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 let tooltip_request = self.window.next_frame.tooltip_requests.last().cloned()?;
1554 let tooltip_request = tooltip_request.unwrap();
1555 let mut element = tooltip_request.tooltip.view.clone().into_any();
1556 let mouse_position = tooltip_request.tooltip.mouse_position;
1557 let tooltip_size = element.layout_as_root(AvailableSpace::min_size(), self);
1558
1559 let mut tooltip_bounds = Bounds::new(mouse_position + point(px(1.), px(1.)), tooltip_size);
1560 let window_bounds = Bounds {
1561 origin: Point::default(),
1562 size: self.viewport_size(),
1563 };
1564
1565 if tooltip_bounds.right() > window_bounds.right() {
1566 let new_x = mouse_position.x - tooltip_bounds.size.width - px(1.);
1567 if new_x >= Pixels::ZERO {
1568 tooltip_bounds.origin.x = new_x;
1569 } else {
1570 tooltip_bounds.origin.x = cmp::max(
1571 Pixels::ZERO,
1572 tooltip_bounds.origin.x - tooltip_bounds.right() - window_bounds.right(),
1573 );
1574 }
1575 }
1576
1577 if tooltip_bounds.bottom() > window_bounds.bottom() {
1578 let new_y = mouse_position.y - tooltip_bounds.size.height - px(1.);
1579 if new_y >= Pixels::ZERO {
1580 tooltip_bounds.origin.y = new_y;
1581 } else {
1582 tooltip_bounds.origin.y = cmp::max(
1583 Pixels::ZERO,
1584 tooltip_bounds.origin.y - tooltip_bounds.bottom() - window_bounds.bottom(),
1585 );
1586 }
1587 }
1588
1589 // Element's parent can get hidden (e.g. via the `visible_on_hover` method),
1590 // and element's `paint` won't be called (ergo, mouse listeners also won't be active) to detect that the tooltip has to be removed.
1591 // Ensure it's not stuck around in such cases.
1592 let invalidate_tooltip = !tooltip_request
1593 .tooltip
1594 .origin_bounds
1595 .contains(&self.mouse_position())
1596 && (!tooltip_request.tooltip.hoverable
1597 || !tooltip_bounds.contains(&self.mouse_position()));
1598 if invalidate_tooltip {
1599 return None;
1600 }
1601
1602 self.with_absolute_element_offset(tooltip_bounds.origin, |cx| element.prepaint(cx));
1603
1604 self.window.tooltip_bounds = Some(TooltipBounds {
1605 id: tooltip_request.id,
1606 bounds: tooltip_bounds,
1607 });
1608 Some(element)
1609 }
1610
1611 fn prepaint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1612 assert_eq!(self.window.element_id_stack.len(), 0);
1613
1614 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1615 for deferred_draw_ix in deferred_draw_indices {
1616 let deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1617 self.window
1618 .element_id_stack
1619 .clone_from(&deferred_draw.element_id_stack);
1620 self.window
1621 .text_style_stack
1622 .clone_from(&deferred_draw.text_style_stack);
1623 self.window
1624 .next_frame
1625 .dispatch_tree
1626 .set_active_node(deferred_draw.parent_node);
1627
1628 let prepaint_start = self.prepaint_index();
1629 if let Some(element) = deferred_draw.element.as_mut() {
1630 self.with_absolute_element_offset(deferred_draw.absolute_offset, |cx| {
1631 element.prepaint(cx)
1632 });
1633 } else {
1634 self.reuse_prepaint(deferred_draw.prepaint_range.clone());
1635 }
1636 let prepaint_end = self.prepaint_index();
1637 deferred_draw.prepaint_range = prepaint_start..prepaint_end;
1638 }
1639 assert_eq!(
1640 self.window.next_frame.deferred_draws.len(),
1641 0,
1642 "cannot call defer_draw during deferred drawing"
1643 );
1644 self.window.next_frame.deferred_draws = deferred_draws;
1645 self.window.element_id_stack.clear();
1646 self.window.text_style_stack.clear();
1647 }
1648
1649 fn paint_deferred_draws(&mut self, deferred_draw_indices: &[usize]) {
1650 assert_eq!(self.window.element_id_stack.len(), 0);
1651
1652 let mut deferred_draws = mem::take(&mut self.window.next_frame.deferred_draws);
1653 for deferred_draw_ix in deferred_draw_indices {
1654 let mut deferred_draw = &mut deferred_draws[*deferred_draw_ix];
1655 self.window
1656 .element_id_stack
1657 .clone_from(&deferred_draw.element_id_stack);
1658 self.window
1659 .next_frame
1660 .dispatch_tree
1661 .set_active_node(deferred_draw.parent_node);
1662
1663 let paint_start = self.paint_index();
1664 if let Some(element) = deferred_draw.element.as_mut() {
1665 element.paint(self);
1666 } else {
1667 self.reuse_paint(deferred_draw.paint_range.clone());
1668 }
1669 let paint_end = self.paint_index();
1670 deferred_draw.paint_range = paint_start..paint_end;
1671 }
1672 self.window.next_frame.deferred_draws = deferred_draws;
1673 self.window.element_id_stack.clear();
1674 }
1675
1676 pub(crate) fn prepaint_index(&self) -> PrepaintStateIndex {
1677 PrepaintStateIndex {
1678 hitboxes_index: self.window.next_frame.hitboxes.len(),
1679 tooltips_index: self.window.next_frame.tooltip_requests.len(),
1680 deferred_draws_index: self.window.next_frame.deferred_draws.len(),
1681 dispatch_tree_index: self.window.next_frame.dispatch_tree.len(),
1682 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1683 line_layout_index: self.window.text_system.layout_index(),
1684 }
1685 }
1686
1687 pub(crate) fn reuse_prepaint(&mut self, range: Range<PrepaintStateIndex>) {
1688 let window = &mut self.window;
1689 window.next_frame.hitboxes.extend(
1690 window.rendered_frame.hitboxes[range.start.hitboxes_index..range.end.hitboxes_index]
1691 .iter()
1692 .cloned(),
1693 );
1694 window.next_frame.tooltip_requests.extend(
1695 window.rendered_frame.tooltip_requests
1696 [range.start.tooltips_index..range.end.tooltips_index]
1697 .iter_mut()
1698 .map(|request| request.take()),
1699 );
1700 window.next_frame.accessed_element_states.extend(
1701 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1702 ..range.end.accessed_element_states_index]
1703 .iter()
1704 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1705 );
1706 window
1707 .text_system
1708 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1709
1710 let reused_subtree = window.next_frame.dispatch_tree.reuse_subtree(
1711 range.start.dispatch_tree_index..range.end.dispatch_tree_index,
1712 &mut window.rendered_frame.dispatch_tree,
1713 window.focus,
1714 );
1715
1716 if reused_subtree.contains_focus() {
1717 window.next_frame.focus = window.focus;
1718 }
1719
1720 window.next_frame.deferred_draws.extend(
1721 window.rendered_frame.deferred_draws
1722 [range.start.deferred_draws_index..range.end.deferred_draws_index]
1723 .iter()
1724 .map(|deferred_draw| DeferredDraw {
1725 parent_node: reused_subtree.refresh_node_id(deferred_draw.parent_node),
1726 element_id_stack: deferred_draw.element_id_stack.clone(),
1727 text_style_stack: deferred_draw.text_style_stack.clone(),
1728 priority: deferred_draw.priority,
1729 element: None,
1730 absolute_offset: deferred_draw.absolute_offset,
1731 prepaint_range: deferred_draw.prepaint_range.clone(),
1732 paint_range: deferred_draw.paint_range.clone(),
1733 }),
1734 );
1735 }
1736
1737 pub(crate) fn paint_index(&self) -> PaintIndex {
1738 PaintIndex {
1739 scene_index: self.window.next_frame.scene.len(),
1740 mouse_listeners_index: self.window.next_frame.mouse_listeners.len(),
1741 input_handlers_index: self.window.next_frame.input_handlers.len(),
1742 cursor_styles_index: self.window.next_frame.cursor_styles.len(),
1743 accessed_element_states_index: self.window.next_frame.accessed_element_states.len(),
1744 line_layout_index: self.window.text_system.layout_index(),
1745 }
1746 }
1747
1748 pub(crate) fn reuse_paint(&mut self, range: Range<PaintIndex>) {
1749 let window = &mut self.window;
1750
1751 window.next_frame.cursor_styles.extend(
1752 window.rendered_frame.cursor_styles
1753 [range.start.cursor_styles_index..range.end.cursor_styles_index]
1754 .iter()
1755 .cloned(),
1756 );
1757 window.next_frame.input_handlers.extend(
1758 window.rendered_frame.input_handlers
1759 [range.start.input_handlers_index..range.end.input_handlers_index]
1760 .iter_mut()
1761 .map(|handler| handler.take()),
1762 );
1763 window.next_frame.mouse_listeners.extend(
1764 window.rendered_frame.mouse_listeners
1765 [range.start.mouse_listeners_index..range.end.mouse_listeners_index]
1766 .iter_mut()
1767 .map(|listener| listener.take()),
1768 );
1769 window.next_frame.accessed_element_states.extend(
1770 window.rendered_frame.accessed_element_states[range.start.accessed_element_states_index
1771 ..range.end.accessed_element_states_index]
1772 .iter()
1773 .map(|(id, type_id)| (GlobalElementId(id.0.clone()), *type_id)),
1774 );
1775
1776 window
1777 .text_system
1778 .reuse_layouts(range.start.line_layout_index..range.end.line_layout_index);
1779 window.next_frame.scene.replay(
1780 range.start.scene_index..range.end.scene_index,
1781 &window.rendered_frame.scene,
1782 );
1783 }
1784
1785 /// Push a text style onto the stack, and call a function with that style active.
1786 /// Use [`AppContext::text_style`] to get the current, combined text style. This method
1787 /// should only be called as part of element drawing.
1788 pub fn with_text_style<F, R>(&mut self, style: Option<TextStyleRefinement>, f: F) -> R
1789 where
1790 F: FnOnce(&mut Self) -> R,
1791 {
1792 debug_assert!(
1793 matches!(
1794 self.window.draw_phase,
1795 DrawPhase::Prepaint | DrawPhase::Paint
1796 ),
1797 "this method can only be called during request_layout, prepaint, or paint"
1798 );
1799 if let Some(style) = style {
1800 self.window.text_style_stack.push(style);
1801 let result = f(self);
1802 self.window.text_style_stack.pop();
1803 result
1804 } else {
1805 f(self)
1806 }
1807 }
1808
1809 /// Updates the cursor style at the platform level. This method should only be called
1810 /// during the prepaint phase of element drawing.
1811 pub fn set_cursor_style(&mut self, style: CursorStyle, hitbox: &Hitbox) {
1812 debug_assert_eq!(
1813 self.window.draw_phase,
1814 DrawPhase::Paint,
1815 "this method can only be called during paint"
1816 );
1817 self.window
1818 .next_frame
1819 .cursor_styles
1820 .push(CursorStyleRequest {
1821 hitbox_id: hitbox.id,
1822 style,
1823 });
1824 }
1825
1826 /// Sets a tooltip to be rendered for the upcoming frame. This method should only be called
1827 /// during the paint phase of element drawing.
1828 pub fn set_tooltip(&mut self, tooltip: AnyTooltip) -> TooltipId {
1829 debug_assert_eq!(
1830 self.window.draw_phase,
1831 DrawPhase::Prepaint,
1832 "this method can only be called during prepaint"
1833 );
1834 let id = TooltipId(post_inc(&mut self.window.next_tooltip_id.0));
1835 self.window
1836 .next_frame
1837 .tooltip_requests
1838 .push(Some(TooltipRequest { id, tooltip }));
1839 id
1840 }
1841
1842 /// Invoke the given function with the given content mask after intersecting it
1843 /// with the current mask. This method should only be called during element drawing.
1844 pub fn with_content_mask<R>(
1845 &mut self,
1846 mask: Option<ContentMask<Pixels>>,
1847 f: impl FnOnce(&mut Self) -> R,
1848 ) -> R {
1849 debug_assert!(
1850 matches!(
1851 self.window.draw_phase,
1852 DrawPhase::Prepaint | DrawPhase::Paint
1853 ),
1854 "this method can only be called during request_layout, prepaint, or paint"
1855 );
1856 if let Some(mask) = mask {
1857 let mask = mask.intersect(&self.content_mask());
1858 self.window_mut().content_mask_stack.push(mask);
1859 let result = f(self);
1860 self.window_mut().content_mask_stack.pop();
1861 result
1862 } else {
1863 f(self)
1864 }
1865 }
1866
1867 /// Updates the global element offset relative to the current offset. This is used to implement
1868 /// scrolling. This method should only be called during the prepaint phase of element drawing.
1869 pub fn with_element_offset<R>(
1870 &mut self,
1871 offset: Point<Pixels>,
1872 f: impl FnOnce(&mut Self) -> R,
1873 ) -> R {
1874 debug_assert_eq!(
1875 self.window.draw_phase,
1876 DrawPhase::Prepaint,
1877 "this method can only be called during request_layout, or prepaint"
1878 );
1879
1880 if offset.is_zero() {
1881 return f(self);
1882 };
1883
1884 let abs_offset = self.element_offset() + offset;
1885 self.with_absolute_element_offset(abs_offset, f)
1886 }
1887
1888 /// Updates the global element offset based on the given offset. This is used to implement
1889 /// drag handles and other manual painting of elements. This method should only be called during
1890 /// the prepaint phase of element drawing.
1891 pub fn with_absolute_element_offset<R>(
1892 &mut self,
1893 offset: Point<Pixels>,
1894 f: impl FnOnce(&mut Self) -> R,
1895 ) -> R {
1896 debug_assert_eq!(
1897 self.window.draw_phase,
1898 DrawPhase::Prepaint,
1899 "this method can only be called during request_layout, or prepaint"
1900 );
1901 self.window_mut().element_offset_stack.push(offset);
1902 let result = f(self);
1903 self.window_mut().element_offset_stack.pop();
1904 result
1905 }
1906
1907 pub(crate) fn with_element_opacity<R>(
1908 &mut self,
1909 opacity: Option<f32>,
1910 f: impl FnOnce(&mut Self) -> R,
1911 ) -> R {
1912 if opacity.is_none() {
1913 return f(self);
1914 }
1915
1916 debug_assert!(
1917 matches!(
1918 self.window.draw_phase,
1919 DrawPhase::Prepaint | DrawPhase::Paint
1920 ),
1921 "this method can only be called during prepaint, or paint"
1922 );
1923 self.window_mut().element_opacity = opacity;
1924 let result = f(self);
1925 self.window_mut().element_opacity = None;
1926 result
1927 }
1928
1929 /// Perform prepaint on child elements in a "retryable" manner, so that any side effects
1930 /// of prepaints can be discarded before prepainting again. This is used to support autoscroll
1931 /// where we need to prepaint children to detect the autoscroll bounds, then adjust the
1932 /// element offset and prepaint again. See [`List`] for an example. This method should only be
1933 /// called during the prepaint phase of element drawing.
