1use crate::{
2 point, prelude::*, px, size, transparent_black, Action, AnyDrag, AnyElement, AnyTooltip,
3 AnyView, AppContext, Arena, Asset, AsyncWindowContext, AvailableSpace, Background, Bounds,
4 BoxShadow, Context, Corners, CursorStyle, Decorations, DevicePixels, DispatchActionListener,
5 DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter,
6 FileDropEvent, Flatten, FontId, Global, GlobalElementId, GlyphId, GpuSpecs, 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 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
535 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
536 default_prevented: bool,
537 mouse_position: Point<Pixels>,
538 mouse_hit_test: HitTest,
539 modifiers: Modifiers,
540 scale_factor: f32,
541 bounds_observers: SubscriberSet<(), AnyObserver>,
542 appearance: WindowAppearance,
543 appearance_observers: SubscriberSet<(), AnyObserver>,
544 active: Rc<Cell<bool>>,
545 hovered: Rc<Cell<bool>>,
546 pub(crate) dirty: Rc<Cell<bool>>,
547 pub(crate) needs_present: Rc<Cell<bool>>,
548 pub(crate) last_input_timestamp: Rc<Cell<Instant>>,
549 pub(crate) refreshing: bool,
550 pub(crate) draw_phase: DrawPhase,
551 activation_observers: SubscriberSet<(), AnyObserver>,
552 pub(crate) focus: Option<FocusId>,
553 focus_enabled: bool,
554 pending_input: Option<PendingInput>,
555 pending_modifier: ModifierState,
556 pending_input_observers: SubscriberSet<(), AnyObserver>,
557 prompt: Option<RenderablePromptHandle>,
558}
559
560#[derive(Clone, Debug, Default)]
561struct ModifierState {
562 modifiers: Modifiers,
563 saw_keystroke: bool,
564}
565
566#[derive(Clone, Copy, Debug, Eq, PartialEq)]
567pub(crate) enum DrawPhase {
568 None,
569 Prepaint,
570 Paint,
571 Focus,
572}
573
574#[derive(Default, Debug)]
575struct PendingInput {
576 keystrokes: SmallVec<[Keystroke; 1]>,
577 focus: Option<FocusId>,
578 timer: Option<Task<()>>,
579}
580
581pub(crate) struct ElementStateBox {
582 pub(crate) inner: Box<dyn Any>,
583 #[cfg(debug_assertions)]
584 pub(crate) type_name: &'static str,
585}
586
587fn default_bounds(display_id: Option<DisplayId>, cx: &mut AppContext) -> Bounds<Pixels> {
588 const DEFAULT_WINDOW_OFFSET: Point<Pixels> = point(px(0.), px(35.));
589
590 cx.active_window()
591 .and_then(|w| w.update(cx, |_, cx| cx.bounds()).ok())
592 .map(|mut bounds| {
593 bounds.origin += DEFAULT_WINDOW_OFFSET;
594 bounds
595 })
596 .unwrap_or_else(|| {
597 let display = display_id
598 .map(|id| cx.find_display(id))
599 .unwrap_or_else(|| cx.primary_display());
600
601 display
602 .map(|display| display.default_bounds())
603 .unwrap_or_else(|| Bounds::new(point(px(0.), px(0.)), DEFAULT_WINDOW_SIZE))
604 })
605}
606
607impl Window {
608 pub(crate) fn new(
609 handle: AnyWindowHandle,
610 options: WindowOptions,
611 cx: &mut AppContext,
612 ) -> Result<Self> {
613 let WindowOptions {
614 window_bounds,
615 titlebar,
616 focus,
617 show,
618 kind,
619 is_movable,
620 display_id,
621 window_background,
622 app_id,
623 window_min_size,
624 window_decorations,
625 } = options;
626
627 let bounds = window_bounds
628 .map(|bounds| bounds.get_bounds())
629 .unwrap_or_else(|| default_bounds(display_id, cx));
630 let mut platform_window = cx.platform.open_window(
631 handle,
632 WindowParams {
633 bounds,
634 titlebar,
635 kind,
636 is_movable,
637 focus,
638 show,
639 display_id,
640 window_min_size,
641 },
642 )?;
643 let display_id = platform_window.display().map(|display| display.id());
644 let sprite_atlas = platform_window.sprite_atlas();
645 let mouse_position = platform_window.mouse_position();
646 let modifiers = platform_window.modifiers();
647 let content_size = platform_window.content_size();
648 let scale_factor = platform_window.scale_factor();
649 let appearance = platform_window.appearance();
650 let text_system = Arc::new(WindowTextSystem::new(cx.text_system().clone()));
651 let dirty = Rc::new(Cell::new(true));
652 let active = Rc::new(Cell::new(platform_window.is_active()));
653 let hovered = Rc::new(Cell::new(platform_window.is_hovered()));
654 let needs_present = Rc::new(Cell::new(false));
655 let next_frame_callbacks: Rc<RefCell<Vec<FrameCallback>>> = Default::default();
656 let last_input_timestamp = Rc::new(Cell::new(Instant::now()));
657
658 platform_window
659 .request_decorations(window_decorations.unwrap_or(WindowDecorations::Server));
660 platform_window.set_background_appearance(window_background);
661
662 if let Some(ref window_open_state) = window_bounds {
663 match window_open_state {
664 WindowBounds::Fullscreen(_) => platform_window.toggle_fullscreen(),
665 WindowBounds::Maximized(_) => platform_window.zoom(),
666 WindowBounds::Windowed(_) => {}
667 }
668 }
669
670 platform_window.on_close(Box::new({
671 let mut cx = cx.to_async();
672 move || {
673 let _ = handle.update(&mut cx, |_, cx| cx.remove_window());
674 }
675 }));
676 platform_window.on_request_frame(Box::new({
677 let mut cx = cx.to_async();
678 let dirty = dirty.clone();
679 let active = active.clone();
680 let needs_present = needs_present.clone();
681 let next_frame_callbacks = next_frame_callbacks.clone();
682 let last_input_timestamp = last_input_timestamp.clone();
683 move |request_frame_options| {
684 let next_frame_callbacks = next_frame_callbacks.take();
685 if !next_frame_callbacks.is_empty() {
686 handle
687 .update(&mut cx, |_, cx| {
688 for callback in next_frame_callbacks {
689 callback(cx);
690 }
691 })
692 .log_err();
693 }
694
695 // Keep presenting the current scene for 1 extra second since the
696 // last input to prevent the display from underclocking the refresh rate.
697 let needs_present = request_frame_options.require_presentation
698 || needs_present.get()
699 || (active.get()
700 && last_input_timestamp.get().elapsed() < Duration::from_secs(1));
701
702 if dirty.get() {
703 measure("frame duration", || {
704 handle
705 .update(&mut cx, |_, cx| {
706 cx.draw();
707 cx.present();
708 })
709 .log_err();
710 })
711 } else if needs_present {
712 handle.update(&mut cx, |_, cx| cx.present()).log_err();
713 }
714
715 handle
716 .update(&mut cx, |_, cx| {
717 cx.complete_frame();
718 })
719 .log_err();
720 }
721 }));
722 platform_window.on_resize(Box::new({
723 let mut cx = cx.to_async();
724 move |_, _| {
725 handle
726 .update(&mut cx, |_, cx| cx.bounds_changed())
727 .log_err();
728 }
729 }));
730 platform_window.on_moved(Box::new({
731 let mut cx = cx.to_async();
732 move || {
733 handle
734 .update(&mut cx, |_, cx| cx.bounds_changed())
735 .log_err();
736 }
737 }));
738 platform_window.on_appearance_changed(Box::new({
739 let mut cx = cx.to_async();
740 move || {
741 handle
742 .update(&mut cx, |_, cx| cx.appearance_changed())
743 .log_err();
744 }
745 }));
746 platform_window.on_active_status_change(Box::new({
747 let mut cx = cx.to_async();
748 move |active| {
749 handle
750 .update(&mut cx, |_, cx| {
751 cx.window.active.set(active);
752 cx.window
753 .activation_observers
754 .clone()
755 .retain(&(), |callback| callback(cx));
756 cx.refresh();
757 })
758 .log_err();
759 }
760 }));
761 platform_window.on_hover_status_change(Box::new({
762 let mut cx = cx.to_async();
763 move |active| {
764 handle
765 .update(&mut cx, |_, cx| {
766 cx.window.hovered.set(active);
767 cx.refresh();
768 })
769 .log_err();
770 }
771 }));
772 platform_window.on_input({
773 let mut cx = cx.to_async();
774 Box::new(move |event| {
775 handle
776 .update(&mut cx, |_, cx| cx.dispatch_event(event))
777 .log_err()
778 .unwrap_or(DispatchEventResult::default())
779 })
780 });
781
782 if let Some(app_id) = app_id {
783 platform_window.set_app_id(&app_id);
784 }
785
786 Ok(Window {
787 handle,
788 removed: false,
789 platform_window,
790 display_id,
791 sprite_atlas,
792 text_system,
793 rem_size: px(16.),
794 rem_size_override_stack: SmallVec::new(),
795 viewport_size: content_size,
796 layout_engine: Some(TaffyLayoutEngine::new()),
797 root_view: None,
798 element_id_stack: SmallVec::default(),
799 text_style_stack: Vec::new(),
800 element_offset_stack: Vec::new(),
801 content_mask_stack: Vec::new(),
802 element_opacity: None,
803 requested_autoscroll: None,
804 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
805 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
806 next_frame_callbacks,
807 next_hitbox_id: HitboxId::default(),
808 next_tooltip_id: TooltipId::default(),
809 tooltip_bounds: None,
810 dirty_views: FxHashSet::default(),
811 focus_listeners: SubscriberSet::new(),
812 focus_lost_listeners: SubscriberSet::new(),
813 default_prevented: true,
814 mouse_position,
815 mouse_hit_test: HitTest::default(),
816 modifiers,
817 scale_factor,
818 bounds_observers: SubscriberSet::new(),
819 appearance,
820 appearance_observers: SubscriberSet::new(),
821 active,
822 hovered,
823 dirty,
824 needs_present,
825 last_input_timestamp,
826 refreshing: false,
827 draw_phase: DrawPhase::None,
828 activation_observers: SubscriberSet::new(),
829 focus: None,
830 focus_enabled: true,
831 pending_input: None,
832 pending_modifier: ModifierState::default(),
833 pending_input_observers: SubscriberSet::new(),
834 prompt: None,
835 })
836 }
837 fn new_focus_listener(&self, value: AnyWindowFocusListener) -> (Subscription, impl FnOnce()) {
838 self.focus_listeners.insert((), value)
839 }
840}
841
842#[derive(Clone, Debug, Default, PartialEq, Eq)]
843pub(crate) struct DispatchEventResult {
844 pub propagate: bool,
845 pub default_prevented: bool,
846}
847
848/// Indicates which region of the window is visible. Content falling outside of this mask will not be
849/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
850/// to leave room to support more complex shapes in the future.
851#[derive(Clone, Debug, Default, PartialEq, Eq)]
852#[repr(C)]
853pub struct ContentMask<P: Clone + Default + Debug> {
854 /// The bounds
855 pub bounds: Bounds<P>,
856}
857
858impl ContentMask<Pixels> {
859 /// Scale the content mask's pixel units by the given scaling factor.
860 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
861 ContentMask {
862 bounds: self.bounds.scale(factor),
863 }
864 }
865
866 /// Intersect the content mask with the given content mask.
867 pub fn intersect(&self, other: &Self) -> Self {
868 let bounds = self.bounds.intersect(&other.bounds);
869 ContentMask { bounds }
870 }
871}
872
873/// Provides access to application state in the context of a single window. Derefs
874/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
875/// an [`AppContext`] and call any [`AppContext`] methods.
876pub struct WindowContext<'a> {
877 pub(crate) app: &'a mut AppContext,
878 pub(crate) window: &'a mut Window,
879}
880
881impl<'a> WindowContext<'a> {
882 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
883 Self { app, window }
884 }
885
886 /// Obtain a handle to the window that belongs to this context.
887 pub fn window_handle(&self) -> AnyWindowHandle {
888 self.window.handle
889 }
890
891 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
892 pub fn refresh(&mut self) {
893 if self.window.draw_phase == DrawPhase::None {
894 self.window.refreshing = true;
895 self.window.dirty.set(true);
896 }
897 }
898
899 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
900 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
901 /// Note that this method will always cause a redraw, the entire window is refreshed if view_id is None.
902 pub fn notify(&mut self, view_id: Option<EntityId>) {
903 let Some(view_id) = view_id else {
904 self.refresh();
905 return;
906 };
907
908 for view_id in self
909 .window
910 .rendered_frame
911 .dispatch_tree
912 .view_path(view_id)
913 .into_iter()
914 .rev()
915 {
916 if !self.window.dirty_views.insert(view_id) {
917 break;
918 }
919 }
920
921 if self.window.draw_phase == DrawPhase::None {
922 self.window.dirty.set(true);
923 self.app.push_effect(Effect::Notify { emitter: view_id });
924 }
925 }
926
927 /// Close this window.
928 pub fn remove_window(&mut self) {
929 self.window.removed = true;
930 }
931
932 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
933 pub fn focused(&self) -> Option<FocusHandle> {
934 self.window
935 .focus
936 .and_then(|id| FocusHandle::for_id(id, &self.app.focus_handles))
937 }
938
939 /// Move focus to the element associated with the given [`FocusHandle`].
940 pub fn focus(&mut self, handle: &FocusHandle) {
941 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
942 return;
943 }
944
945 self.window.focus = Some(handle.id);
946 self.clear_pending_keystrokes();
947 self.refresh();
948 }
949
950 /// Remove focus from all elements within this context's window.
951 pub fn blur(&mut self) {
952 if !self.window.focus_enabled {
953 return;
954 }
955
956 self.window.focus = None;
957 self.refresh();
958 }
959
960 /// Blur the window and don't allow anything in it to be focused again.
961 pub fn disable_focus(&mut self) {
962 self.blur();
963 self.window.focus_enabled = false;
964 }
965
966 /// Accessor for the text system.
967 pub fn text_system(&self) -> &Arc<WindowTextSystem> {
968 &self.window.text_system
969 }
970
971 /// The current text style. Which is composed of all the style refinements provided to `with_text_style`.
972 pub fn text_style(&self) -> TextStyle {
973 let mut style = TextStyle::default();
974 for refinement in &self.window.text_style_stack {
975 style.refine(refinement);
976 }
977 style
978 }
979
980 /// Check if the platform window is maximized
981 /// On some platforms (namely Windows) this is different than the bounds being the size of the display
982 pub fn is_maximized(&self) -> bool {
983 self.window.platform_window.is_maximized()
984 }
985
986 /// request a certain window decoration (Wayland)
987 pub fn request_decorations(&self, decorations: WindowDecorations) {
988 self.window.platform_window.request_decorations(decorations);
989 }
990
991 /// Start a window resize operation (Wayland)
992 pub fn start_window_resize(&self, edge: ResizeEdge) {
993 self.window.platform_window.start_window_resize(edge);
994 }
995
996 /// Return the `WindowBounds` to indicate that how a window should be opened
997 /// after it has been closed
998 pub fn window_bounds(&self) -> WindowBounds {
999 self.window.platform_window.window_bounds()
1000 }
1001
1002 /// Return the `WindowBounds` excluding insets (Wayland and X11)
1003 pub fn inner_window_bounds(&self) -> WindowBounds {
1004 self.window.platform_window.inner_window_bounds()
1005 }
1006
1007 /// Dispatch the given action on the currently focused element.
1008 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
1009 let focus_handle = self.focused();
1010
1011 let window = self.window.handle;
1012 self.app.defer(move |cx| {
1013 window
1014 .update(cx, |_, cx| {
1015 let node_id = focus_handle
1016 .and_then(|handle| {
1017 cx.window
1018 .rendered_frame
1019 .dispatch_tree
1020 .focusable_node_id(handle.id)
1021 })
1022 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
1023
1024 cx.dispatch_action_on_node(node_id, action.as_ref());
1025 })
1026 .log_err();
1027 })
1028 }
1029
1030 pub(crate) fn dispatch_keystroke_observers(
1031 &mut self,
1032 event: &dyn Any,
1033 action: Option<Box<dyn Action>>,
1034 ) {
1035 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
1036 return;
1037 };
1038
1039 self.keystroke_observers
1040 .clone()
1041 .retain(&(), move |callback| {
1042 (callback)(
1043 &KeystrokeEvent {
1044 keystroke: key_down_event.keystroke.clone(),
1045 action: action.as_ref().map(|action| action.boxed_clone()),
1046 },
1047 self,
1048 )
1049 });
1050 }
1051
1052 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1053 /// that are currently on the stack to be returned to the app.
1054 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
1055 let handle = self.window.handle;
1056 self.app.defer(move |cx| {
1057 handle.update(cx, |_, cx| f(cx)).ok();
1058 });
1059 }
1060
1061 /// Subscribe to events emitted by a model or view.
1062 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1063 /// 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.
1064 pub fn observe<E, T>(
1065 &mut self,
1066 entity: &E,
1067 mut on_notify: impl FnMut(E, &mut WindowContext<'_>) + 'static,
1068 ) -> Subscription
1069 where
1070 E: Entity<T>,
1071 {
1072 let entity_id = entity.entity_id();
1073 let entity = entity.downgrade();
1074 let window_handle = self.window.handle;
1075 self.app.new_observer(
1076 entity_id,
1077 Box::new(move |cx| {
1078 window_handle
1079 .update(cx, |_, cx| {
1080 if let Some(handle) = E::upgrade_from(&entity) {
1081 on_notify(handle, cx);
1082 true
1083 } else {
1084 false
1085 }
1086 })
1087 .unwrap_or(false)
1088 }),
1089 )
1090 }
1091
1092 /// Subscribe to events emitted by a model or view.
