1use crate::{
2 point, prelude::*, px, size, transparent_black, Action, AnyDrag, AnyElement, AnyTooltip,
3 AnyView, AppContext, Arena, Asset, AsyncWindowContext, AvailableSpace, Bounds, BoxShadow,
4 Context, Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener,
5 DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
6 FileDropEvent, Flatten, FontId, GPUSpecs, Global, GlobalElementId, GlyphId, Hsla, InputHandler,
7 IsZero, KeyBinding, KeyContext, KeyDownEvent, KeyEvent, Keystroke, KeystrokeEvent,
8 KeystrokeObserver, LayoutId, LineLayoutIndex, Model, ModelContext, Modifiers,
9 ModifiersChangedEvent, MonochromeSprite, MouseButton, MouseEvent, MouseMoveEvent, MouseUpEvent,
10 Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInput, PlatformInputHandler,
11 PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams,
12 RenderImage, RenderImageParams, RenderSvgParams, Replay, ResizeEdge, ScaledPixels, Scene,
13 Shadow, SharedString, Size, StrikethroughStyle, Style, SubscriberSet, Subscription,
14 TaffyLayoutEngine, Task, TextStyle, TextStyleRefinement, TransformationMatrix, Underline,
15 UnderlineStyle, View, VisualContext, WeakView, WindowAppearance, WindowBackgroundAppearance,
16 WindowBounds, WindowControls, WindowDecorations, WindowOptions, WindowParams, WindowTextSystem,
17 SUBPIXEL_VARIANTS,
18};
19use anyhow::{anyhow, Context as _, Result};
20use collections::{FxHashMap, FxHashSet};
21use derive_more::{Deref, DerefMut};
22use futures::channel::oneshot;
23use futures::FutureExt;
24#[cfg(target_os = "macos")]
25use media::core_video::CVImageBuffer;
26use parking_lot::RwLock;
27use refineable::Refineable;
28use slotmap::SlotMap;
29use smallvec::SmallVec;
30use std::{
31 any::{Any, TypeId},
32 borrow::{Borrow, BorrowMut, Cow},
33 cell::{Cell, RefCell},
34 cmp,
35 fmt::{Debug, Display},
36 future::Future,
37 hash::{Hash, Hasher},
38 marker::PhantomData,
39 mem,
40 ops::Range,
41 rc::Rc,
42 sync::{
43 atomic::{AtomicUsize, Ordering::SeqCst},
44 Arc, Weak,
45 },
46 time::{Duration, Instant},
47};
48use util::post_inc;
49use util::{measure, ResultExt};
50use uuid::Uuid;
51
52mod prompts;
53
54pub use prompts::*;
55
56pub(crate) const DEFAULT_WINDOW_SIZE: Size<Pixels> = size(px(1024.), px(700.));
57
58/// Represents the two different phases when dispatching events.
59#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
60pub enum DispatchPhase {
61 /// After the capture phase comes the bubble phase, in which mouse event listeners are
62 /// invoked front to back and keyboard event listeners are invoked from the focused element
63 /// to the root of the element tree. This is the phase you'll most commonly want to use when
64 /// registering event listeners.
65 #[default]
66 Bubble,
67 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
68 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
69 /// is used for special purposes such as clearing the "pressed" state for click events. If
70 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
71 /// outside of the immediate region may rely on detecting non-local events during this phase.
72 Capture,
73}
74
75impl DispatchPhase {
76 /// Returns true if this represents the "bubble" phase.
77 pub fn bubble(self) -> bool {
78 self == DispatchPhase::Bubble
79 }
80
81 /// Returns true if this represents the "capture" phase.
82 pub fn capture(self) -> bool {
83 self == DispatchPhase::Capture
84 }
85}
86
87type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
88
89type AnyWindowFocusListener =
90 Box<dyn FnMut(&WindowFocusEvent, &mut WindowContext) -> bool + 'static>;
91
92struct WindowFocusEvent {
93 previous_focus_path: SmallVec<[FocusId; 8]>,
94 current_focus_path: SmallVec<[FocusId; 8]>,
95}
96
97impl WindowFocusEvent {
98 pub fn is_focus_in(&self, focus_id: FocusId) -> bool {
99 !self.previous_focus_path.contains(&focus_id) && self.current_focus_path.contains(&focus_id)
100 }
101
102 pub fn is_focus_out(&self, focus_id: FocusId) -> bool {
103 self.previous_focus_path.contains(&focus_id) && !self.current_focus_path.contains(&focus_id)
104 }
105}
106
107/// This is provided when subscribing for `ViewContext::on_focus_out` events.
108pub struct FocusOutEvent {
109 /// A weak focus handle representing what was blurred.
110 pub blurred: WeakFocusHandle,
111}
112
113slotmap::new_key_type! {
114 /// A globally unique identifier for a focusable element.
115 pub struct FocusId;
116}
117
118thread_local! {
119 /// 8MB wasn't quite enough...
120 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(32 * 1024 * 1024));
121}
122
123impl FocusId {
124 /// Obtains whether the element associated with this handle is currently focused.
125 pub fn is_focused(&self, cx: &WindowContext) -> bool {
126 cx.window.focus == Some(*self)
127 }
128
129 /// Obtains whether the element associated with this handle contains the focused
130 /// element or is itself focused.
131 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
132 cx.focused()
133 .map_or(false, |focused| self.contains(focused.id, cx))
134 }
135
136 /// Obtains whether the element associated with this handle is contained within the
137 /// focused element or is itself focused.
138 pub fn within_focused(&self, cx: &WindowContext) -> bool {
139 let focused = cx.focused();
140 focused.map_or(false, |focused| focused.id.contains(*self, cx))
141 }
142
143 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
144 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
145 cx.window
146 .rendered_frame
147 .dispatch_tree
148 .focus_contains(*self, other)
149 }
150}
151
152/// A handle which can be used to track and manipulate the focused element in a window.
153pub struct FocusHandle {
154 pub(crate) id: FocusId,
155 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
156}
157
158impl std::fmt::Debug for FocusHandle {
159 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
160 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
161 }
162}
163
164impl FocusHandle {
165 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
166 let id = handles.write().insert(AtomicUsize::new(1));
167 Self {
168 id,
169 handles: handles.clone(),
170 }
171 }
172
173 pub(crate) fn for_id(
174 id: FocusId,
175 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
176 ) -> Option<Self> {
177 let lock = handles.read();
178 let ref_count = lock.get(id)?;
179 if ref_count.load(SeqCst) == 0 {
180 None
181 } else {
182 ref_count.fetch_add(1, SeqCst);
183 Some(Self {
184 id,
185 handles: handles.clone(),
186 })
187 }
188 }
189
190 /// Converts this focus handle into a weak variant, which does not prevent it from being released.
191 pub fn downgrade(&self) -> WeakFocusHandle {
192 WeakFocusHandle {
193 id: self.id,
194 handles: Arc::downgrade(&self.handles),
195 }
196 }
197
198 /// Moves the focus to the element associated with this handle.
199 pub fn focus(&self, cx: &mut WindowContext) {
200 cx.focus(self)
201 }
202
203 /// Obtains whether the element associated with this handle is currently focused.
204 pub fn is_focused(&self, cx: &WindowContext) -> bool {
205 self.id.is_focused(cx)
206 }
207
208 /// Obtains whether the element associated with this handle contains the focused
209 /// element or is itself focused.
210 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
211 self.id.contains_focused(cx)
212 }
213
214 /// Obtains whether the element associated with this handle is contained within the
215 /// focused element or is itself focused.
216 pub fn within_focused(&self, cx: &WindowContext) -> bool {
217 self.id.within_focused(cx)
218 }
219
220 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
221 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
222 self.id.contains(other.id, cx)
223 }
224
225 /// Dispatch an action on the element that rendered this focus handle
226 pub fn dispatch_action(&self, action: &dyn Action, cx: &mut WindowContext) {
227 if let Some(node_id) = cx
228 .window
229 .rendered_frame
230 .dispatch_tree
231 .focusable_node_id(self.id)
232 {
233 cx.dispatch_action_on_node(node_id, action)
234 }
235 }
236}
237
238impl Clone for FocusHandle {
239 fn clone(&self) -> Self {
240 Self::for_id(self.id, &self.handles).unwrap()
241 }
242}
243
244impl PartialEq for FocusHandle {
245 fn eq(&self, other: &Self) -> bool {
246 self.id == other.id
247 }
248}
249
250impl Eq for FocusHandle {}
251
252impl Drop for FocusHandle {
253 fn drop(&mut self) {
254 self.handles
255 .read()
256 .get(self.id)
257 .unwrap()
258 .fetch_sub(1, SeqCst);
259 }
260}
261
262/// A weak reference to a focus handle.
263#[derive(Clone, Debug)]
264pub struct WeakFocusHandle {
265 pub(crate) id: FocusId,
266 handles: Weak<RwLock<SlotMap<FocusId, AtomicUsize>>>,
267}
268
269impl WeakFocusHandle {
270 /// Attempts to upgrade the [WeakFocusHandle] to a [FocusHandle].
271 pub fn upgrade(&self) -> Option<FocusHandle> {
272 let handles = self.handles.upgrade()?;
273 FocusHandle::for_id(self.id, &handles)
274 }
275}
276
277impl PartialEq for WeakFocusHandle {
278 fn eq(&self, other: &WeakFocusHandle) -> bool {
279 self.id == other.id
280 }
281}
282
283impl Eq for WeakFocusHandle {}
284
285impl PartialEq<FocusHandle> for WeakFocusHandle {
286 fn eq(&self, other: &FocusHandle) -> bool {
287 self.id == other.id
288 }
289}
290
291impl PartialEq<WeakFocusHandle> for FocusHandle {
292 fn eq(&self, other: &WeakFocusHandle) -> bool {
293 self.id == other.id
294 }
295}
296
297/// FocusableView allows users of your view to easily
298/// focus it (using cx.focus_view(view))
299pub trait FocusableView: 'static + Render {
300 /// Returns the focus handle associated with this view.
301 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
302}
303
304/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
305/// where the lifecycle of the view is handled by another view.
306pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
307
308impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
309
310/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
311pub struct DismissEvent;
312
313type FrameCallback = Box<dyn FnOnce(&mut WindowContext)>;
314
315pub(crate) type AnyMouseListener =
316 Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
317
318#[derive(Clone)]
319pub(crate) struct CursorStyleRequest {
320 pub(crate) hitbox_id: HitboxId,
321 pub(crate) style: CursorStyle,
322}
323
324/// An identifier for a [Hitbox].
325#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
326pub struct HitboxId(usize);
327
328impl HitboxId {
329 /// Checks if the hitbox with this id is currently hovered.
330 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
331 cx.window.mouse_hit_test.0.contains(self)
332 }
333}
334
335/// A rectangular region that potentially blocks hitboxes inserted prior.
336/// See [WindowContext::insert_hitbox] for more details.
337#[derive(Clone, Debug, Deref)]
338pub struct Hitbox {
339 /// A unique identifier for the hitbox.
340 pub id: HitboxId,
341 /// The bounds of the hitbox.
342 #[deref]
343 pub bounds: Bounds<Pixels>,
344 /// The content mask when the hitbox was inserted.
345 pub content_mask: ContentMask<Pixels>,
346 /// Whether the hitbox occludes other hitboxes inserted prior.
347 pub opaque: bool,
348}
349
350impl Hitbox {
351 /// Checks if the hitbox is currently hovered.
352 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
353 self.id.is_hovered(cx)
354 }
355}
356
357#[derive(Default, Eq, PartialEq)]
358pub(crate) struct HitTest(SmallVec<[HitboxId; 8]>);
359
360/// An identifier for a tooltip.
361#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
362pub struct TooltipId(usize);
363
364impl TooltipId {
365 /// Checks if the tooltip is currently hovered.
366 pub fn is_hovered(&self, cx: &WindowContext) -> bool {
367 cx.window
368 .tooltip_bounds
369 .as_ref()
370 .map_or(false, |tooltip_bounds| {
371 tooltip_bounds.id == *self && tooltip_bounds.bounds.contains(&cx.mouse_position())
372 })
373 }
374}
375
376pub(crate) struct TooltipBounds {
377 id: TooltipId,
378 bounds: Bounds<Pixels>,
379}
380
381#[derive(Clone)]
382pub(crate) struct TooltipRequest {
383 id: TooltipId,
384 tooltip: AnyTooltip,
385}
386
387pub(crate) struct DeferredDraw {
388 priority: usize,
389 parent_node: DispatchNodeId,
390 element_id_stack: SmallVec<[ElementId; 32]>,
391 text_style_stack: Vec<TextStyleRefinement>,
392 element: Option<AnyElement>,
393 absolute_offset: Point<Pixels>,
394 prepaint_range: Range<PrepaintStateIndex>,
395 paint_range: Range<PaintIndex>,
396}
397
398pub(crate) struct Frame {
399 pub(crate) focus: Option<FocusId>,
400 pub(crate) window_active: bool,
401 pub(crate) element_states: FxHashMap<(GlobalElementId, TypeId), ElementStateBox>,
402 accessed_element_states: Vec<(GlobalElementId, TypeId)>,
403 pub(crate) mouse_listeners: Vec<Option<AnyMouseListener>>,
404 pub(crate) dispatch_tree: DispatchTree,
405 pub(crate) scene: Scene,
406 pub(crate) hitboxes: Vec<Hitbox>,
407 pub(crate) deferred_draws: Vec<DeferredDraw>,
408 pub(crate) input_handlers: Vec<Option<PlatformInputHandler>>,
409 pub(crate) tooltip_requests: Vec<Option<TooltipRequest>>,
410 pub(crate) cursor_styles: Vec<CursorStyleRequest>,
411 #[cfg(any(test, feature = "test-support"))]
412 pub(crate) debug_bounds: FxHashMap<String, Bounds<Pixels>>,
413}
414
415#[derive(Clone, Default)]
416pub(crate) struct PrepaintStateIndex {
417 hitboxes_index: usize,
418 tooltips_index: usize,
419 deferred_draws_index: usize,
420 dispatch_tree_index: usize,
421 accessed_element_states_index: usize,
422 line_layout_index: LineLayoutIndex,
423}
424
425#[derive(Clone, Default)]
426pub(crate) struct PaintIndex {
427 scene_index: usize,
428 mouse_listeners_index: usize,
429 input_handlers_index: usize,
430 cursor_styles_index: usize,
431 accessed_element_states_index: usize,
432 line_layout_index: LineLayoutIndex,
433}
434
435impl Frame {
436 pub(crate) fn new(dispatch_tree: DispatchTree) -> Self {
437 Frame {
438 focus: None,
439 window_active: false,
440 element_states: FxHashMap::default(),
441 accessed_element_states: Vec::new(),
442 mouse_listeners: Vec::new(),
443 dispatch_tree,
444 scene: Scene::default(),
445 hitboxes: Vec::new(),
446 deferred_draws: Vec::new(),
447 input_handlers: Vec::new(),
448 tooltip_requests: Vec::new(),
449 cursor_styles: Vec::new(),
450
451 #[cfg(any(test, feature = "test-support"))]
452 debug_bounds: FxHashMap::default(),
453 }
454 }
455
456 pub(crate) fn clear(&mut self) {
457 self.element_states.clear();
458 self.accessed_element_states.clear();
459 self.mouse_listeners.clear();
460 self.dispatch_tree.clear();
461 self.scene.clear();
462 self.input_handlers.clear();
463 self.tooltip_requests.clear();
464 self.cursor_styles.clear();
465 self.hitboxes.clear();
466 self.deferred_draws.clear();
467 self.focus = None;
468 }
469
470 pub(crate) fn hit_test(&self, position: Point<Pixels>) -> HitTest {
471 let mut hit_test = HitTest::default();
472 for hitbox in self.hitboxes.iter().rev() {
473 let bounds = hitbox.bounds.intersect(&hitbox.content_mask.bounds);
474 if bounds.contains(&position) {
475 hit_test.0.push(hitbox.id);
476 if hitbox.opaque {
477 break;
478 }
479 }
480 }
481 hit_test
482 }
483
484 pub(crate) fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
485 self.focus
486 .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
487 .unwrap_or_default()
488 }
489
490 pub(crate) fn finish(&mut self, prev_frame: &mut Self) {
491 for element_state_key in &self.accessed_element_states {
492 if let Some((element_state_key, element_state)) =
493 prev_frame.element_states.remove_entry(element_state_key)
494 {
495 self.element_states.insert(element_state_key, element_state);
496 }
497 }
498
499 self.scene.finish();
500 }
501}
502
503// Holds the state for a specific window.
504#[doc(hidden)]
505pub struct Window {
506 pub(crate) handle: AnyWindowHandle,
507 pub(crate) removed: bool,
508 pub(crate) platform_window: Box<dyn PlatformWindow>,
509 display_id: Option<DisplayId>,
510 sprite_atlas: Arc<dyn PlatformAtlas>,
511 text_system: Arc<WindowTextSystem>,
512 rem_size: Pixels,
513 /// The stack of override values for the window's rem size.
514 ///
515 /// This is used by `with_rem_size` to allow rendering an element tree with
516 /// a given rem size.
