1use crate::{
2 px, size, Action, AnyBox, AnyDrag, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
3 Bounds, BoxShadow, Context, Corners, CursorStyle, DevicePixels, DispatchContext, DisplayId,
4 Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, FocusEvent, FontId,
5 GlobalElementId, GlyphId, Hsla, ImageData, InputEvent, InputHandler, IsZero, KeyListener,
6 KeyMatch, KeyMatcher, Keystroke, LayoutId, Model, ModelContext, Modifiers, MonochromeSprite,
7 MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas,
8 PlatformDisplay, PlatformInputHandler, PlatformWindow, Point, PolychromeSprite, PromptLevel,
9 Quad, Render, RenderGlyphParams, RenderImageParams, RenderSvgParams, ScaledPixels,
10 SceneBuilder, Shadow, SharedString, Size, Style, SubscriberSet, Subscription,
11 TaffyLayoutEngine, Task, Underline, UnderlineStyle, View, VisualContext, WeakView,
12 WindowBounds, WindowInputHandler, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use parking_lot::RwLock;
22use slotmap::SlotMap;
23use smallvec::SmallVec;
24use std::{
25 any::{Any, TypeId},
26 borrow::{Borrow, BorrowMut, Cow},
27 fmt::Debug,
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37};
38use util::ResultExt;
39
40/// A global stacking order, which is created by stacking successive z-index values.
41/// Each z-index will always be interpreted in the context of its parent z-index.
42#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
43pub(crate) struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
44
45/// Represents the two different phases when dispatching events.
46#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
47pub enum DispatchPhase {
48 /// After the capture phase comes the bubble phase, in which mouse event listeners are
49 /// invoked front to back and keyboard event listeners are invoked from the focused element
50 /// to the root of the element tree. This is the phase you'll most commonly want to use when
51 /// registering event listeners.
52 #[default]
53 Bubble,
54 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
55 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
56 /// is used for special purposes such as clearing the "pressed" state for click events. If
57 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
58 /// outside of the immediate region may rely on detecting non-local events during this phase.
59 Capture,
60}
61
62type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
63type AnyListener = Box<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
64type AnyKeyListener = Box<
65 dyn Fn(
66 &dyn Any,
67 &[&DispatchContext],
68 DispatchPhase,
69 &mut WindowContext,
70 ) -> Option<Box<dyn Action>>
71 + 'static,
72>;
73type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
74
75slotmap::new_key_type! { pub struct FocusId; }
76
77/// A handle which can be used to track and manipulate the focused element in a window.
78pub struct FocusHandle {
79 pub(crate) id: FocusId,
80 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
81}
82
83impl FocusHandle {
84 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
85 let id = handles.write().insert(AtomicUsize::new(1));
86 Self {
87 id,
88 handles: handles.clone(),
89 }
90 }
91
92 pub(crate) fn for_id(
93 id: FocusId,
94 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
95 ) -> Option<Self> {
96 let lock = handles.read();
97 let ref_count = lock.get(id)?;
98 if ref_count.load(SeqCst) == 0 {
99 None
100 } else {
101 ref_count.fetch_add(1, SeqCst);
102 Some(Self {
103 id,
104 handles: handles.clone(),
105 })
106 }
107 }
108
109 /// Obtains whether the element associated with this handle is currently focused.
110 pub fn is_focused(&self, cx: &WindowContext) -> bool {
111 cx.window.focus == Some(self.id)
112 }
113
114 /// Obtains whether the element associated with this handle contains the focused
115 /// element or is itself focused.
116 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
117 cx.focused()
118 .map_or(false, |focused| self.contains(&focused, cx))
119 }
120
121 /// Obtains whether the element associated with this handle is contained within the
122 /// focused element or is itself focused.
123 pub fn within_focused(&self, cx: &WindowContext) -> bool {
124 let focused = cx.focused();
125 focused.map_or(false, |focused| focused.contains(self, cx))
126 }
127
128 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
129 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
130 let mut ancestor = Some(other.id);
131 while let Some(ancestor_id) = ancestor {
132 if self.id == ancestor_id {
133 return true;
134 } else {
135 ancestor = cx.window.focus_parents_by_child.get(&ancestor_id).copied();
136 }
137 }
138 false
139 }
140}
141
142impl Clone for FocusHandle {
143 fn clone(&self) -> Self {
144 Self::for_id(self.id, &self.handles).unwrap()
145 }
146}
147
148impl PartialEq for FocusHandle {
149 fn eq(&self, other: &Self) -> bool {
150 self.id == other.id
151 }
152}
153
154impl Eq for FocusHandle {}
155
156impl Drop for FocusHandle {
157 fn drop(&mut self) {
158 self.handles
159 .read()
160 .get(self.id)
161 .unwrap()
162 .fetch_sub(1, SeqCst);
163 }
164}
165
166// Holds the state for a specific window.
167pub struct Window {
168 pub(crate) handle: AnyWindowHandle,
169 pub(crate) removed: bool,
170 platform_window: Box<dyn PlatformWindow>,
171 display_id: DisplayId,
172 sprite_atlas: Arc<dyn PlatformAtlas>,
173 rem_size: Pixels,
174 content_size: Size<Pixels>,
175 pub(crate) layout_engine: TaffyLayoutEngine,
176 pub(crate) root_view: Option<AnyView>,
177 pub(crate) element_id_stack: GlobalElementId,
178 prev_frame_element_states: HashMap<GlobalElementId, AnyBox>,
179 element_states: HashMap<GlobalElementId, AnyBox>,
180 prev_frame_key_matchers: HashMap<GlobalElementId, KeyMatcher>,
181 key_matchers: HashMap<GlobalElementId, KeyMatcher>,
182 z_index_stack: StackingOrder,
183 content_mask_stack: Vec<ContentMask<Pixels>>,
184 element_offset_stack: Vec<Point<Pixels>>,
185 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyListener)>>,
186 key_dispatch_stack: Vec<KeyDispatchStackFrame>,
187 freeze_key_dispatch_stack: bool,
188 focus_stack: Vec<FocusId>,
189 focus_parents_by_child: HashMap<FocusId, FocusId>,
190 pub(crate) focus_listeners: Vec<AnyFocusListener>,
191 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
192 default_prevented: bool,
193 mouse_position: Point<Pixels>,
194 requested_cursor_style: Option<CursorStyle>,
195 requested_input_handler: Option<Box<dyn PlatformInputHandler>>,
196 scale_factor: f32,
197 bounds: WindowBounds,
198 bounds_observers: SubscriberSet<(), AnyObserver>,
199 active: bool,
200 activation_observers: SubscriberSet<(), AnyObserver>,
201 pub(crate) scene_builder: SceneBuilder,
202 pub(crate) dirty: bool,
203 pub(crate) last_blur: Option<Option<FocusId>>,
204 pub(crate) focus: Option<FocusId>,
205}
206
207impl Window {
208 pub(crate) fn new(
209 handle: AnyWindowHandle,
210 options: WindowOptions,
211 cx: &mut AppContext,
212 ) -> Self {
213 let platform_window = cx.platform.open_window(handle, options);
214 let display_id = platform_window.display().id();
215 let sprite_atlas = platform_window.sprite_atlas();
216 let mouse_position = platform_window.mouse_position();
217 let content_size = platform_window.content_size();
218 let scale_factor = platform_window.scale_factor();
219 let bounds = platform_window.bounds();
220
221 platform_window.on_resize(Box::new({
222 let mut cx = cx.to_async();
223 move |_, _| {
224 handle
225 .update(&mut cx, |_, cx| cx.window_bounds_changed())
226 .log_err();
227 }
228 }));
229 platform_window.on_moved(Box::new({
230 let mut cx = cx.to_async();
231 move || {
232 handle
233 .update(&mut cx, |_, cx| cx.window_bounds_changed())
234 .log_err();
235 }
236 }));
237 platform_window.on_active_status_change(Box::new({
238 let mut cx = cx.to_async();
239 move |active| {
240 handle
241 .update(&mut cx, |_, cx| {
242 cx.window.active = active;
243 cx.window
244 .activation_observers
245 .clone()
246 .retain(&(), |callback| callback(cx));
247 })
248 .log_err();
249 }
250 }));
251
252 platform_window.on_input({
253 let mut cx = cx.to_async();
254 Box::new(move |event| {
255 handle
256 .update(&mut cx, |_, cx| cx.dispatch_event(event))
257 .log_err()
258 .unwrap_or(true)
259 })
260 });
261
262 Window {
263 handle,
264 removed: false,
265 platform_window,
266 display_id,
267 sprite_atlas,
268 rem_size: px(16.),
269 content_size,
270 layout_engine: TaffyLayoutEngine::new(),
271 root_view: None,
272 element_id_stack: GlobalElementId::default(),
273 prev_frame_element_states: HashMap::default(),
274 element_states: HashMap::default(),
275 prev_frame_key_matchers: HashMap::default(),
276 key_matchers: HashMap::default(),
277 z_index_stack: StackingOrder(SmallVec::new()),
278 content_mask_stack: Vec::new(),
279 element_offset_stack: Vec::new(),
280 mouse_listeners: HashMap::default(),
281 key_dispatch_stack: Vec::new(),
282 freeze_key_dispatch_stack: false,
283 focus_stack: Vec::new(),
284 focus_parents_by_child: HashMap::default(),
285 focus_listeners: Vec::new(),
286 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
287 default_prevented: true,
288 mouse_position,
289 requested_cursor_style: None,
290 requested_input_handler: None,
291 scale_factor,
292 bounds,
293 bounds_observers: SubscriberSet::new(),
294 active: false,
295 activation_observers: SubscriberSet::new(),
296 scene_builder: SceneBuilder::new(),
297 dirty: true,
298 last_blur: None,
299 focus: None,
300 }
301 }
302}
303
304/// When constructing the element tree, we maintain a stack of key dispatch frames until we
305/// find the focused element. We interleave key listeners with dispatch contexts so we can use the
306/// contexts when matching key events against the keymap. A key listener can be either an action
307/// handler or a [KeyDown] / [KeyUp] event listener.
