2090    #[inline]
2091    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
2092    where
2093        F: FnOnce(&mut Self) -> R,
2094    {
2095        self.invalidator.debug_assert_paint_or_prepaint();
2096
2097        if let Some(rem_size) = rem_size {
2098            self.rem_size_override_stack.push(rem_size.into());
2099            let result = f(self);
2100            self.rem_size_override_stack.pop();
2101            result
2102        } else {
2103            f(self)
2104        }
2105    }
2106
2107    /// The line height associated with the current text style.
2108    pub fn line_height(&self) -> Pixels {
2109        self.text_style().line_height_in_pixels(self.rem_size())
2110    }
2111
2112    /// Call to prevent the default action of an event. Currently only used to prevent
2113    /// parent elements from becoming focused on mouse down.
2114    pub fn prevent_default(&mut self) {
2115        self.default_prevented = true;
2116    }
2117
2118    /// Obtain whether default has been prevented for the event currently being dispatched.
2119    pub fn default_prevented(&self) -> bool {
2120        self.default_prevented
2121    }
2122
2123    /// Determine whether the given action is available along the dispatch path to the currently focused element.
2124    pub fn is_action_available(&self, action: &dyn Action, cx: &App) -> bool {
2125        let node_id =
2126            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
2127        self.rendered_frame
2128            .dispatch_tree
2129            .is_action_available(action, node_id)
2130    }
2131
2132    /// Determine whether the given action is available along the dispatch path to the given focus_handle.
2133    pub fn is_action_available_in(&self, action: &dyn Action, focus_handle: &FocusHandle) -> bool {
2134        let node_id = self.focus_node_id_in_rendered_frame(Some(focus_handle.id));
2135        self.rendered_frame
2136            .dispatch_tree
2137            .is_action_available(action, node_id)
2138    }
2139
2140    /// The position of the mouse relative to the window.
2141    pub fn mouse_position(&self) -> Point<Pixels> {
2142        self.mouse_position
2143    }
2144
2145    /// The current state of the keyboard's modifiers
2146    pub fn modifiers(&self) -> Modifiers {
2147        self.modifiers
2148    }
2149
2150    /// Returns true if the last input event was keyboard-based (key press, tab navigation, etc.)
2151    /// This is used for focus-visible styling to show focus indicators only for keyboard navigation.
2152    pub fn last_input_was_keyboard(&self) -> bool {
2153        self.last_input_modality == InputModality::Keyboard
2154    }
2155
2156    /// The current state of the keyboard's capslock
2157    pub fn capslock(&self) -> Capslock {
2158        self.capslock
2159    }
2160
2161    fn complete_frame(&self) {
2162        self.platform_window.completed_frame();
2163    }
2164
2165    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
2166    /// the contents of the new [`Scene`], use [`Self::present`].
2167    #[profiling::function]
2168    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
2169        // Set up the per-App arena for element allocation during this draw.
2170        // This ensures that multiple test Apps have isolated arenas.
2171        let _arena_scope = ElementArenaScope::enter(&cx.element_arena);
2172
2173        self.invalidate_entities();
2174        cx.entities.clear_accessed();
2175        debug_assert!(self.rendered_entity_stack.is_empty());
2176        self.invalidator.set_dirty(false);
2177        self.requested_autoscroll = None;
2178
2179        // Restore the previously-used input handler.
2180        if let Some(input_handler) = self.platform_window.take_input_handler() {
2181            self.rendered_frame.input_handlers.push(Some(input_handler));
2182        }
2183        if !cx.mode.skip_drawing() {
2184            self.draw_roots(cx);
2185        }
2186        self.dirty_views.clear();
2187        self.next_frame.window_active = self.active.get();
2188
2189        // Register requested input handler with the platform window.
2190        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
2191            self.platform_window
2192                .set_input_handler(input_handler.unwrap());
2193        }
2194
2195        self.layout_engine.as_mut().unwrap().clear();
2196        self.text_system().finish_frame();
2197        self.next_frame.finish(&mut self.rendered_frame);
2198
2199        self.invalidator.set_phase(DrawPhase::Focus);
2200        let previous_focus_path = self.rendered_frame.focus_path();
2201        let previous_window_active = self.rendered_frame.window_active;
2202        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
2203        self.next_frame.clear();
2204        let current_focus_path = self.rendered_frame.focus_path();
2205        let current_window_active = self.rendered_frame.window_active;
2206
2207        if previous_focus_path != current_focus_path
2208            || previous_window_active != current_window_active
2209        {
2210            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
2211                self.focus_lost_listeners
2212                    .clone()
2213                    .retain(&(), |listener| listener(self, cx));
2214            }
2215
2216            let event = WindowFocusEvent {
2217                previous_focus_path: if previous_window_active {
2218                    previous_focus_path
2219                } else {
2220                    Default::default()
2221                },
2222                current_focus_path: if current_window_active {
2223                    current_focus_path
2224                } else {
2225                    Default::default()
2226                },
2227            };
2228            self.focus_listeners
2229                .clone()
2230                .retain(&(), |listener| listener(&event, self, cx));
2231        }
2232
2233        debug_assert!(self.rendered_entity_stack.is_empty());
2234        self.record_entities_accessed(cx);
2235        self.reset_cursor_style(cx);
2236        self.refreshing = false;
2237        self.invalidator.set_phase(DrawPhase::None);
2238        self.needs_present.set(true);
2239
2240        ArenaClearNeeded::new(&cx.element_arena)
2241    }
2242
2243    fn record_entities_accessed(&mut self, cx: &mut App) {
2244        let mut entities_ref = cx.entities.accessed_entities.get_mut();
2245        let mut entities = mem::take(entities_ref.deref_mut());
2246        let handle = self.handle;
2247        cx.record_entities_accessed(
2248            handle,
2249            // Try moving window invalidator into the Window
2250            self.invalidator.clone(),
2251            &entities,
2252        );
2253        let mut entities_ref = cx.entities.accessed_entities.get_mut();
2254        mem::swap(&mut entities, entities_ref.deref_mut());
2255    }
2256
2257    fn invalidate_entities(&mut self) {
2258        let mut views = self.invalidator.take_views();
2259        for entity in views.drain() {
2260            self.mark_view_dirty(entity);
2261        }
2262        self.invalidator.replace_views(views);
2263    }
2264
2265    #[profiling::function]
2266    fn present(&self) {
2267        self.platform_window.draw(&self.rendered_frame.scene);
2268        self.needs_present.set(false);
2269        profiling::finish_frame!();
2270    }
2271
2272    fn draw_roots(&mut self, cx: &mut App) {
2273        self.invalidator.set_phase(DrawPhase::Prepaint);
2274        self.tooltip_bounds.take();
2275
2276        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
2277        let root_size = {
2278            #[cfg(any(feature = "inspector", debug_assertions))]
2279            {
2280                if self.inspector.is_some() {
2281                    let mut size = self.viewport_size;
2282                    size.width = (size.width - _inspector_width).max(px(0.0));
2283                    size
2284                } else {
2285                    self.viewport_size
2286                }
2287            }
2288            #[cfg(not(any(feature = "inspector", debug_assertions)))]
2289            {
2290                self.viewport_size
2291            }
2292        };
2293
2294        // Layout all root elements.
2295        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
2296        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2297
2298        #[cfg(any(feature = "inspector", debug_assertions))]
2299        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
2300
2301        let mut sorted_deferred_draws =
2302            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
2303        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
2304        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
2305
2306        let mut prompt_element = None;
2307        let mut active_drag_element = None;
2308        let mut tooltip_element = None;
2309        if let Some(prompt) = self.prompt.take() {
2310            let mut element = prompt.view.any_view().into_any();
2311            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2312            prompt_element = Some(element);
2313            self.prompt = Some(prompt);
2314        } else if let Some(active_drag) = cx.active_drag.take() {
2315            let mut element = active_drag.view.clone().into_any();
2316            let offset = self.mouse_position() - active_drag.cursor_offset;
2317            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
2318            active_drag_element = Some(element);
2319            cx.active_drag = Some(active_drag);
2320        } else {
2321            tooltip_element = self.prepaint_tooltip(cx);
2322        }
2323
2324        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
2325
2326        // Now actually paint the elements.
2327        self.invalidator.set_phase(DrawPhase::Paint);
2328        root_element.paint(self, cx);
2329
2330        #[cfg(any(feature = "inspector", debug_assertions))]
2331        self.paint_inspector(inspector_element, cx);
2332
2333        self.paint_deferred_draws(&sorted_deferred_draws, cx);
2334
2335        if let Some(mut prompt_element) = prompt_element {
2336            prompt_element.paint(self, cx);
2337        } else if let Some(mut drag_element) = active_drag_element {
2338            drag_element.paint(self, cx);
2339        } else if let Some(mut tooltip_element) = tooltip_element {
2340            tooltip_element.paint(self, cx);
2341        }
2342
2343        #[cfg(any(feature = "inspector", debug_assertions))]
2344        self.paint_inspector_hitbox(cx);
2345    }
2346
2347    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
2348        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
2349        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
2350            let Some(Some(tooltip_request)) = self
2351                .next_frame
2352                .tooltip_requests
2353                .get(tooltip_request_index)
2354                .cloned()
2355            else {
2356                log::error!("Unexpectedly absent TooltipRequest");
2357                continue;
2358            };
2359            let mut element = tooltip_request.tooltip.view.clone().into_any();
2360            let mouse_position = tooltip_request.tooltip.mouse_position;
2361            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
2362
2363            let mut tooltip_bounds =
2364                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
2365            let window_bounds = Bounds {
2366                origin: Point::default(),
2367                size: self.viewport_size(),
2368            };
2369
2370            if tooltip_bounds.right() > window_bounds.right() {
2371                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
2372                if new_x >= Pixels::ZERO {
2373                    tooltip_bounds.origin.x = new_x;
2374                } else {
2375                    tooltip_bounds.origin.x = cmp::max(
2376                        Pixels::ZERO,
2377                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
2378                    );
2379                }
2380            }
2381
2382            if tooltip_bounds.bottom() > window_bounds.bottom() {
2383                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
2384                if new_y >= Pixels::ZERO {
2385                    tooltip_bounds.origin.y = new_y;
2386                } else {
2387                    tooltip_bounds.origin.y = cmp::max(
2388                        Pixels::ZERO,
2389                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
2390                    );
2391                }
2392            }
2393
2394            // It's possible for an element to have an active tooltip while not being painted (e.g.
2395            // via the `visible_on_hover` method). Since mouse listeners are not active in this
2396            // case, instead update the tooltip's visibility here.
