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_pending_keystrokes();
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 let focus_handle = self.focused();
457
458 self.defer(move |cx| {
459 let node_id = focus_handle
460 .and_then(|handle| {
461 cx.window
462 .current_frame
463 .dispatch_tree
464 .focusable_node_id(handle.id)
465 })
466 .unwrap_or_else(|| cx.window.current_frame.dispatch_tree.root_node_id());
467
468 cx.propagate_event = true;
469 cx.dispatch_action_on_node(node_id, action);
470 })
471 }
472
473 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
474 /// that are currently on the stack to be returned to the app.
475 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
476 let handle = self.window.handle;
477 self.app.defer(move |cx| {
478 handle.update(cx, |_, cx| f(cx)).ok();
479 });
480 }
481
482 pub fn subscribe<Emitter, E, Evt>(
483 &mut self,
484 entity: &E,
485 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
486 ) -> Subscription
487 where
488 Emitter: EventEmitter<Evt>,
489 E: Entity<Emitter>,
490 Evt: 'static,
491 {
492 let entity_id = entity.entity_id();
493 let entity = entity.downgrade();
494 let window_handle = self.window.handle;
495 let (subscription, activate) = self.app.event_listeners.insert(
496 entity_id,
497 (
498 TypeId::of::<Evt>(),
499 Box::new(move |event, cx| {
500 window_handle
501 .update(cx, |_, cx| {
502 if let Some(handle) = E::upgrade_from(&entity) {
503 let event = event.downcast_ref().expect("invalid event type");
504 on_event(handle, event, cx);
505 true
506 } else {
507 false
508 }
509 })
510 .unwrap_or(false)
511 }),
512 ),
513 );
514 self.app.defer(move |_| activate());
515 subscription
516 }
517
518 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
519 /// await points in async code.
520 pub fn to_async(&self) -> AsyncWindowContext {
521 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
522 }
523
524 /// Schedule the given closure to be run directly after the current frame is rendered.
525 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
526 let handle = self.window.handle;
527 let display_id = self.window.display_id;
528
529 if !self.frame_consumers.contains_key(&display_id) {
530 let (tx, mut rx) = mpsc::unbounded::<()>();
531 self.platform.set_display_link_output_callback(
532 display_id,
533 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
534 );
535
536 let consumer_task = self.app.spawn(|cx| async move {
537 while rx.next().await.is_some() {
538 cx.update(|cx| {
539 for callback in cx
540 .next_frame_callbacks
541 .get_mut(&display_id)
542 .unwrap()
543 .drain(..)
544 .collect::<SmallVec<[_; 32]>>()
545 {
546 callback(cx);
547 }
548 })
549 .ok();
550
551 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
552
553 cx.update(|cx| {
554 if cx.next_frame_callbacks.is_empty() {
555 cx.platform.stop_display_link(display_id);
556 }
557 })
558 .ok();
559 }
560 });
561 self.frame_consumers.insert(display_id, consumer_task);
562 }
563
564 if self.next_frame_callbacks.is_empty() {
565 self.platform.start_display_link(display_id);
566 }
567
568 self.next_frame_callbacks
569 .entry(display_id)
570 .or_default()
571 .push(Box::new(move |cx: &mut AppContext| {
572 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
573 }));
574 }
575
576 /// Spawn the future returned by the given closure on the application thread pool.
577 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
578 /// use within your future.
579 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
580 where
581 R: 'static,
582 Fut: Future<Output = R> + 'static,
583 {
584 self.app
585 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
586 }
587
588 /// Update the global of the given type. The given closure is given simultaneous mutable
589 /// access both to the global and the context.
590 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
591 where
592 G: 'static,
593 {
594 let mut global = self.app.lease_global::<G>();
595 let result = f(&mut global, self);
596 self.app.end_global_lease(global);
597 result
598 }
599
600 #[must_use]
601 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
602 /// layout is being requested, along with the layout ids of any children. This method is called during
603 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
604 pub fn request_layout(
605 &mut self,
606 style: &Style,
607 children: impl IntoIterator<Item = LayoutId>,
608 ) -> LayoutId {
609 self.app.layout_id_buffer.clear();
610 self.app.layout_id_buffer.extend(children.into_iter());
611 let rem_size = self.rem_size();
612
613 self.window.layout_engine.as_mut().unwrap().request_layout(
614 style,
615 rem_size,
616 &self.app.layout_id_buffer,
617 )
618 }
619
620 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
621 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
622 /// determine the element's size. One place this is used internally is when measuring text.
623 ///
624 /// The given closure is invoked at layout time with the known dimensions and available space and
625 /// returns a `Size`.
626 pub fn request_measured_layout<
627 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
628 + 'static,
629 >(
630 &mut self,
631 style: Style,
632 measure: F,
633 ) -> LayoutId {
634 let rem_size = self.rem_size();
635 self.window
636 .layout_engine
637 .as_mut()
638 .unwrap()
639 .request_measured_layout(style, rem_size, measure)
640 }
641
642 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
643 let mut layout_engine = self.window.layout_engine.take().unwrap();
644 layout_engine.compute_layout(layout_id, available_space, self);
645 self.window.layout_engine = Some(layout_engine);
646 }
647
648 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
649 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
650 /// in order to pass your element its `Bounds` automatically.
651 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
652 let mut bounds = self
653 .window
654 .layout_engine
655 .as_mut()
656 .unwrap()
657 .layout_bounds(layout_id)
658 .map(Into::into);
659 bounds.origin += self.element_offset();
660 bounds
661 }
662
663 fn window_bounds_changed(&mut self) {
664 self.window.scale_factor = self.window.platform_window.scale_factor();
665 self.window.viewport_size = self.window.platform_window.content_size();
666 self.window.bounds = self.window.platform_window.bounds();
667 self.window.display_id = self.window.platform_window.display().id();
668 self.window.dirty = true;
669
670 self.window
671 .bounds_observers
672 .clone()
673 .retain(&(), |callback| callback(self));
674 }
675
676 pub fn window_bounds(&self) -> WindowBounds {
677 self.window.bounds
678 }
679
680 pub fn viewport_size(&self) -> Size<Pixels> {
681 self.window.viewport_size
682 }
683
684 pub fn is_window_active(&self) -> bool {
685 self.window.active
686 }
687
688 pub fn zoom_window(&self) {
689 self.window.platform_window.zoom();
690 }
691
692 pub fn set_window_title(&mut self, title: &str) {
693 self.window.platform_window.set_title(title);
694 }
695
696 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
697 self.platform
698 .displays()
699 .into_iter()
700 .find(|display| display.id() == self.window.display_id)
701 }
702
703 pub fn show_character_palette(&self) {
704 self.window.platform_window.show_character_palette();
705 }
706
707 /// The scale factor of the display associated with the window. For example, it could
708 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
709 /// be rendered as two pixels on screen.
710 pub fn scale_factor(&self) -> f32 {
711 self.window.scale_factor
712 }
713
714 /// The size of an em for the base font of the application. Adjusting this value allows the
715 /// UI to scale, just like zooming a web page.
716 pub fn rem_size(&self) -> Pixels {
717 self.window.rem_size
718 }
719
720 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
721 /// UI to scale, just like zooming a web page.
722 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
723 self.window.rem_size = rem_size.into();
724 }
725
726 /// The line height associated with the current text style.
727 pub fn line_height(&self) -> Pixels {
728 let rem_size = self.rem_size();
729 let text_style = self.text_style();
730 text_style
731 .line_height
732 .to_pixels(text_style.font_size.into(), rem_size)
733 }
734
735 /// Call to prevent the default action of an event. Currently only used to prevent
736 /// parent elements from becoming focused on mouse down.
737 pub fn prevent_default(&mut self) {
738 self.window.default_prevented = true;
739 }
740
741 /// Obtain whether default has been prevented for the event currently being dispatched.
742 pub fn default_prevented(&self) -> bool {
743 self.window.default_prevented
744 }
745
746 /// Register a mouse event listener on the window for the current frame. The type of event
747 /// is determined by the first parameter of the given listener. When the next frame is rendered
748 /// the listener will be cleared.
749 ///
750 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
751 /// a specific need to register a global listener.
