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, cx: &mut App) {
 349        window.focus(self, cx)
 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        // If this hitbox has captured the pointer, it's always considered hovered
 510        if window.captured_hitbox == Some(self) {
 511            return true;
 512        }
 513        let hit_test = &window.mouse_hit_test;
 514        for id in hit_test.ids.iter().take(hit_test.hover_hitbox_count) {
 515            if self == *id {
 516                return true;
 517            }
 518        }
 519        false
 520    }
 521
 522    /// Checks if the hitbox with this ID contains the mouse and should handle scroll events.
 523    /// Typically this should only be used when handling `ScrollWheelEvent`, and otherwise
 524    /// `is_hovered` should be used. See the documentation of `Hitbox::is_hovered` for details about
 525    /// this distinction.
 526    pub fn should_handle_scroll(self, window: &Window) -> bool {
 527        window.mouse_hit_test.ids.contains(&self)
 528    }
 529
 530    fn next(mut self) -> HitboxId {
 531        HitboxId(self.0.wrapping_add(1))
 532    }
 533}
 534
 535/// A rectangular region that potentially blocks hitboxes inserted prior.
 536/// See [Window::insert_hitbox] for more details.
 537#[derive(Clone, Debug, Deref)]
 538pub struct Hitbox {
 539    /// A unique identifier for the hitbox.
 540    pub id: HitboxId,
 541    /// The bounds of the hitbox.
 542    #[deref]
 543    pub bounds: Bounds<Pixels>,
 544    /// The content mask when the hitbox was inserted.
 545    pub content_mask: ContentMask<Pixels>,
 546    /// Flags that specify hitbox behavior.
 547    pub behavior: HitboxBehavior,
 548}
 549
 550impl Hitbox {
 551    /// Checks if the hitbox is currently hovered. Except when handling `ScrollWheelEvent`, this is
 552    /// typically what you want when determining whether to handle mouse events or paint hover
 553    /// styles.
 554    ///
 555    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 556    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`) or
 557    /// `HitboxBehavior::BlockMouseExceptScroll` (`InteractiveElement::block_mouse_except_scroll`).
 558    ///
 559    /// Handling of `ScrollWheelEvent` should typically use `should_handle_scroll` instead.
 560    /// Concretely, this is due to use-cases like overlays that cause the elements under to be
 561    /// non-interactive while still allowing scrolling. More abstractly, this is because
 562    /// `is_hovered` is about element interactions directly under the mouse - mouse moves, clicks,
 563    /// hover styling, etc. In contrast, scrolling is about finding the current outer scrollable
 564    /// container.
 565    pub fn is_hovered(&self, window: &Window) -> bool {
 566        self.id.is_hovered(window)
 567    }
 568
 569    /// Checks if the hitbox contains the mouse and should handle scroll events. Typically this
 570    /// should only be used when handling `ScrollWheelEvent`, and otherwise `is_hovered` should be
 571    /// used. See the documentation of `Hitbox::is_hovered` for details about this distinction.
 572    ///
 573    /// This can return `false` even when the hitbox contains the mouse, if a hitbox in front of
 574    /// this sets `HitboxBehavior::BlockMouse` (`InteractiveElement::occlude`).
 575    pub fn should_handle_scroll(&self, window: &Window) -> bool {
 576        self.id.should_handle_scroll(window)
 577    }
 578}
 579
 580/// How the hitbox affects mouse behavior.
 581#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 582pub enum HitboxBehavior {
 583    /// Normal hitbox mouse behavior, doesn't affect mouse handling for other hitboxes.
 584    #[default]
 585    Normal,
 586
 587    /// All hitboxes behind this hitbox will be ignored and so will have `hitbox.is_hovered() ==
 588    /// false` and `hitbox.should_handle_scroll() == false`. Typically for elements this causes
 589    /// skipping of all mouse events, hover styles, and tooltips. This flag is set by
 590    /// [`InteractiveElement::occlude`].
 591    ///
 592    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 593    /// bubble-phase handler for every mouse event type:
 594    ///
 595    /// ```ignore
 596    /// window.on_mouse_event(move |_: &EveryMouseEventTypeHere, phase, window, cx| {
 597    ///     if phase == DispatchPhase::Capture && hitbox.is_hovered(window) {
 598    ///         cx.stop_propagation();
 599    ///     }
 600    /// })
 601    /// ```
 602    ///
 603    /// This has effects beyond event handling - any use of hitbox checking, such as hover
 604    /// styles and tooltips. These other behaviors are the main point of this mechanism. An
 605    /// alternative might be to not affect mouse event handling - but this would allow
 606    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 607    /// be hovered.
 608    BlockMouse,
 609
 610    /// All hitboxes behind this hitbox will have `hitbox.is_hovered() == false`, even when
 611    /// `hitbox.should_handle_scroll() == true`. Typically for elements this causes all mouse
 612    /// interaction except scroll events to be ignored - see the documentation of
 613    /// [`Hitbox::is_hovered`] for details. This flag is set by
 614    /// [`InteractiveElement::block_mouse_except_scroll`].
 615    ///
 616    /// For mouse handlers that check those hitboxes, this behaves the same as registering a
 617    /// bubble-phase handler for every mouse event type **except** `ScrollWheelEvent`:
 618    ///
 619    /// ```ignore
 620    /// window.on_mouse_event(move |_: &EveryMouseEventTypeExceptScroll, phase, window, cx| {
 621    ///     if phase == DispatchPhase::Bubble && hitbox.should_handle_scroll(window) {
 622    ///         cx.stop_propagation();
 623    ///     }
 624    /// })
 625    /// ```
 626    ///
 627    /// See the documentation of [`Hitbox::is_hovered`] for details of why `ScrollWheelEvent` is
 628    /// handled differently than other mouse events. If also blocking these scroll events is
 629    /// desired, then a `cx.stop_propagation()` handler like the one above can be used.
 630    ///
 631    /// This has effects beyond event handling - this affects any use of `is_hovered`, such as
 632    /// hover styles and tooltips. These other behaviors are the main point of this mechanism.
 633    /// An alternative might be to not affect mouse event handling - but this would allow
 634    /// inconsistent UI where clicks and moves interact with elements that are not considered to
 635    /// be hovered.
 636    BlockMouseExceptScroll,
 637}
 638
 639/// An identifier for a tooltip.
 640#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 641pub struct TooltipId(usize);
 642
 643impl TooltipId {
 644    /// Checks if the tooltip is currently hovered.
 645    pub fn is_hovered(&self, window: &Window) -> bool {
 646        window
 647            .tooltip_bounds
 648            .as_ref()
 649            .is_some_and(|tooltip_bounds| {
 650                tooltip_bounds.id == *self
 651                    && tooltip_bounds.bounds.contains(&window.mouse_position())
 652            })
 653    }
 654}
 655
 656pub(crate) struct TooltipBounds {
 657    id: TooltipId,
 658    bounds: Bounds<Pixels>,
 659}
 660
 661#[derive(Clone)]
 662pub(crate) struct TooltipRequest {
 663    id: TooltipId,
 664    tooltip: AnyTooltip,
 665}
 666
 667pub(crate) struct DeferredDraw {
 668    current_view: EntityId,
 669    priority: usize,
 670    parent_node: DispatchNodeId,
 671    element_id_stack: SmallVec<[ElementId; 32]>,
 672    text_style_stack: Vec<TextStyleRefinement>,
 673    element: Option<AnyElement>,
 674    absolute_offset: Point<Pixels>,
 675    prepaint_range: Range<PrepaintStateIndex>,
 676    paint_range: Range<PaintIndex>,
 677}
 678
 679pub(crate) struct Frame {
 680    pub(crate) focus: Option<FocusId>,
 681    pub(crate) window_active: bool,
 682    pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
 683    accessed_element_states: Vec<(GlobalElementId, TypeId)>,
 684    pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
 685    pub(crate) dispatch_tree: DispatchTree,
 686    pub(crate) scene: Scene,
 687    pub(crate) hitboxes: Vec<Hitbox>,
 688    pub(crate) window_control_hitboxes: Vec<(WindowControlArea, Hitbox)>,
 689    pub(crate) deferred_draws: Vec<DeferredDraw>,
 690    pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
 691    pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
 692    pub(crate) cursor_styles: Vec<CursorStyleRequest>,
 693    #[cfg(any(test, feature = "test-support"))]
 694    pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
 695    #[cfg(any(feature = "inspector", debug_assertions))]
 696    pub(crate) next_inspector_instance_ids: FxHashMap<Rc<crate::InspectorElementPath>, usize>,
 697    #[cfg(any(feature = "inspector", debug_assertions))]
 698    pub(crate) inspector_hitboxes: FxHashMap<HitboxId, crate::InspectorElementId>,
 699    pub(crate) tab_stops: TabStopMap,
 700}
 701
 702#[derive(Clone, Default)]
 703pub(crate) struct PrepaintStateIndex {
 704    hitboxes_index: usize,
 705    tooltips_index: usize,
 706    deferred_draws_index: usize,
 707    dispatch_tree_index: usize,
 708    accessed_element_states_index: usize,
 709    line_layout_index: LineLayoutIndex,
 710}
 711
 712#[derive(Clone, Default)]
 713pub(crate) struct PaintIndex {
 714    scene_index: usize,
 715    mouse_listeners_index: usize,
 716    input_handlers_index: usize,
 717    cursor_styles_index: usize,
 718    accessed_element_states_index: usize,
 719    tab_handle_index: usize,
 720    line_layout_index: LineLayoutIndex,
 721}
 722
 723impl Frame {
 724    pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
 725        Frame {
 726            focus: None,
 727            window_active: false,
 728            element_states: FxHashMap::default(),
 729            accessed_element_states: Vec::new(),
 730            mouse_listeners: Vec::new(),
 731            dispatch_tree,
 732            scene: Scene::default(),
 733            hitboxes: Vec::new(),
 734            window_control_hitboxes: Vec::new(),
 735            deferred_draws: Vec::new(),
 736            input_handlers: Vec::new(),
 737            tooltip_requests: Vec::new(),
 738            cursor_styles: Vec::new(),
 739
 740            #[cfg(any(test, feature = "test-support"))]
 741            debug_bounds: FxHashMap::default(),
 742
 743            #[cfg(any(feature = "inspector", debug_assertions))]
 744            next_inspector_instance_ids: FxHashMap::default(),
 745
 746            #[cfg(any(feature = "inspector", debug_assertions))]
 747            inspector_hitboxes: FxHashMap::default(),
 748            tab_stops: TabStopMap::default(),
 749        }
 750    }
 751
 752    pub(crate) fn clear(&mut self) {
 753        self.element_states.clear();
 754        self.accessed_element_states.clear();
 755        self.mouse_listeners.clear();
 756        self.dispatch_tree.clear();
 757        self.scene.clear();
 758        self.input_handlers.clear();
 759        self.tooltip_requests.clear();
 760        self.cursor_styles.clear();
 761        self.hitboxes.clear();
 762        self.window_control_hitboxes.clear();
 763        self.deferred_draws.clear();
 764        self.tab_stops.clear();
 765        self.focus = None;
 766
 767        #[cfg(any(test, feature = "test-support"))]
 768        {
 769            self.debug_bounds.clear();
 770        }
 771
 772        #[cfg(any(feature = "inspector", debug_assertions))]
 773        {
 774            self.next_inspector_instance_ids.clear();
 775            self.inspector_hitboxes.clear();
 776        }
 777    }
 778
 779    pub(crate) fn cursor_style(&self, window: &Window) -> Option<CursorStyle> {
 780        self.cursor_styles
 781            .iter()
 782            .rev()
 783            .fold_while(None, |style, request| match request.hitbox_id {
 784                None => Done(Some(request.style)),
 785                Some(hitbox_id) => Continue(
 786                    style.or_else(|| hitbox_id.is_hovered(window).then_some(request.style)),
 787                ),
 788            })
 789            .into_inner()
 790    }
 791
 792    pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
 793        let mut set_hover_hitbox_count = false;
 794        let mut hit_test = HitTest::default();
 795        for hitbox in self.hitboxes.iter().rev() {
 796            let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
 797            if bounds.contains(&position) {
 798                hit_test.ids.push(hitbox.id);
 799                if !set_hover_hitbox_count
 800                    && hitbox.behavior == HitboxBehavior::BlockMouseExceptScroll
 801                {
 802                    hit_test.hover_hitbox_count = hit_test.ids.len();
 803                    set_hover_hitbox_count = true;
 804                }
 805                if hitbox.behavior == HitboxBehavior::BlockMouse {
 806                    break;
 807                }
 808            }
 809        }
 810        if !set_hover_hitbox_count {
 811            hit_test.hover_hitbox_count = hit_test.ids.len();
 812        }
 813        hit_test
 814    }
 815
 816    pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
 817        self.focus
 818            .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
 819            .unwrap_or_default()
 820    }
 821
 822    pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
 823        for element_state_key in &self.accessed_element_states {
 824            if let Some((element_state_key, element_state)) =
 825                prev_frame.element_states.remove_entry(element_state_key)
 826            {
 827                self.element_states.insert(element_state_key, element_state);
 828            }
 829        }
 830
 831        self.scene.finish();
 832    }
 833}
 834
 835#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 836enum InputModality {
 837    Mouse,
 838    Keyboard,
 839}
 840
 841/// Holds the state for a specific window.
 842pub struct Window {
 843    pub(crate) handle: AnyWindowHandle,
 844    pub(crate) invalidator: WindowInvalidator,
 845    pub(crate) removed: bool,
 846    pub(crate) platform_window: Box<dyn PlatformWindow>,
 847    display_id: Option<DisplayId>,
 848    sprite_atlas: Arc<dyn PlatformAtlas>,
 849    text_system: Arc<WindowTextSystem>,
 850    rem_size: Pixels,
 851    /// The stack of override values for the window's rem size.
 852    ///
 853    /// This is used by `with_rem_size` to allow rendering an element tree with
 854    /// a given rem size.
 855    rem_size_override_stack: SmallVec<[Pixels; 8]>,
 856    pub(crate) viewport_size: Size<Pixels>,
 857    layout_engine: Option<TaffyLayoutEngine>,
 858    pub(crate) root: Option<AnyView>,
 859    pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
 860    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
 861    pub(crate) rendered_entity_stack: Vec<EntityId>,
 862    pub(crate) element_offset_stack: Vec<Point<Pixels>>,
 863    pub(crate) element_opacity: f32,
 864    pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
 865    pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
 866    pub(crate) image_cache_stack: Vec<AnyImageCache>,
 867    pub(crate) rendered_frame: Frame,
 868    pub(crate) next_frame: Frame,
 869    next_hitbox_id: HitboxId,
 870    pub(crate) next_tooltip_id: TooltipId,
 871    pub(crate) tooltip_bounds: Option<TooltipBounds>,
 872    next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
 873    pub(crate) dirty_views: FxHashSet<EntityId>,
 874    focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
 875    pub(crate) focus_lost_listeners: SubscriberSet<(), AnyObserver>,
 876    default_prevented: bool,
 877    mouse_position: Point<Pixels>,
 878    mouse_hit_test: HitTest,
 879    modifiers: Modifiers,
 880    capslock: Capslock,
 881    scale_factor: f32,
 882    pub(crate) bounds_observers: SubscriberSet<(), AnyObserver>,
 883    appearance: WindowAppearance,
 884    pub(crate) appearance_observers: SubscriberSet<(), AnyObserver>,
 885    active: Rc<Cell<bool>>,
 886    hovered: Rc<Cell<bool>>,
 887    pub(crate) needs_present: Rc<Cell<bool>>,
 888    pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
 889    last_input_modality: InputModality,
 890    pub(crate) refreshing: bool,
 891    pub(crate) activation_observers: SubscriberSet<(), AnyObserver>,
 892    pub(crate) focus: Option<FocusId>,
 893    focus_enabled: bool,
 894    pending_input: Option<PendingInput>,
 895    pending_modifier: ModifierState,
 896    pub(crate) pending_input_observers: SubscriberSet<(), AnyObserver>,
 897    prompt: Option<RenderablePromptHandle>,
 898    pub(crate) client_inset: Option<Pixels>,
 899    /// The hitbox that has captured the pointer, if any.
 900    /// While captured, mouse events route to this hitbox regardless of hit testing.
 901    captured_hitbox: Option<HitboxId>,
 902    #[cfg(any(feature = "inspector", debug_assertions))]
 903    inspector: Option<Entity<Inspector>>,
 904}
 905
 906#[derive(Clone, Debug, Default)]
 907struct ModifierState {
 908    modifiers: Modifiers,
 909    saw_keystroke: bool,
 910}
 911
 912#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 913pub(crate) enum DrawPhase {
 914    None,
 915    Prepaint,
 916    Paint,
 917    Focus,
 918}
 919
 920#[derive(Default, Debug)]
 921struct PendingInput {
 922    keystrokes: SmallVec<[Keystroke; 1]>,
 923    focus: Option<FocusId>,
 924    timer: Option<Task<()>>,
 925    needs_timeout: bool,
 926}
 927
 928pub(crate) struct ElementStateBox {
 929    pub(crate) inner: Box<dyn Any>,
 930    #[cfg(debug_assertions)]
 931    pub(crate) type_name: &'static str,
 932}
 933
 934fn default_bounds(display_id: Option<DisplayId>, cx: &mut App) -> WindowBounds {
 935    // TODO, BUG: if you open a window with the currently active window
 936    // on the stack, this will erroneously fallback to `None`
 937    //
 938    // TODO these should be the initial window bounds not considering maximized/fullscreen
 939    let active_window_bounds = cx
 940        .active_window()
 941        .and_then(|w| w.update(cx, |_, window, _| window.window_bounds()).ok());
 942
 943    const CASCADE_OFFSET: f32 = 25.0;
 944
 945    let display = display_id
 946        .map(|id| cx.find_display(id))
 947        .unwrap_or_else(|| cx.primary_display());
 948
 949    let default_placement = || Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE);
 950
 951    // Use visible_bounds to exclude taskbar/dock areas
 952    let display_bounds = display
 953        .as_ref()
 954        .map(|d| d.visible_bounds())
 955        .unwrap_or_else(default_placement);
 956
 957    let (
 958        Bounds {
 959            origin: base_origin,
 960            size: base_size,
 961        },
 962        window_bounds_ctor,
 963    ): (_, fn(Bounds<Pixels>) -> WindowBounds) = match active_window_bounds {
 964        Some(bounds) => match bounds {
 965            WindowBounds::Windowed(bounds) => (bounds, WindowBounds::Windowed),
 966            WindowBounds::Maximized(bounds) => (bounds, WindowBounds::Maximized),
 967            WindowBounds::Fullscreen(bounds) => (bounds, WindowBounds::Fullscreen),
 968        },
 969        None => (
 970            display
 971                .as_ref()
 972                .map(|d| d.default_bounds())
 973                .unwrap_or_else(default_placement),
 974            WindowBounds::Windowed,
 975        ),
 976    };
 977
 978    let cascade_offset = point(px(CASCADE_OFFSET), px(CASCADE_OFFSET));
 979    let proposed_origin = base_origin + cascade_offset;
 980    let proposed_bounds = Bounds::new(proposed_origin, base_size);
 981
 982    let display_right = display_bounds.origin.x + display_bounds.size.width;
 983    let display_bottom = display_bounds.origin.y + display_bounds.size.height;
 984    let window_right = proposed_bounds.origin.x + proposed_bounds.size.width;
 985    let window_bottom = proposed_bounds.origin.y + proposed_bounds.size.height;
 986
 987    let fits_horizontally = window_right <= display_right;
 988    let fits_vertically = window_bottom <= display_bottom;
 989
 990    let final_origin = match (fits_horizontally, fits_vertically) {
 991        (true, true) => proposed_origin,
 992        (false, true) => point(display_bounds.origin.x, base_origin.y),
 993        (true, false) => point(base_origin.x, display_bounds.origin.y),
 994        (false, false) => display_bounds.origin,
 995    };
 996    window_bounds_ctor(Bounds::new(final_origin, base_size))
 997}
 998
 999impl Window {
1000    pub(crate) fn new(
1001        handle: AnyWindowHandle,
1002        options: WindowOptions,
1003        cx: &mut App,
1004    ) -> Result<Self> {
1005        let WindowOptions {
1006            window_bounds,
1007            titlebar,
1008            focus,
1009            show,
1010            kind,
1011            is_movable,
1012            is_resizable,
1013            is_minimizable,
1014            display_id,
1015            window_background,
1016            app_id,
1017            window_min_size,
1018            window_decorations,
1019            #[cfg_attr(not(target_os = "macos"), allow(unused_variables))]
1020            tabbing_identifier,
1021        } = options;
1022
1023        let window_bounds = window_bounds.unwrap_or_else(|| default_bounds(display_id, cx));
1024        let mut platform_window = cx.platform.open_window(
1025            handle,
1026            WindowParams {
1027                bounds: window_bounds.get_bounds(),
1028                titlebar,
1029                kind,
1030                is_movable,
1031                is_resizable,
1032                is_minimizable,
1033                focus,
1034                show,
1035                display_id,
1036                window_min_size,
1037                #[cfg(target_os = "macos")]
1038                tabbing_identifier,
1039            },
1040        )?;
1041
1042        let tab_bar_visible = platform_window.tab_bar_visible();
1043        SystemWindowTabController::init_visible(cx, tab_bar_visible);
1044        if let Some(tabs) = platform_window.tabbed_windows() {
1045            SystemWindowTabController::add_tab(cx, handle.window_id(), tabs);
1046        }
1047
1048        let display_id = platform_window.display().map(|display| display.id());
1049        let sprite_atlas = platform_window.sprite_atlas();
1050        let mouse_position = platform_window.mouse_position();
1051        let modifiers = platform_window.modifiers();
1052        let capslock = platform_window.capslock();
1053        let content_size = platform_window.content_size();
1054        let scale_factor = platform_window.scale_factor();
1055        let appearance = platform_window.appearance();
1056        let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
1057        let invalidator = WindowInvalidator::new();
1058        let active = Rc::new(Cell::new(platform_window.is_active()));
1059        let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
1060        let needs_present = Rc::new(Cell::new(false));
1061        let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
1062        let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
1063
1064        platform_window
1065            .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
1066        platform_window.set_background_appearance(window_background);
1067
1068        match window_bounds {
1069            WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
1070            WindowBounds::Maximized(_) => platform_window.zoom(),
1071            WindowBounds::Windowed(_) => {}
1072        }
1073
1074        platform_window.on_close(Box::new({
1075            let window_id = handle.window_id();
1076            let mut cx = cx.to_async();
1077            move || {
1078                let _ = handle.update(&mut cx, |_, window, _| window.remove_window());
1079                let _ = cx.update(|cx| {
1080                    SystemWindowTabController::remove_tab(cx, window_id);
1081                });
1082            }
1083        }));
1084        platform_window.on_request_frame(Box::new({
1085            let mut cx = cx.to_async();
1086            let invalidator = invalidator.clone();
1087            let active = active.clone();
1088            let needs_present = needs_present.clone();
1089            let next_frame_callbacks = next_frame_callbacks.clone();
1090            let last_input_timestamp = last_input_timestamp.clone();
1091            move |request_frame_options| {
1092                let next_frame_callbacks = next_frame_callbacks.take();
1093                if !next_frame_callbacks.is_empty() {
1094                    handle
1095                        .update(&mut cx, |_, window, cx| {
1096                            for callback in next_frame_callbacks {
1097                                callback(window, cx);
1098                            }
1099                        })
1100                        .log_err();
1101                }
1102
1103                // Keep presenting the current scene for 1 extra second since the
1104                // last input to prevent the display from underclocking the refresh rate.