308enum KeyDispatchStackFrame {
309 Listener {
310 event_type: TypeId,
311 listener: AnyKeyListener,
312 },
313 Context(DispatchContext),
314}
315
316/// Indicates which region of the window is visible. Content falling outside of this mask will not be
317/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
318/// to leave room to support more complex shapes in the future.
319#[derive(Clone, Debug, Default, PartialEq, Eq)]
320#[repr(C)]
321pub struct ContentMask<P: Clone + Default + Debug> {
322 pub bounds: Bounds<P>,
323}
324
325impl ContentMask<Pixels> {
326 /// Scale the content mask's pixel units by the given scaling factor.
327 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
328 ContentMask {
329 bounds: self.bounds.scale(factor),
330 }
331 }
332
333 /// Intersect the content mask with the given content mask.
334 pub fn intersect(&self, other: &Self) -> Self {
335 let bounds = self.bounds.intersect(&other.bounds);
336 ContentMask { bounds }
337 }
338}
339
340/// Provides access to application state in the context of a single window. Derefs
341/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
342/// an `AppContext` and call any `AppContext` methods.
343pub struct WindowContext<'a> {
344 pub(crate) app: &'a mut AppContext,
345 pub(crate) window: &'a mut Window,
346}
347
348impl<'a> WindowContext<'a> {
349 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
350 Self { app, window }
351 }
352
353 /// Obtain a handle to the window that belongs to this context.
354 pub fn window_handle(&self) -> AnyWindowHandle {
355 self.window.handle
356 }
357
358 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
359 pub fn notify(&mut self) {
360 self.window.dirty = true;
361 }
362
363 /// Close this window.
364 pub fn remove_window(&mut self) {
365 self.window.removed = true;
366 }
367
368 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
369 /// for elements rendered within this window.
370 pub fn focus_handle(&mut self) -> FocusHandle {
371 FocusHandle::new(&self.window.focus_handles)
372 }
373
374 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
375 pub fn focused(&self) -> Option<FocusHandle> {
376 self.window
377 .focus
378 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
379 }
380
381 /// Move focus to the element associated with the given `FocusHandle`.
382 pub fn focus(&mut self, handle: &FocusHandle) {
383 if self.window.last_blur.is_none() {
384 self.window.last_blur = Some(self.window.focus);
385 }
386
387 self.window.focus = Some(handle.id);
388 self.app.push_effect(Effect::FocusChanged {
389 window_handle: self.window.handle,
390 focused: Some(handle.id),
391 });
392 self.notify();
393 }
394
395 /// Remove focus from all elements within this context's window.
396 pub fn blur(&mut self) {
397 if self.window.last_blur.is_none() {
398 self.window.last_blur = Some(self.window.focus);
399 }
400
401 self.window.focus = None;
402 self.app.push_effect(Effect::FocusChanged {
403 window_handle: self.window.handle,
404 focused: None,
405 });
406 self.notify();
407 }
408
409 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
410 /// that are currently on the stack to be returned to the app.
411 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
412 let handle = self.window.handle;
413 self.app.defer(move |cx| {
414 handle.update(cx, |_, cx| f(cx)).ok();
415 });
416 }
417
418 pub fn subscribe<Emitter, E>(
419 &mut self,
420 entity: &E,
421 mut on_event: impl FnMut(E, &Emitter::Event, &mut WindowContext<'_>) + 'static,
422 ) -> Subscription
423 where
424 Emitter: EventEmitter,
425 E: Entity<Emitter>,
426 {
427 let entity_id = entity.entity_id();
428 let entity = entity.downgrade();
429 let window_handle = self.window.handle;
430 self.app.event_listeners.insert(
431 entity_id,
432 Box::new(move |event, cx| {
433 window_handle
434 .update(cx, |_, cx| {
435 if let Some(handle) = E::upgrade_from(&entity) {
436 let event = event.downcast_ref().expect("invalid event type");
437 on_event(handle, event, cx);
438 true
439 } else {
440 false
441 }
442 })
443 .unwrap_or(false)
444 }),
445 )
446 }
447
448 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
449 /// await points in async code.
450 pub fn to_async(&self) -> AsyncWindowContext {
451 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
452 }
453
454 /// Schedule the given closure to be run directly after the current frame is rendered.
455 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
456 let handle = self.window.handle;
457 let display_id = self.window.display_id;
458
459 if !self.frame_consumers.contains_key(&display_id) {
460 let (tx, mut rx) = mpsc::unbounded::<()>();
461 self.platform.set_display_link_output_callback(
462 display_id,
463 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
464 );
465
466 let consumer_task = self.app.spawn(|cx| async move {
467 while rx.next().await.is_some() {
468 cx.update(|cx| {
469 for callback in cx
470 .next_frame_callbacks
471 .get_mut(&display_id)
472 .unwrap()
473 .drain(..)
474 .collect::<SmallVec<[_; 32]>>()
475 {
476 callback(cx);
477 }
478 })
479 .ok();
480
481 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
482
483 cx.update(|cx| {
484 if cx.next_frame_callbacks.is_empty() {
485 cx.platform.stop_display_link(display_id);
486 }
487 })
488 .ok();
489 }
490 });
491 self.frame_consumers.insert(display_id, consumer_task);
492 }
493
494 if self.next_frame_callbacks.is_empty() {
495 self.platform.start_display_link(display_id);
496 }
497
498 self.next_frame_callbacks
499 .entry(display_id)
500 .or_default()
501 .push(Box::new(move |cx: &mut AppContext| {
502 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
503 }));
504 }
505
506 /// Spawn the future returned by the given closure on the application thread pool.
507 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
508 /// use within your future.
509 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
510 where
511 R: 'static,
512 Fut: Future<Output = R> + 'static,
513 {
514 self.app
515 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
516 }
517
518 /// Update the global of the given type. The given closure is given simultaneous mutable
519 /// access both to the global and the context.
