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