1105                let needs_present = request_frame_options.require_presentation
1106                    || needs_present.get()
1107                    || (active.get()
1108                        && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
1109
1110                if invalidator.is_dirty() || request_frame_options.force_render {
1111                    measure("frame duration", || {
1112                        handle
1113                            .update(&mut cx, |_, window, cx| {
1114                                let arena_clear_needed = window.draw(cx);
1115                                window.present();
1116                                // drop the arena elements after present to reduce latency
1117                                arena_clear_needed.clear();
1118                            })
1119                            .log_err();
1120                    })
1121                } else if needs_present {
1122                    handle
1123                        .update(&mut cx, |_, window, _| window.present())
1124                        .log_err();
1125                }
1126
1127                handle
1128                    .update(&mut cx, |_, window, _| {
1129                        window.complete_frame();
1130                    })
1131                    .log_err();
1132            }
1133        }));
1134        platform_window.on_resize(Box::new({
1135            let mut cx = cx.to_async();
1136            move |_, _| {
1137                handle
1138                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1139                    .log_err();
1140            }
1141        }));
1142        platform_window.on_moved(Box::new({
1143            let mut cx = cx.to_async();
1144            move || {
1145                handle
1146                    .update(&mut cx, |_, window, cx| window.bounds_changed(cx))
1147                    .log_err();
1148            }
1149        }));
1150        platform_window.on_appearance_changed(Box::new({
1151            let mut cx = cx.to_async();
1152            move || {
1153                handle
1154                    .update(&mut cx, |_, window, cx| window.appearance_changed(cx))
1155                    .log_err();
1156            }
1157        }));
1158        platform_window.on_active_status_change(Box::new({
1159            let mut cx = cx.to_async();
1160            move |active| {
1161                handle
1162                    .update(&mut cx, |_, window, cx| {
1163                        window.active.set(active);
1164                        window.modifiers = window.platform_window.modifiers();
1165                        window.capslock = window.platform_window.capslock();
1166                        window
1167                            .activation_observers
1168                            .clone()
1169                            .retain(&(), |callback| callback(window, cx));
1170
1171                        window.bounds_changed(cx);
1172                        window.refresh();
1173
1174                        SystemWindowTabController::update_last_active(cx, window.handle.id);
1175                    })
1176                    .log_err();
1177            }
1178        }));
1179        platform_window.on_hover_status_change(Box::new({
1180            let mut cx = cx.to_async();
1181            move |active| {
1182                handle
1183                    .update(&mut cx, |_, window, _| {
1184                        window.hovered.set(active);
1185                        window.refresh();
1186                    })
1187                    .log_err();
1188            }
1189        }));
1190        platform_window.on_input({
1191            let mut cx = cx.to_async();
1192            Box::new(move |event| {
1193                handle
1194                    .update(&mut cx, |_, window, cx| window.dispatch_event(event, cx))
1195                    .log_err()
1196                    .unwrap_or(DispatchEventResult::default())
1197            })
1198        });
1199        platform_window.on_hit_test_window_control({
1200            let mut cx = cx.to_async();
1201            Box::new(move || {
1202                handle
1203                    .update(&mut cx, |_, window, _cx| {
1204                        for (area, hitbox) in &window.rendered_frame.window_control_hitboxes {
1205                            if window.mouse_hit_test.ids.contains(&hitbox.id) {
1206                                return Some(*area);
1207                            }
1208                        }
1209                        None
1210                    })
1211                    .log_err()
1212                    .unwrap_or(None)
1213            })
1214        });
1215        platform_window.on_move_tab_to_new_window({
1216            let mut cx = cx.to_async();
1217            Box::new(move || {
1218                handle
1219                    .update(&mut cx, |_, _window, cx| {
1220                        SystemWindowTabController::move_tab_to_new_window(cx, handle.window_id());
1221                    })
1222                    .log_err();
1223            })
1224        });
1225        platform_window.on_merge_all_windows({
1226            let mut cx = cx.to_async();
1227            Box::new(move || {
1228                handle
1229                    .update(&mut cx, |_, _window, cx| {
1230                        SystemWindowTabController::merge_all_windows(cx, handle.window_id());
1231                    })
1232                    .log_err();
1233            })
1234        });
1235        platform_window.on_select_next_tab({
1236            let mut cx = cx.to_async();
1237            Box::new(move || {
1238                handle
1239                    .update(&mut cx, |_, _window, cx| {
1240                        SystemWindowTabController::select_next_tab(cx, handle.window_id());
1241                    })
1242                    .log_err();
1243            })
1244        });
1245        platform_window.on_select_previous_tab({
1246            let mut cx = cx.to_async();
1247            Box::new(move || {
1248                handle
1249                    .update(&mut cx, |_, _window, cx| {
1250                        SystemWindowTabController::select_previous_tab(cx, handle.window_id())
1251                    })
1252                    .log_err();
1253            })
1254        });
1255        platform_window.on_toggle_tab_bar({
1256            let mut cx = cx.to_async();
1257            Box::new(move || {
1258                handle
1259                    .update(&mut cx, |_, window, cx| {
1260                        let tab_bar_visible = window.platform_window.tab_bar_visible();
1261                        SystemWindowTabController::set_visible(cx, tab_bar_visible);
1262                    })
1263                    .log_err();
1264            })
1265        });
1266
1267        if let Some(app_id) = app_id {
1268            platform_window.set_app_id(&app_id);
1269        }
1270
1271        platform_window.map_window().unwrap();
1272
1273        Ok(Window {
1274            handle,
1275            invalidator,
1276            removed: false,
1277            platform_window,
1278            display_id,
1279            sprite_atlas,
1280            text_system,
1281            rem_size: px(16.),
1282            rem_size_override_stack: SmallVec::new(),
1283            viewport_size: content_size,
1284            layout_engine: Some(TaffyLayoutEngine::new()),
1285            root: None,
1286            element_id_stack: SmallVec::default(),
1287            text_style_stack: Vec::new(),
1288            rendered_entity_stack: Vec::new(),
1289            element_offset_stack: Vec::new(),
1290            content_mask_stack: Vec::new(),
1291            element_opacity: 1.0,
1292            requested_autoscroll: None,
1293            rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1294            next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
1295            next_frame_callbacks,
1296            next_hitbox_id: HitboxId(0),
1297            next_tooltip_id: TooltipId::default(),
1298            tooltip_bounds: None,
1299            dirty_views: FxHashSet::default(),
1300            focus_listeners: SubscriberSet::new(),
1301            focus_lost_listeners: SubscriberSet::new(),
1302            default_prevented: true,
1303            mouse_position,
1304            mouse_hit_test: HitTest::default(),
1305            modifiers,
1306            capslock,
1307            scale_factor,
1308            bounds_observers: SubscriberSet::new(),
1309            appearance,
1310            appearance_observers: SubscriberSet::new(),
1311            active,
1312            hovered,
1313            needs_present,
1314            last_input_timestamp,
1315            last_input_modality: InputModality::Mouse,
1316            refreshing: false,
1317            activation_observers: SubscriberSet::new(),
1318            focus: None,
1319            focus_enabled: true,
1320            pending_input: None,
1321            pending_modifier: ModifierState::default(),
1322            pending_input_observers: SubscriberSet::new(),
1323            prompt: None,
1324            client_inset: None,
1325            image_cache_stack: Vec::new(),
1326            captured_hitbox: None,
1327            #[cfg(any(feature = "inspector", debug_assertions))]
1328            inspector: None,
1329        })
1330    }
1331
1332    pub(crate) fn new_focus_listener(
1333        &self,
1334        value: AnyWindowFocusListener,
1335    ) -> (Subscription, impl FnOnce() + use<>) {
1336        self.focus_listeners.insert((), value)
1337    }
1338}
1339
1340#[derive(Clone, Debug, Default, PartialEq, Eq)]
1341pub(crate) struct DispatchEventResult {
1342    pub propagate: bool,
1343    pub default_prevented: bool,
1344}
1345
1346/// Indicates which region of the window is visible. Content falling outside of this mask will not be
1347/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
1348/// to leave room to support more complex shapes in the future.
1349#[derive(Clone, Debug, Default, PartialEq, Eq)]
1350#[repr(C)]
1351pub struct ContentMask<P: Clone + Debug + Default + PartialEq> {
1352    /// The bounds
1353    pub bounds: Bounds<P>,
1354}
1355
1356impl ContentMask<Pixels> {
1357    /// Scale the content mask's pixel units by the given scaling factor.
1358    pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
1359        ContentMask {
1360            bounds: self.bounds.scale(factor),
1361        }
1362    }
1363
1364    /// Intersect the content mask with the given content mask.
1365    pub fn intersect(&self, other: &Self) -> Self {
1366        let bounds = self.bounds.intersect(&other.bounds);
1367        ContentMask { bounds }
1368    }
1369}
1370
1371impl Window {
1372    fn mark_view_dirty(&mut self, view_id: EntityId) {
1373        // Mark ancestor views as dirty. If already in the `dirty_views` set, then all its ancestors
1374        // should already be dirty.
1375        for view_id in self
1376            .rendered_frame
1377            .dispatch_tree
1378            .view_path_reversed(view_id)
1379        {
1380            if !self.dirty_views.insert(view_id) {
1381                break;
1382            }
1383        }
1384    }
1385
1386    /// Registers a callback to be invoked when the window appearance changes.
1387    pub fn observe_window_appearance(
1388        &self,
1389        mut callback: impl FnMut(&mut Window, &mut App) + 'static,
1390    ) -> Subscription {
1391        let (subscription, activate) = self.appearance_observers.insert(
1392            (),
1393            Box::new(move |window, cx| {
1394                callback(window, cx);
1395                true
1396            }),
1397        );
1398        activate();
1399        subscription
1400    }
1401
1402    /// Replaces the root entity of the window with a new one.
1403    pub fn replace_root<E>(
1404        &mut self,
1405        cx: &mut App,
1406        build_view: impl FnOnce(&mut Window, &mut Context<E>) -> E,
1407    ) -> Entity<E>
1408    where
1409        E: 'static + Render,
1410    {
1411        let view = cx.new(|cx| build_view(self, cx));
1412        self.root = Some(view.clone().into());
1413        self.refresh();
1414        view
1415    }
1416
1417    /// Returns the root entity of the window, if it has one.
1418    pub fn root<E>(&self) -> Option<Option<Entity<E>>>
1419    where
1420        E: 'static + Render,
1421    {
1422        self.root
1423            .as_ref()
1424            .map(|view| view.clone().downcast::<E>().ok())
1425    }
1426
1427    /// Obtain a handle to the window that belongs to this context.
1428    pub fn window_handle(&self) -> AnyWindowHandle {
1429        self.handle
1430    }
1431
1432    /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
1433    pub fn refresh(&mut self) {
1434        if self.invalidator.not_drawing() {
1435            self.refreshing = true;
1436            self.invalidator.set_dirty(true);
1437        }
1438    }
1439
1440    /// Close this window.
1441    pub fn remove_window(&mut self) {
1442        self.removed = true;
1443    }
1444
1445    /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
1446    pub fn focused(&self, cx: &App) -> Option<FocusHandle> {
1447        self.focus
1448            .and_then(|id| FocusHandle::for_id(id, &cx.focus_handles))
1449    }
1450
1451    /// Move focus to the element associated with the given [`FocusHandle`].
1452    pub fn focus(&mut self, handle: &FocusHandle, cx: &mut App) {
1453        if !self.focus_enabled || self.focus == Some(handle.id) {
1454            return;
1455        }
1456
1457        self.focus = Some(handle.id);
1458        self.clear_pending_keystrokes();
1459
1460        // Avoid re-entrant entity updates by deferring observer notifications to the end of the
1461        // current effect cycle, and only for this window.
1462        let window_handle = self.handle;
1463        cx.defer(move |cx| {
1464            window_handle
1465                .update(cx, |_, window, cx| {
1466                    window.pending_input_changed(cx);
1467                })
1468                .ok();
1469        });
1470
1471        self.refresh();
1472    }
1473
1474    /// Remove focus from all elements within this context's window.
1475    pub fn blur(&mut self) {
1476        if !self.focus_enabled {
1477            return;
1478        }
1479
1480        self.focus = None;
1481        self.refresh();
1482    }
1483
1484    /// Blur the window and don't allow anything in it to be focused again.
1485    pub fn disable_focus(&mut self) {
1486        self.blur();
1487        self.focus_enabled = false;
1488    }
1489
1490    /// Move focus to next tab stop.
1491    pub fn focus_next(&mut self, cx: &mut App) {
1492        if !self.focus_enabled {
1493            return;
1494        }
1495
1496        if let Some(handle) = self.rendered_frame.tab_stops.next(self.focus.as_ref()) {
1497            self.focus(&handle, cx)
1498        }
1499    }
1500
1501    /// Move focus to previous tab stop.
1502    pub fn focus_prev(&mut self, cx: &mut App) {
1503        if !self.focus_enabled {
1504            return;
1505        }
1506
1507        if let Some(handle) = self.rendered_frame.tab_stops.prev(self.focus.as_ref()) {
1508            self.focus(&handle, cx)
1509        }
1510    }
1511
1512    /// Accessor for the text system.
1513    pub fn text_system(&self) -> &Arc<WindowTextSystem> {
1514        &self.text_system
1515    }
1516
1517    /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
1518    pub fn text_style(&self) -> TextStyle {
1519        let mut style = TextStyle::default();
1520        for refinement in &self.text_style_stack {
1521            style.refine(refinement);
1522        }
1523        style
1524    }
1525
1526    /// Check if the platform window is maximized.
1527    ///
1528    /// On some platforms (namely Windows) this is different than the bounds being the size of the display
1529    pub fn is_maximized(&self) -> bool {
1530        self.platform_window.is_maximized()
1531    }
1532
1533    /// request a certain window decoration (Wayland)
1534    pub fn request_decorations(&self, decorations: WindowDecorations) {
1535        self.platform_window.request_decorations(decorations);
1536    }
1537
1538    /// Start a window resize operation (Wayland)
1539    pub fn start_window_resize(&self, edge: ResizeEdge) {
1540        self.platform_window.start_window_resize(edge);
1541    }
1542
1543    /// Return the `WindowBounds` to indicate that how a window should be opened
1544    /// after it has been closed
1545    pub fn window_bounds(&self) -> WindowBounds {
1546        self.platform_window.window_bounds()
1547    }
1548
1549    /// Return the `WindowBounds` excluding insets (Wayland and X11)
1550    pub fn inner_window_bounds(&self) -> WindowBounds {
1551        self.platform_window.inner_window_bounds()
1552    }
1553
1554    /// Dispatch the given action on the currently focused element.
1555    pub fn dispatch_action(&mut self, action: Box<dyn Action>, cx: &mut App) {
1556        let focus_id = self.focused(cx).map(|handle| handle.id);
1557
1558        let window = self.handle;
1559        cx.defer(move |cx| {
1560            window
1561                .update(cx, |_, window, cx| {
1562                    let node_id = window.focus_node_id_in_rendered_frame(focus_id);
1563                    window.dispatch_action_on_node(node_id, action.as_ref(), cx);
1564                })
1565                .log_err();
1566        })
1567    }
1568
1569    pub(crate) fn dispatch_keystroke_observers(
1570        &mut self,
1571        event: &dyn Any,
1572        action: Option<Box<dyn Action>>,
1573        context_stack: Vec<KeyContext>,
1574        cx: &mut App,
1575    ) {
1576        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1577            return;
1578        };
1579
1580        cx.keystroke_observers.clone().retain(&(), move |callback| {
1581            (callback)(
1582                &KeystrokeEvent {
1583                    keystroke: key_down_event.keystroke.clone(),
1584                    action: action.as_ref().map(|action| action.boxed_clone()),
1585                    context_stack: context_stack.clone(),
1586                },
1587                self,
1588                cx,
1589            )
1590        });
1591    }
1592
1593    pub(crate) fn dispatch_keystroke_interceptors(
1594        &mut self,
1595        event: &dyn Any,
1596        context_stack: Vec<KeyContext>,
1597        cx: &mut App,
1598    ) {
1599        let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1600            return;
1601        };
1602
1603        cx.keystroke_interceptors
1604            .clone()
1605            .retain(&(), move |callback| {
1606                (callback)(
1607                    &KeystrokeEvent {
1608                        keystroke: key_down_event.keystroke.clone(),
1609                        action: None,
1610                        context_stack: context_stack.clone(),
1611                    },
1612                    self,
1613                    cx,
1614                )
1615            });
1616    }
1617
1618    /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1619    /// that are currently on the stack to be returned to the app.
1620    pub fn defer(&self, cx: &mut App, f: impl FnOnce(&mut Window, &mut App) + 'static) {
1621        let handle = self.handle;
1622        cx.defer(move |cx| {
1623            handle.update(cx, |_, window, cx| f(window, cx)).ok();
1624        });
1625    }
1626
1627    /// Subscribe to events emitted by a entity.
1628    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1629    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1630    pub fn observe<T: 'static>(
1631        &mut self,
1632        observed: &Entity<T>,
1633        cx: &mut App,
1634        mut on_notify: impl FnMut(Entity<T>, &mut Window, &mut App) + 'static,
1635    ) -> Subscription {
1636        let entity_id = observed.entity_id();
1637        let observed = observed.downgrade();
1638        let window_handle = self.handle;
1639        cx.new_observer(
1640            entity_id,
1641            Box::new(move |cx| {
1642                window_handle
1643                    .update(cx, |_, window, cx| {
1644                        if let Some(handle) = observed.upgrade() {
1645                            on_notify(handle, window, cx);
1646                            true
1647                        } else {
1648                            false
1649                        }
1650                    })
1651                    .unwrap_or(false)
1652            }),
1653        )
1654    }
1655
1656    /// Subscribe to events emitted by a entity.
1657    /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1658    /// The callback will be invoked a handle to the emitting entity, the event, and a window context for the current window.
1659    pub fn subscribe<Emitter, Evt>(
1660        &mut self,
1661        entity: &Entity<Emitter>,
1662        cx: &mut App,
1663        mut on_event: impl FnMut(Entity<Emitter>, &Evt, &mut Window, &mut App) + 'static,
1664    ) -> Subscription
1665    where
1666        Emitter: EventEmitter<Evt>,
1667        Evt: 'static,
1668    {
1669        let entity_id = entity.entity_id();
1670        let handle = entity.downgrade();
1671        let window_handle = self.handle;
1672        cx.new_subscription(
1673            entity_id,
1674            (
1675                TypeId::of::<Evt>(),
1676                Box::new(move |event, cx| {
1677                    window_handle
1678                        .update(cx, |_, window, cx| {
1679                            if let Some(entity) = handle.upgrade() {
1680                                let event = event.downcast_ref().expect("invalid event type");
1681                                on_event(entity, event, window, cx);
1682                                true
1683                            } else {
1684                                false
1685                            }
1686                        })
1687                        .unwrap_or(false)
1688                }),
1689            ),
1690        )
1691    }
1692
1693    /// Register a callback to be invoked when the given `Entity` is released.
