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