520 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
521 where
522 G: 'static,
523 {
524 let mut global = self.app.lease_global::<G>();
525 let result = f(&mut global, self);
526 self.app.end_global_lease(global);
527 result
528 }
529
530 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
531 /// layout is being requested, along with the layout ids of any children. This method is called during
532 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
533 pub fn request_layout(
534 &mut self,
535 style: &Style,
536 children: impl IntoIterator<Item = LayoutId>,
537 ) -> LayoutId {
538 self.app.layout_id_buffer.clear();
539 self.app.layout_id_buffer.extend(children.into_iter());
540 let rem_size = self.rem_size();
541
542 self.window
543 .layout_engine
544 .request_layout(style, rem_size, &self.app.layout_id_buffer)
545 }
546
547 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
548 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
549 /// determine the element's size. One place this is used internally is when measuring text.
550 ///
551 /// The given closure is invoked at layout time with the known dimensions and available space and
552 /// returns a `Size`.
553 pub fn request_measured_layout<
554 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
555 >(
556 &mut self,
557 style: Style,
558 rem_size: Pixels,
559 measure: F,
560 ) -> LayoutId {
561 self.window
562 .layout_engine
563 .request_measured_layout(style, rem_size, measure)
564 }
565
566 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
567 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
568 /// in order to pass your element its `Bounds` automatically.
569 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
570 let mut bounds = self
571 .window
572 .layout_engine
573 .layout_bounds(layout_id)
574 .map(Into::into);
575 bounds.origin += self.element_offset();
576 bounds
577 }
578
579 fn window_bounds_changed(&mut self) {
580 self.window.scale_factor = self.window.platform_window.scale_factor();
581 self.window.content_size = self.window.platform_window.content_size();
582 self.window.bounds = self.window.platform_window.bounds();
583 self.window.display_id = self.window.platform_window.display().id();
584 self.window.dirty = true;
585
586 self.window
587 .bounds_observers
588 .clone()
589 .retain(&(), |callback| callback(self));
590 }
591
592 pub fn window_bounds(&self) -> WindowBounds {
593 self.window.bounds
594 }
595
596 pub fn is_window_active(&self) -> bool {
597 self.window.active
598 }
599
600 pub fn zoom_window(&self) {
601 self.window.platform_window.zoom();
602 }
603
604 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
605 self.platform
606 .displays()
607 .into_iter()
608 .find(|display| display.id() == self.window.display_id)
609 }
610
611 /// The scale factor of the display associated with the window. For example, it could
612 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
613 /// be rendered as two pixels on screen.
614 pub fn scale_factor(&self) -> f32 {
615 self.window.scale_factor
616 }
617
618 /// The size of an em for the base font of the application. Adjusting this value allows the
619 /// UI to scale, just like zooming a web page.
620 pub fn rem_size(&self) -> Pixels {
621 self.window.rem_size
622 }
623
624 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
625 /// UI to scale, just like zooming a web page.
626 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
627 self.window.rem_size = rem_size.into();
628 }
629
630 /// The line height associated with the current text style.
631 pub fn line_height(&self) -> Pixels {
632 let rem_size = self.rem_size();
633 let text_style = self.text_style();
634 text_style
635 .line_height
636 .to_pixels(text_style.font_size.into(), rem_size)
637 }
638
639 /// Call to prevent the default action of an event. Currently only used to prevent
640 /// parent elements from becoming focused on mouse down.
641 pub fn prevent_default(&mut self) {
642 self.window.default_prevented = true;
643 }
644
645 /// Obtain whether default has been prevented for the event currently being dispatched.
646 pub fn default_prevented(&self) -> bool {
647 self.window.default_prevented
648 }
649
650 /// Register a mouse event listener on the window for the current frame. The type of event
651 /// is determined by the first parameter of the given listener. When the next frame is rendered
652 /// the listener will be cleared.
653 ///
654 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
655 /// a specific need to register a global listener.
656 pub fn on_mouse_event<Event: 'static>(
657 &mut self,
658 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
659 ) {
660 let order = self.window.z_index_stack.clone();
661 self.window
662 .mouse_listeners
663 .entry(TypeId::of::<Event>())
664 .or_default()
665 .push((
666 order,
667 Box::new(move |event: &dyn Any, phase, cx| {
668 handler(event.downcast_ref().unwrap(), phase, cx)
669 }),
670 ))
671 }
672
673 /// The position of the mouse relative to the window.
674 pub fn mouse_position(&self) -> Point<Pixels> {
675 self.window.mouse_position
676 }
677
678 pub fn set_cursor_style(&mut self, style: CursorStyle) {
679 self.window.requested_cursor_style = Some(style)
680 }
681
682 /// Called during painting to invoke the given closure in a new stacking context. The given
683 /// z-index is interpreted relative to the previous call to `stack`.
684 pub fn stack<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
685 self.window.z_index_stack.push(z_index);
686 let result = f(self);
687 self.window.z_index_stack.pop();
688 result
689 }
690
691 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
692 pub fn paint_shadows(
693 &mut self,
694 bounds: Bounds<Pixels>,
695 corner_radii: Corners<Pixels>,
696 shadows: &[BoxShadow],
697 ) {
698 let scale_factor = self.scale_factor();
699 let content_mask = self.content_mask();
700 let window = &mut *self.window;
701 for shadow in shadows {
702 let mut shadow_bounds = bounds;
703 shadow_bounds.origin += shadow.offset;
704 shadow_bounds.dilate(shadow.spread_radius);
705 window.scene_builder.insert(
706 &window.z_index_stack,
707 Shadow {
708 order: 0,
709 bounds: shadow_bounds.scale(scale_factor),
710 content_mask: content_mask.scale(scale_factor),
711 corner_radii: corner_radii.scale(scale_factor),
712 color: shadow.color,
713 blur_radius: shadow.blur_radius.scale(scale_factor),
714 },
715 );
716 }
717 }
718
719 /// Paint one or more quads into the scene for the current frame at the current stacking context.
720 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
721 pub fn paint_quad(
722 &mut self,
723 bounds: Bounds<Pixels>,
724 corner_radii: Corners<Pixels>,
725 background: impl Into<Hsla>,
726 border_widths: Edges<Pixels>,
727 border_color: impl Into<Hsla>,
728 ) {
729 let scale_factor = self.scale_factor();
730 let content_mask = self.content_mask();
731
732 let window = &mut *self.window;
733 window.scene_builder.insert(
734 &window.z_index_stack,
735 Quad {
736 order: 0,
737 bounds: bounds.scale(scale_factor),
738 content_mask: content_mask.scale(scale_factor),
739 background: background.into(),
740 border_color: border_color.into(),
741 corner_radii: corner_radii.scale(scale_factor),
742 border_widths: border_widths.scale(scale_factor),
743 },
744 );
745 }
746
747 /// Paint the given `Path` into the scene for the current frame at the current z-index.
748 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
749 let scale_factor = self.scale_factor();
750 let content_mask = self.content_mask();
751 path.content_mask = content_mask;
752 path.color = color.into();
753 let window = &mut *self.window;
754 window
755 .scene_builder
756 .insert(&window.z_index_stack, path.scale(scale_factor));
757 }
758
759 /// Paint an underline into the scene for the current frame at the current z-index.
760 pub fn paint_underline(
761 &mut self,
762 origin: Point<Pixels>,
763 width: Pixels,
764 style: &UnderlineStyle,
765 ) -> Result<()> {
766 let scale_factor = self.scale_factor();
767 let height = if style.wavy {
768 style.thickness * 3.
