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(false)
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 pub fn show_character_palette(&self) {
612 self.window.platform_window.show_character_palette();
613 }
614
615 /// The scale factor of the display associated with the window. For example, it could
616 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
617 /// be rendered as two pixels on screen.
618 pub fn scale_factor(&self) -> f32 {
619 self.window.scale_factor
620 }
621
622 /// The size of an em for the base font of the application. Adjusting this value allows the
623 /// UI to scale, just like zooming a web page.
624 pub fn rem_size(&self) -> Pixels {
625 self.window.rem_size
626 }
627
628 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
629 /// UI to scale, just like zooming a web page.
630 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
631 self.window.rem_size = rem_size.into();
632 }
633
634 /// The line height associated with the current text style.
635 pub fn line_height(&self) -> Pixels {
636 let rem_size = self.rem_size();
637 let text_style = self.text_style();
638 text_style
639 .line_height
640 .to_pixels(text_style.font_size.into(), rem_size)
641 }
642
643 /// Call to prevent the default action of an event. Currently only used to prevent
644 /// parent elements from becoming focused on mouse down.
645 pub fn prevent_default(&mut self) {
646 self.window.default_prevented = true;
647 }
648
649 /// Obtain whether default has been prevented for the event currently being dispatched.
650 pub fn default_prevented(&self) -> bool {
651 self.window.default_prevented
652 }
653
654 /// Register a mouse event listener on the window for the current frame. The type of event
655 /// is determined by the first parameter of the given listener. When the next frame is rendered
656 /// the listener will be cleared.
657 ///
658 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
659 /// a specific need to register a global listener.
660 pub fn on_mouse_event<Event: 'static>(
661 &mut self,
662 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
663 ) {
664 let order = self.window.z_index_stack.clone();
665 self.window
666 .mouse_listeners
667 .entry(TypeId::of::<Event>())
668 .or_default()
669 .push((
670 order,
671 Box::new(move |event: &dyn Any, phase, cx| {
672 handler(event.downcast_ref().unwrap(), phase, cx)
673 }),
674 ))
675 }
676
677 /// The position of the mouse relative to the window.
678 pub fn mouse_position(&self) -> Point<Pixels> {
679 self.window.mouse_position
680 }
681
682 pub fn set_cursor_style(&mut self, style: CursorStyle) {
683 self.window.requested_cursor_style = Some(style)
684 }
685
686 /// Called during painting to invoke the given closure in a new stacking context. The given
687 /// z-index is interpreted relative to the previous call to `stack`.
688 pub fn stack<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
689 self.window.z_index_stack.push(z_index);
690 let result = f(self);
691 self.window.z_index_stack.pop();
692 result
693 }
694
695 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
696 pub fn paint_shadows(
697 &mut self,
698 bounds: Bounds<Pixels>,
699 corner_radii: Corners<Pixels>,
700 shadows: &[BoxShadow],
701 ) {
702 let scale_factor = self.scale_factor();
703 let content_mask = self.content_mask();
704 let window = &mut *self.window;
705 for shadow in shadows {
706 let mut shadow_bounds = bounds;
707 shadow_bounds.origin += shadow.offset;
708 shadow_bounds.dilate(shadow.spread_radius);
709 window.scene_builder.insert(
710 &window.z_index_stack,
711 Shadow {
712 order: 0,
713 bounds: shadow_bounds.scale(scale_factor),
714 content_mask: content_mask.scale(scale_factor),
715 corner_radii: corner_radii.scale(scale_factor),
716 color: shadow.color,
717 blur_radius: shadow.blur_radius.scale(scale_factor),
718 },
719 );
720 }
721 }
722
723 /// Paint one or more quads into the scene for the current frame at the current stacking context.
724 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
725 pub fn paint_quad(
726 &mut self,
727 bounds: Bounds<Pixels>,
728 corner_radii: Corners<Pixels>,
729 background: impl Into<Hsla>,
730 border_widths: Edges<Pixels>,
731 border_color: impl Into<Hsla>,
732 ) {
733 let scale_factor = self.scale_factor();
734 let content_mask = self.content_mask();
735
736 let window = &mut *self.window;
737 window.scene_builder.insert(
738 &window.z_index_stack,
739 Quad {
740 order: 0,
741 bounds: bounds.scale(scale_factor),
742 content_mask: content_mask.scale(scale_factor),
743 background: background.into(),
744 border_color: border_color.into(),
745 corner_radii: corner_radii.scale(scale_factor),
746 border_widths: border_widths.scale(scale_factor),
747 },
748 );
749 }
750
751 /// Paint the given `Path` into the scene for the current frame at the current z-index.
752 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
753 let scale_factor = self.scale_factor();
754 let content_mask = self.content_mask();
755 path.content_mask = content_mask;
756 path.color = color.into();
757 let window = &mut *self.window;
758 window
759 .scene_builder
760 .insert(&window.z_index_stack, path.scale(scale_factor));
761 }
762
763 /// Paint an underline into the scene for the current frame at the current z-index.
764 pub fn paint_underline(
765 &mut self,
766 origin: Point<Pixels>,
767 width: Pixels,
768 style: &UnderlineStyle,
769 ) -> Result<()> {
770 let scale_factor = self.scale_factor();
771 let height = if style.wavy {
772 style.thickness * 3.
