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