1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle,
4 DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId,
5 EventEmitter, FileDropEvent, Flatten, FocusEvent, FontId, GlobalElementId, GlyphId, Hsla,
6 ImageData, InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, LayoutId, Model,
7 ModelContext, Modifiers, MonochromeSprite, MouseButton, MouseDownEvent, MouseMoveEvent,
8 MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler,
9 PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams,
10 RenderImageParams, RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size,
11 Style, SubscriberSet, Subscription, Surface, TaffyLayoutEngine, Task, Underline,
12 UnderlineStyle, View, VisualContext, WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Context as _, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use media::core_video::CVImageBuffer;
22use parking_lot::RwLock;
23use slotmap::SlotMap;
24use smallvec::SmallVec;
25use std::{
26 any::{Any, TypeId},
27 borrow::{Borrow, BorrowMut, Cow},
28 fmt::Debug,
29 future::Future,
30 hash::{Hash, Hasher},
31 marker::PhantomData,
32 mem,
33 rc::Rc,
34 sync::{
35 atomic::{AtomicUsize, Ordering::SeqCst},
36 Arc,
37 },
38};
39use util::ResultExt;
40
41/// A global stacking order, which is created by stacking successive z-index values.
42/// Each z-index will always be interpreted in the context of its parent z-index.
43#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default, Debug)]
44pub struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
45
46/// Represents the two different phases when dispatching events.
47#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
48pub enum DispatchPhase {
49 /// After the capture phase comes the bubble phase, in which mouse event listeners are
50 /// invoked front to back and keyboard event listeners are invoked from the focused element
51 /// to the root of the element tree. This is the phase you'll most commonly want to use when
52 /// registering event listeners.
53 #[default]
54 Bubble,
55 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
56 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
57 /// is used for special purposes such as clearing the "pressed" state for click events. If
58 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
59 /// outside of the immediate region may rely on detecting non-local events during this phase.
60 Capture,
61}
62
63type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
64type AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
65type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
66type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
67
68slotmap::new_key_type! { pub struct FocusId; }
69
70impl FocusId {
71 /// Obtains whether the element associated with this handle is currently focused.
72 pub fn is_focused(&self, cx: &WindowContext) -> bool {
73 cx.window.focus == Some(*self)
74 }
75
76 /// Obtains whether the element associated with this handle contains the focused
77 /// element or is itself focused.
78 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
79 cx.focused()
80 .map_or(false, |focused| self.contains(focused.id, cx))
81 }
82
83 /// Obtains whether the element associated with this handle is contained within the
84 /// focused element or is itself focused.
85 pub fn within_focused(&self, cx: &WindowContext) -> bool {
86 let focused = cx.focused();
87 focused.map_or(false, |focused| focused.id.contains(*self, cx))
88 }
89
90 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
91 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
92 cx.window
93 .current_frame
94 .dispatch_tree
95 .focus_contains(*self, other)
96 }
97}
98
99/// A handle which can be used to track and manipulate the focused element in a window.
100pub struct FocusHandle {
101 pub(crate) id: FocusId,
102 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
103}
104
105impl std::fmt::Debug for FocusHandle {
106 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
107 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
108 }
109}
110
111impl FocusHandle {
112 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
113 let id = handles.write().insert(AtomicUsize::new(1));
114 Self {
115 id,
116 handles: handles.clone(),
117 }
118 }
119
120 pub(crate) fn for_id(
121 id: FocusId,
122 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
123 ) -> Option<Self> {
124 let lock = handles.read();
125 let ref_count = lock.get(id)?;
126 if ref_count.load(SeqCst) == 0 {
127 None
128 } else {
129 ref_count.fetch_add(1, SeqCst);
130 Some(Self {
131 id,
132 handles: handles.clone(),
133 })
134 }
135 }
136
137 /// Moves the focus to the element associated with this handle.
138 pub fn focus(&self, cx: &mut WindowContext) {
139 cx.focus(self)
140 }
141
142 /// Obtains whether the element associated with this handle is currently focused.
143 pub fn is_focused(&self, cx: &WindowContext) -> bool {
144 self.id.is_focused(cx)
145 }
146
147 /// Obtains whether the element associated with this handle contains the focused
148 /// element or is itself focused.
149 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
150 self.id.contains_focused(cx)
151 }
152
153 /// Obtains whether the element associated with this handle is contained within the
154 /// focused element or is itself focused.
