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 gpui_util::post_inc;
  30use gpui_util::{ResultExt, measure};
  31use itertools::FoldWhile::{Continue, Done};
  32use itertools::Itertools;
  33use parking_lot::RwLock;
  34use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
  35use refineable::Refineable;
  36use scheduler::Instant;
  37use slotmap::SlotMap;
  38use smallvec::SmallVec;
  39use std::{
  40    any::{Any, TypeId},
  41    borrow::Cow,
  42    cell::{Cell, RefCell},
  43    cmp,
  44    fmt::{Debug, Display},
  45    hash::{Hash, Hasher},
  46    marker::PhantomData,
  47    mem,
  48    ops::{DerefMut, Range},
  49    rc::Rc,
  50    sync::{
  51        Arc, Weak,
  52        atomic::{AtomicUsize, Ordering::SeqCst},
  53    },
  54    time::Duration,
  55};
  56use uuid::Uuid;
  57
  58mod prompts;
  59
  60use crate::util::atomic_incr_if_not_zero;
  61pub use prompts::*;
  62
  63/// Default window size used when no explicit size is provided.
  64pub const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1536.), px(1095.));
  65
  66/// A 6:5 aspect ratio minimum window size to be used for functional,
  67/// additional-to-main-Zed windows, like the settings and rules library windows.
  68pub const DEFAULT_ADDITIONAL_WINDOW_SIZE: Size<Pixels> = Size {
  69    width: Pixels(900.),
  70    height: Pixels(750.),
  71};
  72
  73/// Represents the two different phases when dispatching events.
  74#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  75pub enum DispatchPhase {
  76    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  77    /// invoked front to back and keyboard event listeners are invoked from the focused element
  78    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  79    /// registering event listeners.
  80    #[default]
  81    Bubble,
  82    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  83    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  84    /// is used for special purposes such as clearing the "pressed" state for click events. If
  85    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  86    /// outside of the immediate region may rely on detecting non-local events during this phase.
  87    Capture,
  88}
  89
  90impl DispatchPhase {
  91    /// Returns true if this represents the "bubble" phase.
  92    #[inline]
  93    pub fn bubble(self) -> bool {
  94        self == DispatchPhase::Bubble
  95    }
  96
  97    /// Returns true if this represents the "capture" phase.
  98    #[inline]
  99    pub fn capture(self) -> bool {
 100        self == DispatchPhase::Capture
 101    }
 102}
 103
 104struct WindowInvalidatorInner {
 105    pub dirty: bool,
 106    pub draw_phase: DrawPhase,
 107    pub dirty_views: FxHashSet<EntityId>,
 108}
 109
 110#[derive(Clone)]
 111pub(crate) struct WindowInvalidator {
 112    inner: Rc<RefCell<WindowInvalidatorInner>>,
 113}
 114
 115impl WindowInvalidator {
 116    pub fn new() -> Self {
 117        WindowInvalidator {
 118            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 119                dirty: true,
 120                draw_phase: DrawPhase::None,
 121                dirty_views: FxHashSet::default(),
 122            })),
 123        }
 124    }
 125
 126    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 127        let mut inner = self.inner.borrow_mut();
 128        inner.dirty_views.insert(entity);
 129        if inner.draw_phase == DrawPhase::None {
 130            inner.dirty = true;
 131            cx.push_effect(Effect::Notify { emitter: entity });
 132            true
 133        } else {
 134            false
 135        }
 136    }
 137
 138    pub fn is_dirty(&self) -> bool {
 139        self.inner.borrow().dirty
 140    }
 141
 142    pub fn set_dirty(&self, dirty: bool) {
 143        self.inner.borrow_mut().dirty = dirty
 144    }
 145
 146    pub fn set_phase(&self, phase: DrawPhase) {
 147        self.inner.borrow_mut().draw_phase = phase
 148    }
 149
 150    pub fn take_views(&self) -> FxHashSet<EntityId> {
 151        mem::take(&mut self.inner.borrow_mut().dirty_views)
 152    }
 153
 154    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 155        self.inner.borrow_mut().dirty_views = views;
 156    }
 157
 158    pub fn not_drawing(&self) -> bool {
 159        self.inner.borrow().draw_phase == DrawPhase::None
 160    }
 161
 162    #[track_caller]
 163    pub fn debug_assert_paint(&self) {
 164        debug_assert!(
 165            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 166            "this method can only be called during paint"
 167        );
 168    }
 169
 170    #[track_caller]
 171    pub fn debug_assert_prepaint(&self) {
 172        debug_assert!(
 173            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 174            "this method can only be called during request_layout, or prepaint"
 175        );
 176    }
 177
 178    #[track_caller]
 179    pub fn debug_assert_paint_or_prepaint(&self) {
 180        debug_assert!(
 181            matches!(
 182                self.inner.borrow().draw_phase,
 183                DrawPhase::Paint | DrawPhase::Prepaint
 184            ),
 185            "this method can only be called during request_layout, prepaint, or paint"
 186        );
 187    }
 188}
 189
 190type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 191
 192pub(crate) type AnyWindowFocusListener =
 193    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 194
 195pub(crate) struct WindowFocusEvent {
 196    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 197    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 198}
 199
 200impl WindowFocusEvent {
 201    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 202        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 203    }
 204
 205    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 206        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 207    }
 208}
 209
 210/// This is provided when subscribing for `Context::on_focus_out` events.
 211pub struct FocusOutEvent {
 212    /// A weak focus handle representing what was blurred.
 213    pub blurred: WeakFocusHandle,
 214}
 215
 216slotmap::new_key_type! {
 217    /// A globally unique identifier for a focusable element.
 218    pub struct FocusId;
 219}
 220
 221thread_local! {
 222    /// Fallback arena used when no app-specific arena is active.
 223    /// In production, each window draw sets CURRENT_ELEMENT_ARENA to the app's arena.
 224    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(1024 * 1024));
 225
 226    /// Points to the current App's element arena during draw operations.
 227    /// This allows multiple test Apps to have isolated arenas, preventing
 228    /// cross-session corruption when the scheduler interleaves their tasks.
 229    static CURRENT_ELEMENT_ARENA: Cell<Option<*const RefCell<Arena>>> = const { Cell::new(None) };
 230}
 231
 232/// Allocates an element in the current arena. Uses the app-specific arena if one
 233/// is active (during draw), otherwise falls back to the thread-local ELEMENT_ARENA.
 234pub(crate) fn with_element_arena<R>(f: impl FnOnce(&mut Arena) -> R) -> R {
 235    CURRENT_ELEMENT_ARENA.with(|current| {
 236        if let Some(arena_ptr) = current.get() {
 237            // SAFETY: The pointer is valid for the duration of the draw operation
 238            // that set it, and we're being called during that same draw.
 239            let arena_cell = unsafe { &*arena_ptr };
 240            f(&mut arena_cell.borrow_mut())
 241        } else {
 242            ELEMENT_ARENA.with_borrow_mut(f)
 243        }
 244    })
 245}
 246
 247/// RAII guard that sets CURRENT_ELEMENT_ARENA for the duration of a draw operation.
 248/// When dropped, restores the previous arena (supporting nested draws).
 249pub(crate) struct ElementArenaScope {
 250    previous: Option<*const RefCell<Arena>>,
 251}
 252
 253impl ElementArenaScope {
 254    /// Enter a scope where element allocations use the given arena.
 255    pub(crate) fn enter(arena: &RefCell<Arena>) -> Self {
 256        let previous = CURRENT_ELEMENT_ARENA.with(|current| {
 257            let prev = current.get();
 258            current.set(Some(arena as *const RefCell<Arena>));
 259            prev
 260        });
 261        Self { previous }
 262    }
 263}
 264
 265impl Drop for ElementArenaScope {
 266    fn drop(&mut self) {
 267        CURRENT_ELEMENT_ARENA.with(|current| {
 268            current.set(self.previous);
 269        });
 270    }
 271}
 272
 273/// Returned when the element arena has been used and so must be cleared before the next draw.
 274#[must_use]
 275pub struct ArenaClearNeeded {
 276    arena: *const RefCell<Arena>,
 277}
 278
 279impl ArenaClearNeeded {
 280    /// Create a new ArenaClearNeeded that will clear the given arena.
 281    pub(crate) fn new(arena: &RefCell<Arena>) -> Self {
 282        Self {
 283            arena: arena as *const RefCell<Arena>,
 284        }
 285    }
 286
 287    /// Clear the element arena.
 288    pub fn clear(self) {
 289        // SAFETY: The arena pointer is valid because ArenaClearNeeded is created
 290        // at the end of draw() and must be cleared before the next draw.
 291        let arena_cell = unsafe { &*self.arena };
 292        arena_cell.borrow_mut().clear();
 293    }
 294}
 295
 296pub(crate) type FocusMap = RwLock<SlotMap<FocusId, FocusRef>>;
 297pub(crate) struct FocusRef {
 298    pub(crate) ref_count: AtomicUsize,
 299    pub(crate) tab_index: isize,
 300    pub(crate) tab_stop: bool,
 301}
 302
 303impl FocusId {
 304    /// Obtains whether the element associated with this handle is currently focused.
 305    pub fn is_focused(&self, window: &Window) -> bool {
 306        window.focus == Some(*self)
 307    }
 308
 309    /// Obtains whether the element associated with this handle contains the focused
 310    /// element or is itself focused.
 311    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 312        window
 313            .focused(cx)
 314            .is_some_and(|focused| self.contains(focused.id, window))
 315    }
 316
 317    /// Obtains whether the element associated with this handle is contained within the
 318    /// focused element or is itself focused.
 319    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 320        let focused = window.focused(cx);
 321        focused.is_some_and(|focused| focused.id.contains(*self, window))
 322    }
 323
 324    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 325    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 326        window
 327            .rendered_frame
 328            .dispatch_tree
 329            .focus_contains(*self, other)
 330    }
 331}
 332
 333/// A handle which can be used to track and manipulate the focused element in a window.
 334pub struct FocusHandle {
 335    pub(crate) id: FocusId,
 336    handles: Arc<FocusMap>,
 337    /// The index of this element in the tab order.
 338    pub tab_index: isize,
 339    /// Whether this element can be focused by tab navigation.
 340    pub tab_stop: bool,
 341}
 342
 343impl std::fmt::Debug for FocusHandle {
 344    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 345        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 346    }
 347}
 348
 349impl FocusHandle {
 350    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 351        let id = handles.write().insert(FocusRef {
 352            ref_count: AtomicUsize::new(1),
 353            tab_index: 0,
 354            tab_stop: false,
 355        });
 356
 357        Self {
 358            id,
 359            tab_index: 0,
 360            tab_stop: false,
 361            handles: handles.clone(),
 362        }
 363    }
 364
 365    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 366        let lock = handles.read();
 367        let focus = lock.get(id)?;
 368        if atomic_incr_if_not_zero(&focus.ref_count) == 0 {
 369            return None;
 370        }
 371        Some(Self {
 372            id,
 373            tab_index: focus.tab_index,
 374            tab_stop: focus.tab_stop,
 375            handles: handles.clone(),
 376        })
 377    }
 378
 379    /// Sets the tab index of the element associated with this handle.
 380    pub fn tab_index(mut self, index: isize) -> Self {
 381        self.tab_index = index;
 382        if let Some(focus) = self.handles.write().get_mut(self.id) {
 383            focus.tab_index = index;
 384        }
 385        self
 386    }
 387
 388    /// Sets whether the element associated with this handle is a tab stop.
 389    ///
 390    /// When `false`, the element will not be included in the tab order.
 391    pub fn tab_stop(mut self, tab_stop: bool) -> Self {
 392        self.tab_stop = tab_stop;
 393        if let Some(focus) = self.handles.write().get_mut(self.id) {
 394            focus.tab_stop = tab_stop;
 395        }
 396        self
 397    }
 398
 399    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 400    pub fn downgrade(&self) -> WeakFocusHandle {
 401        WeakFocusHandle {
 402            id: self.id,
 403            handles: Arc::downgrade(&self.handles),
 404        }
 405    }
 406
 407    /// Moves the focus to the element associated with this handle.
 408    pub fn focus(&self, window: &mut Window, cx: &mut App) {
 409        window.focus(self, cx)
 410    }
 411
 412    /// Obtains whether the element associated with this handle is currently focused.
 413    pub fn is_focused(&self, window: &Window) -> bool {
 414        self.id.is_focused(window)
 415    }
 416
 417    /// Obtains whether the element associated with this handle contains the focused
 418    /// element or is itself focused.
 419    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 420        self.id.contains_focused(window, cx)
 421    }
 422
 423    /// Obtains whether the element associated with this handle is contained within the
 424    /// focused element or is itself focused.
 425    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 426        self.id.within_focused(window, cx)
 427    }
 428
 429    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 430    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 431        self.id.contains(other.id, window)
 432    }
 433
 434    /// Dispatch an action on the element that rendered this focus handle
 435    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 436        if let Some(node_id) = window
 437            .rendered_frame
 438            .dispatch_tree
 439            .focusable_node_id(self.id)
 440        {
 441            window.dispatch_action_on_node(node_id, action, cx)
 442        }
 443    }
 444}
 445
 446impl Clone for FocusHandle {
 447    fn clone(&self) -> Self {
 448        Self::for_id(self.id, &self.handles).unwrap()
 449    }
 450}
 451
 452impl PartialEq for FocusHandle {
 453    fn eq(&self, other: &Self) -> bool {
 454        self.id == other.id
 455    }
 456}
 457
 458impl Eq for FocusHandle {}
 459
 460impl Drop for FocusHandle {
 461    fn drop(&mut self) {
 462        self.handles
 463            .read()
 464            .get(self.id)
 465            .unwrap()
 466            .ref_count
 467            .fetch_sub(1, SeqCst);
 468    }
 469}
 470
 471/// A weak reference to a focus handle.
 472#[derive(Clone, Debug)]
 473pub struct WeakFocusHandle {
 474    pub(crate) id: FocusId,
 475    pub(crate) handles: Weak<FocusMap>,
 476}
 477
 478impl WeakFocusHandle {
 479    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 480    pub fn upgrade(&self) -> Option<FocusHandle> {
 481        let handles = self.handles.upgrade()?;
 482        FocusHandle::for_id(self.id, &handles)
 483    }
 484}
 485
 486impl PartialEq for WeakFocusHandle {
 487    fn eq(&self, other: &WeakFocusHandle) -> bool {
 488        self.id == other.id
 489    }
 490}
 491
 492impl Eq for WeakFocusHandle {}
 493
 494impl PartialEq<FocusHandle> for WeakFocusHandle {
 495    fn eq(&self, other: &FocusHandle) -> bool {
 496        self.id == other.id
 497    }
 498}
 499
 500impl PartialEq<WeakFocusHandle> for FocusHandle {
 501    fn eq(&self, other: &WeakFocusHandle) -> bool {
 502        self.id == other.id
 503    }
 504}
 505
 506/// Focusable allows users of your view to easily
 507/// focus it (using window.focus_view(cx, view))
 508pub trait Focusable: 'static {
 509    /// Returns the focus handle associated with this view.
 510    fn focus_handle(&self, cx: &App) -> FocusHandle;
 511}
 512
 513impl<V: Focusable> Focusable for Entity<V> {
 514    fn focus_handle(&self, cx: &App) -> FocusHandle {
 515        self.read(cx).focus_handle(cx)
 516    }
 517}
 518
 519/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 520/// where the lifecycle of the view is handled by another view.
 521pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 522
 523impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 524
 525/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 526pub struct DismissEvent;
 527
 528type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 529
 530pub(crate) type AnyMouseListener =
 531    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 532
 533#[derive(Clone)]
 534pub(crate) struct CursorStyleRequest {
 535    pub(crate) hitbox_id: Option<HitboxId>,
 536    pub(crate) style: CursorStyle,
 537}
 538
 539#[derive(Default, Eq, PartialEq)]
 540pub(crate) struct HitTest {
 541    pub(crate) ids: SmallVec<[HitboxId; 8]>,
 542    pub(crate) hover_hitbox_count: usize,
 543}
 544
 545/// A type of window control area that corresponds to the platform window.
 546#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 547pub enum WindowControlArea {
 548    /// An area that allows dragging of the platform window.
 549    Drag,
 550    /// An area that allows closing of the platform window.
 551    Close,
 552    /// An area that allows maximizing of the platform window.
 553    Max,
 554    /// An area that allows minimizing of the platform window.
 555    Min,
 556}
 557
 558/// An identifier for a [Hitbox] which also includes [HitboxBehavior].
 559#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 560pub struct HitboxId(u64);
 561
 562impl HitboxId {
 563    /// Checks if the hitbox with this ID is currently hovered. Returns `false` during keyboard
 564    /// input modality so that keyboard navigation suppresses hover highlights. Except when handling
 565    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 566    /// events or paint hover styles.
 567    ///
 568    /// See [`Hitbox::is_hovered`] for details.
 569    pub fn is_hovered(self, window: &Window) -> bool {
 570        // If this hitbox has captured the pointer, it's always considered hovered
 571        if window.captured_hitbox == Some(self) {
 572            return true;
 573        }
 574        if window.last_input_was_keyboard() {
 575            return false;
 576        }
 577        let hit_test = &window.mouse_hit_test;
 578        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 579            if self == *id {
 580                return true;
 581            }
 582        }
 583        false
 584    }
 585
 586    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 587    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 588    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 589    /// this distinction.
 590    pub fn should_handle_scroll(self, window: &Window) -> bool {
 591        window.mouse_hit_test.ids.contains(&self)
 592    }
 593
 594    fn next(mut self) -> HitboxId {
 595        HitboxId(self.0.wrapping_add(1))
 596    }
 597}
 598
 599/// A rectangular region that potentially blocks hitboxes inserted prior.
 600/// See [Window::insert_hitbox] for more details.
 601#[derive(Clone, Debug, Deref)]
 602pub struct Hitbox {
 603    /// A unique identifier for the hitbox.
 604    pub id: HitboxId,
 605    /// The bounds of the hitbox.
 606    #[deref]
 607    pub bounds: Bounds<Pixels>,
 608    /// The content mask when the hitbox was inserted.
 609    pub content_mask: ContentMask<Pixels>,
 610    /// Flags that specify hitbox behavior.
 611    pub behavior: HitboxBehavior,
 612}
 613
 614impl Hitbox {
 615    /// Checks if the hitbox is currently hovered. Returns `false` during keyboard input modality
 616    /// so that keyboard navigation suppresses hover highlights. Except when handling
 617    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 618    /// events or paint hover styles.
 619    ///
 620    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 621    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 622    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`),
 623    /// or if the current input modality is keyboard (see [`Window::last_input_was_keyboard`]).
 624    ///
 625    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 626    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 627    /// non-interactive while still allowing scrolling. More abstractly, this is because
 628    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 629    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 630    /// container.
 631    pub fn is_hovered(&self, window: &Window) -> bool {
 632        self.id.is_hovered(window)
 633    }
 634
 635    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 636    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 637    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 638    ///
 639    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 640    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 641    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 642        self.id.should_handle_scroll(window)
 643    }
 644}
 645
 646/// How the hitbox affects mouse behavior.
 647#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 648pub enum HitboxBehavior {
 649    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 650    #[default]
 651    Normal,
 652
 653    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 654    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 655    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 656    /// [`InteractiveElement::occlude`].
 657    ///
 658    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 659    /// bubble-phase handler for every mouse event type:
 660    ///
 661    /// ```ignore
 662    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 663    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 664    ///         cx.stop_propagation();
 665    ///     }
 666    /// })
 667    /// ```
 668    ///
 669    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 670    /// styles and tooltips. These other behaviors are the main point of this mechanism. An
 671    /// alternative might be to not affect mouse event handling - but this would allow
 672    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 673    /// be hovered.
 674    BlockMouse,
 675
 676    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 677    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 678    /// interaction except scroll events to be ignored - see the documentation of
 679    /// [`Hitbox::is_hovered`] for details. This flag is set by
 680    /// [`InteractiveElement::block_mouse_except_scroll`].
 681    ///
 682    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 683    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 684    ///
 685    /// ```ignore
 686    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, cx| {
 687    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 688    ///         cx.stop_propagation();
 689    ///     }
 690    /// })
 691    /// ```
 692    ///
 693    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 694    /// handled differently than other mouse events. If also blocking these scroll events is
 695    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 696    ///
 697    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 698    /// hover styles and tooltips. These other behaviors are the main point of this mechanism.
 699    /// An alternative might be to not affect mouse event handling - but this would allow
 700    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 701    /// be hovered.
 702    BlockMouseExceptScroll,
 703}
 704
 705/// An identifier for a tooltip.
 706#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 707pub struct TooltipId(usize);
 708
 709impl TooltipId {
 710    /// Checks if the tooltip is currently hovered.