773 } else {
774 style.thickness
775 };
776 let bounds = Bounds {
777 origin,
778 size: size(width, height),
779 };
780 let content_mask = self.content_mask();
781 let window = &mut *self.window;
782 window.scene_builder.insert(
783 &window.z_index_stack,
784 Underline {
785 order: 0,
786 bounds: bounds.scale(scale_factor),
787 content_mask: content_mask.scale(scale_factor),
788 thickness: style.thickness.scale(scale_factor),
789 color: style.color.unwrap_or_default(),
790 wavy: style.wavy,
791 },
792 );
793 Ok(())
794 }
795
796 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
797 pub fn paint_glyph(
798 &mut self,
799 origin: Point<Pixels>,
800 font_id: FontId,
801 glyph_id: GlyphId,
802 font_size: Pixels,
803 color: Hsla,
804 ) -> Result<()> {
805 let scale_factor = self.scale_factor();
806 let glyph_origin = origin.scale(scale_factor);
807 let subpixel_variant = Point {
808 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
809 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
810 };
811 let params = RenderGlyphParams {
812 font_id,
813 glyph_id,
814 font_size,
815 subpixel_variant,
816 scale_factor,
817 is_emoji: false,
818 };
819
820 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
821 if !raster_bounds.is_zero() {
822 let tile =
823 self.window
824 .sprite_atlas
825 .get_or_insert_with(¶ms.clone().into(), &mut || {
826 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
827 Ok((size, Cow::Owned(bytes)))
828 })?;
829 let bounds = Bounds {
830 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
831 size: tile.bounds.size.map(Into::into),
832 };
833 let content_mask = self.content_mask().scale(scale_factor);
834 let window = &mut *self.window;
835 window.scene_builder.insert(
836 &window.z_index_stack,
837 MonochromeSprite {
838 order: 0,
839 bounds,
840 content_mask,
841 color,
842 tile,
843 },
844 );
845 }
846 Ok(())
847 }
848
849 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
850 pub fn paint_emoji(
851 &mut self,
852 origin: Point<Pixels>,
853 font_id: FontId,
854 glyph_id: GlyphId,
855 font_size: Pixels,
856 ) -> Result<()> {
857 let scale_factor = self.scale_factor();
858 let glyph_origin = origin.scale(scale_factor);
859 let params = RenderGlyphParams {
860 font_id,
861 glyph_id,
862 font_size,
863 // We don't render emojis with subpixel variants.
864 subpixel_variant: Default::default(),
865 scale_factor,
866 is_emoji: true,
867 };
868
869 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
870 if !raster_bounds.is_zero() {
871 let tile =
872 self.window
873 .sprite_atlas
874 .get_or_insert_with(¶ms.clone().into(), &mut || {
875 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
876 Ok((size, Cow::Owned(bytes)))
877 })?;
878 let bounds = Bounds {
879 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
880 size: tile.bounds.size.map(Into::into),
881 };
882 let content_mask = self.content_mask().scale(scale_factor);
883 let window = &mut *self.window;
884
885 window.scene_builder.insert(
886 &window.z_index_stack,
887 PolychromeSprite {
888 order: 0,
889 bounds,
890 corner_radii: Default::default(),
891 content_mask,
892 tile,
893 grayscale: false,
894 },
895 );
896 }
897 Ok(())
898 }
899
900 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
901 pub fn paint_svg(
902 &mut self,
903 bounds: Bounds<Pixels>,
904 path: SharedString,
905 color: Hsla,
906 ) -> Result<()> {
907 let scale_factor = self.scale_factor();
908 let bounds = bounds.scale(scale_factor);
909 // Render the SVG at twice the size to get a higher quality result.
910 let params = RenderSvgParams {
911 path,
912 size: bounds
913 .size
914 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
915 };
916
917 let tile =
918 self.window
919 .sprite_atlas
920 .get_or_insert_with(¶ms.clone().into(), &mut || {
921 let bytes = self.svg_renderer.render(¶ms)?;
922 Ok((params.size, Cow::Owned(bytes)))
923 })?;
924 let content_mask = self.content_mask().scale(scale_factor);
925
926 let window = &mut *self.window;
927 window.scene_builder.insert(
928 &window.z_index_stack,
929 MonochromeSprite {
930 order: 0,
931 bounds,
932 content_mask,
933 color,
934 tile,
935 },
936 );
937
938 Ok(())
939 }
940
941 /// Paint an image into the scene for the current frame at the current z-index.
942 pub fn paint_image(
943 &mut self,
944 bounds: Bounds<Pixels>,
945 corner_radii: Corners<Pixels>,
946 data: Arc<ImageData>,
947 grayscale: bool,
948 ) -> Result<()> {
949 let scale_factor = self.scale_factor();
950 let bounds = bounds.scale(scale_factor);
951 let params = RenderImageParams { image_id: data.id };
952
953 let tile = self
954 .window
955 .sprite_atlas
956 .get_or_insert_with(¶ms.clone().into(), &mut || {
957 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
958 })?;
959 let content_mask = self.content_mask().scale(scale_factor);
960 let corner_radii = corner_radii.scale(scale_factor);
961
962 let window = &mut *self.window;
963 window.scene_builder.insert(
964 &window.z_index_stack,
965 PolychromeSprite {
966 order: 0,
967 bounds,
968 content_mask,
969 corner_radii,
970 tile,
971 grayscale,
972 },
973 );
974 Ok(())
975 }
976
977 /// Draw pixels to the display for this window based on the contents of its scene.
978 pub(crate) fn draw(&mut self) {
979 let root_view = self.window.root_view.take().unwrap();
980
981 self.start_frame();
982
983 self.stack(0, |cx| {
984 let available_space = cx.window.content_size.map(Into::into);
985 root_view.draw(available_space, cx);
986 });
987
988 if let Some(active_drag) = self.app.active_drag.take() {
989 self.stack(1, |cx| {
990 let offset = cx.mouse_position() - active_drag.cursor_offset;
991 cx.with_element_offset(Some(offset), |cx| {
992 let available_space =
993 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
994 active_drag.view.draw(available_space, cx);
995 cx.active_drag = Some(active_drag);
996 });
997 });
998 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
999 self.stack(1, |cx| {
1000 cx.with_element_offset(Some(active_tooltip.cursor_offset), |cx| {
1001 let available_space =
1002 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1003 active_tooltip.view.draw(available_space, cx);
1004 });
1005 });
1006 }
1007
1008 self.window.root_view = Some(root_view);
1009 let scene = self.window.scene_builder.build();
1010
1011 self.window.platform_window.draw(scene);
1012 let cursor_style = self
1013 .window
1014 .requested_cursor_style
1015 .take()
1016 .unwrap_or(CursorStyle::Arrow);
1017 self.platform.set_cursor_style(cursor_style);
1018 if let Some(handler) = self.window.requested_input_handler.take() {
1019 self.window.platform_window.set_input_handler(handler);
1020 }
1021
1022 self.window.dirty = false;
1023 }
1024
1025 fn start_frame(&mut self) {
1026 self.text_system().start_frame();
1027
1028 let window = &mut *self.window;
1029
1030 // Move the current frame element states to the previous frame.