2397            let is_visible =
2398                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
2399            if !is_visible {
2400                continue;
2401            }
2402
2403            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2404                element.prepaint(window, cx)
2405            });
2406
2407            self.tooltip_bounds = Some(TooltipBounds {
2408                id: tooltip_request.id,
2409                bounds: tooltip_bounds,
2410            });
2411            return Some(element);
2412        }
2413        None
2414    }
2415
2416    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2417        assert_eq!(self.element_id_stack.len(), 0);
2418
2419        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2420        for deferred_draw_ix in deferred_draw_indices {
2421            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2422            self.element_id_stack
2423                .clone_from(&deferred_draw.element_id_stack);
2424            self.text_style_stack
2425                .clone_from(&deferred_draw.text_style_stack);
2426            self.next_frame
2427                .dispatch_tree
2428                .set_active_node(deferred_draw.parent_node);
2429
2430            let prepaint_start = self.prepaint_index();
2431            if let Some(element) = deferred_draw.element.as_mut() {
2432                self.with_rendered_view(deferred_draw.current_view, |window| {
2433                    window.with_rem_size(Some(deferred_draw.rem_size), |window| {
2434                        window.with_absolute_element_offset(
2435                            deferred_draw.absolute_offset,
2436                            |window| {
2437                                element.prepaint(window, cx);
2438                            },
2439                        );
2440                    });
2441                })
2442            } else {
2443                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2444            }
2445            let prepaint_end = self.prepaint_index();
2446            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2447        }
2448        assert_eq!(
2449            self.next_frame.deferred_draws.len(),
2450            0,
2451            "cannot call defer_draw during deferred drawing"
2452        );
2453        self.next_frame.deferred_draws = deferred_draws;
2454        self.element_id_stack.clear();
2455        self.text_style_stack.clear();
2456    }
2457
2458    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2459        assert_eq!(self.element_id_stack.len(), 0);
2460
2461        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2462        for deferred_draw_ix in deferred_draw_indices {
2463            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2464            self.element_id_stack
2465                .clone_from(&deferred_draw.element_id_stack);
2466            self.next_frame
2467                .dispatch_tree
2468                .set_active_node(deferred_draw.parent_node);
2469
2470            let paint_start = self.paint_index();
2471            if let Some(element) = deferred_draw.element.as_mut() {
2472                self.with_rendered_view(deferred_draw.current_view, |window| {
2473                    window.with_rem_size(Some(deferred_draw.rem_size), |window| {
2474                        element.paint(window, cx);
2475                    })
2476                })
2477            } else {
2478                self.reuse_paint(deferred_draw.paint_range.clone());
2479            }
2480            let paint_end = self.paint_index();
2481            deferred_draw.paint_range = paint_start..paint_end;
2482        }
2483        self.next_frame.deferred_draws = deferred_draws;
2484        self.element_id_stack.clear();
2485    }
2486
2487    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2488        PrepaintStateIndex {
2489            hitboxes_index: self.next_frame.hitboxes.len(),
2490            tooltips_index: self.next_frame.tooltip_requests.len(),
2491            deferred_draws_index: self.next_frame.deferred_draws.len(),
2492            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2493            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2494            line_layout_index: self.text_system.layout_index(),
2495        }
2496    }
2497
2498    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2499        self.next_frame.hitboxes.extend(
2500            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2501                .iter()
2502                .cloned(),
2503        );
2504        self.next_frame.tooltip_requests.extend(
2505            self.rendered_frame.tooltip_requests
2506                [range.start.tooltips_index..range.end.tooltips_index]
2507                .iter_mut()
2508                .map(|request| request.take()),
2509        );
2510        self.next_frame.accessed_element_states.extend(
2511            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2512                ..range.end.accessed_element_states_index]
2513                .iter()
2514                .map(|(id, type_id)| (id.clone(), *type_id)),
2515        );
2516        self.text_system
2517            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2518
2519        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2520            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2521            &mut self.rendered_frame.dispatch_tree,
2522            self.focus,
2523        );
2524
2525        if reused_subtree.contains_focus() {
2526            self.next_frame.focus = self.focus;
2527        }
2528
2529        self.next_frame.deferred_draws.extend(
2530            self.rendered_frame.deferred_draws
2531                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2532                .iter()
2533                .map(|deferred_draw| DeferredDraw {
2534                    current_view: deferred_draw.current_view,
2535                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2536                    element_id_stack: deferred_draw.element_id_stack.clone(),
2537                    text_style_stack: deferred_draw.text_style_stack.clone(),
2538                    rem_size: deferred_draw.rem_size,
2539                    priority: deferred_draw.priority,
2540                    element: None,
2541                    absolute_offset: deferred_draw.absolute_offset,
2542                    prepaint_range: deferred_draw.prepaint_range.clone(),
2543                    paint_range: deferred_draw.paint_range.clone(),
2544                }),
2545        );
2546    }
2547
2548    pub(crate) fn paint_index(&self) -> PaintIndex {
2549        PaintIndex {
2550            scene_index: self.next_frame.scene.len(),
2551            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2552            input_handlers_index: self.next_frame.input_handlers.len(),
2553            cursor_styles_index: self.next_frame.cursor_styles.len(),
2554            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2555            tab_handle_index: self.next_frame.tab_stops.paint_index(),
2556            line_layout_index: self.text_system.layout_index(),
2557        }
2558    }
2559
2560    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2561        self.next_frame.cursor_styles.extend(
2562            self.rendered_frame.cursor_styles
2563                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2564                .iter()
2565                .cloned(),
2566        );
2567        self.next_frame.input_handlers.extend(
2568            self.rendered_frame.input_handlers
2569                [range.start.input_handlers_index..range.end.input_handlers_index]
2570                .iter_mut()
2571                .map(|handler| handler.take()),
2572        );
2573        self.next_frame.mouse_listeners.extend(
2574            self.rendered_frame.mouse_listeners
2575                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2576                .iter_mut()
2577                .map(|listener| listener.take()),
2578        );
2579        self.next_frame.accessed_element_states.extend(
2580            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2581                ..range.end.accessed_element_states_index]
2582                .iter()
2583                .map(|(id, type_id)| (id.clone(), *type_id)),
2584        );
2585        self.next_frame.tab_stops.replay(
2586            &self.rendered_frame.tab_stops.insertion_history
2587                [range.start.tab_handle_index..range.end.tab_handle_index],
2588        );
2589
2590        self.text_system
2591            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2592        self.next_frame.scene.replay(
2593            range.start.scene_index..range.end.scene_index,
2594            &self.rendered_frame.scene,
2595        );
2596    }
2597
2598    /// Push a text style onto the stack, and call a function with that style active.
2599    /// Use [`Window::text_style`] to get the current, combined text style. This method
2600    /// should only be called as part of element drawing.
2601    // This function is called in a highly recursive manner in editor
2602    // prepainting, make sure its inlined to reduce the stack burden
2603    #[inline]
2604    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2605    where
2606        F: FnOnce(&mut Self) -> R,
2607    {
2608        self.invalidator.debug_assert_paint_or_prepaint();
2609        if let Some(style) = style {
2610            self.text_style_stack.push(style);
2611            let result = f(self);
2612            self.text_style_stack.pop();
2613            result
2614        } else {
2615            f(self)
2616        }
2617    }
2618
2619    /// Updates the cursor style at the platform level. This method should only be called
2620    /// during the paint phase of element drawing.
2621    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2622        self.invalidator.debug_assert_paint();
2623        self.next_frame.cursor_styles.push(CursorStyleRequest {
2624            hitbox_id: Some(hitbox.id),
2625            style,
2626        });
2627    }
2628
2629    /// Updates the cursor style for the entire window at the platform level. A cursor
2630    /// style using this method will have precedence over any cursor style set using
2631    /// `set_cursor_style`. This method should only be called during the paint
2632    /// phase of element drawing.
2633    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2634        self.invalidator.debug_assert_paint();
2635        self.next_frame.cursor_styles.push(CursorStyleRequest {
2636            hitbox_id: None,
2637            style,
2638        })
2639    }
2640
2641    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2642    /// during the paint phase of element drawing.
2643    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2644        self.invalidator.debug_assert_prepaint();
2645        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2646        self.next_frame
2647            .tooltip_requests
2648            .push(Some(TooltipRequest { id, tooltip }));
2649        id
2650    }
2651
2652    /// Invoke the given function with the given content mask after intersecting it
2653    /// with the current mask. This method should only be called during element drawing.
2654    // This function is called in a highly recursive manner in editor
2655    // prepainting, make sure its inlined to reduce the stack burden
2656    #[inline]
2657    pub fn with_content_mask<R>(
2658        &mut self,
2659        mask: Option<ContentMask<Pixels>>,
2660        f: impl FnOnce(&mut Self) -> R,
2661    ) -> R {
2662        self.invalidator.debug_assert_paint_or_prepaint();
2663        if let Some(mask) = mask {
2664            let mask = mask.intersect(&self.content_mask());
2665            self.content_mask_stack.push(mask);
2666            let result = f(self);
2667            self.content_mask_stack.pop();
2668            result
2669        } else {
2670            f(self)
2671        }
2672    }
2673
2674    /// Updates the global element offset relative to the current offset. This is used to implement
2675    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2676    pub fn with_element_offset<R>(
2677        &mut self,
2678        offset: Point<Pixels>,
2679        f: impl FnOnce(&mut Self) -> R,
2680    ) -> R {
2681        self.invalidator.debug_assert_prepaint();
2682
2683        if offset.is_zero() {
2684            return f(self);
2685        };
2686
2687        let abs_offset = self.element_offset() + offset;
2688        self.with_absolute_element_offset(abs_offset, f)
2689    }
2690
2691    /// Updates the global element offset based on the given offset. This is used to implement
2692    /// drag handles and other manual painting of elements. This method should only be called during
2693    /// the prepaint phase of element drawing.
2694    pub fn with_absolute_element_offset<R>(
2695        &mut self,
2696        offset: Point<Pixels>,
2697        f: impl FnOnce(&mut Self) -> R,
2698    ) -> R {
2699        self.invalidator.debug_assert_prepaint();
2700        self.element_offset_stack.push(offset);
2701        let result = f(self);
2702        self.element_offset_stack.pop();
2703        result
2704    }
2705
2706    pub(crate) fn with_element_opacity<R>(
2707        &mut self,
2708        opacity: Option<f32>,
2709        f: impl FnOnce(&mut Self) -> R,
2710    ) -> R {
2711        self.invalidator.debug_assert_paint_or_prepaint();
2712
2713        let Some(opacity) = opacity else {
2714            return f(self);
2715        };
2716
2717        let previous_opacity = self.element_opacity;
2718        self.element_opacity = previous_opacity * opacity;
2719        let result = f(self);
2720        self.element_opacity = previous_opacity;
2721        result
2722    }
2723
2724    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2725    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2726    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2727    /// element offset and prepaint again. See [`crate::List`] for an example. This method should only be
2728    /// called during the prepaint phase of element drawing.
2729    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2730        self.invalidator.debug_assert_prepaint();
2731        let index = self.prepaint_index();
2732        let result = f(self);
2733        if result.is_err() {
2734            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2735            self.next_frame
2736                .tooltip_requests
2737                .truncate(index.tooltips_index);
2738            self.next_frame
2739                .deferred_draws
2740                .truncate(index.deferred_draws_index);
2741            self.next_frame
2742                .dispatch_tree
2743                .truncate(index.dispatch_tree_index);
2744            self.next_frame
2745                .accessed_element_states
2746                .truncate(index.accessed_element_states_index);
2747            self.text_system.truncate_layouts(index.line_layout_index);
2748        }
2749        result
2750    }
2751
2752    /// When you call this method during [`Element::prepaint`], containing elements will attempt to
2753    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2754    /// [`Element::prepaint`] again with a new set of bounds. See [`crate::List`] for an example of an element
2755    /// that supports this method being called on the elements it contains. This method should only be
2756    /// called during the prepaint phase of element drawing.
2757    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2758        self.invalidator.debug_assert_prepaint();
2759        self.requested_autoscroll = Some(bounds);
2760    }
2761
2762    /// This method can be called from a containing element such as [`crate::List`] to support the autoscroll behavior
2763    /// described in [`Self::request_autoscroll`].
2764    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2765        self.invalidator.debug_assert_prepaint();
2766        self.requested_autoscroll.take()
2767    }
2768
2769    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2770    /// Your view will be re-drawn once the asset has finished loading.
2771    ///
2772    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2773    /// time.
2774    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2775        let (task, is_first) = cx.fetch_asset::<A>(source);
2776        task.clone().now_or_never().or_else(|| {
2777            if is_first {
2778                let entity_id = self.current_view();
2779                self.spawn(cx, {
2780                    let task = task.clone();
2781                    async move |cx| {
2782                        task.await;
2783
2784                        cx.on_next_frame(move |_, cx| {
2785                            cx.notify(entity_id);
2786                        });
2787                    }
2788                })
2789                .detach();
2790            }
2791
2792            None
2793        })
2794    }
2795
2796    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2797    /// Your view will not be re-drawn once the asset has finished loading.
2798    ///
2799    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2800    /// time.
2801    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2802        let (task, _) = cx.fetch_asset::<A>(source);
2803        task.now_or_never()
2804    }
2805    /// Obtain the current element offset. This method should only be called during the
2806    /// prepaint phase of element drawing.
2807    pub fn element_offset(&self) -> Point<Pixels> {
2808        self.invalidator.debug_assert_prepaint();
2809        self.element_offset_stack
2810            .last()
2811            .copied()
2812            .unwrap_or_default()
2813    }
2814
2815    /// Obtain the current element opacity. This method should only be called during the
2816    /// prepaint phase of element drawing.
2817    #[inline]
2818    pub(crate) fn element_opacity(&self) -> f32 {
2819        self.invalidator.debug_assert_paint_or_prepaint();
2820        self.element_opacity
2821    }
2822
2823    /// Obtain the current content mask. This method should only be called during element drawing.
2824    pub fn content_mask(&self) -> ContentMask<Pixels> {
2825        self.invalidator.debug_assert_paint_or_prepaint();
2826        self.content_mask_stack
2827            .last()
2828            .cloned()
2829            .unwrap_or_else(|| ContentMask {
2830                bounds: Bounds {
2831                    origin: Point::default(),
2832                    size: self.viewport_size,
2833                },
2834            })
2835    }
2836
2837    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2838    /// This can be used within a custom element to distinguish multiple sets of child elements.
2839    pub fn with_element_namespace<R>(
2840        &mut self,
2841        element_id: impl Into<ElementId>,
2842        f: impl FnOnce(&mut Self) -> R,
2843    ) -> R {
2844        self.element_id_stack.push(element_id.into());
2845        let result = f(self);
2846        self.element_id_stack.pop();
2847        result
2848    }
2849
2850    /// Use a piece of state that exists as long this element is being rendered in consecutive frames.
2851    pub fn use_keyed_state<S: 'static>(
2852        &mut self,
2853        key: impl Into<ElementId>,
2854        cx: &mut App,
2855        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2856    ) -> Entity<S> {
2857        let current_view = self.current_view();
2858        self.with_global_id(key.into(), |global_id, window| {
2859            window.with_element_state(global_id, |state: Option<Entity<S>>, window| {
2860                if let Some(state) = state {
2861                    (state.clone(), state)
2862                } else {
2863                    let new_state = cx.new(|cx| init(window, cx));
2864                    cx.observe(&new_state, move |_, cx| {
2865                        cx.notify(current_view);
2866                    })
2867                    .detach();
2868                    (new_state.clone(), new_state)
2869                }
2870            })
2871        })
2872    }
2873
2874    /// Use a piece of state that exists as long this element is being rendered in consecutive frames, without needing to specify a key
2875    ///
2876    /// NOTE: This method uses the location of the caller to generate an ID for this state.
2877    ///       If this is not sufficient to identify your state (e.g. you're rendering a list item),
2878    ///       you can provide a custom ElementID using the `use_keyed_state` method.
2879    #[track_caller]
2880    pub fn use_state<S: 'static>(
2881        &mut self,
2882        cx: &mut App,
2883        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2884    ) -> Entity<S> {
2885        self.use_keyed_state(
2886            ElementId::CodeLocation(*core::panic::Location::caller()),
2887            cx,
2888            init,
2889        )
2890    }
2891
2892    /// Updates or initializes state for an element with the given id that lives across multiple
2893    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2894    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2895    /// when drawing the next frame. This method should only be called as part of element drawing.
