1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle,
4 DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId,
5 EventEmitter, FileDropEvent, Flatten, FocusEvent, FontId, GlobalElementId, GlyphId, Hsla,
6 ImageData, InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, KeystrokeEvent, LayoutId,
7 Model, ModelContext, Modifiers, MonochromeSprite, MouseButton, MouseMoveEvent, MouseUpEvent,
8 Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler, PlatformWindow, Point,
9 PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams, RenderImageParams,
10 RenderSvgParams, ScaledPixels, Scene, SceneBuilder, Shadow, SharedString, Size, Style,
11 SubscriberSet, Subscription, Surface, TaffyLayoutEngine, Task, Underline, UnderlineStyle, View,
12 VisualContext, WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Context as _, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use media::core_video::CVImageBuffer;
22use parking_lot::RwLock;
23use slotmap::SlotMap;
24use smallvec::SmallVec;
25use std::{
26 any::{Any, TypeId},
27 borrow::{Borrow, BorrowMut, Cow},
28 fmt::Debug,
29 future::Future,
30 hash::{Hash, Hasher},
31 marker::PhantomData,
32 mem,
33 rc::Rc,
34 sync::{
35 atomic::{AtomicUsize, Ordering::SeqCst},
36 Arc,
37 },
38};
39use util::ResultExt;
40
41const ACTIVE_DRAG_Z_INDEX: u32 = 1;
42
43/// A global stacking order, which is created by stacking successive z-index values.
44/// Each z-index will always be interpreted in the context of its parent z-index.
45#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default, Debug)]
46pub struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
47
48/// Represents the two different phases when dispatching events.
49#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
50pub enum DispatchPhase {
51 /// After the capture phase comes the bubble phase, in which mouse event listeners are
52 /// invoked front to back and keyboard event listeners are invoked from the focused element
53 /// to the root of the element tree. This is the phase you'll most commonly want to use when
54 /// registering event listeners.
55 #[default]
56 Bubble,
57 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
58 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
59 /// is used for special purposes such as clearing the "pressed" state for click events. If
60 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
61 /// outside of the immediate region may rely on detecting non-local events during this phase.
62 Capture,
63}
64
65impl DispatchPhase {
66 pub fn bubble(self) -> bool {
67 self == DispatchPhase::Bubble
68 }
69
70 pub fn capture(self) -> bool {
71 self == DispatchPhase::Capture
72 }
73}
74
75type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
76type AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
77type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
78type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
79
80slotmap::new_key_type! { pub struct FocusId; }
81
82impl FocusId {
83 /// Obtains whether the element associated with this handle is currently focused.
84 pub fn is_focused(&self, cx: &WindowContext) -> bool {
85 cx.window.focus == Some(*self)
86 }
87
88 /// Obtains whether the element associated with this handle contains the focused
89 /// element or is itself focused.
90 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
91 cx.focused()
92 .map_or(false, |focused| self.contains(focused.id, cx))
93 }
94
95 /// Obtains whether the element associated with this handle is contained within the
96 /// focused element or is itself focused.
97 pub fn within_focused(&self, cx: &WindowContext) -> bool {
98 let focused = cx.focused();
99 focused.map_or(false, |focused| focused.id.contains(*self, cx))
100 }
101
102 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
103 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
104 cx.window
105 .rendered_frame
106 .dispatch_tree
107 .focus_contains(*self, other)
108 }
109}
110
111/// A handle which can be used to track and manipulate the focused element in a window.
112pub struct FocusHandle {
113 pub(crate) id: FocusId,
114 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
115}
116
117impl std::fmt::Debug for FocusHandle {
118 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
119 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
120 }
121}
122
123impl FocusHandle {
124 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
125 let id = handles.write().insert(AtomicUsize::new(1));
126 Self {
127 id,
128 handles: handles.clone(),
129 }
130 }
131
132 pub(crate) fn for_id(
133 id: FocusId,
134 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
135 ) -> Option<Self> {
136 let lock = handles.read();
137 let ref_count = lock.get(id)?;
138 if ref_count.load(SeqCst) == 0 {
139 None
140 } else {
141 ref_count.fetch_add(1, SeqCst);
142 Some(Self {
143 id,
144 handles: handles.clone(),
145 })
146 }
147 }
148
149 /// Moves the focus to the element associated with this handle.
150 pub fn focus(&self, cx: &mut WindowContext) {
151 cx.focus(self)
152 }
153
154 /// Obtains whether the element associated with this handle is currently focused.
155 pub fn is_focused(&self, cx: &WindowContext) -> bool {
156 self.id.is_focused(cx)
157 }
158
159 /// Obtains whether the element associated with this handle contains the focused
160 /// element or is itself focused.
161 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
162 self.id.contains_focused(cx)
163 }
164
165 /// Obtains whether the element associated with this handle is contained within the
166 /// focused element or is itself focused.
167 pub fn within_focused(&self, cx: &WindowContext) -> bool {
168 self.id.within_focused(cx)
169 }
170
171 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
172 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
173 self.id.contains(other.id, cx)
174 }
175}
176
177impl Clone for FocusHandle {
178 fn clone(&self) -> Self {
179 Self::for_id(self.id, &self.handles).unwrap()
180 }
181}
182
183impl PartialEq for FocusHandle {
184 fn eq(&self, other: &Self) -> bool {
185 self.id == other.id
186 }
187}
188
189impl Eq for FocusHandle {}
190
191impl Drop for FocusHandle {
192 fn drop(&mut self) {
193 self.handles
194 .read()
195 .get(self.id)
196 .unwrap()
197 .fetch_sub(1, SeqCst);
198 }
199}
200
201/// FocusableView allows users of your view to easily
202/// focus it (using cx.focus_view(view))
203pub trait FocusableView: 'static + Render {
204 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
205}
206
207/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
208/// where the lifecycle of the view is handled by another view.
209pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
210
211impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
212
213pub struct DismissEvent;
214
215// Holds the state for a specific window.
216pub struct Window {
217 pub(crate) handle: AnyWindowHandle,
218 pub(crate) removed: bool,
219 pub(crate) platform_window: Box<dyn PlatformWindow>,
220 display_id: DisplayId,
221 sprite_atlas: Arc<dyn PlatformAtlas>,
222 rem_size: Pixels,
223 viewport_size: Size<Pixels>,
224 layout_engine: Option<TaffyLayoutEngine>,
225 pub(crate) root_view: Option<AnyView>,
226 pub(crate) element_id_stack: GlobalElementId,
227 pub(crate) rendered_frame: Frame,
228 pub(crate) next_frame: Frame,
229 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
230 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
231 pub(crate) blur_listeners: SubscriberSet<(), AnyObserver>,
232 default_prevented: bool,
233 mouse_position: Point<Pixels>,
234 requested_cursor_style: Option<CursorStyle>,
235 scale_factor: f32,
236 bounds: WindowBounds,
237 bounds_observers: SubscriberSet<(), AnyObserver>,
238 active: bool,
239 pub(crate) dirty: bool,
240 activation_observers: SubscriberSet<(), AnyObserver>,
241 pub(crate) last_blur: Option<Option<FocusId>>,
242 pub(crate) focus: Option<FocusId>,
243}
244
245pub(crate) struct ElementStateBox {
246 inner: Box<dyn Any>,
247 #[cfg(debug_assertions)]
248 type_name: &'static str,
249}
250
251// #[derive(Default)]
252pub(crate) struct Frame {
253 pub(crate) element_states: HashMap<GlobalElementId, ElementStateBox>,
254 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
255 pub(crate) dispatch_tree: DispatchTree,
256 pub(crate) focus_listeners: Vec<AnyFocusListener>,
257 pub(crate) scene_builder: SceneBuilder,
258 pub(crate) depth_map: Vec<(StackingOrder, Bounds<Pixels>)>,
259 pub(crate) z_index_stack: StackingOrder,
260 content_mask_stack: Vec<ContentMask<Pixels>>,
261 element_offset_stack: Vec<Point<Pixels>>,
262}
263
264impl Frame {
265 fn new(dispatch_tree: DispatchTree) -> Self {
266 Frame {
267 element_states: HashMap::default(),
268 mouse_listeners: HashMap::default(),
269 dispatch_tree,
270 focus_listeners: Vec::new(),
271 scene_builder: SceneBuilder::default(),
272 z_index_stack: StackingOrder::default(),
273 depth_map: Default::default(),
274 content_mask_stack: Vec::new(),
275 element_offset_stack: Vec::new(),
276 }
277 }
278
279 fn clear(&mut self) {
280 self.element_states.clear();
281 self.mouse_listeners.values_mut().for_each(Vec::clear);
282 self.focus_listeners.clear();
283 self.dispatch_tree.clear();
284 self.depth_map.clear();
285 }
286}
287
288impl Window {
289 pub(crate) fn new(
290 handle: AnyWindowHandle,
291 options: WindowOptions,
292 cx: &mut AppContext,
293 ) -> Self {
294 let platform_window = cx.platform.open_window(
295 handle,
296 options,
297 Box::new({
298 let mut cx = cx.to_async();
299 move || handle.update(&mut cx, |_, cx| cx.draw())
300 }),
301 );
302 let display_id = platform_window.display().id();
303 let sprite_atlas = platform_window.sprite_atlas();
304 let mouse_position = platform_window.mouse_position();
305 let content_size = platform_window.content_size();
306 let scale_factor = platform_window.scale_factor();
307 let bounds = platform_window.bounds();
308
309 platform_window.on_resize(Box::new({
310 let mut cx = cx.to_async();
311 move |_, _| {
312 handle
313 .update(&mut cx, |_, cx| cx.window_bounds_changed())
314 .log_err();
315 }
316 }));
317 platform_window.on_moved(Box::new({
318 let mut cx = cx.to_async();
319 move || {
320 handle
321 .update(&mut cx, |_, cx| cx.window_bounds_changed())
322 .log_err();
323 }
324 }));
325 platform_window.on_active_status_change(Box::new({
326 let mut cx = cx.to_async();
327 move |active| {
328 handle
329 .update(&mut cx, |_, cx| {
330 cx.window.active = active;
331 cx.window
332 .activation_observers
333 .clone()
334 .retain(&(), |callback| callback(cx));
335 })
336 .log_err();
337 }
338 }));
339
340 platform_window.on_input({
341 let mut cx = cx.to_async();
342 Box::new(move |event| {
343 handle
344 .update(&mut cx, |_, cx| cx.dispatch_event(event))
345 .log_err()
346 .unwrap_or(false)
347 })
348 });
349
350 Window {
351 handle,
352 removed: false,
353 platform_window,
354 display_id,
355 sprite_atlas,
356 rem_size: px(16.),
357 viewport_size: content_size,
358 layout_engine: Some(TaffyLayoutEngine::new()),
359 root_view: None,
360 element_id_stack: GlobalElementId::default(),
361 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
362 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
363 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
364 focus_listeners: SubscriberSet::new(),
365 blur_listeners: SubscriberSet::new(),
366 default_prevented: true,
367 mouse_position,
368 requested_cursor_style: None,
369 scale_factor,
370 bounds,
371 bounds_observers: SubscriberSet::new(),
372 active: false,
373 dirty: false,
374 activation_observers: SubscriberSet::new(),
375 last_blur: None,
376 focus: None,
377 }
378 }
379}
380
381/// Indicates which region of the window is visible. Content falling outside of this mask will not be
382/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
383/// to leave room to support more complex shapes in the future.