769 } else {
770 style.thickness
771 };
772 let bounds = Bounds {
773 origin,
774 size: size(width, height),
775 };
776 let content_mask = self.content_mask();
777 let window = &mut *self.window;
778 window.scene_builder.insert(
779 &window.z_index_stack,
780 Underline {
781 order: 0,
782 bounds: bounds.scale(scale_factor),
783 content_mask: content_mask.scale(scale_factor),
784 thickness: style.thickness.scale(scale_factor),
785 color: style.color.unwrap_or_default(),
786 wavy: style.wavy,
787 },
788 );
789 Ok(())
790 }
791
792 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
793 pub fn paint_glyph(
794 &mut self,
795 origin: Point<Pixels>,
796 font_id: FontId,
797 glyph_id: GlyphId,
798 font_size: Pixels,
799 color: Hsla,
800 ) -> Result<()> {
801 let scale_factor = self.scale_factor();
802 let glyph_origin = origin.scale(scale_factor);
803 let subpixel_variant = Point {
804 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
805 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
806 };
807 let params = RenderGlyphParams {
808 font_id,
809 glyph_id,
810 font_size,
811 subpixel_variant,
812 scale_factor,
813 is_emoji: false,
814 };
815
816 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
817 if !raster_bounds.is_zero() {
818 let tile =
819 self.window
820 .sprite_atlas
821 .get_or_insert_with(¶ms.clone().into(), &mut || {
822 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
823 Ok((size, Cow::Owned(bytes)))
824 })?;
825 let bounds = Bounds {
826 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
827 size: tile.bounds.size.map(Into::into),
828 };
829 let content_mask = self.content_mask().scale(scale_factor);
830 let window = &mut *self.window;
831 window.scene_builder.insert(
832 &window.z_index_stack,
833 MonochromeSprite {
834 order: 0,
835 bounds,
836 content_mask,
837 color,
838 tile,
839 },
840 );
841 }
842 Ok(())
843 }
844
845 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
846 pub fn paint_emoji(
847 &mut self,
848 origin: Point<Pixels>,
849 font_id: FontId,
850 glyph_id: GlyphId,
851 font_size: Pixels,
852 ) -> Result<()> {
853 let scale_factor = self.scale_factor();
854 let glyph_origin = origin.scale(scale_factor);
855 let params = RenderGlyphParams {
856 font_id,
857 glyph_id,
858 font_size,
859 // We don't render emojis with subpixel variants.
860 subpixel_variant: Default::default(),
861 scale_factor,
862 is_emoji: true,
863 };
864
865 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
866 if !raster_bounds.is_zero() {
867 let tile =
868 self.window
869 .sprite_atlas
870 .get_or_insert_with(¶ms.clone().into(), &mut || {
871 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
872 Ok((size, Cow::Owned(bytes)))
873 })?;
874 let bounds = Bounds {
875 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
876 size: tile.bounds.size.map(Into::into),
877 };
878 let content_mask = self.content_mask().scale(scale_factor);
879 let window = &mut *self.window;
880
881 window.scene_builder.insert(
882 &window.z_index_stack,
883 PolychromeSprite {
884 order: 0,
885 bounds,
886 corner_radii: Default::default(),
887 content_mask,
888 tile,
889 grayscale: false,
890 },
891 );
892 }
893 Ok(())
894 }
895
896 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
897 pub fn paint_svg(
898 &mut self,
899 bounds: Bounds<Pixels>,
900 path: SharedString,
901 color: Hsla,
902 ) -> Result<()> {
903 let scale_factor = self.scale_factor();
904 let bounds = bounds.scale(scale_factor);
905 // Render the SVG at twice the size to get a higher quality result.
906 let params = RenderSvgParams {
907 path,
908 size: bounds
909 .size
910 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
911 };
912
913 let tile =
914 self.window
915 .sprite_atlas
916 .get_or_insert_with(¶ms.clone().into(), &mut || {
917 let bytes = self.svg_renderer.render(¶ms)?;
918 Ok((params.size, Cow::Owned(bytes)))
919 })?;
920 let content_mask = self.content_mask().scale(scale_factor);
921
922 let window = &mut *self.window;
923 window.scene_builder.insert(
924 &window.z_index_stack,
925 MonochromeSprite {
926 order: 0,
927 bounds,
928 content_mask,
929 color,
930 tile,
931 },
932 );
933
934 Ok(())
935 }
936
937 /// Paint an image into the scene for the current frame at the current z-index.
938 pub fn paint_image(
939 &mut self,
940 bounds: Bounds<Pixels>,
941 corner_radii: Corners<Pixels>,
942 data: Arc<ImageData>,
943 grayscale: bool,
944 ) -> Result<()> {
945 let scale_factor = self.scale_factor();
946 let bounds = bounds.scale(scale_factor);
947 let params = RenderImageParams { image_id: data.id };
948
949 let tile = self
950 .window
951 .sprite_atlas
952 .get_or_insert_with(¶ms.clone().into(), &mut || {
953 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
954 })?;
955 let content_mask = self.content_mask().scale(scale_factor);
956 let corner_radii = corner_radii.scale(scale_factor);
957
958 let window = &mut *self.window;
959 window.scene_builder.insert(
960 &window.z_index_stack,
961 PolychromeSprite {
962 order: 0,
963 bounds,
964 content_mask,
965 corner_radii,
966 tile,
967 grayscale,
968 },
969 );
970 Ok(())
971 }
972
973 /// Draw pixels to the display for this window based on the contents of its scene.
974 pub(crate) fn draw(&mut self) {
975 let root_view = self.window.root_view.take().unwrap();
976
977 self.start_frame();
978
979 self.stack(0, |cx| {
980 let available_space = cx.window.content_size.map(Into::into);
981 root_view.draw(available_space, cx);
982 });
983
984 if let Some(active_drag) = self.app.active_drag.take() {
985 self.stack(1, |cx| {
986 let offset = cx.mouse_position() - active_drag.cursor_offset;
987 cx.with_element_offset(Some(offset), |cx| {
988 let available_space =
989 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
990 active_drag.view.draw(available_space, cx);
991 cx.active_drag = Some(active_drag);
992 });
993 });
994 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
995 self.stack(1, |cx| {
996 cx.with_element_offset(Some(active_tooltip.cursor_offset), |cx| {
997 let available_space =
998 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
999 active_tooltip.view.draw(available_space, cx);
1000 });
1001 });
1002 }
1003
1004 self.window.root_view = Some(root_view);
1005 let scene = self.window.scene_builder.build();
1006
1007 self.window.platform_window.draw(scene);
1008 let cursor_style = self
1009 .window
1010 .requested_cursor_style
1011 .take()
1012 .unwrap_or(CursorStyle::Arrow);
1013 self.platform.set_cursor_style(cursor_style);
1014
1015 self.window.dirty = false;
1016 }
1017
1018 fn start_frame(&mut self) {
1019 self.text_system().start_frame();
1020
1021 let window = &mut *self.window;
1022
1023 // Move the current frame element states to the previous frame.
1024 // The new empty element states map will be populated for any element states we
1025 // reference during the upcoming frame.
1026 mem::swap(
1027 &mut window.element_states,
1028 &mut window.prev_frame_element_states,
1029 );
1030 window.element_states.clear();
1031
1032 // Make the current key matchers the previous, and then clear the current.
1033 // An empty key matcher map will be created for every identified element in the
1034 // upcoming frame.
1035 mem::swap(
1036 &mut window.key_matchers,
1037 &mut window.prev_frame_key_matchers,
1038 );
1039 window.key_matchers.clear();
1040
1041 // Clear mouse event listeners, because elements add new element listeners
1042 // when the upcoming frame is painted.
1043 window.mouse_listeners.values_mut().for_each(Vec::clear);
1044
1045 // Clear focus state, because we determine what is focused when the new elements
1046 // in the upcoming frame are initialized.
1047 window.focus_listeners.clear();
1048 window.key_dispatch_stack.clear();
1049 window.focus_parents_by_child.clear();
1050 window.freeze_key_dispatch_stack = false;
1051 }
1052
1053 /// Dispatch a mouse or keyboard event on the window.
1054 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1055 // Handlers may set this to false by calling `stop_propagation`
1056 self.app.propagate_event = true;
1057 self.window.default_prevented = false;
1058
1059 let event = match event {
1060 // Track the mouse position with our own state, since accessing the platform
1061 // API for the mouse position can only occur on the main thread.
1062 InputEvent::MouseMove(mouse_move) => {
1063 self.window.mouse_position = mouse_move.position;
1064 InputEvent::MouseMove(mouse_move)
1065 }
1066 // Translate dragging and dropping of external files from the operating system
1067 // to internal drag and drop events.