1031 // The new empty element states map will be populated for any element states we
1032 // reference during the upcoming frame.
1033 mem::swap(
1034 &mut window.element_states,
1035 &mut window.prev_frame_element_states,
1036 );
1037 window.element_states.clear();
1038
1039 // Make the current key matchers the previous, and then clear the current.
1040 // An empty key matcher map will be created for every identified element in the
1041 // upcoming frame.
1042 mem::swap(
1043 &mut window.key_matchers,
1044 &mut window.prev_frame_key_matchers,
1045 );
1046 window.key_matchers.clear();
1047
1048 // Clear mouse event listeners, because elements add new element listeners
1049 // when the upcoming frame is painted.
1050 window.mouse_listeners.values_mut().for_each(Vec::clear);
1051
1052 // Clear focus state, because we determine what is focused when the new elements
1053 // in the upcoming frame are initialized.
1054 window.focus_listeners.clear();
1055 window.key_dispatch_stack.clear();
1056 window.focus_parents_by_child.clear();
1057 window.freeze_key_dispatch_stack = false;
1058 }
1059
1060 /// Dispatch a mouse or keyboard event on the window.
1061 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1062 // Handlers may set this to false by calling `stop_propagation`
1063 self.app.propagate_event = true;
1064 self.window.default_prevented = false;
1065
1066 let event = match event {
1067 // Track the mouse position with our own state, since accessing the platform
1068 // API for the mouse position can only occur on the main thread.
1069 InputEvent::MouseMove(mouse_move) => {
1070 self.window.mouse_position = mouse_move.position;
1071 InputEvent::MouseMove(mouse_move)
1072 }
1073 // Translate dragging and dropping of external files from the operating system
1074 // to internal drag and drop events.
1075 InputEvent::FileDrop(file_drop) => match file_drop {
1076 FileDropEvent::Entered { position, files } => {
1077 self.window.mouse_position = position;
1078 if self.active_drag.is_none() {
1079 self.active_drag = Some(AnyDrag {
1080 view: self.build_view(|_| files).into(),
1081 cursor_offset: position,
1082 });
1083 }
1084 InputEvent::MouseDown(MouseDownEvent {
1085 position,
1086 button: MouseButton::Left,
1087 click_count: 1,
1088 modifiers: Modifiers::default(),
1089 })
1090 }
1091 FileDropEvent::Pending { position } => {
1092 self.window.mouse_position = position;
1093 InputEvent::MouseMove(MouseMoveEvent {
1094 position,
1095 pressed_button: Some(MouseButton::Left),
1096 modifiers: Modifiers::default(),
1097 })
1098 }
1099 FileDropEvent::Submit { position } => {
1100 self.window.mouse_position = position;
1101 InputEvent::MouseUp(MouseUpEvent {
1102 button: MouseButton::Left,
1103 position,
1104 modifiers: Modifiers::default(),
1105 click_count: 1,
1106 })
1107 }
1108 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1109 button: MouseButton::Left,
1110 position: Point::default(),
1111 modifiers: Modifiers::default(),
1112 click_count: 1,
1113 }),
1114 },
1115 _ => event,
1116 };
1117
1118 if let Some(any_mouse_event) = event.mouse_event() {
1119 if let Some(mut handlers) = self
1120 .window
1121 .mouse_listeners
1122 .remove(&any_mouse_event.type_id())
1123 {
1124 // Because handlers may add other handlers, we sort every time.
1125 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1126
1127 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1128 // special purposes, such as detecting events outside of a given Bounds.
1129 for (_, handler) in &handlers {
1130 handler(any_mouse_event, DispatchPhase::Capture, self);
1131 if !self.app.propagate_event {
1132 break;
1133 }
1134 }
1135
1136 // Bubble phase, where most normal handlers do their work.
1137 if self.app.propagate_event {
1138 for (_, handler) in handlers.iter().rev() {
1139 handler(any_mouse_event, DispatchPhase::Bubble, self);
1140 if !self.app.propagate_event {
1141 break;
1142 }
1143 }
1144 }
1145
1146 if self.app.propagate_event
1147 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
1148 {
1149 self.active_drag = None;
1150 }
1151
1152 // Just in case any handlers added new handlers, which is weird, but possible.
1153 handlers.extend(
1154 self.window
1155 .mouse_listeners
1156 .get_mut(&any_mouse_event.type_id())
1157 .into_iter()
1158 .flat_map(|handlers| handlers.drain(..)),
1159 );
1160 self.window
1161 .mouse_listeners
1162 .insert(any_mouse_event.type_id(), handlers);
1163 }
1164 } else if let Some(any_key_event) = event.keyboard_event() {
1165 let mut did_handle_action = false;
1166 let key_dispatch_stack = mem::take(&mut self.window.key_dispatch_stack);
1167 let key_event_type = any_key_event.type_id();
1168 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
1169
1170 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
1171 match frame {
1172 KeyDispatchStackFrame::Listener {
1173 event_type,
1174 listener,
1175 } => {
1176 if key_event_type == *event_type {
1177 if let Some(action) = listener(
1178 any_key_event,
1179 &context_stack,
1180 DispatchPhase::Capture,
1181 self,
1182 ) {
1183 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1184 }
1185 if !self.app.propagate_event {
1186 did_handle_action = true;
1187 break;
1188 }
1189 }
1190 }
1191 KeyDispatchStackFrame::Context(context) => {
1192 context_stack.push(&context);
1193 }
1194 }
1195 }
1196
1197 if self.app.propagate_event {
1198 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
1199 match frame {
1200 KeyDispatchStackFrame::Listener {
1201 event_type,
1202 listener,
1203 } => {
1204 if key_event_type == *event_type {
1205 if let Some(action) = listener(
1206 any_key_event,
1207 &context_stack,
1208 DispatchPhase::Bubble,
1209 self,
1210 ) {
1211 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1212 }
1213
1214 if !self.app.propagate_event {
1215 did_handle_action = true;
1216 break;
1217 }
1218 }
1219 }
1220 KeyDispatchStackFrame::Context(_) => {
1221 context_stack.pop();
1222 }
1223 }
1224 }
1225 }
1226
1227 drop(context_stack);
1228 self.window.key_dispatch_stack = key_dispatch_stack;
1229 return did_handle_action;
1230 }
1231
1232 true
1233 }
1234
1235 /// Attempt to map a keystroke to an action based on the keymap.