 711    pub fn is_hovered(&self, window: &Window) -> bool {
 712        window
 713            .tooltip_bounds
 714            .as_ref()
 715            .is_some_and(|tooltip_bounds| {
 716                tooltip_bounds.id == *self
 717                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 718            })
 719    }
 720}
 721
 722pub(crate) struct TooltipBounds {
 723    id: TooltipId,
 724    bounds: Bounds<Pixels>,
 725}
 726
 727#[derive(Clone)]
 728pub(crate) struct TooltipRequest {
 729    id: TooltipId,
 730    tooltip: AnyTooltip,
 731}
 732
 733pub(crate) struct DeferredDraw {
 734    current_view: EntityId,
 735    priority: usize,
 736    parent_node: DispatchNodeId,
 737    element_id_stack: SmallVec<[ElementId; 32]>,
 738    text_style_stack: Vec<TextStyleRefinement>,
 739    content_mask: Option<ContentMask<Pixels>>,
 740    rem_size: Pixels,
 741    element: Option<AnyElement>,
 742    absolute_offset: Point<Pixels>,
 743    prepaint_range: Range<PrepaintStateIndex>,
 744    paint_range: Range<PaintIndex>,
 745}
 746
 747pub(crate) struct Frame {
 748    pub(crate) focus: Option<FocusId>,
 749    pub(crate) window_active: bool,
 750    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 751    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 752    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 753    pub(crate) dispatch_tree: DispatchTree,
 754    pub(crate) scene: Scene,
 755    pub(crate) hitboxes: Vec<Hitbox>,
 756    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 757    pub(crate) deferred_draws: Vec<DeferredDraw>,
 758    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 759    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 760    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 761    #[cfg(any(test, feature = "test-support"))]
 762    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 763    #[cfg(any(feature = "inspector", debug_assertions))]
 764    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 765    #[cfg(any(feature = "inspector", debug_assertions))]
 766    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 767    pub(crate) tab_stops: TabStopMap,
 768}
 769
 770#[derive(Clone, Default)]
 771pub(crate) struct PrepaintStateIndex {
 772    hitboxes_index: usize,
 773    tooltips_index: usize,
 774    deferred_draws_index: usize,
 775    dispatch_tree_index: usize,
 776    accessed_element_states_index: usize,
 777    line_layout_index: LineLayoutIndex,
 778}
 779
 780#[derive(Clone, Default)]
 781pub(crate) struct PaintIndex {
 782    scene_index: usize,
 783    mouse_listeners_index: usize,
 784    input_handlers_index: usize,
 785    cursor_styles_index: usize,
 786    accessed_element_states_index: usize,
 787    tab_handle_index: usize,
 788    line_layout_index: LineLayoutIndex,
 789}
 790
 791impl Frame {
 792    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 793        Frame {
 794            focus: None,
 795            window_active: false,
 796            element_states: FxHashMap::default(),
 797            accessed_element_states: Vec::new(),
 798            mouse_listeners: Vec::new(),
 799            dispatch_tree,
 800            scene: Scene::default(),
 801            hitboxes: Vec::new(),
 802            window_control_hitboxes: Vec::new(),
 803            deferred_draws: Vec::new(),
 804            input_handlers: Vec::new(),
 805            tooltip_requests: Vec::new(),
 806            cursor_styles: Vec::new(),
 807
 808            #[cfg(any(test, feature = "test-support"))]
 809            debug_bounds: FxHashMap::default(),
 810
 811            #[cfg(any(feature = "inspector", debug_assertions))]
 812            next_inspector_instance_ids: FxHashMap::default(),
 813
 814            #[cfg(any(feature = "inspector", debug_assertions))]
 815            inspector_hitboxes: FxHashMap::default(),
 816            tab_stops: TabStopMap::default(),
 817        }
 818    }
 819
 820    pub(crate) fn clear(&mut self) {
 821        self.element_states.clear();
 822        self.accessed_element_states.clear();
 823        self.mouse_listeners.clear();
 824        self.dispatch_tree.clear();
 825        self.scene.clear();
 826        self.input_handlers.clear();
 827        self.tooltip_requests.clear();
 828        self.cursor_styles.clear();
 829        self.hitboxes.clear();
 830        self.window_control_hitboxes.clear();
 831        self.deferred_draws.clear();
 832        self.tab_stops.clear();
 833        self.focus = None;
 834
 835        #[cfg(any(test, feature = "test-support"))]
 836        {
 837            self.debug_bounds.clear();
 838        }
 839
 840        #[cfg(any(feature = "inspector", debug_assertions))]
 841        {
 842            self.next_inspector_instance_ids.clear();
 843            self.inspector_hitboxes.clear();
 844        }
 845    }
 846
 847    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 848        self.cursor_styles
 849            .iter()
 850            .rev()
 851            .fold_while(None, |style, request| match request.hitbox_id {
 852                None => Done(Some(request.style)),
 853                Some(hitbox_id) => Continue(
 854                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 855                ),
 856            })
 857            .into_inner()
 858    }
 859
 860    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 861        let mut set_hover_hitbox_count = false;
 862        let mut hit_test = HitTest::default();
 863        for hitbox in self.hitboxes.iter().rev() {
 864            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 865            if bounds.contains(&position) {
 866                hit_test.ids.push(hitbox.id);
 867                if !set_hover_hitbox_count
 868                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 869                {
 870                    hit_test.hover_hitbox_count = hit_test.ids.len();
 871                    set_hover_hitbox_count = true;
 872                }
 873                if hitbox.behavior == HitboxBehavior::BlockMouse {
 874                    break;
 875                }
 876            }
 877        }
 878        if !set_hover_hitbox_count {
 879            hit_test.hover_hitbox_count = hit_test.ids.len();
 880        }
 881        hit_test
 882    }
 883
 884    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 885        self.focus
 886            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 887            .unwrap_or_default()
 888    }
 889
 890    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 891        for element_state_key in &self.accessed_element_states {
 892            if let Some((element_state_key, element_state)) =
 893                prev_frame.element_states.remove_entry(element_state_key)
 894            {
 895                self.element_states.insert(element_state_key, element_state);
 896            }
 897        }
 898
 899        self.scene.finish();
 900    }
 901}
 902
 903#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 904enum InputModality {
 905    Mouse,
 906    Keyboard,
 907}
 908
 909/// Holds the state for a specific window.
 910pub struct Window {
 911    pub(crate) handle: AnyWindowHandle,
 912    pub(crate) invalidator: WindowInvalidator,
 913    pub(crate) removed: bool,
 914    pub(crate) platform_window: Box<dyn PlatformWindow>,
 915    display_id: Option<DisplayId>,
 916    sprite_atlas: Arc<dyn PlatformAtlas>,
 917    text_system: Arc<WindowTextSystem>,
 918    text_rendering_mode: Rc<Cell<TextRenderingMode>>,
 919    rem_size: Pixels,
 920    /// The stack of override values for the window's rem size.
 921    ///
 922    /// This is used by `with_rem_size` to allow rendering an element tree with
 923    /// a given rem size.
 924    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 925    pub(crate) viewport_size: Size<Pixels>,
 926    layout_engine: Option<TaffyLayoutEngine>,
 927    pub(crate) root: Option<AnyView>,
 928    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 929    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 930    pub(crate) rendered_entity_stack: Vec<EntityId>,
 931    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 932    pub(crate) element_opacity: f32,
 933    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 934    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 935    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 936    pub(crate) rendered_frame: Frame,
 937    pub(crate) next_frame: Frame,
 938    next_hitbox_id: HitboxId,
 939    pub(crate) next_tooltip_id: TooltipId,
 940    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 941    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 942    pub(crate) dirty_views: FxHashSet<EntityId>,
 943    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 944    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 945    default_prevented: bool,
 946    mouse_position: Point<Pixels>,
 947    mouse_hit_test: HitTest,
 948    modifiers: Modifiers,
 949    capslock: Capslock,
 950    scale_factor: f32,
 951    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 952    appearance: WindowAppearance,
 953    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 954    pub(crate) button_layout_observers: SubscriberSet<(), AnyObserver>,
 955    active: Rc<Cell<bool>>,
 956    hovered: Rc<Cell<bool>>,
 957    pub(crate) needs_present: Rc<Cell<bool>>,
 958    /// Tracks recent input event timestamps to determine if input is arriving at a high rate.
 959    /// Used to selectively enable VRR optimization only when input rate exceeds 60fps.
 960    pub(crate) input_rate_tracker: Rc<RefCell<InputRateTracker>>,
 961    last_input_modality: InputModality,
 962    pub(crate) refreshing: bool,
 963    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 964    pub(crate) focus: Option<FocusId>,
 965    focus_enabled: bool,
 966    pending_input: Option<PendingInput>,
 967    pending_modifier: ModifierState,
 968    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 969    prompt: Option<RenderablePromptHandle>,
 970    pub(crate) client_inset: Option<Pixels>,
 971    /// The hitbox that has captured the pointer, if any.
 972    /// While captured, mouse events route to this hitbox regardless of hit testing.
 973    captured_hitbox: Option<HitboxId>,
 974    #[cfg(any(feature = "inspector", debug_assertions))]
 975    inspector: Option<Entity<Inspector>>,
 976}
 977
 978#[derive(Clone, Debug, Default)]
 979struct ModifierState {
 980    modifiers: Modifiers,
 981    saw_keystroke: bool,
 982}
 983
 984/// Tracks input event timestamps to determine if input is arriving at a high rate.
 985/// Used for selective VRR (Variable Refresh Rate) optimization.
 986#[derive(Clone, Debug)]
 987pub(crate) struct InputRateTracker {
 988    timestamps: Vec<Instant>,
 989    window: Duration,
 990    inputs_per_second: u32,
 991    sustain_until: Instant,
 992    sustain_duration: Duration,
 993}
 994
 995impl Default for InputRateTracker {
 996    fn default() -> Self {
 997        Self {
 998            timestamps: Vec::new(),
 999            window: Duration::from_millis(100),
1000            inputs_per_second: 60,
1001            sustain_until: Instant::now(),
1002            sustain_duration: Duration::from_secs(1),
1003        }
1004    }
1005}
1006
1007impl InputRateTracker {
1008    pub fn record_input(&mut self) {
1009        let now = Instant::now();
1010        self.timestamps.push(now);
1011        self.prune_old_timestamps(now);
1012
1013        let min_events = self.inputs_per_second as u128 * self.window.as_millis() / 1000;
1014        if self.timestamps.len() as u128 >= min_events {
1015            self.sustain_until = now + self.sustain_duration;
1016        }
1017    }
1018
1019    pub fn is_high_rate(&self) -> bool {
1020        Instant::now() < self.sustain_until
1021    }
1022
1023    fn prune_old_timestamps(&mut self, now: Instant) {
1024        self.timestamps
1025            .retain(|&t| now.duration_since(t) <= self.window);
1026    }
1027}
1028
1029#[derive(Clone, Copy, Debug, Eq, PartialEq)]
1030pub(crate) enum DrawPhase {
1031    None,
1032    Prepaint,
1033    Paint,
1034    Focus,
1035}
1036
1037#[derive(Default, Debug)]
1038struct PendingInput {
1039    keystrokes: SmallVec<[Keystroke; 1]>,
1040    focus: Option<FocusId>,
1041    timer: Option<Task<()>>,
1042    needs_timeout: bool,
1043}
1044
1045pub(crate) struct ElementStateBox {
1046    pub(crate) inner: Box<dyn Any>,
1047    #[cfg(debug_assertions)]
1048    pub(crate) type_name: &'static str,
1049}
1050
1051fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> WindowBounds {
1052    // TODO, BUG: if you open a window with the currently active window
1053    // on the stack, this will erroneously fallback to `None`
1054    //
1055    // TODO these should be the initial window bounds not considering maximized/fullscreen
1056    let active_window_bounds = cx
1057        .active_window()
1058        .and_then(|w| w.update(cx, |_, window, _| window.window_bounds()).ok());
1059
1060    const CASCADE_OFFSET: f32 = 25.0;
1061
1062    let display = display_id
1063        .map(|id| cx.find_display(id))
1064        .unwrap_or_else(|| cx.primary_display());
1065
1066    let default_placement = || Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE);
1067
1068    // Use visible_bounds to exclude taskbar/dock areas
1069    let display_bounds = display
1070        .as_ref()
1071        .map(|d| d.visible_bounds())
1072        .unwrap_or_else(default_placement);
1073
1074    let (
1075        Bounds {
1076            origin: base_origin,
1077            size: base_size,
1078        },
1079        window_bounds_ctor,
1080    ): (_, fn(Bounds<Pixels>) -> WindowBounds) = match active_window_bounds {
1081        Some(bounds) => match bounds {
1082            WindowBounds::Windowed(bounds) => (bounds, WindowBounds::Windowed),
1083            WindowBounds::Maximized(bounds) => (bounds, WindowBounds::Maximized),
1084            WindowBounds::Fullscreen(bounds) => (bounds, WindowBounds::Fullscreen),
1085        },
1086        None => (
1087            display
1088                .as_ref()
1089                .map(|d| d.default_bounds())
1090                .unwrap_or_else(default_placement),
1091            WindowBounds::Windowed,
1092        ),
1093    };
1094
1095    let cascade_offset = point(px(CASCADE_OFFSET), px(CASCADE_OFFSET));
1096    let proposed_origin = base_origin + cascade_offset;
1097    let proposed_bounds = Bounds::new(proposed_origin, base_size);
1098
1099    let display_right = display_bounds.origin.x + display_bounds.size.width;
1100    let display_bottom = display_bounds.origin.y + display_bounds.size.height;
1101    let window_right = proposed_bounds.origin.x + proposed_bounds.size.width;
1102    let window_bottom = proposed_bounds.origin.y + proposed_bounds.size.height;
1103
1104    let fits_horizontally = window_right <= display_right;
1105    let fits_vertically = window_bottom <= display_bottom;
1106
1107    let final_origin = match (fits_horizontally, fits_vertically) {
1108        (true, true) => proposed_origin,
1109        (false, true) => point(display_bounds.origin.x, base_origin.y),
1110        (true, false) => point(base_origin.x, display_bounds.origin.y),
1111        (false, false) => display_bounds.origin,
1112    };
1113    window_bounds_ctor(Bounds::new(final_origin, base_size))
1114}
1115
1116impl Window {
1117    pub(crate) fn new(
1118        handle: AnyWindowHandle,
1119        options: WindowOptions,
1120        cx: &mut App,
1121    ) -> Result<Self> {
1122        let WindowOptions {
1123            window_bounds,
1124            titlebar,
1125            focus,
1126            show,
1127            kind,
1128            is_movable,
1129            is_resizable,
1130            is_minimizable,
1131            display_id,
1132            window_background,
1133            app_id,
1134            window_min_size,
1135            window_decorations,
1136            #[cfg_attr(
1137                not(any(target_os = "linux", target_os = "freebsd")),
1138                allow(unused_variables)
1139            )]
1140            icon,
1141            #[cfg_attr(not(target_os = "macos"), allow(unused_variables))]
1142            tabbing_identifier,
1143        } = options;
1144
1145        let window_bounds = window_bounds.unwrap_or_else(|| default_bounds(display_id, cx));
1146        let mut platform_window = cx.platform.open_window(
1147            handle,
1148            WindowParams {
1149                bounds: window_bounds.get_bounds(),
1150                titlebar,
1151                kind,
1152                is_movable,
1153                is_resizable,
1154                is_minimizable,
1155                focus,
1156                show,
1157                display_id,
1158                window_min_size,
1159                icon,
1160                #[cfg(target_os = "macos")]
1161                tabbing_identifier,
1162            },
1163        )?;
1164
1165        let tab_bar_visible = platform_window.tab_bar_visible();
1166        SystemWindowTabController::init_visible(cx, tab_bar_visible);
1167        if let Some(tabs) = platform_window.tabbed_windows() {
1168            SystemWindowTabController::add_tab(cx, handle.window_id(), tabs);
1169        }
1170
1171        let display_id = platform_window.display().map(|display| display.id());
1172        let sprite_atlas = platform_window.sprite_atlas();
1173        let mouse_position = platform_window.mouse_position();
1174        let modifiers = platform_window.modifiers();
1175        let capslock = platform_window.capslock();
1176        let content_size = platform_window.content_size();
1177        let scale_factor = platform_window.scale_factor();
1178        let appearance = platform_window.appearance();
1179        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
1180        let invalidator = WindowInvalidator::new();
1181        let active = Rc::new(Cell::new(platform_window.is_active()));
1182        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
1183        let needs_present = Rc::new(Cell::new(false));
1184        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
1185        let input_rate_tracker = Rc::new(RefCell::new(InputRateTracker::default()));
1186        let last_frame_time = Rc::new(Cell::new(None));
1187
1188        platform_window
1189            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
1190        platform_window.set_background_appearance(window_background);
1191
1192        match window_bounds {
1193            WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
1194            WindowBounds::Maximized(_) => platform_window.zoom(),
1195            WindowBounds::Windowed(_) => {}
1196        }
1197
1198        platform_window.on_close(Box::new({
1199            let window_id = handle.window_id();
1200            let mut cx = cx.to_async();
1201            move || {
1202                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
1203                let _ = cx.update(|cx| {
1204                    SystemWindowTabController::remove_tab(cx, window_id);
1205                });
1206            }
1207        }));
1208        platform_window.on_request_frame(Box::new({
1209            let mut cx = cx.to_async();
1210            let invalidator = invalidator.clone();
1211            let active = active.clone();
1212            let needs_present = needs_present.clone();
1213            let next_frame_callbacks = next_frame_callbacks.clone();
1214            let input_rate_tracker = input_rate_tracker.clone();
1215            move |request_frame_options| {
1216                let thermal_state = handle
1217                    .update(&mut cx, |_, _, cx| cx.thermal_state())
1218                    .log_err();
1219
1220                // Throttle frame rate based on conditions:
1221                // - Thermal pressure (Serious/Critical): cap to ~60fps
1222                // - Inactive window (not focused): cap to ~30fps to save energy
1223                let min_frame_interval = if !request_frame_options.force_render
1224                    && !request_frame_options.require_presentation
1225                    && next_frame_callbacks.borrow().is_empty()
1226                {
1227                    None
1228                } else if !active.get() {
1229                    Some(Duration::from_micros(33333))
1230                } else if let Some(ThermalState::Critical | ThermalState::Serious) = thermal_state {
1231                    Some(Duration::from_micros(16667))
1232                } else {
1233                    None
1234                };
1235
1236                let now = Instant::now();
1237                if let Some(min_interval) = min_frame_interval {
1238                    if let Some(last_frame) = last_frame_time.get()
1239                        && now.duration_since(last_frame) < min_interval
1240                    {
1241                        return;
1242                    }
1243                }
1244                last_frame_time.set(Some(now));
1245
1246                let next_frame_callbacks = next_frame_callbacks.take();
1247                if !next_frame_callbacks.is_empty() {
1248                    handle
1249                        .update(&mut cx, |_, window, cx| {
1250                            for callback in next_frame_callbacks {
1251                                callback(window, cx);
1252                            }
1253                        })
1254                        .log_err();
1255                }
1256
1257                // Keep presenting if input was recently arriving at a high rate (>= 60fps).
1258                // Once high-rate input is detected, we sustain presentation for 1 second
1259                // to prevent display underclocking during active input.
1260                let needs_present = request_frame_options.require_presentation
1261                    || needs_present.get()
1262                    || (active.get() && input_rate_tracker.borrow_mut().is_high_rate());
1263
1264                if invalidator.is_dirty() || request_frame_options.force_render {
1265                    measure("frame duration", || {
1266                        handle
1267                            .update(&mut cx, |_, window, cx| {
1268                                let arena_clear_needed = window.draw(cx);
1269                                window.present();
1270                                arena_clear_needed.clear();
1271                            })
1272                            .log_err();
1273                    })
1274                } else if needs_present {
1275                    handle
1276                        .update(&mut cx, |_, window, _| window.present())
1277                        .log_err();
1278                }
1279
1280                handle
1281                    .update(&mut cx, |_, window, _| {
1282                        window.complete_frame();
1283                    })
1284                    .log_err();
1285            }
1286        }));
1287        platform_window.on_resize(Box::new({
1288            let mut cx = cx.to_async();
1289            move |_, _| {
1290                handle
1291                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1292                    .log_err();
1293            }
1294        }));
1295        platform_window.on_moved(Box::new({
1296            let mut cx = cx.to_async();
1297            move || {
1298                handle
1299                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1300                    .log_err();
1301            }
1302        }));
1303        platform_window.on_appearance_changed(Box::new({
1304            let mut cx = cx.to_async();
1305            move || {
1306                handle
1307                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1308                    .log_err();
1309            }
1310        }));
1311        platform_window.on_button_layout_changed(Box::new({
1312            let mut cx = cx.to_async();
1313            move || {
1314                handle
1315                    .update(&mut cx, |_, window, cx| window.button_layout_changed(cx))
1316                    .log_err();
1317            }
1318        }));
1319        platform_window.on_active_status_change(Box::new({
1320            let mut cx = cx.to_async();
1321            move |active| {
1322                handle
1323                    .update(&mut cx, |_, window, cx| {
1324                        window.active.set(active);
1325                        window.modifiers = window.platform_window.modifiers();
1326                        window.capslock = window.platform_window.capslock();
1327                        window
1328                            .activation_observers
1329                            .clone()
1330                            .retain(&(), |callback| callback(window, cx));
1331
1332                        window.bounds_changed(cx);
1333                        window.refresh();
1334
1335                        SystemWindowTabController::update_last_active(cx, window.handle.id);
1336                    })
1337                    .log_err();
1338            }
1339        }));
1340        platform_window.on_hover_status_change(Box::new({
1341            let mut cx = cx.to_async();
1342            move |active| {
1343                handle
1344                    .update(&mut cx, |_, window, _| {
1345                        window.hovered.set(active);
1346                        window.refresh();
1347                    })
1348                    .log_err();
1349            }
1350        }));
1351        platform_window.on_input({
1352            let mut cx = cx.to_async();
1353            Box::new(move |event| {
1354                handle
1355                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1356                    .log_err()
1357                    .unwrap_or(DispatchEventResult::default())
1358            })
1359        });
1360        platform_window.on_hit_test_window_control({
1361            let mut cx = cx.to_async();
1362            Box::new(move || {
1363                handle
1364                    .update(&mut cx, |_, window, _cx| {
1365                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1366                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1367                                return Some(*area);
1368                            }
1369                        }
1370                        None
1371                    })
1372                    .log_err()
1373                    .unwrap_or(None)
1374            })
1375        });
1376        platform_window.on_move_tab_to_new_window({
1377            let mut cx = cx.to_async();
1378            Box::new(move || {
1379                handle
1380                    .update(&mut cx, |_, _window, cx| {
1381                        SystemWindowTabController::move_tab_to_new_window(cx, handle.window_id());
1382                    })
1383                    .log_err();
1384            })
1385        });
1386        platform_window.on_merge_all_windows({
1387            let mut cx = cx.to_async();
1388            Box::new(move || {
1389                handle
1390                    .update(&mut cx, |_, _window, cx| {
1391                        SystemWindowTabController::merge_all_windows(cx, handle.window_id());
1392                    })
1393                    .log_err();
1394            })
1395        });
1396        platform_window.on_select_next_tab({
1397            let mut cx = cx.to_async();
1398            Box::new(move || {
1399                handle
1400                    .update(&mut cx, |_, _window, cx| {
1401                        SystemWindowTabController::select_next_tab(cx, handle.window_id());
1402                    })
1403                    .log_err();
1404            })
1405        });
1406        platform_window.on_select_previous_tab({
1407            let mut cx = cx.to_async();
1408            Box::new(move || {
1409                handle
1410                    .update(&mut cx, |_, _window, cx| {
1411                        SystemWindowTabController::select_previous_tab(cx, handle.window_id())
1412                    })
1413                    .log_err();
1414            })
1415        });
1416        platform_window.on_toggle_tab_bar({
1417            let mut cx = cx.to_async();
1418            Box::new(move || {
1419                handle
1420                    .update(&mut cx, |_, window, cx| {
1421                        let tab_bar_visible = window.platform_window.tab_bar_visible();
1422                        SystemWindowTabController::set_visible(cx, tab_bar_visible);
1423                    })
1424                    .log_err();
1425            })
1426        });
1427
1428        if let Some(app_id) = app_id {
1429            platform_window.set_app_id(&app_id);
1430        }
1431
1432        platform_window.map_window().unwrap();
1433
1434        Ok(Window {
1435            handle,
1436            invalidator,
1437            removed: false,
1438            platform_window,
1439            display_id,
1440            sprite_atlas,
1441            text_system,
1442            text_rendering_mode: cx.text_rendering_mode.clone(),
1443            rem_size: px(16.),
1444            rem_size_override_stack: SmallVec::new(),
1445            viewport_size: content_size,
1446            layout_engine: Some(TaffyLayoutEngine::new()),
1447            root: None,
1448            element_id_stack: SmallVec::default(),
1449            text_style_stack: Vec::new(),
1450            rendered_entity_stack: Vec::new(),
1451            element_offset_stack: Vec::new(),
1452            content_mask_stack: Vec::new(),
1453            element_opacity: 1.0,
1454            requested_autoscroll: None,
1455            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1456            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1457            next_frame_callbacks,
1458            next_hitbox_id: HitboxId(0),
1459            next_tooltip_id: TooltipId::default(),
1460            tooltip_bounds: None,
1461            dirty_views: FxHashSet::default(),
1462            focus_listeners: SubscriberSet::new(),
1463            focus_lost_listeners: SubscriberSet::new(),
1464            default_prevented: true,
1465            mouse_position,
1466            mouse_hit_test: HitTest::default(),
1467            modifiers,
1468            capslock,
1469            scale_factor,
1470            bounds_observers: SubscriberSet::new(),
1471            appearance,
1472            appearance_observers: SubscriberSet::new(),
1473            button_layout_observers: SubscriberSet::new(),
1474            active,
1475            hovered,
1476            needs_present,
1477            input_rate_tracker,
1478            last_input_modality: InputModality::Mouse,
1479            refreshing: false,
1480            activation_observers: SubscriberSet::new(),
1481            focus: None,
1482            focus_enabled: true,
1483            pending_input: None,
1484            pending_modifier: ModifierState::default(),
1485            pending_input_observers: SubscriberSet::new(),
1486            prompt: None,
1487            client_inset: None,
1488            image_cache_stack: Vec::new(),
1489            captured_hitbox: None,
1490            #[cfg(any(feature = "inspector", debug_assertions))]
1491            inspector: None,
1492        })
1493    }
1494
1495    pub(crate) fn new_focus_listener(
1496        &self,
1497        value: AnyWindowFocusListener,
1498    ) -> (Subscription, impl FnOnce() + use<>) {
1499        self.focus_listeners.insert((), value)
1500    }
1501}
1502
1503#[derive(Clone, Debug, Default, PartialEq, Eq)]
1504#[expect(missing_docs)]
1505pub struct DispatchEventResult {
1506    pub propagate: bool,
1507    pub default_prevented: bool,
1508}
1509
1510/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1511/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1512/// to leave room to support more complex shapes in the future.
