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 /// 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 if let Some(handler) = self.window.requested_input_handler.take() {
1015 self.window.platform_window.set_input_handler(handler);
1016 }
1017
1018 self.window.dirty = false;
1019 }
1020
1021 fn start_frame(&mut self) {
1022 self.text_system().start_frame();
1023
1024 let window = &mut *self.window;
1025
1026 // Move the current frame element states to the previous frame.
1027 // The new empty element states map will be populated for any element states we
1028 // reference during the upcoming frame.
1029 mem::swap(
1030 &mut window.element_states,
1031 &mut window.prev_frame_element_states,
1032 );
1033 window.element_states.clear();
1034
1035 // Make the current key matchers the previous, and then clear the current.
1036 // An empty key matcher map will be created for every identified element in the
1037 // upcoming frame.
1038 mem::swap(
1039 &mut window.key_matchers,
1040 &mut window.prev_frame_key_matchers,
1041 );
1042 window.key_matchers.clear();
1043
1044 // Clear mouse event listeners, because elements add new element listeners
1045 // when the upcoming frame is painted.
1046 window.mouse_listeners.values_mut().for_each(Vec::clear);
1047
1048 // Clear focus state, because we determine what is focused when the new elements
1049 // in the upcoming frame are initialized.
1050 window.focus_listeners.clear();
1051 window.key_dispatch_stack.clear();
1052 window.focus_parents_by_child.clear();
1053 window.freeze_key_dispatch_stack = false;
1054 }
1055
1056 /// Dispatch a mouse or keyboard event on the window.
1057 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1058 // Handlers may set this to false by calling `stop_propagation`
1059 self.app.propagate_event = true;
1060 self.window.default_prevented = false;
1061
1062 let event = match event {
1063 // Track the mouse position with our own state, since accessing the platform
1064 // API for the mouse position can only occur on the main thread.
1065 InputEvent::MouseMove(mouse_move) => {
1066 self.window.mouse_position = mouse_move.position;
1067 InputEvent::MouseMove(mouse_move)
1068 }
1069 // Translate dragging and dropping of external files from the operating system
1070 // to internal drag and drop events.
1071 InputEvent::FileDrop(file_drop) => match file_drop {
1072 FileDropEvent::Entered { position, files } => {
1073 self.window.mouse_position = position;
1074 if self.active_drag.is_none() {
1075 self.active_drag = Some(AnyDrag {
1076 view: self.build_view(|_| files).into(),
1077 cursor_offset: position,
1078 });
1079 }
1080 InputEvent::MouseDown(MouseDownEvent {
1081 position,
1082 button: MouseButton::Left,
1083 click_count: 1,
1084 modifiers: Modifiers::default(),
1085 })
1086 }
1087 FileDropEvent::Pending { position } => {
1088 self.window.mouse_position = position;
1089 InputEvent::MouseMove(MouseMoveEvent {
1090 position,
1091 pressed_button: Some(MouseButton::Left),
1092 modifiers: Modifiers::default(),
1093 })
1094 }
1095 FileDropEvent::Submit { position } => {
1096 self.window.mouse_position = position;
1097 InputEvent::MouseUp(MouseUpEvent {
1098 button: MouseButton::Left,
1099 position,
1100 modifiers: Modifiers::default(),
1101 click_count: 1,
1102 })
1103 }
1104 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1105 button: MouseButton::Left,
1106 position: Point::default(),
1107 modifiers: Modifiers::default(),
1108 click_count: 1,
1109 }),
1110 },
1111 _ => event,
1112 };
1113
1114 if let Some(any_mouse_event) = event.mouse_event() {
1115 if let Some(mut handlers) = self
1116 .window
1117 .mouse_listeners
1118 .remove(&any_mouse_event.type_id())
1119 {
1120 // Because handlers may add other handlers, we sort every time.
1121 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1122
1123 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1124 // special purposes, such as detecting events outside of a given Bounds.
1125 for (_, handler) in &handlers {
1126 handler(any_mouse_event, DispatchPhase::Capture, self);
1127 if !self.app.propagate_event {
1128 break;
1129 }
1130 }
1131
1132 // Bubble phase, where most normal handlers do their work.
1133 if self.app.propagate_event {
1134 for (_, handler) in handlers.iter().rev() {
1135 handler(any_mouse_event, DispatchPhase::Bubble, self);
1136 if !self.app.propagate_event {
1137 break;
1138 }
1139 }
1140 }
1141
1142 if self.app.propagate_event
1143 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
1144 {
1145 self.active_drag = None;
1146 }
1147
1148 // Just in case any handlers added new handlers, which is weird, but possible.