1934 pub fn transact<T, U>(&mut self, f: impl FnOnce(&mut Self) -> Result<T, U>) -> Result<T, U> {
1935 debug_assert_eq!(
1936 self.window.draw_phase,
1937 DrawPhase::Prepaint,
1938 "this method can only be called during prepaint"
1939 );
1940 let index = self.prepaint_index();
1941 let result = f(self);
1942 if result.is_err() {
1943 self.window
1944 .next_frame
1945 .hitboxes
1946 .truncate(index.hitboxes_index);
1947 self.window
1948 .next_frame
1949 .tooltip_requests
1950 .truncate(index.tooltips_index);
1951 self.window
1952 .next_frame
1953 .deferred_draws
1954 .truncate(index.deferred_draws_index);
1955 self.window
1956 .next_frame
1957 .dispatch_tree
1958 .truncate(index.dispatch_tree_index);
1959 self.window
1960 .next_frame
1961 .accessed_element_states
1962 .truncate(index.accessed_element_states_index);
1963 self.window
1964 .text_system
1965 .truncate_layouts(index.line_layout_index);
1966 }
1967 result
1968 }
1969
1970 /// When you call this method during [`prepaint`], containing elements will attempt to
1971 /// scroll to cause the specified bounds to become visible. When they decide to autoscroll, they will call
1972 /// [`prepaint`] again with a new set of bounds. See [`List`] for an example of an element
1973 /// that supports this method being called on the elements it contains. This method should only be
1974 /// called during the prepaint phase of element drawing.
1975 pub fn request_autoscroll(&mut self, bounds: Bounds<Pixels>) {
1976 debug_assert_eq!(
1977 self.window.draw_phase,
1978 DrawPhase::Prepaint,
1979 "this method can only be called during prepaint"
1980 );
1981 self.window.requested_autoscroll = Some(bounds);
1982 }
1983
1984 /// This method can be called from a containing element such as [`List`] to support the autoscroll behavior
1985 /// described in [`request_autoscroll`].
1986 pub fn take_autoscroll(&mut self) -> Option<Bounds<Pixels>> {
1987 debug_assert_eq!(
1988 self.window.draw_phase,
1989 DrawPhase::Prepaint,
1990 "this method can only be called during prepaint"
1991 );
1992 self.window.requested_autoscroll.take()
1993 }
1994
1995 /// Asynchronously load an asset, if the asset hasn't finished loading this will return None.
1996 /// Your view will be re-drawn once the asset has finished loading.
1997 ///
1998 /// Note that the multiple calls to this method will only result in one `Asset::load` call at a
1999 /// time.
2000 pub fn use_asset<A: Asset>(&mut self, source: &A::Source) -> Option<A::Output> {
2001 let (task, is_first) = self.fetch_asset::<A>(source);
2002 task.clone().now_or_never().or_else(|| {
2003 if is_first {
2004 let parent_id = self.parent_view_id();
2005 self.spawn({
2006 let task = task.clone();
2007 |mut cx| async move {
2008 task.await;
2009
2010 cx.on_next_frame(move |cx| cx.notify(parent_id));
2011 }
2012 })
2013 .detach();
2014 }
2015
2016 None
2017 })
2018 }
2019 /// Obtain the current element offset. This method should only be called during the
2020 /// prepaint phase of element drawing.
2021 pub fn element_offset(&self) -> Point<Pixels> {
2022 debug_assert_eq!(
2023 self.window.draw_phase,
2024 DrawPhase::Prepaint,
2025 "this method can only be called during prepaint"
2026 );
2027 self.window()
2028 .element_offset_stack
2029 .last()
2030 .copied()
2031 .unwrap_or_default()
2032 }
2033
2034 /// Obtain the current element opacity. This method should only be called during the
2035 /// prepaint phase of element drawing.
2036 pub(crate) fn element_opacity(&self) -> f32 {
2037 debug_assert!(
2038 matches!(
2039 self.window.draw_phase,
2040 DrawPhase::Prepaint | DrawPhase::Paint
2041 ),
2042 "this method can only be called during prepaint, or paint"
2043 );
2044 self.window().element_opacity.unwrap_or(1.0)
2045 }
2046
2047 /// Obtain the current content mask. This method should only be called during element drawing.
2048 pub fn content_mask(&self) -> ContentMask<Pixels> {
2049 debug_assert!(
2050 matches!(
2051 self.window.draw_phase,
2052 DrawPhase::Prepaint | DrawPhase::Paint
2053 ),
2054 "this method can only be called during prepaint, or paint"
2055 );
2056 self.window()
2057 .content_mask_stack
2058 .last()
2059 .cloned()
2060 .unwrap_or_else(|| ContentMask {
2061 bounds: Bounds {
2062 origin: Point::default(),
2063 size: self.window().viewport_size,
2064 },
2065 })
2066 }
2067
2068 /// Provide elements in the called function with a new namespace in which their identifiers must be unique.
2069 /// This can be used within a custom element to distinguish multiple sets of child elements.
2070 pub fn with_element_namespace<R>(
2071 &mut self,
2072 element_id: impl Into<ElementId>,
2073 f: impl FnOnce(&mut Self) -> R,
2074 ) -> R {
2075 self.window.element_id_stack.push(element_id.into());
2076 let result = f(self);
2077 self.window.element_id_stack.pop();
2078 result
2079 }
2080
2081 /// Updates or initializes state for an element with the given id that lives across multiple
2082 /// frames. If an element with this ID existed in the rendered frame, its state will be passed
2083 /// to the given closure. The state returned by the closure will be stored so it can be referenced
2084 /// when drawing the next frame. This method should only be called as part of element drawing.
2085 pub fn with_element_state<S, R>(
2086 &mut self,
2087 global_id: &GlobalElementId,
2088 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2089 ) -> R
2090 where
2091 S: 'static,
2092 {
2093 debug_assert!(
2094 matches!(
2095 self.window.draw_phase,
2096 DrawPhase::Prepaint | DrawPhase::Paint
2097 ),
2098 "this method can only be called during request_layout, prepaint, or paint"
2099 );
2100
2101 let key = (GlobalElementId(global_id.0.clone()), TypeId::of::<S>());
2102 self.window
2103 .next_frame
2104 .accessed_element_states
2105 .push((GlobalElementId(key.0.clone()), TypeId::of::<S>()));
2106
2107 if let Some(any) = self
2108 .window
2109 .next_frame
2110 .element_states
2111 .remove(&key)
2112 .or_else(|| self.window.rendered_frame.element_states.remove(&key))
2113 {
2114 let ElementStateBox {
2115 inner,
2116 #[cfg(debug_assertions)]
2117 type_name,
2118 } = any;
2119 // Using the extra inner option to avoid needing to reallocate a new box.
2120 let mut state_box = inner
2121 .downcast::<Option<S>>()
2122 .map_err(|_| {
2123 #[cfg(debug_assertions)]
2124 {
2125 anyhow::anyhow!(
2126 "invalid element state type for id, requested {:?}, actual: {:?}",
2127 std::any::type_name::<S>(),
2128 type_name
2129 )
2130 }
2131
2132 #[cfg(not(debug_assertions))]
2133 {
2134 anyhow::anyhow!(
2135 "invalid element state type for id, requested {:?}",
2136 std::any::type_name::<S>(),
2137 )
2138 }
2139 })
2140 .unwrap();
2141
2142 let state = state_box.take().expect(
2143 "reentrant call to with_element_state for the same state type and element id",
2144 );
2145 let (result, state) = f(Some(state), self);
2146 state_box.replace(state);
2147 self.window.next_frame.element_states.insert(
2148 key,
2149 ElementStateBox {
2150 inner: state_box,
2151 #[cfg(debug_assertions)]
2152 type_name,
2153 },
2154 );
2155 result
2156 } else {
2157 let (result, state) = f(None, self);
2158 self.window.next_frame.element_states.insert(
2159 key,
2160 ElementStateBox {
2161 inner: Box::new(Some(state)),
2162 #[cfg(debug_assertions)]
2163 type_name: std::any::type_name::<S>(),
2164 },
2165 );
2166 result
2167 }
2168 }
2169
2170 /// A variant of `with_element_state` that allows the element's id to be optional. This is a convenience
2171 /// method for elements where the element id may or may not be assigned. Prefer using `with_element_state`
2172 /// when the element is guaranteed to have an id.
2173 ///
2174 /// The first option means 'no ID provided'
2175 /// The second option means 'not yet initialized'
2176 pub fn with_optional_element_state<S, R>(
2177 &mut self,
2178 global_id: Option<&GlobalElementId>,
2179 f: impl FnOnce(Option<Option<S>>, &mut Self) -> (R, Option<S>),
2180 ) -> R
2181 where
2182 S: 'static,
2183 {
2184 debug_assert!(
2185 matches!(
2186 self.window.draw_phase,
2187 DrawPhase::Prepaint | DrawPhase::Paint
2188 ),
2189 "this method can only be called during request_layout, prepaint, or paint"
2190 );
2191
2192 if let Some(global_id) = global_id {
2193 self.with_element_state(global_id, |state, cx| {
2194 let (result, state) = f(Some(state), cx);
2195 let state =
2196 state.expect("you must return some state when you pass some element id");
2197 (result, state)
2198 })
2199 } else {
2200 let (result, state) = f(None, self);
2201 debug_assert!(
2202 state.is_none(),
2203 "you must not return an element state when passing None for the global id"
2204 );
2205 result
2206 }
2207 }
2208
2209 /// Defers the drawing of the given element, scheduling it to be painted on top of the currently-drawn tree
2210 /// at a later time. The `priority` parameter determines the drawing order relative to other deferred elements,
2211 /// with higher values being drawn on top.
2212 ///
2213 /// This method should only be called as part of the prepaint phase of element drawing.
2214 pub fn defer_draw(
2215 &mut self,
2216 element: AnyElement,
2217 absolute_offset: Point<Pixels>,
2218 priority: usize,
2219 ) {
2220 let window = &mut self.window;
2221 debug_assert_eq!(
2222 window.draw_phase,
2223 DrawPhase::Prepaint,
2224 "this method can only be called during request_layout or prepaint"
2225 );
2226 let parent_node = window.next_frame.dispatch_tree.active_node_id().unwrap();
2227 window.next_frame.deferred_draws.push(DeferredDraw {
2228 parent_node,
2229 element_id_stack: window.element_id_stack.clone(),
2230 text_style_stack: window.text_style_stack.clone(),
2231 priority,
2232 element: Some(element),
2233 absolute_offset,
2234 prepaint_range: PrepaintStateIndex::default()..PrepaintStateIndex::default(),
2235 paint_range: PaintIndex::default()..PaintIndex::default(),
2236 });
2237 }
2238
2239 /// Creates a new painting layer for the specified bounds. A "layer" is a batch
2240 /// of geometry that are non-overlapping and have the same draw order. This is typically used
2241 /// for performance reasons.
2242 ///
2243 /// This method should only be called as part of the paint phase of element drawing.
2244 pub fn paint_layer<R>(&mut self, bounds: Bounds<Pixels>, f: impl FnOnce(&mut Self) -> R) -> R {
2245 debug_assert_eq!(
2246 self.window.draw_phase,
2247 DrawPhase::Paint,
2248 "this method can only be called during paint"
2249 );
2250
2251 let scale_factor = self.scale_factor();
2252 let content_mask = self.content_mask();
2253 let clipped_bounds = bounds.intersect(&content_mask.bounds);
2254 if !clipped_bounds.is_empty() {
2255 self.window
2256 .next_frame
2257 .scene
2258 .push_layer(clipped_bounds.scale(scale_factor));
2259 }
2260
2261 let result = f(self);
2262
2263 if !clipped_bounds.is_empty() {
2264 self.window.next_frame.scene.pop_layer();
2265 }
2266
2267 result
2268 }
2269
2270 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
2271 ///
2272 /// This method should only be called as part of the paint phase of element drawing.
2273 pub fn paint_shadows(
2274 &mut self,
2275 bounds: Bounds<Pixels>,
2276 corner_radii: Corners<Pixels>,
2277 shadows: &[BoxShadow],
2278 ) {
2279 debug_assert_eq!(
2280 self.window.draw_phase,
2281 DrawPhase::Paint,
2282 "this method can only be called during paint"
2283 );
2284
2285 let scale_factor = self.scale_factor();
2286 let content_mask = self.content_mask();
2287 let opacity = self.element_opacity();
2288 for shadow in shadows {
2289 let shadow_bounds = (bounds + shadow.offset).dilate(shadow.spread_radius);
2290 self.window.next_frame.scene.insert_primitive(Shadow {
2291 order: 0,
2292 blur_radius: shadow.blur_radius.scale(scale_factor),
2293 bounds: shadow_bounds.scale(scale_factor),
2294 content_mask: content_mask.scale(scale_factor),
2295 corner_radii: corner_radii.scale(scale_factor),
2296 color: shadow.color.opacity(opacity),
2297 });
2298 }
2299 }
2300
2301 /// Paint one or more quads into the scene for the next frame at the current stacking context.
2302 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
2303 /// see [`fill`](crate::fill), [`outline`](crate::outline), and [`quad`](crate::quad) to construct this type.
2304 ///
2305 /// This method should only be called as part of the paint phase of element drawing.