752 pub fn on_mouse_event<Event: 'static>(
753 &mut self,
754 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
755 ) {
756 let order = self.window.current_frame.z_index_stack.clone();
757 self.window
758 .current_frame
759 .mouse_listeners
760 .entry(TypeId::of::<Event>())
761 .or_default()
762 .push((
763 order,
764 Box::new(move |event: &dyn Any, phase, cx| {
765 handler(event.downcast_ref().unwrap(), phase, cx)
766 }),
767 ))
768 }
769
770 /// Register a key event listener on the window for the current frame. The type of event
771 /// is determined by the first parameter of the given listener. When the next frame is rendered
772 /// the listener will be cleared.
773 ///
774 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
775 /// a specific need to register a global listener.
776 pub fn on_key_event<Event: 'static>(
777 &mut self,
778 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
779 ) {
780 self.window
781 .current_frame
782 .dispatch_tree
783 .on_key_event(Rc::new(move |event, phase, cx| {
784 if let Some(event) = event.downcast_ref::<Event>() {
785 handler(event, phase, cx)
786 }
787 }));
788 }
789
790 /// Register an action listener on the window for the current frame. The type of action
791 /// is determined by the first parameter of the given listener. When the next frame is rendered
792 /// the listener will be cleared.
793 ///
794 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
795 /// a specific need to register a global listener.
796 pub fn on_action(
797 &mut self,
798 action_type: TypeId,
799 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
800 ) {
801 self.window.current_frame.dispatch_tree.on_action(
802 action_type,
803 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
804 );
805 }
806
807 pub fn is_action_available(&self, action: &dyn Action) -> bool {
808 let target = self
809 .focused()
810 .and_then(|focused_handle| {
811 self.window
812 .current_frame
813 .dispatch_tree
814 .focusable_node_id(focused_handle.id)
815 })
816 .unwrap_or_else(|| self.window.current_frame.dispatch_tree.root_node_id());
817 self.window
818 .current_frame
819 .dispatch_tree
820 .is_action_available(action, target)
821 }
822
823 /// The position of the mouse relative to the window.
824 pub fn mouse_position(&self) -> Point<Pixels> {
825 self.window.mouse_position
826 }
827
828 pub fn set_cursor_style(&mut self, style: CursorStyle) {
829 self.window.requested_cursor_style = Some(style)
830 }
831
832 /// Called during painting to invoke the given closure in a new stacking context. The given
833 /// z-index is interpreted relative to the previous call to `stack`.
834 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
835 self.window.current_frame.z_index_stack.push(z_index);
836 let result = f(self);
837 self.window.current_frame.z_index_stack.pop();
838 result
839 }
840
841 /// Called during painting to track which z-index is on top at each pixel position
842 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
843 let stacking_order = self.window.current_frame.z_index_stack.clone();
844 let depth_map = &mut self.window.current_frame.depth_map;
845 match depth_map.binary_search_by(|(level, _)| stacking_order.cmp(&level)) {
846 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, bounds)),
847 }
848 }
849
850 /// Returns true if the top-most opaque layer painted over this point was part of the
851 /// same layer as the given stacking order.
852 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
853 for (stack, bounds) in self.window.previous_frame.depth_map.iter() {
854 if bounds.contains_point(point) {
855 return level.starts_with(stack) || stack.starts_with(level);
856 }
857 }
858
859 false
860 }
861
862 /// Called during painting to get the current stacking order.
863 pub fn stacking_order(&self) -> &StackingOrder {
864 &self.window.current_frame.z_index_stack
865 }
866
867 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
868 pub fn paint_shadows(
869 &mut self,
870 bounds: Bounds<Pixels>,
871 corner_radii: Corners<Pixels>,
872 shadows: &[BoxShadow],
873 ) {
874 let scale_factor = self.scale_factor();
875 let content_mask = self.content_mask();
876 let window = &mut *self.window;
877 for shadow in shadows {
878 let mut shadow_bounds = bounds;
879 shadow_bounds.origin += shadow.offset;
880 shadow_bounds.dilate(shadow.spread_radius);
881 window.current_frame.scene_builder.insert(
882 &window.current_frame.z_index_stack,
883 Shadow {
884 order: 0,
885 bounds: shadow_bounds.scale(scale_factor),
886 content_mask: content_mask.scale(scale_factor),
887 corner_radii: corner_radii.scale(scale_factor),
888 color: shadow.color,
889 blur_radius: shadow.blur_radius.scale(scale_factor),
890 },
891 );
892 }
893 }
894
895 /// Paint one or more quads into the scene for the current frame at the current stacking context.
896 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
897 pub fn paint_quad(
898 &mut self,
899 bounds: Bounds<Pixels>,
900 corner_radii: Corners<Pixels>,
901 background: impl Into<Hsla>,
902 border_widths: Edges<Pixels>,
903 border_color: impl Into<Hsla>,
904 ) {
905 let scale_factor = self.scale_factor();
906 let content_mask = self.content_mask();
907
908 let window = &mut *self.window;
909 window.current_frame.scene_builder.insert(
910 &window.current_frame.z_index_stack,
911 Quad {
912 order: 0,
913 bounds: bounds.scale(scale_factor),
914 content_mask: content_mask.scale(scale_factor),
915 background: background.into(),
916 border_color: border_color.into(),
917 corner_radii: corner_radii.scale(scale_factor),
918 border_widths: border_widths.scale(scale_factor),
919 },
920 );
921 }
922
923 /// Paint the given `Path` into the scene for the current frame at the current z-index.
924 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
925 let scale_factor = self.scale_factor();
926 let content_mask = self.content_mask();
927 path.content_mask = content_mask;
928 path.color = color.into();
929 let window = &mut *self.window;
930 window.current_frame.scene_builder.insert(
931 &window.current_frame.z_index_stack,
932 path.scale(scale_factor),
933 );
934 }
935
936 /// Paint an underline into the scene for the current frame at the current z-index.
937 pub fn paint_underline(
938 &mut self,
939 origin: Point<Pixels>,
940 width: Pixels,
941 style: &UnderlineStyle,
942 ) {
943 let scale_factor = self.scale_factor();
944 let height = if style.wavy {
945 style.thickness * 3.
946 } else {
947 style.thickness
948 };
949 let bounds = Bounds {
950 origin,
951 size: size(width, height),
952 };
953 let content_mask = self.content_mask();
954 let window = &mut *self.window;
955 window.current_frame.scene_builder.insert(
956 &window.current_frame.z_index_stack,
957 Underline {
958 order: 0,
959 bounds: bounds.scale(scale_factor),
960 content_mask: content_mask.scale(scale_factor),
961 thickness: style.thickness.scale(scale_factor),
962 color: style.color.unwrap_or_default(),
963 wavy: style.wavy,
964 },
965 );
966 }
967
968 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
969 /// The y component of the origin is the baseline of the glyph.
970 pub fn paint_glyph(
971 &mut self,
972 origin: Point<Pixels>,
973 font_id: FontId,
974 glyph_id: GlyphId,
975 font_size: Pixels,
976 color: Hsla,
977 ) -> Result<()> {
978 let scale_factor = self.scale_factor();
979 let glyph_origin = origin.scale(scale_factor);
980 let subpixel_variant = Point {
981 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
982 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
983 };
984 let params = RenderGlyphParams {
985 font_id,
986 glyph_id,
987 font_size,
988 subpixel_variant,
989 scale_factor,
990 is_emoji: false,
991 };
992
993 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
994 if !raster_bounds.is_zero() {
995 let tile =
996 self.window
997 .sprite_atlas
998 .get_or_insert_with(¶ms.clone().into(), &mut || {
999 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1000 Ok((size, Cow::Owned(bytes)))
1001 })?;
1002 let bounds = Bounds {
1003 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1004 size: tile.bounds.size.map(Into::into),
1005 };
1006 let content_mask = self.content_mask().scale(scale_factor);
1007 let window = &mut *self.window;
1008 window.current_frame.scene_builder.insert(
1009 &window.current_frame.z_index_stack,
1010 MonochromeSprite {
1011 order: 0,
1012 bounds,
1013 content_mask,
1014 color,
1015 tile,
1016 },
1017 );
1018 }
1019 Ok(())
1020 }
1021
1022 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
1023 /// The y component of the origin is the baseline of the glyph.
1024 pub fn paint_emoji(
1025 &mut self,
1026 origin: Point<Pixels>,
1027 font_id: FontId,
1028 glyph_id: GlyphId,
1029 font_size: Pixels,
1030 ) -> Result<()> {
1031 let scale_factor = self.scale_factor();
1032 let glyph_origin = origin.scale(scale_factor);
1033 let params = RenderGlyphParams {
1034 font_id,
1035 glyph_id,
1036 font_size,
1037 // We don't render emojis with subpixel variants.