1149 handlers.extend(
1150 self.window
1151 .mouse_listeners
1152 .get_mut(&any_mouse_event.type_id())
1153 .into_iter()
1154 .flat_map(|handlers| handlers.drain(..)),
1155 );
1156 self.window
1157 .mouse_listeners
1158 .insert(any_mouse_event.type_id(), handlers);
1159 }
1160 } else if let Some(any_key_event) = event.keyboard_event() {
1161 let mut did_handle_action = false;
1162 let key_dispatch_stack = mem::take(&mut self.window.key_dispatch_stack);
1163 let key_event_type = any_key_event.type_id();
1164 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
1165
1166 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
1167 match frame {
1168 KeyDispatchStackFrame::Listener {
1169 event_type,
1170 listener,
1171 } => {
1172 if key_event_type == *event_type {
1173 if let Some(action) = listener(
1174 any_key_event,
1175 &context_stack,
1176 DispatchPhase::Capture,
1177 self,
1178 ) {
1179 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1180 }
1181 if !self.app.propagate_event {
1182 did_handle_action = true;
1183 break;
1184 }
1185 }
1186 }
1187 KeyDispatchStackFrame::Context(context) => {
1188 context_stack.push(&context);
1189 }
1190 }
1191 }
1192
1193 if self.app.propagate_event {
1194 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
1195 match frame {
1196 KeyDispatchStackFrame::Listener {
1197 event_type,
1198 listener,
1199 } => {
1200 if key_event_type == *event_type {
1201 if let Some(action) = listener(
1202 any_key_event,
1203 &context_stack,
1204 DispatchPhase::Bubble,
1205 self,
1206 ) {
1207 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1208 }
1209
1210 if !self.app.propagate_event {
1211 did_handle_action = true;
1212 break;
1213 }
1214 }
1215 }
1216 KeyDispatchStackFrame::Context(_) => {
1217 context_stack.pop();
1218 }
1219 }
1220 }
1221 }
1222
1223 drop(context_stack);
1224 self.window.key_dispatch_stack = key_dispatch_stack;
1225 return did_handle_action;
1226 }
1227
1228 true
1229 }
1230
1231 /// Attempt to map a keystroke to an action based on the keymap.
1232 pub fn match_keystroke(
1233 &mut self,
1234 element_id: &GlobalElementId,
1235 keystroke: &Keystroke,
1236 context_stack: &[&DispatchContext],
1237 ) -> KeyMatch {
1238 let key_match = self
1239 .window
1240 .key_matchers
1241 .get_mut(element_id)
1242 .unwrap()
1243 .match_keystroke(keystroke, context_stack);
1244
1245 if key_match.is_some() {
1246 for matcher in self.window.key_matchers.values_mut() {
1247 matcher.clear_pending();
1248 }
1249 }
1250
1251 key_match
1252 }
1253
1254 /// Register the given handler to be invoked whenever the global of the given type
1255 /// is updated.
1256 pub fn observe_global<G: 'static>(
1257 &mut self,
1258 f: impl Fn(&mut WindowContext<'_>) + 'static,
1259 ) -> Subscription {
1260 let window_handle = self.window.handle;
1261 self.global_observers.insert(
1262 TypeId::of::<G>(),
1263 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1264 )
1265 }
1266
1267 pub fn activate_window(&self) {
1268 self.window.platform_window.activate();
1269 }
1270
1271 pub fn prompt(
1272 &self,
1273 level: PromptLevel,
1274 msg: &str,
1275 answers: &[&str],
1276 ) -> oneshot::Receiver<usize> {
1277 self.window.platform_window.prompt(level, msg, answers)
1278 }
1279
1280 fn dispatch_action(
1281 &mut self,
1282 action: Box<dyn Action>,
1283 dispatch_stack: &[KeyDispatchStackFrame],
1284 ) {
1285 let action_type = action.as_any().type_id();
1286
1287 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1288 for listener in &global_listeners {
1289 listener(action.as_ref(), DispatchPhase::Capture, self);
1290 if !self.app.propagate_event {
1291 break;
1292 }
1293 }
1294 global_listeners.extend(
1295 self.global_action_listeners
1296 .remove(&action_type)
1297 .unwrap_or_default(),
1298 );
1299 self.global_action_listeners
1300 .insert(action_type, global_listeners);
1301 }
1302
1303 if self.app.propagate_event {
1304 for stack_frame in dispatch_stack {
1305 if let KeyDispatchStackFrame::Listener {
1306 event_type,
1307 listener,
1308 } = stack_frame
1309 {
1310 if action_type == *event_type {
1311 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1312 if !self.app.propagate_event {
1313 break;
1314 }
1315 }
1316 }
1317 }
1318 }
1319
1320 if self.app.propagate_event {
1321 for stack_frame in dispatch_stack.iter().rev() {
1322 if let KeyDispatchStackFrame::Listener {
1323 event_type,
1324 listener,
1325 } = stack_frame
1326 {
1327 if action_type == *event_type {