1513#[derive(Clone, Debug, Default, PartialEq, Eq)]
1514#[repr(C)]
1515pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1516    /// The bounds
1517    pub bounds: Bounds<P>,
1518}
1519
1520impl ContentMask<Pixels> {
1521    /// Scale the content mask's pixel units by the given scaling factor.
1522    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1523        ContentMask {
1524            bounds: self.bounds.scale(factor),
1525        }
1526    }
1527
1528    /// Intersect the content mask with the given content mask.
1529    pub fn intersect(&self, other: &Self) -> Self {
1530        let bounds = self.bounds.intersect(&other.bounds);
1531        ContentMask { bounds }
1532    }
1533}
1534
1535impl Window {
1536    fn mark_view_dirty(&mut self, view_id: EntityId) {
1537        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1538        // should already be dirty.
1539        for view_id in self
1540            .rendered_frame
1541            .dispatch_tree
1542            .view_path_reversed(view_id)
1543        {
1544            if !self.dirty_views.insert(view_id) {
1545                break;
1546            }
1547        }
1548    }
1549
1550    /// Registers a callback to be invoked when the window appearance changes.
1551    pub fn observe_window_appearance(
1552        &self,
1553        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1554    ) -> Subscription {
1555        let (subscription, activate) = self.appearance_observers.insert(
1556            (),
1557            Box::new(move |window, cx| {
1558                callback(window, cx);
1559                true
1560            }),
1561        );
1562        activate();
1563        subscription
1564    }
1565
1566    /// Registers a callback to be invoked when the window button layout changes.
1567    pub fn observe_button_layout_changed(
1568        &self,
1569        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1570    ) -> Subscription {
1571        let (subscription, activate) = self.button_layout_observers.insert(
1572            (),
1573            Box::new(move |window, cx| {
1574                callback(window, cx);
1575                true
1576            }),
1577        );
1578        activate();
1579        subscription
1580    }
1581
1582    /// Replaces the root entity of the window with a new one.
1583    pub fn replace_root<E>(
1584        &mut self,
1585        cx: &mut App,
1586        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1587    ) -> Entity<E>
1588    where
1589        E: 'static + Render,
1590    {
1591        let view = cx.new(|cx| build_view(self, cx));
1592        self.root = Some(view.clone().into());
1593        self.refresh();
1594        view
1595    }
1596
1597    /// Returns the root entity of the window, if it has one.
1598    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1599    where
1600        E: 'static + Render,
1601    {
1602        self.root
1603            .as_ref()
1604            .map(|view| view.clone().downcast::<E>().ok())
1605    }
1606
1607    /// Obtain a handle to the window that belongs to this context.
1608    pub fn window_handle(&self) -> AnyWindowHandle {
1609        self.handle
1610    }
1611
1612    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1613    pub fn refresh(&mut self) {
1614        if self.invalidator.not_drawing() {
1615            self.refreshing = true;
1616            self.invalidator.set_dirty(true);
1617        }
1618    }
1619
1620    /// Close this window.
1621    pub fn remove_window(&mut self) {
1622        self.removed = true;
1623    }
1624
1625    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1626    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1627        self.focus
1628            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1629    }
1630
1631    /// Move focus to the element associated with the given [`FocusHandle`].
1632    pub fn focus(&mut self, handle: &FocusHandle, cx: &mut App) {
1633        if !self.focus_enabled || self.focus == Some(handle.id) {
1634            return;
1635        }
1636
1637        self.focus = Some(handle.id);
1638        self.clear_pending_keystrokes();
1639
1640        // Avoid re-entrant entity updates by deferring observer notifications to the end of the
1641        // current effect cycle, and only for this window.
1642        let window_handle = self.handle;
1643        cx.defer(move |cx| {
1644            window_handle
1645                .update(cx, |_, window, cx| {
1646                    window.pending_input_changed(cx);
1647                })
1648                .ok();
1649        });
1650
1651        self.refresh();
1652    }
1653
1654    /// Remove focus from all elements within this context's window.
1655    pub fn blur(&mut self) {
1656        if !self.focus_enabled {
1657            return;
1658        }
1659
1660        self.focus = None;
1661        self.refresh();
1662    }
1663
1664    /// Blur the window and don't allow anything in it to be focused again.
1665    pub fn disable_focus(&mut self) {
1666        self.blur();
1667        self.focus_enabled = false;
1668    }
1669
1670    /// Move focus to next tab stop.
1671    pub fn focus_next(&mut self, cx: &mut App) {
1672        if !self.focus_enabled {
1673            return;
1674        }
1675
1676        if let Some(handle) = self.rendered_frame.tab_stops.next(self.focus.as_ref()) {
1677            self.focus(&handle, cx)
1678        }
1679    }
1680
1681    /// Move focus to previous tab stop.
1682    pub fn focus_prev(&mut self, cx: &mut App) {
1683        if !self.focus_enabled {
1684            return;
1685        }
1686
1687        if let Some(handle) = self.rendered_frame.tab_stops.prev(self.focus.as_ref()) {
1688            self.focus(&handle, cx)
1689        }
1690    }
1691
1692    /// Accessor for the text system.
1693    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1694        &self.text_system
1695    }
1696
1697    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1698    pub fn text_style(&self) -> TextStyle {
1699        let mut style = TextStyle::default();
1700        for refinement in &self.text_style_stack {
1701            style.refine(refinement);
1702        }
1703        style
1704    }
1705
1706    /// Check if the platform window is maximized.
1707    ///
1708    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1709    pub fn is_maximized(&self) -> bool {
1710        self.platform_window.is_maximized()
1711    }
1712
1713    /// request a certain window decoration (Wayland)
1714    pub fn request_decorations(&self, decorations: WindowDecorations) {
1715        self.platform_window.request_decorations(decorations);
1716    }
1717
1718    /// Start a window resize operation (Wayland)
1719    pub fn start_window_resize(&self, edge: ResizeEdge) {
1720        self.platform_window.start_window_resize(edge);
1721    }
1722
1723    /// Return the `WindowBounds` to indicate that how a window should be opened
1724    /// after it has been closed
1725    pub fn window_bounds(&self) -> WindowBounds {
1726        self.platform_window.window_bounds()
1727    }
1728
1729    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1730    pub fn inner_window_bounds(&self) -> WindowBounds {
1731        self.platform_window.inner_window_bounds()
1732    }
1733
1734    /// Dispatch the given action on the currently focused element.
1735    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1736        let focus_id = self.focused(cx).map(|handle| handle.id);
1737
1738        let window = self.handle;
1739        cx.defer(move |cx| {
1740            window
1741                .update(cx, |_, window, cx| {
1742                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1743                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1744                })
1745                .log_err();
1746        })
1747    }
1748
1749    pub(crate) fn dispatch_keystroke_observers(
1750        &mut self,
1751        event: &dyn Any,
1752        action: Option<Box<dyn Action>>,
1753        context_stack: Vec<KeyContext>,
1754        cx: &mut App,
1755    ) {
1756        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1757            return;
1758        };
1759
1760        cx.keystroke_observers.clone().retain(&(), move |callback| {
1761            (callback)(
1762                &KeystrokeEvent {
1763                    keystroke: key_down_event.keystroke.clone(),
1764                    action: action.as_ref().map(|action| action.boxed_clone()),
1765                    context_stack: context_stack.clone(),
1766                },
1767                self,
1768                cx,
1769            )
1770        });
1771    }
1772
1773    pub(crate) fn dispatch_keystroke_interceptors(
1774        &mut self,
1775        event: &dyn Any,
1776        context_stack: Vec<KeyContext>,
1777        cx: &mut App,
1778    ) {
1779        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1780            return;
1781        };
1782
1783        cx.keystroke_interceptors
1784            .clone()
1785            .retain(&(), move |callback| {
1786                (callback)(
1787                    &KeystrokeEvent {
1788                        keystroke: key_down_event.keystroke.clone(),
1789                        action: None,
1790                        context_stack: context_stack.clone(),
1791                    },
1792                    self,
1793                    cx,
1794                )
1795            });
1796    }
1797
1798    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1799    /// that are currently on the stack to be returned to the app.
1800    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1801        let handle = self.handle;
1802        cx.defer(move |cx| {
1803            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1804        });
1805    }
1806
1807    /// Subscribe to events emitted by a entity.
1808    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1809    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1810    pub fn observe<T: 'static>(
1811        &mut self,
1812        observed: &Entity<T>,
1813        cx: &mut App,
1814        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1815    ) -> Subscription {
1816        let entity_id = observed.entity_id();
1817        let observed = observed.downgrade();
1818        let window_handle = self.handle;
1819        cx.new_observer(
1820            entity_id,
1821            Box::new(move |cx| {
1822                window_handle
1823                    .update(cx, |_, window, cx| {
1824                        if let Some(handle) = observed.upgrade() {
1825                            on_notify(handle, window, cx);
1826                            true
1827                        } else {
1828                            false
1829                        }
1830                    })
1831                    .unwrap_or(false)
1832            }),
1833        )
1834    }
1835
1836    /// Subscribe to events emitted by a entity.
1837    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1838    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1839    pub fn subscribe<Emitter, Evt>(
1840        &mut self,
1841        entity: &Entity<Emitter>,
1842        cx: &mut App,
1843        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1844    ) -> Subscription
1845    where
1846        Emitter: EventEmitter<Evt>,
1847        Evt: 'static,
1848    {
1849        let entity_id = entity.entity_id();
1850        let handle = entity.downgrade();
1851        let window_handle = self.handle;
1852        cx.new_subscription(
1853            entity_id,
1854            (
1855                TypeId::of::<Evt>(),
1856                Box::new(move |event, cx| {
1857                    window_handle
1858                        .update(cx, |_, window, cx| {
1859                            if let Some(entity) = handle.upgrade() {
1860                                let event = event.downcast_ref().expect("invalid event type");
1861                                on_event(entity, event, window, cx);
1862                                true
1863                            } else {
1864                                false
1865                            }
1866                        })
1867                        .unwrap_or(false)
1868                }),
1869            ),
1870        )
1871    }
1872
1873    /// Register a callback to be invoked when the given `Entity` is released.
1874    pub fn observe_release<T>(
1875        &self,
1876        entity: &Entity<T>,
1877        cx: &mut App,
1878        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1879    ) -> Subscription
1880    where
1881        T: 'static,
1882    {
1883        let entity_id = entity.entity_id();
1884        let window_handle = self.handle;
1885        let (subscription, activate) = cx.release_listeners.insert(
1886            entity_id,
1887            Box::new(move |entity, cx| {
1888                let entity = entity.downcast_mut().expect("invalid entity type");
1889                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1890            }),
1891        );
1892        activate();
1893        subscription
1894    }
1895
1896    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1897    /// await points in async code.
1898    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1899        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1900    }
1901
1902    /// Schedule the given closure to be run directly after the current frame is rendered.
1903    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1904        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1905    }
1906
1907    /// Schedule a frame to be drawn on the next animation frame.
1908    ///
1909    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1910    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1911    ///
1912    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1913    pub fn request_animation_frame(&self) {
1914        let entity = self.current_view();
1915        self.on_next_frame(move |_, cx| cx.notify(entity));
1916    }
1917
1918    /// Spawn the future returned by the given closure on the application thread pool.
1919    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1920    /// use within your future.
1921    #[track_caller]
1922    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1923    where
1924        R: 'static,
1925        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1926    {
1927        let handle = self.handle;
1928        cx.spawn(async move |app| {
1929            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1930            f(&mut async_window_cx).await
1931        })
1932    }
1933
1934    /// Spawn the future returned by the given closure on the application thread
1935    /// pool, with the given priority. The closure is provided a handle to the
1936    /// current window and an `AsyncWindowContext` for use within your future.
1937    #[track_caller]
1938    pub fn spawn_with_priority<AsyncFn, R>(
1939        &self,
1940        priority: Priority,
1941        cx: &App,
1942        f: AsyncFn,
1943    ) -> Task<R>
1944    where
1945        R: 'static,
1946        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1947    {
1948        let handle = self.handle;
1949        cx.spawn_with_priority(priority, async move |app| {
1950            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1951            f(&mut async_window_cx).await
1952        })
1953    }
1954
1955    /// Notify the window that its bounds have changed.
1956    ///
1957    /// This updates internal state like `viewport_size` and `scale_factor` from
1958    /// the platform window, then notifies observers. Normally called automatically
1959    /// by the platform's resize callback, but exposed publicly for test infrastructure.
1960    pub fn bounds_changed(&mut self, cx: &mut App) {
1961        self.scale_factor = self.platform_window.scale_factor();
1962        self.viewport_size = self.platform_window.content_size();
1963        self.display_id = self.platform_window.display().map(|display| display.id());
1964
1965        self.refresh();
1966
1967        self.bounds_observers
1968            .clone()
1969            .retain(&(), |callback| callback(self, cx));
1970    }
1971
1972    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1973    pub fn bounds(&self) -> Bounds<Pixels> {
1974        self.platform_window.bounds()
1975    }
1976
1977    /// Renders the current frame's scene to a texture and returns the pixel data as an RGBA image.
1978    /// This does not present the frame to screen - useful for visual testing where we want
1979    /// to capture what would be rendered without displaying it or requiring the window to be visible.
1980    #[cfg(any(test, feature = "test-support"))]
1981    pub fn render_to_image(&self) -> anyhow::Result<image::RgbaImage> {
1982        self.platform_window
1983            .render_to_image(&self.rendered_frame.scene)
1984    }
1985
1986    /// Set the content size of the window.
1987    pub fn resize(&mut self, size: Size<Pixels>) {
1988        self.platform_window.resize(size);
1989    }
1990
1991    /// Returns whether or not the window is currently fullscreen
1992    pub fn is_fullscreen(&self) -> bool {
1993        self.platform_window.is_fullscreen()
1994    }
1995
1996    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1997        self.appearance = self.platform_window.appearance();
1998
1999        self.appearance_observers
2000            .clone()
2001            .retain(&(), |callback| callback(self, cx));
2002    }
2003
2004    pub(crate) fn button_layout_changed(&mut self, cx: &mut App) {
2005        self.button_layout_observers
2006            .clone()
2007            .retain(&(), |callback| callback(self, cx));
2008    }
2009
2010    /// Returns the appearance of the current window.
2011    pub fn appearance(&self) -> WindowAppearance {
2012        self.appearance
2013    }
2014
2015    /// Returns the size of the drawable area within the window.
2016    pub fn viewport_size(&self) -> Size<Pixels> {
2017        self.viewport_size
2018    }
2019
2020    /// Returns whether this window is focused by the operating system (receiving key events).
2021    pub fn is_window_active(&self) -> bool {
2022        self.active.get()
2023    }
2024
2025    /// Returns whether this window is considered to be the window
2026    /// that currently owns the mouse cursor.
2027    /// On mac, this is equivalent to `is_window_active`.
2028    pub fn is_window_hovered(&self) -> bool {
2029        if cfg!(any(
2030            target_os = "windows",
2031            target_os = "linux",
2032            target_os = "freebsd"
2033        )) {
2034            self.hovered.get()
2035        } else {
2036            self.is_window_active()
2037        }
2038    }
2039
2040    /// Toggle zoom on the window.
2041    pub fn zoom_window(&self) {
2042        self.platform_window.zoom();
2043    }
2044
2045    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
2046    pub fn show_window_menu(&self, position: Point<Pixels>) {
2047        self.platform_window.show_window_menu(position)
2048    }
2049
2050    /// Handle window movement for Linux and macOS.
2051    /// Tells the compositor to take control of window movement (Wayland and X11)
2052    ///
2053    /// Events may not be received during a move operation.
2054    pub fn start_window_move(&self) {
2055        self.platform_window.start_window_move()
2056    }
2057
2058    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
2059    pub fn set_client_inset(&mut self, inset: Pixels) {
2060        self.client_inset = Some(inset);
2061        self.platform_window.set_client_inset(inset);
2062    }
2063
2064    /// Returns the client_inset value by [`Self::set_client_inset`].
2065    pub fn client_inset(&self) -> Option<Pixels> {
2066        self.client_inset
2067    }
2068
2069    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
2070    pub fn window_decorations(&self) -> Decorations {
2071        self.platform_window.window_decorations()
2072    }
2073
2074    /// Returns which window controls are currently visible (Wayland)
2075    pub fn window_controls(&self) -> WindowControls {
2076        self.platform_window.window_controls()
2077    }
2078
2079    /// Updates the window's title at the platform level.
2080    pub fn set_window_title(&mut self, title: &str) {
2081        self.platform_window.set_title(title);
2082    }
2083
2084    /// Sets the application identifier.
2085    pub fn set_app_id(&mut self, app_id: &str) {
2086        self.platform_window.set_app_id(app_id);
2087    }
2088
2089    /// Sets the window background appearance.
2090    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
2091        self.platform_window
2092            .set_background_appearance(background_appearance);
2093    }
2094
2095    /// Mark the window as dirty at the platform level.
2096    pub fn set_window_edited(&mut self, edited: bool) {
2097        self.platform_window.set_edited(edited);
2098    }
2099
2100    /// Determine the display on which the window is visible.
2101    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
2102        cx.platform
2103            .displays()
2104            .into_iter()
2105            .find(|display| Some(display.id()) == self.display_id)
2106    }
2107
2108    /// Show the platform character palette.
2109    pub fn show_character_palette(&self) {
2110        self.platform_window.show_character_palette();
2111    }
2112
2113    /// The scale factor of the display associated with the window. For example, it could
2114    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
2115    /// be rendered as two pixels on screen.
2116    pub fn scale_factor(&self) -> f32 {
2117        self.scale_factor
2118    }
2119
2120    /// The size of an em for the base font of the application. Adjusting this value allows the
2121    /// UI to scale, just like zooming a web page.
2122    pub fn rem_size(&self) -> Pixels {
2123        self.rem_size_override_stack
2124            .last()
2125            .copied()
2126            .unwrap_or(self.rem_size)
2127    }
2128
2129    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
2130    /// UI to scale, just like zooming a web page.
2131    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
2132        self.rem_size = rem_size.into();
2133    }
2134
2135    /// Acquire a globally unique identifier for the given ElementId.
2136    /// Only valid for the duration of the provided closure.
2137    pub fn with_global_id<R>(
2138        &mut self,
2139        element_id: ElementId,
2140        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
2141    ) -> R {
2142        self.with_id(element_id, |this| {
2143            let global_id = GlobalElementId(Arc::from(&*this.element_id_stack));
2144
2145            f(&global_id, this)
2146        })
2147    }
2148
2149    /// Calls the provided closure with the element ID pushed on the stack.
2150    #[inline]
2151    pub fn with_id<R>(
2152        &mut self,
2153        element_id: impl Into<ElementId>,
2154        f: impl FnOnce(&mut Self) -> R,
2155    ) -> R {
2156        self.element_id_stack.push(element_id.into());
2157        let result = f(self);
2158        self.element_id_stack.pop();
2159        result
2160    }
2161
2162    /// Executes the provided function with the specified rem size.
2163    ///
2164    /// This method must only be called as part of element drawing.
2165    // This function is called in a highly recursive manner in editor
2166    // prepainting, make sure its inlined to reduce the stack burden
2167    #[inline]
2168    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
2169    where
2170        F: FnOnce(&mut Self) -> R,
2171    {
2172        self.invalidator.debug_assert_paint_or_prepaint();
2173
2174        if let Some(rem_size) = rem_size {
2175            self.rem_size_override_stack.push(rem_size.into());
2176            let result = f(self);
2177            self.rem_size_override_stack.pop();
2178            result
2179        } else {
2180            f(self)
2181        }
2182    }
2183
2184    /// The line height associated with the current text style.
2185    pub fn line_height(&self) -> Pixels {
2186        self.text_style().line_height_in_pixels(self.rem_size())
2187    }
2188
2189    /// Call to prevent the default action of an event. Currently only used to prevent
2190    /// parent elements from becoming focused on mouse down.
2191    pub fn prevent_default(&mut self) {
2192        self.default_prevented = true;
2193    }
2194
2195    /// Obtain whether default has been prevented for the event currently being dispatched.
2196    pub fn default_prevented(&self) -> bool {
2197        self.default_prevented
2198    }
2199
2200    /// Determine whether the given action is available along the dispatch path to the currently focused element.
2201    pub fn is_action_available(&self, action: &dyn Action, cx: &App) -> bool {
2202        let node_id =
2203            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
2204        self.rendered_frame
2205            .dispatch_tree
2206            .is_action_available(action, node_id)
2207    }
2208
2209    /// Determine whether the given action is available along the dispatch path to the given focus_handle.