1236 pub fn match_keystroke(
1237 &mut self,
1238 element_id: &GlobalElementId,
1239 keystroke: &Keystroke,
1240 context_stack: &[&DispatchContext],
1241 ) -> KeyMatch {
1242 let key_match = self
1243 .window
1244 .key_matchers
1245 .get_mut(element_id)
1246 .unwrap()
1247 .match_keystroke(keystroke, context_stack);
1248
1249 if key_match.is_some() {
1250 for matcher in self.window.key_matchers.values_mut() {
1251 matcher.clear_pending();
1252 }
1253 }
1254
1255 key_match
1256 }
1257
1258 /// Register the given handler to be invoked whenever the global of the given type
1259 /// is updated.
1260 pub fn observe_global<G: 'static>(
1261 &mut self,
1262 f: impl Fn(&mut WindowContext<'_>) + 'static,
1263 ) -> Subscription {
1264 let window_handle = self.window.handle;
1265 self.global_observers.insert(
1266 TypeId::of::<G>(),
1267 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1268 )
1269 }
1270
1271 pub fn activate_window(&self) {
1272 self.window.platform_window.activate();
1273 }
1274
1275 pub fn prompt(
1276 &self,
1277 level: PromptLevel,
1278 msg: &str,
1279 answers: &[&str],
1280 ) -> oneshot::Receiver<usize> {
1281 self.window.platform_window.prompt(level, msg, answers)
1282 }
1283
1284 fn dispatch_action(
1285 &mut self,
1286 action: Box<dyn Action>,
1287 dispatch_stack: &[KeyDispatchStackFrame],
1288 ) {
1289 let action_type = action.as_any().type_id();
1290
1291 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1292 for listener in &global_listeners {
1293 listener(action.as_ref(), DispatchPhase::Capture, self);
1294 if !self.app.propagate_event {
1295 break;
1296 }
1297 }
1298 global_listeners.extend(
1299 self.global_action_listeners
1300 .remove(&action_type)
1301 .unwrap_or_default(),
1302 );
1303 self.global_action_listeners
1304 .insert(action_type, global_listeners);
1305 }
1306
1307 if self.app.propagate_event {
1308 for stack_frame in dispatch_stack {
1309 if let KeyDispatchStackFrame::Listener {
1310 event_type,
1311 listener,
1312 } = stack_frame
1313 {
1314 if action_type == *event_type {
1315 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1316 if !self.app.propagate_event {
1317 break;
1318 }
1319 }
1320 }
1321 }
1322 }
1323
1324 if self.app.propagate_event {
1325 for stack_frame in dispatch_stack.iter().rev() {
1326 if let KeyDispatchStackFrame::Listener {
1327 event_type,
1328 listener,
1329 } = stack_frame
1330 {
1331 if action_type == *event_type {
1332 self.app.propagate_event = false;
1333 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1334 if !self.app.propagate_event {
1335 break;
1336 }
1337 }
1338 }
1339 }
1340 }
1341
1342 if self.app.propagate_event {
1343 if let Some(mut global_listeners) =
1344 self.app.global_action_listeners.remove(&action_type)
1345 {
1346 for listener in global_listeners.iter().rev() {
1347 self.app.propagate_event = false;
1348 listener(action.as_ref(), DispatchPhase::Bubble, self);
1349 if !self.app.propagate_event {
1350 break;
1351 }
1352 }
1353 global_listeners.extend(
1354 self.global_action_listeners
1355 .remove(&action_type)
1356 .unwrap_or_default(),
1357 );
1358 self.global_action_listeners
1359 .insert(action_type, global_listeners);
1360 }
1361 }
1362 }
1363}
1364
1365impl Context for WindowContext<'_> {
1366 type Result<T> = T;
1367
1368 fn build_model<T>(
1369 &mut self,
1370 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1371 ) -> Model<T>
1372 where
1373 T: 'static,
1374 {
1375 let slot = self.app.entities.reserve();
1376 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1377 self.entities.insert(slot, model)
1378 }
1379
1380 fn update_model<T: 'static, R>(
1381 &mut self,
1382 model: &Model<T>,
1383 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1384 ) -> R {
1385 let mut entity = self.entities.lease(model);
1386 let result = update(
1387 &mut *entity,
1388 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1389 );
1390 self.entities.end_lease(entity);
1391 result
1392 }
1393
1394 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1395 where
1396 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1397 {
1398 if window == self.window.handle {
1399 let root_view = self.window.root_view.clone().unwrap();
1400 Ok(update(root_view, self))
1401 } else {
1402 window.update(self.app, update)
1403 }
1404 }
1405}
1406
1407impl VisualContext for WindowContext<'_> {
1408 fn build_view<V>(
1409 &mut self,
1410 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1411 ) -> Self::Result<View<V>>
1412 where
1413 V: 'static,
1414 {
1415 let slot = self.app.entities.reserve();
1416 let view = View {
1417 model: slot.clone(),
1418 };
1419 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1420 let entity = build_view_state(&mut cx);
1421 self.entities.insert(slot, entity);
1422 view
1423 }
1424
1425 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1426 fn update_view<T: 'static, R>(
1427 &mut self,
1428 view: &View<T>,
1429 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1430 ) -> Self::Result<R> {
1431 let mut lease = self.app.entities.lease(&view.model);
1432 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1433 let result = update(&mut *lease, &mut cx);
1434 cx.app.entities.end_lease(lease);
1435 result
1436 }
1437
1438 fn replace_root_view<V>(
1439 &mut self,
1440 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1441 ) -> Self::Result<View<V>>