2896    pub fn with_element_state<S, R>(
2897        &mut self,
2898        global_id: &GlobalElementId,
2899        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2900    ) -> R
2901    where
2902        S: 'static,
2903    {
2904        self.invalidator.debug_assert_paint_or_prepaint();
2905
2906        let key = (global_id.clone(), TypeId::of::<S>());
2907        self.next_frame.accessed_element_states.push(key.clone());
2908
2909        if let Some(any) = self
2910            .next_frame
2911            .element_states
2912            .remove(&key)
2913            .or_else(|| self.rendered_frame.element_states.remove(&key))
2914        {
2915            let ElementStateBox {
2916                inner,
2917                #[cfg(debug_assertions)]
2918                type_name,
2919            } = any;
2920            // Using the extra inner option to avoid needing to reallocate a new box.
2921            let mut state_box = inner
2922                .downcast::<Option<S>>()
2923                .map_err(|_| {
2924                    #[cfg(debug_assertions)]
2925                    {
2926                        anyhow::anyhow!(
2927                            "invalid element state type for id, requested {:?}, actual: {:?}",
2928                            std::any::type_name::<S>(),
2929                            type_name
2930                        )
2931                    }
2932
2933                    #[cfg(not(debug_assertions))]
2934                    {
2935                        anyhow::anyhow!(
2936                            "invalid element state type for id, requested {:?}",
2937                            std::any::type_name::<S>(),
2938                        )
2939                    }
2940                })
2941                .unwrap();
2942
2943            let state = state_box.take().expect(
2944                "reentrant call to with_element_state for the same state type and element id",
2945            );
2946            let (result, state) = f(Some(state), self);
2947            state_box.replace(state);
2948            self.next_frame.element_states.insert(
2949                key,
2950                ElementStateBox {
2951                    inner: state_box,
2952                    #[cfg(debug_assertions)]
2953                    type_name,
2954                },
2955            );
2956            result
2957        } else {
2958            let (result, state) = f(None, self);
2959            self.next_frame.element_states.insert(
2960                key,
2961                ElementStateBox {
2962                    inner: Box::new(Some(state)),
2963                    #[cfg(debug_assertions)]
2964                    type_name: std::any::type_name::<S>(),
2965                },
2966            );
2967            result
2968        }
2969    }
2970
2971    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2972    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2973    /// when the element is guaranteed to have an id.
2974    ///
2975    /// The first option means 'no ID provided'
2976    /// The second option means 'not yet initialized'
2977    pub fn with_optional_element_state<S, R>(
2978        &mut self,
2979        global_id: Option<&GlobalElementId>,
2980        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2981    ) -> R
2982    where
2983        S: 'static,
2984    {
2985        self.invalidator.debug_assert_paint_or_prepaint();
2986
2987        if let Some(global_id) = global_id {
2988            self.with_element_state(global_id, |state, cx| {
2989                let (result, state) = f(Some(state), cx);
2990                let state =
2991                    state.expect("you must return some state when you pass some element id");
2992                (result, state)
2993            })
2994        } else {
2995            let (result, state) = f(None, self);
2996            debug_assert!(
2997                state.is_none(),
2998                "you must not return an element state when passing None for the global id"
2999            );
3000            result
3001        }
3002    }
3003
3004    /// Executes the given closure within the context of a tab group.
3005    #[inline]
3006    pub fn with_tab_group<R>(&mut self, index: Option<isize>, f: impl FnOnce(&mut Self) -> R) -> R {
3007        if let Some(index) = index {
3008            self.next_frame.tab_stops.begin_group(index);
3009            let result = f(self);
3010            self.next_frame.tab_stops.end_group();
3011            result
3012        } else {
3013            f(self)
3014        }
3015    }
3016
3017    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
3018    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
3019    /// with higher values being drawn on top.
3020    ///
3021    /// This method should only be called as part of the prepaint phase of element drawing.
3022    pub fn defer_draw(
3023        &mut self,
3024        element: AnyElement,
3025        absolute_offset: Point<Pixels>,
3026        priority: usize,
3027    ) {
3028        self.invalidator.debug_assert_prepaint();
3029        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
3030        self.next_frame.deferred_draws.push(DeferredDraw {
3031            current_view: self.current_view(),
3032            parent_node,
3033            element_id_stack: self.element_id_stack.clone(),
3034            text_style_stack: self.text_style_stack.clone(),
3035            rem_size: self.rem_size(),
3036            priority,
3037            element: Some(element),
3038            absolute_offset,
3039            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
3040            paint_range: PaintIndex::default()..PaintIndex::default(),
3041        });
3042    }
3043
3044    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
3045    /// of geometry that are non-overlapping and have the same draw order. This is typically used
3046    /// for performance reasons.
3047    ///
3048    /// This method should only be called as part of the paint phase of element drawing.
3049    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
3050        self.invalidator.debug_assert_paint();
3051
3052        let scale_factor = self.scale_factor();
3053        let content_mask = self.content_mask();
3054        let clipped_bounds = bounds.intersect(&content_mask.bounds);
3055        if !clipped_bounds.is_empty() {
3056            self.next_frame
3057                .scene
3058                .push_layer(clipped_bounds.scale(scale_factor));
3059        }
3060
3061        let result = f(self);
3062
3063        if !clipped_bounds.is_empty() {
3064            self.next_frame.scene.pop_layer();
3065        }
3066
3067        result
3068    }
3069
3070    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
3071    ///
3072    /// This method should only be called as part of the paint phase of element drawing.
3073    pub fn paint_shadows(
3074        &mut self,
3075        bounds: Bounds<Pixels>,
3076        corner_radii: Corners<Pixels>,
3077        shadows: &[BoxShadow],
3078    ) {
3079        self.invalidator.debug_assert_paint();
3080
3081        let scale_factor = self.scale_factor();
3082        let content_mask = self.content_mask();
3083        let opacity = self.element_opacity();
3084        for shadow in shadows {
3085            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
3086            self.next_frame.scene.insert_primitive(Shadow {
3087                order: 0,
3088                blur_radius: shadow.blur_radius.scale(scale_factor),
3089                bounds: shadow_bounds.scale(scale_factor),
3090                content_mask: content_mask.scale(scale_factor),
3091                corner_radii: corner_radii.scale(scale_factor),
3092                color: shadow.color.opacity(opacity),
3093            });
3094        }
3095    }
3096
3097    /// Paint one or more quads into the scene for the next frame at the current stacking context.
3098    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
3099    /// see [`fill`], [`outline`], and [`quad`] to construct this type.
3100    ///
3101    /// This method should only be called as part of the paint phase of element drawing.
3102    ///
3103    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
3104    /// where the circular arcs meet. This will not display well when combined with dashed borders.
3105    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
3106    pub fn paint_quad(&mut self, quad: PaintQuad) {
3107        self.invalidator.debug_assert_paint();
3108
3109        let scale_factor = self.scale_factor();
3110        let content_mask = self.content_mask();
3111        let opacity = self.element_opacity();
3112        self.next_frame.scene.insert_primitive(Quad {
3113            order: 0,
3114            bounds: quad.bounds.scale(scale_factor),
3115            content_mask: content_mask.scale(scale_factor),
3116            background: quad.background.opacity(opacity),
3117            border_color: quad.border_color.opacity(opacity),
3118            corner_radii: quad.corner_radii.scale(scale_factor),
3119            border_widths: quad.border_widths.scale(scale_factor),
3120            border_style: quad.border_style,
3121        });
3122    }
3123
3124    /// Paint the given `Path` into the scene for the next frame at the current z-index.
3125    ///
3126    /// This method should only be called as part of the paint phase of element drawing.
3127    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
3128        self.invalidator.debug_assert_paint();
3129
3130        let scale_factor = self.scale_factor();
3131        let content_mask = self.content_mask();
3132        let opacity = self.element_opacity();
3133        path.content_mask = content_mask;
3134        let color: Background = color.into();
3135        path.color = color.opacity(opacity);
3136        self.next_frame
3137            .scene
3138            .insert_primitive(path.scale(scale_factor));
3139    }
3140
3141    /// Paint an underline into the scene for the next frame at the current z-index.
3142    ///
3143    /// This method should only be called as part of the paint phase of element drawing.
3144    pub fn paint_underline(
3145        &mut self,
3146        origin: Point<Pixels>,
3147        width: Pixels,
3148        style: &UnderlineStyle,
3149    ) {
3150        self.invalidator.debug_assert_paint();
3151
3152        let scale_factor = self.scale_factor();
3153        let height = if style.wavy {
3154            style.thickness * 3.
3155        } else {
3156            style.thickness
3157        };
3158        let bounds = Bounds {
3159            origin,
3160            size: size(width, height),
3161        };
3162        let content_mask = self.content_mask();
3163        let element_opacity = self.element_opacity();
3164
3165        self.next_frame.scene.insert_primitive(Underline {
3166            order: 0,
3167            pad: 0,
3168            bounds: bounds.scale(scale_factor),
3169            content_mask: content_mask.scale(scale_factor),
3170            color: style.color.unwrap_or_default().opacity(element_opacity),
3171            thickness: style.thickness.scale(scale_factor),
3172            wavy: if style.wavy { 1 } else { 0 },
3173        });
3174    }
3175
3176    /// Paint a strikethrough into the scene for the next frame at the current z-index.
3177    ///
3178    /// This method should only be called as part of the paint phase of element drawing.
3179    pub fn paint_strikethrough(
3180        &mut self,
3181        origin: Point<Pixels>,
3182        width: Pixels,
3183        style: &StrikethroughStyle,
3184    ) {
3185        self.invalidator.debug_assert_paint();
3186
3187        let scale_factor = self.scale_factor();
3188        let height = style.thickness;
3189        let bounds = Bounds {
3190            origin,
3191            size: size(width, height),
3192        };
3193        let content_mask = self.content_mask();
3194        let opacity = self.element_opacity();
3195
3196        self.next_frame.scene.insert_primitive(Underline {
3197            order: 0,
3198            pad: 0,
3199            bounds: bounds.scale(scale_factor),
3200            content_mask: content_mask.scale(scale_factor),
3201            thickness: style.thickness.scale(scale_factor),
3202            color: style.color.unwrap_or_default().opacity(opacity),
3203            wavy: 0,
3204        });
3205    }
3206
3207    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
3208    ///
3209    /// The y component of the origin is the baseline of the glyph.
3210    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3211    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3212    /// This method is only useful if you need to paint a single glyph that has already been shaped.
3213    ///
3214    /// This method should only be called as part of the paint phase of element drawing.
3215    pub fn paint_glyph(
3216        &mut self,
3217        origin: Point<Pixels>,
3218        font_id: FontId,
3219        glyph_id: GlyphId,
3220        font_size: Pixels,
3221        color: Hsla,
3222    ) -> Result<()> {
3223        self.invalidator.debug_assert_paint();
3224
3225        let element_opacity = self.element_opacity();
3226        let scale_factor = self.scale_factor();
3227        let glyph_origin = origin.scale(scale_factor);
3228
3229        let subpixel_variant = Point {
3230            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS_X as f32).floor() as u8,
3231            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS_Y as f32).floor() as u8,
3232        };
3233        let subpixel_rendering = self.should_use_subpixel_rendering(font_id, font_size);
3234        let params = RenderGlyphParams {
3235            font_id,
3236            glyph_id,
3237            font_size,
3238            subpixel_variant,
3239            scale_factor,
3240            is_emoji: false,
3241            subpixel_rendering,
3242        };
3243
3244        let raster_bounds = self.text_system().raster_bounds(&params)?;
3245        if !raster_bounds.is_zero() {
3246            let tile = self
3247                .sprite_atlas
3248                .get_or_insert_with(&params.clone().into(), &mut || {
3249                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3250                    Ok(Some((size, Cow::Owned(bytes))))
3251                })?
3252                .expect("Callback above only errors or returns Some");
3253            let bounds = Bounds {
3254                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3255                size: tile.bounds.size.map(Into::into),
3256            };
3257            let content_mask = self.content_mask().scale(scale_factor);
3258
3259            if subpixel_rendering {
3260                self.next_frame.scene.insert_primitive(SubpixelSprite {
3261                    order: 0,
3262                    pad: 0,
3263                    bounds,
3264                    content_mask,
3265                    color: color.opacity(element_opacity),
3266                    tile,
3267                    transformation: TransformationMatrix::unit(),
3268                });
3269            } else {
3270                self.next_frame.scene.insert_primitive(MonochromeSprite {
3271                    order: 0,
3272                    pad: 0,
3273                    bounds,
3274                    content_mask,
3275                    color: color.opacity(element_opacity),
3276                    tile,
3277                    transformation: TransformationMatrix::unit(),
3278                });
3279            }
3280        }
3281        Ok(())
3282    }
3283
3284    fn should_use_subpixel_rendering(&self, font_id: FontId, font_size: Pixels) -> bool {
3285        if self.platform_window.background_appearance() != WindowBackgroundAppearance::Opaque {
3286            return false;
3287        }
3288
3289        if !self.platform_window.is_subpixel_rendering_supported() {
3290            return false;
3291        }
3292
3293        let mode = match self.text_rendering_mode.get() {
3294            TextRenderingMode::PlatformDefault => self
3295                .text_system()
3296                .recommended_rendering_mode(font_id, font_size),
3297            mode => mode,
3298        };
3299
3300        mode == TextRenderingMode::Subpixel
3301    }
3302
3303    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
3304    ///
3305    /// The y component of the origin is the baseline of the glyph.
3306    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3307    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3308    /// This method is only useful if you need to paint a single emoji that has already been shaped.
3309    ///
3310    /// This method should only be called as part of the paint phase of element drawing.