1038 subpixel_variant: Default::default(),
1039 scale_factor,
1040 is_emoji: true,
1041 };
1042
1043 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1044 if !raster_bounds.is_zero() {
1045 let tile =
1046 self.window
1047 .sprite_atlas
1048 .get_or_insert_with(¶ms.clone().into(), &mut || {
1049 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1050 Ok((size, Cow::Owned(bytes)))
1051 })?;
1052 let bounds = Bounds {
1053 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1054 size: tile.bounds.size.map(Into::into),
1055 };
1056 let content_mask = self.content_mask().scale(scale_factor);
1057 let window = &mut *self.window;
1058
1059 window.current_frame.scene_builder.insert(
1060 &window.current_frame.z_index_stack,
1061 PolychromeSprite {
1062 order: 0,
1063 bounds,
1064 corner_radii: Default::default(),
1065 content_mask,
1066 tile,
1067 grayscale: false,
1068 },
1069 );
1070 }
1071 Ok(())
1072 }
1073
1074 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1075 pub fn paint_svg(
1076 &mut self,
1077 bounds: Bounds<Pixels>,
1078 path: SharedString,
1079 color: Hsla,
1080 ) -> Result<()> {
1081 let scale_factor = self.scale_factor();
1082 let bounds = bounds.scale(scale_factor);
1083 // Render the SVG at twice the size to get a higher quality result.
1084 let params = RenderSvgParams {
1085 path,
1086 size: bounds
1087 .size
1088 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1089 };
1090
1091 let tile =
1092 self.window
1093 .sprite_atlas
1094 .get_or_insert_with(¶ms.clone().into(), &mut || {
1095 let bytes = self.svg_renderer.render(¶ms)?;
1096 Ok((params.size, Cow::Owned(bytes)))
1097 })?;
1098 let content_mask = self.content_mask().scale(scale_factor);
1099
1100 let window = &mut *self.window;
1101 window.current_frame.scene_builder.insert(
1102 &window.current_frame.z_index_stack,
1103 MonochromeSprite {
1104 order: 0,
1105 bounds,
1106 content_mask,
1107 color,
1108 tile,
1109 },
1110 );
1111
1112 Ok(())
1113 }
1114
1115 /// Paint an image into the scene for the current frame at the current z-index.
1116 pub fn paint_image(
1117 &mut self,
1118 bounds: Bounds<Pixels>,
1119 corner_radii: Corners<Pixels>,
1120 data: Arc<ImageData>,
1121 grayscale: bool,
1122 ) -> Result<()> {
1123 let scale_factor = self.scale_factor();
1124 let bounds = bounds.scale(scale_factor);
1125 let params = RenderImageParams { image_id: data.id };
1126
1127 let tile = self
1128 .window
1129 .sprite_atlas
1130 .get_or_insert_with(¶ms.clone().into(), &mut || {
1131 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1132 })?;
1133 let content_mask = self.content_mask().scale(scale_factor);
1134 let corner_radii = corner_radii.scale(scale_factor);
1135
1136 let window = &mut *self.window;
1137 window.current_frame.scene_builder.insert(
1138 &window.current_frame.z_index_stack,
1139 PolychromeSprite {
1140 order: 0,
1141 bounds,
1142 content_mask,
1143 corner_radii,
1144 tile,
1145 grayscale,
1146 },
1147 );
1148 Ok(())
1149 }
1150
1151 /// Paint a surface into the scene for the current frame at the current z-index.
1152 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
1153 let scale_factor = self.scale_factor();
1154 let bounds = bounds.scale(scale_factor);
1155 let content_mask = self.content_mask().scale(scale_factor);
1156 let window = &mut *self.window;
1157 window.current_frame.scene_builder.insert(
1158 &window.current_frame.z_index_stack,
1159 Surface {
1160 order: 0,
1161 bounds,
1162 content_mask,
1163 image_buffer,
1164 },
1165 );
1166 }
1167
1168 /// Draw pixels to the display for this window based on the contents of its scene.
1169 pub(crate) fn draw(&mut self) {
1170 let root_view = self.window.root_view.take().unwrap();
1171
1172 self.start_frame();
1173
1174 self.with_z_index(0, |cx| {
1175 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
1176 for (action_type, action_listeners) in &cx.app.global_action_listeners {
1177 for action_listener in action_listeners.iter().cloned() {
1178 cx.window.current_frame.dispatch_tree.on_action(
1179 *action_type,
1180 Rc::new(move |action, phase, cx| action_listener(action, phase, cx)),
1181 )
1182 }
1183 }
1184
1185 let available_space = cx.window.viewport_size.map(Into::into);
1186 root_view.draw(Point::default(), available_space, cx);
1187 })
1188 });
1189
1190 if let Some(active_drag) = self.app.active_drag.take() {
1191 if let Some(active_drag) = active_drag.any_drag() {
1192 self.with_z_index(1, |cx| {
1193 let offset = cx.mouse_position() - active_drag.cursor_offset;
1194 let available_space =
1195 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1196 active_drag.view.draw(offset, available_space, cx);
1197 });
1198 }
1199 self.active_drag = Some(active_drag);
1200 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1201 self.with_z_index(1, |cx| {
1202 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1203 active_tooltip
1204 .view
1205 .draw(active_tooltip.cursor_offset, available_space, cx);
1206 });
1207 }
1208
1209 self.window
1210 .current_frame
1211 .dispatch_tree
1212 .preserve_pending_keystrokes(
1213 &mut self.window.previous_frame.dispatch_tree,
1214 self.window.focus,
1215 );
1216
1217 self.window.root_view = Some(root_view);
1218 let scene = self.window.current_frame.scene_builder.build();
1219
1220 self.window.platform_window.draw(scene);
1221 let cursor_style = self
1222 .window
1223 .requested_cursor_style
1224 .take()
1225 .unwrap_or(CursorStyle::Arrow);
1226 self.platform.set_cursor_style(cursor_style);
1227
1228 self.window.dirty = false;
1229 }
1230
1231 /// Rotate the current frame and the previous frame, then clear the current frame.
1232 /// We repopulate all state in the current frame during each paint.
1233 fn start_frame(&mut self) {
1234 self.window.platform_window.clear_input_handler();
1235 self.text_system().start_frame();
1236
1237 let window = &mut *self.window;
1238 window.layout_engine.as_mut().unwrap().clear();
1239
1240 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1241 let frame = &mut window.current_frame;
1242 frame.element_states.clear();
1243 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1244 frame.focus_listeners.clear();
1245 frame.dispatch_tree.clear();
1246 frame.depth_map.clear();
1247 }
1248
1249 /// Dispatch a mouse or keyboard event on the window.
1250 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1251 // Handlers may set this to false by calling `stop_propagation`
1252 self.app.propagate_event = true;
1253 self.window.default_prevented = false;
1254
1255 let event = match event {
1256 // Track the mouse position with our own state, since accessing the platform
1257 // API for the mouse position can only occur on the main thread.
1258 InputEvent::MouseMove(mouse_move) => {
1259 self.window.mouse_position = mouse_move.position;
1260 InputEvent::MouseMove(mouse_move)
1261 }
1262 InputEvent::MouseDown(mouse_down) => {
1263 self.window.mouse_position = mouse_down.position;
1264 InputEvent::MouseDown(mouse_down)
1265 }
1266 InputEvent::MouseUp(mouse_up) => {
1267 self.window.mouse_position = mouse_up.position;
1268 InputEvent::MouseUp(mouse_up)
1269 }
1270 // Translate dragging and dropping of external files from the operating system
1271 // to internal drag and drop events.