1442 where
1443 V: Render,
1444 {
1445 let slot = self.app.entities.reserve();
1446 let view = View {
1447 model: slot.clone(),
1448 };
1449 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1450 let entity = build_view(&mut cx);
1451 self.entities.insert(slot, entity);
1452 self.window.root_view = Some(view.clone().into());
1453 view
1454 }
1455}
1456
1457impl<'a> std::ops::Deref for WindowContext<'a> {
1458 type Target = AppContext;
1459
1460 fn deref(&self) -> &Self::Target {
1461 &self.app
1462 }
1463}
1464
1465impl<'a> std::ops::DerefMut for WindowContext<'a> {
1466 fn deref_mut(&mut self) -> &mut Self::Target {
1467 &mut self.app
1468 }
1469}
1470
1471impl<'a> Borrow<AppContext> for WindowContext<'a> {
1472 fn borrow(&self) -> &AppContext {
1473 &self.app
1474 }
1475}
1476
1477impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1478 fn borrow_mut(&mut self) -> &mut AppContext {
1479 &mut self.app
1480 }
1481}
1482
1483pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1484 fn app_mut(&mut self) -> &mut AppContext {
1485 self.borrow_mut()
1486 }
1487
1488 fn window(&self) -> &Window {
1489 self.borrow()
1490 }
1491
1492 fn window_mut(&mut self) -> &mut Window {
1493 self.borrow_mut()
1494 }
1495
1496 /// Pushes the given element id onto the global stack and invokes the given closure
1497 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1498 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1499 /// used to associate state with identified elements across separate frames.
1500 fn with_element_id<R>(
1501 &mut self,
1502 id: impl Into<ElementId>,
1503 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1504 ) -> R {
1505 let keymap = self.app_mut().keymap.clone();
1506 let window = self.window_mut();
1507 window.element_id_stack.push(id.into());
1508 let global_id = window.element_id_stack.clone();
1509
1510 if window.key_matchers.get(&global_id).is_none() {
1511 window.key_matchers.insert(
1512 global_id.clone(),
1513 window
1514 .prev_frame_key_matchers
1515 .remove(&global_id)
1516 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1517 );
1518 }
1519
1520 let result = f(global_id, self);
1521 let window: &mut Window = self.borrow_mut();
1522 window.element_id_stack.pop();
1523 result
1524 }
1525
1526 /// Invoke the given function with the given content mask after intersecting it
1527 /// with the current mask.
1528 fn with_content_mask<R>(
1529 &mut self,
1530 mask: ContentMask<Pixels>,
1531 f: impl FnOnce(&mut Self) -> R,
1532 ) -> R {
1533 let mask = mask.intersect(&self.content_mask());
1534 self.window_mut().content_mask_stack.push(mask);
1535 let result = f(self);
1536 self.window_mut().content_mask_stack.pop();
1537 result
1538 }
1539
1540 /// Update the global element offset based on the given offset. This is used to implement
1541 /// scrolling and position drag handles.
1542 fn with_element_offset<R>(
1543 &mut self,
1544 offset: Option<Point<Pixels>>,
1545 f: impl FnOnce(&mut Self) -> R,
1546 ) -> R {
1547 let Some(offset) = offset else {
1548 return f(self);
1549 };
1550
1551 let offset = self.element_offset() + offset;
1552 self.window_mut().element_offset_stack.push(offset);
1553 let result = f(self);
1554 self.window_mut().element_offset_stack.pop();
1555 result
1556 }
1557
1558 /// Obtain the current element offset.
1559 fn element_offset(&self) -> Point<Pixels> {
1560 self.window()
1561 .element_offset_stack
1562 .last()
1563 .copied()
1564 .unwrap_or_default()
1565 }
1566
1567 /// Update or intialize state for an element with the given id that lives across multiple
1568 /// frames. If an element with this id existed in the previous frame, its state will be passed
1569 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1570 /// when drawing the next frame.
1571 fn with_element_state<S, R>(
1572 &mut self,
1573 id: ElementId,
1574 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1575 ) -> R
1576 where
1577 S: 'static,
1578 {
1579 self.with_element_id(id, |global_id, cx| {
1580 if let Some(any) = cx
1581 .window_mut()
1582 .element_states
1583 .remove(&global_id)
1584 .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
1585 {
1586 // Using the extra inner option to avoid needing to reallocate a new box.
1587 let mut state_box = any
1588 .downcast::<Option<S>>()
1589 .expect("invalid element state type for id");
1590 let state = state_box
1591 .take()
1592 .expect("element state is already on the stack");
1593 let (result, state) = f(Some(state), cx);
1594 state_box.replace(state);
1595 cx.window_mut().element_states.insert(global_id, state_box);
1596 result
1597 } else {
1598 let (result, state) = f(None, cx);
1599 cx.window_mut()
1600 .element_states
1601 .insert(global_id, Box::new(Some(state)));
1602 result
1603 }
1604 })
1605 }
1606
1607 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1608 /// id is `None`, no state will be retrieved or stored.
1609 fn with_optional_element_state<S, R>(
1610 &mut self,
1611 element_id: Option<ElementId>,
1612 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1613 ) -> R
1614 where
1615 S: 'static,
1616 {
1617 if let Some(element_id) = element_id {
1618 self.with_element_state(element_id, f)
1619 } else {
1620 f(None, self).0
1621 }
1622 }
1623
1624 /// Obtain the current content mask.