2210    pub fn is_action_available_in(&self, action: &dyn Action, focus_handle: &FocusHandle) -> bool {
2211        let node_id = self.focus_node_id_in_rendered_frame(Some(focus_handle.id));
2212        self.rendered_frame
2213            .dispatch_tree
2214            .is_action_available(action, node_id)
2215    }
2216
2217    /// The position of the mouse relative to the window.
2218    pub fn mouse_position(&self) -> Point<Pixels> {
2219        self.mouse_position
2220    }
2221
2222    /// Captures the pointer for the given hitbox. While captured, all mouse move and mouse up
2223    /// events will be routed to listeners that check this hitbox's `is_hovered` status,
2224    /// regardless of actual hit testing. This enables drag operations that continue
2225    /// even when the pointer moves outside the element's bounds.
2226    ///
2227    /// The capture is automatically released on mouse up.
2228    pub fn capture_pointer(&mut self, hitbox_id: HitboxId) {
2229        self.captured_hitbox = Some(hitbox_id);
2230    }
2231
2232    /// Releases any active pointer capture.
2233    pub fn release_pointer(&mut self) {
2234        self.captured_hitbox = None;
2235    }
2236
2237    /// Returns the hitbox that has captured the pointer, if any.
2238    pub fn captured_hitbox(&self) -> Option<HitboxId> {
2239        self.captured_hitbox
2240    }
2241
2242    /// The current state of the keyboard's modifiers
2243    pub fn modifiers(&self) -> Modifiers {
2244        self.modifiers
2245    }
2246
2247    /// Returns true if the last input event was keyboard-based (key press, tab navigation, etc.)
2248    /// This is used for focus-visible styling to show focus indicators only for keyboard navigation.
2249    pub fn last_input_was_keyboard(&self) -> bool {
2250        self.last_input_modality == InputModality::Keyboard
2251    }
2252
2253    /// The current state of the keyboard's capslock
2254    pub fn capslock(&self) -> Capslock {
2255        self.capslock
2256    }
2257
2258    fn complete_frame(&self) {
2259        self.platform_window.completed_frame();
2260    }
2261
2262    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
2263    /// the contents of the new [`Scene`], use [`Self::present`].
2264    #[profiling::function]
2265    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
2266        // Set up the per-App arena for element allocation during this draw.
2267        // This ensures that multiple test Apps have isolated arenas.
2268        let _arena_scope = ElementArenaScope::enter(&cx.element_arena);
2269
2270        self.invalidate_entities();
2271        cx.entities.clear_accessed();
2272        debug_assert!(self.rendered_entity_stack.is_empty());
2273        self.invalidator.set_dirty(false);
2274        self.requested_autoscroll = None;
2275
2276        // Restore the previously-used input handler.
2277        if let Some(input_handler) = self.platform_window.take_input_handler() {
2278            self.rendered_frame.input_handlers.push(Some(input_handler));
2279        }
2280        if !cx.mode.skip_drawing() {
2281            self.draw_roots(cx);
2282        }
2283        self.dirty_views.clear();
2284        self.next_frame.window_active = self.active.get();
2285
2286        // Register requested input handler with the platform window.
2287        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
2288            self.platform_window
2289                .set_input_handler(input_handler.unwrap());
2290        }
2291
2292        self.layout_engine.as_mut().unwrap().clear();
2293        self.text_system().finish_frame();
2294        self.next_frame.finish(&mut self.rendered_frame);
2295
2296        self.invalidator.set_phase(DrawPhase::Focus);
2297        let previous_focus_path = self.rendered_frame.focus_path();
2298        let previous_window_active = self.rendered_frame.window_active;
2299        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
2300        self.next_frame.clear();
2301        let current_focus_path = self.rendered_frame.focus_path();
2302        let current_window_active = self.rendered_frame.window_active;
2303
2304        if previous_focus_path != current_focus_path
2305            || previous_window_active != current_window_active
2306        {
2307            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
2308                self.focus_lost_listeners
2309                    .clone()
2310                    .retain(&(), |listener| listener(self, cx));
2311            }
2312
2313            let event = WindowFocusEvent {
2314                previous_focus_path: if previous_window_active {
2315                    previous_focus_path
2316                } else {
2317                    Default::default()
2318                },
2319                current_focus_path: if current_window_active {
2320                    current_focus_path
2321                } else {
2322                    Default::default()
2323                },
2324            };
2325            self.focus_listeners
2326                .clone()
2327                .retain(&(), |listener| listener(&event, self, cx));
2328        }
2329
2330        debug_assert!(self.rendered_entity_stack.is_empty());
2331        self.record_entities_accessed(cx);
2332        self.reset_cursor_style(cx);
2333        self.refreshing = false;
2334        self.invalidator.set_phase(DrawPhase::None);
2335        self.needs_present.set(true);
2336
2337        ArenaClearNeeded::new(&cx.element_arena)
2338    }
2339
2340    fn record_entities_accessed(&mut self, cx: &mut App) {
2341        let mut entities_ref = cx.entities.accessed_entities.get_mut();
2342        let mut entities = mem::take(entities_ref.deref_mut());
2343        let handle = self.handle;
2344        cx.record_entities_accessed(
2345            handle,
2346            // Try moving window invalidator into the Window
2347            self.invalidator.clone(),
2348            &entities,
2349        );
2350        let mut entities_ref = cx.entities.accessed_entities.get_mut();
2351        mem::swap(&mut entities, entities_ref.deref_mut());
2352    }
2353
2354    fn invalidate_entities(&mut self) {
2355        let mut views = self.invalidator.take_views();
2356        for entity in views.drain() {
2357            self.mark_view_dirty(entity);
2358        }
2359        self.invalidator.replace_views(views);
2360    }
2361
2362    #[profiling::function]
2363    fn present(&self) {
2364        self.platform_window.draw(&self.rendered_frame.scene);
2365        self.needs_present.set(false);
2366        profiling::finish_frame!();
2367    }
2368
2369    fn draw_roots(&mut self, cx: &mut App) {
2370        self.invalidator.set_phase(DrawPhase::Prepaint);
2371        self.tooltip_bounds.take();
2372
2373        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
2374        let root_size = {
2375            #[cfg(any(feature = "inspector", debug_assertions))]
2376            {
2377                if self.inspector.is_some() {
2378                    let mut size = self.viewport_size;
2379                    size.width = (size.width - _inspector_width).max(px(0.0));
2380                    size
2381                } else {
2382                    self.viewport_size
2383                }
2384            }
2385            #[cfg(not(any(feature = "inspector", debug_assertions)))]
2386            {
2387                self.viewport_size
2388            }
2389        };
2390
2391        // Layout all root elements.
2392        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
2393        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2394
2395        #[cfg(any(feature = "inspector", debug_assertions))]
2396        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
2397
2398        self.prepaint_deferred_draws(cx);
2399
2400        let mut prompt_element = None;
2401        let mut active_drag_element = None;
2402        let mut tooltip_element = None;
2403        if let Some(prompt) = self.prompt.take() {
2404            let mut element = prompt.view.any_view().into_any();
2405            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2406            prompt_element = Some(element);
2407            self.prompt = Some(prompt);
2408        } else if let Some(active_drag) = cx.active_drag.take() {
2409            let mut element = active_drag.view.clone().into_any();
2410            let offset = self.mouse_position() - active_drag.cursor_offset;
2411            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
2412            active_drag_element = Some(element);
2413            cx.active_drag = Some(active_drag);
2414        } else {
2415            tooltip_element = self.prepaint_tooltip(cx);
2416        }
2417
2418        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
2419
2420        // Now actually paint the elements.
2421        self.invalidator.set_phase(DrawPhase::Paint);
2422        root_element.paint(self, cx);
2423
2424        #[cfg(any(feature = "inspector", debug_assertions))]
2425        self.paint_inspector(inspector_element, cx);
2426
2427        self.paint_deferred_draws(cx);
2428
2429        if let Some(mut prompt_element) = prompt_element {
2430            prompt_element.paint(self, cx);
2431        } else if let Some(mut drag_element) = active_drag_element {
2432            drag_element.paint(self, cx);
2433        } else if let Some(mut tooltip_element) = tooltip_element {
2434            tooltip_element.paint(self, cx);
2435        }
2436
2437        #[cfg(any(feature = "inspector", debug_assertions))]
2438        self.paint_inspector_hitbox(cx);
2439    }
2440
2441    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
2442        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
2443        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
2444            let Some(Some(tooltip_request)) = self
2445                .next_frame
2446                .tooltip_requests
2447                .get(tooltip_request_index)
2448                .cloned()
2449            else {
2450                log::error!("Unexpectedly absent TooltipRequest");
2451                continue;
2452            };
2453            let mut element = tooltip_request.tooltip.view.clone().into_any();
2454            let mouse_position = tooltip_request.tooltip.mouse_position;
2455            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
2456
2457            let mut tooltip_bounds =
2458                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
2459            let window_bounds = Bounds {
2460                origin: Point::default(),
2461                size: self.viewport_size(),
2462            };
2463
2464            if tooltip_bounds.right() > window_bounds.right() {
2465                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
2466                if new_x >= Pixels::ZERO {
2467                    tooltip_bounds.origin.x = new_x;
2468                } else {
2469                    tooltip_bounds.origin.x = cmp::max(
2470                        Pixels::ZERO,
2471                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
2472                    );
2473                }
2474            }
2475
2476            if tooltip_bounds.bottom() > window_bounds.bottom() {
2477                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
2478                if new_y >= Pixels::ZERO {
2479                    tooltip_bounds.origin.y = new_y;
2480                } else {
2481                    tooltip_bounds.origin.y = cmp::max(
2482                        Pixels::ZERO,
2483                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
2484                    );
2485                }
2486            }
2487
2488            // It's possible for an element to have an active tooltip while not being painted (e.g.
2489            // via the `visible_on_hover` method). Since mouse listeners are not active in this
2490            // case, instead update the tooltip's visibility here.
2491            let is_visible =
2492                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
2493            if !is_visible {
2494                continue;
2495            }
2496
2497            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2498                element.prepaint(window, cx)
2499            });
2500
2501            self.tooltip_bounds = Some(TooltipBounds {
2502                id: tooltip_request.id,
2503                bounds: tooltip_bounds,
2504            });
2505            return Some(element);
2506        }
2507        None
2508    }
2509
2510    fn prepaint_deferred_draws(&mut self, cx: &mut App) {
2511        assert_eq!(self.element_id_stack.len(), 0);
2512
2513        let mut completed_draws = Vec::new();
2514
2515        // Process deferred draws in multiple rounds to support nesting.
2516        // Each round processes all current deferred draws, which may produce new ones.
2517        let mut depth = 0;
2518        loop {
2519            // Limit maximum nesting depth to prevent infinite loops.
2520            assert!(depth < 10, "Exceeded maximum (10) deferred depth");
2521            depth += 1;
2522            let deferred_count = self.next_frame.deferred_draws.len();
2523            if deferred_count == 0 {
2524                break;
2525            }
2526
2527            // Sort by priority for this round
2528            let traversal_order = self.deferred_draw_traversal_order();
2529            let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2530
2531            for deferred_draw_ix in traversal_order {
2532                let deferred_draw = &mut deferred_draws[deferred_draw_ix];
2533                self.element_id_stack
2534                    .clone_from(&deferred_draw.element_id_stack);
2535                self.text_style_stack
2536                    .clone_from(&deferred_draw.text_style_stack);
2537                self.next_frame
2538                    .dispatch_tree
2539                    .set_active_node(deferred_draw.parent_node);
2540
2541                let prepaint_start = self.prepaint_index();
2542                if let Some(element) = deferred_draw.element.as_mut() {
2543                    self.with_rendered_view(deferred_draw.current_view, |window| {
2544                        window.with_rem_size(Some(deferred_draw.rem_size), |window| {
2545                            window.with_absolute_element_offset(
2546                                deferred_draw.absolute_offset,
2547                                |window| {
2548                                    element.prepaint(window, cx);
2549                                },
2550                            );
2551                        });
2552                    })
2553                } else {
2554                    self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2555                }
2556                let prepaint_end = self.prepaint_index();
2557                deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2558            }
2559
2560            // Save completed draws and continue with newly added ones
2561            completed_draws.append(&mut deferred_draws);
2562
2563            self.element_id_stack.clear();
2564            self.text_style_stack.clear();
2565        }
2566
2567        // Restore all completed draws
2568        self.next_frame.deferred_draws = completed_draws;
2569    }
2570
2571    fn paint_deferred_draws(&mut self, cx: &mut App) {
2572        assert_eq!(self.element_id_stack.len(), 0);
2573
2574        // Paint all deferred draws in priority order.
2575        // Since prepaint has already processed nested deferreds, we just paint them all.
2576        if self.next_frame.deferred_draws.len() == 0 {
2577            return;
2578        }
2579
2580        let traversal_order = self.deferred_draw_traversal_order();
2581        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2582        for deferred_draw_ix in traversal_order {
2583            let mut deferred_draw = &mut deferred_draws[deferred_draw_ix];
2584            self.element_id_stack
2585                .clone_from(&deferred_draw.element_id_stack);
2586            self.next_frame
2587                .dispatch_tree
2588                .set_active_node(deferred_draw.parent_node);
2589
2590            let paint_start = self.paint_index();
2591            let content_mask = deferred_draw.content_mask.clone();
2592            if let Some(element) = deferred_draw.element.as_mut() {
2593                self.with_rendered_view(deferred_draw.current_view, |window| {
2594                    window.with_content_mask(content_mask, |window| {
2595                        window.with_rem_size(Some(deferred_draw.rem_size), |window| {
2596                            element.paint(window, cx);
2597                        });
2598                    })
2599                })
2600            } else {
2601                self.reuse_paint(deferred_draw.paint_range.clone());
2602            }
2603            let paint_end = self.paint_index();
2604            deferred_draw.paint_range = paint_start..paint_end;
2605        }
2606        self.next_frame.deferred_draws = deferred_draws;
2607        self.element_id_stack.clear();
2608    }
2609
2610    fn deferred_draw_traversal_order(&mut self) -> SmallVec<[usize; 8]> {
2611        let deferred_count = self.next_frame.deferred_draws.len();
2612        let mut sorted_indices = (0..deferred_count).collect::<SmallVec<[_; 8]>>();
2613        sorted_indices.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
2614        sorted_indices
2615    }
2616
2617    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2618        PrepaintStateIndex {
2619            hitboxes_index: self.next_frame.hitboxes.len(),
2620            tooltips_index: self.next_frame.tooltip_requests.len(),
2621            deferred_draws_index: self.next_frame.deferred_draws.len(),
2622            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2623            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2624            line_layout_index: self.text_system.layout_index(),
2625        }
2626    }
2627
2628    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2629        self.next_frame.hitboxes.extend(
2630            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2631                .iter()
2632                .cloned(),
2633        );
2634        self.next_frame.tooltip_requests.extend(
2635            self.rendered_frame.tooltip_requests
2636                [range.start.tooltips_index..range.end.tooltips_index]
2637                .iter_mut()
2638                .map(|request| request.take()),
2639        );
2640        self.next_frame.accessed_element_states.extend(
2641            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2642                ..range.end.accessed_element_states_index]
2643                .iter()
2644                .map(|(id, type_id)| (id.clone(), *type_id)),
2645        );
2646        self.text_system
2647            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2648
2649        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2650            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2651            &mut self.rendered_frame.dispatch_tree,
2652            self.focus,
2653        );
2654
2655        if reused_subtree.contains_focus() {
2656            self.next_frame.focus = self.focus;
2657        }
2658
2659        self.next_frame.deferred_draws.extend(
2660            self.rendered_frame.deferred_draws
2661                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2662                .iter()
2663                .map(|deferred_draw| DeferredDraw {
2664                    current_view: deferred_draw.current_view,
2665                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2666                    element_id_stack: deferred_draw.element_id_stack.clone(),
2667                    text_style_stack: deferred_draw.text_style_stack.clone(),
2668                    content_mask: deferred_draw.content_mask.clone(),
2669                    rem_size: deferred_draw.rem_size,
2670                    priority: deferred_draw.priority,
2671                    element: None,
2672                    absolute_offset: deferred_draw.absolute_offset,
2673                    prepaint_range: deferred_draw.prepaint_range.clone(),
2674                    paint_range: deferred_draw.paint_range.clone(),
2675                }),
2676        );
2677    }
2678
2679    pub(crate) fn paint_index(&self) -> PaintIndex {
2680        PaintIndex {
2681            scene_index: self.next_frame.scene.len(),
2682            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2683            input_handlers_index: self.next_frame.input_handlers.len(),
2684            cursor_styles_index: self.next_frame.cursor_styles.len(),
2685            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2686            tab_handle_index: self.next_frame.tab_stops.paint_index(),
2687            line_layout_index: self.text_system.layout_index(),
2688        }
2689    }
2690
2691    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2692        self.next_frame.cursor_styles.extend(
2693            self.rendered_frame.cursor_styles
2694                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2695                .iter()
2696                .cloned(),
2697        );
2698        self.next_frame.input_handlers.extend(
2699            self.rendered_frame.input_handlers
2700                [range.start.input_handlers_index..range.end.input_handlers_index]
2701                .iter_mut()
2702                .map(|handler| handler.take()),
2703        );
2704        self.next_frame.mouse_listeners.extend(
2705            self.rendered_frame.mouse_listeners
2706                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2707                .iter_mut()
2708                .map(|listener| listener.take()),
2709        );
2710        self.next_frame.accessed_element_states.extend(
2711            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2712                ..range.end.accessed_element_states_index]
2713                .iter()
2714                .map(|(id, type_id)| (id.clone(), *type_id)),
2715        );
2716        self.next_frame.tab_stops.replay(
2717            &self.rendered_frame.tab_stops.insertion_history
2718                [range.start.tab_handle_index..range.end.tab_handle_index],
2719        );
2720
2721        self.text_system
2722            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2723        self.next_frame.scene.replay(
2724            range.start.scene_index..range.end.scene_index,
2725            &self.rendered_frame.scene,
2726        );
2727    }
2728
2729    /// Push a text style onto the stack, and call a function with that style active.
2730    /// Use [`Window::text_style`] to get the current, combined text style. This method
2731    /// should only be called as part of element drawing.
2732    // This function is called in a highly recursive manner in editor
2733    // prepainting, make sure its inlined to reduce the stack burden
2734    #[inline]
2735    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2736    where
2737        F: FnOnce(&mut Self) -> R,
2738    {
2739        self.invalidator.debug_assert_paint_or_prepaint();
2740        if let Some(style) = style {
2741            self.text_style_stack.push(style);
2742            let result = f(self);
2743            self.text_style_stack.pop();
2744            result
2745        } else {
2746            f(self)
2747        }
2748    }
2749
2750    /// Updates the cursor style at the platform level. This method should only be called
2751    /// during the paint phase of element drawing.
2752    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2753        self.invalidator.debug_assert_paint();
2754        self.next_frame.cursor_styles.push(CursorStyleRequest {
2755            hitbox_id: Some(hitbox.id),
2756            style,
2757        });
2758    }
2759
2760    /// Updates the cursor style for the entire window at the platform level. A cursor
2761    /// style using this method will have precedence over any cursor style set using
2762    /// `set_cursor_style`. This method should only be called during the paint
2763    /// phase of element drawing.
2764    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2765        self.invalidator.debug_assert_paint();
2766        self.next_frame.cursor_styles.push(CursorStyleRequest {
2767            hitbox_id: None,
2768            style,
2769        })
2770    }
2771
2772    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2773    /// during the paint phase of element drawing.
2774    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2775        self.invalidator.debug_assert_prepaint();
2776        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2777        self.next_frame
2778            .tooltip_requests
2779            .push(Some(TooltipRequest { id, tooltip }));
2780        id
2781    }
2782
2783    /// Invoke the given function with the given content mask after intersecting it
2784    /// with the current mask. This method should only be called during element drawing.
2785    // This function is called in a highly recursive manner in editor
2786    // prepainting, make sure its inlined to reduce the stack burden
2787    #[inline]
2788    pub fn with_content_mask<R>(
2789        &mut self,
2790        mask: Option<ContentMask<Pixels>>,
2791        f: impl FnOnce(&mut Self) -> R,
2792    ) -> R {
2793        self.invalidator.debug_assert_paint_or_prepaint();
2794        if let Some(mask) = mask {
2795            let mask = mask.intersect(&self.content_mask());
2796            self.content_mask_stack.push(mask);
2797            let result = f(self);
2798            self.content_mask_stack.pop();
2799            result
2800        } else {
2801            f(self)
2802        }
2803    }
2804
2805    /// Updates the global element offset relative to the current offset. This is used to implement
2806    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2807    pub fn with_element_offset<R>(
2808        &mut self,
2809        offset: Point<Pixels>,
2810        f: impl FnOnce(&mut Self) -> R,
2811    ) -> R {
2812        self.invalidator.debug_assert_prepaint();
2813
2814        if offset.is_zero() {
2815            return f(self);
2816        };
2817
2818        let abs_offset = self.element_offset() + offset;
2819        self.with_absolute_element_offset(abs_offset, f)
2820    }
2821
2822    /// Updates the global element offset based on the given offset. This is used to implement
2823    /// drag handles and other manual painting of elements. This method should only be called during
2824    /// the prepaint phase of element drawing.
2825    pub fn with_absolute_element_offset<R>(
2826        &mut self,
2827        offset: Point<Pixels>,
2828        f: impl FnOnce(&mut Self) -> R,
2829    ) -> R {
2830        self.invalidator.debug_assert_prepaint();
2831        self.element_offset_stack.push(offset);
2832        let result = f(self);
2833        self.element_offset_stack.pop();
2834        result
2835    }
2836
2837    pub(crate) fn with_element_opacity<R>(
2838        &mut self,
2839        opacity: Option<f32>,
2840        f: impl FnOnce(&mut Self) -> R,
2841    ) -> R {
2842        self.invalidator.debug_assert_paint_or_prepaint();
2843
2844        let Some(opacity) = opacity else {
2845            return f(self);
2846        };
2847
2848        let previous_opacity = self.element_opacity;
2849        self.element_opacity = previous_opacity * opacity;
2850        let result = f(self);
2851        self.element_opacity = previous_opacity;
2852        result
2853    }
2854
2855    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2856    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2857    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2858    /// element offset and prepaint again. See [`crate::List`] for an example. This method should only be
2859    /// called during the prepaint phase of element drawing.
2860    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2861        self.invalidator.debug_assert_prepaint();
2862        let index = self.prepaint_index();
2863        let result = f(self);
2864        if result.is_err() {
2865            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2866            self.next_frame
2867                .tooltip_requests
2868                .truncate(index.tooltips_index);
2869            self.next_frame
2870                .deferred_draws
2871                .truncate(index.deferred_draws_index);
2872            self.next_frame
2873                .dispatch_tree
2874                .truncate(index.dispatch_tree_index);
2875            self.next_frame
2876                .accessed_element_states
2877                .truncate(index.accessed_element_states_index);
2878            self.text_system.truncate_layouts(index.line_layout_index);
2879        }
2880        result
2881    }
2882
2883    /// When you call this method during [`Element::prepaint`], containing elements will attempt to
2884    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2885    /// [`Element::prepaint`] again with a new set of bounds. See [`crate::List`] for an example of an element
2886    /// that supports this method being called on the elements it contains. This method should only be
2887    /// called during the prepaint phase of element drawing.