384#[derive(Clone, Debug, Default, PartialEq, Eq)]
385#[repr(C)]
386pub struct ContentMask<P: Clone + Default + Debug> {
387 pub bounds: Bounds<P>,
388}
389
390impl ContentMask<Pixels> {
391 /// Scale the content mask's pixel units by the given scaling factor.
392 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
393 ContentMask {
394 bounds: self.bounds.scale(factor),
395 }
396 }
397
398 /// Intersect the content mask with the given content mask.
399 pub fn intersect(&self, other: &Self) -> Self {
400 let bounds = self.bounds.intersect(&other.bounds);
401 ContentMask { bounds }
402 }
403}
404
405/// Provides access to application state in the context of a single window. Derefs
406/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
407/// an `AppContext` and call any `AppContext` methods.
408pub struct WindowContext<'a> {
409 pub(crate) app: &'a mut AppContext,
410 pub(crate) window: &'a mut Window,
411}
412
413impl<'a> WindowContext<'a> {
414 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
415 Self { app, window }
416 }
417
418 /// Obtain a handle to the window that belongs to this context.
419 pub fn window_handle(&self) -> AnyWindowHandle {
420 self.window.handle
421 }
422
423 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
424 pub fn notify(&mut self) {
425 self.window.dirty = true;
426 }
427
428 /// Close this window.
429 pub fn remove_window(&mut self) {
430 self.window.removed = true;
431 }
432
433 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
434 /// for elements rendered within this window.
435 pub fn focus_handle(&mut self) -> FocusHandle {
436 FocusHandle::new(&self.window.focus_handles)
437 }
438
439 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
440 pub fn focused(&self) -> Option<FocusHandle> {
441 self.window
442 .focus
443 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
444 }
445
446 /// Move focus to the element associated with the given `FocusHandle`.
447 pub fn focus(&mut self, handle: &FocusHandle) {
448 if self.window.focus == Some(handle.id) {
449 return;
450 }
451
452 let focus_id = handle.id;
453
454 if self.window.last_blur.is_none() {
455 self.window.last_blur = Some(self.window.focus);
456 }
457
458 self.window.focus = Some(focus_id);
459 self.window
460 .rendered_frame
461 .dispatch_tree
462 .clear_pending_keystrokes();
463 self.app.push_effect(Effect::FocusChanged {
464 window_handle: self.window.handle,
465 focused: Some(focus_id),
466 });
467 self.notify();
468 }
469
470 /// Remove focus from all elements within this context's window.
471 pub fn blur(&mut self) {
472 if self.window.last_blur.is_none() {
473 self.window.last_blur = Some(self.window.focus);
474 }
475
476 self.window.focus = None;
477 self.app.push_effect(Effect::FocusChanged {
478 window_handle: self.window.handle,
479 focused: None,
480 });
481 self.notify();
482 }
483
484 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
485 let focus_handle = self.focused();
486
487 self.defer(move |cx| {
488 let node_id = focus_handle
489 .and_then(|handle| {
490 cx.window
491 .rendered_frame
492 .dispatch_tree
493 .focusable_node_id(handle.id)
494 })
495 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
496
497 cx.propagate_event = true;
498 cx.dispatch_action_on_node(node_id, action);
499 })
500 }
501
502 pub(crate) fn dispatch_keystroke_observers(
503 &mut self,
504 event: &dyn Any,
505 action: Option<Box<dyn Action>>,
506 ) {
507 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
508 return;
509 };
510
511 self.keystroke_observers
512 .clone()
513 .retain(&(), move |callback| {
514 (callback)(
515 &KeystrokeEvent {
516 keystroke: key_down_event.keystroke.clone(),
517 action: action.as_ref().map(|action| action.boxed_clone()),
518 },
519 self,
520 );
521 true
522 });
523 }
524
525 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
526 /// that are currently on the stack to be returned to the app.
527 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
528 let handle = self.window.handle;
529 self.app.defer(move |cx| {
530 handle.update(cx, |_, cx| f(cx)).ok();
531 });
532 }
533
534 pub fn subscribe<Emitter, E, Evt>(
535 &mut self,
536 entity: &E,
537 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
538 ) -> Subscription
539 where
540 Emitter: EventEmitter<Evt>,
541 E: Entity<Emitter>,
542 Evt: 'static,
543 {
544 let entity_id = entity.entity_id();
545 let entity = entity.downgrade();
546 let window_handle = self.window.handle;
547 let (subscription, activate) = self.app.event_listeners.insert(
548 entity_id,
549 (
550 TypeId::of::<Evt>(),
551 Box::new(move |event, cx| {
552 window_handle
553 .update(cx, |_, cx| {
554 if let Some(handle) = E::upgrade_from(&entity) {
555 let event = event.downcast_ref().expect("invalid event type");
556 on_event(handle, event, cx);
557 true
558 } else {
559 false
560 }
561 })
562 .unwrap_or(false)
563 }),
564 ),
565 );
566 self.app.defer(move |_| activate());
567 subscription
568 }
569
570 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
571 /// await points in async code.
572 pub fn to_async(&self) -> AsyncWindowContext {
573 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
574 }
575
576 /// Schedule the given closure to be run directly after the current frame is rendered.
577 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
578 let handle = self.window.handle;
579 let display_id = self.window.display_id;
580
581 if !self.frame_consumers.contains_key(&display_id) {
582 let (tx, mut rx) = mpsc::unbounded::<()>();
583 self.platform.set_display_link_output_callback(
584 display_id,
585 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
586 );
587
588 let consumer_task = self.app.spawn(|cx| async move {
589 while rx.next().await.is_some() {
590 cx.update(|cx| {
591 for callback in cx
592 .next_frame_callbacks
593 .get_mut(&display_id)
594 .unwrap()
595 .drain(..)
596 .collect::<SmallVec<[_; 32]>>()
597 {
598 callback(cx);
599 }
600 })
601 .ok();
602
603 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
604
605 cx.update(|cx| {
606 if cx.next_frame_callbacks.is_empty() {
607 cx.platform.stop_display_link(display_id);
608 }
609 })
610 .ok();
611 }
612 });
613 self.frame_consumers.insert(display_id, consumer_task);
614 }
615
616 if self.next_frame_callbacks.is_empty() {
617 self.platform.start_display_link(display_id);
618 }
619
620 self.next_frame_callbacks
621 .entry(display_id)
622 .or_default()
623 .push(Box::new(move |cx: &mut AppContext| {
624 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
625 }));
626 }
627
628 /// Spawn the future returned by the given closure on the application thread pool.
629 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
630 /// use within your future.
631 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
632 where
633 R: 'static,
634 Fut: Future<Output = R> + 'static,
635 {
636 self.app
637 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
638 }
639
640 /// Update the global of the given type. The given closure is given simultaneous mutable
641 /// access both to the global and the context.
642 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
643 where
644 G: 'static,
645 {
646 let mut global = self.app.lease_global::<G>();
647 let result = f(&mut global, self);
648 self.app.end_global_lease(global);
649 result
650 }
651
652 #[must_use]
653 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
654 /// layout is being requested, along with the layout ids of any children. This method is called during
655 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
656 pub fn request_layout(
657 &mut self,
658 style: &Style,
659 children: impl IntoIterator<Item = LayoutId>,
660 ) -> LayoutId {
661 self.app.layout_id_buffer.clear();
662 self.app.layout_id_buffer.extend(children.into_iter());
663 let rem_size = self.rem_size();
664
665 self.window.layout_engine.as_mut().unwrap().request_layout(
666 style,
667 rem_size,
668 &self.app.layout_id_buffer,
669 )
670 }
671
672 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
673 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
674 /// determine the element's size. One place this is used internally is when measuring text.
675 ///
676 /// The given closure is invoked at layout time with the known dimensions and available space and
677 /// returns a `Size`.
678 pub fn request_measured_layout<
679 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
680 + 'static,
681 >(
682 &mut self,
683 style: Style,
684 measure: F,
685 ) -> LayoutId {
686 let rem_size = self.rem_size();
687 self.window
688 .layout_engine
689 .as_mut()
690 .unwrap()
691 .request_measured_layout(style, rem_size, measure)
692 }
693
694 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
695 let mut layout_engine = self.window.layout_engine.take().unwrap();
696 layout_engine.compute_layout(layout_id, available_space, self);
697 self.window.layout_engine = Some(layout_engine);
698 }
699
700 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
701 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
702 /// in order to pass your element its `Bounds` automatically.
703 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
704 let mut bounds = self
705 .window
706 .layout_engine
707 .as_mut()
708 .unwrap()
709 .layout_bounds(layout_id)
710 .map(Into::into);
711 bounds.origin += self.element_offset();
712 bounds
713 }
714
715 fn window_bounds_changed(&mut self) {
716 self.window.scale_factor = self.window.platform_window.scale_factor();
717 self.window.viewport_size = self.window.platform_window.content_size();
718 self.window.bounds = self.window.platform_window.bounds();
719 self.window.display_id = self.window.platform_window.display().id();
720 self.notify();
721
722 self.window
723 .bounds_observers
724 .clone()
725 .retain(&(), |callback| callback(self));
726 }
727
728 pub fn window_bounds(&self) -> WindowBounds {
729 self.window.bounds
730 }
731
732 pub fn viewport_size(&self) -> Size<Pixels> {
733 self.window.viewport_size
734 }
735
736 pub fn is_window_active(&self) -> bool {
737 self.window.active
738 }
739
740 pub fn zoom_window(&self) {
741 self.window.platform_window.zoom();
742 }
743
744 pub fn set_window_title(&mut self, title: &str) {
745 self.window.platform_window.set_title(title);
746 }
747
748 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
749 self.platform
750 .displays()
751 .into_iter()
752 .find(|display| display.id() == self.window.display_id)
753 }
754
755 pub fn show_character_palette(&self) {
756 self.window.platform_window.show_character_palette();
757 }
758
759 /// The scale factor of the display associated with the window. For example, it could
760 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
761 /// be rendered as two pixels on screen.