1625 fn content_mask(&self) -> ContentMask<Pixels> {
1626 self.window()
1627 .content_mask_stack
1628 .last()
1629 .cloned()
1630 .unwrap_or_else(|| ContentMask {
1631 bounds: Bounds {
1632 origin: Point::default(),
1633 size: self.window().content_size,
1634 },
1635 })
1636 }
1637
1638 /// The size of an em for the base font of the application. Adjusting this value allows the
1639 /// UI to scale, just like zooming a web page.
1640 fn rem_size(&self) -> Pixels {
1641 self.window().rem_size
1642 }
1643}
1644
1645impl Borrow<Window> for WindowContext<'_> {
1646 fn borrow(&self) -> &Window {
1647 &self.window
1648 }
1649}
1650
1651impl BorrowMut<Window> for WindowContext<'_> {
1652 fn borrow_mut(&mut self) -> &mut Window {
1653 &mut self.window
1654 }
1655}
1656
1657impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1658
1659pub struct ViewContext<'a, V> {
1660 window_cx: WindowContext<'a>,
1661 view: &'a View<V>,
1662}
1663
1664impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1665 fn borrow(&self) -> &AppContext {
1666 &*self.window_cx.app
1667 }
1668}
1669
1670impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1671 fn borrow_mut(&mut self) -> &mut AppContext {
1672 &mut *self.window_cx.app
1673 }
1674}
1675
1676impl<V> Borrow<Window> for ViewContext<'_, V> {
1677 fn borrow(&self) -> &Window {
1678 &*self.window_cx.window
1679 }
1680}
1681
1682impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1683 fn borrow_mut(&mut self) -> &mut Window {
1684 &mut *self.window_cx.window
1685 }
1686}
1687
1688impl<'a, V: 'static> ViewContext<'a, V> {
1689 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1690 Self {
1691 window_cx: WindowContext::new(app, window),
1692 view,
1693 }
1694 }
1695
1696 // todo!("change this to return a reference");
1697 pub fn view(&self) -> View<V> {
1698 self.view.clone()
1699 }
1700
1701 pub fn model(&self) -> Model<V> {
1702 self.view.model.clone()
1703 }
1704
1705 /// Access the underlying window context.
1706 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1707 &mut self.window_cx
1708 }
1709
1710 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1711 self.window.z_index_stack.push(order);
1712 let result = f(self);
1713 self.window.z_index_stack.pop();
1714 result
1715 }
1716
1717 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1718 where
1719 V: 'static,
1720 {
1721 let view = self.view();
1722 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1723 }
1724
1725 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1726 /// that are currently on the stack to be returned to the app.
1727 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1728 let view = self.view().downgrade();
1729 self.window_cx.defer(move |cx| {
1730 view.update(cx, f).ok();
1731 });
1732 }
1733
1734 pub fn observe<V2, E>(
1735 &mut self,
1736 entity: &E,
1737 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1738 ) -> Subscription
1739 where
1740 V2: 'static,
1741 V: 'static,
1742 E: Entity<V2>,
1743 {
1744 let view = self.view().downgrade();
1745 let entity_id = entity.entity_id();
1746 let entity = entity.downgrade();
1747 let window_handle = self.window.handle;
1748 self.app.observers.insert(
1749 entity_id,
1750 Box::new(move |cx| {
1751 window_handle
1752 .update(cx, |_, cx| {
1753 if let Some(handle) = E::upgrade_from(&entity) {
1754 view.update(cx, |this, cx| on_notify(this, handle, cx))
1755 .is_ok()
1756 } else {
1757 false
1758 }
1759 })
1760 .unwrap_or(false)
1761 }),
1762 )
1763 }
1764
1765 pub fn subscribe<V2, E>(
1766 &mut self,
1767 entity: &E,
1768 mut on_event: impl FnMut(&mut V, E, &V2::Event, &mut ViewContext<'_, V>) + 'static,
1769 ) -> Subscription
1770 where
1771 V2: EventEmitter,
1772 E: Entity<V2>,
1773 {
1774 let view = self.view().downgrade();
1775 let entity_id = entity.entity_id();
1776 let handle = entity.downgrade();
1777 let window_handle = self.window.handle;
1778 self.app.event_listeners.insert(
1779 entity_id,
1780 Box::new(move |event, cx| {
1781 window_handle
1782 .update(cx, |_, cx| {
1783 if let Some(handle) = E::upgrade_from(&handle) {
1784 let event = event.downcast_ref().expect("invalid event type");
1785 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1786 .is_ok()
1787 } else {
1788 false
1789 }
1790 })
1791 .unwrap_or(false)
1792 }),
1793 )
1794 }
1795
1796 pub fn on_release(
1797 &mut self,
1798 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
1799 ) -> Subscription {
1800 let window_handle = self.window.handle;
1801 self.app.release_listeners.insert(
1802 self.view.model.entity_id,
1803 Box::new(move |this, cx| {
1804 let this = this.downcast_mut().expect("invalid entity type");
1805 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
1806 }),
1807 )
1808 }
1809
1810 pub fn observe_release<V2, E>(
1811 &mut self,
1812 entity: &E,
1813 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1814 ) -> Subscription
1815 where
1816 V: 'static,
1817 V2: 'static,
1818 E: Entity<V2>,
1819 {
1820 let view = self.view().downgrade();
1821 let entity_id = entity.entity_id();
1822 let window_handle = self.window.handle;
1823 self.app.release_listeners.insert(
1824 entity_id,
1825 Box::new(move |entity, cx| {
1826 let entity = entity.downcast_mut().expect("invalid entity type");