2888    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2889        self.invalidator.debug_assert_prepaint();
2890        self.requested_autoscroll = Some(bounds);
2891    }
2892
2893    /// This method can be called from a containing element such as [`crate::List`] to support the autoscroll behavior
2894    /// described in [`Self::request_autoscroll`].
2895    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2896        self.invalidator.debug_assert_prepaint();
2897        self.requested_autoscroll.take()
2898    }
2899
2900    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2901    /// Your view will be re-drawn once the asset has finished loading.
2902    ///
2903    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2904    /// time.
2905    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2906        let (task, is_first) = cx.fetch_asset::<A>(source);
2907        task.clone().now_or_never().or_else(|| {
2908            if is_first {
2909                let entity_id = self.current_view();
2910                self.spawn(cx, {
2911                    let task = task.clone();
2912                    async move |cx| {
2913                        task.await;
2914
2915                        cx.on_next_frame(move |_, cx| {
2916                            cx.notify(entity_id);
2917                        });
2918                    }
2919                })
2920                .detach();
2921            }
2922
2923            None
2924        })
2925    }
2926
2927    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2928    /// Your view will not be re-drawn once the asset has finished loading.
2929    ///
2930    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2931    /// time.
2932    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2933        let (task, _) = cx.fetch_asset::<A>(source);
2934        task.now_or_never()
2935    }
2936    /// Obtain the current element offset. This method should only be called during the
2937    /// prepaint phase of element drawing.
2938    pub fn element_offset(&self) -> Point<Pixels> {
2939        self.invalidator.debug_assert_prepaint();
2940        self.element_offset_stack
2941            .last()
2942            .copied()
2943            .unwrap_or_default()
2944    }
2945
2946    /// Obtain the current element opacity. This method should only be called during the
2947    /// prepaint phase of element drawing.
2948    #[inline]
2949    pub(crate) fn element_opacity(&self) -> f32 {
2950        self.invalidator.debug_assert_paint_or_prepaint();
2951        self.element_opacity
2952    }
2953
2954    /// Obtain the current content mask. This method should only be called during element drawing.
2955    pub fn content_mask(&self) -> ContentMask<Pixels> {
2956        self.invalidator.debug_assert_paint_or_prepaint();
2957        self.content_mask_stack
2958            .last()
2959            .cloned()
2960            .unwrap_or_else(|| ContentMask {
2961                bounds: Bounds {
2962                    origin: Point::default(),
2963                    size: self.viewport_size,
2964                },
2965            })
2966    }
2967
2968    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2969    /// This can be used within a custom element to distinguish multiple sets of child elements.
2970    pub fn with_element_namespace<R>(
2971        &mut self,
2972        element_id: impl Into<ElementId>,
2973        f: impl FnOnce(&mut Self) -> R,
2974    ) -> R {
2975        self.element_id_stack.push(element_id.into());
2976        let result = f(self);
2977        self.element_id_stack.pop();
2978        result
2979    }
2980
2981    /// Use a piece of state that exists as long this element is being rendered in consecutive frames.
2982    pub fn use_keyed_state<S: 'static>(
2983        &mut self,
2984        key: impl Into<ElementId>,
2985        cx: &mut App,
2986        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2987    ) -> Entity<S> {
2988        let current_view = self.current_view();
2989        self.with_global_id(key.into(), |global_id, window| {
2990            window.with_element_state(global_id, |state: Option<Entity<S>>, window| {
2991                if let Some(state) = state {
2992                    (state.clone(), state)
2993                } else {
2994                    let new_state = cx.new(|cx| init(window, cx));
2995                    cx.observe(&new_state, move |_, cx| {
2996                        cx.notify(current_view);
2997                    })
2998                    .detach();
2999                    (new_state.clone(), new_state)
3000                }
3001            })
3002        })
3003    }
3004
3005    /// Use a piece of state that exists as long this element is being rendered in consecutive frames, without needing to specify a key
3006    ///
3007    /// NOTE: This method uses the location of the caller to generate an ID for this state.
3008    ///       If this is not sufficient to identify your state (e.g. you're rendering a list item),
3009    ///       you can provide a custom ElementID using the `use_keyed_state` method.
3010    #[track_caller]
3011    pub fn use_state<S: 'static>(
3012        &mut self,
3013        cx: &mut App,
3014        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
3015    ) -> Entity<S> {
3016        self.use_keyed_state(
3017            ElementId::CodeLocation(*core::panic::Location::caller()),
3018            cx,
3019            init,
3020        )
3021    }
3022
3023    /// Updates or initializes state for an element with the given id that lives across multiple
3024    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
3025    /// to the given closure. The state returned by the closure will be stored so it can be referenced
3026    /// when drawing the next frame. This method should only be called as part of element drawing.
3027    pub fn with_element_state<S, R>(
3028        &mut self,
3029        global_id: &GlobalElementId,
3030        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
3031    ) -> R
3032    where
3033        S: 'static,
3034    {
3035        self.invalidator.debug_assert_paint_or_prepaint();
3036
3037        let key = (global_id.clone(), TypeId::of::<S>());
3038        self.next_frame.accessed_element_states.push(key.clone());
3039
3040        if let Some(any) = self
3041            .next_frame
3042            .element_states
3043            .remove(&key)
3044            .or_else(|| self.rendered_frame.element_states.remove(&key))
3045        {
3046            let ElementStateBox {
3047                inner,
3048                #[cfg(debug_assertions)]
3049                type_name,
3050            } = any;
3051            // Using the extra inner option to avoid needing to reallocate a new box.
3052            let mut state_box = inner
3053                .downcast::<Option<S>>()
3054                .map_err(|_| {
3055                    #[cfg(debug_assertions)]
3056                    {
3057                        anyhow::anyhow!(
3058                            "invalid element state type for id, requested {:?}, actual: {:?}",
3059                            std::any::type_name::<S>(),
3060                            type_name
3061                        )
3062                    }
3063
3064                    #[cfg(not(debug_assertions))]
3065                    {
3066                        anyhow::anyhow!(
3067                            "invalid element state type for id, requested {:?}",
3068                            std::any::type_name::<S>(),
3069                        )
3070                    }
3071                })
3072                .unwrap();
3073
3074            let state = state_box.take().expect(
3075                "reentrant call to with_element_state for the same state type and element id",
3076            );
3077            let (result, state) = f(Some(state), self);
3078            state_box.replace(state);
3079            self.next_frame.element_states.insert(
3080                key,
3081                ElementStateBox {
3082                    inner: state_box,
3083                    #[cfg(debug_assertions)]
3084                    type_name,
3085                },
3086            );
3087            result
3088        } else {
3089            let (result, state) = f(None, self);
3090            self.next_frame.element_states.insert(
3091                key,
3092                ElementStateBox {
3093                    inner: Box::new(Some(state)),
3094                    #[cfg(debug_assertions)]
3095                    type_name: std::any::type_name::<S>(),
3096                },
3097            );
3098            result
3099        }
3100    }
3101
3102    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
3103    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
3104    /// when the element is guaranteed to have an id.
3105    ///
3106    /// The first option means 'no ID provided'
3107    /// The second option means 'not yet initialized'
3108    pub fn with_optional_element_state<S, R>(
3109        &mut self,
3110        global_id: Option<&GlobalElementId>,
3111        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
3112    ) -> R
3113    where
3114        S: 'static,
3115    {
3116        self.invalidator.debug_assert_paint_or_prepaint();
3117
3118        if let Some(global_id) = global_id {
3119            self.with_element_state(global_id, |state, cx| {
3120                let (result, state) = f(Some(state), cx);
3121                let state =
3122                    state.expect("you must return some state when you pass some element id");
3123                (result, state)
3124            })
3125        } else {
3126            let (result, state) = f(None, self);
3127            debug_assert!(
3128                state.is_none(),
3129                "you must not return an element state when passing None for the global id"
3130            );
3131            result
3132        }
3133    }
3134
3135    /// Executes the given closure within the context of a tab group.
3136    #[inline]
3137    pub fn with_tab_group<R>(&mut self, index: Option<isize>, f: impl FnOnce(&mut Self) -> R) -> R {
3138        if let Some(index) = index {
3139            self.next_frame.tab_stops.begin_group(index);
3140            let result = f(self);
3141            self.next_frame.tab_stops.end_group();
3142            result
3143        } else {
3144            f(self)
3145        }
3146    }
3147
3148    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
3149    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
3150    /// with higher values being drawn on top.
3151    ///
3152    /// When `content_mask` is provided, the deferred element will be clipped to that region during
3153    /// both prepaint and paint. When `None`, no additional clipping is applied.
3154    ///
3155    /// This method should only be called as part of the prepaint phase of element drawing.
3156    pub fn defer_draw(
3157        &mut self,
3158        element: AnyElement,
3159        absolute_offset: Point<Pixels>,
3160        priority: usize,
3161        content_mask: Option<ContentMask<Pixels>>,
3162    ) {
3163        self.invalidator.debug_assert_prepaint();
3164        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
3165        self.next_frame.deferred_draws.push(DeferredDraw {
3166            current_view: self.current_view(),
3167            parent_node,
3168            element_id_stack: self.element_id_stack.clone(),
3169            text_style_stack: self.text_style_stack.clone(),
3170            content_mask,
3171            rem_size: self.rem_size(),
3172            priority,
3173            element: Some(element),
3174            absolute_offset,
3175            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
3176            paint_range: PaintIndex::default()..PaintIndex::default(),
3177        });
3178    }
3179
3180    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
3181    /// of geometry that are non-overlapping and have the same draw order. This is typically used
3182    /// for performance reasons.
3183    ///
3184    /// This method should only be called as part of the paint phase of element drawing.
3185    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
3186        self.invalidator.debug_assert_paint();
3187
3188        let scale_factor = self.scale_factor();
3189        let content_mask = self.content_mask();
3190        let clipped_bounds = bounds.intersect(&content_mask.bounds);
3191        if !clipped_bounds.is_empty() {
3192            self.next_frame
3193                .scene
3194                .push_layer(clipped_bounds.scale(scale_factor));
3195        }
3196
3197        let result = f(self);
3198
3199        if !clipped_bounds.is_empty() {
3200            self.next_frame.scene.pop_layer();
3201        }
3202
3203        result
3204    }
3205
3206    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
3207    ///
3208    /// This method should only be called as part of the paint phase of element drawing.
3209    pub fn paint_shadows(
3210        &mut self,
3211        bounds: Bounds<Pixels>,
3212        corner_radii: Corners<Pixels>,
3213        shadows: &[BoxShadow],
3214    ) {
3215        self.invalidator.debug_assert_paint();
3216
3217        let scale_factor = self.scale_factor();
3218        let content_mask = self.content_mask();
3219        let opacity = self.element_opacity();
3220        for shadow in shadows {
3221            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
3222            self.next_frame.scene.insert_primitive(Shadow {
3223                order: 0,
3224                blur_radius: shadow.blur_radius.scale(scale_factor),
3225                bounds: shadow_bounds.scale(scale_factor),
3226                content_mask: content_mask.scale(scale_factor),
3227                corner_radii: corner_radii.scale(scale_factor),
3228                color: shadow.color.opacity(opacity),
3229            });
3230        }
3231    }
3232
3233    /// Paint one or more quads into the scene for the next frame at the current stacking context.
3234    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
3235    /// see [`fill`], [`outline`], and [`quad`] to construct this type.
3236    ///
3237    /// This method should only be called as part of the paint phase of element drawing.
3238    ///
3239    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
3240    /// where the circular arcs meet. This will not display well when combined with dashed borders.
3241    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
3242    pub fn paint_quad(&mut self, quad: PaintQuad) {
3243        self.invalidator.debug_assert_paint();
3244
3245        let scale_factor = self.scale_factor();
3246        let content_mask = self.content_mask();
3247        let opacity = self.element_opacity();
3248        self.next_frame.scene.insert_primitive(Quad {
3249            order: 0,
3250            bounds: quad.bounds.scale(scale_factor),
3251            content_mask: content_mask.scale(scale_factor),
3252            background: quad.background.opacity(opacity),
3253            border_color: quad.border_color.opacity(opacity),
3254            corner_radii: quad.corner_radii.scale(scale_factor),
3255            border_widths: quad.border_widths.scale(scale_factor),
3256            border_style: quad.border_style,
3257        });
3258    }
3259
3260    /// Paint the given `Path` into the scene for the next frame at the current z-index.
3261    ///
3262    /// This method should only be called as part of the paint phase of element drawing.
3263    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
3264        self.invalidator.debug_assert_paint();
3265
3266        let scale_factor = self.scale_factor();
3267        let content_mask = self.content_mask();
3268        let opacity = self.element_opacity();
3269        path.content_mask = content_mask;
3270        let color: Background = color.into();
3271        path.color = color.opacity(opacity);
3272        self.next_frame
3273            .scene
3274            .insert_primitive(path.scale(scale_factor));
3275    }
3276
3277    /// Paint an underline into the scene for the next frame at the current z-index.
3278    ///
3279    /// This method should only be called as part of the paint phase of element drawing.
3280    pub fn paint_underline(
3281        &mut self,
3282        origin: Point<Pixels>,
3283        width: Pixels,
3284        style: &UnderlineStyle,
3285    ) {
3286        self.invalidator.debug_assert_paint();
3287
3288        let scale_factor = self.scale_factor();
3289        let height = if style.wavy {
3290            style.thickness * 3.
3291        } else {
3292            style.thickness
3293        };
3294        let bounds = Bounds {
3295            origin,
3296            size: size(width, height),
3297        };
3298        let content_mask = self.content_mask();
3299        let element_opacity = self.element_opacity();
3300
3301        self.next_frame.scene.insert_primitive(Underline {
3302            order: 0,
3303            pad: 0,
3304            bounds: bounds.scale(scale_factor),
3305            content_mask: content_mask.scale(scale_factor),
3306            color: style.color.unwrap_or_default().opacity(element_opacity),
3307            thickness: style.thickness.scale(scale_factor),
3308            wavy: if style.wavy { 1 } else { 0 },
3309        });
3310    }
3311
3312    /// Paint a strikethrough into the scene for the next frame at the current z-index.
3313    ///
3314    /// This method should only be called as part of the paint phase of element drawing.
3315    pub fn paint_strikethrough(
3316        &mut self,
3317        origin: Point<Pixels>,
3318        width: Pixels,
3319        style: &StrikethroughStyle,
3320    ) {
3321        self.invalidator.debug_assert_paint();
3322
3323        let scale_factor = self.scale_factor();
3324        let height = style.thickness;
3325        let bounds = Bounds {
3326            origin,
3327            size: size(width, height),
3328        };
3329        let content_mask = self.content_mask();
3330        let opacity = self.element_opacity();
3331
3332        self.next_frame.scene.insert_primitive(Underline {
3333            order: 0,
3334            pad: 0,
3335            bounds: bounds.scale(scale_factor),
3336            content_mask: content_mask.scale(scale_factor),
3337            thickness: style.thickness.scale(scale_factor),
3338            color: style.color.unwrap_or_default().opacity(opacity),
3339            wavy: 0,
3340        });
3341    }
3342
3343    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
3344    ///
3345    /// The y component of the origin is the baseline of the glyph.
3346    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3347    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3348    /// This method is only useful if you need to paint a single glyph that has already been shaped.
3349    ///
3350    /// This method should only be called as part of the paint phase of element drawing.
3351    pub fn paint_glyph(
3352        &mut self,
3353        origin: Point<Pixels>,
3354        font_id: FontId,
3355        glyph_id: GlyphId,
3356        font_size: Pixels,
3357        color: Hsla,
3358    ) -> Result<()> {
3359        self.invalidator.debug_assert_paint();
3360
3361        let element_opacity = self.element_opacity();
3362        let scale_factor = self.scale_factor();
3363        let glyph_origin = origin.scale(scale_factor);
3364
3365        let subpixel_variant = Point {
3366            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS_X as f32).floor() as u8,
3367            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS_Y as f32).floor() as u8,
3368        };
3369        let subpixel_rendering = self.should_use_subpixel_rendering(font_id, font_size);
3370        let params = RenderGlyphParams {
3371            font_id,
3372            glyph_id,
3373            font_size,
3374            subpixel_variant,
3375            scale_factor,
3376            is_emoji: false,
3377            subpixel_rendering,
3378        };
3379
3380        let raster_bounds = self.text_system().raster_bounds(&params)?;
3381        if !raster_bounds.is_zero() {
3382            let tile = self
3383                .sprite_atlas
3384                .get_or_insert_with(&params.clone().into(), &mut || {
3385                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3386                    Ok(Some((size, Cow::Owned(bytes))))
3387                })?
3388                .expect("Callback above only errors or returns Some");
3389            let bounds = Bounds {
3390                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3391                size: tile.bounds.size.map(Into::into),
3392            };
3393            let content_mask = self.content_mask().scale(scale_factor);
3394
3395            if subpixel_rendering {
3396                self.next_frame.scene.insert_primitive(SubpixelSprite {
3397                    order: 0,
3398                    pad: 0,
3399                    bounds,
3400                    content_mask,
3401                    color: color.opacity(element_opacity),
3402                    tile,
3403                    transformation: TransformationMatrix::unit(),
3404                });
3405            } else {
3406                self.next_frame.scene.insert_primitive(MonochromeSprite {
3407                    order: 0,
3408                    pad: 0,
3409                    bounds,
3410                    content_mask,
3411                    color: color.opacity(element_opacity),
3412                    tile,
3413                    transformation: TransformationMatrix::unit(),
3414                });
3415            }
3416        }
3417        Ok(())
3418    }
3419
3420    /// Paints a monochrome glyph with pre-computed raster bounds.
3421    ///
3422    /// This is faster than `paint_glyph` because it skips the per-glyph cache lookup.
3423    /// Use `ShapedLine::compute_glyph_raster_data` to batch-compute raster bounds during prepaint.
3424    pub fn paint_glyph_with_raster_bounds(
3425        &mut self,
3426        origin: Point<Pixels>,
3427        _font_id: FontId,
3428        _glyph_id: GlyphId,
3429        _font_size: Pixels,
3430        color: Hsla,
3431        raster_bounds: Bounds<DevicePixels>,
3432        params: &RenderGlyphParams,
3433    ) -> Result<()> {
3434        self.invalidator.debug_assert_paint();
3435
3436        let element_opacity = self.element_opacity();
3437        let scale_factor = self.scale_factor();
3438        let glyph_origin = origin.scale(scale_factor);
3439
3440        if !raster_bounds.is_zero() {
3441            let tile = self
3442                .sprite_atlas
3443                .get_or_insert_with(&params.clone().into(), &mut || {
3444                    let (size, bytes) = self.text_system().rasterize_glyph(params)?;
3445                    Ok(Some((size, Cow::Owned(bytes))))
3446                })?
3447                .expect("Callback above only errors or returns Some");
3448            let bounds = Bounds {
3449                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3450                size: tile.bounds.size.map(Into::into),
3451            };
3452            let content_mask = self.content_mask().scale(scale_factor);
3453            self.next_frame.scene.insert_primitive(MonochromeSprite {
3454                order: 0,
3455                pad: 0,
3456                bounds,
3457                content_mask,
3458                color: color.opacity(element_opacity),
3459                tile,
3460                transformation: TransformationMatrix::unit(),
3461            });
3462        }
3463        Ok(())
3464    }
3465
3466    /// Paints an emoji glyph with pre-computed raster bounds.
3467    ///
3468    /// This is faster than `paint_emoji` because it skips the per-glyph cache lookup.
3469    /// Use `ShapedLine::compute_glyph_raster_data` to batch-compute raster bounds during prepaint.
3470    pub fn paint_emoji_with_raster_bounds(
3471        &mut self,
3472        origin: Point<Pixels>,
3473        _font_id: FontId,
3474        _glyph_id: GlyphId,
3475        _font_size: Pixels,
3476        raster_bounds: Bounds<DevicePixels>,
3477        params: &RenderGlyphParams,
3478    ) -> Result<()> {
3479        self.invalidator.debug_assert_paint();
3480
3481        let scale_factor = self.scale_factor();
3482        let glyph_origin = origin.scale(scale_factor);
3483
3484        if !raster_bounds.is_zero() {
3485            let tile = self
3486                .sprite_atlas
3487                .get_or_insert_with(&params.clone().into(), &mut || {
3488                    let (size, bytes) = self.text_system().rasterize_glyph(params)?;
3489                    Ok(Some((size, Cow::Owned(bytes))))
3490                })?
3491                .expect("Callback above only errors or returns Some");
3492
3493            let bounds = Bounds {
3494                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3495                size: tile.bounds.size.map(Into::into),
3496            };
3497            let content_mask = self.content_mask().scale(scale_factor);
3498            let opacity = self.element_opacity();
3499
3500            self.next_frame.scene.insert_primitive(PolychromeSprite {
3501                order: 0,
3502                pad: 0,
3503                grayscale: false,
3504                bounds,
3505                corner_radii: Default::default(),
3506                content_mask,
3507                tile,
3508                opacity,
3509            });
3510        }
3511        Ok(())
3512    }
3513
3514    fn should_use_subpixel_rendering(&self, font_id: FontId, font_size: Pixels) -> bool {
3515        if self.platform_window.background_appearance() != WindowBackgroundAppearance::Opaque {
3516            return false;
3517        }
3518
3519        if !self.platform_window.is_subpixel_rendering_supported() {
3520            return false;
3521        }
3522
3523        let mode = match self.text_rendering_mode.get() {
3524            TextRenderingMode::PlatformDefault => self
3525                .text_system()
3526                .recommended_rendering_mode(font_id, font_size),
3527            mode => mode,
3528        };
3529
3530        mode == TextRenderingMode::Subpixel
3531    }
3532
3533    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
3534    ///
3535    /// The y component of the origin is the baseline of the glyph.
3536    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3537    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3538    /// This method is only useful if you need to paint a single emoji that has already been shaped.
3539    ///
3540    /// This method should only be called as part of the paint phase of element drawing.
3541    pub fn paint_emoji(
3542        &mut self,
3543        origin: Point<Pixels>,
3544        font_id: FontId,
3545        glyph_id: GlyphId,
3546        font_size: Pixels,
3547    ) -> Result<()> {
3548        self.invalidator.debug_assert_paint();
3549
3550        let scale_factor = self.scale_factor();
3551        let glyph_origin = origin.scale(scale_factor);
3552        let params = RenderGlyphParams {
3553            font_id,
3554            glyph_id,
3555            font_size,
3556            // We don't render emojis with subpixel variants.
