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