1328 self.app.propagate_event = false;
1329 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1330 if !self.app.propagate_event {
1331 break;
1332 }
1333 }
1334 }
1335 }
1336 }
1337
1338 if self.app.propagate_event {
1339 if let Some(mut global_listeners) =
1340 self.app.global_action_listeners.remove(&action_type)
1341 {
1342 for listener in global_listeners.iter().rev() {
1343 self.app.propagate_event = false;
1344 listener(action.as_ref(), DispatchPhase::Bubble, self);
1345 if !self.app.propagate_event {
1346 break;
1347 }
1348 }
1349 global_listeners.extend(
1350 self.global_action_listeners
1351 .remove(&action_type)
1352 .unwrap_or_default(),
1353 );
1354 self.global_action_listeners
1355 .insert(action_type, global_listeners);
1356 }
1357 }
1358 }
1359}
1360
1361impl Context for WindowContext<'_> {
1362 type Result<T> = T;
1363
1364 fn build_model<T>(
1365 &mut self,
1366 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1367 ) -> Model<T>
1368 where
1369 T: 'static,
1370 {
1371 let slot = self.app.entities.reserve();
1372 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1373 self.entities.insert(slot, model)
1374 }
1375
1376 fn update_model<T: 'static, R>(
1377 &mut self,
1378 model: &Model<T>,
1379 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1380 ) -> R {
1381 let mut entity = self.entities.lease(model);
1382 let result = update(
1383 &mut *entity,
1384 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1385 );
1386 self.entities.end_lease(entity);
1387 result
1388 }
1389
1390 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1391 where
1392 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1393 {
1394 if window == self.window.handle {
1395 let root_view = self.window.root_view.clone().unwrap();
1396 Ok(update(root_view, self))
1397 } else {
1398 window.update(self.app, update)
1399 }
1400 }
1401}
1402
1403impl VisualContext for WindowContext<'_> {
1404 fn build_view<V>(
1405 &mut self,
1406 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1407 ) -> Self::Result<View<V>>
1408 where
1409 V: 'static,
1410 {
1411 let slot = self.app.entities.reserve();
1412 let view = View {
1413 model: slot.clone(),
1414 };
1415 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1416 let entity = build_view_state(&mut cx);
1417 self.entities.insert(slot, entity);
1418 view
1419 }
1420
1421 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1422 fn update_view<T: 'static, R>(
1423 &mut self,
1424 view: &View<T>,
1425 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1426 ) -> Self::Result<R> {
1427 let mut lease = self.app.entities.lease(&view.model);
1428 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1429 let result = update(&mut *lease, &mut cx);
1430 cx.app.entities.end_lease(lease);
1431 result
1432 }
1433
1434 fn replace_root_view<V>(
1435 &mut self,
1436 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1437 ) -> Self::Result<View<V>>
1438 where
1439 V: Render,
1440 {
1441 let slot = self.app.entities.reserve();
1442 let view = View {
1443 model: slot.clone(),
1444 };
1445 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1446 let entity = build_view(&mut cx);
1447 self.entities.insert(slot, entity);
1448 self.window.root_view = Some(view.clone().into());
1449 view
1450 }
1451}
1452
1453impl<'a> std::ops::Deref for WindowContext<'a> {
1454 type Target = AppContext;
1455
1456 fn deref(&self) -> &Self::Target {
1457 &self.app
1458 }
1459}
1460
1461impl<'a> std::ops::DerefMut for WindowContext<'a> {
1462 fn deref_mut(&mut self) -> &mut Self::Target {
1463 &mut self.app
1464 }
1465}
1466
1467impl<'a> Borrow<AppContext> for WindowContext<'a> {
1468 fn borrow(&self) -> &AppContext {
1469 &self.app
1470 }
1471}
1472
1473impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1474 fn borrow_mut(&mut self) -> &mut AppContext {
1475 &mut self.app
1476 }
1477}
1478
1479pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1480 fn app_mut(&mut self) -> &mut AppContext {
1481 self.borrow_mut()
1482 }
1483
1484 fn window(&self) -> &Window {
1485 self.borrow()
1486 }
1487
1488 fn window_mut(&mut self) -> &mut Window {
1489 self.borrow_mut()
1490 }
1491
1492 /// Pushes the given element id onto the global stack and invokes the given closure
1493 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1494 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1495 /// used to associate state with identified elements across separate frames.