155 pub fn within_focused(&self, cx: &WindowContext) -> bool {
156 self.id.within_focused(cx)
157 }
158
159 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
160 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
161 self.id.contains(other.id, cx)
162 }
163}
164
165impl Clone for FocusHandle {
166 fn clone(&self) -> Self {
167 Self::for_id(self.id, &self.handles).unwrap()
168 }
169}
170
171impl PartialEq for FocusHandle {
172 fn eq(&self, other: &Self) -> bool {
173 self.id == other.id
174 }
175}
176
177impl Eq for FocusHandle {}
178
179impl Drop for FocusHandle {
180 fn drop(&mut self) {
181 self.handles
182 .read()
183 .get(self.id)
184 .unwrap()
185 .fetch_sub(1, SeqCst);
186 }
187}
188
189/// FocusableView allows users of your view to easily
190/// focus it (using cx.focus_view(view))
191pub trait FocusableView: 'static + Render {
192 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
193}
194
195/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
196/// where the lifecycle of the view is handled by another view.
197pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
198
199impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
200
201pub struct DismissEvent;
202
203// Holds the state for a specific window.
204pub struct Window {
205 pub(crate) handle: AnyWindowHandle,
206 pub(crate) removed: bool,
207 pub(crate) platform_window: Box<dyn PlatformWindow>,
208 display_id: DisplayId,
209 sprite_atlas: Arc<dyn PlatformAtlas>,
210 rem_size: Pixels,
211 viewport_size: Size<Pixels>,
212 layout_engine: Option<TaffyLayoutEngine>,
213 pub(crate) root_view: Option<AnyView>,
214 pub(crate) element_id_stack: GlobalElementId,
215 pub(crate) previous_frame: Frame,
216 pub(crate) current_frame: Frame,
217 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
218 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
219 default_prevented: bool,
220 mouse_position: Point<Pixels>,
221 requested_cursor_style: Option<CursorStyle>,
222 scale_factor: f32,
223 bounds: WindowBounds,
224 bounds_observers: SubscriberSet<(), AnyObserver>,
225 active: bool,
226 activation_observers: SubscriberSet<(), AnyObserver>,
227 pub(crate) dirty: bool,
228 pub(crate) last_blur: Option<Option<FocusId>>,
229 pub(crate) focus: Option<FocusId>,
230}
231
232pub(crate) struct ElementStateBox {
233 inner: Box<dyn Any>,
234 #[cfg(debug_assertions)]
235 type_name: &'static str,
236}
237
238// #[derive(Default)]
239pub(crate) struct Frame {
240 pub(crate) element_states: HashMap<GlobalElementId, ElementStateBox>,
241 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
242 pub(crate) dispatch_tree: DispatchTree,
243 pub(crate) focus_listeners: Vec<AnyFocusListener>,
244 pub(crate) scene_builder: SceneBuilder,
245 pub(crate) depth_map: Vec<(StackingOrder, Bounds<Pixels>)>,
246 pub(crate) z_index_stack: StackingOrder,
247 content_mask_stack: Vec<ContentMask<Pixels>>,
248 element_offset_stack: Vec<Point<Pixels>>,
249}
250
251impl Frame {
252 pub fn new(dispatch_tree: DispatchTree) -> Self {
253 Frame {
254 element_states: HashMap::default(),
255 mouse_listeners: HashMap::default(),
256 dispatch_tree,
257 focus_listeners: Vec::new(),
258 scene_builder: SceneBuilder::default(),
259 z_index_stack: StackingOrder::default(),
260 depth_map: Default::default(),
261 content_mask_stack: Vec::new(),
262 element_offset_stack: Vec::new(),
263 }
264 }
265}
266
267impl Window {
268 pub(crate) fn new(
269 handle: AnyWindowHandle,
270 options: WindowOptions,
271 cx: &mut AppContext,
272 ) -> Self {
273 let platform_window = cx.platform.open_window(handle, options);
274 let display_id = platform_window.display().id();
275 let sprite_atlas = platform_window.sprite_atlas();
276 let mouse_position = platform_window.mouse_position();
277 let content_size = platform_window.content_size();
278 let scale_factor = platform_window.scale_factor();
279 let bounds = platform_window.bounds();
280
281 platform_window.on_resize(Box::new({
282 let mut cx = cx.to_async();
283 move |_, _| {
284 handle
285 .update(&mut cx, |_, cx| cx.window_bounds_changed())
286 .log_err();
287 }
288 }));
289 platform_window.on_moved(Box::new({
290 let mut cx = cx.to_async();
291 move || {
292 handle
293 .update(&mut cx, |_, cx| cx.window_bounds_changed())
294 .log_err();
295 }
296 }));
297 platform_window.on_active_status_change(Box::new({
298 let mut cx = cx.to_async();
299 move |active| {
300 handle
301 .update(&mut cx, |_, cx| {
302 cx.window.active = active;
303 cx.window
304 .activation_observers
305 .clone()
306 .retain(&(), |callback| callback(cx));
307 })
308 .log_err();
309 }
310 }));