517 rem_size_override_stack: SmallVec<[Pixels; 8]>,
518 pub(crate) viewport_size: Size<Pixels>,
519 layout_engine: Option<TaffyLayoutEngine>,
520 pub(crate) root_view: Option<AnyView>,
521 pub(crate) element_id_stack: SmallVec<[ElementId; 32]>,
522 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
523 pub(crate) element_offset_stack: Vec<Point<Pixels>>,
524 pub(crate) element_opacity: Option<f32>,
525 pub(crate) content_mask_stack: Vec<ContentMask<Pixels>>,
526 pub(crate) requested_autoscroll: Option<Bounds<Pixels>>,
527 pub(crate) rendered_frame: Frame,
528 pub(crate) next_frame: Frame,
529 pub(crate) next_hitbox_id: HitboxId,
530 pub(crate) next_tooltip_id: TooltipId,
531 pub(crate) tooltip_bounds: Option<TooltipBounds>,
532 next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>>,
533 pub(crate) dirty_views: FxHashSet<EntityId>,
534 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
535 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
536 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
537 default_prevented: bool,
538 mouse_position: Point<Pixels>,
539 mouse_hit_test: HitTest,
540 modifiers: Modifiers,
541 scale_factor: f32,
542 bounds_observers: SubscriberSet<(), AnyObserver>,
543 appearance: WindowAppearance,
544 appearance_observers: SubscriberSet<(), AnyObserver>,
545 active: Rc<Cell<bool>>,
546 hovered: Rc<Cell<bool>>,
547 pub(crate) dirty: Rc<Cell<bool>>,
548 pub(crate) needs_present: Rc<Cell<bool>>,
549 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
550 pub(crate) refreshing: bool,
551 pub(crate) draw_phase: DrawPhase,
552 activation_observers: SubscriberSet<(), AnyObserver>,
553 pub(crate) focus: Option<FocusId>,
554 focus_enabled: bool,
555 pending_input: Option<PendingInput>,
556 pending_modifier: ModifierState,
557 pending_input_observers: SubscriberSet<(), AnyObserver>,
558 prompt: Option<RenderablePromptHandle>,
559}
560
561#[derive(Clone, Debug, Default)]
562struct ModifierState {
563 modifiers: Modifiers,
564 saw_keystroke: bool,
565}
566
567#[derive(Clone, Copy, Debug, Eq, PartialEq)]
568pub(crate) enum DrawPhase {
569 None,
570 Prepaint,
571 Paint,
572 Focus,
573}
574
575#[derive(Default, Debug)]
576struct PendingInput {
577 keystrokes: SmallVec<[Keystroke; 1]>,
578 focus: Option<FocusId>,
579 timer: Option<Task<()>>,
580}
581
582pub(crate) struct ElementStateBox {
583 pub(crate) inner: Box<dyn Any>,
584 #[cfg(debug_assertions)]
585 pub(crate) type_name: &'static str,
586}
587
588fn default_bounds(display_id: Option<DisplayId>, cx: &mut AppContext) -> Bounds<Pixels> {
589 const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
590
591 cx.active_window()
592 .and_then(|w| w.update(cx, |_, cx| cx.bounds()).ok())
593 .map(|mut bounds| {
594 bounds.origin += DEFAULT_WINDOW_OFFSET;
595 bounds
596 })
597 .unwrap_or_else(|| {
598 let display = display_id
599 .map(|id| cx.find_display(id))
600 .unwrap_or_else(|| cx.primary_display());
601
602 display
603 .map(|display| display.default_bounds())
604 .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
605 })
606}
607
608impl Window {
609 pub(crate) fn new(
610 handle: AnyWindowHandle,
611 options: WindowOptions,
612 cx: &mut AppContext,
613 ) -> Result<Self> {
614 let WindowOptions {
615 window_bounds,
616 titlebar,
617 focus,
618 show,
619 kind,
620 is_movable,
621 display_id,
622 window_background,
623 app_id,
624 window_min_size,
625 window_decorations,
626 } = options;
627
628 let bounds = window_bounds
629 .map(|bounds| bounds.get_bounds())
630 .unwrap_or_else(|| default_bounds(display_id, cx));
631 let mut platform_window = cx.platform.open_window(
632 handle,
633 WindowParams {
634 bounds,
635 titlebar,
636 kind,
637 is_movable,
638 focus,
639 show,
640 display_id,
641 window_min_size,
642 },
643 )?;
644 let display_id = platform_window.display().map(|display| display.id());
645 let sprite_atlas = platform_window.sprite_atlas();
646 let mouse_position = platform_window.mouse_position();
647 let modifiers = platform_window.modifiers();
648 let content_size = platform_window.content_size();
649 let scale_factor = platform_window.scale_factor();
650 let appearance = platform_window.appearance();
651 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
652 let dirty = Rc::new(Cell::new(true));
653 let active = Rc::new(Cell::new(platform_window.is_active()));
654 let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
655 let needs_present = Rc::new(Cell::new(false));
656 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
657 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
658
659 platform_window
660 .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
661 platform_window.set_background_appearance(window_background);
662
663 if let Some(ref window_open_state) = window_bounds {
664 match window_open_state {
665 WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
666 WindowBounds::Maximized(_) => platform_window.zoom(),
667 WindowBounds::Windowed(_) => {}
668 }
669 }
670
671 platform_window.on_close(Box::new({
672 let mut cx = cx.to_async();
673 move || {
674 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
675 }
676 }));
677 platform_window.on_request_frame(Box::new({
678 let mut cx = cx.to_async();
679 let dirty = dirty.clone();
680 let active = active.clone();
681 let needs_present = needs_present.clone();
682 let next_frame_callbacks = next_frame_callbacks.clone();
683 let last_input_timestamp = last_input_timestamp.clone();
684 move |request_frame_options| {
685 let next_frame_callbacks = next_frame_callbacks.take();
686 if !next_frame_callbacks.is_empty() {
687 handle
688 .update(&mut cx, |_, cx| {
689 for callback in next_frame_callbacks {
690 callback(cx);
691 }
692 })
693 .log_err();
694 }
695
696 // Keep presenting the current scene for 1 extra second since the
697 // last input to prevent the display from underclocking the refresh rate.
698 let needs_present = request_frame_options.require_presentation
699 || needs_present.get()
700 || (active.get()
701 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
702
703 if dirty.get() {
704 measure("frame duration", || {
705 handle
706 .update(&mut cx, |_, cx| {
707 cx.draw();
708 cx.present();
709 })
710 .log_err();
711 })
712 } else if needs_present {
713 handle.update(&mut cx, |_, cx| cx.present()).log_err();
714 }
715
716 handle
717 .update(&mut cx, |_, cx| {
718 cx.complete_frame();
719 })
720 .log_err();
721 }
722 }));
723 platform_window.on_resize(Box::new({
724 let mut cx = cx.to_async();
725 move |_, _| {
726 handle
727 .update(&mut cx, |_, cx| cx.bounds_changed())
728 .log_err();
729 }
730 }));
731 platform_window.on_moved(Box::new({
732 let mut cx = cx.to_async();
733 move || {
734 handle
735 .update(&mut cx, |_, cx| cx.bounds_changed())
736 .log_err();
737 }
738 }));
739 platform_window.on_appearance_changed(Box::new({
740 let mut cx = cx.to_async();
741 move || {
742 handle
743 .update(&mut cx, |_, cx| cx.appearance_changed())
744 .log_err();
745 }
746 }));
747 platform_window.on_active_status_change(Box::new({
748 let mut cx = cx.to_async();
749 move |active| {
750 handle
751 .update(&mut cx, |_, cx| {
752 cx.window.active.set(active);
753 cx.window
754 .activation_observers
755 .clone()
756 .retain(&(), |callback| callback(cx));
757 cx.refresh();
758 })
759 .log_err();
760 }
761 }));
762 platform_window.on_hover_status_change(Box::new({
763 let mut cx = cx.to_async();
764 move |active| {
765 handle
766 .update(&mut cx, |_, cx| {
767 cx.window.hovered.set(active);
768 cx.refresh();
769 })
770 .log_err();
771 }
772 }));
773 platform_window.on_input({
774 let mut cx = cx.to_async();
775 Box::new(move |event| {
776 handle
777 .update(&mut cx, |_, cx| cx.dispatch_event(event))
778 .log_err()
779 .unwrap_or(DispatchEventResult::default())
780 })
781 });
782
783 if let Some(app_id) = app_id {
784 platform_window.set_app_id(&app_id);
785 }
786
787 Ok(Window {
788 handle,
789 removed: false,
790 platform_window,
791 display_id,
792 sprite_atlas,
793 text_system,
794 rem_size: px(16.),
795 rem_size_override_stack: SmallVec::new(),
796 viewport_size: content_size,
797 layout_engine: Some(TaffyLayoutEngine::new()),
798 root_view: None,
799 element_id_stack: SmallVec::default(),
800 text_style_stack: Vec::new(),
801 element_offset_stack: Vec::new(),
802 content_mask_stack: Vec::new(),
803 element_opacity: None,
804 requested_autoscroll: None,
805 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
806 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
807 next_frame_callbacks,
808 next_hitbox_id: HitboxId::default(),
809 next_tooltip_id: TooltipId::default(),
810 tooltip_bounds: None,
811 dirty_views: FxHashSet::default(),
812 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
813 focus_listeners: SubscriberSet::new(),
814 focus_lost_listeners: SubscriberSet::new(),
815 default_prevented: true,
816 mouse_position,
817 mouse_hit_test: HitTest::default(),
818 modifiers,
819 scale_factor,
820 bounds_observers: SubscriberSet::new(),
821 appearance,
822 appearance_observers: SubscriberSet::new(),
823 active,
824 hovered,
825 dirty,
826 needs_present,
827 last_input_timestamp,
828 refreshing: false,
829 draw_phase: DrawPhase::None,
830 activation_observers: SubscriberSet::new(),
831 focus: None,
832 focus_enabled: true,
833 pending_input: None,
834 pending_modifier: ModifierState::default(),
835 pending_input_observers: SubscriberSet::new(),
836 prompt: None,
837 })
838 }
839 fn new_focus_listener(&self, value: AnyWindowFocusListener) -> (Subscription, impl FnOnce()) {
840 self.focus_listeners.insert((), value)
841 }
842}
843
844#[derive(Clone, Debug, Default, PartialEq, Eq)]
845pub(crate) struct DispatchEventResult {
846 pub propagate: bool,
847 pub default_prevented: bool,
848}
849
850/// Indicates which region of the window is visible. Content falling outside of this mask will not be
851/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
852/// to leave room to support more complex shapes in the future.
853#[derive(Clone, Debug, Default, PartialEq, Eq)]
854#[repr(C)]
855pub struct ContentMask<P: Clone + Default + Debug> {
856 /// The bounds
857 pub bounds: Bounds<P>,
858}
859
860impl ContentMask<Pixels> {
861 /// Scale the content mask's pixel units by the given scaling factor.
862 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
863 ContentMask {
864 bounds: self.bounds.scale(factor),
865 }
866 }
867
868 /// Intersect the content mask with the given content mask.
869 pub fn intersect(&self, other: &Self) -> Self {
870 let bounds = self.bounds.intersect(&other.bounds);
871 ContentMask { bounds }
872 }
873}
874
875/// Provides access to application state in the context of a single window. Derefs
876/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
877/// an [`AppContext`] and call any [`AppContext`] methods.
878pub struct WindowContext<'a> {
879 pub(crate) app: &'a mut AppContext,
880 pub(crate) window: &'a mut Window,
881}
882
883impl<'a> WindowContext<'a> {
884 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
885 Self { app, window }
886 }
887
888 /// Obtain a handle to the window that belongs to this context.
889 pub fn window_handle(&self) -> AnyWindowHandle {
890 self.window.handle
891 }
892
893 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
894 pub fn refresh(&mut self) {
895 if self.window.draw_phase == DrawPhase::None {
896 self.window.refreshing = true;
897 self.window.dirty.set(true);
898 }
899 }
900
901 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
902 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
903 /// Note that this method will always cause a redraw, the entire window is refreshed if view_id is None.
904 pub fn notify(&mut self, view_id: Option<EntityId>) {
905 let Some(view_id) = view_id else {
906 self.refresh();
907 return;
908 };
909
910 for view_id in self
911 .window
912 .rendered_frame
913 .dispatch_tree
914 .view_path(view_id)
915 .into_iter()
916 .rev()
917 {
918 if !self.window.dirty_views.insert(view_id) {
919 break;
920 }
921 }
922
923 if self.window.draw_phase == DrawPhase::None {
924 self.window.dirty.set(true);
925 self.app.push_effect(Effect::Notify { emitter: view_id });
926 }
927 }
928
929 /// Close this window.
930 pub fn remove_window(&mut self) {
931 self.window.removed = true;
932 }
933
934 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
935 /// for elements rendered within this window.
936 pub fn focus_handle(&self) -> FocusHandle {
937 FocusHandle::new(&self.window.focus_handles)
938 }
939
940 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
941 pub fn focused(&self) -> Option<FocusHandle> {
942 self.window
943 .focus
944 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
945 }
946
947 /// Move focus to the element associated with the given [`FocusHandle`].
948 pub fn focus(&mut self, handle: &FocusHandle) {
949 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
950 return;
951 }
952
953 self.window.focus = Some(handle.id);
954 self.clear_pending_keystrokes();
955 self.refresh();
956 }
957
958 /// Remove focus from all elements within this context's window.
959 pub fn blur(&mut self) {
960 if !self.window.focus_enabled {
961 return;
962 }
963
964 self.window.focus = None;
965 self.refresh();
966 }
967
968 /// Blur the window and don't allow anything in it to be focused again.
969 pub fn disable_focus(&mut self) {
970 self.blur();
971 self.window.focus_enabled = false;
972 }
973
974 /// Accessor for the text system.
975 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
976 &self.window.text_system
977 }
978
979 /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
980 pub fn text_style(&self) -> TextStyle {
981 let mut style = TextStyle::default();
982 for refinement in &self.window.text_style_stack {
983 style.refine(refinement);
984 }
985 style
986 }
987
988 /// Check if the platform window is maximized
989 /// On some platforms (namely Windows) this is different than the bounds being the size of the display
990 pub fn is_maximized(&self) -> bool {
991 self.window.platform_window.is_maximized()
992 }
993
994 /// request a certain window decoration (Wayland)
995 pub fn request_decorations(&self, decorations: WindowDecorations) {
996 self.window.platform_window.request_decorations(decorations);
997 }
998
999 /// Start a window resize operation (Wayland)
1000 pub fn start_window_resize(&self, edge: ResizeEdge) {
1001 self.window.platform_window.start_window_resize(edge);
1002 }
1003
1004 /// Return the `WindowBounds` to indicate that how a window should be opened
1005 /// after it has been closed
1006 pub fn window_bounds(&self) -> WindowBounds {
1007 self.window.platform_window.window_bounds()
1008 }
1009
1010 /// Dispatch the given action on the currently focused element.
1011 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
1012 let focus_handle = self.focused();
1013
1014 let window = self.window.handle;
1015 self.app.defer(move |cx| {
1016 window
1017 .update(cx, |_, cx| {
1018 let node_id = focus_handle
1019 .and_then(|handle| {
1020 cx.window
1021 .rendered_frame
1022 .dispatch_tree
1023 .focusable_node_id(handle.id)
1024 })
1025 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
1026
1027 cx.dispatch_action_on_node(node_id, action.as_ref());
1028 })
1029 .log_err();
1030 })
1031 }
1032
1033 pub(crate) fn dispatch_keystroke_observers(
1034 &mut self,
1035 event: &dyn Any,
1036 action: Option<Box<dyn Action>>,
1037 ) {
1038 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1039 return;
1040 };
1041
1042 self.keystroke_observers
1043 .clone()
1044 .retain(&(), move |callback| {
1045 (callback)(
1046 &KeystrokeEvent {
1047 keystroke: key_down_event.keystroke.clone(),
1048 action: action.as_ref().map(|action| action.boxed_clone()),
1049 },
1050 self,
1051 )
1052 });
1053 }
1054
1055 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1056 /// that are currently on the stack to be returned to the app.
1057 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
1058 let handle = self.window.handle;
1059 self.app.defer(move |cx| {
1060 handle.update(cx, |_, cx| f(cx)).ok();
1061 });
1062 }
1063
1064 /// Subscribe to events emitted by a model or view.
1065 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1066 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
1067 pub fn observe<E, T>(
1068 &mut self,
1069 entity: &E,
1070 mut on_notify: impl FnMut(E, &mut WindowContext<'_>) + 'static,
1071 ) -> Subscription
1072 where
1073 E: Entity<T>,
1074 {
1075 let entity_id = entity.entity_id();
1076 let entity = entity.downgrade();
1077 let window_handle = self.window.handle;
1078 self.app.new_observer(
1079 entity_id,
1080 Box::new(move |cx| {
1081 window_handle
1082 .update(cx, |_, cx| {
1083 if let Some(handle) = E::upgrade_from(&entity) {
1084 on_notify(handle, cx);
1085 true
1086 } else {
1087 false
1088 }
1089 })
1090 .unwrap_or(false)
1091 }),
1092 )
1093 }
1094
1095 /// Subscribe to events emitted by a model or view.
1096 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1097 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
1098 pub fn subscribe<Emitter, E, Evt>(
1099 &mut self,
1100 entity: &E,
1101 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
1102 ) -> Subscription
1103 where
1104 Emitter: EventEmitter<Evt>,
1105 E: Entity<Emitter>,
1106 Evt: 'static,
1107 {
1108 let entity_id = entity.entity_id();
1109 let entity = entity.downgrade();
1110 let window_handle = self.window.handle;
1111 self.app.new_subscription(
1112 entity_id,
1113 (
1114 TypeId::of::<Evt>(),
1115 Box::new(move |event, cx| {
1116 window_handle
1117 .update(cx, |_, cx| {
1118 if let Some(handle) = E::upgrade_from(&entity) {
1119 let event = event.downcast_ref().expect("invalid event type");
1120 on_event(handle, event, cx);
1121 true
1122 } else {
1123 false
1124 }
1125 })
1126 .unwrap_or(false)
1127 }),
1128 ),
1129 )
1130 }
1131
1132 /// Register a callback to be invoked when the given Model or View is released.
1133 pub fn observe_release<E, T>(
1134 &self,
1135 entity: &E,
1136 mut on_release: impl FnOnce(&mut T, &mut WindowContext) + 'static,
1137 ) -> Subscription
1138 where
1139 E: Entity<T>,
1140 T: 'static,
1141 {
1142 let entity_id = entity.entity_id();
1143 let window_handle = self.window.handle;
1144 let (subscription, activate) = self.app.release_listeners.insert(
1145 entity_id,
1146 Box::new(move |entity, cx| {
1147 let entity = entity.downcast_mut().expect("invalid entity type");
1148 let _ = window_handle.update(cx, |_, cx| on_release(entity, cx));
1149 }),
1150 );
1151 activate();
1152 subscription
1153 }
1154
1155 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1156 /// await points in async code.
1157 pub fn to_async(&self) -> AsyncWindowContext {
1158 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
1159 }
1160
1161 /// Schedule the given closure to be run directly after the current frame is rendered.
1162 pub fn on_next_frame(&self, callback: impl FnOnce(&mut WindowContext) + 'static) {
1163 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
1164 }
1165
1166 /// Schedule a frame to be drawn on the next animation frame.
1167 ///
1168 /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1169 /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1170 ///
1171 /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1172 pub fn request_animation_frame(&self) {
1173 let parent_id = self.parent_view_id();
1174 self.on_next_frame(move |cx| cx.notify(parent_id));
1175 }
1176
1177 /// Spawn the future returned by the given closure on the application thread pool.
1178 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1179 /// use within your future.
1180 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
1181 where
1182 R: 'static,
1183 Fut: Future<Output = R> + 'static,
1184 {
1185 self.app
1186 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
1187 }
1188
1189 fn bounds_changed(&mut self) {
1190 self.window.scale_factor = self.window.platform_window.scale_factor();
1191 self.window.viewport_size = self.window.platform_window.content_size();
1192 self.window.display_id = self
1193 .window
1194 .platform_window
1195 .display()
1196 .map(|display| display.id());
1197
1198 self.refresh();
1199
1200 self.window
1201 .bounds_observers
1202 .clone()
1203 .retain(&(), |callback| callback(self));
1204 }
1205
1206 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1207 pub fn bounds(&self) -> Bounds<Pixels> {
1208 self.window.platform_window.bounds()
1209 }
1210
1211 /// Returns whether or not the window is currently fullscreen
1212 pub fn is_fullscreen(&self) -> bool {
1213 self.window.platform_window.is_fullscreen()
1214 }
1215
1216 pub(crate) fn appearance_changed(&mut self) {
1217 self.window.appearance = self.window.platform_window.appearance();
1218
1219 self.window
1220 .appearance_observers
1221 .clone()
1222 .retain(&(), |callback| callback(self));
1223 }
1224
1225 /// Returns the appearance of the current window.
1226 pub fn appearance(&self) -> WindowAppearance {
1227 self.window.appearance
1228 }
1229
1230 /// Returns the size of the drawable area within the window.
1231 pub fn viewport_size(&self) -> Size<Pixels> {
1232 self.window.viewport_size
1233 }
1234
1235 /// Returns whether this window is focused by the operating system (receiving key events).
1236 pub fn is_window_active(&self) -> bool {
1237 self.window.active.get()
1238 }
1239
1240 /// Returns whether this window is considered to be the window
1241 /// that currently owns the mouse cursor.
1242 /// On mac, this is equivalent to `is_window_active`.