762 pub fn scale_factor(&self) -> f32 {
763 self.window.scale_factor
764 }
765
766 /// The size of an em for the base font of the application. Adjusting this value allows the
767 /// UI to scale, just like zooming a web page.
768 pub fn rem_size(&self) -> Pixels {
769 self.window.rem_size
770 }
771
772 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
773 /// UI to scale, just like zooming a web page.
774 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
775 self.window.rem_size = rem_size.into();
776 }
777
778 /// The line height associated with the current text style.
779 pub fn line_height(&self) -> Pixels {
780 let rem_size = self.rem_size();
781 let text_style = self.text_style();
782 text_style
783 .line_height
784 .to_pixels(text_style.font_size.into(), rem_size)
785 }
786
787 /// Call to prevent the default action of an event. Currently only used to prevent
788 /// parent elements from becoming focused on mouse down.
789 pub fn prevent_default(&mut self) {
790 self.window.default_prevented = true;
791 }
792
793 /// Obtain whether default has been prevented for the event currently being dispatched.
794 pub fn default_prevented(&self) -> bool {
795 self.window.default_prevented
796 }
797
798 /// Register a mouse event listener on the window for the next frame. The type of event
799 /// is determined by the first parameter of the given listener. When the next frame is rendered
800 /// the listener will be cleared.
801 ///
802 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
803 /// a specific need to register a global listener.
804 pub fn on_mouse_event<Event: 'static>(
805 &mut self,
806 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
807 ) {
808 let order = self.window.next_frame.z_index_stack.clone();
809 self.window
810 .next_frame
811 .mouse_listeners
812 .entry(TypeId::of::<Event>())
813 .or_default()
814 .push((
815 order,
816 Box::new(move |event: &dyn Any, phase, cx| {
817 handler(event.downcast_ref().unwrap(), phase, cx)
818 }),
819 ))
820 }
821
822 /// Register a key event listener on the window for the next frame. The type of event
823 /// is determined by the first parameter of the given listener. When the next frame is rendered
824 /// the listener will be cleared.
825 ///
826 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
827 /// a specific need to register a global listener.
828 pub fn on_key_event<Event: 'static>(
829 &mut self,
830 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
831 ) {
832 self.window
833 .next_frame
834 .dispatch_tree
835 .on_key_event(Rc::new(move |event, phase, cx| {
836 if let Some(event) = event.downcast_ref::<Event>() {
837 handler(event, phase, cx)
838 }
839 }));
840 }
841
842 /// Register an action listener on the window for the next frame. The type of action
843 /// is determined by the first parameter of the given listener. When the next frame is rendered
844 /// the listener will be cleared.
845 ///
846 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
847 /// a specific need to register a global listener.
848 pub fn on_action(
849 &mut self,
850 action_type: TypeId,
851 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
852 ) {
853 self.window.next_frame.dispatch_tree.on_action(
854 action_type,
855 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
856 );
857 }
858
859 pub fn is_action_available(&self, action: &dyn Action) -> bool {
860 let target = self
861 .focused()
862 .and_then(|focused_handle| {
863 self.window
864 .rendered_frame
865 .dispatch_tree
866 .focusable_node_id(focused_handle.id)
867 })
868 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
869 self.window
870 .rendered_frame
871 .dispatch_tree
872 .is_action_available(action, target)
873 }
874
875 /// The position of the mouse relative to the window.
876 pub fn mouse_position(&self) -> Point<Pixels> {
877 self.window.mouse_position
878 }
879
880 pub fn set_cursor_style(&mut self, style: CursorStyle) {
881 self.window.requested_cursor_style = Some(style)
882 }
883
884 /// Called during painting to invoke the given closure in a new stacking context. The given
885 /// z-index is interpreted relative to the previous call to `stack`.
886 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
887 self.window.next_frame.z_index_stack.push(z_index);
888 let result = f(self);
889 self.window.next_frame.z_index_stack.pop();
890 result
891 }
892
893 /// Called during painting to track which z-index is on top at each pixel position
894 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
895 let stacking_order = self.window.next_frame.z_index_stack.clone();
896 let depth_map = &mut self.window.next_frame.depth_map;
897 match depth_map.binary_search_by(|(level, _)| stacking_order.cmp(&level)) {
898 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, bounds)),
899 }
900 }
901
902 /// Returns true if the top-most opaque layer painted over this point was part of the
903 /// same layer as the given stacking order.
904 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
905 for (stack, bounds) in self.window.rendered_frame.depth_map.iter() {
906 if bounds.contains(point) {
907 return level.starts_with(stack) || stack.starts_with(level);
908 }
909 }
910
911 false
912 }
913
914 pub fn was_top_layer_under_active_drag(
915 &self,
916 point: &Point<Pixels>,
917 level: &StackingOrder,
918 ) -> bool {
919 for (stack, bounds) in self.window.rendered_frame.depth_map.iter() {
920 if stack.starts_with(&[ACTIVE_DRAG_Z_INDEX]) {
921 continue;
922 }
923 if bounds.contains(point) {
924 return level.starts_with(stack) || stack.starts_with(level);
925 }
926 }
927
928 false
929 }
930
931 /// Called during painting to get the current stacking order.
932 pub fn stacking_order(&self) -> &StackingOrder {
933 &self.window.next_frame.z_index_stack
934 }
935
936 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
937 pub fn paint_shadows(
938 &mut self,
939 bounds: Bounds<Pixels>,
940 corner_radii: Corners<Pixels>,
941 shadows: &[BoxShadow],
942 ) {
943 let scale_factor = self.scale_factor();
944 let content_mask = self.content_mask();
945 let window = &mut *self.window;
946 for shadow in shadows {
947 let mut shadow_bounds = bounds;
948 shadow_bounds.origin += shadow.offset;
949 shadow_bounds.dilate(shadow.spread_radius);
950 window.next_frame.scene_builder.insert(
951 &window.next_frame.z_index_stack,
952 Shadow {
953 order: 0,
954 bounds: shadow_bounds.scale(scale_factor),
955 content_mask: content_mask.scale(scale_factor),
956 corner_radii: corner_radii.scale(scale_factor),
957 color: shadow.color,
958 blur_radius: shadow.blur_radius.scale(scale_factor),
959 },
960 );
961 }
962 }
963
964 /// Paint one or more quads into the scene for the next frame at the current stacking context.
965 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
966 pub fn paint_quad(
967 &mut self,
968 bounds: Bounds<Pixels>,
969 corner_radii: Corners<Pixels>,
970 background: impl Into<Hsla>,
971 border_widths: Edges<Pixels>,
972 border_color: impl Into<Hsla>,
973 ) {
974 let scale_factor = self.scale_factor();
975 let content_mask = self.content_mask();
976
977 let window = &mut *self.window;
978 window.next_frame.scene_builder.insert(
979 &window.next_frame.z_index_stack,
980 Quad {
981 order: 0,
982 bounds: bounds.scale(scale_factor),
983 content_mask: content_mask.scale(scale_factor),
984 background: background.into(),
985 border_color: border_color.into(),
986 corner_radii: corner_radii.scale(scale_factor),
987 border_widths: border_widths.scale(scale_factor),
988 },
989 );
990 }
991
992 /// Paint the given `Path` into the scene for the next frame at the current z-index.
993 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
994 let scale_factor = self.scale_factor();
995 let content_mask = self.content_mask();
996 path.content_mask = content_mask;
997 path.color = color.into();
998 let window = &mut *self.window;
999 window
1000 .next_frame
1001 .scene_builder
1002 .insert(&window.next_frame.z_index_stack, path.scale(scale_factor));
1003 }
1004
1005 /// Paint an underline into the scene for the next frame at the current z-index.
1006 pub fn paint_underline(
1007 &mut self,
1008 origin: Point<Pixels>,
1009 width: Pixels,
1010 style: &UnderlineStyle,
1011 ) {
1012 let scale_factor = self.scale_factor();
1013 let height = if style.wavy {
1014 style.thickness * 3.
1015 } else {
1016 style.thickness
1017 };
1018 let bounds = Bounds {
1019 origin,
1020 size: size(width, height),
1021 };
1022 let content_mask = self.content_mask();
1023 let window = &mut *self.window;
1024 window.next_frame.scene_builder.insert(
1025 &window.next_frame.z_index_stack,
1026 Underline {
1027 order: 0,
1028 bounds: bounds.scale(scale_factor),
1029 content_mask: content_mask.scale(scale_factor),
1030 thickness: style.thickness.scale(scale_factor),
1031 color: style.color.unwrap_or_default(),
1032 wavy: style.wavy,
1033 },
1034 );
1035 }
1036
1037 /// Paint a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
1038 /// The y component of the origin is the baseline of the glyph.
1039 pub fn paint_glyph(
1040 &mut self,
1041 origin: Point<Pixels>,
1042 font_id: FontId,
1043 glyph_id: GlyphId,
1044 font_size: Pixels,
1045 color: Hsla,
1046 ) -> Result<()> {
1047 let scale_factor = self.scale_factor();
1048 let glyph_origin = origin.scale(scale_factor);
1049 let subpixel_variant = Point {
1050 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
1051 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
1052 };
1053 let params = RenderGlyphParams {
1054 font_id,
1055 glyph_id,
1056 font_size,
1057 subpixel_variant,
1058 scale_factor,
1059 is_emoji: false,
1060 };
1061
1062 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1063 if !raster_bounds.is_zero() {
1064 let tile =
1065 self.window
1066 .sprite_atlas
1067 .get_or_insert_with(¶ms.clone().into(), &mut || {
1068 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1069 Ok((size, Cow::Owned(bytes)))
1070 })?;
1071 let bounds = Bounds {
1072 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1073 size: tile.bounds.size.map(Into::into),
1074 };
1075 let content_mask = self.content_mask().scale(scale_factor);
1076 let window = &mut *self.window;
1077 window.next_frame.scene_builder.insert(
1078 &window.next_frame.z_index_stack,
1079 MonochromeSprite {
1080 order: 0,
1081 bounds,
1082 content_mask,
1083 color,
1084 tile,
1085 },
1086 );
1087 }
1088 Ok(())
1089 }
1090
1091 /// Paint an emoji glyph into the scene for the next frame at the current z-index.
