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