1272 InputEvent::FileDrop(file_drop) => match file_drop {
1273 FileDropEvent::Entered { position, files } => {
1274 self.window.mouse_position = position;
1275 if self.active_drag.is_none() {
1276 self.active_drag = Some(crate::AnyDragState::AnyDrag(AnyDrag {
1277 view: self.build_view(|_| files).into(),
1278 cursor_offset: position,
1279 }));
1280 }
1281 InputEvent::MouseDown(MouseDownEvent {
1282 position,
1283 button: MouseButton::Left,
1284 click_count: 1,
1285 modifiers: Modifiers::default(),
1286 })
1287 }
1288 FileDropEvent::Pending { position } => {
1289 self.window.mouse_position = position;
1290 InputEvent::MouseMove(MouseMoveEvent {
1291 position,
1292 pressed_button: Some(MouseButton::Left),
1293 modifiers: Modifiers::default(),
1294 })
1295 }
1296 FileDropEvent::Submit { position } => {
1297 self.window.mouse_position = position;
1298 InputEvent::MouseUp(MouseUpEvent {
1299 button: MouseButton::Left,
1300 position,
1301 modifiers: Modifiers::default(),
1302 click_count: 1,
1303 })
1304 }
1305 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1306 button: MouseButton::Left,
1307 position: Point::default(),
1308 modifiers: Modifiers::default(),
1309 click_count: 1,
1310 }),
1311 },
1312 _ => event,
1313 };
1314
1315 if let Some(any_mouse_event) = event.mouse_event() {
1316 self.dispatch_mouse_event(any_mouse_event);
1317 } else if let Some(any_key_event) = event.keyboard_event() {
1318 self.dispatch_key_event(any_key_event);
1319 }
1320
1321 !self.app.propagate_event
1322 }
1323
1324 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1325 if let Some(mut handlers) = self
1326 .window
1327 .current_frame
1328 .mouse_listeners
1329 .remove(&event.type_id())
1330 {
1331 // Because handlers may add other handlers, we sort every time.
1332 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1333
1334 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1335 // special purposes, such as detecting events outside of a given Bounds.
1336 for (_, handler) in &mut handlers {
1337 handler(event, DispatchPhase::Capture, self);
1338 if !self.app.propagate_event {
1339 break;
1340 }
1341 }
1342
1343 // Bubble phase, where most normal handlers do their work.
1344 if self.app.propagate_event {
1345 for (_, handler) in handlers.iter_mut().rev() {
1346 handler(event, DispatchPhase::Bubble, self);
1347 if !self.app.propagate_event {
1348 break;
1349 }
1350 }
1351 }
1352
1353 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1354 self.active_drag = None;
1355 }
1356
1357 // Just in case any handlers added new handlers, which is weird, but possible.
1358 handlers.extend(
1359 self.window
1360 .current_frame
1361 .mouse_listeners
1362 .get_mut(&event.type_id())
1363 .into_iter()
1364 .flat_map(|handlers| handlers.drain(..)),
1365 );
1366 self.window
1367 .current_frame
1368 .mouse_listeners
1369 .insert(event.type_id(), handlers);
1370 }
1371 }
1372
1373 fn dispatch_key_event(&mut self, event: &dyn Any) {
1374 let node_id = self
1375 .window
1376 .focus
1377 .and_then(|focus_id| {
1378 self.window
1379 .current_frame
1380 .dispatch_tree
1381 .focusable_node_id(focus_id)
1382 })
1383 .unwrap_or_else(|| self.window.current_frame.dispatch_tree.root_node_id());
1384
1385 let dispatch_path = self
1386 .window
1387 .current_frame
1388 .dispatch_tree
1389 .dispatch_path(node_id);
1390
1391 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1392
1393 // Capture phase
1394 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1395 self.propagate_event = true;
1396
1397 for node_id in &dispatch_path {
1398 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1399
1400 if let Some(context) = node.context.clone() {
1401 context_stack.push(context);
1402 }
1403
1404 for key_listener in node.key_listeners.clone() {
1405 key_listener(event, DispatchPhase::Capture, self);
1406 if !self.propagate_event {
1407 return;
1408 }
1409 }
1410 }
1411
1412 // Bubble phase
1413 for node_id in dispatch_path.iter().rev() {
1414 // Handle low level key events
1415 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1416 for key_listener in node.key_listeners.clone() {
1417 key_listener(event, DispatchPhase::Bubble, self);
1418 if !self.propagate_event {
1419 return;
1420 }
1421 }
1422
1423 // Match keystrokes
1424 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1425 if node.context.is_some() {
1426 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1427 if let Some(found) = self
1428 .window
1429 .current_frame
1430 .dispatch_tree
1431 .dispatch_key(&key_down_event.keystroke, &context_stack)
1432 {
1433 actions.push(found.boxed_clone())
1434 }
1435 }
1436
1437 context_stack.pop();
1438 }
1439 }
1440
1441 for action in actions {
1442 self.dispatch_action_on_node(node_id, action);
1443 if !self.propagate_event {
1444 return;
1445 }
1446 }
1447 }
1448
1449 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1450 let dispatch_path = self
1451 .window
1452 .current_frame
1453 .dispatch_tree
1454 .dispatch_path(node_id);
1455
1456 // Capture phase
1457 for node_id in &dispatch_path {
1458 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1459 for DispatchActionListener {
1460 action_type,
1461 listener,
1462 } in node.action_listeners.clone()
1463 {
1464 let any_action = action.as_any();
1465 if action_type == any_action.type_id() {
1466 listener(any_action, DispatchPhase::Capture, self);
1467 if !self.propagate_event {
1468 return;
1469 }
1470 }
1471 }
1472 }
1473 // Bubble phase
1474 for node_id in dispatch_path.iter().rev() {
1475 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1476 for DispatchActionListener {
1477 action_type,
1478 listener,
1479 } in node.action_listeners.clone()
1480 {
1481 let any_action = action.as_any();
1482 if action_type == any_action.type_id() {
1483 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1484 listener(any_action, DispatchPhase::Bubble, self);
1485 if !self.propagate_event {
1486 return;
1487 }
1488 }
1489 }
1490 }
1491 }
1492
1493 /// Register the given handler to be invoked whenever the global of the given type
1494 /// is updated.
1495 pub fn observe_global<G: 'static>(
1496 &mut self,
1497 f: impl Fn(&mut WindowContext<'_>) + 'static,
1498 ) -> Subscription {
1499 let window_handle = self.window.handle;
1500 let (subscription, activate) = self.global_observers.insert(
1501 TypeId::of::<G>(),
1502 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1503 );
1504 self.app.defer(move |_| activate());
1505 subscription
1506 }
1507
1508 pub fn activate_window(&self) {
1509 self.window.platform_window.activate();
1510 }
1511
1512 pub fn minimize_window(&self) {
1513 self.window.platform_window.minimize();
1514 }
1515
1516 pub fn toggle_full_screen(&self) {
1517 self.window.platform_window.toggle_full_screen();
1518 }
1519
1520 pub fn prompt(
1521 &self,
1522 level: PromptLevel,
1523 msg: &str,
1524 answers: &[&str],
1525 ) -> oneshot::Receiver<usize> {
1526 self.window.platform_window.prompt(level, msg, answers)
1527 }
1528
1529 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1530 let node_id = self
1531 .window
1532 .focus
1533 .and_then(|focus_id| {
1534 self.window
1535 .current_frame
1536 .dispatch_tree
1537 .focusable_node_id(focus_id)
1538 })
1539 .unwrap_or_else(|| self.window.current_frame.dispatch_tree.root_node_id());
1540
1541 self.window
1542 .current_frame
1543 .dispatch_tree
1544 .available_actions(node_id)
1545 }
1546
1547 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1548 self.window
1549 .previous_frame
1550 .dispatch_tree
1551 .bindings_for_action(
1552 action,
1553 &self.window.previous_frame.dispatch_tree.context_stack,
1554 )
1555 }
1556
1557 pub fn bindings_for_action_in(
1558 &self,
1559 action: &dyn Action,
1560 focus_handle: &FocusHandle,
1561 ) -> Vec<KeyBinding> {
1562 let dispatch_tree = &self.window.previous_frame.dispatch_tree;
1563
1564 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1565 return vec![];
1566 };
1567 let context_stack = dispatch_tree
1568 .dispatch_path(node_id)
1569 .into_iter()
1570 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1571 .collect();
1572 dispatch_tree.bindings_for_action(action, &context_stack)
1573 }
1574
1575 pub fn listener_for<V: Render, E>(
1576 &self,
1577 view: &View<V>,
1578 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1579 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1580 let view = view.downgrade();
1581 move |e: &E, cx: &mut WindowContext| {
1582 view.update(cx, |view, cx| f(view, e, cx)).ok();
1583 }
1584 }
1585
1586 pub fn handler_for<V: Render>(
1587 &self,
1588 view: &View<V>,
1589 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1590 ) -> impl Fn(&mut WindowContext) {
1591 let view = view.downgrade();
1592 move |cx: &mut WindowContext| {
1593 view.update(cx, |view, cx| f(view, cx)).ok();
1594 }
1595 }
1596
1597 //========== ELEMENT RELATED FUNCTIONS ===========
1598 pub fn with_key_dispatch<R>(
1599 &mut self,
1600 context: Option<KeyContext>,
1601 focus_handle: Option<FocusHandle>,
1602 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1603 ) -> R {
1604 let window = &mut self.window;
1605 window
1606 .current_frame
1607 .dispatch_tree
1608 .push_node(context.clone());
1609 if let Some(focus_handle) = focus_handle.as_ref() {
1610 window
1611 .current_frame
1612 .dispatch_tree
1613 .make_focusable(focus_handle.id);
1614 }
1615 let result = f(focus_handle, self);
1616
1617 self.window.current_frame.dispatch_tree.pop_node();
1618
1619 result
1620 }
1621
1622 /// Register a focus listener for the current frame only. It will be cleared
1623 /// on the next frame render. You should use this method only from within elements,
1624 /// and we may want to enforce that better via a different context type.
