window.rs

   1#[cfg(any(feature = "inspector", debug_assertions))]
   2use crate::Inspector;
   3use crate::{
   4    Action, AnyDrag, AnyElement, AnyImageCache, AnyTooltip, AnyView, App, AppContext, Arena, Asset,
   5    AsyncWindowContext, AvailableSpace, Background, BorderStyle, Bounds, BoxShadow, Capslock,
   6    Context, Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener,
   7    DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
   8    FileDropEvent, FontId, Global, GlobalElementId, GlyphId, GpuSpecs, Hsla, InputHandler, IsZero,
   9    KeyBinding, KeyContext, KeyDownEvent, KeyEvent, Keystroke, KeystrokeEvent, LayoutId,
  10    LineLayoutIndex, Modifiers, ModifiersChangedEvent, MonochromeSprite, MouseButton, MouseEvent,
  11    MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput,
  12    PlatformInputHandler, PlatformWindow, Point, PolychromeSprite, Priority, PromptButton,
  13    PromptLevel, Quad, Render, RenderGlyphParams, RenderImage, RenderImageParams, RenderSvgParams,
  14    Replay, ResizeEdge, SMOOTH_SVG_SCALE_FACTOR, SUBPIXEL_VARIANTS_X, SUBPIXEL_VARIANTS_Y,
  15    ScaledPixels, Scene, Shadow, SharedString, Size, StrikethroughStyle, Style, SubscriberSet,
  16    Subscription, SystemWindowTab, SystemWindowTabController, TabStopMap, TaffyLayoutEngine, Task,
  17    TextStyle, TextStyleRefinement, TransformationMatrix, Underline, UnderlineStyle,
  18    WindowAppearance, WindowBackgroundAppearance, WindowBounds, WindowControls, WindowDecorations,
  19    WindowOptions, WindowParams, WindowTextSystem, point, prelude::*, px, rems, size,
  20    transparent_black,
  21};
  22use anyhow::{Context as _, Result, anyhow};
  23use collections::{FxHashMap, FxHashSet};
  24#[cfg(target_os = "macos")]
  25use core_video::pixel_buffer::CVPixelBuffer;
  26use derive_more::{Deref, DerefMut};
  27use futures::FutureExt;
  28use futures::channel::oneshot;
  29use itertools::FoldWhile::{Continue, Done};
  30use itertools::Itertools;
  31use parking_lot::RwLock;
  32use raw_window_handle::{HandleError, HasDisplayHandle, HasWindowHandle};
  33use refineable::Refineable;
  34use slotmap::SlotMap;
  35use smallvec::SmallVec;
  36use std::{
  37    any::{Any, TypeId},
  38    borrow::Cow,
  39    cell::{Cell, RefCell},
  40    cmp,
  41    fmt::{Debug, Display},
  42    hash::{Hash, Hasher},
  43    marker::PhantomData,
  44    mem,
  45    ops::{DerefMut, Range},
  46    rc::Rc,
  47    sync::{
  48        Arc, Weak,
  49        atomic::{AtomicUsize, Ordering::SeqCst},
  50    },
  51    time::{Duration, Instant},
  52};
  53use util::post_inc;
  54use util::{ResultExt, measure};
  55use uuid::Uuid;
  56
  57mod prompts;
  58
  59use crate::util::atomic_incr_if_not_zero;
  60pub use prompts::*;
  61
  62pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1536.), px(864.));
  63
  64/// A 6:5 aspect ratio minimum window size to be used for functional,
  65/// additional-to-main-Zed windows, like the settings and rules library windows.
  66pub const DEFAULT_ADDITIONAL_WINDOW_SIZE: Size<Pixels> = Size {
  67    width: Pixels(900.),
  68    height: Pixels(750.),
  69};
  70
  71/// Represents the two different phases when dispatching events.
  72#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
  73pub enum DispatchPhase {
  74    /// After the capture phase comes the bubble phase, in which mouse event listeners are
  75    /// invoked front to back and keyboard event listeners are invoked from the focused element
  76    /// to the root of the element tree. This is the phase you'll most commonly want to use when
  77    /// registering event listeners.
  78    #[default]
  79    Bubble,
  80    /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
  81    /// listeners are invoked from the root of the tree downward toward the focused element. This phase
  82    /// is used for special purposes such as clearing the "pressed" state for click events. If
  83    /// you stop event propagation during this phase, you need to know what you're doing. Handlers
  84    /// outside of the immediate region may rely on detecting non-local events during this phase.
  85    Capture,
  86}
  87
  88impl DispatchPhase {
  89    /// Returns true if this represents the "bubble" phase.
  90    #[inline]
  91    pub fn bubble(self) -> bool {
  92        self == DispatchPhase::Bubble
  93    }
  94
  95    /// Returns true if this represents the "capture" phase.
  96    #[inline]
  97    pub fn capture(self) -> bool {
  98        self == DispatchPhase::Capture
  99    }
 100}
 101
 102struct WindowInvalidatorInner {
 103    pub dirty: bool,
 104    pub draw_phase: DrawPhase,
 105    pub dirty_views: FxHashSet<EntityId>,
 106}
 107
 108#[derive(Clone)]
 109pub(crate) struct WindowInvalidator {
 110    inner: Rc<RefCell<WindowInvalidatorInner>>,
 111}
 112
 113impl WindowInvalidator {
 114    pub fn new() -> Self {
 115        WindowInvalidator {
 116            inner: Rc::new(RefCell::new(WindowInvalidatorInner {
 117                dirty: true,
 118                draw_phase: DrawPhase::None,
 119                dirty_views: FxHashSet::default(),
 120            })),
 121        }
 122    }
 123
 124    pub fn invalidate_view(&self, entity: EntityId, cx: &mut App) -> bool {
 125        let mut inner = self.inner.borrow_mut();
 126        inner.dirty_views.insert(entity);
 127        if inner.draw_phase == DrawPhase::None {
 128            inner.dirty = true;
 129            cx.push_effect(Effect::Notify { emitter: entity });
 130            true
 131        } else {
 132            false
 133        }
 134    }
 135
 136    pub fn is_dirty(&self) -> bool {
 137        self.inner.borrow().dirty
 138    }
 139
 140    pub fn set_dirty(&self, dirty: bool) {
 141        self.inner.borrow_mut().dirty = dirty
 142    }
 143
 144    pub fn set_phase(&self, phase: DrawPhase) {
 145        self.inner.borrow_mut().draw_phase = phase
 146    }
 147
 148    pub fn take_views(&self) -> FxHashSet<EntityId> {
 149        mem::take(&mut self.inner.borrow_mut().dirty_views)
 150    }
 151
 152    pub fn replace_views(&self, views: FxHashSet<EntityId>) {
 153        self.inner.borrow_mut().dirty_views = views;
 154    }
 155
 156    pub fn not_drawing(&self) -> bool {
 157        self.inner.borrow().draw_phase == DrawPhase::None
 158    }
 159
 160    #[track_caller]
 161    pub fn debug_assert_paint(&self) {
 162        debug_assert!(
 163            matches!(self.inner.borrow().draw_phase, DrawPhase::Paint),
 164            "this method can only be called during paint"
 165        );
 166    }
 167
 168    #[track_caller]
 169    pub fn debug_assert_prepaint(&self) {
 170        debug_assert!(
 171            matches!(self.inner.borrow().draw_phase, DrawPhase::Prepaint),
 172            "this method can only be called during request_layout, or prepaint"
 173        );
 174    }
 175
 176    #[track_caller]
 177    pub fn debug_assert_paint_or_prepaint(&self) {
 178        debug_assert!(
 179            matches!(
 180                self.inner.borrow().draw_phase,
 181                DrawPhase::Paint | DrawPhase::Prepaint
 182            ),
 183            "this method can only be called during request_layout, prepaint, or paint"
 184        );
 185    }
 186}
 187
 188type AnyObserver = Box<dyn FnMut(&mut Window, &mut App) -> bool + 'static>;
 189
 190pub(crate) type AnyWindowFocusListener =
 191    Box<dyn FnMut(&WindowFocusEvent, &mut Window, &mut App) -> bool + 'static>;
 192
 193pub(crate) struct WindowFocusEvent {
 194    pub(crate) previous_focus_path: SmallVec<[FocusId; 8]>,
 195    pub(crate) current_focus_path: SmallVec<[FocusId; 8]>,
 196}
 197
 198impl WindowFocusEvent {
 199    pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
 200        !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
 201    }
 202
 203    pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
 204        self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
 205    }
 206}
 207
 208/// This is provided when subscribing for `Context::on_focus_out` events.
 209pub struct FocusOutEvent {
 210    /// A weak focus handle representing what was blurred.
 211    pub blurred: WeakFocusHandle,
 212}
 213
 214slotmap::new_key_type! {
 215    /// A globally unique identifier for a focusable element.
 216    pub struct FocusId;
 217}
 218
 219thread_local! {
 220    pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(1024 * 1024));
 221}
 222
 223/// Returned when the element arena has been used and so must be cleared before the next draw.
 224#[must_use]
 225pub struct ArenaClearNeeded;
 226
 227impl ArenaClearNeeded {
 228    /// Clear the element arena.
 229    pub fn clear(self) {
 230        ELEMENT_ARENA.with_borrow_mut(|element_arena| {
 231            element_arena.clear();
 232        });
 233    }
 234}
 235
 236pub(crate) type FocusMap = RwLock<SlotMap<FocusId, FocusRef>>;
 237pub(crate) struct FocusRef {
 238    pub(crate) ref_count: AtomicUsize,
 239    pub(crate) tab_index: isize,
 240    pub(crate) tab_stop: bool,
 241}
 242
 243impl FocusId {
 244    /// Obtains whether the element associated with this handle is currently focused.
 245    pub fn is_focused(&self, window: &Window) -> bool {
 246        window.focus == Some(*self)
 247    }
 248
 249    /// Obtains whether the element associated with this handle contains the focused
 250    /// element or is itself focused.
 251    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 252        window
 253            .focused(cx)
 254            .is_some_and(|focused| self.contains(focused.id, window))
 255    }
 256
 257    /// Obtains whether the element associated with this handle is contained within the
 258    /// focused element or is itself focused.
 259    pub fn within_focused(&self, window: &Window, cx: &App) -> bool {
 260        let focused = window.focused(cx);
 261        focused.is_some_and(|focused| focused.id.contains(*self, window))
 262    }
 263
 264    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 265    pub(crate) fn contains(&self, other: Self, window: &Window) -> bool {
 266        window
 267            .rendered_frame
 268            .dispatch_tree
 269            .focus_contains(*self, other)
 270    }
 271}
 272
 273/// A handle which can be used to track and manipulate the focused element in a window.
 274pub struct FocusHandle {
 275    pub(crate) id: FocusId,
 276    handles: Arc<FocusMap>,
 277    /// The index of this element in the tab order.
 278    pub tab_index: isize,
 279    /// Whether this element can be focused by tab navigation.
 280    pub tab_stop: bool,
 281}
 282
 283impl std::fmt::Debug for FocusHandle {
 284    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 285        f.write_fmt(format_args!("FocusHandle({:?})", self.id))
 286    }
 287}
 288
 289impl FocusHandle {
 290    pub(crate) fn new(handles: &Arc<FocusMap>) -> Self {
 291        let id = handles.write().insert(FocusRef {
 292            ref_count: AtomicUsize::new(1),
 293            tab_index: 0,
 294            tab_stop: false,
 295        });
 296
 297        Self {
 298            id,
 299            tab_index: 0,
 300            tab_stop: false,
 301            handles: handles.clone(),
 302        }
 303    }
 304
 305    pub(crate) fn for_id(id: FocusId, handles: &Arc<FocusMap>) -> Option<Self> {
 306        let lock = handles.read();
 307        let focus = lock.get(id)?;
 308        if atomic_incr_if_not_zero(&focus.ref_count) == 0 {
 309            return None;
 310        }
 311        Some(Self {
 312            id,
 313            tab_index: focus.tab_index,
 314            tab_stop: focus.tab_stop,
 315            handles: handles.clone(),
 316        })
 317    }
 318
 319    /// Sets the tab index of the element associated with this handle.
 320    pub fn tab_index(mut self, index: isize) -> Self {
 321        self.tab_index = index;
 322        if let Some(focus) = self.handles.write().get_mut(self.id) {
 323            focus.tab_index = index;
 324        }
 325        self
 326    }
 327
 328    /// Sets whether the element associated with this handle is a tab stop.
 329    ///
 330    /// When `false`, the element will not be included in the tab order.
 331    pub fn tab_stop(mut self, tab_stop: bool) -> Self {
 332        self.tab_stop = tab_stop;
 333        if let Some(focus) = self.handles.write().get_mut(self.id) {
 334            focus.tab_stop = tab_stop;
 335        }
 336        self
 337    }
 338
 339    /// Converts this focus handle into a weak variant, which does not prevent it from being released.
 340    pub fn downgrade(&self) -> WeakFocusHandle {
 341        WeakFocusHandle {
 342            id: self.id,
 343            handles: Arc::downgrade(&self.handles),
 344        }
 345    }
 346
 347    /// Moves the focus to the element associated with this handle.
 348    pub fn focus(&self, window: &mut Window) {
 349        window.focus(self)
 350    }
 351
 352    /// Obtains whether the element associated with this handle is currently focused.
 353    pub fn is_focused(&self, window: &Window) -> bool {
 354        self.id.is_focused(window)
 355    }
 356
 357    /// Obtains whether the element associated with this handle contains the focused
 358    /// element or is itself focused.
 359    pub fn contains_focused(&self, window: &Window, cx: &App) -> bool {
 360        self.id.contains_focused(window, cx)
 361    }
 362
 363    /// Obtains whether the element associated with this handle is contained within the
 364    /// focused element or is itself focused.
 365    pub fn within_focused(&self, window: &Window, cx: &mut App) -> bool {
 366        self.id.within_focused(window, cx)
 367    }
 368
 369    /// Obtains whether this handle contains the given handle in the most recently rendered frame.
 370    pub fn contains(&self, other: &Self, window: &Window) -> bool {
 371        self.id.contains(other.id, window)
 372    }
 373
 374    /// Dispatch an action on the element that rendered this focus handle
 375    pub fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut App) {
 376        if let Some(node_id) = window
 377            .rendered_frame
 378            .dispatch_tree
 379            .focusable_node_id(self.id)
 380        {
 381            window.dispatch_action_on_node(node_id, action, cx)
 382        }
 383    }
 384}
 385
 386impl Clone for FocusHandle {
 387    fn clone(&self) -> Self {
 388        Self::for_id(self.id, &self.handles).unwrap()
 389    }
 390}
 391
 392impl PartialEq for FocusHandle {
 393    fn eq(&self, other: &Self) -> bool {
 394        self.id == other.id
 395    }
 396}
 397
 398impl Eq for FocusHandle {}
 399
 400impl Drop for FocusHandle {
 401    fn drop(&mut self) {
 402        self.handles
 403            .read()
 404            .get(self.id)
 405            .unwrap()
 406            .ref_count
 407            .fetch_sub(1, SeqCst);
 408    }
 409}
 410
 411/// A weak reference to a focus handle.
 412#[derive(Clone, Debug)]
 413pub struct WeakFocusHandle {
 414    pub(crate) id: FocusId,
 415    pub(crate) handles: Weak<FocusMap>,
 416}
 417
 418impl WeakFocusHandle {
 419    /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
 420    pub fn upgrade(&self) -> Option<FocusHandle> {
 421        let handles = self.handles.upgrade()?;
 422        FocusHandle::for_id(self.id, &handles)
 423    }
 424}
 425
 426impl PartialEq for WeakFocusHandle {
 427    fn eq(&self, other: &WeakFocusHandle) -> bool {
 428        self.id == other.id
 429    }
 430}
 431
 432impl Eq for WeakFocusHandle {}
 433
 434impl PartialEq<FocusHandle> for WeakFocusHandle {
 435    fn eq(&self, other: &FocusHandle) -> bool {
 436        self.id == other.id
 437    }
 438}
 439
 440impl PartialEq<WeakFocusHandle> for FocusHandle {
 441    fn eq(&self, other: &WeakFocusHandle) -> bool {
 442        self.id == other.id
 443    }
 444}
 445
 446/// Focusable allows users of your view to easily
 447/// focus it (using window.focus_view(cx, view))
 448pub trait Focusable: 'static {
 449    /// Returns the focus handle associated with this view.
 450    fn focus_handle(&self, cx: &App) -> FocusHandle;
 451}
 452
 453impl<V: Focusable> Focusable for Entity<V> {
 454    fn focus_handle(&self, cx: &App) -> FocusHandle {
 455        self.read(cx).focus_handle(cx)
 456    }
 457}
 458
 459/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
 460/// where the lifecycle of the view is handled by another view.
 461pub trait ManagedView: Focusable + EventEmitter<DismissEvent> + Render {}
 462
 463impl<M: Focusable + EventEmitter<DismissEvent> + Render> ManagedView for M {}
 464
 465/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
 466pub struct DismissEvent;
 467
 468type FrameCallback = Box<dyn FnOnce(&mut Window, &mut App)>;
 469
 470pub(crate) type AnyMouseListener =
 471    Box<dyn FnMut(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static>;
 472
 473#[derive(Clone)]
 474pub(crate) struct CursorStyleRequest {
 475    pub(crate) hitbox_id: Option<HitboxId>,
 476    pub(crate) style: CursorStyle,
 477}
 478
 479#[derive(Default, Eq, PartialEq)]
 480pub(crate) struct HitTest {
 481    pub(crate) ids: SmallVec<[HitboxId; 8]>,
 482    pub(crate) hover_hitbox_count: usize,
 483}
 484
 485/// A type of window control area that corresponds to the platform window.
 486#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 487pub enum WindowControlArea {
 488    /// An area that allows dragging of the platform window.
 489    Drag,
 490    /// An area that allows closing of the platform window.
 491    Close,
 492    /// An area that allows maximizing of the platform window.
 493    Max,
 494    /// An area that allows minimizing of the platform window.
 495    Min,
 496}
 497
 498/// An identifier for a [Hitbox] which also includes [HitboxBehavior].
 499#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 500pub struct HitboxId(u64);
 501
 502impl HitboxId {
 503    /// Checks if the hitbox with this ID is currently hovered. Except when handling
 504    /// `ScrollWheelEvent`, this is typically what you want when determining whether to handle mouse
 505    /// events or paint hover styles.
 506    ///
 507    /// See [`Hitbox::is_hovered`] for details.
 508    pub fn is_hovered(self, window: &Window) -> bool {
 509        let hit_test = &window.mouse_hit_test;
 510        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 511            if self == *id {
 512                return true;
 513            }
 514        }
 515        false
 516    }
 517
 518    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 519    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 520    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 521    /// this distinction.
 522    pub fn should_handle_scroll(self, window: &Window) -> bool {
 523        window.mouse_hit_test.ids.contains(&self)
 524    }
 525
 526    fn next(mut self) -> HitboxId {
 527        HitboxId(self.0.wrapping_add(1))
 528    }
 529}
 530
 531/// A rectangular region that potentially blocks hitboxes inserted prior.
 532/// See [Window::insert_hitbox] for more details.
 533#[derive(Clone, Debug, Deref)]
 534pub struct Hitbox {
 535    /// A unique identifier for the hitbox.
 536    pub id: HitboxId,
 537    /// The bounds of the hitbox.
 538    #[deref]
 539    pub bounds: Bounds<Pixels>,
 540    /// The content mask when the hitbox was inserted.
 541    pub content_mask: ContentMask<Pixels>,
 542    /// Flags that specify hitbox behavior.
 543    pub behavior: HitboxBehavior,
 544}
 545
 546impl Hitbox {
 547    /// Checks if the hitbox is currently hovered. Except when handling `ScrollWheelEvent`, this is
 548    /// typically what you want when determining whether to handle mouse events or paint hover
 549    /// styles.
 550    ///
 551    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 552    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 553    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`).
 554    ///
 555    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 556    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 557    /// non-interactive while still allowing scrolling. More abstractly, this is because
 558    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 559    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 560    /// container.
 561    pub fn is_hovered(&self, window: &Window) -> bool {
 562        self.id.is_hovered(window)
 563    }
 564
 565    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 566    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 567    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 568    ///
 569    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 570    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 571    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 572        self.id.should_handle_scroll(window)
 573    }
 574}
 575
 576/// How the hitbox affects mouse behavior.
 577#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 578pub enum HitboxBehavior {
 579    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 580    #[default]
 581    Normal,
 582
 583    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 584    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 585    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 586    /// [`InteractiveElement::occlude`].
 587    ///
 588    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 589    /// bubble-phase handler for every mouse event type:
 590    ///
 591    /// ```ignore
 592    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 593    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 594    ///         cx.stop_propagation();
 595    ///     }
 596    /// })
 597    /// ```
 598    ///
 599    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 600    /// styles and tooltips. These other behaviors are the main point of this mechanism. An
 601    /// alternative might be to not affect mouse event handling - but this would allow
 602    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 603    /// be hovered.