1694    pub fn observe_release<T>(
1695        &self,
1696        entity: &Entity<T>,
1697        cx: &mut App,
1698        mut on_release: impl FnOnce(&mut T, &mut Window, &mut App) + 'static,
1699    ) -> Subscription
1700    where
1701        T: 'static,
1702    {
1703        let entity_id = entity.entity_id();
1704        let window_handle = self.handle;
1705        let (subscription, activate) = cx.release_listeners.insert(
1706            entity_id,
1707            Box::new(move |entity, cx| {
1708                let entity = entity.downcast_mut().expect("invalid entity type");
1709                let _ = window_handle.update(cx, |_, window, cx| on_release(entity, window, cx));
1710            }),
1711        );
1712        activate();
1713        subscription
1714    }
1715
1716    /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1717    /// await points in async code.
1718    pub fn to_async(&self, cx: &App) -> AsyncWindowContext {
1719        AsyncWindowContext::new_context(cx.to_async(), self.handle)
1720    }
1721
1722    /// Schedule the given closure to be run directly after the current frame is rendered.
1723    pub fn on_next_frame(&self, callback: impl FnOnce(&mut Window, &mut App) + 'static) {
1724        RefCell::borrow_mut(&self.next_frame_callbacks).push(Box::new(callback));
1725    }
1726
1727    /// Schedule a frame to be drawn on the next animation frame.
1728    ///
1729    /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1730    /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1731    ///
1732    /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1733    pub fn request_animation_frame(&self) {
1734        let entity = self.current_view();
1735        self.on_next_frame(move |_, cx| cx.notify(entity));
1736    }
1737
1738    /// Spawn the future returned by the given closure on the application thread pool.
1739    /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1740    /// use within your future.
1741    #[track_caller]
1742    pub fn spawn<AsyncFn, R>(&self, cx: &App, f: AsyncFn) -> Task<R>
1743    where
1744        R: 'static,
1745        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1746    {
1747        let handle = self.handle;
1748        cx.spawn(async move |app| {
1749            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1750            f(&mut async_window_cx).await
1751        })
1752    }
1753
1754    /// Spawn the future returned by the given closure on the application thread
1755    /// pool, with the given priority. The closure is provided a handle to the
1756    /// current window and an `AsyncWindowContext` for use within your future.
1757    #[track_caller]
1758    pub fn spawn_with_priority<AsyncFn, R>(
1759        &self,
1760        priority: Priority,
1761        cx: &App,
1762        f: AsyncFn,
1763    ) -> Task<R>
1764    where
1765        R: 'static,
1766        AsyncFn: AsyncFnOnce(&mut AsyncWindowContext) -> R + 'static,
1767    {
1768        let handle = self.handle;
1769        cx.spawn_with_priority(priority, async move |app| {
1770            let mut async_window_cx = AsyncWindowContext::new_context(app.clone(), handle);
1771            f(&mut async_window_cx).await
1772        })
1773    }
1774
1775    fn bounds_changed(&mut self, cx: &mut App) {
1776        self.scale_factor = self.platform_window.scale_factor();
1777        self.viewport_size = self.platform_window.content_size();
1778        self.display_id = self.platform_window.display().map(|display| display.id());
1779
1780        self.refresh();
1781
1782        self.bounds_observers
1783            .clone()
1784            .retain(&(), |callback| callback(self, cx));
1785    }
1786
1787    /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1788    pub fn bounds(&self) -> Bounds<Pixels> {
1789        self.platform_window.bounds()
1790    }
1791
1792    /// Set the content size of the window.
1793    pub fn resize(&mut self, size: Size<Pixels>) {
1794        self.platform_window.resize(size);
1795    }
1796
1797    /// Returns whether or not the window is currently fullscreen
1798    pub fn is_fullscreen(&self) -> bool {
1799        self.platform_window.is_fullscreen()
1800    }
1801
1802    pub(crate) fn appearance_changed(&mut self, cx: &mut App) {
1803        self.appearance = self.platform_window.appearance();
1804
1805        self.appearance_observers
1806            .clone()
1807            .retain(&(), |callback| callback(self, cx));
1808    }
1809
1810    /// Returns the appearance of the current window.
1811    pub fn appearance(&self) -> WindowAppearance {
1812        self.appearance
1813    }
1814
1815    /// Returns the size of the drawable area within the window.
1816    pub fn viewport_size(&self) -> Size<Pixels> {
1817        self.viewport_size
1818    }
1819
1820    /// Returns whether this window is focused by the operating system (receiving key events).
1821    pub fn is_window_active(&self) -> bool {
1822        self.active.get()
1823    }
1824
1825    /// Returns whether this window is considered to be the window
1826    /// that currently owns the mouse cursor.
1827    /// On mac, this is equivalent to `is_window_active`.
1828    pub fn is_window_hovered(&self) -> bool {
1829        if cfg!(any(
1830            target_os = "windows",
1831            target_os = "linux",
1832            target_os = "freebsd"
1833        )) {
1834            self.hovered.get()
1835        } else {
1836            self.is_window_active()
1837        }
1838    }
1839
1840    /// Toggle zoom on the window.
1841    pub fn zoom_window(&self) {
1842        self.platform_window.zoom();
1843    }
1844
1845    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1846    pub fn show_window_menu(&self, position: Point<Pixels>) {
1847        self.platform_window.show_window_menu(position)
1848    }
1849
1850    /// Handle window movement for Linux and macOS.
1851    /// Tells the compositor to take control of window movement (Wayland and X11)
1852    ///
1853    /// Events may not be received during a move operation.
1854    pub fn start_window_move(&self) {
1855        self.platform_window.start_window_move()
1856    }
1857
1858    /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1859    pub fn set_client_inset(&mut self, inset: Pixels) {
1860        self.client_inset = Some(inset);
1861        self.platform_window.set_client_inset(inset);
1862    }
1863
1864    /// Returns the client_inset value by [`Self::set_client_inset`].
1865    pub fn client_inset(&self) -> Option<Pixels> {
1866        self.client_inset
1867    }
1868
1869    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1870    pub fn window_decorations(&self) -> Decorations {
1871        self.platform_window.window_decorations()
1872    }
1873
1874    /// Returns which window controls are currently visible (Wayland)
1875    pub fn window_controls(&self) -> WindowControls {
1876        self.platform_window.window_controls()
1877    }
1878
1879    /// Updates the window's title at the platform level.
1880    pub fn set_window_title(&mut self, title: &str) {
1881        self.platform_window.set_title(title);
1882    }
1883
1884    /// Sets the application identifier.
1885    pub fn set_app_id(&mut self, app_id: &str) {
1886        self.platform_window.set_app_id(app_id);
1887    }
1888
1889    /// Sets the window background appearance.
1890    pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1891        self.platform_window
1892            .set_background_appearance(background_appearance);
1893    }
1894
1895    /// Mark the window as dirty at the platform level.
1896    pub fn set_window_edited(&mut self, edited: bool) {
1897        self.platform_window.set_edited(edited);
1898    }
1899
1900    /// Determine the display on which the window is visible.
1901    pub fn display(&self, cx: &App) -> Option<Rc<dyn PlatformDisplay>> {
1902        cx.platform
1903            .displays()
1904            .into_iter()
1905            .find(|display| Some(display.id()) == self.display_id)
1906    }
1907
1908    /// Show the platform character palette.
1909    pub fn show_character_palette(&self) {
1910        self.platform_window.show_character_palette();
1911    }
1912
1913    /// The scale factor of the display associated with the window. For example, it could
1914    /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1915    /// be rendered as two pixels on screen.
1916    pub fn scale_factor(&self) -> f32 {
1917        self.scale_factor
1918    }
1919
1920    /// The size of an em for the base font of the application. Adjusting this value allows the
1921    /// UI to scale, just like zooming a web page.
1922    pub fn rem_size(&self) -> Pixels {
1923        self.rem_size_override_stack
1924            .last()
1925            .copied()
1926            .unwrap_or(self.rem_size)
1927    }
1928
1929    /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1930    /// UI to scale, just like zooming a web page.
1931    pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1932        self.rem_size = rem_size.into();
1933    }
1934
1935    /// Acquire a globally unique identifier for the given ElementId.
1936    /// Only valid for the duration of the provided closure.
1937    pub fn with_global_id<R>(
1938        &mut self,
1939        element_id: ElementId,
1940        f: impl FnOnce(&GlobalElementId, &mut Self) -> R,
1941    ) -> R {
1942        self.element_id_stack.push(element_id);
1943        let global_id = GlobalElementId(Arc::from(&*self.element_id_stack));
1944
1945        let result = f(&global_id, self);
1946        self.element_id_stack.pop();
1947        result
1948    }
1949
1950    /// Executes the provided function with the specified rem size.
1951    ///
1952    /// This method must only be called as part of element drawing.
1953    // This function is called in a highly recursive manner in editor
1954    // prepainting, make sure its inlined to reduce the stack burden
1955    #[inline]
1956    pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1957    where
1958        F: FnOnce(&mut Self) -> R,
1959    {
1960        self.invalidator.debug_assert_paint_or_prepaint();
1961
1962        if let Some(rem_size) = rem_size {
1963            self.rem_size_override_stack.push(rem_size.into());
1964            let result = f(self);
1965            self.rem_size_override_stack.pop();
1966            result
1967        } else {
1968            f(self)
1969        }
1970    }
1971
1972    /// The line height associated with the current text style.
1973    pub fn line_height(&self) -> Pixels {
1974        self.text_style().line_height_in_pixels(self.rem_size())
1975    }
1976
1977    /// Call to prevent the default action of an event. Currently only used to prevent
1978    /// parent elements from becoming focused on mouse down.
1979    pub fn prevent_default(&mut self) {
1980        self.default_prevented = true;
1981    }
1982
1983    /// Obtain whether default has been prevented for the event currently being dispatched.
1984    pub fn default_prevented(&self) -> bool {
1985        self.default_prevented
1986    }
1987
1988    /// Determine whether the given action is available along the dispatch path to the currently focused element.
1989    pub fn is_action_available(&self, action: &dyn Action, cx: &App) -> bool {
1990        let node_id =
1991            self.focus_node_id_in_rendered_frame(self.focused(cx).map(|handle| handle.id));
1992        self.rendered_frame
1993            .dispatch_tree
1994            .is_action_available(action, node_id)
1995    }
1996
1997    /// Determine whether the given action is available along the dispatch path to the given focus_handle.
1998    pub fn is_action_available_in(&self, action: &dyn Action, focus_handle: &FocusHandle) -> bool {
1999        let node_id = self.focus_node_id_in_rendered_frame(Some(focus_handle.id));
2000        self.rendered_frame
2001            .dispatch_tree
2002            .is_action_available(action, node_id)
2003    }
2004
2005    /// The position of the mouse relative to the window.
2006    pub fn mouse_position(&self) -> Point<Pixels> {
2007        self.mouse_position
2008    }
2009
2010    /// Captures the pointer for the given hitbox. While captured, all mouse move and mouse up
2011    /// events will be routed to listeners that check this hitbox's `is_hovered` status,
2012    /// regardless of actual hit testing. This enables drag operations that continue
2013    /// even when the pointer moves outside the element's bounds.
2014    ///
2015    /// The capture is automatically released on mouse up.
2016    pub fn capture_pointer(&mut self, hitbox_id: HitboxId) {
2017        self.captured_hitbox = Some(hitbox_id);
2018    }
2019
2020    /// Releases any active pointer capture.
2021    pub fn release_pointer(&mut self) {
2022        self.captured_hitbox = None;
2023    }
2024
2025    /// Returns the hitbox that has captured the pointer, if any.
2026    pub fn captured_hitbox(&self) -> Option<HitboxId> {
2027        self.captured_hitbox
2028    }
2029
2030    /// The current state of the keyboard's modifiers
2031    pub fn modifiers(&self) -> Modifiers {
2032        self.modifiers
2033    }
2034
2035    /// Returns true if the last input event was keyboard-based (key press, tab navigation, etc.)
2036    /// This is used for focus-visible styling to show focus indicators only for keyboard navigation.
2037    pub fn last_input_was_keyboard(&self) -> bool {
2038        self.last_input_modality == InputModality::Keyboard
2039    }
2040
2041    /// The current state of the keyboard's capslock
2042    pub fn capslock(&self) -> Capslock {
2043        self.capslock
2044    }
2045
2046    fn complete_frame(&self) {
2047        self.platform_window.completed_frame();
2048    }
2049
2050    /// Produces a new frame and assigns it to `rendered_frame`. To actually show
2051    /// the contents of the new [`Scene`], use [`Self::present`].
2052    #[profiling::function]
2053    pub fn draw(&mut self, cx: &mut App) -> ArenaClearNeeded {
2054        self.invalidate_entities();
2055        cx.entities.clear_accessed();
2056        debug_assert!(self.rendered_entity_stack.is_empty());
2057        self.invalidator.set_dirty(false);
2058        self.requested_autoscroll = None;
2059
2060        // Restore the previously-used input handler.
2061        if let Some(input_handler) = self.platform_window.take_input_handler() {
2062            self.rendered_frame.input_handlers.push(Some(input_handler));
2063        }
2064        if !cx.mode.skip_drawing() {
2065            self.draw_roots(cx);
2066        }
2067        self.dirty_views.clear();
2068        self.next_frame.window_active = self.active.get();
2069
2070        // Register requested input handler with the platform window.
2071        if let Some(input_handler) = self.next_frame.input_handlers.pop() {
2072            self.platform_window
2073                .set_input_handler(input_handler.unwrap());
2074        }
2075
2076        self.layout_engine.as_mut().unwrap().clear();
2077        self.text_system().finish_frame();
2078        self.next_frame.finish(&mut self.rendered_frame);
2079
2080        self.invalidator.set_phase(DrawPhase::Focus);
2081        let previous_focus_path = self.rendered_frame.focus_path();
2082        let previous_window_active = self.rendered_frame.window_active;
2083        mem::swap(&mut self.rendered_frame, &mut self.next_frame);
2084        self.next_frame.clear();
2085        let current_focus_path = self.rendered_frame.focus_path();
2086        let current_window_active = self.rendered_frame.window_active;
2087
2088        if previous_focus_path != current_focus_path
2089            || previous_window_active != current_window_active
2090        {
2091            if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
2092                self.focus_lost_listeners
2093                    .clone()
2094                    .retain(&(), |listener| listener(self, cx));
2095            }
2096
2097            let event = WindowFocusEvent {
2098                previous_focus_path: if previous_window_active {
2099                    previous_focus_path
2100                } else {
2101                    Default::default()
2102                },
2103                current_focus_path: if current_window_active {
2104                    current_focus_path
2105                } else {
2106                    Default::default()
2107                },
2108            };
2109            self.focus_listeners
2110                .clone()
2111                .retain(&(), |listener| listener(&event, self, cx));
2112        }
2113
2114        debug_assert!(self.rendered_entity_stack.is_empty());
2115        self.record_entities_accessed(cx);
2116        self.reset_cursor_style(cx);
2117        self.refreshing = false;
2118        self.invalidator.set_phase(DrawPhase::None);
2119        self.needs_present.set(true);
2120
2121        ArenaClearNeeded
2122    }
2123
2124    fn record_entities_accessed(&mut self, cx: &mut App) {
2125        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
2126        let mut entities = mem::take(entities_ref.deref_mut());
2127        drop(entities_ref);
2128        let handle = self.handle;
2129        cx.record_entities_accessed(
2130            handle,
2131            // Try moving window invalidator into the Window
2132            self.invalidator.clone(),
2133            &entities,
2134        );
2135        let mut entities_ref = cx.entities.accessed_entities.borrow_mut();
2136        mem::swap(&mut entities, entities_ref.deref_mut());
2137    }
2138
2139    fn invalidate_entities(&mut self) {
2140        let mut views = self.invalidator.take_views();
2141        for entity in views.drain() {
2142            self.mark_view_dirty(entity);
2143        }
2144        self.invalidator.replace_views(views);
2145    }
2146
2147    #[profiling::function]
2148    fn present(&self) {
2149        self.platform_window.draw(&self.rendered_frame.scene);
2150        self.needs_present.set(false);
2151        profiling::finish_frame!();
2152    }
2153
2154    fn draw_roots(&mut self, cx: &mut App) {
2155        self.invalidator.set_phase(DrawPhase::Prepaint);
2156        self.tooltip_bounds.take();
2157
2158        let _inspector_width: Pixels = rems(30.0).to_pixels(self.rem_size());
2159        let root_size = {
2160            #[cfg(any(feature = "inspector", debug_assertions))]
2161            {
2162                if self.inspector.is_some() {
2163                    let mut size = self.viewport_size;
2164                    size.width = (size.width - _inspector_width).max(px(0.0));
2165                    size
2166                } else {
2167                    self.viewport_size
2168                }
2169            }
2170            #[cfg(not(any(feature = "inspector", debug_assertions)))]
2171            {
2172                self.viewport_size
2173            }
2174        };
2175
2176        // Layout all root elements.
2177        let mut root_element = self.root.as_ref().unwrap().clone().into_any();
2178        root_element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2179
2180        #[cfg(any(feature = "inspector", debug_assertions))]
2181        let inspector_element = self.prepaint_inspector(_inspector_width, cx);
2182
2183        let mut sorted_deferred_draws =
2184            (0..self.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
2185        sorted_deferred_draws.sort_by_key(|ix| self.next_frame.deferred_draws[*ix].priority);
2186        self.prepaint_deferred_draws(&sorted_deferred_draws, cx);
2187
2188        let mut prompt_element = None;
2189        let mut active_drag_element = None;
2190        let mut tooltip_element = None;
2191        if let Some(prompt) = self.prompt.take() {
2192            let mut element = prompt.view.any_view().into_any();
2193            element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
2194            prompt_element = Some(element);
2195            self.prompt = Some(prompt);
2196        } else if let Some(active_drag) = cx.active_drag.take() {
2197            let mut element = active_drag.view.clone().into_any();
2198            let offset = self.mouse_position() - active_drag.cursor_offset;
2199            element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
2200            active_drag_element = Some(element);
2201            cx.active_drag = Some(active_drag);
2202        } else {
2203            tooltip_element = self.prepaint_tooltip(cx);
2204        }
2205
2206        self.mouse_hit_test = self.next_frame.hit_test(self.mouse_position);
2207
2208        // Now actually paint the elements.
2209        self.invalidator.set_phase(DrawPhase::Paint);
2210        root_element.paint(self, cx);
2211
2212        #[cfg(any(feature = "inspector", debug_assertions))]
2213        self.paint_inspector(inspector_element, cx);
2214
2215        self.paint_deferred_draws(&sorted_deferred_draws, cx);
2216
2217        if let Some(mut prompt_element) = prompt_element {
2218            prompt_element.paint(self, cx);
2219        } else if let Some(mut drag_element) = active_drag_element {
2220            drag_element.paint(self, cx);
2221        } else if let Some(mut tooltip_element) = tooltip_element {
2222            tooltip_element.paint(self, cx);
2223        }
2224
2225        #[cfg(any(feature = "inspector", debug_assertions))]
2226        self.paint_inspector_hitbox(cx);
2227    }
2228
2229    fn prepaint_tooltip(&mut self, cx: &mut App) -> Option<AnyElement> {
2230        // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
2231        for tooltip_request_index in (0..self.next_frame.tooltip_requests.len()).rev() {
2232            let Some(Some(tooltip_request)) = self
2233                .next_frame
2234                .tooltip_requests
2235                .get(tooltip_request_index)
2236                .cloned()
2237            else {
2238                log::error!("Unexpectedly absent TooltipRequest");
2239                continue;
2240            };
2241            let mut element = tooltip_request.tooltip.view.clone().into_any();
2242            let mouse_position = tooltip_request.tooltip.mouse_position;
2243            let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self, cx);
2244
2245            let mut tooltip_bounds =
2246                Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
2247            let window_bounds = Bounds {
2248                origin: Point::default(),
2249                size: self.viewport_size(),
2250            };
2251
2252            if tooltip_bounds.right() > window_bounds.right() {
2253                let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
2254                if new_x >= Pixels::ZERO {
2255                    tooltip_bounds.origin.x = new_x;
2256                } else {
2257                    tooltip_bounds.origin.x = cmp::max(
2258                        Pixels::ZERO,
2259                        tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
2260                    );
2261                }
2262            }
2263
2264            if tooltip_bounds.bottom() > window_bounds.bottom() {
2265                let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
2266                if new_y >= Pixels::ZERO {
2267                    tooltip_bounds.origin.y = new_y;
2268                } else {
2269                    tooltip_bounds.origin.y = cmp::max(
2270                        Pixels::ZERO,
2271                        tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
2272                    );
2273                }
2274            }
2275
2276            // It's possible for an element to have an active tooltip while not being painted (e.g.
2277            // via the `visible_on_hover` method). Since mouse listeners are not active in this
2278            // case, instead update the tooltip's visibility here.