1496 fn with_element_id<R>(
1497 &mut self,
1498 id: impl Into<ElementId>,
1499 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1500 ) -> R {
1501 let keymap = self.app_mut().keymap.clone();
1502 let window = self.window_mut();
1503 window.element_id_stack.push(id.into());
1504 let global_id = window.element_id_stack.clone();
1505
1506 if window.key_matchers.get(&global_id).is_none() {
1507 window.key_matchers.insert(
1508 global_id.clone(),
1509 window
1510 .prev_frame_key_matchers
1511 .remove(&global_id)
1512 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1513 );
1514 }
1515
1516 let result = f(global_id, self);
1517 let window: &mut Window = self.borrow_mut();
1518 window.element_id_stack.pop();
1519 result
1520 }
1521
1522 /// Invoke the given function with the given content mask after intersecting it
1523 /// with the current mask.
1524 fn with_content_mask<R>(
1525 &mut self,
1526 mask: ContentMask<Pixels>,
1527 f: impl FnOnce(&mut Self) -> R,
1528 ) -> R {
1529 let mask = mask.intersect(&self.content_mask());
1530 self.window_mut().content_mask_stack.push(mask);
1531 let result = f(self);
1532 self.window_mut().content_mask_stack.pop();
1533 result
1534 }
1535
1536 /// Update the global element offset based on the given offset. This is used to implement
1537 /// scrolling and position drag handles.
1538 fn with_element_offset<R>(
1539 &mut self,
1540 offset: Option<Point<Pixels>>,
1541 f: impl FnOnce(&mut Self) -> R,
1542 ) -> R {
1543 let Some(offset) = offset else {
1544 return f(self);
1545 };
1546
1547 let offset = self.element_offset() + offset;
1548 self.window_mut().element_offset_stack.push(offset);
1549 let result = f(self);
1550 self.window_mut().element_offset_stack.pop();
1551 result
1552 }
1553
1554 /// Obtain the current element offset.
1555 fn element_offset(&self) -> Point<Pixels> {
1556 self.window()
1557 .element_offset_stack
1558 .last()
1559 .copied()
1560 .unwrap_or_default()
1561 }
1562
1563 /// Update or intialize state for an element with the given id that lives across multiple
1564 /// frames. If an element with this id existed in the previous frame, its state will be passed
1565 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1566 /// when drawing the next frame.
1567 fn with_element_state<S, R>(
1568 &mut self,
1569 id: ElementId,
1570 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1571 ) -> R
1572 where
1573 S: 'static,
1574 {
1575 self.with_element_id(id, |global_id, cx| {
1576 if let Some(any) = cx
1577 .window_mut()
1578 .element_states
1579 .remove(&global_id)
1580 .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
1581 {
1582 // Using the extra inner option to avoid needing to reallocate a new box.
1583 let mut state_box = any
1584 .downcast::<Option<S>>()
1585 .expect("invalid element state type for id");
1586 let state = state_box
1587 .take()
1588 .expect("element state is already on the stack");
1589 let (result, state) = f(Some(state), cx);
1590 state_box.replace(state);
1591 cx.window_mut().element_states.insert(global_id, state_box);
1592 result
1593 } else {
1594 let (result, state) = f(None, cx);
1595 cx.window_mut()
1596 .element_states
1597 .insert(global_id, Box::new(Some(state)));
1598 result
1599 }
1600 })
1601 }
1602
1603 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1604 /// id is `None`, no state will be retrieved or stored.
1605 fn with_optional_element_state<S, R>(
1606 &mut self,
1607 element_id: Option<ElementId>,
1608 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1609 ) -> R
1610 where
1611 S: 'static,
1612 {
1613 if let Some(element_id) = element_id {
1614 self.with_element_state(element_id, f)
1615 } else {
1616 f(None, self).0
1617 }
1618 }
1619
1620 /// Obtain the current content mask.