1093 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1094 /// 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.
1095 pub fn subscribe<Emitter, E, Evt>(
1096 &mut self,
1097 entity: &E,
1098 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
1099 ) -> Subscription
1100 where
1101 Emitter: EventEmitter<Evt>,
1102 E: Entity<Emitter>,
1103 Evt: 'static,
1104 {
1105 let entity_id = entity.entity_id();
1106 let entity = entity.downgrade();
1107 let window_handle = self.window.handle;
1108 self.app.new_subscription(
1109 entity_id,
1110 (
1111 TypeId::of::<Evt>(),
1112 Box::new(move |event, cx| {
1113 window_handle
1114 .update(cx, |_, cx| {
1115 if let Some(handle) = E::upgrade_from(&entity) {
1116 let event = event.downcast_ref().expect("invalid event type");
1117 on_event(handle, event, cx);
1118 true
1119 } else {
1120 false
1121 }
1122 })
1123 .unwrap_or(false)
1124 }),
1125 ),
1126 )
1127 }
1128
1129 /// Register a callback to be invoked when the given Model or View is released.
1130 pub fn observe_release<E, T>(
1131 &self,
1132 entity: &E,
1133 mut on_release: impl FnOnce(&mut T, &mut WindowContext) + 'static,
1134 ) -> Subscription
1135 where
1136 E: Entity<T>,
1137 T: 'static,
1138 {
1139 let entity_id = entity.entity_id();
1140 let window_handle = self.window.handle;
1141 let (subscription, activate) = self.app.release_listeners.insert(
1142 entity_id,
1143 Box::new(move |entity, cx| {
1144 let entity = entity.downcast_mut().expect("invalid entity type");
1145 let _ = window_handle.update(cx, |_, cx| on_release(entity, cx));
1146 }),
1147 );
1148 activate();
1149 subscription
1150 }
1151
1152 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
1153 /// await points in async code.
1154 pub fn to_async(&self) -> AsyncWindowContext {
1155 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
1156 }
1157
1158 /// Schedule the given closure to be run directly after the current frame is rendered.
1159 pub fn on_next_frame(&self, callback: impl FnOnce(&mut WindowContext) + 'static) {
1160 RefCell::borrow_mut(&self.window.next_frame_callbacks).push(Box::new(callback));
1161 }
1162
1163 /// Schedule a frame to be drawn on the next animation frame.
1164 ///
1165 /// This is useful for elements that need to animate continuously, such as a video player or an animated GIF.
1166 /// It will cause the window to redraw on the next frame, even if no other changes have occurred.
1167 ///
1168 /// If called from within a view, it will notify that view on the next frame. Otherwise, it will refresh the entire window.
1169 pub fn request_animation_frame(&self) {
1170 let parent_id = self.parent_view_id();
1171 self.on_next_frame(move |cx| cx.notify(parent_id));
1172 }
1173
1174 /// Spawn the future returned by the given closure on the application thread pool.
1175 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
1176 /// use within your future.
1177 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
1178 where
1179 R: 'static,
1180 Fut: Future<Output = R> + 'static,
1181 {
1182 self.app
1183 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
1184 }
1185
1186 fn bounds_changed(&mut self) {
1187 self.window.scale_factor = self.window.platform_window.scale_factor();
1188 self.window.viewport_size = self.window.platform_window.content_size();
1189 self.window.display_id = self
1190 .window
1191 .platform_window
1192 .display()
1193 .map(|display| display.id());
1194
1195 self.refresh();
1196
1197 self.window
1198 .bounds_observers
1199 .clone()
1200 .retain(&(), |callback| callback(self));
1201 }
1202
1203 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
1204 pub fn bounds(&self) -> Bounds<Pixels> {
1205 self.window.platform_window.bounds()
1206 }
1207
1208 /// Returns whether or not the window is currently fullscreen
1209 pub fn is_fullscreen(&self) -> bool {
1210 self.window.platform_window.is_fullscreen()
1211 }
1212
1213 pub(crate) fn appearance_changed(&mut self) {
1214 self.window.appearance = self.window.platform_window.appearance();
1215
1216 self.window
1217 .appearance_observers
1218 .clone()
1219 .retain(&(), |callback| callback(self));
1220 }
1221
1222 /// Returns the appearance of the current window.
1223 pub fn appearance(&self) -> WindowAppearance {
1224 self.window.appearance
1225 }
1226
1227 /// Returns the size of the drawable area within the window.
1228 pub fn viewport_size(&self) -> Size<Pixels> {
1229 self.window.viewport_size
1230 }
1231
1232 /// Returns whether this window is focused by the operating system (receiving key events).
1233 pub fn is_window_active(&self) -> bool {
1234 self.window.active.get()
1235 }
1236
1237 /// Returns whether this window is considered to be the window
1238 /// that currently owns the mouse cursor.
1239 /// On mac, this is equivalent to `is_window_active`.
1240 pub fn is_window_hovered(&self) -> bool {
1241 if cfg!(any(
1242 target_os = "windows",
1243 target_os = "linux",
1244 target_os = "freebsd"
1245 )) {
1246 self.window.hovered.get()
1247 } else {
1248 self.is_window_active()
1249 }
1250 }
1251
1252 /// Toggle zoom on the window.
1253 pub fn zoom_window(&self) {
1254 self.window.platform_window.zoom();
1255 }
1256
1257 /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland and X11)
1258 pub fn show_window_menu(&self, position: Point<Pixels>) {
1259 self.window.platform_window.show_window_menu(position)
1260 }
1261
1262 /// Tells the compositor to take control of window movement (Wayland and X11)
1263 ///
1264 /// Events may not be received during a move operation.
1265 pub fn start_window_move(&self) {
1266 self.window.platform_window.start_window_move()
1267 }
1268
1269 /// When using client side decorations, set this to the width of the invisible decorations (Wayland and X11)
1270 pub fn set_client_inset(&self, inset: Pixels) {
1271 self.window.platform_window.set_client_inset(inset);
1272 }
1273
1274 /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
1275 pub fn window_decorations(&self) -> Decorations {
1276 self.window.platform_window.window_decorations()
1277 }
1278
1279 /// Returns which window controls are currently visible (Wayland)
1280 pub fn window_controls(&self) -> WindowControls {
1281 self.window.platform_window.window_controls()
1282 }
1283
1284 /// Updates the window's title at the platform level.
1285 pub fn set_window_title(&mut self, title: &str) {
1286 self.window.platform_window.set_title(title);
1287 }
1288
1289 /// Sets the application identifier.
1290 pub fn set_app_id(&mut self, app_id: &str) {
1291 self.window.platform_window.set_app_id(app_id);
1292 }
1293
1294 /// Sets the window background appearance.
1295 pub fn set_background_appearance(&self, background_appearance: WindowBackgroundAppearance) {
1296 self.window
1297 .platform_window
1298 .set_background_appearance(background_appearance);
1299 }
1300
1301 /// Mark the window as dirty at the platform level.
1302 pub fn set_window_edited(&mut self, edited: bool) {
1303 self.window.platform_window.set_edited(edited);
1304 }
1305
1306 /// Determine the display on which the window is visible.
1307 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
1308 self.platform
1309 .displays()
1310 .into_iter()
1311 .find(|display| Some(display.id()) == self.window.display_id)
1312 }
1313
1314 /// Show the platform character palette.
1315 pub fn show_character_palette(&self) {
1316 self.window.platform_window.show_character_palette();
1317 }
1318
1319 /// The scale factor of the display associated with the window. For example, it could
1320 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
1321 /// be rendered as two pixels on screen.
1322 pub fn scale_factor(&self) -> f32 {
1323 self.window.scale_factor
1324 }
1325
1326 /// The size of an em for the base font of the application. Adjusting this value allows the
1327 /// UI to scale, just like zooming a web page.
1328 pub fn rem_size(&self) -> Pixels {
1329 self.window
1330 .rem_size_override_stack
1331 .last()
1332 .copied()
1333 .unwrap_or(self.window.rem_size)
1334 }
1335
1336 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
1337 /// UI to scale, just like zooming a web page.
1338 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
1339 self.window.rem_size = rem_size.into();
1340 }
1341
1342 /// Executes the provided function with the specified rem size.
1343 ///
1344 /// This method must only be called as part of element drawing.
1345 pub fn with_rem_size<F, R>(&mut self, rem_size: Option<impl Into<Pixels>>, f: F) -> R
1346 where
1347 F: FnOnce(&mut Self) -> R,
1348 {
1349 debug_assert!(
1350 matches!(
1351 self.window.draw_phase,
1352 DrawPhase::Prepaint | DrawPhase::Paint
1353 ),
1354 "this method can only be called during request_layout, prepaint, or paint"
1355 );
1356
1357 if let Some(rem_size) = rem_size {
1358 self.window.rem_size_override_stack.push(rem_size.into());
1359 let result = f(self);
1360 self.window.rem_size_override_stack.pop();
1361 result
1362 } else {
1363 f(self)
1364 }
1365 }
1366
1367 /// The line height associated with the current text style.
1368 pub fn line_height(&self) -> Pixels {
1369 self.text_style().line_height_in_pixels(self.rem_size())
1370 }
1371
1372 /// Call to prevent the default action of an event. Currently only used to prevent
1373 /// parent elements from becoming focused on mouse down.
1374 pub fn prevent_default(&mut self) {
1375 self.window.default_prevented = true;
1376 }
1377
1378 /// Obtain whether default has been prevented for the event currently being dispatched.
1379 pub fn default_prevented(&self) -> bool {
1380 self.window.default_prevented
1381 }
1382
1383 /// Determine whether the given action is available along the dispatch path to the currently focused element.
1384 pub fn is_action_available(&self, action: &dyn Action) -> bool {
1385 let target = self
1386 .focused()
1387 .and_then(|focused_handle| {
1388 self.window
1389 .rendered_frame
1390 .dispatch_tree
1391 .focusable_node_id(focused_handle.id)
1392 })
1393 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1394 self.window
1395 .rendered_frame
1396 .dispatch_tree
1397 .is_action_available(action, target)
1398 }
1399
1400 /// The position of the mouse relative to the window.
1401 pub fn mouse_position(&self) -> Point<Pixels> {
1402 self.window.mouse_position
1403 }
1404
1405 /// The current state of the keyboard's modifiers
1406 pub fn modifiers(&self) -> Modifiers {
1407 self.window.modifiers
1408 }
1409
1410 fn complete_frame(&self) {
1411 self.window.platform_window.completed_frame();
1412 }
1413
1414 /// Produces a new frame and assigns it to `rendered_frame`. To actually show
1415 /// the contents of the new [Scene], use [present].
1416 #[profiling::function]
1417 pub fn draw(&mut self) {
1418 self.window.dirty.set(false);
1419 self.window.requested_autoscroll = None;
1420
1421 // Restore the previously-used input handler.
1422 if let Some(input_handler) = self.window.platform_window.take_input_handler() {
1423 self.window
1424 .rendered_frame
1425 .input_handlers
1426 .push(Some(input_handler));
1427 }
1428
1429 self.draw_roots();
1430 self.window.dirty_views.clear();
1431 self.window.next_frame.window_active = self.window.active.get();
1432
1433 // Register requested input handler with the platform window.
1434 if let Some(input_handler) = self.window.next_frame.input_handlers.pop() {
1435 self.window
1436 .platform_window
1437 .set_input_handler(input_handler.unwrap());
1438 }
1439
1440 self.window.layout_engine.as_mut().unwrap().clear();
1441 self.text_system().finish_frame();
1442 self.window
1443 .next_frame
1444 .finish(&mut self.window.rendered_frame);
1445 ELEMENT_ARENA.with_borrow_mut(|element_arena| {
1446 let percentage = (element_arena.len() as f32 / element_arena.capacity() as f32) * 100.;
1447 if percentage >= 80. {
1448 log::warn!("elevated element arena occupation: {}.", percentage);
1449 }
1450 element_arena.clear();
1451 });
1452
1453 self.window.draw_phase = DrawPhase::Focus;
1454 let previous_focus_path = self.window.rendered_frame.focus_path();
1455 let previous_window_active = self.window.rendered_frame.window_active;
1456 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1457 self.window.next_frame.clear();
1458 let current_focus_path = self.window.rendered_frame.focus_path();
1459 let current_window_active = self.window.rendered_frame.window_active;
1460
1461 if previous_focus_path != current_focus_path
1462 || previous_window_active != current_window_active
1463 {
1464 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1465 self.window
1466 .focus_lost_listeners
1467 .clone()
1468 .retain(&(), |listener| listener(self));
1469 }
1470
1471 let event = WindowFocusEvent {
1472 previous_focus_path: if previous_window_active {
1473 previous_focus_path
1474 } else {
1475 Default::default()
1476 },
1477 current_focus_path: if current_window_active {
1478 current_focus_path
1479 } else {
1480 Default::default()
1481 },
1482 };
1483 self.window
1484 .focus_listeners
1485 .clone()
1486 .retain(&(), |listener| listener(&event, self));
1487 }
1488
1489 self.reset_cursor_style();
1490 self.window.refreshing = false;
1491 self.window.draw_phase = DrawPhase::None;
1492 self.window.needs_present.set(true);
1493 }
1494
1495 #[profiling::function]
1496 fn present(&self) {
1497 self.window
1498 .platform_window
1499 .draw(&self.window.rendered_frame.scene);
1500 self.window.needs_present.set(false);
1501 profiling::finish_frame!();
1502 }
1503
1504 fn draw_roots(&mut self) {
1505 self.window.draw_phase = DrawPhase::Prepaint;
1506 self.window.tooltip_bounds.take();
1507
1508 // Layout all root elements.
1509 let mut root_element = self.window.root_view.as_ref().unwrap().clone().into_any();
1510 root_element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1511
1512 let mut sorted_deferred_draws =
1513 (0..self.window.next_frame.deferred_draws.len()).collect::<SmallVec<[_; 8]>>();
1514 sorted_deferred_draws.sort_by_key(|ix| self.window.next_frame.deferred_draws[*ix].priority);
1515 self.prepaint_deferred_draws(&sorted_deferred_draws);
1516
1517 let mut prompt_element = None;
1518 let mut active_drag_element = None;
1519 let mut tooltip_element = None;
1520 if let Some(prompt) = self.window.prompt.take() {
1521 let mut element = prompt.view.any_view().into_any();
1522 element.prepaint_as_root(Point::default(), self.window.viewport_size.into(), self);
1523 prompt_element = Some(element);
1524 self.window.prompt = Some(prompt);
1525 } else if let Some(active_drag) = self.app.active_drag.take() {
1526 let mut element = active_drag.view.clone().into_any();
1527 let offset = self.mouse_position() - active_drag.cursor_offset;
1528 element.prepaint_as_root(offset, AvailableSpace::min_size(), self);
1529 active_drag_element = Some(element);
1530 self.app.active_drag = Some(active_drag);
1531 } else {
1532 tooltip_element = self.prepaint_tooltip();
1533 }
1534
1535 self.window.mouse_hit_test = self.window.next_frame.hit_test(self.window.mouse_position);
1536
1537 // Now actually paint the elements.
1538 self.window.draw_phase = DrawPhase::Paint;
1539 root_element.paint(self);
1540
1541 self.paint_deferred_draws(&sorted_deferred_draws);
1542
1543 if let Some(mut prompt_element) = prompt_element {
1544 prompt_element.paint(self);
1545 } else if let Some(mut drag_element) = active_drag_element {
1546 drag_element.paint(self);
1547 } else if let Some(mut tooltip_element) = tooltip_element {
1548 tooltip_element.paint(self);
1549 }
1550 }
1551
1552 fn prepaint_tooltip(&mut self) -> Option<AnyElement> {
1553 // Use indexing instead of iteration to avoid borrowing self for the duration of the loop.
1554 for tooltip_request_index in (0..self.window.next_frame.tooltip_requests.len()).rev() {
1555 let Some(Some(tooltip_request)) = self
1556 .window
1557 .next_frame
1558 .tooltip_requests
1559 .get(tooltip_request_index)
1560 .cloned()
1561 else {
1562 log::error!("Unexpectedly absent TooltipRequest");
1563 continue;
1564 };
1565 let mut element = tooltip_request.tooltip.view.clone().into_any();
1566 let mouse_position = tooltip_request.tooltip.mouse_position;
1567 let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self);
1568
1569 let mut tooltip_bounds =
1570 Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1571 let window_bounds = Bounds {
1572 origin: Point::default(),
1573 size: self.viewport_size(),
1574 };
1575
1576 if tooltip_bounds.right() > window_bounds.right() {
1577 let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1578 if new_x >= Pixels::ZERO {
1579 tooltip_bounds.origin.x = new_x;
1580 } else {
1581 tooltip_bounds.origin.x = cmp::max(
1582 Pixels::ZERO,
1583 tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1584 );
1585 }
1586 }
1587
1588 if tooltip_bounds.bottom() > window_bounds.bottom() {
1589 let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1590 if new_y >= Pixels::ZERO {
1591 tooltip_bounds.origin.y = new_y;
1592 } else {
1593 tooltip_bounds.origin.y = cmp::max(
1594 Pixels::ZERO,
1595 tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1596 );
1597 }
1598 }
1599
1600 // It's possible for an element to have an active tooltip while not being painted (e.g.
1601 // via the `visible_on_hover` method). Since mouse listeners are not active in this
1602 // case, instead update the tooltip's visibility here.