1243 pub fn is_window_hovered(&self) -> bool {
1244 if cfg!(any(
1245 target_os = "windows",
1246 target_os = "linux",
1247 target_os = "freebsd"
1248 )) {
1249 self.window.hovered.get()
1250 } else {
1251 self.is_window_active()
1252 }
1253 }
1254
1255 /// Toggle zoom on the window.
1256 pub fn zoom_window(&self) {
1257 self.window.platform_window.zoom();
1258 }
1259
1260 /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1261 pub fn show_window_menu(&self, position: Point<Pixels>) {
1262 self.window.platform_window.show_window_menu(position)
1263 }
1264
1265 /// Tells the compositor to take control of window movement (Wayland and X11)
1266 ///
1267 /// Events may not be received during a move operation.
1268 pub fn start_window_move(&self) {
1269 self.window.platform_window.start_window_move()
1270 }
1271
1272 /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1273 pub fn set_client_inset(&self, inset: Pixels) {
1274 self.window.platform_window.set_client_inset(inset);
1275 }
1276
1277 /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1278 pub fn window_decorations(&self) -> Decorations {
1279 self.window.platform_window.window_decorations()
1280 }
1281
1282 /// Returns which window controls are currently visible (Wayland)
1283 pub fn window_controls(&self) -> WindowControls {
1284 self.window.platform_window.window_controls()
1285 }
1286
1287 /// Updates the window's title at the platform level.
1288 pub fn set_window_title(&mut self, title: &str) {
1289 self.window.platform_window.set_title(title);
1290 }
1291
1292 /// Sets the application identifier.
1293 pub fn set_app_id(&mut self, app_id: &str) {
1294 self.window.platform_window.set_app_id(app_id);
1295 }
1296
1297 /// Sets the window background appearance.
1298 pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1299 self.window
1300 .platform_window
1301 .set_background_appearance(background_appearance);
1302 }
1303
1304 /// Mark the window as dirty at the platform level.
1305 pub fn set_window_edited(&mut self, edited: bool) {
1306 self.window.platform_window.set_edited(edited);
1307 }
1308
1309 /// Determine the display on which the window is visible.
1310 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
1311 self.platform
1312 .displays()
1313 .into_iter()
1314 .find(|display| Some(display.id()) == self.window.display_id)
1315 }
1316
1317 /// Show the platform character palette.
1318 pub fn show_character_palette(&self) {
1319 self.window.platform_window.show_character_palette();
1320 }
1321
1322 /// The scale factor of the display associated with the window. For example, it could
1323 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1324 /// be rendered as two pixels on screen.
1325 pub fn scale_factor(&self) -> f32 {
1326 self.window.scale_factor
1327 }
1328
1329 /// The size of an em for the base font of the application. Adjusting this value allows the
1330 /// UI to scale, just like zooming a web page.
1331 pub fn rem_size(&self) -> Pixels {
1332 self.window
1333 .rem_size_override_stack
1334 .last()
1335 .copied()
1336 .unwrap_or(self.window.rem_size)
1337 }
1338
1339 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1340 /// UI to scale, just like zooming a web page.
1341 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1342 self.window.rem_size = rem_size.into();
1343 }
1344
1345 /// Executes the provided function with the specified rem size.
1346 ///
1347 /// This method must only be called as part of element drawing.
1348 pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1349 where
1350 F: FnOnce(&mut Self) -> R,
1351 {
1352 debug_assert!(
1353 matches!(
1354 self.window.draw_phase,
1355 DrawPhase::Prepaint | DrawPhase::Paint
1356 ),
1357 "this method can only be called during request_layout, prepaint, or paint"
1358 );
1359
1360 if let Some(rem_size) = rem_size {
1361 self.window.rem_size_override_stack.push(rem_size.into());
1362 let result = f(self);
1363 self.window.rem_size_override_stack.pop();
1364 result
1365 } else {
1366 f(self)
1367 }
1368 }
1369
1370 /// The line height associated with the current text style.
1371 pub fn line_height(&self) -> Pixels {
1372 self.text_style().line_height_in_pixels(self.rem_size())
1373 }
1374
1375 /// Call to prevent the default action of an event. Currently only used to prevent
1376 /// parent elements from becoming focused on mouse down.
1377 pub fn prevent_default(&mut self) {
1378 self.window.default_prevented = true;
1379 }
1380
1381 /// Obtain whether default has been prevented for the event currently being dispatched.
1382 pub fn default_prevented(&self) -> bool {
1383 self.window.default_prevented
1384 }
1385
1386 /// Determine whether the given action is available along the dispatch path to the currently focused element.
1387 pub fn is_action_available(&self, action: &dyn Action) -> bool {
1388 let target = self
1389 .focused()
1390 .and_then(|focused_handle| {
1391 self.window
1392 .rendered_frame
1393 .dispatch_tree
1394 .focusable_node_id(focused_handle.id)
1395 })
1396 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1397 self.window
1398 .rendered_frame
1399 .dispatch_tree
1400 .is_action_available(action, target)
1401 }
1402
1403 /// The position of the mouse relative to the window.
1404 pub fn mouse_position(&self) -> Point<Pixels> {
1405 self.window.mouse_position
1406 }
1407
1408 /// The current state of the keyboard's modifiers
1409 pub fn modifiers(&self) -> Modifiers {
1410 self.window.modifiers
1411 }
1412
1413 fn complete_frame(&self) {
1414 self.window.platform_window.completed_frame();
1415 }
1416
1417 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1418 /// the contents of the new [Scene], use [present].
1419 #[profiling::function]
1420 pub fn draw(&mut self) {
1421 self.window.dirty.set(false);
1422 self.window.requested_autoscroll = None;
1423
1424 // Restore the previously-used input handler.
1425 if let Some(input_handler) = self.window.platform_window.take_input_handler() {
1426 self.window
1427 .rendered_frame
1428 .input_handlers
1429 .push(Some(input_handler));
1430 }
1431
1432 self.draw_roots();
1433 self.window.dirty_views.clear();
1434 self.window.next_frame.window_active = self.window.active.get();
1435
1436 // Register requested input handler with the platform window.
1437 if let Some(input_handler) = self.window.next_frame.input_handlers.pop() {
1438 self.window
1439 .platform_window
1440 .set_input_handler(input_handler.unwrap());
1441 }
1442
1443 self.window.layout_engine.as_mut().unwrap().clear();
1444 self.text_system().finish_frame();
1445 self.window
1446 .next_frame
1447 .finish(&mut self.window.rendered_frame);
1448 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1449 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1450 if percentage >= 80. {
1451 log::warn!("elevated element arena occupation: {}.", percentage);
1452 }
1453 element_arena.clear();
1454 });
1455
1456 self.window.draw_phase = DrawPhase::Focus;
1457 let previous_focus_path = self.window.rendered_frame.focus_path();
1458 let previous_window_active = self.window.rendered_frame.window_active;
1459 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1460 self.window.next_frame.clear();
1461 let current_focus_path = self.window.rendered_frame.focus_path();
1462 let current_window_active = self.window.rendered_frame.window_active;
1463
1464 if previous_focus_path != current_focus_path
1465 || previous_window_active != current_window_active
1466 {
1467 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1468 self.window
1469 .focus_lost_listeners
1470 .clone()
1471 .retain(&(), |listener| listener(self));
1472 }
1473
1474 let event = WindowFocusEvent {
1475 previous_focus_path: if previous_window_active {
1476 previous_focus_path
1477 } else {
1478 Default::default()
1479 },
1480 current_focus_path: if current_window_active {
1481 current_focus_path
1482 } else {
1483 Default::default()
1484 },
1485 };
1486 self.window
1487 .focus_listeners
1488 .clone()
1489 .retain(&(), |listener| listener(&event, self));
1490 }
1491
1492 self.reset_cursor_style();
1493 self.window.refreshing = false;
1494 self.window.draw_phase = DrawPhase::None;
1495 self.window.needs_present.set(true);
1496 }
1497
1498 #[profiling::function]
1499 fn present(&self) {
1500 self.window
1501 .platform_window
1502 .draw(&self.window.rendered_frame.scene);
1503 self.window.needs_present.set(false);
1504 profiling::finish_frame!();
1505 }
1506
1507 fn draw_roots(&mut self) {
1508 self.window.draw_phase = DrawPhase::Prepaint;
1509 self.window.tooltip_bounds.take();
1510
1511 // Layout all root elements.
1512 let mut root_element = self.window.root_view.as_ref().unwrap().clone().into_any();
1513 root_element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1514
1515 let mut sorted_deferred_draws =
1516 (0..self.window.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1517 sorted_deferred_draws.sort_by_key(|ix| self.window.next_frame.deferred_draws[*ix].priority);
1518 self.prepaint_deferred_draws(&sorted_deferred_draws);
1519
1520 let mut prompt_element = None;
1521 let mut active_drag_element = None;
1522 let mut tooltip_element = None;
1523 if let Some(prompt) = self.window.prompt.take() {
1524 let mut element = prompt.view.any_view().into_any();
1525 element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1526 prompt_element = Some(element);
1527 self.window.prompt = Some(prompt);
1528 } else if let Some(active_drag) = self.app.active_drag.take() {
1529 let mut element = active_drag.view.clone().into_any();
1530 let offset = self.mouse_position() - active_drag.cursor_offset;
1531 element.prepaint_as_root(offset, AvailableSpace::min_size(), self);
1532 active_drag_element = Some(element);
1533 self.app.active_drag = Some(active_drag);
1534 } else {
1535 tooltip_element = self.prepaint_tooltip();
1536 }
1537
1538 self.window.mouse_hit_test = self.window.next_frame.hit_test(self.window.mouse_position);
1539
1540 // Now actually paint the elements.
1541 self.window.draw_phase = DrawPhase::Paint;
1542 root_element.paint(self);
1543
1544 self.paint_deferred_draws(&sorted_deferred_draws);
1545
1546 if let Some(mut prompt_element) = prompt_element {
1547 prompt_element.paint(self);
1548 } else if let Some(mut drag_element) = active_drag_element {
1549 drag_element.paint(self);
1550 } else if let Some(mut tooltip_element) = tooltip_element {
1551 tooltip_element.paint(self);
1552 }
1553 }
1554
1555 fn prepaint_tooltip(&mut self) -> Option<AnyElement> {
1556 let tooltip_request = self.window.next_frame.tooltip_requests.last().cloned()?;
1557 let tooltip_request = tooltip_request.unwrap();
1558 let mut element = tooltip_request.tooltip.view.clone().into_any();
1559 let mouse_position = tooltip_request.tooltip.mouse_position;
1560 let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self);
1561
1562 let mut tooltip_bounds = Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1563 let window_bounds = Bounds {
1564 origin: Point::default(),
1565 size: self.viewport_size(),
1566 };
1567
1568 if tooltip_bounds.right() > window_bounds.right() {
1569 let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1570 if new_x >= Pixels::ZERO {
1571 tooltip_bounds.origin.x = new_x;
1572 } else {
1573 tooltip_bounds.origin.x = cmp::max(
1574 Pixels::ZERO,
1575 tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1576 );
1577 }
1578 }
1579
1580 if tooltip_bounds.bottom() > window_bounds.bottom() {
1581 let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1582 if new_y >= Pixels::ZERO {
1583 tooltip_bounds.origin.y = new_y;
1584 } else {
1585 tooltip_bounds.origin.y = cmp::max(
1586 Pixels::ZERO,
1587 tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1588 );
1589 }
1590 }
1591
1592 self.with_absolute_element_offset(tooltip_bounds.origin, |cx| element.prepaint(cx));
1593
1594 self.window.tooltip_bounds = Some(TooltipBounds {
1595 id: tooltip_request.id,
1596 bounds: tooltip_bounds,
1597 });
1598 Some(element)
1599 }
1600
1601 fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1602 assert_eq!(self.window.element_id_stack.len(), 0);
1603
1604 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1605 for deferred_draw_ix in deferred_draw_indices {
1606 let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1607 self.window
1608 .element_id_stack
1609 .clone_from(&deferred_draw.element_id_stack);
1610 self.window
1611 .text_style_stack
1612 .clone_from(&deferred_draw.text_style_stack);
1613 self.window
1614 .next_frame
1615 .dispatch_tree
1616 .set_active_node(deferred_draw.parent_node);
1617
1618 let prepaint_start = self.prepaint_index();
1619 if let Some(element) = deferred_draw.element.as_mut() {
1620 self.with_absolute_element_offset(deferred_draw.absolute_offset, |cx| {
1621 element.prepaint(cx)
1622 });
1623 } else {
1624 self.reuse_prepaint(deferred_draw.prepaint_range.clone());
1625 }
1626 let prepaint_end = self.prepaint_index();
1627 deferred_draw.prepaint_range = prepaint_start..prepaint_end;
1628 }
1629 assert_eq!(
1630 self.window.next_frame.deferred_draws.len(),
1631 0,
1632 "cannot call defer_draw during deferred drawing"
1633 );
1634 self.window.next_frame.deferred_draws = deferred_draws;
1635 self.window.element_id_stack.clear();
1636 self.window.text_style_stack.clear();
1637 }
1638
1639 fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1640 assert_eq!(self.window.element_id_stack.len(), 0);
1641
1642 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1643 for deferred_draw_ix in deferred_draw_indices {
1644 let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1645 self.window
1646 .element_id_stack
1647 .clone_from(&deferred_draw.element_id_stack);
1648 self.window
1649 .next_frame
1650 .dispatch_tree
1651 .set_active_node(deferred_draw.parent_node);
1652
1653 let paint_start = self.paint_index();
1654 if let Some(element) = deferred_draw.element.as_mut() {
1655 element.paint(self);
1656 } else {
1657 self.reuse_paint(deferred_draw.paint_range.clone());
1658 }
1659 let paint_end = self.paint_index();
1660 deferred_draw.paint_range = paint_start..paint_end;
1661 }
1662 self.window.next_frame.deferred_draws = deferred_draws;
1663 self.window.element_id_stack.clear();
1664 }
1665
1666 pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
1667 PrepaintStateIndex {
1668 hitboxes_index: self.window.next_frame.hitboxes.len(),
1669 tooltips_index: self.window.next_frame.tooltip_requests.len(),
1670 deferred_draws_index: self.window.next_frame.deferred_draws.len(),
1671 dispatch_tree_index: self.window.next_frame.dispatch_tree.len(),
1672 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1673 line_layout_index: self.window.text_system.layout_index(),
1674 }
1675 }
1676
1677 pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
1678 let window = &mut self.window;
1679 window.next_frame.hitboxes.extend(
1680 window.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
1681 .iter()
1682 .cloned(),
1683 );
1684 window.next_frame.tooltip_requests.extend(
1685 window.rendered_frame.tooltip_requests
1686 [range.start.tooltips_index..range.end.tooltips_index]
1687 .iter_mut()
1688 .map(|request| request.take()),
1689 );
1690 window.next_frame.accessed_element_states.extend(
1691 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1692 ..range.end.accessed_element_states_index]
1693 .iter()
1694 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1695 );
1696 window
1697 .text_system
1698 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1699
1700 let reused_subtree = window.next_frame.dispatch_tree.reuse_subtree(
1701 range.start.dispatch_tree_index..range.end.dispatch_tree_index,
1702 &mut window.rendered_frame.dispatch_tree,
1703 window.focus,
1704 );
1705
1706 if reused_subtree.contains_focus() {
1707 window.next_frame.focus = window.focus;
1708 }
1709
1710 window.next_frame.deferred_draws.extend(
1711 window.rendered_frame.deferred_draws
1712 [range.start.deferred_draws_index..range.end.deferred_draws_index]
1713 .iter()
1714 .map(|deferred_draw| DeferredDraw {
1715 parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
1716 element_id_stack: deferred_draw.element_id_stack.clone(),
1717 text_style_stack: deferred_draw.text_style_stack.clone(),
1718 priority: deferred_draw.priority,
1719 element: None,
1720 absolute_offset: deferred_draw.absolute_offset,
1721 prepaint_range: deferred_draw.prepaint_range.clone(),
1722 paint_range: deferred_draw.paint_range.clone(),
1723 }),
1724 );
1725 }
1726
1727 pub(crate) fn paint_index(&self) -> PaintIndex {
1728 PaintIndex {
1729 scene_index: self.window.next_frame.scene.len(),
1730 mouse_listeners_index: self.window.next_frame.mouse_listeners.len(),
1731 input_handlers_index: self.window.next_frame.input_handlers.len(),
1732 cursor_styles_index: self.window.next_frame.cursor_styles.len(),
1733 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1734 line_layout_index: self.window.text_system.layout_index(),
1735 }
1736 }
1737
1738 pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
1739 let window = &mut self.window;
1740
1741 window.next_frame.cursor_styles.extend(
1742 window.rendered_frame.cursor_styles
1743 [range.start.cursor_styles_index..range.end.cursor_styles_index]
1744 .iter()
1745 .cloned(),
1746 );
1747 window.next_frame.input_handlers.extend(
1748 window.rendered_frame.input_handlers
1749 [range.start.input_handlers_index..range.end.input_handlers_index]
1750 .iter_mut()
1751 .map(|handler| handler.take()),
1752 );
1753 window.next_frame.mouse_listeners.extend(
1754 window.rendered_frame.mouse_listeners
1755 [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
1756 .iter_mut()
1757 .map(|listener| listener.take()),
1758 );
1759 if let Some(element_states) = window
1760 .rendered_frame
1761 .accessed_element_states
1762 .get(range.start.accessed_element_states_index..range.end.accessed_element_states_index)
1763 {
1764 window.next_frame.accessed_element_states.extend(
1765 element_states
1766 .iter()
1767 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1768 );
1769 }
1770
1771 window
1772 .text_system
1773 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1774 window.next_frame.scene.replay(
1775 range.start.scene_index..range.end.scene_index,
1776 &window.rendered_frame.scene,
1777 );
1778 }
1779
1780 /// Push a text style onto the stack, and call a function with that style active.
1781 /// Use [`AppContext::text_style`] to get the current, combined text style. This method
1782 /// should only be called as part of element drawing.
1783 pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
1784 where
1785 F: FnOnce(&mut Self) -> R,
1786 {
1787 debug_assert!(
1788 matches!(
1789 self.window.draw_phase,
1790 DrawPhase::Prepaint | DrawPhase::Paint
1791 ),
1792 "this method can only be called during request_layout, prepaint, or paint"
1793 );
1794 if let Some(style) = style {
1795 self.window.text_style_stack.push(style);
1796 let result = f(self);
1797 self.window.text_style_stack.pop();
1798 result
1799 } else {
1800 f(self)
1801 }
1802 }
1803
1804 /// Updates the cursor style at the platform level. This method should only be called
1805 /// during the prepaint phase of element drawing.
1806 pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
1807 debug_assert_eq!(
1808 self.window.draw_phase,
1809 DrawPhase::Paint,
1810 "this method can only be called during paint"
1811 );
1812 self.window
1813 .next_frame
1814 .cursor_styles
1815 .push(CursorStyleRequest {
1816 hitbox_id: hitbox.id,
1817 style,
1818 });
1819 }
1820
1821 /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
1822 /// during the paint phase of element drawing.