1621 fn content_mask(&self) -> ContentMask<Pixels> {
1622 self.window()
1623 .content_mask_stack
1624 .last()
1625 .cloned()
1626 .unwrap_or_else(|| ContentMask {
1627 bounds: Bounds {
1628 origin: Point::default(),
1629 size: self.window().content_size,
1630 },
1631 })
1632 }
1633
1634 /// The size of an em for the base font of the application. Adjusting this value allows the
1635 /// UI to scale, just like zooming a web page.
1636 fn rem_size(&self) -> Pixels {
1637 self.window().rem_size
1638 }
1639}
1640
1641impl Borrow<Window> for WindowContext<'_> {
1642 fn borrow(&self) -> &Window {
1643 &self.window
1644 }
1645}
1646
1647impl BorrowMut<Window> for WindowContext<'_> {
1648 fn borrow_mut(&mut self) -> &mut Window {
1649 &mut self.window
1650 }
1651}
1652
1653impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1654
1655pub struct ViewContext<'a, V> {
1656 window_cx: WindowContext<'a>,
1657 view: &'a View<V>,
1658}
1659
1660impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1661 fn borrow(&self) -> &AppContext {
1662 &*self.window_cx.app
1663 }
1664}
1665
1666impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1667 fn borrow_mut(&mut self) -> &mut AppContext {
1668 &mut *self.window_cx.app
1669 }
1670}
1671
1672impl<V> Borrow<Window> for ViewContext<'_, V> {
1673 fn borrow(&self) -> &Window {
1674 &*self.window_cx.window
1675 }
1676}
1677
1678impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1679 fn borrow_mut(&mut self) -> &mut Window {
1680 &mut *self.window_cx.window
1681 }
1682}
1683
1684impl<'a, V: 'static> ViewContext<'a, V> {
1685 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1686 Self {
1687 window_cx: WindowContext::new(app, window),
1688 view,
1689 }
1690 }
1691
1692 // todo!("change this to return a reference");
1693 pub fn view(&self) -> View<V> {
1694 self.view.clone()
1695 }
1696
1697 pub fn model(&self) -> Model<V> {
1698 self.view.model.clone()
1699 }
1700
1701 /// Access the underlying window context.
1702 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1703 &mut self.window_cx
1704 }
1705
1706 pub fn stack<R>(&mut self, order: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1707 self.window.z_index_stack.push(order);
1708 let result = f(self);
1709 self.window.z_index_stack.pop();
1710 result
1711 }
1712
1713 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1714 where
1715 V: 'static,
1716 {
1717 let view = self.view();
1718 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1719 }
1720
1721 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1722 /// that are currently on the stack to be returned to the app.
1723 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1724 let view = self.view().downgrade();
1725 self.window_cx.defer(move |cx| {
1726 view.update(cx, f).ok();
1727 });
1728 }
1729
1730 pub fn observe<V2, E>(
1731 &mut self,
1732 entity: &E,
1733 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1734 ) -> Subscription
1735 where
1736 V2: 'static,
1737 V: 'static,
1738 E: Entity<V2>,
1739 {
1740 let view = self.view().downgrade();
1741 let entity_id = entity.entity_id();
1742 let entity = entity.downgrade();
1743 let window_handle = self.window.handle;
1744 self.app.observers.insert(
1745 entity_id,
1746 Box::new(move |cx| {
1747 window_handle
1748 .update(cx, |_, cx| {
1749 if let Some(handle) = E::upgrade_from(&entity) {
1750 view.update(cx, |this, cx| on_notify(this, handle, cx))
1751 .is_ok()
1752 } else {
1753 false
1754 }
1755 })
1756 .unwrap_or(false)
1757 }),
1758 )
1759 }
1760
1761 pub fn subscribe<V2, E>(
1762 &mut self,
1763 entity: &E,
1764 mut on_event: impl FnMut(&mut V, E, &V2::Event, &mut ViewContext<'_, V>) + 'static,
1765 ) -> Subscription
1766 where
1767 V2: EventEmitter,
1768 E: Entity<V2>,
1769 {
1770 let view = self.view().downgrade();
1771 let entity_id = entity.entity_id();
1772 let handle = entity.downgrade();
1773 let window_handle = self.window.handle;
1774 self.app.event_listeners.insert(
1775 entity_id,