3557            subpixel_variant: Default::default(),
3558            scale_factor,
3559            is_emoji: true,
3560            subpixel_rendering: false,
3561        };
3562
3563        let raster_bounds = self.text_system().raster_bounds(&params)?;
3564        if !raster_bounds.is_zero() {
3565            let tile = self
3566                .sprite_atlas
3567                .get_or_insert_with(&params.clone().into(), &mut || {
3568                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3569                    Ok(Some((size, Cow::Owned(bytes))))
3570                })?
3571                .expect("Callback above only errors or returns Some");
3572
3573            let bounds = Bounds {
3574                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3575                size: tile.bounds.size.map(Into::into),
3576            };
3577            let content_mask = self.content_mask().scale(scale_factor);
3578            let opacity = self.element_opacity();
3579
3580            self.next_frame.scene.insert_primitive(PolychromeSprite {
3581                order: 0,
3582                pad: 0,
3583                grayscale: false,
3584                bounds,
3585                corner_radii: Default::default(),
3586                content_mask,
3587                tile,
3588                opacity,
3589            });
3590        }
3591        Ok(())
3592    }
3593
3594    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
3595    ///
3596    /// This method should only be called as part of the paint phase of element drawing.
3597    pub fn paint_svg(
3598        &mut self,
3599        bounds: Bounds<Pixels>,
3600        path: SharedString,
3601        mut data: Option<&[u8]>,
3602        transformation: TransformationMatrix,
3603        color: Hsla,
3604        cx: &App,
3605    ) -> Result<()> {
3606        self.invalidator.debug_assert_paint();
3607
3608        let element_opacity = self.element_opacity();
3609        let scale_factor = self.scale_factor();
3610
3611        let bounds = bounds.scale(scale_factor);
3612        let params = RenderSvgParams {
3613            path,
3614            size: bounds.size.map(|pixels| {
3615                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
3616            }),
3617        };
3618
3619        let Some(tile) =
3620            self.sprite_atlas
3621                .get_or_insert_with(&params.clone().into(), &mut || {
3622                    let Some((size, bytes)) = cx.svg_renderer.render_alpha_mask(&params, data)?
3623                    else {
3624                        return Ok(None);
3625                    };
3626                    Ok(Some((size, Cow::Owned(bytes))))
3627                })?
3628        else {
3629            return Ok(());
3630        };
3631        let content_mask = self.content_mask().scale(scale_factor);
3632        let svg_bounds = Bounds {
3633            origin: bounds.center()
3634                - Point::new(
3635                    ScaledPixels(tile.bounds.size.width.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3636                    ScaledPixels(tile.bounds.size.height.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3637                ),
3638            size: tile
3639                .bounds
3640                .size
3641                .map(|value| ScaledPixels(value.0 as f32 / SMOOTH_SVG_SCALE_FACTOR)),
3642        };
3643
3644        self.next_frame.scene.insert_primitive(MonochromeSprite {
3645            order: 0,
3646            pad: 0,
3647            bounds: svg_bounds
3648                .map_origin(|origin| origin.round())
3649                .map_size(|size| size.ceil()),
3650            content_mask,
3651            color: color.opacity(element_opacity),
3652            tile,
3653            transformation,
3654        });
3655
3656        Ok(())
3657    }
3658
3659    /// Paint an image into the scene for the next frame at the current z-index.
3660    /// This method will panic if the frame_index is not valid
3661    ///
3662    /// This method should only be called as part of the paint phase of element drawing.
3663    pub fn paint_image(
3664        &mut self,
3665        bounds: Bounds<Pixels>,
3666        corner_radii: Corners<Pixels>,
3667        data: Arc<RenderImage>,
3668        frame_index: usize,
3669        grayscale: bool,
3670    ) -> Result<()> {
3671        self.invalidator.debug_assert_paint();
3672
3673        let scale_factor = self.scale_factor();
3674        let bounds = bounds.scale(scale_factor);
3675        let params = RenderImageParams {
3676            image_id: data.id,
3677            frame_index,
3678        };
3679
3680        let tile = self
3681            .sprite_atlas
3682            .get_or_insert_with(&params.into(), &mut || {
3683                Ok(Some((
3684                    data.size(frame_index),
3685                    Cow::Borrowed(
3686                        data.as_bytes(frame_index)
3687                            .expect("It's the caller's job to pass a valid frame index"),
3688                    ),
3689                )))
3690            })?
3691            .expect("Callback above only returns Some");
3692        let content_mask = self.content_mask().scale(scale_factor);
3693        let corner_radii = corner_radii.scale(scale_factor);
3694        let opacity = self.element_opacity();
3695
3696        self.next_frame.scene.insert_primitive(PolychromeSprite {
3697            order: 0,
3698            pad: 0,
3699            grayscale,
3700            bounds: bounds
3701                .map_origin(|origin| origin.floor())
3702                .map_size(|size| size.ceil()),
3703            content_mask,
3704            corner_radii,
3705            tile,
3706            opacity,
3707        });
3708        Ok(())
3709    }
3710
3711    /// Paint a surface into the scene for the next frame at the current z-index.
3712    ///
3713    /// This method should only be called as part of the paint phase of element drawing.
3714    #[cfg(target_os = "macos")]
3715    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
3716        use crate::PaintSurface;
3717
3718        self.invalidator.debug_assert_paint();
3719
3720        let scale_factor = self.scale_factor();
3721        let bounds = bounds.scale(scale_factor);
3722        let content_mask = self.content_mask().scale(scale_factor);
3723        self.next_frame.scene.insert_primitive(PaintSurface {
3724            order: 0,
3725            bounds,
3726            content_mask,
3727            image_buffer,
3728        });
3729    }
3730
3731    /// Removes an image from the sprite atlas.
3732    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
3733        for frame_index in 0..data.frame_count() {
3734            let params = RenderImageParams {
3735                image_id: data.id,
3736                frame_index,
3737            };
3738
3739            self.sprite_atlas.remove(&params.clone().into());
3740        }
3741
3742        Ok(())
3743    }
3744
3745    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
3746    /// layout is being requested, along with the layout ids of any children. This method is called during
3747    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
3748    ///
3749    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3750    #[must_use]
3751    pub fn request_layout(
3752        &mut self,
3753        style: Style,
3754        children: impl IntoIterator<Item = LayoutId>,
3755        cx: &mut App,
3756    ) -> LayoutId {
3757        self.invalidator.debug_assert_prepaint();
3758
3759        cx.layout_id_buffer.clear();
3760        cx.layout_id_buffer.extend(children);
3761        let rem_size = self.rem_size();
3762        let scale_factor = self.scale_factor();
3763
3764        self.layout_engine.as_mut().unwrap().request_layout(
3765            style,
3766            rem_size,
3767            scale_factor,
3768            &cx.layout_id_buffer,
3769        )
3770    }
3771
3772    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3773    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3774    /// determine the element's size. One place this is used internally is when measuring text.
3775    ///
3776    /// The given closure is invoked at layout time with the known dimensions and available space and
3777    /// returns a `Size`.
3778    ///
3779    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3780    pub fn request_measured_layout<F>(&mut self, style: Style, measure: F) -> LayoutId
3781    where
3782        F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3783            + 'static,
3784    {
3785        self.invalidator.debug_assert_prepaint();
3786
3787        let rem_size = self.rem_size();
3788        let scale_factor = self.scale_factor();
3789        self.layout_engine
3790            .as_mut()
3791            .unwrap()
3792            .request_measured_layout(style, rem_size, scale_factor, measure)
3793    }
3794
3795    /// Compute the layout for the given id within the given available space.
3796    /// This method is called for its side effect, typically by the framework prior to painting.
3797    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3798    ///
3799    /// This method should only be called as part of the prepaint phase of element drawing.
3800    pub fn compute_layout(
3801        &mut self,
3802        layout_id: LayoutId,
3803        available_space: Size<AvailableSpace>,
3804        cx: &mut App,
3805    ) {
3806        self.invalidator.debug_assert_prepaint();
3807
3808        let mut layout_engine = self.layout_engine.take().unwrap();
3809        layout_engine.compute_layout(layout_id, available_space, self, cx);
3810        self.layout_engine = Some(layout_engine);
3811    }
3812
3813    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3814    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3815    ///
3816    /// This method should only be called as part of element drawing.
3817    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3818        self.invalidator.debug_assert_prepaint();
3819
3820        let scale_factor = self.scale_factor();
3821        let mut bounds = self
3822            .layout_engine
3823            .as_mut()
3824            .unwrap()
3825            .layout_bounds(layout_id, scale_factor)
3826            .map(Into::into);
3827        bounds.origin += self.element_offset();
3828        bounds
3829    }
3830
3831    /// This method should be called during `prepaint`. You can use
3832    /// the returned [Hitbox] during `paint` or in an event handler
3833    /// to determine whether the inserted hitbox was the topmost.
3834    ///
3835    /// This method should only be called as part of the prepaint phase of element drawing.
3836    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3837        self.invalidator.debug_assert_prepaint();
3838
3839        let content_mask = self.content_mask();
3840        let mut id = self.next_hitbox_id;
3841        self.next_hitbox_id = self.next_hitbox_id.next();
3842        let hitbox = Hitbox {
3843            id,
3844            bounds,
3845            content_mask,
3846            behavior,
3847        };
3848        self.next_frame.hitboxes.push(hitbox.clone());
3849        hitbox
3850    }
3851
3852    /// Set a hitbox which will act as a control area of the platform window.
3853    ///
3854    /// This method should only be called as part of the paint phase of element drawing.
3855    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3856        self.invalidator.debug_assert_paint();
3857        self.next_frame.window_control_hitboxes.push((area, hitbox));
3858    }
3859
3860    /// Sets the key context for the current element. This context will be used to translate
3861    /// keybindings into actions.
3862    ///
3863    /// This method should only be called as part of the paint phase of element drawing.
3864    pub fn set_key_context(&mut self, context: KeyContext) {
3865        self.invalidator.debug_assert_paint();
3866        self.next_frame.dispatch_tree.set_key_context(context);
3867    }
3868
3869    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3870    /// and keyboard event dispatch for the element.
3871    ///
3872    /// This method should only be called as part of the prepaint phase of element drawing.
3873    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3874        self.invalidator.debug_assert_prepaint();
3875        if focus_handle.is_focused(self) {
3876            self.next_frame.focus = Some(focus_handle.id);
3877        }
3878        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3879    }
3880
3881    /// Sets the view id for the current element, which will be used to manage view caching.
3882    ///
3883    /// This method should only be called as part of element prepaint. We plan on removing this
3884    /// method eventually when we solve some issues that require us to construct editor elements
3885    /// directly instead of always using editors via views.
3886    pub fn set_view_id(&mut self, view_id: EntityId) {
3887        self.invalidator.debug_assert_prepaint();
3888        self.next_frame.dispatch_tree.set_view_id(view_id);
3889    }
3890
3891    /// Get the entity ID for the currently rendering view
3892    pub fn current_view(&self) -> EntityId {
3893        self.invalidator.debug_assert_paint_or_prepaint();
3894        self.rendered_entity_stack.last().copied().unwrap()
3895    }
3896
3897    #[inline]
3898    pub(crate) fn with_rendered_view<R>(
3899        &mut self,
3900        id: EntityId,
3901        f: impl FnOnce(&mut Self) -> R,
3902    ) -> R {
3903        self.rendered_entity_stack.push(id);
3904        let result = f(self);
3905        self.rendered_entity_stack.pop();
3906        result
3907    }
3908
3909    /// Executes the provided function with the specified image cache.
3910    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3911    where
3912        F: FnOnce(&mut Self) -> R,
3913    {
3914        if let Some(image_cache) = image_cache {
3915            self.image_cache_stack.push(image_cache);
3916            let result = f(self);
3917            self.image_cache_stack.pop();
3918            result
3919        } else {
3920            f(self)
3921        }
3922    }
3923
3924    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3925    /// platform to receive textual input with proper integration with concerns such
3926    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3927    /// rendered.
3928    ///
3929    /// This method should only be called as part of the paint phase of element drawing.
3930    ///
3931    /// [element_input_handler]: crate::ElementInputHandler
3932    pub fn handle_input(
3933        &mut self,
3934        focus_handle: &FocusHandle,
3935        input_handler: impl InputHandler,
3936        cx: &App,
3937    ) {
3938        self.invalidator.debug_assert_paint();
3939
3940        if focus_handle.is_focused(self) {
3941            let cx = self.to_async(cx);
3942            self.next_frame
3943                .input_handlers
3944                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3945        }
3946    }
3947
3948    /// Register a mouse event listener on the window for the next frame. The type of event
3949    /// is determined by the first parameter of the given listener. When the next frame is rendered
3950    /// the listener will be cleared.
3951    ///
3952    /// This method should only be called as part of the paint phase of element drawing.
3953    pub fn on_mouse_event<Event: MouseEvent>(
3954        &mut self,
3955        mut listener: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3956    ) {
3957        self.invalidator.debug_assert_paint();
3958
3959        self.next_frame.mouse_listeners.push(Some(Box::new(
3960            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3961                if let Some(event) = event.downcast_ref() {
3962                    listener(event, phase, window, cx)
3963                }
3964            },
3965        )));
3966    }
3967
3968    /// Register a key event listener on this node for the next frame. The type of event
3969    /// is determined by the first parameter of the given listener. When the next frame is rendered
3970    /// the listener will be cleared.
3971    ///
3972    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3973    /// a specific need to register a listener yourself.
3974    ///
3975    /// This method should only be called as part of the paint phase of element drawing.
3976    pub fn on_key_event<Event: KeyEvent>(
3977        &mut self,
3978        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3979    ) {
3980        self.invalidator.debug_assert_paint();
3981
3982        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3983            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3984                if let Some(event) = event.downcast_ref::<Event>() {
3985                    listener(event, phase, window, cx)
3986                }
3987            },
3988        ));
3989    }
3990
3991    /// Register a modifiers changed event listener on the window for the next frame.
3992    ///
3993    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3994    /// a specific need to register a global listener.
3995    ///
3996    /// This method should only be called as part of the paint phase of element drawing.
3997    pub fn on_modifiers_changed(
3998        &mut self,
3999        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
4000    ) {
4001        self.invalidator.debug_assert_paint();
4002
4003        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
4004            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
4005                listener(event, window, cx)
4006            },
4007        ));
4008    }
4009
4010    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
4011    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
4012    /// Returns a subscription and persists until the subscription is dropped.
4013    pub fn on_focus_in(
4014        &mut self,
4015        handle: &FocusHandle,
4016        cx: &mut App,
4017        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
4018    ) -> Subscription {
4019        let focus_id = handle.id;
4020        let (subscription, activate) =
4021            self.new_focus_listener(Box::new(move |event, window, cx| {
4022                if event.is_focus_in(focus_id) {
4023                    listener(window, cx);
4024                }
4025                true
4026            }));
4027        cx.defer(move |_| activate());
4028        subscription
4029    }
4030
4031    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
4032    /// Returns a subscription and persists until the subscription is dropped.
4033    pub fn on_focus_out(
4034        &mut self,
4035        handle: &FocusHandle,
4036        cx: &mut App,
4037        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
4038    ) -> Subscription {
4039        let focus_id = handle.id;
4040        let (subscription, activate) =
4041            self.new_focus_listener(Box::new(move |event, window, cx| {
4042                if let Some(blurred_id) = event.previous_focus_path.last().copied()
4043                    && event.is_focus_out(focus_id)
4044                {
4045                    let event = FocusOutEvent {
4046                        blurred: WeakFocusHandle {
4047                            id: blurred_id,
4048                            handles: Arc::downgrade(&cx.focus_handles),
4049                        },
4050                    };
4051                    listener(event, window, cx)
4052                }
4053                true
4054            }));
4055        cx.defer(move |_| activate());
4056        subscription
4057    }
4058
4059    fn reset_cursor_style(&self, cx: &mut App) {
4060        // Set the cursor only if we're the active window.
4061        if self.is_window_hovered() {
4062            let style = self
4063                .rendered_frame
4064                .cursor_style(self)
4065                .unwrap_or(CursorStyle::Arrow);
4066            cx.platform.set_cursor_style(style);
4067        }
4068    }
4069
4070    /// Dispatch a given keystroke as though the user had typed it.
4071    /// You can create a keystroke with Keystroke::parse("").
4072    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
4073        let keystroke = keystroke.with_simulated_ime();
4074        let result = self.dispatch_event(
4075            PlatformInput::KeyDown(KeyDownEvent {
4076                keystroke: keystroke.clone(),
4077                is_held: false,
4078                prefer_character_input: false,
4079            }),
4080            cx,
4081        );
4082        if !result.propagate {
4083            return true;
4084        }
4085
4086        if let Some(input) = keystroke.key_char
4087            && let Some(mut input_handler) = self.platform_window.take_input_handler()
4088        {
4089            input_handler.dispatch_input(&input, self, cx);
4090            self.platform_window.set_input_handler(input_handler);
4091            return true;
4092        }
4093
4094        false
4095    }
4096
4097    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
4098    /// binding for the action (last binding added to the keymap).
4099    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
4100        self.highest_precedence_binding_for_action(action)
4101            .map(|binding| {
4102                binding
4103                    .keystrokes()
4104                    .iter()
4105                    .map(ToString::to_string)
4106                    .collect::<Vec<_>>()
4107                    .join(" ")
4108            })
4109            .unwrap_or_else(|| action.name().to_string())
4110    }
4111
4112    /// Dispatch a mouse or keyboard event on the window.
4113    #[profiling::function]
4114    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
4115        // Track input modality for focus-visible styling and hover suppression.
4116        // Hover is suppressed during keyboard modality so that keyboard navigation
4117        // doesn't show hover highlights on the item under the mouse cursor.
4118        let old_modality = self.last_input_modality;
4119        self.last_input_modality = match &event {
4120            PlatformInput::KeyDown(_) => InputModality::Keyboard,
4121            PlatformInput::MouseMove(_) | PlatformInput::MouseDown(_) => InputModality::Mouse,
4122            _ => self.last_input_modality,
4123        };
4124        if self.last_input_modality != old_modality {
4125            self.refresh();
4126        }
4127
4128        // Handlers may set this to false by calling `stop_propagation`.
4129        cx.propagate_event = true;
4130        // Handlers may set this to true by calling `prevent_default`.
4131        self.default_prevented = false;
4132
4133        let event = match event {
4134            // Track the mouse position with our own state, since accessing the platform
4135            // API for the mouse position can only occur on the main thread.
4136            PlatformInput::MouseMove(mouse_move) => {
4137                self.mouse_position = mouse_move.position;
4138                self.modifiers = mouse_move.modifiers;
4139                PlatformInput::MouseMove(mouse_move)
4140            }
4141            PlatformInput::MouseDown(mouse_down) => {
4142                self.mouse_position = mouse_down.position;
4143                self.modifiers = mouse_down.modifiers;
4144                PlatformInput::MouseDown(mouse_down)
4145            }
4146            PlatformInput::MouseUp(mouse_up) => {
4147                self.mouse_position = mouse_up.position;
4148                self.modifiers = mouse_up.modifiers;
4149                PlatformInput::MouseUp(mouse_up)
4150            }
4151            PlatformInput::MousePressure(mouse_pressure) => {
4152                PlatformInput::MousePressure(mouse_pressure)
4153            }
4154            PlatformInput::MouseExited(mouse_exited) => {
4155                self.modifiers = mouse_exited.modifiers;
4156                PlatformInput::MouseExited(mouse_exited)
4157            }
4158            PlatformInput::ModifiersChanged(modifiers_changed) => {
4159                self.modifiers = modifiers_changed.modifiers;
4160                self.capslock = modifiers_changed.capslock;
4161                PlatformInput::ModifiersChanged(modifiers_changed)
4162            }
4163            PlatformInput::ScrollWheel(scroll_wheel) => {
4164                self.mouse_position = scroll_wheel.position;
4165                self.modifiers = scroll_wheel.modifiers;
4166                PlatformInput::ScrollWheel(scroll_wheel)
4167            }
4168            PlatformInput::Pinch(pinch) => {
4169                self.mouse_position = pinch.position;
4170                self.modifiers = pinch.modifiers;
4171                PlatformInput::Pinch(pinch)
4172            }
4173            // Translate dragging and dropping of external files from the operating system
4174            // to internal drag and drop events.
4175            PlatformInput::FileDrop(file_drop) => match file_drop {
4176                FileDropEvent::Entered { position, paths } => {
4177                    self.mouse_position = position;
4178                    if cx.active_drag.is_none() {
4179                        cx.active_drag = Some(AnyDrag {
4180                            value: Arc::new(paths.clone()),
4181                            view: cx.new(|_| paths).into(),
4182                            cursor_offset: position,
4183                            cursor_style: None,
4184                        });
4185                    }
4186                    PlatformInput::MouseMove(MouseMoveEvent {
4187                        position,
4188                        pressed_button: Some(MouseButton::Left),
4189                        modifiers: Modifiers::default(),
4190                    })
4191                }
4192                FileDropEvent::Pending { position } => {
4193                    self.mouse_position = position;
4194                    PlatformInput::MouseMove(MouseMoveEvent {
4195                        position,
4196                        pressed_button: Some(MouseButton::Left),
4197                        modifiers: Modifiers::default(),
4198                    })
4199                }
4200                FileDropEvent::Submit { position } => {
4201                    cx.activate(true);
4202                    self.mouse_position = position;
4203                    PlatformInput::MouseUp(MouseUpEvent {
4204                        button: MouseButton::Left,
4205                        position,
4206                        modifiers: Modifiers::default(),
4207                        click_count: 1,
4208                    })
4209                }
4210                FileDropEvent::Exited => {
4211                    cx.active_drag.take();
4212                    PlatformInput::FileDrop(FileDropEvent::Exited)
4213                }
4214            },
4215            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
4216        };
4217
4218        if let Some(any_mouse_event) = event.mouse_event() {
4219            self.dispatch_mouse_event(any_mouse_event, cx);
4220        } else if let Some(any_key_event) = event.keyboard_event() {
4221            self.dispatch_key_event(any_key_event, cx);
4222        }
4223
4224        if self.invalidator.is_dirty() {
4225            self.input_rate_tracker.borrow_mut().record_input();
4226        }
4227
4228        DispatchEventResult {
4229            propagate: cx.propagate_event,
4230            default_prevented: self.default_prevented,
4231        }
4232    }
4233
4234    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4235        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
4236        if hit_test != self.mouse_hit_test {
4237            self.mouse_hit_test = hit_test;
4238            self.reset_cursor_style(cx);
4239        }
4240
4241        #[cfg(any(feature = "inspector", debug_assertions))]
4242        if self.is_inspector_picking(cx) {
4243            self.handle_inspector_mouse_event(event, cx);
4244            // When inspector is picking, all other mouse handling is skipped.
4245            return;
4246        }
4247
4248        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
4249
4250        // Capture phase, events bubble from back to front. Handlers for this phase are used for
4251        // special purposes, such as detecting events outside of a given Bounds.