1092 /// The y component of the origin is the baseline of the glyph.
1093 pub fn paint_emoji(
1094 &mut self,
1095 origin: Point<Pixels>,
1096 font_id: FontId,
1097 glyph_id: GlyphId,
1098 font_size: Pixels,
1099 ) -> Result<()> {
1100 let scale_factor = self.scale_factor();
1101 let glyph_origin = origin.scale(scale_factor);
1102 let params = RenderGlyphParams {
1103 font_id,
1104 glyph_id,
1105 font_size,
1106 // We don't render emojis with subpixel variants.
1107 subpixel_variant: Default::default(),
1108 scale_factor,
1109 is_emoji: true,
1110 };
1111
1112 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1113 if !raster_bounds.is_zero() {
1114 let tile =
1115 self.window
1116 .sprite_atlas
1117 .get_or_insert_with(¶ms.clone().into(), &mut || {
1118 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1119 Ok((size, Cow::Owned(bytes)))
1120 })?;
1121 let bounds = Bounds {
1122 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1123 size: tile.bounds.size.map(Into::into),
1124 };
1125 let content_mask = self.content_mask().scale(scale_factor);
1126 let window = &mut *self.window;
1127
1128 window.next_frame.scene_builder.insert(
1129 &window.next_frame.z_index_stack,
1130 PolychromeSprite {
1131 order: 0,
1132 bounds,
1133 corner_radii: Default::default(),
1134 content_mask,
1135 tile,
1136 grayscale: false,
1137 },
1138 );
1139 }
1140 Ok(())
1141 }
1142
1143 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
1144 pub fn paint_svg(
1145 &mut self,
1146 bounds: Bounds<Pixels>,
1147 path: SharedString,
1148 color: Hsla,
1149 ) -> Result<()> {
1150 let scale_factor = self.scale_factor();
1151 let bounds = bounds.scale(scale_factor);
1152 // Render the SVG at twice the size to get a higher quality result.
1153 let params = RenderSvgParams {
1154 path,
1155 size: bounds
1156 .size
1157 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1158 };
1159
1160 let tile =
1161 self.window
1162 .sprite_atlas
1163 .get_or_insert_with(¶ms.clone().into(), &mut || {
1164 let bytes = self.svg_renderer.render(¶ms)?;
1165 Ok((params.size, Cow::Owned(bytes)))
1166 })?;
1167 let content_mask = self.content_mask().scale(scale_factor);
1168
1169 let window = &mut *self.window;
1170 window.next_frame.scene_builder.insert(
1171 &window.next_frame.z_index_stack,
1172 MonochromeSprite {
1173 order: 0,
1174 bounds,
1175 content_mask,
1176 color,
1177 tile,
1178 },
1179 );
1180
1181 Ok(())
1182 }
1183
1184 /// Paint an image into the scene for the next frame at the current z-index.
1185 pub fn paint_image(
1186 &mut self,
1187 bounds: Bounds<Pixels>,
1188 corner_radii: Corners<Pixels>,
1189 data: Arc<ImageData>,
1190 grayscale: bool,
1191 ) -> Result<()> {
1192 let scale_factor = self.scale_factor();
1193 let bounds = bounds.scale(scale_factor);
1194 let params = RenderImageParams { image_id: data.id };
1195
1196 let tile = self
1197 .window
1198 .sprite_atlas
1199 .get_or_insert_with(¶ms.clone().into(), &mut || {
1200 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1201 })?;
1202 let content_mask = self.content_mask().scale(scale_factor);
1203 let corner_radii = corner_radii.scale(scale_factor);
1204
1205 let window = &mut *self.window;
1206 window.next_frame.scene_builder.insert(
1207 &window.next_frame.z_index_stack,
1208 PolychromeSprite {
1209 order: 0,
1210 bounds,
1211 content_mask,
1212 corner_radii,
1213 tile,
1214 grayscale,
1215 },
1216 );
1217 Ok(())
1218 }
1219
1220 /// Paint a surface into the scene for the next frame at the current z-index.
1221 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
1222 let scale_factor = self.scale_factor();
1223 let bounds = bounds.scale(scale_factor);
1224 let content_mask = self.content_mask().scale(scale_factor);
1225 let window = &mut *self.window;
1226 window.next_frame.scene_builder.insert(
1227 &window.next_frame.z_index_stack,
1228 Surface {
1229 order: 0,
1230 bounds,
1231 content_mask,
1232 image_buffer,
1233 },
1234 );
1235 }
1236
1237 /// Draw pixels to the display for this window based on the contents of its scene.
1238 pub(crate) fn draw(&mut self) -> Scene {
1239 let window_was_focused = self
1240 .window
1241 .focus
1242 .and_then(|focus_id| {
1243 self.window
1244 .rendered_frame
1245 .dispatch_tree
1246 .focusable_node_id(focus_id)
1247 })
1248 .is_some();
1249 self.text_system().start_frame();
1250 self.window.platform_window.clear_input_handler();
1251 self.window.layout_engine.as_mut().unwrap().clear();
1252 self.window.next_frame.clear();
1253 let root_view = self.window.root_view.take().unwrap();
1254
1255 self.with_z_index(0, |cx| {
1256 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
1257 for (action_type, action_listeners) in &cx.app.global_action_listeners {
1258 for action_listener in action_listeners.iter().cloned() {
1259 cx.window.next_frame.dispatch_tree.on_action(
1260 *action_type,
1261 Rc::new(move |action, phase, cx| action_listener(action, phase, cx)),
1262 )
1263 }
1264 }
1265
1266 let available_space = cx.window.viewport_size.map(Into::into);
1267 root_view.draw(Point::default(), available_space, cx);
1268 })
1269 });
1270
1271 if let Some(active_drag) = self.app.active_drag.take() {
1272 self.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
1273 let offset = cx.mouse_position() - active_drag.cursor_offset;
1274 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1275 active_drag.view.draw(offset, available_space, cx);
1276 });
1277 self.active_drag = Some(active_drag);
1278 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1279 self.with_z_index(1, |cx| {
1280 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1281 active_tooltip
1282 .view
1283 .draw(active_tooltip.cursor_offset, available_space, cx);
1284 });
1285 }
1286
1287 let window_is_focused = self
1288 .window
1289 .focus
1290 .and_then(|focus_id| {
1291 self.window
1292 .next_frame
1293 .dispatch_tree
1294 .focusable_node_id(focus_id)
1295 })
1296 .is_some();
1297 if window_was_focused && !window_is_focused {
1298 self.window
1299 .blur_listeners
1300 .clone()
1301 .retain(&(), |listener| listener(self));
1302 }
1303
1304 self.window
1305 .next_frame
1306 .dispatch_tree
1307 .preserve_pending_keystrokes(
1308 &mut self.window.rendered_frame.dispatch_tree,
1309 self.window.focus,
1310 );
1311 self.window.root_view = Some(root_view);
1312
1313 let window = &mut self.window;
1314 mem::swap(&mut window.rendered_frame, &mut window.next_frame);
1315
1316 let scene = self.window.rendered_frame.scene_builder.build();
1317
1318 // Set the cursor only if we're the active window.
1319 let cursor_style = self
1320 .window
1321 .requested_cursor_style
1322 .take()
1323 .unwrap_or(CursorStyle::Arrow);
1324 if self.is_window_active() {
1325 self.platform.set_cursor_style(cursor_style);
1326 }
1327
1328 self.window.dirty = false;
1329
1330 scene
1331 }
1332
1333 /// Dispatch a mouse or keyboard event on the window.
1334 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1335 // Handlers may set this to false by calling `stop_propagation`
1336 self.app.propagate_event = true;
1337 self.window.default_prevented = false;
1338
1339 let event = match event {
1340 // Track the mouse position with our own state, since accessing the platform
1341 // API for the mouse position can only occur on the main thread.
1342 InputEvent::MouseMove(mouse_move) => {
1343 self.window.mouse_position = mouse_move.position;
1344 InputEvent::MouseMove(mouse_move)
1345 }
1346 InputEvent::MouseDown(mouse_down) => {
1347 self.window.mouse_position = mouse_down.position;
1348 InputEvent::MouseDown(mouse_down)
1349 }
1350 InputEvent::MouseUp(mouse_up) => {
1351 self.window.mouse_position = mouse_up.position;
1352 InputEvent::MouseUp(mouse_up)
1353 }
1354 // Translate dragging and dropping of external files from the operating system
1355 // to internal drag and drop events.
1356 InputEvent::FileDrop(file_drop) => match file_drop {
1357 FileDropEvent::Entered { position, files } => {
1358 self.window.mouse_position = position;
1359 if self.active_drag.is_none() {
1360 self.active_drag = Some(AnyDrag {
1361 view: self.build_view(|_| files).into(),
1362 cursor_offset: position,
1363 });
1364 }
1365 InputEvent::MouseMove(MouseMoveEvent {
1366 position,
1367 pressed_button: Some(MouseButton::Left),
1368 modifiers: Modifiers::default(),
1369 })
1370 }
1371 FileDropEvent::Pending { position } => {
1372 self.window.mouse_position = position;
1373 InputEvent::MouseMove(MouseMoveEvent {
1374 position,
1375 pressed_button: Some(MouseButton::Left),
1376 modifiers: Modifiers::default(),
1377 })
1378 }
1379 FileDropEvent::Submit { position } => {
1380 self.activate(true);
1381 self.window.mouse_position = position;
1382 InputEvent::MouseUp(MouseUpEvent {
1383 button: MouseButton::Left,
1384 position,
1385 modifiers: Modifiers::default(),
1386 click_count: 1,
1387 })
1388 }
1389 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1390 button: MouseButton::Left,
1391 position: Point::default(),
1392 modifiers: Modifiers::default(),
1393 click_count: 1,
1394 }),
1395 },
1396 _ => event,
1397 };
1398
1399 if let Some(any_mouse_event) = event.mouse_event() {
1400 self.dispatch_mouse_event(any_mouse_event);
1401 } else if let Some(any_key_event) = event.keyboard_event() {
1402 self.dispatch_key_event(any_key_event);
1403 }
1404
1405 !self.app.propagate_event
1406 }
1407
1408 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1409 if let Some(mut handlers) = self
1410 .window
1411 .rendered_frame
1412 .mouse_listeners
1413 .remove(&event.type_id())
1414 {
1415 // Because handlers may add other handlers, we sort every time.