1603 let is_visible =
1604 (tooltip_request.tooltip.check_visible_and_update)(tooltip_bounds, self);
1605 if !is_visible {
1606 continue;
1607 }
1608
1609 self.with_absolute_element_offset(tooltip_bounds.origin, |cx| element.prepaint(cx));
1610
1611 self.window.tooltip_bounds = Some(TooltipBounds {
1612 id: tooltip_request.id,
1613 bounds: tooltip_bounds,
1614 });
1615 return Some(element);
1616 }
1617 None
1618 }
1619
1620 fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1621 assert_eq!(self.window.element_id_stack.len(), 0);
1622
1623 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1624 for deferred_draw_ix in deferred_draw_indices {
1625 let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1626 self.window
1627 .element_id_stack
1628 .clone_from(&deferred_draw.element_id_stack);
1629 self.window
1630 .text_style_stack
1631 .clone_from(&deferred_draw.text_style_stack);
1632 self.window
1633 .next_frame
1634 .dispatch_tree
1635 .set_active_node(deferred_draw.parent_node);
1636
1637 let prepaint_start = self.prepaint_index();
1638 if let Some(element) = deferred_draw.element.as_mut() {
1639 self.with_absolute_element_offset(deferred_draw.absolute_offset, |cx| {
1640 element.prepaint(cx)
1641 });
1642 } else {
1643 self.reuse_prepaint(deferred_draw.prepaint_range.clone());
1644 }
1645 let prepaint_end = self.prepaint_index();
1646 deferred_draw.prepaint_range = prepaint_start..prepaint_end;
1647 }
1648 assert_eq!(
1649 self.window.next_frame.deferred_draws.len(),
1650 0,
1651 "cannot call defer_draw during deferred drawing"
1652 );
1653 self.window.next_frame.deferred_draws = deferred_draws;
1654 self.window.element_id_stack.clear();
1655 self.window.text_style_stack.clear();
1656 }
1657
1658 fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1659 assert_eq!(self.window.element_id_stack.len(), 0);
1660
1661 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1662 for deferred_draw_ix in deferred_draw_indices {
1663 let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1664 self.window
1665 .element_id_stack
1666 .clone_from(&deferred_draw.element_id_stack);
1667 self.window
1668 .next_frame
1669 .dispatch_tree
1670 .set_active_node(deferred_draw.parent_node);
1671
1672 let paint_start = self.paint_index();
1673 if let Some(element) = deferred_draw.element.as_mut() {
1674 element.paint(self);
1675 } else {
1676 self.reuse_paint(deferred_draw.paint_range.clone());
1677 }
1678 let paint_end = self.paint_index();
1679 deferred_draw.paint_range = paint_start..paint_end;
1680 }
1681 self.window.next_frame.deferred_draws = deferred_draws;
1682 self.window.element_id_stack.clear();
1683 }
1684
1685 pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
1686 PrepaintStateIndex {
1687 hitboxes_index: self.window.next_frame.hitboxes.len(),
1688 tooltips_index: self.window.next_frame.tooltip_requests.len(),
1689 deferred_draws_index: self.window.next_frame.deferred_draws.len(),
1690 dispatch_tree_index: self.window.next_frame.dispatch_tree.len(),
1691 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1692 line_layout_index: self.window.text_system.layout_index(),
1693 }
1694 }
1695
1696 pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
1697 let window = &mut self.window;
1698 window.next_frame.hitboxes.extend(
1699 window.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
1700 .iter()
1701 .cloned(),
1702 );
1703 window.next_frame.tooltip_requests.extend(
1704 window.rendered_frame.tooltip_requests
1705 [range.start.tooltips_index..range.end.tooltips_index]
1706 .iter_mut()
1707 .map(|request| request.take()),
1708 );
1709 window.next_frame.accessed_element_states.extend(
1710 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1711 ..range.end.accessed_element_states_index]
1712 .iter()
1713 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1714 );
1715 window
1716 .text_system
1717 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1718
1719 let reused_subtree = window.next_frame.dispatch_tree.reuse_subtree(
1720 range.start.dispatch_tree_index..range.end.dispatch_tree_index,
1721 &mut window.rendered_frame.dispatch_tree,
1722 window.focus,
1723 );
1724
1725 if reused_subtree.contains_focus() {
1726 window.next_frame.focus = window.focus;
1727 }
1728
1729 window.next_frame.deferred_draws.extend(
1730 window.rendered_frame.deferred_draws
1731 [range.start.deferred_draws_index..range.end.deferred_draws_index]
1732 .iter()
1733 .map(|deferred_draw| DeferredDraw {
1734 parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
1735 element_id_stack: deferred_draw.element_id_stack.clone(),
1736 text_style_stack: deferred_draw.text_style_stack.clone(),
1737 priority: deferred_draw.priority,
1738 element: None,
1739 absolute_offset: deferred_draw.absolute_offset,
1740 prepaint_range: deferred_draw.prepaint_range.clone(),
1741 paint_range: deferred_draw.paint_range.clone(),
1742 }),
1743 );
1744 }
1745
1746 pub(crate) fn paint_index(&self) -> PaintIndex {
1747 PaintIndex {
1748 scene_index: self.window.next_frame.scene.len(),
1749 mouse_listeners_index: self.window.next_frame.mouse_listeners.len(),
1750 input_handlers_index: self.window.next_frame.input_handlers.len(),
1751 cursor_styles_index: self.window.next_frame.cursor_styles.len(),
1752 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1753 line_layout_index: self.window.text_system.layout_index(),
1754 }
1755 }
1756
1757 pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
1758 let window = &mut self.window;
1759
1760 window.next_frame.cursor_styles.extend(
1761 window.rendered_frame.cursor_styles
1762 [range.start.cursor_styles_index..range.end.cursor_styles_index]
1763 .iter()
1764 .cloned(),
1765 );
1766 window.next_frame.input_handlers.extend(
1767 window.rendered_frame.input_handlers
1768 [range.start.input_handlers_index..range.end.input_handlers_index]
1769 .iter_mut()
1770 .map(|handler| handler.take()),
1771 );
1772 window.next_frame.mouse_listeners.extend(
1773 window.rendered_frame.mouse_listeners
1774 [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
1775 .iter_mut()
1776 .map(|listener| listener.take()),
1777 );
1778 window.next_frame.accessed_element_states.extend(
1779 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1780 ..range.end.accessed_element_states_index]
1781 .iter()
1782 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1783 );
1784
1785 window
1786 .text_system
1787 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1788 window.next_frame.scene.replay(
1789 range.start.scene_index..range.end.scene_index,
1790 &window.rendered_frame.scene,
1791 );
1792 }
1793
1794 /// Push a text style onto the stack, and call a function with that style active.
1795 /// Use [`AppContext::text_style`] to get the current, combined text style. This method
1796 /// should only be called as part of element drawing.
1797 pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
1798 where
1799 F: FnOnce(&mut Self) -> R,
1800 {
1801 debug_assert!(
1802 matches!(
1803 self.window.draw_phase,
1804 DrawPhase::Prepaint | DrawPhase::Paint
1805 ),
1806 "this method can only be called during request_layout, prepaint, or paint"
1807 );
1808 if let Some(style) = style {
1809 self.window.text_style_stack.push(style);
1810 let result = f(self);
1811 self.window.text_style_stack.pop();
1812 result
1813 } else {
1814 f(self)
1815 }
1816 }
1817
1818 /// Updates the cursor style at the platform level. This method should only be called
1819 /// during the prepaint phase of element drawing.
1820 pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
1821 debug_assert_eq!(
1822 self.window.draw_phase,
1823 DrawPhase::Paint,
1824 "this method can only be called during paint"
1825 );
1826 self.window
1827 .next_frame
1828 .cursor_styles
1829 .push(CursorStyleRequest {
1830 hitbox_id: hitbox.id,
1831 style,
1832 });
1833 }
1834
1835 /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
1836 /// during the paint phase of element drawing.
1837 pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
1838 debug_assert_eq!(
1839 self.window.draw_phase,
1840 DrawPhase::Prepaint,
1841 "this method can only be called during prepaint"
1842 );
1843 let id = TooltipId(post_inc(&mut self.window.next_tooltip_id.0));
1844 self.window
1845 .next_frame
1846 .tooltip_requests
1847 .push(Some(TooltipRequest { id, tooltip }));
1848 id
1849 }
1850
1851 /// Invoke the given function with the given content mask after intersecting it
1852 /// with the current mask. This method should only be called during element drawing.
1853 pub fn with_content_mask<R>(
1854 &mut self,
1855 mask: Option<ContentMask<Pixels>>,
1856 f: impl FnOnce(&mut Self) -> R,
1857 ) -> R {
1858 debug_assert!(
1859 matches!(
1860 self.window.draw_phase,
1861 DrawPhase::Prepaint | DrawPhase::Paint
1862 ),
1863 "this method can only be called during request_layout, prepaint, or paint"
1864 );
1865 if let Some(mask) = mask {
1866 let mask = mask.intersect(&self.content_mask());
1867 self.window_mut().content_mask_stack.push(mask);
1868 let result = f(self);
1869 self.window_mut().content_mask_stack.pop();
1870 result
1871 } else {
1872 f(self)
1873 }
1874 }
1875
1876 /// Updates the global element offset relative to the current offset. This is used to implement
1877 /// scrolling. This method should only be called during the prepaint phase of element drawing.
1878 pub fn with_element_offset<R>(
1879 &mut self,
1880 offset: Point<Pixels>,
1881 f: impl FnOnce(&mut Self) -> R,
1882 ) -> R {
1883 debug_assert_eq!(
1884 self.window.draw_phase,
1885 DrawPhase::Prepaint,
1886 "this method can only be called during request_layout, or prepaint"
1887 );
1888
1889 if offset.is_zero() {
1890 return f(self);
1891 };
1892
1893 let abs_offset = self.element_offset() + offset;
1894 self.with_absolute_element_offset(abs_offset, f)
1895 }
1896
1897 /// Updates the global element offset based on the given offset. This is used to implement
1898 /// drag handles and other manual painting of elements. This method should only be called during
1899 /// the prepaint phase of element drawing.
1900 pub fn with_absolute_element_offset<R>(
1901 &mut self,
1902 offset: Point<Pixels>,
1903 f: impl FnOnce(&mut Self) -> R,
1904 ) -> R {
1905 debug_assert_eq!(
1906 self.window.draw_phase,
1907 DrawPhase::Prepaint,
1908 "this method can only be called during request_layout, or prepaint"
1909 );
1910 self.window_mut().element_offset_stack.push(offset);
1911 let result = f(self);
1912 self.window_mut().element_offset_stack.pop();
1913 result
1914 }
1915
1916 pub(crate) fn with_element_opacity<R>(
1917 &mut self,
1918 opacity: Option<f32>,
1919 f: impl FnOnce(&mut Self) -> R,
1920 ) -> R {
1921 if opacity.is_none() {
1922 return f(self);
1923 }
1924
1925 debug_assert!(
1926 matches!(
1927 self.window.draw_phase,
1928 DrawPhase::Prepaint | DrawPhase::Paint
1929 ),
1930 "this method can only be called during prepaint, or paint"
1931 );
1932 self.window_mut().element_opacity = opacity;
1933 let result = f(self);
1934 self.window_mut().element_opacity = None;
1935 result
1936 }
1937
1938 /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
1939 /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
1940 /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
1941 /// element offset and prepaint again. See [`List`] for an example. This method should only be
1942 /// called during the prepaint phase of element drawing.
1943 pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
1944 debug_assert_eq!(
1945 self.window.draw_phase,
1946 DrawPhase::Prepaint,
1947 "this method can only be called during prepaint"
1948 );
1949 let index = self.prepaint_index();
1950 let result = f(self);
1951 if result.is_err() {
1952 self.window
1953 .next_frame
1954 .hitboxes
1955 .truncate(index.hitboxes_index);
1956 self.window
1957 .next_frame
1958 .tooltip_requests
1959 .truncate(index.tooltips_index);
1960 self.window
1961 .next_frame
1962 .deferred_draws
1963 .truncate(index.deferred_draws_index);
1964 self.window
1965 .next_frame
1966 .dispatch_tree
1967 .truncate(index.dispatch_tree_index);
1968 self.window
1969 .next_frame
1970 .accessed_element_states
1971 .truncate(index.accessed_element_states_index);
1972 self.window
1973 .text_system
1974 .truncate_layouts(index.line_layout_index);
1975 }
1976 result
1977 }
1978
1979 /// When you call this method during [`prepaint`], containing elements will attempt to
1980 /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
1981 /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
1982 /// that supports this method being called on the elements it contains. This method should only be
1983 /// called during the prepaint phase of element drawing.
1984 pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
1985 debug_assert_eq!(
1986 self.window.draw_phase,
1987 DrawPhase::Prepaint,
1988 "this method can only be called during prepaint"
1989 );
1990 self.window.requested_autoscroll = Some(bounds);
1991 }
1992
1993 /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
1994 /// described in [`request_autoscroll`].
1995 pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
1996 debug_assert_eq!(
1997 self.window.draw_phase,
1998 DrawPhase::Prepaint,
1999 "this method can only be called during prepaint"
2000 );
2001 self.window.requested_autoscroll.take()
2002 }
2003
2004 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
2005 /// Your view will be re-drawn once the asset has finished loading.
2006 ///
2007 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
2008 /// time.
2009 pub fn use_asset<A: Asset>(&mut self, source: &A::Source) -> Option<A::Output> {
2010 let (task, is_first) = self.fetch_asset::<A>(source);
2011 task.clone().now_or_never().or_else(|| {
2012 if is_first {
2013 let parent_id = self.parent_view_id();
2014 self.spawn({
2015 let task = task.clone();
2016 |mut cx| async move {
2017 task.await;
2018
2019 cx.on_next_frame(move |cx| cx.notify(parent_id));
2020 }
2021 })
2022 .detach();
2023 }
2024
2025 None
2026 })
2027 }
2028 /// Obtain the current element offset. This method should only be called during the
2029 /// prepaint phase of element drawing.
2030 pub fn element_offset(&self) -> Point<Pixels> {
2031 debug_assert_eq!(
2032 self.window.draw_phase,
2033 DrawPhase::Prepaint,
2034 "this method can only be called during prepaint"
2035 );
2036 self.window()
2037 .element_offset_stack
2038 .last()
2039 .copied()
2040 .unwrap_or_default()
2041 }
2042
2043 /// Obtain the current element opacity. This method should only be called during the
2044 /// prepaint phase of element drawing.
2045 pub(crate) fn element_opacity(&self) -> f32 {
2046 debug_assert!(
2047 matches!(
2048 self.window.draw_phase,
2049 DrawPhase::Prepaint | DrawPhase::Paint
2050 ),
2051 "this method can only be called during prepaint, or paint"
2052 );
2053 self.window().element_opacity.unwrap_or(1.0)
2054 }
2055
2056 /// Obtain the current content mask. This method should only be called during element drawing.
2057 pub fn content_mask(&self) -> ContentMask<Pixels> {
2058 debug_assert!(
2059 matches!(
2060 self.window.draw_phase,
2061 DrawPhase::Prepaint | DrawPhase::Paint
2062 ),
2063 "this method can only be called during prepaint, or paint"
2064 );
2065 self.window()
2066 .content_mask_stack
2067 .last()
2068 .cloned()
2069 .unwrap_or_else(|| ContentMask {
2070 bounds: Bounds {
2071 origin: Point::default(),
2072 size: self.window().viewport_size,
2073 },
2074 })
2075 }
2076
2077 /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2078 /// This can be used within a custom element to distinguish multiple sets of child elements.
2079 pub fn with_element_namespace<R>(
2080 &mut self,
2081 element_id: impl Into<ElementId>,
2082 f: impl FnOnce(&mut Self) -> R,
2083 ) -> R {
2084 self.window.element_id_stack.push(element_id.into());
2085 let result = f(self);
2086 self.window.element_id_stack.pop();
2087 result
2088 }
2089
2090 /// Updates or initializes state for an element with the given id that lives across multiple
2091 /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2092 /// to the given closure. The state returned by the closure will be stored so it can be referenced
2093 /// when drawing the next frame. This method should only be called as part of element drawing.
2094 pub fn with_element_state<S, R>(
2095 &mut self,
2096 global_id: &GlobalElementId,
2097 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2098 ) -> R
2099 where
2100 S: 'static,
2101 {
2102 debug_assert!(
2103 matches!(
2104 self.window.draw_phase,
2105 DrawPhase::Prepaint | DrawPhase::Paint
2106 ),
2107 "this method can only be called during request_layout, prepaint, or paint"
2108 );
2109
2110 let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2111 self.window
2112 .next_frame
2113 .accessed_element_states
2114 .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2115
2116 if let Some(any) = self
2117 .window
2118 .next_frame
2119 .element_states
2120 .remove(&key)
2121 .or_else(|| self.window.rendered_frame.element_states.remove(&key))
2122 {
2123 let ElementStateBox {
2124 inner,
2125 #[cfg(debug_assertions)]
2126 type_name,
2127 } = any;
2128 // Using the extra inner option to avoid needing to reallocate a new box.