2279            let is_visible =
2280                (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self, cx);
2281            if !is_visible {
2282                continue;
2283            }
2284
2285            self.with_absolute_element_offset(tooltip_bounds.origin, |window| {
2286                element.prepaint(window, cx)
2287            });
2288
2289            self.tooltip_bounds = Some(TooltipBounds {
2290                id: tooltip_request.id,
2291                bounds: tooltip_bounds,
2292            });
2293            return Some(element);
2294        }
2295        None
2296    }
2297
2298    fn prepaint_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 deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2304            self.element_id_stack
2305                .clone_from(&deferred_draw.element_id_stack);
2306            self.text_style_stack
2307                .clone_from(&deferred_draw.text_style_stack);
2308            self.next_frame
2309                .dispatch_tree
2310                .set_active_node(deferred_draw.parent_node);
2311
2312            let prepaint_start = self.prepaint_index();
2313            if let Some(element) = deferred_draw.element.as_mut() {
2314                self.with_rendered_view(deferred_draw.current_view, |window| {
2315                    window.with_absolute_element_offset(deferred_draw.absolute_offset, |window| {
2316                        element.prepaint(window, cx)
2317                    });
2318                })
2319            } else {
2320                self.reuse_prepaint(deferred_draw.prepaint_range.clone());
2321            }
2322            let prepaint_end = self.prepaint_index();
2323            deferred_draw.prepaint_range = prepaint_start..prepaint_end;
2324        }
2325        assert_eq!(
2326            self.next_frame.deferred_draws.len(),
2327            0,
2328            "cannot call defer_draw during deferred drawing"
2329        );
2330        self.next_frame.deferred_draws = deferred_draws;
2331        self.element_id_stack.clear();
2332        self.text_style_stack.clear();
2333    }
2334
2335    fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize], cx: &mut App) {
2336        assert_eq!(self.element_id_stack.len(), 0);
2337
2338        let mut deferred_draws = mem::take(&mut self.next_frame.deferred_draws);
2339        for deferred_draw_ix in deferred_draw_indices {
2340            let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
2341            self.element_id_stack
2342                .clone_from(&deferred_draw.element_id_stack);
2343            self.next_frame
2344                .dispatch_tree
2345                .set_active_node(deferred_draw.parent_node);
2346
2347            let paint_start = self.paint_index();
2348            if let Some(element) = deferred_draw.element.as_mut() {
2349                self.with_rendered_view(deferred_draw.current_view, |window| {
2350                    element.paint(window, cx);
2351                })
2352            } else {
2353                self.reuse_paint(deferred_draw.paint_range.clone());
2354            }
2355            let paint_end = self.paint_index();
2356            deferred_draw.paint_range = paint_start..paint_end;
2357        }
2358        self.next_frame.deferred_draws = deferred_draws;
2359        self.element_id_stack.clear();
2360    }
2361
2362    pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
2363        PrepaintStateIndex {
2364            hitboxes_index: self.next_frame.hitboxes.len(),
2365            tooltips_index: self.next_frame.tooltip_requests.len(),
2366            deferred_draws_index: self.next_frame.deferred_draws.len(),
2367            dispatch_tree_index: self.next_frame.dispatch_tree.len(),
2368            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2369            line_layout_index: self.text_system.layout_index(),
2370        }
2371    }
2372
2373    pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
2374        self.next_frame.hitboxes.extend(
2375            self.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
2376                .iter()
2377                .cloned(),
2378        );
2379        self.next_frame.tooltip_requests.extend(
2380            self.rendered_frame.tooltip_requests
2381                [range.start.tooltips_index..range.end.tooltips_index]
2382                .iter_mut()
2383                .map(|request| request.take()),
2384        );
2385        self.next_frame.accessed_element_states.extend(
2386            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2387                ..range.end.accessed_element_states_index]
2388                .iter()
2389                .map(|(id, type_id)| (id.clone(), *type_id)),
2390        );
2391        self.text_system
2392            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2393
2394        let reused_subtree = self.next_frame.dispatch_tree.reuse_subtree(
2395            range.start.dispatch_tree_index..range.end.dispatch_tree_index,
2396            &mut self.rendered_frame.dispatch_tree,
2397            self.focus,
2398        );
2399
2400        if reused_subtree.contains_focus() {
2401            self.next_frame.focus = self.focus;
2402        }
2403
2404        self.next_frame.deferred_draws.extend(
2405            self.rendered_frame.deferred_draws
2406                [range.start.deferred_draws_index..range.end.deferred_draws_index]
2407                .iter()
2408                .map(|deferred_draw| DeferredDraw {
2409                    current_view: deferred_draw.current_view,
2410                    parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
2411                    element_id_stack: deferred_draw.element_id_stack.clone(),
2412                    text_style_stack: deferred_draw.text_style_stack.clone(),
2413                    priority: deferred_draw.priority,
2414                    element: None,
2415                    absolute_offset: deferred_draw.absolute_offset,
2416                    prepaint_range: deferred_draw.prepaint_range.clone(),
2417                    paint_range: deferred_draw.paint_range.clone(),
2418                }),
2419        );
2420    }
2421
2422    pub(crate) fn paint_index(&self) -> PaintIndex {
2423        PaintIndex {
2424            scene_index: self.next_frame.scene.len(),
2425            mouse_listeners_index: self.next_frame.mouse_listeners.len(),
2426            input_handlers_index: self.next_frame.input_handlers.len(),
2427            cursor_styles_index: self.next_frame.cursor_styles.len(),
2428            accessed_element_states_index: self.next_frame.accessed_element_states.len(),
2429            tab_handle_index: self.next_frame.tab_stops.paint_index(),
2430            line_layout_index: self.text_system.layout_index(),
2431        }
2432    }
2433
2434    pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
2435        self.next_frame.cursor_styles.extend(
2436            self.rendered_frame.cursor_styles
2437                [range.start.cursor_styles_index..range.end.cursor_styles_index]
2438                .iter()
2439                .cloned(),
2440        );
2441        self.next_frame.input_handlers.extend(
2442            self.rendered_frame.input_handlers
2443                [range.start.input_handlers_index..range.end.input_handlers_index]
2444                .iter_mut()
2445                .map(|handler| handler.take()),
2446        );
2447        self.next_frame.mouse_listeners.extend(
2448            self.rendered_frame.mouse_listeners
2449                [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
2450                .iter_mut()
2451                .map(|listener| listener.take()),
2452        );
2453        self.next_frame.accessed_element_states.extend(
2454            self.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
2455                ..range.end.accessed_element_states_index]
2456                .iter()
2457                .map(|(id, type_id)| (id.clone(), *type_id)),
2458        );
2459        self.next_frame.tab_stops.replay(
2460            &self.rendered_frame.tab_stops.insertion_history
2461                [range.start.tab_handle_index..range.end.tab_handle_index],
2462        );
2463
2464        self.text_system
2465            .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
2466        self.next_frame.scene.replay(
2467            range.start.scene_index..range.end.scene_index,
2468            &self.rendered_frame.scene,
2469        );
2470    }
2471
2472    /// Push a text style onto the stack, and call a function with that style active.
2473    /// Use [`Window::text_style`] to get the current, combined text style. This method
2474    /// should only be called as part of element drawing.
2475    // This function is called in a highly recursive manner in editor
2476    // prepainting, make sure its inlined to reduce the stack burden
2477    #[inline]
2478    pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
2479    where
2480        F: FnOnce(&mut Self) -> R,
2481    {
2482        self.invalidator.debug_assert_paint_or_prepaint();
2483        if let Some(style) = style {
2484            self.text_style_stack.push(style);
2485            let result = f(self);
2486            self.text_style_stack.pop();
2487            result
2488        } else {
2489            f(self)
2490        }
2491    }
2492
2493    /// Updates the cursor style at the platform level. This method should only be called
2494    /// during the paint phase of element drawing.
2495    pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
2496        self.invalidator.debug_assert_paint();
2497        self.next_frame.cursor_styles.push(CursorStyleRequest {
2498            hitbox_id: Some(hitbox.id),
2499            style,
2500        });
2501    }
2502
2503    /// Updates the cursor style for the entire window at the platform level. A cursor
2504    /// style using this method will have precedence over any cursor style set using
2505    /// `set_cursor_style`. This method should only be called during the paint
2506    /// phase of element drawing.
2507    pub fn set_window_cursor_style(&mut self, style: CursorStyle) {
2508        self.invalidator.debug_assert_paint();
2509        self.next_frame.cursor_styles.push(CursorStyleRequest {
2510            hitbox_id: None,
2511            style,
2512        })
2513    }
2514
2515    /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
2516    /// during the paint phase of element drawing.
2517    pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
2518        self.invalidator.debug_assert_prepaint();
2519        let id = TooltipId(post_inc(&mut self.next_tooltip_id.0));
2520        self.next_frame
2521            .tooltip_requests
2522            .push(Some(TooltipRequest { id, tooltip }));
2523        id
2524    }
2525
2526    /// Invoke the given function with the given content mask after intersecting it
2527    /// with the current mask. This method should only be called during element drawing.
2528    // This function is called in a highly recursive manner in editor
2529    // prepainting, make sure its inlined to reduce the stack burden
2530    #[inline]
2531    pub fn with_content_mask<R>(
2532        &mut self,
2533        mask: Option<ContentMask<Pixels>>,
2534        f: impl FnOnce(&mut Self) -> R,
2535    ) -> R {
2536        self.invalidator.debug_assert_paint_or_prepaint();
2537        if let Some(mask) = mask {
2538            let mask = mask.intersect(&self.content_mask());
2539            self.content_mask_stack.push(mask);
2540            let result = f(self);
2541            self.content_mask_stack.pop();
2542            result
2543        } else {
2544            f(self)
2545        }
2546    }
2547
2548    /// Updates the global element offset relative to the current offset. This is used to implement
2549    /// scrolling. This method should only be called during the prepaint phase of element drawing.
2550    pub fn with_element_offset<R>(
2551        &mut self,
2552        offset: Point<Pixels>,
2553        f: impl FnOnce(&mut Self) -> R,
2554    ) -> R {
2555        self.invalidator.debug_assert_prepaint();
2556
2557        if offset.is_zero() {
2558            return f(self);
2559        };
2560
2561        let abs_offset = self.element_offset() + offset;
2562        self.with_absolute_element_offset(abs_offset, f)
2563    }
2564
2565    /// Updates the global element offset based on the given offset. This is used to implement
2566    /// drag handles and other manual painting of elements. This method should only be called during
2567    /// the prepaint phase of element drawing.
2568    pub fn with_absolute_element_offset<R>(
2569        &mut self,
2570        offset: Point<Pixels>,
2571        f: impl FnOnce(&mut Self) -> R,
2572    ) -> R {
2573        self.invalidator.debug_assert_prepaint();
2574        self.element_offset_stack.push(offset);
2575        let result = f(self);
2576        self.element_offset_stack.pop();
2577        result
2578    }
2579
2580    pub(crate) fn with_element_opacity<R>(
2581        &mut self,
2582        opacity: Option<f32>,
2583        f: impl FnOnce(&mut Self) -> R,
2584    ) -> R {
2585        self.invalidator.debug_assert_paint_or_prepaint();
2586
2587        let Some(opacity) = opacity else {
2588            return f(self);
2589        };
2590
2591        let previous_opacity = self.element_opacity;
2592        self.element_opacity = previous_opacity * opacity;
2593        let result = f(self);
2594        self.element_opacity = previous_opacity;
2595        result
2596    }
2597
2598    /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
2599    /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
2600    /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
2601    /// element offset and prepaint again. See [`crate::List`] for an example. This method should only be
2602    /// called during the prepaint phase of element drawing.
2603    pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
2604        self.invalidator.debug_assert_prepaint();
2605        let index = self.prepaint_index();
2606        let result = f(self);
2607        if result.is_err() {
2608            self.next_frame.hitboxes.truncate(index.hitboxes_index);
2609            self.next_frame
2610                .tooltip_requests
2611                .truncate(index.tooltips_index);
2612            self.next_frame
2613                .deferred_draws
2614                .truncate(index.deferred_draws_index);
2615            self.next_frame
2616                .dispatch_tree
2617                .truncate(index.dispatch_tree_index);
2618            self.next_frame
2619                .accessed_element_states
2620                .truncate(index.accessed_element_states_index);
2621            self.text_system.truncate_layouts(index.line_layout_index);
2622        }
2623        result
2624    }
2625
2626    /// When you call this method during [`Element::prepaint`], containing elements will attempt to
2627    /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
2628    /// [`Element::prepaint`] again with a new set of bounds. See [`crate::List`] for an example of an element
2629    /// that supports this method being called on the elements it contains. This method should only be
2630    /// called during the prepaint phase of element drawing.
2631    pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
2632        self.invalidator.debug_assert_prepaint();
2633        self.requested_autoscroll = Some(bounds);
2634    }
2635
2636    /// This method can be called from a containing element such as [`crate::List`] to support the autoscroll behavior
2637    /// described in [`Self::request_autoscroll`].
2638    pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
2639        self.invalidator.debug_assert_prepaint();
2640        self.requested_autoscroll.take()
2641    }
2642
2643    /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2644    /// Your view will be re-drawn once the asset has finished loading.
2645    ///
2646    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2647    /// time.
2648    pub fn use_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2649        let (task, is_first) = cx.fetch_asset::<A>(source);
2650        task.clone().now_or_never().or_else(|| {
2651            if is_first {
2652                let entity_id = self.current_view();
2653                self.spawn(cx, {
2654                    let task = task.clone();
2655                    async move |cx| {
2656                        task.await;
2657
2658                        cx.on_next_frame(move |_, cx| {
2659                            cx.notify(entity_id);
2660                        });
2661                    }
2662                })
2663                .detach();
2664            }
2665
2666            None
2667        })
2668    }
2669
2670    /// Asynchronously load an asset, if the asset hasn't finished loading or doesn't exist this will return None.
2671    /// Your view will not be re-drawn once the asset has finished loading.
2672    ///
2673    /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2674    /// time.
2675    pub fn get_asset<A: Asset>(&mut self, source: &A::Source, cx: &mut App) -> Option<A::Output> {
2676        let (task, _) = cx.fetch_asset::<A>(source);
2677        task.now_or_never()
2678    }
2679    /// Obtain the current element offset. This method should only be called during the
2680    /// prepaint phase of element drawing.
2681    pub fn element_offset(&self) -> Point<Pixels> {
2682        self.invalidator.debug_assert_prepaint();
2683        self.element_offset_stack
2684            .last()
2685            .copied()
2686            .unwrap_or_default()
2687    }
2688
2689    /// Obtain the current element opacity. This method should only be called during the
2690    /// prepaint phase of element drawing.
2691    #[inline]
2692    pub(crate) fn element_opacity(&self) -> f32 {
2693        self.invalidator.debug_assert_paint_or_prepaint();
2694        self.element_opacity
2695    }
2696
2697    /// Obtain the current content mask. This method should only be called during element drawing.
2698    pub fn content_mask(&self) -> ContentMask<Pixels> {
2699        self.invalidator.debug_assert_paint_or_prepaint();
2700        self.content_mask_stack
2701            .last()
2702            .cloned()
2703            .unwrap_or_else(|| ContentMask {
2704                bounds: Bounds {
2705                    origin: Point::default(),
2706                    size: self.viewport_size,
2707                },
2708            })
2709    }
2710
2711    /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2712    /// This can be used within a custom element to distinguish multiple sets of child elements.
2713    pub fn with_element_namespace<R>(
2714        &mut self,
2715        element_id: impl Into<ElementId>,
2716        f: impl FnOnce(&mut Self) -> R,
2717    ) -> R {
2718        self.element_id_stack.push(element_id.into());
2719        let result = f(self);
2720        self.element_id_stack.pop();
2721        result
2722    }
2723
2724    /// Use a piece of state that exists as long this element is being rendered in consecutive frames.
2725    pub fn use_keyed_state<S: 'static>(
2726        &mut self,
2727        key: impl Into<ElementId>,
2728        cx: &mut App,
2729        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2730    ) -> Entity<S> {
2731        let current_view = self.current_view();
2732        self.with_global_id(key.into(), |global_id, window| {
2733            window.with_element_state(global_id, |state: Option<Entity<S>>, window| {
2734                if let Some(state) = state {
2735                    (state.clone(), state)
2736                } else {
2737                    let new_state = cx.new(|cx| init(window, cx));
2738                    cx.observe(&new_state, move |_, cx| {
2739                        cx.notify(current_view);
2740                    })
2741                    .detach();
2742                    (new_state.clone(), new_state)
2743                }
2744            })
2745        })
2746    }
2747
2748    /// Immediately push an element ID onto the stack. Useful for simplifying IDs in lists
2749    pub fn with_id<R>(&mut self, id: impl Into<ElementId>, f: impl FnOnce(&mut Self) -> R) -> R {
2750        self.with_global_id(id.into(), |_, window| f(window))
2751    }
2752
2753    /// Use a piece of state that exists as long this element is being rendered in consecutive frames, without needing to specify a key
2754    ///
2755    /// NOTE: This method uses the location of the caller to generate an ID for this state.
2756    ///       If this is not sufficient to identify your state (e.g. you're rendering a list item),
2757    ///       you can provide a custom ElementID using the `use_keyed_state` method.
2758    #[track_caller]
2759    pub fn use_state<S: 'static>(
2760        &mut self,
2761        cx: &mut App,
2762        init: impl FnOnce(&mut Self, &mut Context<S>) -> S,
2763    ) -> Entity<S> {
2764        self.use_keyed_state(
2765            ElementId::CodeLocation(*core::panic::Location::caller()),
2766            cx,
2767            init,
2768        )
2769    }
2770
2771    /// Updates or initializes state for an element with the given id that lives across multiple
2772    /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2773    /// to the given closure. The state returned by the closure will be stored so it can be referenced
2774    /// when drawing the next frame. This method should only be called as part of element drawing.
2775    pub fn with_element_state<S, R>(
2776        &mut self,
2777        global_id: &GlobalElementId,
2778        f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2779    ) -> R
2780    where
2781        S: 'static,
2782    {
2783        self.invalidator.debug_assert_paint_or_prepaint();
2784
2785        let key = (global_id.clone(), TypeId::of::<S>());
2786        self.next_frame.accessed_element_states.push(key.clone());
2787
2788        if let Some(any) = self
2789            .next_frame
2790            .element_states
2791            .remove(&key)
2792            .or_else(|| self.rendered_frame.element_states.remove(&key))
2793        {
2794            let ElementStateBox {
2795                inner,
2796                #[cfg(debug_assertions)]
2797                type_name,
2798            } = any;
2799            // Using the extra inner option to avoid needing to reallocate a new box.
2800            let mut state_box = inner
2801                .downcast::<Option<S>>()
2802                .map_err(|_| {
2803                    #[cfg(debug_assertions)]
2804                    {
2805                        anyhow::anyhow!(
2806                            "invalid element state type for id, requested {:?}, actual: {:?}",
2807                            std::any::type_name::<S>(),
2808                            type_name
2809                        )
2810                    }
2811
2812                    #[cfg(not(debug_assertions))]
2813                    {
2814                        anyhow::anyhow!(
2815                            "invalid element state type for id, requested {:?}",
2816                            std::any::type_name::<S>(),
2817                        )
2818                    }
2819                })
2820                .unwrap();
2821
2822            let state = state_box.take().expect(
2823                "reentrant call to with_element_state for the same state type and element id",
2824            );
2825            let (result, state) = f(Some(state), self);
2826            state_box.replace(state);
2827            self.next_frame.element_states.insert(
2828                key,
2829                ElementStateBox {
2830                    inner: state_box,
2831                    #[cfg(debug_assertions)]
2832                    type_name,
2833                },
2834            );
2835            result
2836        } else {
2837            let (result, state) = f(None, self);
2838            self.next_frame.element_states.insert(
2839                key,
2840                ElementStateBox {
2841                    inner: Box::new(Some(state)),
2842                    #[cfg(debug_assertions)]
2843                    type_name: std::any::type_name::<S>(),
2844                },
2845            );
2846            result
2847        }
2848    }
2849
2850    /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2851    /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2852    /// when the element is guaranteed to have an id.
2853    ///
2854    /// The first option means 'no ID provided'
2855    /// The second option means 'not yet initialized'
2856    pub fn with_optional_element_state<S, R>(
2857        &mut self,
2858        global_id: Option<&GlobalElementId>,
2859        f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2860    ) -> R
2861    where
2862        S: 'static,
2863    {
2864        self.invalidator.debug_assert_paint_or_prepaint();
2865
2866        if let Some(global_id) = global_id {
2867            self.with_element_state(global_id, |state, cx| {
2868                let (result, state) = f(Some(state), cx);
2869                let state =
2870                    state.expect("you must return some state when you pass some element id");
2871                (result, state)
2872            })
2873        } else {
2874            let (result, state) = f(None, self);
2875            debug_assert!(
2876                state.is_none(),
2877                "you must not return an element state when passing None for the global id"
2878            );
2879            result
2880        }
2881    }
2882
2883    /// Executes the given closure within the context of a tab group.
2884    #[inline]
2885    pub fn with_tab_group<R>(&mut self, index: Option<isize>, f: impl FnOnce(&mut Self) -> R) -> R {
2886        if let Some(index) = index {
2887            self.next_frame.tab_stops.begin_group(index);
2888            let result = f(self);
2889            self.next_frame.tab_stops.end_group();
2890            result
2891        } else {
2892            f(self)
2893        }
2894    }
2895
2896    /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2897    /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2898    /// with higher values being drawn on top.
2899    ///
2900    /// This method should only be called as part of the prepaint phase of element drawing.