1068 InputEvent::FileDrop(file_drop) => match file_drop {
1069 FileDropEvent::Entered { position, files } => {
1070 self.window.mouse_position = position;
1071 if self.active_drag.is_none() {
1072 self.active_drag = Some(AnyDrag {
1073 view: self.build_view(|_| files).into(),
1074 cursor_offset: position,
1075 });
1076 }
1077 InputEvent::MouseDown(MouseDownEvent {
1078 position,
1079 button: MouseButton::Left,
1080 click_count: 1,
1081 modifiers: Modifiers::default(),
1082 })
1083 }
1084 FileDropEvent::Pending { position } => {
1085 self.window.mouse_position = position;
1086 InputEvent::MouseMove(MouseMoveEvent {
1087 position,
1088 pressed_button: Some(MouseButton::Left),
1089 modifiers: Modifiers::default(),
1090 })
1091 }
1092 FileDropEvent::Submit { position } => {
1093 self.window.mouse_position = position;
1094 InputEvent::MouseUp(MouseUpEvent {
1095 button: MouseButton::Left,
1096 position,
1097 modifiers: Modifiers::default(),
1098 click_count: 1,
1099 })
1100 }
1101 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1102 button: MouseButton::Left,
1103 position: Point::default(),
1104 modifiers: Modifiers::default(),
1105 click_count: 1,
1106 }),
1107 },
1108 _ => event,
1109 };
1110
1111 if let Some(any_mouse_event) = event.mouse_event() {
1112 if let Some(mut handlers) = self
1113 .window
1114 .mouse_listeners
1115 .remove(&any_mouse_event.type_id())
1116 {
1117 // Because handlers may add other handlers, we sort every time.
1118 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1119
1120 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1121 // special purposes, such as detecting events outside of a given Bounds.
1122 for (_, handler) in &handlers {
1123 handler(any_mouse_event, DispatchPhase::Capture, self);
1124 if !self.app.propagate_event {
1125 break;
1126 }
1127 }
1128
1129 // Bubble phase, where most normal handlers do their work.
1130 if self.app.propagate_event {
1131 for (_, handler) in handlers.iter().rev() {
1132 handler(any_mouse_event, DispatchPhase::Bubble, self);
1133 if !self.app.propagate_event {
1134 break;
1135 }
1136 }
1137 }
1138
1139 if self.app.propagate_event
1140 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
1141 {
1142 self.active_drag = None;
1143 }
1144
1145 // Just in case any handlers added new handlers, which is weird, but possible.
1146 handlers.extend(
1147 self.window
1148 .mouse_listeners
1149 .get_mut(&any_mouse_event.type_id())
1150 .into_iter()
1151 .flat_map(|handlers| handlers.drain(..)),
1152 );
1153 self.window
1154 .mouse_listeners
1155 .insert(any_mouse_event.type_id(), handlers);
1156 }
1157 } else if let Some(any_key_event) = event.keyboard_event() {
1158 let key_dispatch_stack = mem::take(&mut self.window.key_dispatch_stack);
1159 let key_event_type = any_key_event.type_id();
1160 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
1161
1162 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
1163 match frame {
1164 KeyDispatchStackFrame::Listener {
1165 event_type,
1166 listener,
1167 } => {
1168 if key_event_type == *event_type {
1169 if let Some(action) = listener(
1170 any_key_event,
1171 &context_stack,
1172 DispatchPhase::Capture,
1173 self,
1174 ) {
1175 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1176 }
1177 if !self.app.propagate_event {
1178 break;
1179 }
1180 }
1181 }
1182 KeyDispatchStackFrame::Context(context) => {
1183 context_stack.push(&context);
1184 }
1185 }
1186 }
1187
1188 if self.app.propagate_event {
1189 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
1190 match frame {
1191 KeyDispatchStackFrame::Listener {
1192 event_type,
1193 listener,
1194 } => {
1195 if key_event_type == *event_type {
1196 if let Some(action) = listener(
1197 any_key_event,
1198 &context_stack,
1199 DispatchPhase::Bubble,
1200 self,
1201 ) {
1202 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1203 }
1204
1205 if !self.app.propagate_event {
1206 break;
1207 }
1208 }
1209 }
1210 KeyDispatchStackFrame::Context(_) => {
1211 context_stack.pop();
1212 }
1213 }
1214 }
1215 }
1216
1217 drop(context_stack);
1218 self.window.key_dispatch_stack = key_dispatch_stack;
1219 }
1220
1221 true
1222 }
1223
1224 /// Attempt to map a keystroke to an action based on the keymap.
1225 pub fn match_keystroke(
1226 &mut self,
1227 element_id: &GlobalElementId,
1228 keystroke: &Keystroke,
1229 context_stack: &[&DispatchContext],
1230 ) -> KeyMatch {
1231 let key_match = self
1232 .window
1233 .key_matchers
1234 .get_mut(element_id)
1235 .unwrap()
1236 .match_keystroke(keystroke, context_stack);
1237
1238 if key_match.is_some() {
1239 for matcher in self.window.key_matchers.values_mut() {
1240 matcher.clear_pending();
1241 }
1242 }
1243
1244 key_match
1245 }
1246
1247 /// Register the given handler to be invoked whenever the global of the given type
1248 /// is updated.
1249 pub fn observe_global<G: 'static>(
1250 &mut self,
1251 f: impl Fn(&mut WindowContext<'_>) + 'static,
1252 ) -> Subscription {
1253 let window_handle = self.window.handle;
1254 self.global_observers.insert(
1255 TypeId::of::<G>(),
1256 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1257 )
1258 }
1259
1260 pub fn activate_window(&self) {
1261 self.window.platform_window.activate();
1262 }
1263
1264 pub fn prompt(
1265 &self,
1266 level: PromptLevel,
1267 msg: &str,
1268 answers: &[&str],
1269 ) -> oneshot::Receiver<usize> {
1270 self.window.platform_window.prompt(level, msg, answers)
1271 }
1272
1273 fn dispatch_action(
1274 &mut self,
1275 action: Box<dyn Action>,
1276 dispatch_stack: &[KeyDispatchStackFrame],
1277 ) {
1278 let action_type = action.as_any().type_id();
1279
1280 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1281 for listener in &global_listeners {
1282 listener(action.as_ref(), DispatchPhase::Capture, self);
1283 if !self.app.propagate_event {
1284 break;
1285 }
1286 }
1287 global_listeners.extend(
1288 self.global_action_listeners
1289 .remove(&action_type)
1290 .unwrap_or_default(),
1291 );
1292 self.global_action_listeners
1293 .insert(action_type, global_listeners);
1294 }
1295
1296 if self.app.propagate_event {
1297 for stack_frame in dispatch_stack {
1298 if let KeyDispatchStackFrame::Listener {
1299 event_type,
1300 listener,
1301 } = stack_frame
1302 {
1303 if action_type == *event_type {
1304 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1305 if !self.app.propagate_event {
1306 break;
1307 }
1308 }
1309 }
1310 }
1311 }
1312
1313 if self.app.propagate_event {
1314 for stack_frame in dispatch_stack.iter().rev() {
1315 if let KeyDispatchStackFrame::Listener {
1316 event_type,
1317 listener,
1318 } = stack_frame
1319 {
1320 if action_type == *event_type {
1321 self.app.propagate_event = false;
1322 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1323 if !self.app.propagate_event {
1324 break;
1325 }
1326 }
1327 }
1328 }
1329 }
1330
1331 if self.app.propagate_event {
1332 if let Some(mut global_listeners) =
1333 self.app.global_action_listeners.remove(&action_type)
1334 {
1335 for listener in global_listeners.iter().rev() {
1336 self.app.propagate_event = false;
1337 listener(action.as_ref(), DispatchPhase::Bubble, self);
1338 if !self.app.propagate_event {
1339 break;
1340 }
1341 }
1342 global_listeners.extend(
1343 self.global_action_listeners
1344 .remove(&action_type)
1345 .unwrap_or_default(),
1346 );
1347 self.global_action_listeners
1348 .insert(action_type, global_listeners);
1349 }
1350 }
1351 }
1352}
1353
1354impl Context for WindowContext<'_> {
1355 type Result<T> = T;
1356
1357 fn build_model<T>(
1358 &mut self,
1359 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1360 ) -> Model<T>
1361 where
1362 T: 'static,