1625 // todo!() Move this to `FrameContext` to emphasize its individuality?
1626 pub fn on_focus_changed(
1627 &mut self,
1628 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1629 ) {
1630 self.window
1631 .current_frame
1632 .focus_listeners
1633 .push(Box::new(move |event, cx| {
1634 listener(event, cx);
1635 }));
1636 }
1637
1638 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1639 /// platform to receive textual input with proper integration with concerns such
1640 /// as IME interactions.
1641 pub fn handle_input(
1642 &mut self,
1643 focus_handle: &FocusHandle,
1644 input_handler: impl PlatformInputHandler,
1645 ) {
1646 if focus_handle.is_focused(self) {
1647 self.window
1648 .platform_window
1649 .set_input_handler(Box::new(input_handler));
1650 }
1651 }
1652
1653 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1654 let mut this = self.to_async();
1655 self.window
1656 .platform_window
1657 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1658 }
1659}
1660
1661impl Context for WindowContext<'_> {
1662 type Result<T> = T;
1663
1664 fn build_model<T>(
1665 &mut self,
1666 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1667 ) -> Model<T>
1668 where
1669 T: 'static,
1670 {
1671 let slot = self.app.entities.reserve();
1672 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1673 self.entities.insert(slot, model)
1674 }
1675
1676 fn update_model<T: 'static, R>(
1677 &mut self,
1678 model: &Model<T>,
1679 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1680 ) -> R {
1681 let mut entity = self.entities.lease(model);
1682 let result = update(
1683 &mut *entity,
1684 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1685 );
1686 self.entities.end_lease(entity);
1687 result
1688 }
1689
1690 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1691 where
1692 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1693 {
1694 if window == self.window.handle {
1695 let root_view = self.window.root_view.clone().unwrap();
1696 Ok(update(root_view, self))
1697 } else {
1698 window.update(self.app, update)
1699 }
1700 }
1701
1702 fn read_model<T, R>(
1703 &self,
1704 handle: &Model<T>,
1705 read: impl FnOnce(&T, &AppContext) -> R,
1706 ) -> Self::Result<R>
1707 where
1708 T: 'static,
1709 {
1710 let entity = self.entities.read(handle);
1711 read(&*entity, &*self.app)
1712 }
1713
1714 fn read_window<T, R>(
1715 &self,
1716 window: &WindowHandle<T>,
1717 read: impl FnOnce(View<T>, &AppContext) -> R,
1718 ) -> Result<R>
1719 where
1720 T: 'static,
1721 {
1722 if window.any_handle == self.window.handle {
1723 let root_view = self
1724 .window
1725 .root_view
1726 .clone()
1727 .unwrap()
1728 .downcast::<T>()
1729 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1730 Ok(read(root_view, self))
1731 } else {
1732 self.app.read_window(window, read)
1733 }
1734 }
1735}
1736
1737impl VisualContext for WindowContext<'_> {
1738 fn build_view<V>(
1739 &mut self,
1740 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1741 ) -> Self::Result<View<V>>
1742 where
1743 V: 'static + Render,
1744 {
1745 let slot = self.app.entities.reserve();
1746 let view = View {
1747 model: slot.clone(),
1748 };
1749 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1750 let entity = build_view_state(&mut cx);
1751 cx.entities.insert(slot, entity);
1752
1753 cx.new_view_observers
1754 .clone()
1755 .retain(&TypeId::of::<V>(), |observer| {
1756 let any_view = AnyView::from(view.clone());
1757 (observer)(any_view, self);
1758 true
1759 });
1760
1761 view
1762 }
1763
1764 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1765 fn update_view<T: 'static, R>(
1766 &mut self,
1767 view: &View<T>,
1768 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1769 ) -> Self::Result<R> {
1770 let mut lease = self.app.entities.lease(&view.model);
1771 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1772 let result = update(&mut *lease, &mut cx);
1773 cx.app.entities.end_lease(lease);
1774 result
1775 }
1776
1777 fn replace_root_view<V>(
1778 &mut self,
1779 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1780 ) -> Self::Result<View<V>>
1781 where
1782 V: 'static + Render,
1783 {
1784 let slot = self.app.entities.reserve();
1785 let view = View {
1786 model: slot.clone(),
1787 };
1788 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1789 let entity = build_view(&mut cx);
1790 self.entities.insert(slot, entity);
1791 self.window.root_view = Some(view.clone().into());
1792 view
1793 }
1794
1795 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1796 self.update_view(view, |view, cx| {
1797 view.focus_handle(cx).clone().focus(cx);
1798 })
1799 }
1800
1801 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1802 where
1803 V: ManagedView,
1804 {
1805 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1806 }
1807}
1808
1809impl<'a> std::ops::Deref for WindowContext<'a> {
1810 type Target = AppContext;
1811
1812 fn deref(&self) -> &Self::Target {
1813 &self.app
1814 }
1815}
1816
1817impl<'a> std::ops::DerefMut for WindowContext<'a> {
1818 fn deref_mut(&mut self) -> &mut Self::Target {
1819 &mut self.app
1820 }
1821}
1822
1823impl<'a> Borrow<AppContext> for WindowContext<'a> {
1824 fn borrow(&self) -> &AppContext {
1825 &self.app
1826 }
1827}
1828
1829impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1830 fn borrow_mut(&mut self) -> &mut AppContext {
1831 &mut self.app
1832 }
1833}
1834
1835pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1836 fn app_mut(&mut self) -> &mut AppContext {
1837 self.borrow_mut()
1838 }
1839
1840 fn app(&self) -> &AppContext {
1841 self.borrow()
1842 }
1843
1844 fn window(&self) -> &Window {
1845 self.borrow()
1846 }
1847
1848 fn window_mut(&mut self) -> &mut Window {
1849 self.borrow_mut()
1850 }
1851
1852 /// Pushes the given element id onto the global stack and invokes the given closure
1853 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1854 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1855 /// used to associate state with identified elements across separate frames.
1856 fn with_element_id<R>(
1857 &mut self,
1858 id: Option<impl Into<ElementId>>,
1859 f: impl FnOnce(&mut Self) -> R,
1860 ) -> R {
1861 if let Some(id) = id.map(Into::into) {
1862 let window = self.window_mut();
1863 window.element_id_stack.push(id.into());
1864 let result = f(self);
1865 let window: &mut Window = self.borrow_mut();
1866 window.element_id_stack.pop();
1867 result
1868 } else {
1869 f(self)
1870 }
1871 }
1872
1873 /// Invoke the given function with the given content mask after intersecting it
1874 /// with the current mask.
1875 fn with_content_mask<R>(
1876 &mut self,
1877 mask: Option<ContentMask<Pixels>>,
1878 f: impl FnOnce(&mut Self) -> R,
1879 ) -> R {
1880 if let Some(mask) = mask {
1881 let mask = mask.intersect(&self.content_mask());
1882 self.window_mut()
1883 .current_frame
1884 .content_mask_stack
1885 .push(mask);
1886 let result = f(self);
1887 self.window_mut().current_frame.content_mask_stack.pop();
1888 result
1889 } else {
1890 f(self)
1891 }
1892 }
1893
1894 /// Invoke the given function with the content mask reset to that
1895 /// of the window.
1896 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1897 let mask = ContentMask {
1898 bounds: Bounds {
1899 origin: Point::default(),
1900 size: self.window().viewport_size,
1901 },
1902 };
1903 self.window_mut()
1904 .current_frame
1905 .content_mask_stack
1906 .push(mask);
1907 let result = f(self);
1908 self.window_mut().current_frame.content_mask_stack.pop();
1909 result
1910 }
1911
1912 /// Update the global element offset relative to the current offset. This is used to implement
1913 /// scrolling.