3311    pub fn paint_emoji(
3312        &mut self,
3313        origin: Point<Pixels>,
3314        font_id: FontId,
3315        glyph_id: GlyphId,
3316        font_size: Pixels,
3317    ) -> Result<()> {
3318        self.invalidator.debug_assert_paint();
3319
3320        let scale_factor = self.scale_factor();
3321        let glyph_origin = origin.scale(scale_factor);
3322        let params = RenderGlyphParams {
3323            font_id,
3324            glyph_id,
3325            font_size,
3326            // We don't render emojis with subpixel variants.
3327            subpixel_variant: Default::default(),
3328            scale_factor,
3329            is_emoji: true,
3330            subpixel_rendering: false,
3331        };
3332
3333        let raster_bounds = self.text_system().raster_bounds(&params)?;
3334        if !raster_bounds.is_zero() {
3335            let tile = self
3336                .sprite_atlas
3337                .get_or_insert_with(&params.clone().into(), &mut || {
3338                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3339                    Ok(Some((size, Cow::Owned(bytes))))
3340                })?
3341                .expect("Callback above only errors or returns Some");
3342
3343            let bounds = Bounds {
3344                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3345                size: tile.bounds.size.map(Into::into),
3346            };
3347            let content_mask = self.content_mask().scale(scale_factor);
3348            let opacity = self.element_opacity();
3349
3350            self.next_frame.scene.insert_primitive(PolychromeSprite {
3351                order: 0,
3352                pad: 0,
3353                grayscale: false,
3354                bounds,
3355                corner_radii: Default::default(),
3356                content_mask,
3357                tile,
3358                opacity,
3359            });
3360        }
3361        Ok(())
3362    }
3363
3364    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
3365    ///
3366    /// This method should only be called as part of the paint phase of element drawing.
3367    pub fn paint_svg(
3368        &mut self,
3369        bounds: Bounds<Pixels>,
3370        path: SharedString,
3371        mut data: Option<&[u8]>,
3372        transformation: TransformationMatrix,
3373        color: Hsla,
3374        cx: &App,
3375    ) -> Result<()> {
3376        self.invalidator.debug_assert_paint();
3377
3378        let element_opacity = self.element_opacity();
3379        let scale_factor = self.scale_factor();
3380
3381        let bounds = bounds.scale(scale_factor);
3382        let params = RenderSvgParams {
3383            path,
3384            size: bounds.size.map(|pixels| {
3385                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
3386            }),
3387        };
3388
3389        let Some(tile) =
3390            self.sprite_atlas
3391                .get_or_insert_with(&params.clone().into(), &mut || {
3392                    let Some((size, bytes)) = cx.svg_renderer.render_alpha_mask(&params, data)?
3393                    else {
3394                        return Ok(None);
3395                    };
3396                    Ok(Some((size, Cow::Owned(bytes))))
3397                })?
3398        else {
3399            return Ok(());
3400        };
3401        let content_mask = self.content_mask().scale(scale_factor);
3402        let svg_bounds = Bounds {
3403            origin: bounds.center()
3404                - Point::new(
3405                    ScaledPixels(tile.bounds.size.width.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3406                    ScaledPixels(tile.bounds.size.height.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3407                ),
3408            size: tile
3409                .bounds
3410                .size
3411                .map(|value| ScaledPixels(value.0 as f32 / SMOOTH_SVG_SCALE_FACTOR)),
3412        };
3413
3414        self.next_frame.scene.insert_primitive(MonochromeSprite {
3415            order: 0,
3416            pad: 0,
3417            bounds: svg_bounds
3418                .map_origin(|origin| origin.round())
3419                .map_size(|size| size.ceil()),
3420            content_mask,
3421            color: color.opacity(element_opacity),
3422            tile,
3423            transformation,
3424        });
3425
3426        Ok(())
3427    }
3428
3429    /// Paint an image into the scene for the next frame at the current z-index.
3430    /// This method will panic if the frame_index is not valid
3431    ///
3432    /// This method should only be called as part of the paint phase of element drawing.
3433    pub fn paint_image(
3434        &mut self,
3435        bounds: Bounds<Pixels>,
3436        corner_radii: Corners<Pixels>,
3437        data: Arc<RenderImage>,
3438        frame_index: usize,
3439        grayscale: bool,
3440    ) -> Result<()> {
3441        self.invalidator.debug_assert_paint();
3442
3443        let scale_factor = self.scale_factor();
3444        let bounds = bounds.scale(scale_factor);
3445        let params = RenderImageParams {
3446            image_id: data.id,
3447            frame_index,
3448        };
3449
3450        let tile = self
3451            .sprite_atlas
3452            .get_or_insert_with(&params.into(), &mut || {
3453                Ok(Some((
3454                    data.size(frame_index),
3455                    Cow::Borrowed(
3456                        data.as_bytes(frame_index)
3457                            .expect("It's the caller's job to pass a valid frame index"),
3458                    ),
3459                )))
3460            })?
3461            .expect("Callback above only returns Some");
3462        let content_mask = self.content_mask().scale(scale_factor);
3463        let corner_radii = corner_radii.scale(scale_factor);
3464        let opacity = self.element_opacity();
3465
3466        self.next_frame.scene.insert_primitive(PolychromeSprite {
3467            order: 0,
3468            pad: 0,
3469            grayscale,
3470            bounds: bounds
3471                .map_origin(|origin| origin.floor())
3472                .map_size(|size| size.ceil()),
3473            content_mask,
3474            corner_radii,
3475            tile,
3476            opacity,
3477        });
3478        Ok(())
3479    }
3480
3481    /// Paint a surface into the scene for the next frame at the current z-index.
3482    ///
3483    /// This method should only be called as part of the paint phase of element drawing.
3484    #[cfg(target_os = "macos")]
3485    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
3486        use crate::PaintSurface;
3487
3488        self.invalidator.debug_assert_paint();
3489
3490        let scale_factor = self.scale_factor();
3491        let bounds = bounds.scale(scale_factor);
3492        let content_mask = self.content_mask().scale(scale_factor);
3493        self.next_frame.scene.insert_primitive(PaintSurface {
3494            order: 0,
3495            bounds,
3496            content_mask,
3497            image_buffer,
3498        });
3499    }
3500
3501    /// Removes an image from the sprite atlas.
3502    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
3503        for frame_index in 0..data.frame_count() {
3504            let params = RenderImageParams {
3505                image_id: data.id,
3506                frame_index,
3507            };
3508
3509            self.sprite_atlas.remove(&params.clone().into());
3510        }
3511
3512        Ok(())
3513    }
3514
3515    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
3516    /// layout is being requested, along with the layout ids of any children. This method is called during
3517    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
3518    ///
3519    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3520    #[must_use]
3521    pub fn request_layout(
3522        &mut self,
3523        style: Style,
3524        children: impl IntoIterator<Item = LayoutId>,
3525        cx: &mut App,
3526    ) -> LayoutId {
3527        self.invalidator.debug_assert_prepaint();
3528
3529        cx.layout_id_buffer.clear();
3530        cx.layout_id_buffer.extend(children);
3531        let rem_size = self.rem_size();
3532        let scale_factor = self.scale_factor();
3533
3534        self.layout_engine.as_mut().unwrap().request_layout(
3535            style,
3536            rem_size,
3537            scale_factor,
3538            &cx.layout_id_buffer,
3539        )
3540    }
3541
3542    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3543    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3544    /// determine the element's size. One place this is used internally is when measuring text.
3545    ///
3546    /// The given closure is invoked at layout time with the known dimensions and available space and
3547    /// returns a `Size`.
3548    ///
3549    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3550    pub fn request_measured_layout<F>(&mut self, style: Style, measure: F) -> LayoutId
3551    where
3552        F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3553            + 'static,
3554    {
3555        self.invalidator.debug_assert_prepaint();
3556
3557        let rem_size = self.rem_size();
3558        let scale_factor = self.scale_factor();
3559        self.layout_engine
3560            .as_mut()
3561            .unwrap()
3562            .request_measured_layout(style, rem_size, scale_factor, measure)
3563    }
3564
3565    /// Compute the layout for the given id within the given available space.
3566    /// This method is called for its side effect, typically by the framework prior to painting.
3567    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3568    ///
3569    /// This method should only be called as part of the prepaint phase of element drawing.
3570    pub fn compute_layout(
3571        &mut self,
3572        layout_id: LayoutId,
3573        available_space: Size<AvailableSpace>,
3574        cx: &mut App,
3575    ) {
3576        self.invalidator.debug_assert_prepaint();
3577
3578        let mut layout_engine = self.layout_engine.take().unwrap();
3579        layout_engine.compute_layout(layout_id, available_space, self, cx);
3580        self.layout_engine = Some(layout_engine);
3581    }
3582
3583    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3584    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3585    ///
3586    /// This method should only be called as part of element drawing.
3587    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3588        self.invalidator.debug_assert_prepaint();
3589
3590        let scale_factor = self.scale_factor();
3591        let mut bounds = self
3592            .layout_engine
3593            .as_mut()
3594            .unwrap()
3595            .layout_bounds(layout_id, scale_factor)
3596            .map(Into::into);
3597        bounds.origin += self.element_offset();
3598        bounds
3599    }
3600
3601    /// This method should be called during `prepaint`. You can use
3602    /// the returned [Hitbox] during `paint` or in an event handler
3603    /// to determine whether the inserted hitbox was the topmost.
3604    ///
3605    /// This method should only be called as part of the prepaint phase of element drawing.
3606    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3607        self.invalidator.debug_assert_prepaint();
3608
3609        let content_mask = self.content_mask();
3610        let mut id = self.next_hitbox_id;
3611        self.next_hitbox_id = self.next_hitbox_id.next();
3612        let hitbox = Hitbox {
3613            id,
3614            bounds,
3615            content_mask,
3616            behavior,
3617        };
3618        self.next_frame.hitboxes.push(hitbox.clone());
3619        hitbox
3620    }
3621
3622    /// Set a hitbox which will act as a control area of the platform window.
3623    ///
3624    /// This method should only be called as part of the paint phase of element drawing.
3625    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3626        self.invalidator.debug_assert_paint();
3627        self.next_frame.window_control_hitboxes.push((area, hitbox));
3628    }
3629
3630    /// Sets the key context for the current element. This context will be used to translate
3631    /// keybindings into actions.
3632    ///
3633    /// This method should only be called as part of the paint phase of element drawing.
3634    pub fn set_key_context(&mut self, context: KeyContext) {
3635        self.invalidator.debug_assert_paint();
3636        self.next_frame.dispatch_tree.set_key_context(context);
3637    }
3638
3639    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3640    /// and keyboard event dispatch for the element.
3641    ///
3642    /// This method should only be called as part of the prepaint phase of element drawing.
3643    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3644        self.invalidator.debug_assert_prepaint();
3645        if focus_handle.is_focused(self) {
3646            self.next_frame.focus = Some(focus_handle.id);
3647        }
3648        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3649    }
3650
3651    /// Sets the view id for the current element, which will be used to manage view caching.
3652    ///
3653    /// This method should only be called as part of element prepaint. We plan on removing this
3654    /// method eventually when we solve some issues that require us to construct editor elements
3655    /// directly instead of always using editors via views.
3656    pub fn set_view_id(&mut self, view_id: EntityId) {
3657        self.invalidator.debug_assert_prepaint();
3658        self.next_frame.dispatch_tree.set_view_id(view_id);
3659    }
3660
3661    /// Get the entity ID for the currently rendering view
3662    pub fn current_view(&self) -> EntityId {
3663        self.invalidator.debug_assert_paint_or_prepaint();
3664        self.rendered_entity_stack.last().copied().unwrap()
3665    }
3666
3667    #[inline]
3668    pub(crate) fn with_rendered_view<R>(
3669        &mut self,
3670        id: EntityId,
3671        f: impl FnOnce(&mut Self) -> R,
3672    ) -> R {
3673        self.rendered_entity_stack.push(id);
3674        let result = f(self);
3675        self.rendered_entity_stack.pop();
3676        result
3677    }
3678
3679    /// Executes the provided function with the specified image cache.
3680    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3681    where
3682        F: FnOnce(&mut Self) -> R,
3683    {
3684        if let Some(image_cache) = image_cache {
3685            self.image_cache_stack.push(image_cache);
3686            let result = f(self);
3687            self.image_cache_stack.pop();
3688            result
3689        } else {
3690            f(self)
3691        }
3692    }
3693
3694    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3695    /// platform to receive textual input with proper integration with concerns such
3696    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3697    /// rendered.
3698    ///
3699    /// This method should only be called as part of the paint phase of element drawing.
3700    ///
3701    /// [element_input_handler]: crate::ElementInputHandler
3702    pub fn handle_input(
3703        &mut self,
3704        focus_handle: &FocusHandle,
3705        input_handler: impl InputHandler,
3706        cx: &App,
3707    ) {
3708        self.invalidator.debug_assert_paint();
3709
3710        if focus_handle.is_focused(self) {
3711            let cx = self.to_async(cx);
3712            self.next_frame
3713                .input_handlers
3714                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3715        }
3716    }
3717
3718    /// Register a mouse event listener on the window for the next frame. The type of event
3719    /// is determined by the first parameter of the given listener. When the next frame is rendered
3720    /// the listener will be cleared.
3721    ///
3722    /// This method should only be called as part of the paint phase of element drawing.
3723    pub fn on_mouse_event<Event: MouseEvent>(
3724        &mut self,
3725        mut listener: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3726    ) {
3727        self.invalidator.debug_assert_paint();
3728
3729        self.next_frame.mouse_listeners.push(Some(Box::new(
3730            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3731                if let Some(event) = event.downcast_ref() {
3732                    listener(event, phase, window, cx)
3733                }
3734            },
3735        )));
3736    }
3737
3738    /// Register a key event listener on this node for the next frame. The type of event
3739    /// is determined by the first parameter of the given listener. When the next frame is rendered
3740    /// the listener will be cleared.