311
312 platform_window.on_input({
313 let mut cx = cx.to_async();
314 Box::new(move |event| {
315 handle
316 .update(&mut cx, |_, cx| cx.dispatch_event(event))
317 .log_err()
318 .unwrap_or(false)
319 })
320 });
321
322 Window {
323 handle,
324 removed: false,
325 platform_window,
326 display_id,
327 sprite_atlas,
328 rem_size: px(16.),
329 viewport_size: content_size,
330 layout_engine: Some(TaffyLayoutEngine::new()),
331 root_view: None,
332 element_id_stack: GlobalElementId::default(),
333 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
334 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
335 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
336 focus_listeners: SubscriberSet::new(),
337 default_prevented: true,
338 mouse_position,
339 requested_cursor_style: None,
340 scale_factor,
341 bounds,
342 bounds_observers: SubscriberSet::new(),
343 active: false,
344 activation_observers: SubscriberSet::new(),
345 dirty: true,
346 last_blur: None,
347 focus: None,
348 }
349 }
350}
351
352/// Indicates which region of the window is visible. Content falling outside of this mask will not be
353/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
354/// to leave room to support more complex shapes in the future.
355#[derive(Clone, Debug, Default, PartialEq, Eq)]
356#[repr(C)]
357pub struct ContentMask<P: Clone + Default + Debug> {
358 pub bounds: Bounds<P>,
359}
360
361impl ContentMask<Pixels> {
362 /// Scale the content mask's pixel units by the given scaling factor.
363 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
364 ContentMask {
365 bounds: self.bounds.scale(factor),
366 }
367 }
368
369 /// Intersect the content mask with the given content mask.
370 pub fn intersect(&self, other: &Self) -> Self {
371 let bounds = self.bounds.intersect(&other.bounds);
372 ContentMask { bounds }
373 }
374}
375
376/// Provides access to application state in the context of a single window. Derefs
377/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
378/// an `AppContext` and call any `AppContext` methods.
379pub struct WindowContext<'a> {
380 pub(crate) app: &'a mut AppContext,
381 pub(crate) window: &'a mut Window,
382}
383
384impl<'a> WindowContext<'a> {
385 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
386 Self { app, window }
387 }
388
389 /// Obtain a handle to the window that belongs to this context.
390 pub fn window_handle(&self) -> AnyWindowHandle {
391 self.window.handle
392 }
393
394 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
395 pub fn notify(&mut self) {
396 self.window.dirty = true;
397 }
398
399 /// Close this window.
400 pub fn remove_window(&mut self) {
401 self.window.removed = true;
402 }
403
404 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
405 /// for elements rendered within this window.
406 pub fn focus_handle(&mut self) -> FocusHandle {
407 FocusHandle::new(&self.window.focus_handles)
408 }
409
410 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
411 pub fn focused(&self) -> Option<FocusHandle> {
412 self.window
413 .focus
414 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
415 }
416
417 /// Move focus to the element associated with the given `FocusHandle`.
418 pub fn focus(&mut self, handle: &FocusHandle) {
419 if self.window.focus == Some(handle.id) {
420 return;
421 }
422
423 let focus_id = handle.id;
424
425 if self.window.last_blur.is_none() {
426 self.window.last_blur = Some(self.window.focus);
427 }
428
429 self.window.focus = Some(focus_id);
430 self.window
431 .current_frame
432 .dispatch_tree
433 .clear_keystroke_matchers();
434 self.app.push_effect(Effect::FocusChanged {
435 window_handle: self.window.handle,
436 focused: Some(focus_id),
437 });
438 self.notify();
439 }
440
441 /// Remove focus from all elements within this context's window.
442 pub fn blur(&mut self) {
443 if self.window.last_blur.is_none() {
444 self.window.last_blur = Some(self.window.focus);
445 }
446
447 self.window.focus = None;
448 self.app.push_effect(Effect::FocusChanged {
449 window_handle: self.window.handle,
450 focused: None,
451 });
452 self.notify();
453 }
454
455 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
456 if let Some(focus_handle) = self.focused() {
457 self.defer(move |cx| {
458 if let Some(node_id) = cx
459 .window
460 .current_frame
461 .dispatch_tree
462 .focusable_node_id(focus_handle.id)
463 {
464 cx.propagate_event = true;
465 cx.dispatch_action_on_node(node_id, action);
466 }
467 })
468 }
469 }
470
471 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
472 /// that are currently on the stack to be returned to the app.