2306 pub fn paint_quad(&mut self, quad: PaintQuad) {
2307 debug_assert_eq!(
2308 self.window.draw_phase,
2309 DrawPhase::Paint,
2310 "this method can only be called during paint"
2311 );
2312
2313 let scale_factor = self.scale_factor();
2314 let content_mask = self.content_mask();
2315 let opacity = self.element_opacity();
2316 self.window.next_frame.scene.insert_primitive(Quad {
2317 order: 0,
2318 pad: 0,
2319 bounds: quad.bounds.scale(scale_factor),
2320 content_mask: content_mask.scale(scale_factor),
2321 background: quad.background.opacity(opacity),
2322 border_color: quad.border_color.opacity(opacity),
2323 corner_radii: quad.corner_radii.scale(scale_factor),
2324 border_widths: quad.border_widths.scale(scale_factor),
2325 });
2326 }
2327
2328 /// Paint the given `Path` into the scene for the next frame at the current z-index.
2329 ///
2330 /// This method should only be called as part of the paint phase of element drawing.
2331 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Background>) {
2332 debug_assert_eq!(
2333 self.window.draw_phase,
2334 DrawPhase::Paint,
2335 "this method can only be called during paint"
2336 );
2337
2338 let scale_factor = self.scale_factor();
2339 let content_mask = self.content_mask();
2340 let opacity = self.element_opacity();
2341 path.content_mask = content_mask;
2342 let color: Background = color.into();
2343 path.color = color.opacity(opacity);
2344 self.window
2345 .next_frame
2346 .scene
2347 .insert_primitive(path.scale(scale_factor));
2348 }
2349
2350 /// Paint an underline into the scene for the next frame at the current z-index.
2351 ///
2352 /// This method should only be called as part of the paint phase of element drawing.
2353 pub fn paint_underline(
2354 &mut self,
2355 origin: Point<Pixels>,
2356 width: Pixels,
2357 style: &UnderlineStyle,
2358 ) {
2359 debug_assert_eq!(
2360 self.window.draw_phase,
2361 DrawPhase::Paint,
2362 "this method can only be called during paint"
2363 );
2364
2365 let scale_factor = self.scale_factor();
2366 let height = if style.wavy {
2367 style.thickness * 3.
2368 } else {
2369 style.thickness
2370 };
2371 let bounds = Bounds {
2372 origin,
2373 size: size(width, height),
2374 };
2375 let content_mask = self.content_mask();
2376 let element_opacity = self.element_opacity();
2377
2378 self.window.next_frame.scene.insert_primitive(Underline {
2379 order: 0,
2380 pad: 0,
2381 bounds: bounds.scale(scale_factor),
2382 content_mask: content_mask.scale(scale_factor),
2383 color: style.color.unwrap_or_default().opacity(element_opacity),
2384 thickness: style.thickness.scale(scale_factor),
2385 wavy: style.wavy,
2386 });
2387 }
2388
2389 /// Paint a strikethrough into the scene for the next frame at the current z-index.
2390 ///
2391 /// This method should only be called as part of the paint phase of element drawing.
2392 pub fn paint_strikethrough(
2393 &mut self,
2394 origin: Point<Pixels>,
2395 width: Pixels,
2396 style: &StrikethroughStyle,
2397 ) {
2398 debug_assert_eq!(
2399 self.window.draw_phase,
2400 DrawPhase::Paint,
2401 "this method can only be called during paint"
2402 );
2403
2404 let scale_factor = self.scale_factor();
2405 let height = style.thickness;
2406 let bounds = Bounds {
2407 origin,
2408 size: size(width, height),
2409 };
2410 let content_mask = self.content_mask();
2411 let opacity = self.element_opacity();
2412
2413 self.window.next_frame.scene.insert_primitive(Underline {
2414 order: 0,
2415 pad: 0,
2416 bounds: bounds.scale(scale_factor),
2417 content_mask: content_mask.scale(scale_factor),
2418 thickness: style.thickness.scale(scale_factor),
2419 color: style.color.unwrap_or_default().opacity(opacity),
2420 wavy: false,
2421 });
2422 }
2423
2424 /// Paints a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
2425 ///
2426 /// The y component of the origin is the baseline of the glyph.
2427 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2428 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2429 /// This method is only useful if you need to paint a single glyph that has already been shaped.
2430 ///
2431 /// This method should only be called as part of the paint phase of element drawing.
2432 pub fn paint_glyph(
2433 &mut self,
2434 origin: Point<Pixels>,
2435 font_id: FontId,
2436 glyph_id: GlyphId,
2437 font_size: Pixels,
2438 color: Hsla,
2439 ) -> Result<()> {
2440 debug_assert_eq!(
2441 self.window.draw_phase,
2442 DrawPhase::Paint,
2443 "this method can only be called during paint"
2444 );
2445
2446 let element_opacity = self.element_opacity();
2447 let scale_factor = self.scale_factor();
2448 let glyph_origin = origin.scale(scale_factor);
2449 let subpixel_variant = Point {
2450 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2451 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
2452 };
2453 let params = RenderGlyphParams {
2454 font_id,
2455 glyph_id,
2456 font_size,
2457 subpixel_variant,
2458 scale_factor,
2459 is_emoji: false,
2460 };
2461
2462 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2463 if !raster_bounds.is_zero() {
2464 let tile = self
2465 .window
2466 .sprite_atlas
2467 .get_or_insert_with(¶ms.clone().into(), &mut || {
2468 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2469 Ok(Some((size, Cow::Owned(bytes))))
2470 })?
2471 .expect("Callback above only errors or returns Some");
2472 let bounds = Bounds {
2473 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2474 size: tile.bounds.size.map(Into::into),
2475 };
2476 let content_mask = self.content_mask().scale(scale_factor);
2477 self.window
2478 .next_frame
2479 .scene
2480 .insert_primitive(MonochromeSprite {
2481 order: 0,
2482 pad: 0,
2483 bounds,
2484 content_mask,
2485 color: color.opacity(element_opacity),
2486 tile,
2487 transformation: TransformationMatrix::unit(),
2488 });
2489 }
2490 Ok(())
2491 }
2492
2493 /// Paints an emoji glyph into the scene for the next frame at the current z-index.
2494 ///
2495 /// The y component of the origin is the baseline of the glyph.
2496 /// You should generally prefer to use the [`ShapedLine::paint`](crate::ShapedLine::paint) or
2497 /// [`WrappedLine::paint`](crate::WrappedLine::paint) methods in the [`TextSystem`](crate::TextSystem).
2498 /// This method is only useful if you need to paint a single emoji that has already been shaped.
2499 ///
2500 /// This method should only be called as part of the paint phase of element drawing.
2501 pub fn paint_emoji(
2502 &mut self,
2503 origin: Point<Pixels>,
2504 font_id: FontId,
2505 glyph_id: GlyphId,
2506 font_size: Pixels,
2507 ) -> Result<()> {
2508 debug_assert_eq!(
2509 self.window.draw_phase,
2510 DrawPhase::Paint,
2511 "this method can only be called during paint"
2512 );
2513
2514 let scale_factor = self.scale_factor();
2515 let glyph_origin = origin.scale(scale_factor);
2516 let params = RenderGlyphParams {
2517 font_id,
2518 glyph_id,
2519 font_size,
2520 // We don't render emojis with subpixel variants.
2521 subpixel_variant: Default::default(),
2522 scale_factor,
2523 is_emoji: true,
2524 };
2525
2526 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
2527 if !raster_bounds.is_zero() {
2528 let tile = self
2529 .window
2530 .sprite_atlas
2531 .get_or_insert_with(¶ms.clone().into(), &mut || {
2532 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
2533 Ok(Some((size, Cow::Owned(bytes))))
2534 })?
2535 .expect("Callback above only errors or returns Some");
2536
2537 let bounds = Bounds {
2538 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
2539 size: tile.bounds.size.map(Into::into),
2540 };
2541 let content_mask = self.content_mask().scale(scale_factor);
2542 let opacity = self.element_opacity();
2543
2544 self.window
2545 .next_frame
2546 .scene
2547 .insert_primitive(PolychromeSprite {
2548 order: 0,
2549 pad: 0,
2550 grayscale: false,
2551 bounds,
2552 corner_radii: Default::default(),
2553 content_mask,
2554 tile,
2555 opacity,
2556 });
2557 }
2558 Ok(())
2559 }
2560
2561 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
2562 ///
2563 /// This method should only be called as part of the paint phase of element drawing.
2564 pub fn paint_svg(
2565 &mut self,
2566 bounds: Bounds<Pixels>,
2567 path: SharedString,
2568 transformation: TransformationMatrix,
2569 color: Hsla,
2570 ) -> Result<()> {
2571 debug_assert_eq!(
2572 self.window.draw_phase,
2573 DrawPhase::Paint,
2574 "this method can only be called during paint"
2575 );
2576
2577 let element_opacity = self.element_opacity();
2578 let scale_factor = self.scale_factor();
2579 let bounds = bounds.scale(scale_factor);
2580 // Render the SVG at twice the size to get a higher quality result.
2581 let params = RenderSvgParams {
2582 path,
2583 size: bounds
2584 .size
2585 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
2586 };
2587
2588 let Some(tile) =
2589 self.window
2590 .sprite_atlas
2591 .get_or_insert_with(¶ms.clone().into(), &mut || {
2592 let Some(bytes) = self.svg_renderer.render(¶ms)? else {
2593 return Ok(None);
2594 };
2595 Ok(Some((params.size, Cow::Owned(bytes))))
2596 })?
2597 else {
2598 return Ok(());
2599 };
2600 let content_mask = self.content_mask().scale(scale_factor);
2601
2602 self.window
2603 .next_frame
2604 .scene
2605 .insert_primitive(MonochromeSprite {
2606 order: 0,
2607 pad: 0,
2608 bounds: bounds
2609 .map_origin(|origin| origin.floor())
2610 .map_size(|size| size.ceil()),
2611 content_mask,
2612 color: color.opacity(element_opacity),
2613 tile,
2614 transformation,
2615 });
2616
2617 Ok(())
2618 }
2619
2620 /// Paint an image into the scene for the next frame at the current z-index.
2621 /// This method will panic if the frame_index is not valid
2622 ///
2623 /// This method should only be called as part of the paint phase of element drawing.
2624 pub fn paint_image(
2625 &mut self,
2626 bounds: Bounds<Pixels>,
2627 corner_radii: Corners<Pixels>,
2628 data: Arc<RenderImage>,
2629 frame_index: usize,
2630 grayscale: bool,
2631 ) -> Result<()> {
2632 debug_assert_eq!(
2633 self.window.draw_phase,
2634 DrawPhase::Paint,
2635 "this method can only be called during paint"
2636 );
2637
2638 let scale_factor = self.scale_factor();
2639 let bounds = bounds.scale(scale_factor);
2640 let params = RenderImageParams {
2641 image_id: data.id,
2642 frame_index,
2643 };
2644
2645 let tile = self
2646 .window
2647 .sprite_atlas
2648 .get_or_insert_with(¶ms.clone().into(), &mut || {
2649 Ok(Some((
2650 data.size(frame_index),
2651 Cow::Borrowed(
2652 data.as_bytes(frame_index)
2653 .expect("It's the caller's job to pass a valid frame index"),
2654 ),
2655 )))
2656 })?
2657 .expect("Callback above only returns Some");
2658 let content_mask = self.content_mask().scale(scale_factor);
2659 let corner_radii = corner_radii.scale(scale_factor);
2660 let opacity = self.element_opacity();
2661
2662 self.window
2663 .next_frame
2664 .scene
2665 .insert_primitive(PolychromeSprite {
2666 order: 0,
2667 pad: 0,
2668 grayscale,
2669 bounds,
2670 content_mask,
2671 corner_radii,
2672 tile,
2673 opacity,
2674 });
2675 Ok(())
2676 }
2677
2678 /// Paint a surface into the scene for the next frame at the current z-index.
2679 ///
2680 /// This method should only be called as part of the paint phase of element drawing.
2681 #[cfg(target_os = "macos")]
2682 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
2683 use crate::PaintSurface;
2684
2685 debug_assert_eq!(
2686 self.window.draw_phase,
2687 DrawPhase::Paint,
2688 "this method can only be called during paint"
2689 );
2690
2691 let scale_factor = self.scale_factor();
2692 let bounds = bounds.scale(scale_factor);
2693 let content_mask = self.content_mask().scale(scale_factor);
2694 self.window.next_frame.scene.insert_primitive(PaintSurface {
2695 order: 0,
2696 bounds,
2697 content_mask,
2698 image_buffer,
2699 });
2700 }
2701
2702 /// Removes an image from the sprite atlas.
2703 pub fn drop_image(&mut self, data: Arc<RenderImage>) -> Result<()> {
2704 for frame_index in 0..data.frame_count() {
2705 let params = RenderImageParams {
2706 image_id: data.id,
2707 frame_index,
2708 };
2709
2710 self.window.sprite_atlas.remove(¶ms.clone().into());
2711 }
2712
2713 Ok(())
2714 }
2715
2716 #[must_use]
2717 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
2718 /// layout is being requested, along with the layout ids of any children. This method is called during
2719 /// calls to the [`Element::request_layout`] trait method and enables any element to participate in layout.
2720 ///
2721 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2722 pub fn request_layout(
2723 &mut self,
2724 style: Style,
2725 children: impl IntoIterator<Item = LayoutId>,
2726 ) -> LayoutId {
2727 debug_assert_eq!(
2728 self.window.draw_phase,
2729 DrawPhase::Prepaint,
2730 "this method can only be called during request_layout, or prepaint"
2731 );
2732
2733 self.app.layout_id_buffer.clear();
2734 self.app.layout_id_buffer.extend(children);
2735 let rem_size = self.rem_size();
2736
2737 self.window.layout_engine.as_mut().unwrap().request_layout(
2738 style,
2739 rem_size,
2740 &self.app.layout_id_buffer,
2741 )
2742 }
2743
2744 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
2745 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
2746 /// determine the element's size. One place this is used internally is when measuring text.
2747 ///
2748 /// The given closure is invoked at layout time with the known dimensions and available space and
2749 /// returns a `Size`.
2750 ///
2751 /// This method should only be called as part of the request_layout or prepaint phase of element drawing.
2752 pub fn request_measured_layout<
2753 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
2754 + 'static,
2755 >(
2756 &mut self,
2757 style: Style,
2758 measure: F,
2759 ) -> LayoutId {
2760 debug_assert_eq!(
2761 self.window.draw_phase,
2762 DrawPhase::Prepaint,
2763 "this method can only be called during request_layout, or prepaint"
2764 );
2765
2766 let rem_size = self.rem_size();
2767 self.window
2768 .layout_engine
2769 .as_mut()
2770 .unwrap()
2771 .request_measured_layout(style, rem_size, measure)
2772 }
2773
2774 /// Compute the layout for the given id within the given available space.
