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