2129 let mut state_box = inner
2130 .downcast::<Option<S>>()
2131 .map_err(|_| {
2132 #[cfg(debug_assertions)]
2133 {
2134 anyhow::anyhow!(
2135 "invalid element state type for id, requested {:?}, actual: {:?}",
2136 std::any::type_name::<S>(),
2137 type_name
2138 )
2139 }
2140
2141 #[cfg(not(debug_assertions))]
2142 {
2143 anyhow::anyhow!(
2144 "invalid element state type for id, requested {:?}",
2145 std::any::type_name::<S>(),
2146 )
2147 }
2148 })
2149 .unwrap();
2150
2151 let state = state_box.take().expect(
2152 "reentrant call to with_element_state for the same state type and element id",
2153 );
2154 let (result, state) = f(Some(state), self);
2155 state_box.replace(state);
2156 self.window.next_frame.element_states.insert(
2157 key,
2158 ElementStateBox {
2159 inner: state_box,
2160 #[cfg(debug_assertions)]
2161 type_name,
2162 },
2163 );
2164 result
2165 } else {
2166 let (result, state) = f(None, self);
2167 self.window.next_frame.element_states.insert(
2168 key,
2169 ElementStateBox {
2170 inner: Box::new(Some(state)),
2171 #[cfg(debug_assertions)]
2172 type_name: std::any::type_name::<S>(),
2173 },
2174 );
2175 result
2176 }
2177 }
2178
2179 /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2180 /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2181 /// when the element is guaranteed to have an id.
2182 ///
2183 /// The first option means 'no ID provided'
2184 /// The second option means 'not yet initialized'
2185 pub fn with_optional_element_state<S, R>(
2186 &mut self,
2187 global_id: Option<&GlobalElementId>,
2188 f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2189 ) -> R
2190 where
2191 S: 'static,
2192 {
2193 debug_assert!(
2194 matches!(
2195 self.window.draw_phase,
2196 DrawPhase::Prepaint | DrawPhase::Paint
2197 ),
2198 "this method can only be called during request_layout, prepaint, or paint"
2199 );
2200
2201 if let Some(global_id) = global_id {
2202 self.with_element_state(global_id, |state, cx| {
2203 let (result, state) = f(Some(state), cx);
2204 let state =
2205 state.expect("you must return some state when you pass some element id");
2206 (result, state)
2207 })
2208 } else {
2209 let (result, state) = f(None, self);
2210 debug_assert!(
2211 state.is_none(),
2212 "you must not return an element state when passing None for the global id"
2213 );
2214 result
2215 }
2216 }
2217
2218 /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2219 /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2220 /// with higher values being drawn on top.
2221 ///
2222 /// This method should only be called as part of the prepaint phase of element drawing.
2223 pub fn defer_draw(
2224 &mut self,
2225 element: AnyElement,
2226 absolute_offset: Point<Pixels>,
2227 priority: usize,
2228 ) {
2229 let window = &mut self.window;
2230 debug_assert_eq!(
2231 window.draw_phase,
2232 DrawPhase::Prepaint,
2233 "this method can only be called during request_layout or prepaint"
2234 );
2235 let parent_node = window.next_frame.dispatch_tree.active_node_id().unwrap();
2236 window.next_frame.deferred_draws.push(DeferredDraw {
2237 parent_node,
2238 element_id_stack: window.element_id_stack.clone(),
2239 text_style_stack: window.text_style_stack.clone(),
2240 priority,
2241 element: Some(element),
2242 absolute_offset,
2243 prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2244 paint_range: PaintIndex::default()..PaintIndex::default(),
2245 });
2246 }
2247
2248 /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2249 /// of geometry that are non-overlapping and have the same draw order. This is typically used
2250 /// for performance reasons.
2251 ///
2252 /// This method should only be called as part of the paint phase of element drawing.
2253 pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2254 debug_assert_eq!(
2255 self.window.draw_phase,
2256 DrawPhase::Paint,
2257 "this method can only be called during paint"
2258 );
2259
2260 let scale_factor = self.scale_factor();
2261 let content_mask = self.content_mask();
2262 let clipped_bounds = bounds.intersect(&content_mask.bounds);
2263 if !clipped_bounds.is_empty() {
2264 self.window
2265 .next_frame
2266 .scene
2267 .push_layer(clipped_bounds.scale(scale_factor));
2268 }
2269
2270 let result = f(self);
2271
2272 if !clipped_bounds.is_empty() {
2273 self.window.next_frame.scene.pop_layer();
2274 }
2275
2276 result
2277 }
2278
2279 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2280 ///
2281 /// This method should only be called as part of the paint phase of element drawing.
2282 pub fn paint_shadows(
2283 &mut self,
2284 bounds: Bounds<Pixels>,
2285 corner_radii: Corners<Pixels>,
2286 shadows: &[BoxShadow],
2287 ) {
2288 debug_assert_eq!(
2289 self.window.draw_phase,
2290 DrawPhase::Paint,
2291 "this method can only be called during paint"
2292 );
2293
2294 let scale_factor = self.scale_factor();
2295 let content_mask = self.content_mask();
2296 let opacity = self.element_opacity();
2297 for shadow in shadows {
2298 let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2299 self.window.next_frame.scene.insert_primitive(Shadow {
2300 order: 0,
2301 blur_radius: shadow.blur_radius.scale(scale_factor),
2302 bounds: shadow_bounds.scale(scale_factor),
2303 content_mask: content_mask.scale(scale_factor),
2304 corner_radii: corner_radii.scale(scale_factor),
2305 color: shadow.color.opacity(opacity),
2306 });
2307 }
2308 }
2309
2310 /// Paint one or more quads into the scene for the next frame at the current stacking context.
2311 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2312 /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2313 ///
2314 /// This method should only be called as part of the paint phase of element drawing.
2315 pub fn paint_quad(&mut self, quad: PaintQuad) {
2316 debug_assert_eq!(
2317 self.window.draw_phase,
2318 DrawPhase::Paint,
2319 "this method can only be called during paint"
2320 );
2321
2322 let scale_factor = self.scale_factor();
2323 let content_mask = self.content_mask();
2324 let opacity = self.element_opacity();
2325 self.window.next_frame.scene.insert_primitive(Quad {
2326 order: 0,
2327 pad: 0,
2328 bounds: quad.bounds.scale(scale_factor),
2329 content_mask: content_mask.scale(scale_factor),
2330 background: quad.background.opacity(opacity),
2331 border_color: quad.border_color.opacity(opacity),
2332 corner_radii: quad.corner_radii.scale(scale_factor),
2333 border_widths: quad.border_widths.scale(scale_factor),
2334 });
2335 }
2336
2337 /// Paint the given `Path` into the scene for the next frame at the current z-index.
2338 ///
2339 /// This method should only be called as part of the paint phase of element drawing.
2340 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2341 debug_assert_eq!(
2342 self.window.draw_phase,
2343 DrawPhase::Paint,
2344 "this method can only be called during paint"
2345 );
2346
2347 let scale_factor = self.scale_factor();
2348 let content_mask = self.content_mask();
2349 let opacity = self.element_opacity();
2350 path.content_mask = content_mask;
2351 let color: Background = color.into();
2352 path.color = color.opacity(opacity);
2353 self.window
2354 .next_frame
2355 .scene
2356 .insert_primitive(path.scale(scale_factor));
2357 }
2358
2359 /// Paint an underline into the scene for the next frame at the current z-index.
2360 ///
2361 /// This method should only be called as part of the paint phase of element drawing.
2362 pub fn paint_underline(
2363 &mut self,
2364 origin: Point<Pixels>,
2365 width: Pixels,
2366 style: &UnderlineStyle,
2367 ) {
2368 debug_assert_eq!(
2369 self.window.draw_phase,
2370 DrawPhase::Paint,
2371 "this method can only be called during paint"
2372 );
2373
2374 let scale_factor = self.scale_factor();
2375 let height = if style.wavy {
2376 style.thickness * 3.
2377 } else {
2378 style.thickness
2379 };
2380 let bounds = Bounds {
2381 origin,
2382 size: size(width, height),
2383 };
2384 let content_mask = self.content_mask();
2385 let element_opacity = self.element_opacity();
2386
2387 self.window.next_frame.scene.insert_primitive(Underline {
2388 order: 0,
2389 pad: 0,
2390 bounds: bounds.scale(scale_factor),
2391 content_mask: content_mask.scale(scale_factor),
2392 color: style.color.unwrap_or_default().opacity(element_opacity),
2393 thickness: style.thickness.scale(scale_factor),
2394 wavy: style.wavy,
2395 });
2396 }
2397
2398 /// Paint a strikethrough into the scene for the next frame at the current z-index.
2399 ///
2400 /// This method should only be called as part of the paint phase of element drawing.
2401 pub fn paint_strikethrough(
2402 &mut self,
2403 origin: Point<Pixels>,
2404 width: Pixels,
2405 style: &StrikethroughStyle,
2406 ) {
2407 debug_assert_eq!(
2408 self.window.draw_phase,
2409 DrawPhase::Paint,
2410 "this method can only be called during paint"
2411 );
2412
2413 let scale_factor = self.scale_factor();
2414 let height = style.thickness;
2415 let bounds = Bounds {
2416 origin,
2417 size: size(width, height),
2418 };
2419 let content_mask = self.content_mask();
2420 let opacity = self.element_opacity();
2421
2422 self.window.next_frame.scene.insert_primitive(Underline {
2423 order: 0,
2424 pad: 0,
2425 bounds: bounds.scale(scale_factor),
2426 content_mask: content_mask.scale(scale_factor),
2427 thickness: style.thickness.scale(scale_factor),
2428 color: style.color.unwrap_or_default().opacity(opacity),
2429 wavy: false,
2430 });
2431 }
2432
2433 /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2434 ///
2435 /// The y component of the origin is the baseline of the glyph.
2436 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2437 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2438 /// This method is only useful if you need to paint a single glyph that has already been shaped.
2439 ///
2440 /// This method should only be called as part of the paint phase of element drawing.
2441 pub fn paint_glyph(
2442 &mut self,
2443 origin: Point<Pixels>,
2444 font_id: FontId,
2445 glyph_id: GlyphId,
2446 font_size: Pixels,
2447 color: Hsla,
2448 ) -> Result<()> {
2449 debug_assert_eq!(
2450 self.window.draw_phase,
2451 DrawPhase::Paint,
2452 "this method can only be called during paint"
2453 );
2454
2455 let element_opacity = self.element_opacity();
2456 let scale_factor = self.scale_factor();
2457 let glyph_origin = origin.scale(scale_factor);
2458 let subpixel_variant = Point {
2459 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2460 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2461 };
2462 let params = RenderGlyphParams {
2463 font_id,
2464 glyph_id,
2465 font_size,
2466 subpixel_variant,
2467 scale_factor,
2468 is_emoji: false,
2469 };
2470
2471 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2472 if !raster_bounds.is_zero() {
2473 let tile = self
2474 .window
2475 .sprite_atlas
2476 .get_or_insert_with(¶ms.clone().into(), &mut || {
2477 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2478 Ok(Some((size, Cow::Owned(bytes))))
2479 })?
2480 .expect("Callback above only errors or returns Some");
2481 let bounds = Bounds {
2482 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2483 size: tile.bounds.size.map(Into::into),
2484 };
2485 let content_mask = self.content_mask().scale(scale_factor);
2486 self.window
2487 .next_frame
2488 .scene
2489 .insert_primitive(MonochromeSprite {
2490 order: 0,
2491 pad: 0,
2492 bounds,
2493 content_mask,
2494 color: color.opacity(element_opacity),
2495 tile,
2496 transformation: TransformationMatrix::unit(),
2497 });
2498 }
2499 Ok(())
2500 }
2501
2502 /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2503 ///
2504 /// The y component of the origin is the baseline of the glyph.
2505 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2506 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2507 /// This method is only useful if you need to paint a single emoji that has already been shaped.
2508 ///
2509 /// This method should only be called as part of the paint phase of element drawing.
2510 pub fn paint_emoji(
2511 &mut self,
2512 origin: Point<Pixels>,
2513 font_id: FontId,
2514 glyph_id: GlyphId,
2515 font_size: Pixels,
2516 ) -> Result<()> {
2517 debug_assert_eq!(
2518 self.window.draw_phase,
2519 DrawPhase::Paint,
2520 "this method can only be called during paint"
2521 );
2522
2523 let scale_factor = self.scale_factor();
2524 let glyph_origin = origin.scale(scale_factor);
2525 let params = RenderGlyphParams {
2526 font_id,
2527 glyph_id,
2528 font_size,
2529 // We don't render emojis with subpixel variants.
2530 subpixel_variant: Default::default(),
2531 scale_factor,
2532 is_emoji: true,
2533 };
2534
2535 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2536 if !raster_bounds.is_zero() {
2537 let tile = self
2538 .window
2539 .sprite_atlas
2540 .get_or_insert_with(¶ms.clone().into(), &mut || {
2541 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2542 Ok(Some((size, Cow::Owned(bytes))))
2543 })?
2544 .expect("Callback above only errors or returns Some");
2545
2546 let bounds = Bounds {
2547 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2548 size: tile.bounds.size.map(Into::into),
2549 };
2550 let content_mask = self.content_mask().scale(scale_factor);
2551 let opacity = self.element_opacity();
2552
2553 self.window
2554 .next_frame
2555 .scene
2556 .insert_primitive(PolychromeSprite {
2557 order: 0,
2558 pad: 0,
2559 grayscale: false,
2560 bounds,
2561 corner_radii: Default::default(),
2562 content_mask,
2563 tile,
2564 opacity,
2565 });
2566 }
2567 Ok(())
2568 }
2569
2570 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2571 ///
2572 /// This method should only be called as part of the paint phase of element drawing.
2573 pub fn paint_svg(
2574 &mut self,
2575 bounds: Bounds<Pixels>,
2576 path: SharedString,
2577 transformation: TransformationMatrix,
2578 color: Hsla,
2579 ) -> Result<()> {
2580 debug_assert_eq!(
2581 self.window.draw_phase,
2582 DrawPhase::Paint,
2583 "this method can only be called during paint"
2584 );
2585
2586 let element_opacity = self.element_opacity();
2587 let scale_factor = self.scale_factor();
2588 let bounds = bounds.scale(scale_factor);
2589 // Render the SVG at twice the size to get a higher quality result.
2590 let params = RenderSvgParams {
2591 path,
2592 size: bounds
2593 .size
2594 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
2595 };
2596
2597 let Some(tile) =
2598 self.window
2599 .sprite_atlas
2600 .get_or_insert_with(¶ms.clone().into(), &mut || {
2601 let Some(bytes) = self.svg_renderer.render(¶ms)? else {
2602 return Ok(None);
2603 };
2604 Ok(Some((params.size, Cow::Owned(bytes))))
2605 })?
2606 else {
2607 return Ok(());
2608 };
2609 let content_mask = self.content_mask().scale(scale_factor);
2610
2611 self.window
2612 .next_frame
2613 .scene
2614 .insert_primitive(MonochromeSprite {
2615 order: 0,
2616 pad: 0,
2617 bounds: bounds
2618 .map_origin(|origin| origin.floor())
2619 .map_size(|size| size.ceil()),
2620 content_mask,
2621 color: color.opacity(element_opacity),
2622 tile,
2623 transformation,
2624 });
2625
2626 Ok(())
2627 }
2628
2629 /// Paint an image into the scene for the next frame at the current z-index.
2630 /// This method will panic if the frame_index is not valid
2631 ///
2632 /// This method should only be called as part of the paint phase of element drawing.
2633 pub fn paint_image(
2634 &mut self,
2635 bounds: Bounds<Pixels>,
2636 corner_radii: Corners<Pixels>,
2637 data: Arc<RenderImage>,
2638 frame_index: usize,
2639 grayscale: bool,
2640 ) -> Result<()> {
2641 debug_assert_eq!(
2642 self.window.draw_phase,
2643 DrawPhase::Paint,
2644 "this method can only be called during paint"
2645 );
2646
2647 let scale_factor = self.scale_factor();
2648 let bounds = bounds.scale(scale_factor);
2649 let params = RenderImageParams {
2650 image_id: data.id,
2651 frame_index,
2652 };
2653
2654 let tile = self
2655 .window
2656 .sprite_atlas
2657 .get_or_insert_with(¶ms.clone().into(), &mut || {
2658 Ok(Some((
2659 data.size(frame_index),
2660 Cow::Borrowed(
2661 data.as_bytes(frame_index)
2662 .expect("It's the caller's job to pass a valid frame index"),
2663 ),
2664 )))
2665 })?
2666 .expect("Callback above only returns Some");
2667 let content_mask = self.content_mask().scale(scale_factor);
2668 let corner_radii = corner_radii.scale(scale_factor);
2669 let opacity = self.element_opacity();
2670
2671 self.window
2672 .next_frame
2673 .scene
2674 .insert_primitive(PolychromeSprite {
2675 order: 0,
2676 pad: 0,
2677 grayscale,
2678 bounds,
2679 content_mask,
2680 corner_radii,
2681 tile,
2682 opacity,
2683 });
2684 Ok(())
2685 }
2686
2687 /// Paint a surface into the scene for the next frame at the current z-index.
2688 ///
2689 /// This method should only be called as part of the paint phase of element drawing.
2690 #[cfg(target_os = "macos")]
2691 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
2692 use crate::PaintSurface;
2693
2694 debug_assert_eq!(
2695 self.window.draw_phase,
2696 DrawPhase::Paint,
2697 "this method can only be called during paint"
2698 );
2699
2700 let scale_factor = self.scale_factor();
2701 let bounds = bounds.scale(scale_factor);
2702 let content_mask = self.content_mask().scale(scale_factor);
2703 self.window.next_frame.scene.insert_primitive(PaintSurface {
2704 order: 0,
2705 bounds,
2706 content_mask,
2707 image_buffer,
2708 });
2709 }
2710
2711 /// Removes an image from the sprite atlas.