1914 fn with_element_offset<R>(
1915 &mut self,
1916 offset: Point<Pixels>,
1917 f: impl FnOnce(&mut Self) -> R,
1918 ) -> R {
1919 if offset.is_zero() {
1920 return f(self);
1921 };
1922
1923 let abs_offset = self.element_offset() + offset;
1924 self.with_absolute_element_offset(abs_offset, f)
1925 }
1926
1927 /// Update the global element offset based on the given offset. This is used to implement
1928 /// drag handles and other manual painting of elements.
1929 fn with_absolute_element_offset<R>(
1930 &mut self,
1931 offset: Point<Pixels>,
1932 f: impl FnOnce(&mut Self) -> R,
1933 ) -> R {
1934 self.window_mut()
1935 .current_frame
1936 .element_offset_stack
1937 .push(offset);
1938 let result = f(self);
1939 self.window_mut().current_frame.element_offset_stack.pop();
1940 result
1941 }
1942
1943 /// Obtain the current element offset.
1944 fn element_offset(&self) -> Point<Pixels> {
1945 self.window()
1946 .current_frame
1947 .element_offset_stack
1948 .last()
1949 .copied()
1950 .unwrap_or_default()
1951 }
1952
1953 /// Update or intialize state for an element with the given id that lives across multiple
1954 /// frames. If an element with this id existed in the previous frame, its state will be passed
1955 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1956 /// when drawing the next frame.
1957 fn with_element_state<S, R>(
1958 &mut self,
1959 id: ElementId,
1960 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1961 ) -> R
1962 where
1963 S: 'static,
1964 {
1965 self.with_element_id(Some(id), |cx| {
1966 let global_id = cx.window().element_id_stack.clone();
1967
1968 if let Some(any) = cx
1969 .window_mut()
1970 .current_frame
1971 .element_states
1972 .remove(&global_id)
1973 .or_else(|| {
1974 cx.window_mut()
1975 .previous_frame
1976 .element_states
1977 .remove(&global_id)
1978 })
1979 {
1980 let ElementStateBox {
1981 inner,
1982
1983 #[cfg(debug_assertions)]
1984 type_name
1985 } = any;
1986 // Using the extra inner option to avoid needing to reallocate a new box.
1987 let mut state_box = inner
1988 .downcast::<Option<S>>()
1989 .map_err(|_| {
1990 #[cfg(debug_assertions)]
1991 {
1992 anyhow!(
1993 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1994 std::any::type_name::<S>(),
1995 type_name
1996 )
1997 }
1998
1999 #[cfg(not(debug_assertions))]
2000 {
2001 anyhow!(
2002 "invalid element state type for id, requested_type {:?}",
2003 std::any::type_name::<S>(),
2004 )
2005 }
2006 })
2007 .unwrap();
2008
2009 // Actual: Option<AnyElement> <- View
2010 // Requested: () <- AnyElemet
2011 let state = state_box
2012 .take()
2013 .expect("element state is already on the stack");
2014 let (result, state) = f(Some(state), cx);
2015 state_box.replace(state);
2016 cx.window_mut()
2017 .current_frame
2018 .element_states
2019 .insert(global_id, ElementStateBox {
2020 inner: state_box,
2021
2022 #[cfg(debug_assertions)]
2023 type_name
2024 });
2025 result
2026 } else {
2027 let (result, state) = f(None, cx);
2028 cx.window_mut()
2029 .current_frame
2030 .element_states
2031 .insert(global_id,
2032 ElementStateBox {
2033 inner: Box::new(Some(state)),
2034
2035 #[cfg(debug_assertions)]
2036 type_name: std::any::type_name::<S>()
2037 }
2038
2039 );
2040 result
2041 }
2042 })
2043 }
2044
2045 /// Obtain the current content mask.
2046 fn content_mask(&self) -> ContentMask<Pixels> {
2047 self.window()
2048 .current_frame
2049 .content_mask_stack
2050 .last()
2051 .cloned()
2052 .unwrap_or_else(|| ContentMask {
2053 bounds: Bounds {
2054 origin: Point::default(),
2055 size: self.window().viewport_size,
2056 },
2057 })
2058 }
2059
2060 /// The size of an em for the base font of the application. Adjusting this value allows the
2061 /// UI to scale, just like zooming a web page.
2062 fn rem_size(&self) -> Pixels {
2063 self.window().rem_size
2064 }
2065}
2066
2067impl Borrow<Window> for WindowContext<'_> {
2068 fn borrow(&self) -> &Window {
2069 &self.window
2070 }
2071}
2072
2073impl BorrowMut<Window> for WindowContext<'_> {
2074 fn borrow_mut(&mut self) -> &mut Window {
2075 &mut self.window
2076 }
2077}
2078
2079impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
2080
2081pub struct ViewContext<'a, V> {
2082 window_cx: WindowContext<'a>,
2083 view: &'a View<V>,
2084}
2085
2086impl<V> Borrow<AppContext> for ViewContext<'_, V> {
2087 fn borrow(&self) -> &AppContext {
2088 &*self.window_cx.app
2089 }
2090}
2091
2092impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
2093 fn borrow_mut(&mut self) -> &mut AppContext {
2094 &mut *self.window_cx.app
2095 }
2096}
2097
2098impl<V> Borrow<Window> for ViewContext<'_, V> {
2099 fn borrow(&self) -> &Window {
2100 &*self.window_cx.window
2101 }
2102}
2103
2104impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2105 fn borrow_mut(&mut self) -> &mut Window {
2106 &mut *self.window_cx.window
2107 }
2108}
2109
2110impl<'a, V: 'static> ViewContext<'a, V> {
2111 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2112 Self {
2113 window_cx: WindowContext::new(app, window),
2114 view,
2115 }
2116 }
2117
2118 pub fn entity_id(&self) -> EntityId {
2119 self.view.entity_id()
2120 }
2121
2122 pub fn view(&self) -> &View<V> {
2123 self.view
2124 }
2125
2126 pub fn model(&self) -> &Model<V> {
2127 &self.view.model
2128 }
2129
2130 /// Access the underlying window context.
2131 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2132 &mut self.window_cx
2133 }
2134
2135 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2136 self.window.current_frame.z_index_stack.push(z_index);
2137 let result = f(self);
2138 self.window.current_frame.z_index_stack.pop();
2139 result
2140 }
2141
2142 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2143 where
2144 V: 'static,
2145 {
2146 let view = self.view().clone();
2147 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2148 }
2149
2150 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2151 /// that are currently on the stack to be returned to the app.
