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