3741    ///
3742    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3743    /// a specific need to register a listener yourself.
3744    ///
3745    /// This method should only be called as part of the paint phase of element drawing.
3746    pub fn on_key_event<Event: KeyEvent>(
3747        &mut self,
3748        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3749    ) {
3750        self.invalidator.debug_assert_paint();
3751
3752        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3753            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3754                if let Some(event) = event.downcast_ref::<Event>() {
3755                    listener(event, phase, window, cx)
3756                }
3757            },
3758        ));
3759    }
3760
3761    /// Register a modifiers changed event listener on the window for the next frame.
3762    ///
3763    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3764    /// a specific need to register a global listener.
3765    ///
3766    /// This method should only be called as part of the paint phase of element drawing.
3767    pub fn on_modifiers_changed(
3768        &mut self,
3769        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3770    ) {
3771        self.invalidator.debug_assert_paint();
3772
3773        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3774            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3775                listener(event, window, cx)
3776            },
3777        ));
3778    }
3779
3780    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3781    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3782    /// Returns a subscription and persists until the subscription is dropped.
3783    pub fn on_focus_in(
3784        &mut self,
3785        handle: &FocusHandle,
3786        cx: &mut App,
3787        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3788    ) -> Subscription {
3789        let focus_id = handle.id;
3790        let (subscription, activate) =
3791            self.new_focus_listener(Box::new(move |event, window, cx| {
3792                if event.is_focus_in(focus_id) {
3793                    listener(window, cx);
3794                }
3795                true
3796            }));
3797        cx.defer(move |_| activate());
3798        subscription
3799    }
3800
3801    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3802    /// Returns a subscription and persists until the subscription is dropped.
3803    pub fn on_focus_out(
3804        &mut self,
3805        handle: &FocusHandle,
3806        cx: &mut App,
3807        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3808    ) -> Subscription {
3809        let focus_id = handle.id;
3810        let (subscription, activate) =
3811            self.new_focus_listener(Box::new(move |event, window, cx| {
3812                if let Some(blurred_id) = event.previous_focus_path.last().copied()
3813                    && event.is_focus_out(focus_id)
3814                {
3815                    let event = FocusOutEvent {
3816                        blurred: WeakFocusHandle {
3817                            id: blurred_id,
3818                            handles: Arc::downgrade(&cx.focus_handles),
3819                        },
3820                    };
3821                    listener(event, window, cx)
3822                }
3823                true
3824            }));
3825        cx.defer(move |_| activate());
3826        subscription
3827    }
3828
3829    fn reset_cursor_style(&self, cx: &mut App) {
3830        // Set the cursor only if we're the active window.
3831        if self.is_window_hovered() {
3832            let style = self
3833                .rendered_frame
3834                .cursor_style(self)
3835                .unwrap_or(CursorStyle::Arrow);
3836            cx.platform.set_cursor_style(style);
3837        }
3838    }
3839
3840    /// Dispatch a given keystroke as though the user had typed it.
3841    /// You can create a keystroke with Keystroke::parse("").
3842    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3843        let keystroke = keystroke.with_simulated_ime();
3844        let result = self.dispatch_event(
3845            PlatformInput::KeyDown(KeyDownEvent {
3846                keystroke: keystroke.clone(),
3847                is_held: false,
3848                prefer_character_input: false,
3849            }),
3850            cx,
3851        );
3852        if !result.propagate {
3853            return true;
3854        }
3855
3856        if let Some(input) = keystroke.key_char
3857            && let Some(mut input_handler) = self.platform_window.take_input_handler()
3858        {
3859            input_handler.dispatch_input(&input, self, cx);
3860            self.platform_window.set_input_handler(input_handler);
3861            return true;
3862        }
3863
3864        false
3865    }
3866
3867    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3868    /// binding for the action (last binding added to the keymap).
3869    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3870        self.highest_precedence_binding_for_action(action)
3871            .map(|binding| {
3872                binding
3873                    .keystrokes()
3874                    .iter()
3875                    .map(ToString::to_string)
3876                    .collect::<Vec<_>>()
3877                    .join(" ")
3878            })
3879            .unwrap_or_else(|| action.name().to_string())
3880    }
3881
3882    /// Dispatch a mouse or keyboard event on the window.
3883    #[profiling::function]
3884    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3885        // Track whether this input was keyboard-based for focus-visible styling
3886        self.last_input_modality = match &event {
3887            PlatformInput::KeyDown(_) | PlatformInput::ModifiersChanged(_) => {
3888                InputModality::Keyboard
3889            }
3890            PlatformInput::MouseDown(e) if e.is_focusing() => InputModality::Mouse,
3891            _ => self.last_input_modality,
3892        };
3893
3894        // Handlers may set this to false by calling `stop_propagation`.
3895        cx.propagate_event = true;
3896        // Handlers may set this to true by calling `prevent_default`.
3897        self.default_prevented = false;
3898
3899        let event = match event {
3900            // Track the mouse position with our own state, since accessing the platform
3901            // API for the mouse position can only occur on the main thread.
3902            PlatformInput::MouseMove(mouse_move) => {
3903                self.mouse_position = mouse_move.position;
3904                self.modifiers = mouse_move.modifiers;
3905                PlatformInput::MouseMove(mouse_move)
3906            }
3907            PlatformInput::MouseDown(mouse_down) => {
3908                self.mouse_position = mouse_down.position;
3909                self.modifiers = mouse_down.modifiers;
3910                PlatformInput::MouseDown(mouse_down)
3911            }
3912            PlatformInput::MouseUp(mouse_up) => {
3913                self.mouse_position = mouse_up.position;
3914                self.modifiers = mouse_up.modifiers;
3915                PlatformInput::MouseUp(mouse_up)
3916            }
3917            PlatformInput::MousePressure(mouse_pressure) => {
3918                PlatformInput::MousePressure(mouse_pressure)
3919            }
3920            PlatformInput::MouseExited(mouse_exited) => {
3921                self.modifiers = mouse_exited.modifiers;
3922                PlatformInput::MouseExited(mouse_exited)
3923            }
3924            PlatformInput::ModifiersChanged(modifiers_changed) => {
3925                self.modifiers = modifiers_changed.modifiers;
3926                self.capslock = modifiers_changed.capslock;
3927                PlatformInput::ModifiersChanged(modifiers_changed)
3928            }
3929            PlatformInput::ScrollWheel(scroll_wheel) => {
3930                self.mouse_position = scroll_wheel.position;
3931                self.modifiers = scroll_wheel.modifiers;
3932                PlatformInput::ScrollWheel(scroll_wheel)
3933            }
3934            // Translate dragging and dropping of external files from the operating system
3935            // to internal drag and drop events.
3936            PlatformInput::FileDrop(file_drop) => match file_drop {
3937                FileDropEvent::Entered { position, paths } => {
3938                    self.mouse_position = position;
3939                    if cx.active_drag.is_none() {
3940                        cx.active_drag = Some(AnyDrag {
3941                            value: Arc::new(paths.clone()),
3942                            view: cx.new(|_| paths).into(),
3943                            cursor_offset: position,
3944                            cursor_style: None,
3945                        });
3946                    }
3947                    PlatformInput::MouseMove(MouseMoveEvent {
3948                        position,
3949                        pressed_button: Some(MouseButton::Left),
3950                        modifiers: Modifiers::default(),
3951                    })
3952                }
3953                FileDropEvent::Pending { position } => {
3954                    self.mouse_position = position;
3955                    PlatformInput::MouseMove(MouseMoveEvent {
3956                        position,
3957                        pressed_button: Some(MouseButton::Left),
3958                        modifiers: Modifiers::default(),
3959                    })
3960                }
3961                FileDropEvent::Submit { position } => {
3962                    cx.activate(true);
3963                    self.mouse_position = position;
3964                    PlatformInput::MouseUp(MouseUpEvent {
3965                        button: MouseButton::Left,
3966                        position,
3967                        modifiers: Modifiers::default(),
3968                        click_count: 1,
3969                    })
3970                }
3971                FileDropEvent::Exited => {
3972                    cx.active_drag.take();
3973                    PlatformInput::FileDrop(FileDropEvent::Exited)
3974                }
3975            },
3976            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3977        };
3978
3979        if let Some(any_mouse_event) = event.mouse_event() {
3980            self.dispatch_mouse_event(any_mouse_event, cx);
3981        } else if let Some(any_key_event) = event.keyboard_event() {
3982            self.dispatch_key_event(any_key_event, cx);
3983        }
3984
3985        if self.invalidator.is_dirty() {
3986            self.input_rate_tracker.borrow_mut().record_input();
3987        }
3988
3989        DispatchEventResult {
3990            propagate: cx.propagate_event,
3991            default_prevented: self.default_prevented,
3992        }
3993    }
3994
3995    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3996        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3997        if hit_test != self.mouse_hit_test {
3998            self.mouse_hit_test = hit_test;
3999            self.reset_cursor_style(cx);
4000        }
4001
4002        #[cfg(any(feature = "inspector", debug_assertions))]
4003        if self.is_inspector_picking(cx) {
4004            self.handle_inspector_mouse_event(event, cx);
4005            // When inspector is picking, all other mouse handling is skipped.
4006            return;
4007        }
4008
4009        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
4010
4011        // Capture phase, events bubble from back to front. Handlers for this phase are used for
4012        // special purposes, such as detecting events outside of a given Bounds.
4013        for listener in &mut mouse_listeners {
4014            let listener = listener.as_mut().unwrap();
4015            listener(event, DispatchPhase::Capture, self, cx);
4016            if !cx.propagate_event {
4017                break;
4018            }
4019        }
4020
4021        // Bubble phase, where most normal handlers do their work.
4022        if cx.propagate_event {
4023            for listener in mouse_listeners.iter_mut().rev() {
4024                let listener = listener.as_mut().unwrap();
4025                listener(event, DispatchPhase::Bubble, self, cx);
4026                if !cx.propagate_event {
4027                    break;
4028                }
4029            }
4030        }
4031
4032        self.rendered_frame.mouse_listeners = mouse_listeners;
4033
4034        if cx.has_active_drag() {
4035            if event.is::<MouseMoveEvent>() {
4036                // If this was a mouse move event, redraw the window so that the
4037                // active drag can follow the mouse cursor.
4038                self.refresh();
4039            } else if event.is::<MouseUpEvent>() {
4040                // If this was a mouse up event, cancel the active drag and redraw
4041                // the window.
4042                cx.active_drag = None;
4043                self.refresh();
4044            }
4045        }
4046    }
4047
4048    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
4049        if self.invalidator.is_dirty() {
4050            self.draw(cx).clear();
4051        }
4052
4053        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4054        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4055
4056        let mut keystroke: Option<Keystroke> = None;
4057
4058        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
4059            if event.modifiers.number_of_modifiers() == 0
4060                && self.pending_modifier.modifiers.number_of_modifiers() == 1
4061                && !self.pending_modifier.saw_keystroke
4062            {
4063                let key = match self.pending_modifier.modifiers {
4064                    modifiers if modifiers.shift => Some("shift"),
4065                    modifiers if modifiers.control => Some("control"),
4066                    modifiers if modifiers.alt => Some("alt"),
4067                    modifiers if modifiers.platform => Some("platform"),
4068                    modifiers if modifiers.function => Some("function"),
4069                    _ => None,
4070                };
4071                if let Some(key) = key {
4072                    keystroke = Some(Keystroke {
4073                        key: key.to_string(),
4074                        key_char: None,
4075                        modifiers: Modifiers::default(),
4076                    });
4077                }
4078            }
4079
4080            if self.pending_modifier.modifiers.number_of_modifiers() == 0
4081                && event.modifiers.number_of_modifiers() == 1
4082            {
4083                self.pending_modifier.saw_keystroke = false
4084            }
4085            self.pending_modifier.modifiers = event.modifiers
4086        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
4087            self.pending_modifier.saw_keystroke = true;
4088            keystroke = Some(key_down_event.keystroke.clone());
4089        }
4090
4091        let Some(keystroke) = keystroke else {
4092            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
4093            return;
4094        };
4095
4096        cx.propagate_event = true;
4097        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
4098        if !cx.propagate_event {
4099            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
4100            return;
4101        }
4102
4103        let mut currently_pending = self.pending_input.take().unwrap_or_default();
4104        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
4105            currently_pending = PendingInput::default();
4106        }
4107
4108        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
4109            currently_pending.keystrokes,
4110            keystroke,
4111            &dispatch_path,
4112        );
4113
4114        if !match_result.to_replay.is_empty() {
4115            self.replay_pending_input(match_result.to_replay, cx);
4116            cx.propagate_event = true;
4117        }
4118
4119        if !match_result.pending.is_empty() {
4120            currently_pending.timer.take();
4121            currently_pending.keystrokes = match_result.pending;
4122            currently_pending.focus = self.focus;
4123
4124            let text_input_requires_timeout = event
4125                .downcast_ref::<KeyDownEvent>()
4126                .filter(|key_down| key_down.keystroke.key_char.is_some())
4127                .and_then(|_| self.platform_window.take_input_handler())
4128                .map_or(false, |mut input_handler| {
4129                    let accepts = input_handler.accepts_text_input(self, cx);
4130                    self.platform_window.set_input_handler(input_handler);
4131                    accepts
4132                });
4133
4134            currently_pending.needs_timeout |=
4135                match_result.pending_has_binding || text_input_requires_timeout;
4136
4137            if currently_pending.needs_timeout {
4138                currently_pending.timer = Some(self.spawn(cx, async move |cx| {
4139                    cx.background_executor.timer(Duration::from_secs(1)).await;
4140                    cx.update(move |window, cx| {
4141                        let Some(currently_pending) = window
4142                            .pending_input
4143                            .take()
4144                            .filter(|pending| pending.focus == window.focus)
4145                        else {
4146                            return;
4147                        };
4148
4149                        let node_id = window.focus_node_id_in_rendered_frame(window.focus);
4150                        let dispatch_path =
4151                            window.rendered_frame.dispatch_tree.dispatch_path(node_id);
4152
4153                        let to_replay = window
4154                            .rendered_frame
4155                            .dispatch_tree
4156                            .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
4157
4158                        window.pending_input_changed(cx);
4159                        window.replay_pending_input(to_replay, cx)
4160                    })
4161                    .log_err();
4162                }));
4163            } else {
4164                currently_pending.timer = None;
4165            }
4166            self.pending_input = Some(currently_pending);
4167            self.pending_input_changed(cx);
4168            cx.propagate_event = false;
4169            return;
4170        }
4171
4172        let skip_bindings = event
4173            .downcast_ref::<KeyDownEvent>()
4174            .filter(|key_down_event| key_down_event.prefer_character_input)
4175            .map(|_| {
4176                self.platform_window
4177                    .take_input_handler()
4178                    .map_or(false, |mut input_handler| {
4179                        let accepts = input_handler.accepts_text_input(self, cx);
4180                        self.platform_window.set_input_handler(input_handler);
4181                        // If modifiers are not excessive (e.g. AltGr), and the input handler is accepting text input,
4182                        // we prefer the text input over bindings.
