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, PromptButton, PromptLevel, Quad,
  13    Render, RenderGlyphParams, RenderImage, RenderImageParams, RenderSvgParams, Replay, ResizeEdge,
  14    SMOOTH_SVG_SCALE_FACTOR, SUBPIXEL_VARIANTS_X, SUBPIXEL_VARIANTS_Y, ScaledPixels, Scene, Shadow,
  15    SharedString, Size, StrikethroughStyle, Style, SubscriberSet, Subscription, SystemWindowTab,
  16    SystemWindowTabController, TabStopMap, TaffyLayoutEngine, Task, TextStyle, TextStyleRefinement,
  17    TransformationMatrix, Underline, UnderlineStyle, WindowAppearance, WindowBackgroundAppearance,
  18    WindowBounds, WindowControls, WindowDecorations, WindowOptions, WindowParams, WindowTextSystem,
  19    point, prelude::*, px, rems, size, transparent_black,
  20};
  21use anyhow::{Context as _, Result, anyhow};
  22use collections::{FxHashMap, FxHashSet};
  23#[cfg(target_os = "macos")]
  24use core_video::pixel_buffer::CVPixelBuffer;
  25use derive_more::{Deref, DerefMut};
  26use futures::FutureExt;
  27use futures::channel::oneshot;
  28use itertools::FoldWhile::{Continue, Done};
  29use itertools::Itertools;
  30use parking_lot::RwLock;
  31use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
  32use refineable::Refineable;
  33use slotmap::SlotMap;
  34use smallvec::SmallVec;
  35use std::{
  36    any::{Any, TypeId},
  37    borrow::Cow,
  38    cell::{Cell, RefCell},
  39    cmp,
  40    fmt::{Debug, Display},
  41    hash::{Hash, Hasher},
  42    marker::PhantomData,
  43    mem,
  44    ops::{DerefMut, Range},
  45    rc::Rc,
  46    sync::{
  47        Arc, Weak,
  48        atomic::{AtomicUsize, Ordering::SeqCst},
  49    },
  50    time::{Duration, Instant},
  51};
  52use util::post_inc;
  53use util::{ResultExt, measure};
  54use uuid::Uuid;
  55
  56mod prompts;
  57
  58use crate::util::atomic_incr_if_not_zero;
  59pub use prompts::*;
  60
  61pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1536.), px(864.));
  62
  63/// A 6:5 aspect ratio minimum window size to be used for functional,
  64/// additional-to-main-Zed windows, like the settings and rules library windows.
  65pub const DEFAULT_ADDITIONAL_WINDOW_SIZE: Size<Pixels> = Size {
  66    width: Pixels(900.),
  67    height: Pixels(750.),
  68};
  69
  70/// Represents the two different phases when dispatching events.
  71#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  72pub enum DispatchPhase {
  73    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  74    /// invoked front to back and keyboard event listeners are invoked from the focused element
  75    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  76    /// registering event listeners.
  77    #[default]
  78    Bubble,
  79    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  80    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  81    /// is used for special purposes such as clearing the "pressed" state for click events. If
  82    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  83    /// outside of the immediate region may rely on detecting non-local events during this phase.
  84    Capture,
  85}
  86
  87impl DispatchPhase {
  88    /// Returns true if this represents the "bubble" phase.
  89    #[inline]
  90    pub fn bubble(self) -> bool {
  91        self == DispatchPhase::Bubble
  92    }
  93
  94    /// Returns true if this represents the "capture" phase.
  95    #[inline]
  96    pub fn capture(self) -> bool {
  97        self == DispatchPhase::Capture
  98    }
  99}
 100
 101struct WindowInvalidatorInner {
 102    pub dirty: bool,
 103    pub draw_phase: DrawPhase,
 104    pub dirty_views: FxHashSet<EntityId>,
 105}
 106
 107#[derive(Clone)]
 108pub(crate) struct WindowInvalidator {
 109    inner: Rc<RefCell<WindowInvalidatorInner>>,
 110}
 111
 112impl WindowInvalidator {
 113    pub fn new() -> Self {
 114        WindowInvalidator {
 115            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 116                dirty: true,
 117                draw_phase: DrawPhase::None,
 118                dirty_views: FxHashSet::default(),
 119            })),
 120        }
 121    }
 122
 123    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 124        let mut inner = self.inner.borrow_mut();
 125        inner.dirty_views.insert(entity);
 126        if inner.draw_phase == DrawPhase::None {
 127            inner.dirty = true;
 128            cx.push_effect(Effect::Notify { emitter: entity });
 129            true
 130        } else {
 131            false
 132        }
 133    }
 134
 135    pub fn is_dirty(&self) -> bool {
 136        self.inner.borrow().dirty
 137    }
 138
 139    pub fn set_dirty(&self, dirty: bool) {
 140        self.inner.borrow_mut().dirty = dirty
 141    }
 142
 143    pub fn set_phase(&self, phase: DrawPhase) {
 144        self.inner.borrow_mut().draw_phase = phase
 145    }
 146
 147    pub fn take_views(&self) -> FxHashSet<EntityId> {
 148        mem::take(&mut self.inner.borrow_mut().dirty_views)
 149    }
 150
 151    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 152        self.inner.borrow_mut().dirty_views = views;
 153    }
 154
 155    pub fn not_drawing(&self) -> bool {
 156        self.inner.borrow().draw_phase == DrawPhase::None
 157    }
 158
 159    #[track_caller]
 160    pub fn debug_assert_paint(&self) {
 161        debug_assert!(
 162            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 163            "this method can only be called during paint"
 164        );
 165    }
 166
 167    #[track_caller]
 168    pub fn debug_assert_prepaint(&self) {
 169        debug_assert!(
 170            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 171            "this method can only be called during request_layout, or prepaint"
 172        );
 173    }
 174
 175    #[track_caller]
 176    pub fn debug_assert_paint_or_prepaint(&self) {
 177        debug_assert!(
 178            matches!(
 179                self.inner.borrow().draw_phase,
 180                DrawPhase::Paint | DrawPhase::Prepaint
 181            ),
 182            "this method can only be called during request_layout, prepaint, or paint"
 183        );
 184    }
 185}
 186
 187type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 188
 189pub(crate) type AnyWindowFocusListener =
 190    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 191
 192pub(crate) struct WindowFocusEvent {
 193    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 194    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 195}
 196
 197impl WindowFocusEvent {
 198    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 199        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 200    }
 201
 202    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 203        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 204    }
 205}
 206
 207/// This is provided when subscribing for `Context::on_focus_out` events.
 208pub struct FocusOutEvent {
 209    /// A weak focus handle representing what was blurred.
 210    pub blurred: WeakFocusHandle,
 211}
 212
 213slotmap::new_key_type! {
 214    /// A globally unique identifier for a focusable element.
 215    pub struct FocusId;
 216}
 217
 218thread_local! {
 219    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(1024 * 1024));
 220}
 221
 222/// Returned when the element arena has been used and so must be cleared before the next draw.
 223#[must_use]
 224pub struct ArenaClearNeeded;
 225
 226impl ArenaClearNeeded {
 227    /// Clear the element arena.
 228    pub fn clear(self) {
 229        ELEMENT_ARENA.with_borrow_mut(|element_arena| {
 230            element_arena.clear();
 231        });
 232    }
 233}
 234
 235pub(crate) type FocusMap = RwLock<SlotMap<FocusId, FocusRef>>;
 236pub(crate) struct FocusRef {
 237    pub(crate) ref_count: AtomicUsize,
 238    pub(crate) tab_index: isize,
 239    pub(crate) tab_stop: bool,
 240}
 241
 242impl FocusId {
 243    /// Obtains whether the element associated with this handle is currently focused.
 244    pub fn is_focused(&self, window: &Window) -> bool {
 245        window.focus == Some(*self)
 246    }
 247
 248    /// Obtains whether the element associated with this handle contains the focused
 249    /// element or is itself focused.
 250    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 251        window
 252            .focused(cx)
 253            .is_some_and(|focused| self.contains(focused.id, window))
 254    }
 255
 256    /// Obtains whether the element associated with this handle is contained within the
 257    /// focused element or is itself focused.
 258    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 259        let focused = window.focused(cx);
 260        focused.is_some_and(|focused| focused.id.contains(*self, window))
 261    }
 262
 263    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 264    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 265        window
 266            .rendered_frame
 267            .dispatch_tree
 268            .focus_contains(*self, other)
 269    }
 270}
 271
 272/// A handle which can be used to track and manipulate the focused element in a window.
 273pub struct FocusHandle {
 274    pub(crate) id: FocusId,
 275    handles: Arc<FocusMap>,
 276    /// The index of this element in the tab order.
 277    pub tab_index: isize,
 278    /// Whether this element can be focused by tab navigation.
 279    pub tab_stop: bool,
 280}
 281
 282impl std::fmt::Debug for FocusHandle {
 283    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 284        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 285    }
 286}
 287
 288impl FocusHandle {
 289    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 290        let id = handles.write().insert(FocusRef {
 291            ref_count: AtomicUsize::new(1),
 292            tab_index: 0,
 293            tab_stop: false,
 294        });
 295
 296        Self {
 297            id,
 298            tab_index: 0,
 299            tab_stop: false,
 300            handles: handles.clone(),
 301        }
 302    }
 303
 304    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 305        let lock = handles.read();
 306        let focus = lock.get(id)?;
 307        if atomic_incr_if_not_zero(&focus.ref_count) == 0 {
 308            return None;
 309        }
 310        Some(Self {
 311            id,
 312            tab_index: focus.tab_index,
 313            tab_stop: focus.tab_stop,
 314            handles: handles.clone(),
 315        })
 316    }
 317
 318    /// Sets the tab index of the element associated with this handle.
 319    pub fn tab_index(mut self, index: isize) -> Self {
 320        self.tab_index = index;
 321        if let Some(focus) = self.handles.write().get_mut(self.id) {
 322            focus.tab_index = index;
 323        }
 324        self
 325    }
 326
 327    /// Sets whether the element associated with this handle is a tab stop.
 328    ///
 329    /// When `false`, the element will not be included in the tab order.
 330    pub fn tab_stop(mut self, tab_stop: bool) -> Self {
 331        self.tab_stop = tab_stop;
 332        if let Some(focus) = self.handles.write().get_mut(self.id) {
 333            focus.tab_stop = tab_stop;
 334        }
 335        self
 336    }
 337
 338    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 339    pub fn downgrade(&self) -> WeakFocusHandle {
 340        WeakFocusHandle {
 341            id: self.id,
 342            handles: Arc::downgrade(&self.handles),
 343        }
 344    }
 345
 346    /// Moves the focus to the element associated with this handle.
 347    pub fn focus(&self, window: &mut Window) {
 348        window.focus(self)
 349    }
 350
 351    /// Obtains whether the element associated with this handle is currently focused.
 352    pub fn is_focused(&self, window: &Window) -> bool {
 353        self.id.is_focused(window)
 354    }
 355
 356    /// Obtains whether the element associated with this handle contains the focused
 357    /// element or is itself focused.
 358    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 359        self.id.contains_focused(window, cx)
 360    }
 361
 362    /// Obtains whether the element associated with this handle is contained within the
 363    /// focused element or is itself focused.
 364    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 365        self.id.within_focused(window, cx)
 366    }
 367
 368    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 369    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 370        self.id.contains(other.id, window)
 371    }
 372
 373    /// Dispatch an action on the element that rendered this focus handle
 374    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 375        if let Some(node_id) = window
 376            .rendered_frame
 377            .dispatch_tree
 378            .focusable_node_id(self.id)
 379        {
 380            window.dispatch_action_on_node(node_id, action, cx)
 381        }
 382    }
 383}
 384
 385impl Clone for FocusHandle {
 386    fn clone(&self) -> Self {
 387        Self::for_id(self.id, &self.handles).unwrap()
 388    }
 389}
 390
 391impl PartialEq for FocusHandle {
 392    fn eq(&self, other: &Self) -> bool {
 393        self.id == other.id
 394    }
 395}
 396
 397impl Eq for FocusHandle {}
 398
 399impl Drop for FocusHandle {
 400    fn drop(&mut self) {
 401        self.handles
 402            .read()
 403            .get(self.id)
 404            .unwrap()
 405            .ref_count
 406            .fetch_sub(1, SeqCst);
 407    }
 408}
 409
 410/// A weak reference to a focus handle.
 411#[derive(Clone, Debug)]
 412pub struct WeakFocusHandle {
 413    pub(crate) id: FocusId,
 414    pub(crate) handles: Weak<FocusMap>,
 415}
 416
 417impl WeakFocusHandle {
 418    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 419    pub fn upgrade(&self) -> Option<FocusHandle> {
 420        let handles = self.handles.upgrade()?;
 421        FocusHandle::for_id(self.id, &handles)
 422    }
 423}
 424
 425impl PartialEq for WeakFocusHandle {
 426    fn eq(&self, other: &WeakFocusHandle) -> bool {
 427        self.id == other.id
 428    }
 429}
 430
 431impl Eq for WeakFocusHandle {}
 432
 433impl PartialEq<FocusHandle> for WeakFocusHandle {
 434    fn eq(&self, other: &FocusHandle) -> bool {
 435        self.id == other.id
 436    }
 437}
 438
 439impl PartialEq<WeakFocusHandle> for FocusHandle {
 440    fn eq(&self, other: &WeakFocusHandle) -> bool {
 441        self.id == other.id
 442    }
 443}
 444
 445/// Focusable allows users of your view to easily
 446/// focus it (using window.focus_view(cx, view))
 447pub trait Focusable: 'static {
 448    /// Returns the focus handle associated with this view.
 449    fn focus_handle(&self, cx: &App) -> FocusHandle;
 450}
 451
 452impl<V: Focusable> Focusable for Entity<V> {
 453    fn focus_handle(&self, cx: &App) -> FocusHandle {
 454        self.read(cx).focus_handle(cx)
 455    }
 456}
 457
 458/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 459/// where the lifecycle of the view is handled by another view.
 460pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 461
 462impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 463
 464/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 465pub struct DismissEvent;
 466
 467type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 468
 469pub(crate) type AnyMouseListener =
 470    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 471
 472#[derive(Clone)]
 473pub(crate) struct CursorStyleRequest {
 474    pub(crate) hitbox_id: Option<HitboxId>,
 475    pub(crate) style: CursorStyle,
 476}
 477
 478#[derive(Default, Eq, PartialEq)]
 479pub(crate) struct HitTest {
 480    pub(crate) ids: SmallVec<[HitboxId; 8]>,
 481    pub(crate) hover_hitbox_count: usize,
 482}
 483
 484/// A type of window control area that corresponds to the platform window.
 485#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 486pub enum WindowControlArea {
 487    /// An area that allows dragging of the platform window.
 488    Drag,
 489    /// An area that allows closing of the platform window.
 490    Close,
 491    /// An area that allows maximizing of the platform window.
 492    Max,
 493    /// An area that allows minimizing of the platform window.
 494    Min,
 495}
 496
 497/// An identifier for a [Hitbox] which also includes [HitboxBehavior].
 498#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 499pub struct HitboxId(u64);
 500
 501impl HitboxId {
 502    /// Checks if the hitbox with this ID is currently hovered. Except when handling
 503    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 504    /// events or paint hover styles.
 505    ///
 506    /// See [`Hitbox::is_hovered`] for details.
 507    pub fn is_hovered(self, window: &Window) -> bool {
 508        let hit_test = &window.mouse_hit_test;
 509        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 510            if self == *id {
 511                return true;
 512            }
 513        }
 514        false
 515    }
 516
 517    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 518    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 519    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 520    /// this distinction.
 521    pub fn should_handle_scroll(self, window: &Window) -> bool {
 522        window.mouse_hit_test.ids.contains(&self)
 523    }
 524
 525    fn next(mut self) -> HitboxId {
 526        HitboxId(self.0.wrapping_add(1))
 527    }
 528}
 529
 530/// A rectangular region that potentially blocks hitboxes inserted prior.
 531/// See [Window::insert_hitbox] for more details.
 532#[derive(Clone, Debug, Deref)]
 533pub struct Hitbox {
 534    /// A unique identifier for the hitbox.
 535    pub id: HitboxId,
 536    /// The bounds of the hitbox.
 537    #[deref]
 538    pub bounds: Bounds<Pixels>,
 539    /// The content mask when the hitbox was inserted.
 540    pub content_mask: ContentMask<Pixels>,
 541    /// Flags that specify hitbox behavior.
 542    pub behavior: HitboxBehavior,
 543}
 544
 545impl Hitbox {
 546    /// Checks if the hitbox is currently hovered. Except when handling `ScrollWheelEvent`, this is
 547    /// typically what you want when determining whether to handle mouse events or paint hover
 548    /// styles.
 549    ///
 550    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 551    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 552    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`).
 553    ///
 554    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 555    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 556    /// non-interactive while still allowing scrolling. More abstractly, this is because
 557    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 558    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 559    /// container.
 560    pub fn is_hovered(&self, window: &Window) -> bool {
 561        self.id.is_hovered(window)
 562    }
 563
 564    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 565    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 566    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 567    ///
 568    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 569    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 570    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 571        self.id.should_handle_scroll(window)
 572    }
 573}
 574
 575/// How the hitbox affects mouse behavior.
 576#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 577pub enum HitboxBehavior {
 578    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 579    #[default]
 580    Normal,
 581
 582    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 583    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 584    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 585    /// [`InteractiveElement::occlude`].
 586    ///
 587    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 588    /// bubble-phase handler for every mouse event type:
 589    ///
 590    /// ```ignore
 591    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 592    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 593    ///         cx.stop_propagation();
 594    ///     }
 595    /// })
 596    /// ```
 597    ///
 598    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 599    /// styles and tooltops. These other behaviors are the main point of this mechanism. An
 600    /// alternative might be to not affect mouse event handling - but this would allow
 601    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 602    /// be hovered.
 603    BlockMouse,
 604
 605    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 606    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 607    /// interaction except scroll events to be ignored - see the documentation of
 608    /// [`Hitbox::is_hovered`] for details. This flag is set by
 609    /// [`InteractiveElement::block_mouse_except_scroll`].
 610    ///
 611    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 612    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 613    ///
 614    /// ```ignore
 615    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, cx| {
 616    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 617    ///         cx.stop_propagation();
 618    ///     }
 619    /// })
 620    /// ```
 621    ///
 622    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 623    /// handled differently than other mouse events. If also blocking these scroll events is
 624    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 625    ///
 626    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 627    /// hover styles and tooltops. These other behaviors are the main point of this mechanism.
 628    /// An alternative might be to not affect mouse event handling - but this would allow
 629    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 630    /// be hovered.
 631    BlockMouseExceptScroll,
 632}
 633
 634/// An identifier for a tooltip.
 635#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 636pub struct TooltipId(usize);
 637
 638impl TooltipId {
 639    /// Checks if the tooltip is currently hovered.
 640    pub fn is_hovered(&self, window: &Window) -> bool {
 641        window
 642            .tooltip_bounds
 643            .as_ref()
 644            .is_some_and(|tooltip_bounds| {
 645                tooltip_bounds.id == *self
 646                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 647            })
 648    }
 649}
 650
 651pub(crate) struct TooltipBounds {
 652    id: TooltipId,
 653    bounds: Bounds<Pixels>,
 654}
 655
 656#[derive(Clone)]
 657pub(crate) struct TooltipRequest {
 658    id: TooltipId,
 659    tooltip: AnyTooltip,
 660}
 661
 662pub(crate) struct DeferredDraw {
 663    current_view: EntityId,
 664    priority: usize,
 665    parent_node: DispatchNodeId,
 666    element_id_stack: SmallVec<[ElementId; 32]>,
 667    text_style_stack: Vec<TextStyleRefinement>,
 668    element: Option<AnyElement>,
 669    absolute_offset: Point<Pixels>,
 670    prepaint_range: Range<PrepaintStateIndex>,
 671    paint_range: Range<PaintIndex>,
 672}
 673
 674pub(crate) struct Frame {
 675    pub(crate) focus: Option<FocusId>,
 676    pub(crate) window_active: bool,
 677    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 678    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 679    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 680    pub(crate) dispatch_tree: DispatchTree,
 681    pub(crate) scene: Scene,
 682    pub(crate) hitboxes: Vec<Hitbox>,
 683    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 684    pub(crate) deferred_draws: Vec<DeferredDraw>,
 685    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 686    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 687    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 688    #[cfg(any(test, feature = "test-support"))]
 689    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 690    #[cfg(any(feature = "inspector", debug_assertions))]
 691    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 692    #[cfg(any(feature = "inspector", debug_assertions))]
 693    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 694    pub(crate) tab_stops: TabStopMap,
 695}
 696
 697#[derive(Clone, Default)]
 698pub(crate) struct PrepaintStateIndex {
 699    hitboxes_index: usize,
 700    tooltips_index: usize,
 701    deferred_draws_index: usize,
 702    dispatch_tree_index: usize,
 703    accessed_element_states_index: usize,
 704    line_layout_index: LineLayoutIndex,
 705}
 706
 707#[derive(Clone, Default)]
 708pub(crate) struct PaintIndex {
 709    scene_index: usize,
 710    mouse_listeners_index: usize,
 711    input_handlers_index: usize,
 712    cursor_styles_index: usize,
 713    accessed_element_states_index: usize,
 714    tab_handle_index: usize,
 715    line_layout_index: LineLayoutIndex,
 716}
 717
 718impl Frame {
 719    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 720        Frame {
 721            focus: None,
 722            window_active: false,
 723            element_states: FxHashMap::default(),
 724            accessed_element_states: Vec::new(),
 725            mouse_listeners: Vec::new(),
 726            dispatch_tree,
 727            scene: Scene::default(),
 728            hitboxes: Vec::new(),
 729            window_control_hitboxes: Vec::new(),
 730            deferred_draws: Vec::new(),
 731            input_handlers: Vec::new(),
 732            tooltip_requests: Vec::new(),
 733            cursor_styles: Vec::new(),
 734
 735            #[cfg(any(test, feature = "test-support"))]
 736            debug_bounds: FxHashMap::default(),
 737
 738            #[cfg(any(feature = "inspector", debug_assertions))]
 739            next_inspector_instance_ids: FxHashMap::default(),
 740
 741            #[cfg(any(feature = "inspector", debug_assertions))]
 742            inspector_hitboxes: FxHashMap::default(),
 743            tab_stops: TabStopMap::default(),
 744        }
 745    }
 746
 747    pub(crate) fn clear(&mut self) {
 748        self.element_states.clear();
 749        self.accessed_element_states.clear();
 750        self.mouse_listeners.clear();
 751        self.dispatch_tree.clear();
 752        self.scene.clear();
 753        self.input_handlers.clear();
 754        self.tooltip_requests.clear();
 755        self.cursor_styles.clear();
 756        self.hitboxes.clear();
 757        self.window_control_hitboxes.clear();
 758        self.deferred_draws.clear();
 759        self.tab_stops.clear();
 760        self.focus = None;
 761
 762        #[cfg(any(feature = "inspector", debug_assertions))]
 763        {
 764            self.next_inspector_instance_ids.clear();
 765            self.inspector_hitboxes.clear();
 766        }
 767    }
 768
 769    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 770        self.cursor_styles
 771            .iter()
 772            .rev()
 773            .fold_while(None, |style, request| match request.hitbox_id {
 774                None => Done(Some(request.style)),
 775                Some(hitbox_id) => Continue(
 776                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 777                ),
 778            })
 779            .into_inner()
 780    }
 781
 782    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 783        let mut set_hover_hitbox_count = false;
 784        let mut hit_test = HitTest::default();
 785        for hitbox in self.hitboxes.iter().rev() {
 786            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 787            if bounds.contains(&position) {
 788                hit_test.ids.push(hitbox.id);
 789                if !set_hover_hitbox_count
 790                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 791                {
 792                    hit_test.hover_hitbox_count = hit_test.ids.len();
 793                    set_hover_hitbox_count = true;
 794                }
 795                if hitbox.behavior == HitboxBehavior::BlockMouse {
 796                    break;
 797                }
 798            }
 799        }
 800        if !set_hover_hitbox_count {
 801            hit_test.hover_hitbox_count = hit_test.ids.len();
 802        }
 803        hit_test
 804    }
 805
 806    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 807        self.focus
 808            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 809            .unwrap_or_default()
 810    }
 811
 812    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 813        for element_state_key in &self.accessed_element_states {
 814            if let Some((element_state_key, element_state)) =
 815                prev_frame.element_states.remove_entry(element_state_key)
 816            {
 817                self.element_states.insert(element_state_key, element_state);
 818            }
 819        }
 820
 821        self.scene.finish();
 822    }
 823}
 824
 825/// Holds the state for a specific window.
 826pub struct Window {
 827    pub(crate) handle: AnyWindowHandle,
 828    pub(crate) invalidator: WindowInvalidator,
 829    pub(crate) removed: bool,
 830    pub(crate) platform_window: Box<dyn PlatformWindow>,
 831    display_id: Option<DisplayId>,
 832    sprite_atlas: Arc<dyn PlatformAtlas>,
 833    text_system: Arc<WindowTextSystem>,
 834    rem_size: Pixels,
 835    /// The stack of override values for the window's rem size.
 836    ///
 837    /// This is used by `with_rem_size` to allow rendering an element tree with
 838    /// a given rem size.
 839    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 840    pub(crate) viewport_size: Size<Pixels>,
 841    layout_engine: Option<TaffyLayoutEngine>,
 842    pub(crate) root: Option<AnyView>,
 843    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 844    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 845    pub(crate) rendered_entity_stack: Vec<EntityId>,
 846    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 847    pub(crate) element_opacity: f32,
 848    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 849    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 850    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 851    pub(crate) rendered_frame: Frame,
 852    pub(crate) next_frame: Frame,
 853    next_hitbox_id: HitboxId,
 854    pub(crate) next_tooltip_id: TooltipId,
 855    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 856    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 857    pub(crate) dirty_views: FxHashSet<EntityId>,
 858    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 859    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 860    default_prevented: bool,
 861    mouse_position: Point<Pixels>,
 862    mouse_hit_test: HitTest,
 863    modifiers: Modifiers,
 864    capslock: Capslock,
 865    scale_factor: f32,
 866    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 867    appearance: WindowAppearance,
 868    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 869    active: Rc<Cell<bool>>,
 870    hovered: Rc<Cell<bool>>,
 871    pub(crate) needs_present: Rc<Cell<bool>>,
 872    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 873    last_input_was_keyboard: bool,
 874    pub(crate) refreshing: bool,
 875    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 876    pub(crate) focus: Option<FocusId>,
 877    focus_enabled: bool,
 878    pending_input: Option<PendingInput>,
 879    pending_modifier: ModifierState,
 880    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 881    prompt: Option<RenderablePromptHandle>,
 882    pub(crate) client_inset: Option<Pixels>,
 883    #[cfg(any(feature = "inspector", debug_assertions))]
 884    inspector: Option<Entity<Inspector>>,
 885}
 886
 887#[derive(Clone, Debug, Default)]
 888struct ModifierState {
 889    modifiers: Modifiers,
 890    saw_keystroke: bool,
 891}
 892
 893#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 894pub(crate) enum DrawPhase {
 895    None,
 896    Prepaint,
 897    Paint,
 898    Focus,
 899}
 900
 901#[derive(Default, Debug)]
 902struct PendingInput {
 903    keystrokes: SmallVec<[Keystroke; 1]>,
 904    focus: Option<FocusId>,
 905    timer: Option<Task<()>>,
 906}
 907
 908pub(crate) struct ElementStateBox {
 909    pub(crate) inner: Box<dyn Any>,
 910    #[cfg(debug_assertions)]
 911    pub(crate) type_name: &'static str,
 912}
 913
 914fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> Bounds<Pixels> {
 915    const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
 916
 917    // TODO, BUG: if you open a window with the currently active window
 918    // on the stack, this will erroneously select the 'unwrap_or_else'
 919    // code path
 920    cx.active_window()
 921        .and_then(|w| w.update(cx, |_, window, _| window.bounds()).ok())
 922        .map(|mut bounds| {
 923            bounds.origin += DEFAULT_WINDOW_OFFSET;
 924            bounds
 925        })
 926        .unwrap_or_else(|| {
 927            let display = display_id
 928                .map(|id| cx.find_display(id))
 929                .unwrap_or_else(|| cx.primary_display());
 930
 931            display
 932                .map(|display| display.default_bounds())
 933                .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
 934        })
 935}
 936
 937impl Window {
 938    pub(crate) fn new(
 939        handle: AnyWindowHandle,
 940        options: WindowOptions,
 941        cx: &mut App,
 942    ) -> Result<Self> {
 943        let WindowOptions {
 944            window_bounds,
 945            titlebar,
 946            focus,
 947            show,
 948            kind,
 949            is_movable,
 950            is_resizable,
 951            is_minimizable,
 952            display_id,
 953            window_background,
 954            app_id,
 955            window_min_size,
 956            window_decorations,
 957            #[cfg_attr(not(target_os = "macos"), allow(unused_variables))]
 958            tabbing_identifier,
 959        } = options;
 960
 961        let bounds = window_bounds
 962            .map(|bounds| bounds.get_bounds())
 963            .unwrap_or_else(|| default_bounds(display_id, cx));
 964        let mut platform_window = cx.platform.open_window(
 965            handle,
 966            WindowParams {
 967                bounds,
 968                titlebar,
 969                kind,
 970                is_movable,
 971                is_resizable,
 972                is_minimizable,
 973                focus,
 974                show,
 975                display_id,
 976                window_min_size,
 977                #[cfg(target_os = "macos")]
 978                tabbing_identifier,
 979            },
 980        )?;
 981
 982        let tab_bar_visible = platform_window.tab_bar_visible();
 983        SystemWindowTabController::init_visible(cx, tab_bar_visible);
 984        if let Some(tabs) = platform_window.tabbed_windows() {
 985            SystemWindowTabController::add_tab(cx, handle.window_id(), tabs);
 986        }
 987
 988        let display_id = platform_window.display().map(|display| display.id());
 989        let sprite_atlas = platform_window.sprite_atlas();
 990        let mouse_position = platform_window.mouse_position();
 991        let modifiers = platform_window.modifiers();
 992        let capslock = platform_window.capslock();
 993        let content_size = platform_window.content_size();
 994        let scale_factor = platform_window.scale_factor();
 995        let appearance = platform_window.appearance();
 996        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
 997        let invalidator = WindowInvalidator::new();
 998        let active = Rc::new(Cell::new(platform_window.is_active()));
 999        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
1000        let needs_present = Rc::new(Cell::new(false));
1001        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
1002        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
1003
1004        platform_window
1005            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
1006        platform_window.set_background_appearance(window_background);
1007
1008        if let Some(ref window_open_state) = window_bounds {
1009            match window_open_state {
1010                WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
1011                WindowBounds::Maximized(_) => platform_window.zoom(),
1012                WindowBounds::Windowed(_) => {}
1013            }
1014        }
1015
1016        platform_window.on_close(Box::new({
1017            let window_id = handle.window_id();
1018            let mut cx = cx.to_async();
1019            move || {
1020                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
1021                let _ = cx.update(|cx| {
1022                    SystemWindowTabController::remove_tab(cx, window_id);
1023                });
1024            }
1025        }));
1026        platform_window.on_request_frame(Box::new({
1027            let mut cx = cx.to_async();
1028            let invalidator = invalidator.clone();
1029            let active = active.clone();
1030            let needs_present = needs_present.clone();
1031            let next_frame_callbacks = next_frame_callbacks.clone();
1032            let last_input_timestamp = last_input_timestamp.clone();
1033            move |request_frame_options| {
1034                let next_frame_callbacks = next_frame_callbacks.take();
1035                if !next_frame_callbacks.is_empty() {
1036                    handle
1037                        .update(&mut cx, |_, window, cx| {
1038                            for callback in next_frame_callbacks {
1039                                callback(window, cx);
1040                            }
1041                        })
1042                        .log_err();
1043                }
1044
1045                // Keep presenting the current scene for 1 extra second since the
1046                // last input to prevent the display from underclocking the refresh rate.
1047                let needs_present = request_frame_options.require_presentation
1048                    || needs_present.get()
1049                    || (active.get()
1050                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
1051
1052                if invalidator.is_dirty() || request_frame_options.force_render {
1053                    measure("frame duration", || {
1054                        handle
1055                            .update(&mut cx, |_, window, cx| {
1056                                let arena_clear_needed = window.draw(cx);
1057                                window.present();
1058                                // drop the arena elements after present to reduce latency
1059                                arena_clear_needed.clear();
1060                            })
1061                            .log_err();
1062                    })
1063                } else if needs_present {
1064                    handle
1065                        .update(&mut cx, |_, window, _| window.present())
1066                        .log_err();
1067                }
1068
1069                handle
1070                    .update(&mut cx, |_, window, _| {
1071                        window.complete_frame();
1072                    })
1073                    .log_err();
1074            }
1075        }));
1076        platform_window.on_resize(Box::new({
1077            let mut cx = cx.to_async();
1078            move |_, _| {
1079                handle
1080                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1081                    .log_err();
1082            }
1083        }));
1084        platform_window.on_moved(Box::new({
1085            let mut cx = cx.to_async();
1086            move || {
1087                handle
1088                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1089                    .log_err();
1090            }
1091        }));
1092        platform_window.on_appearance_changed(Box::new({
1093            let mut cx = cx.to_async();
1094            move || {
1095                handle
1096                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1097                    .log_err();
1098            }
1099        }));
1100        platform_window.on_active_status_change(Box::new({
1101            let mut cx = cx.to_async();
1102            move |active| {
1103                handle
1104                    .update(&mut cx, |_, window, cx| {
1105                        window.active.set(active);
1106                        window.modifiers = window.platform_window.modifiers();
1107                        window.capslock = window.platform_window.capslock();
1108                        window
1109                            .activation_observers
1110                            .clone()
1111                            .retain(&(), |callback| callback(window, cx));
1112
1113                        window.bounds_changed(cx);
1114                        window.refresh();
1115
1116                        SystemWindowTabController::update_last_active(cx, window.handle.id);
1117                    })
1118                    .log_err();
1119            }
1120        }));
1121        platform_window.on_hover_status_change(Box::new({
1122            let mut cx = cx.to_async();
1123            move |active| {
1124                handle
1125                    .update(&mut cx, |_, window, _| {
1126                        window.hovered.set(active);
1127                        window.refresh();
1128                    })
1129                    .log_err();
1130            }
1131        }));
1132        platform_window.on_input({
1133            let mut cx = cx.to_async();
1134            Box::new(move |event| {
1135                handle
1136                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1137                    .log_err()
1138                    .unwrap_or(DispatchEventResult::default())
1139            })
1140        });
1141        platform_window.on_hit_test_window_control({
1142            let mut cx = cx.to_async();
1143            Box::new(move || {
1144                handle
1145                    .update(&mut cx, |_, window, _cx| {
1146                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1147                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1148                                return Some(*area);
1149                            }
1150                        }
1151                        None
1152                    })
1153                    .log_err()
1154                    .unwrap_or(None)
1155            })
1156        });
1157        platform_window.on_move_tab_to_new_window({
1158            let mut cx = cx.to_async();
1159            Box::new(move || {
1160                handle
1161                    .update(&mut cx, |_, _window, cx| {
1162                        SystemWindowTabController::move_tab_to_new_window(cx, handle.window_id());
1163                    })
1164                    .log_err();
1165            })
1166        });
1167        platform_window.on_merge_all_windows({
1168            let mut cx = cx.to_async();
1169            Box::new(move || {
1170                handle
1171                    .update(&mut cx, |_, _window, cx| {
1172                        SystemWindowTabController::merge_all_windows(cx, handle.window_id());
1173                    })
1174                    .log_err();
1175            })
1176        });
1177        platform_window.on_select_next_tab({
1178            let mut cx = cx.to_async();
1179            Box::new(move || {
1180                handle
1181                    .update(&mut cx, |_, _window, cx| {
1182                        SystemWindowTabController::select_next_tab(cx, handle.window_id());
1183                    })
1184                    .log_err();
1185            })
1186        });
1187        platform_window.on_select_previous_tab({
1188            let mut cx = cx.to_async();
1189            Box::new(move || {
1190                handle
1191                    .update(&mut cx, |_, _window, cx| {
1192                        SystemWindowTabController::select_previous_tab(cx, handle.window_id())
1193                    })
1194                    .log_err();
1195            })
1196        });
1197        platform_window.on_toggle_tab_bar({
1198            let mut cx = cx.to_async();
1199            Box::new(move || {
1200                handle
1201                    .update(&mut cx, |_, window, cx| {
1202                        let tab_bar_visible = window.platform_window.tab_bar_visible();
1203                        SystemWindowTabController::set_visible(cx, tab_bar_visible);
1204                    })
1205                    .log_err();
1206            })
1207        });
1208
1209        if let Some(app_id) = app_id {
1210            platform_window.set_app_id(&app_id);
1211        }
1212
1213        platform_window.map_window().unwrap();
1214
1215        Ok(Window {
1216            handle,
1217            invalidator,
1218            removed: false,
1219            platform_window,
1220            display_id,
1221            sprite_atlas,
1222            text_system,
1223            rem_size: px(16.),
1224            rem_size_override_stack: SmallVec::new(),
1225            viewport_size: content_size,
1226            layout_engine: Some(TaffyLayoutEngine::new()),
1227            root: None,
1228            element_id_stack: SmallVec::default(),
1229            text_style_stack: Vec::new(),
1230            rendered_entity_stack: Vec::new(),
1231            element_offset_stack: Vec::new(),
1232            content_mask_stack: Vec::new(),
1233            element_opacity: 1.0,
1234            requested_autoscroll: None,
1235            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1236            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1237            next_frame_callbacks,
1238            next_hitbox_id: HitboxId(0),
1239            next_tooltip_id: TooltipId::default(),
1240            tooltip_bounds: None,
1241            dirty_views: FxHashSet::default(),
1242            focus_listeners: SubscriberSet::new(),
1243            focus_lost_listeners: SubscriberSet::new(),
1244            default_prevented: true,
1245            mouse_position,
1246            mouse_hit_test: HitTest::default(),
1247            modifiers,
1248            capslock,
1249            scale_factor,
1250            bounds_observers: SubscriberSet::new(),
1251            appearance,
1252            appearance_observers: SubscriberSet::new(),
1253            active,
1254            hovered,
1255            needs_present,
1256            last_input_timestamp,
1257            last_input_was_keyboard: false,
1258            refreshing: false,
1259            activation_observers: SubscriberSet::new(),
1260            focus: None,
1261            focus_enabled: true,
1262            pending_input: None,
1263            pending_modifier: ModifierState::default(),
1264            pending_input_observers: SubscriberSet::new(),
1265            prompt: None,
1266            client_inset: None,
1267            image_cache_stack: Vec::new(),
1268            #[cfg(any(feature = "inspector", debug_assertions))]
1269            inspector: None,
1270        })
1271    }
1272
1273    pub(crate) fn new_focus_listener(
1274        &self,
1275        value: AnyWindowFocusListener,
1276    ) -> (Subscription, impl FnOnce() + use<>) {
1277        self.focus_listeners.insert((), value)
1278    }
1279}
1280
1281#[derive(Clone, Debug, Default, PartialEq, Eq)]
1282pub(crate) struct DispatchEventResult {
1283    pub propagate: bool,
1284    pub default_prevented: bool,
1285}
1286
1287/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1288/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1289/// to leave room to support more complex shapes in the future.