2712 pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2713 for frame_index in 0..data.frame_count() {
2714 let params = RenderImageParams {
2715 image_id: data.id,
2716 frame_index,
2717 };
2718
2719 self.window.sprite_atlas.remove(¶ms.clone().into());
2720 }
2721
2722 Ok(())
2723 }
2724
2725 #[must_use]
2726 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2727 /// layout is being requested, along with the layout ids of any children. This method is called during
2728 /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2729 ///
2730 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2731 pub fn request_layout(
2732 &mut self,
2733 style: Style,
2734 children: impl IntoIterator<Item = LayoutId>,
2735 ) -> LayoutId {
2736 debug_assert_eq!(
2737 self.window.draw_phase,
2738 DrawPhase::Prepaint,
2739 "this method can only be called during request_layout, or prepaint"
2740 );
2741
2742 self.app.layout_id_buffer.clear();
2743 self.app.layout_id_buffer.extend(children);
2744 let rem_size = self.rem_size();
2745
2746 self.window.layout_engine.as_mut().unwrap().request_layout(
2747 style,
2748 rem_size,
2749 &self.app.layout_id_buffer,
2750 )
2751 }
2752
2753 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
2754 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
2755 /// determine the element's size. One place this is used internally is when measuring text.
2756 ///
2757 /// The given closure is invoked at layout time with the known dimensions and available space and
2758 /// returns a `Size`.
2759 ///
2760 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2761 pub fn request_measured_layout<
2762 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
2763 + 'static,
2764 >(
2765 &mut self,
2766 style: Style,
2767 measure: F,
2768 ) -> LayoutId {
2769 debug_assert_eq!(
2770 self.window.draw_phase,
2771 DrawPhase::Prepaint,
2772 "this method can only be called during request_layout, or prepaint"
2773 );
2774
2775 let rem_size = self.rem_size();
2776 self.window
2777 .layout_engine
2778 .as_mut()
2779 .unwrap()
2780 .request_measured_layout(style, rem_size, measure)
2781 }
2782
2783 /// Compute the layout for the given id within the given available space.
2784 /// This method is called for its side effect, typically by the framework prior to painting.
2785 /// After calling it, you can request the bounds of the given layout node id or any descendant.
2786 ///
2787 /// This method should only be called as part of the prepaint phase of element drawing.
2788 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
2789 debug_assert_eq!(
2790 self.window.draw_phase,
2791 DrawPhase::Prepaint,
2792 "this method can only be called during request_layout, or prepaint"
2793 );
2794
2795 let mut layout_engine = self.window.layout_engine.take().unwrap();
2796 layout_engine.compute_layout(layout_id, available_space, self);
2797 self.window.layout_engine = Some(layout_engine);
2798 }
2799
2800 /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
2801 /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
2802 ///
2803 /// This method should only be called as part of element drawing.
2804 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
2805 debug_assert_eq!(
2806 self.window.draw_phase,
2807 DrawPhase::Prepaint,
2808 "this method can only be called during request_layout, prepaint, or paint"
2809 );
2810
2811 let mut bounds = self
2812 .window
2813 .layout_engine
2814 .as_mut()
2815 .unwrap()
2816 .layout_bounds(layout_id)
2817 .map(Into::into);
2818 bounds.origin += self.element_offset();
2819 bounds
2820 }
2821
2822 /// This method should be called during `prepaint`. You can use
2823 /// the returned [Hitbox] during `paint` or in an event handler
2824 /// to determine whether the inserted hitbox was the topmost.
2825 ///
2826 /// This method should only be called as part of the prepaint phase of element drawing.
2827 pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, opaque: bool) -> Hitbox {
2828 debug_assert_eq!(
2829 self.window.draw_phase,
2830 DrawPhase::Prepaint,
2831 "this method can only be called during prepaint"
2832 );
2833
2834 let content_mask = self.content_mask();
2835 let window = &mut self.window;
2836 let id = window.next_hitbox_id;
2837 window.next_hitbox_id.0 += 1;
2838 let hitbox = Hitbox {
2839 id,
2840 bounds,
2841 content_mask,
2842 opaque,
2843 };
2844 window.next_frame.hitboxes.push(hitbox.clone());
2845 hitbox
2846 }
2847
2848 /// Sets the key context for the current element. This context will be used to translate
2849 /// keybindings into actions.
2850 ///
2851 /// This method should only be called as part of the paint phase of element drawing.
2852 pub fn set_key_context(&mut self, context: KeyContext) {
2853 debug_assert_eq!(
2854 self.window.draw_phase,
2855 DrawPhase::Paint,
2856 "this method can only be called during paint"
2857 );
2858 self.window
2859 .next_frame
2860 .dispatch_tree
2861 .set_key_context(context);
2862 }
2863
2864 /// Sets the focus handle for the current element. This handle will be used to manage focus state
2865 /// and keyboard event dispatch for the element.
2866 ///
2867 /// This method should only be called as part of the prepaint phase of element drawing.
2868 pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle) {
2869 debug_assert_eq!(
2870 self.window.draw_phase,
2871 DrawPhase::Prepaint,
2872 "this method can only be called during prepaint"
2873 );
2874 if focus_handle.is_focused(self) {
2875 self.window.next_frame.focus = Some(focus_handle.id);
2876 }
2877 self.window
2878 .next_frame
2879 .dispatch_tree
2880 .set_focus_id(focus_handle.id);
2881 }
2882
2883 /// Sets the view id for the current element, which will be used to manage view caching.
2884 ///
2885 /// This method should only be called as part of element prepaint. We plan on removing this
2886 /// method eventually when we solve some issues that require us to construct editor elements
2887 /// directly instead of always using editors via views.
2888 pub fn set_view_id(&mut self, view_id: EntityId) {
2889 debug_assert_eq!(
2890 self.window.draw_phase,
2891 DrawPhase::Prepaint,
2892 "this method can only be called during prepaint"
2893 );
2894 self.window.next_frame.dispatch_tree.set_view_id(view_id);
2895 }
2896
2897 /// Get the last view id for the current element
2898 pub fn parent_view_id(&self) -> Option<EntityId> {
2899 self.window.next_frame.dispatch_tree.parent_view_id()
2900 }
2901
2902 /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2903 /// platform to receive textual input with proper integration with concerns such
2904 /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
2905 /// rendered.
2906 ///
2907 /// This method should only be called as part of the paint phase of element drawing.
2908 ///
2909 /// [element_input_handler]: crate::ElementInputHandler
2910 pub fn handle_input(&mut self, focus_handle: &FocusHandle, input_handler: impl InputHandler) {
2911 debug_assert_eq!(
2912 self.window.draw_phase,
2913 DrawPhase::Paint,
2914 "this method can only be called during paint"
2915 );
2916
2917 if focus_handle.is_focused(self) {
2918 let cx = self.to_async();
2919 self.window
2920 .next_frame
2921 .input_handlers
2922 .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
2923 }
2924 }
2925
2926 /// Register a mouse event listener on the window for the next frame. The type of event
2927 /// is determined by the first parameter of the given listener. When the next frame is rendered
2928 /// the listener will be cleared.
2929 ///
2930 /// This method should only be called as part of the paint phase of element drawing.
2931 pub fn on_mouse_event<Event: MouseEvent>(
2932 &mut self,
2933 mut handler: impl FnMut(&Event, DispatchPhase, &mut WindowContext) + 'static,
2934 ) {
2935 debug_assert_eq!(
2936 self.window.draw_phase,
2937 DrawPhase::Paint,
2938 "this method can only be called during paint"
2939 );
2940
2941 self.window.next_frame.mouse_listeners.push(Some(Box::new(
2942 move |event: &dyn Any, phase: DispatchPhase, cx: &mut WindowContext<'_>| {
2943 if let Some(event) = event.downcast_ref() {
2944 handler(event, phase, cx)
2945 }
2946 },
2947 )));
2948 }
2949
2950 /// Register a key event listener on the window for the next frame. The type of event
2951 /// is determined by the first parameter of the given listener. When the next frame is rendered
2952 /// the listener will be cleared.
2953 ///
2954 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2955 /// a specific need to register a global listener.
2956 ///
2957 /// This method should only be called as part of the paint phase of element drawing.
2958 pub fn on_key_event<Event: KeyEvent>(
2959 &mut self,
2960 listener: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
2961 ) {
2962 debug_assert_eq!(
2963 self.window.draw_phase,
2964 DrawPhase::Paint,
2965 "this method can only be called during paint"
2966 );
2967
2968 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
2969 move |event: &dyn Any, phase, cx: &mut WindowContext<'_>| {
2970 if let Some(event) = event.downcast_ref::<Event>() {
2971 listener(event, phase, cx)
2972 }
2973 },
2974 ));
2975 }
2976
2977 /// Register a modifiers changed event listener on the window for the next frame.
2978 ///
2979 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2980 /// a specific need to register a global listener.
2981 ///
2982 /// This method should only be called as part of the paint phase of element drawing.
2983 pub fn on_modifiers_changed(
2984 &mut self,
2985 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
2986 ) {
2987 debug_assert_eq!(
2988 self.window.draw_phase,
2989 DrawPhase::Paint,
2990 "this method can only be called during paint"
2991 );
2992
2993 self.window
2994 .next_frame
2995 .dispatch_tree
2996 .on_modifiers_changed(Rc::new(
2997 move |event: &ModifiersChangedEvent, cx: &mut WindowContext<'_>| {
2998 listener(event, cx)
2999 },
3000 ));
3001 }
3002
3003 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
3004 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
3005 /// Returns a subscription and persists until the subscription is dropped.
3006 pub fn on_focus_in(
3007 &mut self,
3008 handle: &FocusHandle,
3009 mut listener: impl FnMut(&mut WindowContext) + 'static,
3010 ) -> Subscription {
3011 let focus_id = handle.id;
3012 let (subscription, activate) =
3013 self.window.new_focus_listener(Box::new(move |event, cx| {
3014 if event.is_focus_in(focus_id) {
3015 listener(cx);
3016 }
3017 true
3018 }));
3019 self.app.defer(move |_| activate());
3020 subscription
3021 }
3022
3023 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3024 /// Returns a subscription and persists until the subscription is dropped.
3025 pub fn on_focus_out(
3026 &mut self,
3027 handle: &FocusHandle,
3028 mut listener: impl FnMut(FocusOutEvent, &mut WindowContext) + 'static,
3029 ) -> Subscription {
3030 let focus_id = handle.id;
3031 let (subscription, activate) =
3032 self.window.new_focus_listener(Box::new(move |event, cx| {
3033 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3034 if event.is_focus_out(focus_id) {
3035 let event = FocusOutEvent {
3036 blurred: WeakFocusHandle {
3037 id: blurred_id,
3038 handles: Arc::downgrade(&cx.app.focus_handles),
3039 },
3040 };
3041 listener(event, cx)
3042 }
3043 }
3044 true
3045 }));
3046 self.app.defer(move |_| activate());
3047 subscription
3048 }
3049
3050 fn reset_cursor_style(&self) {
3051 // Set the cursor only if we're the active window.
3052 if self.is_window_hovered() {
3053 let style = self
3054 .window
3055 .rendered_frame
3056 .cursor_styles
3057 .iter()
3058 .rev()
3059 .find(|request| request.hitbox_id.is_hovered(self))
3060 .map(|request| request.style)
3061 .unwrap_or(CursorStyle::Arrow);
3062 self.platform.set_cursor_style(style);
3063 }
3064 }
3065
3066 /// Dispatch a given keystroke as though the user had typed it.
3067 /// You can create a keystroke with Keystroke::parse("").
3068 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
3069 let keystroke = keystroke.with_simulated_ime();
3070 let result = self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
3071 keystroke: keystroke.clone(),
3072 is_held: false,
3073 }));
3074 if !result.propagate {
3075 return true;
3076 }
3077
3078 if let Some(input) = keystroke.key_char {
3079 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3080 input_handler.dispatch_input(&input, self);
3081 self.window.platform_window.set_input_handler(input_handler);
3082 return true;
3083 }
3084 }
3085
3086 false
3087 }
3088
3089 /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3090 /// binding for the action (last binding added to the keymap).
3091 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3092 self.bindings_for_action(action)
3093 .into_iter()
3094 .next()
3095 .map(|binding| {
3096 binding
3097 .keystrokes()
3098 .iter()
3099 .map(ToString::to_string)
3100 .collect::<Vec<_>>()
3101 .join(" ")
3102 })
3103 .unwrap_or_else(|| action.name().to_string())
3104 }
3105
3106 /// Dispatch a mouse or keyboard event on the window.
3107 #[profiling::function]
3108 pub fn dispatch_event(&mut self, event: PlatformInput) -> DispatchEventResult {
3109 self.window.last_input_timestamp.set(Instant::now());
3110 // Handlers may set this to false by calling `stop_propagation`.
3111 self.app.propagate_event = true;
3112 // Handlers may set this to true by calling `prevent_default`.
3113 self.window.default_prevented = false;
3114
3115 let event = match event {
3116 // Track the mouse position with our own state, since accessing the platform
3117 // API for the mouse position can only occur on the main thread.
3118 PlatformInput::MouseMove(mouse_move) => {
3119 self.window.mouse_position = mouse_move.position;
3120 self.window.modifiers = mouse_move.modifiers;
3121 PlatformInput::MouseMove(mouse_move)
3122 }
3123 PlatformInput::MouseDown(mouse_down) => {
3124 self.window.mouse_position = mouse_down.position;
3125 self.window.modifiers = mouse_down.modifiers;
3126 PlatformInput::MouseDown(mouse_down)
3127 }
3128 PlatformInput::MouseUp(mouse_up) => {
3129 self.window.mouse_position = mouse_up.position;
3130 self.window.modifiers = mouse_up.modifiers;
3131 PlatformInput::MouseUp(mouse_up)
3132 }
3133 PlatformInput::MouseExited(mouse_exited) => {
3134 self.window.modifiers = mouse_exited.modifiers;
3135 PlatformInput::MouseExited(mouse_exited)
3136 }
3137 PlatformInput::ModifiersChanged(modifiers_changed) => {
3138 self.window.modifiers = modifiers_changed.modifiers;
3139 PlatformInput::ModifiersChanged(modifiers_changed)
3140 }
3141 PlatformInput::ScrollWheel(scroll_wheel) => {
3142 self.window.mouse_position = scroll_wheel.position;
3143 self.window.modifiers = scroll_wheel.modifiers;
3144 PlatformInput::ScrollWheel(scroll_wheel)
3145 }
3146 // Translate dragging and dropping of external files from the operating system
3147 // to internal drag and drop events.
3148 PlatformInput::FileDrop(file_drop) => match file_drop {
3149 FileDropEvent::Entered { position, paths } => {
3150 self.window.mouse_position = position;
3151 if self.active_drag.is_none() {
3152 self.active_drag = Some(AnyDrag {
3153 value: Arc::new(paths.clone()),
3154 view: self.new_view(|_| paths).into(),
3155 cursor_offset: position,
3156 });
3157 }
3158 PlatformInput::MouseMove(MouseMoveEvent {
3159 position,
3160 pressed_button: Some(MouseButton::Left),
3161 modifiers: Modifiers::default(),
3162 })
3163 }
3164 FileDropEvent::Pending { position } => {
3165 self.window.mouse_position = position;
3166 PlatformInput::MouseMove(MouseMoveEvent {
3167 position,
3168 pressed_button: Some(MouseButton::Left),
3169 modifiers: Modifiers::default(),
3170 })
3171 }
3172 FileDropEvent::Submit { position } => {
3173 self.activate(true);
3174 self.window.mouse_position = position;
3175 PlatformInput::MouseUp(MouseUpEvent {
3176 button: MouseButton::Left,
3177 position,
3178 modifiers: Modifiers::default(),
3179 click_count: 1,
3180 })
3181 }
3182 FileDropEvent::Exited => {
3183 self.active_drag.take();
3184 PlatformInput::FileDrop(FileDropEvent::Exited)
3185 }
3186 },
3187 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3188 };
3189
3190 if let Some(any_mouse_event) = event.mouse_event() {
3191 self.dispatch_mouse_event(any_mouse_event);
3192 } else if let Some(any_key_event) = event.keyboard_event() {
3193 self.dispatch_key_event(any_key_event);
3194 }
3195
3196 DispatchEventResult {
3197 propagate: self.app.propagate_event,
3198 default_prevented: self.window.default_prevented,
3199 }
3200 }
3201
3202 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
3203 let hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
3204 if hit_test != self.window.mouse_hit_test {
3205 self.window.mouse_hit_test = hit_test;
3206 self.reset_cursor_style();
3207 }
3208
3209 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
3210
3211 // Capture phase, events bubble from back to front. Handlers for this phase are used for
3212 // special purposes, such as detecting events outside of a given Bounds.
3213 for listener in &mut mouse_listeners {
3214 let listener = listener.as_mut().unwrap();
3215 listener(event, DispatchPhase::Capture, self);
3216 if !self.app.propagate_event {
3217 break;
3218 }
3219 }
3220
3221 // Bubble phase, where most normal handlers do their work.
3222 if self.app.propagate_event {
3223 for listener in mouse_listeners.iter_mut().rev() {
3224 let listener = listener.as_mut().unwrap();
3225 listener(event, DispatchPhase::Bubble, self);
3226 if !self.app.propagate_event {
3227 break;
3228 }
3229 }
3230 }
3231
3232 self.window.rendered_frame.mouse_listeners = mouse_listeners;
3233
3234 if self.has_active_drag() {
3235 if event.is::<MouseMoveEvent>() {
3236 // If this was a mouse move event, redraw the window so that the
3237 // active drag can follow the mouse cursor.