1776 Box::new(move |event, cx| {
1777 window_handle
1778 .update(cx, |_, cx| {
1779 if let Some(handle) = E::upgrade_from(&handle) {
1780 let event = event.downcast_ref().expect("invalid event type");
1781 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1782 .is_ok()
1783 } else {
1784 false
1785 }
1786 })
1787 .unwrap_or(false)
1788 }),
1789 )
1790 }
1791
1792 pub fn on_release(
1793 &mut self,
1794 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
1795 ) -> Subscription {
1796 let window_handle = self.window.handle;
1797 self.app.release_listeners.insert(
1798 self.view.model.entity_id,
1799 Box::new(move |this, cx| {
1800 let this = this.downcast_mut().expect("invalid entity type");
1801 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
1802 }),
1803 )
1804 }
1805
1806 pub fn observe_release<V2, E>(
1807 &mut self,
1808 entity: &E,
1809 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1810 ) -> Subscription
1811 where
1812 V: 'static,
1813 V2: 'static,
1814 E: Entity<V2>,
1815 {
1816 let view = self.view().downgrade();
1817 let entity_id = entity.entity_id();
1818 let window_handle = self.window.handle;
1819 self.app.release_listeners.insert(
1820 entity_id,
1821 Box::new(move |entity, cx| {
1822 let entity = entity.downcast_mut().expect("invalid entity type");
1823 let _ = window_handle.update(cx, |_, cx| {
1824 view.update(cx, |this, cx| on_release(this, entity, cx))
1825 });
1826 }),
1827 )
1828 }
1829
1830 pub fn notify(&mut self) {
1831 self.window_cx.notify();
1832 self.window_cx.app.push_effect(Effect::Notify {
1833 emitter: self.view.model.entity_id,
1834 });
1835 }
1836
1837 pub fn observe_window_bounds(
1838 &mut self,
1839 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1840 ) -> Subscription {
1841 let view = self.view.downgrade();
1842 self.window.bounds_observers.insert(
1843 (),
1844 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1845 )
1846 }
1847
1848 pub fn observe_window_activation(
1849 &mut self,
1850 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1851 ) -> Subscription {
1852 let view = self.view.downgrade();
1853 self.window.activation_observers.insert(
1854 (),
1855 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1856 )
1857 }
1858
1859 pub fn on_focus_changed(
1860 &mut self,
1861 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + 'static,
1862 ) {
1863 let handle = self.view().downgrade();
1864 self.window.focus_listeners.push(Box::new(move |event, cx| {
1865 handle
1866 .update(cx, |view, cx| listener(view, event, cx))
1867 .log_err();
1868 }));
1869 }
1870
1871 pub fn with_key_listeners<R>(
1872 &mut self,
1873 key_listeners: impl IntoIterator<Item = (TypeId, KeyListener<V>)>,
1874 f: impl FnOnce(&mut Self) -> R,
1875 ) -> R {
1876 let old_stack_len = self.window.key_dispatch_stack.len();
1877 if !self.window.freeze_key_dispatch_stack {
1878 for (event_type, listener) in key_listeners {
1879 let handle = self.view().downgrade();
1880 let listener = Box::new(
1881 move |event: &dyn Any,
1882 context_stack: &[&DispatchContext],
1883 phase: DispatchPhase,
1884 cx: &mut WindowContext<'_>| {
1885 handle
1886 .update(cx, |view, cx| {
1887 listener(view, event, context_stack, phase, cx)
1888 })
1889 .log_err()
1890 .flatten()
1891 },
1892 );
1893 self.window
1894 .key_dispatch_stack
1895 .push(KeyDispatchStackFrame::Listener {
1896 event_type,
1897 listener,
1898 });
1899 }
1900 }
1901
1902 let result = f(self);
1903
1904 if !self.window.freeze_key_dispatch_stack {
1905 self.window.key_dispatch_stack.truncate(old_stack_len);
1906 }
1907
1908 result
1909 }
1910
1911 pub fn with_key_dispatch_context<R>(
1912 &mut self,
1913 context: DispatchContext,
1914 f: impl FnOnce(&mut Self) -> R,
1915 ) -> R {
1916 if context.is_empty() {
1917 return f(self);
1918 }
1919
1920 if !self.window.freeze_key_dispatch_stack {
1921 self.window
1922 .key_dispatch_stack
1923 .push(KeyDispatchStackFrame::Context(context));
1924 }
1925
1926 let result = f(self);
1927