1363 {
1364 let slot = self.app.entities.reserve();
1365 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1366 self.entities.insert(slot, model)
1367 }
1368
1369 fn update_model<T: 'static, R>(
1370 &mut self,
1371 model: &Model<T>,
1372 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1373 ) -> R {
1374 let mut entity = self.entities.lease(model);
1375 let result = update(
1376 &mut *entity,
1377 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1378 );
1379 self.entities.end_lease(entity);
1380 result
1381 }
1382
1383 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1384 where
1385 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1386 {
1387 if window == self.window.handle {
1388 let root_view = self.window.root_view.clone().unwrap();
1389 Ok(update(root_view, self))
1390 } else {
1391 window.update(self.app, update)
1392 }
1393 }
1394}
1395
1396impl VisualContext for WindowContext<'_> {
1397 fn build_view<V>(
1398 &mut self,
1399 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1400 ) -> Self::Result<View<V>>
1401 where
1402 V: 'static,
1403 {
1404 let slot = self.app.entities.reserve();
1405 let view = View {
1406 model: slot.clone(),
1407 };
1408 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1409 let entity = build_view_state(&mut cx);
1410 self.entities.insert(slot, entity);
1411 view
1412 }
1413
1414 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1415 fn update_view<T: 'static, R>(
1416 &mut self,
1417 view: &View<T>,
1418 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1419 ) -> Self::Result<R> {
1420 let mut lease = self.app.entities.lease(&view.model);
1421 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1422 let result = update(&mut *lease, &mut cx);
1423 cx.app.entities.end_lease(lease);
1424 result
1425 }
1426
1427 fn replace_root_view<V>(
1428 &mut self,
1429 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1430 ) -> Self::Result<View<V>>
1431 where
1432 V: Render,
1433 {
1434 let slot = self.app.entities.reserve();
1435 let view = View {
1436 model: slot.clone(),
1437 };
1438 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1439 let entity = build_view(&mut cx);
1440 self.entities.insert(slot, entity);
1441 self.window.root_view = Some(view.clone().into());
1442 view
1443 }
1444}
1445
1446impl<'a> std::ops::Deref for WindowContext<'a> {
1447 type Target = AppContext;
1448
1449 fn deref(&self) -> &Self::Target {
1450 &self.app
1451 }
1452}
1453
1454impl<'a> std::ops::DerefMut for WindowContext<'a> {
1455 fn deref_mut(&mut self) -> &mut Self::Target {
1456 &mut self.app
1457 }
1458}
1459
1460impl<'a> Borrow<AppContext> for WindowContext<'a> {
1461 fn borrow(&self) -> &AppContext {
1462 &self.app
1463 }
1464}
1465
1466impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1467 fn borrow_mut(&mut self) -> &mut AppContext {
1468 &mut self.app
1469 }
1470}
1471
1472pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1473 fn app_mut(&mut self) -> &mut AppContext {
1474 self.borrow_mut()
1475 }
1476
1477 fn window(&self) -> &Window {
1478 self.borrow()
1479 }
1480
1481 fn window_mut(&mut self) -> &mut Window {
1482 self.borrow_mut()
1483 }
1484
1485 /// Pushes the given element id onto the global stack and invokes the given closure
1486 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1487 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1488 /// used to associate state with identified elements across separate frames.
1489 fn with_element_id<R>(
1490 &mut self,
1491 id: impl Into<ElementId>,
1492 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1493 ) -> R {
1494 let keymap = self.app_mut().keymap.clone();
1495 let window = self.window_mut();
1496 window.element_id_stack.push(id.into());
1497 let global_id = window.element_id_stack.clone();
1498
1499 if window.key_matchers.get(&global_id).is_none() {
1500 window.key_matchers.insert(
1501 global_id.clone(),
1502 window
1503 .prev_frame_key_matchers
1504 .remove(&global_id)
1505 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1506 );
1507 }
1508
1509 let result = f(global_id, self);
1510 let window: &mut Window = self.borrow_mut();
1511 window.element_id_stack.pop();
1512 result
1513 }
1514
1515 /// Invoke the given function with the given content mask after intersecting it
1516 /// with the current mask.
1517 fn with_content_mask<R>(
1518 &mut self,
1519 mask: ContentMask<Pixels>,
1520 f: impl FnOnce(&mut Self) -> R,
1521 ) -> R {
1522 let mask = mask.intersect(&self.content_mask());
1523 self.window_mut().content_mask_stack.push(mask);
1524 let result = f(self);
1525 self.window_mut().content_mask_stack.pop();
1526 result
1527 }
1528
1529 /// Update the global element offset based on the given offset. This is used to implement
1530 /// scrolling and position drag handles.
1531 fn with_element_offset<R>(
1532 &mut self,
1533 offset: Option<Point<Pixels>>,
1534 f: impl FnOnce(&mut Self) -> R,
1535 ) -> R {
1536 let Some(offset) = offset else {
1537 return f(self);
1538 };
1539
1540 let offset = self.element_offset() + offset;
1541 self.window_mut().element_offset_stack.push(offset);
1542 let result = f(self);
1543 self.window_mut().element_offset_stack.pop();
1544 result
1545 }
1546
1547 /// Obtain the current element offset.
1548 fn element_offset(&self) -> Point<Pixels> {
1549 self.window()
1550 .element_offset_stack
1551 .last()
1552 .copied()
1553 .unwrap_or_default()
1554 }
1555
1556 /// Update or intialize state for an element with the given id that lives across multiple
1557 /// frames. If an element with this id existed in the previous frame, its state will be passed
1558 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1559 /// when drawing the next frame.
1560 fn with_element_state<S, R>(
1561 &mut self,
1562 id: ElementId,
1563 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1564 ) -> R
1565 where
1566 S: 'static,
1567 {
1568 self.with_element_id(id, |global_id, cx| {
1569 if let Some(any) = cx
1570 .window_mut()
1571 .element_states
1572 .remove(&global_id)
1573 .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
1574 {
1575 // Using the extra inner option to avoid needing to reallocate a new box.
1576 let mut state_box = any
1577 .downcast::<Option<S>>()
1578 .expect("invalid element state type for id");
1579 let state = state_box
1580 .take()
1581 .expect("element state is already on the stack");
1582 let (result, state) = f(Some(state), cx);
1583 state_box.replace(state);
1584 cx.window_mut().element_states.insert(global_id, state_box);
1585 result
1586 } else {
1587 let (result, state) = f(None, cx);
1588 cx.window_mut()
1589 .element_states
1590 .insert(global_id, Box::new(Some(state)));
1591 result
1592 }
1593 })
1594 }
1595
1596 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1597 /// id is `None`, no state will be retrieved or stored.
1598 fn with_optional_element_state<S, R>(
1599 &mut self,
1600 element_id: Option<ElementId>,
1601 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1602 ) -> R
1603 where
1604 S: 'static,
1605 {
1606 if let Some(element_id) = element_id {
1607 self.with_element_state(element_id, f)
1608 } else {
1609 f(None, self).0
1610 }
1611 }
1612
1613 /// Obtain the current content mask.
1614 fn content_mask(&self) -> ContentMask<Pixels> {
1615 self.window()
1616 .content_mask_stack
1617 .last()
1618 .cloned()
1619 .unwrap_or_else(|| ContentMask {
1620 bounds: Bounds {
1621 origin: Point::default(),
1622 size: self.window().content_size,
1623 },
1624 })
1625 }
1626
1627 /// The size of an em for the base font of the application. Adjusting this value allows the
1628 /// UI to scale, just like zooming a web page.