1416 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1417
1418 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1419 // special purposes, such as detecting events outside of a given Bounds.
1420 for (_, handler) in &mut handlers {
1421 handler(event, DispatchPhase::Capture, self);
1422 if !self.app.propagate_event {
1423 break;
1424 }
1425 }
1426
1427 // Bubble phase, where most normal handlers do their work.
1428 if self.app.propagate_event {
1429 for (_, handler) in handlers.iter_mut().rev() {
1430 handler(event, DispatchPhase::Bubble, self);
1431 if !self.app.propagate_event {
1432 break;
1433 }
1434 }
1435 }
1436
1437 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1438 self.active_drag = None;
1439 }
1440
1441 self.window
1442 .rendered_frame
1443 .mouse_listeners
1444 .insert(event.type_id(), handlers);
1445 }
1446 }
1447
1448 fn dispatch_key_event(&mut self, event: &dyn Any) {
1449 let node_id = self
1450 .window
1451 .focus
1452 .and_then(|focus_id| {
1453 self.window
1454 .rendered_frame
1455 .dispatch_tree
1456 .focusable_node_id(focus_id)
1457 })
1458 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1459
1460 let dispatch_path = self
1461 .window
1462 .rendered_frame
1463 .dispatch_tree
1464 .dispatch_path(node_id);
1465
1466 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1467
1468 // Capture phase
1469 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1470 self.propagate_event = true;
1471
1472 for node_id in &dispatch_path {
1473 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1474
1475 if let Some(context) = node.context.clone() {
1476 context_stack.push(context);
1477 }
1478
1479 for key_listener in node.key_listeners.clone() {
1480 key_listener(event, DispatchPhase::Capture, self);
1481 if !self.propagate_event {
1482 return;
1483 }
1484 }
1485 }
1486
1487 // Bubble phase
1488 for node_id in dispatch_path.iter().rev() {
1489 // Handle low level key events
1490 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1491 for key_listener in node.key_listeners.clone() {
1492 key_listener(event, DispatchPhase::Bubble, self);
1493 if !self.propagate_event {
1494 return;
1495 }
1496 }
1497
1498 // Match keystrokes
1499 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1500 if node.context.is_some() {
1501 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1502 let mut new_actions = self
1503 .window
1504 .rendered_frame
1505 .dispatch_tree
1506 .dispatch_key(&key_down_event.keystroke, &context_stack);
1507 actions.append(&mut new_actions);
1508 }
1509
1510 context_stack.pop();
1511 }
1512 }
1513
1514 for action in actions {
1515 self.dispatch_action_on_node(node_id, action.boxed_clone());
1516 if !self.propagate_event {
1517 self.dispatch_keystroke_observers(event, Some(action));
1518 return;
1519 }
1520 }
1521 self.dispatch_keystroke_observers(event, None);
1522 }
1523
1524 pub fn has_pending_keystrokes(&self) -> bool {
1525 self.window
1526 .rendered_frame
1527 .dispatch_tree
1528 .has_pending_keystrokes()
1529 }
1530
1531 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1532 let dispatch_path = self
1533 .window
1534 .rendered_frame
1535 .dispatch_tree
1536 .dispatch_path(node_id);
1537
1538 // Capture phase
1539 for node_id in &dispatch_path {
1540 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1541 for DispatchActionListener {
1542 action_type,
1543 listener,
1544 } in node.action_listeners.clone()
1545 {
1546 let any_action = action.as_any();
1547 if action_type == any_action.type_id() {
1548 listener(any_action, DispatchPhase::Capture, self);
1549 if !self.propagate_event {
1550 return;
1551 }
1552 }
1553 }
1554 }
1555 // Bubble phase
1556 for node_id in dispatch_path.iter().rev() {
1557 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1558 for DispatchActionListener {
1559 action_type,
1560 listener,
1561 } in node.action_listeners.clone()
1562 {
1563 let any_action = action.as_any();
1564 if action_type == any_action.type_id() {
1565 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1566 listener(any_action, DispatchPhase::Bubble, self);
1567 if !self.propagate_event {
1568 return;
1569 }
1570 }
1571 }
1572 }
1573 }
1574
1575 /// Register the given handler to be invoked whenever the global of the given type
1576 /// is updated.
1577 pub fn observe_global<G: 'static>(
1578 &mut self,
1579 f: impl Fn(&mut WindowContext<'_>) + 'static,
1580 ) -> Subscription {
1581 let window_handle = self.window.handle;
1582 let (subscription, activate) = self.global_observers.insert(
1583 TypeId::of::<G>(),
1584 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1585 );
1586 self.app.defer(move |_| activate());
1587 subscription
1588 }
1589
1590 pub fn activate_window(&self) {
1591 self.window.platform_window.activate();
1592 }
1593
1594 pub fn minimize_window(&self) {
1595 self.window.platform_window.minimize();
1596 }
1597
1598 pub fn toggle_full_screen(&self) {
1599 self.window.platform_window.toggle_full_screen();
1600 }
1601
1602 pub fn prompt(
1603 &self,
1604 level: PromptLevel,
1605 msg: &str,
1606 answers: &[&str],
1607 ) -> oneshot::Receiver<usize> {
1608 self.window.platform_window.prompt(level, msg, answers)
1609 }
1610
1611 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1612 let node_id = self
1613 .window
1614 .focus
1615 .and_then(|focus_id| {
1616 self.window
1617 .rendered_frame
1618 .dispatch_tree
1619 .focusable_node_id(focus_id)
1620 })
1621 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1622
1623 self.window
1624 .rendered_frame
1625 .dispatch_tree
1626 .available_actions(node_id)
1627 }
1628
1629 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1630 self.window
1631 .rendered_frame
1632 .dispatch_tree
1633 .bindings_for_action(
1634 action,
1635 &self.window.rendered_frame.dispatch_tree.context_stack,
1636 )
1637 }
1638
1639 pub fn bindings_for_action_in(
1640 &self,
1641 action: &dyn Action,
1642 focus_handle: &FocusHandle,
1643 ) -> Vec<KeyBinding> {
1644 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1645
1646 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1647 return vec![];
1648 };
1649 let context_stack = dispatch_tree
1650 .dispatch_path(node_id)
1651 .into_iter()
1652 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1653 .collect();
1654 dispatch_tree.bindings_for_action(action, &context_stack)
1655 }
1656
1657 pub fn listener_for<V: Render, E>(
1658 &self,
1659 view: &View<V>,
1660 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1661 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1662 let view = view.downgrade();
1663 move |e: &E, cx: &mut WindowContext| {
1664 view.update(cx, |view, cx| f(view, e, cx)).ok();
1665 }
1666 }
1667
1668 pub fn handler_for<V: Render>(
1669 &self,
1670 view: &View<V>,
1671 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1672 ) -> impl Fn(&mut WindowContext) {
1673 let view = view.downgrade();
1674 move |cx: &mut WindowContext| {
1675 view.update(cx, |view, cx| f(view, cx)).ok();
1676 }
1677 }
1678
1679 //========== ELEMENT RELATED FUNCTIONS ===========
1680 pub fn with_key_dispatch<R>(
1681 &mut self,
1682 context: Option<KeyContext>,
1683 focus_handle: Option<FocusHandle>,
1684 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1685 ) -> R {
1686 let window = &mut self.window;
1687 window.next_frame.dispatch_tree.push_node(context.clone());
1688 if let Some(focus_handle) = focus_handle.as_ref() {
1689 window
1690 .next_frame
1691 .dispatch_tree
1692 .make_focusable(focus_handle.id);
1693 }
1694 let result = f(focus_handle, self);
1695
1696 self.window.next_frame.dispatch_tree.pop_node();
1697
1698 result
1699 }
1700
1701 /// Register a focus listener for the next frame only. It will be cleared
1702 /// on the next frame render. You should use this method only from within elements,
1703 /// and we may want to enforce that better via a different context type.
1704 // todo!() Move this to `FrameContext` to emphasize its individuality?
1705 pub fn on_focus_changed(
1706 &mut self,
1707 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1708 ) {
1709 self.window
1710 .next_frame
1711 .focus_listeners
1712 .push(Box::new(move |event, cx| {
1713 listener(event, cx);
1714 }));
1715 }
1716
1717 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1718 /// platform to receive textual input with proper integration with concerns such
1719 /// as IME interactions.