 604    BlockMouse,
 605
 606    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 607    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 608    /// interaction except scroll events to be ignored - see the documentation of
 609    /// [`Hitbox::is_hovered`] for details. This flag is set by
 610    /// [`InteractiveElement::block_mouse_except_scroll`].
 611    ///
 612    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 613    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 614    ///
 615    /// ```ignore
 616    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, cx| {
 617    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 618    ///         cx.stop_propagation();
 619    ///     }
 620    /// })
 621    /// ```
 622    ///
 623    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 624    /// handled differently than other mouse events. If also blocking these scroll events is
 625    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 626    ///
 627    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 628    /// hover styles and tooltips. These other behaviors are the main point of this mechanism.
 629    /// An alternative might be to not affect mouse event handling - but this would allow
 630    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 631    /// be hovered.
 632    BlockMouseExceptScroll,
 633}
 634
 635/// An identifier for a tooltip.
 636#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 637pub struct TooltipId(usize);
 638
 639impl TooltipId {
 640    /// Checks if the tooltip is currently hovered.
 641    pub fn is_hovered(&self, window: &Window) -> bool {
 642        window
 643            .tooltip_bounds
 644            .as_ref()
 645            .is_some_and(|tooltip_bounds| {
 646                tooltip_bounds.id == *self
 647                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 648            })
 649    }
 650}
 651
 652pub(crate) struct TooltipBounds {
 653    id: TooltipId,
 654    bounds: Bounds<Pixels>,
 655}
 656
 657#[derive(Clone)]
 658pub(crate) struct TooltipRequest {
 659    id: TooltipId,
 660    tooltip: AnyTooltip,
 661}
 662
 663pub(crate) struct DeferredDraw {
 664    current_view: EntityId,
 665    priority: usize,
 666    parent_node: DispatchNodeId,
 667    element_id_stack: SmallVec<[ElementId; 32]>,
 668    text_style_stack: Vec<TextStyleRefinement>,
 669    element: Option<AnyElement>,
 670    absolute_offset: Point<Pixels>,
 671    prepaint_range: Range<PrepaintStateIndex>,
 672    paint_range: Range<PaintIndex>,
 673}
 674
 675pub(crate) struct Frame {
 676    pub(crate) focus: Option<FocusId>,
 677    pub(crate) window_active: bool,
 678    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 679    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 680    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 681    pub(crate) dispatch_tree: DispatchTree,
 682    pub(crate) scene: Scene,
 683    pub(crate) hitboxes: Vec<Hitbox>,
 684    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 685    pub(crate) deferred_draws: Vec<DeferredDraw>,
 686    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 687    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 688    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 689    #[cfg(any(test, feature = "test-support"))]
 690    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 691    #[cfg(any(feature = "inspector", debug_assertions))]
 692    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 693    #[cfg(any(feature = "inspector", debug_assertions))]
 694    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 695    pub(crate) tab_stops: TabStopMap,
 696}
 697
 698#[derive(Clone, Default)]
 699pub(crate) struct PrepaintStateIndex {
 700    hitboxes_index: usize,
 701    tooltips_index: usize,
 702    deferred_draws_index: usize,
 703    dispatch_tree_index: usize,
 704    accessed_element_states_index: usize,
 705    line_layout_index: LineLayoutIndex,
 706}
 707
 708#[derive(Clone, Default)]
 709pub(crate) struct PaintIndex {
 710    scene_index: usize,
 711    mouse_listeners_index: usize,
 712    input_handlers_index: usize,
 713    cursor_styles_index: usize,
 714    accessed_element_states_index: usize,
 715    tab_handle_index: usize,
 716    line_layout_index: LineLayoutIndex,
 717}
 718
 719impl Frame {
 720    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 721        Frame {
 722            focus: None,
 723            window_active: false,
 724            element_states: FxHashMap::default(),
 725            accessed_element_states: Vec::new(),
 726            mouse_listeners: Vec::new(),
 727            dispatch_tree,
 728            scene: Scene::default(),
 729            hitboxes: Vec::new(),
 730            window_control_hitboxes: Vec::new(),
 731            deferred_draws: Vec::new(),
 732            input_handlers: Vec::new(),
 733            tooltip_requests: Vec::new(),
 734            cursor_styles: Vec::new(),
 735
 736            #[cfg(any(test, feature = "test-support"))]
 737            debug_bounds: FxHashMap::default(),
 738
 739            #[cfg(any(feature = "inspector", debug_assertions))]
 740            next_inspector_instance_ids: FxHashMap::default(),
 741
 742            #[cfg(any(feature = "inspector", debug_assertions))]
 743            inspector_hitboxes: FxHashMap::default(),
 744            tab_stops: TabStopMap::default(),
 745        }
 746    }
 747
 748    pub(crate) fn clear(&mut self) {
 749        self.element_states.clear();
 750        self.accessed_element_states.clear();
 751        self.mouse_listeners.clear();
 752        self.dispatch_tree.clear();
 753        self.scene.clear();
 754        self.input_handlers.clear();
 755        self.tooltip_requests.clear();
 756        self.cursor_styles.clear();
 757        self.hitboxes.clear();
 758        self.window_control_hitboxes.clear();
 759        self.deferred_draws.clear();
 760        self.tab_stops.clear();
 761        self.focus = None;
 762
 763        #[cfg(any(feature = "inspector", debug_assertions))]
 764        {
 765            self.next_inspector_instance_ids.clear();
 766            self.inspector_hitboxes.clear();
 767        }
 768    }
 769
 770    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 771        self.cursor_styles
 772            .iter()
 773            .rev()
 774            .fold_while(None, |style, request| match request.hitbox_id {
 775                None => Done(Some(request.style)),
 776                Some(hitbox_id) => Continue(
 777                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 778                ),
 779            })
 780            .into_inner()
 781    }
 782
 783    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 784        let mut set_hover_hitbox_count = false;
 785        let mut hit_test = HitTest::default();
 786        for hitbox in self.hitboxes.iter().rev() {
 787            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 788            if bounds.contains(&position) {
 789                hit_test.ids.push(hitbox.id);
 790                if !set_hover_hitbox_count
 791                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 792                {
 793                    hit_test.hover_hitbox_count = hit_test.ids.len();
 794                    set_hover_hitbox_count = true;
 795                }
 796                if hitbox.behavior == HitboxBehavior::BlockMouse {
 797                    break;
 798                }
 799            }
 800        }
 801        if !set_hover_hitbox_count {
 802            hit_test.hover_hitbox_count = hit_test.ids.len();
 803        }
 804        hit_test
 805    }
 806
 807    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 808        self.focus
 809            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 810            .unwrap_or_default()
 811    }
 812
 813    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 814        for element_state_key in &self.accessed_element_states {
 815            if let Some((element_state_key, element_state)) =
 816                prev_frame.element_states.remove_entry(element_state_key)
 817            {
 818                self.element_states.insert(element_state_key, element_state);
 819            }
 820        }
 821
 822        self.scene.finish();
 823    }
 824}
 825
 826#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 827enum InputModality {
 828    Mouse,
 829    Keyboard,
 830}
 831
 832/// Holds the state for a specific window.
 833pub struct Window {
 834    pub(crate) handle: AnyWindowHandle,
 835    pub(crate) invalidator: WindowInvalidator,
 836    pub(crate) removed: bool,
 837    pub(crate) platform_window: Box<dyn PlatformWindow>,
 838    display_id: Option<DisplayId>,
 839    sprite_atlas: Arc<dyn PlatformAtlas>,
 840    text_system: Arc<WindowTextSystem>,
 841    rem_size: Pixels,
 842    /// The stack of override values for the window's rem size.
 843    ///
 844    /// This is used by `with_rem_size` to allow rendering an element tree with
 845    /// a given rem size.
 846    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 847    pub(crate) viewport_size: Size<Pixels>,
 848    layout_engine: Option<TaffyLayoutEngine>,
 849    pub(crate) root: Option<AnyView>,
 850    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 851    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 852    pub(crate) rendered_entity_stack: Vec<EntityId>,
 853    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 854    pub(crate) element_opacity: f32,
 855    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 856    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 857    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 858    pub(crate) rendered_frame: Frame,
 859    pub(crate) next_frame: Frame,
 860    next_hitbox_id: HitboxId,
 861    pub(crate) next_tooltip_id: TooltipId,
 862    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 863    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 864    pub(crate) dirty_views: FxHashSet<EntityId>,
 865    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 866    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 867    default_prevented: bool,
 868    mouse_position: Point<Pixels>,
 869    mouse_hit_test: HitTest,
 870    modifiers: Modifiers,
 871    capslock: Capslock,
 872    scale_factor: f32,
 873    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 874    appearance: WindowAppearance,
 875    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 876    active: Rc<Cell<bool>>,
 877    hovered: Rc<Cell<bool>>,
 878    pub(crate) needs_present: Rc<Cell<bool>>,
 879    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 880    last_input_modality: InputModality,
 881    pub(crate) refreshing: bool,
 882    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 883    pub(crate) focus: Option<FocusId>,
 884    focus_enabled: bool,
 885    pending_input: Option<PendingInput>,
 886    pending_modifier: ModifierState,
 887    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 888    prompt: Option<RenderablePromptHandle>,
 889    pub(crate) client_inset: Option<Pixels>,
 890    #[cfg(any(feature = "inspector", debug_assertions))]
 891    inspector: Option<Entity<Inspector>>,
 892}
 893
 894#[derive(Clone, Debug, Default)]
 895struct ModifierState {
 896    modifiers: Modifiers,
 897    saw_keystroke: bool,
 898}
 899
 900#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 901pub(crate) enum DrawPhase {
 902    None,
 903    Prepaint,
 904    Paint,
 905    Focus,
 906}
 907
 908#[derive(Default, Debug)]
 909struct PendingInput {
 910    keystrokes: SmallVec<[Keystroke; 1]>,
 911    focus: Option<FocusId>,
 912    timer: Option<Task<()>>,
 913    needs_timeout: bool,
 914}
 915
 916pub(crate) struct ElementStateBox {
 917    pub(crate) inner: Box<dyn Any>,
 918    #[cfg(debug_assertions)]
 919    pub(crate) type_name: &'static str,
 920}
 921
 922fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> WindowBounds {
 923    // TODO, BUG: if you open a window with the currently active window
 924    // on the stack, this will erroneously fallback to `None`
 925    //
 926    // TODO these should be the initial window bounds not considering maximized/fullscreen
 927    let active_window_bounds = cx
 928        .active_window()
 929        .and_then(|w| w.update(cx, |_, window, _| window.window_bounds()).ok());
 930
 931    const CASCADE_OFFSET: f32 = 25.0;
 932
 933    let display = display_id
 934        .map(|id| cx.find_display(id))
 935        .unwrap_or_else(|| cx.primary_display());
 936
 937    let default_placement = || Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE);
 938
 939    // Use visible_bounds to exclude taskbar/dock areas
 940    let display_bounds = display
 941        .as_ref()
 942        .map(|d| d.visible_bounds())
 943        .unwrap_or_else(default_placement);
 944
 945    let (
 946        Bounds {
 947            origin: base_origin,
 948            size: base_size,
 949        },
 950        window_bounds_ctor,
 951    ): (_, fn(Bounds<Pixels>) -> WindowBounds) = match active_window_bounds {
 952        Some(bounds) => match bounds {
 953            WindowBounds::Windowed(bounds) => (bounds, WindowBounds::Windowed),
 954            WindowBounds::Maximized(bounds) => (bounds, WindowBounds::Maximized),
 955            WindowBounds::Fullscreen(bounds) => (bounds, WindowBounds::Fullscreen),
 956        },
 957        None => (
 958            display
 959                .as_ref()
 960                .map(|d| d.default_bounds())
 961                .unwrap_or_else(default_placement),
 962            WindowBounds::Windowed,
 963        ),
 964    };
 965
 966    let cascade_offset = point(px(CASCADE_OFFSET), px(CASCADE_OFFSET));
 967    let proposed_origin = base_origin + cascade_offset;
 968    let proposed_bounds = Bounds::new(proposed_origin, base_size);
 969
 970    let display_right = display_bounds.origin.x + display_bounds.size.width;
 971    let display_bottom = display_bounds.origin.y + display_bounds.size.height;
 972    let window_right = proposed_bounds.origin.x + proposed_bounds.size.width;
 973    let window_bottom = proposed_bounds.origin.y + proposed_bounds.size.height;
 974
 975    let fits_horizontally = window_right <= display_right;
 976    let fits_vertically = window_bottom <= display_bottom;
 977
 978    let final_origin = match (fits_horizontally, fits_vertically) {
 979        (true, true) => proposed_origin,
 980        (false, true) => point(display_bounds.origin.x, base_origin.y),
 981        (true, false) => point(base_origin.x, display_bounds.origin.y),
 982        (false, false) => display_bounds.origin,
 983    };
 984    window_bounds_ctor(Bounds::new(final_origin, base_size))
 985}
 986
 987impl Window {
 988    pub(crate) fn new(
 989        handle: AnyWindowHandle,
 990        options: WindowOptions,
 991        cx: &mut App,
 992    ) -> Result<Self> {
 993        let WindowOptions {
 994            window_bounds,
 995            titlebar,
 996            focus,
 997            show,
 998            kind,
 999            is_movable,
1000            is_resizable,
1001            is_minimizable,
1002            display_id,
1003            window_background,
1004            app_id,
1005            window_min_size,
1006            window_decorations,
1007            #[cfg_attr(not(target_os = "macos"), allow(unused_variables))]
1008            tabbing_identifier,
1009        } = options;
1010
1011        let window_bounds = window_bounds.unwrap_or_else(|| default_bounds(display_id, cx));
1012        let mut platform_window = cx.platform.open_window(
1013            handle,
1014            WindowParams {
1015                bounds: window_bounds.get_bounds(),
1016                titlebar,
1017                kind,
1018                is_movable,
1019                is_resizable,
1020                is_minimizable,
1021                focus,
1022                show,
1023                display_id,
1024                window_min_size,
1025                #[cfg(target_os = "macos")]
1026                tabbing_identifier,
1027            },
1028        )?;
1029
1030        let tab_bar_visible = platform_window.tab_bar_visible();
1031        SystemWindowTabController::init_visible(cx, tab_bar_visible);
1032        if let Some(tabs) = platform_window.tabbed_windows() {
1033            SystemWindowTabController::add_tab(cx, handle.window_id(), tabs);
1034        }
1035
1036        let display_id = platform_window.display().map(|display| display.id());
1037        let sprite_atlas = platform_window.sprite_atlas();
1038        let mouse_position = platform_window.mouse_position();
1039        let modifiers = platform_window.modifiers();
1040        let capslock = platform_window.capslock();
1041        let content_size = platform_window.content_size();
1042        let scale_factor = platform_window.scale_factor();
1043        let appearance = platform_window.appearance();
1044        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
1045        let invalidator = WindowInvalidator::new();
1046        let active = Rc::new(Cell::new(platform_window.is_active()));
1047        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
1048        let needs_present = Rc::new(Cell::new(false));
1049        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
1050        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
1051
1052        platform_window
1053            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
1054        platform_window.set_background_appearance(window_background);
1055
1056        match window_bounds {
1057            WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
1058            WindowBounds::Maximized(_) => platform_window.zoom(),
1059            WindowBounds::Windowed(_) => {}
1060        }
1061
1062        platform_window.on_close(Box::new({
1063            let window_id = handle.window_id();
1064            let mut cx = cx.to_async();
1065            move || {
1066                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
1067                let _ = cx.update(|cx| {
1068                    SystemWindowTabController::remove_tab(cx, window_id);
1069                });
1070            }
1071        }));
1072        platform_window.on_request_frame(Box::new({
1073            let mut cx = cx.to_async();
1074            let invalidator = invalidator.clone();
1075            let active = active.clone();
1076            let needs_present = needs_present.clone();
1077            let next_frame_callbacks = next_frame_callbacks.clone();
1078            let last_input_timestamp = last_input_timestamp.clone();
1079            move |request_frame_options| {
1080                let next_frame_callbacks = next_frame_callbacks.take();
1081                if !next_frame_callbacks.is_empty() {
1082                    handle
1083                        .update(&mut cx, |_, window, cx| {
1084                            for callback in next_frame_callbacks {
1085                                callback(window, cx);
1086                            }
1087                        })
1088                        .log_err();
1089                }
1090
1091                // Keep presenting the current scene for 1 extra second since the
1092                // last input to prevent the display from underclocking the refresh rate.
1093                let needs_present = request_frame_options.require_presentation
1094                    || needs_present.get()
1095                    || (active.get()
1096                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
1097
1098                if invalidator.is_dirty() || request_frame_options.force_render {
1099                    measure("frame duration", || {
1100                        handle
1101                            .update(&mut cx, |_, window, cx| {
1102                                let arena_clear_needed = window.draw(cx);
1103                                window.present();
1104                                // drop the arena elements after present to reduce latency
1105                                arena_clear_needed.clear();
1106                            })
1107                            .log_err();
1108                    })
1109                } else if needs_present {
1110                    handle
1111                        .update(&mut cx, |_, window, _| window.present())
1112                        .log_err();
1113                }
1114
1115                handle
1116                    .update(&mut cx, |_, window, _| {
1117                        window.complete_frame();
1118                    })
1119                    .log_err();
1120            }
1121        }));
1122        platform_window.on_resize(Box::new({
1123            let mut cx = cx.to_async();
1124            move |_, _| {
1125                handle
1126                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1127                    .log_err();
1128            }
1129        }));
1130        platform_window.on_moved(Box::new({
1131            let mut cx = cx.to_async();
1132            move || {
1133                handle
1134                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1135                    .log_err();
1136            }
1137        }));
1138        platform_window.on_appearance_changed(Box::new({
1139            let mut cx = cx.to_async();
1140            move || {
1141                handle
1142                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1143                    .log_err();
1144            }
1145        }));
1146        platform_window.on_active_status_change(Box::new({
1147            let mut cx = cx.to_async();
1148            move |active| {
1149                handle
1150                    .update(&mut cx, |_, window, cx| {
1151                        window.active.set(active);
1152                        window.modifiers = window.platform_window.modifiers();
1153                        window.capslock = window.platform_window.capslock();
1154                        window
1155                            .activation_observers
1156                            .clone()
1157                            .retain(&(), |callback| callback(window, cx));
1158
1159                        window.bounds_changed(cx);
1160                        window.refresh();
1161
1162                        SystemWindowTabController::update_last_active(cx, window.handle.id);
1163                    })
1164                    .log_err();
1165            }
1166        }));
1167        platform_window.on_hover_status_change(Box::new({
1168            let mut cx = cx.to_async();
1169            move |active| {
1170                handle
1171                    .update(&mut cx, |_, window, _| {
1172                        window.hovered.set(active);
1173                        window.refresh();
1174                    })
1175                    .log_err();
1176            }
1177        }));
1178        platform_window.on_input({
1179            let mut cx = cx.to_async();
1180            Box::new(move |event| {
1181                handle
1182                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1183                    .log_err()
1184                    .unwrap_or(DispatchEventResult::default())
1185            })
1186        });
1187        platform_window.on_hit_test_window_control({
1188            let mut cx = cx.to_async();
1189            Box::new(move || {
1190                handle
1191                    .update(&mut cx, |_, window, _cx| {
1192                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1193                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1194                                return Some(*area);
1195                            }
1196                        }
1197                        None
1198                    })
1199                    .log_err()
1200                    .unwrap_or(None)
1201            })
1202        });
1203        platform_window.on_move_tab_to_new_window({
1204            let mut cx = cx.to_async();
1205            Box::new(move || {
1206                handle
1207                    .update(&mut cx, |_, _window, cx| {
1208                        SystemWindowTabController::move_tab_to_new_window(cx, handle.window_id());
1209                    })
1210                    .log_err();
1211            })
1212        });
1213        platform_window.on_merge_all_windows({
1214            let mut cx = cx.to_async();
1215            Box::new(move || {
1216                handle
1217                    .update(&mut cx, |_, _window, cx| {
1218                        SystemWindowTabController::merge_all_windows(cx, handle.window_id());
1219                    })
1220                    .log_err();
1221            })
1222        });
1223        platform_window.on_select_next_tab({
1224            let mut cx = cx.to_async();
1225            Box::new(move || {
1226                handle
1227                    .update(&mut cx, |_, _window, cx| {
1228                        SystemWindowTabController::select_next_tab(cx, handle.window_id());
1229                    })
1230                    .log_err();
1231            })
1232        });
1233        platform_window.on_select_previous_tab({
1234            let mut cx = cx.to_async();
1235            Box::new(move || {
1236                handle
1237                    .update(&mut cx, |_, _window, cx| {
1238                        SystemWindowTabController::select_previous_tab(cx, handle.window_id())
1239                    })
1240                    .log_err();
1241            })
1242        });
1243        platform_window.on_toggle_tab_bar({
1244            let mut cx = cx.to_async();
1245            Box::new(move || {
1246                handle
1247                    .update(&mut cx, |_, window, cx| {
1248                        let tab_bar_visible = window.platform_window.tab_bar_visible();
1249                        SystemWindowTabController::set_visible(cx, tab_bar_visible);
1250                    })
1251                    .log_err();
1252            })
1253        });
1254
1255        if let Some(app_id) = app_id {
1256            platform_window.set_app_id(&app_id);
1257        }
1258
1259        platform_window.map_window().unwrap();
1260
1261        Ok(Window {
1262            handle,
1263            invalidator,
1264            removed: false,
1265            platform_window,
1266            display_id,
1267            sprite_atlas,
1268            text_system,
1269            rem_size: px(16.),
1270            rem_size_override_stack: SmallVec::new(),
1271            viewport_size: content_size,
1272            layout_engine: Some(TaffyLayoutEngine::new()),
1273            root: None,
1274            element_id_stack: SmallVec::default(),
1275            text_style_stack: Vec::new(),
1276            rendered_entity_stack: Vec::new(),
1277            element_offset_stack: Vec::new(),
1278            content_mask_stack: Vec::new(),
1279            element_opacity: 1.0,
1280            requested_autoscroll: None,
1281            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1282            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1283            next_frame_callbacks,
1284            next_hitbox_id: HitboxId(0),
1285            next_tooltip_id: TooltipId::default(),
1286            tooltip_bounds: None,
1287            dirty_views: FxHashSet::default(),
1288            focus_listeners: SubscriberSet::new(),
1289            focus_lost_listeners: SubscriberSet::new(),
1290            default_prevented: true,
1291            mouse_position,
1292            mouse_hit_test: HitTest::default(),
1293            modifiers,
1294            capslock,
1295            scale_factor,
1296            bounds_observers: SubscriberSet::new(),
1297            appearance,
1298            appearance_observers: SubscriberSet::new(),
1299            active,
1300            hovered,
1301            needs_present,
1302            last_input_timestamp,
1303            last_input_modality: InputModality::Mouse,
1304            refreshing: false,
1305            activation_observers: SubscriberSet::new(),
1306            focus: None,
1307            focus_enabled: true,
1308            pending_input: None,
1309            pending_modifier: ModifierState::default(),
1310            pending_input_observers: SubscriberSet::new(),
1311            prompt: None,
1312            client_inset: None,
1313            image_cache_stack: Vec::new(),
1314            #[cfg(any(feature = "inspector", debug_assertions))]
1315            inspector: None,
1316        })
1317    }
1318
1319    pub(crate) fn new_focus_listener(
1320        &self,
1321        value: AnyWindowFocusListener,
1322    ) -> (Subscription, impl FnOnce() + use<>) {
1323        self.focus_listeners.insert((), value)
1324    }
1325}
1326
1327#[derive(Clone, Debug, Default, PartialEq, Eq)]
1328pub(crate) struct DispatchEventResult {
1329    pub propagate: bool,
1330    pub default_prevented: bool,
1331}
1332
1333/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1334/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1335/// to leave room to support more complex shapes in the future.