1823 pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
1824 debug_assert_eq!(
1825 self.window.draw_phase,
1826 DrawPhase::Prepaint,
1827 "this method can only be called during prepaint"
1828 );
1829 let id = TooltipId(post_inc(&mut self.window.next_tooltip_id.0));
1830 self.window
1831 .next_frame
1832 .tooltip_requests
1833 .push(Some(TooltipRequest { id, tooltip }));
1834 id
1835 }
1836
1837 /// Invoke the given function with the given content mask after intersecting it
1838 /// with the current mask. This method should only be called during element drawing.
1839 pub fn with_content_mask<R>(
1840 &mut self,
1841 mask: Option<ContentMask<Pixels>>,
1842 f: impl FnOnce(&mut Self) -> R,
1843 ) -> R {
1844 debug_assert!(
1845 matches!(
1846 self.window.draw_phase,
1847 DrawPhase::Prepaint | DrawPhase::Paint
1848 ),
1849 "this method can only be called during request_layout, prepaint, or paint"
1850 );
1851 if let Some(mask) = mask {
1852 let mask = mask.intersect(&self.content_mask());
1853 self.window_mut().content_mask_stack.push(mask);
1854 let result = f(self);
1855 self.window_mut().content_mask_stack.pop();
1856 result
1857 } else {
1858 f(self)
1859 }
1860 }
1861
1862 /// Updates the global element offset relative to the current offset. This is used to implement
1863 /// scrolling. This method should only be called during the prepaint phase of element drawing.
1864 pub fn with_element_offset<R>(
1865 &mut self,
1866 offset: Point<Pixels>,
1867 f: impl FnOnce(&mut Self) -> R,
1868 ) -> R {
1869 debug_assert_eq!(
1870 self.window.draw_phase,
1871 DrawPhase::Prepaint,
1872 "this method can only be called during request_layout, or prepaint"
1873 );
1874
1875 if offset.is_zero() {
1876 return f(self);
1877 };
1878
1879 let abs_offset = self.element_offset() + offset;
1880 self.with_absolute_element_offset(abs_offset, f)
1881 }
1882
1883 /// Updates the global element offset based on the given offset. This is used to implement
1884 /// drag handles and other manual painting of elements. This method should only be called during
1885 /// the prepaint phase of element drawing.
1886 pub fn with_absolute_element_offset<R>(
1887 &mut self,
1888 offset: Point<Pixels>,
1889 f: impl FnOnce(&mut Self) -> R,
1890 ) -> R {
1891 debug_assert_eq!(
1892 self.window.draw_phase,
1893 DrawPhase::Prepaint,
1894 "this method can only be called during request_layout, or prepaint"
1895 );
1896 self.window_mut().element_offset_stack.push(offset);
1897 let result = f(self);
1898 self.window_mut().element_offset_stack.pop();
1899 result
1900 }
1901
1902 pub(crate) fn with_element_opacity<R>(
1903 &mut self,
1904 opacity: Option<f32>,
1905 f: impl FnOnce(&mut Self) -> R,
1906 ) -> R {
1907 if opacity.is_none() {
1908 return f(self);
1909 }
1910
1911 debug_assert!(
1912 matches!(
1913 self.window.draw_phase,
1914 DrawPhase::Prepaint | DrawPhase::Paint
1915 ),
1916 "this method can only be called during prepaint, or paint"
1917 );
1918 self.window_mut().element_opacity = opacity;
1919 let result = f(self);
1920 self.window_mut().element_opacity = None;
1921 result
1922 }
1923
1924 /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
1925 /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
1926 /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
1927 /// element offset and prepaint again. See [`List`] for an example. This method should only be
1928 /// called during the prepaint phase of element drawing.
1929 pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
1930 debug_assert_eq!(
1931 self.window.draw_phase,
1932 DrawPhase::Prepaint,
1933 "this method can only be called during prepaint"
1934 );
1935 let index = self.prepaint_index();
1936 let result = f(self);
1937 if result.is_err() {
1938 self.window
1939 .next_frame
1940 .hitboxes
1941 .truncate(index.hitboxes_index);
1942 self.window
1943 .next_frame
1944 .tooltip_requests
1945 .truncate(index.tooltips_index);
1946 self.window
1947 .next_frame
1948 .deferred_draws
1949 .truncate(index.deferred_draws_index);
1950 self.window
1951 .next_frame
1952 .dispatch_tree
1953 .truncate(index.dispatch_tree_index);
1954 self.window
1955 .next_frame
1956 .accessed_element_states
1957 .truncate(index.accessed_element_states_index);
1958 self.window
1959 .text_system
1960 .truncate_layouts(index.line_layout_index);
1961 }
1962 result
1963 }
1964
1965 /// When you call this method during [`prepaint`], containing elements will attempt to
1966 /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
1967 /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
1968 /// that supports this method being called on the elements it contains. This method should only be
1969 /// called during the prepaint phase of element drawing.
1970 pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
1971 debug_assert_eq!(
1972 self.window.draw_phase,
1973 DrawPhase::Prepaint,
1974 "this method can only be called during prepaint"
1975 );
1976 self.window.requested_autoscroll = Some(bounds);
1977 }
1978
1979 /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
1980 /// described in [`request_autoscroll`].
1981 pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
1982 debug_assert_eq!(
1983 self.window.draw_phase,
1984 DrawPhase::Prepaint,
1985 "this method can only be called during prepaint"
1986 );
1987 self.window.requested_autoscroll.take()
1988 }
1989
1990 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1991 /// Your view will be re-drawn once the asset has finished loading.
1992 ///
1993 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
1994 /// time.
1995 pub fn use_asset<A: Asset>(&mut self, source: &A::Source) -> Option<A::Output> {
1996 let (task, is_first) = self.fetch_asset::<A>(source);
1997 task.clone().now_or_never().or_else(|| {
1998 if is_first {
1999 let parent_id = self.parent_view_id();
2000 self.spawn({
2001 let task = task.clone();
2002 |mut cx| async move {
2003 task.await;
2004
2005 cx.on_next_frame(move |cx| cx.notify(parent_id));
2006 }
2007 })
2008 .detach();
2009 }
2010
2011 None
2012 })
2013 }
2014 /// Obtain the current element offset. This method should only be called during the
2015 /// prepaint phase of element drawing.
2016 pub fn element_offset(&self) -> Point<Pixels> {
2017 debug_assert_eq!(
2018 self.window.draw_phase,
2019 DrawPhase::Prepaint,
2020 "this method can only be called during prepaint"
2021 );
2022 self.window()
2023 .element_offset_stack
2024 .last()
2025 .copied()
2026 .unwrap_or_default()
2027 }
2028
2029 /// Obtain the current element opacity. This method should only be called during the
2030 /// prepaint phase of element drawing.
2031 pub(crate) fn element_opacity(&self) -> f32 {
2032 debug_assert!(
2033 matches!(
2034 self.window.draw_phase,
2035 DrawPhase::Prepaint | DrawPhase::Paint
2036 ),
2037 "this method can only be called during prepaint, or paint"
2038 );
2039 self.window().element_opacity.unwrap_or(1.0)
2040 }
2041
2042 /// Obtain the current content mask. This method should only be called during element drawing.
2043 pub fn content_mask(&self) -> ContentMask<Pixels> {
2044 debug_assert!(
2045 matches!(
2046 self.window.draw_phase,
2047 DrawPhase::Prepaint | DrawPhase::Paint
2048 ),
2049 "this method can only be called during prepaint, or paint"
2050 );
2051 self.window()
2052 .content_mask_stack
2053 .last()
2054 .cloned()
2055 .unwrap_or_else(|| ContentMask {
2056 bounds: Bounds {
2057 origin: Point::default(),
2058 size: self.window().viewport_size,
2059 },
2060 })
2061 }
2062
2063 /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2064 /// This can be used within a custom element to distinguish multiple sets of child elements.
2065 pub fn with_element_namespace<R>(
2066 &mut self,
2067 element_id: impl Into<ElementId>,
2068 f: impl FnOnce(&mut Self) -> R,
2069 ) -> R {
2070 self.window.element_id_stack.push(element_id.into());
2071 let result = f(self);
2072 self.window.element_id_stack.pop();
2073 result
2074 }
2075
2076 /// Updates or initializes state for an element with the given id that lives across multiple
2077 /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2078 /// to the given closure. The state returned by the closure will be stored so it can be referenced
2079 /// when drawing the next frame. This method should only be called as part of element drawing.
2080 pub fn with_element_state<S, R>(
2081 &mut self,
2082 global_id: &GlobalElementId,
2083 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2084 ) -> R
2085 where
2086 S: 'static,
2087 {
2088 debug_assert!(
2089 matches!(
2090 self.window.draw_phase,
2091 DrawPhase::Prepaint | DrawPhase::Paint
2092 ),
2093 "this method can only be called during request_layout, prepaint, or paint"
2094 );
2095
2096 let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2097 self.window
2098 .next_frame
2099 .accessed_element_states
2100 .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2101
2102 if let Some(any) = self
2103 .window
2104 .next_frame
2105 .element_states
2106 .remove(&key)
2107 .or_else(|| self.window.rendered_frame.element_states.remove(&key))
2108 {
2109 let ElementStateBox {
2110 inner,
2111 #[cfg(debug_assertions)]
2112 type_name,
2113 } = any;
2114 // Using the extra inner option to avoid needing to reallocate a new box.
2115 let mut state_box = inner
2116 .downcast::<Option<S>>()
2117 .map_err(|_| {
2118 #[cfg(debug_assertions)]
2119 {
2120 anyhow::anyhow!(
2121 "invalid element state type for id, requested {:?}, actual: {:?}",
2122 std::any::type_name::<S>(),
2123 type_name
2124 )
2125 }
2126
2127 #[cfg(not(debug_assertions))]
2128 {
2129 anyhow::anyhow!(
2130 "invalid element state type for id, requested {:?}",
2131 std::any::type_name::<S>(),
2132 )
2133 }
2134 })
2135 .unwrap();
2136
2137 let state = state_box.take().expect(
2138 "reentrant call to with_element_state for the same state type and element id",
2139 );
2140 let (result, state) = f(Some(state), self);
2141 state_box.replace(state);
2142 self.window.next_frame.element_states.insert(
2143 key,
2144 ElementStateBox {
2145 inner: state_box,
2146 #[cfg(debug_assertions)]
2147 type_name,
2148 },
2149 );
2150 result
2151 } else {
2152 let (result, state) = f(None, self);
2153 self.window.next_frame.element_states.insert(
2154 key,
2155 ElementStateBox {
2156 inner: Box::new(Some(state)),
2157 #[cfg(debug_assertions)]
2158 type_name: std::any::type_name::<S>(),
2159 },
2160 );
2161 result
2162 }
2163 }
2164
2165 /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2166 /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2167 /// when the element is guaranteed to have an id.
2168 ///
2169 /// The first option means 'no ID provided'
2170 /// The second option means 'not yet initialized'
2171 pub fn with_optional_element_state<S, R>(
2172 &mut self,
2173 global_id: Option<&GlobalElementId>,
2174 f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2175 ) -> R
2176 where
2177 S: 'static,
2178 {
2179 debug_assert!(
2180 matches!(
2181 self.window.draw_phase,
2182 DrawPhase::Prepaint | DrawPhase::Paint
2183 ),
2184 "this method can only be called during request_layout, prepaint, or paint"
2185 );
2186
2187 if let Some(global_id) = global_id {
2188 self.with_element_state(global_id, |state, cx| {
2189 let (result, state) = f(Some(state), cx);
2190 let state =
2191 state.expect("you must return some state when you pass some element id");
2192 (result, state)
2193 })
2194 } else {
2195 let (result, state) = f(None, self);
2196 debug_assert!(
2197 state.is_none(),
2198 "you must not return an element state when passing None for the global id"
2199 );
2200 result
2201 }
2202 }
2203
2204 /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2205 /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2206 /// with higher values being drawn on top.
2207 ///
2208 /// This method should only be called as part of the prepaint phase of element drawing.
2209 pub fn defer_draw(
2210 &mut self,
2211 element: AnyElement,
2212 absolute_offset: Point<Pixels>,
2213 priority: usize,
2214 ) {
2215 let window = &mut self.window;
2216 debug_assert_eq!(
2217 window.draw_phase,
2218 DrawPhase::Prepaint,
2219 "this method can only be called during request_layout or prepaint"
2220 );
2221 let parent_node = window.next_frame.dispatch_tree.active_node_id().unwrap();
2222 window.next_frame.deferred_draws.push(DeferredDraw {
2223 parent_node,
2224 element_id_stack: window.element_id_stack.clone(),
2225 text_style_stack: window.text_style_stack.clone(),
2226 priority,
2227 element: Some(element),
2228 absolute_offset,
2229 prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2230 paint_range: PaintIndex::default()..PaintIndex::default(),
2231 });
2232 }
2233
2234 /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2235 /// of geometry that are non-overlapping and have the same draw order. This is typically used
2236 /// for performance reasons.
2237 ///
2238 /// This method should only be called as part of the paint phase of element drawing.
2239 pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2240 debug_assert_eq!(
2241 self.window.draw_phase,
2242 DrawPhase::Paint,
2243 "this method can only be called during paint"
2244 );
2245
2246 let scale_factor = self.scale_factor();
2247 let content_mask = self.content_mask();
2248 let clipped_bounds = bounds.intersect(&content_mask.bounds);
2249 if !clipped_bounds.is_empty() {
2250 self.window
2251 .next_frame
2252 .scene
2253 .push_layer(clipped_bounds.scale(scale_factor));
2254 }
2255
2256 let result = f(self);
2257
2258 if !clipped_bounds.is_empty() {
2259 self.window.next_frame.scene.pop_layer();
2260 }
2261
2262 result
2263 }
2264
2265 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2266 ///
2267 /// This method should only be called as part of the paint phase of element drawing.
2268 pub fn paint_shadows(
2269 &mut self,
2270 bounds: Bounds<Pixels>,
2271 corner_radii: Corners<Pixels>,
2272 shadows: &[BoxShadow],
2273 ) {
2274 debug_assert_eq!(
2275 self.window.draw_phase,
2276 DrawPhase::Paint,
2277 "this method can only be called during paint"
2278 );
2279
2280 let scale_factor = self.scale_factor();
2281 let content_mask = self.content_mask();
2282 let opacity = self.element_opacity();
2283 for shadow in shadows {
2284 let mut shadow_bounds = bounds;
2285 shadow_bounds.origin += shadow.offset;
2286 shadow_bounds.dilate(shadow.spread_radius);
2287 self.window.next_frame.scene.insert_primitive(Shadow {
2288 order: 0,
2289 blur_radius: shadow.blur_radius.scale(scale_factor),
2290 bounds: shadow_bounds.scale(scale_factor),
2291 content_mask: content_mask.scale(scale_factor),
2292 corner_radii: corner_radii.scale(scale_factor),
2293 color: shadow.color.opacity(opacity),
2294 });
2295 }
2296 }
2297
2298 /// Paint one or more quads into the scene for the next frame at the current stacking context.
2299 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2300 /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2301 ///
2302 /// This method should only be called as part of the paint phase of element drawing.
2303 pub fn paint_quad(&mut self, quad: PaintQuad) {
2304 debug_assert_eq!(
2305 self.window.draw_phase,
2306 DrawPhase::Paint,
2307 "this method can only be called during paint"
2308 );
2309
2310 let scale_factor = self.scale_factor();
2311 let content_mask = self.content_mask();
2312 let opacity = self.element_opacity();
2313 self.window.next_frame.scene.insert_primitive(Quad {
2314 order: 0,
2315 pad: 0,
2316 bounds: quad.bounds.scale(scale_factor),
2317 content_mask: content_mask.scale(scale_factor),
2318 background: quad.background.opacity(opacity),
2319 border_color: quad.border_color.opacity(opacity),
2320 corner_radii: quad.corner_radii.scale(scale_factor),
2321 border_widths: quad.border_widths.scale(scale_factor),
2322 });
2323 }
2324
2325 /// Paint the given `Path` into the scene for the next frame at the current z-index.
2326 ///
2327 /// This method should only be called as part of the paint phase of element drawing.
2328 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
2329 debug_assert_eq!(
2330 self.window.draw_phase,
2331 DrawPhase::Paint,
2332 "this method can only be called during paint"
2333 );
2334
2335 let scale_factor = self.scale_factor();
2336 let content_mask = self.content_mask();
2337 let opacity = self.element_opacity();
2338 path.content_mask = content_mask;
2339 path.color = color.into().opacity(opacity);
2340 self.window
2341 .next_frame
2342 .scene
2343 .insert_primitive(path.scale(scale_factor));
2344 }
2345
2346 /// Paint an underline into the scene for the next frame at the current z-index.
2347 ///
2348 /// This method should only be called as part of the paint phase of element drawing.
2349 pub fn paint_underline(
2350 &mut self,
2351 origin: Point<Pixels>,
2352 width: Pixels,
2353 style: &UnderlineStyle,
2354 ) {
2355 debug_assert_eq!(
2356 self.window.draw_phase,
2357 DrawPhase::Paint,
2358 "this method can only be called during paint"
2359 );
2360
2361 let scale_factor = self.scale_factor();
2362 let height = if style.wavy {
2363 style.thickness * 3.
2364 } else {
2365 style.thickness
2366 };
2367 let bounds = Bounds {
2368 origin,
2369 size: size(width, height),
2370 };
2371 let content_mask = self.content_mask();
2372 let element_opacity = self.element_opacity();
2373
2374 self.window.next_frame.scene.insert_primitive(Underline {
2375 order: 0,
2376 pad: 0,
2377 bounds: bounds.scale(scale_factor),
2378 content_mask: content_mask.scale(scale_factor),
2379 color: style.color.unwrap_or_default().opacity(element_opacity),
2380 thickness: style.thickness.scale(scale_factor),
2381 wavy: style.wavy,
2382 });
2383 }
2384
2385 /// Paint a strikethrough into the scene for the next frame at the current z-index.
2386 ///
2387 /// This method should only be called as part of the paint phase of element drawing.
2388 pub fn paint_strikethrough(
2389 &mut self,
2390 origin: Point<Pixels>,
2391 width: Pixels,
2392 style: &StrikethroughStyle,
2393 ) {
2394 debug_assert_eq!(
2395 self.window.draw_phase,
2396 DrawPhase::Paint,
2397 "this method can only be called during paint"
2398 );
2399
2400 let scale_factor = self.scale_factor();
2401 let height = style.thickness;
2402 let bounds = Bounds {
2403 origin,
2404 size: size(width, height),
2405 };
2406 let content_mask = self.content_mask();
2407 let opacity = self.element_opacity();
2408
2409 self.window.next_frame.scene.insert_primitive(Underline {
2410 order: 0,
2411 pad: 0,
2412 bounds: bounds.scale(scale_factor),
2413 content_mask: content_mask.scale(scale_factor),
2414 thickness: style.thickness.scale(scale_factor),
2415 color: style.color.unwrap_or_default().opacity(opacity),
2416 wavy: false,
2417 });
2418 }
2419
2420 /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2421 ///
2422 /// The y component of the origin is the baseline of the glyph.
2423 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2424 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2425 /// This method is only useful if you need to paint a single glyph that has already been shaped.
2426 ///
2427 /// This method should only be called as part of the paint phase of element drawing.