3238 self.refresh();
3239 } else if event.is::<MouseUpEvent>() {
3240 // If this was a mouse up event, cancel the active drag and redraw
3241 // the window.
3242 self.active_drag = None;
3243 self.refresh();
3244 }
3245 }
3246 }
3247
3248 fn dispatch_key_event(&mut self, event: &dyn Any) {
3249 if self.window.dirty.get() {
3250 self.draw();
3251 }
3252
3253 let node_id = self
3254 .window
3255 .focus
3256 .and_then(|focus_id| {
3257 self.window
3258 .rendered_frame
3259 .dispatch_tree
3260 .focusable_node_id(focus_id)
3261 })
3262 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3263
3264 let dispatch_path = self
3265 .window
3266 .rendered_frame
3267 .dispatch_tree
3268 .dispatch_path(node_id);
3269
3270 let mut keystroke: Option<Keystroke> = None;
3271
3272 if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3273 if event.modifiers.number_of_modifiers() == 0
3274 && self.window.pending_modifier.modifiers.number_of_modifiers() == 1
3275 && !self.window.pending_modifier.saw_keystroke
3276 {
3277 let key = match self.window.pending_modifier.modifiers {
3278 modifiers if modifiers.shift => Some("shift"),
3279 modifiers if modifiers.control => Some("control"),
3280 modifiers if modifiers.alt => Some("alt"),
3281 modifiers if modifiers.platform => Some("platform"),
3282 modifiers if modifiers.function => Some("function"),
3283 _ => None,
3284 };
3285 if let Some(key) = key {
3286 keystroke = Some(Keystroke {
3287 key: key.to_string(),
3288 key_char: None,
3289 modifiers: Modifiers::default(),
3290 });
3291 }
3292 }
3293
3294 if self.window.pending_modifier.modifiers.number_of_modifiers() == 0
3295 && event.modifiers.number_of_modifiers() == 1
3296 {
3297 self.window.pending_modifier.saw_keystroke = false
3298 }
3299 self.window.pending_modifier.modifiers = event.modifiers
3300 } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3301 self.window.pending_modifier.saw_keystroke = true;
3302 keystroke = Some(key_down_event.keystroke.clone());
3303 }
3304
3305 let Some(keystroke) = keystroke else {
3306 self.finish_dispatch_key_event(event, dispatch_path);
3307 return;
3308 };
3309
3310 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
3311 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus {
3312 currently_pending = PendingInput::default();
3313 }
3314
3315 let match_result = self.window.rendered_frame.dispatch_tree.dispatch_key(
3316 currently_pending.keystrokes,
3317 keystroke,
3318 &dispatch_path,
3319 );
3320 if !match_result.to_replay.is_empty() {
3321 self.replay_pending_input(match_result.to_replay)
3322 }
3323
3324 if !match_result.pending.is_empty() {
3325 currently_pending.keystrokes = match_result.pending;
3326 currently_pending.focus = self.window.focus;
3327 currently_pending.timer = Some(self.spawn(|mut cx| async move {
3328 cx.background_executor.timer(Duration::from_secs(1)).await;
3329 cx.update(move |cx| {
3330 let Some(currently_pending) = cx
3331 .window
3332 .pending_input
3333 .take()
3334 .filter(|pending| pending.focus == cx.window.focus)
3335 else {
3336 return;
3337 };
3338
3339 let dispatch_path = cx
3340 .window
3341 .rendered_frame
3342 .dispatch_tree
3343 .dispatch_path(node_id);
3344
3345 let to_replay = cx
3346 .window
3347 .rendered_frame
3348 .dispatch_tree
3349 .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3350
3351 cx.replay_pending_input(to_replay)
3352 })
3353 .log_err();
3354 }));
3355 self.window.pending_input = Some(currently_pending);
3356 self.pending_input_changed();
3357 self.propagate_event = false;
3358 return;
3359 }
3360
3361 self.propagate_event = true;
3362 for binding in match_result.bindings {
3363 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3364 if !self.propagate_event {
3365 self.dispatch_keystroke_observers(event, Some(binding.action));
3366 self.pending_input_changed();
3367 return;
3368 }
3369 }
3370
3371 self.finish_dispatch_key_event(event, dispatch_path);
3372 self.pending_input_changed();
3373 }
3374
3375 fn finish_dispatch_key_event(
3376 &mut self,
3377 event: &dyn Any,
3378 dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3379 ) {
3380 self.dispatch_key_down_up_event(event, &dispatch_path);
3381 if !self.propagate_event {
3382 return;
3383 }
3384
3385 self.dispatch_modifiers_changed_event(event, &dispatch_path);
3386 if !self.propagate_event {
3387 return;
3388 }
3389
3390 self.dispatch_keystroke_observers(event, None);
3391 }
3392
3393 fn pending_input_changed(&mut self) {
3394 self.window
3395 .pending_input_observers
3396 .clone()
3397 .retain(&(), |callback| callback(self));
3398 }
3399
3400 fn dispatch_key_down_up_event(
3401 &mut self,
3402 event: &dyn Any,
3403 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3404 ) {
3405 // Capture phase
3406 for node_id in dispatch_path {
3407 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3408
3409 for key_listener in node.key_listeners.clone() {
3410 key_listener(event, DispatchPhase::Capture, self);
3411 if !self.propagate_event {
3412 return;
3413 }
3414 }
3415 }
3416
3417 // Bubble phase
3418 for node_id in dispatch_path.iter().rev() {
3419 // Handle low level key events
3420 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3421 for key_listener in node.key_listeners.clone() {
3422 key_listener(event, DispatchPhase::Bubble, self);
3423 if !self.propagate_event {
3424 return;
3425 }
3426 }
3427 }
3428 }
3429
3430 fn dispatch_modifiers_changed_event(
3431 &mut self,
3432 event: &dyn Any,
3433 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3434 ) {
3435 let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3436 return;
3437 };
3438 for node_id in dispatch_path.iter().rev() {
3439 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3440 for listener in node.modifiers_changed_listeners.clone() {
3441 listener(event, self);
3442 if !self.propagate_event {
3443 return;
3444 }
3445 }
3446 }
3447 }
3448
3449 /// Determine whether a potential multi-stroke key binding is in progress on this window.
3450 pub fn has_pending_keystrokes(&self) -> bool {
3451 self.window.pending_input.is_some()
3452 }
3453
3454 pub(crate) fn clear_pending_keystrokes(&mut self) {
3455 self.window.pending_input.take();
3456 }
3457
3458 /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3459 pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3460 self.window
3461 .pending_input
3462 .as_ref()
3463 .map(|pending_input| pending_input.keystrokes.as_slice())
3464 }
3465
3466 fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>) {
3467 let node_id = self
3468 .window
3469 .focus
3470 .and_then(|focus_id| {
3471 self.window
3472 .rendered_frame
3473 .dispatch_tree
3474 .focusable_node_id(focus_id)
3475 })
3476 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3477
3478 let dispatch_path = self
3479 .window
3480 .rendered_frame
3481 .dispatch_tree
3482 .dispatch_path(node_id);
3483
3484 'replay: for replay in replays {
3485 let event = KeyDownEvent {
3486 keystroke: replay.keystroke.clone(),
3487 is_held: false,
3488 };
3489
3490 self.propagate_event = true;
3491 for binding in replay.bindings {
3492 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3493 if !self.propagate_event {
3494 self.dispatch_keystroke_observers(&event, Some(binding.action));
3495 continue 'replay;
3496 }
3497 }
3498
3499 self.dispatch_key_down_up_event(&event, &dispatch_path);
3500 if !self.propagate_event {
3501 continue 'replay;
3502 }
3503 if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3504 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3505 input_handler.dispatch_input(&input, self);
3506 self.window.platform_window.set_input_handler(input_handler)
3507 }
3508 }
3509 }
3510 }
3511
3512 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
3513 let dispatch_path = self
3514 .window
3515 .rendered_frame
3516 .dispatch_tree
3517 .dispatch_path(node_id);
3518
3519 // Capture phase for global actions.
3520 self.propagate_event = true;
3521 if let Some(mut global_listeners) = self
3522 .global_action_listeners
3523 .remove(&action.as_any().type_id())
3524 {
3525 for listener in &global_listeners {
3526 listener(action.as_any(), DispatchPhase::Capture, self);
3527 if !self.propagate_event {
3528 break;
3529 }
3530 }
3531
3532 global_listeners.extend(
3533 self.global_action_listeners
3534 .remove(&action.as_any().type_id())
3535 .unwrap_or_default(),
3536 );
3537
3538 self.global_action_listeners
3539 .insert(action.as_any().type_id(), global_listeners);
3540 }
3541
3542 if !self.propagate_event {
3543 return;
3544 }
3545
3546 // Capture phase for window actions.
3547 for node_id in &dispatch_path {
3548 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3549 for DispatchActionListener {
3550 action_type,
3551 listener,
3552 } in node.action_listeners.clone()
3553 {
3554 let any_action = action.as_any();
3555 if action_type == any_action.type_id() {
3556 listener(any_action, DispatchPhase::Capture, self);
3557
3558 if !self.propagate_event {
3559 return;
3560 }
3561 }
3562 }
3563 }
3564
3565 // Bubble phase for window actions.
3566 for node_id in dispatch_path.iter().rev() {
3567 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3568 for DispatchActionListener {
3569 action_type,
3570 listener,
3571 } in node.action_listeners.clone()
3572 {
3573 let any_action = action.as_any();
3574 if action_type == any_action.type_id() {
3575 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3576 listener(any_action, DispatchPhase::Bubble, self);
3577
3578 if !self.propagate_event {
3579 return;
3580 }
3581 }
3582 }
3583 }
3584
3585 // Bubble phase for global actions.
3586 if let Some(mut global_listeners) = self
3587 .global_action_listeners
3588 .remove(&action.as_any().type_id())
3589 {
3590 for listener in global_listeners.iter().rev() {
3591 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3592
3593 listener(action.as_any(), DispatchPhase::Bubble, self);
3594 if !self.propagate_event {
3595 break;
3596 }
3597 }
3598
3599 global_listeners.extend(
3600 self.global_action_listeners
3601 .remove(&action.as_any().type_id())
3602 .unwrap_or_default(),
3603 );
3604
3605 self.global_action_listeners
3606 .insert(action.as_any().type_id(), global_listeners);
3607 }
3608 }
3609
3610 /// Register the given handler to be invoked whenever the global of the given type
3611 /// is updated.
3612 pub fn observe_global<G: Global>(
3613 &mut self,
3614 f: impl Fn(&mut WindowContext<'_>) + 'static,
3615 ) -> Subscription {
3616 let window_handle = self.window.handle;
3617 let (subscription, activate) = self.global_observers.insert(
3618 TypeId::of::<G>(),
3619 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
3620 );
3621 self.app.defer(move |_| activate());
3622 subscription
3623 }
3624
3625 /// Focus the current window and bring it to the foreground at the platform level.
3626 pub fn activate_window(&self) {
3627 self.window.platform_window.activate();
3628 }
3629
3630 /// Minimize the current window at the platform level.
3631 pub fn minimize_window(&self) {
3632 self.window.platform_window.minimize();
3633 }
3634
3635 /// Toggle full screen status on the current window at the platform level.
3636 pub fn toggle_fullscreen(&self) {
3637 self.window.platform_window.toggle_fullscreen();
3638 }
3639
3640 /// Updates the IME panel position suggestions for languages like japanese, chinese.
3641 pub fn invalidate_character_coordinates(&self) {
3642 self.on_next_frame(|cx| {
3643 if let Some(mut input_handler) = cx.window.platform_window.take_input_handler() {
3644 if let Some(bounds) = input_handler.selected_bounds(cx) {
3645 cx.window
3646 .platform_window
3647 .update_ime_position(bounds.scale(cx.scale_factor()));
3648 }
3649 cx.window.platform_window.set_input_handler(input_handler);
3650 }
3651 });
3652 }
3653
3654 /// Present a platform dialog.
3655 /// The provided message will be presented, along with buttons for each answer.
3656 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3657 pub fn prompt(
3658 &mut self,
3659 level: PromptLevel,
3660 message: &str,
3661 detail: Option<&str>,
3662 answers: &[&str],
3663 ) -> oneshot::Receiver<usize> {
3664 let prompt_builder = self.app.prompt_builder.take();
3665 let Some(prompt_builder) = prompt_builder else {
3666 unreachable!("Re-entrant window prompting is not supported by GPUI");
3667 };
3668
3669 let receiver = match &prompt_builder {
3670 PromptBuilder::Default => self
3671 .window
3672 .platform_window
3673 .prompt(level, message, detail, answers)
3674 .unwrap_or_else(|| {
3675 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3676 }),
3677 PromptBuilder::Custom(_) => {
3678 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3679 }
3680 };
3681
3682 self.app.prompt_builder = Some(prompt_builder);
3683
3684 receiver
3685 }
3686
3687 fn build_custom_prompt(
3688 &mut self,
3689 prompt_builder: &PromptBuilder,
3690 level: PromptLevel,
3691 message: &str,
3692 detail: Option<&str>,
3693 answers: &[&str],
3694 ) -> oneshot::Receiver<usize> {
3695 let (sender, receiver) = oneshot::channel();
3696 let handle = PromptHandle::new(sender);
3697 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
3698 self.window.prompt = Some(handle);
3699 receiver
3700 }
3701
3702 /// Returns the current context stack.
3703 pub fn context_stack(&self) -> Vec<KeyContext> {
3704 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3705 let node_id = self
3706 .window
3707 .focus
3708 .and_then(|focus_id| dispatch_tree.focusable_node_id(focus_id))
3709 .unwrap_or_else(|| dispatch_tree.root_node_id());
3710
3711 dispatch_tree
3712 .dispatch_path(node_id)
3713 .iter()
3714 .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
3715 .collect()
3716 }
3717
3718 /// Returns all available actions for the focused element.
3719 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
3720 let node_id = self
3721 .window
3722 .focus
3723 .and_then(|focus_id| {
3724 self.window
3725 .rendered_frame
3726 .dispatch_tree
3727 .focusable_node_id(focus_id)
3728 })
3729 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3730
3731 let mut actions = self
3732 .window
3733 .rendered_frame
3734 .dispatch_tree
3735 .available_actions(node_id);
3736 for action_type in self.global_action_listeners.keys() {
3737 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3738 let action = self.actions.build_action_type(action_type).ok();
3739 if let Some(action) = action {
3740 actions.insert(ix, action);
3741 }
3742 }
3743 }
3744 actions
3745 }
3746
3747 /// Returns key bindings that invoke an action on the currently focused element, in precedence
3748 /// order (reverse of the order they were added to the keymap).
3749 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3750 self.window
3751 .rendered_frame
3752 .dispatch_tree
3753 .bindings_for_action(
3754 action,
3755 &self.window.rendered_frame.dispatch_tree.context_stack,
3756 )
3757 }
3758
3759 /// Returns key bindings that invoke the given action on the currently focused element, without
3760 /// checking context. Bindings are returned returned in precedence order (reverse of the order
3761 /// they were added to the keymap).
3762 pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
3763 RefCell::borrow(&self.keymap).all_bindings_for_input(input)
3764 }
3765
3766 /// Returns any bindings that would invoke an action on the given focus handle if it were
3767 /// focused. Bindings are returned returned in precedence order (reverse of the order
3768 /// they were added to the keymap).
3769 pub fn bindings_for_action_in(
3770 &self,
3771 action: &dyn Action,
3772 focus_handle: &FocusHandle,
3773 ) -> Vec<KeyBinding> {
3774 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3775
3776 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
3777 return vec![];
3778 };
3779 let context_stack: Vec<_> = dispatch_tree
3780 .dispatch_path(node_id)
3781 .into_iter()
3782 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
3783 .collect();
3784 dispatch_tree.bindings_for_action(action, &context_stack)
3785 }
3786
3787 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
3788 pub fn listener_for<V: Render, E>(
3789 &self,
3790 view: &View<V>,
3791 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
3792 ) -> impl Fn(&E, &mut WindowContext) + 'static {
3793 let view = view.downgrade();
3794 move |e: &E, cx: &mut WindowContext| {
3795 view.update(cx, |view, cx| f(view, e, cx)).ok();
3796 }
3797 }
3798
3799 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
3800 pub fn handler_for<V: Render>(
3801 &self,
3802 view: &View<V>,
3803 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
3804 ) -> impl Fn(&mut WindowContext) {
3805 let view = view.downgrade();
3806 move |cx: &mut WindowContext| {
3807 view.update(cx, |view, cx| f(view, cx)).ok();
3808 }
3809 }
3810
3811 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
3812 /// If the callback returns false, the window won't be closed.
3813 pub fn on_window_should_close(&self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
3814 let mut this = self.to_async();
3815 self.window
3816 .platform_window
3817 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
3818 }
3819
3820 /// Register an action listener on the window for the next frame. The type of action
3821 /// is determined by the first parameter of the given listener. When the next frame is rendered
3822 /// the listener will be cleared.
3823 ///
3824 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
3825 /// a specific need to register a global listener.
3826 pub fn on_action(
3827 &mut self,
3828 action_type: TypeId,
3829 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
3830 ) {
3831 self.window
3832 .next_frame
3833 .dispatch_tree
3834 .on_action(action_type, Rc::new(listener));
3835 }
3836
3837 /// Read information about the GPU backing this window.
3838 /// Currently returns None on Mac and Windows.
3839 pub fn gpu_specs(&self) -> Option<GpuSpecs> {
3840 self.window.platform_window.gpu_specs()
3841 }
3842}
3843
3844#[cfg(target_os = "windows")]
3845impl WindowContext<'_> {
3846 /// Returns the raw HWND handle for the window.