2775 /// This method is called for its side effect, typically by the framework prior to painting.
2776 /// After calling it, you can request the bounds of the given layout node id or any descendant.
2777 ///
2778 /// This method should only be called as part of the prepaint phase of element drawing.
2779 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
2780 debug_assert_eq!(
2781 self.window.draw_phase,
2782 DrawPhase::Prepaint,
2783 "this method can only be called during request_layout, or prepaint"
2784 );
2785
2786 let mut layout_engine = self.window.layout_engine.take().unwrap();
2787 layout_engine.compute_layout(layout_id, available_space, self);
2788 self.window.layout_engine = Some(layout_engine);
2789 }
2790
2791 /// Obtain the bounds computed for the given LayoutId relative to the window. This method will usually be invoked by
2792 /// GPUI itself automatically in order to pass your element its `Bounds` automatically.
2793 ///
2794 /// This method should only be called as part of element drawing.
2795 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
2796 debug_assert_eq!(
2797 self.window.draw_phase,
2798 DrawPhase::Prepaint,
2799 "this method can only be called during request_layout, prepaint, or paint"
2800 );
2801
2802 let mut bounds = self
2803 .window
2804 .layout_engine
2805 .as_mut()
2806 .unwrap()
2807 .layout_bounds(layout_id)
2808 .map(Into::into);
2809 bounds.origin += self.element_offset();
2810 bounds
2811 }
2812
2813 /// This method should be called during `prepaint`. You can use
2814 /// the returned [Hitbox] during `paint` or in an event handler
2815 /// to determine whether the inserted hitbox was the topmost.
2816 ///
2817 /// This method should only be called as part of the prepaint phase of element drawing.
2818 pub fn insert_hitbox(&mut self, bounds: Bounds<Pixels>, opaque: bool) -> Hitbox {
2819 debug_assert_eq!(
2820 self.window.draw_phase,
2821 DrawPhase::Prepaint,
2822 "this method can only be called during prepaint"
2823 );
2824
2825 let content_mask = self.content_mask();
2826 let window = &mut self.window;
2827 let id = window.next_hitbox_id;
2828 window.next_hitbox_id.0 += 1;
2829 let hitbox = Hitbox {
2830 id,
2831 bounds,
2832 content_mask,
2833 opaque,
2834 };
2835 window.next_frame.hitboxes.push(hitbox.clone());
2836 hitbox
2837 }
2838
2839 /// Sets the key context for the current element. This context will be used to translate
2840 /// keybindings into actions.
2841 ///
2842 /// This method should only be called as part of the paint phase of element drawing.
2843 pub fn set_key_context(&mut self, context: KeyContext) {
2844 debug_assert_eq!(
2845 self.window.draw_phase,
2846 DrawPhase::Paint,
2847 "this method can only be called during paint"
2848 );
2849 self.window
2850 .next_frame
2851 .dispatch_tree
2852 .set_key_context(context);
2853 }
2854
2855 /// Sets the focus handle for the current element. This handle will be used to manage focus state
2856 /// and keyboard event dispatch for the element.
2857 ///
2858 /// This method should only be called as part of the prepaint phase of element drawing.
2859 pub fn set_focus_handle(&mut self, focus_handle: &FocusHandle) {
2860 debug_assert_eq!(
2861 self.window.draw_phase,
2862 DrawPhase::Prepaint,
2863 "this method can only be called during prepaint"
2864 );
2865 if focus_handle.is_focused(self) {
2866 self.window.next_frame.focus = Some(focus_handle.id);
2867 }
2868 self.window
2869 .next_frame
2870 .dispatch_tree
2871 .set_focus_id(focus_handle.id);
2872 }
2873
2874 /// Sets the view id for the current element, which will be used to manage view caching.
2875 ///
2876 /// This method should only be called as part of element prepaint. We plan on removing this
2877 /// method eventually when we solve some issues that require us to construct editor elements
2878 /// directly instead of always using editors via views.
2879 pub fn set_view_id(&mut self, view_id: EntityId) {
2880 debug_assert_eq!(
2881 self.window.draw_phase,
2882 DrawPhase::Prepaint,
2883 "this method can only be called during prepaint"
2884 );
2885 self.window.next_frame.dispatch_tree.set_view_id(view_id);
2886 }
2887
2888 /// Get the last view id for the current element
2889 pub fn parent_view_id(&self) -> Option<EntityId> {
2890 self.window.next_frame.dispatch_tree.parent_view_id()
2891 }
2892
2893 /// Sets an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2894 /// platform to receive textual input with proper integration with concerns such
2895 /// as IME interactions. This handler will be active for the upcoming frame until the following frame is
2896 /// rendered.
2897 ///
2898 /// This method should only be called as part of the paint phase of element drawing.
2899 ///
2900 /// [element_input_handler]: crate::ElementInputHandler
2901 pub fn handle_input(&mut self, focus_handle: &FocusHandle, input_handler: impl InputHandler) {
2902 debug_assert_eq!(
2903 self.window.draw_phase,
2904 DrawPhase::Paint,
2905 "this method can only be called during paint"
2906 );
2907
2908 if focus_handle.is_focused(self) {
2909 let cx = self.to_async();
2910 self.window
2911 .next_frame
2912 .input_handlers
2913 .push(Some(PlatformInputHandler::new(cx, Box::new(input_handler))));
2914 }
2915 }
2916
2917 /// Register a mouse event listener on the window for the next frame. The type of event
2918 /// is determined by the first parameter of the given listener. When the next frame is rendered
2919 /// the listener will be cleared.
2920 ///
2921 /// This method should only be called as part of the paint phase of element drawing.
2922 pub fn on_mouse_event<Event: MouseEvent>(
2923 &mut self,
2924 mut handler: impl FnMut(&Event, DispatchPhase, &mut WindowContext) + 'static,
2925 ) {
2926 debug_assert_eq!(
2927 self.window.draw_phase,
2928 DrawPhase::Paint,
2929 "this method can only be called during paint"
2930 );
2931
2932 self.window.next_frame.mouse_listeners.push(Some(Box::new(
2933 move |event: &dyn Any, phase: DispatchPhase, cx: &mut WindowContext<'_>| {
2934 if let Some(event) = event.downcast_ref() {
2935 handler(event, phase, cx)
2936 }
2937 },
2938 )));
2939 }
2940
2941 /// Register a key event listener on the window for the next frame. The type of event
2942 /// is determined by the first parameter of the given listener. When the next frame is rendered
2943 /// the listener will be cleared.
2944 ///
2945 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2946 /// a specific need to register a global listener.
2947 ///
2948 /// This method should only be called as part of the paint phase of element drawing.
2949 pub fn on_key_event<Event: KeyEvent>(
2950 &mut self,
2951 listener: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
2952 ) {
2953 debug_assert_eq!(
2954 self.window.draw_phase,
2955 DrawPhase::Paint,
2956 "this method can only be called during paint"
2957 );
2958
2959 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
2960 move |event: &dyn Any, phase, cx: &mut WindowContext<'_>| {
2961 if let Some(event) = event.downcast_ref::<Event>() {
2962 listener(event, phase, cx)
2963 }
2964 },
2965 ));
2966 }
2967
2968 /// Register a modifiers changed event listener on the window for the next frame.
2969 ///
2970 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
2971 /// a specific need to register a global listener.
2972 ///
2973 /// This method should only be called as part of the paint phase of element drawing.
2974 pub fn on_modifiers_changed(
2975 &mut self,
2976 listener: impl Fn(&ModifiersChangedEvent, &mut WindowContext) + 'static,
2977 ) {
2978 debug_assert_eq!(
2979 self.window.draw_phase,
2980 DrawPhase::Paint,
2981 "this method can only be called during paint"
2982 );
2983
2984 self.window
2985 .next_frame
2986 .dispatch_tree
2987 .on_modifiers_changed(Rc::new(
2988 move |event: &ModifiersChangedEvent, cx: &mut WindowContext<'_>| {
2989 listener(event, cx)
2990 },
2991 ));
2992 }
2993
2994 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2995 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
2996 /// Returns a subscription and persists until the subscription is dropped.
2997 pub fn on_focus_in(
2998 &mut self,
2999 handle: &FocusHandle,
3000 mut listener: impl FnMut(&mut WindowContext) + 'static,
3001 ) -> Subscription {
3002 let focus_id = handle.id;
3003 let (subscription, activate) =
3004 self.window.new_focus_listener(Box::new(move |event, cx| {
3005 if event.is_focus_in(focus_id) {
3006 listener(cx);
3007 }
3008 true
3009 }));
3010 self.app.defer(move |_| activate());
3011 subscription
3012 }
3013
3014 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
3015 /// Returns a subscription and persists until the subscription is dropped.
3016 pub fn on_focus_out(
3017 &mut self,
3018 handle: &FocusHandle,
3019 mut listener: impl FnMut(FocusOutEvent, &mut WindowContext) + 'static,
3020 ) -> Subscription {
3021 let focus_id = handle.id;
3022 let (subscription, activate) =
3023 self.window.new_focus_listener(Box::new(move |event, cx| {
3024 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
3025 if event.is_focus_out(focus_id) {
3026 let event = FocusOutEvent {
3027 blurred: WeakFocusHandle {
3028 id: blurred_id,
3029 handles: Arc::downgrade(&cx.app.focus_handles),
3030 },
3031 };
3032 listener(event, cx)
3033 }
3034 }
3035 true
3036 }));
3037 self.app.defer(move |_| activate());
3038 subscription
3039 }
3040
3041 fn reset_cursor_style(&self) {
3042 // Set the cursor only if we're the active window.
3043 if self.is_window_hovered() {
3044 let style = self
3045 .window
3046 .rendered_frame
3047 .cursor_styles
3048 .iter()
3049 .rev()
3050 .find(|request| request.hitbox_id.is_hovered(self))
3051 .map(|request| request.style)
3052 .unwrap_or(CursorStyle::Arrow);
3053 self.platform.set_cursor_style(style);
3054 }
3055 }
3056
3057 /// Dispatch a given keystroke as though the user had typed it.
3058 /// You can create a keystroke with Keystroke::parse("").
3059 pub fn dispatch_keystroke(&mut self, keystroke: Keystroke) -> bool {
3060 let keystroke = keystroke.with_simulated_ime();
3061 let result = self.dispatch_event(PlatformInput::KeyDown(KeyDownEvent {
3062 keystroke: keystroke.clone(),
3063 is_held: false,
3064 }));
3065 if !result.propagate {
3066 return true;
3067 }
3068
3069 if let Some(input) = keystroke.key_char {
3070 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3071 input_handler.dispatch_input(&input, self);
3072 self.window.platform_window.set_input_handler(input_handler);
3073 return true;
3074 }
3075 }
3076
3077 false
3078 }
3079
3080 /// Return a key binding string for an action, to display in the UI. Uses the highest precedence
3081 /// binding for the action (last binding added to the keymap).
3082 pub fn keystroke_text_for(&self, action: &dyn Action) -> String {
3083 self.bindings_for_action(action)
3084 .into_iter()
3085 .next()
3086 .map(|binding| {
3087 binding
3088 .keystrokes()
3089 .iter()
3090 .map(ToString::to_string)
3091 .collect::<Vec<_>>()
3092 .join(" ")
3093 })
3094 .unwrap_or_else(|| action.name().to_string())
3095 }
3096
3097 /// Dispatch a mouse or keyboard event on the window.
3098 #[profiling::function]
3099 pub fn dispatch_event(&mut self, event: PlatformInput) -> DispatchEventResult {
3100 self.window.last_input_timestamp.set(Instant::now());
3101 // Handlers may set this to false by calling `stop_propagation`.
3102 self.app.propagate_event = true;
3103 // Handlers may set this to true by calling `prevent_default`.
3104 self.window.default_prevented = false;
3105
3106 let event = match event {
3107 // Track the mouse position with our own state, since accessing the platform
3108 // API for the mouse position can only occur on the main thread.
3109 PlatformInput::MouseMove(mouse_move) => {
3110 self.window.mouse_position = mouse_move.position;
3111 self.window.modifiers = mouse_move.modifiers;
3112 PlatformInput::MouseMove(mouse_move)
3113 }
3114 PlatformInput::MouseDown(mouse_down) => {
3115 self.window.mouse_position = mouse_down.position;
3116 self.window.modifiers = mouse_down.modifiers;
3117 PlatformInput::MouseDown(mouse_down)
3118 }
3119 PlatformInput::MouseUp(mouse_up) => {
3120 self.window.mouse_position = mouse_up.position;
3121 self.window.modifiers = mouse_up.modifiers;
3122 PlatformInput::MouseUp(mouse_up)
3123 }
3124 PlatformInput::MouseExited(mouse_exited) => {
3125 self.window.modifiers = mouse_exited.modifiers;
3126 PlatformInput::MouseExited(mouse_exited)
3127 }
3128 PlatformInput::ModifiersChanged(modifiers_changed) => {
3129 self.window.modifiers = modifiers_changed.modifiers;
3130 PlatformInput::ModifiersChanged(modifiers_changed)
3131 }
3132 PlatformInput::ScrollWheel(scroll_wheel) => {
3133 self.window.mouse_position = scroll_wheel.position;
3134 self.window.modifiers = scroll_wheel.modifiers;
3135 PlatformInput::ScrollWheel(scroll_wheel)
3136 }
3137 // Translate dragging and dropping of external files from the operating system
3138 // to internal drag and drop events.