1336#[derive(Clone, Debug, Default, PartialEq, Eq)]
1337#[repr(C)]
1338pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1339    /// The bounds
1340    pub bounds: Bounds<P>,
1341}
1342
1343impl ContentMask<Pixels> {
1344    /// Scale the content mask's pixel units by the given scaling factor.
1345    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1346        ContentMask {
1347            bounds: self.bounds.scale(factor),
1348        }
1349    }
1350
1351    /// Intersect the content mask with the given content mask.
1352    pub fn intersect(&self, other: &Self) -> Self {
1353        let bounds = self.bounds.intersect(&other.bounds);
1354        ContentMask { bounds }
1355    }
1356}
1357
1358impl Window {
1359    fn mark_view_dirty(&mut self, view_id: EntityId) {
1360        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1361        // should already be dirty.
1362        for view_id in self
1363            .rendered_frame
1364            .dispatch_tree
1365            .view_path_reversed(view_id)
1366        {
1367            if !self.dirty_views.insert(view_id) {
1368                break;
1369            }
1370        }
1371    }
1372
1373    /// Registers a callback to be invoked when the window appearance changes.
1374    pub fn observe_window_appearance(
1375        &self,
1376        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1377    ) -> Subscription {
1378        let (subscription, activate) = self.appearance_observers.insert(
1379            (),
1380            Box::new(move |window, cx| {
1381                callback(window, cx);
1382                true
1383            }),
1384        );
1385        activate();
1386        subscription
1387    }
1388
1389    /// Replaces the root entity of the window with a new one.
1390    pub fn replace_root<E>(
1391        &mut self,
1392        cx: &mut App,
1393        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1394    ) -> Entity<E>
1395    where
1396        E: 'static + Render,
1397    {
1398        let view = cx.new(|cx| build_view(self, cx));
1399        self.root = Some(view.clone().into());
1400        self.refresh();
1401        view
1402    }
1403
1404    /// Returns the root entity of the window, if it has one.
1405    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1406    where
1407        E: 'static + Render,
1408    {
1409        self.root
1410            .as_ref()
1411            .map(|view| view.clone().downcast::<E>().ok())
1412    }
1413
1414    /// Obtain a handle to the window that belongs to this context.
1415    pub fn window_handle(&self) -> AnyWindowHandle {
1416        self.handle
1417    }
1418
1419    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1420    pub fn refresh(&mut self) {
1421        if self.invalidator.not_drawing() {
1422            self.refreshing = true;
1423            self.invalidator.set_dirty(true);
1424        }
1425    }
1426
1427    /// Close this window.
1428    pub fn remove_window(&mut self) {
1429        self.removed = true;
1430    }
1431
1432    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1433    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1434        self.focus
1435            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1436    }
1437
1438    /// Move focus to the element associated with the given [`FocusHandle`].
1439    pub fn focus(&mut self, handle: &FocusHandle) {
1440        if !self.focus_enabled || self.focus == Some(handle.id) {
1441            return;
1442        }
1443
1444        self.focus = Some(handle.id);
1445        self.clear_pending_keystrokes();
1446        self.refresh();
1447    }
1448
1449    /// Remove focus from all elements within this context's window.
1450    pub fn blur(&mut self) {
1451        if !self.focus_enabled {
1452            return;
1453        }
1454
1455        self.focus = None;
1456        self.refresh();
1457    }
1458
1459    /// Blur the window and don't allow anything in it to be focused again.
1460    pub fn disable_focus(&mut self) {
1461        self.blur();
1462        self.focus_enabled = false;
1463    }
1464
1465    /// Move focus to next tab stop.
1466    pub fn focus_next(&mut self) {
1467        if !self.focus_enabled {
1468            return;
1469        }
1470
1471        if let Some(handle) = self.rendered_frame.tab_stops.next(self.focus.as_ref()) {
1472            self.focus(&handle)
1473        }
1474    }
1475
1476    /// Move focus to previous tab stop.
1477    pub fn focus_prev(&mut self) {
1478        if !self.focus_enabled {
1479            return;
1480        }
1481
1482        if let Some(handle) = self.rendered_frame.tab_stops.prev(self.focus.as_ref()) {
1483            self.focus(&handle)
1484        }
1485    }
1486
1487    /// Accessor for the text system.
1488    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1489        &self.text_system
1490    }
1491
1492    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1493    pub fn text_style(&self) -> TextStyle {
1494        let mut style = TextStyle::default();
1495        for refinement in &self.text_style_stack {
1496            style.refine(refinement);
1497        }
1498        style
1499    }
1500
1501    /// Check if the platform window is maximized.
1502    ///
1503    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1504    pub fn is_maximized(&self) -> bool {
1505        self.platform_window.is_maximized()
1506    }
1507
1508    /// request a certain window decoration (Wayland)
1509    pub fn request_decorations(&self, decorations: WindowDecorations) {
1510        self.platform_window.request_decorations(decorations);
1511    }
1512
1513    /// Start a window resize operation (Wayland)
1514    pub fn start_window_resize(&self, edge: ResizeEdge) {
1515        self.platform_window.start_window_resize(edge);
1516    }
1517
1518    /// Return the `WindowBounds` to indicate that how a window should be opened
1519    /// after it has been closed
1520    pub fn window_bounds(&self) -> WindowBounds {
1521        self.platform_window.window_bounds()
1522    }
1523
1524    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1525    pub fn inner_window_bounds(&self) -> WindowBounds {
1526        self.platform_window.inner_window_bounds()
1527    }
1528
1529    /// Dispatch the given action on the currently focused element.
1530    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1531        let focus_id = self.focused(cx).map(|handle| handle.id);
1532
1533        let window = self.handle;
1534        cx.defer(move |cx| {
1535            window
1536                .update(cx, |_, window, cx| {
1537                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1538                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1539                })
1540                .log_err();
1541        })
1542    }
1543
1544    pub(crate) fn dispatch_keystroke_observers(
1545        &mut self,
1546        event: &dyn Any,
1547        action: Option<Box<dyn Action>>,
1548        context_stack: Vec<KeyContext>,
1549        cx: &mut App,
1550    ) {
1551        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1552            return;
1553        };
1554
1555        cx.keystroke_observers.clone().retain(&(), move |callback| {
1556            (callback)(
1557                &KeystrokeEvent {
1558                    keystroke: key_down_event.keystroke.clone(),
1559                    action: action.as_ref().map(|action| action.boxed_clone()),
1560                    context_stack: context_stack.clone(),
1561                },
1562                self,
1563                cx,
1564            )
1565        });
1566    }
1567
1568    pub(crate) fn dispatch_keystroke_interceptors(
1569        &mut self,
1570        event: &dyn Any,
1571        context_stack: Vec<KeyContext>,
1572        cx: &mut App,
1573    ) {
1574        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1575            return;
1576        };
1577
1578        cx.keystroke_interceptors
1579            .clone()
1580            .retain(&(), move |callback| {
1581                (callback)(
1582                    &KeystrokeEvent {
1583                        keystroke: key_down_event.keystroke.clone(),
1584                        action: None,
1585                        context_stack: context_stack.clone(),
1586                    },
1587                    self,
1588                    cx,
1589                )
1590            });
1591    }
1592
1593    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1594    /// that are currently on the stack to be returned to the app.
1595    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1596        let handle = self.handle;
1597        cx.defer(move |cx| {
1598            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1599        });
1600    }
1601
1602    /// Subscribe to events emitted by a entity.
1603    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1604    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1605    pub fn observe<T: 'static>(
1606        &mut self,
1607        observed: &Entity<T>,
1608        cx: &mut App,
1609        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1610    ) -> Subscription {
1611        let entity_id = observed.entity_id();
1612        let observed = observed.downgrade();
1613        let window_handle = self.handle;
1614        cx.new_observer(
1615            entity_id,
1616            Box::new(move |cx| {
1617                window_handle
1618                    .update(cx, |_, window, cx| {
1619                        if let Some(handle) = observed.upgrade() {
1620                            on_notify(handle, window, cx);
1621                            true
1622                        } else {
1623                            false
1624                        }
1625                    })
1626                    .unwrap_or(false)
1627            }),
1628        )
1629    }
1630
1631    /// Subscribe to events emitted by a entity.
1632    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1633    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1634    pub fn subscribe<Emitter, Evt>(
1635        &mut self,
1636        entity: &Entity<Emitter>,
1637        cx: &mut App,
1638        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1639    ) -> Subscription
1640    where
1641        Emitter: EventEmitter<Evt>,
1642        Evt: 'static,
1643    {
1644        let entity_id = entity.entity_id();
1645        let handle = entity.downgrade();
1646        let window_handle = self.handle;
1647        cx.new_subscription(
1648            entity_id,
1649            (
1650                TypeId::of::<Evt>(),
1651                Box::new(move |event, cx| {
1652                    window_handle
1653                        .update(cx, |_, window, cx| {
1654                            if let Some(entity) = handle.upgrade() {
1655                                let event = event.downcast_ref().expect("invalid event type");
1656                                on_event(entity, event, window, cx);
1657                                true
1658                            } else {
1659                                false
1660                            }
1661                        })
1662                        .unwrap_or(false)
1663                }),
1664            ),
1665        )
1666    }
1667
1668    /// Register a callback to be invoked when the given `Entity` is released.
1669    pub fn observe_release<T>(
1670        &self,
1671        entity: &Entity<T>,
1672        cx: &mut App,
1673        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1674    ) -> Subscription
1675    where
1676        T: 'static,
1677    {
1678        let entity_id = entity.entity_id();
1679        let window_handle = self.handle;
1680        let (subscription, activate) = cx.release_listeners.insert(
1681            entity_id,
1682            Box::new(move |entity, cx| {
1683                let entity = entity.downcast_mut().expect("invalid entity type");
1684                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1685            }),
1686        );
1687        activate();
1688        subscription
1689    }
1690
1691    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1692    /// await points in async code.
1693    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1694        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1695    }
1696
1697    /// Schedule the given closure to be run directly after the current frame is rendered.
1698    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1699        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1700    }
1701
1702    /// Schedule a frame to be drawn on the next animation frame.
1703    ///
1704    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1705    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1706    ///
1707    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1708    pub fn request_animation_frame(&self) {
1709        let entity = self.current_view();
1710        self.on_next_frame(move |_, cx| cx.notify(entity));
1711    }
1712
1713    /// Spawn the future returned by the given closure on the application thread pool.
1714    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1715    /// use within your future.
1716    #[track_caller]
1717    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1718    where
1719        R: 'static,
1720        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1721    {
1722        let handle = self.handle;
1723        cx.spawn(async move |app| {
1724            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1725            f(&mut async_window_cx).await
1726        })
1727    }
1728
1729    /// Spawn the future returned by the given closure on the application thread
1730    /// pool, with the given priority. The closure is provided a handle to the
1731    /// current window and an `AsyncWindowContext` for use within your future.
1732    #[track_caller]
1733    pub fn spawn_with_priority<AsyncFn, R>(
1734        &self,
1735        priority: Priority,
1736        cx: &App,
1737        f: AsyncFn,
1738    ) -> Task<R>
1739    where
1740        R: 'static,
1741        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1742    {
1743        let handle = self.handle;
1744        cx.spawn_with_priority(priority, async move |app| {
1745            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1746            f(&mut async_window_cx).await
1747        })
1748    }
1749
1750    fn bounds_changed(&mut self, cx: &mut App) {
1751        self.scale_factor = self.platform_window.scale_factor();
1752        self.viewport_size = self.platform_window.content_size();
1753        self.display_id = self.platform_window.display().map(|display| display.id());
1754
1755        self.refresh();
1756
1757        self.bounds_observers
1758            .clone()
1759            .retain(&(), |callback| callback(self, cx));
1760    }
1761
1762    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1763    pub fn bounds(&self) -> Bounds<Pixels> {
1764        self.platform_window.bounds()
1765    }
1766
1767    /// Returns the native window ID (CGWindowID on macOS) for window capture.
1768    /// This is used by visual testing infrastructure to capture window screenshots.
1769    /// Returns None on platforms that don't support this or in non-test builds.
1770    #[cfg(any(test, feature = "test-support"))]
1771    pub fn native_window_id(&self) -> Option<u32> {
1772        self.platform_window.native_window_id()
1773    }
1774
1775    /// Set the content size of the window.
1776    pub fn resize(&mut self, size: Size<Pixels>) {
1777        self.platform_window.resize(size);
1778    }
1779
1780    /// Returns whether or not the window is currently fullscreen
1781    pub fn is_fullscreen(&self) -> bool {
1782        self.platform_window.is_fullscreen()
1783    }
1784
1785    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1786        self.appearance = self.platform_window.appearance();
1787
1788        self.appearance_observers
1789            .clone()
1790            .retain(&(), |callback| callback(self, cx));
1791    }
1792
1793    /// Returns the appearance of the current window.
1794    pub fn appearance(&self) -> WindowAppearance {
1795        self.appearance
1796    }
1797
1798    /// Returns the size of the drawable area within the window.
1799    pub fn viewport_size(&self) -> Size<Pixels> {
1800        self.viewport_size
1801    }
1802
1803    /// Returns whether this window is focused by the operating system (receiving key events).
1804    pub fn is_window_active(&self) -> bool {
1805        self.active.get()
1806    }
1807
1808    /// Returns whether this window is considered to be the window
1809    /// that currently owns the mouse cursor.
1810    /// On mac, this is equivalent to `is_window_active`.
1811    pub fn is_window_hovered(&self) -> bool {
1812        if cfg!(any(
1813            target_os = "windows",
1814            target_os = "linux",
1815            target_os = "freebsd"
1816        )) {
1817            self.hovered.get()
1818        } else {
1819            self.is_window_active()
1820        }
1821    }
1822
1823    /// Toggle zoom on the window.
1824    pub fn zoom_window(&self) {
1825        self.platform_window.zoom();
1826    }
1827
1828    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1829    pub fn show_window_menu(&self, position: Point<Pixels>) {
1830        self.platform_window.show_window_menu(position)
1831    }
1832
1833    /// Handle window movement for Linux and macOS.
1834    /// Tells the compositor to take control of window movement (Wayland and X11)
1835    ///
1836    /// Events may not be received during a move operation.
1837    pub fn start_window_move(&self) {
1838        self.platform_window.start_window_move()
1839    }
1840
1841    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1842    pub fn set_client_inset(&mut self, inset: Pixels) {
1843        self.client_inset = Some(inset);
1844        self.platform_window.set_client_inset(inset);
1845    }
1846
1847    /// Returns the client_inset value by [`Self::set_client_inset`].
1848    pub fn client_inset(&self) -> Option<Pixels> {
1849        self.client_inset
1850    }
1851
1852    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1853    pub fn window_decorations(&self) -> Decorations {
1854        self.platform_window.window_decorations()
1855    }
1856
1857    /// Returns which window controls are currently visible (Wayland)
1858    pub fn window_controls(&self) -> WindowControls {
1859        self.platform_window.window_controls()
1860    }
1861
1862    /// Updates the window's title at the platform level.
1863    pub fn set_window_title(&mut self, title: &str) {
1864        self.platform_window.set_title(title);
1865    }
1866
1867    /// Sets the application identifier.
1868    pub fn set_app_id(&mut self, app_id: &str) {
1869        self.platform_window.set_app_id(app_id);
1870    }
1871
1872    /// Sets the window background appearance.
1873    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1874        self.platform_window
1875            .set_background_appearance(background_appearance);
1876    }
1877
1878    /// Mark the window as dirty at the platform level.
1879    pub fn set_window_edited(&mut self, edited: bool) {
1880        self.platform_window.set_edited(edited);
1881    }
1882
1883    /// Determine the display on which the window is visible.
1884    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1885        cx.platform
1886            .displays()
1887            .into_iter()
1888            .find(|display| Some(display.id()) == self.display_id)
1889    }
1890
1891    /// Show the platform character palette.
1892    pub fn show_character_palette(&self) {
1893        self.platform_window.show_character_palette();
1894    }
1895
1896    /// The scale factor of the display associated with the window. For example, it could
1897    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1898    /// be rendered as two pixels on screen.
1899    pub fn scale_factor(&self) -> f32 {
1900        self.scale_factor
1901    }
1902
1903    /// The size of an em for the base font of the application. Adjusting this value allows the
1904    /// UI to scale, just like zooming a web page.
1905    pub fn rem_size(&self) -> Pixels {
1906        self.rem_size_override_stack
1907            .last()
1908            .copied()
1909            .unwrap_or(self.rem_size)
1910    }
1911
1912    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1913    /// UI to scale, just like zooming a web page.
1914    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1915        self.rem_size = rem_size.into();
1916    }
1917
1918    /// Acquire a globally unique identifier for the given ElementId.
1919    /// Only valid for the duration of the provided closure.
1920    pub fn with_global_id<R>(
1921        &mut self,
1922        element_id: ElementId,
1923        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1924    ) -> R {
1925        self.element_id_stack.push(element_id);
1926        let global_id = GlobalElementId(Arc::from(&*self.element_id_stack));
1927
1928        let result = f(&global_id, self);
1929        self.element_id_stack.pop();
1930        result
1931    }
1932
1933    /// Executes the provided function with the specified rem size.
1934    ///
1935    /// This method must only be called as part of element drawing.
1936    // This function is called in a highly recursive manner in editor
1937    // prepainting, make sure its inlined to reduce the stack burden
1938    #[inline]
1939    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1940    where
1941        F: FnOnce(&mut Self) -> R,
1942    {
1943        self.invalidator.debug_assert_paint_or_prepaint();
1944
1945        if let Some(rem_size) = rem_size {
1946            self.rem_size_override_stack.push(rem_size.into());
1947            let result = f(self);
1948            self.rem_size_override_stack.pop();
1949            result
1950        } else {
1951            f(self)
1952        }
1953    }
1954
1955    /// The line height associated with the current text style.