4183                        accepts
4184                    })
4185            })
4186            .unwrap_or(false);
4187
4188        if !skip_bindings {
4189            for binding in match_result.bindings {
4190                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
4191                if !cx.propagate_event {
4192                    self.dispatch_keystroke_observers(
4193                        event,
4194                        Some(binding.action),
4195                        match_result.context_stack,
4196                        cx,
4197                    );
4198                    self.pending_input_changed(cx);
4199                    return;
4200                }
4201            }
4202        }
4203
4204        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
4205        self.pending_input_changed(cx);
4206    }
4207
4208    fn finish_dispatch_key_event(
4209        &mut self,
4210        event: &dyn Any,
4211        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
4212        context_stack: Vec<KeyContext>,
4213        cx: &mut App,
4214    ) {
4215        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
4216        if !cx.propagate_event {
4217            return;
4218        }
4219
4220        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
4221        if !cx.propagate_event {
4222            return;
4223        }
4224
4225        self.dispatch_keystroke_observers(event, None, context_stack, cx);
4226    }
4227
4228    pub(crate) fn pending_input_changed(&mut self, cx: &mut App) {
4229        self.pending_input_observers
4230            .clone()
4231            .retain(&(), |callback| callback(self, cx));
4232    }
4233
4234    fn dispatch_key_down_up_event(
4235        &mut self,
4236        event: &dyn Any,
4237        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4238        cx: &mut App,
4239    ) {
4240        // Capture phase
4241        for node_id in dispatch_path {
4242            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4243
4244            for key_listener in node.key_listeners.clone() {
4245                key_listener(event, DispatchPhase::Capture, self, cx);
4246                if !cx.propagate_event {
4247                    return;
4248                }
4249            }
4250        }
4251
4252        // Bubble phase
4253        for node_id in dispatch_path.iter().rev() {
4254            // Handle low level key events
4255            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4256            for key_listener in node.key_listeners.clone() {
4257                key_listener(event, DispatchPhase::Bubble, self, cx);
4258                if !cx.propagate_event {
4259                    return;
4260                }
4261            }
4262        }
4263    }
4264
4265    fn dispatch_modifiers_changed_event(
4266        &mut self,
4267        event: &dyn Any,
4268        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4269        cx: &mut App,
4270    ) {
4271        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
4272            return;
4273        };
4274        for node_id in dispatch_path.iter().rev() {
4275            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4276            for listener in node.modifiers_changed_listeners.clone() {
4277                listener(event, self, cx);
4278                if !cx.propagate_event {
4279                    return;
4280                }
4281            }
4282        }
4283    }
4284
4285    /// Determine whether a potential multi-stroke key binding is in progress on this window.
4286    pub fn has_pending_keystrokes(&self) -> bool {
4287        self.pending_input.is_some()
4288    }
4289
4290    pub(crate) fn clear_pending_keystrokes(&mut self) {
4291        self.pending_input.take();
4292    }
4293
4294    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
4295    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
4296        self.pending_input
4297            .as_ref()
4298            .map(|pending_input| pending_input.keystrokes.as_slice())
4299    }
4300
4301    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
4302        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4303        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4304
4305        'replay: for replay in replays {
4306            let event = KeyDownEvent {
4307                keystroke: replay.keystroke.clone(),
4308                is_held: false,
4309                prefer_character_input: true,
4310            };
4311
4312            cx.propagate_event = true;
4313            for binding in replay.bindings {
4314                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
4315                if !cx.propagate_event {
4316                    self.dispatch_keystroke_observers(
4317                        &event,
4318                        Some(binding.action),
4319                        Vec::default(),
4320                        cx,
4321                    );
4322                    continue 'replay;
4323                }
4324            }
4325
4326            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
4327            if !cx.propagate_event {
4328                continue 'replay;
4329            }
4330            if let Some(input) = replay.keystroke.key_char.as_ref().cloned()
4331                && let Some(mut input_handler) = self.platform_window.take_input_handler()
4332            {
4333                input_handler.dispatch_input(&input, self, cx);
4334                self.platform_window.set_input_handler(input_handler)
4335            }
4336        }
4337    }
4338
4339    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
4340        focus_id
4341            .and_then(|focus_id| {
4342                self.rendered_frame
4343                    .dispatch_tree
4344                    .focusable_node_id(focus_id)
4345            })
4346            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id())
4347    }
4348
4349    fn dispatch_action_on_node(
4350        &mut self,
4351        node_id: DispatchNodeId,
4352        action: &dyn Action,
4353        cx: &mut App,
4354    ) {
4355        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4356
4357        // Capture phase for global actions.
4358        cx.propagate_event = true;
4359        if let Some(mut global_listeners) = cx
4360            .global_action_listeners
4361            .remove(&action.as_any().type_id())
4362        {
4363            for listener in &global_listeners {
4364                listener(action.as_any(), DispatchPhase::Capture, cx);
4365                if !cx.propagate_event {
4366                    break;
4367                }
4368            }
4369
4370            global_listeners.extend(
4371                cx.global_action_listeners
4372                    .remove(&action.as_any().type_id())
4373                    .unwrap_or_default(),
4374            );
4375
4376            cx.global_action_listeners
4377                .insert(action.as_any().type_id(), global_listeners);
4378        }
4379
4380        if !cx.propagate_event {
4381            return;
4382        }
4383
4384        // Capture phase for window actions.
4385        for node_id in &dispatch_path {
4386            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4387            for DispatchActionListener {
4388                action_type,
4389                listener,
4390            } in node.action_listeners.clone()
4391            {
4392                let any_action = action.as_any();
4393                if action_type == any_action.type_id() {
4394                    listener(any_action, DispatchPhase::Capture, self, cx);
4395
4396                    if !cx.propagate_event {
4397                        return;
4398                    }
4399                }
4400            }
4401        }
4402
4403        // Bubble phase for window actions.
4404        for node_id in dispatch_path.iter().rev() {
4405            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4406            for DispatchActionListener {
4407                action_type,
4408                listener,
4409            } in node.action_listeners.clone()
4410            {
4411                let any_action = action.as_any();
4412                if action_type == any_action.type_id() {
4413                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4414                    listener(any_action, DispatchPhase::Bubble, self, cx);
4415
4416                    if !cx.propagate_event {
4417                        return;
4418                    }
4419                }
4420            }
4421        }
4422
4423        // Bubble phase for global actions.
4424        if let Some(mut global_listeners) = cx
4425            .global_action_listeners
4426            .remove(&action.as_any().type_id())
4427        {
4428            for listener in global_listeners.iter().rev() {
4429                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4430
4431                listener(action.as_any(), DispatchPhase::Bubble, cx);
4432                if !cx.propagate_event {
4433                    break;
4434                }
4435            }
4436
4437            global_listeners.extend(
4438                cx.global_action_listeners
4439                    .remove(&action.as_any().type_id())
4440                    .unwrap_or_default(),
4441            );
4442
4443            cx.global_action_listeners
4444                .insert(action.as_any().type_id(), global_listeners);
4445        }
4446    }
4447
4448    /// Register the given handler to be invoked whenever the global of the given type
4449    /// is updated.
4450    pub fn observe_global<G: Global>(
4451        &mut self,
4452        cx: &mut App,
4453        f: impl Fn(&mut Window, &mut App) + 'static,
4454    ) -> Subscription {
4455        let window_handle = self.handle;
4456        let (subscription, activate) = cx.global_observers.insert(
4457            TypeId::of::<G>(),
4458            Box::new(move |cx| {
4459                window_handle
4460                    .update(cx, |_, window, cx| f(window, cx))
4461                    .is_ok()
4462            }),
4463        );
4464        cx.defer(move |_| activate());
4465        subscription
4466    }
4467
4468    /// Focus the current window and bring it to the foreground at the platform level.
4469    pub fn activate_window(&self) {
4470        self.platform_window.activate();
4471    }
4472
4473    /// Minimize the current window at the platform level.
4474    pub fn minimize_window(&self) {
4475        self.platform_window.minimize();
4476    }
4477
4478    /// Toggle full screen status on the current window at the platform level.
4479    pub fn toggle_fullscreen(&self) {
4480        self.platform_window.toggle_fullscreen();
4481    }
4482
4483    /// Updates the IME panel position suggestions for languages like japanese, chinese.
4484    pub fn invalidate_character_coordinates(&self) {
4485        self.on_next_frame(|window, cx| {
4486            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
4487                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
4488                    window.platform_window.update_ime_position(bounds);
4489                }
4490                window.platform_window.set_input_handler(input_handler);
4491            }
4492        });
4493    }
4494
4495    /// Present a platform dialog.
4496    /// The provided message will be presented, along with buttons for each answer.
4497    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
4498    pub fn prompt<T>(
4499        &mut self,
4500        level: PromptLevel,
4501        message: &str,
4502        detail: Option<&str>,
4503        answers: &[T],
4504        cx: &mut App,
4505    ) -> oneshot::Receiver<usize>
4506    where
4507        T: Clone + Into<PromptButton>,
4508    {
4509        let prompt_builder = cx.prompt_builder.take();
4510        let Some(prompt_builder) = prompt_builder else {
4511            unreachable!("Re-entrant window prompting is not supported by GPUI");
4512        };
4513
4514        let answers = answers
4515            .iter()
4516            .map(|answer| answer.clone().into())
4517            .collect::<Vec<_>>();
4518
4519        let receiver = match &prompt_builder {
4520            PromptBuilder::Default => self
4521                .platform_window
4522                .prompt(level, message, detail, &answers)
4523                .unwrap_or_else(|| {
4524                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4525                }),
4526            PromptBuilder::Custom(_) => {
4527                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4528            }
4529        };
4530
4531        cx.prompt_builder = Some(prompt_builder);
4532
4533        receiver
4534    }
4535
4536    fn build_custom_prompt(
4537        &mut self,
4538        prompt_builder: &PromptBuilder,
4539        level: PromptLevel,
4540        message: &str,
4541        detail: Option<&str>,
4542        answers: &[PromptButton],
4543        cx: &mut App,
4544    ) -> oneshot::Receiver<usize> {
4545        let (sender, receiver) = oneshot::channel();
4546        let handle = PromptHandle::new(sender);
4547        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
4548        self.prompt = Some(handle);
4549        receiver
4550    }
4551
4552    /// Returns the current context stack.
4553    pub fn context_stack(&self) -> Vec<KeyContext> {
4554        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4555        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4556        dispatch_tree
4557            .dispatch_path(node_id)
4558            .iter()
4559            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4560            .collect()
4561    }
4562
4563    /// Returns all available actions for the focused element.
4564    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4565        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4566        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4567        for action_type in cx.global_action_listeners.keys() {
4568            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4569                let action = cx.actions.build_action_type(action_type).ok();
4570                if let Some(action) = action {
4571                    actions.insert(ix, action);
4572                }
4573            }
4574        }
4575        actions
4576    }
4577
4578    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4579    /// returned in the order they were added. For display, the last binding should take precedence.
4580    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4581        self.rendered_frame
4582            .dispatch_tree
4583            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4584    }
4585
4586    /// Returns the highest precedence key binding that invokes an action on the currently focused
4587    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4588    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4589        self.rendered_frame
4590            .dispatch_tree
4591            .highest_precedence_binding_for_action(
4592                action,
4593                &self.rendered_frame.dispatch_tree.context_stack,
4594            )
4595    }
4596
4597    /// Returns the key bindings for an action in a context.
4598    pub fn bindings_for_action_in_context(
4599        &self,
4600        action: &dyn Action,
4601        context: KeyContext,
4602    ) -> Vec<KeyBinding> {
4603        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4604        dispatch_tree.bindings_for_action(action, &[context])
4605    }
4606
4607    /// Returns the highest precedence key binding for an action in a context. This is more
4608    /// efficient than getting the last result of `bindings_for_action_in_context`.