2901    pub fn defer_draw(
2902        &mut self,
2903        element: AnyElement,
2904        absolute_offset: Point<Pixels>,
2905        priority: usize,
2906    ) {
2907        self.invalidator.debug_assert_prepaint();
2908        let parent_node = self.next_frame.dispatch_tree.active_node_id().unwrap();
2909        self.next_frame.deferred_draws.push(DeferredDraw {
2910            current_view: self.current_view(),
2911            parent_node,
2912            element_id_stack: self.element_id_stack.clone(),
2913            text_style_stack: self.text_style_stack.clone(),
2914            priority,
2915            element: Some(element),
2916            absolute_offset,
2917            prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2918            paint_range: PaintIndex::default()..PaintIndex::default(),
2919        });
2920    }
2921
2922    /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2923    /// of geometry that are non-overlapping and have the same draw order. This is typically used
2924    /// for performance reasons.
2925    ///
2926    /// This method should only be called as part of the paint phase of element drawing.
2927    pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2928        self.invalidator.debug_assert_paint();
2929
2930        let scale_factor = self.scale_factor();
2931        let content_mask = self.content_mask();
2932        let clipped_bounds = bounds.intersect(&content_mask.bounds);
2933        if !clipped_bounds.is_empty() {
2934            self.next_frame
2935                .scene
2936                .push_layer(clipped_bounds.scale(scale_factor));
2937        }
2938
2939        let result = f(self);
2940
2941        if !clipped_bounds.is_empty() {
2942            self.next_frame.scene.pop_layer();
2943        }
2944
2945        result
2946    }
2947
2948    /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2949    ///
2950    /// This method should only be called as part of the paint phase of element drawing.
2951    pub fn paint_shadows(
2952        &mut self,
2953        bounds: Bounds<Pixels>,
2954        corner_radii: Corners<Pixels>,
2955        shadows: &[BoxShadow],
2956    ) {
2957        self.invalidator.debug_assert_paint();
2958
2959        let scale_factor = self.scale_factor();
2960        let content_mask = self.content_mask();
2961        let opacity = self.element_opacity();
2962        for shadow in shadows {
2963            let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2964            self.next_frame.scene.insert_primitive(Shadow {
2965                order: 0,
2966                blur_radius: shadow.blur_radius.scale(scale_factor),
2967                bounds: shadow_bounds.scale(scale_factor),
2968                content_mask: content_mask.scale(scale_factor),
2969                corner_radii: corner_radii.scale(scale_factor),
2970                color: shadow.color.opacity(opacity),
2971            });
2972        }
2973    }
2974
2975    /// Paint one or more quads into the scene for the next frame at the current stacking context.
2976    /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2977    /// see [`fill`], [`outline`], and [`quad`] to construct this type.
2978    ///
2979    /// This method should only be called as part of the paint phase of element drawing.
2980    ///
2981    /// Note that the `quad.corner_radii` are allowed to exceed the bounds, creating sharp corners
2982    /// where the circular arcs meet. This will not display well when combined with dashed borders.
2983    /// Use `Corners::clamp_radii_for_quad_size` if the radii should fit within the bounds.
2984    pub fn paint_quad(&mut self, quad: PaintQuad) {
2985        self.invalidator.debug_assert_paint();
2986
2987        let scale_factor = self.scale_factor();
2988        let content_mask = self.content_mask();
2989        let opacity = self.element_opacity();
2990        self.next_frame.scene.insert_primitive(Quad {
2991            order: 0,
2992            bounds: quad.bounds.scale(scale_factor),
2993            content_mask: content_mask.scale(scale_factor),
2994            background: quad.background.opacity(opacity),
2995            border_color: quad.border_color.opacity(opacity),
2996            corner_radii: quad.corner_radii.scale(scale_factor),
2997            border_widths: quad.border_widths.scale(scale_factor),
2998            border_style: quad.border_style,
2999        });
3000    }
3001
3002    #[cfg(any(test, feature = "test-support"))]
3003    /// Record a named diagnostic quad for test/debug snapshots.
3004    ///
3005    /// This is intended for debugging and asserting against imperative painting logic. The
3006    /// recorded quad does not affect rendering; it is captured alongside the rendered scene and
3007    /// exposed via `scene_snapshot()`.
3008    pub fn record_diagnostic_quad(
3009        &mut self,
3010        name: impl Into<SharedString>,
3011        bounds: Bounds<Pixels>,
3012        color: Option<Hsla>,
3013    ) {
3014        self.invalidator.debug_assert_paint();
3015
3016        let scale_factor = self.scale_factor();
3017        self.next_frame.scene.diagnostic_quads.push(crate::test_scene::DiagnosticQuad {
3018            name: name.into(),
3019            bounds: bounds.scale(scale_factor),
3020            color,
3021        });
3022    }
3023
3024    #[cfg(not(any(test, feature = "test-support")))]
3025    #[inline]
3026    /// Record a named diagnostic quad for test/debug snapshots.
3027    ///
3028    /// This is a no-op unless tests or the `test-support` feature are enabled.
3029    pub fn record_diagnostic_quad(
3030        &mut self,
3031        _name: impl Into<SharedString>,
3032        _bounds: Bounds<Pixels>,
3033        _color: Option<Hsla>,
3034    ) {
3035    }
3036
3037    /// Paint the given `Path` into the scene for the next frame at the current z-index.
3038    ///
3039    /// This method should only be called as part of the paint phase of element drawing.
3040    pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
3041        self.invalidator.debug_assert_paint();
3042
3043        let scale_factor = self.scale_factor();
3044        let content_mask = self.content_mask();
3045        let opacity = self.element_opacity();
3046        path.content_mask = content_mask;
3047        let color: Background = color.into();
3048        path.color = color.opacity(opacity);
3049        self.next_frame
3050            .scene
3051            .insert_primitive(path.scale(scale_factor));
3052    }
3053
3054    /// Paint an underline into the scene for the next frame at the current z-index.
3055    ///
3056    /// This method should only be called as part of the paint phase of element drawing.
3057    pub fn paint_underline(
3058        &mut self,
3059        origin: Point<Pixels>,
3060        width: Pixels,
3061        style: &UnderlineStyle,
3062    ) {
3063        self.invalidator.debug_assert_paint();
3064
3065        let scale_factor = self.scale_factor();
3066        let height = if style.wavy {
3067            style.thickness * 3.
3068        } else {
3069            style.thickness
3070        };
3071        let bounds = Bounds {
3072            origin,
3073            size: size(width, height),
3074        };
3075        let content_mask = self.content_mask();
3076        let element_opacity = self.element_opacity();
3077
3078        self.next_frame.scene.insert_primitive(Underline {
3079            order: 0,
3080            pad: 0,
3081            bounds: bounds.scale(scale_factor),
3082            content_mask: content_mask.scale(scale_factor),
3083            color: style.color.unwrap_or_default().opacity(element_opacity),
3084            thickness: style.thickness.scale(scale_factor),
3085            wavy: if style.wavy { 1 } else { 0 },
3086        });
3087    }
3088
3089    /// Paint a strikethrough into the scene for the next frame at the current z-index.
3090    ///
3091    /// This method should only be called as part of the paint phase of element drawing.
3092    pub fn paint_strikethrough(
3093        &mut self,
3094        origin: Point<Pixels>,
3095        width: Pixels,
3096        style: &StrikethroughStyle,
3097    ) {
3098        self.invalidator.debug_assert_paint();
3099
3100        let scale_factor = self.scale_factor();
3101        let height = style.thickness;
3102        let bounds = Bounds {
3103            origin,
3104            size: size(width, height),
3105        };
3106        let content_mask = self.content_mask();
3107        let opacity = self.element_opacity();
3108
3109        self.next_frame.scene.insert_primitive(Underline {
3110            order: 0,
3111            pad: 0,
3112            bounds: bounds.scale(scale_factor),
3113            content_mask: content_mask.scale(scale_factor),
3114            thickness: style.thickness.scale(scale_factor),
3115            color: style.color.unwrap_or_default().opacity(opacity),
3116            wavy: 0,
3117        });
3118    }
3119
3120    /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
3121    ///
3122    /// The y component of the origin is the baseline of the glyph.
3123    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3124    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3125    /// This method is only useful if you need to paint a single glyph that has already been shaped.
3126    ///
3127    /// This method should only be called as part of the paint phase of element drawing.
3128    pub fn paint_glyph(
3129        &mut self,
3130        origin: Point<Pixels>,
3131        font_id: FontId,
3132        glyph_id: GlyphId,
3133        font_size: Pixels,
3134        color: Hsla,
3135    ) -> Result<()> {
3136        self.invalidator.debug_assert_paint();
3137
3138        let element_opacity = self.element_opacity();
3139        let scale_factor = self.scale_factor();
3140        let glyph_origin = origin.scale(scale_factor);
3141
3142        let subpixel_variant = Point {
3143            x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS_X as f32).floor() as u8,
3144            y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS_Y as f32).floor() as u8,
3145        };
3146        let params = RenderGlyphParams {
3147            font_id,
3148            glyph_id,
3149            font_size,
3150            subpixel_variant,
3151            scale_factor,
3152            is_emoji: false,
3153        };
3154
3155        let raster_bounds = self.text_system().raster_bounds(&params)?;
3156        if !raster_bounds.is_zero() {
3157            let tile = self
3158                .sprite_atlas
3159                .get_or_insert_with(&params.clone().into(), &mut || {
3160                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3161                    Ok(Some((size, Cow::Owned(bytes))))
3162                })?
3163                .expect("Callback above only errors or returns Some");
3164            let bounds = Bounds {
3165                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3166                size: tile.bounds.size.map(Into::into),
3167            };
3168            let content_mask = self.content_mask().scale(scale_factor);
3169            self.next_frame.scene.insert_primitive(MonochromeSprite {
3170                order: 0,
3171                pad: 0,
3172                bounds,
3173                content_mask,
3174                color: color.opacity(element_opacity),
3175                tile,
3176                transformation: TransformationMatrix::unit(),
3177            });
3178        }
3179        Ok(())
3180    }
3181
3182    /// Paints an emoji glyph into the scene for the next frame at the current z-index.
3183    ///
3184    /// The y component of the origin is the baseline of the glyph.
3185    /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
3186    /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
3187    /// This method is only useful if you need to paint a single emoji that has already been shaped.
3188    ///
3189    /// This method should only be called as part of the paint phase of element drawing.
3190    pub fn paint_emoji(
3191        &mut self,
3192        origin: Point<Pixels>,
3193        font_id: FontId,
3194        glyph_id: GlyphId,
3195        font_size: Pixels,
3196    ) -> Result<()> {
3197        self.invalidator.debug_assert_paint();
3198
3199        let scale_factor = self.scale_factor();
3200        let glyph_origin = origin.scale(scale_factor);
3201        let params = RenderGlyphParams {
3202            font_id,
3203            glyph_id,
3204            font_size,
3205            // We don't render emojis with subpixel variants.
3206            subpixel_variant: Default::default(),
3207            scale_factor,
3208            is_emoji: true,
3209        };
3210
3211        let raster_bounds = self.text_system().raster_bounds(&params)?;
3212        if !raster_bounds.is_zero() {
3213            let tile = self
3214                .sprite_atlas
3215                .get_or_insert_with(&params.clone().into(), &mut || {
3216                    let (size, bytes) = self.text_system().rasterize_glyph(&params)?;
3217                    Ok(Some((size, Cow::Owned(bytes))))
3218                })?
3219                .expect("Callback above only errors or returns Some");
3220
3221            let bounds = Bounds {
3222                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
3223                size: tile.bounds.size.map(Into::into),
3224            };
3225            let content_mask = self.content_mask().scale(scale_factor);
3226            let opacity = self.element_opacity();
3227
3228            self.next_frame.scene.insert_primitive(PolychromeSprite {
3229                order: 0,
3230                pad: 0,
3231                grayscale: false,
3232                bounds,
3233                corner_radii: Default::default(),
3234                content_mask,
3235                tile,
3236                opacity,
3237            });
3238        }
3239        Ok(())
3240    }
3241
3242    /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
3243    ///
3244    /// This method should only be called as part of the paint phase of element drawing.
3245    pub fn paint_svg(
3246        &mut self,
3247        bounds: Bounds<Pixels>,
3248        path: SharedString,
3249        mut data: Option<&[u8]>,
3250        transformation: TransformationMatrix,
3251        color: Hsla,
3252        cx: &App,
3253    ) -> Result<()> {
3254        self.invalidator.debug_assert_paint();
3255
3256        let element_opacity = self.element_opacity();
3257        let scale_factor = self.scale_factor();
3258
3259        let bounds = bounds.scale(scale_factor);
3260        let params = RenderSvgParams {
3261            path,
3262            size: bounds.size.map(|pixels| {
3263                DevicePixels::from((pixels.0 * SMOOTH_SVG_SCALE_FACTOR).ceil() as i32)
3264            }),
3265        };
3266
3267        let Some(tile) =
3268            self.sprite_atlas
3269                .get_or_insert_with(&params.clone().into(), &mut || {
3270                    let Some((size, bytes)) = cx.svg_renderer.render_alpha_mask(&params, data)?
3271                    else {
3272                        return Ok(None);
3273                    };
3274                    Ok(Some((size, Cow::Owned(bytes))))
3275                })?
3276        else {
3277            return Ok(());
3278        };
3279        let content_mask = self.content_mask().scale(scale_factor);
3280        let svg_bounds = Bounds {
3281            origin: bounds.center()
3282                - Point::new(
3283                    ScaledPixels(tile.bounds.size.width.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3284                    ScaledPixels(tile.bounds.size.height.0 as f32 / SMOOTH_SVG_SCALE_FACTOR / 2.),
3285                ),
3286            size: tile
3287                .bounds
3288                .size
3289                .map(|value| ScaledPixels(value.0 as f32 / SMOOTH_SVG_SCALE_FACTOR)),
3290        };
3291
3292        self.next_frame.scene.insert_primitive(MonochromeSprite {
3293            order: 0,
3294            pad: 0,
3295            bounds: svg_bounds
3296                .map_origin(|origin| origin.round())
3297                .map_size(|size| size.ceil()),
3298            content_mask,
3299            color: color.opacity(element_opacity),
3300            tile,
3301            transformation,
3302        });
3303
3304        Ok(())
3305    }
3306
3307    /// Paint an image into the scene for the next frame at the current z-index.
3308    /// This method will panic if the frame_index is not valid
3309    ///
3310    /// This method should only be called as part of the paint phase of element drawing.
3311    pub fn paint_image(
3312        &mut self,
3313        bounds: Bounds<Pixels>,
3314        corner_radii: Corners<Pixels>,
3315        data: Arc<RenderImage>,
3316        frame_index: usize,
3317        grayscale: bool,
3318    ) -> Result<()> {
3319        self.invalidator.debug_assert_paint();
3320
3321        let scale_factor = self.scale_factor();
3322        let bounds = bounds.scale(scale_factor);
3323        let params = RenderImageParams {
3324            image_id: data.id,
3325            frame_index,
3326        };
3327
3328        let tile = self
3329            .sprite_atlas
3330            .get_or_insert_with(&params.into(), &mut || {
3331                Ok(Some((
3332                    data.size(frame_index),
3333                    Cow::Borrowed(
3334                        data.as_bytes(frame_index)
3335                            .expect("It's the caller's job to pass a valid frame index"),
3336                    ),
3337                )))
3338            })?
3339            .expect("Callback above only returns Some");
3340        let content_mask = self.content_mask().scale(scale_factor);
3341        let corner_radii = corner_radii.scale(scale_factor);
3342        let opacity = self.element_opacity();
3343
3344        self.next_frame.scene.insert_primitive(PolychromeSprite {
3345            order: 0,
3346            pad: 0,
3347            grayscale,
3348            bounds: bounds
3349                .map_origin(|origin| origin.floor())
3350                .map_size(|size| size.ceil()),
3351            content_mask,
3352            corner_radii,
3353            tile,
3354            opacity,
3355        });
3356        Ok(())
3357    }
3358
3359    /// Paint a surface into the scene for the next frame at the current z-index.
3360    ///
3361    /// This method should only be called as part of the paint phase of element drawing.
3362    #[cfg(target_os = "macos")]
3363    pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVPixelBuffer) {
3364        use crate::PaintSurface;
3365
3366        self.invalidator.debug_assert_paint();
3367
3368        let scale_factor = self.scale_factor();
3369        let bounds = bounds.scale(scale_factor);
3370        let content_mask = self.content_mask().scale(scale_factor);
3371        self.next_frame.scene.insert_primitive(PaintSurface {
3372            order: 0,
3373            bounds,
3374            content_mask,
3375            image_buffer,
3376        });
3377    }
3378
3379    /// Removes an image from the sprite atlas.
3380    pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
3381        for frame_index in 0..data.frame_count() {
3382            let params = RenderImageParams {
3383                image_id: data.id,
3384                frame_index,
3385            };
3386
3387            self.sprite_atlas.remove(&params.clone().into());
3388        }
3389
3390        Ok(())
3391    }
3392
3393    /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
3394    /// layout is being requested, along with the layout ids of any children. This method is called during
3395    /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
3396    ///
3397    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3398    #[must_use]
3399    pub fn request_layout(
3400        &mut self,
3401        style: Style,
3402        children: impl IntoIterator<Item = LayoutId>,
3403        cx: &mut App,
3404    ) -> LayoutId {
3405        self.invalidator.debug_assert_prepaint();
3406
3407        cx.layout_id_buffer.clear();
3408        cx.layout_id_buffer.extend(children);
3409        let rem_size = self.rem_size();
3410        let scale_factor = self.scale_factor();
3411
3412        self.layout_engine.as_mut().unwrap().request_layout(
3413            style,
3414            rem_size,
3415            scale_factor,
3416            &cx.layout_id_buffer,
3417        )
3418    }
3419
3420    /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
3421    /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
3422    /// determine the element's size. One place this is used internally is when measuring text.
3423    ///
3424    /// The given closure is invoked at layout time with the known dimensions and available space and
3425    /// returns a `Size`.
3426    ///
3427    /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
3428    pub fn request_measured_layout<F>(&mut self, style: Style, measure: F) -> LayoutId
3429    where
3430        F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>, &mut Window, &mut App) -> Size<Pixels>
3431            + 'static,
3432    {
3433        self.invalidator.debug_assert_prepaint();
3434
3435        let rem_size = self.rem_size();
3436        let scale_factor = self.scale_factor();
3437        self.layout_engine
3438            .as_mut()
3439            .unwrap()
3440            .request_measured_layout(style, rem_size, scale_factor, measure)
3441    }
3442
3443    /// Compute the layout for the given id within the given available space.
3444    /// This method is called for its side effect, typically by the framework prior to painting.
3445    /// After calling it, you can request the bounds of the given layout node id or any descendant.
3446    ///
3447    /// This method should only be called as part of the prepaint phase of element drawing.
3448    pub fn compute_layout(
3449        &mut self,
3450        layout_id: LayoutId,
3451        available_space: Size<AvailableSpace>,
3452        cx: &mut App,
3453    ) {
3454        self.invalidator.debug_assert_prepaint();
3455
3456        let mut layout_engine = self.layout_engine.take().unwrap();
3457        layout_engine.compute_layout(layout_id, available_space, self, cx);
3458        self.layout_engine = Some(layout_engine);
3459    }
3460
3461    /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
3462    /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
3463    ///
3464    /// This method should only be called as part of element drawing.
3465    pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
3466        self.invalidator.debug_assert_prepaint();
3467
3468        let scale_factor = self.scale_factor();
3469        let mut bounds = self
3470            .layout_engine
3471            .as_mut()
3472            .unwrap()
3473            .layout_bounds(layout_id, scale_factor)
3474            .map(Into::into);
3475        bounds.origin += self.element_offset();
3476        bounds
3477    }
3478
3479    /// This method should be called during `prepaint`. You can use
3480    /// the returned [Hitbox] during `paint` or in an event handler
3481    /// to determine whether the inserted hitbox was the topmost.
3482    ///
3483    /// This method should only be called as part of the prepaint phase of element drawing.
3484    pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, behavior: HitboxBehavior) -> Hitbox {
3485        self.invalidator.debug_assert_prepaint();
3486
3487        let content_mask = self.content_mask();
3488        let mut id = self.next_hitbox_id;
3489        self.next_hitbox_id = self.next_hitbox_id.next();
3490        let hitbox = Hitbox {
3491            id,
3492            bounds,
3493            content_mask,
3494            behavior,
3495        };
3496        self.next_frame.hitboxes.push(hitbox.clone());
3497        hitbox
3498    }
3499
3500    /// Set a hitbox which will act as a control area of the platform window.
3501    ///
3502    /// This method should only be called as part of the paint phase of element drawing.
3503    pub fn insert_window_control_hitbox(&mut self, area: WindowControlArea, hitbox: Hitbox) {
3504        self.invalidator.debug_assert_paint();
3505        self.next_frame.window_control_hitboxes.push((area, hitbox));
3506    }
3507
3508    /// Sets the key context for the current element. This context will be used to translate
3509    /// keybindings into actions.
3510    ///
3511    /// This method should only be called as part of the paint phase of element drawing.
3512    pub fn set_key_context(&mut self, context: KeyContext) {
3513        self.invalidator.debug_assert_paint();
3514        self.next_frame.dispatch_tree.set_key_context(context);
3515    }
3516
3517    /// Sets the focus handle for the current element. This handle will be used to manage focus state
3518    /// and keyboard event dispatch for the element.