1720 pub fn handle_input(
1721 &mut self,
1722 focus_handle: &FocusHandle,
1723 input_handler: impl PlatformInputHandler,
1724 ) {
1725 if focus_handle.is_focused(self) {
1726 self.window
1727 .platform_window
1728 .set_input_handler(Box::new(input_handler));
1729 }
1730 }
1731
1732 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1733 let mut this = self.to_async();
1734 self.window
1735 .platform_window
1736 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1737 }
1738}
1739
1740impl Context for WindowContext<'_> {
1741 type Result<T> = T;
1742
1743 fn build_model<T>(
1744 &mut self,
1745 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1746 ) -> Model<T>
1747 where
1748 T: 'static,
1749 {
1750 let slot = self.app.entities.reserve();
1751 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1752 self.entities.insert(slot, model)
1753 }
1754
1755 fn update_model<T: 'static, R>(
1756 &mut self,
1757 model: &Model<T>,
1758 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1759 ) -> R {
1760 let mut entity = self.entities.lease(model);
1761 let result = update(
1762 &mut *entity,
1763 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1764 );
1765 self.entities.end_lease(entity);
1766 result
1767 }
1768
1769 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1770 where
1771 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1772 {
1773 if window == self.window.handle {
1774 let root_view = self.window.root_view.clone().unwrap();
1775 Ok(update(root_view, self))
1776 } else {
1777 window.update(self.app, update)
1778 }
1779 }
1780
1781 fn read_model<T, R>(
1782 &self,
1783 handle: &Model<T>,
1784 read: impl FnOnce(&T, &AppContext) -> R,
1785 ) -> Self::Result<R>
1786 where
1787 T: 'static,
1788 {
1789 let entity = self.entities.read(handle);
1790 read(&*entity, &*self.app)
1791 }
1792
1793 fn read_window<T, R>(
1794 &self,
1795 window: &WindowHandle<T>,
1796 read: impl FnOnce(View<T>, &AppContext) -> R,
1797 ) -> Result<R>
1798 where
1799 T: 'static,
1800 {
1801 if window.any_handle == self.window.handle {
1802 let root_view = self
1803 .window
1804 .root_view
1805 .clone()
1806 .unwrap()
1807 .downcast::<T>()
1808 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1809 Ok(read(root_view, self))
1810 } else {
1811 self.app.read_window(window, read)
1812 }
1813 }
1814}
1815
1816impl VisualContext for WindowContext<'_> {
1817 fn build_view<V>(
1818 &mut self,
1819 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1820 ) -> Self::Result<View<V>>
1821 where
1822 V: 'static + Render,
1823 {
1824 let slot = self.app.entities.reserve();
1825 let view = View {
1826 model: slot.clone(),
1827 };
1828 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1829 let entity = build_view_state(&mut cx);
1830 cx.entities.insert(slot, entity);
1831
1832 cx.new_view_observers
1833 .clone()
1834 .retain(&TypeId::of::<V>(), |observer| {
1835 let any_view = AnyView::from(view.clone());
1836 (observer)(any_view, self);
1837 true
1838 });
1839
1840 view
1841 }
1842
1843 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1844 fn update_view<T: 'static, R>(
1845 &mut self,
1846 view: &View<T>,
1847 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1848 ) -> Self::Result<R> {
1849 let mut lease = self.app.entities.lease(&view.model);
1850 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1851 let result = update(&mut *lease, &mut cx);
1852 cx.app.entities.end_lease(lease);
1853 result
1854 }
1855
1856 fn replace_root_view<V>(
1857 &mut self,
1858 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1859 ) -> Self::Result<View<V>>
1860 where
1861 V: 'static + Render,
1862 {
1863 let slot = self.app.entities.reserve();
1864 let view = View {
1865 model: slot.clone(),
1866 };
1867 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1868 let entity = build_view(&mut cx);
1869 self.entities.insert(slot, entity);
1870 self.window.root_view = Some(view.clone().into());
1871 view
1872 }
1873
1874 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1875 self.update_view(view, |view, cx| {
1876 view.focus_handle(cx).clone().focus(cx);
1877 })
1878 }
1879
1880 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1881 where
1882 V: ManagedView,
1883 {
1884 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1885 }
1886}
1887
1888impl<'a> std::ops::Deref for WindowContext<'a> {
1889 type Target = AppContext;
1890
1891 fn deref(&self) -> &Self::Target {
1892 &self.app
1893 }
1894}
1895
1896impl<'a> std::ops::DerefMut for WindowContext<'a> {
1897 fn deref_mut(&mut self) -> &mut Self::Target {
1898 &mut self.app
1899 }
1900}
1901
1902impl<'a> Borrow<AppContext> for WindowContext<'a> {
1903 fn borrow(&self) -> &AppContext {
1904 &self.app
1905 }
1906}
1907
1908impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1909 fn borrow_mut(&mut self) -> &mut AppContext {
1910 &mut self.app
1911 }
1912}
1913
1914pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1915 fn app_mut(&mut self) -> &mut AppContext {
1916 self.borrow_mut()
1917 }
1918
1919 fn app(&self) -> &AppContext {
1920 self.borrow()
1921 }
1922
1923 fn window(&self) -> &Window {
1924 self.borrow()
1925 }
1926
1927 fn window_mut(&mut self) -> &mut Window {
1928 self.borrow_mut()
1929 }
1930
1931 /// Pushes the given element id onto the global stack and invokes the given closure
1932 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1933 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1934 /// used to associate state with identified elements across separate frames.
1935 fn with_element_id<R>(
1936 &mut self,
1937 id: Option<impl Into<ElementId>>,
1938 f: impl FnOnce(&mut Self) -> R,
1939 ) -> R {
1940 if let Some(id) = id.map(Into::into) {
1941 let window = self.window_mut();
1942 window.element_id_stack.push(id.into());
1943 let result = f(self);
1944 let window: &mut Window = self.borrow_mut();
1945 window.element_id_stack.pop();
1946 result
1947 } else {
1948 f(self)
1949 }
1950 }
1951
1952 /// Invoke the given function with the given content mask after intersecting it
1953 /// with the current mask.
1954 fn with_content_mask<R>(
1955 &mut self,
1956 mask: Option<ContentMask<Pixels>>,
1957 f: impl FnOnce(&mut Self) -> R,
1958 ) -> R {
1959 if let Some(mask) = mask {
1960 let mask = mask.intersect(&self.content_mask());
1961 self.window_mut().next_frame.content_mask_stack.push(mask);
1962 let result = f(self);
1963 self.window_mut().next_frame.content_mask_stack.pop();
1964 result
1965 } else {
1966 f(self)
1967 }
1968 }
1969
1970 /// Invoke the given function with the content mask reset to that
1971 /// of the window.
1972 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1973 let mask = ContentMask {
1974 bounds: Bounds {
1975 origin: Point::default(),
1976 size: self.window().viewport_size,
1977 },
1978 };
1979 self.window_mut().next_frame.content_mask_stack.push(mask);
1980 let result = f(self);
1981 self.window_mut().next_frame.content_mask_stack.pop();
1982 result
1983 }
1984
1985 /// Update the global element offset relative to the current offset. This is used to implement
1986 /// scrolling.
1987 fn with_element_offset<R>(
1988 &mut self,
1989 offset: Point<Pixels>,
1990 f: impl FnOnce(&mut Self) -> R,
1991 ) -> R {
1992 if offset.is_zero() {
1993 return f(self);
1994 };
1995
1996 let abs_offset = self.element_offset() + offset;
1997 self.with_absolute_element_offset(abs_offset, f)
1998 }
1999
2000 /// Update the global element offset based on the given offset. This is used to implement
2001 /// drag handles and other manual painting of elements.
2002 fn with_absolute_element_offset<R>(
2003 &mut self,
2004 offset: Point<Pixels>,
2005 f: impl FnOnce(&mut Self) -> R,
2006 ) -> R {
2007 self.window_mut()
2008 .next_frame
2009 .element_offset_stack
2010 .push(offset);
2011 let result = f(self);
2012 self.window_mut().next_frame.element_offset_stack.pop();
2013 result
2014 }
2015
2016 /// Obtain the current element offset.
2017 fn element_offset(&self) -> Point<Pixels> {
2018 self.window()
2019 .next_frame
2020 .element_offset_stack
2021 .last()
2022 .copied()
2023 .unwrap_or_default()
2024 }
2025
2026 /// Update or initialize state for an element with the given id that lives across multiple
2027 /// frames. If an element with this id existed in the rendered frame, its state will be passed
2028 /// to the given closure. The state returned by the closure will be stored so it can be referenced
2029 /// when drawing the next frame.
2030 fn with_element_state<S, R>(
2031 &mut self,
2032 id: ElementId,
2033 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
2034 ) -> R
2035 where
2036 S: 'static,
2037 {
2038 self.with_element_id(Some(id), |cx| {
2039 let global_id = cx.window().element_id_stack.clone();
2040
2041 if let Some(any) = cx
2042 .window_mut()
2043 .next_frame
2044 .element_states
2045 .remove(&global_id)
2046 .or_else(|| {
2047 cx.window_mut()
2048 .rendered_frame
2049 .element_states
2050 .remove(&global_id)
2051 })
2052 {
2053 let ElementStateBox {
2054 inner,
2055
2056 #[cfg(debug_assertions)]
2057 type_name
2058 } = any;
2059 // Using the extra inner option to avoid needing to reallocate a new box.
2060 let mut state_box = inner
2061 .downcast::<Option<S>>()
2062 .map_err(|_| {
2063 #[cfg(debug_assertions)]
2064 {
2065 anyhow!(
2066 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
2067 std::any::type_name::<S>(),
2068 type_name
2069 )
2070 }
2071
2072 #[cfg(not(debug_assertions))]
2073 {
2074 anyhow!(
2075 "invalid element state type for id, requested_type {:?}",
2076 std::any::type_name::<S>(),
2077 )
2078 }
2079 })
2080 .unwrap();
2081
2082 // Actual: Option<AnyElement> <- View
2083 // Requested: () <- AnyElemet
2084 let state = state_box
2085 .take()
2086 .expect("element state is already on the stack");
2087 let (result, state) = f(Some(state), cx);
2088 state_box.replace(state);
2089 cx.window_mut()
2090 .next_frame
2091 .element_states
2092 .insert(global_id, ElementStateBox {
2093 inner: state_box,
2094
2095 #[cfg(debug_assertions)]
2096 type_name
2097 });
2098 result
2099 } else {
2100 let (result, state) = f(None, cx);
2101 cx.window_mut()
2102 .next_frame
2103 .element_states
2104 .insert(global_id,
2105 ElementStateBox {
2106 inner: Box::new(Some(state)),
2107
2108 #[cfg(debug_assertions)]
2109 type_name: std::any::type_name::<S>()
2110 }
2111
2112 );
2113 result
2114 }
2115 })
2116 }
2117
2118 /// Obtain the current content mask.
2119 fn content_mask(&self) -> ContentMask<Pixels> {
2120 self.window()
2121 .next_frame
2122 .content_mask_stack
2123 .last()
2124 .cloned()
2125 .unwrap_or_else(|| ContentMask {
2126 bounds: Bounds {
2127 origin: Point::default(),
2128 size: self.window().viewport_size,
2129 },
2130 })
2131 }
2132
2133 /// The size of an em for the base font of the application. Adjusting this value allows the
2134 /// UI to scale, just like zooming a web page.
