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