3139 PlatformInput::FileDrop(file_drop) => match file_drop {
3140 FileDropEvent::Entered { position, paths } => {
3141 self.window.mouse_position = position;
3142 if self.active_drag.is_none() {
3143 self.active_drag = Some(AnyDrag {
3144 value: Arc::new(paths.clone()),
3145 view: self.new_view(|_| paths).into(),
3146 cursor_offset: position,
3147 });
3148 }
3149 PlatformInput::MouseMove(MouseMoveEvent {
3150 position,
3151 pressed_button: Some(MouseButton::Left),
3152 modifiers: Modifiers::default(),
3153 })
3154 }
3155 FileDropEvent::Pending { position } => {
3156 self.window.mouse_position = position;
3157 PlatformInput::MouseMove(MouseMoveEvent {
3158 position,
3159 pressed_button: Some(MouseButton::Left),
3160 modifiers: Modifiers::default(),
3161 })
3162 }
3163 FileDropEvent::Submit { position } => {
3164 self.activate(true);
3165 self.window.mouse_position = position;
3166 PlatformInput::MouseUp(MouseUpEvent {
3167 button: MouseButton::Left,
3168 position,
3169 modifiers: Modifiers::default(),
3170 click_count: 1,
3171 })
3172 }
3173 FileDropEvent::Exited => {
3174 self.active_drag.take();
3175 PlatformInput::FileDrop(FileDropEvent::Exited)
3176 }
3177 },
3178 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
3179 };
3180
3181 if let Some(any_mouse_event) = event.mouse_event() {
3182 self.dispatch_mouse_event(any_mouse_event);
3183 } else if let Some(any_key_event) = event.keyboard_event() {
3184 self.dispatch_key_event(any_key_event);
3185 }
3186
3187 DispatchEventResult {
3188 propagate: self.app.propagate_event,
3189 default_prevented: self.window.default_prevented,
3190 }
3191 }
3192
3193 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
3194 let hit_test = self.window.rendered_frame.hit_test(self.mouse_position());
3195 if hit_test != self.window.mouse_hit_test {
3196 self.window.mouse_hit_test = hit_test;
3197 self.reset_cursor_style();
3198 }
3199
3200 let mut mouse_listeners = mem::take(&mut self.window.rendered_frame.mouse_listeners);
3201
3202 // Capture phase, events bubble from back to front. Handlers for this phase are used for
3203 // special purposes, such as detecting events outside of a given Bounds.
3204 for listener in &mut mouse_listeners {
3205 let listener = listener.as_mut().unwrap();
3206 listener(event, DispatchPhase::Capture, self);
3207 if !self.app.propagate_event {
3208 break;
3209 }
3210 }
3211
3212 // Bubble phase, where most normal handlers do their work.
3213 if self.app.propagate_event {
3214 for listener in mouse_listeners.iter_mut().rev() {
3215 let listener = listener.as_mut().unwrap();
3216 listener(event, DispatchPhase::Bubble, self);
3217 if !self.app.propagate_event {
3218 break;
3219 }
3220 }
3221 }
3222
3223 self.window.rendered_frame.mouse_listeners = mouse_listeners;
3224
3225 if self.has_active_drag() {
3226 if event.is::<MouseMoveEvent>() {
3227 // If this was a mouse move event, redraw the window so that the
3228 // active drag can follow the mouse cursor.
3229 self.refresh();
3230 } else if event.is::<MouseUpEvent>() {
3231 // If this was a mouse up event, cancel the active drag and redraw
3232 // the window.
3233 self.active_drag = None;
3234 self.refresh();
3235 }
3236 }
3237 }
3238
3239 fn dispatch_key_event(&mut self, event: &dyn Any) {
3240 if self.window.dirty.get() {
3241 self.draw();
3242 }
3243
3244 let node_id = self
3245 .window
3246 .focus
3247 .and_then(|focus_id| {
3248 self.window
3249 .rendered_frame
3250 .dispatch_tree
3251 .focusable_node_id(focus_id)
3252 })
3253 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3254
3255 let dispatch_path = self
3256 .window
3257 .rendered_frame
3258 .dispatch_tree
3259 .dispatch_path(node_id);
3260
3261 let mut keystroke: Option<Keystroke> = None;
3262
3263 if let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() {
3264 if event.modifiers.number_of_modifiers() == 0
3265 && self.window.pending_modifier.modifiers.number_of_modifiers() == 1
3266 && !self.window.pending_modifier.saw_keystroke
3267 {
3268 let key = match self.window.pending_modifier.modifiers {
3269 modifiers if modifiers.shift => Some("shift"),
3270 modifiers if modifiers.control => Some("control"),
3271 modifiers if modifiers.alt => Some("alt"),
3272 modifiers if modifiers.platform => Some("platform"),
3273 modifiers if modifiers.function => Some("function"),
3274 _ => None,
3275 };
3276 if let Some(key) = key {
3277 keystroke = Some(Keystroke {
3278 key: key.to_string(),
3279 key_char: None,
3280 modifiers: Modifiers::default(),
3281 });
3282 }
3283 }
3284
3285 if self.window.pending_modifier.modifiers.number_of_modifiers() == 0
3286 && event.modifiers.number_of_modifiers() == 1
3287 {
3288 self.window.pending_modifier.saw_keystroke = false
3289 }
3290 self.window.pending_modifier.modifiers = event.modifiers
3291 } else if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
3292 self.window.pending_modifier.saw_keystroke = true;
3293 keystroke = Some(key_down_event.keystroke.clone());
3294 }
3295
3296 let Some(keystroke) = keystroke else {
3297 self.finish_dispatch_key_event(event, dispatch_path);
3298 return;
3299 };
3300
3301 let mut currently_pending = self.window.pending_input.take().unwrap_or_default();
3302 if currently_pending.focus.is_some() && currently_pending.focus != self.window.focus {
3303 currently_pending = PendingInput::default();
3304 }
3305
3306 let match_result = self.window.rendered_frame.dispatch_tree.dispatch_key(
3307 currently_pending.keystrokes,
3308 keystroke,
3309 &dispatch_path,
3310 );
3311 if !match_result.to_replay.is_empty() {
3312 self.replay_pending_input(match_result.to_replay)
3313 }
3314
3315 if !match_result.pending.is_empty() {
3316 currently_pending.keystrokes = match_result.pending;
3317 currently_pending.focus = self.window.focus;
3318 currently_pending.timer = Some(self.spawn(|mut cx| async move {
3319 cx.background_executor.timer(Duration::from_secs(1)).await;
3320 cx.update(move |cx| {
3321 let Some(currently_pending) = cx
3322 .window
3323 .pending_input
3324 .take()
3325 .filter(|pending| pending.focus == cx.window.focus)
3326 else {
3327 return;
3328 };
3329
3330 let dispatch_path = cx
3331 .window
3332 .rendered_frame
3333 .dispatch_tree
3334 .dispatch_path(node_id);
3335
3336 let to_replay = cx
3337 .window
3338 .rendered_frame
3339 .dispatch_tree
3340 .flush_dispatch(currently_pending.keystrokes, &dispatch_path);
3341
3342 cx.replay_pending_input(to_replay)
3343 })
3344 .log_err();
3345 }));
3346 self.window.pending_input = Some(currently_pending);
3347 self.pending_input_changed();
3348 self.propagate_event = false;
3349 return;
3350 }
3351
3352 self.propagate_event = true;
3353 for binding in match_result.bindings {
3354 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3355 if !self.propagate_event {
3356 self.dispatch_keystroke_observers(event, Some(binding.action));
3357 self.pending_input_changed();
3358 return;
3359 }
3360 }
3361
3362 self.finish_dispatch_key_event(event, dispatch_path);
3363 self.pending_input_changed();
3364 }
3365
3366 fn finish_dispatch_key_event(
3367 &mut self,
3368 event: &dyn Any,
3369 dispatch_path: SmallVec<[DispatchNodeId; 32]>,
3370 ) {
3371 self.dispatch_key_down_up_event(event, &dispatch_path);
3372 if !self.propagate_event {
3373 return;
3374 }
3375
3376 self.dispatch_modifiers_changed_event(event, &dispatch_path);
3377 if !self.propagate_event {
3378 return;
3379 }
3380
3381 self.dispatch_keystroke_observers(event, None);
3382 }
3383
3384 fn pending_input_changed(&mut self) {
3385 self.window
3386 .pending_input_observers
3387 .clone()
3388 .retain(&(), |callback| callback(self));
3389 }
3390
3391 fn dispatch_key_down_up_event(
3392 &mut self,
3393 event: &dyn Any,
3394 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3395 ) {
3396 // Capture phase
3397 for node_id in dispatch_path {
3398 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3399
3400 for key_listener in node.key_listeners.clone() {
3401 key_listener(event, DispatchPhase::Capture, self);
3402 if !self.propagate_event {
3403 return;
3404 }
3405 }
3406 }
3407
3408 // Bubble phase
3409 for node_id in dispatch_path.iter().rev() {
3410 // Handle low level key events
3411 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3412 for key_listener in node.key_listeners.clone() {
3413 key_listener(event, DispatchPhase::Bubble, self);
3414 if !self.propagate_event {
3415 return;
3416 }
3417 }
3418 }
3419 }
3420
3421 fn dispatch_modifiers_changed_event(
3422 &mut self,
3423 event: &dyn Any,
3424 dispatch_path: &SmallVec<[DispatchNodeId; 32]>,
3425 ) {
3426 let Some(event) = event.downcast_ref::<ModifiersChangedEvent>() else {
3427 return;
3428 };
3429 for node_id in dispatch_path.iter().rev() {
3430 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3431 for listener in node.modifiers_changed_listeners.clone() {
3432 listener(event, self);
3433 if !self.propagate_event {
3434 return;
3435 }
3436 }
3437 }
3438 }
3439
3440 /// Determine whether a potential multi-stroke key binding is in progress on this window.
3441 pub fn has_pending_keystrokes(&self) -> bool {
3442 self.window.pending_input.is_some()
3443 }
3444
3445 pub(crate) fn clear_pending_keystrokes(&mut self) {
3446 self.window.pending_input.take();
3447 }
3448
3449 /// Returns the currently pending input keystrokes that might result in a multi-stroke key binding.
3450 pub fn pending_input_keystrokes(&self) -> Option<&[Keystroke]> {
3451 self.window
3452 .pending_input
3453 .as_ref()
3454 .map(|pending_input| pending_input.keystrokes.as_slice())
3455 }
3456
3457 fn replay_pending_input(&mut self, replays: SmallVec<[Replay; 1]>) {
3458 let node_id = self
3459 .window
3460 .focus
3461 .and_then(|focus_id| {
3462 self.window
3463 .rendered_frame
3464 .dispatch_tree
3465 .focusable_node_id(focus_id)
3466 })
3467 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3468
3469 let dispatch_path = self
3470 .window
3471 .rendered_frame
3472 .dispatch_tree
3473 .dispatch_path(node_id);
3474
3475 'replay: for replay in replays {
3476 let event = KeyDownEvent {
3477 keystroke: replay.keystroke.clone(),
3478 is_held: false,
3479 };
3480
3481 self.propagate_event = true;
3482 for binding in replay.bindings {
3483 self.dispatch_action_on_node(node_id, binding.action.as_ref());
3484 if !self.propagate_event {
3485 self.dispatch_keystroke_observers(&event, Some(binding.action));
3486 continue 'replay;
3487 }
3488 }
3489
3490 self.dispatch_key_down_up_event(&event, &dispatch_path);
3491 if !self.propagate_event {
3492 continue 'replay;
3493 }
3494 if let Some(input) = replay.keystroke.key_char.as_ref().cloned() {
3495 if let Some(mut input_handler) = self.window.platform_window.take_input_handler() {
3496 input_handler.dispatch_input(&input, self);
3497 self.window.platform_window.set_input_handler(input_handler)
3498 }
3499 }
3500 }
3501 }
3502
3503 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: &dyn Action) {
3504 let dispatch_path = self
3505 .window
3506 .rendered_frame
3507 .dispatch_tree
3508 .dispatch_path(node_id);
3509
3510 // Capture phase for global actions.
3511 self.propagate_event = true;
3512 if let Some(mut global_listeners) = self
3513 .global_action_listeners
3514 .remove(&action.as_any().type_id())
3515 {
3516 for listener in &global_listeners {
3517 listener(action.as_any(), DispatchPhase::Capture, self);
3518 if !self.propagate_event {
3519 break;
3520 }
3521 }
3522
3523 global_listeners.extend(
3524 self.global_action_listeners
3525 .remove(&action.as_any().type_id())
3526 .unwrap_or_default(),
3527 );
3528
3529 self.global_action_listeners
3530 .insert(action.as_any().type_id(), global_listeners);
3531 }
3532
3533 if !self.propagate_event {
3534 return;
3535 }
3536
3537 // Capture phase for window actions.
3538 for node_id in &dispatch_path {
3539 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3540 for DispatchActionListener {
3541 action_type,
3542 listener,
3543 } in node.action_listeners.clone()
3544 {
3545 let any_action = action.as_any();
3546 if action_type == any_action.type_id() {
3547 listener(any_action, DispatchPhase::Capture, self);
3548
3549 if !self.propagate_event {
3550 return;
3551 }
3552 }
3553 }
3554 }
3555
3556 // Bubble phase for window actions.
3557 for node_id in dispatch_path.iter().rev() {
3558 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
3559 for DispatchActionListener {
3560 action_type,
3561 listener,
3562 } in node.action_listeners.clone()
3563 {
3564 let any_action = action.as_any();
3565 if action_type == any_action.type_id() {
3566 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3567 listener(any_action, DispatchPhase::Bubble, self);
3568
3569 if !self.propagate_event {
3570 return;
3571 }
3572 }
3573 }
3574 }
3575
3576 // Bubble phase for global actions.
3577 if let Some(mut global_listeners) = self
3578 .global_action_listeners
3579 .remove(&action.as_any().type_id())
3580 {
3581 for listener in global_listeners.iter().rev() {
3582 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
3583
3584 listener(action.as_any(), DispatchPhase::Bubble, self);
3585 if !self.propagate_event {
3586 break;
3587 }
3588 }
3589
3590 global_listeners.extend(
3591 self.global_action_listeners
3592 .remove(&action.as_any().type_id())
3593 .unwrap_or_default(),
3594 );
3595
3596 self.global_action_listeners
3597 .insert(action.as_any().type_id(), global_listeners);
3598 }
3599 }
3600
3601 /// Register the given handler to be invoked whenever the global of the given type
3602 /// is updated.
3603 pub fn observe_global<G: Global>(
3604 &mut self,
3605 f: impl Fn(&mut WindowContext<'_>) + 'static,
3606 ) -> Subscription {
3607 let window_handle = self.window.handle;
3608 let (subscription, activate) = self.global_observers.insert(
3609 TypeId::of::<G>(),
3610 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
3611 );
3612 self.app.defer(move |_| activate());
3613 subscription
3614 }
3615
3616 /// Focus the current window and bring it to the foreground at the platform level.
3617 pub fn activate_window(&self) {
3618 self.window.platform_window.activate();
3619 }
3620
3621 /// Minimize the current window at the platform level.
3622 pub fn minimize_window(&self) {
3623 self.window.platform_window.minimize();
3624 }
3625
3626 /// Toggle full screen status on the current window at the platform level.