4252        for listener in &mut mouse_listeners {
4253            let listener = listener.as_mut().unwrap();
4254            listener(event, DispatchPhase::Capture, self, cx);
4255            if !cx.propagate_event {
4256                break;
4257            }
4258        }
4259
4260        // Bubble phase, where most normal handlers do their work.
4261        if cx.propagate_event {
4262            for listener in mouse_listeners.iter_mut().rev() {
4263                let listener = listener.as_mut().unwrap();
4264                listener(event, DispatchPhase::Bubble, self, cx);
4265                if !cx.propagate_event {
4266                    break;
4267                }
4268            }
4269        }
4270
4271        self.rendered_frame.mouse_listeners = mouse_listeners;
4272
4273        if cx.has_active_drag() {
4274            if event.is::<MouseMoveEvent>() {
4275                // If this was a mouse move event, redraw the window so that the
4276                // active drag can follow the mouse cursor.
4277                self.refresh();
4278            } else if event.is::<MouseUpEvent>() {
4279                // If this was a mouse up event, cancel the active drag and redraw
4280                // the window.
4281                cx.active_drag = None;
4282                self.refresh();
4283            }
4284        }
4285
4286        // Auto-release pointer capture on mouse up
4287        if event.is::<MouseUpEvent>() && self.captured_hitbox.is_some() {
4288            self.captured_hitbox = None;
4289        }
4290    }
4291
4292    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
4293        if self.invalidator.is_dirty() {
4294            self.draw(cx).clear();
4295        }
4296
4297        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4298        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4299
4300        let mut keystroke: Option<Keystroke> = None;
4301
4302        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
4303            if event.modifiers.number_of_modifiers() == 0
4304                && self.pending_modifier.modifiers.number_of_modifiers() == 1
4305                && !self.pending_modifier.saw_keystroke
4306            {
4307                let key = match self.pending_modifier.modifiers {
4308                    modifiers if modifiers.shift => Some("shift"),
4309                    modifiers if modifiers.control => Some("control"),
4310                    modifiers if modifiers.alt => Some("alt"),
4311                    modifiers if modifiers.platform => Some("platform"),
4312                    modifiers if modifiers.function => Some("function"),
4313                    _ => None,
4314                };
4315                if let Some(key) = key {
4316                    keystroke = Some(Keystroke {
4317                        key: key.to_string(),
4318                        key_char: None,
4319                        modifiers: Modifiers::default(),
4320                    });
4321                }
4322            }
4323
4324            if self.pending_modifier.modifiers.number_of_modifiers() == 0
4325                && event.modifiers.number_of_modifiers() == 1
4326            {
4327                self.pending_modifier.saw_keystroke = false
4328            }
4329            self.pending_modifier.modifiers = event.modifiers
4330        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
4331            self.pending_modifier.saw_keystroke = true;
4332            keystroke = Some(key_down_event.keystroke.clone());
4333        }
4334
4335        let Some(keystroke) = keystroke else {
4336            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
4337            return;
4338        };
4339
4340        cx.propagate_event = true;
4341        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
4342        if !cx.propagate_event {
4343            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
4344            return;
4345        }
4346
4347        let mut currently_pending = self.pending_input.take().unwrap_or_default();
4348        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
4349            currently_pending = PendingInput::default();
4350        }
4351
4352        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
4353            currently_pending.keystrokes,
4354            keystroke,
4355            &dispatch_path,
4356        );
4357
4358        if !match_result.to_replay.is_empty() {
4359            self.replay_pending_input(match_result.to_replay, cx);
4360            cx.propagate_event = true;
4361        }
4362
4363        if !match_result.pending.is_empty() {
4364            currently_pending.timer.take();
4365            currently_pending.keystrokes = match_result.pending;
4366            currently_pending.focus = self.focus;
4367
4368            let text_input_requires_timeout = event
4369                .downcast_ref::<KeyDownEvent>()
4370                .filter(|key_down| key_down.keystroke.key_char.is_some())
4371                .and_then(|_| self.platform_window.take_input_handler())
4372                .map_or(false, |mut input_handler| {
4373                    let accepts = input_handler.accepts_text_input(self, cx);
4374                    self.platform_window.set_input_handler(input_handler);
4375                    accepts
4376                });
4377
4378            currently_pending.needs_timeout |=
4379                match_result.pending_has_binding || text_input_requires_timeout;
4380
4381            if currently_pending.needs_timeout {
4382                currently_pending.timer = Some(self.spawn(cx, async move |cx| {
4383                    cx.background_executor.timer(Duration::from_secs(1)).await;
4384                    cx.update(move |window, cx| {
4385                        let Some(currently_pending) = window
4386                            .pending_input
4387                            .take()
4388                            .filter(|pending| pending.focus == window.focus)
4389                        else {
4390                            return;
4391                        };
4392
4393                        let node_id = window.focus_node_id_in_rendered_frame(window.focus);
4394                        let dispatch_path =
4395                            window.rendered_frame.dispatch_tree.dispatch_path(node_id);
4396
4397                        let to_replay = window
4398                            .rendered_frame
4399                            .dispatch_tree
4400                            .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
4401
4402                        window.pending_input_changed(cx);
4403                        window.replay_pending_input(to_replay, cx)
4404                    })
4405                    .log_err();
4406                }));
4407            } else {
4408                currently_pending.timer = None;
4409            }
4410            self.pending_input = Some(currently_pending);
4411            self.pending_input_changed(cx);
4412            cx.propagate_event = false;
4413            return;
4414        }
4415
4416        let skip_bindings = event
4417            .downcast_ref::<KeyDownEvent>()
4418            .filter(|key_down_event| key_down_event.prefer_character_input)
4419            .map(|_| {
4420                self.platform_window
4421                    .take_input_handler()
4422                    .map_or(false, |mut input_handler| {
4423                        let accepts = input_handler.accepts_text_input(self, cx);
4424                        self.platform_window.set_input_handler(input_handler);
4425                        // If modifiers are not excessive (e.g. AltGr), and the input handler is accepting text input,
4426                        // we prefer the text input over bindings.
4427                        accepts
4428                    })
4429            })
4430            .unwrap_or(false);
4431
4432        if !skip_bindings {
4433            for binding in match_result.bindings {
4434                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
4435                if !cx.propagate_event {
4436                    self.dispatch_keystroke_observers(
4437                        event,
4438                        Some(binding.action),
4439                        match_result.context_stack,
4440                        cx,
4441                    );
4442                    self.pending_input_changed(cx);
4443                    return;
4444                }
4445            }
4446        }
4447
4448        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
4449        self.pending_input_changed(cx);
4450    }
4451
4452    fn finish_dispatch_key_event(
4453        &mut self,
4454        event: &dyn Any,
4455        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
4456        context_stack: Vec<KeyContext>,
4457        cx: &mut App,
4458    ) {
4459        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
4460        if !cx.propagate_event {
4461            return;
4462        }
4463
4464        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
4465        if !cx.propagate_event {
4466            return;
4467        }
4468
4469        self.dispatch_keystroke_observers(event, None, context_stack, cx);
4470    }
4471
4472    pub(crate) fn pending_input_changed(&mut self, cx: &mut App) {
4473        self.pending_input_observers
4474            .clone()
4475            .retain(&(), |callback| callback(self, cx));
4476    }
4477
4478    fn dispatch_key_down_up_event(
4479        &mut self,
4480        event: &dyn Any,
4481        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4482        cx: &mut App,
4483    ) {
4484        // Capture phase
4485        for node_id in dispatch_path {
4486            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4487
4488            for key_listener in node.key_listeners.clone() {
4489                key_listener(event, DispatchPhase::Capture, self, cx);
4490                if !cx.propagate_event {
4491                    return;
4492                }
4493            }
4494        }
4495
4496        // Bubble phase
4497        for node_id in dispatch_path.iter().rev() {
4498            // Handle low level key events
4499            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4500            for key_listener in node.key_listeners.clone() {
4501                key_listener(event, DispatchPhase::Bubble, self, cx);
4502                if !cx.propagate_event {
4503                    return;
4504                }
4505            }
4506        }
4507    }
4508
4509    fn dispatch_modifiers_changed_event(
4510        &mut self,
4511        event: &dyn Any,
4512        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4513        cx: &mut App,
4514    ) {
4515        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
4516            return;
4517        };
4518        for node_id in dispatch_path.iter().rev() {
4519            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4520            for listener in node.modifiers_changed_listeners.clone() {
4521                listener(event, self, cx);
4522                if !cx.propagate_event {
4523                    return;
4524                }
4525            }
4526        }
4527    }
4528
4529    /// Determine whether a potential multi-stroke key binding is in progress on this window.
4530    pub fn has_pending_keystrokes(&self) -> bool {
4531        self.pending_input.is_some()
4532    }
4533
4534    pub(crate) fn clear_pending_keystrokes(&mut self) {
4535        self.pending_input.take();
4536    }
4537
4538    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
4539    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
4540        self.pending_input
4541            .as_ref()
4542            .map(|pending_input| pending_input.keystrokes.as_slice())
4543    }
4544
4545    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
4546        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4547        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4548
4549        'replay: for replay in replays {
4550            let event = KeyDownEvent {
4551                keystroke: replay.keystroke.clone(),
4552                is_held: false,
4553                prefer_character_input: true,
4554            };
4555
4556            cx.propagate_event = true;
4557            for binding in replay.bindings {
4558                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
4559                if !cx.propagate_event {
4560                    self.dispatch_keystroke_observers(
4561                        &event,
4562                        Some(binding.action),
4563                        Vec::default(),
4564                        cx,
4565                    );
4566                    continue 'replay;
4567                }
4568            }
4569
4570            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
4571            if !cx.propagate_event {
4572                continue 'replay;
4573            }
4574            if let Some(input) = replay.keystroke.key_char.as_ref().cloned()
4575                && let Some(mut input_handler) = self.platform_window.take_input_handler()
4576            {
4577                input_handler.dispatch_input(&input, self, cx);
4578                self.platform_window.set_input_handler(input_handler)
4579            }
4580        }
4581    }
4582
4583    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
4584        focus_id
4585            .and_then(|focus_id| {
4586                self.rendered_frame
4587                    .dispatch_tree
4588                    .focusable_node_id(focus_id)
4589            })
4590            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id())
4591    }
4592
4593    fn dispatch_action_on_node(
4594        &mut self,
4595        node_id: DispatchNodeId,
4596        action: &dyn Action,
4597        cx: &mut App,
4598    ) {
4599        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4600
4601        // Capture phase for global actions.
4602        cx.propagate_event = true;
4603        if let Some(mut global_listeners) = cx
4604            .global_action_listeners
4605            .remove(&action.as_any().type_id())
4606        {
4607            for listener in &global_listeners {
4608                listener(action.as_any(), DispatchPhase::Capture, cx);
4609                if !cx.propagate_event {
4610                    break;
4611                }
4612            }
4613
4614            global_listeners.extend(
4615                cx.global_action_listeners
4616                    .remove(&action.as_any().type_id())
4617                    .unwrap_or_default(),
4618            );
4619
4620            cx.global_action_listeners
4621                .insert(action.as_any().type_id(), global_listeners);
4622        }
4623
4624        if !cx.propagate_event {
4625            return;
4626        }
4627
4628        // Capture phase for window actions.
4629        for node_id in &dispatch_path {
4630            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4631            for DispatchActionListener {
4632                action_type,
4633                listener,
4634            } in node.action_listeners.clone()
4635            {
4636                let any_action = action.as_any();
4637                if action_type == any_action.type_id() {
4638                    listener(any_action, DispatchPhase::Capture, self, cx);
4639
4640                    if !cx.propagate_event {
4641                        return;
4642                    }
4643                }
4644            }
4645        }
4646
4647        // Bubble phase for window actions.
4648        for node_id in dispatch_path.iter().rev() {
4649            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4650            for DispatchActionListener {
4651                action_type,
4652                listener,
4653            } in node.action_listeners.clone()
4654            {
4655                let any_action = action.as_any();
4656                if action_type == any_action.type_id() {
4657                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4658                    listener(any_action, DispatchPhase::Bubble, self, cx);
4659
4660                    if !cx.propagate_event {
4661                        return;
4662                    }
4663                }
4664            }
4665        }
4666
4667        // Bubble phase for global actions.
4668        if let Some(mut global_listeners) = cx
4669            .global_action_listeners
4670            .remove(&action.as_any().type_id())
4671        {
4672            for listener in global_listeners.iter().rev() {
4673                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4674
4675                listener(action.as_any(), DispatchPhase::Bubble, cx);
4676                if !cx.propagate_event {
4677                    break;
4678                }
4679            }
4680
4681            global_listeners.extend(
4682                cx.global_action_listeners
4683                    .remove(&action.as_any().type_id())
4684                    .unwrap_or_default(),
4685            );
4686
4687            cx.global_action_listeners
4688                .insert(action.as_any().type_id(), global_listeners);
4689        }
4690    }
4691
4692    /// Register the given handler to be invoked whenever the global of the given type
4693    /// is updated.
4694    pub fn observe_global<G: Global>(
4695        &mut self,
4696        cx: &mut App,
4697        f: impl Fn(&mut Window, &mut App) + 'static,
4698    ) -> Subscription {
4699        let window_handle = self.handle;
4700        let (subscription, activate) = cx.global_observers.insert(
4701            TypeId::of::<G>(),
4702            Box::new(move |cx| {
4703                window_handle
4704                    .update(cx, |_, window, cx| f(window, cx))
4705                    .is_ok()
4706            }),
4707        );
4708        cx.defer(move |_| activate());
4709        subscription
4710    }
4711
4712    /// Focus the current window and bring it to the foreground at the platform level.
4713    pub fn activate_window(&self) {
4714        self.platform_window.activate();
4715    }
4716
4717    /// Minimize the current window at the platform level.
4718    pub fn minimize_window(&self) {
4719        self.platform_window.minimize();
4720    }
4721
4722    /// Toggle full screen status on the current window at the platform level.
4723    pub fn toggle_fullscreen(&self) {
4724        self.platform_window.toggle_fullscreen();
4725    }
4726
4727    /// Updates the IME panel position suggestions for languages like japanese, chinese.
4728    pub fn invalidate_character_coordinates(&self) {
4729        self.on_next_frame(|window, cx| {
4730            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
4731                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
4732                    window.platform_window.update_ime_position(bounds);
4733                }
4734                window.platform_window.set_input_handler(input_handler);
4735            }
4736        });
4737    }
4738
4739    /// Present a platform dialog.
4740    /// The provided message will be presented, along with buttons for each answer.
4741    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
4742    pub fn prompt<T>(
4743        &mut self,
4744        level: PromptLevel,
4745        message: &str,
4746        detail: Option<&str>,
4747        answers: &[T],
4748        cx: &mut App,
4749    ) -> oneshot::Receiver<usize>
4750    where
4751        T: Clone + Into<PromptButton>,
4752    {
4753        let prompt_builder = cx.prompt_builder.take();
4754        let Some(prompt_builder) = prompt_builder else {
4755            unreachable!("Re-entrant window prompting is not supported by GPUI");
4756        };
4757
4758        let answers = answers
4759            .iter()
4760            .map(|answer| answer.clone().into())
4761            .collect::<Vec<_>>();
4762
4763        let receiver = match &prompt_builder {
4764            PromptBuilder::Default => self
4765                .platform_window
4766                .prompt(level, message, detail, &answers)
4767                .unwrap_or_else(|| {
4768                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4769                }),
4770            PromptBuilder::Custom(_) => {
4771                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4772            }
4773        };
4774
4775        cx.prompt_builder = Some(prompt_builder);
4776
4777        receiver
4778    }
4779
4780    fn build_custom_prompt(
4781        &mut self,
4782        prompt_builder: &PromptBuilder,
4783        level: PromptLevel,
4784        message: &str,
4785        detail: Option<&str>,
4786        answers: &[PromptButton],
4787        cx: &mut App,
4788    ) -> oneshot::Receiver<usize> {
4789        let (sender, receiver) = oneshot::channel();
4790        let handle = PromptHandle::new(sender);
4791        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
4792        self.prompt = Some(handle);
4793        receiver
4794    }
4795
4796    /// Returns the current context stack.
4797    pub fn context_stack(&self) -> Vec<KeyContext> {
4798        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4799        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4800        dispatch_tree
4801            .dispatch_path(node_id)
4802            .iter()
4803            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4804            .collect()
4805    }
4806
4807    /// Returns all available actions for the focused element.
4808    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4809        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4810        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4811        for action_type in cx.global_action_listeners.keys() {
4812            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4813                let action = cx.actions.build_action_type(action_type).ok();
4814                if let Some(action) = action {
4815                    actions.insert(ix, action);
4816                }
4817            }
4818        }
4819        actions
4820    }
4821
4822    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4823    /// returned in the order they were added. For display, the last binding should take precedence.
4824    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4825        self.rendered_frame
4826            .dispatch_tree
4827            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4828    }
4829
4830    /// Returns the highest precedence key binding that invokes an action on the currently focused
4831    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4832    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4833        self.rendered_frame
4834            .dispatch_tree
4835            .highest_precedence_binding_for_action(
4836                action,
4837                &self.rendered_frame.dispatch_tree.context_stack,
4838            )
4839    }
4840
4841    /// Returns the key bindings for an action in a context.
4842    pub fn bindings_for_action_in_context(
4843        &self,
4844        action: &dyn Action,
4845        context: KeyContext,
4846    ) -> Vec<KeyBinding> {
4847        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4848        dispatch_tree.bindings_for_action(action, &[context])
4849    }
4850
4851    /// Returns the highest precedence key binding for an action in a context. This is more
4852    /// efficient than getting the last result of `bindings_for_action_in_context`.
4853    pub fn highest_precedence_binding_for_action_in_context(
4854        &self,
4855        action: &dyn Action,
4856        context: KeyContext,
4857    ) -> Option<KeyBinding> {
4858        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4859        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4860    }
4861
4862    /// Returns any bindings that would invoke an action on the given focus handle if it were
4863    /// focused. Bindings are returned in the order they were added. For display, the last binding
4864    /// should take precedence.
4865    pub fn bindings_for_action_in(
4866        &self,
4867        action: &dyn Action,
4868        focus_handle: &FocusHandle,
4869    ) -> Vec<KeyBinding> {
4870        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4871        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4872            return vec![];
4873        };
4874        dispatch_tree.bindings_for_action(action, &context_stack)
4875    }
4876
4877    /// Returns the highest precedence key binding that would invoke an action on the given focus
4878    /// handle if it were focused. This is more efficient than getting the last result of
4879    /// `bindings_for_action_in`.
4880    pub fn highest_precedence_binding_for_action_in(
4881        &self,
4882        action: &dyn Action,
4883        focus_handle: &FocusHandle,
4884    ) -> Option<KeyBinding> {
4885        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4886        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4887        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4888    }
4889
4890    /// Find the bindings that can follow the current input sequence for the current context stack.
4891    pub fn possible_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
4892        self.rendered_frame
4893            .dispatch_tree
4894            .possible_next_bindings_for_input(input, &self.context_stack())
4895    }
4896
4897    fn context_stack_for_focus_handle(
4898        &self,
4899        focus_handle: &FocusHandle,
4900    ) -> Option<Vec<KeyContext>> {
4901        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4902        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4903        let context_stack: Vec<_> = dispatch_tree
4904            .dispatch_path(node_id)
4905            .into_iter()
4906            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4907            .collect();
4908        Some(context_stack)
4909    }
4910
4911    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4912    pub fn listener_for<T: 'static, E>(
4913        &self,
4914        view: &Entity<T>,
4915        f: impl Fn(&mut T, &E, &mut Window, &mut Context<T>) + 'static,
4916    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4917        let view = view.downgrade();
4918        move |e: &E, window: &mut Window, cx: &mut App| {
4919            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4920        }
4921    }
4922
4923    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4924    pub fn handler_for<E: 'static, Callback: Fn(&mut E, &mut Window, &mut Context<E>) + 'static>(
4925        &self,
4926        entity: &Entity<E>,
4927        f: Callback,
4928    ) -> impl Fn(&mut Window, &mut App) + 'static {
4929        let entity = entity.downgrade();
4930        move |window: &mut Window, cx: &mut App| {
4931            entity.update(cx, |entity, cx| f(entity, window, cx)).ok();
4932        }
4933    }
4934
4935    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4936    /// If the callback returns false, the window won't be closed.
4937    pub fn on_window_should_close(
4938        &self,
4939        cx: &App,
4940        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4941    ) {
4942        let mut cx = self.to_async(cx);
4943        self.platform_window.on_should_close(Box::new(move || {
4944            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4945        }))
4946    }
4947
4948    /// Register an action listener on this node for the next frame. The type of action
4949    /// is determined by the first parameter of the given listener. When the next frame is rendered
4950    /// the listener will be cleared.
4951    ///
4952    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4953    /// a specific need to register a listener yourself.
4954    ///
4955    /// This method should only be called as part of the paint phase of element drawing.
4956    pub fn on_action(
4957        &mut self,
4958        action_type: TypeId,
4959        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4960    ) {
4961        self.invalidator.debug_assert_paint();
4962
4963        self.next_frame
4964            .dispatch_tree
4965            .on_action(action_type, Rc::new(listener));
4966    }
4967
4968    /// Register a capturing action listener on this node for the next frame if the condition is true.
4969    /// The type of action is determined by the first parameter of the given listener. When the next
4970    /// frame is rendered the listener will be cleared.
4971    ///
4972    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4973    /// a specific need to register a listener yourself.
4974    ///
4975    /// This method should only be called as part of the paint phase of element drawing.
4976    pub fn on_action_when(
4977        &mut self,
4978        condition: bool,
4979        action_type: TypeId,
4980        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4981    ) {
4982        self.invalidator.debug_assert_paint();
4983
4984        if condition {
4985            self.next_frame
4986                .dispatch_tree
4987                .on_action(action_type, Rc::new(listener));
4988        }
4989    }
4990
4991    /// Read information about the GPU backing this window.
4992    /// Currently returns None on Mac and Windows.
4993    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4994        self.platform_window.gpu_specs()
4995    }
4996
4997    /// Perform titlebar double-click action.
4998    /// This is macOS specific.
4999    pub fn titlebar_double_click(&self) {
5000        self.platform_window.titlebar_double_click();
5001    }
5002
5003    /// Gets the window's title at the platform level.
5004    /// This is macOS specific.
5005    pub fn window_title(&self) -> String {
5006        self.platform_window.get_title()
5007    }
5008
5009    /// Returns a list of all tabbed windows and their titles.
5010    /// This is macOS specific.
5011    pub fn tabbed_windows(&self) -> Option<Vec<SystemWindowTab>> {
5012        self.platform_window.tabbed_windows()
5013    }
5014
5015    /// Returns the tab bar visibility.
5016    /// This is macOS specific.