3519    ///
3520    /// This method should only be called as part of the prepaint phase of element drawing.
3521    pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle, _: &App) {
3522        self.invalidator.debug_assert_prepaint();
3523        if focus_handle.is_focused(self) {
3524            self.next_frame.focus = Some(focus_handle.id);
3525        }
3526        self.next_frame.dispatch_tree.set_focus_id(focus_handle.id);
3527    }
3528
3529    /// Sets the view id for the current element, which will be used to manage view caching.
3530    ///
3531    /// This method should only be called as part of element prepaint. We plan on removing this
3532    /// method eventually when we solve some issues that require us to construct editor elements
3533    /// directly instead of always using editors via views.
3534    pub fn set_view_id(&mut self, view_id: EntityId) {
3535        self.invalidator.debug_assert_prepaint();
3536        self.next_frame.dispatch_tree.set_view_id(view_id);
3537    }
3538
3539    /// Get the entity ID for the currently rendering view
3540    pub fn current_view(&self) -> EntityId {
3541        self.invalidator.debug_assert_paint_or_prepaint();
3542        self.rendered_entity_stack.last().copied().unwrap()
3543    }
3544
3545    pub(crate) fn with_rendered_view<R>(
3546        &mut self,
3547        id: EntityId,
3548        f: impl FnOnce(&mut Self) -> R,
3549    ) -> R {
3550        self.rendered_entity_stack.push(id);
3551        let result = f(self);
3552        self.rendered_entity_stack.pop();
3553        result
3554    }
3555
3556    /// Executes the provided function with the specified image cache.
3557    pub fn with_image_cache<F, R>(&mut self, image_cache: Option<AnyImageCache>, f: F) -> R
3558    where
3559        F: FnOnce(&mut Self) -> R,
3560    {
3561        if let Some(image_cache) = image_cache {
3562            self.image_cache_stack.push(image_cache);
3563            let result = f(self);
3564            self.image_cache_stack.pop();
3565            result
3566        } else {
3567            f(self)
3568        }
3569    }
3570
3571    /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
3572    /// platform to receive textual input with proper integration with concerns such
3573    /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
3574    /// rendered.
3575    ///
3576    /// This method should only be called as part of the paint phase of element drawing.
3577    ///
3578    /// [element_input_handler]: crate::ElementInputHandler
3579    pub fn handle_input(
3580        &mut self,
3581        focus_handle: &FocusHandle,
3582        input_handler: impl InputHandler,
3583        cx: &App,
3584    ) {
3585        self.invalidator.debug_assert_paint();
3586
3587        if focus_handle.is_focused(self) {
3588            let cx = self.to_async(cx);
3589            self.next_frame
3590                .input_handlers
3591                .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
3592        }
3593    }
3594
3595    /// Register a mouse event listener on the window for the next frame. The type of event
3596    /// is determined by the first parameter of the given listener. When the next frame is rendered
3597    /// the listener will be cleared.
3598    ///
3599    /// This method should only be called as part of the paint phase of element drawing.
3600    pub fn on_mouse_event<Event: MouseEvent>(
3601        &mut self,
3602        mut listener: impl FnMut(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3603    ) {
3604        self.invalidator.debug_assert_paint();
3605
3606        self.next_frame.mouse_listeners.push(Some(Box::new(
3607            move |event: &dyn Any, phase: DispatchPhase, window: &mut Window, cx: &mut App| {
3608                if let Some(event) = event.downcast_ref() {
3609                    listener(event, phase, window, cx)
3610                }
3611            },
3612        )));
3613    }
3614
3615    /// Register a key event listener on this node for the next frame. The type of event
3616    /// is determined by the first parameter of the given listener. When the next frame is rendered
3617    /// the listener will be cleared.
3618    ///
3619    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3620    /// a specific need to register a listener yourself.
3621    ///
3622    /// This method should only be called as part of the paint phase of element drawing.
3623    pub fn on_key_event<Event: KeyEvent>(
3624        &mut self,
3625        listener: impl Fn(&Event, DispatchPhase, &mut Window, &mut App) + 'static,
3626    ) {
3627        self.invalidator.debug_assert_paint();
3628
3629        self.next_frame.dispatch_tree.on_key_event(Rc::new(
3630            move |event: &dyn Any, phase, window: &mut Window, cx: &mut App| {
3631                if let Some(event) = event.downcast_ref::<Event>() {
3632                    listener(event, phase, window, cx)
3633                }
3634            },
3635        ));
3636    }
3637
3638    /// Register a modifiers changed event listener on the window for the next frame.
3639    ///
3640    /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
3641    /// a specific need to register a global listener.
3642    ///
3643    /// This method should only be called as part of the paint phase of element drawing.
3644    pub fn on_modifiers_changed(
3645        &mut self,
3646        listener: impl Fn(&ModifiersChangedEvent, &mut Window, &mut App) + 'static,
3647    ) {
3648        self.invalidator.debug_assert_paint();
3649
3650        self.next_frame.dispatch_tree.on_modifiers_changed(Rc::new(
3651            move |event: &ModifiersChangedEvent, window: &mut Window, cx: &mut App| {
3652                listener(event, window, cx)
3653            },
3654        ));
3655    }
3656
3657    /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3658    /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3659    /// Returns a subscription and persists until the subscription is dropped.
3660    pub fn on_focus_in(
3661        &mut self,
3662        handle: &FocusHandle,
3663        cx: &mut App,
3664        mut listener: impl FnMut(&mut Window, &mut App) + 'static,
3665    ) -> Subscription {
3666        let focus_id = handle.id;
3667        let (subscription, activate) =
3668            self.new_focus_listener(Box::new(move |event, window, cx| {
3669                if event.is_focus_in(focus_id) {
3670                    listener(window, cx);
3671                }
3672                true
3673            }));
3674        cx.defer(move |_| activate());
3675        subscription
3676    }
3677
3678    /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3679    /// Returns a subscription and persists until the subscription is dropped.
3680    pub fn on_focus_out(
3681        &mut self,
3682        handle: &FocusHandle,
3683        cx: &mut App,
3684        mut listener: impl FnMut(FocusOutEvent, &mut Window, &mut App) + 'static,
3685    ) -> Subscription {
3686        let focus_id = handle.id;
3687        let (subscription, activate) =
3688            self.new_focus_listener(Box::new(move |event, window, cx| {
3689                if let Some(blurred_id) = event.previous_focus_path.last().copied()
3690                    && event.is_focus_out(focus_id)
3691                {
3692                    let event = FocusOutEvent {
3693                        blurred: WeakFocusHandle {
3694                            id: blurred_id,
3695                            handles: Arc::downgrade(&cx.focus_handles),
3696                        },
3697                    };
3698                    listener(event, window, cx)
3699                }
3700                true
3701            }));
3702        cx.defer(move |_| activate());
3703        subscription
3704    }
3705
3706    fn reset_cursor_style(&self, cx: &mut App) {
3707        // Set the cursor only if we're the active window.
3708        if self.is_window_hovered() {
3709            let style = self
3710                .rendered_frame
3711                .cursor_style(self)
3712                .unwrap_or(CursorStyle::Arrow);
3713            cx.platform.set_cursor_style(style);
3714        }
3715    }
3716
3717    /// Dispatch a given keystroke as though the user had typed it.
3718    /// You can create a keystroke with Keystroke::parse("").
3719    pub fn dispatch_keystroke(&mut self, keystroke: Keystroke, cx: &mut App) -> bool {
3720        let keystroke = keystroke.with_simulated_ime();
3721        let result = self.dispatch_event(
3722            PlatformInput::KeyDown(KeyDownEvent {
3723                keystroke: keystroke.clone(),
3724                is_held: false,
3725                prefer_character_input: false,
3726            }),
3727            cx,
3728        );
3729        if !result.propagate {
3730            return true;
3731        }
3732
3733        if let Some(input) = keystroke.key_char
3734            && let Some(mut input_handler) = self.platform_window.take_input_handler()
3735        {
3736            input_handler.dispatch_input(&input, self, cx);
3737            self.platform_window.set_input_handler(input_handler);
3738            return true;
3739        }
3740
3741        false
3742    }
3743
3744    /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3745    /// binding for the action (last binding added to the keymap).
3746    pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3747        self.highest_precedence_binding_for_action(action)
3748            .map(|binding| {
3749                binding
3750                    .keystrokes()
3751                    .iter()
3752                    .map(ToString::to_string)
3753                    .collect::<Vec<_>>()
3754                    .join(" ")
3755            })
3756            .unwrap_or_else(|| action.name().to_string())
3757    }
3758
3759    /// Dispatch a mouse or keyboard event on the window.
3760    #[profiling::function]
3761    pub fn dispatch_event(&mut self, event: PlatformInput, cx: &mut App) -> DispatchEventResult {
3762        self.last_input_timestamp.set(Instant::now());
3763
3764        // Track whether this input was keyboard-based for focus-visible styling
3765        self.last_input_modality = match &event {
3766            PlatformInput::KeyDown(_) | PlatformInput::ModifiersChanged(_) => {
3767                InputModality::Keyboard
3768            }
3769            PlatformInput::MouseDown(e) if e.is_focusing() => InputModality::Mouse,
3770            _ => self.last_input_modality,
3771        };
3772
3773        // Handlers may set this to false by calling `stop_propagation`.
3774        cx.propagate_event = true;
3775        // Handlers may set this to true by calling `prevent_default`.
3776        self.default_prevented = false;
3777
3778        let event = match event {
3779            // Track the mouse position with our own state, since accessing the platform
3780            // API for the mouse position can only occur on the main thread.
3781            PlatformInput::MouseMove(mouse_move) => {
3782                self.mouse_position = mouse_move.position;
3783                self.modifiers = mouse_move.modifiers;
3784                PlatformInput::MouseMove(mouse_move)
3785            }
3786            PlatformInput::MouseDown(mouse_down) => {
3787                self.mouse_position = mouse_down.position;
3788                self.modifiers = mouse_down.modifiers;
3789                PlatformInput::MouseDown(mouse_down)
3790            }
3791            PlatformInput::MouseUp(mouse_up) => {
3792                self.mouse_position = mouse_up.position;
3793                self.modifiers = mouse_up.modifiers;
3794                PlatformInput::MouseUp(mouse_up)
3795            }
3796            PlatformInput::MousePressure(mouse_pressure) => {
3797                PlatformInput::MousePressure(mouse_pressure)
3798            }
3799            PlatformInput::MouseExited(mouse_exited) => {
3800                self.modifiers = mouse_exited.modifiers;
3801                PlatformInput::MouseExited(mouse_exited)
3802            }
3803            PlatformInput::ModifiersChanged(modifiers_changed) => {
3804                self.modifiers = modifiers_changed.modifiers;
3805                self.capslock = modifiers_changed.capslock;
3806                PlatformInput::ModifiersChanged(modifiers_changed)
3807            }
3808            PlatformInput::ScrollWheel(scroll_wheel) => {
3809                self.mouse_position = scroll_wheel.position;
3810                self.modifiers = scroll_wheel.modifiers;
3811                PlatformInput::ScrollWheel(scroll_wheel)
3812            }
3813            // Translate dragging and dropping of external files from the operating system
3814            // to internal drag and drop events.
3815            PlatformInput::FileDrop(file_drop) => match file_drop {
3816                FileDropEvent::Entered { position, paths } => {
3817                    self.mouse_position = position;
3818                    if cx.active_drag.is_none() {
3819                        cx.active_drag = Some(AnyDrag {
3820                            value: Arc::new(paths.clone()),
3821                            view: cx.new(|_| paths).into(),
3822                            cursor_offset: position,
3823                            cursor_style: None,
3824                        });
3825                    }
3826                    PlatformInput::MouseMove(MouseMoveEvent {
3827                        position,
3828                        pressed_button: Some(MouseButton::Left),
3829                        modifiers: Modifiers::default(),
3830                    })
3831                }
3832                FileDropEvent::Pending { position } => {
3833                    self.mouse_position = position;
3834                    PlatformInput::MouseMove(MouseMoveEvent {
3835                        position,
3836                        pressed_button: Some(MouseButton::Left),
3837                        modifiers: Modifiers::default(),
3838                    })
3839                }
3840                FileDropEvent::Submit { position } => {
3841                    cx.activate(true);
3842                    self.mouse_position = position;
3843                    PlatformInput::MouseUp(MouseUpEvent {
3844                        button: MouseButton::Left,
3845                        position,
3846                        modifiers: Modifiers::default(),
3847                        click_count: 1,
3848                    })
3849                }
3850                FileDropEvent::Exited => {
3851                    cx.active_drag.take();
3852                    PlatformInput::FileDrop(FileDropEvent::Exited)
3853                }
3854            },
3855            PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3856        };
3857
3858        if let Some(any_mouse_event) = event.mouse_event() {
3859            self.dispatch_mouse_event(any_mouse_event, cx);
3860        } else if let Some(any_key_event) = event.keyboard_event() {
3861            self.dispatch_key_event(any_key_event, cx);
3862        }
3863
3864        DispatchEventResult {
3865            propagate: cx.propagate_event,
3866            default_prevented: self.default_prevented,
3867        }
3868    }
3869
3870    fn dispatch_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
3871        let hit_test = self.rendered_frame.hit_test(self.mouse_position());
3872        if hit_test != self.mouse_hit_test {
3873            self.mouse_hit_test = hit_test;
3874            self.reset_cursor_style(cx);
3875        }
3876
3877        #[cfg(any(feature = "inspector", debug_assertions))]
3878        if self.is_inspector_picking(cx) {
3879            self.handle_inspector_mouse_event(event, cx);
3880            // When inspector is picking, all other mouse handling is skipped.
3881            return;
3882        }
3883
3884        let mut mouse_listeners = mem::take(&mut self.rendered_frame.mouse_listeners);
3885
3886        // Capture phase, events bubble from back to front. Handlers for this phase are used for
3887        // special purposes, such as detecting events outside of a given Bounds.
3888        for listener in &mut mouse_listeners {
3889            let listener = listener.as_mut().unwrap();
3890            listener(event, DispatchPhase::Capture, self, cx);
3891            if !cx.propagate_event {
3892                break;
3893            }
3894        }
3895
3896        // Bubble phase, where most normal handlers do their work.
3897        if cx.propagate_event {
3898            for listener in mouse_listeners.iter_mut().rev() {
3899                let listener = listener.as_mut().unwrap();
3900                listener(event, DispatchPhase::Bubble, self, cx);
3901                if !cx.propagate_event {
3902                    break;
3903                }
3904            }
3905        }
3906
3907        self.rendered_frame.mouse_listeners = mouse_listeners;
3908
3909        if cx.has_active_drag() {
3910            if event.is::<MouseMoveEvent>() {
3911                // If this was a mouse move event, redraw the window so that the
3912                // active drag can follow the mouse cursor.
3913                self.refresh();
3914            } else if event.is::<MouseUpEvent>() {
3915                // If this was a mouse up event, cancel the active drag and redraw
3916                // the window.
3917                cx.active_drag = None;
3918                self.refresh();
3919            }
3920        }
3921
3922        // Auto-release pointer capture on mouse up
3923        if event.is::<MouseUpEvent>() && self.captured_hitbox.is_some() {
3924            self.captured_hitbox = None;
3925        }
3926    }
3927
3928    fn dispatch_key_event(&mut self, event: &dyn Any, cx: &mut App) {
3929        if self.invalidator.is_dirty() {
3930            self.draw(cx).clear();
3931        }
3932
3933        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
3934        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
3935
3936        let mut keystroke: Option<Keystroke> = None;
3937
3938        if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3939            if event.modifiers.number_of_modifiers() == 0
3940                && self.pending_modifier.modifiers.number_of_modifiers() == 1
3941                && !self.pending_modifier.saw_keystroke
3942            {
3943                let key = match self.pending_modifier.modifiers {
3944                    modifiers if modifiers.shift => Some("shift"),
3945                    modifiers if modifiers.control => Some("control"),
3946                    modifiers if modifiers.alt => Some("alt"),
3947                    modifiers if modifiers.platform => Some("platform"),
3948                    modifiers if modifiers.function => Some("function"),
3949                    _ => None,
3950                };
3951                if let Some(key) = key {
3952                    keystroke = Some(Keystroke {
3953                        key: key.to_string(),
3954                        key_char: None,
3955                        modifiers: Modifiers::default(),
3956                    });
3957                }
3958            }
3959
3960            if self.pending_modifier.modifiers.number_of_modifiers() == 0
3961                && event.modifiers.number_of_modifiers() == 1
3962            {
3963                self.pending_modifier.saw_keystroke = false
3964            }
3965            self.pending_modifier.modifiers = event.modifiers
3966        } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3967            self.pending_modifier.saw_keystroke = true;
3968            keystroke = Some(key_down_event.keystroke.clone());
3969        }
3970
3971        let Some(keystroke) = keystroke else {
3972            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3973            return;
3974        };
3975
3976        cx.propagate_event = true;
3977        self.dispatch_keystroke_interceptors(event, self.context_stack(), cx);
3978        if !cx.propagate_event {
3979            self.finish_dispatch_key_event(event, dispatch_path, self.context_stack(), cx);
3980            return;
3981        }
3982
3983        let mut currently_pending = self.pending_input.take().unwrap_or_default();
3984        if currently_pending.focus.is_some() && currently_pending.focus != self.focus {
3985            currently_pending = PendingInput::default();
3986        }
3987
3988        let match_result = self.rendered_frame.dispatch_tree.dispatch_key(
3989            currently_pending.keystrokes,
3990            keystroke,
3991            &dispatch_path,
3992        );
3993
3994        if !match_result.to_replay.is_empty() {
3995            self.replay_pending_input(match_result.to_replay, cx);
3996            cx.propagate_event = true;
3997        }
3998
3999        if !match_result.pending.is_empty() {
4000            currently_pending.timer.take();
4001            currently_pending.keystrokes = match_result.pending;
4002            currently_pending.focus = self.focus;
4003
4004            let text_input_requires_timeout = event
4005                .downcast_ref::<KeyDownEvent>()
4006                .filter(|key_down| key_down.keystroke.key_char.is_some())
4007                .and_then(|_| self.platform_window.take_input_handler())
4008                .map_or(false, |mut input_handler| {
4009                    let accepts = input_handler.accepts_text_input(self, cx);
4010                    self.platform_window.set_input_handler(input_handler);
4011                    accepts
4012                });
4013
4014            currently_pending.needs_timeout |=
4015                match_result.pending_has_binding || text_input_requires_timeout;
4016
4017            if currently_pending.needs_timeout {
4018                currently_pending.timer = Some(self.spawn(cx, async move |cx| {
4019                    cx.background_executor.timer(Duration::from_secs(1)).await;
4020                    cx.update(move |window, cx| {
4021                        let Some(currently_pending) = window
4022                            .pending_input
4023                            .take()
4024                            .filter(|pending| pending.focus == window.focus)
4025                        else {
4026                            return;
4027                        };
4028
4029                        let node_id = window.focus_node_id_in_rendered_frame(window.focus);
4030                        let dispatch_path =
4031                            window.rendered_frame.dispatch_tree.dispatch_path(node_id);
4032
4033                        let to_replay = window
4034                            .rendered_frame
4035                            .dispatch_tree
4036                            .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
4037
4038                        window.pending_input_changed(cx);
4039                        window.replay_pending_input(to_replay, cx)
4040                    })
4041                    .log_err();
4042                }));
4043            } else {
4044                currently_pending.timer = None;
4045            }
4046            self.pending_input = Some(currently_pending);
4047            self.pending_input_changed(cx);
4048            cx.propagate_event = false;
4049            return;
4050        }
4051
4052        let skip_bindings = event
4053            .downcast_ref::<KeyDownEvent>()
4054            .filter(|key_down_event| key_down_event.prefer_character_input)
4055            .map(|_| {
4056                self.platform_window
4057                    .take_input_handler()
4058                    .map_or(false, |mut input_handler| {
4059                        let accepts = input_handler.accepts_text_input(self, cx);
4060                        self.platform_window.set_input_handler(input_handler);
4061                        // If modifiers are not excessive (e.g. AltGr), and the input handler is accepting text input,
4062                        // we prefer the text input over bindings.