3627 pub fn toggle_fullscreen(&self) {
3628 self.window.platform_window.toggle_fullscreen();
3629 }
3630
3631 /// Updates the IME panel position suggestions for languages like japanese, chinese.
3632 pub fn invalidate_character_coordinates(&self) {
3633 self.on_next_frame(|cx| {
3634 if let Some(mut input_handler) = cx.window.platform_window.take_input_handler() {
3635 if let Some(bounds) = input_handler.selected_bounds(cx) {
3636 cx.window
3637 .platform_window
3638 .update_ime_position(bounds.scale(cx.scale_factor()));
3639 }
3640 cx.window.platform_window.set_input_handler(input_handler);
3641 }
3642 });
3643 }
3644
3645 /// Present a platform dialog.
3646 /// The provided message will be presented, along with buttons for each answer.
3647 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
3648 pub fn prompt(
3649 &mut self,
3650 level: PromptLevel,
3651 message: &str,
3652 detail: Option<&str>,
3653 answers: &[&str],
3654 ) -> oneshot::Receiver<usize> {
3655 let prompt_builder = self.app.prompt_builder.take();
3656 let Some(prompt_builder) = prompt_builder else {
3657 unreachable!("Re-entrant window prompting is not supported by GPUI");
3658 };
3659
3660 let receiver = match &prompt_builder {
3661 PromptBuilder::Default => self
3662 .window
3663 .platform_window
3664 .prompt(level, message, detail, answers)
3665 .unwrap_or_else(|| {
3666 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3667 }),
3668 PromptBuilder::Custom(_) => {
3669 self.build_custom_prompt(&prompt_builder, level, message, detail, answers)
3670 }
3671 };
3672
3673 self.app.prompt_builder = Some(prompt_builder);
3674
3675 receiver
3676 }
3677
3678 fn build_custom_prompt(
3679 &mut self,
3680 prompt_builder: &PromptBuilder,
3681 level: PromptLevel,
3682 message: &str,
3683 detail: Option<&str>,
3684 answers: &[&str],
3685 ) -> oneshot::Receiver<usize> {
3686 let (sender, receiver) = oneshot::channel();
3687 let handle = PromptHandle::new(sender);
3688 let handle = (prompt_builder)(level, message, detail, answers, handle, self);
3689 self.window.prompt = Some(handle);
3690 receiver
3691 }
3692
3693 /// Returns the current context stack.
3694 pub fn context_stack(&self) -> Vec<KeyContext> {
3695 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3696 let node_id = self
3697 .window
3698 .focus
3699 .and_then(|focus_id| dispatch_tree.focusable_node_id(focus_id))
3700 .unwrap_or_else(|| dispatch_tree.root_node_id());
3701
3702 dispatch_tree
3703 .dispatch_path(node_id)
3704 .iter()
3705 .filter_map(move |&node_id| dispatch_tree.node(node_id).context.clone())
3706 .collect()
3707 }
3708
3709 /// Returns all available actions for the focused element.
3710 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
3711 let node_id = self
3712 .window
3713 .focus
3714 .and_then(|focus_id| {
3715 self.window
3716 .rendered_frame
3717 .dispatch_tree
3718 .focusable_node_id(focus_id)
3719 })
3720 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
3721
3722 let mut actions = self
3723 .window
3724 .rendered_frame
3725 .dispatch_tree
3726 .available_actions(node_id);
3727 for action_type in self.global_action_listeners.keys() {
3728 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id()) {
3729 let action = self.actions.build_action_type(action_type).ok();
3730 if let Some(action) = action {
3731 actions.insert(ix, action);
3732 }
3733 }
3734 }
3735 actions
3736 }
3737
3738 /// Returns key bindings that invoke an action on the currently focused element, in precedence
3739 /// order (reverse of the order they were added to the keymap).
3740 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
3741 self.window
3742 .rendered_frame
3743 .dispatch_tree
3744 .bindings_for_action(
3745 action,
3746 &self.window.rendered_frame.dispatch_tree.context_stack,
3747 )
3748 }
3749
3750 /// Returns key bindings that invoke the given action on the currently focused element, without
3751 /// checking context. Bindings are returned returned in precedence order (reverse of the order
3752 /// they were added to the keymap).
3753 pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
3754 RefCell::borrow(&self.keymap).all_bindings_for_input(input)
3755 }
3756
3757 /// Returns any bindings that would invoke an action on the given focus handle if it were
3758 /// focused. Bindings are returned returned in precedence order (reverse of the order
3759 /// they were added to the keymap).
3760 pub fn bindings_for_action_in(
3761 &self,
3762 action: &dyn Action,
3763 focus_handle: &FocusHandle,
3764 ) -> Vec<KeyBinding> {
3765 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
3766
3767 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
3768 return vec![];
3769 };
3770 let context_stack: Vec<_> = dispatch_tree
3771 .dispatch_path(node_id)
3772 .into_iter()
3773 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
3774 .collect();
3775 dispatch_tree.bindings_for_action(action, &context_stack)
3776 }
3777
3778 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
3779 pub fn listener_for<V: Render, E>(
3780 &self,
3781 view: &View<V>,
3782 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
3783 ) -> impl Fn(&E, &mut WindowContext) + 'static {
3784 let view = view.downgrade();
3785 move |e: &E, cx: &mut WindowContext| {
3786 view.update(cx, |view, cx| f(view, e, cx)).ok();
3787 }
3788 }
3789
3790 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
3791 pub fn handler_for<V: Render>(
3792 &self,
3793 view: &View<V>,
3794 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
3795 ) -> impl Fn(&mut WindowContext) {
3796 let view = view.downgrade();
3797 move |cx: &mut WindowContext| {
3798 view.update(cx, |view, cx| f(view, cx)).ok();
3799 }
3800 }
3801
3802 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
3803 /// If the callback returns false, the window won't be closed.
3804 pub fn on_window_should_close(&self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
3805 let mut this = self.to_async();
3806 self.window
3807 .platform_window
3808 .on_should_close(Box::new(move || this.update(|cx| f(cx)).unwrap_or(true)))
3809 }
3810
3811 /// Register an action listener on the window for the next frame. The type of action
3812 /// is determined by the first parameter of the given listener. When the next frame is rendered
3813 /// the listener will be cleared.
3814 ///
3815 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
3816 /// a specific need to register a global listener.
3817 pub fn on_action(
3818 &mut self,
3819 action_type: TypeId,
3820 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
3821 ) {
3822 self.window
3823 .next_frame
3824 .dispatch_tree
3825 .on_action(action_type, Rc::new(listener));
3826 }
3827
3828 /// Read information about the GPU backing this window.
3829 /// Currently returns None on Mac and Windows.
3830 pub fn gpu_specs(&self) -> Option<GpuSpecs> {
3831 self.window.platform_window.gpu_specs()
3832 }
3833}
3834
3835#[cfg(target_os = "windows")]
3836impl WindowContext<'_> {
3837 /// Returns the raw HWND handle for the window.
3838 pub fn get_raw_handle(&self) -> windows::Win32::Foundation::HWND {
3839 self.window.platform_window.get_raw_handle()
3840 }
3841}
3842
3843impl Context for WindowContext<'_> {
3844 type Result<T> = T;
3845
3846 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
3847 where
3848 T: 'static,
3849 {
3850 let slot = self.app.entities.reserve();
3851 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
3852 self.entities.insert(slot, model)
3853 }
3854
3855 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
3856 self.app.reserve_model()
3857 }
3858
3859 fn insert_model<T: 'static>(
3860 &mut self,
3861 reservation: crate::Reservation<T>,
3862 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
3863 ) -> Self::Result<Model<T>> {
3864 self.app.insert_model(reservation, build_model)
3865 }
3866
3867 fn update_model<T: 'static, R>(
3868 &mut self,
3869 model: &Model<T>,
3870 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
3871 ) -> R {
3872 let mut entity = self.entities.lease(model);
3873 let result = update(
3874 &mut *entity,
3875 &mut ModelContext::new(&mut *self.app, model.downgrade()),
3876 );
3877 self.entities.end_lease(entity);
3878 result
3879 }
3880
3881 fn read_model<T, R>(
3882 &self,
3883 handle: &Model<T>,
3884 read: impl FnOnce(&T, &AppContext) -> R,
3885 ) -> Self::Result<R>
3886 where
3887 T: 'static,
3888 {
3889 let entity = self.entities.read(handle);
3890 read(entity, &*self.app)
3891 }
3892
3893 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
3894 where
3895 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
3896 {
3897 if window == self.window.handle {
3898 let root_view = self.window.root_view.clone().unwrap();
3899 Ok(update(root_view, self))
3900 } else {
3901 window.update(self.app, update)
3902 }
3903 }
3904
3905 fn read_window<T, R>(
3906 &self,
3907 window: &WindowHandle<T>,
3908 read: impl FnOnce(View<T>, &AppContext) -> R,
3909 ) -> Result<R>
3910 where
3911 T: 'static,
3912 {
3913 if window.any_handle == self.window.handle {
3914 let root_view = self
3915 .window
3916 .root_view
3917 .clone()
3918 .unwrap()
3919 .downcast::<T>()
3920 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3921 Ok(read(root_view, self))
3922 } else {
3923 self.app.read_window(window, read)
3924 }
3925 }
3926}
3927
3928impl VisualContext for WindowContext<'_> {
3929 fn new_view<V>(
3930 &mut self,
3931 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3932 ) -> Self::Result<View<V>>
3933 where
3934 V: 'static + Render,
3935 {
3936 let slot = self.app.entities.reserve();
3937 let view = View {
3938 model: slot.clone(),
3939 };
3940 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
3941 let entity = build_view_state(&mut cx);
3942 cx.entities.insert(slot, entity);
3943
3944 // Non-generic part to avoid leaking SubscriberSet to invokers of `new_view`.
3945 fn notify_observers(cx: &mut WindowContext, tid: TypeId, view: AnyView) {
3946 cx.new_view_observers.clone().retain(&tid, |observer| {
3947 let any_view = view.clone();
3948 (observer)(any_view, cx);
3949 true
3950 });
3951 }
3952 notify_observers(self, TypeId::of::<V>(), AnyView::from(view.clone()));
3953
3954 view
3955 }
3956
3957 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
3958 fn update_view<T: 'static, R>(
3959 &mut self,
3960 view: &View<T>,
3961 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
3962 ) -> Self::Result<R> {
3963 let mut lease = self.app.entities.lease(&view.model);
3964 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
3965 let result = update(&mut *lease, &mut cx);
3966 cx.app.entities.end_lease(lease);
3967 result
3968 }
3969
3970 fn replace_root_view<V>(
3971 &mut self,
3972 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
3973 ) -> Self::Result<View<V>>
3974 where
3975 V: 'static + Render,
3976 {
3977 let view = self.new_view(build_view);
3978 self.window.root_view = Some(view.clone().into());
3979 self.refresh();
3980 view
3981 }
3982
3983 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
3984 self.update_view(view, |view, cx| {
3985 view.focus_handle(cx).clone().focus(cx);
3986 })
3987 }
3988
3989 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
3990 where
3991 V: ManagedView,
3992 {
3993 self.update_view(view, |_, cx| cx.emit(DismissEvent))
3994 }
3995}
3996
3997impl<'a> std::ops::Deref for WindowContext<'a> {
3998 type Target = AppContext;
3999
4000 fn deref(&self) -> &Self::Target {
4001 self.app
4002 }
4003}
4004
4005impl<'a> std::ops::DerefMut for WindowContext<'a> {
4006 fn deref_mut(&mut self) -> &mut Self::Target {
4007 self.app
4008 }
4009}
4010
4011impl<'a> Borrow<AppContext> for WindowContext<'a> {
4012 fn borrow(&self) -> &AppContext {
4013 self.app
4014 }
4015}
4016
4017impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
4018 fn borrow_mut(&mut self) -> &mut AppContext {
4019 self.app
4020 }
4021}
4022
4023/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
4024pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
4025 #[doc(hidden)]
4026 fn app_mut(&mut self) -> &mut AppContext {
4027 self.borrow_mut()
4028 }
4029
4030 #[doc(hidden)]
4031 fn app(&self) -> &AppContext {
4032 self.borrow()
4033 }
4034
4035 #[doc(hidden)]
4036 fn window(&self) -> &Window {
4037 self.borrow()
4038 }
4039
4040 #[doc(hidden)]
4041 fn window_mut(&mut self) -> &mut Window {
4042 self.borrow_mut()
4043 }
4044}
4045
4046impl Borrow<Window> for WindowContext<'_> {
4047 fn borrow(&self) -> &Window {
4048 self.window
4049 }
4050}
4051
4052impl BorrowMut<Window> for WindowContext<'_> {
4053 fn borrow_mut(&mut self) -> &mut Window {
4054 self.window
4055 }
4056}
4057
4058impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
4059
4060/// Provides access to application state that is specialized for a particular [`View`].
4061/// Allows you to interact with focus, emit events, etc.
4062/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
4063/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
4064pub struct ViewContext<'a, V> {
4065 window_cx: WindowContext<'a>,
4066 view: &'a View<V>,
4067}
4068
4069impl<V> Borrow<AppContext> for ViewContext<'_, V> {
4070 fn borrow(&self) -> &AppContext {
4071 &*self.window_cx.app
4072 }
4073}
4074
4075impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
4076 fn borrow_mut(&mut self) -> &mut AppContext {
4077 &mut *self.window_cx.app
4078 }
4079}
4080
4081impl<V> Borrow<Window> for ViewContext<'_, V> {
4082 fn borrow(&self) -> &Window {
4083 &*self.window_cx.window
4084 }
4085}
4086
4087impl<V> BorrowMut<Window> for ViewContext<'_, V> {
4088 fn borrow_mut(&mut self) -> &mut Window {
4089 &mut *self.window_cx.window
4090 }
4091}
4092
4093impl<'a, V: 'static> ViewContext<'a, V> {
4094 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
4095 Self {
4096 window_cx: WindowContext::new(app, window),
4097 view,
4098 }
4099 }
4100
4101 /// Get the entity_id of this view.
4102 pub fn entity_id(&self) -> EntityId {
4103 self.view.entity_id()
4104 }
4105
4106 /// Get the view pointer underlying this context.
4107 pub fn view(&self) -> &View<V> {
4108 self.view
4109 }
4110
4111 /// Get the model underlying this view.