3847 pub fn get_raw_handle(&self) -> windows::Win32::Foundation::HWND {
3848 self.window.platform_window.get_raw_handle()
3849 }
3850}
3851
3852impl Context for WindowContext<'_> {
3853 type Result<T> = T;
3854
3855 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
3856 where
3857 T: 'static,
3858 {
3859 let slot = self.app.entities.reserve();
3860 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
3861 self.entities.insert(slot, model)
3862 }
3863
3864 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
3865 self.app.reserve_model()
3866 }
3867
3868 fn insert_model<T: 'static>(
3869 &mut self,
3870 reservation: crate::Reservation<T>,
3871 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
3872 ) -> Self::Result<Model<T>> {
3873 self.app.insert_model(reservation, build_model)
3874 }
3875
3876 fn update_model<T: 'static, R>(
3877 &mut self,
3878 model: &Model<T>,
3879 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
3880 ) -> R {
3881 let mut entity = self.entities.lease(model);
3882 let result = update(
3883 &mut *entity,
3884 &mut ModelContext::new(&mut *self.app, model.downgrade()),
3885 );
3886 self.entities.end_lease(entity);
3887 result
3888 }
3889
3890 fn read_model<T, R>(
3891 &self,
3892 handle: &Model<T>,
3893 read: impl FnOnce(&T, &AppContext) -> R,
3894 ) -> Self::Result<R>
3895 where
3896 T: 'static,
3897 {
3898 let entity = self.entities.read(handle);
3899 read(entity, &*self.app)
3900 }
3901
3902 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
3903 where
3904 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
3905 {
3906 if window == self.window.handle {
3907 let root_view = self.window.root_view.clone().unwrap();
3908 Ok(update(root_view, self))
3909 } else {
3910 window.update(self.app, update)
3911 }
3912 }
3913
3914 fn read_window<T, R>(
3915 &self,
3916 window: &WindowHandle<T>,
3917 read: impl FnOnce(View<T>, &AppContext) -> R,
3918 ) -> Result<R>
3919 where
3920 T: 'static,
3921 {
3922 if window.any_handle == self.window.handle {
3923 let root_view = self
3924 .window
3925 .root_view
3926 .clone()
3927 .unwrap()
3928 .downcast::<T>()
3929 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3930 Ok(read(root_view, self))
3931 } else {
3932 self.app.read_window(window, read)
3933 }
3934 }
3935}
3936
3937impl VisualContext for WindowContext<'_> {
3938 fn new_view<V>(
3939 &mut self,
3940 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3941 ) -> Self::Result<View<V>>
3942 where
3943 V: 'static + Render,
3944 {
3945 let slot = self.app.entities.reserve();
3946 let view = View {
3947 model: slot.clone(),
3948 };
3949 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
3950 let entity = build_view_state(&mut cx);
3951 cx.entities.insert(slot, entity);
3952
3953 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
3954 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
3955 cx.new_view_observers.clone().retain(&tid, |observer| {
3956 let any_view = view.clone();
3957 (observer)(any_view, cx);
3958 true
3959 });
3960 }
3961 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
3962
3963 view
3964 }
3965
3966 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
3967 fn update_view<T: 'static, R>(
3968 &mut self,
3969 view: &View<T>,
3970 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
3971 ) -> Self::Result<R> {
3972 let mut lease = self.app.entities.lease(&view.model);
3973 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
3974 let result = update(&mut *lease, &mut cx);
3975 cx.app.entities.end_lease(lease);
3976 result
3977 }
3978
3979 fn replace_root_view<V>(
3980 &mut self,
3981 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3982 ) -> Self::Result<View<V>>
3983 where
3984 V: 'static + Render,
3985 {
3986 let view = self.new_view(build_view);
3987 self.window.root_view = Some(view.clone().into());
3988 self.refresh();
3989 view
3990 }
3991
3992 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
3993 self.update_view(view, |view, cx| {
3994 view.focus_handle(cx).clone().focus(cx);
3995 })
3996 }
3997
3998 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
3999 where
4000 V: ManagedView,
4001 {
4002 self.update_view(view, |_, cx| cx.emit(DismissEvent))
4003 }
4004}
4005
4006impl<'a> std::ops::Deref for WindowContext<'a> {
4007 type Target = AppContext;
4008
4009 fn deref(&self) -> &Self::Target {
4010 self.app
4011 }
4012}
4013
4014impl<'a> std::ops::DerefMut for WindowContext<'a> {
4015 fn deref_mut(&mut self) -> &mut Self::Target {
4016 self.app
4017 }
4018}
4019
4020impl<'a> Borrow<AppContext> for WindowContext<'a> {
4021 fn borrow(&self) -> &AppContext {
4022 self.app
4023 }
4024}
4025
4026impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
4027 fn borrow_mut(&mut self) -> &mut AppContext {
4028 self.app
4029 }
4030}
4031
4032/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
4033pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
4034 #[doc(hidden)]
4035 fn app_mut(&mut self) -> &mut AppContext {
4036 self.borrow_mut()
4037 }
4038
4039 #[doc(hidden)]
4040 fn app(&self) -> &AppContext {
4041 self.borrow()
4042 }
4043
4044 #[doc(hidden)]
4045 fn window(&self) -> &Window {
4046 self.borrow()
4047 }
4048
4049 #[doc(hidden)]
4050 fn window_mut(&mut self) -> &mut Window {
4051 self.borrow_mut()
4052 }
4053}
4054
4055impl Borrow<Window> for WindowContext<'_> {
4056 fn borrow(&self) -> &Window {
4057 self.window
4058 }
4059}
4060
4061impl BorrowMut<Window> for WindowContext<'_> {
4062 fn borrow_mut(&mut self) -> &mut Window {
4063 self.window
4064 }
4065}
4066
4067impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
4068
4069/// Provides access to application state that is specialized for a particular [`View`].
4070/// Allows you to interact with focus, emit events, etc.
4071/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
4072/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
4073pub struct ViewContext<'a, V> {
4074 window_cx: WindowContext<'a>,
4075 view: &'a View<V>,
4076}
4077
4078impl<V> Borrow<AppContext> for ViewContext<'_, V> {
4079 fn borrow(&self) -> &AppContext {
4080 &*self.window_cx.app
4081 }
4082}
4083
4084impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
4085 fn borrow_mut(&mut self) -> &mut AppContext {
4086 &mut *self.window_cx.app
4087 }
4088}
4089
4090impl<V> Borrow<Window> for ViewContext<'_, V> {
4091 fn borrow(&self) -> &Window {
4092 &*self.window_cx.window
4093 }
4094}
4095
4096impl<V> BorrowMut<Window> for ViewContext<'_, V> {
4097 fn borrow_mut(&mut self) -> &mut Window {
4098 &mut *self.window_cx.window
4099 }
4100}
4101
4102impl<'a, V: 'static> ViewContext<'a, V> {
4103 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
4104 Self {
4105 window_cx: WindowContext::new(app, window),
4106 view,
4107 }
4108 }
4109
4110 /// Get the entity_id of this view.
4111 pub fn entity_id(&self) -> EntityId {
4112 self.view.entity_id()
4113 }
4114
4115 /// Get the view pointer underlying this context.
4116 pub fn view(&self) -> &View<V> {
4117 self.view
4118 }
4119
4120 /// Get the model underlying this view.
4121 pub fn model(&self) -> &Model<V> {
4122 &self.view.model
4123 }
4124
4125 /// Access the underlying window context.
4126 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
4127 &mut self.window_cx
4128 }
4129
4130 /// Sets a given callback to be run on the next frame.
4131 pub fn on_next_frame(&self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
4132 where
4133 V: 'static,
4134 {
4135 let view = self.view().clone();
4136 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
4137 }
4138
4139 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
4140 /// that are currently on the stack to be returned to the app.
4141 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
4142 let view = self.view().downgrade();
4143 self.window_cx.defer(move |cx| {
4144 view.update(cx, f).ok();
4145 });
4146 }
4147
4148 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
4149 pub fn observe<V2, E>(
4150 &mut self,
4151 entity: &E,
4152 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
4153 ) -> Subscription
4154 where
4155 V2: 'static,
4156 V: 'static,
4157 E: Entity<V2>,
4158 {
4159 let view = self.view().downgrade();
4160 let entity_id = entity.entity_id();
4161 let entity = entity.downgrade();
4162 let window_handle = self.window.handle;
4163 self.app.new_observer(
4164 entity_id,
4165 Box::new(move |cx| {
4166 window_handle
4167 .update(cx, |_, cx| {
4168 if let Some(handle) = E::upgrade_from(&entity) {
4169 view.update(cx, |this, cx| on_notify(this, handle, cx))
4170 .is_ok()
4171 } else {
4172 false
4173 }
4174 })
4175 .unwrap_or(false)
4176 }),
4177 )
4178 }
4179
4180 /// Subscribe to events emitted by another model or view.
4181 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
4182 /// 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.
4183 pub fn subscribe<V2, E, Evt>(
4184 &mut self,
4185 entity: &E,
4186 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
4187 ) -> Subscription
4188 where
4189 V2: EventEmitter<Evt>,
4190 E: Entity<V2>,
4191 Evt: 'static,
4192 {
4193 let view = self.view().downgrade();
4194 let entity_id = entity.entity_id();
4195 let handle = entity.downgrade();
4196 let window_handle = self.window.handle;
4197 self.app.new_subscription(
4198 entity_id,
4199 (
4200 TypeId::of::<Evt>(),
4201 Box::new(move |event, cx| {
4202 window_handle
4203 .update(cx, |_, cx| {
4204 if let Some(handle) = E::upgrade_from(&handle) {
4205 let event = event.downcast_ref().expect("invalid event type");
4206 view.update(cx, |this, cx| on_event(this, handle, event, cx))
4207 .is_ok()
4208 } else {
4209 false
4210 }
4211 })
4212 .unwrap_or(false)
4213 }),
4214 ),
4215 )
4216 }
4217
4218 /// Register a callback to be invoked when the view is released.
4219 ///
4220 /// The callback receives a handle to the view's window. This handle may be
4221 /// invalid, if the window was closed before the view was released.
4222 pub fn on_release(
4223 &self,
4224 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
4225 ) -> Subscription {
4226 let window_handle = self.window.handle;
4227 let (subscription, activate) = self.app.release_listeners.insert(
4228 self.view.model.entity_id,
4229 Box::new(move |this, cx| {
4230 let this = this.downcast_mut().expect("invalid entity type");
4231 on_release(this, window_handle, cx)
4232 }),
4233 );
4234 activate();
4235 subscription
4236 }
4237
4238 /// Register a callback to be invoked when the given Model or View is released.
4239 pub fn observe_release<V2, E>(
4240 &self,
4241 entity: &E,
4242 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
4243 ) -> Subscription
4244 where
4245 V: 'static,
4246 V2: 'static,
4247 E: Entity<V2>,
4248 {
4249 let view = self.view().downgrade();
4250 let entity_id = entity.entity_id();
4251 let window_handle = self.window.handle;
4252 let (subscription, activate) = self.app.release_listeners.insert(
4253 entity_id,
4254 Box::new(move |entity, cx| {
4255 let entity = entity.downcast_mut().expect("invalid entity type");
4256 let _ = window_handle.update(cx, |_, cx| {
4257 view.update(cx, |this, cx| on_release(this, entity, cx))
4258 });
4259 }),
4260 );
4261 activate();
4262 subscription
4263 }
4264
4265 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
4266 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
4267 pub fn notify(&mut self) {
4268 self.window_cx.notify(Some(self.view.entity_id()));
4269 }
4270
4271 /// Register a callback to be invoked when the window is resized.
4272 pub fn observe_window_bounds(
4273 &self,
4274 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4275 ) -> Subscription {
4276 let view = self.view.downgrade();
4277 let (subscription, activate) = self.window.bounds_observers.insert(
4278 (),
4279 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4280 );
4281 activate();
4282 subscription
4283 }
4284
4285 /// Register a callback to be invoked when the window is activated or deactivated.
4286 pub fn observe_window_activation(
4287 &self,
4288 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4289 ) -> Subscription {
4290 let view = self.view.downgrade();
4291 let (subscription, activate) = self.window.activation_observers.insert(
4292 (),
4293 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4294 );
4295 activate();
4296 subscription
4297 }
4298
4299 /// Registers a callback to be invoked when the window appearance changes.
4300 pub fn observe_window_appearance(
4301 &self,
4302 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4303 ) -> Subscription {
4304 let view = self.view.downgrade();
4305 let (subscription, activate) = self.window.appearance_observers.insert(
4306 (),
4307 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4308 );
4309 activate();
4310 subscription
4311 }
4312
4313 /// Register a callback to be invoked when a keystroke is received by the application
4314 /// in any window. Note that this fires after all other action and event mechanisms have resolved
4315 /// and that this API will not be invoked if the event's propagation is stopped.
4316 pub fn observe_keystrokes(
4317 &mut self,
4318 mut f: impl FnMut(&mut V, &KeystrokeEvent, &mut ViewContext<V>) + 'static,
4319 ) -> Subscription {
4320 fn inner(
4321 keystroke_observers: &SubscriberSet<(), KeystrokeObserver>,
4322 handler: KeystrokeObserver,
4323 ) -> Subscription {
4324 let (subscription, activate) = keystroke_observers.insert((), handler);
4325 activate();
4326 subscription
4327 }
4328
4329 let view = self.view.downgrade();
4330 inner(
4331 &mut self.keystroke_observers,
4332 Box::new(move |event, cx| {
4333 if let Some(view) = view.upgrade() {
4334 view.update(cx, |view, cx| f(view, event, cx));
4335 true
4336 } else {
4337 false
4338 }
4339 }),
4340 )
4341 }
4342
4343 /// Register a callback to be invoked when the window's pending input changes.
4344 pub fn observe_pending_input(
4345 &self,
4346 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4347 ) -> Subscription {
4348 let view = self.view.downgrade();
4349 let (subscription, activate) = self.window.pending_input_observers.insert(
4350 (),
4351 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4352 );
4353 activate();
4354 subscription
4355 }
4356
4357 /// Register a listener to be called when the given focus handle receives focus.
4358 /// Returns a subscription and persists until the subscription is dropped.
4359 pub fn on_focus(
4360 &mut self,
4361 handle: &FocusHandle,
4362 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4363 ) -> Subscription {
4364 let view = self.view.downgrade();
4365 let focus_id = handle.id;
4366 let (subscription, activate) =
4367 self.window.new_focus_listener(Box::new(move |event, cx| {
4368 view.update(cx, |view, cx| {
4369 if event.previous_focus_path.last() != Some(&focus_id)
4370 && event.current_focus_path.last() == Some(&focus_id)
4371 {
4372 listener(view, cx)
4373 }
4374 })
4375 .is_ok()
4376 }));
4377 self.app.defer(|_| activate());
4378 subscription
4379 }
4380
4381 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
4382 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
4383 /// Returns a subscription and persists until the subscription is dropped.
4384 pub fn on_focus_in(
4385 &mut self,
4386 handle: &FocusHandle,
4387 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4388 ) -> Subscription {
4389 let view = self.view.downgrade();
4390 let focus_id = handle.id;
4391 let (subscription, activate) =
4392 self.window.new_focus_listener(Box::new(move |event, cx| {
4393 view.update(cx, |view, cx| {
4394 if event.is_focus_in(focus_id) {
4395 listener(view, cx)
4396 }
4397 })
4398 .is_ok()
4399 }));
4400 self.app.defer(move |_| activate());
4401 subscription
4402 }
4403
4404 /// Register a listener to be called when the given focus handle loses focus.
4405 /// Returns a subscription and persists until the subscription is dropped.
4406 pub fn on_blur(
4407 &mut self,
4408 handle: &FocusHandle,
4409 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4410 ) -> Subscription {
4411 let view = self.view.downgrade();
4412 let focus_id = handle.id;
4413 let (subscription, activate) =
4414 self.window.new_focus_listener(Box::new(move |event, cx| {
4415 view.update(cx, |view, cx| {
4416 if event.previous_focus_path.last() == Some(&focus_id)
4417 && event.current_focus_path.last() != Some(&focus_id)
4418 {
4419 listener(view, cx)
4420 }
4421 })
4422 .is_ok()
4423 }));
4424 self.app.defer(move |_| activate());
4425 subscription
4426 }
4427
4428 /// Register a listener to be called when nothing in the window has focus.
4429 /// This typically happens when the node that was focused is removed from the tree,
4430 /// and this callback lets you chose a default place to restore the users focus.
4431 /// Returns a subscription and persists until the subscription is dropped.
4432 pub fn on_focus_lost(
4433 &self,
4434 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4435 ) -> Subscription {
4436 let view = self.view.downgrade();
4437 let (subscription, activate) = self.window.focus_lost_listeners.insert(
4438 (),
4439 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
4440 );
4441 activate();
4442 subscription
4443 }
4444
4445 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
4446 /// Returns a subscription and persists until the subscription is dropped.
4447 pub fn on_focus_out(
4448 &mut self,
4449 handle: &FocusHandle,
4450 mut listener: impl FnMut(&mut V, FocusOutEvent, &mut ViewContext<V>) + 'static,
4451 ) -> Subscription {
4452 let view = self.view.downgrade();
4453 let focus_id = handle.id;
4454 let (subscription, activate) =
4455 self.window.new_focus_listener(Box::new(move |event, cx| {
4456 view.update(cx, |view, cx| {
4457 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
4458 if event.is_focus_out(focus_id) {
4459 let event = FocusOutEvent {
4460 blurred: WeakFocusHandle {
4461 id: blurred_id,
4462 handles: Arc::downgrade(&cx.app.focus_handles),
4463 },
4464 };
4465 listener(view, event, cx)
4466 }
4467 }
4468 })
4469 .is_ok()
4470 }));
4471 self.app.defer(move |_| activate());
4472 subscription
4473 }
4474
4475 /// Schedule a future to be run asynchronously.