5017    pub fn tab_bar_visible(&self) -> bool {
5018        self.platform_window.tab_bar_visible()
5019    }
5020
5021    /// Merges all open windows into a single tabbed window.
5022    /// This is macOS specific.
5023    pub fn merge_all_windows(&self) {
5024        self.platform_window.merge_all_windows()
5025    }
5026
5027    /// Moves the tab to a new containing window.
5028    /// This is macOS specific.
5029    pub fn move_tab_to_new_window(&self) {
5030        self.platform_window.move_tab_to_new_window()
5031    }
5032
5033    /// Shows or hides the window tab overview.
5034    /// This is macOS specific.
5035    pub fn toggle_window_tab_overview(&self) {
5036        self.platform_window.toggle_window_tab_overview()
5037    }
5038
5039    /// Sets the tabbing identifier for the window.
5040    /// This is macOS specific.
5041    pub fn set_tabbing_identifier(&self, tabbing_identifier: Option<String>) {
5042        self.platform_window
5043            .set_tabbing_identifier(tabbing_identifier)
5044    }
5045
5046    /// Request the OS to play an alert sound. On some platforms this is associated
5047    /// with the window, for others it's just a simple global function call.
5048    pub fn play_system_bell(&self) {
5049        self.platform_window.play_system_bell()
5050    }
5051
5052    /// Toggles the inspector mode on this window.
5053    #[cfg(any(feature = "inspector", debug_assertions))]
5054    pub fn toggle_inspector(&mut self, cx: &mut App) {
5055        self.inspector = match self.inspector {
5056            None => Some(cx.new(|_| Inspector::new())),
5057            Some(_) => None,
5058        };
5059        self.refresh();
5060    }
5061
5062    /// Returns true if the window is in inspector mode.
5063    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
5064        #[cfg(any(feature = "inspector", debug_assertions))]
5065        {
5066            if let Some(inspector) = &self.inspector {
5067                return inspector.read(_cx).is_picking();
5068            }
5069        }
5070        false
5071    }
5072
5073    /// Executes the provided function with mutable access to an inspector state.
5074    #[cfg(any(feature = "inspector", debug_assertions))]
5075    pub fn with_inspector_state<T: 'static, R>(
5076        &mut self,
5077        _inspector_id: Option<&crate::InspectorElementId>,
5078        cx: &mut App,
5079        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
5080    ) -> R {
5081        if let Some(inspector_id) = _inspector_id
5082            && let Some(inspector) = &self.inspector
5083        {
5084            let inspector = inspector.clone();
5085            let active_element_id = inspector.read(cx).active_element_id();
5086            if Some(inspector_id) == active_element_id {
5087                return inspector.update(cx, |inspector, _cx| {
5088                    inspector.with_active_element_state(self, f)
5089                });
5090            }
5091        }
5092        f(&mut None, self)
5093    }
5094
5095    #[cfg(any(feature = "inspector", debug_assertions))]
5096    pub(crate) fn build_inspector_element_id(
5097        &mut self,
5098        path: crate::InspectorElementPath,
5099    ) -> crate::InspectorElementId {
5100        self.invalidator.debug_assert_paint_or_prepaint();
5101        let path = Rc::new(path);
5102        let next_instance_id = self
5103            .next_frame
5104            .next_inspector_instance_ids
5105            .entry(path.clone())
5106            .or_insert(0);
5107        let instance_id = *next_instance_id;
5108        *next_instance_id += 1;
5109        crate::InspectorElementId { path, instance_id }
5110    }
5111
5112    #[cfg(any(feature = "inspector", debug_assertions))]
5113    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
5114        if let Some(inspector) = self.inspector.take() {
5115            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
5116            inspector_element.prepaint_as_root(
5117                point(self.viewport_size.width - inspector_width, px(0.0)),
5118                size(inspector_width, self.viewport_size.height).into(),
5119                self,
5120                cx,
5121            );
5122            self.inspector = Some(inspector);
5123            Some(inspector_element)
5124        } else {
5125            None
5126        }
5127    }
5128
5129    #[cfg(any(feature = "inspector", debug_assertions))]
5130    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
5131        if let Some(mut inspector_element) = inspector_element {
5132            inspector_element.paint(self, cx);
5133        };
5134    }
5135
5136    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
5137    /// inspect UI elements by clicking on them.
5138    #[cfg(any(feature = "inspector", debug_assertions))]
5139    pub fn insert_inspector_hitbox(
5140        &mut self,
5141        hitbox_id: HitboxId,
5142        inspector_id: Option<&crate::InspectorElementId>,
5143        cx: &App,
5144    ) {
5145        self.invalidator.debug_assert_paint_or_prepaint();
5146        if !self.is_inspector_picking(cx) {
5147            return;
5148        }
5149        if let Some(inspector_id) = inspector_id {
5150            self.next_frame
5151                .inspector_hitboxes
5152                .insert(hitbox_id, inspector_id.clone());
5153        }
5154    }
5155
5156    #[cfg(any(feature = "inspector", debug_assertions))]
5157    fn paint_inspector_hitbox(&mut self, cx: &App) {
5158        if let Some(inspector) = self.inspector.as_ref() {
5159            let inspector = inspector.read(cx);
5160            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
5161                && let Some(hitbox) = self
5162                    .next_frame
5163                    .hitboxes
5164                    .iter()
5165                    .find(|hitbox| hitbox.id == hitbox_id)
5166            {
5167                self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
5168            }
5169        }
5170    }
5171
5172    #[cfg(any(feature = "inspector", debug_assertions))]
5173    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
5174        let Some(inspector) = self.inspector.clone() else {
5175            return;
5176        };
5177        if event.downcast_ref::<MouseMoveEvent>().is_some() {
5178            inspector.update(cx, |inspector, _cx| {
5179                if let Some((_, inspector_id)) =
5180                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
5181                {
5182                    inspector.hover(inspector_id, self);
5183                }
5184            });
5185        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
5186            inspector.update(cx, |inspector, _cx| {
5187                if let Some((_, inspector_id)) =
5188                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
5189                {
5190                    inspector.select(inspector_id, self);
5191                }
5192            });
5193        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
5194            // This should be kept in sync with SCROLL_LINES in x11 platform.
5195            const SCROLL_LINES: f32 = 3.0;
5196            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
5197            let delta_y = event
5198                .delta
5199                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
5200                .y;
5201            if let Some(inspector) = self.inspector.clone() {
5202                inspector.update(cx, |inspector, _cx| {
5203                    if let Some(depth) = inspector.pick_depth.as_mut() {
5204                        *depth += f32::from(delta_y) / SCROLL_PIXELS_PER_LAYER;
5205                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
5206                        if *depth < 0.0 {
5207                            *depth = 0.0;
5208                        } else if *depth > max_depth {
5209                            *depth = max_depth;
5210                        }
5211                        if let Some((_, inspector_id)) =
5212                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
5213                        {
5214                            inspector.set_active_element_id(inspector_id, self);
5215                        }
5216                    }
5217                });
5218            }
5219        }
5220    }
5221
5222    #[cfg(any(feature = "inspector", debug_assertions))]
5223    fn hovered_inspector_hitbox(
5224        &self,
5225        inspector: &Inspector,
5226        frame: &Frame,
5227    ) -> Option<(HitboxId, crate::InspectorElementId)> {
5228        if let Some(pick_depth) = inspector.pick_depth {
5229            let depth = (pick_depth as i64).try_into().unwrap_or(0);
5230            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
5231            let skip_count = (depth as usize).min(max_skipped);
5232            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
5233                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
5234                    return Some((*hitbox_id, inspector_id.clone()));
5235                }
5236            }
5237        }
5238        None
5239    }
5240
5241    /// For testing: set the current modifier keys state.
5242    /// This does not generate any events.
5243    #[cfg(any(test, feature = "test-support"))]
5244    pub fn set_modifiers(&mut self, modifiers: Modifiers) {
5245        self.modifiers = modifiers;
5246    }
5247
5248    /// For testing: simulate a mouse move event to the given position.
5249    /// This dispatches the event through the normal event handling path,
5250    /// which will trigger hover states and tooltips.
5251    #[cfg(any(test, feature = "test-support"))]
5252    pub fn simulate_mouse_move(&mut self, position: Point<Pixels>, cx: &mut App) {
5253        let event = PlatformInput::MouseMove(MouseMoveEvent {
5254            position,
5255            modifiers: self.modifiers,
5256            pressed_button: None,
5257        });
5258        let _ = self.dispatch_event(event, cx);
5259    }
5260}
5261
5262// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
5263slotmap::new_key_type! {
5264    /// A unique identifier for a window.
5265    pub struct WindowId;
5266}
5267
5268impl WindowId {
5269    /// Converts this window ID to a `u64`.
5270    pub fn as_u64(&self) -> u64 {
5271        self.0.as_ffi()
5272    }
5273}
5274
5275impl From<u64> for WindowId {
5276    fn from(value: u64) -> Self {
5277        WindowId(slotmap::KeyData::from_ffi(value))
5278    }
5279}
5280
5281/// A handle to a window with a specific root view type.
5282/// Note that this does not keep the window alive on its own.
5283#[derive(Deref, DerefMut)]
5284pub struct WindowHandle<V> {
5285    #[deref]
5286    #[deref_mut]
5287    pub(crate) any_handle: AnyWindowHandle,
5288    state_type: PhantomData<fn(V) -> V>,
5289}
5290
5291impl<V> Debug for WindowHandle<V> {
5292    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
5293        f.debug_struct("WindowHandle")
5294            .field("any_handle", &self.any_handle.id.as_u64())
5295            .finish()
5296    }
5297}
5298
5299impl<V: 'static + Render> WindowHandle<V> {
5300    /// Creates a new handle from a window ID.
5301    /// This does not check if the root type of the window is `V`.
5302    pub fn new(id: WindowId) -> Self {
5303        WindowHandle {
5304            any_handle: AnyWindowHandle {
5305                id,
5306                state_type: TypeId::of::<V>(),
5307            },
5308            state_type: PhantomData,
5309        }
5310    }
5311
5312    /// Get the root view out of this window.
5313    ///
5314    /// This will fail if the window is closed or if the root view's type does not match `V`.
5315    #[cfg(any(test, feature = "test-support"))]
5316    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
5317    where
5318        C: AppContext,
5319    {
5320        cx.update_window(self.any_handle, |root_view, _, _| {
5321            root_view
5322                .downcast::<V>()
5323                .map_err(|_| anyhow!("the type of the window's root view has changed"))
5324        })?
5325    }
5326
5327    /// Updates the root view of this window.
5328    ///
5329    /// This will fail if the window has been closed or if the root view's type does not match
5330    pub fn update<C, R>(
5331        &self,
5332        cx: &mut C,
5333        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
5334    ) -> Result<R>
5335    where
5336        C: AppContext,
5337    {
5338        cx.update_window(self.any_handle, |root_view, window, cx| {
5339            let view = root_view
5340                .downcast::<V>()
5341                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
5342
5343            Ok(view.update(cx, |view, cx| update(view, window, cx)))
5344        })?
5345    }
5346
5347    /// Read the root view out of this window.
5348    ///
5349    /// This will fail if the window is closed or if the root view's type does not match `V`.
5350    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
5351        let x = cx
5352            .windows
5353            .get(self.id)
5354            .and_then(|window| {
5355                window
5356                    .as_deref()
5357                    .and_then(|window| window.root.clone())
5358                    .map(|root_view| root_view.downcast::<V>())
5359            })
5360            .context("window not found")?
5361            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
5362
5363        Ok(x.read(cx))
5364    }
5365
5366    /// Read the root view out of this window, with a callback
5367    ///
5368    /// This will fail if the window is closed or if the root view's type does not match `V`.
5369    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
5370    where
5371        C: AppContext,
5372    {
5373        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
5374    }
5375
5376    /// Read the root view pointer off of this window.
5377    ///
5378    /// This will fail if the window is closed or if the root view's type does not match `V`.
5379    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
5380    where
5381        C: AppContext,
5382    {
5383        cx.read_window(self, |root_view, _cx| root_view)
5384    }
5385
5386    /// Check if this window is 'active'.
5387    ///
5388    /// Will return `None` if the window is closed or currently
5389    /// borrowed.
5390    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
5391        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
5392            .ok()
5393    }
5394}
5395
5396impl<V> Copy for WindowHandle<V> {}
5397
5398impl<V> Clone for WindowHandle<V> {
5399    fn clone(&self) -> Self {
5400        *self
5401    }
5402}
5403
5404impl<V> PartialEq for WindowHandle<V> {
5405    fn eq(&self, other: &Self) -> bool {
5406        self.any_handle == other.any_handle
5407    }
5408}
5409
5410impl<V> Eq for WindowHandle<V> {}
5411
5412impl<V> Hash for WindowHandle<V> {
5413    fn hash<H: Hasher>(&self, state: &mut H) {
5414        self.any_handle.hash(state);
5415    }
5416}
5417
5418impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
5419    fn from(val: WindowHandle<V>) -> Self {
5420        val.any_handle
5421    }
5422}
5423
5424/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
5425#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
5426pub struct AnyWindowHandle {
5427    pub(crate) id: WindowId,
5428    state_type: TypeId,
5429}
5430
5431impl AnyWindowHandle {
5432    /// Get the ID of this window.
5433    pub fn window_id(&self) -> WindowId {
5434        self.id
5435    }
5436
5437    /// Attempt to convert this handle to a window handle with a specific root view type.
5438    /// If the types do not match, this will return `None`.
5439    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
5440        if TypeId::of::<T>() == self.state_type {
5441            Some(WindowHandle {
5442                any_handle: *self,
5443                state_type: PhantomData,
5444            })
5445        } else {
5446            None
5447        }
5448    }
5449
5450    /// Updates the state of the root view of this window.
5451    ///
5452    /// This will fail if the window has been closed.
5453    pub fn update<C, R>(
5454        self,
5455        cx: &mut C,
5456        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
5457    ) -> Result<R>
5458    where
5459        C: AppContext,
5460    {
5461        cx.update_window(self, update)
5462    }
5463
5464    /// Read the state of the root view of this window.
5465    ///
5466    /// This will fail if the window has been closed.
5467    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
5468    where
5469        C: AppContext,
5470        T: 'static,
5471    {
5472        let view = self
5473            .downcast::<T>()
5474            .context("the type of the window's root view has changed")?;
5475
5476        cx.read_window(&view, read)
5477    }
5478}
5479
5480impl HasWindowHandle for Window {
5481    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
5482        self.platform_window.window_handle()
5483    }
5484}
5485
5486impl HasDisplayHandle for Window {
5487    fn display_handle(
5488        &self,
5489    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
5490        self.platform_window.display_handle()
5491    }
5492}
5493
5494/// An identifier for an [`Element`].
5495///
5496/// Can be constructed with a string, a number, or both, as well
5497/// as other internal representations.
5498#[derive(Clone, Debug, Eq, PartialEq, Hash)]
5499pub enum ElementId {
5500    /// The ID of a View element
5501    View(EntityId),
5502    /// An integer ID.
5503    Integer(u64),
5504    /// A string based ID.
5505    Name(SharedString),
5506    /// A UUID.
5507    Uuid(Uuid),
5508    /// An ID that's equated with a focus handle.
5509    FocusHandle(FocusId),
5510    /// A combination of a name and an integer.
5511    NamedInteger(SharedString, u64),
5512    /// A path.
5513    Path(Arc<std::path::Path>),
5514    /// A code location.
5515    CodeLocation(core::panic::Location<'static>),
5516    /// A labeled child of an element.
5517    NamedChild(Arc<ElementId>, SharedString),
5518    /// A byte array ID (used for text-anchors)
5519    OpaqueId([u8; 20]),
5520}
5521
5522impl ElementId {
5523    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
5524    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
5525        Self::NamedInteger(name.into(), integer as u64)
5526    }
5527}
5528
5529impl Display for ElementId {
5530    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
5531        match self {
5532            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
5533            ElementId::Integer(ix) => write!(f, "{}", ix)?,
5534            ElementId::Name(name) => write!(f, "{}", name)?,
5535            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
5536            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
5537            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
5538            ElementId::Path(path) => write!(f, "{}", path.display())?,
5539            ElementId::CodeLocation(location) => write!(f, "{}", location)?,
5540            ElementId::NamedChild(id, name) => write!(f, "{}-{}", id, name)?,
5541            ElementId::OpaqueId(opaque_id) => write!(f, "{:x?}", opaque_id)?,
5542        }
5543
5544        Ok(())
5545    }
5546}
5547
5548impl TryInto<SharedString> for ElementId {
5549    type Error = anyhow::Error;
5550
5551    fn try_into(self) -> anyhow::Result<SharedString> {
5552        if let ElementId::Name(name) = self {
5553            Ok(name)
5554        } else {
5555            anyhow::bail!("element id is not string")
5556        }
5557    }
5558}
5559
5560impl From<usize> for ElementId {
5561    fn from(id: usize) -> Self {
5562        ElementId::Integer(id as u64)
5563    }
5564}
5565
5566impl From<i32> for ElementId {
5567    fn from(id: i32) -> Self {
5568        Self::Integer(id as u64)
5569    }
5570}
5571
5572impl From<SharedString> for ElementId {
5573    fn from(name: SharedString) -> Self {
5574        ElementId::Name(name)
5575    }
5576}
5577
5578impl From<String> for ElementId {
5579    fn from(name: String) -> Self {
5580        ElementId::Name(name.into())
5581    }
5582}
5583
5584impl From<Arc<str>> for ElementId {
5585    fn from(name: Arc<str>) -> Self {
5586        ElementId::Name(name.into())
5587    }
5588}
5589
5590impl From<Arc<std::path::Path>> for ElementId {
5591    fn from(path: Arc<std::path::Path>) -> Self {
5592        ElementId::Path(path)
5593    }
5594}
5595
5596impl From<&'static str> for ElementId {
5597    fn from(name: &'static str) -> Self {
5598        ElementId::Name(name.into())
5599    }
5600}
5601
5602impl<'a> From<&'a FocusHandle> for ElementId {
5603    fn from(handle: &'a FocusHandle) -> Self {
5604        ElementId::FocusHandle(handle.id)
5605    }
5606}
5607
5608impl From<(&'static str, EntityId)> for ElementId {
5609    fn from((name, id): (&'static str, EntityId)) -> Self {
5610        ElementId::NamedInteger(name.into(), id.as_u64())
5611    }
5612}
5613
5614impl From<(&'static str, usize)> for ElementId {
5615    fn from((name, id): (&'static str, usize)) -> Self {
5616        ElementId::NamedInteger(name.into(), id as u64)
5617    }
5618}
5619
5620impl From<(SharedString, usize)> for ElementId {
5621    fn from((name, id): (SharedString, usize)) -> Self {
5622        ElementId::NamedInteger(name, id as u64)
5623    }
5624}
5625
5626impl From<(&'static str, u64)> for ElementId {
5627    fn from((name, id): (&'static str, u64)) -> Self {
5628        ElementId::NamedInteger(name.into(), id)
5629    }
5630}
5631
5632impl From<Uuid> for ElementId {
5633    fn from(value: Uuid) -> Self {
5634        Self::Uuid(value)
5635    }
5636}
5637
5638impl From<(&'static str, u32)> for ElementId {
5639    fn from((name, id): (&'static str, u32)) -> Self {
5640        ElementId::NamedInteger(name.into(), id.into())
5641    }
5642}
5643
5644impl<T: Into<SharedString>> From<(ElementId, T)> for ElementId {
5645    fn from((id, name): (ElementId, T)) -> Self {
5646        ElementId::NamedChild(Arc::new(id), name.into())
5647    }
5648}
5649
5650impl From<&'static core::panic::Location<'static>> for ElementId {
5651    fn from(location: &'static core::panic::Location<'static>) -> Self {
5652        ElementId::CodeLocation(*location)
5653    }
5654}
5655
5656impl From<[u8; 20]> for ElementId {
5657    fn from(opaque_id: [u8; 20]) -> Self {
5658        ElementId::OpaqueId(opaque_id)
5659    }
5660}
5661
5662/// A rectangle to be rendered in the window at the given position and size.
5663/// Passed as an argument [`Window::paint_quad`].
5664#[derive(Clone)]
5665pub struct PaintQuad {
5666    /// The bounds of the quad within the window.
5667    pub bounds: Bounds<Pixels>,
5668    /// The radii of the quad's corners.
5669    pub corner_radii: Corners<Pixels>,
5670    /// The background color of the quad.
5671    pub background: Background,
5672    /// The widths of the quad's borders.
5673    pub border_widths: Edges<Pixels>,
5674    /// The color of the quad's borders.
5675    pub border_color: Hsla,
5676    /// The style of the quad's borders.
5677    pub border_style: BorderStyle,
5678}
5679
5680impl PaintQuad {
5681    /// Sets the corner radii of the quad.
5682    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
5683        PaintQuad {
5684            corner_radii: corner_radii.into(),
5685            ..self
5686        }
5687    }
5688
5689    /// Sets the border widths of the quad.
5690    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5691        PaintQuad {
5692            border_widths: border_widths.into(),
5693            ..self
5694        }
5695    }
5696
5697    /// Sets the border color of the quad.
5698    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5699        PaintQuad {
5700            border_color: border_color.into(),
5701            ..self
5702        }
5703    }
5704
5705    /// Sets the background color of the quad.
5706    pub fn background(self, background: impl Into<Background>) -> Self {
5707        PaintQuad {
5708            background: background.into(),
5709            ..self
5710        }
5711    }
5712}
5713
5714/// Creates a quad with the given parameters.
5715pub fn quad(
5716    bounds: Bounds<Pixels>,
5717    corner_radii: impl Into<Corners<Pixels>>,
5718    background: impl Into<Background>,
5719    border_widths: impl Into<Edges<Pixels>>,
5720    border_color: impl Into<Hsla>,
5721    border_style: BorderStyle,
5722) -> PaintQuad {
5723    PaintQuad {
5724        bounds,
5725        corner_radii: corner_radii.into(),
5726        background: background.into(),
5727        border_widths: border_widths.into(),
5728        border_color: border_color.into(),
5729        border_style,
5730    }
5731}
5732
5733/// Creates a filled quad with the given bounds and background color.
5734pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5735    PaintQuad {
5736        bounds: bounds.into(),
5737        corner_radii: (0.).into(),
5738        background: background.into(),
5739        border_widths: (0.).into(),
5740        border_color: transparent_black(),
5741        border_style: BorderStyle::default(),
5742    }
5743}
5744
5745/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5746pub fn outline(
5747    bounds: impl Into<Bounds<Pixels>>,
5748    border_color: impl Into<Hsla>,
5749    border_style: BorderStyle,
5750) -> PaintQuad {
5751    PaintQuad {
5752        bounds: bounds.into(),
5753        corner_radii: (0.).into(),
5754        background: transparent_black().into(),
5755        border_widths: (1.).into(),
5756        border_color: border_color.into(),
5757        border_style,
5758    }
5759}