4112 pub fn model(&self) -> &Model<V> {
4113 &self.view.model
4114 }
4115
4116 /// Access the underlying window context.
4117 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
4118 &mut self.window_cx
4119 }
4120
4121 /// Sets a given callback to be run on the next frame.
4122 pub fn on_next_frame(&self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
4123 where
4124 V: 'static,
4125 {
4126 let view = self.view().clone();
4127 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
4128 }
4129
4130 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
4131 /// that are currently on the stack to be returned to the app.
4132 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
4133 let view = self.view().downgrade();
4134 self.window_cx.defer(move |cx| {
4135 view.update(cx, f).ok();
4136 });
4137 }
4138
4139 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
4140 pub fn observe<V2, E>(
4141 &mut self,
4142 entity: &E,
4143 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
4144 ) -> Subscription
4145 where
4146 V2: 'static,
4147 V: 'static,
4148 E: Entity<V2>,
4149 {
4150 let view = self.view().downgrade();
4151 let entity_id = entity.entity_id();
4152 let entity = entity.downgrade();
4153 let window_handle = self.window.handle;
4154 self.app.new_observer(
4155 entity_id,
4156 Box::new(move |cx| {
4157 window_handle
4158 .update(cx, |_, cx| {
4159 if let Some(handle) = E::upgrade_from(&entity) {
4160 view.update(cx, |this, cx| on_notify(this, handle, cx))
4161 .is_ok()
4162 } else {
4163 false
4164 }
4165 })
4166 .unwrap_or(false)
4167 }),
4168 )
4169 }
4170
4171 /// Subscribe to events emitted by another model or view.
4172 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
4173 /// 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.
4174 pub fn subscribe<V2, E, Evt>(
4175 &mut self,
4176 entity: &E,
4177 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
4178 ) -> Subscription
4179 where
4180 V2: EventEmitter<Evt>,
4181 E: Entity<V2>,
4182 Evt: 'static,
4183 {
4184 let view = self.view().downgrade();
4185 let entity_id = entity.entity_id();
4186 let handle = entity.downgrade();
4187 let window_handle = self.window.handle;
4188 self.app.new_subscription(
4189 entity_id,
4190 (
4191 TypeId::of::<Evt>(),
4192 Box::new(move |event, cx| {
4193 window_handle
4194 .update(cx, |_, cx| {
4195 if let Some(handle) = E::upgrade_from(&handle) {
4196 let event = event.downcast_ref().expect("invalid event type");
4197 view.update(cx, |this, cx| on_event(this, handle, event, cx))
4198 .is_ok()
4199 } else {
4200 false
4201 }
4202 })
4203 .unwrap_or(false)
4204 }),
4205 ),
4206 )
4207 }
4208
4209 /// Register a callback to be invoked when the view is released.
4210 ///
4211 /// The callback receives a handle to the view's window. This handle may be
4212 /// invalid, if the window was closed before the view was released.
4213 pub fn on_release(
4214 &self,
4215 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
4216 ) -> Subscription {
4217 let window_handle = self.window.handle;
4218 let (subscription, activate) = self.app.release_listeners.insert(
4219 self.view.model.entity_id,
4220 Box::new(move |this, cx| {
4221 let this = this.downcast_mut().expect("invalid entity type");
4222 on_release(this, window_handle, cx)
4223 }),
4224 );
4225 activate();
4226 subscription
4227 }
4228
4229 /// Register a callback to be invoked when the given Model or View is released.
4230 pub fn observe_release<V2, E>(
4231 &self,
4232 entity: &E,
4233 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
4234 ) -> Subscription
4235 where
4236 V: 'static,
4237 V2: 'static,
4238 E: Entity<V2>,
4239 {
4240 let view = self.view().downgrade();
4241 let entity_id = entity.entity_id();
4242 let window_handle = self.window.handle;
4243 let (subscription, activate) = self.app.release_listeners.insert(
4244 entity_id,
4245 Box::new(move |entity, cx| {
4246 let entity = entity.downcast_mut().expect("invalid entity type");
4247 let _ = window_handle.update(cx, |_, cx| {
4248 view.update(cx, |this, cx| on_release(this, entity, cx))
4249 });
4250 }),
4251 );
4252 activate();
4253 subscription
4254 }
4255
4256 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
4257 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
4258 pub fn notify(&mut self) {
4259 self.window_cx.notify(Some(self.view.entity_id()));
4260 }
4261
4262 /// Register a callback to be invoked when the window is resized.
4263 pub fn observe_window_bounds(
4264 &self,
4265 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4266 ) -> Subscription {
4267 let view = self.view.downgrade();
4268 let (subscription, activate) = self.window.bounds_observers.insert(
4269 (),
4270 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4271 );
4272 activate();
4273 subscription
4274 }
4275
4276 /// Register a callback to be invoked when the window is activated or deactivated.
4277 pub fn observe_window_activation(
4278 &self,
4279 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4280 ) -> Subscription {
4281 let view = self.view.downgrade();
4282 let (subscription, activate) = self.window.activation_observers.insert(
4283 (),
4284 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4285 );
4286 activate();
4287 subscription
4288 }
4289
4290 /// Registers a callback to be invoked when the window appearance changes.
4291 pub fn observe_window_appearance(
4292 &self,
4293 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4294 ) -> Subscription {
4295 let view = self.view.downgrade();
4296 let (subscription, activate) = self.window.appearance_observers.insert(
4297 (),
4298 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4299 );
4300 activate();
4301 subscription
4302 }
4303
4304 /// Register a callback to be invoked when a keystroke is received by the application
4305 /// in any window. Note that this fires after all other action and event mechanisms have resolved
4306 /// and that this API will not be invoked if the event's propagation is stopped.
4307 pub fn observe_keystrokes(
4308 &mut self,
4309 mut f: impl FnMut(&mut V, &KeystrokeEvent, &mut ViewContext<V>) + 'static,
4310 ) -> Subscription {
4311 fn inner(
4312 keystroke_observers: &SubscriberSet<(), KeystrokeObserver>,
4313 handler: KeystrokeObserver,
4314 ) -> Subscription {
4315 let (subscription, activate) = keystroke_observers.insert((), handler);
4316 activate();
4317 subscription
4318 }
4319
4320 let view = self.view.downgrade();
4321 inner(
4322 &mut self.keystroke_observers,
4323 Box::new(move |event, cx| {
4324 if let Some(view) = view.upgrade() {
4325 view.update(cx, |view, cx| f(view, event, cx));
4326 true
4327 } else {
4328 false
4329 }
4330 }),
4331 )
4332 }
4333
4334 /// Register a callback to be invoked when the window's pending input changes.
4335 pub fn observe_pending_input(
4336 &self,
4337 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4338 ) -> Subscription {
4339 let view = self.view.downgrade();
4340 let (subscription, activate) = self.window.pending_input_observers.insert(
4341 (),
4342 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
4343 );
4344 activate();
4345 subscription
4346 }
4347
4348 /// Register a listener to be called when the given focus handle receives focus.
4349 /// Returns a subscription and persists until the subscription is dropped.
4350 pub fn on_focus(
4351 &mut self,
4352 handle: &FocusHandle,
4353 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4354 ) -> Subscription {
4355 let view = self.view.downgrade();
4356 let focus_id = handle.id;
4357 let (subscription, activate) =
4358 self.window.new_focus_listener(Box::new(move |event, cx| {
4359 view.update(cx, |view, cx| {
4360 if event.previous_focus_path.last() != Some(&focus_id)
4361 && event.current_focus_path.last() == Some(&focus_id)
4362 {
4363 listener(view, cx)
4364 }
4365 })
4366 .is_ok()
4367 }));
4368 self.app.defer(|_| activate());
4369 subscription
4370 }
4371
4372 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
4373 /// This does not fire if the given focus handle - or one of its descendants - was previously focused.
4374 /// Returns a subscription and persists until the subscription is dropped.
4375 pub fn on_focus_in(
4376 &mut self,
4377 handle: &FocusHandle,
4378 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4379 ) -> Subscription {
4380 let view = self.view.downgrade();
4381 let focus_id = handle.id;
4382 let (subscription, activate) =
4383 self.window.new_focus_listener(Box::new(move |event, cx| {
4384 view.update(cx, |view, cx| {
4385 if event.is_focus_in(focus_id) {
4386 listener(view, cx)
4387 }
4388 })
4389 .is_ok()
4390 }));
4391 self.app.defer(move |_| activate());
4392 subscription
4393 }
4394
4395 /// Register a listener to be called when the given focus handle loses focus.
4396 /// Returns a subscription and persists until the subscription is dropped.
4397 pub fn on_blur(
4398 &mut self,
4399 handle: &FocusHandle,
4400 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4401 ) -> Subscription {
4402 let view = self.view.downgrade();
4403 let focus_id = handle.id;
4404 let (subscription, activate) =
4405 self.window.new_focus_listener(Box::new(move |event, cx| {
4406 view.update(cx, |view, cx| {
4407 if event.previous_focus_path.last() == Some(&focus_id)
4408 && event.current_focus_path.last() != Some(&focus_id)
4409 {
4410 listener(view, cx)
4411 }
4412 })
4413 .is_ok()
4414 }));
4415 self.app.defer(move |_| activate());
4416 subscription
4417 }
4418
4419 /// Register a listener to be called when nothing in the window has focus.
4420 /// This typically happens when the node that was focused is removed from the tree,
4421 /// and this callback lets you chose a default place to restore the users focus.
4422 /// Returns a subscription and persists until the subscription is dropped.
4423 pub fn on_focus_lost(
4424 &self,
4425 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
4426 ) -> Subscription {
4427 let view = self.view.downgrade();
4428 let (subscription, activate) = self.window.focus_lost_listeners.insert(
4429 (),
4430 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
4431 );
4432 activate();
4433 subscription
4434 }
4435
4436 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
4437 /// Returns a subscription and persists until the subscription is dropped.
4438 pub fn on_focus_out(
4439 &mut self,
4440 handle: &FocusHandle,
4441 mut listener: impl FnMut(&mut V, FocusOutEvent, &mut ViewContext<V>) + 'static,
4442 ) -> Subscription {
4443 let view = self.view.downgrade();
4444 let focus_id = handle.id;
4445 let (subscription, activate) =
4446 self.window.new_focus_listener(Box::new(move |event, cx| {
4447 view.update(cx, |view, cx| {
4448 if let Some(blurred_id) = event.previous_focus_path.last().copied() {
4449 if event.is_focus_out(focus_id) {
4450 let event = FocusOutEvent {
4451 blurred: WeakFocusHandle {
4452 id: blurred_id,
4453 handles: Arc::downgrade(&cx.app.focus_handles),
4454 },
4455 };
4456 listener(view, event, cx)
4457 }
4458 }
4459 })
4460 .is_ok()
4461 }));
4462 self.app.defer(move |_| activate());
4463 subscription
4464 }
4465
4466 /// Schedule a future to be run asynchronously.
4467 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
4468 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
4469 /// The returned future will be polled on the main thread.
4470 pub fn spawn<Fut, R>(&self, f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut) -> Task<R>
4471 where
4472 R: 'static,
4473 Fut: Future<Output = R> + 'static,
4474 {
4475 let view = self.view().downgrade();
4476 self.window_cx.spawn(|cx| f(view, cx))
4477 }
4478
4479 /// Register a callback to be invoked when the given global state changes.
4480 pub fn observe_global<G: Global>(
4481 &mut self,
4482 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
4483 ) -> Subscription {
4484 let window_handle = self.window.handle;
4485 let view = self.view().downgrade();
4486 let (subscription, activate) = self.global_observers.insert(
4487 TypeId::of::<G>(),
4488 Box::new(move |cx| {
4489 window_handle
4490 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
4491 .unwrap_or(false)
4492 }),
4493 );
4494 self.app.defer(move |_| activate());
4495 subscription
4496 }
4497
4498 /// Register a callback to be invoked when the given Action type is dispatched to the window.
4499 pub fn on_action(
4500 &mut self,
4501 action_type: TypeId,
4502 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
4503 ) {
4504 let handle = self.view().clone();
4505 self.window_cx
4506 .on_action(action_type, move |action, phase, cx| {
4507 handle.update(cx, |view, cx| {
4508 listener(view, action, phase, cx);
4509 })
4510 });
4511 }
4512
4513 /// Emit an event to be handled by any other views that have subscribed via [ViewContext::subscribe].
4514 pub fn emit<Evt>(&mut self, event: Evt)
4515 where
4516 Evt: 'static,
4517 V: EventEmitter<Evt>,
4518 {
4519 let emitter = self.view.model.entity_id;
4520 self.app.push_effect(Effect::Emit {
4521 emitter,
4522 event_type: TypeId::of::<Evt>(),
4523 event: Box::new(event),
4524 });
4525 }
4526
4527 /// Move focus to the current view, assuming it implements [`FocusableView`].
4528 pub fn focus_self(&mut self)
4529 where
4530 V: FocusableView,
4531 {
4532 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
4533 }
4534
4535 /// Convenience method for accessing view state in an event callback.
4536 ///
4537 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
4538 /// but it's often useful to be able to access view state in these
4539 /// callbacks. This method provides a convenient way to do so.