4063                        accepts
4064                    })
4065            })
4066            .unwrap_or(false);
4067
4068        if !skip_bindings {
4069            for binding in match_result.bindings {
4070                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
4071                if !cx.propagate_event {
4072                    self.dispatch_keystroke_observers(
4073                        event,
4074                        Some(binding.action),
4075                        match_result.context_stack,
4076                        cx,
4077                    );
4078                    self.pending_input_changed(cx);
4079                    return;
4080                }
4081            }
4082        }
4083
4084        self.finish_dispatch_key_event(event, dispatch_path, match_result.context_stack, cx);
4085        self.pending_input_changed(cx);
4086    }
4087
4088    fn finish_dispatch_key_event(
4089        &mut self,
4090        event: &dyn Any,
4091        dispatch_path: SmallVec<[DispatchNodeId; 32]>,
4092        context_stack: Vec<KeyContext>,
4093        cx: &mut App,
4094    ) {
4095        self.dispatch_key_down_up_event(event, &dispatch_path, cx);
4096        if !cx.propagate_event {
4097            return;
4098        }
4099
4100        self.dispatch_modifiers_changed_event(event, &dispatch_path, cx);
4101        if !cx.propagate_event {
4102            return;
4103        }
4104
4105        self.dispatch_keystroke_observers(event, None, context_stack, cx);
4106    }
4107
4108    pub(crate) fn pending_input_changed(&mut self, cx: &mut App) {
4109        self.pending_input_observers
4110            .clone()
4111            .retain(&(), |callback| callback(self, cx));
4112    }
4113
4114    fn dispatch_key_down_up_event(
4115        &mut self,
4116        event: &dyn Any,
4117        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4118        cx: &mut App,
4119    ) {
4120        // Capture phase
4121        for node_id in dispatch_path {
4122            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4123
4124            for key_listener in node.key_listeners.clone() {
4125                key_listener(event, DispatchPhase::Capture, self, cx);
4126                if !cx.propagate_event {
4127                    return;
4128                }
4129            }
4130        }
4131
4132        // Bubble phase
4133        for node_id in dispatch_path.iter().rev() {
4134            // Handle low level key events
4135            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4136            for key_listener in node.key_listeners.clone() {
4137                key_listener(event, DispatchPhase::Bubble, self, cx);
4138                if !cx.propagate_event {
4139                    return;
4140                }
4141            }
4142        }
4143    }
4144
4145    fn dispatch_modifiers_changed_event(
4146        &mut self,
4147        event: &dyn Any,
4148        dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
4149        cx: &mut App,
4150    ) {
4151        let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
4152            return;
4153        };
4154        for node_id in dispatch_path.iter().rev() {
4155            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4156            for listener in node.modifiers_changed_listeners.clone() {
4157                listener(event, self, cx);
4158                if !cx.propagate_event {
4159                    return;
4160                }
4161            }
4162        }
4163    }
4164
4165    /// Determine whether a potential multi-stroke key binding is in progress on this window.
4166    pub fn has_pending_keystrokes(&self) -> bool {
4167        self.pending_input.is_some()
4168    }
4169
4170    pub(crate) fn clear_pending_keystrokes(&mut self) {
4171        self.pending_input.take();
4172    }
4173
4174    /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
4175    pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
4176        self.pending_input
4177            .as_ref()
4178            .map(|pending_input| pending_input.keystrokes.as_slice())
4179    }
4180
4181    fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>, cx: &mut App) {
4182        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4183        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4184
4185        'replay: for replay in replays {
4186            let event = KeyDownEvent {
4187                keystroke: replay.keystroke.clone(),
4188                is_held: false,
4189                prefer_character_input: true,
4190            };
4191
4192            cx.propagate_event = true;
4193            for binding in replay.bindings {
4194                self.dispatch_action_on_node(node_id, binding.action.as_ref(), cx);
4195                if !cx.propagate_event {
4196                    self.dispatch_keystroke_observers(
4197                        &event,
4198                        Some(binding.action),
4199                        Vec::default(),
4200                        cx,
4201                    );
4202                    continue 'replay;
4203                }
4204            }
4205
4206            self.dispatch_key_down_up_event(&event, &dispatch_path, cx);
4207            if !cx.propagate_event {
4208                continue 'replay;
4209            }
4210            if let Some(input) = replay.keystroke.key_char.as_ref().cloned()
4211                && let Some(mut input_handler) = self.platform_window.take_input_handler()
4212            {
4213                input_handler.dispatch_input(&input, self, cx);
4214                self.platform_window.set_input_handler(input_handler)
4215            }
4216        }
4217    }
4218
4219    fn focus_node_id_in_rendered_frame(&self, focus_id: Option<FocusId>) -> DispatchNodeId {
4220        focus_id
4221            .and_then(|focus_id| {
4222                self.rendered_frame
4223                    .dispatch_tree
4224                    .focusable_node_id(focus_id)
4225            })
4226            .unwrap_or_else(|| self.rendered_frame.dispatch_tree.root_node_id())
4227    }
4228
4229    fn dispatch_action_on_node(
4230        &mut self,
4231        node_id: DispatchNodeId,
4232        action: &dyn Action,
4233        cx: &mut App,
4234    ) {
4235        let dispatch_path = self.rendered_frame.dispatch_tree.dispatch_path(node_id);
4236
4237        // Capture phase for global actions.
4238        cx.propagate_event = true;
4239        if let Some(mut global_listeners) = cx
4240            .global_action_listeners
4241            .remove(&action.as_any().type_id())
4242        {
4243            for listener in &global_listeners {
4244                listener(action.as_any(), DispatchPhase::Capture, cx);
4245                if !cx.propagate_event {
4246                    break;
4247                }
4248            }
4249
4250            global_listeners.extend(
4251                cx.global_action_listeners
4252                    .remove(&action.as_any().type_id())
4253                    .unwrap_or_default(),
4254            );
4255
4256            cx.global_action_listeners
4257                .insert(action.as_any().type_id(), global_listeners);
4258        }
4259
4260        if !cx.propagate_event {
4261            return;
4262        }
4263
4264        // Capture phase for window actions.
4265        for node_id in &dispatch_path {
4266            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4267            for DispatchActionListener {
4268                action_type,
4269                listener,
4270            } in node.action_listeners.clone()
4271            {
4272                let any_action = action.as_any();
4273                if action_type == any_action.type_id() {
4274                    listener(any_action, DispatchPhase::Capture, self, cx);
4275
4276                    if !cx.propagate_event {
4277                        return;
4278                    }
4279                }
4280            }
4281        }
4282
4283        // Bubble phase for window actions.
4284        for node_id in dispatch_path.iter().rev() {
4285            let node = self.rendered_frame.dispatch_tree.node(*node_id);
4286            for DispatchActionListener {
4287                action_type,
4288                listener,
4289            } in node.action_listeners.clone()
4290            {
4291                let any_action = action.as_any();
4292                if action_type == any_action.type_id() {
4293                    cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4294                    listener(any_action, DispatchPhase::Bubble, self, cx);
4295
4296                    if !cx.propagate_event {
4297                        return;
4298                    }
4299                }
4300            }
4301        }
4302
4303        // Bubble phase for global actions.
4304        if let Some(mut global_listeners) = cx
4305            .global_action_listeners
4306            .remove(&action.as_any().type_id())
4307        {
4308            for listener in global_listeners.iter().rev() {
4309                cx.propagate_event = false; // Actions stop propagation by default during the bubble phase
4310
4311                listener(action.as_any(), DispatchPhase::Bubble, cx);
4312                if !cx.propagate_event {
4313                    break;
4314                }
4315            }
4316
4317            global_listeners.extend(
4318                cx.global_action_listeners
4319                    .remove(&action.as_any().type_id())
4320                    .unwrap_or_default(),
4321            );
4322
4323            cx.global_action_listeners
4324                .insert(action.as_any().type_id(), global_listeners);
4325        }
4326    }
4327
4328    /// Register the given handler to be invoked whenever the global of the given type
4329    /// is updated.
4330    pub fn observe_global<G: Global>(
4331        &mut self,
4332        cx: &mut App,
4333        f: impl Fn(&mut Window, &mut App) + 'static,
4334    ) -> Subscription {
4335        let window_handle = self.handle;
4336        let (subscription, activate) = cx.global_observers.insert(
4337            TypeId::of::<G>(),
4338            Box::new(move |cx| {
4339                window_handle
4340                    .update(cx, |_, window, cx| f(window, cx))
4341                    .is_ok()
4342            }),
4343        );
4344        cx.defer(move |_| activate());
4345        subscription
4346    }
4347
4348    /// Focus the current window and bring it to the foreground at the platform level.
4349    pub fn activate_window(&self) {
4350        self.platform_window.activate();
4351    }
4352
4353    /// Minimize the current window at the platform level.
4354    pub fn minimize_window(&self) {
4355        self.platform_window.minimize();
4356    }
4357
4358    /// Toggle full screen status on the current window at the platform level.
4359    pub fn toggle_fullscreen(&self) {
4360        self.platform_window.toggle_fullscreen();
4361    }
4362
4363    /// Updates the IME panel position suggestions for languages like japanese, chinese.
4364    pub fn invalidate_character_coordinates(&self) {
4365        self.on_next_frame(|window, cx| {
4366            if let Some(mut input_handler) = window.platform_window.take_input_handler() {
4367                if let Some(bounds) = input_handler.selected_bounds(window, cx) {
4368                    window.platform_window.update_ime_position(bounds);
4369                }
4370                window.platform_window.set_input_handler(input_handler);
4371            }
4372        });
4373    }
4374
4375    /// Present a platform dialog.
4376    /// The provided message will be presented, along with buttons for each answer.
4377    /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
4378    pub fn prompt<T>(
4379        &mut self,
4380        level: PromptLevel,
4381        message: &str,
4382        detail: Option<&str>,
4383        answers: &[T],
4384        cx: &mut App,
4385    ) -> oneshot::Receiver<usize>
4386    where
4387        T: Clone + Into<PromptButton>,
4388    {
4389        let prompt_builder = cx.prompt_builder.take();
4390        let Some(prompt_builder) = prompt_builder else {
4391            unreachable!("Re-entrant window prompting is not supported by GPUI");
4392        };
4393
4394        let answers = answers
4395            .iter()
4396            .map(|answer| answer.clone().into())
4397            .collect::<Vec<_>>();
4398
4399        let receiver = match &prompt_builder {
4400            PromptBuilder::Default => self
4401                .platform_window
4402                .prompt(level, message, detail, &answers)
4403                .unwrap_or_else(|| {
4404                    self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4405                }),
4406            PromptBuilder::Custom(_) => {
4407                self.build_custom_prompt(&prompt_builder, level, message, detail, &answers, cx)
4408            }
4409        };
4410
4411        cx.prompt_builder = Some(prompt_builder);
4412
4413        receiver
4414    }
4415
4416    fn build_custom_prompt(
4417        &mut self,
4418        prompt_builder: &PromptBuilder,
4419        level: PromptLevel,
4420        message: &str,
4421        detail: Option<&str>,
4422        answers: &[PromptButton],
4423        cx: &mut App,
4424    ) -> oneshot::Receiver<usize> {
4425        let (sender, receiver) = oneshot::channel();
4426        let handle = PromptHandle::new(sender);
4427        let handle = (prompt_builder)(level, message, detail, answers, handle, self, cx);
4428        self.prompt = Some(handle);
4429        receiver
4430    }
4431
4432    /// Returns the current context stack.
4433    pub fn context_stack(&self) -> Vec<KeyContext> {
4434        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4435        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4436        dispatch_tree
4437            .dispatch_path(node_id)
4438            .iter()
4439            .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
4440            .collect()
4441    }
4442
4443    /// Returns all available actions for the focused element.
4444    pub fn available_actions(&self, cx: &App) -> Vec<Box<dyn Action>> {
4445        let node_id = self.focus_node_id_in_rendered_frame(self.focus);
4446        let mut actions = self.rendered_frame.dispatch_tree.available_actions(node_id);
4447        for action_type in cx.global_action_listeners.keys() {
4448            if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
4449                let action = cx.actions.build_action_type(action_type).ok();
4450                if let Some(action) = action {
4451                    actions.insert(ix, action);
4452                }
4453            }
4454        }
4455        actions
4456    }
4457
4458    /// Returns key bindings that invoke an action on the currently focused element. Bindings are
4459    /// returned in the order they were added. For display, the last binding should take precedence.
4460    pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
4461        self.rendered_frame
4462            .dispatch_tree
4463            .bindings_for_action(action, &self.rendered_frame.dispatch_tree.context_stack)
4464    }
4465
4466    /// Returns the highest precedence key binding that invokes an action on the currently focused
4467    /// element. This is more efficient than getting the last result of `bindings_for_action`.
4468    pub fn highest_precedence_binding_for_action(&self, action: &dyn Action) -> Option<KeyBinding> {
4469        self.rendered_frame
4470            .dispatch_tree
4471            .highest_precedence_binding_for_action(
4472                action,
4473                &self.rendered_frame.dispatch_tree.context_stack,
4474            )
4475    }
4476
4477    /// Returns the key bindings for an action in a context.
4478    pub fn bindings_for_action_in_context(
4479        &self,
4480        action: &dyn Action,
4481        context: KeyContext,
4482    ) -> Vec<KeyBinding> {
4483        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4484        dispatch_tree.bindings_for_action(action, &[context])
4485    }
4486
4487    /// Returns the highest precedence key binding for an action in a context. This is more
4488    /// efficient than getting the last result of `bindings_for_action_in_context`.
4489    pub fn highest_precedence_binding_for_action_in_context(
4490        &self,
4491        action: &dyn Action,
4492        context: KeyContext,
4493    ) -> Option<KeyBinding> {
4494        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4495        dispatch_tree.highest_precedence_binding_for_action(action, &[context])
4496    }
4497
4498    /// Returns any bindings that would invoke an action on the given focus handle if it were
4499    /// focused. Bindings are returned in the order they were added. For display, the last binding
4500    /// should take precedence.
4501    pub fn bindings_for_action_in(
4502        &self,
4503        action: &dyn Action,
4504        focus_handle: &FocusHandle,
4505    ) -> Vec<KeyBinding> {
4506        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4507        let Some(context_stack) = self.context_stack_for_focus_handle(focus_handle) else {
4508            return vec![];
4509        };
4510        dispatch_tree.bindings_for_action(action, &context_stack)
4511    }
4512
4513    /// Returns the highest precedence key binding that would invoke an action on the given focus
4514    /// handle if it were focused. This is more efficient than getting the last result of
4515    /// `bindings_for_action_in`.
4516    pub fn highest_precedence_binding_for_action_in(
4517        &self,
4518        action: &dyn Action,
4519        focus_handle: &FocusHandle,
4520    ) -> Option<KeyBinding> {
4521        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4522        let context_stack = self.context_stack_for_focus_handle(focus_handle)?;
4523        dispatch_tree.highest_precedence_binding_for_action(action, &context_stack)
4524    }
4525
4526    /// Find the bindings that can follow the current input sequence for the current context stack.
4527    pub fn possible_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
4528        self.rendered_frame
4529            .dispatch_tree
4530            .possible_next_bindings_for_input(input, &self.context_stack())
4531    }
4532
4533    fn context_stack_for_focus_handle(
4534        &self,
4535        focus_handle: &FocusHandle,
4536    ) -> Option<Vec<KeyContext>> {
4537        let dispatch_tree = &self.rendered_frame.dispatch_tree;
4538        let node_id = dispatch_tree.focusable_node_id(focus_handle.id)?;
4539        let context_stack: Vec<_> = dispatch_tree
4540            .dispatch_path(node_id)
4541            .into_iter()
4542            .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
4543            .collect();
4544        Some(context_stack)
4545    }
4546
4547    /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
4548    pub fn listener_for<T: 'static, E>(
4549        &self,
4550        view: &Entity<T>,
4551        f: impl Fn(&mut T, &E, &mut Window, &mut Context<T>) + 'static,
4552    ) -> impl Fn(&E, &mut Window, &mut App) + 'static {
4553        let view = view.downgrade();
4554        move |e: &E, window: &mut Window, cx: &mut App| {
4555            view.update(cx, |view, cx| f(view, e, window, cx)).ok();
4556        }
4557    }
4558
4559    /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
4560    pub fn handler_for<E: 'static, Callback: Fn(&mut E, &mut Window, &mut Context<E>) + 'static>(
4561        &self,
4562        entity: &Entity<E>,
4563        f: Callback,
4564    ) -> impl Fn(&mut Window, &mut App) + 'static {
4565        let entity = entity.downgrade();
4566        move |window: &mut Window, cx: &mut App| {
4567            entity.update(cx, |entity, cx| f(entity, window, cx)).ok();
4568        }
4569    }
4570
4571    /// Register a callback that can interrupt the closing of the current window based the returned boolean.
4572    /// If the callback returns false, the window won't be closed.
4573    pub fn on_window_should_close(
4574        &self,
4575        cx: &App,
4576        f: impl Fn(&mut Window, &mut App) -> bool + 'static,
4577    ) {
4578        let mut cx = self.to_async(cx);
4579        self.platform_window.on_should_close(Box::new(move || {
4580            cx.update(|window, cx| f(window, cx)).unwrap_or(true)
4581        }))
4582    }
4583
4584    /// Register an action listener on this node for the next frame. The type of action
4585    /// is determined by the first parameter of the given listener. When the next frame is rendered
4586    /// the listener will be cleared.
4587    ///
4588    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4589    /// a specific need to register a listener yourself.
4590    ///
4591    /// This method should only be called as part of the paint phase of element drawing.
4592    pub fn on_action(
4593        &mut self,
4594        action_type: TypeId,
4595        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4596    ) {
4597        self.invalidator.debug_assert_paint();
4598
4599        self.next_frame
4600            .dispatch_tree
4601            .on_action(action_type, Rc::new(listener));
4602    }
4603
4604    /// Register a capturing action listener on this node for the next frame if the condition is true.
4605    /// The type of action is determined by the first parameter of the given listener. When the next
4606    /// frame is rendered the listener will be cleared.
4607    ///
4608    /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
4609    /// a specific need to register a listener yourself.
4610    ///
4611    /// This method should only be called as part of the paint phase of element drawing.
4612    pub fn on_action_when(
4613        &mut self,
4614        condition: bool,
4615        action_type: TypeId,
4616        listener: impl Fn(&dyn Any, DispatchPhase, &mut Window, &mut App) + 'static,
4617    ) {
4618        self.invalidator.debug_assert_paint();
4619
4620        if condition {
4621            self.next_frame
4622                .dispatch_tree
4623                .on_action(action_type, Rc::new(listener));
4624        }
4625    }
4626
4627    /// Read information about the GPU backing this window.
4628    /// Currently returns None on Mac and Windows.
4629    pub fn gpu_specs(&self) -> Option<GpuSpecs> {
4630        self.platform_window.gpu_specs()
4631    }
4632
4633    /// Perform titlebar double-click action.
4634    /// This is macOS specific.
4635    pub fn titlebar_double_click(&self) {
4636        self.platform_window.titlebar_double_click();
4637    }
4638
4639    /// Gets the window's title at the platform level.
4640    /// This is macOS specific.
4641    pub fn window_title(&self) -> String {
4642        self.platform_window.get_title()
4643    }
4644
4645    /// Returns a list of all tabbed windows and their titles.
4646    /// This is macOS specific.
4647    pub fn tabbed_windows(&self) -> Option<Vec<SystemWindowTab>> {
4648        self.platform_window.tabbed_windows()
4649    }
4650
4651    /// Returns the tab bar visibility.
4652    /// This is macOS specific.
4653    pub fn tab_bar_visible(&self) -> bool {
4654        self.platform_window.tab_bar_visible()
4655    }
4656
4657    /// Merges all open windows into a single tabbed window.
4658    /// This is macOS specific.
4659    pub fn merge_all_windows(&self) {
4660        self.platform_window.merge_all_windows()
4661    }
4662
4663    /// Moves the tab to a new containing window.
4664    /// This is macOS specific.
4665    pub fn move_tab_to_new_window(&self) {
4666        self.platform_window.move_tab_to_new_window()
4667    }
4668
4669    /// Shows or hides the window tab overview.
4670    /// This is macOS specific.
4671    pub fn toggle_window_tab_overview(&self) {
4672        self.platform_window.toggle_window_tab_overview()
4673    }
4674
4675    /// Sets the tabbing identifier for the window.
4676    /// This is macOS specific.
4677    pub fn set_tabbing_identifier(&self, tabbing_identifier: Option<String>) {
4678        self.platform_window
4679            .set_tabbing_identifier(tabbing_identifier)
4680    }
4681
4682    /// Toggles the inspector mode on this window.
4683    #[cfg(any(feature = "inspector", debug_assertions))]
4684    pub fn toggle_inspector(&mut self, cx: &mut App) {
4685        self.inspector = match self.inspector {
4686            None => Some(cx.new(|_| Inspector::new())),
4687            Some(_) => None,
4688        };
4689        self.refresh();
4690    }
4691
4692    /// Returns true if the window is in inspector mode.
4693    pub fn is_inspector_picking(&self, _cx: &App) -> bool {
4694        #[cfg(any(feature = "inspector", debug_assertions))]
4695        {
4696            if let Some(inspector) = &self.inspector {
4697                return inspector.read(_cx).is_picking();
4698            }
4699        }
4700        false
4701    }
4702
4703    /// Executes the provided function with mutable access to an inspector state.