2428 pub fn paint_glyph(
2429 &mut self,
2430 origin: Point<Pixels>,
2431 font_id: FontId,
2432 glyph_id: GlyphId,
2433 font_size: Pixels,
2434 color: Hsla,
2435 ) -> Result<()> {
2436 debug_assert_eq!(
2437 self.window.draw_phase,
2438 DrawPhase::Paint,
2439 "this method can only be called during paint"
2440 );
2441
2442 let element_opacity = self.element_opacity();
2443 let scale_factor = self.scale_factor();
2444 let glyph_origin = origin.scale(scale_factor);
2445 let subpixel_variant = Point {
2446 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2447 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2448 };
2449 let params = RenderGlyphParams {
2450 font_id,
2451 glyph_id,
2452 font_size,
2453 subpixel_variant,
2454 scale_factor,
2455 is_emoji: false,
2456 };
2457
2458 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2459 if !raster_bounds.is_zero() {
2460 let tile = self
2461 .window
2462 .sprite_atlas
2463 .get_or_insert_with(¶ms.clone().into(), &mut || {
2464 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2465 Ok(Some((size, Cow::Owned(bytes))))
2466 })?
2467 .expect("Callback above only errors or returns Some");
2468 let bounds = Bounds {
2469 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2470 size: tile.bounds.size.map(Into::into),
2471 };
2472 let content_mask = self.content_mask().scale(scale_factor);
2473 self.window
2474 .next_frame
2475 .scene
2476 .insert_primitive(MonochromeSprite {
2477 order: 0,
2478 pad: 0,
2479 bounds,
2480 content_mask,
2481 color: color.opacity(element_opacity),
2482 tile,
2483 transformation: TransformationMatrix::unit(),
2484 });
2485 }
2486 Ok(())
2487 }
2488
2489 /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2490 ///
2491 /// The y component of the origin is the baseline of the glyph.
2492 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2493 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2494 /// This method is only useful if you need to paint a single emoji that has already been shaped.
2495 ///
2496 /// This method should only be called as part of the paint phase of element drawing.
2497 pub fn paint_emoji(
2498 &mut self,
2499 origin: Point<Pixels>,
2500 font_id: FontId,
2501 glyph_id: GlyphId,
2502 font_size: Pixels,
2503 ) -> Result<()> {
2504 debug_assert_eq!(
2505 self.window.draw_phase,
2506 DrawPhase::Paint,
2507 "this method can only be called during paint"
2508 );
2509
2510 let scale_factor = self.scale_factor();
2511 let glyph_origin = origin.scale(scale_factor);
2512 let params = RenderGlyphParams {
2513 font_id,
2514 glyph_id,
2515 font_size,
2516 // We don't render emojis with subpixel variants.
2517 subpixel_variant: Default::default(),
2518 scale_factor,
2519 is_emoji: true,
2520 };
2521
2522 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2523 if !raster_bounds.is_zero() {
2524 let tile = self
2525 .window
2526 .sprite_atlas
2527 .get_or_insert_with(¶ms.clone().into(), &mut || {
2528 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2529 Ok(Some((size, Cow::Owned(bytes))))
2530 })?
2531 .expect("Callback above only errors or returns Some");
2532
2533 let bounds = Bounds {
2534 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2535 size: tile.bounds.size.map(Into::into),
2536 };
2537 let content_mask = self.content_mask().scale(scale_factor);
2538 let opacity = self.element_opacity();
2539
2540 self.window
2541 .next_frame
2542 .scene
2543 .insert_primitive(PolychromeSprite {
2544 order: 0,
2545 pad: 0,
2546 grayscale: false,
2547 bounds,
2548 corner_radii: Default::default(),
2549 content_mask,
2550 tile,
2551 opacity,
2552 });
2553 }
2554 Ok(())
2555 }
2556
2557 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2558 ///
2559 /// This method should only be called as part of the paint phase of element drawing.
2560 pub fn paint_svg(
2561 &mut self,
2562 bounds: Bounds<Pixels>,
2563 path: SharedString,
2564 transformation: TransformationMatrix,
2565 color: Hsla,
2566 ) -> Result<()> {
2567 debug_assert_eq!(
2568 self.window.draw_phase,
2569 DrawPhase::Paint,
2570 "this method can only be called during paint"
2571 );
2572
2573 let element_opacity = self.element_opacity();
2574 let scale_factor = self.scale_factor();
2575 let bounds = bounds.scale(scale_factor);
2576 // Render the SVG at twice the size to get a higher quality result.
2577 let params = RenderSvgParams {
2578 path,
2579 size: bounds
2580 .size
2581 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
2582 };
2583
2584 let Some(tile) =
2585 self.window
2586 .sprite_atlas
2587 .get_or_insert_with(¶ms.clone().into(), &mut || {
2588 let Some(bytes) = self.svg_renderer.render(¶ms)? else {
2589 return Ok(None);
2590 };
2591 Ok(Some((params.size, Cow::Owned(bytes))))
2592 })?
2593 else {
2594 return Ok(());
2595 };
2596 let content_mask = self.content_mask().scale(scale_factor);
2597
2598 self.window
2599 .next_frame
2600 .scene
2601 .insert_primitive(MonochromeSprite {
2602 order: 0,
2603 pad: 0,
2604 bounds: bounds
2605 .map_origin(|origin| origin.floor())
2606 .map_size(|size| size.ceil()),
2607 content_mask,
2608 color: color.opacity(element_opacity),
2609 tile,
2610 transformation,
2611 });
2612
2613 Ok(())
2614 }
2615
2616 /// Paint an image into the scene for the next frame at the current z-index.
2617 /// This method will panic if the frame_index is not valid
2618 ///
2619 /// This method should only be called as part of the paint phase of element drawing.
2620 pub fn paint_image(
2621 &mut self,
2622 bounds: Bounds<Pixels>,
2623 corner_radii: Corners<Pixels>,
2624 data: Arc<RenderImage>,
2625 frame_index: usize,
2626 grayscale: bool,
2627 ) -> Result<()> {
2628 debug_assert_eq!(
2629 self.window.draw_phase,
2630 DrawPhase::Paint,
2631 "this method can only be called during paint"
2632 );
2633
2634 let scale_factor = self.scale_factor();
2635 let bounds = bounds.scale(scale_factor);
2636 let params = RenderImageParams {
2637 image_id: data.id,
2638 frame_index,
2639 };
2640
2641 let tile = self
2642 .window
2643 .sprite_atlas
2644 .get_or_insert_with(¶ms.clone().into(), &mut || {
2645 Ok(Some((
2646 data.size(frame_index),
2647 Cow::Borrowed(
2648 data.as_bytes(frame_index)
2649 .expect("It's the caller's job to pass a valid frame index"),
2650 ),
2651 )))
2652 })?
2653 .expect("Callback above only returns Some");
2654 let content_mask = self.content_mask().scale(scale_factor);
2655 let corner_radii = corner_radii.scale(scale_factor);
2656 let opacity = self.element_opacity();
2657
2658 self.window
2659 .next_frame
2660 .scene
2661 .insert_primitive(PolychromeSprite {
2662 order: 0,
2663 pad: 0,
2664 grayscale,
2665 bounds,
2666 content_mask,
2667 corner_radii,
2668 tile,
2669 opacity,
2670 });
2671 Ok(())
2672 }
2673
2674 /// Paint a surface into the scene for the next frame at the current z-index.
2675 ///
2676 /// This method should only be called as part of the paint phase of element drawing.
2677 #[cfg(target_os = "macos")]
2678 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
2679 use crate::PaintSurface;
2680
2681 debug_assert_eq!(
2682 self.window.draw_phase,
2683 DrawPhase::Paint,
2684 "this method can only be called during paint"
2685 );
2686
2687 let scale_factor = self.scale_factor();
2688 let bounds = bounds.scale(scale_factor);
2689 let content_mask = self.content_mask().scale(scale_factor);
2690 self.window.next_frame.scene.insert_primitive(PaintSurface {
2691 order: 0,
2692 bounds,
2693 content_mask,
2694 image_buffer,
2695 });
2696 }
2697
2698 /// Removes an image from the sprite atlas.
2699 pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2700 for frame_index in 0..data.frame_count() {
2701 let params = RenderImageParams {
2702 image_id: data.id,
2703 frame_index,
2704 };
2705
2706 self.window.sprite_atlas.remove(¶ms.clone().into());
2707 }
2708
2709 Ok(())
2710 }
2711
2712 #[must_use]
2713 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2714 /// layout is being requested, along with the layout ids of any children. This method is called during
2715 /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2716 ///
2717 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2718 pub fn request_layout(
2719 &mut self,
2720 style: Style,
2721 children: impl IntoIterator<Item = LayoutId>,
2722 ) -> LayoutId {
2723 debug_assert_eq!(
2724 self.window.draw_phase,
2725 DrawPhase::Prepaint,
2726 "this method can only be called during request_layout, or prepaint"
2727 );
2728
2729 self.app.layout_id_buffer.clear();
2730 self.app.layout_id_buffer.extend(children);
2731 let rem_size = self.rem_size();
2732
2733 self.window.layout_engine.as_mut().unwrap().request_layout(
2734 style,
2735 rem_size,
2736 &self.app.layout_id_buffer,
2737 )
2738 }
2739
2740 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
2741 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
2742 /// determine the element's size. One place this is used internally is when measuring text.
2743 ///
2744 /// The given closure is invoked at layout time with the known dimensions and available space and
2745 /// returns a `Size`.
2746 ///
2747 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2748 pub fn request_measured_layout<
2749 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
2750 + 'static,
2751 >(
2752 &mut self,
2753 style: Style,
2754 measure: F,
2755 ) -> LayoutId {
2756 debug_assert_eq!(
2757 self.window.draw_phase,
2758 DrawPhase::Prepaint,
2759 "this method can only be called during request_layout, or prepaint"
2760 );
2761
2762 let rem_size = self.rem_size();
2763 self.window
2764 .layout_engine
2765 .as_mut()
2766 .unwrap()
2767 .request_measured_layout(style, rem_size, measure)
2768 }
2769
2770 /// Compute the layout for the given id within the given available space.
2771 /// This method is called for its side effect, typically by the framework prior to painting.
2772 /// After calling it, you can request the bounds of the given layout node id or any descendant.
2773 ///
2774 /// This method should only be called as part of the prepaint phase of element drawing.
2775 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
2776 debug_assert_eq!(
2777 self.window.draw_phase,
2778 DrawPhase::Prepaint,
2779 "this method can only be called during request_layout, or prepaint"
2780 );
2781
2782 let mut layout_engine = self.window.layout_engine.take().unwrap();
2783 layout_engine.compute_layout(layout_id, available_space, self);
2784 self.window.layout_engine = Some(layout_engine);
2785 }
2786
2787 /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
2788 /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
2789 ///
2790 /// This method should only be called as part of element drawing.
2791 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
2792 debug_assert_eq!(
2793 self.window.draw_phase,
2794 DrawPhase::Prepaint,
2795 "this method can only be called during request_layout, prepaint, or paint"
2796 );
2797
2798 let mut bounds = self
2799 .window
2800 .layout_engine
2801 .as_mut()
2802 .unwrap()
2803 .layout_bounds(layout_id)
2804 .map(Into::into);
2805 bounds.origin += self.element_offset();
2806 bounds
2807 }
2808
2809 /// This method should be called during `prepaint`. You can use
2810 /// the returned [Hitbox] during `paint` or in an event handler
2811 /// to determine whether the inserted hitbox was the topmost.
2812 ///
2813 /// This method should only be called as part of the prepaint phase of element drawing.
2814 pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, opaque: bool) -> Hitbox {
2815 debug_assert_eq!(
2816 self.window.draw_phase,
2817 DrawPhase::Prepaint,
2818 "this method can only be called during prepaint"
2819 );
2820
2821 let content_mask = self.content_mask();
2822 let window = &mut self.window;
2823 let id = window.next_hitbox_id;
2824 window.next_hitbox_id.0 += 1;
2825 let hitbox = Hitbox {
2826 id,
2827 bounds,
2828 content_mask,
2829 opaque,
2830 };
2831 window.next_frame.hitboxes.push(hitbox.clone());
2832 hitbox
2833 }
2834
2835 /// Sets the key context for the current element. This context will be used to translate
2836 /// keybindings into actions.
2837 ///
2838 /// This method should only be called as part of the paint phase of element drawing.
2839 pub fn set_key_context(&mut self, context: KeyContext) {
2840 debug_assert_eq!(
2841 self.window.draw_phase,
2842 DrawPhase::Paint,
2843 "this method can only be called during paint"
2844 );
2845 self.window
2846 .next_frame
2847 .dispatch_tree
2848 .set_key_context(context);
2849 }
2850
2851 /// Sets the focus handle for the current element. This handle will be used to manage focus state
2852 /// and keyboard event dispatch for the element.
2853 ///
2854 /// This method should only be called as part of the prepaint phase of element drawing.
2855 pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle) {
2856 debug_assert_eq!(
2857 self.window.draw_phase,
2858 DrawPhase::Prepaint,
2859 "this method can only be called during prepaint"
2860 );
2861 if focus_handle.is_focused(self) {
2862 self.window.next_frame.focus = Some(focus_handle.id);
2863 }
2864 self.window
2865 .next_frame
2866 .dispatch_tree
2867 .set_focus_id(focus_handle.id);
2868 }
2869
2870 /// Sets the view id for the current element, which will be used to manage view caching.
2871 ///
2872 /// This method should only be called as part of element prepaint. We plan on removing this
2873 /// method eventually when we solve some issues that require us to construct editor elements
2874 /// directly instead of always using editors via views.
2875 pub fn set_view_id(&mut self, view_id: EntityId) {
2876 debug_assert_eq!(
2877 self.window.draw_phase,
2878 DrawPhase::Prepaint,
2879 "this method can only be called during prepaint"
2880 );
2881 self.window.next_frame.dispatch_tree.set_view_id(view_id);
2882 }
2883
2884 /// Get the last view id for the current element
2885 pub fn parent_view_id(&self) -> Option<EntityId> {
2886 self.window.next_frame.dispatch_tree.parent_view_id()
2887 }
2888
2889 /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2890 /// platform to receive textual input with proper integration with concerns such
2891 /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
2892 /// rendered.
2893 ///
2894 /// This method should only be called as part of the paint phase of element drawing.
2895 ///
2896 /// [element_input_handler]: crate::ElementInputHandler
2897 pub fn handle_input(&mut self, focus_handle: &FocusHandle, input_handler: impl InputHandler) {
2898 debug_assert_eq!(
2899 self.window.draw_phase,
2900 DrawPhase::Paint,
2901 "this method can only be called during paint"
2902 );
2903
2904 if focus_handle.is_focused(self) {
2905 let cx = self.to_async();
2906 self.window
2907 .next_frame
2908 .input_handlers
2909 .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
2910 }
2911 }
2912
2913 /// Register a mouse event listener on the window for the next frame. The type of event
2914 /// is determined by the first parameter of the given listener. When the next frame is rendered
2915 /// the listener will be cleared.
2916 ///
2917 /// This method should only be called as part of the paint phase of element drawing.
2918 pub fn on_mouse_event<Event: MouseEvent>(
2919 &mut self,
2920 mut handler: impl FnMut(&Event, DispatchPhase, &mut WindowContext) + 'static,
2921 ) {
2922 debug_assert_eq!(
2923 self.window.draw_phase,
2924 DrawPhase::Paint,
2925 "this method can only be called during paint"
2926 );
2927
2928 self.window.next_frame.mouse_listeners.push(Some(Box::new(
2929 move |event: &dyn Any, phase: DispatchPhase, cx: &mut WindowContext<'_>| {
2930 if let Some(event) = event.downcast_ref() {
2931 handler(event, phase, cx)
2932 }
2933 },
2934 )));
2935 }
2936
2937 /// Register a key event listener on the window for the next frame. The type of event
2938 /// is determined by the first parameter of the given listener. When the next frame is rendered
2939 /// the listener will be cleared.
2940 ///
2941 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2942 /// a specific need to register a global listener.
2943 ///
2944 /// This method should only be called as part of the paint phase of element drawing.
2945 pub fn on_key_event<Event: KeyEvent>(
2946 &mut self,
2947 listener: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
2948 ) {
2949 debug_assert_eq!(
2950 self.window.draw_phase,
2951 DrawPhase::Paint,
2952 "this method can only be called during paint"
2953 );
2954
2955 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
2956 move |event: &dyn Any, phase, cx: &mut WindowContext<'_>| {
2957 if let Some(event) = event.downcast_ref::<Event>() {
2958 listener(event, phase, cx)
2959 }
2960 },
2961 ));
2962 }
2963
2964 /// Register a modifiers changed event listener on the window for the next frame.
2965 ///
2966 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2967 /// a specific need to register a global listener.
2968 ///
2969 /// This method should only be called as part of the paint phase of element drawing.
2970 pub fn on_modifiers_changed(
2971 &mut self,
2972 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
2973 ) {
2974 debug_assert_eq!(
2975 self.window.draw_phase,
2976 DrawPhase::Paint,
2977 "this method can only be called during paint"
2978 );
2979
2980 self.window
2981 .next_frame
2982 .dispatch_tree
2983 .on_modifiers_changed(Rc::new(
2984 move |event: &ModifiersChangedEvent, cx: &mut WindowContext<'_>| {
2985 listener(event, cx)
2986 },
2987 ));
2988 }
2989
2990 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2991 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
2992 /// Returns a subscription and persists until the subscription is dropped.
2993 pub fn on_focus_in(
2994 &mut self,
2995 handle: &FocusHandle,
2996 mut listener: impl FnMut(&mut WindowContext) + 'static,
2997 ) -> Subscription {
2998 let focus_id = handle.id;
2999 let (subscription, activate) =
3000 self.window.new_focus_listener(Box::new(move |event, cx| {
3001 if event.is_focus_in(focus_id) {
3002 listener(cx);
3003 }
3004 true
3005 }));
3006 self.app.defer(move |_| activate());
3007 subscription
3008 }
3009
3010 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3011 /// Returns a subscription and persists until the subscription is dropped.
3012 pub fn on_focus_out(
3013 &mut self,
3014 handle: &FocusHandle,
3015 mut listener: impl FnMut(FocusOutEvent, &mut WindowContext) + 'static,
3016 ) -> Subscription {
3017 let focus_id = handle.id;
3018 let (subscription, activate) =
3019 self.window.new_focus_listener(Box::new(move |event, cx| {
3020 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3021 if event.is_focus_out(focus_id) {
3022 let event = FocusOutEvent {
3023 blurred: WeakFocusHandle {
3024 id: blurred_id,
3025 handles: Arc::downgrade(&cx.window.focus_handles),
3026 },
3027 };
3028 listener(event, cx)
3029 }
3030 }
3031 true
3032 }));
3033 self.app.defer(move |_| activate());
3034 subscription
3035 }
3036
3037 fn reset_cursor_style(&self) {
3038 // Set the cursor only if we're the active window.
3039 if self.is_window_hovered() {
3040 let style = self
3041 .window
3042 .rendered_frame
3043 .cursor_styles
3044 .iter()
3045 .rev()
3046 .find(|request| request.hitbox_id.is_hovered(self))
3047 .map(|request| request.style)
3048 .unwrap_or(CursorStyle::Arrow);
3049 self.platform.set_cursor_style(style);
3050 }
3051 }
3052
3053 /// Dispatch a given keystroke as though the user had typed it.
3054 /// You can create a keystroke with Keystroke::parse("").