1629 fn rem_size(&self) -> Pixels {
1630 self.window().rem_size
1631 }
1632}
1633
1634impl Borrow<Window> for WindowContext<'_> {
1635 fn borrow(&self) -> &Window {
1636 &self.window
1637 }
1638}
1639
1640impl BorrowMut<Window> for WindowContext<'_> {
1641 fn borrow_mut(&mut self) -> &mut Window {
1642 &mut self.window
1643 }
1644}
1645
1646impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1647
1648pub struct ViewContext<'a, V> {
1649 window_cx: WindowContext<'a>,
1650 view: &'a View<V>,
1651}
1652
1653impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1654 fn borrow(&self) -> &AppContext {
1655 &*self.window_cx.app
1656 }
1657}
1658
1659impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1660 fn borrow_mut(&mut self) -> &mut AppContext {
1661 &mut *self.window_cx.app
1662 }
1663}
1664
1665impl<V> Borrow<Window> for ViewContext<'_, V> {
1666 fn borrow(&self) -> &Window {
1667 &*self.window_cx.window
1668 }
1669}
1670
1671impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1672 fn borrow_mut(&mut self) -> &mut Window {
1673 &mut *self.window_cx.window
1674 }
1675}
1676
1677impl<'a, V: 'static> ViewContext<'a, V> {
1678 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1679 Self {
1680 window_cx: WindowContext::new(app, window),
1681 view,
1682 }
1683 }
1684
1685 // todo!("change this to return a reference");
1686 pub fn view(&self) -> View<V> {
1687 self.view.clone()
1688 }
1689
1690 pub fn model(&self) -> Model<V> {
1691 self.view.model.clone()
1692 }
1693
1694 /// Access the underlying window context.
1695 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1696 &mut self.window_cx
1697 }
1698
1699 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1700 self.window.z_index_stack.push(order);
1701 let result = f(self);
1702 self.window.z_index_stack.pop();
1703 result
1704 }
1705
1706 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1707 where
1708 V: 'static,
1709 {
1710 let view = self.view();
1711 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1712 }
1713
1714 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1715 /// that are currently on the stack to be returned to the app.
1716 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1717 let view = self.view().downgrade();
1718 self.window_cx.defer(move |cx| {
1719 view.update(cx, f).ok();
1720 });
1721 }
1722
1723 pub fn observe<V2, E>(
1724 &mut self,
1725 entity: &E,
1726 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1727 ) -> Subscription
1728 where
1729 V2: 'static,
1730 V: 'static,
1731 E: Entity<V2>,
1732 {
1733 let view = self.view().downgrade();
1734 let entity_id = entity.entity_id();
1735 let entity = entity.downgrade();
1736 let window_handle = self.window.handle;
1737 self.app.observers.insert(
1738 entity_id,
1739 Box::new(move |cx| {
1740 window_handle
1741 .update(cx, |_, cx| {
1742 if let Some(handle) = E::upgrade_from(&entity) {
1743 view.update(cx, |this, cx| on_notify(this, handle, cx))
1744 .is_ok()
1745 } else {
1746 false
1747 }
1748 })
1749 .unwrap_or(false)
1750 }),
1751 )
1752 }
1753
1754 pub fn subscribe<V2, E>(
1755 &mut self,
1756 entity: &E,
1757 mut on_event: impl FnMut(&mut V, E, &V2::Event, &mut ViewContext<'_, V>) + 'static,
1758 ) -> Subscription
1759 where
1760 V2: EventEmitter,
1761 E: Entity<V2>,
1762 {
1763 let view = self.view().downgrade();
1764 let entity_id = entity.entity_id();
1765 let handle = entity.downgrade();
1766 let window_handle = self.window.handle;
1767 self.app.event_listeners.insert(
1768 entity_id,
1769 Box::new(move |event, cx| {
1770 window_handle
1771 .update(cx, |_, cx| {
1772 if let Some(handle) = E::upgrade_from(&handle) {
1773 let event = event.downcast_ref().expect("invalid event type");
1774 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1775 .is_ok()
1776 } else {
1777 false
1778 }
1779 })
1780 .unwrap_or(false)
1781 }),
1782 )
1783 }
1784
1785 pub fn on_release(
1786 &mut self,
1787 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
1788 ) -> Subscription {
1789 let window_handle = self.window.handle;
1790 self.app.release_listeners.insert(
1791 self.view.model.entity_id,
1792 Box::new(move |this, cx| {
1793 let this = this.downcast_mut().expect("invalid entity type");
1794 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
1795 }),
1796 )
1797 }
1798
1799 pub fn observe_release<V2, E>(
1800 &mut self,
1801 entity: &E,
1802 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1803 ) -> Subscription
1804 where
1805 V: 'static,
1806 V2: 'static,
1807 E: Entity<V2>,
1808 {
1809 let view = self.view().downgrade();
1810 let entity_id = entity.entity_id();
1811 let window_handle = self.window.handle;
1812 self.app.release_listeners.insert(
1813 entity_id,
1814 Box::new(move |entity, cx| {
1815 let entity = entity.downcast_mut().expect("invalid entity type");
1816 let _ = window_handle.update(cx, |_, cx| {
1817 view.update(cx, |this, cx| on_release(this, entity, cx))
1818 });
1819 }),
1820 )
1821 }
1822
1823 pub fn notify(&mut self) {
1824 self.window_cx.notify();
1825 self.window_cx.app.push_effect(Effect::Notify {
1826 emitter: self.view.model.entity_id,
1827 });
1828 }
1829
1830 pub fn observe_window_bounds(
1831 &mut self,
1832 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1833 ) -> Subscription {
1834 let view = self.view.downgrade();
1835 self.window.bounds_observers.insert(
1836 (),
1837 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1838 )
1839 }
1840
1841 pub fn observe_window_activation(
1842 &mut self,
1843 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1844 ) -> Subscription {
1845 let view = self.view.downgrade();
1846 self.window.activation_observers.insert(
1847 (),
1848 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1849 )
1850 }
1851
1852 pub fn on_focus_changed(
1853 &mut self,
1854 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + 'static,
1855 ) {
1856 let handle = self.view().downgrade();
1857 self.window.focus_listeners.push(Box::new(move |event, cx| {
1858 handle
1859 .update(cx, |view, cx| listener(view, event, cx))
1860 .log_err();
1861 }));
1862 }
1863
1864 pub fn with_key_listeners<R>(
1865 &mut self,
1866 key_listeners: impl IntoIterator<Item = (TypeId, KeyListener<V>)>,
1867 f: impl FnOnce(&mut Self) -> R,
1868 ) -> R {
1869 let old_stack_len = self.window.key_dispatch_stack.len();
1870 if !self.window.freeze_key_dispatch_stack {
1871 for (event_type, listener) in key_listeners {
1872 let handle = self.view().downgrade();
1873 let listener = Box::new(
1874 move |event: &dyn Any,
1875 context_stack: &[&DispatchContext],
1876 phase: DispatchPhase,
1877 cx: &mut WindowContext<'_>| {
1878 handle
1879 .update(cx, |view, cx| {
1880 listener(view, event, context_stack, phase, cx)
1881 })
1882 .log_err()
1883 .flatten()
1884 },
1885 );
1886 self.window
1887 .key_dispatch_stack
1888 .push(KeyDispatchStackFrame::Listener {
1889 event_type,
1890 listener,
1891 });
1892 }
1893 }
1894
1895 let result = f(self);
1896
1897 if !self.window.freeze_key_dispatch_stack {
1898 self.window.key_dispatch_stack.truncate(old_stack_len);
1899 }
1900
1901 result
1902 }
1903
1904 pub fn with_key_dispatch_context<R>(
1905 &mut self,
1906 context: DispatchContext,
1907 f: impl FnOnce(&mut Self) -> R,
1908 ) -> R {
1909 if context.is_empty() {
1910 return f(self);
1911 }
1912
1913 if !self.window.freeze_key_dispatch_stack {
1914 self.window
1915 .key_dispatch_stack
1916 .push(KeyDispatchStackFrame::Context(context));
1917 }
1918
1919 let result = f(self);
1920
1921 if !self.window.freeze_key_dispatch_stack {
1922 self.window.key_dispatch_stack.pop();
1923 }
1924
1925 result
1926 }
1927
1928 pub fn with_focus<R>(
1929 &mut self,
1930 focus_handle: FocusHandle,
1931 f: impl FnOnce(&mut Self) -> R,