1956    pub fn line_height(&self) -> Pixels {
1957        self.text_style().line_height_in_pixels(self.rem_size())
1958    }
1959
1960    /// Call to prevent the default action of an event. Currently only used to prevent
1961    /// parent elements from becoming focused on mouse down.
1962    pub fn prevent_default(&mut self) {
1963        self.default_prevented = true;
1964    }
1965
1966    /// Obtain whether default has been prevented for the event currently being dispatched.
1967    pub fn default_prevented(&self) -> bool {
1968        self.default_prevented
1969    }
1970
1971    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1972    pub fn is_action_available(&self, action: &dyn Action, cx: &App) -> bool {
1973        let node_id =
1974            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
1975        self.rendered_frame
1976            .dispatch_tree
1977            .is_action_available(action, node_id)
1978    }
1979
1980    /// Determine whether the given action is available along the dispatch path to the given focus_handle.
1981    pub fn is_action_available_in(&self, action: &dyn Action, focus_handle: &FocusHandle) -> bool {
1982        let node_id = self.focus_node_id_in_rendered_frame(Some(focus_handle.id));
1983        self.rendered_frame
1984            .dispatch_tree
1985            .is_action_available(action, node_id)
1986    }
1987
1988    /// The position of the mouse relative to the window.
1989    pub fn mouse_position(&self) -> Point<Pixels> {
1990        self.mouse_position
1991    }
1992
1993    /// The current state of the keyboard's modifiers
1994    pub fn modifiers(&self) -> Modifiers {
1995        self.modifiers
1996    }
1997
1998    /// Returns true if the last input event was keyboard-based (key press, tab navigation, etc.)
1999    /// This is used for focus-visible styling to show focus indicators only for keyboard navigation.
2000    pub fn last_input_was_keyboard(&self) -> bool {
2001        self.last_input_modality == InputModality::Keyboard
2002    }
2003
2004    /// The current state of the keyboard's capslock
2005    pub fn capslock(&self) -> Capslock {
2006        self.capslock
2007    }
2008
2009    fn complete_frame(&self) {
2010        self.platform_window.completed_frame();
2011    }
2012
2013    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
2014    /// the contents of the new [`Scene`], use [`Self::present`].
2015    #[profiling::function]
2016    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
2017        self.invalidate_entities();
2018        cx.entities.clear_accessed();
2019        debug_assert!(self.rendered_entity_stack.is_empty());
2020        self.invalidator.set_dirty(false);
2021        self.requested_autoscroll = None;
2022
2023        // Restore the previously-used input handler.
2024        if let Some(input_handler) = self.platform_window.take_input_handler() {
2025            self.rendered_frame.input_handlers.push(Some(input_handler));
2026        }
2027        if !cx.mode.skip_drawing() {
2028            self.draw_roots(cx);
2029        }
2030        self.dirty_views.clear();
2031        self.next_frame.window_active = self.active.get();
2032
2033        // Register requested input handler with the platform window.
2034        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
2035            self.platform_window
2036                .set_input_handler(input_handler.unwrap());
2037        }
2038
2039        self.layout_engine.as_mut().unwrap().clear();
2040        self.text_system().finish_frame();
2041        self.next_frame.finish(&mut self.rendered_frame);
2042
2043        self.invalidator.set_phase(DrawPhase::Focus);
2044        let previous_focus_path = self.rendered_frame.focus_path();
2045        let previous_window_active = self.rendered_frame.window_active;
2046        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
2047        self.next_frame.clear();
2048        let current_focus_path = self.rendered_frame.focus_path();
2049        let current_window_active = self.rendered_frame.window_active;
2050
2051        if previous_focus_path != current_focus_path
2052            || previous_window_active != current_window_active
2053        {
2054            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
2055                self.focus_lost_listeners
2056                    .clone()
2057                    .retain(&(), |listener| listener(self, cx));
2058            }
2059
2060            let event = WindowFocusEvent {
2061                previous_focus_path: if previous_window_active {
2062                    previous_focus_path
2063                } else {
2064                    Default::default()
2065                },
2066                current_focus_path: if current_window_active {
2067                    current_focus_path
2068                } else {
2069                    Default::default()
2070                },
2071            };
2072            self.focus_listeners
2073                .clone()
2074                .retain(&(), |listener| listener(&event, self, cx));
2075        }
2076
2077        debug_assert!(self.rendered_entity_stack.is_empty());
2078        self.record_entities_accessed(cx);
2079        self.reset_cursor_style(cx);
2080        self.refreshing = false;
2081        self.invalidator.set_phase(DrawPhase::None);
2082        self.needs_present.set(true);
2083
2084        ArenaClearNeeded
2085    }
2086
2087    fn record_entities_accessed(&mut self, cx: &mut App) {
2088        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
2089        let mut entities = mem::take(entities_ref.deref_mut());
2090        drop(entities_ref);
2091        let handle = self.handle;
2092        cx.record_entities_accessed(
2093            handle,
2094            // Try moving window invalidator into the Window
2095            self.invalidator.clone(),
2096            &entities,
2097        );
2098        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
2099        mem::swap(&mut entities, entities_ref.deref_mut());
2100    }
2101
2102    fn invalidate_entities(&mut self) {
2103        let mut views = self.invalidator.take_views();
2104        for entity in views.drain() {
2105            self.mark_view_dirty(entity);
2106        }
2107        self.invalidator.replace_views(views);
2108    }
2109
2110    #[profiling::function]
2111    fn present(&self) {
2112        self.platform_window.draw(&self.rendered_frame.scene);
2113        self.needs_present.set(false);
2114        profiling::finish_frame!();
2115    }
2116
2117    fn draw_roots(&mut self, cx: &mut App) {
2118        self.invalidator.set_phase(DrawPhase::Prepaint);
2119        self.tooltip_bounds.take();
2120
2121        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
2122        let root_size = {
2123            #[cfg(any(feature = "inspector", debug_assertions))]
2124            {
2125                if self.inspector.is_some() {
2126                    let mut size = self.viewport_size;
2127                    size.width = (size.width - _inspector_width).max(px(0.0));
2128                    size
2129                } else {
2130                    self.viewport_size
2131                }
2132            }
2133            #[cfg(not(any(feature = "inspector", debug_assertions)))]
2134            {
2135                self.viewport_size
2136            }
2137        };
2138
2139        // Layout all root elements.
2140        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
2141        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2142
2143        #[cfg(any(feature = "inspector", debug_assertions))]
2144        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
2145
2146        let mut sorted_deferred_draws =
2147            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
2148        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
2149        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
2150
2151        let mut prompt_element = None;
2152        let mut active_drag_element = None;
2153        let mut tooltip_element = None;
2154        if let Some(prompt) = self.prompt.take() {
2155            let mut element = prompt.view.any_view().into_any();
2156            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2157            prompt_element = Some(element);
2158            self.prompt = Some(prompt);
2159        } else if let Some(active_drag) = cx.active_drag.take() {
2160            let mut element = active_drag.view.clone().into_any();
2161            let offset = self.mouse_position() - active_drag.cursor_offset;
2162            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
2163            active_drag_element = Some(element);
2164            cx.active_drag = Some(active_drag);
2165        } else {
2166            tooltip_element = self.prepaint_tooltip(cx);
2167        }
2168
2169        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
2170
2171        // Now actually paint the elements.
2172        self.invalidator.set_phase(DrawPhase::Paint);
2173        root_element.paint(self, cx);
2174
2175        #[cfg(any(feature = "inspector", debug_assertions))]
2176        self.paint_inspector(inspector_element, cx);
2177
2178        self.paint_deferred_draws(&sorted_deferred_draws, cx);
2179
2180        if let Some(mut prompt_element) = prompt_element {
2181            prompt_element.paint(self, cx);
2182        } else if let Some(mut drag_element) = active_drag_element {
2183            drag_element.paint(self, cx);
2184        } else if let Some(mut tooltip_element) = tooltip_element {
2185            tooltip_element.paint(self, cx);
2186        }
2187
2188        #[cfg(any(feature = "inspector", debug_assertions))]
2189        self.paint_inspector_hitbox(cx);
2190    }
2191
2192    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
2193        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
2194        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
2195            let Some(Some(tooltip_request)) = self
2196                .next_frame
2197                .tooltip_requests
2198                .get(tooltip_request_index)
2199                .cloned()
2200            else {
2201                log::error!("Unexpectedly absent TooltipRequest");
2202                continue;
2203            };
2204            let mut element = tooltip_request.tooltip.view.clone().into_any();
2205            let mouse_position = tooltip_request.tooltip.mouse_position;
2206            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
2207
2208            let mut tooltip_bounds =
2209                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
2210            let window_bounds = Bounds {
2211                origin: Point::default(),
2212                size: self.viewport_size(),
2213            };
2214
2215            if tooltip_bounds.right() > window_bounds.right() {
2216                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
2217                if new_x >= Pixels::ZERO {
2218                    tooltip_bounds.origin.x = new_x;
2219                } else {
2220                    tooltip_bounds.origin.x = cmp::max(
2221                        Pixels::ZERO,
2222                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
2223                    );
2224                }
2225            }
2226
2227            if tooltip_bounds.bottom() > window_bounds.bottom() {
2228                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
2229                if new_y >= Pixels::ZERO {
2230                    tooltip_bounds.origin.y = new_y;
2231                } else {
2232                    tooltip_bounds.origin.y = cmp::max(
2233                        Pixels::ZERO,
2234                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
2235                    );
2236                }
2237            }
2238
2239            // It's possible for an element to have an active tooltip while not being painted (e.g.
2240            // via the `visible_on_hover` method). Since mouse listeners are not active in this
2241            // case, instead update the tooltip's visibility here.
2242            let is_visible =
2243                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
2244            if !is_visible {
2245                continue;
2246            }
2247
2248            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2249                element.prepaint(window, cx)
2250            });
2251
2252            self.tooltip_bounds = Some(TooltipBounds {
2253                id: tooltip_request.id,
2254                bounds: tooltip_bounds,
2255            });
2256            return Some(element);
2257        }
2258        None
2259    }
2260
2261    fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2262        assert_eq!(self.element_id_stack.len(), 0);
2263
2264        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2265        for deferred_draw_ix in deferred_draw_indices {
2266            let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2267            self.element_id_stack
2268                .clone_from(&deferred_draw.element_id_stack);
2269            self.text_style_stack
2270                .clone_from(&deferred_draw.text_style_stack);
2271            self.next_frame
2272                .dispatch_tree
2273                .set_active_node(deferred_draw.parent_node);
2274
2275            let prepaint_start = self.prepaint_index();
2276            if let Some(element) = deferred_draw.element.as_mut() {
2277                self.with_rendered_view(deferred_draw.current_view, |window| {
2278                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
2279                        element.prepaint(window, cx)
2280                    });
2281                })
2282            } else {
2283                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2284            }
2285            let prepaint_end = self.prepaint_index();
2286            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2287        }
2288        assert_eq!(
2289            self.next_frame.deferred_draws.len(),
2290            0,
2291            "cannot call defer_draw during deferred drawing"
2292        );
2293        self.next_frame.deferred_draws = deferred_draws;
2294        self.element_id_stack.clear();
2295        self.text_style_stack.clear();
2296    }
2297
2298    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2299        assert_eq!(self.element_id_stack.len(), 0);
2300
2301        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2302        for deferred_draw_ix in deferred_draw_indices {
2303            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2304            self.element_id_stack
2305                .clone_from(&deferred_draw.element_id_stack);
2306            self.next_frame
2307                .dispatch_tree
2308                .set_active_node(deferred_draw.parent_node);
2309
2310            let paint_start = self.paint_index();
2311            if let Some(element) = deferred_draw.element.as_mut() {
2312                self.with_rendered_view(deferred_draw.current_view, |window| {
2313                    element.paint(window, cx);
2314                })
2315            } else {
2316                self.reuse_paint(deferred_draw.paint_range.clone());
2317            }
2318            let paint_end = self.paint_index();
2319            deferred_draw.paint_range = paint_start..paint_end;
2320        }
2321        self.next_frame.deferred_draws = deferred_draws;
2322        self.element_id_stack.clear();
2323    }
2324
2325    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2326        PrepaintStateIndex {
2327            hitboxes_index: self.next_frame.hitboxes.len(),
2328            tooltips_index: self.next_frame.tooltip_requests.len(),
2329            deferred_draws_index: self.next_frame.deferred_draws.len(),
2330            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2331            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2332            line_layout_index: self.text_system.layout_index(),
2333        }
2334    }
2335
2336    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2337        self.next_frame.hitboxes.extend(
2338            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2339                .iter()
2340                .cloned(),
2341        );
2342        self.next_frame.tooltip_requests.extend(
2343            self.rendered_frame.tooltip_requests
2344                [range.start.tooltips_index..range.end.tooltips_index]
2345                .iter_mut()
2346                .map(|request| request.take()),
2347        );
2348        self.next_frame.accessed_element_states.extend(
2349            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2350                ..range.end.accessed_element_states_index]
2351                .iter()
2352                .map(|(id, type_id)| (id.clone(), *type_id)),
2353        );
2354        self.text_system
2355            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2356
2357        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2358            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2359            &mut self.rendered_frame.dispatch_tree,
2360            self.focus,
2361        );
2362
2363        if reused_subtree.contains_focus() {
2364            self.next_frame.focus = self.focus;
2365        }
2366
2367        self.next_frame.deferred_draws.extend(
2368            self.rendered_frame.deferred_draws
2369                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2370                .iter()
2371                .map(|deferred_draw| DeferredDraw {
2372                    current_view: deferred_draw.current_view,
2373                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2374                    element_id_stack: deferred_draw.element_id_stack.clone(),
2375                    text_style_stack: deferred_draw.text_style_stack.clone(),
2376                    priority: deferred_draw.priority,
2377                    element: None,
2378                    absolute_offset: deferred_draw.absolute_offset,
2379                    prepaint_range: deferred_draw.prepaint_range.clone(),
2380                    paint_range: deferred_draw.paint_range.clone(),
2381                }),
2382        );
2383    }
2384
2385    pub(crate) fn paint_index(&self) -> PaintIndex {
2386        PaintIndex {
2387            scene_index: self.next_frame.scene.len(),
2388            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2389            input_handlers_index: self.next_frame.input_handlers.len(),
2390            cursor_styles_index: self.next_frame.cursor_styles.len(),
2391            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2392            tab_handle_index: self.next_frame.tab_stops.paint_index(),
2393            line_layout_index: self.text_system.layout_index(),
2394        }
2395    }
2396
2397    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2398        self.next_frame.cursor_styles.extend(
2399            self.rendered_frame.cursor_styles
2400                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2401                .iter()
2402                .cloned(),
2403        );
2404        self.next_frame.input_handlers.extend(
2405            self.rendered_frame.input_handlers
2406                [range.start.input_handlers_index..range.end.input_handlers_index]
2407                .iter_mut()
2408                .map(|handler| handler.take()),
2409        );
2410        self.next_frame.mouse_listeners.extend(
2411            self.rendered_frame.mouse_listeners
2412                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2413                .iter_mut()
2414                .map(|listener| listener.take()),
2415        );
2416        self.next_frame.accessed_element_states.extend(
2417            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2418                ..range.end.accessed_element_states_index]
2419                .iter()
2420                .map(|(id, type_id)| (id.clone(), *type_id)),
2421        );
2422        self.next_frame.tab_stops.replay(
2423            &self.rendered_frame.tab_stops.insertion_history
2424                [range.start.tab_handle_index..range.end.tab_handle_index],
2425        );
2426
2427        self.text_system
2428            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2429        self.next_frame.scene.replay(
2430            range.start.scene_index..range.end.scene_index,
2431            &self.rendered_frame.scene,
2432        );
2433    }
2434
2435    /// Push a text style onto the stack, and call a function with that style active.
2436    /// Use [`Window::text_style`] to get the current, combined text style. This method
2437    /// should only be called as part of element drawing.
2438    // This function is called in a highly recursive manner in editor
2439    // prepainting, make sure its inlined to reduce the stack burden
2440    #[inline]
2441    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2442    where
2443        F: FnOnce(&mut Self) -> R,
2444    {
2445        self.invalidator.debug_assert_paint_or_prepaint();
2446        if let Some(style) = style {
2447            self.text_style_stack.push(style);
2448            let result = f(self);
2449            self.text_style_stack.pop();
2450            result
2451        } else {
2452            f(self)
2453        }
2454    }
2455
2456    /// Updates the cursor style at the platform level. This method should only be called
2457    /// during the paint phase of element drawing.
2458    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2459        self.invalidator.debug_assert_paint();
2460        self.next_frame.cursor_styles.push(CursorStyleRequest {
2461            hitbox_id: Some(hitbox.id),
2462            style,
2463        });
2464    }
2465
2466    /// Updates the cursor style for the entire window at the platform level. A cursor
2467    /// style using this method will have precedence over any cursor style set using
2468    /// `set_cursor_style`. This method should only be called during the paint
2469    /// phase of element drawing.
2470    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2471        self.invalidator.debug_assert_paint();
2472        self.next_frame.cursor_styles.push(CursorStyleRequest {
2473            hitbox_id: None,
2474            style,
2475        })
2476    }
2477
2478    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2479    /// during the paint phase of element drawing.
2480    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2481        self.invalidator.debug_assert_prepaint();
2482        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2483        self.next_frame
2484            .tooltip_requests
2485            .push(Some(TooltipRequest { id, tooltip }));
2486        id
2487    }
2488
2489    /// Invoke the given function with the given content mask after intersecting it
2490    /// with the current mask. This method should only be called during element drawing.
2491    // This function is called in a highly recursive manner in editor
2492    // prepainting, make sure its inlined to reduce the stack burden
2493    #[inline]
2494    pub fn with_content_mask<R>(
2495        &mut self,
2496        mask: Option<ContentMask<Pixels>>,
2497        f: impl FnOnce(&mut Self) -> R,
2498    ) -> R {
2499        self.invalidator.debug_assert_paint_or_prepaint();
2500        if let Some(mask) = mask {
2501            let mask = mask.intersect(&self.content_mask());
2502            self.content_mask_stack.push(mask);
2503            let result = f(self);
2504            self.content_mask_stack.pop();
2505            result
2506        } else {
2507            f(self)
2508        }
2509    }
2510
2511    /// Updates the global element offset relative to the current offset. This is used to implement
2512    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2513    pub fn with_element_offset<R>(
2514        &mut self,
2515        offset: Point<Pixels>,
2516        f: impl FnOnce(&mut Self) -> R,
2517    ) -> R {
2518        self.invalidator.debug_assert_prepaint();
2519
2520        if offset.is_zero() {
2521            return f(self);
2522        };
2523
2524        let abs_offset = self.element_offset() + offset;
2525        self.with_absolute_element_offset(abs_offset, f)
2526    }
2527
2528    /// Updates the global element offset based on the given offset. This is used to implement
2529    /// drag handles and other manual painting of elements. This method should only be called during
2530    /// the prepaint phase of element drawing.
2531    pub fn with_absolute_element_offset<R>(
2532        &mut self,
2533        offset: Point<Pixels>,
2534        f: impl FnOnce(&mut Self) -> R,
2535    ) -> R {
2536        self.invalidator.debug_assert_prepaint();
2537        self.element_offset_stack.push(offset);
2538        let result = f(self);
2539        self.element_offset_stack.pop();
2540        result
2541    }
2542
2543    pub(crate) fn with_element_opacity<R>(
2544        &mut self,
2545        opacity: Option<f32>,
2546        f: impl FnOnce(&mut Self) -> R,
2547    ) -> R {
2548        self.invalidator.debug_assert_paint_or_prepaint();
2549
2550        let Some(opacity) = opacity else {
2551            return f(self);
2552        };
2553
2554        let previous_opacity = self.element_opacity;
2555        self.element_opacity = previous_opacity * opacity;
2556        let result = f(self);
2557        self.element_opacity = previous_opacity;
2558        result
2559    }
2560
2561    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2562    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2563    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2564    /// element offset and prepaint again. See [`crate::List`] for an example. This method should only be
2565    /// called during the prepaint phase of element drawing.
2566    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2567        self.invalidator.debug_assert_prepaint();
2568        let index = self.prepaint_index();
2569        let result = f(self);
2570        if result.is_err() {
2571            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2572            self.next_frame
2573                .tooltip_requests
2574                .truncate(index.tooltips_index);
2575            self.next_frame
2576                .deferred_draws
2577                .truncate(index.deferred_draws_index);
2578            self.next_frame
2579                .dispatch_tree
2580                .truncate(index.dispatch_tree_index);
2581            self.next_frame
2582                .accessed_element_states
2583                .truncate(index.accessed_element_states_index);
2584            self.text_system.truncate_layouts(index.line_layout_index);
2585        }
2586        result
2587    }
2588
2589    /// When you call this method during [`Element::prepaint`], containing elements will attempt to
2590    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2591    /// [`Element::prepaint`] again with a new set of bounds. See [`crate::List`] for an example of an element
2592    /// that supports this method being called on the elements it contains. This method should only be
2593    /// called during the prepaint phase of element drawing.