3055 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
3056 let keystroke = keystroke.with_simulated_ime();
3057 let result = self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
3058 keystroke: keystroke.clone(),
3059 is_held: false,
3060 }));
3061 if !result.propagate {
3062 return true;
3063 }
3064
3065 if let Some(input) = keystroke.key_char {
3066 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3067 input_handler.dispatch_input(&input, self);
3068 self.window.platform_window.set_input_handler(input_handler);
3069 return true;
3070 }
3071 }
3072
3073 false
3074 }
3075
3076 /// Represent this action as a key binding string, to display in the UI.
3077 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3078 self.bindings_for_action(action)
3079 .into_iter()
3080 .next()
3081 .map(|binding| {
3082 binding
3083 .keystrokes()
3084 .iter()
3085 .map(ToString::to_string)
3086 .collect::<Vec<_>>()
3087 .join(" ")
3088 })
3089 .unwrap_or_else(|| action.name().to_string())
3090 }
3091
3092 /// Dispatch a mouse or keyboard event on the window.
3093 #[profiling::function]
3094 pub fn dispatch_event(&mut self, event: PlatformInput) -> DispatchEventResult {
3095 self.window.last_input_timestamp.set(Instant::now());
3096 // Handlers may set this to false by calling `stop_propagation`.
3097 self.app.propagate_event = true;
3098 // Handlers may set this to true by calling `prevent_default`.
3099 self.window.default_prevented = false;
3100
3101 let event = match event {
3102 // Track the mouse position with our own state, since accessing the platform
3103 // API for the mouse position can only occur on the main thread.
3104 PlatformInput::MouseMove(mouse_move) => {
3105 self.window.mouse_position = mouse_move.position;
3106 self.window.modifiers = mouse_move.modifiers;
3107 PlatformInput::MouseMove(mouse_move)
3108 }
3109 PlatformInput::MouseDown(mouse_down) => {
3110 self.window.mouse_position = mouse_down.position;
3111 self.window.modifiers = mouse_down.modifiers;
3112 PlatformInput::MouseDown(mouse_down)
3113 }
3114 PlatformInput::MouseUp(mouse_up) => {
3115 self.window.mouse_position = mouse_up.position;
3116 self.window.modifiers = mouse_up.modifiers;
3117 PlatformInput::MouseUp(mouse_up)
3118 }
3119 PlatformInput::MouseExited(mouse_exited) => {
3120 self.window.modifiers = mouse_exited.modifiers;
3121 PlatformInput::MouseExited(mouse_exited)
3122 }
3123 PlatformInput::ModifiersChanged(modifiers_changed) => {
3124 self.window.modifiers = modifiers_changed.modifiers;
3125 PlatformInput::ModifiersChanged(modifiers_changed)
3126 }
3127 PlatformInput::ScrollWheel(scroll_wheel) => {
3128 self.window.mouse_position = scroll_wheel.position;
3129 self.window.modifiers = scroll_wheel.modifiers;
3130 PlatformInput::ScrollWheel(scroll_wheel)
3131 }
3132 // Translate dragging and dropping of external files from the operating system
3133 // to internal drag and drop events.
3134 PlatformInput::FileDrop(file_drop) => match file_drop {
3135 FileDropEvent::Entered { position, paths } => {
3136 self.window.mouse_position = position;
3137 if self.active_drag.is_none() {
3138 self.active_drag = Some(AnyDrag {
3139 value: Arc::new(paths.clone()),
3140 view: self.new_view(|_| paths).into(),
3141 cursor_offset: position,
3142 });
3143 }
3144 PlatformInput::MouseMove(MouseMoveEvent {
3145 position,
3146 pressed_button: Some(MouseButton::Left),
3147 modifiers: Modifiers::default(),
3148 })
3149 }
3150 FileDropEvent::Pending { position } => {
3151 self.window.mouse_position = position;
3152 PlatformInput::MouseMove(MouseMoveEvent {
3153 position,
3154 pressed_button: Some(MouseButton::Left),
3155 modifiers: Modifiers::default(),
3156 })
3157 }
3158 FileDropEvent::Submit { position } => {
3159 self.activate(true);
3160 self.window.mouse_position = position;
3161 PlatformInput::MouseUp(MouseUpEvent {
3162 button: MouseButton::Left,
3163 position,
3164 modifiers: Modifiers::default(),
3165 click_count: 1,
3166 })
3167 }
3168 FileDropEvent::Exited => {
3169 self.active_drag.take();
3170 PlatformInput::FileDrop(FileDropEvent::Exited)
3171 }
3172 },
3173 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3174 };
3175
3176 if let Some(any_mouse_event) = event.mouse_event() {
3177 self.dispatch_mouse_event(any_mouse_event);
3178 } else if let Some(any_key_event) = event.keyboard_event() {
3179 self.dispatch_key_event(any_key_event);
3180 }
3181
3182 DispatchEventResult {
3183 propagate: self.app.propagate_event,
3184 default_prevented: self.window.default_prevented,
3185 }
3186 }
3187
3188 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
3189 let hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
3190 if hit_test != self.window.mouse_hit_test {
3191 self.window.mouse_hit_test = hit_test;
3192 self.reset_cursor_style();
3193 }
3194
3195 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
3196
3197 // Capture phase, events bubble from back to front. Handlers for this phase are used for
3198 // special purposes, such as detecting events outside of a given Bounds.
3199 for listener in &mut mouse_listeners {
3200 let listener = listener.as_mut().unwrap();
3201 listener(event, DispatchPhase::Capture, self);
3202 if !self.app.propagate_event {
3203 break;
3204 }
3205 }
3206
3207 // Bubble phase, where most normal handlers do their work.
3208 if self.app.propagate_event {
3209 for listener in mouse_listeners.iter_mut().rev() {
3210 let listener = listener.as_mut().unwrap();
3211 listener(event, DispatchPhase::Bubble, self);
3212 if !self.app.propagate_event {
3213 break;
3214 }
3215 }
3216 }
3217
3218 self.window.rendered_frame.mouse_listeners = mouse_listeners;
3219
3220 if self.has_active_drag() {
3221 if event.is::<MouseMoveEvent>() {
3222 // If this was a mouse move event, redraw the window so that the
3223 // active drag can follow the mouse cursor.
3224 self.refresh();
3225 } else if event.is::<MouseUpEvent>() {
3226 // If this was a mouse up event, cancel the active drag and redraw
3227 // the window.
3228 self.active_drag = None;
3229 self.refresh();
3230 }
3231 }
3232 }
3233
3234 fn dispatch_key_event(&mut self, event: &dyn Any) {
3235 if self.window.dirty.get() {
3236 self.draw();
3237 }
3238
3239 let node_id = self
3240 .window
3241 .focus
3242 .and_then(|focus_id| {
3243 self.window
3244 .rendered_frame
3245 .dispatch_tree
3246 .focusable_node_id(focus_id)
3247 })
3248 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3249
3250 let dispatch_path = self
3251 .window
3252 .rendered_frame
3253 .dispatch_tree
3254 .dispatch_path(node_id);
3255
3256 let mut keystroke: Option<Keystroke> = None;
3257
3258 if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3259 if event.modifiers.number_of_modifiers() == 0
3260 && self.window.pending_modifier.modifiers.number_of_modifiers() == 1
3261 && !self.window.pending_modifier.saw_keystroke
3262 {
3263 let key = match self.window.pending_modifier.modifiers {
3264 modifiers if modifiers.shift => Some("shift"),
3265 modifiers if modifiers.control => Some("control"),
3266 modifiers if modifiers.alt => Some("alt"),
3267 modifiers if modifiers.platform => Some("platform"),
3268 modifiers if modifiers.function => Some("function"),
3269 _ => None,
3270 };
3271 if let Some(key) = key {
3272 keystroke = Some(Keystroke {
3273 key: key.to_string(),
3274 key_char: None,
3275 modifiers: Modifiers::default(),
3276 });
3277 }
3278 }
3279
3280 if self.window.pending_modifier.modifiers.number_of_modifiers() == 0
3281 && event.modifiers.number_of_modifiers() == 1
3282 {
3283 self.window.pending_modifier.saw_keystroke = false
3284 }
3285 self.window.pending_modifier.modifiers = event.modifiers
3286 } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3287 self.window.pending_modifier.saw_keystroke = true;
3288 keystroke = Some(key_down_event.keystroke.clone());
3289 }
3290
3291 let Some(keystroke) = keystroke else {
3292 self.finish_dispatch_key_event(event, dispatch_path);
3293 return;
3294 };
3295
3296 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
3297 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus {
3298 currently_pending = PendingInput::default();
3299 }
3300
3301 let match_result = self.window.rendered_frame.dispatch_tree.dispatch_key(
3302 currently_pending.keystrokes,
3303 keystroke,
3304 &dispatch_path,
3305 );
3306 if !match_result.to_replay.is_empty() {
3307 self.replay_pending_input(match_result.to_replay)
3308 }
3309
3310 if !match_result.pending.is_empty() {
3311 currently_pending.keystrokes = match_result.pending;
3312 currently_pending.focus = self.window.focus;
3313 currently_pending.timer = Some(self.spawn(|mut cx| async move {
3314 cx.background_executor.timer(Duration::from_secs(1)).await;
3315 cx.update(move |cx| {
3316 let Some(currently_pending) = cx
3317 .window
3318 .pending_input
3319 .take()
3320 .filter(|pending| pending.focus == cx.window.focus)
3321 else {
3322 return;
3323 };
3324
3325 let dispatch_path = cx
3326 .window
3327 .rendered_frame
3328 .dispatch_tree
3329 .dispatch_path(node_id);
3330
3331 let to_replay = cx
3332 .window
3333 .rendered_frame
3334 .dispatch_tree
3335 .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3336
3337 cx.replay_pending_input(to_replay)
3338 })
3339 .log_err();
3340 }));
3341 self.window.pending_input = Some(currently_pending);
3342 self.pending_input_changed();
3343 self.propagate_event = false;
3344 return;
3345 }
3346
3347 self.propagate_event = true;
3348 for binding in match_result.bindings {
3349 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3350 if !self.propagate_event {
3351 self.dispatch_keystroke_observers(event, Some(binding.action));
3352 self.pending_input_changed();
3353 return;
3354 }
3355 }
3356
3357 self.finish_dispatch_key_event(event, dispatch_path);
3358 self.pending_input_changed();
3359 }
3360
3361 fn finish_dispatch_key_event(
3362 &mut self,
3363 event: &dyn Any,
3364 dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3365 ) {
3366 self.dispatch_key_down_up_event(event, &dispatch_path);
3367 if !self.propagate_event {
3368 return;
3369 }
3370
3371 self.dispatch_modifiers_changed_event(event, &dispatch_path);
3372 if !self.propagate_event {
3373 return;
3374 }
3375
3376 self.dispatch_keystroke_observers(event, None);
3377 }
3378
3379 fn pending_input_changed(&mut self) {
3380 self.window
3381 .pending_input_observers
3382 .clone()
3383 .retain(&(), |callback| callback(self));
3384 }
3385
3386 fn dispatch_key_down_up_event(
3387 &mut self,
3388 event: &dyn Any,
3389 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3390 ) {
3391 // Capture phase
3392 for node_id in dispatch_path {
3393 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3394
3395 for key_listener in node.key_listeners.clone() {
3396 key_listener(event, DispatchPhase::Capture, self);
3397 if !self.propagate_event {
3398 return;
3399 }
3400 }
3401 }
3402
3403 // Bubble phase
3404 for node_id in dispatch_path.iter().rev() {
3405 // Handle low level key events
3406 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3407 for key_listener in node.key_listeners.clone() {
3408 key_listener(event, DispatchPhase::Bubble, self);
3409 if !self.propagate_event {
3410 return;
3411 }
3412 }
3413 }
3414 }
3415
3416 fn dispatch_modifiers_changed_event(
3417 &mut self,
3418 event: &dyn Any,
3419 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3420 ) {
3421 let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3422 return;
3423 };
3424 for node_id in dispatch_path.iter().rev() {
3425 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3426 for listener in node.modifiers_changed_listeners.clone() {
3427 listener(event, self);
3428 if !self.propagate_event {
3429 return;
3430 }
3431 }
3432 }
3433 }
3434
3435 /// Determine whether a potential multi-stroke key binding is in progress on this window.
3436 pub fn has_pending_keystrokes(&self) -> bool {
3437 self.window.pending_input.is_some()
3438 }
3439
3440 pub(crate) fn clear_pending_keystrokes(&mut self) {
3441 self.window.pending_input.take();
3442 }
3443
3444 /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3445 pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3446 self.window
3447 .pending_input
3448 .as_ref()
3449 .map(|pending_input| pending_input.keystrokes.as_slice())
3450 }
3451
3452 fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>) {
3453 let node_id = self
3454 .window
3455 .focus
3456 .and_then(|focus_id| {
3457 self.window
3458 .rendered_frame
3459 .dispatch_tree
3460 .focusable_node_id(focus_id)
3461 })
3462 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3463
3464 let dispatch_path = self
3465 .window
3466 .rendered_frame
3467 .dispatch_tree
3468 .dispatch_path(node_id);
3469
3470 'replay: for replay in replays {
3471 let event = KeyDownEvent {
3472 keystroke: replay.keystroke.clone(),
3473 is_held: false,
3474 };
3475
3476 self.propagate_event = true;
3477 for binding in replay.bindings {
3478 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3479 if !self.propagate_event {
3480 self.dispatch_keystroke_observers(&event, Some(binding.action));
3481 continue 'replay;
3482 }
3483 }
3484
3485 self.dispatch_key_down_up_event(&event, &dispatch_path);
3486 if !self.propagate_event {
3487 continue 'replay;
3488 }
3489 if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3490 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3491 input_handler.dispatch_input(&input, self);
3492 self.window.platform_window.set_input_handler(input_handler)
3493 }
3494 }
3495 }
3496 }
3497
3498 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
3499 let dispatch_path = self
3500 .window
3501 .rendered_frame
3502 .dispatch_tree
3503 .dispatch_path(node_id);
3504
3505 // Capture phase for global actions.
3506 self.propagate_event = true;
3507 if let Some(mut global_listeners) = self
3508 .global_action_listeners
3509 .remove(&action.as_any().type_id())
3510 {
3511 for listener in &global_listeners {
3512 listener(action.as_any(), DispatchPhase::Capture, self);
3513 if !self.propagate_event {
3514 break;
3515 }
3516 }
3517
3518 global_listeners.extend(
3519 self.global_action_listeners
3520 .remove(&action.as_any().type_id())
3521 .unwrap_or_default(),
3522 );
3523
3524 self.global_action_listeners
3525 .insert(action.as_any().type_id(), global_listeners);
3526 }
3527
3528 if !self.propagate_event {
3529 return;
3530 }
3531
3532 // Capture phase for window actions.
3533 for node_id in &dispatch_path {
3534 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3535 for DispatchActionListener {
3536 action_type,
3537 listener,
3538 } in node.action_listeners.clone()
3539 {
3540 let any_action = action.as_any();
3541 if action_type == any_action.type_id() {
3542 listener(any_action, DispatchPhase::Capture, self);
3543
3544 if !self.propagate_event {
3545 return;
3546 }
3547 }
3548 }
3549 }
3550
3551 // Bubble phase for window actions.
3552 for node_id in dispatch_path.iter().rev() {
3553 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3554 for DispatchActionListener {
3555 action_type,
3556 listener,
3557 } in node.action_listeners.clone()
3558 {
3559 let any_action = action.as_any();
3560 if action_type == any_action.type_id() {
3561 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3562 listener(any_action, DispatchPhase::Bubble, self);
3563
3564 if !self.propagate_event {
3565 return;
3566 }
3567 }
3568 }
3569 }
3570
3571 // Bubble phase for global actions.
3572 if let Some(mut global_listeners) = self
3573 .global_action_listeners
3574 .remove(&action.as_any().type_id())
3575 {
3576 for listener in global_listeners.iter().rev() {
3577 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3578
3579 listener(action.as_any(), DispatchPhase::Bubble, self);
3580 if !self.propagate_event {
3581 break;
3582 }
3583 }
3584
3585 global_listeners.extend(
3586 self.global_action_listeners
3587 .remove(&action.as_any().type_id())
3588 .unwrap_or_default(),
3589 );
3590
3591 self.global_action_listeners
3592 .insert(action.as_any().type_id(), global_listeners);
3593 }
3594 }
3595
3596 /// Register the given handler to be invoked whenever the global of the given type
3597 /// is updated.
3598 pub fn observe_global<G: Global>(
3599 &mut self,
3600 f: impl Fn(&mut WindowContext<'_>) + 'static,
3601 ) -> Subscription {
3602 let window_handle = self.window.handle;
3603 let (subscription, activate) = self.global_observers.insert(
3604 TypeId::of::<G>(),
3605 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
3606 );
3607 self.app.defer(move |_| activate());
3608 subscription
3609 }
3610
3611 /// Focus the current window and bring it to the foreground at the platform level.
3612 pub fn activate_window(&self) {
3613 self.window.platform_window.activate();
3614 }
3615
3616 /// Minimize the current window at the platform level.
3617 pub fn minimize_window(&self) {
3618 self.window.platform_window.minimize();
3619 }
3620
3621 /// Toggle full screen status on the current window at the platform level.
3622 pub fn toggle_fullscreen(&self) {
3623 self.window.platform_window.toggle_fullscreen();
3624 }
3625
3626 /// Updates the IME panel position suggestions for languages like japanese, chinese.
3627 pub fn invalidate_character_coordinates(&self) {
3628 self.on_next_frame(|cx| {
3629 if let Some(mut input_handler) = cx.window.platform_window.take_input_handler() {
3630 if let Some(bounds) = input_handler.selected_bounds(cx) {
3631 cx.window
3632 .platform_window
3633 .update_ime_position(bounds.scale(cx.scale_factor()));
3634 }
3635 cx.window.platform_window.set_input_handler(input_handler);
3636 }
3637 });
3638 }
3639
3640 /// Present a platform dialog.
3641 /// The provided message will be presented, along with buttons for each answer.
3642 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3643 pub fn prompt(
3644 &mut self,
3645 level: PromptLevel,
3646 message: &str,
3647 detail: Option<&str>,
3648 answers: &[&str],
3649 ) -> oneshot::Receiver<usize> {
3650 let prompt_builder = self.app.prompt_builder.take();
3651 let Some(prompt_builder) = prompt_builder else {
3652 unreachable!("Re-entrant window prompting is not supported by GPUI");
3653 };
3654
3655 let receiver = match &prompt_builder {
3656 PromptBuilder::Default => self
3657 .window
3658 .platform_window
3659 .prompt(level, message, detail, answers)
3660 .unwrap_or_else(|| {
3661 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3662 }),
3663 PromptBuilder::Custom(_) => {
3664 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3665 }
3666 };
3667
3668 self.app.prompt_builder = Some(prompt_builder);
3669
3670 receiver
3671 }
3672
3673 fn build_custom_prompt(
3674 &mut self,
3675 prompt_builder: &PromptBuilder,
3676 level: PromptLevel,
3677 message: &str,
3678 detail: Option<&str>,
3679 answers: &[&str],
3680 ) -> oneshot::Receiver<usize> {
3681 let (sender, receiver) = oneshot::channel();
3682 let handle = PromptHandle::new(sender);
3683 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
3684 self.window.prompt = Some(handle);
3685 receiver
3686 }
3687
3688 /// Returns the current context stack.