2152 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2153 let view = self.view().downgrade();
2154 self.window_cx.defer(move |cx| {
2155 view.update(cx, f).ok();
2156 });
2157 }
2158
2159 pub fn observe<V2, E>(
2160 &mut self,
2161 entity: &E,
2162 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2163 ) -> Subscription
2164 where
2165 V2: 'static,
2166 V: 'static,
2167 E: Entity<V2>,
2168 {
2169 let view = self.view().downgrade();
2170 let entity_id = entity.entity_id();
2171 let entity = entity.downgrade();
2172 let window_handle = self.window.handle;
2173 let (subscription, activate) = self.app.observers.insert(
2174 entity_id,
2175 Box::new(move |cx| {
2176 window_handle
2177 .update(cx, |_, cx| {
2178 if let Some(handle) = E::upgrade_from(&entity) {
2179 view.update(cx, |this, cx| on_notify(this, handle, cx))
2180 .is_ok()
2181 } else {
2182 false
2183 }
2184 })
2185 .unwrap_or(false)
2186 }),
2187 );
2188 self.app.defer(move |_| activate());
2189 subscription
2190 }
2191
2192 pub fn subscribe<V2, E, Evt>(
2193 &mut self,
2194 entity: &E,
2195 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2196 ) -> Subscription
2197 where
2198 V2: EventEmitter<Evt>,
2199 E: Entity<V2>,
2200 Evt: 'static,
2201 {
2202 let view = self.view().downgrade();
2203 let entity_id = entity.entity_id();
2204 let handle = entity.downgrade();
2205 let window_handle = self.window.handle;
2206 let (subscription, activate) = self.app.event_listeners.insert(
2207 entity_id,
2208 (
2209 TypeId::of::<Evt>(),
2210 Box::new(move |event, cx| {
2211 window_handle
2212 .update(cx, |_, cx| {
2213 if let Some(handle) = E::upgrade_from(&handle) {
2214 let event = event.downcast_ref().expect("invalid event type");
2215 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2216 .is_ok()
2217 } else {
2218 false
2219 }
2220 })
2221 .unwrap_or(false)
2222 }),
2223 ),
2224 );
2225 self.app.defer(move |_| activate());
2226 subscription
2227 }
2228
2229 pub fn on_release(
2230 &mut self,
2231 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2232 ) -> Subscription {
2233 let window_handle = self.window.handle;
2234 let (subscription, activate) = self.app.release_listeners.insert(
2235 self.view.model.entity_id,
2236 Box::new(move |this, cx| {
2237 let this = this.downcast_mut().expect("invalid entity type");
2238 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2239 }),
2240 );
2241 activate();
2242 subscription
2243 }
2244
2245 pub fn observe_release<V2, E>(
2246 &mut self,
2247 entity: &E,
2248 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2249 ) -> Subscription
2250 where
2251 V: 'static,
2252 V2: 'static,
2253 E: Entity<V2>,
2254 {
2255 let view = self.view().downgrade();
2256 let entity_id = entity.entity_id();
2257 let window_handle = self.window.handle;
2258 let (subscription, activate) = self.app.release_listeners.insert(
2259 entity_id,
2260 Box::new(move |entity, cx| {
2261 let entity = entity.downcast_mut().expect("invalid entity type");
2262 let _ = window_handle.update(cx, |_, cx| {
2263 view.update(cx, |this, cx| on_release(this, entity, cx))
2264 });
2265 }),
2266 );
2267 activate();
2268 subscription
2269 }
2270
2271 pub fn notify(&mut self) {
2272 self.window_cx.notify();
2273 self.window_cx.app.push_effect(Effect::Notify {
2274 emitter: self.view.model.entity_id,
2275 });
2276 }
2277
2278 pub fn observe_window_bounds(
2279 &mut self,
2280 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2281 ) -> Subscription {
2282 let view = self.view.downgrade();
2283 let (subscription, activate) = self.window.bounds_observers.insert(
2284 (),
2285 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2286 );
2287 activate();
2288 subscription
2289 }
2290
2291 pub fn observe_window_activation(
2292 &mut self,
2293 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2294 ) -> Subscription {
2295 let view = self.view.downgrade();
2296 let (subscription, activate) = self.window.activation_observers.insert(
2297 (),
2298 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2299 );
2300 activate();
2301 subscription
2302 }
2303
2304 /// Register a listener to be called when the given focus handle receives focus.
2305 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2306 /// is dropped.
2307 pub fn on_focus(
2308 &mut self,
2309 handle: &FocusHandle,
2310 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2311 ) -> Subscription {
2312 let view = self.view.downgrade();
2313 let focus_id = handle.id;
2314 let (subscription, activate) = self.window.focus_listeners.insert(
2315 (),
2316 Box::new(move |event, cx| {
2317 view.update(cx, |view, cx| {
2318 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2319 listener(view, cx)
2320 }
2321 })
2322 .is_ok()
2323 }),
2324 );
2325 self.app.defer(move |_| activate());
2326 subscription
2327 }
2328
2329 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2330 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2331 /// is dropped.
2332 pub fn on_focus_in(
2333 &mut self,
2334 handle: &FocusHandle,
2335 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2336 ) -> Subscription {
2337 let view = self.view.downgrade();
2338 let focus_id = handle.id;
2339 let (subscription, activate) = self.window.focus_listeners.insert(
2340 (),
2341 Box::new(move |event, cx| {
2342 view.update(cx, |view, cx| {
2343 if event
2344 .focused
2345 .as_ref()
2346 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2347 {
2348 listener(view, cx)
2349 }
2350 })
2351 .is_ok()
2352 }),
2353 );
2354 self.app.defer(move |_| activate());
2355 subscription
2356 }
2357
2358 /// Register a listener to be called when the given focus handle loses focus.
2359 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2360 /// is dropped.
2361 pub fn on_blur(
2362 &mut self,
2363 handle: &FocusHandle,
2364 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2365 ) -> Subscription {
2366 let view = self.view.downgrade();
2367 let focus_id = handle.id;
2368 let (subscription, activate) = self.window.focus_listeners.insert(
2369 (),
2370 Box::new(move |event, cx| {
2371 view.update(cx, |view, cx| {
2372 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2373 listener(view, cx)
2374 }
2375 })
2376 .is_ok()
2377 }),
2378 );
2379 self.app.defer(move |_| activate());
2380 subscription
2381 }
2382
2383 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2384 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2385 /// is dropped.
2386 pub fn on_focus_out(
2387 &mut self,
2388 handle: &FocusHandle,
2389 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2390 ) -> Subscription {
2391 let view = self.view.downgrade();
2392 let focus_id = handle.id;
2393 let (subscription, activate) = self.window.focus_listeners.insert(
2394 (),
2395 Box::new(move |event, cx| {
2396 view.update(cx, |view, cx| {
2397 if event
2398 .blurred
2399 .as_ref()
2400 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2401 {
2402 listener(view, cx)
2403 }
2404 })
2405 .is_ok()
2406 }),
2407 );
2408 self.app.defer(move |_| activate());
2409 subscription
2410 }
2411
2412 pub fn spawn<Fut, R>(
2413 &mut self,
2414 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2415 ) -> Task<R>
2416 where
2417 R: 'static,
2418 Fut: Future<Output = R> + 'static,
2419 {
2420 let view = self.view().downgrade();
2421 self.window_cx.spawn(|cx| f(view, cx))
2422 }
2423
2424 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2425 where
2426 G: 'static,
2427 {
2428 let mut global = self.app.lease_global::<G>();
2429 let result = f(&mut global, self);
2430 self.app.end_global_lease(global);
2431 result
2432 }
2433
2434 pub fn observe_global<G: 'static>(
2435 &mut self,
2436 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2437 ) -> Subscription {
2438 let window_handle = self.window.handle;
2439 let view = self.view().downgrade();
2440 let (subscription, activate) = self.global_observers.insert(
2441 TypeId::of::<G>(),
2442 Box::new(move |cx| {
2443 window_handle
2444 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2445 .unwrap_or(false)
2446 }),
2447 );
2448 self.app.defer(move |_| activate());
2449 subscription
2450 }
2451
2452 pub fn on_mouse_event<Event: 'static>(
2453 &mut self,
2454 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2455 ) {
2456 let handle = self.view().clone();
2457 self.window_cx.on_mouse_event(move |event, phase, cx| {
2458 handle.update(cx, |view, cx| {
2459 handler(view, event, phase, cx);
2460 })
2461 });
2462 }
2463
2464 pub fn on_key_event<Event: 'static>(
2465 &mut self,
2466 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2467 ) {
2468 let handle = self.view().clone();
2469 self.window_cx.on_key_event(move |event, phase, cx| {
2470 handle.update(cx, |view, cx| {
2471 handler(view, event, phase, cx);
2472 })
2473 });
2474 }
2475
2476 pub fn on_action(
2477 &mut self,
2478 action_type: TypeId,
2479 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2480 ) {
2481 let handle = self.view().clone();
2482 self.window_cx
2483 .on_action(action_type, move |action, phase, cx| {
2484 handle.update(cx, |view, cx| {
2485 handler(view, action, phase, cx);