1932 ) -> R {
1933 if let Some(parent_focus_id) = self.window.focus_stack.last().copied() {
1934 self.window
1935 .focus_parents_by_child
1936 .insert(focus_handle.id, parent_focus_id);
1937 }
1938 self.window.focus_stack.push(focus_handle.id);
1939
1940 if Some(focus_handle.id) == self.window.focus {
1941 self.window.freeze_key_dispatch_stack = true;
1942 }
1943
1944 let result = f(self);
1945
1946 self.window.focus_stack.pop();
1947 result
1948 }
1949
1950 pub fn spawn<Fut, R>(
1951 &mut self,
1952 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
1953 ) -> Task<R>
1954 where
1955 R: 'static,
1956 Fut: Future<Output = R> + 'static,
1957 {
1958 let view = self.view().downgrade();
1959 self.window_cx.spawn(|cx| f(view, cx))
1960 }
1961
1962 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1963 where
1964 G: 'static,
1965 {
1966 let mut global = self.app.lease_global::<G>();
1967 let result = f(&mut global, self);
1968 self.app.end_global_lease(global);
1969 result
1970 }
1971
1972 pub fn observe_global<G: 'static>(
1973 &mut self,
1974 f: impl Fn(&mut V, &mut ViewContext<'_, V>) + 'static,
1975 ) -> Subscription {
1976 let window_handle = self.window.handle;
1977 let view = self.view().downgrade();
1978 self.global_observers.insert(
1979 TypeId::of::<G>(),
1980 Box::new(move |cx| {
1981 window_handle
1982 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
1983 .unwrap_or(false)
1984 }),
1985 )
1986 }
1987
1988 pub fn on_mouse_event<Event: 'static>(
1989 &mut self,
1990 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
1991 ) {
1992 let handle = self.view();
1993 self.window_cx.on_mouse_event(move |event, phase, cx| {
1994 handle.update(cx, |view, cx| {
1995 handler(view, event, phase, cx);
1996 })
1997 });
1998 }
1999}
2000
2001impl<V> ViewContext<'_, V>
2002where
2003 V: InputHandler + 'static,
2004{
2005 pub fn handle_text_input(&mut self) {
2006 self.window.requested_input_handler = Some(Box::new(WindowInputHandler {
2007 cx: self.app.this.clone(),
2008 window: self.window_handle(),
2009 handler: self.view().downgrade(),
2010 }))
2011 }
2012}
2013
2014impl<V> ViewContext<'_, V>
2015where
2016 V: EventEmitter,
2017 V::Event: 'static,
2018{
2019 pub fn emit(&mut self, event: V::Event) {
2020 let emitter = self.view.model.entity_id;
2021 self.app.push_effect(Effect::Emit {
2022 emitter,
2023 event: Box::new(event),
2024 });
2025 }
2026}
2027
2028impl<V> Context for ViewContext<'_, V> {
2029 type Result<U> = U;
2030
2031 fn build_model<T: 'static>(
2032 &mut self,
2033 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2034 ) -> Model<T> {
2035 self.window_cx.build_model(build_model)
2036 }
2037
2038 fn update_model<T: 'static, R>(
2039 &mut self,
2040 model: &Model<T>,
2041 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2042 ) -> R {
2043 self.window_cx.update_model(model, update)
2044 }
2045
2046 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2047 where
2048 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2049 {
2050 self.window_cx.update_window(window, update)
2051 }
2052}
2053
2054impl<V: 'static> VisualContext for ViewContext<'_, V> {
2055 fn build_view<W: 'static>(
2056 &mut self,
2057 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2058 ) -> Self::Result<View<W>> {
2059 self.window_cx.build_view(build_view_state)
2060 }
2061
2062 fn update_view<V2: 'static, R>(
2063 &mut self,
2064 view: &View<V2>,
2065 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2066 ) -> Self::Result<R> {
2067 self.window_cx.update_view(view, update)
2068 }
2069
2070 fn replace_root_view<W>(
2071 &mut self,
2072 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2073 ) -> Self::Result<View<W>>
2074 where
2075 W: Render,
2076 {
2077 self.window_cx.replace_root_view(build_view)
2078 }
2079}
2080
2081impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2082 type Target = WindowContext<'a>;
2083
2084 fn deref(&self) -> &Self::Target {
2085 &self.window_cx
2086 }
2087}
2088
2089impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2090 fn deref_mut(&mut self) -> &mut Self::Target {
2091 &mut self.window_cx
2092 }
2093}
2094
2095// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2096slotmap::new_key_type! { pub struct WindowId; }
2097
2098impl WindowId {
2099 pub fn as_u64(&self) -> u64 {
2100 self.0.as_ffi()
2101 }
2102}
2103
2104#[derive(Deref, DerefMut)]
2105pub struct WindowHandle<V> {
2106 #[deref]
2107 #[deref_mut]
2108 pub(crate) any_handle: AnyWindowHandle,
2109 state_type: PhantomData<V>,
2110}
2111
2112impl<V: 'static + Render> WindowHandle<V> {
2113 pub fn new(id: WindowId) -> Self {
2114 WindowHandle {
2115 any_handle: AnyWindowHandle {
2116 id,
2117 state_type: TypeId::of::<V>(),
2118 },
2119 state_type: PhantomData,
2120 }
2121 }
2122
2123 pub fn update<C, R>(
2124 self,
2125 cx: &mut C,
2126 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2127 ) -> Result<R>
2128 where
2129 C: Context,
2130 {
2131 cx.update_window(self.any_handle, |root_view, cx| {
2132 let view = root_view
2133 .downcast::<V>()
2134 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2135 Ok(cx.update_view(&view, update))
2136 })?
2137 }
2138}
2139
2140impl<V> Copy for WindowHandle<V> {}
2141
2142impl<V> Clone for WindowHandle<V> {
2143 fn clone(&self) -> Self {
2144 WindowHandle {
2145 any_handle: self.any_handle,
2146 state_type: PhantomData,
2147 }
2148 }
2149}
2150
2151impl<V> PartialEq for WindowHandle<V> {
2152 fn eq(&self, other: &Self) -> bool {
2153 self.any_handle == other.any_handle
2154 }
2155}
2156
2157impl<V> Eq for WindowHandle<V> {}
2158
2159impl<V> Hash for WindowHandle<V> {
2160 fn hash<H: Hasher>(&self, state: &mut H) {
2161 self.any_handle.hash(state);
2162 }
2163}
2164
2165impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2166 fn into(self) -> AnyWindowHandle {
2167 self.any_handle
2168 }
2169}
2170
2171#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2172pub struct AnyWindowHandle {
2173 pub(crate) id: WindowId,
2174 state_type: TypeId,
2175}
2176
2177impl AnyWindowHandle {
2178 pub fn window_id(&self) -> WindowId {
2179 self.id
2180 }
2181
2182 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2183 if TypeId::of::<T>() == self.state_type {
2184 Some(WindowHandle {
2185 any_handle: *self,
2186 state_type: PhantomData,
2187 })
2188 } else {
2189 None
2190 }
2191 }
2192
2193 pub fn update<C, R>(
2194 self,
2195 cx: &mut C,
2196 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2197 ) -> Result<R>
2198 where
2199 C: Context,
2200 {
2201 cx.update_window(self, update)
2202 }
2203}
2204
2205#[cfg(any(test, feature = "test-support"))]
2206impl From<SmallVec<[u32; 16]>> for StackingOrder {
2207 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2208 StackingOrder(small_vec)
2209 }
2210}
2211
2212#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2213pub enum ElementId {
2214 View(EntityId),
2215 Number(usize),
2216 Name(SharedString),
2217 FocusHandle(FocusId),
2218}
2219
2220impl From<EntityId> for ElementId {
2221 fn from(id: EntityId) -> Self {
2222 ElementId::View(id)
2223 }
2224}
2225
2226impl From<usize> for ElementId {
2227 fn from(id: usize) -> Self {
2228 ElementId::Number(id)
2229 }
2230}
2231
2232impl From<i32> for ElementId {
2233 fn from(id: i32) -> Self {
2234 Self::Number(id as usize)
2235 }
2236}
2237
2238impl From<SharedString> for ElementId {
2239 fn from(name: SharedString) -> Self {
2240 ElementId::Name(name)
2241 }
2242}
2243
2244impl From<&'static str> for ElementId {
2245 fn from(name: &'static str) -> Self {
2246 ElementId::Name(name.into())
2247 }
2248}
2249
2250impl<'a> From<&'a FocusHandle> for ElementId {
2251 fn from(handle: &'a FocusHandle) -> Self {
2252 ElementId::FocusHandle(handle.id)
2253 }
2254}