4609    pub fn highest_precedence_binding_for_action_in_context(
4610        &self,
4611        action: &dyn Action,
4612        context: KeyContext,
4613    ) -> Option<KeyBinding> {
4614        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4615        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4616    }
4617
4618    /// Returns any bindings that would invoke an action on the given focus handle if it were
4619    /// focused. Bindings are returned in the order they were added. For display, the last binding
4620    /// should take precedence.
4621    pub fn bindings_for_action_in(
4622        &self,
4623        action: &dyn Action,
4624        focus_handle: &FocusHandle,
4625    ) -> Vec<KeyBinding> {
4626        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4627        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4628            return vec![];
4629        };
4630        dispatch_tree.bindings_for_action(action, &context_stack)
4631    }
4632
4633    /// Returns the highest precedence key binding that would invoke an action on the given focus
4634    /// handle if it were focused. This is more efficient than getting the last result of
4635    /// `bindings_for_action_in`.
4636    pub fn highest_precedence_binding_for_action_in(
4637        &self,
4638        action: &dyn Action,
4639        focus_handle: &FocusHandle,
4640    ) -> Option<KeyBinding> {
4641        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4642        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4643        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4644    }
4645
4646    /// Find the bindings that can follow the current input sequence for the current context stack.
4647    pub fn possible_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
4648        self.rendered_frame
4649            .dispatch_tree
4650            .possible_next_bindings_for_input(input, &self.context_stack())
4651    }
4652
4653    fn context_stack_for_focus_handle(
4654        &self,
4655        focus_handle: &FocusHandle,
4656    ) -> Option<Vec<KeyContext>> {
4657        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4658        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4659        let context_stack: Vec<_> = dispatch_tree
4660            .dispatch_path(node_id)
4661            .into_iter()
4662            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4663            .collect();
4664        Some(context_stack)
4665    }
4666
4667    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4668    pub fn listener_for<T: 'static, E>(
4669        &self,
4670        view: &Entity<T>,
4671        f: impl Fn(&mut T, &E, &mut Window, &mut Context<T>) + 'static,
4672    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4673        let view = view.downgrade();
4674        move |e: &E, window: &mut Window, cx: &mut App| {
4675            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4676        }
4677    }
4678
4679    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4680    pub fn handler_for<E: 'static, Callback: Fn(&mut E, &mut Window, &mut Context<E>) + 'static>(
4681        &self,
4682        entity: &Entity<E>,
4683        f: Callback,
4684    ) -> impl Fn(&mut Window, &mut App) + 'static {
4685        let entity = entity.downgrade();
4686        move |window: &mut Window, cx: &mut App| {
4687            entity.update(cx, |entity, cx| f(entity, window, cx)).ok();
4688        }
4689    }
4690
4691    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4692    /// If the callback returns false, the window won't be closed.
4693    pub fn on_window_should_close(
4694        &self,
4695        cx: &App,
4696        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4697    ) {
4698        let mut cx = self.to_async(cx);
4699        self.platform_window.on_should_close(Box::new(move || {
4700            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4701        }))
4702    }
4703
4704    /// Register an action listener on this node for the next frame. The type of action
4705    /// is determined by the first parameter of the given listener. When the next frame is rendered
4706    /// the listener will be cleared.
4707    ///
4708    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4709    /// a specific need to register a listener yourself.
4710    ///
4711    /// This method should only be called as part of the paint phase of element drawing.
4712    pub fn on_action(
4713        &mut self,
4714        action_type: TypeId,
4715        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4716    ) {
4717        self.invalidator.debug_assert_paint();
4718
4719        self.next_frame
4720            .dispatch_tree
4721            .on_action(action_type, Rc::new(listener));
4722    }
4723
4724    /// Register a capturing action listener on this node for the next frame if the condition is true.
4725    /// The type of action is determined by the first parameter of the given listener. When the next
4726    /// frame is rendered the listener will be cleared.
4727    ///
4728    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4729    /// a specific need to register a listener yourself.
4730    ///
4731    /// This method should only be called as part of the paint phase of element drawing.
4732    pub fn on_action_when(
4733        &mut self,
4734        condition: bool,
4735        action_type: TypeId,
4736        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4737    ) {
4738        self.invalidator.debug_assert_paint();
4739
4740        if condition {
4741            self.next_frame
4742                .dispatch_tree
4743                .on_action(action_type, Rc::new(listener));
4744        }
4745    }
4746
4747    /// Read information about the GPU backing this window.
4748    /// Currently returns None on Mac and Windows.
4749    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4750        self.platform_window.gpu_specs()
4751    }
4752
4753    /// Perform titlebar double-click action.
4754    /// This is macOS specific.
4755    pub fn titlebar_double_click(&self) {
4756        self.platform_window.titlebar_double_click();
4757    }
4758
4759    /// Gets the window's title at the platform level.
4760    /// This is macOS specific.
4761    pub fn window_title(&self) -> String {
4762        self.platform_window.get_title()
4763    }
4764
4765    /// Returns a list of all tabbed windows and their titles.
4766    /// This is macOS specific.
4767    pub fn tabbed_windows(&self) -> Option<Vec<SystemWindowTab>> {
4768        self.platform_window.tabbed_windows()
4769    }
4770
4771    /// Returns the tab bar visibility.
4772    /// This is macOS specific.
4773    pub fn tab_bar_visible(&self) -> bool {
4774        self.platform_window.tab_bar_visible()
4775    }
4776
4777    /// Merges all open windows into a single tabbed window.
4778    /// This is macOS specific.
4779    pub fn merge_all_windows(&self) {
4780        self.platform_window.merge_all_windows()
4781    }
4782
4783    /// Moves the tab to a new containing window.
4784    /// This is macOS specific.
4785    pub fn move_tab_to_new_window(&self) {
4786        self.platform_window.move_tab_to_new_window()
4787    }
4788
4789    /// Shows or hides the window tab overview.
4790    /// This is macOS specific.
4791    pub fn toggle_window_tab_overview(&self) {
4792        self.platform_window.toggle_window_tab_overview()
4793    }
4794
4795    /// Sets the tabbing identifier for the window.
4796    /// This is macOS specific.
4797    pub fn set_tabbing_identifier(&self, tabbing_identifier: Option<String>) {
4798        self.platform_window
4799            .set_tabbing_identifier(tabbing_identifier)
4800    }
4801
4802    /// Toggles the inspector mode on this window.
4803    #[cfg(any(feature = "inspector", debug_assertions))]
4804    pub fn toggle_inspector(&mut self, cx: &mut App) {
4805        self.inspector = match self.inspector {
4806            None => Some(cx.new(|_| Inspector::new())),
4807            Some(_) => None,
4808        };
4809        self.refresh();
4810    }
4811
4812    /// Returns true if the window is in inspector mode.
4813    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4814        #[cfg(any(feature = "inspector", debug_assertions))]
4815        {
4816            if let Some(inspector) = &self.inspector {
4817                return inspector.read(_cx).is_picking();
4818            }
4819        }
4820        false
4821    }
4822
4823    /// Executes the provided function with mutable access to an inspector state.
4824    #[cfg(any(feature = "inspector", debug_assertions))]
4825    pub fn with_inspector_state<T: 'static, R>(
4826        &mut self,
4827        _inspector_id: Option<&crate::InspectorElementId>,
4828        cx: &mut App,
4829        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4830    ) -> R {
4831        if let Some(inspector_id) = _inspector_id
4832            && let Some(inspector) = &self.inspector
4833        {
4834            let inspector = inspector.clone();
4835            let active_element_id = inspector.read(cx).active_element_id();
4836            if Some(inspector_id) == active_element_id {
4837                return inspector.update(cx, |inspector, _cx| {
4838                    inspector.with_active_element_state(self, f)
4839                });
4840            }
4841        }
4842        f(&mut None, self)
4843    }
4844
4845    #[cfg(any(feature = "inspector", debug_assertions))]
4846    pub(crate) fn build_inspector_element_id(
4847        &mut self,
4848        path: crate::InspectorElementPath,
4849    ) -> crate::InspectorElementId {
4850        self.invalidator.debug_assert_paint_or_prepaint();
4851        let path = Rc::new(path);
4852        let next_instance_id = self
4853            .next_frame
4854            .next_inspector_instance_ids
4855            .entry(path.clone())
4856            .or_insert(0);
4857        let instance_id = *next_instance_id;
4858        *next_instance_id += 1;
4859        crate::InspectorElementId { path, instance_id }
4860    }
4861
4862    #[cfg(any(feature = "inspector", debug_assertions))]
4863    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4864        if let Some(inspector) = self.inspector.take() {
4865            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4866            inspector_element.prepaint_as_root(
4867                point(self.viewport_size.width - inspector_width, px(0.0)),
4868                size(inspector_width, self.viewport_size.height).into(),
4869                self,
4870                cx,
4871            );
4872            self.inspector = Some(inspector);
4873            Some(inspector_element)
4874        } else {
4875            None
4876        }
4877    }
4878
4879    #[cfg(any(feature = "inspector", debug_assertions))]
4880    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4881        if let Some(mut inspector_element) = inspector_element {
4882            inspector_element.paint(self, cx);
4883        };
4884    }
4885
4886    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4887    /// inspect UI elements by clicking on them.
4888    #[cfg(any(feature = "inspector", debug_assertions))]
4889    pub fn insert_inspector_hitbox(
4890        &mut self,
4891        hitbox_id: HitboxId,
4892        inspector_id: Option<&crate::InspectorElementId>,
4893        cx: &App,
4894    ) {
4895        self.invalidator.debug_assert_paint_or_prepaint();
4896        if !self.is_inspector_picking(cx) {
4897            return;
4898        }
4899        if let Some(inspector_id) = inspector_id {
4900            self.next_frame
4901                .inspector_hitboxes
4902                .insert(hitbox_id, inspector_id.clone());
4903        }
4904    }
4905
4906    #[cfg(any(feature = "inspector", debug_assertions))]
4907    fn paint_inspector_hitbox(&mut self, cx: &App) {
4908        if let Some(inspector) = self.inspector.as_ref() {
4909            let inspector = inspector.read(cx);
4910            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4911                && let Some(hitbox) = self
4912                    .next_frame
4913                    .hitboxes
4914                    .iter()
4915                    .find(|hitbox| hitbox.id == hitbox_id)
4916            {
4917                self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4918            }
4919        }
4920    }
4921
4922    #[cfg(any(feature = "inspector", debug_assertions))]
4923    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4924        let Some(inspector) = self.inspector.clone() else {
4925            return;
4926        };
4927        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4928            inspector.update(cx, |inspector, _cx| {
4929                if let Some((_, inspector_id)) =
4930                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4931                {
4932                    inspector.hover(inspector_id, self);
4933                }
4934            });
4935        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4936            inspector.update(cx, |inspector, _cx| {
4937                if let Some((_, inspector_id)) =
4938                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4939                {
4940                    inspector.select(inspector_id, self);
4941                }
4942            });
4943        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4944            // This should be kept in sync with SCROLL_LINES in x11 platform.
4945            const SCROLL_LINES: f32 = 3.0;
4946            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4947            let delta_y = event
4948                .delta
4949                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4950                .y;
4951            if let Some(inspector) = self.inspector.clone() {
4952                inspector.update(cx, |inspector, _cx| {
4953                    if let Some(depth) = inspector.pick_depth.as_mut() {
4954                        *depth += f32::from(delta_y) / SCROLL_PIXELS_PER_LAYER;
4955                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4956                        if *depth < 0.0 {
4957                            *depth = 0.0;
4958                        } else if *depth > max_depth {
4959                            *depth = max_depth;
4960                        }
4961                        if let Some((_, inspector_id)) =
4962                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4963                        {
4964                            inspector.set_active_element_id(inspector_id, self);
4965                        }
4966                    }
4967                });
4968            }
4969        }
4970    }
4971
4972    #[cfg(any(feature = "inspector", debug_assertions))]
4973    fn hovered_inspector_hitbox(
4974        &self,
4975        inspector: &Inspector,
4976        frame: &Frame,
4977    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4978        if let Some(pick_depth) = inspector.pick_depth {
4979            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4980            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4981            let skip_count = (depth as usize).min(max_skipped);
4982            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4983                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4984                    return Some((*hitbox_id, inspector_id.clone()));
4985                }
4986            }
4987        }
4988        None
4989    }
4990
4991    /// For testing: set the current modifier keys state.
4992    /// This does not generate any events.
4993    #[cfg(any(test, feature = "test-support"))]
4994    pub fn set_modifiers(&mut self, modifiers: Modifiers) {
4995        self.modifiers = modifiers;
4996    }
4997
4998    /// For testing: simulate a mouse move event to the given position.
4999    /// This dispatches the event through the normal event handling path,
5000    /// which will trigger hover states and tooltips.
5001    #[cfg(any(test, feature = "test-support"))]
5002    pub fn simulate_mouse_move(&mut self, position: Point<Pixels>, cx: &mut App) {
5003        let event = PlatformInput::MouseMove(MouseMoveEvent {
5004            position,
5005            modifiers: self.modifiers,
5006            pressed_button: None,
5007        });
5008        let _ = self.dispatch_event(event, cx);
5009    }
5010}
5011
5012// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
5013slotmap::new_key_type! {
5014    /// A unique identifier for a window.
5015    pub struct WindowId;
5016}
5017
5018impl WindowId {
5019    /// Converts this window ID to a `u64`.
5020    pub fn as_u64(&self) -> u64 {
5021        self.0.as_ffi()
5022    }
5023}
5024
5025impl From<u64> for WindowId {
5026    fn from(value: u64) -> Self {
5027        WindowId(slotmap::KeyData::from_ffi(value))
5028    }
5029}
5030
5031/// A handle to a window with a specific root view type.
5032/// Note that this does not keep the window alive on its own.