473 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
474 let handle = self.window.handle;
475 self.app.defer(move |cx| {
476 handle.update(cx, |_, cx| f(cx)).ok();
477 });
478 }
479
480 pub fn subscribe<Emitter, E, Evt>(
481 &mut self,
482 entity: &E,
483 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
484 ) -> Subscription
485 where
486 Emitter: EventEmitter<Evt>,
487 E: Entity<Emitter>,
488 Evt: 'static,
489 {
490 let entity_id = entity.entity_id();
491 let entity = entity.downgrade();
492 let window_handle = self.window.handle;
493 let (subscription, activate) = 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 self.app.defer(move |_| activate());
513 subscription
514 }
515
516 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
517 /// await points in async code.
518 pub fn to_async(&self) -> AsyncWindowContext {
519 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
520 }
521
522 /// Schedule the given closure to be run directly after the current frame is rendered.
523 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
524 let handle = self.window.handle;
525 let display_id = self.window.display_id;
526
527 if !self.frame_consumers.contains_key(&display_id) {
528 let (tx, mut rx) = mpsc::unbounded::<()>();
529 self.platform.set_display_link_output_callback(
530 display_id,
531 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
532 );
533
534 let consumer_task = self.app.spawn(|cx| async move {
535 while rx.next().await.is_some() {
536 cx.update(|cx| {
537 for callback in cx
538 .next_frame_callbacks
539 .get_mut(&display_id)
540 .unwrap()
541 .drain(..)
542 .collect::<SmallVec<[_; 32]>>()
543 {
544 callback(cx);
545 }
546 })
547 .ok();
548
549 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
550
551 cx.update(|cx| {
552 if cx.next_frame_callbacks.is_empty() {
553 cx.platform.stop_display_link(display_id);
554 }
555 })
556 .ok();
557 }
558 });
559 self.frame_consumers.insert(display_id, consumer_task);
560 }
561
562 if self.next_frame_callbacks.is_empty() {
563 self.platform.start_display_link(display_id);
564 }
565
566 self.next_frame_callbacks
567 .entry(display_id)
568 .or_default()
569 .push(Box::new(move |cx: &mut AppContext| {
570 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
571 }));
572 }
573
574 /// Spawn the future returned by the given closure on the application thread pool.
575 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
576 /// use within your future.
577 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
578 where
579 R: 'static,
580 Fut: Future<Output = R> + 'static,
581 {
582 self.app
583 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
584 }
585
586 /// Update the global of the given type. The given closure is given simultaneous mutable
587 /// access both to the global and the context.
588 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
589 where
590 G: 'static,
591 {
592 let mut global = self.app.lease_global::<G>();
593 let result = f(&mut global, self);
594 self.app.end_global_lease(global);
595 result
596 }
597
598 #[must_use]
599 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
600 /// layout is being requested, along with the layout ids of any children. This method is called during
601 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
602 pub fn request_layout(
603 &mut self,
604 style: &Style,
605 children: impl IntoIterator<Item = LayoutId>,
606 ) -> LayoutId {
607 self.app.layout_id_buffer.clear();
608 self.app.layout_id_buffer.extend(children.into_iter());
609 let rem_size = self.rem_size();
610
611 self.window.layout_engine.as_mut().unwrap().request_layout(
612 style,
613 rem_size,
614 &self.app.layout_id_buffer,
615 )
616 }
617
618 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
619 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
620 /// determine the element's size. One place this is used internally is when measuring text.
621 ///
622 /// The given closure is invoked at layout time with the known dimensions and available space and
623 /// returns a `Size`.
624 pub fn request_measured_layout<
625 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
626 + 'static,
627 >(
628 &mut self,
629 style: Style,
630 measure: F,
631 ) -> LayoutId {
632 let rem_size = self.rem_size();
633 self.window
634 .layout_engine
635 .as_mut()
636 .unwrap()
637 .request_measured_layout(style, rem_size, measure)
638 }
639
640 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
641 let mut layout_engine = self.window.layout_engine.take().unwrap();
642 layout_engine.compute_layout(layout_id, available_space, self);
643 self.window.layout_engine = