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