1290#[derive(Clone, Debug, Default, PartialEq, Eq)]
1291#[repr(C)]
1292pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1293    /// The bounds
1294    pub bounds: Bounds<P>,
1295}
1296
1297impl ContentMask<Pixels> {
1298    /// Scale the content mask's pixel units by the given scaling factor.
1299    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1300        ContentMask {
1301            bounds: self.bounds.scale(factor),
1302        }
1303    }
1304
1305    /// Intersect the content mask with the given content mask.
1306    pub fn intersect(&self, other: &Self) -> Self {
1307        let bounds = self.bounds.intersect(&other.bounds);
1308        ContentMask { bounds }
1309    }
1310}
1311
1312impl Window {
1313    fn mark_view_dirty(&mut self, view_id: EntityId) {
1314        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1315        // should already be dirty.
1316        for view_id in self
1317            .rendered_frame
1318            .dispatch_tree
1319            .view_path(view_id)
1320            .into_iter()
1321            .rev()
1322        {
1323            if !self.dirty_views.insert(view_id) {
1324                break;
1325            }
1326        }
1327    }
1328
1329    /// Registers a callback to be invoked when the window appearance changes.
1330    pub fn observe_window_appearance(
1331        &self,
1332        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1333    ) -> Subscription {
1334        let (subscription, activate) = self.appearance_observers.insert(
1335            (),
1336            Box::new(move |window, cx| {
1337                callback(window, cx);
1338                true
1339            }),
1340        );
1341        activate();
1342        subscription
1343    }
1344
1345    /// Replaces the root entity of the window with a new one.
1346    pub fn replace_root<E>(
1347        &mut self,
1348        cx: &mut App,
1349        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1350    ) -> Entity<E>
1351    where
1352        E: 'static + Render,
1353    {
1354        let view = cx.new(|cx| build_view(self, cx));
1355        self.root = Some(view.clone().into());
1356        self.refresh();
1357        view
1358    }
1359
1360    /// Returns the root entity of the window, if it has one.
1361    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1362    where
1363        E: 'static + Render,
1364    {
1365        self.root
1366            .as_ref()
1367            .map(|view| view.clone().downcast::<E>().ok())
1368    }
1369
1370    /// Obtain a handle to the window that belongs to this context.
1371    pub fn window_handle(&self) -> AnyWindowHandle {
1372        self.handle
1373    }
1374
1375    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1376    pub fn refresh(&mut self) {
1377        if self.invalidator.not_drawing() {
1378            self.refreshing = true;
1379            self.invalidator.set_dirty(true);
1380        }
1381    }
1382
1383    /// Close this window.
1384    pub fn remove_window(&mut self) {
1385        self.removed = true;
1386    }
1387
1388    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1389    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1390        self.focus
1391            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1392    }
1393
1394    /// Move focus to the element associated with the given [`FocusHandle`].
1395    pub fn focus(&mut self, handle: &FocusHandle) {
1396        if !self.focus_enabled || self.focus == Some(handle.id) {
1397            return;
1398        }
1399
1400        self.focus = Some(handle.id);
1401        self.clear_pending_keystrokes();
1402        self.refresh();
1403    }
1404
1405    /// Remove focus from all elements within this context's window.
1406    pub fn blur(&mut self) {
1407        if !self.focus_enabled {
1408            return;
1409        }
1410
1411        self.focus = None;
1412        self.refresh();
1413    }
1414
1415    /// Blur the window and don't allow anything in it to be focused again.
1416    pub fn disable_focus(&mut self) {
1417        self.blur();
1418        self.focus_enabled = false;
1419    }
1420
1421    /// Move focus to next tab stop.
1422    pub fn focus_next(&mut self) {
1423        if !self.focus_enabled {
1424            return;
1425        }
1426
1427        if let Some(handle) = self.rendered_frame.tab_stops.next(self.focus.as_ref()) {
1428            self.focus(&handle)
1429        }
1430    }
1431
1432    /// Move focus to previous tab stop.
1433    pub fn focus_prev(&mut self) {
1434        if !self.focus_enabled {
1435            return;
1436        }
1437
1438        if let Some(handle) = self.rendered_frame.tab_stops.prev(self.focus.as_ref()) {
1439            self.focus(&handle)
1440        }
1441    }
1442
1443    /// Accessor for the text system.
1444    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1445        &self.text_system
1446    }
1447
1448    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1449    pub fn text_style(&self) -> TextStyle {
1450        let mut style = TextStyle::default();
1451        for refinement in &self.text_style_stack {
1452            style.refine(refinement);
1453        }
1454        style
1455    }
1456
1457    /// Check if the platform window is maximized
1458    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1459    pub fn is_maximized(&self) -> bool {
1460        self.platform_window.is_maximized()
1461    }
1462
1463    /// request a certain window decoration (Wayland)
1464    pub fn request_decorations(&self, decorations: WindowDecorations) {
1465        self.platform_window.request_decorations(decorations);
1466    }
1467
1468    /// Start a window resize operation (Wayland)
1469    pub fn start_window_resize(&self, edge: ResizeEdge) {
1470        self.platform_window.start_window_resize(edge);
1471    }
1472
1473    /// Return the `WindowBounds` to indicate that how a window should be opened
1474    /// after it has been closed
1475    pub fn window_bounds(&self) -> WindowBounds {
1476        self.platform_window.window_bounds()
1477    }
1478
1479    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1480    pub fn inner_window_bounds(&self) -> WindowBounds {
1481        self.platform_window.inner_window_bounds()
1482    }
1483
1484    /// Dispatch the given action on the currently focused element.
1485    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1486        let focus_id = self.focused(cx).map(|handle| handle.id);
1487
1488        let window = self.handle;
1489        cx.defer(move |cx| {
1490            window
1491                .update(cx, |_, window, cx| {
1492                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1493                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1494                })
1495                .log_err();
1496        })
1497    }
1498
1499    pub(crate) fn dispatch_keystroke_observers(
1500        &mut self,
1501        event: &dyn Any,
1502        action: Option<Box<dyn Action>>,
1503        context_stack: Vec<KeyContext>,
1504        cx: &mut App,
1505    ) {
1506        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1507            return;
1508        };
1509
1510        cx.keystroke_observers.clone().retain(&(), move |callback| {
1511            (callback)(
1512                &KeystrokeEvent {
1513                    keystroke: key_down_event.keystroke.clone(),
1514                    action: action.as_ref().map(|action| action.boxed_clone()),
1515                    context_stack: context_stack.clone(),
1516                },
1517                self,
1518                cx,
1519            )
1520        });
1521    }
1522
1523    pub(crate) fn dispatch_keystroke_interceptors(
1524        &mut self,
1525        event: &dyn Any,
1526        context_stack: Vec<KeyContext>,
1527        cx: &mut App,
1528    ) {
1529        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1530            return;
1531        };
1532
1533        cx.keystroke_interceptors
1534            .clone()
1535            .retain(&(), move |callback| {
1536                (callback)(
1537                    &KeystrokeEvent {
1538                        keystroke: key_down_event.keystroke.clone(),
1539                        action: None,
1540                        context_stack: context_stack.clone(),
1541                    },
1542                    self,
1543                    cx,
1544                )
1545            });
1546    }
1547
1548    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1549    /// that are currently on the stack to be returned to the app.
1550    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1551        let handle = self.handle;
1552        cx.defer(move |cx| {
1553            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1554        });
1555    }
1556
1557    /// Subscribe to events emitted by a entity.
1558    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1559    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1560    pub fn observe<T: 'static>(
1561        &mut self,
1562        observed: &Entity<T>,
1563        cx: &mut App,
1564        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1565    ) -> Subscription {
1566        let entity_id = observed.entity_id();
1567        let observed = observed.downgrade();
1568        let window_handle = self.handle;
1569        cx.new_observer(
1570            entity_id,
1571            Box::new(move |cx| {
1572                window_handle
1573                    .update(cx, |_, window, cx| {
1574                        if let Some(handle) = observed.upgrade() {
1575                            on_notify(handle, window, cx);
1576                            true
1577                        } else {
1578                            false
1579                        }
1580                    })
1581                    .unwrap_or(false)
1582            }),
1583        )
1584    }
1585
1586    /// Subscribe to events emitted by a entity.
1587    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1588    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1589    pub fn subscribe<Emitter, Evt>(
1590        &mut self,
1591        entity: &Entity<Emitter>,
1592        cx: &mut App,
1593        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1594    ) -> Subscription
1595    where
1596        Emitter: EventEmitter<Evt>,
1597        Evt: 'static,
1598    {
1599        let entity_id = entity.entity_id();
1600        let handle = entity.downgrade();
1601        let window_handle = self.handle;
1602        cx.new_subscription(
1603            entity_id,
1604            (
1605                TypeId::of::<Evt>(),
1606                Box::new(move |event, cx| {
1607                    window_handle
1608                        .update(cx, |_, window, cx| {
1609                            if let Some(entity) = handle.upgrade() {
1610                                let event = event.downcast_ref().expect("invalid event type");
1611                                on_event(entity, event, window, cx);
1612                                true
1613                            } else {
1614                                false
1615                            }
1616                        })
1617                        .unwrap_or(false)
1618                }),
1619            ),
1620        )
1621    }
1622
1623    /// Register a callback to be invoked when the given `Entity` is released.
1624    pub fn observe_release<T>(
1625        &self,
1626        entity: &Entity<T>,
1627        cx: &mut App,
1628        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1629    ) -> Subscription
1630    where
1631        T: 'static,
1632    {
1633        let entity_id = entity.entity_id();
1634        let window_handle = self.handle;
1635        let (subscription, activate) = cx.release_listeners.insert(
1636            entity_id,
1637            Box::new(move |entity, cx| {
1638                let entity = entity.downcast_mut().expect("invalid entity type");
1639                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1640            }),
1641        );
1642        activate();
1643        subscription
1644    }
1645
1646    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1647    /// await points in async code.
1648    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1649        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1650    }
1651
1652    /// Schedule the given closure to be run directly after the current frame is rendered.
1653    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1654        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1655    }
1656
1657    /// Schedule a frame to be drawn on the next animation frame.
1658    ///
1659    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1660    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1661    ///
1662    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1663    pub fn request_animation_frame(&self) {
1664        let entity = self.current_view();
1665        self.on_next_frame(move |_, cx| cx.notify(entity));
1666    }
1667
1668    /// Spawn the future returned by the given closure on the application thread pool.
1669    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1670    /// use within your future.
1671    #[track_caller]
1672    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1673    where
1674        R: 'static,
1675        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1676    {
1677        let handle = self.handle;
1678        cx.spawn(async move |app| {
1679            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1680            f(&mut async_window_cx).await
1681        })
1682    }
1683
1684    fn bounds_changed(&mut self, cx: &mut App) {
1685        self.scale_factor = self.platform_window.scale_factor();
1686        self.viewport_size = self.platform_window.content_size();
1687        self.display_id = self.platform_window.display().map(|display| display.id());
1688
1689        self.refresh();
1690
1691        self.bounds_observers
1692            .clone()
1693            .retain(&(), |callback| callback(self, cx));
1694    }
1695
1696    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1697    pub fn bounds(&self) -> Bounds<Pixels> {
1698        self.platform_window.bounds()
1699    }
1700
1701    /// Set the content size of the window.
1702    pub fn resize(&mut self, size: Size<Pixels>) {
1703        self.platform_window.resize(size);
1704    }
1705
1706    /// Returns whether or not the window is currently fullscreen
1707    pub fn is_fullscreen(&self) -> bool {
1708        self.platform_window.is_fullscreen()
1709    }
1710
1711    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1712        self.appearance = self.platform_window.appearance();
1713
1714        self.appearance_observers
1715            .clone()
1716            .retain(&(), |callback| callback(self, cx));
1717    }
1718
1719    /// Returns the appearance of the current window.
1720    pub fn appearance(&self) -> WindowAppearance {
1721        self.appearance
1722    }
1723
1724    /// Returns the size of the drawable area within the window.
1725    pub fn viewport_size(&self) -> Size<Pixels> {
1726        self.viewport_size
1727    }
1728
1729    /// Returns whether this window is focused by the operating system (receiving key events).
1730    pub fn is_window_active(&self) -> bool {
1731        self.active.get()
1732    }
1733
1734    /// Returns whether this window is considered to be the window
1735    /// that currently owns the mouse cursor.
1736    /// On mac, this is equivalent to `is_window_active`.
1737    pub fn is_window_hovered(&self) -> bool {
1738        if cfg!(any(
1739            target_os = "windows",
1740            target_os = "linux",
1741            target_os = "freebsd"
1742        )) {
1743            self.hovered.get()
1744        } else {
1745            self.is_window_active()
1746        }
1747    }
1748
1749    /// Toggle zoom on the window.
1750    pub fn zoom_window(&self) {
1751        self.platform_window.zoom();
1752    }
1753
1754    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1755    pub fn show_window_menu(&self, position: Point<Pixels>) {
1756        self.platform_window.show_window_menu(position)
1757    }
1758
1759    /// Tells the compositor to take control of window movement (Wayland and X11)
1760    ///
1761    /// Events may not be received during a move operation.
1762    pub fn start_window_move(&self) {
1763        self.platform_window.start_window_move()
1764    }
1765
1766    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1767    pub fn set_client_inset(&mut self, inset: Pixels) {
1768        self.client_inset = Some(inset);
1769        self.platform_window.set_client_inset(inset);
1770    }
1771
1772    /// Returns the client_inset value by [`Self::set_client_inset`].
1773    pub fn client_inset(&self) -> Option<Pixels> {
1774        self.client_inset
1775    }
1776
1777    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1778    pub fn window_decorations(&self) -> Decorations {
1779        self.platform_window.window_decorations()
1780    }
1781
1782    /// Returns which window controls are currently visible (Wayland)
1783    pub fn window_controls(&self) -> WindowControls {
1784        self.platform_window.window_controls()
1785    }
1786
1787    /// Updates the window's title at the platform level.
1788    pub fn set_window_title(&mut self, title: &str) {
1789        self.platform_window.set_title(title);
1790    }
1791
1792    /// Sets the application identifier.
1793    pub fn set_app_id(&mut self, app_id: &str) {
1794        self.platform_window.set_app_id(app_id);
1795    }
1796
1797    /// Sets the window background appearance.
1798    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1799        self.platform_window
1800            .set_background_appearance(background_appearance);
1801    }
1802
1803    /// Mark the window as dirty at the platform level.
1804    pub fn set_window_edited(&mut self, edited: bool) {
1805        self.platform_window.set_edited(edited);
1806    }
1807
1808    /// Determine the display on which the window is visible.
1809    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1810        cx.platform
1811            .displays()
1812            .into_iter()
1813            .find(|display| Some(display.id()) == self.display_id)
1814    }
1815
1816    /// Show the platform character palette.
1817    pub fn show_character_palette(&self) {
1818        self.platform_window.show_character_palette();
1819    }
1820
1821    /// The scale factor of the display associated with the window. For example, it could
1822    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1823    /// be rendered as two pixels on screen.
1824    pub fn scale_factor(&self) -> f32 {
1825        self.scale_factor
1826    }
1827
1828    /// The size of an em for the base font of the application. Adjusting this value allows the
1829    /// UI to scale, just like zooming a web page.
1830    pub fn rem_size(&self) -> Pixels {
1831        self.rem_size_override_stack
1832            .last()
1833            .copied()
1834            .unwrap_or(self.rem_size)
1835    }
1836
1837    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1838    /// UI to scale, just like zooming a web page.
1839    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1840        self.rem_size = rem_size.into();
1841    }
1842
1843    /// Acquire a globally unique identifier for the given ElementId.
1844    /// Only valid for the duration of the provided closure.
1845    pub fn with_global_id<R>(
1846        &mut self,
1847        element_id: ElementId,
1848        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1849    ) -> R {
1850        self.element_id_stack.push(element_id);
1851        let global_id = GlobalElementId(Arc::from(&*self.element_id_stack));
1852
1853        let result = f(&global_id, self);
1854        self.element_id_stack.pop();
1855        result
1856    }
1857
1858    /// Executes the provided function with the specified rem size.
1859    ///
1860    /// This method must only be called as part of element drawing.
1861    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1862    where
1863        F: FnOnce(&mut Self) -> R,
1864    {
1865        self.invalidator.debug_assert_paint_or_prepaint();
1866
1867        if let Some(rem_size) = rem_size {
1868            self.rem_size_override_stack.push(rem_size.into());
1869            let result = f(self);
1870            self.rem_size_override_stack.pop();
1871            result
1872        } else {
1873            f(self)
1874        }
1875    }
1876
1877    /// The line height associated with the current text style.
1878    pub fn line_height(&self) -> Pixels {
1879        self.text_style().line_height_in_pixels(self.rem_size())
1880    }
1881
1882    /// Call to prevent the default action of an event. Currently only used to prevent
1883    /// parent elements from becoming focused on mouse down.
1884    pub fn prevent_default(&mut self) {
1885        self.default_prevented = true;
1886    }
1887
1888    /// Obtain whether default has been prevented for the event currently being dispatched.
1889    pub fn default_prevented(&self) -> bool {
1890        self.default_prevented
1891    }
1892
1893    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1894    pub fn is_action_available(&self, action: &dyn Action, cx: &mut App) -> bool {
1895        let node_id =
1896            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
1897        self.rendered_frame
1898            .dispatch_tree
1899            .is_action_available(action, node_id)
1900    }
1901
1902    /// The position of the mouse relative to the window.
1903    pub fn mouse_position(&self) -> Point<Pixels> {
1904        self.mouse_position
1905    }
1906
1907    /// The current state of the keyboard's modifiers
1908    pub fn modifiers(&self) -> Modifiers {
1909        self.modifiers
1910    }
1911
1912    /// Returns true if the last input event was keyboard-based (key press, tab navigation, etc.)
1913    /// This is used for focus-visible styling to show focus indicators only for keyboard navigation.
1914    pub fn last_input_was_keyboard(&self) -> bool {
1915        self.last_input_was_keyboard
1916    }
1917
1918    /// The current state of the keyboard's capslock
1919    pub fn capslock(&self) -> Capslock {
1920        self.capslock
1921    }
1922
1923    fn complete_frame(&self) {
1924        self.platform_window.completed_frame();
1925    }
1926
1927    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1928    /// the contents of the new [`Scene`], use [`Self::present`].
1929    #[profiling::function]
1930    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
1931        self.invalidate_entities();
1932        cx.entities.clear_accessed();
1933        debug_assert!(self.rendered_entity_stack.is_empty());
1934        self.invalidator.set_dirty(false);
1935        self.requested_autoscroll = None;
1936
1937        // Restore the previously-used input handler.
1938        if let Some(input_handler) = self.platform_window.take_input_handler() {
1939            self.rendered_frame.input_handlers.push(Some(input_handler));
1940        }
1941        self.draw_roots(cx);
1942        self.dirty_views.clear();
1943        self.next_frame.window_active = self.active.get();
1944
1945        // Register requested input handler with the platform window.
1946        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
1947            self.platform_window
1948                .set_input_handler(input_handler.unwrap());
1949        }
1950
1951        self.layout_engine.as_mut().unwrap().clear();
1952        self.text_system().finish_frame();
1953        self.next_frame.finish(&mut self.rendered_frame);
1954
1955        self.invalidator.set_phase(DrawPhase::Focus);
1956        let previous_focus_path = self.rendered_frame.focus_path();
1957        let previous_window_active = self.rendered_frame.window_active;
1958        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
1959        self.next_frame.clear();
1960        let current_focus_path = self.rendered_frame.focus_path();
1961        let current_window_active = self.rendered_frame.window_active;
1962
1963        if previous_focus_path != current_focus_path
1964            || previous_window_active != current_window_active
1965        {
1966            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1967                self.focus_lost_listeners
1968                    .clone()
1969                    .retain(&(), |listener| listener(self, cx));
1970            }
1971
1972            let event = WindowFocusEvent {
1973                previous_focus_path: if previous_window_active {
1974                    previous_focus_path
1975                } else {
1976                    Default::default()
1977                },
1978                current_focus_path: if current_window_active {
1979                    current_focus_path
1980                } else {
1981                    Default::default()
1982                },
1983            };
1984            self.focus_listeners
1985                .clone()
1986                .retain(&(), |listener| listener(&event, self, cx));
1987        }
1988
1989        debug_assert!(self.rendered_entity_stack.is_empty());
1990        self.record_entities_accessed(cx);
1991        self.reset_cursor_style(cx);
1992        self.refreshing = false;
1993        self.invalidator.set_phase(DrawPhase::None);
1994        self.needs_present.set(true);
1995
1996        ArenaClearNeeded
1997    }
1998
1999    fn record_entities_accessed(&mut self, cx: &mut App) {
2000        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
2001        let mut entities = mem::take(entities_ref.deref_mut());
2002        drop(entities_ref);
2003        let handle = self.handle;
2004        cx.record_entities_accessed(
2005            handle,
2006            // Try moving window invalidator into the Window
2007            self.invalidator.clone(),
2008            &entities,
2009        );
2010        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
2011        mem::swap(&mut entities, entities_ref.deref_mut());
2012    }
2013
2014    fn invalidate_entities(&mut self) {
2015        let mut views = self.invalidator.take_views();
2016        for entity in views.drain() {
2017            self.mark_view_dirty(entity);
2018        }
2019        self.invalidator.replace_views(views);
2020    }
2021
2022    #[profiling::function]
2023    fn present(&self) {
2024        self.platform_window.draw(&self.rendered_frame.scene);
2025        self.needs_present.set(false);
2026        profiling::finish_frame!();
2027    }
2028
2029    fn draw_roots(&mut self, cx: &mut App) {
2030        self.invalidator.set_phase(DrawPhase::Prepaint);
2031        self.tooltip_bounds.take();
2032
2033        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
2034        let root_size = {
2035            #[cfg(any(feature = "inspector", debug_assertions))]
2036            {
2037                if self.inspector.is_some() {
2038                    let mut size = self.viewport_size;
2039                    size.width = (size.width - _inspector_width).max(px(0.0));
2040                    size
2041                } else {
2042                    self.viewport_size
2043                }
2044            }
2045            #[cfg(not(any(feature = "inspector", debug_assertions)))]
2046            {
2047                self.viewport_size
2048            }
2049        };
2050
2051        // Layout all root elements.
2052        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
2053        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2054
2055        #[cfg(any(feature = "inspector", debug_assertions))]
2056        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
2057
2058        let mut sorted_deferred_draws =
2059            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
2060        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
2061        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
2062
2063        let mut prompt_element = None;
2064        let mut active_drag_element = None;
2065        let mut tooltip_element = None;
2066        if let Some(prompt) = self.prompt.take() {
2067            let mut element = prompt.view.any_view().into_any();
2068            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2069            prompt_element = Some(element);
2070            self.prompt = Some(prompt);
2071        } else if let Some(active_drag) = cx.active_drag.take() {
2072            let mut element = active_drag.view.clone().into_any();
2073            let offset = self.mouse_position() - active_drag.cursor_offset;
2074            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
2075            active_drag_element = Some(element);
2076            cx.active_drag = Some(active_drag);
2077        } else {
2078            tooltip_element = self.prepaint_tooltip(cx);
2079        }
2080
2081        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
2082
2083        // Now actually paint the elements.
2084        self.invalidator.set_phase(DrawPhase::Paint);
2085        root_element.paint(self, cx);
2086
2087        #[cfg(any(feature = "inspector", debug_assertions))]
2088        self.paint_inspector(inspector_element, cx);
2089
2090        self.paint_deferred_draws(&sorted_deferred_draws, cx);
2091
2092        if let Some(mut prompt_element) = prompt_element {
2093            prompt_element.paint(self, cx);
2094        } else if let Some(mut drag_element) = active_drag_element {
2095            drag_element.paint(self, cx);
2096        } else if let Some(mut tooltip_element) = tooltip_element {
2097            tooltip_element.paint(self, cx);
2098        }
2099
2100        #[cfg(any(feature = "inspector", debug_assertions))]
2101        self.paint_inspector_hitbox(cx);
2102    }
2103
2104    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
2105        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
2106        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
2107            let Some(Some(tooltip_request)) = self
2108                .next_frame
2109                .tooltip_requests
2110                .get(tooltip_request_index)
2111                .cloned()
2112            else {
2113                log::error!("Unexpectedly absent TooltipRequest");
2114                continue;
2115            };
2116            let mut element = tooltip_request.tooltip.view.clone().into_any();
2117            let mouse_position = tooltip_request.tooltip.mouse_position;
2118            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
2119
2120            let mut tooltip_bounds =
2121                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
2122            let window_bounds = Bounds {
2123                origin: Point::default(),
2124                size: self.viewport_size(),
2125            };
2126
2127            if tooltip_bounds.right() > window_bounds.right() {
2128                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
2129                if new_x >= Pixels::ZERO {
2130                    tooltip_bounds.origin.x = new_x;
2131                } else {
2132                    tooltip_bounds.origin.x = cmp::max(
2133                        Pixels::ZERO,
2134                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
2135                    );
2136                }
2137            }
2138
2139            if tooltip_bounds.bottom() > window_bounds.bottom() {
2140                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
2141                if new_y >= Pixels::ZERO {
2142                    tooltip_bounds.origin.y = new_y;
2143                } else {
2144                    tooltip_bounds.origin.y = cmp::max(
2145                        Pixels::ZERO,
2146                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
2147                    );
2148                }
2149            }
2150
2151            // It's possible for an element to have an active tooltip while not being painted (e.g.
2152            // via the `visible_on_hover` method). Since mouse listeners are not active in this
2153            // case, instead update the tooltip's visibility here.
2154            let is_visible =
2155                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
2156            if !is_visible {
2157                continue;
2158            }
2159
2160            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2161                element.prepaint(window, cx)
2162            });
2163
2164            self.tooltip_bounds = Some(TooltipBounds {
2165                id: tooltip_request.id,
2166                bounds: tooltip_bounds,
2167            });
2168            return Some(element);
2169        }
2170        None
2171    }
2172
2173    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2174        assert_eq!(self.element_id_stack.len(), 0);
2175
2176        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2177        for deferred_draw_ix in deferred_draw_indices {
2178            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2179            self.element_id_stack
2180                .clone_from(&deferred_draw.element_id_stack);
2181            self.text_style_stack
2182                .clone_from(&deferred_draw.text_style_stack);
2183            self.next_frame
2184                .dispatch_tree
2185                .set_active_node(deferred_draw.parent_node);
2186
2187            let prepaint_start = self.prepaint_index();
2188            if let Some(element) = deferred_draw.element.as_mut() {
2189                self.with_rendered_view(deferred_draw.current_view, |window| {
2190                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
2191                        element.prepaint(window, cx)
2192                    });
2193                })
2194            } else {
2195                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2196            }
2197            let prepaint_end = self.prepaint_index();
2198            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2199        }
2200        assert_eq!(
2201            self.next_frame.deferred_draws.len(),
2202            0,
2203            "cannot call defer_draw during deferred drawing"
2204        );
2205        self.next_frame.deferred_draws = deferred_draws;
2206        self.element_id_stack.clear();
2207        self.text_style_stack.clear();
2208    }
2209
2210    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2211        assert_eq!(self.element_id_stack.len(), 0);
2212
2213        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2214        for deferred_draw_ix in deferred_draw_indices {
2215            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2216            self.element_id_stack
2217                .clone_from(&deferred_draw.element_id_stack);
2218            self.next_frame
2219                .dispatch_tree
2220                .set_active_node(deferred_draw.parent_node);
2221
2222            let paint_start = self.paint_index();
2223            if let Some(element) = deferred_draw.element.as_mut() {
2224                self.with_rendered_view(deferred_draw.current_view, |window| {
2225                    element.paint(window, cx);
2226                })
2227            } else {
2228                self.reuse_paint(deferred_draw.paint_range.clone());
2229            }
2230            let paint_end = self.paint_index();
2231            deferred_draw.paint_range = paint_start..paint_end;
2232        }
2233        self.next_frame.deferred_draws = deferred_draws;
2234        self.element_id_stack.clear();
2235    }
2236
2237    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2238        PrepaintStateIndex {
2239            hitboxes_index: self.next_frame.hitboxes.len(),
2240            tooltips_index: self.next_frame.tooltip_requests.len(),
2241            deferred_draws_index: self.next_frame.deferred_draws.len(),
2242            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2243            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2244            line_layout_index: self.text_system.layout_index(),
2245        }
2246    }
2247
2248    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2249        self.next_frame.hitboxes.extend(
2250            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2251                .iter()
2252                .cloned(),
2253        );
2254        self.next_frame.tooltip_requests.extend(
2255            self.rendered_frame.tooltip_requests
2256                [range.start.tooltips_index..range.end.tooltips_index]
2257                .iter_mut()
2258                .map(|request| request.take()),
2259        );
2260        self.next_frame.accessed_element_states.extend(
2261            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2262                ..range.end.accessed_element_states_index]
2263                .iter()
2264                .map(|(id, type_id)| (id.clone(), *type_id)),
2265        );
2266        self.text_system
2267            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2268
2269        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2270            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2271            &mut self.rendered_frame.dispatch_tree,
2272            self.focus,
2273        );
2274
2275        if reused_subtree.contains_focus() {
2276            self.next_frame.focus = self.focus;
2277        }
2278
2279        self.next_frame.deferred_draws.extend(
2280            self.rendered_frame.deferred_draws
2281                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2282                .iter()
2283                .map(|deferred_draw| DeferredDraw {
2284                    current_view: deferred_draw.current_view,
2285                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2286                    element_id_stack: deferred_draw.element_id_stack.clone(),
2287                    text_style_stack: deferred_draw.text_style_stack.clone(),
2288                    priority: deferred_draw.priority,
2289                    element: None,
2290                    absolute_offset: deferred_draw.absolute_offset,
2291                    prepaint_range: deferred_draw.prepaint_range.clone(),
2292                    paint_range: deferred_draw.paint_range.clone(),
2293                }),
2294        );
2295    }
2296
2297    pub(crate) fn paint_index(&self) -> PaintIndex {
2298        PaintIndex {
2299            scene_index: self.next_frame.scene.len(),
2300            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2301            input_handlers_index: self.next_frame.input_handlers.len(),
2302            cursor_styles_index: self.next_frame.cursor_styles.len(),
2303            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2304            tab_handle_index: self.next_frame.tab_stops.paint_index(),
2305            line_layout_index: self.text_system.layout_index(),
2306        }
2307    }
2308
2309    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2310        self.next_frame.cursor_styles.extend(
2311            self.rendered_frame.cursor_styles
2312                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2313                .iter()
2314                .cloned(),
2315        );
2316        self.next_frame.input_handlers.extend(
2317            self.rendered_frame.input_handlers
2318                [range.start.input_handlers_index..range.end.input_handlers_index]
2319                .iter_mut()
2320                .map(|handler| handler.take()),
2321        );
2322        self.next_frame.mouse_listeners.extend(
2323            self.rendered_frame.mouse_listeners
2324                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2325                .iter_mut()
2326                .map(|listener| listener.take()),
2327        );
2328        self.next_frame.accessed_element_states.extend(
2329            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2330                ..range.end.accessed_element_states_index]
2331                .iter()
2332                .map(|(id, type_id)| (id.clone(), *type_id)),
2333        );
2334        self.next_frame.tab_stops.replay(
2335            &self.rendered_frame.tab_stops.insertion_history
2336                [range.start.tab_handle_index..range.end.tab_handle_index],
2337        );
2338
2339        self.text_system
2340            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2341        self.next_frame.scene.replay(
2342            range.start.scene_index..range.end.scene_index,
2343            &self.rendered_frame.scene,
2344        );
2345    }
2346
2347    /// Push a text style onto the stack, and call a function with that style active.
2348    /// Use [`Window::text_style`] to get the current, combined text style. This method
2349    /// should only be called as part of element drawing.
2350    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2351    where
2352        F: FnOnce(&mut Self) -> R,
2353    {
2354        self.invalidator.debug_assert_paint_or_prepaint();
2355        if let Some(style) = style {
2356            self.text_style_stack.push(style);
2357            let result = f(self);
2358            self.text_style_stack.pop();
2359            result
2360        } else {
2361            f(self)
2362        }
2363    }
2364
2365    /// Updates the cursor style at the platform level. This method should only be called
2366    /// during the prepaint phase of element drawing.
2367    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2368        self.invalidator.debug_assert_paint();
2369        self.next_frame.cursor_styles.push(CursorStyleRequest {
2370            hitbox_id: Some(hitbox.id),
2371            style,
2372        });
2373    }
2374
2375    /// Updates the cursor style for the entire window at the platform level. A cursor
2376    /// style using this method will have precedence over any cursor style set using
2377    /// `set_cursor_style`. This method should only be called during the prepaint
2378    /// phase of element drawing.
2379    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2380        self.invalidator.debug_assert_paint();
2381        self.next_frame.cursor_styles.push(CursorStyleRequest {
2382            hitbox_id: None,
2383            style,
2384        })
2385    }
2386
2387    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2388    /// during the paint phase of element drawing.
2389    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2390        self.invalidator.debug_assert_prepaint();
2391        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2392        self.next_frame
2393            .tooltip_requests
2394            .push(Some(TooltipRequest { id, tooltip }));
2395        id
2396    }
2397
2398    /// Invoke the given function with the given content mask after intersecting it
2399    /// with the current mask. This method should only be called during element drawing.
2400    pub fn with_content_mask<R>(
2401        &mut self,
2402        mask: Option<ContentMask<Pixels>>,
2403        f: impl FnOnce(&mut Self) -> R,
2404    ) -> R {
2405        self.invalidator.debug_assert_paint_or_prepaint();
2406        if let Some(mask) = mask {
2407            let mask = mask.intersect(&self.content_mask());
2408            self.content_mask_stack.push(mask);
2409            let result = f(self);
2410            self.content_mask_stack.pop();
2411            result
2412        } else {
2413            f(self)
2414        }
2415    }
2416
2417    /// Updates the global element offset relative to the current offset. This is used to implement
2418    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2419    pub fn with_element_offset<R>(
2420        &mut self,
2421        offset: Point<Pixels>,
2422        f: impl FnOnce(&mut Self) -> R,
2423    ) -> R {
2424        self.invalidator.debug_assert_prepaint();
2425
2426        if offset.is_zero() {
2427            return f(self);
2428        };
2429
2430        let abs_offset = self.element_offset() + offset;
2431        self.with_absolute_element_offset(abs_offset, f)
2432    }
2433
2434    /// Updates the global element offset based on the given offset. This is used to implement
2435    /// drag handles and other manual painting of elements. This method should only be called during
2436    /// the prepaint phase of element drawing.
2437    pub fn with_absolute_element_offset<R>(
2438        &mut self,
2439        offset: Point<Pixels>,
2440        f: impl FnOnce(&mut Self) -> R,
2441    ) -> R {
2442        self.invalidator.debug_assert_prepaint();
2443        self.element_offset_stack.push(offset);
2444        let result = f(self);
2445        self.element_offset_stack.pop();
2446        result
2447    }
2448
2449    pub(crate) fn with_element_opacity<R>(
2450        &mut self,
2451        opacity: Option<f32>,
2452        f: impl FnOnce(&mut Self) -> R,
2453    ) -> R {
2454        self.invalidator.debug_assert_paint_or_prepaint();
2455
2456        let Some(opacity) = opacity else {
2457            return f(self);
2458        };
2459
2460        let previous_opacity = self.element_opacity;
2461        self.element_opacity = previous_opacity * opacity;
2462        let result = f(self);
2463        self.element_opacity = previous_opacity;
2464        result
2465    }
2466
2467    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2468    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2469    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2470    /// element offset and prepaint again. See [`crate::List`] for an example. This method should only be
2471    /// called during the prepaint phase of element drawing.
2472    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2473        self.invalidator.debug_assert_prepaint();
2474        let index = self.prepaint_index();
2475        let result = f(self);
2476        if result.is_err() {
2477            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2478            self.next_frame
2479                .tooltip_requests
2480                .truncate(index.tooltips_index);
2481            self.next_frame
2482                .deferred_draws
2483                .truncate(index.deferred_draws_index);
2484            self.next_frame
2485                .dispatch_tree
2486                .truncate(index.dispatch_tree_index);
2487            self.next_frame
2488                .accessed_element_states
2489                .truncate(index.accessed_element_states_index);
2490            self.text_system.truncate_layouts(index.line_layout_index);
2491        }
2492        result
2493    }
2494
2495    /// When you call this method during [`Element::prepaint`], containing elements will attempt to
2496    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2497    /// [`Element::prepaint`] again with a new set of bounds. See [`crate::List`] for an example of an element
2498    /// that supports this method being called on the elements it contains. This method should only be
2499    /// called during the prepaint phase of element drawing.
2500    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2501        self.invalidator.debug_assert_prepaint();
2502        self.requested_autoscroll = Some(bounds);
2503    }
2504
2505    /// This method can be called from a containing element such as [`crate::List`] to support the autoscroll behavior
2506    /// described in [`Self::request_autoscroll`].
2507    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2508        self.invalidator.debug_assert_prepaint();
2509        self.requested_autoscroll.take()
2510    }
2511
2512    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2513    /// Your view will be re-drawn once the asset has finished loading.
2514    ///
2515    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2516    /// time.
2517    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2518        let (task, is_first) = cx.fetch_asset::<A>(source);
2519        task.clone().now_or_never().or_else(|| {
2520            if is_first {
2521                let entity_id = self.current_view();
2522                self.spawn(cx, {
2523                    let task = task.clone();
2524                    async move |cx| {
2525                        task.await;
2526
2527                        cx.on_next_frame(move |_, cx| {
2528                            cx.notify(entity_id);
2529                        });
2530                    }
2531                })
2532                .detach();
2533            }
2534
2535            None
2536        })
2537    }
2538
2539    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2540    /// Your view will not be re-drawn once the asset has finished loading.
2541    ///
2542    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2543    /// time.
2544    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2545        let (task, _) = cx.fetch_asset::<A>(source);
2546        task.now_or_never()
2547    }
2548    /// Obtain the current element offset. This method should only be called during the
2549    /// prepaint phase of element drawing.
2550    pub fn element_offset(&self) -> Point<Pixels> {
2551        self.invalidator.debug_assert_prepaint();
2552        self.element_offset_stack
2553            .last()
2554            .copied()
2555            .unwrap_or_default()
2556    }
2557
2558    /// Obtain the current element opacity. This method should only be called during the
2559    /// prepaint phase of element drawing.
2560    #[inline]
2561    pub(crate) fn element_opacity(&self) -> f32 {
2562        self.invalidator.debug_assert_paint_or_prepaint();
2563        self.element_opacity
2564    }
2565
2566    /// Obtain the current content mask. This method should only be called during element drawing.
2567    pub fn content_mask(&self) -> ContentMask<Pixels> {
2568        self.invalidator.debug_assert_paint_or_prepaint();
2569        self.content_mask_stack
2570            .last()
2571            .cloned()
2572            .unwrap_or_else(|| ContentMask {
2573                bounds: Bounds {
2574                    origin: Point::default(),
2575                    size: self.viewport_size,
2576                },
2577            })
2578    }
2579
2580    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2581    /// This can be used within a custom element to distinguish multiple sets of child elements.
2582    pub fn with_element_namespace<R>(
2583        &mut self,
2584        element_id: impl Into<ElementId>,
2585        f: impl FnOnce(&mut Self) -> R,
2586    ) -> R {
2587        self.element_id_stack.push(element_id.into());
2588        let result = f(self);
2589        self.element_id_stack.pop();
2590        result
2591    }
2592
2593    /// Use a piece of state that exists as long this element is being rendered in consecutive frames.
2594    pub fn use_keyed_state<S: 'static>(
2595        &mut self,
2596        key: impl Into<ElementId>,
2597        cx: &mut App,
2598        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2599    ) -> Entity<S> {
2600        let current_view = self.current_view();
2601        self.with_global_id(key.into(), |global_id, window| {
2602            window.with_element_state(global_id, |state: Option<Entity<S>>, window| {
2603                if let Some(state) = state {
2604                    (state.clone(), state)
2605                } else {
2606                    let new_state = cx.new(|cx| init(window, cx));
2607                    cx.observe(&new_state, move |_, cx| {
2608                        cx.notify(current_view);
2609                    })
2610                    .detach();
2611                    (new_state.clone(), new_state)
2612                }
2613            })
2614        })
2615    }
2616
2617    /// Immediately push an element ID onto the stack. Useful for simplifying IDs in lists
2618    pub fn with_id<R>(&mut self, id: impl Into<ElementId>, f: impl FnOnce(&mut Self) -> R) -> R {
2619        self.with_global_id(id.into(), |_, window| f(window))
2620    }
2621
2622    /// Use a piece of state that exists as long this element is being rendered in consecutive frames, without needing to specify a key
2623    ///
2624    /// NOTE: This method uses the location of the caller to generate an ID for this state.
2625    ///       If this is not sufficient to identify your state (e.g. you're rendering a list item),
2626    ///       you can provide a custom ElementID using the `use_keyed_state` method.
2627    #[track_caller]
2628    pub fn use_state<S: 'static>(
2629        &mut self,
2630        cx: &mut App,
2631        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2632    ) -> Entity<S> {
2633        self.use_keyed_state(
2634            ElementId::CodeLocation(*core::panic::Location::caller()),
2635            cx,
2636            init,
2637        )
2638    }
2639
2640    /// Updates or initializes state for an element with the given id that lives across multiple
2641    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2642    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2643    /// when drawing the next frame. This method should only be called as part of element drawing.
2644    pub fn with_element_state<S, R>(
2645        &mut self,
2646        global_id: &GlobalElementId,
2647        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2648    ) -> R
2649    where
2650        S: 'static,
2651    {
2652        self.invalidator.debug_assert_paint_or_prepaint();
2653
2654        let key = (global_id.clone(), TypeId::of::<S>());
2655        self.next_frame.accessed_element_states.push(key.clone());
2656
2657        if let Some(any) = self
2658            .next_frame
2659            .element_states
2660            .remove(&key)
2661            .or_else(|| self.rendered_frame.element_states.remove(&key))
2662        {
2663            let ElementStateBox {
2664                inner,
2665                #[cfg(debug_assertions)]
2666                type_name,
2667            } = any;
2668            // Using the extra inner option to avoid needing to reallocate a new box.
2669            let mut state_box = inner
2670                .downcast::<Option<S>>()
2671                .map_err(|_| {
2672                    #[cfg(debug_assertions)]
2673                    {
2674                        anyhow::anyhow!(
2675                            "invalid element state type for id, requested {:?}, actual: {:?}",
2676                            std::any::type_name::<S>(),
2677                            type_name
2678                        )
2679                    }
2680
2681                    #[cfg(not(debug_assertions))]
2682                    {
2683                        anyhow::anyhow!(
2684                            "invalid element state type for id, requested {:?}",
2685                            std::any::type_name::<S>(),
2686                        )
2687                    }
2688                })
2689                .unwrap();
2690
2691            let state = state_box.take().expect(
2692                "reentrant call to with_element_state for the same state type and element id",
2693            );
2694            let (result, state) = f(Some(state), self);
2695            state_box.replace(state);
2696            self.next_frame.element_states.insert(
2697                key,
2698                ElementStateBox {
2699                    inner: state_box,
2700                    #[cfg(debug_assertions)]
2701                    type_name,
2702                },
2703            );
2704            result
2705        } else {
2706            let (result, state) = f(None, self);
2707            self.next_frame.element_states.insert(
2708                key,
2709                ElementStateBox {
2710                    inner: Box::new(Some(state)),
2711                    #[cfg(debug_assertions)]
2712                    type_name: std::any::type_name::<S>(),
2713                },
2714            );
2715            result
2716        }
2717    }
2718
2719    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2720    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2721    /// when the element is guaranteed to have an id.
2722    ///
2723    /// The first option means 'no ID provided'
2724    /// The second option means 'not yet initialized'
2725    pub fn with_optional_element_state<S, R>(
2726        &mut self,
2727        global_id: Option<&GlobalElementId>,
2728        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2729    ) -> R
2730    where
2731        S: 'static,
2732    {
2733        self.invalidator.debug_assert_paint_or_prepaint();
2734
2735        if let Some(global_id) = global_id {
2736            self.with_element_state(global_id, |state, cx| {
2737                let (result, state) = f(Some(state), cx);
2738                let state =
2739                    state.expect("you must return some state when you pass some element id");
2740                (result, state)
2741            })
2742        } else {
2743            let (result, state) = f(None, self);
2744            debug_assert!(
2745                state.is_none(),
2746                "you must not return an element state when passing None for the global id"
2747            );
2748            result
2749        }
2750    }
2751
2752    /// Executes the given closure within the context of a tab group.
2753    #[inline]
2754    pub fn with_tab_group<R>(&mut self, index: Option<isize>, f: impl FnOnce(&mut Self) -> R) -> R {
2755        if let Some(index) = index {
2756            self.next_frame.tab_stops.begin_group(index);
2757            let result = f(self);
2758            self.next_frame.tab_stops.end_group();
2759            result
2760        } else {
2761            f(self)
2762        }
2763    }
2764
2765    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2766    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2767    /// with higher values being drawn on top.
2768    ///
2769    /// This method should only be called as part of the prepaint phase of element drawing.
2770    pub fn defer_draw(
2771        &mut self,
2772        element: AnyElement,
2773        absolute_offset: Point<Pixels>,
2774        priority: usize,
2775    ) {
2776        self.invalidator.debug_assert_prepaint();
2777        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2778        self.next_frame.deferred_draws.push(DeferredDraw {
2779            current_view: self.current_view(),
2780            parent_node,
2781            element_id_stack: self.element_id_stack.clone(),
2782            text_style_stack: self.text_style_stack.clone(),
2783            priority,
2784            element: Some(element),
2785            absolute_offset,
2786            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2787            paint_range: PaintIndex::default()..PaintIndex::default(),
2788        });
2789    }
2790
2791    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2792    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2793    /// for performance reasons.
2794    ///
2795    /// This method should only be called as part of the paint phase of element drawing.
2796    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2797        self.invalidator.debug_assert_paint();
2798
2799        let scale_factor = self.scale_factor();
2800        let content_mask = self.content_mask();
2801        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2802        if !clipped_bounds.is_empty() {
2803            self.next_frame
2804                .scene
2805                .push_layer(clipped_bounds.scale(scale_factor));
2806        }
2807
2808        let result = f(self);
2809
2810        if !clipped_bounds.is_empty() {
2811            self.next_frame.scene.pop_layer();
2812        }
2813
2814        result
2815    }
2816
2817    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2818    ///
2819    /// This method should only be called as part of the paint phase of element drawing.
2820    pub fn paint_shadows(
2821        &mut self,
2822        bounds: Bounds<Pixels>,
2823        corner_radii: Corners<Pixels>,
2824        shadows: &[BoxShadow],
2825    ) {
2826        self.invalidator.debug_assert_paint();
2827
2828        let scale_factor = self.scale_factor();
2829        let content_mask = self.content_mask();
2830        let opacity = self.element_opacity();
2831        for shadow in shadows {
2832            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2833            self.next_frame.scene.insert_primitive(Shadow {
2834                order: 0,
2835                blur_radius: shadow.blur_radius.scale(scale_factor),
2836                bounds: shadow_bounds.scale(scale_factor),
2837                content_mask: content_mask.scale(scale_factor),
2838                corner_radii: corner_radii.scale(scale_factor),
2839                color: shadow.color.opacity(opacity),
2840            });
2841        }
2842    }
2843
2844    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2845    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2846    /// see [`fill`], [`outline`], and [`quad`] to construct this type.
2847    ///
2848    /// This method should only be called as part of the paint phase of element drawing.
2849    ///
2850    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2851    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2852    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2853    pub fn paint_quad(&mut self, quad: PaintQuad) {
2854        self.invalidator.debug_assert_paint();
2855
2856        let scale_factor = self.scale_factor();
2857        let content_mask = self.content_mask();
2858        let opacity = self.element_opacity();
2859        self.next_frame.scene.insert_primitive(Quad {
2860            order: 0,
2861            bounds: quad.bounds.scale(scale_factor),
2862            content_mask: content_mask.scale(scale_factor),
2863            background: quad.background.opacity(opacity),
2864            border_color: quad.border_color.opacity(opacity),
2865            corner_radii: quad.corner_radii.scale(scale_factor),
2866            border_widths: quad.border_widths.scale(scale_factor),
2867            border_style: quad.border_style,
2868        });
2869    }
2870
2871    /// Paint the given `Path` into the scene for the next frame at the current z-index.
2872    ///
2873    /// This method should only be called as part of the paint phase of element drawing.
2874    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2875        self.invalidator.debug_assert_paint();
2876
2877        let scale_factor = self.scale_factor();
2878        let content_mask = self.content_mask();
2879        let opacity = self.element_opacity();
2880        path.content_mask = content_mask;
2881        let color: Background = color.into();
2882        path.color = color.opacity(opacity);
2883        self.next_frame
2884            .scene
2885            .insert_primitive(path.scale(scale_factor));
2886    }
2887
2888    /// Paint an underline into the scene for the next frame at the current z-index.
2889    ///
2890    /// This method should only be called as part of the paint phase of element drawing.
2891    pub fn paint_underline(
2892        &mut self,
2893        origin: Point<Pixels>,
2894        width: Pixels,
2895        style: &UnderlineStyle,
2896    ) {
2897        self.invalidator.debug_assert_paint();
2898
2899        let scale_factor = self.scale_factor();
2900        let height = if style.wavy {
2901            style.thickness * 3.
2902        } else {
2903            style.thickness
2904        };
2905        let bounds = Bounds {
2906            origin,
2907            size: size(width, height),
2908        };
2909        let content_mask = self.content_mask();
2910        let element_opacity = self.element_opacity();
2911
2912        self.next_frame.scene.insert_primitive(Underline {
2913            order: 0,
2914            pad: 0,
2915            bounds: bounds.scale(scale_factor),
2916            content_mask: content_mask.scale(scale_factor),
2917            color: style.color.unwrap_or_default().opacity(element_opacity),
2918            thickness: style.thickness.scale(scale_factor),
2919            wavy: if style.wavy { 1 } else { 0 },
2920        });
2921    }
2922
2923    /// Paint a strikethrough into the scene for the next frame at the current z-index.
2924    ///
2925    /// This method should only be called as part of the paint phase of element drawing.
2926    pub fn paint_strikethrough(
2927        &mut self,
2928        origin: Point<Pixels>,
2929        width: Pixels,
2930        style: &StrikethroughStyle,
2931    ) {
2932        self.invalidator.debug_assert_paint();
2933
2934        let scale_factor = self.scale_factor();
2935        let height = style.thickness;
2936        let bounds = Bounds {
2937            origin,
2938            size: size(width, height),
2939        };
2940        let content_mask = self.content_mask();
2941        let opacity = self.element_opacity();
2942
2943        self.next_frame.scene.insert_primitive(Underline {
2944            order: 0,
2945            pad: 0,
2946            bounds: bounds.scale(scale_factor),
2947            content_mask: content_mask.scale(scale_factor),
2948            thickness: style.thickness.scale(scale_factor),
2949            color: style.color.unwrap_or_default().opacity(opacity),
2950            wavy: 0,
2951        });
2952    }
2953
2954    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2955    ///
2956    /// The y component of the origin is the baseline of the glyph.
2957    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2958    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2959    /// This method is only useful if you need to paint a single glyph that has already been shaped.
2960    ///
2961    /// This method should only be called as part of the paint phase of element drawing.
2962    pub fn paint_glyph(
2963        &mut self,
2964        origin: Point<Pixels>,
2965        font_id: FontId,
2966        glyph_id: GlyphId,
2967        font_size: Pixels,
2968        color: Hsla,
2969    ) -> Result<()> {
2970        self.invalidator.debug_assert_paint();
2971
2972        let element_opacity = self.element_opacity();
2973        let scale_factor = self.scale_factor();
2974        let glyph_origin = origin.scale(scale_factor);
2975
2976        let subpixel_variant = Point {
2977            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS_X as f32).floor() as u8,
2978            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS_Y as f32).floor() as u8,
2979        };
2980        let params = RenderGlyphParams {
2981            font_id,
2982            glyph_id,
2983            font_size,
2984            subpixel_variant,
2985            scale_factor,
2986            is_emoji: false,
2987        };
2988
2989        let raster_bounds = self.text_system().raster_bounds(&params)?;
2990        if !raster_bounds.is_zero() {
2991            let tile = self
2992                .sprite_atlas
2993                .get_or_insert_with(&params.clone().into(), &mut || {
2994                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
2995                    Ok(Some((size, Cow::Owned(bytes))))
2996                })?
2997                .expect("Callback above only errors or returns Some");
2998            let bounds = Bounds {
2999                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3000                size: tile.bounds.size.map(Into::into),
3001            };
3002            let content_mask = self.content_mask().scale(scale_factor);
3003            self.next_frame.scene.insert_primitive(MonochromeSprite {
3004                order: 0,
3005                pad: 0,
3006                bounds,
3007                content_mask,
3008                color: color.opacity(element_opacity),
3009                tile,
3010                transformation: TransformationMatrix::unit(),
3011            });
3012        }
3013        Ok(())
3014    }
3015
3016    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
3017    ///
3018    /// The y component of the origin is the baseline of the glyph.
3019    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3020    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3021    /// This method is only useful if you need to paint a single emoji that has already been shaped.
3022    ///
3023    /// This method should only be called as part of the paint phase of element drawing.
3024    pub fn paint_emoji(
3025        &mut self,
3026        origin: Point<Pixels>,
3027        font_id: FontId,
3028        glyph_id: GlyphId,
3029        font_size: Pixels,
3030    ) -> Result<()> {
3031        self.invalidator.debug_assert_paint();
3032
3033        let scale_factor = self.scale_factor();
3034        let glyph_origin = origin.scale(scale_factor);
3035        let params = RenderGlyphParams {
3036            font_id,
3037            glyph_id,
3038            font_size,
3039            // We don't render emojis with subpixel variants.
3040            subpixel_variant: Default::default(),
3041            scale_factor,
3042            is_emoji: true,
3043        };
3044
3045        let raster_bounds = self.text_system().raster_bounds(&params)?;
3046        if !raster_bounds.is_zero() {
3047            let tile = self
3048                .sprite_atlas
3049                .get_or_insert_with(&params.clone().into(), &mut || {
3050                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3051                    Ok(Some((size, Cow::Owned(bytes))))
3052                })?
3053                .expect("Callback above only errors or returns Some");
3054
3055            let bounds = Bounds {
3056                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3057                size: tile.bounds.size.map(Into::into),
3058            };
3059            let content_mask = self.content_mask().scale(scale_factor);
3060            let opacity = self.element_opacity();
3061
3062            self.next_frame.scene.insert_primitive(PolychromeSprite {
3063                order: 0,
3064                pad: 0,
3065                grayscale: false,
3066                bounds,
3067                corner_radii: Default::default(),
3068                content_mask,
3069                tile,
3070                opacity,
3071            });
3072        }
3073        Ok(())
3074    }
3075
3076    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
3077    ///
3078    /// This method should only be called as part of the paint phase of element drawing.
3079    pub fn paint_svg(
3080        &mut self,
3081        bounds: Bounds<Pixels>,
3082        path: SharedString,
3083        transformation: TransformationMatrix,
3084        color: Hsla,
3085        cx: &App,
3086    ) -> Result<()> {
3087        self.invalidator.debug_assert_paint();
3088
3089        let element_opacity = self.element_opacity();
3090        let scale_factor = self.scale_factor();
3091
3092        let bounds = bounds.scale(scale_factor);
3093        let params = RenderSvgParams {
3094            path,
3095            size: bounds.size.map(|pixels| {
3096                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
3097            }),
3098        };
3099
3100        let Some(tile) =
3101            self.sprite_atlas
3102                .get_or_insert_with(&params.clone().into(), &mut || {
3103                    let Some((size, bytes)) = cx.svg_renderer.render(&params)? else {
3104                        return Ok(None);
3105                    };
3106                    Ok(Some((size, Cow::Owned(bytes))))
3107                })?
3108        else {
3109            return Ok(());
3110        };
3111        let content_mask = self.content_mask().scale(scale_factor);
3112        let svg_bounds = Bounds {
3113            origin: bounds.center()
3114                - Point::new(
3115                    ScaledPixels(tile.bounds.size.width.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3116                    ScaledPixels(tile.bounds.size.height.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3117                ),
3118            size: tile
3119                .bounds
3120                .size
3121                .map(|value| ScaledPixels(value.0 as f32 / SMOOTH_SVG_SCALE_FACTOR)),
3122        };
3123
3124        self.next_frame.scene.insert_primitive(MonochromeSprite {
3125            order: 0,
3126            pad: 0,
3127            bounds: svg_bounds
3128                .map_origin(|origin| origin.round())
3129                .map_size(|size| size.ceil()),
3130            content_mask,
3131            color: color.opacity(element_opacity),
3132            tile,
3133            transformation,
3134        });
3135
3136        Ok(())
3137    }
3138
3139    /// Paint an image into the scene for the next frame at the current z-index.
3140    /// This method will panic if the frame_index is not valid
3141    ///
3142    /// This method should only be called as part of the paint phase of element drawing.
3143    pub fn paint_image(
3144        &mut self,
3145        bounds: Bounds<Pixels>,
3146        corner_radii: Corners<Pixels>,
3147        data: Arc<RenderImage>,
3148        frame_index: usize,
3149        grayscale: bool,
3150    ) -> Result<()> {
3151        self.invalidator.debug_assert_paint();
3152
3153        let scale_factor = self.scale_factor();
3154        let bounds = bounds.scale(scale_factor);
3155        let params = RenderImageParams {
3156            image_id: data.id,
3157            frame_index,
3158        };
3159
3160        let tile = self
3161            .sprite_atlas
3162            .get_or_insert_with(&params.into(), &mut || {
3163                Ok(Some((
3164                    data.size(frame_index),
3165                    Cow::Borrowed(
3166                        data.as_bytes(frame_index)
3167                            .expect("It's the caller's job to pass a valid frame index"),
3168                    ),
3169                )))
3170            })?
3171            .expect("Callback above only returns Some");
3172        let content_mask = self.content_mask().scale(scale_factor);
3173        let corner_radii = corner_radii.scale(scale_factor);
3174        let opacity = self.element_opacity();
3175
3176        self.next_frame.scene.insert_primitive(PolychromeSprite {
3177            order: 0,
3178            pad: 0,
3179            grayscale,
3180            bounds: bounds
3181                .map_origin(|origin| origin.floor())
3182                .map_size(|size| size.ceil()),
3183            content_mask,
3184            corner_radii,
3185            tile,
3186            opacity,
3187        });
3188        Ok(())
3189    }
3190
3191    /// Paint a surface into the scene for the next frame at the current z-index.
3192    ///
3193    /// This method should only be called as part of the paint phase of element drawing.
3194    #[cfg(target_os = "macos")]
3195    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
3196        use crate::PaintSurface;
3197
3198        self.invalidator.debug_assert_paint();
3199
3200        let scale_factor = self.scale_factor();
3201        let bounds = bounds.scale(scale_factor);
3202        let content_mask = self.content_mask().scale(scale_factor);
3203        self.next_frame.scene.insert_primitive(PaintSurface {
3204            order: 0,
3205            bounds,
3206            content_mask,
3207            image_buffer,
3208        });
3209    }
3210
3211    /// Removes an image from the sprite atlas.
3212    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
3213        for frame_index in 0..data.frame_count() {
3214            let params = RenderImageParams {
3215                image_id: data.id,
3216                frame_index,
3217            };
3218
3219            self.sprite_atlas.remove(&params.clone().into());
3220        }
3221
3222        Ok(())
3223    }
3224
3225    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
3226    /// layout is being requested, along with the layout ids of any children. This method is called during
3227    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
3228    ///
3229    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3230    #[must_use]
3231    pub fn request_layout(
3232        &mut self,
3233        style: Style,
3234        children: impl IntoIterator<Item = LayoutId>,
3235        cx: &mut App,
3236    ) -> LayoutId {
3237        self.invalidator.debug_assert_prepaint();
3238
3239        cx.layout_id_buffer.clear();
3240        cx.layout_id_buffer.extend(children);
3241        let rem_size = self.rem_size();
3242        let scale_factor = self.scale_factor();
3243
3244        self.layout_engine.as_mut().unwrap().request_layout(
3245            style,
3246            rem_size,
3247            scale_factor,
3248            &cx.layout_id_buffer,
3249        )
3250    }
3251
3252    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3253    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3254    /// determine the element's size. One place this is used internally is when measuring text.
3255    ///
3256    /// The given closure is invoked at layout time with the known dimensions and available space and
3257    /// returns a `Size`.
3258    ///
3259    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3260    pub fn request_measured_layout<
3261        F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3262            + 'static,
3263    >(
3264        &mut self,
3265        style: Style,
3266        measure: F,
3267    ) -> LayoutId {
3268        self.invalidator.debug_assert_prepaint();
3269
3270        let rem_size = self.rem_size();
3271        let scale_factor = self.scale_factor();
3272        self.layout_engine
3273            .as_mut()
3274            .unwrap()
3275            .request_measured_layout(style, rem_size, scale_factor, measure)
3276    }
3277
3278    /// Compute the layout for the given id within the given available space.
3279    /// This method is called for its side effect, typically by the framework prior to painting.
3280    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3281    ///
3282    /// This method should only be called as part of the prepaint phase of element drawing.
3283    pub fn compute_layout(
3284        &mut self,
3285        layout_id: LayoutId,
3286        available_space: Size<AvailableSpace>,
3287        cx: &mut App,
3288    ) {
3289        self.invalidator.debug_assert_prepaint();
3290
3291        let mut layout_engine = self.layout_engine.take().unwrap();
3292        layout_engine.compute_layout(layout_id, available_space, self, cx);
3293        self.layout_engine = Some(layout_engine);
3294    }
3295
3296    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3297    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3298    ///
3299    /// This method should only be called as part of element drawing.
3300    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3301        self.invalidator.debug_assert_prepaint();
3302
3303        let scale_factor = self.scale_factor();
3304        let mut bounds = self
3305            .layout_engine
3306            .as_mut()
3307            .unwrap()
3308            .layout_bounds(layout_id, scale_factor)
3309            .map(Into::into);
3310        bounds.origin += self.element_offset();
3311        bounds
3312    }
3313
3314    /// This method should be called during `prepaint`. You can use
3315    /// the returned [Hitbox] during `paint` or in an event handler
3316    /// to determine whether the inserted hitbox was the topmost.
3317    ///
3318    /// This method should only be called as part of the prepaint phase of element drawing.
3319    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3320        self.invalidator.debug_assert_prepaint();
3321
3322        let content_mask = self.content_mask();
3323        let mut id = self.next_hitbox_id;
3324        self.next_hitbox_id = self.next_hitbox_id.next();
3325        let hitbox = Hitbox {
3326            id,
3327            bounds,
3328            content_mask,
3329            behavior,
3330        };
3331        self.next_frame.hitboxes.push(hitbox.clone());
3332        hitbox
3333    }
3334
3335    /// Set a hitbox which will act as a control area of the platform window.
3336    ///
3337    /// This method should only be called as part of the paint phase of element drawing.
3338    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3339        self.invalidator.debug_assert_paint();
3340        self.next_frame.window_control_hitboxes.push((area, hitbox));
3341    }
3342
3343    /// Sets the key context for the current element. This context will be used to translate
3344    /// keybindings into actions.
3345    ///
3346    /// This method should only be called as part of the paint phase of element drawing.
3347    pub fn set_key_context(&mut self, context: KeyContext) {
3348        self.invalidator.debug_assert_paint();
3349        self.next_frame.dispatch_tree.set_key_context(context);
3350    }
3351
3352    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3353    /// and keyboard event dispatch for the element.
3354    ///
3355    /// This method should only be called as part of the prepaint phase of element drawing.
3356    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3357        self.invalidator.debug_assert_prepaint();
3358        if focus_handle.is_focused(self) {
3359            self.next_frame.focus = Some(focus_handle.id);
3360        }
3361        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3362    }
3363
3364    /// Sets the view id for the current element, which will be used to manage view caching.
3365    ///
3366    /// This method should only be called as part of element prepaint. We plan on removing this
3367    /// method eventually when we solve some issues that require us to construct editor elements
3368    /// directly instead of always using editors via views.
3369    pub fn set_view_id(&mut self, view_id: EntityId) {
3370        self.invalidator.debug_assert_prepaint();
3371        self.next_frame.dispatch_tree.set_view_id(view_id);
3372    }
3373
3374    /// Get the entity ID for the currently rendering view
3375    pub fn current_view(&self) -> EntityId {
3376        self.invalidator.debug_assert_paint_or_prepaint();
3377        self.rendered_entity_stack.last().copied().unwrap()
3378    }
3379
3380    pub(crate) fn with_rendered_view<R>(
3381        &mut self,
3382        id: EntityId,
3383        f: impl FnOnce(&mut Self) -> R,
3384    ) -> R {
3385        self.rendered_entity_stack.push(id);
3386        let result = f(self);
3387        self.rendered_entity_stack.pop();
3388        result
3389    }
3390
3391    /// Executes the provided function with the specified image cache.
3392    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3393    where
3394        F: FnOnce(&mut Self) -> R,
3395    {
3396        if let Some(image_cache) = image_cache {
3397            self.image_cache_stack.push(image_cache);
3398            let result = f(self);
3399            self.image_cache_stack.pop();
3400            result
3401        } else {
3402            f(self)
3403        }
3404    }
3405
3406    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3407    /// platform to receive textual input with proper integration with concerns such
3408    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3409    /// rendered.
3410    ///
3411    /// This method should only be called as part of the paint phase of element drawing.
3412    ///
3413    /// [element_input_handler]: crate::ElementInputHandler
3414    pub fn handle_input(
3415        &mut self,
3416        focus_handle: &FocusHandle,
3417        input_handler: impl InputHandler,
3418        cx: &App,
3419    ) {
3420        self.invalidator.debug_assert_paint();
3421
3422        if focus_handle.is_focused(self) {
3423            let cx = self.to_async(cx);
3424            self.next_frame
3425                .input_handlers
3426                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3427        }
3428    }
3429
3430    /// Register a mouse event listener on the window for the next frame. The type of event
3431    /// is determined by the first parameter of the given listener. When the next frame is rendered
3432    /// the listener will be cleared.
3433    ///
3434    /// This method should only be called as part of the paint phase of element drawing.
3435    pub fn on_mouse_event<Event: MouseEvent>(
3436        &mut self,
3437        mut handler: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3438    ) {
3439        self.invalidator.debug_assert_paint();
3440
3441        self.next_frame.mouse_listeners.push(Some(Box::new(
3442            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3443                if let Some(event) = event.downcast_ref() {
3444                    handler(event, phase, window, cx)
3445                }
3446            },
3447        )));
3448    }
3449
3450    /// Register a key event listener on the window for the next frame. The type of event
3451    /// is determined by the first parameter of the given listener. When the next frame is rendered
3452    /// the listener will be cleared.
3453    ///
3454    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3455    /// a specific need to register a global listener.
3456    ///
3457    /// This method should only be called as part of the paint phase of element drawing.
3458    pub fn on_key_event<Event: KeyEvent>(
3459        &mut self,
3460        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3461    ) {
3462        self.invalidator.debug_assert_paint();
3463
3464        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3465            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3466                if let Some(event) = event.downcast_ref::<Event>() {
3467                    listener(event, phase, window, cx)
3468                }
3469            },
3470        ));
3471    }
3472
3473    /// Register a modifiers changed event listener on the window for the next frame.
3474    ///
3475    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3476    /// a specific need to register a global listener.
3477    ///
3478    /// This method should only be called as part of the paint phase of element drawing.
3479    pub fn on_modifiers_changed(
3480        &mut self,
3481        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3482    ) {
3483        self.invalidator.debug_assert_paint();
3484
3485        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3486            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3487                listener(event, window, cx)
3488            },
3489        ));
3490    }
3491
3492    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3493    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3494    /// Returns a subscription and persists until the subscription is dropped.
3495    pub fn on_focus_in(
3496        &mut self,
3497        handle: &FocusHandle,
3498        cx: &mut App,
3499        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3500    ) -> Subscription {
3501        let focus_id = handle.id;
3502        let (subscription, activate) =
3503            self.new_focus_listener(Box::new(move |event, window, cx| {
3504                if event.is_focus_in(focus_id) {
3505                    listener(window, cx);
3506                }
3507                true
3508            }));
3509        cx.defer(move |_| activate());
3510        subscription
3511    }
3512
3513    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3514    /// Returns a subscription and persists until the subscription is dropped.
3515    pub fn on_focus_out(
3516        &mut self,
3517        handle: &FocusHandle,
3518        cx: &mut App,
3519        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3520    ) -> Subscription {
3521        let focus_id = handle.id;
3522        let (subscription, activate) =
3523            self.new_focus_listener(Box::new(move |event, window, cx| {
3524                if let Some(blurred_id) = event.previous_focus_path.last().copied()
3525                    && event.is_focus_out(focus_id)
3526                {
3527                    let event = FocusOutEvent {
3528                        blurred: WeakFocusHandle {
3529                            id: blurred_id,
3530                            handles: Arc::downgrade(&cx.focus_handles),
3531                        },
3532                    };
3533                    listener(event, window, cx)
3534                }
3535                true
3536            }));
3537        cx.defer(move |_| activate());
3538        subscription
3539    }
3540
3541    fn reset_cursor_style(&self, cx: &mut App) {
3542        // Set the cursor only if we're the active window.
3543        if self.is_window_hovered() {
3544            let style = self
3545                .rendered_frame
3546                .cursor_style(self)
3547                .unwrap_or(CursorStyle::Arrow);
3548            cx.platform.set_cursor_style(style);
3549        }
3550    }
3551
3552    /// Dispatch a given keystroke as though the user had typed it.
3553    /// You can create a keystroke with Keystroke::parse("").
3554    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3555        let keystroke = keystroke.with_simulated_ime();
3556        let result = self.dispatch_event(
3557            PlatformInput::KeyDown(KeyDownEvent {
3558                keystroke: keystroke.clone(),
3559                is_held: false,
3560            }),
3561            cx,
3562        );
3563        if !result.propagate {
3564            return true;
3565        }
3566
3567        if let Some(input) = keystroke.key_char
3568            && let Some(mut input_handler) = self.platform_window.take_input_handler()
3569        {
3570            input_handler.dispatch_input(&input, self, cx);
3571            self.platform_window.set_input_handler(input_handler);
3572            return true;
3573        }
3574
3575        false
3576    }
3577
3578    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3579    /// binding for the action (last binding added to the keymap).
3580    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3581        self.highest_precedence_binding_for_action(action)
3582            .map(|binding| {
3583                binding
3584                    .keystrokes()
3585                    .iter()
3586                    .map(ToString::to_string)
3587                    .collect::<Vec<_>>()
3588                    .join(" ")
3589            })
3590            .unwrap_or_else(|| action.name().to_string())
3591    }
3592
3593    /// Dispatch a mouse or keyboard event on the window.
3594    #[profiling::function]
3595    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3596        self.last_input_timestamp.set(Instant::now());
3597
3598        // Track whether this input was keyboard-based for focus-visible styling
3599        self.last_input_was_keyboard = matches!(
3600            event,
3601            PlatformInput::KeyDown(_)
3602                | PlatformInput::KeyUp(_)
3603                | PlatformInput::ModifiersChanged(_)
3604        );
3605
3606        // Handlers may set this to false by calling `stop_propagation`.
3607        cx.propagate_event = true;
3608        // Handlers may set this to true by calling `prevent_default`.
3609        self.default_prevented = false;
3610
3611        let event = match event {
3612            // Track the mouse position with our own state, since accessing the platform
3613            // API for the mouse position can only occur on the main thread.
3614            PlatformInput::MouseMove(mouse_move) => {
3615                self.mouse_position = mouse_move.position;
3616                self.modifiers = mouse_move.modifiers;
3617                PlatformInput::MouseMove(mouse_move)
3618            }
3619            PlatformInput::MouseDown(mouse_down) => {
3620                self.mouse_position = mouse_down.position;
3621                self.modifiers = mouse_down.modifiers;
3622                PlatformInput::MouseDown(mouse_down)
3623            }
3624            PlatformInput::MouseUp(mouse_up) => {
3625                self.mouse_position = mouse_up.position;
3626                self.modifiers = mouse_up.modifiers;
3627                PlatformInput::MouseUp(mouse_up)
3628            }
3629            PlatformInput::MouseExited(mouse_exited) => {
3630                self.modifiers = mouse_exited.modifiers;
3631                PlatformInput::MouseExited(mouse_exited)
3632            }
3633            PlatformInput::ModifiersChanged(modifiers_changed) => {
3634                self.modifiers = modifiers_changed.modifiers;
3635                self.capslock = modifiers_changed.capslock;
3636                PlatformInput::ModifiersChanged(modifiers_changed)
3637            }
3638            PlatformInput::ScrollWheel(scroll_wheel) => {
3639                self.mouse_position = scroll_wheel.position;
3640                self.modifiers = scroll_wheel.modifiers;
3641                PlatformInput::ScrollWheel(scroll_wheel)
3642            }
3643            // Translate dragging and dropping of external files from the operating system
3644            // to internal drag and drop events.
3645            PlatformInput::FileDrop(file_drop) => match file_drop {
3646                FileDropEvent::Entered { position, paths } => {
3647                    self.mouse_position = position;
3648                    if cx.active_drag.is_none() {
3649                        cx.active_drag = Some(AnyDrag {
3650                            value: Arc::new(paths.clone()),
3651                            view: cx.new(|_| paths).into(),
3652                            cursor_offset: position,
3653                            cursor_style: None,
3654                        });
3655                    }
3656                    PlatformInput::MouseMove(MouseMoveEvent {
3657                        position,
3658                        pressed_button: Some(MouseButton::Left),
3659                        modifiers: Modifiers::default(),
3660                    })
3661                }
3662                FileDropEvent::Pending { position } => {
3663                    self.mouse_position = position;
3664                    PlatformInput::MouseMove(MouseMoveEvent {
3665                        position,
3666                        pressed_button: Some(MouseButton::Left),
3667                        modifiers: Modifiers::default(),
3668                    })
3669                }
3670                FileDropEvent::Submit { position } => {
3671                    cx.activate(true);
3672                    self.mouse_position = position;
3673                    PlatformInput::MouseUp(MouseUpEvent {
3674                        button: MouseButton::Left,
3675                        position,
3676                        modifiers: Modifiers::default(),
3677                        click_count: 1,
3678                    })
3679                }
3680                FileDropEvent::Exited => {
3681                    cx.active_drag.take();
3682                    PlatformInput::FileDrop(FileDropEvent::Exited)
3683                }
3684            },
3685            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3686        };
3687
3688        if let Some(any_mouse_event) = event.mouse_event() {
3689            self.dispatch_mouse_event(any_mouse_event, cx);
3690        } else if let Some(any_key_event) = event.keyboard_event() {
3691            self.dispatch_key_event(any_key_event, cx);
3692        }
3693
3694        DispatchEventResult {
3695            propagate: cx.propagate_event,
3696            default_prevented: self.default_prevented,
3697        }
3698    }
3699
3700    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3701        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3702        if hit_test != self.mouse_hit_test {
3703            self.mouse_hit_test = hit_test;
3704            self.reset_cursor_style(cx);
3705        }
3706
3707        #[cfg(any(feature = "inspector", debug_assertions))]
3708        if self.is_inspector_picking(cx) {
3709            self.handle_inspector_mouse_event(event, cx);
3710            // When inspector is picking, all other mouse handling is skipped.
3711            return;
3712        }
3713
3714        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3715
3716        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3717        // special purposes, such as detecting events outside of a given Bounds.
3718        for listener in &mut mouse_listeners {
3719            let listener = listener.as_mut().unwrap();
3720            listener(event, DispatchPhase::Capture, self, cx);
3721            if !cx.propagate_event {
3722                break;
3723            }
3724        }
3725
3726        // Bubble phase, where most normal handlers do their work.
3727        if cx.propagate_event {
3728            for listener in mouse_listeners.iter_mut().rev() {
3729                let listener = listener.as_mut().unwrap();
3730                listener(event, DispatchPhase::Bubble, self, cx);
3731                if !cx.propagate_event {
3732                    break;
3733                }
3734            }
3735        }
3736
3737        self.rendered_frame.mouse_listeners = mouse_listeners;
3738
3739        if cx.has_active_drag() {
3740            if event.is::<MouseMoveEvent>() {
3741                // If this was a mouse move event, redraw the window so that the
3742                // active drag can follow the mouse cursor.
3743                self.refresh();
3744            } else if event.is::<MouseUpEvent>() {
3745                // If this was a mouse up event, cancel the active drag and redraw
3746                // the window.
3747                cx.active_drag = None;
3748                self.refresh();
3749            }
3750        }
3751    }
3752
3753    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3754        if self.invalidator.is_dirty() {
3755            self.draw(cx).clear();
3756        }
3757
3758        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3759        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3760
3761        let mut keystroke: Option<Keystroke> = None;
3762
3763        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3764            if event.modifiers.number_of_modifiers() == 0
3765                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3766                && !self.pending_modifier.saw_keystroke
3767            {
3768                let key = match self.pending_modifier.modifiers {
3769                    modifiers if modifiers.shift => Some("shift"),
3770                    modifiers if modifiers.control => Some("control"),
3771                    modifiers if modifiers.alt => Some("alt"),
3772                    modifiers if modifiers.platform => Some("platform"),
3773                    modifiers if modifiers.function => Some("function"),
3774                    _ => None,
3775                };
3776                if let Some(key) = key {
3777                    keystroke = Some(Keystroke {
3778                        key: key.to_string(),
3779                        key_char: None,
3780                        modifiers: Modifiers::default(),
3781                    });
3782                }
3783            }
3784
3785            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3786                && event.modifiers.number_of_modifiers() == 1
3787            {
3788                self.pending_modifier.saw_keystroke = false
3789            }
3790            self.pending_modifier.modifiers = event.modifiers
3791        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3792            self.pending_modifier.saw_keystroke = true;
3793            keystroke = Some(key_down_event.keystroke.clone());
3794        }
3795
3796        let Some(keystroke) = keystroke else {
3797            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3798            return;
3799        };
3800
3801        cx.propagate_event = true;
3802        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
3803        if !cx.propagate_event {
3804            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3805            return;
3806        }
3807
3808        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3809        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3810            currently_pending = PendingInput::default();
3811        }
3812
3813        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3814            currently_pending.keystrokes,
3815            keystroke,
3816            &dispatch_path,
3817        );
3818
3819        if !match_result.to_replay.is_empty() {
3820            self.replay_pending_input(match_result.to_replay, cx);
3821            cx.propagate_event = true;
3822        }
3823
3824        if !match_result.pending.is_empty() {
3825            currently_pending.keystrokes = match_result.pending;
3826            currently_pending.focus = self.focus;
3827            currently_pending.timer = Some(self.spawn(cx, async move |cx| {
3828                cx.background_executor.timer(Duration::from_secs(1)).await;
3829                cx.update(move |window, cx| {
3830                    let Some(currently_pending) = window
3831                        .pending_input
3832                        .take()
3833                        .filter(|pending| pending.focus == window.focus)
3834                    else {
3835                        return;
3836                    };
3837
3838                    let node_id = window.focus_node_id_in_rendered_frame(window.focus);
3839                    let dispatch_path = window.rendered_frame.dispatch_tree.dispatch_path(node_id);
3840
3841                    let to_replay = window
3842                        .rendered_frame
3843                        .dispatch_tree
3844                        .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3845
3846                    window.pending_input_changed(cx);
3847                    window.replay_pending_input(to_replay, cx)
3848                })
3849                .log_err();
3850            }));
3851            self.pending_input = Some(currently_pending);
3852            self.pending_input_changed(cx);
3853            cx.propagate_event = false;
3854            return;
3855        }
3856
3857        for binding in match_result.bindings {
3858            self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3859            if !cx.propagate_event {
3860                self.dispatch_keystroke_observers(
3861                    event,
3862                    Some(binding.action),
3863                    match_result.context_stack,
3864                    cx,
3865                );
3866                self.pending_input_changed(cx);
3867                return;
3868            }
3869        }
3870
3871        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
3872        self.pending_input_changed(cx);
3873    }
3874
3875    fn finish_dispatch_key_event(
3876        &mut self,
3877        event: &dyn Any,
3878        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3879        context_stack: Vec<KeyContext>,
3880        cx: &mut App,
3881    ) {
3882        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
3883        if !cx.propagate_event {
3884            return;
3885        }
3886
3887        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
3888        if !cx.propagate_event {
3889            return;
3890        }
3891
3892        self.dispatch_keystroke_observers(event, None, context_stack, cx);
3893    }
3894
3895    fn pending_input_changed(&mut self, cx: &mut App) {
3896        self.pending_input_observers
3897            .clone()
3898            .retain(&(), |callback| callback(self, cx));
3899    }
3900
3901    fn dispatch_key_down_up_event(
3902        &mut self,
3903        event: &dyn Any,
3904        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3905        cx: &mut App,
3906    ) {
3907        // Capture phase
3908        for node_id in dispatch_path {
3909            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3910
3911            for key_listener in node.key_listeners.clone() {
3912                key_listener(event, DispatchPhase::Capture, self, cx);
3913                if !cx.propagate_event {
3914                    return;
3915                }
3916            }
3917        }
3918
3919        // Bubble phase
3920        for node_id in dispatch_path.iter().rev() {
3921            // Handle low level key events
3922            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3923            for key_listener in node.key_listeners.clone() {
3924                key_listener(event, DispatchPhase::Bubble, self, cx);
3925                if !cx.propagate_event {
3926                    return;
3927                }
3928            }
3929        }
3930    }
3931
3932    fn dispatch_modifiers_changed_event(
3933        &mut self,
3934        event: &dyn Any,
3935        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3936        cx: &mut App,
3937    ) {
3938        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3939            return;
3940        };
3941        for node_id in dispatch_path.iter().rev() {
3942            let node = self.rendered_frame.dispatch_tree.node(*node_id);
3943            for listener in node.modifiers_changed_listeners.clone() {
3944                listener(event, self, cx);
3945                if !cx.propagate_event {
3946                    return;
3947                }
3948            }
3949        }
3950    }
3951
3952    /// Determine whether a potential multi-stroke key binding is in progress on this window.
3953    pub fn has_pending_keystrokes(&self) -> bool {
3954        self.pending_input.is_some()
3955    }
3956
3957    pub(crate) fn clear_pending_keystrokes(&mut self) {
3958        self.pending_input.take();
3959    }
3960
3961    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3962    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3963        self.pending_input
3964            .as_ref()
3965            .map(|pending_input| pending_input.keystrokes.as_slice())
3966    }
3967
3968    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
3969        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3970        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3971
3972        'replay: for replay in replays {
3973            let event = KeyDownEvent {
3974                keystroke: replay.keystroke.clone(),
3975                is_held: false,
3976            };
3977
3978            cx.propagate_event = true;
3979            for binding in replay.bindings {
3980                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3981                if !cx.propagate_event {
3982                    self.dispatch_keystroke_observers(
3983                        &event,
3984                        Some(binding.action),
3985                        Vec::default(),
3986                        cx,
3987                    );
3988                    continue 'replay;
3989                }
3990            }
3991
3992            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
3993            if !cx.propagate_event {
3994                continue 'replay;
3995            }
3996            if let Some(input) = replay.keystroke.key_char.as_ref().cloned()
3997                && let Some(mut input_handler) = self.platform_window.take_input_handler()
3998            {
3999                input_handler.dispatch_input(&input, self, cx);
4000                self.platform_window.set_input_handler(input_handler)
4001            }
4002        }
4003    }
4004
4005    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
4006        focus_id
4007            .and_then(|focus_id| {
4008                self.rendered_frame
4009                    .dispatch_tree
4010                    .focusable_node_id(focus_id)
4011            })
4012            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id())
4013    }
4014
4015    fn dispatch_action_on_node(
4016        &mut self,
4017        node_id: DispatchNodeId,
4018        action: &dyn Action,
4019        cx: &mut App,
4020    ) {
4021        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4022
4023        // Capture phase for global actions.
4024        cx.propagate_event = true;
4025        if let Some(mut global_listeners) = cx
4026            .global_action_listeners
4027            .remove(&action.as_any().type_id())
4028        {
4029            for listener in &global_listeners {
4030                listener(action.as_any(), DispatchPhase::Capture, cx);
4031                if !cx.propagate_event {
4032                    break;
4033                }
4034            }
4035
4036            global_listeners.extend(
4037                cx.global_action_listeners
4038                    .remove(&action.as_any().type_id())
4039                    .unwrap_or_default(),
4040            );
4041
4042            cx.global_action_listeners
4043                .insert(action.as_any().type_id(), global_listeners);
4044        }
4045
4046        if !cx.propagate_event {
4047            return;
4048        }
4049
4050        // Capture phase for window actions.
4051        for node_id in &dispatch_path {
4052            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4053            for DispatchActionListener {
4054                action_type,
4055                listener,
4056            } in node.action_listeners.clone()
4057            {
4058                let any_action = action.as_any();
4059                if action_type == any_action.type_id() {
4060                    listener(any_action, DispatchPhase::Capture, self, cx);
4061
4062                    if !cx.propagate_event {
4063                        return;
4064                    }
4065                }
4066            }
4067        }
4068
4069        // Bubble phase for window actions.
4070        for node_id in dispatch_path.iter().rev() {
4071            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4072            for DispatchActionListener {
4073                action_type,
4074                listener,
4075            } in node.action_listeners.clone()
4076            {
4077                let any_action = action.as_any();
4078                if action_type == any_action.type_id() {
4079                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4080                    listener(any_action, DispatchPhase::Bubble, self, cx);
4081
4082                    if !cx.propagate_event {
4083                        return;
4084                    }
4085                }
4086            }
4087        }
4088
4089        // Bubble phase for global actions.
4090        if let Some(mut global_listeners) = cx
4091            .global_action_listeners
4092            .remove(&action.as_any().type_id())
4093        {
4094            for listener in global_listeners.iter().rev() {
4095                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4096
4097                listener(action.as_any(), DispatchPhase::Bubble, cx);
4098                if !cx.propagate_event {
4099                    break;
4100                }
4101            }
4102
4103            global_listeners.extend(
4104                cx.global_action_listeners
4105                    .remove(&action.as_any().type_id())
4106                    .unwrap_or_default(),
4107            );
4108
4109            cx.global_action_listeners
4110                .insert(action.as_any().type_id(), global_listeners);
4111        }
4112    }
4113
4114    /// Register the given handler to be invoked whenever the global of the given type
4115    /// is updated.
4116    pub fn observe_global<G: Global>(
4117        &mut self,
4118        cx: &mut App,
4119        f: impl Fn(&mut Window, &mut App) + 'static,
4120    ) -> Subscription {
4121        let window_handle = self.handle;
4122        let (subscription, activate) = cx.global_observers.insert(
4123            TypeId::of::<G>(),
4124            Box::new(move |cx| {
4125                window_handle
4126                    .update(cx, |_, window, cx| f(window, cx))
4127                    .is_ok()
4128            }),
4129        );
4130        cx.defer(move |_| activate());
4131        subscription
4132    }
4133
4134    /// Focus the current window and bring it to the foreground at the platform level.
4135    pub fn activate_window(&self) {
4136        self.platform_window.activate();
4137    }
4138
4139    /// Minimize the current window at the platform level.
4140    pub fn minimize_window(&self) {
4141        self.platform_window.minimize();
4142    }
4143
4144    /// Toggle full screen status on the current window at the platform level.
4145    pub fn toggle_fullscreen(&self) {
4146        self.platform_window.toggle_fullscreen();
4147    }
4148
4149    /// Updates the IME panel position suggestions for languages like japanese, chinese.
4150    pub fn invalidate_character_coordinates(&self) {
4151        self.on_next_frame(|window, cx| {
4152            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
4153                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
4154                    window.platform_window.update_ime_position(bounds);
4155                }
4156                window.platform_window.set_input_handler(input_handler);
4157            }
4158        });
4159    }
4160
4161    /// Present a platform dialog.
4162    /// The provided message will be presented, along with buttons for each answer.
4163    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
4164    pub fn prompt<T>(
4165        &mut self,
4166        level: PromptLevel,
4167        message: &str,
4168        detail: Option<&str>,
4169        answers: &[T],
4170        cx: &mut App,
4171    ) -> oneshot::Receiver<usize>
4172    where
4173        T: Clone + Into<PromptButton>,
4174    {
4175        let prompt_builder = cx.prompt_builder.take();
4176        let Some(prompt_builder) = prompt_builder else {
4177            unreachable!("Re-entrant window prompting is not supported by GPUI");
4178        };
4179
4180        let answers = answers
4181            .iter()
4182            .map(|answer| answer.clone().into())
4183            .collect::<Vec<_>>();
4184
4185        let receiver = match &prompt_builder {
4186            PromptBuilder::Default => self
4187                .platform_window
4188                .prompt(level, message, detail, &answers)
4189                .unwrap_or_else(|| {
4190                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4191                }),
4192            PromptBuilder::Custom(_) => {
4193                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4194            }
4195        };
4196
4197        cx.prompt_builder = Some(prompt_builder);
4198
4199        receiver
4200    }
4201
4202    fn build_custom_prompt(
4203        &mut self,
4204        prompt_builder: &PromptBuilder,
4205        level: PromptLevel,
4206        message: &str,
4207        detail: Option<&str>,
4208        answers: &[PromptButton],
4209        cx: &mut App,
4210    ) -> oneshot::Receiver<usize> {
4211        let (sender, receiver) = oneshot::channel();
4212        let handle = PromptHandle::new(sender);
4213        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
4214        self.prompt = Some(handle);
4215        receiver
4216    }
4217
4218    /// Returns the current context stack.
4219    pub fn context_stack(&self) -> Vec<KeyContext> {
4220        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4221        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4222        dispatch_tree
4223            .dispatch_path(node_id)
4224            .iter()
4225            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4226            .collect()
4227    }
4228
4229    /// Returns all available actions for the focused element.
4230    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4231        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4232        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4233        for action_type in cx.global_action_listeners.keys() {
4234            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4235                let action = cx.actions.build_action_type(action_type).ok();
4236                if let Some(action) = action {
4237                    actions.insert(ix, action);
4238                }
4239            }
4240        }
4241        actions
4242    }
4243
4244    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4245    /// returned in the order they were added. For display, the last binding should take precedence.
4246    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4247        self.rendered_frame
4248            .dispatch_tree
4249            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4250    }
4251
4252    /// Returns the highest precedence key binding that invokes an action on the currently focused
4253    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4254    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4255        self.rendered_frame
4256            .dispatch_tree
4257            .highest_precedence_binding_for_action(
4258                action,
4259                &self.rendered_frame.dispatch_tree.context_stack,
4260            )
4261    }
4262
4263    /// Returns the key bindings for an action in a context.
4264    pub fn bindings_for_action_in_context(
4265        &self,
4266        action: &dyn Action,
4267        context: KeyContext,
4268    ) -> Vec<KeyBinding> {
4269        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4270        dispatch_tree.bindings_for_action(action, &[context])
4271    }
4272
4273    /// Returns the highest precedence key binding for an action in a context. This is more
4274    /// efficient than getting the last result of `bindings_for_action_in_context`.
4275    pub fn highest_precedence_binding_for_action_in_context(
4276        &self,
4277        action: &dyn Action,
4278        context: KeyContext,
4279    ) -> Option<KeyBinding> {
4280        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4281        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4282    }
4283
4284    /// Returns any bindings that would invoke an action on the given focus handle if it were
4285    /// focused. Bindings are returned in the order they were added. For display, the last binding
4286    /// should take precedence.
4287    pub fn bindings_for_action_in(
4288        &self,
4289        action: &dyn Action,
4290        focus_handle: &FocusHandle,
4291    ) -> Vec<KeyBinding> {
4292        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4293        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4294            return vec![];
4295        };
4296        dispatch_tree.bindings_for_action(action, &context_stack)
4297    }
4298
4299    /// Returns the highest precedence key binding that would invoke an action on the given focus
4300    /// handle if it were focused. This is more efficient than getting the last result of
4301    /// `bindings_for_action_in`.
4302    pub fn highest_precedence_binding_for_action_in(
4303        &self,
4304        action: &dyn Action,
4305        focus_handle: &FocusHandle,
4306    ) -> Option<KeyBinding> {
4307        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4308        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4309        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4310    }
4311
4312    fn context_stack_for_focus_handle(
4313        &self,
4314        focus_handle: &FocusHandle,
4315    ) -> Option<Vec<KeyContext>> {
4316        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4317        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4318        let context_stack: Vec<_> = dispatch_tree
4319            .dispatch_path(node_id)
4320            .into_iter()
4321            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4322            .collect();
4323        Some(context_stack)
4324    }
4325
4326    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4327    pub fn listener_for<V: Render, E>(
4328        &self,
4329        view: &Entity<V>,
4330        f: impl Fn(&mut V, &E, &mut Window, &mut Context<V>) + 'static,
4331    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4332        let view = view.downgrade();
4333        move |e: &E, window: &mut Window, cx: &mut App| {
4334            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4335        }
4336    }
4337
4338    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4339    pub fn handler_for<E: 'static, Callback: Fn(&mut E, &mut Window, &mut Context<E>) + 'static>(
4340        &self,
4341        entity: &Entity<E>,
4342        f: Callback,
4343    ) -> impl Fn(&mut Window, &mut App) + 'static {
4344        let entity = entity.downgrade();
4345        move |window: &mut Window, cx: &mut App| {
4346            entity.update(cx, |entity, cx| f(entity, window, cx)).ok();
4347        }
4348    }
4349
4350    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4351    /// If the callback returns false, the window won't be closed.
4352    pub fn on_window_should_close(
4353        &self,
4354        cx: &App,
4355        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4356    ) {
4357        let mut cx = self.to_async(cx);
4358        self.platform_window.on_should_close(Box::new(move || {
4359            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4360        }))
4361    }
4362
4363    /// Register an action listener on the window for the next frame. The type of action
4364    /// is determined by the first parameter of the given listener. When the next frame is rendered
4365    /// the listener will be cleared.
4366    ///
4367    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4368    /// a specific need to register a global listener.
4369    pub fn on_action(
4370        &mut self,
4371        action_type: TypeId,
4372        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4373    ) {
4374        self.next_frame
4375            .dispatch_tree
4376            .on_action(action_type, Rc::new(listener));
4377    }
4378
4379    /// Register an action listener on the window for the next frame if the condition is true.
4380    /// The type of action is determined by the first parameter of the given listener.
4381    /// When the next frame is rendered the listener will be cleared.
4382    ///
4383    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4384    /// a specific need to register a global listener.
4385    pub fn on_action_when(
4386        &mut self,
4387        condition: bool,
4388        action_type: TypeId,
4389        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4390    ) {
4391        if condition {
4392            self.next_frame
4393                .dispatch_tree
4394                .on_action(action_type, Rc::new(listener));
4395        }
4396    }
4397
4398    /// Read information about the GPU backing this window.
4399    /// Currently returns None on Mac and Windows.
4400    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4401        self.platform_window.gpu_specs()
4402    }
4403
4404    /// Perform titlebar double-click action.
4405    /// This is macOS specific.
4406    pub fn titlebar_double_click(&self) {
4407        self.platform_window.titlebar_double_click();
4408    }
4409
4410    /// Gets the window's title at the platform level.
4411    /// This is macOS specific.
4412    pub fn window_title(&self) -> String {
4413        self.platform_window.get_title()
4414    }
4415
4416    /// Returns a list of all tabbed windows and their titles.
4417    /// This is macOS specific.
4418    pub fn tabbed_windows(&self) -> Option<Vec<SystemWindowTab>> {
4419        self.platform_window.tabbed_windows()
4420    }
4421
4422    /// Returns the tab bar visibility.
4423    /// This is macOS specific.
4424    pub fn tab_bar_visible(&self) -> bool {
4425        self.platform_window.tab_bar_visible()
4426    }
4427
4428    /// Merges all open windows into a single tabbed window.
4429    /// This is macOS specific.
4430    pub fn merge_all_windows(&self) {
4431        self.platform_window.merge_all_windows()
4432    }
4433
4434    /// Moves the tab to a new containing window.
4435    /// This is macOS specific.
4436    pub fn move_tab_to_new_window(&self) {
4437        self.platform_window.move_tab_to_new_window()
4438    }
4439
4440    /// Shows or hides the window tab overview.
4441    /// This is macOS specific.
4442    pub fn toggle_window_tab_overview(&self) {
4443        self.platform_window.toggle_window_tab_overview()
4444    }
4445
4446    /// Sets the tabbing identifier for the window.
4447    /// This is macOS specific.
4448    pub fn set_tabbing_identifier(&self, tabbing_identifier: Option<String>) {
4449        self.platform_window
4450            .set_tabbing_identifier(tabbing_identifier)
4451    }
4452
4453    /// Toggles the inspector mode on this window.
4454    #[cfg(any(feature = "inspector", debug_assertions))]
4455    pub fn toggle_inspector(&mut self, cx: &mut App) {
4456        self.inspector = match self.inspector {
4457            None => Some(cx.new(|_| Inspector::new())),
4458            Some(_) => None,
4459        };
4460        self.refresh();
4461    }
4462
4463    /// Returns true if the window is in inspector mode.
4464    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4465        #[cfg(any(feature = "inspector", debug_assertions))]
4466        {
4467            if let Some(inspector) = &self.inspector {
4468                return inspector.read(_cx).is_picking();
4469            }
4470        }
4471        false
4472    }
4473
4474    /// Executes the provided function with mutable access to an inspector state.
4475    #[cfg(any(feature = "inspector", debug_assertions))]
4476    pub fn with_inspector_state<T: 'static, R>(
4477        &mut self,
4478        _inspector_id: Option<&crate::InspectorElementId>,
4479        cx: &mut App,
4480        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4481    ) -> R {
4482        if let Some(inspector_id) = _inspector_id
4483            && let Some(inspector) = &self.inspector
4484        {
4485            let inspector = inspector.clone();
4486            let active_element_id = inspector.read(cx).active_element_id();
4487            if Some(inspector_id) == active_element_id {
4488                return inspector.update(cx, |inspector, _cx| {
4489                    inspector.with_active_element_state(self, f)
4490                });
4491            }
4492        }
4493        f(&mut None, self)
4494    }
4495
4496    #[cfg(any(feature = "inspector", debug_assertions))]
4497    pub(crate) fn build_inspector_element_id(
4498        &mut self,
4499        path: crate::InspectorElementPath,
4500    ) -> crate::InspectorElementId {
4501        self.invalidator.debug_assert_paint_or_prepaint();
4502        let path = Rc::new(path);
4503        let next_instance_id = self
4504            .next_frame
4505            .next_inspector_instance_ids
4506            .entry(path.clone())
4507            .or_insert(0);
4508        let instance_id = *next_instance_id;
4509        *next_instance_id += 1;
4510        crate::InspectorElementId { path, instance_id }
4511    }
4512
4513    #[cfg(any(feature = "inspector", debug_assertions))]
4514    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4515        if let Some(inspector) = self.inspector.take() {
4516            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4517            inspector_element.prepaint_as_root(
4518                point(self.viewport_size.width - inspector_width, px(0.0)),
4519                size(inspector_width, self.viewport_size.height).into(),
4520                self,
4521                cx,
4522            );
4523            self.inspector = Some(inspector);
4524            Some(inspector_element)
4525        } else {
4526            None
4527        }
4528    }
4529
4530    #[cfg(any(feature = "inspector", debug_assertions))]
4531    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4532        if let Some(mut inspector_element) = inspector_element {
4533            inspector_element.paint(self, cx);
4534        };
4535    }
4536
4537    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4538    /// inspect UI elements by clicking on them.
4539    #[cfg(any(feature = "inspector", debug_assertions))]
4540    pub fn insert_inspector_hitbox(
4541        &mut self,
4542        hitbox_id: HitboxId,
4543        inspector_id: Option<&crate::InspectorElementId>,
4544        cx: &App,
4545    ) {
4546        self.invalidator.debug_assert_paint_or_prepaint();
4547        if !self.is_inspector_picking(cx) {
4548            return;
4549        }
4550        if let Some(inspector_id) = inspector_id {
4551            self.next_frame
4552                .inspector_hitboxes
4553                .insert(hitbox_id, inspector_id.clone());
4554        }
4555    }
4556
4557    #[cfg(any(feature = "inspector", debug_assertions))]
4558    fn paint_inspector_hitbox(&mut self, cx: &App) {
4559        if let Some(inspector) = self.inspector.as_ref() {
4560            let inspector = inspector.read(cx);
4561            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4562                && let Some(hitbox) = self
4563                    .next_frame
4564                    .hitboxes
4565                    .iter()
4566                    .find(|hitbox| hitbox.id == hitbox_id)
4567            {
4568                self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4569            }
4570        }
4571    }
4572
4573    #[cfg(any(feature = "inspector", debug_assertions))]
4574    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4575        let Some(inspector) = self.inspector.clone() else {
4576            return;
4577        };
4578        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4579            inspector.update(cx, |inspector, _cx| {
4580                if let Some((_, inspector_id)) =
4581                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4582                {
4583                    inspector.hover(inspector_id, self);
4584                }
4585            });
4586        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4587            inspector.update(cx, |inspector, _cx| {
4588                if let Some((_, inspector_id)) =
4589                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4590                {
4591                    inspector.select(inspector_id, self);
4592                }
4593            });
4594        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4595            // This should be kept in sync with SCROLL_LINES in x11 platform.
4596            const SCROLL_LINES: f32 = 3.0;
4597            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4598            let delta_y = event
4599                .delta
4600                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4601                .y;
4602            if let Some(inspector) = self.inspector.clone() {
4603                inspector.update(cx, |inspector, _cx| {
4604                    if let Some(depth) = inspector.pick_depth.as_mut() {
4605                        *depth += f32::from(delta_y) / SCROLL_PIXELS_PER_LAYER;
4606                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4607                        if *depth < 0.0 {
4608                            *depth = 0.0;
4609                        } else if *depth > max_depth {
4610                            *depth = max_depth;
4611                        }
4612                        if let Some((_, inspector_id)) =
4613                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4614                        {
4615                            inspector.set_active_element_id(inspector_id, self);
4616                        }
4617                    }
4618                });
4619            }
4620        }
4621    }
4622
4623    #[cfg(any(feature = "inspector", debug_assertions))]
4624    fn hovered_inspector_hitbox(
4625        &self,
4626        inspector: &Inspector,
4627        frame: &Frame,
4628    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4629        if let Some(pick_depth) = inspector.pick_depth {
4630            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4631            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4632            let skip_count = (depth as usize).min(max_skipped);
4633            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4634                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4635                    return Some((*hitbox_id, inspector_id.clone()));
4636                }
4637            }
4638        }
4639        None
4640    }
4641
4642    /// For testing: set the current modifier keys state.
4643    /// This does not generate any events.
4644    #[cfg(any(test, feature = "test-support"))]
4645    pub fn set_modifiers(&mut self, modifiers: Modifiers) {
4646        self.modifiers = modifiers;
4647    }
4648}
4649
4650// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4651slotmap::new_key_type! {
4652    /// A unique identifier for a window.
4653    pub struct WindowId;
4654}
4655
4656impl WindowId {
4657    /// Converts this window ID to a `u64`.
4658    pub fn as_u64(&self) -> u64 {
4659        self.0.as_ffi()
4660    }
4661}
4662
4663impl From<u64> for WindowId {
4664    fn from(value: u64) -> Self {
4665        WindowId(slotmap::KeyData::from_ffi(value))
4666    }
4667}
4668
4669/// A handle to a window with a specific root view type.
4670/// Note that this does not keep the window alive on its own.
4671#[derive(Deref, DerefMut)]
4672pub struct WindowHandle<V> {
4673    #[deref]
4674    #[deref_mut]
4675    pub(crate) any_handle: AnyWindowHandle,
4676    state_type: PhantomData<fn(V) -> V>,
4677}
4678
4679impl<V> Debug for WindowHandle<V> {
4680    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4681        f.debug_struct("WindowHandle")
4682            .field("any_handle", &self.any_handle.id.as_u64())
4683            .finish()
4684    }
4685}
4686
4687impl<V: 'static + Render> WindowHandle<V> {
4688    /// Creates a new handle from a window ID.
4689    /// This does not check if the root type of the window is `V`.
4690    pub fn new(id: WindowId) -> Self {
4691        WindowHandle {
4692            any_handle: AnyWindowHandle {
4693                id,
4694                state_type: TypeId::of::<V>(),
4695            },
4696            state_type: PhantomData,
4697        }
4698    }
4699
4700    /// Get the root view out of this window.
4701    ///
4702    /// This will fail if the window is closed or if the root view's type does not match `V`.
4703    #[cfg(any(test, feature = "test-support"))]
4704    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
4705    where
4706        C: AppContext,
4707    {
4708        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
4709            root_view
4710                .downcast::<V>()
4711                .map_err(|_| anyhow!("the type of the window's root view has changed"))
4712        }))
4713    }
4714
4715    /// Updates the root view of this window.
4716    ///
4717    /// This will fail if the window has been closed or if the root view's type does not match
4718    pub fn update<C, R>(
4719        &self,
4720        cx: &mut C,
4721        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
4722    ) -> Result<R>
4723    where
4724        C: AppContext,
4725    {
4726        cx.update_window(self.any_handle, |root_view, window, cx| {
4727            let view = root_view
4728                .downcast::<V>()
4729                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4730
4731            Ok(view.update(cx, |view, cx| update(view, window, cx)))
4732        })?
4733    }
4734
4735    /// Read the root view out of this window.
4736    ///
4737    /// This will fail if the window is closed or if the root view's type does not match `V`.
4738    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
4739        let x = cx
4740            .windows
4741            .get(self.id)
4742            .and_then(|window| {
4743                window
4744                    .as_deref()
4745                    .and_then(|window| window.root.clone())
4746                    .map(|root_view| root_view.downcast::<V>())
4747            })
4748            .context("window not found")?
4749            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4750
4751        Ok(x.read(cx))
4752    }
4753
4754    /// Read the root view out of this window, with a callback
4755    ///
4756    /// This will fail if the window is closed or if the root view's type does not match `V`.
4757    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
4758    where
4759        C: AppContext,
4760    {
4761        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4762    }
4763
4764    /// Read the root view pointer off of this window.
4765    ///
4766    /// This will fail if the window is closed or if the root view's type does not match `V`.
4767    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
4768    where
4769        C: AppContext,
4770    {
4771        cx.read_window(self, |root_view, _cx| root_view)
4772    }
4773
4774    /// Check if this window is 'active'.
4775    ///
4776    /// Will return `None` if the window is closed or currently
4777    /// borrowed.
4778    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
4779        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
4780            .ok()
4781    }
4782}
4783
4784impl<V> Copy for WindowHandle<V> {}
4785
4786impl<V> Clone for WindowHandle<V> {
4787    fn clone(&self) -> Self {
4788        *self
4789    }
4790}
4791
4792impl<V> PartialEq for WindowHandle<V> {
4793    fn eq(&self, other: &Self) -> bool {
4794        self.any_handle == other.any_handle
4795    }
4796}
4797
4798impl<V> Eq for WindowHandle<V> {}
4799
4800impl<V> Hash for WindowHandle<V> {
4801    fn hash<H: Hasher>(&self, state: &mut H) {
4802        self.any_handle.hash(state);
4803    }
4804}
4805
4806impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4807    fn from(val: WindowHandle<V>) -> Self {
4808        val.any_handle
4809    }
4810}
4811
4812/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4813#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4814pub struct AnyWindowHandle {
4815    pub(crate) id: WindowId,
4816    state_type: TypeId,
4817}
4818
4819impl AnyWindowHandle {
4820    /// Get the ID of this window.
4821    pub fn window_id(&self) -> WindowId {
4822        self.id
4823    }
4824
4825    /// Attempt to convert this handle to a window handle with a specific root view type.
4826    /// If the types do not match, this will return `None`.
4827    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4828        if TypeId::of::<T>() == self.state_type {
4829            Some(WindowHandle {
4830                any_handle: *self,
4831                state_type: PhantomData,
4832            })
4833        } else {
4834            None
4835        }
4836    }
4837
4838    /// Updates the state of the root view of this window.
4839    ///
4840    /// This will fail if the window has been closed.
4841    pub fn update<C, R>(
4842        self,
4843        cx: &mut C,
4844        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
4845    ) -> Result<R>
4846    where
4847        C: AppContext,
4848    {
4849        cx.update_window(self, update)
4850    }
4851
4852    /// Read the state of the root view of this window.
4853    ///
4854    /// This will fail if the window has been closed.
4855    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
4856    where
4857        C: AppContext,
4858        T: 'static,
4859    {
4860        let view = self
4861            .downcast::<T>()
4862            .context("the type of the window's root view has changed")?;
4863
4864        cx.read_window(&view, read)
4865    }
4866}
4867
4868impl HasWindowHandle for Window {
4869    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
4870        self.platform_window.window_handle()
4871    }
4872}
4873
4874impl HasDisplayHandle for Window {
4875    fn display_handle(
4876        &self,
4877    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
4878        self.platform_window.display_handle()
4879    }
4880}
4881
4882/// An identifier for an [`Element`].
4883///
4884/// Can be constructed with a string, a number, or both, as well
4885/// as other internal representations.
4886#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4887pub enum ElementId {
4888    /// The ID of a View element
4889    View(EntityId),
4890    /// An integer ID.
4891    Integer(u64),
4892    /// A string based ID.
4893    Name(SharedString),
4894    /// A UUID.
4895    Uuid(Uuid),
4896    /// An ID that's equated with a focus handle.
4897    FocusHandle(FocusId),
4898    /// A combination of a name and an integer.
4899    NamedInteger(SharedString, u64),
4900    /// A path.
4901    Path(Arc<std::path::Path>),
4902    /// A code location.
4903    CodeLocation(core::panic::Location<'static>),
4904    /// A labeled child of an element.
4905    NamedChild(Box<ElementId>, SharedString),
4906}
4907
4908impl ElementId {
4909    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
4910    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
4911        Self::NamedInteger(name.into(), integer as u64)
4912    }
4913}
4914
4915impl Display for ElementId {
4916    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4917        match self {
4918            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4919            ElementId::Integer(ix) => write!(f, "{}", ix)?,
4920            ElementId::Name(name) => write!(f, "{}", name)?,
4921            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4922            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4923            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4924            ElementId::Path(path) => write!(f, "{}", path.display())?,
4925            ElementId::CodeLocation(location) => write!(f, "{}", location)?,
4926            ElementId::NamedChild(id, name) => write!(f, "{}-{}", id, name)?,
4927        }
4928
4929        Ok(())
4930    }
4931}
4932
4933impl TryInto<SharedString> for ElementId {
4934    type Error = anyhow::Error;
4935
4936    fn try_into(self) -> anyhow::Result<SharedString> {
4937        if let ElementId::Name(name) = self {
4938            Ok(name)
4939        } else {
4940            anyhow::bail!("element id is not string")
4941        }
4942    }
4943}
4944
4945impl From<usize> for ElementId {
4946    fn from(id: usize) -> Self {
4947        ElementId::Integer(id as u64)
4948    }
4949}
4950
4951impl From<i32> for ElementId {
4952    fn from(id: i32) -> Self {
4953        Self::Integer(id as u64)
4954    }
4955}
4956
4957impl From<SharedString> for ElementId {
4958    fn from(name: SharedString) -> Self {
4959        ElementId::Name(name)
4960    }
4961}
4962
4963impl From<Arc<std::path::Path>> for ElementId {
4964    fn from(path: Arc<std::path::Path>) -> Self {
4965        ElementId::Path(path)
4966    }
4967}
4968
4969impl From<&'static str> for ElementId {
4970    fn from(name: &'static str) -> Self {
4971        ElementId::Name(name.into())
4972    }
4973}
4974
4975impl<'a> From<&'a FocusHandle> for ElementId {
4976    fn from(handle: &'a FocusHandle) -> Self {
4977        ElementId::FocusHandle(handle.id)
4978    }
4979}
4980
4981impl From<(&'static str, EntityId)> for ElementId {
4982    fn from((name, id): (&'static str, EntityId)) -> Self {
4983        ElementId::NamedInteger(name.into(), id.as_u64())
4984    }
4985}
4986
4987impl From<(&'static str, usize)> for ElementId {
4988    fn from((name, id): (&'static str, usize)) -> Self {
4989        ElementId::NamedInteger(name.into(), id as u64)
4990    }
4991}
4992
4993impl From<(SharedString, usize)> for ElementId {
4994    fn from((name, id): (SharedString, usize)) -> Self {
4995        ElementId::NamedInteger(name, id as u64)
4996    }
4997}
4998
4999impl From<(&'static str, u64)> for ElementId {
5000    fn from((name, id): (&'static str, u64)) -> Self {
5001        ElementId::NamedInteger(name.into(), id)
5002    }
5003}
5004
5005impl From<Uuid> for ElementId {
5006    fn from(value: Uuid) -> Self {
5007        Self::Uuid(value)
5008    }
5009}
5010
5011impl From<(&'static str, u32)> for ElementId {
5012    fn from((name, id): (&'static str, u32)) -> Self {
5013        ElementId::NamedInteger(name.into(), id.into())
5014    }
5015}
5016
5017impl<T: Into<SharedString>> From<(ElementId, T)> for ElementId {
5018    fn from((id, name): (ElementId, T)) -> Self {
5019        ElementId::NamedChild(Box::new(id), name.into())
5020    }
5021}
5022
5023impl From<&'static core::panic::Location<'static>> for ElementId {
5024    fn from(location: &'static core::panic::Location<'static>) -> Self {
5025        ElementId::CodeLocation(*location)
5026    }
5027}
5028
5029/// A rectangle to be rendered in the window at the given position and size.
5030/// Passed as an argument [`Window::paint_quad`].
5031#[derive(Clone)]
5032pub struct PaintQuad {
5033    /// The bounds of the quad within the window.
5034    pub bounds: Bounds<Pixels>,
5035    /// The radii of the quad's corners.
5036    pub corner_radii: Corners<Pixels>,
5037    /// The background color of the quad.
5038    pub background: Background,
5039    /// The widths of the quad's borders.
5040    pub border_widths: Edges<Pixels>,
5041    /// The color of the quad's borders.
5042    pub border_color: Hsla,
5043    /// The style of the quad's borders.
5044    pub border_style: BorderStyle,
5045}
5046
5047impl PaintQuad {
5048    /// Sets the corner radii of the quad.
5049    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
5050        PaintQuad {
5051            corner_radii: corner_radii.into(),
5052            ..self
5053        }
5054    }
5055
5056    /// Sets the border widths of the quad.
5057    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5058        PaintQuad {
5059            border_widths: border_widths.into(),
5060            ..self
5061        }
5062    }
5063
5064    /// Sets the border color of the quad.
5065    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5066        PaintQuad {
5067            border_color: border_color.into(),
5068            ..self
5069        }
5070    }
5071
5072    /// Sets the background color of the quad.
5073    pub fn background(self, background: impl Into<Background>) -> Self {
5074        PaintQuad {
5075            background: background.into(),
5076            ..self
5077        }
5078    }
5079}
5080
5081/// Creates a quad with the given parameters.
5082pub fn quad(
5083    bounds: Bounds<Pixels>,
5084    corner_radii: impl Into<Corners<Pixels>>,
5085    background: impl Into<Background>,
5086    border_widths: impl Into<Edges<Pixels>>,
5087    border_color: impl Into<Hsla>,
5088    border_style: BorderStyle,
5089) -> PaintQuad {
5090    PaintQuad {
5091        bounds,
5092        corner_radii: corner_radii.into(),
5093        background: background.into(),
5094        border_widths: border_widths.into(),
5095        border_color: border_color.into(),
5096        border_style,
5097    }
5098}
5099
5100/// Creates a filled quad with the given bounds and background color.
5101pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5102    PaintQuad {
5103        bounds: bounds.into(),
5104        corner_radii: (0.).into(),
5105        background: background.into(),
5106        border_widths: (0.).into(),
5107        border_color: transparent_black(),
5108        border_style: BorderStyle::default(),
5109    }
5110}
5111
5112/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5113pub fn outline(
5114    bounds: impl Into<Bounds<Pixels>>,
5115    border_color: impl Into<Hsla>,
5116    border_style: BorderStyle,
5117) -> PaintQuad {
5118    PaintQuad {
5119        bounds: bounds.into(),
5120        corner_radii: (0.).into(),
5121        background: transparent_black().into(),
5122        border_widths: (1.).into(),
5123        border_color: border_color.into(),
5124        border_style,
5125    }
5126}