1928 if !self.window.freeze_key_dispatch_stack {
1929 self.window.key_dispatch_stack.pop();
1930 }
1931
1932 result
1933 }
1934
1935 pub fn with_focus<R>(
1936 &mut self,
1937 focus_handle: FocusHandle,
1938 f: impl FnOnce(&mut Self) -> R,
1939 ) -> R {
1940 if let Some(parent_focus_id) = self.window.focus_stack.last().copied() {
1941 self.window
1942 .focus_parents_by_child
1943 .insert(focus_handle.id, parent_focus_id);
1944 }
1945 self.window.focus_stack.push(focus_handle.id);
1946
1947 if Some(focus_handle.id) == self.window.focus {
1948 self.window.freeze_key_dispatch_stack = true;
1949 }
1950
1951 let result = f(self);
1952
1953 self.window.focus_stack.pop();
1954 result
1955 }
1956
1957 pub fn spawn<Fut, R>(
1958 &mut self,
1959 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
1960 ) -> Task<R>
1961 where
1962 R: 'static,
1963 Fut: Future<Output = R> + 'static,
1964 {
1965 let view = self.view().downgrade();
1966 self.window_cx.spawn(|cx| f(view, cx))
1967 }
1968
1969 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1970 where
1971 G: 'static,
1972 {
1973 let mut global = self.app.lease_global::<G>();
1974 let result = f(&mut global, self);
1975 self.app.end_global_lease(global);
1976 result
1977 }
1978
1979 pub fn observe_global<G: 'static>(
1980 &mut self,
1981 f: impl Fn(&mut V, &mut ViewContext<'_, V>) + 'static,
1982 ) -> Subscription {
1983 let window_handle = self.window.handle;
1984 let view = self.view().downgrade();
1985 self.global_observers.insert(
1986 TypeId::of::<G>(),
1987 Box::new(move |cx| {
1988 window_handle
1989 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
1990 .unwrap_or(false)
1991 }),
1992 )
1993 }
1994
1995 pub fn on_mouse_event<Event: 'static>(
1996 &mut self,
1997 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
1998 ) {
1999 let handle = self.view();
2000 self.window_cx.on_mouse_event(move |event, phase, cx| {
2001 handle.update(cx, |view, cx| {
2002 handler(view, event, phase, cx);
2003 })
2004 });
2005 }
2006}
2007
2008impl<V> ViewContext<'_, V>
2009where
2010 V: InputHandler + 'static,
2011{
2012 pub fn handle_text_input(&mut self) {
2013 self.window.requested_input_handler = Some(Box::new(WindowInputHandler {
2014 cx: self.app.this.clone(),
2015 window: self.window_handle(),
2016 handler: self.view().downgrade(),
2017 }));
2018 }
2019}
2020
2021impl<V> ViewContext<'_, V>
2022where
2023 V: EventEmitter,
2024 V::Event: 'static,
2025{
2026 pub fn emit(&mut self, event: V::Event) {
2027 let emitter = self.view.model.entity_id;
2028 self.app.push_effect(Effect::Emit {
2029 emitter,
2030 event: Box::new(event),
2031 });
2032 }
2033}
2034
2035impl<V> Context for ViewContext<'_, V> {
2036 type Result<U> = U;
2037
2038 fn build_model<T: 'static>(
2039 &mut self,
2040 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2041 ) -> Model<T> {
2042 self.window_cx.build_model(build_model)
2043 }
2044
2045 fn update_model<T: 'static, R>(
2046 &mut self,
2047 model: &Model<T>,
2048 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2049 ) -> R {
2050 self.window_cx.update_model(model, update)
2051 }
2052
2053 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2054 where
2055 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2056 {
2057 self.window_cx.update_window(window, update)
2058 }
2059}
2060
2061impl<V: 'static> VisualContext for ViewContext<'_, V> {
2062 fn build_view<W: 'static>(
2063 &mut self,
2064 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2065 ) -> Self::Result<View<W>> {
2066 self.window_cx.build_view(build_view_state)
2067 }
2068
2069 fn update_view<V2: 'static, R>(
2070 &mut self,
2071 view: &View<V2>,
2072 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2073 ) -> Self::Result<R> {
2074 self.window_cx.update_view(view, update)
2075 }
2076
2077 fn replace_root_view<W>(
2078 &mut self,
2079 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2080 ) -> Self::Result<View<W>>
2081 where
2082 W: Render,
2083 {
2084 self.window_cx.replace_root_view(build_view)
