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