4704    #[cfg(any(feature = "inspector", debug_assertions))]
4705    pub fn with_inspector_state<T: 'static, R>(
4706        &mut self,
4707        _inspector_id: Option<&crate::InspectorElementId>,
4708        cx: &mut App,
4709        f: impl FnOnce(&mut Option<T>, &mut Self) -> R,
4710    ) -> R {
4711        if let Some(inspector_id) = _inspector_id
4712            && let Some(inspector) = &self.inspector
4713        {
4714            let inspector = inspector.clone();
4715            let active_element_id = inspector.read(cx).active_element_id();
4716            if Some(inspector_id) == active_element_id {
4717                return inspector.update(cx, |inspector, _cx| {
4718                    inspector.with_active_element_state(self, f)
4719                });
4720            }
4721        }
4722        f(&mut None, self)
4723    }
4724
4725    #[cfg(any(feature = "inspector", debug_assertions))]
4726    pub(crate) fn build_inspector_element_id(
4727        &mut self,
4728        path: crate::InspectorElementPath,
4729    ) -> crate::InspectorElementId {
4730        self.invalidator.debug_assert_paint_or_prepaint();
4731        let path = Rc::new(path);
4732        let next_instance_id = self
4733            .next_frame
4734            .next_inspector_instance_ids
4735            .entry(path.clone())
4736            .or_insert(0);
4737        let instance_id = *next_instance_id;
4738        *next_instance_id += 1;
4739        crate::InspectorElementId { path, instance_id }
4740    }
4741
4742    #[cfg(any(feature = "inspector", debug_assertions))]
4743    fn prepaint_inspector(&mut self, inspector_width: Pixels, cx: &mut App) -> Option<AnyElement> {
4744        if let Some(inspector) = self.inspector.take() {
4745            let mut inspector_element = AnyView::from(inspector.clone()).into_any_element();
4746            inspector_element.prepaint_as_root(
4747                point(self.viewport_size.width - inspector_width, px(0.0)),
4748                size(inspector_width, self.viewport_size.height).into(),
4749                self,
4750                cx,
4751            );
4752            self.inspector = Some(inspector);
4753            Some(inspector_element)
4754        } else {
4755            None
4756        }
4757    }
4758
4759    #[cfg(any(feature = "inspector", debug_assertions))]
4760    fn paint_inspector(&mut self, mut inspector_element: Option<AnyElement>, cx: &mut App) {
4761        if let Some(mut inspector_element) = inspector_element {
4762            inspector_element.paint(self, cx);
4763        };
4764    }
4765
4766    /// Registers a hitbox that can be used for inspector picking mode, allowing users to select and
4767    /// inspect UI elements by clicking on them.
4768    #[cfg(any(feature = "inspector", debug_assertions))]
4769    pub fn insert_inspector_hitbox(
4770        &mut self,
4771        hitbox_id: HitboxId,
4772        inspector_id: Option<&crate::InspectorElementId>,
4773        cx: &App,
4774    ) {
4775        self.invalidator.debug_assert_paint_or_prepaint();
4776        if !self.is_inspector_picking(cx) {
4777            return;
4778        }
4779        if let Some(inspector_id) = inspector_id {
4780            self.next_frame
4781                .inspector_hitboxes
4782                .insert(hitbox_id, inspector_id.clone());
4783        }
4784    }
4785
4786    #[cfg(any(feature = "inspector", debug_assertions))]
4787    fn paint_inspector_hitbox(&mut self, cx: &App) {
4788        if let Some(inspector) = self.inspector.as_ref() {
4789            let inspector = inspector.read(cx);
4790            if let Some((hitbox_id, _)) = self.hovered_inspector_hitbox(inspector, &self.next_frame)
4791                && let Some(hitbox) = self
4792                    .next_frame
4793                    .hitboxes
4794                    .iter()
4795                    .find(|hitbox| hitbox.id == hitbox_id)
4796            {
4797                self.paint_quad(crate::fill(hitbox.bounds, crate::rgba(0x61afef4d)));
4798            }
4799        }
4800    }
4801
4802    #[cfg(any(feature = "inspector", debug_assertions))]
4803    fn handle_inspector_mouse_event(&mut self, event: &dyn Any, cx: &mut App) {
4804        let Some(inspector) = self.inspector.clone() else {
4805            return;
4806        };
4807        if event.downcast_ref::<MouseMoveEvent>().is_some() {
4808            inspector.update(cx, |inspector, _cx| {
4809                if let Some((_, inspector_id)) =
4810                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4811                {
4812                    inspector.hover(inspector_id, self);
4813                }
4814            });
4815        } else if event.downcast_ref::<crate::MouseDownEvent>().is_some() {
4816            inspector.update(cx, |inspector, _cx| {
4817                if let Some((_, inspector_id)) =
4818                    self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4819                {
4820                    inspector.select(inspector_id, self);
4821                }
4822            });
4823        } else if let Some(event) = event.downcast_ref::<crate::ScrollWheelEvent>() {
4824            // This should be kept in sync with SCROLL_LINES in x11 platform.
4825            const SCROLL_LINES: f32 = 3.0;
4826            const SCROLL_PIXELS_PER_LAYER: f32 = 36.0;
4827            let delta_y = event
4828                .delta
4829                .pixel_delta(px(SCROLL_PIXELS_PER_LAYER / SCROLL_LINES))
4830                .y;
4831            if let Some(inspector) = self.inspector.clone() {
4832                inspector.update(cx, |inspector, _cx| {
4833                    if let Some(depth) = inspector.pick_depth.as_mut() {
4834                        *depth += f32::from(delta_y) / SCROLL_PIXELS_PER_LAYER;
4835                        let max_depth = self.mouse_hit_test.ids.len() as f32 - 0.5;
4836                        if *depth < 0.0 {
4837                            *depth = 0.0;
4838                        } else if *depth > max_depth {
4839                            *depth = max_depth;
4840                        }
4841                        if let Some((_, inspector_id)) =
4842                            self.hovered_inspector_hitbox(inspector, &self.rendered_frame)
4843                        {
4844                            inspector.set_active_element_id(inspector_id, self);
4845                        }
4846                    }
4847                });
4848            }
4849        }
4850    }
4851
4852    #[cfg(any(feature = "inspector", debug_assertions))]
4853    fn hovered_inspector_hitbox(
4854        &self,
4855        inspector: &Inspector,
4856        frame: &Frame,
4857    ) -> Option<(HitboxId, crate::InspectorElementId)> {
4858        if let Some(pick_depth) = inspector.pick_depth {
4859            let depth = (pick_depth as i64).try_into().unwrap_or(0);
4860            let max_skipped = self.mouse_hit_test.ids.len().saturating_sub(1);
4861            let skip_count = (depth as usize).min(max_skipped);
4862            for hitbox_id in self.mouse_hit_test.ids.iter().skip(skip_count) {
4863                if let Some(inspector_id) = frame.inspector_hitboxes.get(hitbox_id) {
4864                    return Some((*hitbox_id, inspector_id.clone()));
4865                }
4866            }
4867        }
4868        None
4869    }
4870
4871    /// For testing: set the current modifier keys state.
4872    /// This does not generate any events.
4873    #[cfg(any(test, feature = "test-support"))]
4874    pub fn set_modifiers(&mut self, modifiers: Modifiers) {
4875        self.modifiers = modifiers;
4876    }
4877}
4878
4879// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4880slotmap::new_key_type! {
4881    /// A unique identifier for a window.
4882    pub struct WindowId;
4883}
4884
4885impl WindowId {
4886    /// Converts this window ID to a `u64`.
4887    pub fn as_u64(&self) -> u64 {
4888        self.0.as_ffi()
4889    }
4890}
4891
4892impl From<u64> for WindowId {
4893    fn from(value: u64) -> Self {
4894        WindowId(slotmap::KeyData::from_ffi(value))
4895    }
4896}
4897
4898/// A handle to a window with a specific root view type.
4899/// Note that this does not keep the window alive on its own.
4900#[derive(Deref, DerefMut)]
4901pub struct WindowHandle<V> {
4902    #[deref]
4903    #[deref_mut]
4904    pub(crate) any_handle: AnyWindowHandle,
4905    state_type: PhantomData<fn(V) -> V>,
4906}
4907
4908impl<V> Debug for WindowHandle<V> {
4909    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4910        f.debug_struct("WindowHandle")
4911            .field("any_handle", &self.any_handle.id.as_u64())
4912            .finish()
4913    }
4914}
4915
4916impl<V: 'static + Render> WindowHandle<V> {
4917    /// Creates a new handle from a window ID.
4918    /// This does not check if the root type of the window is `V`.
4919    pub fn new(id: WindowId) -> Self {
4920        WindowHandle {
4921            any_handle: AnyWindowHandle {
4922                id,
4923                state_type: TypeId::of::<V>(),
4924            },
4925            state_type: PhantomData,
4926        }
4927    }
4928
4929    /// Get the root view out of this window.
4930    ///
4931    /// This will fail if the window is closed or if the root view's type does not match `V`.
4932    #[cfg(any(test, feature = "test-support"))]
4933    pub fn root<C>(&self, cx: &mut C) -> Result<Entity<V>>
4934    where
4935        C: AppContext,
4936    {
4937        crate::Flatten::flatten(cx.update_window(self.any_handle, |root_view, _, _| {
4938            root_view
4939                .downcast::<V>()
4940                .map_err(|_| anyhow!("the type of the window's root view has changed"))
4941        }))
4942    }
4943
4944    /// Updates the root view of this window.
4945    ///
4946    /// This will fail if the window has been closed or if the root view's type does not match
4947    pub fn update<C, R>(
4948        &self,
4949        cx: &mut C,
4950        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
4951    ) -> Result<R>
4952    where
4953        C: AppContext,
4954    {
4955        cx.update_window(self.any_handle, |root_view, window, cx| {
4956            let view = root_view
4957                .downcast::<V>()
4958                .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4959
4960            Ok(view.update(cx, |view, cx| update(view, window, cx)))
4961        })?
4962    }
4963
4964    /// Read the root view out of this window.
4965    ///
4966    /// This will fail if the window is closed or if the root view's type does not match `V`.
4967    pub fn read<'a>(&self, cx: &'a App) -> Result<&'a V> {
4968        let x = cx
4969            .windows
4970            .get(self.id)
4971            .and_then(|window| {
4972                window
4973                    .as_deref()
4974                    .and_then(|window| window.root.clone())
4975                    .map(|root_view| root_view.downcast::<V>())
4976            })
4977            .context("window not found")?
4978            .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4979
4980        Ok(x.read(cx))
4981    }
4982
4983    /// Read the root view out of this window, with a callback
4984    ///
4985    /// This will fail if the window is closed or if the root view's type does not match `V`.
4986    pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &App) -> R) -> Result<R>
4987    where
4988        C: AppContext,
4989    {
4990        cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4991    }
4992
4993    /// Read the root view pointer off of this window.
4994    ///
4995    /// This will fail if the window is closed or if the root view's type does not match `V`.
4996    pub fn entity<C>(&self, cx: &C) -> Result<Entity<V>>
4997    where
4998        C: AppContext,
4999    {
5000        cx.read_window(self, |root_view, _cx| root_view)
5001    }
5002
5003    /// Check if this window is 'active'.
5004    ///
5005    /// Will return `None` if the window is closed or currently
5006    /// borrowed.
5007    pub fn is_active(&self, cx: &mut App) -> Option<bool> {
5008        cx.update_window(self.any_handle, |_, window, _| window.is_window_active())
5009            .ok()
5010    }
5011}
5012
5013impl<V> Copy for WindowHandle<V> {}
5014
5015impl<V> Clone for WindowHandle<V> {
5016    fn clone(&self) -> Self {
5017        *self
5018    }
5019}
5020
5021impl<V> PartialEq for WindowHandle<V> {
5022    fn eq(&self, other: &Self) -> bool {
5023        self.any_handle == other.any_handle
5024    }
5025}
5026
5027impl<V> Eq for WindowHandle<V> {}
5028
5029impl<V> Hash for WindowHandle<V> {
5030    fn hash<H: Hasher>(&self, state: &mut H) {
5031        self.any_handle.hash(state);
5032    }
5033}
5034
5035impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
5036    fn from(val: WindowHandle<V>) -> Self {
5037        val.any_handle
5038    }
5039}
5040
5041/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
5042#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
5043pub struct AnyWindowHandle {
5044    pub(crate) id: WindowId,
5045    state_type: TypeId,
5046}
5047
5048impl AnyWindowHandle {
5049    /// Get the ID of this window.
5050    pub fn window_id(&self) -> WindowId {
5051        self.id
5052    }
5053
5054    /// Attempt to convert this handle to a window handle with a specific root view type.
5055    /// If the types do not match, this will return `None`.
5056    pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
5057        if TypeId::of::<T>() == self.state_type {
5058            Some(WindowHandle {
5059                any_handle: *self,
5060                state_type: PhantomData,
5061            })
5062        } else {
5063            None
5064        }
5065    }
5066
5067    /// Updates the state of the root view of this window.
5068    ///
5069    /// This will fail if the window has been closed.
5070    pub fn update<C, R>(
5071        self,
5072        cx: &mut C,
5073        update: impl FnOnce(AnyView, &mut Window, &mut App) -> R,
5074    ) -> Result<R>
5075    where
5076        C: AppContext,
5077    {
5078        cx.update_window(self, update)
5079    }
5080
5081    /// Read the state of the root view of this window.
5082    ///
5083    /// This will fail if the window has been closed.
5084    pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(Entity<T>, &App) -> R) -> Result<R>
5085    where
5086        C: AppContext,
5087        T: 'static,
5088    {
5089        let view = self
5090            .downcast::<T>()
5091            .context("the type of the window's root view has changed")?;
5092
5093        cx.read_window(&view, read)
5094    }
5095}
5096
5097impl HasWindowHandle for Window {
5098    fn window_handle(&self) -> Result<raw_window_handle::WindowHandle<'_>, HandleError> {
5099        self.platform_window.window_handle()
5100    }
5101}
5102
5103impl HasDisplayHandle for Window {
5104    fn display_handle(
5105        &self,
5106    ) -> std::result::Result<raw_window_handle::DisplayHandle<'_>, HandleError> {
5107        self.platform_window.display_handle()
5108    }
5109}
5110
5111/// An identifier for an [`Element`].
5112///
5113/// Can be constructed with a string, a number, or both, as well
5114/// as other internal representations.
5115#[derive(Clone, Debug, Eq, PartialEq, Hash)]
5116pub enum ElementId {
5117    /// The ID of a View element
5118    View(EntityId),
5119    /// An integer ID.
5120    Integer(u64),
5121    /// A string based ID.
5122    Name(SharedString),
5123    /// A UUID.
5124    Uuid(Uuid),
5125    /// An ID that's equated with a focus handle.
5126    FocusHandle(FocusId),
5127    /// A combination of a name and an integer.
5128    NamedInteger(SharedString, u64),
5129    /// A path.
5130    Path(Arc<std::path::Path>),
5131    /// A code location.
5132    CodeLocation(core::panic::Location<'static>),
5133    /// A labeled child of an element.
5134    NamedChild(Arc<ElementId>, SharedString),
5135}
5136
5137impl ElementId {
5138    /// Constructs an `ElementId::NamedInteger` from a name and `usize`.
5139    pub fn named_usize(name: impl Into<SharedString>, integer: usize) -> ElementId {
5140        Self::NamedInteger(name.into(), integer as u64)
5141    }
5142}
5143
5144impl Display for ElementId {
5145    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
5146        match self {
5147            ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
5148            ElementId::Integer(ix) => write!(f, "{}", ix)?,
5149            ElementId::Name(name) => write!(f, "{}", name)?,
5150            ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
5151            ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
5152            ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
5153            ElementId::Path(path) => write!(f, "{}", path.display())?,
5154            ElementId::CodeLocation(location) => write!(f, "{}", location)?,
5155            ElementId::NamedChild(id, name) => write!(f, "{}-{}", id, name)?,
5156        }
5157
5158        Ok(())
5159    }
5160}
5161
5162impl TryInto<SharedString> for ElementId {
5163    type Error = anyhow::Error;
5164
5165    fn try_into(self) -> anyhow::Result<SharedString> {
5166        if let ElementId::Name(name) = self {
5167            Ok(name)
5168        } else {
5169            anyhow::bail!("element id is not string")
5170        }
5171    }
5172}
5173
5174impl From<usize> for ElementId {
5175    fn from(id: usize) -> Self {
5176        ElementId::Integer(id as u64)
5177    }
5178}
5179
5180impl From<i32> for ElementId {
5181    fn from(id: i32) -> Self {
5182        Self::Integer(id as u64)
5183    }
5184}
5185
5186impl From<SharedString> for ElementId {
5187    fn from(name: SharedString) -> Self {
5188        ElementId::Name(name)
5189    }
5190}
5191
5192impl From<String> for ElementId {
5193    fn from(name: String) -> Self {
5194        ElementId::Name(name.into())
5195    }
5196}
5197
5198impl From<Arc<str>> for ElementId {
5199    fn from(name: Arc<str>) -> Self {
5200        ElementId::Name(name.into())
5201    }
5202}
5203
5204impl From<Arc<std::path::Path>> for ElementId {
5205    fn from(path: Arc<std::path::Path>) -> Self {
5206        ElementId::Path(path)
5207    }
5208}
5209
5210impl From<&'static str> for ElementId {
5211    fn from(name: &'static str) -> Self {
5212        ElementId::Name(name.into())
5213    }
5214}
5215
5216impl<'a> From<&'a FocusHandle> for ElementId {
5217    fn from(handle: &'a FocusHandle) -> Self {
5218        ElementId::FocusHandle(handle.id)
5219    }
5220}
5221
5222impl From<(&'static str, EntityId)> for ElementId {
5223    fn from((name, id): (&'static str, EntityId)) -> Self {
5224        ElementId::NamedInteger(name.into(), id.as_u64())
5225    }
5226}
5227
5228impl From<(&'static str, usize)> for ElementId {
5229    fn from((name, id): (&'static str, usize)) -> Self {
5230        ElementId::NamedInteger(name.into(), id as u64)
5231    }
5232}
5233
5234impl From<(SharedString, usize)> for ElementId {
5235    fn from((name, id): (SharedString, usize)) -> Self {
5236        ElementId::NamedInteger(name, id as u64)
5237    }
5238}
5239
5240impl From<(&'static str, u64)> for ElementId {
5241    fn from((name, id): (&'static str, u64)) -> Self {
5242        ElementId::NamedInteger(name.into(), id)
5243    }
5244}
5245
5246impl From<Uuid> for ElementId {
5247    fn from(value: Uuid) -> Self {
5248        Self::Uuid(value)
5249    }
5250}
5251
5252impl From<(&'static str, u32)> for ElementId {
5253    fn from((name, id): (&'static str, u32)) -> Self {
5254        ElementId::NamedInteger(name.into(), id.into())
5255    }
5256}
5257
5258impl<T: Into<SharedString>> From<(ElementId, T)> for ElementId {
5259    fn from((id, name): (ElementId, T)) -> Self {
5260        ElementId::NamedChild(Arc::new(id), name.into())
5261    }
5262}
5263
5264impl From<&'static core::panic::Location<'static>> for ElementId {
5265    fn from(location: &'static core::panic::Location<'static>) -> Self {
5266        ElementId::CodeLocation(*location)
5267    }
5268}
5269
5270/// A rectangle to be rendered in the window at the given position and size.
5271/// Passed as an argument [`Window::paint_quad`].
5272#[derive(Clone)]
5273pub struct PaintQuad {
5274    /// The bounds of the quad within the window.
5275    pub bounds: Bounds<Pixels>,
5276    /// The radii of the quad's corners.
5277    pub corner_radii: Corners<Pixels>,
5278    /// The background color of the quad.
5279    pub background: Background,
5280    /// The widths of the quad's borders.
5281    pub border_widths: Edges<Pixels>,
5282    /// The color of the quad's borders.
5283    pub border_color: Hsla,
5284    /// The style of the quad's borders.
5285    pub border_style: BorderStyle,
5286}
5287
5288impl PaintQuad {
5289    /// Sets the corner radii of the quad.
5290    pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
5291        PaintQuad {
5292            corner_radii: corner_radii.into(),
5293            ..self
5294        }
5295    }
5296
5297    /// Sets the border widths of the quad.
5298    pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5299        PaintQuad {
5300            border_widths: border_widths.into(),
5301            ..self
5302        }
5303    }
5304
5305    /// Sets the border color of the quad.
5306    pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5307        PaintQuad {
5308            border_color: border_color.into(),
5309            ..self
5310        }
5311    }
5312
5313    /// Sets the background color of the quad.
5314    pub fn background(self, background: impl Into<Background>) -> Self {
5315        PaintQuad {
5316            background: background.into(),
5317            ..self
5318        }
5319    }
5320}
5321
5322/// Creates a quad with the given parameters.
5323pub fn quad(
5324    bounds: Bounds<Pixels>,
5325    corner_radii: impl Into<Corners<Pixels>>,
5326    background: impl Into<Background>,
5327    border_widths: impl Into<Edges<Pixels>>,
5328    border_color: impl Into<Hsla>,
5329    border_style: BorderStyle,
5330) -> PaintQuad {
5331    PaintQuad {
5332        bounds,
5333        corner_radii: corner_radii.into(),
5334        background: background.into(),
5335        border_widths: border_widths.into(),
5336        border_color: border_color.into(),
5337        border_style,
5338    }
5339}
5340
5341/// Creates a filled quad with the given bounds and background color.
5342pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5343    PaintQuad {
5344        bounds: bounds.into(),
5345        corner_radii: (0.).into(),
5346        background: background.into(),
5347        border_widths: (0.).into(),
5348        border_color: transparent_black(),
5349        border_style: BorderStyle::default(),
5350    }
5351}
5352
5353/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5354pub fn outline(
5355    bounds: impl Into<Bounds<Pixels>>,
5356    border_color: impl Into<Hsla>,
5357    border_style: BorderStyle,
5358) -> PaintQuad {
5359    PaintQuad {
5360        bounds: bounds.into(),
5361        corner_radii: (0.).into(),
5362        background: transparent_black().into(),
5363        border_widths: (1.).into(),
5364        border_color: border_color.into(),
5365        border_style,
5366    }
5367}