2486 })
2487 });
2488 }
2489
2490 pub fn emit<Evt>(&mut self, event: Evt)
2491 where
2492 Evt: 'static,
2493 V: EventEmitter<Evt>,
2494 {
2495 let emitter = self.view.model.entity_id;
2496 self.app.push_effect(Effect::Emit {
2497 emitter,
2498 event_type: TypeId::of::<Evt>(),
2499 event: Box::new(event),
2500 });
2501 }
2502
2503 pub fn focus_self(&mut self)
2504 where
2505 V: FocusableView,
2506 {
2507 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2508 }
2509
2510 pub fn dismiss_self(&mut self)
2511 where
2512 V: ManagedView,
2513 {
2514 self.defer(|_, cx| cx.emit(DismissEvent))
2515 }
2516
2517 pub fn listener<E>(
2518 &self,
2519 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2520 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2521 let view = self.view().downgrade();
2522 move |e: &E, cx: &mut WindowContext| {
2523 view.update(cx, |view, cx| f(view, e, cx)).ok();
2524 }
2525 }
2526}
2527
2528impl<V> Context for ViewContext<'_, V> {
2529 type Result<U> = U;
2530
2531 fn build_model<T: 'static>(
2532 &mut self,
2533 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2534 ) -> Model<T> {
2535 self.window_cx.build_model(build_model)
2536 }
2537
2538 fn update_model<T: 'static, R>(
2539 &mut self,
2540 model: &Model<T>,
2541 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2542 ) -> R {
2543 self.window_cx.update_model(model, update)
2544 }
2545
2546 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2547 where
2548 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2549 {
2550 self.window_cx.update_window(window, update)
2551 }
2552
2553 fn read_model<T, R>(
2554 &self,
2555 handle: &Model<T>,
2556 read: impl FnOnce(&T, &AppContext) -> R,
2557 ) -> Self::Result<R>
2558 where
2559 T: 'static,
2560 {
2561 self.window_cx.read_model(handle, read)
2562 }
2563
2564 fn read_window<T, R>(
2565 &self,
2566 window: &WindowHandle<T>,
2567 read: impl FnOnce(View<T>, &AppContext) -> R,
2568 ) -> Result<R>
2569 where
2570 T: 'static,
2571 {
2572 self.window_cx.read_window(window, read)
2573 }
2574}
2575
2576impl<V: 'static> VisualContext for ViewContext<'_, V> {
2577 fn build_view<W: Render + 'static>(
2578 &mut self,
2579 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2580 ) -> Self::Result<View<W>> {
2581 self.window_cx.build_view(build_view_state)
2582 }
2583
2584 fn update_view<V2: 'static, R>(
2585 &mut self,
2586 view: &View<V2>,
2587 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2588 ) -> Self::Result<R> {
2589 self.window_cx.update_view(view, update)
2590 }
2591
2592 fn replace_root_view<W>(
2593 &mut self,
2594 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2595 ) -> Self::Result<View<W>>
2596 where
2597 W: 'static + Render,
2598 {
2599 self.window_cx.replace_root_view(build_view)
2600 }
2601
2602 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2603 self.window_cx.focus_view(view)
2604 }
2605
2606 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2607 self.window_cx.dismiss_view(view)
2608 }
2609}
2610
2611impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2612 type Target = WindowContext<'a>;
2613
2614 fn deref(&self) -> &Self::Target {
2615 &self.window_cx
2616 }
2617}
2618
2619impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2620 fn deref_mut(&mut self) -> &mut Self::Target {
2621 &mut self.window_cx
2622 }
2623}
2624
2625// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2626slotmap::new_key_type! { pub struct WindowId; }
2627
2628impl WindowId {
2629 pub fn as_u64(&self) -> u64 {
2630 self.0.as_ffi()
2631 }
2632}
2633
2634#[derive(Deref, DerefMut)]
2635pub struct WindowHandle<V> {
2636 #[deref]
2637 #[deref_mut]
2638 pub(crate) any_handle: AnyWindowHandle,
2639 state_type: PhantomData<V>,
2640}
2641
2642impl<V: 'static + Render> WindowHandle<V> {
2643 pub fn new(id: WindowId) -> Self {
2644 WindowHandle {
2645 any_handle: AnyWindowHandle {
2646 id,
2647 state_type: TypeId::of::<V>(),
2648 },
2649 state_type: PhantomData,
2650 }
2651 }
2652
2653 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2654 where
2655 C: Context,
2656 {
2657 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2658 root_view
2659 .downcast::<V>()
2660 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2661 }))
2662 }
2663
2664 pub fn update<C, R>(
2665 &self,
2666 cx: &mut C,
2667 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2668 ) -> Result<R>
2669 where
2670 C: Context,
2671 {
2672 cx.update_window(self.any_handle, |root_view, cx| {
2673 let view = root_view
2674 .downcast::<V>()
2675 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2676 Ok(cx.update_view(&view, update))
2677 })?
2678 }
2679
2680 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2681 let x = cx
2682 .windows
2683 .get(self.id)
2684 .and_then(|window| {
2685 window
2686 .as_ref()
2687 .and_then(|window| window.root_view.clone())
2688 .map(|root_view| root_view.downcast::<V>())
2689 })
2690 .ok_or_else(|| anyhow!("window not found"))?
2691 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2692
2693 Ok(x.read(cx))
2694 }
2695
2696 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2697 where
2698 C: Context,
2699 {
2700 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2701 }
2702
2703 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2704 where
2705 C: Context,
2706 {
2707 cx.read_window(self, |root_view, _cx| root_view.clone())
2708 }
2709
2710 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2711 cx.windows
2712 .get(self.id)
2713 .and_then(|window| window.as_ref().map(|window| window.active))
2714 }
2715}
2716
2717impl<V> Copy for WindowHandle<V> {}
2718
2719impl<V> Clone for WindowHandle<V> {
2720 fn clone(&self) -> Self {
2721 WindowHandle {
2722 any_handle: self.any_handle,
2723 state_type: PhantomData,
2724 }
2725 }
2726}
2727
2728impl<V> PartialEq for WindowHandle<V> {
2729 fn eq(&self, other: &Self) -> bool {
2730 self.any_handle == other.any_handle
2731 }
2732}
2733
2734impl<V> Eq for WindowHandle<V> {}
2735
2736impl<V> Hash for WindowHandle<V> {
2737 fn hash<H: Hasher>(&self, state: &mut H) {
2738 self.any_handle.hash(state);
2739 }
2740}
2741
2742impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2743 fn into(self) -> AnyWindowHandle {
2744 self.any_handle
2745 }
2746}
2747
2748#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2749pub struct AnyWindowHandle {
2750 pub(crate) id: WindowId,
2751 state_type: TypeId,
2752}
2753
2754impl AnyWindowHandle {
2755 pub fn window_id(&self) -> WindowId {
2756 self.id
2757 }
2758
2759 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2760 if TypeId::of::<T>() == self.state_type {
2761 Some(WindowHandle {
2762 any_handle: *self,
2763 state_type: PhantomData,
2764 })
2765 } else {
2766 None
2767 }
2768 }
2769
2770 pub fn update<C, R>(
2771 self,
2772 cx: &mut C,
2773 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2774 ) -> Result<R>
2775 where
2776 C: Context,
2777 {
2778 cx.update_window(self, update)
2779 }
2780
2781 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2782 where
2783 C: Context,
2784 T: 'static,
2785 {
2786 let view = self
2787 .downcast::<T>()
2788 .context("the type of the window's root view has changed")?;
2789
2790 cx.read_window(&view, read)
2791 }
2792}
2793
2794#[cfg(any(test, feature = "test-support"))]
2795impl From<SmallVec<[u32; 16]>> for StackingOrder {
2796 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2797 StackingOrder(small_vec)
2798 }
2799}
2800
2801#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2802pub enum ElementId {
2803 View(EntityId),
2804 Integer(usize),
2805 Name(SharedString),
2806 FocusHandle(FocusId),
2807 NamedInteger(SharedString, usize),
2808}
2809
2810impl ElementId {
2811 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2812 ElementId::View(entity_id)
2813 }
2814}
2815
2816impl TryInto<SharedString> for ElementId {
2817 type Error = anyhow::Error;
2818
2819 fn try_into(self) -> anyhow::Result<SharedString> {
2820 if let ElementId::Name(name) = self {
2821 Ok(name)
2822 } else {
2823 Err(anyhow!("element id is not string"))
2824 }
2825 }
2826}
2827
2828impl From<usize> for ElementId {
2829 fn from(id: usize) -> Self {
2830 ElementId::Integer(id)
2831 }
2832}
2833
2834impl From<i32> for ElementId {
2835 fn from(id: i32) -> Self {
2836 Self::Integer(id as usize)
2837 }
2838}
2839
2840impl From<SharedString> for ElementId {
2841 fn from(name: SharedString) -> Self {
2842 ElementId::Name(name)
2843 }
2844}
2845
2846impl From<&'static str> for ElementId {
2847 fn from(name: &'static str) -> Self {
2848 ElementId::Name(name.into())
2849 }
2850}
2851
2852impl<'a> From<&'a FocusHandle> for ElementId {
2853 fn from(handle: &'a FocusHandle) -> Self {
2854 ElementId::FocusHandle(handle.id)
2855 }
2856}
2857
2858impl From<(&'static str, EntityId)> for ElementId {
2859 fn from((name, id): (&'static str, EntityId)) -> Self {
2860 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2861 }
2862}
2863
2864impl From<(&'static str, usize)> for ElementId {
2865 fn from((name, id): (&'static str, usize)) -> Self {
2866 ElementId::NamedInteger(name.into(), id)
2867 }
2868}