4540 pub fn listener<E: ?Sized>(
4541 &self,
4542 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
4543 ) -> impl Fn(&E, &mut WindowContext) + 'static {
4544 let view = self.view().downgrade();
4545 move |e: &E, cx: &mut WindowContext| {
4546 view.update(cx, |view, cx| f(view, e, cx)).ok();
4547 }
4548 }
4549}
4550
4551impl<V> Context for ViewContext<'_, V> {
4552 type Result<U> = U;
4553
4554 fn new_model<T: 'static>(
4555 &mut self,
4556 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4557 ) -> Model<T> {
4558 self.window_cx.new_model(build_model)
4559 }
4560
4561 fn reserve_model<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
4562 self.window_cx.reserve_model()
4563 }
4564
4565 fn insert_model<T: 'static>(
4566 &mut self,
4567 reservation: crate::Reservation<T>,
4568 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
4569 ) -> Self::Result<Model<T>> {
4570 self.window_cx.insert_model(reservation, build_model)
4571 }
4572
4573 fn update_model<T: 'static, R>(
4574 &mut self,
4575 model: &Model<T>,
4576 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
4577 ) -> R {
4578 self.window_cx.update_model(model, update)
4579 }
4580
4581 fn read_model<T, R>(
4582 &self,
4583 handle: &Model<T>,
4584 read: impl FnOnce(&T, &AppContext) -> R,
4585 ) -> Self::Result<R>
4586 where
4587 T: 'static,
4588 {
4589 self.window_cx.read_model(handle, read)
4590 }
4591
4592 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
4593 where
4594 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
4595 {
4596 self.window_cx.update_window(window, update)
4597 }
4598
4599 fn read_window<T, R>(
4600 &self,
4601 window: &WindowHandle<T>,
4602 read: impl FnOnce(View<T>, &AppContext) -> R,
4603 ) -> Result<R>
4604 where
4605 T: 'static,
4606 {
4607 self.window_cx.read_window(window, read)
4608 }
4609}
4610
4611impl<V: 'static> VisualContext for ViewContext<'_, V> {
4612 fn new_view<W: Render + 'static>(
4613 &mut self,
4614 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4615 ) -> Self::Result<View<W>> {
4616 self.window_cx.new_view(build_view_state)
4617 }
4618
4619 fn update_view<V2: 'static, R>(
4620 &mut self,
4621 view: &View<V2>,
4622 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
4623 ) -> Self::Result<R> {
4624 self.window_cx.update_view(view, update)
4625 }
4626
4627 fn replace_root_view<W>(
4628 &mut self,
4629 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
4630 ) -> Self::Result<View<W>>
4631 where
4632 W: 'static + Render,
4633 {
4634 self.window_cx.replace_root_view(build_view)
4635 }
4636
4637 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
4638 self.window_cx.focus_view(view)
4639 }
4640
4641 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
4642 self.window_cx.dismiss_view(view)
4643 }
4644}
4645
4646impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
4647 type Target = WindowContext<'a>;
4648
4649 fn deref(&self) -> &Self::Target {
4650 &self.window_cx
4651 }
4652}
4653
4654impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
4655 fn deref_mut(&mut self) -> &mut Self::Target {
4656 &mut self.window_cx
4657 }
4658}
4659
4660// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
4661slotmap::new_key_type! {
4662 /// A unique identifier for a window.
4663 pub struct WindowId;
4664}
4665
4666impl WindowId {
4667 /// Converts this window ID to a `u64`.
4668 pub fn as_u64(&self) -> u64 {
4669 self.0.as_ffi()
4670 }
4671}
4672
4673impl From<u64> for WindowId {
4674 fn from(value: u64) -> Self {
4675 WindowId(slotmap::KeyData::from_ffi(value))
4676 }
4677}
4678
4679/// A handle to a window with a specific root view type.
4680/// Note that this does not keep the window alive on its own.
4681#[derive(Deref, DerefMut)]
4682pub struct WindowHandle<V> {
4683 #[deref]
4684 #[deref_mut]
4685 pub(crate) any_handle: AnyWindowHandle,
4686 state_type: PhantomData<V>,
4687}
4688
4689impl<V: 'static + Render> WindowHandle<V> {
4690 /// Creates a new handle from a window ID.
4691 /// This does not check if the root type of the window is `V`.
4692 pub fn new(id: WindowId) -> Self {
4693 WindowHandle {
4694 any_handle: AnyWindowHandle {
4695 id,
4696 state_type: TypeId::of::<V>(),
4697 },
4698 state_type: PhantomData,
4699 }
4700 }
4701
4702 /// Get the root view out of this window.
4703 ///
4704 /// This will fail if the window is closed or if the root view's type does not match `V`.
4705 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
4706 where
4707 C: Context,
4708 {
4709 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
4710 root_view
4711 .downcast::<V>()
4712 .map_err(|_| anyhow!("the type of the window's root view has changed"))
4713 }))
4714 }
4715
4716 /// Updates the root view of this window.
4717 ///
4718 /// This will fail if the window has been closed or if the root view's type does not match
4719 pub fn update<C, R>(
4720 &self,
4721 cx: &mut C,
4722 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
4723 ) -> Result<R>
4724 where
4725 C: Context,
4726 {
4727 cx.update_window(self.any_handle, |root_view, cx| {
4728 let view = root_view
4729 .downcast::<V>()
4730 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4731 Ok(cx.update_view(&view, update))
4732 })?
4733 }
4734
4735 /// Read the root view out of this window.
4736 ///
4737 /// This will fail if the window is closed or if the root view's type does not match `V`.
4738 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
4739 let x = cx
4740 .windows
4741 .get(self.id)
4742 .and_then(|window| {
4743 window
4744 .as_ref()
4745 .and_then(|window| window.root_view.clone())
4746 .map(|root_view| root_view.downcast::<V>())
4747 })
4748 .ok_or_else(|| anyhow!("window not found"))?
4749 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
4750
4751 Ok(x.read(cx))
4752 }
4753
4754 /// Read the root view out of this window, with a callback
4755 ///
4756 /// This will fail if the window is closed or if the root view's type does not match `V`.
4757 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
4758 where
4759 C: Context,
4760 {
4761 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
4762 }
4763
4764 /// Read the root view pointer off of this window.
4765 ///
4766 /// This will fail if the window is closed or if the root view's type does not match `V`.
4767 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
4768 where
4769 C: Context,
4770 {
4771 cx.read_window(self, |root_view, _cx| root_view.clone())
4772 }
4773
4774 /// Check if this window is 'active'.
4775 ///
4776 /// Will return `None` if the window is closed or currently
4777 /// borrowed.
4778 pub fn is_active(&self, cx: &mut AppContext) -> Option<bool> {
4779 cx.update_window(self.any_handle, |_, cx| cx.is_window_active())
4780 .ok()
4781 }
4782}
4783
4784impl<V> Copy for WindowHandle<V> {}
4785
4786impl<V> Clone for WindowHandle<V> {
4787 fn clone(&self) -> Self {
4788 *self
4789 }
4790}
4791
4792impl<V> PartialEq for WindowHandle<V> {
4793 fn eq(&self, other: &Self) -> bool {
4794 self.any_handle == other.any_handle
4795 }
4796}
4797
4798impl<V> Eq for WindowHandle<V> {}
4799
4800impl<V> Hash for WindowHandle<V> {
4801 fn hash<H: Hasher>(&self, state: &mut H) {
4802 self.any_handle.hash(state);
4803 }
4804}
4805
4806impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
4807 fn from(val: WindowHandle<V>) -> Self {
4808 val.any_handle
4809 }
4810}
4811
4812unsafe impl<V> Send for WindowHandle<V> {}
4813unsafe impl<V> Sync for WindowHandle<V> {}
4814
4815/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
4816#[derive(Copy, Clone, PartialEq, Eq, Hash)]
4817pub struct AnyWindowHandle {
4818 pub(crate) id: WindowId,
4819 state_type: TypeId,
4820}
4821
4822impl AnyWindowHandle {
4823 /// Get the ID of this window.
4824 pub fn window_id(&self) -> WindowId {
4825 self.id
4826 }
4827
4828 /// Attempt to convert this handle to a window handle with a specific root view type.
4829 /// If the types do not match, this will return `None`.
4830 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
4831 if TypeId::of::<T>() == self.state_type {
4832 Some(WindowHandle {
4833 any_handle: *self,
4834 state_type: PhantomData,
4835 })
4836 } else {
4837 None
4838 }
4839 }
4840
4841 /// Updates the state of the root view of this window.
4842 ///
4843 /// This will fail if the window has been closed.
4844 pub fn update<C, R>(
4845 self,
4846 cx: &mut C,
4847 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
4848 ) -> Result<R>
4849 where
4850 C: Context,
4851 {
4852 cx.update_window(self, update)
4853 }
4854
4855 /// Read the state of the root view of this window.
4856 ///
4857 /// This will fail if the window has been closed.
4858 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
4859 where
4860 C: Context,
4861 T: 'static,
4862 {
4863 let view = self
4864 .downcast::<T>()
4865 .context("the type of the window's root view has changed")?;
4866
4867 cx.read_window(&view, read)
4868 }
4869}
4870
4871/// An identifier for an [`Element`](crate::Element).
4872///
4873/// Can be constructed with a string, a number, or both, as well
4874/// as other internal representations.
4875#[derive(Clone, Debug, Eq, PartialEq, Hash)]
4876pub enum ElementId {
4877 /// The ID of a View element
4878 View(EntityId),
4879 /// An integer ID.
4880 Integer(usize),
4881 /// A string based ID.
4882 Name(SharedString),
4883 /// A UUID.
4884 Uuid(Uuid),
4885 /// An ID that's equated with a focus handle.
4886 FocusHandle(FocusId),
4887 /// A combination of a name and an integer.
4888 NamedInteger(SharedString, usize),
4889 /// A path
4890 Path(Arc<std::path::Path>),
4891}
4892
4893impl Display for ElementId {
4894 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
4895 match self {
4896 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
4897 ElementId::Integer(ix) => write!(f, "{}", ix)?,
4898 ElementId::Name(name) => write!(f, "{}", name)?,
4899 ElementId::FocusHandle(_) => write!(f, "FocusHandle")?,
4900 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
4901 ElementId::Uuid(uuid) => write!(f, "{}", uuid)?,
4902 ElementId::Path(path) => write!(f, "{}", path.display())?,
4903 }
4904
4905 Ok(())
4906 }
4907}
4908
4909impl TryInto<SharedString> for ElementId {
4910 type Error = anyhow::Error;
4911
4912 fn try_into(self) -> anyhow::Result<SharedString> {
4913 if let ElementId::Name(name) = self {
4914 Ok(name)
4915 } else {
4916 Err(anyhow!("element id is not string"))
4917 }
4918 }
4919}
4920
4921impl From<usize> for ElementId {
4922 fn from(id: usize) -> Self {
4923 ElementId::Integer(id)
4924 }
4925}
4926
4927impl From<i32> for ElementId {
4928 fn from(id: i32) -> Self {
4929 Self::Integer(id as usize)
4930 }
4931}
4932
4933impl From<SharedString> for ElementId {
4934 fn from(name: SharedString) -> Self {
4935 ElementId::Name(name)
4936 }
4937}
4938
4939impl From<Arc<std::path::Path>> for ElementId {
4940 fn from(path: Arc<std::path::Path>) -> Self {
4941 ElementId::Path(path)
4942 }
4943}
4944
4945impl From<&'static str> for ElementId {
4946 fn from(name: &'static str) -> Self {
4947 ElementId::Name(name.into())
4948 }
4949}
4950
4951impl<'a> From<&'a FocusHandle> for ElementId {
4952 fn from(handle: &'a FocusHandle) -> Self {
4953 ElementId::FocusHandle(handle.id)
4954 }
4955}
4956
4957impl From<(&'static str, EntityId)> for ElementId {
4958 fn from((name, id): (&'static str, EntityId)) -> Self {
4959 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
4960 }
4961}
4962
4963impl From<(&'static str, usize)> for ElementId {
4964 fn from((name, id): (&'static str, usize)) -> Self {
4965 ElementId::NamedInteger(name.into(), id)
4966 }
4967}
4968
4969impl From<(SharedString, usize)> for ElementId {
4970 fn from((name, id): (SharedString, usize)) -> Self {
4971 ElementId::NamedInteger(name, id)
4972 }
4973}
4974
4975impl From<(&'static str, u64)> for ElementId {
4976 fn from((name, id): (&'static str, u64)) -> Self {
4977 ElementId::NamedInteger(name.into(), id as usize)
4978 }
4979}
4980
4981impl From<Uuid> for ElementId {
4982 fn from(value: Uuid) -> Self {
4983 Self::Uuid(value)
4984 }
4985}
4986
4987impl From<(&'static str, u32)> for ElementId {
4988 fn from((name, id): (&'static str, u32)) -> Self {
4989 ElementId::NamedInteger(name.into(), id as usize)
4990 }
4991}
4992
4993/// A rectangle to be rendered in the window at the given position and size.
4994/// Passed as an argument [`WindowContext::paint_quad`].
4995#[derive(Clone)]
4996pub struct PaintQuad {
4997 /// The bounds of the quad within the window.
4998 pub bounds: Bounds<Pixels>,
4999 /// The radii of the quad's corners.
5000 pub corner_radii: Corners<Pixels>,
5001 /// The background color of the quad.
5002 pub background: Background,
5003 /// The widths of the quad's borders.
5004 pub border_widths: Edges<Pixels>,
5005 /// The color of the quad's borders.
5006 pub border_color: Hsla,
5007}
5008
5009impl PaintQuad {
5010 /// Sets the corner radii of the quad.
5011 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
5012 PaintQuad {
5013 corner_radii: corner_radii.into(),
5014 ..self
5015 }
5016 }
5017
5018 /// Sets the border widths of the quad.
5019 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
5020 PaintQuad {
5021 border_widths: border_widths.into(),
5022 ..self
5023 }
5024 }
5025
5026 /// Sets the border color of the quad.
5027 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
5028 PaintQuad {
5029 border_color: border_color.into(),
5030 ..self
5031 }
5032 }
5033
5034 /// Sets the background color of the quad.
5035 pub fn background(self, background: impl Into<Background>) -> Self {
5036 PaintQuad {
5037 background: background.into(),
5038 ..self
5039 }
5040 }
5041}
5042
5043/// Creates a quad with the given parameters.
5044pub fn quad(
5045 bounds: Bounds<Pixels>,
5046 corner_radii: impl Into<Corners<Pixels>>,
5047 background: impl Into<Background>,
5048 border_widths: impl Into<Edges<Pixels>>,
5049 border_color: impl Into<Hsla>,
5050) -> PaintQuad {
5051 PaintQuad {
5052 bounds,
5053 corner_radii: corner_radii.into(),
5054 background: background.into(),
5055 border_widths: border_widths.into(),
5056 border_color: border_color.into(),
5057 }
5058}
5059
5060/// Creates a filled quad with the given bounds and background color.
5061pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Background>) -> PaintQuad {
5062 PaintQuad {
5063 bounds: bounds.into(),
5064 corner_radii: (0.).into(),
5065 background: background.into(),
5066 border_widths: (0.).into(),
5067 border_color: transparent_black(),
5068 }
5069}
5070
5071/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
5072pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
5073 PaintQuad {
5074 bounds: bounds.into(),
5075 corner_radii: (0.).into(),
5076 background: transparent_black().into(),
5077 border_widths: (1.).into(),
5078 border_color: border_color.into(),
5079 }
5080}