4476 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
4477 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
4478 /// The returned future will be polled on the main thread.
4479 pub fn spawn<Fut, R>(&self, f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut) -> Task<R>
4480 where
4481 R: 'static,
4482 Fut: Future<Output = R> + 'static,
4483 {
4484 let view = self.view().downgrade();
4485 self.window_cx.spawn(|cx| f(view, cx))
4486 }
4487
4488 /// Register a callback to be invoked when the given global state changes.
4489 pub fn observe_global<G: Global>(
4490 &mut self,
4491 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
4492 ) -> Subscription {
4493 let window_handle = self.window.handle;
4494 let view = self.view().downgrade();
4495 let (subscription, activate) = self.global_observers.insert(
4496 TypeId::of::<G>(),
4497 Box::new(move |cx| {
4498 window_handle
4499 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
4500 .unwrap_or(false)
4501 }),
4502 );
4503 self.app.defer(move |_| activate());
4504 subscription
4505 }
4506
4507 /// Register a callback to be invoked when the given Action type is dispatched to the window.
4508 pub fn on_action(
4509 &mut self,
4510 action_type: TypeId,
4511 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
4512 ) {
4513 let handle = self.view().clone();
4514 self.window_cx
4515 .on_action(action_type, move |action, phase, cx| {
4516 handle.update(cx, |view, cx| {
4517 listener(view, action, phase, cx);
4518 })
4519 });
4520 }
4521
4522 /// Emit an event to be handled by any other views that have subscribed via [ViewContext::subscribe].
4523 pub fn emit<Evt>(&mut self, event: Evt)
4524 where
4525 Evt: 'static,
4526 V: EventEmitter<Evt>,
4527 {
4528 let emitter = self.view.model.entity_id;
4529 self.app.push_effect(Effect::Emit {
4530 emitter,
4531 event_type: TypeId::of::<Evt>(),
4532 event: Box::new(event),
4533 });
4534 }
4535
4536 /// Move focus to the current view, assuming it implements [`FocusableView`].
4537 pub fn focus_self(&mut self)
4538 where
4539 V: FocusableView,
4540 {
4541 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
4542 }
4543
4544 /// Convenience method for accessing view state in an event callback.
4545 ///
4546 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
4547 /// but it's often useful to be able to access view state in these
4548 /// callbacks. This method provides a convenient way to do so.
4549 pub fn listener<E: ?Sized>(
4550 &self,
4551 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
4552 ) -> impl Fn(&E, &mut WindowContext) + 'static {
4553 let view = self.view().downgrade();
4554 move |e: &E, cx: &mut WindowContext| {
4555 view.update(cx, |view, cx| f(view, e, cx)).ok();
4556 }
4557 }
4558}
4559
4560impl<V> Context for ViewContext<'_, V> {
4561 type Result<U> = U;
4562
4563 fn new_model<T: 'static>(
4564 &mut self,
4565 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4566 ) -> Model<T> {
4567 self.window_cx.new_model(build_model)
4568 }
4569
4570 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
4571 self.window_cx.reserve_model()
4572 }
4573
4574 fn insert_model<T: 'static>(
4575 &mut self,
4576 reservation: crate::Reservation<T>,
4577 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4578 ) -> Self::Result<Model<T>> {
4579 self.window_cx.insert_model(reservation, build_model)
4580 }
4581
4582 fn update_model<T: 'static, R>(
4583 &mut self,
4584 model: &Model<T>,
4585 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
4586 ) -> R {
4587 self.window_cx.update_model(model, update)
4588 }
4589
4590 fn read_model<T, R>(
4591 &self,
4592 handle: &Model<T>,
4593 read: impl FnOnce(&T, &AppContext) -> R,
4594 ) -> Self::Result<R>
4595 where
4596 T: 'static,
4597 {
4598 self.window_cx.read_model(handle, read)
4599 }
4600
4601 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
4602 where
4603 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
4604 {
4605 self.window_cx.update_window(window, update)
4606 }
4607
4608 fn read_window<T, R>(
4609 &self,
4610 window: &WindowHandle<T>,
4611 read: impl FnOnce(View<T>, &AppContext) -> R,
4612 ) -> Result<R>
4613 where
4614 T: 'static,
4615 {
4616 self.window_cx.read_window(window, read)
4617 }
4618}
4619
4620impl<V: 'static> VisualContext for ViewContext<'_, V> {
4621 fn new_view<W: Render + 'static>(
4622 &mut self,
4623 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4624 ) -> Self::Result<View<W>> {
4625 self.window_cx.new_view(build_view_state)
4626 }
4627
4628 fn update_view<V2: 'static, R>(
4629 &mut self,
4630 view: &View<V2>,
4631 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
4632 ) -> Self::Result<R> {
4633 self.window_cx.update_view(view, update)
4634 }
4635
4636 fn replace_root_view<W>(
4637 &mut self,
4638 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4639 ) -> Self::Result<View<W>>
4640 where
4641 W: 'static + Render,
4642 {
4643 self.window_cx.replace_root_view(build_view)
4644 }
4645
4646 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
4647 self.window_cx.focus_view(view)
4648 }
4649
4650 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
4651 self.window_cx.dismiss_view(view)
4652 }
4653}
4654
4655impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
4656 type Target = WindowContext<'a>;
4657
4658 fn deref(&self) -> &Self::Target {
4659 &self.window_cx
4660 }
4661}
4662
4663impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
4664 fn deref_mut(&mut self) -> &mut Self::Target {
4665 &mut self.window_cx
4666 }
4667}
4668
4669// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4670slotmap::new_key_type! {
4671 /// A unique identifier for a window.
4672 pub struct WindowId;
4673}
4674
4675impl WindowId {
4676 /// Converts this window ID to a `u64`.
4677 pub fn as_u64(&self) -> u64 {
4678 self.0.as_ffi()
4679 }
4680}
4681
4682impl From<u64> for WindowId {
4683 fn from(value: u64) -> Self {
4684 WindowId(slotmap::KeyData::from_ffi(value))
4685 }
4686}
4687
4688/// A handle to a window with a specific root view type.
4689/// Note that this does not keep the window alive on its own.
4690#[derive(Deref, DerefMut)]
4691pub struct WindowHandle<V> {
4692 #[deref]
4693 #[deref_mut]
4694 pub(crate) any_handle: AnyWindowHandle,
4695 state_type: PhantomData<V>,
4696}
4697
4698impl<V: 'static + Render> WindowHandle<V> {
4699 /// Creates a new handle from a window ID.
4700 /// This does not check if the root type of the window is `V`.
4701 pub fn new(id: WindowId) -> Self {
4702 WindowHandle {
4703 any_handle: AnyWindowHandle {
4704 id,
4705 state_type: TypeId::of::<V>(),
4706 },
4707 state_type: PhantomData,
4708 }
4709 }
4710
4711 /// Get the root view out of this window.
4712 ///
4713 /// This will fail if the window is closed or if the root view's type does not match `V`.
4714 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
4715 where
4716 C: Context,
4717 {
4718 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
4719 root_view
4720 .downcast::<V>()
4721 .map_err(|_| anyhow!("the type of the window's root view has changed"))
4722 }))
4723 }
4724
4725 /// Updates the root view of this window.
4726 ///
4727 /// This will fail if the window has been closed or if the root view's type does not match
4728 pub fn update<C, R>(
4729 &self,
4730 cx: &mut C,
4731 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
4732 ) -> Result<R>
4733 where
4734 C: Context,
4735 {
4736 cx.update_window(self.any_handle, |root_view, cx| {
4737 let view = root_view
4738 .downcast::<V>()
4739 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4740 Ok(cx.update_view(&view, update))
4741 })?
4742 }
4743
4744 /// Read the root view out of this window.
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<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
4748 let x = cx
4749 .windows
4750 .get(self.id)
4751 .and_then(|window| {
4752 window
4753 .as_ref()
4754 .and_then(|window| window.root_view.clone())
4755 .map(|root_view| root_view.downcast::<V>())
4756 })
4757 .ok_or_else(|| anyhow!("window not found"))?
4758 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4759
4760 Ok(x.read(cx))
4761 }
4762
4763 /// Read the root view out of this window, with a callback
4764 ///
4765 /// This will fail if the window is closed or if the root view's type does not match `V`.
4766 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
4767 where
4768 C: Context,
4769 {
4770 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4771 }
4772
4773 /// Read the root view pointer off of this window.
4774 ///
4775 /// This will fail if the window is closed or if the root view's type does not match `V`.
4776 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
4777 where
4778 C: Context,
4779 {
4780 cx.read_window(self, |root_view, _cx| root_view.clone())
4781 }
4782
4783 /// Check if this window is 'active'.
4784 ///
4785 /// Will return `None` if the window is closed or currently
4786 /// borrowed.
4787 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
4788 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
4789 .ok()
4790 }
4791}
4792
4793impl<V> Copy for WindowHandle<V> {}
4794
4795impl<V> Clone for WindowHandle<V> {
4796 fn clone(&self) -> Self {
4797 *self
4798 }
4799}
4800
4801impl<V> PartialEq for WindowHandle<V> {
4802 fn eq(&self, other: &Self) -> bool {
4803 self.any_handle == other.any_handle
4804 }
4805}
4806
4807impl<V> Eq for WindowHandle<V> {}
4808
4809impl<V> Hash for WindowHandle<V> {
4810 fn hash<H: Hasher>(&self, state: &mut H) {
4811 self.any_handle.hash(state);
4812 }
4813}
4814
4815impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4816 fn from(val: WindowHandle<V>) -> Self {
4817 val.any_handle
4818 }
4819}
4820
4821unsafe impl<V> Send for WindowHandle<V> {}
4822unsafe impl<V> Sync for WindowHandle<V> {}
4823
4824/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4825#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4826pub struct AnyWindowHandle {
4827 pub(crate) id: WindowId,
4828 state_type: TypeId,
4829}
4830
4831impl AnyWindowHandle {
4832 /// Get the ID of this window.
4833 pub fn window_id(&self) -> WindowId {
4834 self.id
4835 }
4836
4837 /// Attempt to convert this handle to a window handle with a specific root view type.
4838 /// If the types do not match, this will return `None`.
4839 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4840 if TypeId::of::<T>() == self.state_type {
4841 Some(WindowHandle {
4842 any_handle: *self,
4843 state_type: PhantomData,
4844 })
4845 } else {
4846 None
4847 }
4848 }
4849
4850 /// Updates the state of the root view of this window.
4851 ///
4852 /// This will fail if the window has been closed.
4853 pub fn update<C, R>(
4854 self,
4855 cx: &mut C,
4856 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
4857 ) -> Result<R>
4858 where
4859 C: Context,
4860 {
4861 cx.update_window(self, update)
4862 }
4863
4864 /// Read the state of the root view of this window.
4865 ///
4866 /// This will fail if the window has been closed.
4867 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
4868 where
4869 C: Context,
4870 T: 'static,
4871 {
4872 let view = self
4873 .downcast::<T>()
4874 .context("the type of the window's root view has changed")?;
4875
4876 cx.read_window(&view, read)
4877 }
4878}
4879
4880/// An identifier for an [`Element`](crate::Element).
4881///
4882/// Can be constructed with a string, a number, or both, as well
4883/// as other internal representations.
4884#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4885pub enum ElementId {
4886 /// The ID of a View element
4887 View(EntityId),
4888 /// An integer ID.
4889 Integer(usize),
4890 /// A string based ID.
4891 Name(SharedString),
4892 /// A UUID.
4893 Uuid(Uuid),
4894 /// An ID that's equated with a focus handle.
4895 FocusHandle(FocusId),
4896 /// A combination of a name and an integer.
4897 NamedInteger(SharedString, usize),
4898 /// A path
4899 Path(Arc<std::path::Path>),
4900}
4901
4902impl Display for ElementId {
4903 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4904 match self {
4905 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4906 ElementId::Integer(ix) => write!(f, "{}", ix)?,
4907 ElementId::Name(name) => write!(f, "{}", name)?,
4908 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4909 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4910 ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4911 ElementId::Path(path) => write!(f, "{}", path.display())?,
4912 }
4913
4914 Ok(())
4915 }
4916}
4917
4918impl TryInto<SharedString> for ElementId {
4919 type Error = anyhow::Error;
4920
4921 fn try_into(self) -> anyhow::Result<SharedString> {
4922 if let ElementId::Name(name) = self {
4923 Ok(name)
4924 } else {
4925 Err(anyhow!("element id is not string"))
4926 }
4927 }
4928}
4929
4930impl From<usize> for ElementId {
4931 fn from(id: usize) -> Self {
4932 ElementId::Integer(id)
4933 }
4934}
4935
4936impl From<i32> for ElementId {
4937 fn from(id: i32) -> Self {
4938 Self::Integer(id as usize)
4939 }
4940}
4941
4942impl From<SharedString> for ElementId {
4943 fn from(name: SharedString) -> Self {
4944 ElementId::Name(name)
4945 }
4946}
4947
4948impl From<Arc<std::path::Path>> for ElementId {
4949 fn from(path: Arc<std::path::Path>) -> Self {
4950 ElementId::Path(path)
4951 }
4952}
4953
4954impl From<&'static str> for ElementId {
4955 fn from(name: &'static str) -> Self {
4956 ElementId::Name(name.into())
4957 }
4958}
4959
4960impl<'a> From<&'a FocusHandle> for ElementId {
4961 fn from(handle: &'a FocusHandle) -> Self {
4962 ElementId::FocusHandle(handle.id)
4963 }
4964}
4965
4966impl From<(&'static str, EntityId)> for ElementId {
4967 fn from((name, id): (&'static str, EntityId)) -> Self {
4968 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
4969 }
4970}
4971
4972impl From<(&'static str, usize)> for ElementId {
4973 fn from((name, id): (&'static str, usize)) -> Self {
4974 ElementId::NamedInteger(name.into(), id)
4975 }
4976}
4977
4978impl From<(SharedString, usize)> for ElementId {
4979 fn from((name, id): (SharedString, usize)) -> Self {
4980 ElementId::NamedInteger(name, id)
4981 }
4982}
4983
4984impl From<(&'static str, u64)> for ElementId {
4985 fn from((name, id): (&'static str, u64)) -> Self {
4986 ElementId::NamedInteger(name.into(), id as usize)
4987 }
4988}
4989
4990impl From<Uuid> for ElementId {
4991 fn from(value: Uuid) -> Self {
4992 Self::Uuid(value)
4993 }
4994}
4995
4996impl From<(&'static str, u32)> for ElementId {
4997 fn from((name, id): (&'static str, u32)) -> Self {
4998 ElementId::NamedInteger(name.into(), id as usize)
4999 }
5000}
5001
5002/// A rectangle to be rendered in the window at the given position and size.
5003/// Passed as an argument [`WindowContext::paint_quad`].
5004#[derive(Clone)]
5005pub struct PaintQuad {
5006 /// The bounds of the quad within the window.
5007 pub bounds: Bounds<Pixels>,
5008 /// The radii of the quad's corners.
5009 pub corner_radii: Corners<Pixels>,
5010 /// The background color of the quad.
5011 pub background: Background,
5012 /// The widths of the quad's borders.
5013 pub border_widths: Edges<Pixels>,
5014 /// The color of the quad's borders.
5015 pub border_color: Hsla,
5016}
5017
5018impl PaintQuad {
5019 /// Sets the corner radii of the quad.
5020 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
5021 PaintQuad {
5022 corner_radii: corner_radii.into(),
5023 ..self
5024 }
5025 }
5026
5027 /// Sets the border widths of the quad.
5028 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5029 PaintQuad {
5030 border_widths: border_widths.into(),
5031 ..self
5032 }
5033 }
5034
5035 /// Sets the border color of the quad.
5036 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5037 PaintQuad {
5038 border_color: border_color.into(),
5039 ..self
5040 }
5041 }
5042
5043 /// Sets the background color of the quad.
5044 pub fn background(self, background: impl Into<Background>) -> Self {
5045 PaintQuad {
5046 background: background.into(),
5047 ..self
5048 }
5049 }
5050}
5051
5052/// Creates a quad with the given parameters.
5053pub fn quad(
5054 bounds: Bounds<Pixels>,
5055 corner_radii: impl Into<Corners<Pixels>>,
5056 background: impl Into<Background>,
5057 border_widths: impl Into<Edges<Pixels>>,
5058 border_color: impl Into<Hsla>,
5059) -> PaintQuad {
5060 PaintQuad {
5061 bounds,
5062 corner_radii: corner_radii.into(),
5063 background: background.into(),
5064 border_widths: border_widths.into(),
5065 border_color: border_color.into(),
5066 }
5067}
5068
5069/// Creates a filled quad with the given bounds and background color.
5070pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5071 PaintQuad {
5072 bounds: bounds.into(),
5073 corner_radii: (0.).into(),
5074 background: background.into(),
5075 border_widths: (0.).into(),
5076 border_color: transparent_black(),
5077 }
5078}
5079
5080/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5081pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
5082 PaintQuad {
5083 bounds: bounds.into(),
5084 corner_radii: (0.).into(),
5085 background: transparent_black().into(),
5086 border_widths: (1.).into(),
5087 border_color: border_color.into(),
5088 }
5089}