1827 let _ = window_handle.update(cx, |_, cx| {
1828 view.update(cx, |this, cx| on_release(this, entity, cx))
1829 });
1830 }),
1831 )
1832 }
1833
1834 pub fn notify(&mut self) {
1835 self.window_cx.notify();
1836 self.window_cx.app.push_effect(Effect::Notify {
1837 emitter: self.view.model.entity_id,
1838 });
1839 }
1840
1841 pub fn observe_window_bounds(
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.bounds_observers.insert(
1847 (),
1848 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1849 )
1850 }
1851
1852 pub fn observe_window_activation(
1853 &mut self,
1854 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1855 ) -> Subscription {
1856 let view = self.view.downgrade();
1857 self.window.activation_observers.insert(
1858 (),
1859 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1860 )
1861 }
1862
1863 pub fn on_focus_changed(
1864 &mut self,
1865 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + 'static,
1866 ) {
1867 let handle = self.view().downgrade();
1868 self.window.focus_listeners.push(Box::new(move |event, cx| {
1869 handle
1870 .update(cx, |view, cx| listener(view, event, cx))
1871 .log_err();
1872 }));
1873 }
1874
1875 pub fn with_key_listeners<R>(
1876 &mut self,
1877 key_listeners: impl IntoIterator<Item = (TypeId, KeyListener<V>)>,
1878 f: impl FnOnce(&mut Self) -> R,
1879 ) -> R {
1880 let old_stack_len = self.window.key_dispatch_stack.len();
1881 if !self.window.freeze_key_dispatch_stack {
1882 for (event_type, listener) in key_listeners {
1883 let handle = self.view().downgrade();
1884 let listener = Box::new(
1885 move |event: &dyn Any,
1886 context_stack: &[&DispatchContext],
1887 phase: DispatchPhase,
1888 cx: &mut WindowContext<'_>| {
1889 handle
1890 .update(cx, |view, cx| {
1891 listener(view, event, context_stack, phase, cx)
1892 })
1893 .log_err()
1894 .flatten()
1895 },
1896 );
1897 self.window
1898 .key_dispatch_stack
1899 .push(KeyDispatchStackFrame::Listener {
1900 event_type,
1901 listener,
1902 });
1903 }
1904 }
1905
1906 let result = f(self);
1907
1908 if !self.window.freeze_key_dispatch_stack {
1909 self.window.key_dispatch_stack.truncate(old_stack_len);
1910 }
1911
1912 result
1913 }
1914
1915 pub fn with_key_dispatch_context<R>(
1916 &mut self,
1917 context: DispatchContext,
1918 f: impl FnOnce(&mut Self) -> R,
1919 ) -> R {
1920 if context.is_empty() {
1921 return f(self);
1922 }
1923
1924 if !self.window.freeze_key_dispatch_stack {
1925 self.window
1926 .key_dispatch_stack
1927 .push(KeyDispatchStackFrame::Context(context));
1928 }
1929
1930 let result = f(self);
1931
1932 if !self.window.freeze_key_dispatch_stack {
1933 self.window.key_dispatch_stack.pop();
1934 }
1935
1936 result
1937 }
1938
1939 pub fn with_focus<R>(
1940 &mut self,
1941 focus_handle: FocusHandle,
1942 f: impl FnOnce(&mut Self) -> R,
1943 ) -> R {
1944 if let Some(parent_focus_id) = self.window.focus_stack.last().copied() {
1945 self.window
1946 .focus_parents_by_child
1947 .insert(focus_handle.id, parent_focus_id);
1948 }
1949 self.window.focus_stack.push(focus_handle.id);
1950
1951 if Some(focus_handle.id) == self.window.focus {
1952 self.window.freeze_key_dispatch_stack = true;
1953 }
1954
1955 let result = f(self);
1956
1957 self.window.focus_stack.pop();
1958 result
1959 }
1960
1961 pub fn spawn<Fut, R>(
1962 &mut self,
1963 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
1964 ) -> Task<R>
1965 where
1966 R: 'static,
1967 Fut: Future<Output = R> + 'static,
1968 {
1969 let view = self.view().downgrade();
1970 self.window_cx.spawn(|cx| f(view, cx))
1971 }
1972
1973 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1974 where
1975 G: 'static,
1976 {
1977 let mut global = self.app.lease_global::<G>();
1978 let result = f(&mut global, self);
1979 self.app.end_global_lease(global);
1980 result
1981 }
1982
1983 pub fn observe_global<G: 'static>(
1984 &mut self,
1985 f: impl Fn(&mut V, &mut ViewContext<'_, V>) + 'static,
1986 ) -> Subscription {
1987 let window_handle = self.window.handle;
1988 let view = self.view().downgrade();
1989 self.global_observers.insert(
1990 TypeId::of::<G>(),
1991 Box::new(move |cx| {
1992 window_handle
1993 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
1994 .unwrap_or(false)
1995 }),
1996 )
1997 }
1998
1999 pub fn on_mouse_event<Event: 'static>(
2000 &mut self,
2001 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2002 ) {
2003 let handle = self.view();
2004 self.window_cx.on_mouse_event(move |event, phase, cx| {
2005 handle.update(cx, |view, cx| {
2006 handler(view, event, phase, cx);
2007 })
2008 });
2009 }
2010}
2011
2012impl<V> ViewContext<'_, V>
2013where
2014 V: InputHandler + 'static,
2015{
2016 pub fn handle_text_input(&mut self) {
2017 self.window.requested_input_handler = Some(Box::new(WindowInputHandler {
2018 cx: self.app.this.clone(),
2019 window: self.window_handle(),
2020 handler: self.view().downgrade(),
2021 }));
2022 }
2023}
2024
2025impl<V> ViewContext<'_, V>
2026where
2027 V: EventEmitter,
2028 V::Event: 'static,
2029{
2030 pub fn emit(&mut self, event: V::Event) {
2031 let emitter = self.view.model.entity_id;
2032 self.app.push_effect(Effect::Emit {
2033 emitter,
2034 event: Box::new(event),
2035 });
2036 }
2037}
2038
2039impl<V> Context for ViewContext<'_, V> {
2040 type Result<U> = U;