5033#[derive(Deref, DerefMut)]
5034pub struct WindowHandle<V> {
5035    #[deref]
5036    #[deref_mut]
5037    pub(crate) any_handle: AnyWindowHandle,
5038    state_type: PhantomData<fn(V) -> V>,
5039}
5040
5041impl<V> Debug for WindowHandle<V> {
5042    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
5043        f.debug_struct("WindowHandle")
5044            .field("any_handle", &self.any_handle.id.as_u64())
5045            .finish()
5046    }
5047}
5048
5049impl<V: 'static + Render> WindowHandle<V> {
5050    /// Creates a new handle from a window ID.
5051    /// This does not check if the root type of the window is `V`.
5052    pub fn new(id: WindowId) -> Self {
5053        WindowHandle {
5054            any_handle: AnyWindowHandle {
5055                id,
5056                state_type: TypeId::of::<V>(),
5057            },
5058            state_type: PhantomData,
5059        }
5060    }
5061
5062    /// Get the root view out of this window.
5063    ///
5064    /// This will fail if the window is closed or if the root view's type does not match `V`.
5065    #[cfg(any(test, feature = "test-support"))]
5066    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
5067    where
5068        C: AppContext,
5069    {
5070        cx.update_window(self.any_handle, |root_view, _, _| {
5071            root_view
5072                .downcast::<V>()
5073                .map_err(|_| anyhow!("the type of the window's root view has changed"))
5074        })?
5075    }
5076
5077    /// Updates the root view of this window.
5078    ///
5079    /// This will fail if the window has been closed or if the root view's type does not match
5080    pub fn update<C, R>(
5081        &self,
5082        cx: &mut C,
5083        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
5084    ) -> Result<R>
5085    where
5086        C: AppContext,
5087    {
5088        cx.update_window(self.any_handle, |root_view, window, cx| {
5089            let view = root_view
5090                .downcast::<V>()
5091                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
5092
5093            Ok(view.update(cx, |view, cx| update(view, window, cx)))
5094        })?
5095    }
5096
5097    /// Read the root view out of this window.
5098    ///
5099    /// This will fail if the window is closed or if the root view's type does not match `V`.
5100    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
5101        let x = cx
5102            .windows
5103            .get(self.id)
5104            .and_then(|window| {
5105                window
5106                    .as_deref()
5107                    .and_then(|window| window.root.clone())
5108                    .map(|root_view| root_view.downcast::<V>())
5109            })
5110            .context("window not found")?
5111            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
5112
5113        Ok(x.read(cx))
5114    }
5115
5116    /// Read the root view out of this window, with a callback
5117    ///
5118    /// This will fail if the window is closed or if the root view's type does not match `V`.
5119    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
5120    where
5121        C: AppContext,
5122    {
5123        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
5124    }
5125
5126    /// Read the root view pointer off of this window.
5127    ///
5128    /// This will fail if the window is closed or if the root view's type does not match `V`.
5129    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
5130    where
5131        C: AppContext,
5132    {
5133        cx.read_window(self, |root_view, _cx| root_view)
5134    }
5135
5136    /// Check if this window is 'active'.
5137    ///
5138    /// Will return `None` if the window is closed or currently
5139    /// borrowed.
5140    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
5141        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
5142            .ok()
5143    }
5144}
5145
5146impl<V> Copy for WindowHandle<V> {}
5147
5148impl<V> Clone for WindowHandle<V> {
5149    fn clone(&self) -> Self {
5150        *self
5151    }
5152}
5153
5154impl<V> PartialEq for WindowHandle<V> {
5155    fn eq(&self, other: &Self) -> bool {
5156        self.any_handle == other.any_handle
5157    }
5158}
5159
5160impl<V> Eq for WindowHandle<V> {}
5161
5162impl<V> Hash for WindowHandle<V> {
5163    fn hash<H: Hasher>(&self, state: &mut H) {
5164        self.any_handle.hash(state);
5165    }
5166}
5167
5168impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
5169    fn from(val: WindowHandle<V>) -> Self {
5170        val.any_handle
5171    }
5172}
5173
5174/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
5175#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
5176pub struct AnyWindowHandle {
5177    pub(crate) id: WindowId,
5178    state_type: TypeId,
5179}
5180
5181impl AnyWindowHandle {
5182    /// Get the ID of this window.
5183    pub fn window_id(&self) -> WindowId {
5184        self.id
5185    }
5186
5187    /// Attempt to convert this handle to a window handle with a specific root view type.
5188    /// If the types do not match, this will return `None`.
5189    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
5190        if TypeId::of::<T>() == self.state_type {
5191            Some(WindowHandle {
5192                any_handle: *self,
5193                state_type: PhantomData,
5194            })
5195        } else {
5196            None
5197        }
5198    }
5199
5200    /// Updates the state of the root view of this window.
5201    ///
5202    /// This will fail if the window has been closed.
5203    pub fn update<C, R>(
5204        self,
5205        cx: &mut C,
5206        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
5207    ) -> Result<R>
5208    where
5209        C: AppContext,
5210    {
5211        cx.update_window(self, update)
5212    }
5213
5214    /// Read the state of the root view of this window.
5215    ///
5216    /// This will fail if the window has been closed.
5217    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
5218    where
5219        C: AppContext,
5220        T: 'static,
5221    {
5222        let view = self
5223            .downcast::<T>()
5224            .context("the type of the window's root view has changed")?;
5225
5226        cx.read_window(&view, read)
5227    }
5228}
5229
5230impl HasWindowHandle for Window {
5231    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
5232        self.platform_window.window_handle()
5233    }
5234}
5235
5236impl HasDisplayHandle for Window {
5237    fn display_handle(
5238        &self,
5239    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
5240        self.platform_window.display_handle()
5241    }
5242}
5243
5244/// An identifier for an [`Element`].
5245///
5246/// Can be constructed with a string, a number, or both, as well
5247/// as other internal representations.
5248#[derive(Clone, Debug, Eq, PartialEq, Hash)]
5249pub enum ElementId {
5250    /// The ID of a View element
5251    View(EntityId),
5252    /// An integer ID.
5253    Integer(u64),
5254    /// A string based ID.
5255    Name(SharedString),
5256    /// A UUID.
5257    Uuid(Uuid),
5258    /// An ID that's equated with a focus handle.
5259    FocusHandle(FocusId),
5260    /// A combination of a name and an integer.
5261    NamedInteger(SharedString, u64),
5262    /// A path.
5263    Path(Arc<std::path::Path>),
5264    /// A code location.
5265    CodeLocation(core::panic::Location<'static>),
5266    /// A labeled child of an element.
5267    NamedChild(Arc<ElementId>, SharedString),
5268}
5269
5270impl ElementId {
5271    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
5272    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
5273        Self::NamedInteger(name.into(), integer as u64)
5274    }
5275}
5276
5277impl Display for ElementId {
5278    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
5279        match self {
5280            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
5281            ElementId::Integer(ix) => write!(f, "{}", ix)?,
5282            ElementId::Name(name) => write!(f, "{}", name)?,
5283            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
5284            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
5285            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
5286            ElementId::Path(path) => write!(f, "{}", path.display())?,
5287            ElementId::CodeLocation(location) => write!(f, "{}", location)?,
5288            ElementId::NamedChild(id, name) => write!(f, "{}-{}", id, name)?,
5289        }
5290
5291        Ok(())
5292    }
5293}
5294
5295impl TryInto<SharedString> for ElementId {
5296    type Error = anyhow::Error;
5297
5298    fn try_into(self) -> anyhow::Result<SharedString> {
5299        if let ElementId::Name(name) = self {
5300            Ok(name)
5301        } else {
5302            anyhow::bail!("element id is not string")
5303        }
5304    }
5305}
5306
5307impl From<usize> for ElementId {
5308    fn from(id: usize) -> Self {
5309        ElementId::Integer(id as u64)
5310    }
5311}
5312
5313impl From<i32> for ElementId {
5314    fn from(id: i32) -> Self {
5315        Self::Integer(id as u64)
5316    }
5317}
5318
5319impl From<SharedString> for ElementId {
5320    fn from(name: SharedString) -> Self {
5321        ElementId::Name(name)
5322    }
5323}
5324
5325impl From<String> for ElementId {
5326    fn from(name: String) -> Self {
5327        ElementId::Name(name.into())
5328    }
5329}
5330
5331impl From<Arc<str>> for ElementId {
5332    fn from(name: Arc<str>) -> Self {
5333        ElementId::Name(name.into())
5334    }
5335}
5336
5337impl From<Arc<std::path::Path>> for ElementId {
5338    fn from(path: Arc<std::path::Path>) -> Self {
5339        ElementId::Path(path)
5340    }
5341}
5342
5343impl From<&'static str> for ElementId {
5344    fn from(name: &'static str) -> Self {
5345        ElementId::Name(name.into())
5346    }
5347}
5348
5349impl<'a> From<&'a FocusHandle> for ElementId {
5350    fn from(handle: &'a FocusHandle) -> Self {
5351        ElementId::FocusHandle(handle.id)
5352    }
5353}
5354
5355impl From<(&'static str, EntityId)> for ElementId {
5356    fn from((name, id): (&'static str, EntityId)) -> Self {
5357        ElementId::NamedInteger(name.into(), id.as_u64())
5358    }
5359}
5360
5361impl From<(&'static str, usize)> for ElementId {
5362    fn from((name, id): (&'static str, usize)) -> Self {
5363        ElementId::NamedInteger(name.into(), id as u64)
5364    }
5365}
5366
5367impl From<(SharedString, usize)> for ElementId {
5368    fn from((name, id): (SharedString, usize)) -> Self {
5369        ElementId::NamedInteger(name, id as u64)
5370    }
5371}
5372
5373impl From<(&'static str, u64)> for ElementId {
5374    fn from((name, id): (&'static str, u64)) -> Self {
5375        ElementId::NamedInteger(name.into(), id)
5376    }
5377}
5378
5379impl From<Uuid> for ElementId {
5380    fn from(value: Uuid) -> Self {
5381        Self::Uuid(value)
5382    }
5383}
5384
5385impl From<(&'static str, u32)> for ElementId {
5386    fn from((name, id): (&'static str, u32)) -> Self {
5387        ElementId::NamedInteger(name.into(), id.into())
5388    }
5389}
5390
5391impl<T: Into<SharedString>> From<(ElementId, T)> for ElementId {
5392    fn from((id, name): (ElementId, T)) -> Self {
5393        ElementId::NamedChild(Arc::new(id), name.into())
5394    }
5395}
5396
5397impl From<&'static core::panic::Location<'static>> for ElementId {
5398    fn from(location: &'static core::panic::Location<'static>) -> Self {
5399        ElementId::CodeLocation(*location)
5400    }
5401}
5402
5403/// A rectangle to be rendered in the window at the given position and size.
5404/// Passed as an argument [`Window::paint_quad`].
5405#[derive(Clone)]
5406pub struct PaintQuad {
5407    /// The bounds of the quad within the window.
5408    pub bounds: Bounds<Pixels>,
5409    /// The radii of the quad's corners.
5410    pub corner_radii: Corners<Pixels>,
5411    /// The background color of the quad.
5412    pub background: Background,
5413    /// The widths of the quad's borders.
5414    pub border_widths: Edges<Pixels>,
5415    /// The color of the quad's borders.
5416    pub border_color: Hsla,
5417    /// The style of the quad's borders.
5418    pub border_style: BorderStyle,
5419}
5420
5421impl PaintQuad {
5422    /// Sets the corner radii of the quad.
5423    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
5424        PaintQuad {
5425            corner_radii: corner_radii.into(),
5426            ..self
5427        }
5428    }
5429
5430    /// Sets the border widths of the quad.
5431    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5432        PaintQuad {
5433            border_widths: border_widths.into(),
5434            ..self
5435        }
5436    }
5437
5438    /// Sets the border color of the quad.
5439    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5440        PaintQuad {
5441            border_color: border_color.into(),
5442            ..self
5443        }
5444    }
5445
5446    /// Sets the background color of the quad.
5447    pub fn background(self, background: impl Into<Background>) -> Self {
5448        PaintQuad {
5449            background: background.into(),
5450            ..self
5451        }
5452    }
5453}
5454
5455/// Creates a quad with the given parameters.
5456pub fn quad(
5457    bounds: Bounds<Pixels>,
5458    corner_radii: impl Into<Corners<Pixels>>,
5459    background: impl Into<Background>,
5460    border_widths: impl Into<Edges<Pixels>>,
5461    border_color: impl Into<Hsla>,
5462    border_style: BorderStyle,
5463) -> PaintQuad {
5464    PaintQuad {
5465        bounds,
5466        corner_radii: corner_radii.into(),
5467        background: background.into(),
5468        border_widths: border_widths.into(),
5469        border_color: border_color.into(),
5470        border_style,
5471    }
5472}
5473
5474/// Creates a filled quad with the given bounds and background color.
5475pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5476    PaintQuad {
5477        bounds: bounds.into(),
5478        corner_radii: (0.).into(),
5479        background: background.into(),
5480        border_widths: (0.).into(),
5481        border_color: transparent_black(),
5482        border_style: BorderStyle::default(),
5483    }
5484}
5485
5486/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5487pub fn outline(
5488    bounds: impl Into<Bounds<Pixels>>,
5489    border_color: impl Into<Hsla>,
5490    border_style: BorderStyle,
5491) -> PaintQuad {
5492    PaintQuad {
5493        bounds: bounds.into(),
5494        corner_radii: (0.).into(),
5495        background: transparent_black().into(),
5496        border_widths: (1.).into(),
5497        border_color: border_color.into(),
5498        border_style,
5499    }
5500}