2594    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2595        self.invalidator.debug_assert_prepaint();
2596        self.requested_autoscroll = Some(bounds);
2597    }
2598
2599    /// This method can be called from a containing element such as [`crate::List`] to support the autoscroll behavior
2600    /// described in [`Self::request_autoscroll`].
2601    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2602        self.invalidator.debug_assert_prepaint();
2603        self.requested_autoscroll.take()
2604    }
2605
2606    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2607    /// Your view will be re-drawn once the asset has finished loading.
2608    ///
2609    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2610    /// time.
2611    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2612        let (task, is_first) = cx.fetch_asset::<A>(source);
2613        task.clone().now_or_never().or_else(|| {
2614            if is_first {
2615                let entity_id = self.current_view();
2616                self.spawn(cx, {
2617                    let task = task.clone();
2618                    async move |cx| {
2619                        task.await;
2620
2621                        cx.on_next_frame(move |_, cx| {
2622                            cx.notify(entity_id);
2623                        });
2624                    }
2625                })
2626                .detach();
2627            }
2628
2629            None
2630        })
2631    }
2632
2633    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2634    /// Your view will not be re-drawn once the asset has finished loading.
2635    ///
2636    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2637    /// time.
2638    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2639        let (task, _) = cx.fetch_asset::<A>(source);
2640        task.now_or_never()
2641    }
2642    /// Obtain the current element offset. This method should only be called during the
2643    /// prepaint phase of element drawing.
2644    pub fn element_offset(&self) -> Point<Pixels> {
2645        self.invalidator.debug_assert_prepaint();
2646        self.element_offset_stack
2647            .last()
2648            .copied()
2649            .unwrap_or_default()
2650    }
2651
2652    /// Obtain the current element opacity. This method should only be called during the
2653    /// prepaint phase of element drawing.
2654    #[inline]
2655    pub(crate) fn element_opacity(&self) -> f32 {
2656        self.invalidator.debug_assert_paint_or_prepaint();
2657        self.element_opacity
2658    }
2659
2660    /// Obtain the current content mask. This method should only be called during element drawing.
2661    pub fn content_mask(&self) -> ContentMask<Pixels> {
2662        self.invalidator.debug_assert_paint_or_prepaint();
2663        self.content_mask_stack
2664            .last()
2665            .cloned()
2666            .unwrap_or_else(|| ContentMask {
2667                bounds: Bounds {
2668                    origin: Point::default(),
2669                    size: self.viewport_size,
2670                },
2671            })
2672    }
2673
2674    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2675    /// This can be used within a custom element to distinguish multiple sets of child elements.
2676    pub fn with_element_namespace<R>(
2677        &mut self,
2678        element_id: impl Into<ElementId>,
2679        f: impl FnOnce(&mut Self) -> R,
2680    ) -> R {
2681        self.element_id_stack.push(element_id.into());
2682        let result = f(self);
2683        self.element_id_stack.pop();
2684        result
2685    }
2686
2687    /// Use a piece of state that exists as long this element is being rendered in consecutive frames.
2688    pub fn use_keyed_state<S: 'static>(
2689        &mut self,
2690        key: impl Into<ElementId>,
2691        cx: &mut App,
2692        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2693    ) -> Entity<S> {
2694        let current_view = self.current_view();
2695        self.with_global_id(key.into(), |global_id, window| {
2696            window.with_element_state(global_id, |state: Option<Entity<S>>, window| {
2697                if let Some(state) = state {
2698                    (state.clone(), state)
2699                } else {
2700                    let new_state = cx.new(|cx| init(window, cx));
2701                    cx.observe(&new_state, move |_, cx| {
2702                        cx.notify(current_view);
2703                    })
2704                    .detach();
2705                    (new_state.clone(), new_state)
2706                }
2707            })
2708        })
2709    }
2710
2711    /// Immediately push an element ID onto the stack. Useful for simplifying IDs in lists
2712    pub fn with_id<R>(&mut self, id: impl Into<ElementId>, f: impl FnOnce(&mut Self) -> R) -> R {
2713        self.with_global_id(id.into(), |_, window| f(window))
2714    }
2715
2716    /// Use a piece of state that exists as long this element is being rendered in consecutive frames, without needing to specify a key
2717    ///
2718    /// NOTE: This method uses the location of the caller to generate an ID for this state.
2719    ///       If this is not sufficient to identify your state (e.g. you're rendering a list item),
2720    ///       you can provide a custom ElementID using the `use_keyed_state` method.
2721    #[track_caller]
2722    pub fn use_state<S: 'static>(
2723        &mut self,
2724        cx: &mut App,
2725        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2726    ) -> Entity<S> {
2727        self.use_keyed_state(
2728            ElementId::CodeLocation(*core::panic::Location::caller()),
2729            cx,
2730            init,
2731        )
2732    }
2733
2734    /// Updates or initializes state for an element with the given id that lives across multiple
2735    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2736    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2737    /// when drawing the next frame. This method should only be called as part of element drawing.
2738    pub fn with_element_state<S, R>(
2739        &mut self,
2740        global_id: &GlobalElementId,
2741        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2742    ) -> R
2743    where
2744        S: 'static,
2745    {
2746        self.invalidator.debug_assert_paint_or_prepaint();
2747
2748        let key = (global_id.clone(), TypeId::of::<S>());
2749        self.next_frame.accessed_element_states.push(key.clone());
2750
2751        if let Some(any) = self
2752            .next_frame
2753            .element_states
2754            .remove(&key)
2755            .or_else(|| self.rendered_frame.element_states.remove(&key))
2756        {
2757            let ElementStateBox {
2758                inner,
2759                #[cfg(debug_assertions)]
2760                type_name,
2761            } = any;
2762            // Using the extra inner option to avoid needing to reallocate a new box.
2763            let mut state_box = inner
2764                .downcast::<Option<S>>()
2765                .map_err(|_| {
2766                    #[cfg(debug_assertions)]
2767                    {
2768                        anyhow::anyhow!(
2769                            "invalid element state type for id, requested {:?}, actual: {:?}",
2770                            std::any::type_name::<S>(),
2771                            type_name
2772                        )
2773                    }
2774
2775                    #[cfg(not(debug_assertions))]
2776                    {
2777                        anyhow::anyhow!(
2778                            "invalid element state type for id, requested {:?}",
2779                            std::any::type_name::<S>(),
2780                        )
2781                    }
2782                })
2783                .unwrap();
2784
2785            let state = state_box.take().expect(
2786                "reentrant call to with_element_state for the same state type and element id",
2787            );
2788            let (result, state) = f(Some(state), self);
2789            state_box.replace(state);
2790            self.next_frame.element_states.insert(
2791                key,
2792                ElementStateBox {
2793                    inner: state_box,
2794                    #[cfg(debug_assertions)]
2795                    type_name,
2796                },
2797            );
2798            result
2799        } else {
2800            let (result, state) = f(None, self);
2801            self.next_frame.element_states.insert(
2802                key,
2803                ElementStateBox {
2804                    inner: Box::new(Some(state)),
2805                    #[cfg(debug_assertions)]
2806                    type_name: std::any::type_name::<S>(),
2807                },
2808            );
2809            result
2810        }
2811    }
2812
2813    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2814    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2815    /// when the element is guaranteed to have an id.
2816    ///
2817    /// The first option means 'no ID provided'
2818    /// The second option means 'not yet initialized'
2819    pub fn with_optional_element_state<S, R>(
2820        &mut self,
2821        global_id: Option<&GlobalElementId>,
2822        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2823    ) -> R
2824    where
2825        S: 'static,
2826    {
2827        self.invalidator.debug_assert_paint_or_prepaint();
2828
2829        if let Some(global_id) = global_id {
2830            self.with_element_state(global_id, |state, cx| {
2831                let (result, state) = f(Some(state), cx);
2832                let state =
2833                    state.expect("you must return some state when you pass some element id");
2834                (result, state)
2835            })
2836        } else {
2837            let (result, state) = f(None, self);
2838            debug_assert!(
2839                state.is_none(),
2840                "you must not return an element state when passing None for the global id"
2841            );
2842            result
2843        }
2844    }
2845
2846    /// Executes the given closure within the context of a tab group.
2847    #[inline]
2848    pub fn with_tab_group<R>(&mut self, index: Option<isize>, f: impl FnOnce(&mut Self) -> R) -> R {
2849        if let Some(index) = index {
2850            self.next_frame.tab_stops.begin_group(index);
2851            let result = f(self);
2852            self.next_frame.tab_stops.end_group();
2853            result
2854        } else {
2855            f(self)
2856        }
2857    }
2858
2859    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2860    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2861    /// with higher values being drawn on top.
2862    ///
2863    /// This method should only be called as part of the prepaint phase of element drawing.
2864    pub fn defer_draw(
2865        &mut self,
2866        element: AnyElement,
2867        absolute_offset: Point<Pixels>,
2868        priority: usize,
2869    ) {
2870        self.invalidator.debug_assert_prepaint();
2871        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2872        self.next_frame.deferred_draws.push(DeferredDraw {
2873            current_view: self.current_view(),
2874            parent_node,
2875            element_id_stack: self.element_id_stack.clone(),
2876            text_style_stack: self.text_style_stack.clone(),
2877            priority,
2878            element: Some(element),
2879            absolute_offset,
2880            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2881            paint_range: PaintIndex::default()..PaintIndex::default(),
2882        });
2883    }
2884
2885    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2886    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2887    /// for performance reasons.
2888    ///
2889    /// This method should only be called as part of the paint phase of element drawing.
2890    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2891        self.invalidator.debug_assert_paint();
2892
2893        let scale_factor = self.scale_factor();
2894        let content_mask = self.content_mask();
2895        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2896        if !clipped_bounds.is_empty() {
2897            self.next_frame
2898                .scene
2899                .push_layer(clipped_bounds.scale(scale_factor));
2900        }
2901
2902        let result = f(self);
2903
2904        if !clipped_bounds.is_empty() {
2905            self.next_frame.scene.pop_layer();
2906        }
2907
2908        result
2909    }
2910
2911    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2912    ///
2913    /// This method should only be called as part of the paint phase of element drawing.
2914    pub fn paint_shadows(
2915        &mut self,
2916        bounds: Bounds<Pixels>,
2917        corner_radii: Corners<Pixels>,
2918        shadows: &[BoxShadow],
2919    ) {
2920        self.invalidator.debug_assert_paint();
2921
2922        let scale_factor = self.scale_factor();
2923        let content_mask = self.content_mask();
2924        let opacity = self.element_opacity();
2925        for shadow in shadows {
2926            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2927            self.next_frame.scene.insert_primitive(Shadow {
2928                order: 0,
2929                blur_radius: shadow.blur_radius.scale(scale_factor),
2930                bounds: shadow_bounds.scale(scale_factor),
2931                content_mask: content_mask.scale(scale_factor),
2932                corner_radii: corner_radii.scale(scale_factor),
2933                color: shadow.color.opacity(opacity),
2934            });
2935        }
2936    }
2937
2938    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2939    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2940    /// see [`fill`], [`outline`], and [`quad`] to construct this type.
2941    ///
2942    /// This method should only be called as part of the paint phase of element drawing.
2943    ///
2944    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2945    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2946    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2947    pub fn paint_quad(&mut self, quad: PaintQuad) {
2948        self.invalidator.debug_assert_paint();
2949
2950        let scale_factor = self.scale_factor();
2951        let content_mask = self.content_mask();
2952        let opacity = self.element_opacity();
2953        self.next_frame.scene.insert_primitive(Quad {
2954            order: 0,
2955            bounds: quad.bounds.scale(scale_factor),
2956            content_mask: content_mask.scale(scale_factor),
2957            background: quad.background.opacity(opacity),
2958            border_color: quad.border_color.opacity(opacity),
2959            corner_radii: quad.corner_radii.scale(scale_factor),
2960            border_widths: quad.border_widths.scale(scale_factor),
2961            border_style: quad.border_style,
2962        });
2963    }
2964
2965    /// Paint the given `Path` into the scene for the next frame at the current z-index.
2966    ///
2967    /// This method should only be called as part of the paint phase of element drawing.
2968    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2969        self.invalidator.debug_assert_paint();
2970
2971        let scale_factor = self.scale_factor();
2972        let content_mask = self.content_mask();
2973        let opacity = self.element_opacity();
2974        path.content_mask = content_mask;
2975        let color: Background = color.into();
2976        path.color = color.opacity(opacity);
2977        self.next_frame
2978            .scene
2979            .insert_primitive(path.scale(scale_factor));
2980    }
2981
2982    /// Paint an underline into the scene for the next frame at the current z-index.
2983    ///
2984    /// This method should only be called as part of the paint phase of element drawing.
2985    pub fn paint_underline(
2986        &mut self,
2987        origin: Point<Pixels>,
2988        width: Pixels,
2989        style: &UnderlineStyle,
2990    ) {
2991        self.invalidator.debug_assert_paint();
2992
2993        let scale_factor = self.scale_factor();
2994        let height = if style.wavy {
2995            style.thickness * 3.
2996        } else {
2997            style.thickness
2998        };
2999        let bounds = Bounds {
3000            origin,
3001            size: size(width, height),
3002        };
3003        let content_mask = self.content_mask();
3004        let element_opacity = self.element_opacity();
3005
3006        self.next_frame.scene.insert_primitive(Underline {
3007            order: 0,
3008            pad: 0,
3009            bounds: bounds.scale(scale_factor),
3010            content_mask: content_mask.scale(scale_factor),
3011            color: style.color.unwrap_or_default().opacity(element_opacity),
3012            thickness: style.thickness.scale(scale_factor),
3013            wavy: if style.wavy { 1 } else { 0 },
3014        });
3015    }
3016
3017    /// Paint a strikethrough into the scene for the next frame at the current z-index.
3018    ///
3019    /// This method should only be called as part of the paint phase of element drawing.
3020    pub fn paint_strikethrough(
3021        &mut self,
3022        origin: Point<Pixels>,
3023        width: Pixels,
3024        style: &StrikethroughStyle,
3025    ) {
3026        self.invalidator.debug_assert_paint();
3027
3028        let scale_factor = self.scale_factor();
3029        let height = style.thickness;
3030        let bounds = Bounds {
3031            origin,
3032            size: size(width, height),
3033        };
3034        let content_mask = self.content_mask();
3035        let opacity = self.element_opacity();
3036
3037        self.next_frame.scene.insert_primitive(Underline {
3038            order: 0,
3039            pad: 0,
3040            bounds: bounds.scale(scale_factor),
3041            content_mask: content_mask.scale(scale_factor),
3042            thickness: style.thickness.scale(scale_factor),
3043            color: style.color.unwrap_or_default().opacity(opacity),
3044            wavy: 0,
3045        });
3046    }
3047
3048    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
3049    ///
3050    /// The y component of the origin is the baseline of the glyph.
3051    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3052    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3053    /// This method is only useful if you need to paint a single glyph that has already been shaped.
3054    ///
3055    /// This method should only be called as part of the paint phase of element drawing.
3056    pub fn paint_glyph(
3057        &mut self,
3058        origin: Point<Pixels>,
3059        font_id: FontId,
3060        glyph_id: GlyphId,
3061        font_size: Pixels,
3062        color: Hsla,
3063    ) -> Result<()> {
3064        self.invalidator.debug_assert_paint();
3065
3066        let element_opacity = self.element_opacity();
3067        let scale_factor = self.scale_factor();
3068        let glyph_origin = origin.scale(scale_factor);
3069
3070        let subpixel_variant = Point {
3071            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS_X as f32).floor() as u8,
3072            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS_Y as f32).floor() as u8,
3073        };
3074        let params = RenderGlyphParams {
3075            font_id,
3076            glyph_id,
3077            font_size,
3078            subpixel_variant,
3079            scale_factor,
3080            is_emoji: false,
3081        };
3082
3083        let raster_bounds = self.text_system().raster_bounds(&params)?;
3084        if !raster_bounds.is_zero() {
3085            let tile = self
3086                .sprite_atlas
3087                .get_or_insert_with(&params.clone().into(), &mut || {
3088                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3089                    Ok(Some((size, Cow::Owned(bytes))))
3090                })?
3091                .expect("Callback above only errors or returns Some");
3092            let bounds = Bounds {
3093                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3094                size: tile.bounds.size.map(Into::into),
3095            };
3096            let content_mask = self.content_mask().scale(scale_factor);
3097            self.next_frame.scene.insert_primitive(MonochromeSprite {
3098                order: 0,
3099                pad: 0,
3100                bounds,
3101                content_mask,
3102                color: color.opacity(element_opacity),
3103                tile,
3104                transformation: TransformationMatrix::unit(),
3105            });
3106        }
3107        Ok(())
3108    }
3109
3110    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
3111    ///
3112    /// The y component of the origin is the baseline of the glyph.
3113    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3114    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3115    /// This method is only useful if you need to paint a single emoji that has already been shaped.
3116    ///
3117    /// This method should only be called as part of the paint phase of element drawing.
3118    pub fn paint_emoji(
3119        &mut self,
3120        origin: Point<Pixels>,
3121        font_id: FontId,
3122        glyph_id: GlyphId,
3123        font_size: Pixels,
3124    ) -> Result<()> {
3125        self.invalidator.debug_assert_paint();
3126
3127        let scale_factor = self.scale_factor();
3128        let glyph_origin = origin.scale(scale_factor);
3129        let params = RenderGlyphParams {
3130            font_id,
3131            glyph_id,
3132            font_size,
3133            // We don't render emojis with subpixel variants.
3134            subpixel_variant: Default::default(),
3135            scale_factor,
3136            is_emoji: true,
3137        };
3138
3139        let raster_bounds = self.text_system().raster_bounds(&params)?;
3140        if !raster_bounds.is_zero() {
3141            let tile = self
3142                .sprite_atlas
3143                .get_or_insert_with(&params.clone().into(), &mut || {
3144                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3145                    Ok(Some((size, Cow::Owned(bytes))))
3146                })?
3147                .expect("Callback above only errors or returns Some");
3148
3149            let bounds = Bounds {
3150                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3151                size: tile.bounds.size.map(Into::into),
3152            };
3153            let content_mask = self.content_mask().scale(scale_factor);
3154            let opacity = self.element_opacity();
3155
3156            self.next_frame.scene.insert_primitive(PolychromeSprite {
3157                order: 0,
3158                pad: 0,
3159                grayscale: false,
3160                bounds,
3161                corner_radii: Default::default(),
3162                content_mask,
3163                tile,
3164                opacity,
3165            });
3166        }
3167        Ok(())
3168    }
3169
3170    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
3171    ///
3172    /// This method should only be called as part of the paint phase of element drawing.
3173    pub fn paint_svg(
3174        &mut self,
3175        bounds: Bounds<Pixels>,
3176        path: SharedString,
3177        mut data: Option<&[u8]>,
3178        transformation: TransformationMatrix,
3179        color: Hsla,
3180        cx: &App,
3181    ) -> Result<()> {
3182        self.invalidator.debug_assert_paint();
3183
3184        let element_opacity = self.element_opacity();
3185        let scale_factor = self.scale_factor();
3186
3187        let bounds = bounds.scale(scale_factor);
3188        let params = RenderSvgParams {
3189            path,
3190            size: bounds.size.map(|pixels| {
3191                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
3192            }),
3193        };
3194
3195        let Some(tile) =
3196            self.sprite_atlas
3197                .get_or_insert_with(&params.clone().into(), &mut || {
3198                    let Some((size, bytes)) = cx.svg_renderer.render_alpha_mask(&params, data)?
3199                    else {
3200                        return Ok(None);
3201                    };
3202                    Ok(Some((size, Cow::Owned(bytes))))
3203                })?
3204        else {
3205            return Ok(());
3206        };
3207        let content_mask = self.content_mask().scale(scale_factor);
3208        let svg_bounds = Bounds {
3209            origin: bounds.center()
3210                - Point::new(
3211                    ScaledPixels(tile.bounds.size.width.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3212                    ScaledPixels(tile.bounds.size.height.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3213                ),
3214            size: tile
3215                .bounds
3216                .size
3217                .map(|value| ScaledPixels(value.0 as f32 / SMOOTH_SVG_SCALE_FACTOR)),
3218        };
3219
3220        self.next_frame.scene.insert_primitive(MonochromeSprite {
3221            order: 0,
3222            pad: 0,
3223            bounds: svg_bounds
3224                .map_origin(|origin| origin.round())
3225                .map_size(|size| size.ceil()),
3226            content_mask,
3227            color: color.opacity(element_opacity),
3228            tile,
3229            transformation,
3230        });
3231
3232        Ok(())
3233    }
3234
3235    /// Paint an image into the scene for the next frame at the current z-index.