2041
2042 fn build_model<T: 'static>(
2043 &mut self,
2044 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2045 ) -> Model<T> {
2046 self.window_cx.build_model(build_model)
2047 }
2048
2049 fn update_model<T: 'static, R>(
2050 &mut self,
2051 model: &Model<T>,
2052 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2053 ) -> R {
2054 self.window_cx.update_model(model, update)
2055 }
2056
2057 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2058 where
2059 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2060 {
2061 self.window_cx.update_window(window, update)
2062 }
2063}
2064
2065impl<V: 'static> VisualContext for ViewContext<'_, V> {
2066 fn build_view<W: 'static>(
2067 &mut self,
2068 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2069 ) -> Self::Result<View<W>> {
2070 self.window_cx.build_view(build_view_state)
2071 }
2072
2073 fn update_view<V2: 'static, R>(
2074 &mut self,
2075 view: &View<V2>,
2076 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2077 ) -> Self::Result<R> {
2078 self.window_cx.update_view(view, update)
2079 }
2080
2081 fn replace_root_view<W>(
2082 &mut self,
2083 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2084 ) -> Self::Result<View<W>>
2085 where
2086 W: Render,
2087 {
2088 self.window_cx.replace_root_view(build_view)
2089 }
2090}
2091
2092impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2093 type Target = WindowContext<'a>;
2094
2095 fn deref(&self) -> &Self::Target {
2096 &self.window_cx
2097 }
2098}
2099
2100impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2101 fn deref_mut(&mut self) -> &mut Self::Target {
2102 &mut self.window_cx
2103 }
2104}
2105
2106// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2107slotmap::new_key_type! { pub struct WindowId; }
2108
2109impl WindowId {
2110 pub fn as_u64(&self) -> u64 {
2111 self.0.as_ffi()
2112 }
2113}
2114
2115#[derive(Deref, DerefMut)]
2116pub struct WindowHandle<V> {
2117 #[deref]
2118 #[deref_mut]
2119 pub(crate) any_handle: AnyWindowHandle,
2120 state_type: PhantomData<V>,
2121}
2122
2123impl<V: 'static + Render> WindowHandle<V> {
2124 pub fn new(id: WindowId) -> Self {
2125 WindowHandle {
2126 any_handle: AnyWindowHandle {
2127 id,
2128 state_type: TypeId::of::<V>(),
2129 },
2130 state_type: PhantomData,
2131 }
2132 }
2133
2134 pub fn update<C, R>(
2135 self,
2136 cx: &mut C,
2137 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2138 ) -> Result<R>
2139 where
2140 C: Context,
2141 {
2142 cx.update_window(self.any_handle, |root_view, cx| {
2143 let view = root_view
2144 .downcast::<V>()
2145 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2146 Ok(cx.update_view(&view, update))
2147 })?
2148 }
2149}
2150
2151impl<V> Copy for WindowHandle<V> {}
2152
2153impl<V> Clone for WindowHandle<V> {
2154 fn clone(&self) -> Self {
2155 WindowHandle {
2156 any_handle: self.any_handle,
2157 state_type: PhantomData,
2158 }
2159 }
2160}
2161
2162impl<V> PartialEq for WindowHandle<V> {
2163 fn eq(&self, other: &Self) -> bool {
2164 self.any_handle == other.any_handle
2165 }
2166}
2167
2168impl<V> Eq for WindowHandle<V> {}
2169
2170impl<V> Hash for WindowHandle<V> {
2171 fn hash<H: Hasher>(&self, state: &mut H) {
2172 self.any_handle.hash(state);
2173 }
2174}
2175
2176impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2177 fn into(self) -> AnyWindowHandle {
2178 self.any_handle
2179 }
2180}
2181
2182#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2183pub struct AnyWindowHandle {
2184 pub(crate) id: WindowId,
2185 state_type: TypeId,
2186}
2187
2188impl AnyWindowHandle {
2189 pub fn window_id(&self) -> WindowId {
2190 self.id
2191 }
2192
2193 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2194 if TypeId::of::<T>() == self.state_type {
2195 Some(WindowHandle {
2196 any_handle: *self,
2197 state_type: PhantomData,
2198 })
2199 } else {
2200 None
2201 }
2202 }
2203
2204 pub fn update<C, R>(
2205 self,
2206 cx: &mut C,
2207 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2208 ) -> Result<R>
2209 where
2210 C: Context,
2211 {
2212 cx.update_window(self, update)
2213 }
2214}
2215
2216#[cfg(any(test, feature = "test-support"))]
2217impl From<SmallVec<[u32; 16]>> for StackingOrder {
2218 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2219 StackingOrder(small_vec)
2220 }
2221}
2222
2223#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2224pub enum ElementId {
2225 View(EntityId),
2226 Number(usize),
2227 Name(SharedString),
2228 FocusHandle(FocusId),
2229}
2230
2231impl From<EntityId> for ElementId {
2232 fn from(id: EntityId) -> Self {
2233 ElementId::View(id)
2234 }
2235}
2236
2237impl From<usize> for ElementId {
2238 fn from(id: usize) -> Self {
2239 ElementId::Number(id)
2240 }
2241}
2242
2243impl From<i32> for ElementId {
2244 fn from(id: i32) -> Self {
2245 Self::Number(id as usize)
2246 }
2247}
2248
2249impl From<SharedString> for ElementId {
2250 fn from(name: SharedString) -> Self {
2251 ElementId::Name(name)
2252 }
2253}
2254
2255impl From<&'static str> for ElementId {
2256 fn from(name: &'static str) -> Self {
2257 ElementId::Name(name.into())
2258 }
2259}
2260
2261impl<'a> From<&'a FocusHandle> for ElementId {
2262 fn from(handle: &'a FocusHandle) -> Self {
2263 ElementId::FocusHandle(handle.id)
2264 }
2265}