3689 pub fn context_stack(&self) -> Vec<KeyContext> {
3690 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3691 let node_id = self
3692 .window
3693 .focus
3694 .and_then(|focus_id| dispatch_tree.focusable_node_id(focus_id))
3695 .unwrap_or_else(|| dispatch_tree.root_node_id());
3696
3697 dispatch_tree
3698 .dispatch_path(node_id)
3699 .iter()
3700 .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
3701 .collect()
3702 }
3703
3704 /// Returns all available actions for the focused element.
3705 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
3706 let node_id = self
3707 .window
3708 .focus
3709 .and_then(|focus_id| {
3710 self.window
3711 .rendered_frame
3712 .dispatch_tree
3713 .focusable_node_id(focus_id)
3714 })
3715 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3716
3717 let mut actions = self
3718 .window
3719 .rendered_frame
3720 .dispatch_tree
3721 .available_actions(node_id);
3722 for action_type in self.global_action_listeners.keys() {
3723 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3724 let action = self.actions.build_action_type(action_type).ok();
3725 if let Some(action) = action {
3726 actions.insert(ix, action);
3727 }
3728 }
3729 }
3730 actions
3731 }
3732
3733 /// Returns key bindings that invoke the given action on the currently focused element.
3734 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3735 self.window
3736 .rendered_frame
3737 .dispatch_tree
3738 .bindings_for_action(
3739 action,
3740 &self.window.rendered_frame.dispatch_tree.context_stack,
3741 )
3742 }
3743
3744 /// Returns key bindings that invoke the given action on the currently focused element.
3745 pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
3746 RefCell::borrow(&self.keymap).all_bindings_for_input(input)
3747 }
3748
3749 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
3750 pub fn bindings_for_action_in(
3751 &self,
3752 action: &dyn Action,
3753 focus_handle: &FocusHandle,
3754 ) -> Vec<KeyBinding> {
3755 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3756
3757 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
3758 return vec![];
3759 };
3760 let context_stack: Vec<_> = dispatch_tree
3761 .dispatch_path(node_id)
3762 .into_iter()
3763 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
3764 .collect();
3765 dispatch_tree.bindings_for_action(action, &context_stack)
3766 }
3767
3768 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
3769 pub fn listener_for<V: Render, E>(
3770 &self,
3771 view: &View<V>,
3772 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
3773 ) -> impl Fn(&E, &mut WindowContext) + 'static {
3774 let view = view.downgrade();
3775 move |e: &E, cx: &mut WindowContext| {
3776 view.update(cx, |view, cx| f(view, e, cx)).ok();
3777 }
3778 }
3779
3780 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
3781 pub fn handler_for<V: Render>(
3782 &self,
3783 view: &View<V>,
3784 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
3785 ) -> impl Fn(&mut WindowContext) {
3786 let view = view.downgrade();
3787 move |cx: &mut WindowContext| {
3788 view.update(cx, |view, cx| f(view, cx)).ok();
3789 }
3790 }
3791
3792 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
3793 /// If the callback returns false, the window won't be closed.
3794 pub fn on_window_should_close(&self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
3795 let mut this = self.to_async();
3796 self.window
3797 .platform_window
3798 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
3799 }
3800
3801 /// Register an action listener on the window for the next frame. The type of action
3802 /// is determined by the first parameter of the given listener. When the next frame is rendered
3803 /// the listener will be cleared.
3804 ///
3805 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
3806 /// a specific need to register a global listener.
3807 pub fn on_action(
3808 &mut self,
3809 action_type: TypeId,
3810 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
3811 ) {
3812 self.window
3813 .next_frame
3814 .dispatch_tree
3815 .on_action(action_type, Rc::new(listener));
3816 }
3817
3818 /// Read information about the GPU backing this window.
3819 /// Currently returns None on Mac and Windows.
3820 pub fn gpu_specs(&self) -> Option<GPUSpecs> {
3821 self.window.platform_window.gpu_specs()
3822 }
3823}
3824
3825#[cfg(target_os = "windows")]
3826impl WindowContext<'_> {
3827 /// Returns the raw HWND handle for the window.
3828 pub fn get_raw_handle(&self) -> windows::Win32::Foundation::HWND {
3829 self.window.platform_window.get_raw_handle()
3830 }
3831}
3832
3833impl Context for WindowContext<'_> {
3834 type Result<T> = T;
3835
3836 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
3837 where
3838 T: 'static,
3839 {
3840 let slot = self.app.entities.reserve();
3841 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
3842 self.entities.insert(slot, model)
3843 }
3844
3845 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
3846 self.app.reserve_model()
3847 }
3848
3849 fn insert_model<T: 'static>(
3850 &mut self,
3851 reservation: crate::Reservation<T>,
3852 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
3853 ) -> Self::Result<Model<T>> {
3854 self.app.insert_model(reservation, build_model)
3855 }
3856
3857 fn update_model<T: 'static, R>(
3858 &mut self,
3859 model: &Model<T>,
3860 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
3861 ) -> R {
3862 let mut entity = self.entities.lease(model);
3863 let result = update(
3864 &mut *entity,
3865 &mut ModelContext::new(&mut *self.app, model.downgrade()),
3866 );
3867 self.entities.end_lease(entity);
3868 result
3869 }
3870
3871 fn read_model<T, R>(
3872 &self,
3873 handle: &Model<T>,
3874 read: impl FnOnce(&T, &AppContext) -> R,
3875 ) -> Self::Result<R>
3876 where
3877 T: 'static,
3878 {
3879 let entity = self.entities.read(handle);
3880 read(entity, &*self.app)
3881 }
3882
3883 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
3884 where
3885 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
3886 {
3887 if window == self.window.handle {
3888 let root_view = self.window.root_view.clone().unwrap();
3889 Ok(update(root_view, self))
3890 } else {
3891 window.update(self.app, update)
3892 }
3893 }
3894
3895 fn read_window<T, R>(
3896 &self,
3897 window: &WindowHandle<T>,
3898 read: impl FnOnce(View<T>, &AppContext) -> R,
3899 ) -> Result<R>
3900 where
3901 T: 'static,
3902 {
3903 if window.any_handle == self.window.handle {
3904 let root_view = self
3905 .window
3906 .root_view
3907 .clone()
3908 .unwrap()
3909 .downcast::<T>()
3910 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3911 Ok(read(root_view, self))
3912 } else {
3913 self.app.read_window(window, read)
3914 }
3915 }
3916}
3917
3918impl VisualContext for WindowContext<'_> {
3919 fn new_view<V>(
3920 &mut self,
3921 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3922 ) -> Self::Result<View<V>>
3923 where
3924 V: 'static + Render,
3925 {
3926 let slot = self.app.entities.reserve();
3927 let view = View {
3928 model: slot.clone(),
3929 };
3930 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
3931 let entity = build_view_state(&mut cx);
3932 cx.entities.insert(slot, entity);
3933
3934 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
3935 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
3936 cx.new_view_observers.clone().retain(&tid, |observer| {
3937 let any_view = view.clone();
3938 (observer)(any_view, cx);
3939 true
3940 });
3941 }
3942 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
3943
3944 view
3945 }
3946
3947 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
3948 fn update_view<T: 'static, R>(
3949 &mut self,
3950 view: &View<T>,
3951 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
3952 ) -> Self::Result<R> {
3953 let mut lease = self.app.entities.lease(&view.model);
3954 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
3955 let result = update(&mut *lease, &mut cx);
3956 cx.app.entities.end_lease(lease);
3957 result
3958 }
3959
3960 fn replace_root_view<V>(
3961 &mut self,
3962 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3963 ) -> Self::Result<View<V>>
3964 where
3965 V: 'static + Render,
3966 {
3967 let view = self.new_view(build_view);
3968 self.window.root_view = Some(view.clone().into());
3969 self.refresh();
3970 view
3971 }
3972
3973 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
3974 self.update_view(view, |view, cx| {
3975 view.focus_handle(cx).clone().focus(cx);
3976 })
3977 }
3978
3979 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
3980 where
3981 V: ManagedView,
3982 {
3983 self.update_view(view, |_, cx| cx.emit(DismissEvent))
3984 }
3985}
3986
3987impl<'a> std::ops::Deref for WindowContext<'a> {
3988 type Target = AppContext;
3989
3990 fn deref(&self) -> &Self::Target {
3991 self.app
3992 }
3993}
3994
3995impl<'a> std::ops::DerefMut for WindowContext<'a> {
3996 fn deref_mut(&mut self) -> &mut Self::Target {
3997 self.app
3998 }
3999}
4000
4001impl<'a> Borrow<AppContext> for WindowContext<'a> {
4002 fn borrow(&self) -> &AppContext {
4003 self.app
4004 }
4005}
4006
4007impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
4008 fn borrow_mut(&mut self) -> &mut AppContext {
4009 self.app
4010 }
4011}
4012
4013/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
4014pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
4015 #[doc(hidden)]
4016 fn app_mut(&mut self) -> &mut AppContext {
4017 self.borrow_mut()
4018 }
4019
4020 #[doc(hidden)]
4021 fn app(&self) -> &AppContext {
4022 self.borrow()
4023 }
4024
4025 #[doc(hidden)]
4026 fn window(&self) -> &Window {
4027 self.borrow()
4028 }
4029
4030 #[doc(hidden)]
4031 fn window_mut(&mut self) -> &mut Window {
4032 self.borrow_mut()
4033 }
4034}
4035
4036impl Borrow<Window> for WindowContext<'_> {
4037 fn borrow(&self) -> &Window {
4038 self.window
4039 }
4040}
4041
4042impl BorrowMut<Window> for WindowContext<'_> {
4043 fn borrow_mut(&mut self) -> &mut Window {
4044 self.window
4045 }
4046}
4047
4048impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
4049
4050/// Provides access to application state that is specialized for a particular [`View`].
4051/// Allows you to interact with focus, emit events, etc.
4052/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
4053/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
4054pub struct ViewContext<'a, V> {
4055 window_cx: WindowContext<'a>,
4056 view: &'a View<V>,
4057}
4058
4059impl<V> Borrow<AppContext> for ViewContext<'_, V> {
4060 fn borrow(&self) -> &AppContext {
4061 &*self.window_cx.app
4062 }
4063}
4064
4065impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
4066 fn borrow_mut(&mut self) -> &mut AppContext {
4067 &mut *self.window_cx.app
4068 }
4069}
4070
4071impl<V> Borrow<Window> for ViewContext<'_, V> {
4072 fn borrow(&self) -> &Window {
4073 &*self.window_cx.window
4074 }
4075}
4076
4077impl<V> BorrowMut<Window> for ViewContext<'_, V> {
4078 fn borrow_mut(&mut self) -> &mut Window {
4079 &mut *self.window_cx.window
4080 }
4081}
4082
4083impl<'a, V: 'static> ViewContext<'a, V> {
4084 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
4085 Self {
4086 window_cx: WindowContext::new(app, window),
4087 view,
4088 }
4089 }
4090
4091 /// Get the entity_id of this view.
4092 pub fn entity_id(&self) -> EntityId {
4093 self.view.entity_id()
4094 }
4095
4096 /// Get the view pointer underlying this context.
4097 pub fn view(&self) -> &View<V> {
4098 self.view
4099 }
4100
4101 /// Get the model underlying this view.
4102 pub fn model(&self) -> &Model<V> {
4103 &self.view.model
4104 }
4105
4106 /// Access the underlying window context.
4107 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
4108 &mut self.window_cx
4109 }
4110
4111 /// Sets a given callback to be run on the next frame.
4112 pub fn on_next_frame(&self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
4113 where
4114 V: 'static,
4115 {
4116 let view = self.view().clone();
4117 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
4118 }
4119
4120 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
4121 /// that are currently on the stack to be returned to the app.
4122 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
4123 let view = self.view().downgrade();
4124 self.window_cx.defer(move |cx| {
4125 view.update(cx, f).ok();
4126 });
4127 }
4128
4129 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
4130 pub fn observe<V2, E>(
4131 &mut self,
4132 entity: &E,
4133 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
4134 ) -> Subscription
4135 where
4136 V2: 'static,
4137 V: 'static,
4138 E: Entity<V2>,
4139 {
4140 let view = self.view().downgrade();
4141 let entity_id = entity.entity_id();
4142 let entity = entity.downgrade();
4143 let window_handle = self.window.handle;
4144 self.app.new_observer(
4145 entity_id,
4146 Box::new(move |cx| {
4147 window_handle
4148 .update(cx, |_, cx| {
4149 if let Some(handle) = E::upgrade_from(&entity) {
4150 view.update(cx, |this, cx| on_notify(this, handle, cx))
4151 .is_ok()
4152 } else {
4153 false
4154 }
4155 })
4156 .unwrap_or(false)
4157 }),
4158 )
4159 }
4160
4161 /// Subscribe to events emitted by another model or view.
4162 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
4163 /// The callback will be invoked with a reference to the current view, a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a view context for the current view.
4164 pub fn subscribe<V2, E, Evt>(
4165 &mut self,
4166 entity: &E,
4167 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
4168 ) -> Subscription
4169 where
4170 V2: EventEmitter<Evt>,
4171 E: Entity<V2>,
4172 Evt: 'static,
4173 {
4174 let view = self.view().downgrade();
4175 let entity_id = entity.entity_id();
4176 let handle = entity.downgrade();
4177 let window_handle = self.window.handle;
4178 self.app.new_subscription(
4179 entity_id,
4180 (
4181 TypeId::of::<Evt>(),
4182 Box::new(move |event, cx| {
4183 window_handle
4184 .update(cx, |_, cx| {
4185 if let Some(handle) = E::upgrade_from(&handle) {
4186 let event = event.downcast_ref().expect("invalid event type");
4187 view.update(cx, |this, cx| on_event(this, handle, event, cx))
4188 .is_ok()
4189 } else {
4190 false
4191 }
4192 })
4193 .unwrap_or(false)
4194 }),
4195 ),
4196 )
4197 }
4198
4199 /// Register a callback to be invoked when the view is released.
4200 ///
4201 /// The callback receives a handle to the view's window. This handle may be
4202 /// invalid, if the window was closed before the view was released.
4203 pub fn on_release(
4204 &self,
4205 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
4206 ) -> Subscription {
4207 let window_handle = self.window.handle;
4208 let (subscription, activate) = self.app.release_listeners.insert(
4209 self.view.model.entity_id,
4210 Box::new(move |this, cx| {
4211 let this = this.downcast_mut().expect("invalid entity type");
4212 on_release(this, window_handle, cx)
4213 }),
4214 );
4215 activate();
4216 subscription
4217 }
4218
4219 /// Register a callback to be invoked when the given Model or View is released.
4220 pub fn observe_release<V2, E>(
4221 &self,
4222 entity: &E,
4223 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
4224 ) -> Subscription
4225 where
4226 V: 'static,
4227 V2: 'static,
4228 E: Entity<V2>,
4229 {
4230 let view = self.view().downgrade();
4231 let entity_id = entity.entity_id();
4232 let window_handle = self.window.handle;
4233 let (subscription, activate) = self.app.release_listeners.insert(
4234 entity_id,
4235 Box::new(move |entity, cx| {
4236 let entity = entity.downcast_mut().expect("invalid entity type");
4237 let _ = window_handle.update(cx, |_, cx| {
4238 view.update(cx, |this, cx| on_release(this, entity, cx))
4239 });
4240 }),
4241 );
4242 activate();
4243 subscription
4244 }
4245
4246 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
4247 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
4248 pub fn notify(&mut self) {
4249 self.window_cx.notify(Some(self.view.entity_id()));
4250 }
4251
4252 /// Register a callback to be invoked when the window is resized.
4253 pub fn observe_window_bounds(
4254 &self,
4255 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4256 ) -> Subscription {
4257 let view = self.view.downgrade();
4258 let (subscription, activate) = self.window.bounds_observers.insert(
4259 (),
4260 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4261 );
4262 activate();
4263 subscription
4264 }
4265
4266 /// Register a callback to be invoked when the window is activated or deactivated.
4267 pub fn observe_window_activation(
4268 &self,
4269 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4270 ) -> Subscription {
4271 let view = self.view.downgrade();
4272 let (subscription, activate) = self.window.activation_observers.insert(
4273 (),
4274 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4275 );
4276 activate();
4277 subscription
4278 }
4279
4280 /// Registers a callback to be invoked when the window appearance changes.
4281 pub fn observe_window_appearance(
4282 &self,
4283 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4284 ) -> Subscription {
4285 let view = self.view.downgrade();
4286 let (subscription, activate) = self.window.appearance_observers.insert(
4287 (),
4288 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4289 );
4290 activate();
4291 subscription
4292 }
4293
4294 /// Register a callback to be invoked when a keystroke is received by the application
4295 /// in any window. Note that this fires after all other action and event mechanisms have resolved
4296 /// and that this API will not be invoked if the event's propagation is stopped.
4297 pub fn observe_keystrokes(
4298 &mut self,
4299 mut f: impl FnMut(&mut V, &KeystrokeEvent, &mut ViewContext<V>) + 'static,
4300 ) -> Subscription {
4301 fn inner(
4302 keystroke_observers: &SubscriberSet<(), KeystrokeObserver>,
4303 handler: KeystrokeObserver,
4304 ) -> Subscription {
4305 let (subscription, activate) = keystroke_observers.insert((), handler);
4306 activate();
4307 subscription
4308 }
4309
4310 let view = self.view.downgrade();
4311 inner(
4312 &mut self.keystroke_observers,
4313 Box::new(move |event, cx| {
4314 if let Some(view) = view.upgrade() {
4315 view.update(cx, |view, cx| f(view, event, cx));
4316 true
4317 } else {
4318 false
4319 }
4320 }),
4321 )
4322 }
4323
4324 /// Register a callback to be invoked when the window's pending input changes.
4325 pub fn observe_pending_input(
4326 &self,
4327 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4328 ) -> Subscription {
4329 let view = self.view.downgrade();
4330 let (subscription, activate) = self.window.pending_input_observers.insert(
4331 (),
4332 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4333 );
4334 activate();
4335 subscription
4336 }
4337
4338 /// Register a listener to be called when the given focus handle receives focus.
4339 /// Returns a subscription and persists until the subscription is dropped.
4340 pub fn on_focus(
4341 &mut self,
4342 handle: &FocusHandle,
4343 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4344 ) -> Subscription {
4345 let view = self.view.downgrade();
4346 let focus_id = handle.id;
4347 let (subscription, activate) =
4348 self.window.new_focus_listener(Box::new(move |event, cx| {
4349 view.update(cx, |view, cx| {
4350 if event.previous_focus_path.last() != Some(&focus_id)
4351 && event.current_focus_path.last() == Some(&focus_id)
4352 {
4353 listener(view, cx)
4354 }
4355 })
4356 .is_ok()
4357 }));
4358 self.app.defer(|_| activate());
4359 subscription
4360 }
4361
4362 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
4363 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
4364 /// Returns a subscription and persists until the subscription is dropped.
4365 pub fn on_focus_in(
4366 &mut self,
4367 handle: &FocusHandle,
4368 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4369 ) -> Subscription {
4370 let view = self.view.downgrade();
4371 let focus_id = handle.id;
4372 let (subscription, activate) =
4373 self.window.new_focus_listener(Box::new(move |event, cx| {
4374 view.update(cx, |view, cx| {
4375 if event.is_focus_in(focus_id) {
4376 listener(view, cx)
4377 }
4378 })
4379 .is_ok()
4380 }));
4381 self.app.defer(move |_| activate());
4382 subscription
4383 }
4384
4385 /// Register a listener to be called when the given focus handle loses focus.