2085 }
2086}
2087
2088impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2089 type Target = WindowContext<'a>;
2090
2091 fn deref(&self) -> &Self::Target {
2092 &self.window_cx
2093 }
2094}
2095
2096impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2097 fn deref_mut(&mut self) -> &mut Self::Target {
2098 &mut self.window_cx
2099 }
2100}
2101
2102// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2103slotmap::new_key_type! { pub struct WindowId; }
2104
2105impl WindowId {
2106 pub fn as_u64(&self) -> u64 {
2107 self.0.as_ffi()
2108 }
2109}
2110
2111#[derive(Deref, DerefMut)]
2112pub struct WindowHandle<V> {
2113 #[deref]
2114 #[deref_mut]
2115 pub(crate) any_handle: AnyWindowHandle,
2116 state_type: PhantomData<V>,
2117}
2118
2119impl<V: 'static + Render> WindowHandle<V> {
2120 pub fn new(id: WindowId) -> Self {
2121 WindowHandle {
2122 any_handle: AnyWindowHandle {
2123 id,
2124 state_type: TypeId::of::<V>(),
2125 },
2126 state_type: PhantomData,
2127 }
2128 }
2129
2130 pub fn update<C, R>(
2131 self,
2132 cx: &mut C,
2133 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2134 ) -> Result<R>
2135 where
2136 C: Context,
2137 {
2138 cx.update_window(self.any_handle, |root_view, cx| {
2139 let view = root_view
2140 .downcast::<V>()
2141 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2142 Ok(cx.update_view(&view, update))
2143 })?
2144 }
2145}
2146
2147impl<V> Copy for WindowHandle<V> {}
2148
2149impl<V> Clone for WindowHandle<V> {
2150 fn clone(&self) -> Self {
2151 WindowHandle {
2152 any_handle: self.any_handle,
2153 state_type: PhantomData,
2154 }
2155 }
2156}
2157
2158impl<V> PartialEq for WindowHandle<V> {
2159 fn eq(&self, other: &Self) -> bool {
2160 self.any_handle == other.any_handle
2161 }
2162}
2163
2164impl<V> Eq for WindowHandle<V> {}
2165
2166impl<V> Hash for WindowHandle<V> {
2167 fn hash<H: Hasher>(&self, state: &mut H) {
2168 self.any_handle.hash(state);
2169 }
2170}
2171
2172impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2173 fn into(self) -> AnyWindowHandle {
2174 self.any_handle
2175 }
2176}
2177
2178#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2179pub struct AnyWindowHandle {
2180 pub(crate) id: WindowId,
2181 state_type: TypeId,
2182}
2183
2184impl AnyWindowHandle {
2185 pub fn window_id(&self) -> WindowId {
2186 self.id
2187 }
2188
2189 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2190 if TypeId::of::<T>() == self.state_type {
2191 Some(WindowHandle {
2192 any_handle: *self,
2193 state_type: PhantomData,
2194 })
2195 } else {
2196 None
2197 }
2198 }
2199
2200 pub fn update<C, R>(
2201 self,
2202 cx: &mut C,
2203 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2204 ) -> Result<R>
2205 where
2206 C: Context,
2207 {
2208 cx.update_window(self, update)
2209 }
2210}
2211
2212#[cfg(any(test, feature = "test-support"))]
2213impl From<SmallVec<[u32; 16]>> for StackingOrder {
2214 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2215 StackingOrder(small_vec)
2216 }
2217}
2218
2219#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2220pub enum ElementId {
2221 View(EntityId),
2222 Number(usize),
2223 Name(SharedString),
2224 FocusHandle(FocusId),
2225}
2226
2227impl From<EntityId> for ElementId {
2228 fn from(id: EntityId) -> Self {
2229 ElementId::View(id)
2230 }
2231}
2232
2233impl From<usize> for ElementId {
2234 fn from(id: usize) -> Self {
2235 ElementId::Number(id)
2236 }
2237}
2238
2239impl From<i32> for ElementId {
2240 fn from(id: i32) -> Self {
2241 Self::Number(id as usize)
2242 }
2243}
2244
2245impl From<SharedString> for ElementId {
2246 fn from(name: SharedString) -> Self {
2247 ElementId::Name(name)
2248 }
2249}
2250
2251impl From<&'static str> for ElementId {
2252 fn from(name: &'static str) -> Self {
2253 ElementId::Name(name.into())
2254 }
2255}
2256
2257impl<'a> From<&'a FocusHandle> for ElementId {
2258 fn from(handle: &'a FocusHandle) -> Self {
2259 ElementId::FocusHandle(handle.id)
2260 }
2261}