3236    /// This method will panic if the frame_index is not valid
3237    ///
3238    /// This method should only be called as part of the paint phase of element drawing.
3239    pub fn paint_image(
3240        &mut self,
3241        bounds: Bounds<Pixels>,
3242        corner_radii: Corners<Pixels>,
3243        data: Arc<RenderImage>,
3244        frame_index: usize,
3245        grayscale: bool,
3246    ) -> Result<()> {
3247        self.invalidator.debug_assert_paint();
3248
3249        let scale_factor = self.scale_factor();
3250        let bounds = bounds.scale(scale_factor);
3251        let params = RenderImageParams {
3252            image_id: data.id,
3253            frame_index,
3254        };
3255
3256        let tile = self
3257            .sprite_atlas
3258            .get_or_insert_with(&params.into(), &mut || {
3259                Ok(Some((
3260                    data.size(frame_index),
3261                    Cow::Borrowed(
3262                        data.as_bytes(frame_index)
3263                            .expect("It's the caller's job to pass a valid frame index"),
3264                    ),
3265                )))
3266            })?
3267            .expect("Callback above only returns Some");
3268        let content_mask = self.content_mask().scale(scale_factor);
3269        let corner_radii = corner_radii.scale(scale_factor);
3270        let opacity = self.element_opacity();
3271
3272        self.next_frame.scene.insert_primitive(PolychromeSprite {
3273            order: 0,
3274            pad: 0,
3275            grayscale,
3276            bounds: bounds
3277                .map_origin(|origin| origin.floor())
3278                .map_size(|size| size.ceil()),
3279            content_mask,
3280            corner_radii,
3281            tile,
3282            opacity,
3283        });
3284        Ok(())
3285    }
3286
3287    /// Paint a surface into the scene for the next frame at the current z-index.
3288    ///
3289    /// This method should only be called as part of the paint phase of element drawing.
3290    #[cfg(target_os = "macos")]
3291    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
3292        use crate::PaintSurface;
3293
3294        self.invalidator.debug_assert_paint();
3295
3296        let scale_factor = self.scale_factor();
3297        let bounds = bounds.scale(scale_factor);
3298        let content_mask = self.content_mask().scale(scale_factor);
3299        self.next_frame.scene.insert_primitive(PaintSurface {
3300            order: 0,
3301            bounds,
3302            content_mask,
3303            image_buffer,
3304        });
3305    }
3306
3307    /// Removes an image from the sprite atlas.
3308    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
3309        for frame_index in 0..data.frame_count() {
3310            let params = RenderImageParams {
3311                image_id: data.id,
3312                frame_index,
3313            };
3314
3315            self.sprite_atlas.remove(&params.clone().into());
3316        }
3317
3318        Ok(())
3319    }
3320
3321    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
3322    /// layout is being requested, along with the layout ids of any children. This method is called during
3323    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
3324    ///
3325    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3326    #[must_use]
3327    pub fn request_layout(
3328        &mut self,
3329        style: Style,
3330        children: impl IntoIterator<Item = LayoutId>,
3331        cx: &mut App,
3332    ) -> LayoutId {
3333        self.invalidator.debug_assert_prepaint();
3334
3335        cx.layout_id_buffer.clear();
3336        cx.layout_id_buffer.extend(children);
3337        let rem_size = self.rem_size();
3338        let scale_factor = self.scale_factor();
3339
3340        self.layout_engine.as_mut().unwrap().request_layout(
3341            style,
3342            rem_size,
3343            scale_factor,
3344            &cx.layout_id_buffer,
3345        )
3346    }
3347
3348    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3349    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3350    /// determine the element's size. One place this is used internally is when measuring text.
3351    ///
3352    /// The given closure is invoked at layout time with the known dimensions and available space and
3353    /// returns a `Size`.
3354    ///
3355    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3356    pub fn request_measured_layout<F>(&mut self, style: Style, measure: F) -> LayoutId
3357    where
3358        F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3359            + 'static,
3360    {
3361        self.invalidator.debug_assert_prepaint();
3362
3363        let rem_size = self.rem_size();
3364        let scale_factor = self.scale_factor();
3365        self.layout_engine
3366            .as_mut()
3367            .unwrap()
3368            .request_measured_layout(style, rem_size, scale_factor, measure)
3369    }
3370
3371    /// Compute the layout for the given id within the given available space.
3372    /// This method is called for its side effect, typically by the framework prior to painting.
3373    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3374    ///
3375    /// This method should only be called as part of the prepaint phase of element drawing.
3376    pub fn compute_layout(
3377        &mut self,
3378        layout_id: LayoutId,
3379        available_space: Size<AvailableSpace>,
3380        cx: &mut App,
3381    ) {
3382        self.invalidator.debug_assert_prepaint();
3383
3384        let mut layout_engine = self.layout_engine.take().unwrap();
3385        layout_engine.compute_layout(layout_id, available_space, self, cx);
3386        self.layout_engine = Some(layout_engine);
3387    }
3388
3389    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3390    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3391    ///
3392    /// This method should only be called as part of element drawing.
3393    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3394        self.invalidator.debug_assert_prepaint();
3395
3396        let scale_factor = self.scale_factor();
3397        let mut bounds = self
3398            .layout_engine
3399            .as_mut()
3400            .unwrap()
3401            .layout_bounds(layout_id, scale_factor)
3402            .map(Into::into);
3403        bounds.origin += self.element_offset();
3404        bounds
3405    }
3406
3407    /// This method should be called during `prepaint`. You can use
3408    /// the returned [Hitbox] during `paint` or in an event handler
3409    /// to determine whether the inserted hitbox was the topmost.
3410    ///
3411    /// This method should only be called as part of the prepaint phase of element drawing.
3412    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3413        self.invalidator.debug_assert_prepaint();
3414
3415        let content_mask = self.content_mask();
3416        let mut id = self.next_hitbox_id;
3417        self.next_hitbox_id = self.next_hitbox_id.next();
3418        let hitbox = Hitbox {
3419            id,
3420            bounds,
3421            content_mask,
3422            behavior,
3423        };
3424        self.next_frame.hitboxes.push(hitbox.clone());
3425        hitbox
3426    }
3427
3428    /// Set a hitbox which will act as a control area of the platform window.
3429    ///
3430    /// This method should only be called as part of the paint phase of element drawing.
3431    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3432        self.invalidator.debug_assert_paint();
3433        self.next_frame.window_control_hitboxes.push((area, hitbox));
3434    }
3435
3436    /// Sets the key context for the current element. This context will be used to translate
3437    /// keybindings into actions.
3438    ///
3439    /// This method should only be called as part of the paint phase of element drawing.
3440    pub fn set_key_context(&mut self, context: KeyContext) {
3441        self.invalidator.debug_assert_paint();
3442        self.next_frame.dispatch_tree.set_key_context(context);
3443    }
3444
3445    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3446    /// and keyboard event dispatch for the element.
3447    ///
3448    /// This method should only be called as part of the prepaint phase of element drawing.
3449    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3450        self.invalidator.debug_assert_prepaint();
3451        if focus_handle.is_focused(self) {
3452            self.next_frame.focus = Some(focus_handle.id);
3453        }
3454        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3455    }
3456
3457    /// Sets the view id for the current element, which will be used to manage view caching.
3458    ///
3459    /// This method should only be called as part of element prepaint. We plan on removing this
3460    /// method eventually when we solve some issues that require us to construct editor elements
3461    /// directly instead of always using editors via views.
3462    pub fn set_view_id(&mut self, view_id: EntityId) {
3463        self.invalidator.debug_assert_prepaint();
3464        self.next_frame.dispatch_tree.set_view_id(view_id);
3465    }
3466
3467    /// Get the entity ID for the currently rendering view
3468    pub fn current_view(&self) -> EntityId {
3469        self.invalidator.debug_assert_paint_or_prepaint();
3470        self.rendered_entity_stack.last().copied().unwrap()
3471    }
3472
3473    pub(crate) fn with_rendered_view<R>(
3474        &mut self,
3475        id: EntityId,
3476        f: impl FnOnce(&mut Self) -> R,
3477    ) -> R {
3478        self.rendered_entity_stack.push(id);
3479        let result = f(self);
3480        self.rendered_entity_stack.pop();
3481        result
3482    }
3483
3484    /// Executes the provided function with the specified image cache.
3485    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3486    where
3487        F: FnOnce(&mut Self) -> R,
3488    {
3489        if let Some(image_cache) = image_cache {
3490            self.image_cache_stack.push(image_cache);
3491            let result = f(self);
3492            self.image_cache_stack.pop();
3493            result
3494        } else {
3495            f(self)
3496        }
3497    }
3498
3499    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3500    /// platform to receive textual input with proper integration with concerns such
3501    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3502    /// rendered.
3503    ///
3504    /// This method should only be called as part of the paint phase of element drawing.
3505    ///
3506    /// [element_input_handler]: crate::ElementInputHandler
3507    pub fn handle_input(
3508        &mut self,
3509        focus_handle: &FocusHandle,
3510        input_handler: impl InputHandler,
3511        cx: &App,
3512    ) {
3513        self.invalidator.debug_assert_paint();
3514
3515        if focus_handle.is_focused(self) {
3516            let cx = self.to_async(cx);
3517            self.next_frame
3518                .input_handlers
3519                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3520        }
3521    }
3522
3523    /// Register a mouse event listener on the window for the next frame. The type of event
3524    /// is determined by the first parameter of the given listener. When the next frame is rendered
3525    /// the listener will be cleared.
3526    ///
3527    /// This method should only be called as part of the paint phase of element drawing.
3528    pub fn on_mouse_event<Event: MouseEvent>(
3529        &mut self,
3530        mut listener: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3531    ) {
3532        self.invalidator.debug_assert_paint();
3533
3534        self.next_frame.mouse_listeners.push(Some(Box::new(
3535            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3536                if let Some(event) = event.downcast_ref() {
3537                    listener(event, phase, window, cx)
3538                }
3539            },
3540        )));
3541    }
3542
3543    /// Register a key event listener on this node for the next frame. The type of event
3544    /// is determined by the first parameter of the given listener. When the next frame is rendered
3545    /// the listener will be cleared.
3546    ///
3547    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3548    /// a specific need to register a listener yourself.
3549    ///
3550    /// This method should only be called as part of the paint phase of element drawing.
3551    pub fn on_key_event<Event: KeyEvent>(
3552        &mut self,
3553        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3554    ) {
3555        self.invalidator.debug_assert_paint();
3556
3557        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3558            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3559                if let Some(event) = event.downcast_ref::<Event>() {
3560                    listener(event, phase, window, cx)
3561                }
3562            },
3563        ));
3564    }
3565
3566    /// Register a modifiers changed event listener on the window for the next frame.
3567    ///
3568    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3569    /// a specific need to register a global listener.
3570    ///
3571    /// This method should only be called as part of the paint phase of element drawing.
3572    pub fn on_modifiers_changed(
3573        &mut self,
3574        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3575    ) {
3576        self.invalidator.debug_assert_paint();
3577
3578        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3579            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3580                listener(event, window, cx)
3581            },
3582        ));
3583    }
3584
3585    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3586    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3587    /// Returns a subscription and persists until the subscription is dropped.
3588    pub fn on_focus_in(
3589        &mut self,
3590        handle: &FocusHandle,
3591        cx: &mut App,
3592        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3593    ) -> Subscription {
3594        let focus_id = handle.id;
3595        let (subscription, activate) =
3596            self.new_focus_listener(Box::new(move |event, window, cx| {
3597                if event.is_focus_in(focus_id) {
3598                    listener(window, cx);
3599                }
3600                true
3601            }));
3602        cx.defer(move |_| activate());
3603        subscription
3604    }
3605
3606    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3607    /// Returns a subscription and persists until the subscription is dropped.
3608    pub fn on_focus_out(
3609        &mut self,
3610        handle: &FocusHandle,
3611        cx: &mut App,
3612        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3613    ) -> Subscription {
3614        let focus_id = handle.id;
3615        let (subscription, activate) =
3616            self.new_focus_listener(Box::new(move |event, window, cx| {
3617                if let Some(blurred_id) = event.previous_focus_path.last().copied()
3618                    && event.is_focus_out(focus_id)
3619                {
3620                    let event = FocusOutEvent {
3621                        blurred: WeakFocusHandle {
3622                            id: blurred_id,
3623                            handles: Arc::downgrade(&cx.focus_handles),
3624                        },
3625                    };
3626                    listener(event, window, cx)
3627                }
3628                true
3629            }));
3630        cx.defer(move |_| activate());
3631        subscription
3632    }
3633
3634    fn reset_cursor_style(&self, cx: &mut App) {
3635        // Set the cursor only if we're the active window.
3636        if self.is_window_hovered() {
3637            let style = self
3638                .rendered_frame
3639                .cursor_style(self)
3640                .unwrap_or(CursorStyle::Arrow);
3641            cx.platform.set_cursor_style(style);
3642        }
3643    }
3644
3645    /// Dispatch a given keystroke as though the user had typed it.
3646    /// You can create a keystroke with Keystroke::parse("").
3647    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3648        let keystroke = keystroke.with_simulated_ime();
3649        let result = self.dispatch_event(
3650            PlatformInput::KeyDown(KeyDownEvent {
3651                keystroke: keystroke.clone(),
3652                is_held: false,
3653                prefer_character_input: false,
3654            }),
3655            cx,
3656        );
3657        if !result.propagate {
3658            return true;
3659        }
3660
3661        if let Some(input) = keystroke.key_char
3662            && let Some(mut input_handler) = self.platform_window.take_input_handler()
3663        {
3664            input_handler.dispatch_input(&input, self, cx);
3665            self.platform_window.set_input_handler(input_handler);
3666            return true;
3667        }
3668
3669        false
3670    }
3671
3672    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3673    /// binding for the action (last binding added to the keymap).
3674    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3675        self.highest_precedence_binding_for_action(action)
3676            .map(|binding| {
3677                binding
3678                    .keystrokes()
3679                    .iter()
3680                    .map(ToString::to_string)
3681                    .collect::<Vec<_>>()
3682                    .join(" ")
3683            })
3684            .unwrap_or_else(|| action.name().to_string())
3685    }
3686
3687    /// Dispatch a mouse or keyboard event on the window.
3688    #[profiling::function]
3689    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3690        self.last_input_timestamp.set(Instant::now());
3691
3692        // Track whether this input was keyboard-based for focus-visible styling
3693        self.last_input_modality = match &event {
3694            PlatformInput::KeyDown(_) | PlatformInput::ModifiersChanged(_) => {
3695                InputModality::Keyboard
3696            }
3697            PlatformInput::MouseDown(e) if e.is_focusing() => InputModality::Mouse,
3698            _ => self.last_input_modality,
3699        };
3700
3701        // Handlers may set this to false by calling `stop_propagation`.
3702        cx.propagate_event = true;
3703        // Handlers may set this to true by calling `prevent_default`.
3704        self.default_prevented = false;
3705
3706        let event = match event {
3707            // Track the mouse position with our own state, since accessing the platform
3708            // API for the mouse position can only occur on the main thread.
3709            PlatformInput::MouseMove(mouse_move) => {
3710                self.mouse_position = mouse_move.position;
3711                self.modifiers = mouse_move.modifiers;
3712                PlatformInput::MouseMove(mouse_move)
3713            }
3714            PlatformInput::MouseDown(mouse_down) => {
3715                self.mouse_position = mouse_down.position;
3716                self.modifiers = mouse_down.modifiers;
3717                PlatformInput::MouseDown(mouse_down)
3718            }
3719            PlatformInput::MouseUp(mouse_up) => {
3720                self.mouse_position = mouse_up.position;
3721                self.modifiers = mouse_up.modifiers;
3722                PlatformInput::MouseUp(mouse_up)
3723            }
3724            PlatformInput::MousePressure(mouse_pressure) => {
3725                PlatformInput::MousePressure(mouse_pressure)
3726            }
3727            PlatformInput::MouseExited(mouse_exited) => {
3728                self.modifiers = mouse_exited.modifiers;
3729                PlatformInput::MouseExited(mouse_exited)
3730            }
3731            PlatformInput::ModifiersChanged(modifiers_changed) => {
3732                self.modifiers = modifiers_changed.modifiers;
3733                self.capslock = modifiers_changed.capslock;
3734                PlatformInput::ModifiersChanged(modifiers_changed)
3735            }
3736            PlatformInput::ScrollWheel(scroll_wheel) => {
3737                self.mouse_position = scroll_wheel.position;
3738                self.modifiers = scroll_wheel.modifiers;
3739                PlatformInput::ScrollWheel(scroll_wheel)
3740            }
3741            // Translate dragging and dropping of external files from the operating system
3742            // to internal drag and drop events.
3743            PlatformInput::FileDrop(file_drop) => match file_drop {
3744                FileDropEvent::Entered { position, paths } => {
3745                    self.mouse_position = position;
3746                    if cx.active_drag.is_none() {
3747                        cx.active_drag = Some(AnyDrag {
3748                            value: Arc::new(paths.clone()),
3749                            view: cx.new(|_| paths).into(),
3750                            cursor_offset: position,
3751                            cursor_style: None,
3752                        });
3753                    }
3754                    PlatformInput::MouseMove(MouseMoveEvent {
3755                        position,
3756                        pressed_button: Some(MouseButton::Left),
3757                        modifiers: Modifiers::default(),
3758                    })
3759                }
3760                FileDropEvent::Pending { position } => {
3761                    self.mouse_position = position;
3762                    PlatformInput::MouseMove(MouseMoveEvent {
3763                        position,
3764                        pressed_button: Some(MouseButton::Left),
3765                        modifiers: Modifiers::default(),
3766                    })
3767                }
3768                FileDropEvent::Submit { position } => {
3769                    cx.activate(true);
3770                    self.mouse_position = position;
3771                    PlatformInput::MouseUp(MouseUpEvent {
3772                        button: MouseButton::Left,
3773                        position,
3774                        modifiers: Modifiers::default(),
3775                        click_count: 1,
3776                    })
3777                }
3778                FileDropEvent::Exited => {
3779                    cx.active_drag.take();
3780                    PlatformInput::FileDrop(FileDropEvent::Exited)
3781                }
3782            },
3783            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3784        };
3785
3786        if let Some(any_mouse_event) = event.mouse_event() {
3787            self.dispatch_mouse_event(any_mouse_event, cx);
3788        } else if let Some(any_key_event) = event.keyboard_event() {
3789            self.dispatch_key_event(any_key_event, cx);
3790        }
3791
3792        DispatchEventResult {
3793            propagate: cx.propagate_event,
3794            default_prevented: self.default_prevented,
3795        }
3796    }
3797
3798    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3799        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3800        if hit_test != self.mouse_hit_test {
3801            self.mouse_hit_test = hit_test;
3802            self.reset_cursor_style(cx);
3803        }
3804
3805        #[cfg(any(feature = "inspector", debug_assertions))]
3806        if self.is_inspector_picking(cx) {
3807            self.handle_inspector_mouse_event(event, cx);
3808            // When inspector is picking, all other mouse handling is skipped.
3809            return;
3810        }
3811
3812        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3813
3814        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3815        // special purposes, such as detecting events outside of a given Bounds.
3816        for listener in &mut mouse_listeners {
3817            let listener = listener.as_mut().unwrap();
3818            listener(event, DispatchPhase::Capture, self, cx);
3819            if !cx.propagate_event {
3820                break;
3821            }
3822        }
3823
3824        // Bubble phase, where most normal handlers do their work.
3825        if cx.propagate_event {
3826            for listener in mouse_listeners.iter_mut().rev() {
3827                let listener = listener.as_mut().unwrap();
3828                listener(event, DispatchPhase::Bubble, self, cx);
3829                if !cx.propagate_event {
3830                    break;
3831                }
3832            }
3833        }
3834
3835        self.rendered_frame.mouse_listeners = mouse_listeners;
3836
3837        if cx.has_active_drag() {
3838            if event.is::<MouseMoveEvent>() {
3839                // If this was a mouse move event, redraw the window so that the
3840                // active drag can follow the mouse cursor.
3841                self.refresh();
3842            } else if event.is::<MouseUpEvent>() {
3843                // If this was a mouse up event, cancel the active drag and redraw
3844                // the window.