2135 fn rem_size(&self) -> Pixels {
2136 self.window().rem_size
2137 }
2138}
2139
2140impl Borrow<Window> for WindowContext<'_> {
2141 fn borrow(&self) -> &Window {
2142 &self.window
2143 }
2144}
2145
2146impl BorrowMut<Window> for WindowContext<'_> {
2147 fn borrow_mut(&mut self) -> &mut Window {
2148 &mut self.window
2149 }
2150}
2151
2152impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
2153
2154pub struct ViewContext<'a, V> {
2155 window_cx: WindowContext<'a>,
2156 view: &'a View<V>,
2157}
2158
2159impl<V> Borrow<AppContext> for ViewContext<'_, V> {
2160 fn borrow(&self) -> &AppContext {
2161 &*self.window_cx.app
2162 }
2163}
2164
2165impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
2166 fn borrow_mut(&mut self) -> &mut AppContext {
2167 &mut *self.window_cx.app
2168 }
2169}
2170
2171impl<V> Borrow<Window> for ViewContext<'_, V> {
2172 fn borrow(&self) -> &Window {
2173 &*self.window_cx.window
2174 }
2175}
2176
2177impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2178 fn borrow_mut(&mut self) -> &mut Window {
2179 &mut *self.window_cx.window
2180 }
2181}
2182
2183impl<'a, V: 'static> ViewContext<'a, V> {
2184 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2185 Self {
2186 window_cx: WindowContext::new(app, window),
2187 view,
2188 }
2189 }
2190
2191 pub fn entity_id(&self) -> EntityId {
2192 self.view.entity_id()
2193 }
2194
2195 pub fn view(&self) -> &View<V> {
2196 self.view
2197 }
2198
2199 pub fn model(&self) -> &Model<V> {
2200 &self.view.model
2201 }
2202
2203 /// Access the underlying window context.
2204 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2205 &mut self.window_cx
2206 }
2207
2208 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2209 self.window.next_frame.z_index_stack.push(z_index);
2210 let result = f(self);
2211 self.window.next_frame.z_index_stack.pop();
2212 result
2213 }
2214
2215 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2216 where
2217 V: 'static,
2218 {
2219 let view = self.view().clone();
2220 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2221 }
2222
2223 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2224 /// that are currently on the stack to be returned to the app.
2225 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2226 let view = self.view().downgrade();
2227 self.window_cx.defer(move |cx| {
2228 view.update(cx, f).ok();
2229 });
2230 }
2231
2232 pub fn observe<V2, E>(
2233 &mut self,
2234 entity: &E,
2235 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2236 ) -> Subscription
2237 where
2238 V2: 'static,
2239 V: 'static,
2240 E: Entity<V2>,
2241 {
2242 let view = self.view().downgrade();
2243 let entity_id = entity.entity_id();
2244 let entity = entity.downgrade();
2245 let window_handle = self.window.handle;
2246 let (subscription, activate) = self.app.observers.insert(
2247 entity_id,
2248 Box::new(move |cx| {
2249 window_handle
2250 .update(cx, |_, cx| {
2251 if let Some(handle) = E::upgrade_from(&entity) {
2252 view.update(cx, |this, cx| on_notify(this, handle, cx))
2253 .is_ok()
2254 } else {
2255 false
2256 }
2257 })
2258 .unwrap_or(false)
2259 }),
2260 );
2261 self.app.defer(move |_| activate());
2262 subscription
2263 }
2264
2265 pub fn subscribe<V2, E, Evt>(
2266 &mut self,
2267 entity: &E,
2268 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2269 ) -> Subscription
2270 where
2271 V2: EventEmitter<Evt>,
2272 E: Entity<V2>,
2273 Evt: 'static,
2274 {
2275 let view = self.view().downgrade();
2276 let entity_id = entity.entity_id();
2277 let handle = entity.downgrade();
2278 let window_handle = self.window.handle;
2279 let (subscription, activate) = self.app.event_listeners.insert(
2280 entity_id,
2281 (
2282 TypeId::of::<Evt>(),
2283 Box::new(move |event, cx| {
2284 window_handle
2285 .update(cx, |_, cx| {
2286 if let Some(handle) = E::upgrade_from(&handle) {
2287 let event = event.downcast_ref().expect("invalid event type");
2288 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2289 .is_ok()
2290 } else {
2291 false
2292 }
2293 })
2294 .unwrap_or(false)
2295 }),
2296 ),
2297 );
2298 self.app.defer(move |_| activate());
2299 subscription
2300 }
2301
2302 pub fn on_release(
2303 &mut self,
2304 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2305 ) -> Subscription {
2306 let window_handle = self.window.handle;
2307 let (subscription, activate) = self.app.release_listeners.insert(
2308 self.view.model.entity_id,
2309 Box::new(move |this, cx| {
2310 let this = this.downcast_mut().expect("invalid entity type");
2311 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2312 }),
2313 );
2314 activate();
2315 subscription
2316 }
2317
2318 pub fn observe_release<V2, E>(
2319 &mut self,
2320 entity: &E,
2321 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2322 ) -> Subscription
2323 where
2324 V: 'static,
2325 V2: 'static,
2326 E: Entity<V2>,
2327 {
2328 let view = self.view().downgrade();
2329 let entity_id = entity.entity_id();
2330 let window_handle = self.window.handle;
2331 let (subscription, activate) = self.app.release_listeners.insert(
2332 entity_id,
2333 Box::new(move |entity, cx| {
2334 let entity = entity.downcast_mut().expect("invalid entity type");
2335 let _ = window_handle.update(cx, |_, cx| {
2336 view.update(cx, |this, cx| on_release(this, entity, cx))
2337 });
2338 }),
2339 );
2340 activate();
2341 subscription
2342 }
2343
2344 pub fn notify(&mut self) {
2345 self.window_cx.notify();
2346 self.window_cx.app.push_effect(Effect::Notify {
2347 emitter: self.view.model.entity_id,
2348 });
2349 }
2350
2351 pub fn observe_window_bounds(
2352 &mut self,
2353 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2354 ) -> Subscription {
2355 let view = self.view.downgrade();
2356 let (subscription, activate) = self.window.bounds_observers.insert(
2357 (),
2358 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2359 );
2360 activate();
2361 subscription
2362 }
2363
2364 pub fn observe_window_activation(
2365 &mut self,
2366 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2367 ) -> Subscription {
2368 let view = self.view.downgrade();
2369 let (subscription, activate) = self.window.activation_observers.insert(
2370 (),
2371 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2372 );
2373 activate();
2374 subscription
2375 }
2376
2377 /// Register a listener to be called when the given focus handle receives focus.
2378 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2379 /// is dropped.
2380 pub fn on_focus(
2381 &mut self,
2382 handle: &FocusHandle,
2383 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2384 ) -> Subscription {
2385 let view = self.view.downgrade();
2386 let focus_id = handle.id;
2387 let (subscription, activate) = self.window.focus_listeners.insert(
2388 (),
2389 Box::new(move |event, cx| {
2390 view.update(cx, |view, cx| {
2391 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2392 listener(view, cx)
2393 }
2394 })
2395 .is_ok()
2396 }),
2397 );
2398 self.app.defer(move |_| activate());
2399 subscription
2400 }
2401
2402 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2403 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2404 /// is dropped.
2405 pub fn on_focus_in(
2406 &mut self,
2407 handle: &FocusHandle,
2408 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2409 ) -> Subscription {
2410 let view = self.view.downgrade();
2411 let focus_id = handle.id;
2412 let (subscription, activate) = self.window.focus_listeners.insert(
2413 (),
2414 Box::new(move |event, cx| {
2415 view.update(cx, |view, cx| {
2416 if event
2417 .focused
2418 .as_ref()
2419 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2420 {
2421 listener(view, cx)
2422 }
2423 })
2424 .is_ok()
2425 }),
2426 );
2427 self.app.defer(move |_| activate());
2428 subscription
2429 }
2430
2431 /// Register a listener to be called when the given focus handle loses focus.
2432 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2433 /// is dropped.
2434 pub fn on_blur(
2435 &mut self,
2436 handle: &FocusHandle,
2437 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2438 ) -> Subscription {
2439 let view = self.view.downgrade();
2440 let focus_id = handle.id;
2441 let (subscription, activate) = self.window.focus_listeners.insert(
2442 (),
2443 Box::new(move |event, cx| {
2444 view.update(cx, |view, cx| {
2445 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2446 listener(view, cx)
2447 }
2448 })
2449 .is_ok()
2450 }),
2451 );
2452 self.app.defer(move |_| activate());
2453 subscription
2454 }
2455
2456 /// Register a listener to be called when the window loses focus.
2457 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2458 /// is dropped.
2459 pub fn on_blur_window(
2460 &mut self,
2461 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2462 ) -> Subscription {
2463 let view = self.view.downgrade();
2464 let (subscription, activate) = self.window.blur_listeners.insert(
2465 (),
2466 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2467 );
2468 activate();
2469 subscription
2470 }
2471
2472 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2473 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2474 /// is dropped.
