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