3845                cx.active_drag = None;
3846                self.refresh();
3847            }
3848        }
3849    }
3850
3851    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3852        if self.invalidator.is_dirty() {
3853            self.draw(cx).clear();
3854        }
3855
3856        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3857        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3858
3859        let mut keystroke: Option<Keystroke> = None;
3860
3861        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3862            if event.modifiers.number_of_modifiers() == 0
3863                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3864                && !self.pending_modifier.saw_keystroke
3865            {
3866                let key = match self.pending_modifier.modifiers {
3867                    modifiers if modifiers.shift => Some("shift"),
3868                    modifiers if modifiers.control => Some("control"),
3869                    modifiers if modifiers.alt => Some("alt"),
3870                    modifiers if modifiers.platform => Some("platform"),
3871                    modifiers if modifiers.function => Some("function"),
3872                    _ => None,
3873                };
3874                if let Some(key) = key {
3875                    keystroke = Some(Keystroke {
3876                        key: key.to_string(),
3877                        key_char: None,
3878                        modifiers: Modifiers::default(),
3879                    });
3880                }
3881            }
3882
3883            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3884                && event.modifiers.number_of_modifiers() == 1
3885            {
3886                self.pending_modifier.saw_keystroke = false
3887            }
3888            self.pending_modifier.modifiers = event.modifiers
3889        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3890            self.pending_modifier.saw_keystroke = true;
3891            keystroke = Some(key_down_event.keystroke.clone());
3892        }
3893
3894        let Some(keystroke) = keystroke else {
3895            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3896            return;
3897        };
3898
3899        cx.propagate_event = true;
3900        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
3901        if !cx.propagate_event {
3902            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3903            return;
3904        }
3905
3906        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3907        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3908            currently_pending = PendingInput::default();
3909        }
3910
3911        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3912            currently_pending.keystrokes,
3913            keystroke,
3914            &dispatch_path,
3915        );
3916
3917        if !match_result.to_replay.is_empty() {
3918            self.replay_pending_input(match_result.to_replay, cx);
3919            cx.propagate_event = true;
3920        }
3921
3922        if !match_result.pending.is_empty() {
3923            currently_pending.timer.take();
3924            currently_pending.keystrokes = match_result.pending;
3925            currently_pending.focus = self.focus;
3926
3927            let text_input_requires_timeout = event
3928                .downcast_ref::<KeyDownEvent>()
3929                .filter(|key_down| key_down.keystroke.key_char.is_some())
3930                .and_then(|_| self.platform_window.take_input_handler())
3931                .map_or(false, |mut input_handler| {
3932                    let accepts = input_handler.accepts_text_input(self, cx);
3933                    self.platform_window.set_input_handler(input_handler);
3934                    accepts
3935                });
3936
3937            currently_pending.needs_timeout |=
3938                match_result.pending_has_binding || text_input_requires_timeout;
3939
3940            if currently_pending.needs_timeout {
3941                currently_pending.timer = Some(self.spawn(cx, async move |cx| {
3942                    cx.background_executor.timer(Duration::from_secs(1)).await;
3943                    cx.update(move |window, cx| {
3944                        let Some(currently_pending) = window
3945                            .pending_input
3946                            .take()
3947                            .filter(|pending| pending.focus == window.focus)
3948                        else {
3949                            return;
3950                        };
3951
3952                        let node_id = window.focus_node_id_in_rendered_frame(window.focus);
3953                        let dispatch_path =
3954                            window.rendered_frame.dispatch_tree.dispatch_path(node_id);
3955
3956                        let to_replay = window
3957                            .rendered_frame
3958                            .dispatch_tree
3959                            .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3960
3961                        window.pending_input_changed(cx);
3962                        window.replay_pending_input(to_replay, cx)
3963                    })
3964                    .log_err();
3965                }));
3966            } else {
3967                currently_pending.timer = None;
3968            }
3969            self.pending_input = Some(currently_pending);
3970            self.pending_input_changed(cx);
3971            cx.propagate_event = false;
3972            return;
3973        }
3974
3975        let skip_bindings = event
3976            .downcast_ref::<KeyDownEvent>()
3977            .filter(|key_down_event| key_down_event.prefer_character_input)
3978            .map(|_| {
3979                self.platform_window
3980                    .take_input_handler()
3981                    .map_or(false, |mut input_handler| {
3982                        let accepts = input_handler.accepts_text_input(self, cx);
3983                        self.platform_window.set_input_handler(input_handler);
3984                        // If modifiers are not excessive (e.g. AltGr), and the input handler is accepting text input,
3985                        // we prefer the text input over bindings.
3986                        accepts
3987                    })
3988            })
3989            .unwrap_or(false);
3990
3991        if !skip_bindings {
3992            for binding in match_result.bindings {
3993                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
3994                if !cx.propagate_event {
3995                    self.dispatch_keystroke_observers(
3996                        event,
3997                        Some(binding.action),
3998                        match_result.context_stack,
3999                        cx,
4000                    );
4001                    self.pending_input_changed(cx);
4002                    return;
4003                }
4004            }
4005        }
4006
4007        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
4008        self.pending_input_changed(cx);
4009    }
4010
4011    fn finish_dispatch_key_event(
4012        &mut self,
4013        event: &dyn Any,
4014        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
4015        context_stack: Vec<KeyContext>,
4016        cx: &mut App,
4017    ) {
4018        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
4019        if !cx.propagate_event {
4020            return;
4021        }
4022
4023        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
4024        if !cx.propagate_event {
4025            return;
4026        }
4027
4028        self.dispatch_keystroke_observers(event, None, context_stack, cx);
4029    }
4030
4031    fn pending_input_changed(&mut self, cx: &mut App) {
4032        self.pending_input_observers
4033            .clone()
4034            .retain(&(), |callback| callback(self, cx));
4035    }
4036
4037    fn dispatch_key_down_up_event(
4038        &mut self,
4039        event: &dyn Any,
4040        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4041        cx: &mut App,
4042    ) {
4043        // Capture phase
4044        for node_id in dispatch_path {
4045            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4046
4047            for key_listener in node.key_listeners.clone() {
4048                key_listener(event, DispatchPhase::Capture, self, cx);
4049                if !cx.propagate_event {
4050                    return;
4051                }
4052            }
4053        }
4054
4055        // Bubble phase
4056        for node_id in dispatch_path.iter().rev() {
4057            // Handle low level key events
4058            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4059            for key_listener in node.key_listeners.clone() {
4060                key_listener(event, DispatchPhase::Bubble, self, cx);
4061                if !cx.propagate_event {
4062                    return;
4063                }
4064            }
4065        }
4066    }
4067
4068    fn dispatch_modifiers_changed_event(
4069        &mut self,
4070        event: &dyn Any,
4071        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4072        cx: &mut App,
4073    ) {
4074        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
4075            return;
4076        };
4077        for node_id in dispatch_path.iter().rev() {
4078            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4079            for listener in node.modifiers_changed_listeners.clone() {
4080                listener(event, self, cx);
4081                if !cx.propagate_event {
4082                    return;
4083                }
4084            }
4085        }
4086    }
4087
4088    /// Determine whether a potential multi-stroke key binding is in progress on this window.
4089    pub fn has_pending_keystrokes(&self) -> bool {
4090        self.pending_input.is_some()
4091    }
4092
4093    pub(crate) fn clear_pending_keystrokes(&mut self) {
4094        self.pending_input.take();
4095    }
4096
4097    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
4098    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
4099        self.pending_input
4100            .as_ref()
4101            .map(|pending_input| pending_input.keystrokes.as_slice())
4102    }
4103
4104    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
4105        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4106        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4107
4108        'replay: for replay in replays {
4109            let event = KeyDownEvent {
4110                keystroke: replay.keystroke.clone(),
4111                is_held: false,
4112                prefer_character_input: true,
4113            };
4114
4115            cx.propagate_event = true;
4116            for binding in replay.bindings {
4117                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
4118                if !cx.propagate_event {
4119                    self.dispatch_keystroke_observers(
4120                        &event,
4121                        Some(binding.action),
4122                        Vec::default(),
4123                        cx,
4124                    );
4125                    continue 'replay;
4126                }
4127            }
4128
4129            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
4130            if !cx.propagate_event {
4131                continue 'replay;
4132            }
4133            if let Some(input) = replay.keystroke.key_char.as_ref().cloned()
4134                && let Some(mut input_handler) = self.platform_window.take_input_handler()
4135            {
4136                input_handler.dispatch_input(&input, self, cx);
4137                self.platform_window.set_input_handler(input_handler)
4138            }
4139        }
4140    }
4141
4142    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
4143        focus_id
4144            .and_then(|focus_id| {
4145                self.rendered_frame
4146                    .dispatch_tree
4147                    .focusable_node_id(focus_id)
4148            })
4149            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id())
4150    }
4151
4152    fn dispatch_action_on_node(
4153        &mut self,
4154        node_id: DispatchNodeId,
4155        action: &dyn Action,
4156        cx: &mut App,
4157    ) {
4158        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4159
4160        // Capture phase for global actions.
4161        cx.propagate_event = true;
4162        if let Some(mut global_listeners) = cx
4163            .global_action_listeners
4164            .remove(&action.as_any().type_id())
4165        {
4166            for listener in &global_listeners {
4167                listener(action.as_any(), DispatchPhase::Capture, cx);
4168                if !cx.propagate_event {
4169                    break;
4170                }
4171            }
4172
4173            global_listeners.extend(
4174                cx.global_action_listeners
4175                    .remove(&action.as_any().type_id())
4176                    .unwrap_or_default(),
4177            );
4178
4179            cx.global_action_listeners
4180                .insert(action.as_any().type_id(), global_listeners);
4181        }
4182
4183        if !cx.propagate_event {
4184            return;
4185        }
4186
4187        // Capture phase for window actions.
4188        for node_id in &dispatch_path {
4189            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4190            for DispatchActionListener {
4191                action_type,
4192                listener,
4193            } in node.action_listeners.clone()
4194            {
4195                let any_action = action.as_any();
4196                if action_type == any_action.type_id() {
4197                    listener(any_action, DispatchPhase::Capture, self, cx);
4198
4199                    if !cx.propagate_event {
4200                        return;
4201                    }
4202                }
4203            }
4204        }
4205
4206        // Bubble phase for window actions.
4207        for node_id in dispatch_path.iter().rev() {
4208            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4209            for DispatchActionListener {
4210                action_type,
4211                listener,
4212            } in node.action_listeners.clone()
4213            {
4214                let any_action = action.as_any();
4215                if action_type == any_action.type_id() {
4216                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4217                    listener(any_action, DispatchPhase::Bubble, self, cx);
4218
4219                    if !cx.propagate_event {
4220                        return;
4221                    }
4222                }
4223            }
4224        }
4225
4226        // Bubble phase for global actions.
4227        if let Some(mut global_listeners) = cx
4228            .global_action_listeners
4229            .remove(&action.as_any().type_id())
4230        {
4231            for listener in global_listeners.iter().rev() {
4232                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4233
4234                listener(action.as_any(), DispatchPhase::Bubble, cx);
4235                if !cx.propagate_event {
4236                    break;
4237                }
4238            }
4239
4240            global_listeners.extend(
4241                cx.global_action_listeners
4242                    .remove(&action.as_any().type_id())
4243                    .unwrap_or_default(),
4244            );
4245
4246            cx.global_action_listeners
4247                .insert(action.as_any().type_id(), global_listeners);
4248        }
4249    }
4250
4251    /// Register the given handler to be invoked whenever the global of the given type
4252    /// is updated.
4253    pub fn observe_global<G: Global>(
4254        &mut self,
4255        cx: &mut App,
4256        f: impl Fn(&mut Window, &mut App) + 'static,
4257    ) -> Subscription {
4258        let window_handle = self.handle;
4259        let (subscription, activate) = cx.global_observers.insert(
4260            TypeId::of::<G>(),
4261            Box::new(move |cx| {
4262                window_handle
4263                    .update(cx, |_, window, cx| f(window, cx))
4264                    .is_ok()
4265            }),
4266        );
4267        cx.defer(move |_| activate());
4268        subscription
4269    }
4270
4271    /// Focus the current window and bring it to the foreground at the platform level.
4272    pub fn activate_window(&self) {
4273        self.platform_window.activate();
4274    }
4275
4276    /// Minimize the current window at the platform level.
4277    pub fn minimize_window(&self) {
4278        self.platform_window.minimize();
4279    }
4280
4281    /// Toggle full screen status on the current window at the platform level.
4282    pub fn toggle_fullscreen(&self) {
4283        self.platform_window.toggle_fullscreen();
4284    }
4285
4286    /// Updates the IME panel position suggestions for languages like japanese, chinese.
4287    pub fn invalidate_character_coordinates(&self) {
4288        self.on_next_frame(|window, cx| {
4289            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
4290                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
4291                    window.platform_window.update_ime_position(bounds);
4292                }
4293                window.platform_window.set_input_handler(input_handler);
4294            }
4295        });
4296    }
4297
4298    /// Present a platform dialog.
4299    /// The provided message will be presented, along with buttons for each answer.
4300    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
4301    pub fn prompt<T>(
4302        &mut self,
4303        level: PromptLevel,
4304        message: &str,
4305        detail: Option<&str>,
4306        answers: &[T],
4307        cx: &mut App,
4308    ) -> oneshot::Receiver<usize>
4309    where
4310        T: Clone + Into<PromptButton>,
4311    {
4312        let prompt_builder = cx.prompt_builder.take();
4313        let Some(prompt_builder) = prompt_builder else {
4314            unreachable!("Re-entrant window prompting is not supported by GPUI");
4315        };
4316
4317        let answers = answers
4318            .iter()
4319            .map(|answer| answer.clone().into())
4320            .collect::<Vec<_>>();
4321
4322        let receiver = match &prompt_builder {
4323            PromptBuilder::Default => self
4324                .platform_window
4325                .prompt(level, message, detail, &answers)
4326                .unwrap_or_else(|| {
4327                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4328                }),
4329            PromptBuilder::Custom(_) => {
4330                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4331            }
4332        };
4333
4334        cx.prompt_builder = Some(prompt_builder);
4335
4336        receiver
4337    }
4338
4339    fn build_custom_prompt(
4340        &mut self,
4341        prompt_builder: &PromptBuilder,
4342        level: PromptLevel,
4343        message: &str,
4344        detail: Option<&str>,
4345        answers: &[PromptButton],
4346        cx: &mut App,
4347    ) -> oneshot::Receiver<usize> {
4348        let (sender, receiver) = oneshot::channel();
4349        let handle = PromptHandle::new(sender);
4350        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
4351        self.prompt = Some(handle);
4352        receiver
4353    }
4354
4355    /// Returns the current context stack.
4356    pub fn context_stack(&self) -> Vec<KeyContext> {
4357        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4358        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4359        dispatch_tree
4360            .dispatch_path(node_id)
4361            .iter()
4362            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4363            .collect()
4364    }
4365
4366    /// Returns all available actions for the focused element.
4367    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4368        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4369        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4370        for action_type in cx.global_action_listeners.keys() {
4371            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4372                let action = cx.actions.build_action_type(action_type).ok();
4373                if let Some(action) = action {
4374                    actions.insert(ix, action);
4375                }
4376            }
4377        }
4378        actions
4379    }
4380
4381    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4382    /// returned in the order they were added. For display, the last binding should take precedence.
4383    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4384        self.rendered_frame
4385            .dispatch_tree
4386            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4387    }
4388
4389    /// Returns the highest precedence key binding that invokes an action on the currently focused
4390    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4391    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4392        self.rendered_frame
4393            .dispatch_tree
4394            .highest_precedence_binding_for_action(
4395                action,
4396                &self.rendered_frame.dispatch_tree.context_stack,
4397            )
4398    }
4399
4400    /// Returns the key bindings for an action in a context.
4401    pub fn bindings_for_action_in_context(
4402        &self,
4403        action: &dyn Action,
4404        context: KeyContext,
4405    ) -> Vec<KeyBinding> {
4406        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4407        dispatch_tree.bindings_for_action(action, &[context])
4408    }
4409
4410    /// Returns the highest precedence key binding for an action in a context. This is more
4411    /// efficient than getting the last result of `bindings_for_action_in_context`.
4412    pub fn highest_precedence_binding_for_action_in_context(
4413        &self,
4414        action: &dyn Action,
4415        context: KeyContext,
4416    ) -> Option<KeyBinding> {
4417        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4418        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4419    }
4420
4421    /// Returns any bindings that would invoke an action on the given focus handle if it were
4422    /// focused. Bindings are returned in the order they were added. For display, the last binding
4423    /// should take precedence.
4424    pub fn bindings_for_action_in(
4425        &self,
4426        action: &dyn Action,
4427        focus_handle: &FocusHandle,
4428    ) -> Vec<KeyBinding> {
4429        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4430        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4431            return vec![];
4432        };
4433        dispatch_tree.bindings_for_action(action, &context_stack)
4434    }
4435
4436    /// Returns the highest precedence key binding that would invoke an action on the given focus
4437    /// handle if it were focused. This is more efficient than getting the last result of
4438    /// `bindings_for_action_in`.
4439    pub fn highest_precedence_binding_for_action_in(
4440        &self,
4441        action: &dyn Action,
4442        focus_handle: &FocusHandle,
4443    ) -> Option<KeyBinding> {
4444        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4445        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4446        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4447    }
4448
4449    fn context_stack_for_focus_handle(
4450        &self,
4451        focus_handle: &FocusHandle,
4452    ) -> Option<Vec<KeyContext>> {
4453        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4454        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4455        let context_stack: Vec<_> = dispatch_tree
4456            .dispatch_path(node_id)
4457            .into_iter()
4458            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4459            .collect();
4460        Some(context_stack)
4461    }
4462
4463    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4464    pub fn listener_for<T: 'static, E>(
4465        &self,
4466        view: &Entity<T>,
4467        f: impl Fn(&mut T, &E, &mut Window, &mut Context<T>) + 'static,
4468    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4469        let view = view.downgrade();
4470        move |e: &E, window: &mut Window, cx: &mut App| {
4471            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4472        }
4473    }
4474
4475    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4476    pub fn handler_for<E: 'static, Callback: Fn(&mut E, &mut Window, &mut Context<E>) + 'static>(
4477        &self,
4478        entity: &Entity<E>,
4479        f: Callback,
4480    ) -> impl Fn(&mut Window, &mut App) + 'static {
4481        let entity = entity.downgrade();
4482        move |window: &mut Window, cx: &mut App| {
4483            entity.update(cx, |entity, cx| f(entity, window, cx)).ok();
4484        }
4485    }
4486
4487    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4488    /// If the callback returns false, the window won't be closed.
4489    pub fn on_window_should_close(
4490        &self,
4491        cx: &App,
4492        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4493    ) {
4494        let mut cx = self.to_async(cx);
4495        self.platform_window.on_should_close(Box::new(move || {
4496            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4497        }))
4498    }
4499
4500    /// Register an action listener on this node for the next frame. The type of action
4501    /// is determined by the first parameter of the given listener. When the next frame is rendered
4502    /// the listener will be cleared.
4503    ///
4504    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4505    /// a specific need to register a listener yourself.
4506    ///
4507    /// This method should only be called as part of the paint phase of element drawing.
4508    pub fn on_action(
4509        &mut self,
4510        action_type: TypeId,
4511        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4512    ) {
4513        self.invalidator.debug_assert_paint();
4514
4515        self.next_frame
4516            .dispatch_tree
4517            .on_action(action_type, Rc::new(listener));
4518    }
4519
4520    /// Register a capturing action listener on this node for the next frame if the condition is true.
4521    /// The type of action is determined by the first parameter of the given listener. When the next
4522    /// frame is rendered the listener will be cleared.
4523    ///
4524    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4525    /// a specific need to register a listener yourself.
4526    ///
4527    /// This method should only be called as part of the paint phase of element drawing.
4528    pub fn on_action_when(
4529        &mut self,
4530        condition: bool,
4531        action_type: TypeId,
4532        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4533    ) {
4534        self.invalidator.debug_assert_paint();
4535
4536        if condition {
4537            self.next_frame
4538                .dispatch_tree
4539                .on_action(action_type, Rc::new(listener));
4540        }
4541    }
4542
4543    /// Read information about the GPU backing this window.
4544    /// Currently returns None on Mac and Windows.
4545    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4546        self.platform_window.gpu_specs()
4547    }
4548
4549    /// Perform titlebar double-click action.
4550    /// This is macOS specific.
4551    pub fn titlebar_double_click(&self) {
4552        self.platform_window.titlebar_double_click();
4553    }
4554
4555    /// Gets the window's title at the platform level.
4556    /// This is macOS specific.
4557    pub fn window_title(&self) -> String {
4558        self.platform_window.get_title()
4559    }
4560
4561    /// Returns a list of all tabbed windows and their titles.
4562    /// This is macOS specific.
4563    pub fn tabbed_windows(&self) -> Option<Vec<SystemWindowTab>> {
4564        self.platform_window.tabbed_windows()
4565    }
4566
4567    /// Returns the tab bar visibility.
4568    /// This is macOS specific.
4569    pub fn tab_bar_visible(&self) -> bool {
4570        self.platform_window.tab_bar_visible()
4571    }
4572
4573    /// Merges all open windows into a single tabbed window.
4574    /// This is macOS specific.
4575    pub fn merge_all_windows(&self) {
4576        self.platform_window.merge_all_windows()
4577    }
4578
4579    /// Moves the tab to a new containing window.
4580    /// This is macOS specific.
4581    pub fn move_tab_to_new_window(&self) {
4582        self.platform_window.move_tab_to_new_window()
4583    }
4584
4585    /// Shows or hides the window tab overview.