2475 pub fn on_focus_out(
2476 &mut self,
2477 handle: &FocusHandle,
2478 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2479 ) -> Subscription {
2480 let view = self.view.downgrade();
2481 let focus_id = handle.id;
2482 let (subscription, activate) = self.window.focus_listeners.insert(
2483 (),
2484 Box::new(move |event, cx| {
2485 view.update(cx, |view, cx| {
2486 if event
2487 .blurred
2488 .as_ref()
2489 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2490 {
2491 listener(view, cx)
2492 }
2493 })
2494 .is_ok()
2495 }),
2496 );
2497 self.app.defer(move |_| activate());
2498 subscription
2499 }
2500
2501 pub fn spawn<Fut, R>(
2502 &mut self,
2503 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2504 ) -> Task<R>
2505 where
2506 R: 'static,
2507 Fut: Future<Output = R> + 'static,
2508 {
2509 let view = self.view().downgrade();
2510 self.window_cx.spawn(|cx| f(view, cx))
2511 }
2512
2513 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2514 where
2515 G: 'static,
2516 {
2517 let mut global = self.app.lease_global::<G>();
2518 let result = f(&mut global, self);
2519 self.app.end_global_lease(global);
2520 result
2521 }
2522
2523 pub fn observe_global<G: 'static>(
2524 &mut self,
2525 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2526 ) -> Subscription {
2527 let window_handle = self.window.handle;
2528 let view = self.view().downgrade();
2529 let (subscription, activate) = self.global_observers.insert(
2530 TypeId::of::<G>(),
2531 Box::new(move |cx| {
2532 window_handle
2533 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2534 .unwrap_or(false)
2535 }),
2536 );
2537 self.app.defer(move |_| activate());
2538 subscription
2539 }
2540
2541 pub fn on_mouse_event<Event: 'static>(
2542 &mut self,
2543 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2544 ) {
2545 let handle = self.view().clone();
2546 self.window_cx.on_mouse_event(move |event, phase, cx| {
2547 handle.update(cx, |view, cx| {
2548 handler(view, event, phase, cx);
2549 })
2550 });
2551 }
2552
2553 pub fn on_key_event<Event: 'static>(
2554 &mut self,
2555 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2556 ) {
2557 let handle = self.view().clone();
2558 self.window_cx.on_key_event(move |event, phase, cx| {
2559 handle.update(cx, |view, cx| {
2560 handler(view, event, phase, cx);
2561 })
2562 });
2563 }
2564
2565 pub fn on_action(
2566 &mut self,
2567 action_type: TypeId,
2568 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2569 ) {
2570 let handle = self.view().clone();
2571 self.window_cx
2572 .on_action(action_type, move |action, phase, cx| {
2573 handle.update(cx, |view, cx| {
2574 handler(view, action, phase, cx);
2575 })
2576 });
2577 }
2578
2579 pub fn emit<Evt>(&mut self, event: Evt)
2580 where
2581 Evt: 'static,
2582 V: EventEmitter<Evt>,
2583 {
2584 let emitter = self.view.model.entity_id;
2585 self.app.push_effect(Effect::Emit {
2586 emitter,
2587 event_type: TypeId::of::<Evt>(),
2588 event: Box::new(event),
2589 });
2590 }
2591
2592 pub fn focus_self(&mut self)
2593 where
2594 V: FocusableView,
2595 {
2596 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2597 }
2598
2599 pub fn dismiss_self(&mut self)
2600 where
2601 V: ManagedView,
2602 {
2603 self.defer(|_, cx| cx.emit(DismissEvent))
2604 }
2605
2606 pub fn listener<E>(
2607 &self,
2608 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2609 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2610 let view = self.view().downgrade();
2611 move |e: &E, cx: &mut WindowContext| {
2612 view.update(cx, |view, cx| f(view, e, cx)).ok();
2613 }
2614 }
2615}
2616
2617impl<V> Context for ViewContext<'_, V> {
2618 type Result<U> = U;
2619
2620 fn build_model<T: 'static>(
2621 &mut self,
2622 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2623 ) -> Model<T> {
2624 self.window_cx.build_model(build_model)
2625 }
2626
2627 fn update_model<T: 'static, R>(
2628 &mut self,
2629 model: &Model<T>,
2630 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2631 ) -> R {
2632 self.window_cx.update_model(model, update)
2633 }
2634
2635 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2636 where
2637 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2638 {
2639 self.window_cx.update_window(window, update)
2640 }
2641
2642 fn read_model<T, R>(
2643 &self,
2644 handle: &Model<T>,
2645 read: impl FnOnce(&T, &AppContext) -> R,
2646 ) -> Self::Result<R>
2647 where
2648 T: 'static,
2649 {
2650 self.window_cx.read_model(handle, read)
2651 }
2652
2653 fn read_window<T, R>(
2654 &self,
2655 window: &WindowHandle<T>,
2656 read: impl FnOnce(View<T>, &AppContext) -> R,
2657 ) -> Result<R>
2658 where
2659 T: 'static,
2660 {
2661 self.window_cx.read_window(window, read)
2662 }
2663}
2664
2665impl<V: 'static> VisualContext for ViewContext<'_, V> {
2666 fn build_view<W: Render + 'static>(
2667 &mut self,
2668 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2669 ) -> Self::Result<View<W>> {
2670 self.window_cx.build_view(build_view_state)
2671 }
2672
2673 fn update_view<V2: 'static, R>(
2674 &mut self,
2675 view: &View<V2>,
2676 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2677 ) -> Self::Result<R> {
2678 self.window_cx.update_view(view, update)
2679 }
2680
2681 fn replace_root_view<W>(
2682 &mut self,
2683 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2684 ) -> Self::Result<View<W>>
2685 where
2686 W: 'static + Render,
2687 {
2688 self.window_cx.replace_root_view(build_view)
2689 }
2690
2691 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2692 self.window_cx.focus_view(view)
2693 }
2694
2695 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2696 self.window_cx.dismiss_view(view)
2697 }
2698}
2699
2700impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2701 type Target = WindowContext<'a>;
2702
2703 fn deref(&self) -> &Self::Target {
2704 &self.window_cx
2705 }
2706}
2707
2708impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2709 fn deref_mut(&mut self) -> &mut Self::Target {
2710 &mut self.window_cx
2711 }
2712}
2713
2714// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2715slotmap::new_key_type! { pub struct WindowId; }
2716
2717impl WindowId {
2718 pub fn as_u64(&self) -> u64 {
2719 self.0.as_ffi()
2720 }
2721}
2722
2723#[derive(Deref, DerefMut)]
2724pub struct WindowHandle<V> {
2725 #[deref]
2726 #[deref_mut]
2727 pub(crate) any_handle: AnyWindowHandle,
2728 state_type: PhantomData<V>,
2729}
2730
2731impl<V: 'static + Render> WindowHandle<V> {
2732 pub fn new(id: WindowId) -> Self {
2733 WindowHandle {
2734 any_handle: AnyWindowHandle {
2735 id,
2736 state_type: TypeId::of::<V>(),
2737 },
2738 state_type: PhantomData,
2739 }
2740 }
2741
2742 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2743 where
2744 C: Context,
2745 {
2746 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2747 root_view
2748 .downcast::<V>()
2749 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2750 }))
2751 }
2752
2753 pub fn update<C, R>(
2754 &self,
2755 cx: &mut C,
2756 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2757 ) -> Result<R>
2758 where
2759 C: Context,
2760 {
2761 cx.update_window(self.any_handle, |root_view, cx| {
2762 let view = root_view
2763 .downcast::<V>()
2764 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2765 Ok(cx.update_view(&view, update))
2766 })?
2767 }
2768
2769 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2770 let x = cx
2771 .windows
2772 .get(self.id)
2773 .and_then(|window| {
2774 window
2775 .as_ref()
2776 .and_then(|window| window.root_view.clone())
2777 .map(|root_view| root_view.downcast::<V>())
2778 })
2779 .ok_or_else(|| anyhow!("window not found"))?
2780 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2781
2782 Ok(x.read(cx))
2783 }
2784
2785 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2786 where
2787 C: Context,
2788 {
2789 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2790 }
2791
2792 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2793 where
2794 C: Context,
2795 {
2796 cx.read_window(self, |root_view, _cx| root_view.clone())
2797 }
2798
2799 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2800 cx.windows
2801 .get(self.id)
2802 .and_then(|window| window.as_ref().map(|window| window.active))
2803 }
2804}
2805
2806impl<V> Copy for WindowHandle<V> {}
2807
2808impl<V> Clone for WindowHandle<V> {
2809 fn clone(&self) -> Self {
2810 WindowHandle {
2811 any_handle: self.any_handle,
2812 state_type: PhantomData,
2813 }
2814 }
2815}
2816
2817impl<V> PartialEq for WindowHandle<V> {
2818 fn eq(&self, other: &Self) -> bool {
2819 self.any_handle == other.any_handle
2820 }
2821}
2822
2823impl<V> Eq for WindowHandle<V> {}
2824
2825impl<V> Hash for WindowHandle<V> {
2826 fn hash<H: Hasher>(&self, state: &mut H) {
2827 self.any_handle.hash(state);
2828 }
2829}
2830
2831impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2832 fn into(self) -> AnyWindowHandle {
2833 self.any_handle
2834 }
2835}
2836
2837#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2838pub struct AnyWindowHandle {
2839 pub(crate) id: WindowId,
2840 state_type: TypeId,
2841}
2842
2843impl AnyWindowHandle {
2844 pub fn window_id(&self) -> WindowId {
2845 self.id
2846 }
2847
2848 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2849 if TypeId::of::<T>() == self.state_type {
2850 Some(WindowHandle {
2851 any_handle: *self,
2852 state_type: PhantomData,
2853 })
2854 } else {
2855 None
2856 }
2857 }
2858
2859 pub fn update<C, R>(
2860 self,
2861 cx: &mut C,
2862 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2863 ) -> Result<R>
2864 where
2865 C: Context,
2866 {
2867 cx.update_window(self, update)
2868 }
2869
2870 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2871 where
2872 C: Context,
2873 T: 'static,
2874 {
2875 let view = self
2876 .downcast::<T>()
2877 .context("the type of the window's root view has changed")?;
2878
2879 cx.read_window(&view, read)
2880 }
2881}
2882
2883#[cfg(any(test, feature = "test-support"))]
2884impl From<SmallVec<[u32; 16]>> for StackingOrder {
2885 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2886 StackingOrder(small_vec)
2887 }
2888}
2889
2890#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2891pub enum ElementId {
2892 View(EntityId),
2893 Integer(usize),
2894 Name(SharedString),
2895 FocusHandle(FocusId),
2896 NamedInteger(SharedString, usize),
2897}
2898
2899impl ElementId {
2900 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2901 ElementId::View(entity_id)
2902 }
2903}
2904
2905impl TryInto<SharedString> for ElementId {
2906 type Error = anyhow::Error;
2907
2908 fn try_into(self) -> anyhow::Result<SharedString> {
2909 if let ElementId::Name(name) = self {
2910 Ok(name)
2911 } else {
2912 Err(anyhow!("element id is not string"))
2913 }
2914 }
2915}
2916
2917impl From<usize> for ElementId {
2918 fn from(id: usize) -> Self {
2919 ElementId::Integer(id)
2920 }
2921}
2922
2923impl From<i32> for ElementId {
2924 fn from(id: i32) -> Self {
2925 Self::Integer(id as usize)
2926 }
2927}
2928
2929impl From<SharedString> for ElementId {
2930 fn from(name: SharedString) -> Self {
2931 ElementId::Name(name)
2932 }
2933}
2934
2935impl From<&'static str> for ElementId {
2936 fn from(name: &'static str) -> Self {
2937 ElementId::Name(name.into())
2938 }
2939}
2940
2941impl<'a> From<&'a FocusHandle> for ElementId {
2942 fn from(handle: &'a FocusHandle) -> Self {
2943 ElementId::FocusHandle(handle.id)
2944 }
2945}
2946
2947impl From<(&'static str, EntityId)> for ElementId {
2948 fn from((name, id): (&'static str, EntityId)) -> Self {
2949 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2950 }
2951}
2952
2953impl From<(&'static str, usize)> for ElementId {
2954 fn from((name, id): (&'static str, usize)) -> Self {
2955 ElementId::NamedInteger(name.into(), id)
2956 }
2957}
2958
2959impl From<(&'static str, u64)> for ElementId {
2960 fn from((name, id): (&'static str, u64)) -> Self {
2961 ElementId::NamedInteger(name.into(), id as usize)
2962 }
2963}