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