4586    /// This is macOS specific.
4587    pub fn toggle_window_tab_overview(&self) {
4588        self.platform_window.toggle_window_tab_overview()
4589    }
4590
4591    /// Sets the tabbing identifier for the window.
4592    /// This is macOS specific.
4593    pub fn set_tabbing_identifier(&self, tabbing_identifier: Option<String>) {
4594        self.platform_window
4595            .set_tabbing_identifier(tabbing_identifier)
4596    }
4597
4598    /// Toggles the inspector mode on this window.
4599    #[cfg(any(feature = "inspector", debug_assertions))]
4600    pub fn toggle_inspector(&mut self, cx: &mut App) {
4601        self.inspector = match self.inspector {
4602            None => Some(cx.new(|_| Inspector::new())),
4603            Some(_) => None,
4604        };
4605        self.refresh();
4606    }
4607
4608    /// Returns true if the window is in inspector mode.
4609    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4610        #[cfg(any(feature = "inspector", debug_assertions))]
4611        {
4612            if let Some(inspector) = &self.inspector {
4613                return inspector.read(_cx).is_picking();
4614            }
4615        }
4616        false
4617    }
4618
4619    /// Executes the provided function with mutable access to an inspector state.
4620    #[cfg(any(feature = "inspector", debug_assertions))]
4621    pub fn with_inspector_state<T: 'static, R>(
4622        &mut self,
4623        _inspector_id: Option<&crate::InspectorElementId>,
4624        cx: &mut App,
4625        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4626    ) -> R {
4627        if let Some(inspector_id) = _inspector_id
4628            && let Some(inspector) = &self.inspector
4629        {
4630            let inspector = inspector.clone();
4631            let active_element_id = inspector.read(cx).active_element_id();
4632            if Some(inspector_id) == active_element_id {
4633                return inspector.update(cx, |inspector, _cx| {
4634                    inspector.with_active_element_state(self, f)
4635                });
4636            }
4637        }
4638        f(&mut None, self)
4639    }
4640
4641    #[cfg(any(feature = "inspector", debug_assertions))]
4642    pub(crate) fn build_inspector_element_id(
4643        &mut self,
4644        path: crate::InspectorElementPath,
4645    ) -> crate::InspectorElementId {
4646        self.invalidator.debug_assert_paint_or_prepaint();
4647        let path = Rc::new(path);
4648        let next_instance_id = self
4649            .next_frame
4650            .next_inspector_instance_ids
4651            .entry(path.clone())
4652            .or_insert(0);
4653        let instance_id = *next_instance_id;
4654        *next_instance_id += 1;
4655        crate::InspectorElementId { path, instance_id }
4656    }
4657
4658    #[cfg(any(feature = "inspector", debug_assertions))]
4659    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4660        if let Some(inspector) = self.inspector.take() {
4661            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4662            inspector_element.prepaint_as_root(
4663                point(self.viewport_size.width - inspector_width, px(0.0)),
4664                size(inspector_width, self.viewport_size.height).into(),
4665                self,
4666                cx,
4667            );
4668            self.inspector = Some(inspector);
4669            Some(inspector_element)
4670        } else {
4671            None
4672        }
4673    }
4674
4675    #[cfg(any(feature = "inspector", debug_assertions))]
4676    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4677        if let Some(mut inspector_element) = inspector_element {
4678            inspector_element.paint(self, cx);
4679        };
4680    }
4681
4682    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4683    /// inspect UI elements by clicking on them.
4684    #[cfg(any(feature = "inspector", debug_assertions))]
4685    pub fn insert_inspector_hitbox(
4686        &mut self,
4687        hitbox_id: HitboxId,
4688        inspector_id: Option<&crate::InspectorElementId>,
4689        cx: &App,
4690    ) {
4691        self.invalidator.debug_assert_paint_or_prepaint();
4692        if !self.is_inspector_picking(cx) {
4693            return;
4694        }
4695        if let Some(inspector_id) = inspector_id {
4696            self.next_frame
4697                .inspector_hitboxes
4698                .insert(hitbox_id, inspector_id.clone());
4699        }
4700    }
4701
4702    #[cfg(any(feature = "inspector", debug_assertions))]
4703    fn paint_inspector_hitbox(&mut self, cx: &App) {
4704        if let Some(inspector) = self.inspector.as_ref() {
4705            let inspector = inspector.read(cx);
4706            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4707                && let Some(hitbox) = self
4708                    .next_frame
4709                    .hitboxes
4710                    .iter()
4711                    .find(|hitbox| hitbox.id == hitbox_id)
4712            {
4713                self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4714            }
4715        }
4716    }
4717
4718    #[cfg(any(feature = "inspector", debug_assertions))]
4719    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4720        let Some(inspector) = self.inspector.clone() else {
4721            return;
4722        };
4723        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4724            inspector.update(cx, |inspector, _cx| {
4725                if let Some((_, inspector_id)) =
4726                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4727                {
4728                    inspector.hover(inspector_id, self);
4729                }
4730            });
4731        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4732            inspector.update(cx, |inspector, _cx| {
4733                if let Some((_, inspector_id)) =
4734                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4735                {
4736                    inspector.select(inspector_id, self);
4737                }
4738            });
4739        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4740            // This should be kept in sync with SCROLL_LINES in x11 platform.
4741            const SCROLL_LINES: f32 = 3.0;
4742            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4743            let delta_y = event
4744                .delta
4745                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4746                .y;
4747            if let Some(inspector) = self.inspector.clone() {
4748                inspector.update(cx, |inspector, _cx| {
4749                    if let Some(depth) = inspector.pick_depth.as_mut() {
4750                        *depth += f32::from(delta_y) / SCROLL_PIXELS_PER_LAYER;
4751                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4752                        if *depth < 0.0 {
4753                            *depth = 0.0;
4754                        } else if *depth > max_depth {
4755                            *depth = max_depth;
4756                        }
4757                        if let Some((_, inspector_id)) =
4758                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4759                        {
4760                            inspector.set_active_element_id(inspector_id, self);
4761                        }
4762                    }
4763                });
4764            }
4765        }
4766    }
4767
4768    #[cfg(any(feature = "inspector", debug_assertions))]
4769    fn hovered_inspector_hitbox(
4770        &self,
4771        inspector: &Inspector,
4772        frame: &Frame,
4773    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4774        if let Some(pick_depth) = inspector.pick_depth {
4775            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4776            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4777            let skip_count = (depth as usize).min(max_skipped);
4778            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4779                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4780                    return Some((*hitbox_id, inspector_id.clone()));
4781                }
4782            }
4783        }
4784        None
4785    }
4786
4787    /// For testing: set the current modifier keys state.
4788    /// This does not generate any events.
4789    #[cfg(any(test, feature = "test-support"))]
4790    pub fn set_modifiers(&mut self, modifiers: Modifiers) {
4791        self.modifiers = modifiers;
4792    }
4793}
4794
4795// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4796slotmap::new_key_type! {
4797    /// A unique identifier for a window.
4798    pub struct WindowId;
4799}
4800
4801impl WindowId {
4802    /// Converts this window ID to a `u64`.
4803    pub fn as_u64(&self) -> u64 {
4804        self.0.as_ffi()
4805    }
4806}
4807
4808impl From<u64> for WindowId {
4809    fn from(value: u64) -> Self {
4810        WindowId(slotmap::KeyData::from_ffi(value))
4811    }
4812}
4813
4814/// A handle to a window with a specific root view type.
4815/// Note that this does not keep the window alive on its own.
4816#[derive(Deref, DerefMut)]
4817pub struct WindowHandle<V> {
4818    #[deref]
4819    #[deref_mut]
4820    pub(crate) any_handle: AnyWindowHandle,
4821    state_type: PhantomData<fn(V) -> V>,
4822}
4823
4824impl<V> Debug for WindowHandle<V> {
4825    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4826        f.debug_struct("WindowHandle")
4827            .field("any_handle", &self.any_handle.id.as_u64())
4828            .finish()
4829    }
4830}
4831
4832impl<V: 'static + Render> WindowHandle<V> {
4833    /// Creates a new handle from a window ID.
4834    /// This does not check if the root type of the window is `V`.
4835    pub fn new(id: WindowId) -> Self {
4836        WindowHandle {
4837            any_handle: AnyWindowHandle {
4838                id,
4839                state_type: TypeId::of::<V>(),
4840            },
4841            state_type: PhantomData,
4842        }
4843    }
4844
4845    /// Get the root view out of this window.
4846    ///
4847    /// This will fail if the window is closed or if the root view's type does not match `V`.
4848    #[cfg(any(test, feature = "test-support"))]
4849    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
4850    where
4851        C: AppContext,
4852    {
4853        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
4854            root_view
4855                .downcast::<V>()
4856                .map_err(|_| anyhow!("the type of the window's root view has changed"))
4857        }))
4858    }
4859
4860    /// Updates the root view of this window.
4861    ///
4862    /// This will fail if the window has been closed or if the root view's type does not match
4863    pub fn update<C, R>(
4864        &self,
4865        cx: &mut C,
4866        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
4867    ) -> Result<R>
4868    where
4869        C: AppContext,
4870    {
4871        cx.update_window(self.any_handle, |root_view, window, cx| {
4872            let view = root_view
4873                .downcast::<V>()
4874                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4875
4876            Ok(view.update(cx, |view, cx| update(view, window, cx)))
4877        })?
4878    }
4879
4880    /// Read the root view out of this window.
4881    ///
4882    /// This will fail if the window is closed or if the root view's type does not match `V`.
4883    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
4884        let x = cx
4885            .windows
4886            .get(self.id)
4887            .and_then(|window| {
4888                window
4889                    .as_deref()
4890                    .and_then(|window| window.root.clone())
4891                    .map(|root_view| root_view.downcast::<V>())
4892            })
4893            .context("window not found")?
4894            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4895
4896        Ok(x.read(cx))
4897    }
4898
4899    /// Read the root view out of this window, with a callback
4900    ///
4901    /// This will fail if the window is closed or if the root view's type does not match `V`.
4902    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
4903    where
4904        C: AppContext,
4905    {
4906        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4907    }
4908
4909    /// Read the root view pointer off of this window.
4910    ///
4911    /// This will fail if the window is closed or if the root view's type does not match `V`.
4912    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
4913    where
4914        C: AppContext,
4915    {
4916        cx.read_window(self, |root_view, _cx| root_view)
4917    }
4918
4919    /// Check if this window is 'active'.
4920    ///
4921    /// Will return `None` if the window is closed or currently
4922    /// borrowed.
4923    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
4924        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
4925            .ok()
4926    }
4927}
4928
4929impl<V> Copy for WindowHandle<V> {}
4930
4931impl<V> Clone for WindowHandle<V> {
4932    fn clone(&self) -> Self {
4933        *self
4934    }
4935}
4936
4937impl<V> PartialEq for WindowHandle<V> {
4938    fn eq(&self, other: &Self) -> bool {
4939        self.any_handle == other.any_handle
4940    }
4941}
4942
4943impl<V> Eq for WindowHandle<V> {}
4944
4945impl<V> Hash for WindowHandle<V> {
4946    fn hash<H: Hasher>(&self, state: &mut H) {
4947        self.any_handle.hash(state);
4948    }
4949}
4950
4951impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4952    fn from(val: WindowHandle<V>) -> Self {
4953        val.any_handle
4954    }
4955}
4956
4957/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4958#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4959pub struct AnyWindowHandle {
4960    pub(crate) id: WindowId,
4961    state_type: TypeId,
4962}
4963
4964impl AnyWindowHandle {
4965    /// Get the ID of this window.
4966    pub fn window_id(&self) -> WindowId {
4967        self.id
4968    }
4969
4970    /// Attempt to convert this handle to a window handle with a specific root view type.
4971    /// If the types do not match, this will return `None`.
4972    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4973        if TypeId::of::<T>() == self.state_type {
4974            Some(WindowHandle {
4975                any_handle: *self,
4976                state_type: PhantomData,
4977            })
4978        } else {
4979            None
4980        }
4981    }
4982
4983    /// Updates the state of the root view of this window.
4984    ///
4985    /// This will fail if the window has been closed.
4986    pub fn update<C, R>(
4987        self,
4988        cx: &mut C,
4989        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
4990    ) -> Result<R>
4991    where
4992        C: AppContext,
4993    {
4994        cx.update_window(self, update)
4995    }
4996
4997    /// Read the state of the root view of this window.
4998    ///
4999    /// This will fail if the window has been closed.
5000    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
5001    where
5002        C: AppContext,
5003        T: 'static,
5004    {
5005        let view = self
5006            .downcast::<T>()
5007            .context("the type of the window's root view has changed")?;
5008
5009        cx.read_window(&view, read)
5010    }
5011}
5012
5013impl HasWindowHandle for Window {
5014    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
5015        self.platform_window.window_handle()
5016    }
5017}
5018
5019impl HasDisplayHandle for Window {
5020    fn display_handle(
5021        &self,
5022    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
5023        self.platform_window.display_handle()
5024    }
5025}
5026
5027/// An identifier for an [`Element`].
5028///
5029/// Can be constructed with a string, a number, or both, as well
5030/// as other internal representations.
5031#[derive(Clone, Debug, Eq, PartialEq, Hash)]
5032pub enum ElementId {
5033    /// The ID of a View element
5034    View(EntityId),
5035    /// An integer ID.
5036    Integer(u64),
5037    /// A string based ID.
5038    Name(SharedString),
5039    /// A UUID.
5040    Uuid(Uuid),
5041    /// An ID that's equated with a focus handle.
5042    FocusHandle(FocusId),
5043    /// A combination of a name and an integer.
5044    NamedInteger(SharedString, u64),
5045    /// A path.
5046    Path(Arc<std::path::Path>),
5047    /// A code location.
5048    CodeLocation(core::panic::Location<'static>),
5049    /// A labeled child of an element.
5050    NamedChild(Arc<ElementId>, SharedString),
5051}
5052
5053impl ElementId {
5054    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
5055    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
5056        Self::NamedInteger(name.into(), integer as u64)
5057    }
5058}
5059
5060impl Display for ElementId {
5061    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
5062        match self {
5063            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
5064            ElementId::Integer(ix) => write!(f, "{}", ix)?,
5065            ElementId::Name(name) => write!(f, "{}", name)?,
5066            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
5067            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
5068            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
5069            ElementId::Path(path) => write!(f, "{}", path.display())?,
5070            ElementId::CodeLocation(location) => write!(f, "{}", location)?,
5071            ElementId::NamedChild(id, name) => write!(f, "{}-{}", id, name)?,
5072        }
5073
5074        Ok(())
5075    }
5076}
5077
5078impl TryInto<SharedString> for ElementId {
5079    type Error = anyhow::Error;
5080
5081    fn try_into(self) -> anyhow::Result<SharedString> {
5082        if let ElementId::Name(name) = self {
5083            Ok(name)
5084        } else {
5085            anyhow::bail!("element id is not string")
5086        }
5087    }
5088}
5089
5090impl From<usize> for ElementId {
5091    fn from(id: usize) -> Self {
5092        ElementId::Integer(id as u64)
5093    }
5094}
5095
5096impl From<i32> for ElementId {
5097    fn from(id: i32) -> Self {
5098        Self::Integer(id as u64)
5099    }
5100}
5101
5102impl From<SharedString> for ElementId {
5103    fn from(name: SharedString) -> Self {
5104        ElementId::Name(name)
5105    }
5106}
5107
5108impl From<String> for ElementId {
5109    fn from(name: String) -> Self {
5110        ElementId::Name(name.into())
5111    }
5112}
5113
5114impl From<Arc<str>> for ElementId {
5115    fn from(name: Arc<str>) -> Self {
5116        ElementId::Name(name.into())
5117    }
5118}
5119
5120impl From<Arc<std::path::Path>> for ElementId {
5121    fn from(path: Arc<std::path::Path>) -> Self {
5122        ElementId::Path(path)
5123    }
5124}
5125
5126impl From<&'static str> for ElementId {
5127    fn from(name: &'static str) -> Self {
5128        ElementId::Name(name.into())
5129    }
5130}
5131
5132impl<'a> From<&'a FocusHandle> for ElementId {
5133    fn from(handle: &'a FocusHandle) -> Self {
5134        ElementId::FocusHandle(handle.id)
5135    }
5136}
5137
5138impl From<(&'static str, EntityId)> for ElementId {
5139    fn from((name, id): (&'static str, EntityId)) -> Self {
5140        ElementId::NamedInteger(name.into(), id.as_u64())
5141    }
5142}
5143
5144impl From<(&'static str, usize)> for ElementId {
5145    fn from((name, id): (&'static str, usize)) -> Self {
5146        ElementId::NamedInteger(name.into(), id as u64)
5147    }
5148}
5149
5150impl From<(SharedString, usize)> for ElementId {
5151    fn from((name, id): (SharedString, usize)) -> Self {
5152        ElementId::NamedInteger(name, id as u64)
5153    }
5154}
5155
5156impl From<(&'static str, u64)> for ElementId {
5157    fn from((name, id): (&'static str, u64)) -> Self {
5158        ElementId::NamedInteger(name.into(), id)
5159    }
5160}
5161
5162impl From<Uuid> for ElementId {
5163    fn from(value: Uuid) -> Self {
5164        Self::Uuid(value)
5165    }
5166}
5167
5168impl From<(&'static str, u32)> for ElementId {
5169    fn from((name, id): (&'static str, u32)) -> Self {
5170        ElementId::NamedInteger(name.into(), id.into())
5171    }
5172}
5173
5174impl<T: Into<SharedString>> From<(ElementId, T)> for ElementId {
5175    fn from((id, name): (ElementId, T)) -> Self {
5176        ElementId::NamedChild(Arc::new(id), name.into())
5177    }
5178}
5179
5180impl From<&'static core::panic::Location<'static>> for ElementId {
5181    fn from(location: &'static core::panic::Location<'static>) -> Self {
5182        ElementId::CodeLocation(*location)
5183    }
5184}
5185
5186/// A rectangle to be rendered in the window at the given position and size.
5187/// Passed as an argument [`Window::paint_quad`].
5188#[derive(Clone)]
5189pub struct PaintQuad {
5190    /// The bounds of the quad within the window.
5191    pub bounds: Bounds<Pixels>,
5192    /// The radii of the quad's corners.
5193    pub corner_radii: Corners<Pixels>,
5194    /// The background color of the quad.
5195    pub background: Background,
5196    /// The widths of the quad's borders.
5197    pub border_widths: Edges<Pixels>,
5198    /// The color of the quad's borders.
5199    pub border_color: Hsla,
5200    /// The style of the quad's borders.
5201    pub border_style: BorderStyle,
5202}
5203
5204impl PaintQuad {
5205    /// Sets the corner radii of the quad.
5206    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
5207        PaintQuad {
5208            corner_radii: corner_radii.into(),
5209            ..self
5210        }
5211    }
5212
5213    /// Sets the border widths of the quad.
5214    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5215        PaintQuad {
5216            border_widths: border_widths.into(),
5217            ..self
5218        }
5219    }
5220
5221    /// Sets the border color of the quad.
5222    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5223        PaintQuad {
5224            border_color: border_color.into(),
5225            ..self
5226        }
5227    }
5228
5229    /// Sets the background color of the quad.
5230    pub fn background(self, background: impl Into<Background>) -> Self {
5231        PaintQuad {
5232            background: background.into(),
5233            ..self
5234        }
5235    }
5236}
5237
5238/// Creates a quad with the given parameters.
5239pub fn quad(
5240    bounds: Bounds<Pixels>,
5241    corner_radii: impl Into<Corners<Pixels>>,
5242    background: impl Into<Background>,
5243    border_widths: impl Into<Edges<Pixels>>,
5244    border_color: impl Into<Hsla>,
5245    border_style: BorderStyle,
5246) -> PaintQuad {
5247    PaintQuad {
5248        bounds,
5249        corner_radii: corner_radii.into(),
5250        background: background.into(),
5251        border_widths: border_widths.into(),
5252        border_color: border_color.into(),
5253        border_style,
5254    }
5255}
5256
5257/// Creates a filled quad with the given bounds and background color.
5258pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5259    PaintQuad {
5260        bounds: bounds.into(),
5261        corner_radii: (0.).into(),
5262        background: background.into(),
5263        border_widths: (0.).into(),
5264        border_color: transparent_black(),
5265        border_style: BorderStyle::default(),
5266    }
5267}
5268
5269/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5270pub fn outline(
5271    bounds: impl Into<Bounds<Pixels>>,
5272    border_color: impl Into<Hsla>,
5273    border_style: BorderStyle,
5274) -> PaintQuad {
5275    PaintQuad {
5276        bounds: bounds.into(),
5277        corner_radii: (0.).into(),
5278        background: transparent_black().into(),
5279        border_widths: (1.).into(),
5280        border_color: border_color.into(),
5281        border_style,
5282    }
5283}