4386 /// Returns a subscription and persists until the subscription is dropped.
4387 pub fn on_blur(
4388 &mut self,
4389 handle: &FocusHandle,
4390 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4391 ) -> Subscription {
4392 let view = self.view.downgrade();
4393 let focus_id = handle.id;
4394 let (subscription, activate) =
4395 self.window.new_focus_listener(Box::new(move |event, cx| {
4396 view.update(cx, |view, cx| {
4397 if event.previous_focus_path.last() == Some(&focus_id)
4398 && event.current_focus_path.last() != Some(&focus_id)
4399 {
4400 listener(view, cx)
4401 }
4402 })
4403 .is_ok()
4404 }));
4405 self.app.defer(move |_| activate());
4406 subscription
4407 }
4408
4409 /// Register a listener to be called when nothing in the window has focus.
4410 /// This typically happens when the node that was focused is removed from the tree,
4411 /// and this callback lets you chose a default place to restore the users focus.
4412 /// Returns a subscription and persists until the subscription is dropped.
4413 pub fn on_focus_lost(
4414 &self,
4415 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4416 ) -> Subscription {
4417 let view = self.view.downgrade();
4418 let (subscription, activate) = self.window.focus_lost_listeners.insert(
4419 (),
4420 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
4421 );
4422 activate();
4423 subscription
4424 }
4425
4426 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
4427 /// Returns a subscription and persists until the subscription is dropped.
4428 pub fn on_focus_out(
4429 &mut self,
4430 handle: &FocusHandle,
4431 mut listener: impl FnMut(&mut V, FocusOutEvent, &mut ViewContext<V>) + 'static,
4432 ) -> Subscription {
4433 let view = self.view.downgrade();
4434 let focus_id = handle.id;
4435 let (subscription, activate) =
4436 self.window.new_focus_listener(Box::new(move |event, cx| {
4437 view.update(cx, |view, cx| {
4438 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
4439 if event.is_focus_out(focus_id) {
4440 let event = FocusOutEvent {
4441 blurred: WeakFocusHandle {
4442 id: blurred_id,
4443 handles: Arc::downgrade(&cx.window.focus_handles),
4444 },
4445 };
4446 listener(view, event, cx)
4447 }
4448 }
4449 })
4450 .is_ok()
4451 }));
4452 self.app.defer(move |_| activate());
4453 subscription
4454 }
4455
4456 /// Schedule a future to be run asynchronously.
4457 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
4458 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
4459 /// The returned future will be polled on the main thread.
4460 pub fn spawn<Fut, R>(&self, f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut) -> Task<R>
4461 where
4462 R: 'static,
4463 Fut: Future<Output = R> + 'static,
4464 {
4465 let view = self.view().downgrade();
4466 self.window_cx.spawn(|cx| f(view, cx))
4467 }
4468
4469 /// Register a callback to be invoked when the given global state changes.
4470 pub fn observe_global<G: Global>(
4471 &mut self,
4472 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
4473 ) -> Subscription {
4474 let window_handle = self.window.handle;
4475 let view = self.view().downgrade();
4476 let (subscription, activate) = self.global_observers.insert(
4477 TypeId::of::<G>(),
4478 Box::new(move |cx| {
4479 window_handle
4480 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
4481 .unwrap_or(false)
4482 }),
4483 );
4484 self.app.defer(move |_| activate());
4485 subscription
4486 }
4487
4488 /// Register a callback to be invoked when the given Action type is dispatched to the window.
4489 pub fn on_action(
4490 &mut self,
4491 action_type: TypeId,
4492 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
4493 ) {
4494 let handle = self.view().clone();
4495 self.window_cx
4496 .on_action(action_type, move |action, phase, cx| {
4497 handle.update(cx, |view, cx| {
4498 listener(view, action, phase, cx);
4499 })
4500 });
4501 }
4502
4503 /// Emit an event to be handled by any other views that have subscribed via [ViewContext::subscribe].
4504 pub fn emit<Evt>(&mut self, event: Evt)
4505 where
4506 Evt: 'static,
4507 V: EventEmitter<Evt>,
4508 {
4509 let emitter = self.view.model.entity_id;
4510 self.app.push_effect(Effect::Emit {
4511 emitter,
4512 event_type: TypeId::of::<Evt>(),
4513 event: Box::new(event),
4514 });
4515 }
4516
4517 /// Move focus to the current view, assuming it implements [`FocusableView`].
4518 pub fn focus_self(&mut self)
4519 where
4520 V: FocusableView,
4521 {
4522 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
4523 }
4524
4525 /// Convenience method for accessing view state in an event callback.
4526 ///
4527 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
4528 /// but it's often useful to be able to access view state in these
4529 /// callbacks. This method provides a convenient way to do so.
4530 pub fn listener<E: ?Sized>(
4531 &self,
4532 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
4533 ) -> impl Fn(&E, &mut WindowContext) + 'static {
4534 let view = self.view().downgrade();
4535 move |e: &E, cx: &mut WindowContext| {
4536 view.update(cx, |view, cx| f(view, e, cx)).ok();
4537 }
4538 }
4539}
4540
4541impl<V> Context for ViewContext<'_, V> {
4542 type Result<U> = U;
4543
4544 fn new_model<T: 'static>(
4545 &mut self,
4546 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4547 ) -> Model<T> {
4548 self.window_cx.new_model(build_model)
4549 }
4550
4551 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
4552 self.window_cx.reserve_model()
4553 }
4554
4555 fn insert_model<T: 'static>(
4556 &mut self,
4557 reservation: crate::Reservation<T>,
4558 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4559 ) -> Self::Result<Model<T>> {
4560 self.window_cx.insert_model(reservation, build_model)
4561 }
4562
4563 fn update_model<T: 'static, R>(
4564 &mut self,
4565 model: &Model<T>,
4566 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
4567 ) -> R {
4568 self.window_cx.update_model(model, update)
4569 }
4570
4571 fn read_model<T, R>(
4572 &self,
4573 handle: &Model<T>,
4574 read: impl FnOnce(&T, &AppContext) -> R,
4575 ) -> Self::Result<R>
4576 where
4577 T: 'static,
4578 {
4579 self.window_cx.read_model(handle, read)
4580 }
4581
4582 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
4583 where
4584 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
4585 {
4586 self.window_cx.update_window(window, update)
4587 }
4588
4589 fn read_window<T, R>(
4590 &self,
4591 window: &WindowHandle<T>,
4592 read: impl FnOnce(View<T>, &AppContext) -> R,
4593 ) -> Result<R>
4594 where
4595 T: 'static,
4596 {
4597 self.window_cx.read_window(window, read)
4598 }
4599}
4600
4601impl<V: 'static> VisualContext for ViewContext<'_, V> {
4602 fn new_view<W: Render + 'static>(
4603 &mut self,
4604 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4605 ) -> Self::Result<View<W>> {
4606 self.window_cx.new_view(build_view_state)
4607 }
4608
4609 fn update_view<V2: 'static, R>(
4610 &mut self,
4611 view: &View<V2>,
4612 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
4613 ) -> Self::Result<R> {
4614 self.window_cx.update_view(view, update)
4615 }
4616
4617 fn replace_root_view<W>(
4618 &mut self,
4619 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4620 ) -> Self::Result<View<W>>
4621 where
4622 W: 'static + Render,
4623 {
4624 self.window_cx.replace_root_view(build_view)
4625 }
4626
4627 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
4628 self.window_cx.focus_view(view)
4629 }
4630
4631 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
4632 self.window_cx.dismiss_view(view)
4633 }
4634}
4635
4636impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
4637 type Target = WindowContext<'a>;
4638
4639 fn deref(&self) -> &Self::Target {
4640 &self.window_cx
4641 }
4642}
4643
4644impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
4645 fn deref_mut(&mut self) -> &mut Self::Target {
4646 &mut self.window_cx
4647 }
4648}
4649
4650// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4651slotmap::new_key_type! {
4652 /// A unique identifier for a window.
4653 pub struct WindowId;
4654}
4655
4656impl WindowId {
4657 /// Converts this window ID to a `u64`.
4658 pub fn as_u64(&self) -> u64 {
4659 self.0.as_ffi()
4660 }
4661}
4662
4663impl From<u64> for WindowId {
4664 fn from(value: u64) -> Self {
4665 WindowId(slotmap::KeyData::from_ffi(value))
4666 }
4667}
4668
4669/// A handle to a window with a specific root view type.
4670/// Note that this does not keep the window alive on its own.
4671#[derive(Deref, DerefMut)]
4672pub struct WindowHandle<V> {
4673 #[deref]
4674 #[deref_mut]
4675 pub(crate) any_handle: AnyWindowHandle,
4676 state_type: PhantomData<V>,
4677}
4678
4679impl<V: 'static + Render> WindowHandle<V> {
4680 /// Creates a new handle from a window ID.
4681 /// This does not check if the root type of the window is `V`.
4682 pub fn new(id: WindowId) -> Self {
4683 WindowHandle {
4684 any_handle: AnyWindowHandle {
4685 id,
4686 state_type: TypeId::of::<V>(),
4687 },
4688 state_type: PhantomData,
4689 }
4690 }
4691
4692 /// Get the root view out of this window.
4693 ///
4694 /// This will fail if the window is closed or if the root view's type does not match `V`.
4695 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
4696 where
4697 C: Context,
4698 {
4699 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
4700 root_view
4701 .downcast::<V>()
4702 .map_err(|_| anyhow!("the type of the window's root view has changed"))
4703 }))
4704 }
4705
4706 /// Updates the root view of this window.
4707 ///
4708 /// This will fail if the window has been closed or if the root view's type does not match
4709 pub fn update<C, R>(
4710 &self,
4711 cx: &mut C,
4712 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
4713 ) -> Result<R>
4714 where
4715 C: Context,
4716 {
4717 cx.update_window(self.any_handle, |root_view, cx| {
4718 let view = root_view
4719 .downcast::<V>()
4720 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4721 Ok(cx.update_view(&view, update))
4722 })?
4723 }
4724
4725 /// Read the root view out of this window.
4726 ///
4727 /// This will fail if the window is closed or if the root view's type does not match `V`.
4728 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
4729 let x = cx
4730 .windows
4731 .get(self.id)
4732 .and_then(|window| {
4733 window
4734 .as_ref()
4735 .and_then(|window| window.root_view.clone())
4736 .map(|root_view| root_view.downcast::<V>())
4737 })
4738 .ok_or_else(|| anyhow!("window not found"))?
4739 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4740
4741 Ok(x.read(cx))
4742 }
4743
4744 /// Read the root view out of this window, with a callback
4745 ///
4746 /// This will fail if the window is closed or if the root view's type does not match `V`.
4747 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
4748 where
4749 C: Context,
4750 {
4751 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4752 }
4753
4754 /// Read the root view pointer off of this window.
4755 ///
4756 /// This will fail if the window is closed or if the root view's type does not match `V`.
4757 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
4758 where
4759 C: Context,
4760 {
4761 cx.read_window(self, |root_view, _cx| root_view.clone())
4762 }
4763
4764 /// Check if this window is 'active'.
4765 ///
4766 /// Will return `None` if the window is closed or currently
4767 /// borrowed.
4768 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
4769 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
4770 .ok()
4771 }
4772}
4773
4774impl<V> Copy for WindowHandle<V> {}
4775
4776impl<V> Clone for WindowHandle<V> {
4777 fn clone(&self) -> Self {
4778 *self
4779 }
4780}
4781
4782impl<V> PartialEq for WindowHandle<V> {
4783 fn eq(&self, other: &Self) -> bool {
4784 self.any_handle == other.any_handle
4785 }
4786}
4787
4788impl<V> Eq for WindowHandle<V> {}
4789
4790impl<V> Hash for WindowHandle<V> {
4791 fn hash<H: Hasher>(&self, state: &mut H) {
4792 self.any_handle.hash(state);
4793 }
4794}
4795
4796impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4797 fn from(val: WindowHandle<V>) -> Self {
4798 val.any_handle
4799 }
4800}
4801
4802unsafe impl<V> Send for WindowHandle<V> {}
4803unsafe impl<V> Sync for WindowHandle<V> {}
4804
4805/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4806#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4807pub struct AnyWindowHandle {
4808 pub(crate) id: WindowId,
4809 state_type: TypeId,
4810}
4811
4812impl AnyWindowHandle {
4813 /// Get the ID of this window.
4814 pub fn window_id(&self) -> WindowId {
4815 self.id
4816 }
4817
4818 /// Attempt to convert this handle to a window handle with a specific root view type.
4819 /// If the types do not match, this will return `None`.
4820 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4821 if TypeId::of::<T>() == self.state_type {
4822 Some(WindowHandle {
4823 any_handle: *self,
4824 state_type: PhantomData,
4825 })
4826 } else {
4827 None
4828 }
4829 }
4830
4831 /// Updates the state of the root view of this window.
4832 ///
4833 /// This will fail if the window has been closed.
4834 pub fn update<C, R>(
4835 self,
4836 cx: &mut C,
4837 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
4838 ) -> Result<R>
4839 where
4840 C: Context,
4841 {
4842 cx.update_window(self, update)
4843 }
4844
4845 /// Read the state of the root view of this window.
4846 ///
4847 /// This will fail if the window has been closed.
4848 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
4849 where
4850 C: Context,
4851 T: 'static,
4852 {
4853 let view = self
4854 .downcast::<T>()
4855 .context("the type of the window's root view has changed")?;
4856
4857 cx.read_window(&view, read)
4858 }
4859}
4860
4861/// An identifier for an [`Element`](crate::Element).
4862///
4863/// Can be constructed with a string, a number, or both, as well
4864/// as other internal representations.
4865#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4866pub enum ElementId {
4867 /// The ID of a View element
4868 View(EntityId),
4869 /// An integer ID.
4870 Integer(usize),
4871 /// A string based ID.
4872 Name(SharedString),
4873 /// A UUID.
4874 Uuid(Uuid),
4875 /// An ID that's equated with a focus handle.
4876 FocusHandle(FocusId),
4877 /// A combination of a name and an integer.
4878 NamedInteger(SharedString, usize),
4879}
4880
4881impl Display for ElementId {
4882 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4883 match self {
4884 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4885 ElementId::Integer(ix) => write!(f, "{}", ix)?,
4886 ElementId::Name(name) => write!(f, "{}", name)?,
4887 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4888 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4889 ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4890 }
4891
4892 Ok(())
4893 }
4894}
4895
4896impl TryInto<SharedString> for ElementId {
4897 type Error = anyhow::Error;
4898
4899 fn try_into(self) -> anyhow::Result<SharedString> {
4900 if let ElementId::Name(name) = self {
4901 Ok(name)
4902 } else {
4903 Err(anyhow!("element id is not string"))
4904 }
4905 }
4906}
4907
4908impl From<usize> for ElementId {
4909 fn from(id: usize) -> Self {
4910 ElementId::Integer(id)
4911 }
4912}
4913
4914impl From<i32> for ElementId {
4915 fn from(id: i32) -> Self {
4916 Self::Integer(id as usize)
4917 }
4918}
4919
4920impl From<SharedString> for ElementId {
4921 fn from(name: SharedString) -> Self {
4922 ElementId::Name(name)
4923 }
4924}
4925
4926impl From<&'static str> for ElementId {
4927 fn from(name: &'static str) -> Self {
4928 ElementId::Name(name.into())
4929 }
4930}
4931
4932impl<'a> From<&'a FocusHandle> for ElementId {
4933 fn from(handle: &'a FocusHandle) -> Self {
4934 ElementId::FocusHandle(handle.id)
4935 }
4936}
4937
4938impl From<(&'static str, EntityId)> for ElementId {
4939 fn from((name, id): (&'static str, EntityId)) -> Self {
4940 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
4941 }
4942}
4943
4944impl From<(&'static str, usize)> for ElementId {
4945 fn from((name, id): (&'static str, usize)) -> Self {
4946 ElementId::NamedInteger(name.into(), id)
4947 }
4948}
4949
4950impl From<(SharedString, usize)> for ElementId {
4951 fn from((name, id): (SharedString, usize)) -> Self {
4952 ElementId::NamedInteger(name, id)
4953 }
4954}
4955
4956impl From<(&'static str, u64)> for ElementId {
4957 fn from((name, id): (&'static str, u64)) -> Self {
4958 ElementId::NamedInteger(name.into(), id as usize)
4959 }
4960}
4961
4962impl From<Uuid> for ElementId {
4963 fn from(value: Uuid) -> Self {
4964 Self::Uuid(value)
4965 }
4966}
4967
4968impl From<(&'static str, u32)> for ElementId {
4969 fn from((name, id): (&'static str, u32)) -> Self {
4970 ElementId::NamedInteger(name.into(), id as usize)
4971 }
4972}
4973
4974/// A rectangle to be rendered in the window at the given position and size.
4975/// Passed as an argument [`WindowContext::paint_quad`].
4976#[derive(Clone)]
4977pub struct PaintQuad {
4978 /// The bounds of the quad within the window.
4979 pub bounds: Bounds<Pixels>,
4980 /// The radii of the quad's corners.
4981 pub corner_radii: Corners<Pixels>,
4982 /// The background color of the quad.
4983 pub background: Hsla,
4984 /// The widths of the quad's borders.
4985 pub border_widths: Edges<Pixels>,
4986 /// The color of the quad's borders.
4987 pub border_color: Hsla,
4988}
4989
4990impl PaintQuad {
4991 /// Sets the corner radii of the quad.
4992 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
4993 PaintQuad {
4994 corner_radii: corner_radii.into(),
4995 ..self
4996 }
4997 }
4998
4999 /// Sets the border widths of the quad.
5000 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5001 PaintQuad {
5002 border_widths: border_widths.into(),
5003 ..self
5004 }
5005 }
5006
5007 /// Sets the border color of the quad.
5008 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5009 PaintQuad {
5010 border_color: border_color.into(),
5011 ..self
5012 }
5013 }
5014
5015 /// Sets the background color of the quad.
5016 pub fn background(self, background: impl Into<Hsla>) -> Self {
5017 PaintQuad {
5018 background: background.into(),
5019 ..self
5020 }
5021 }
5022}
5023
5024/// Creates a quad with the given parameters.
5025pub fn quad(
5026 bounds: Bounds<Pixels>,
5027 corner_radii: impl Into<Corners<Pixels>>,
5028 background: impl Into<Hsla>,
5029 border_widths: impl Into<Edges<Pixels>>,
5030 border_color: impl Into<Hsla>,
5031) -> PaintQuad {
5032 PaintQuad {
5033 bounds,
5034 corner_radii: corner_radii.into(),
5035 background: background.into(),
5036 border_widths: border_widths.into(),
5037 border_color: border_color.into(),
5038 }
5039}
5040
5041/// Creates a filled quad with the given bounds and background color.
5042pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
5043 PaintQuad {
5044 bounds: bounds.into(),
5045 corner_radii: (0.).into(),
5046 background: background.into(),
5047 border_widths: (0.).into(),
5048 border_color: transparent_black(),
5049 }
5050}
5051
5052/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5053pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
5054 PaintQuad {
5055 bounds: bounds.into(),
5056 corner_radii: (0.).into(),
5057 background: transparent_black(),
5058 border_widths: (1.).into(),
5059 border_color: border_color.into(),
5060 }
5061}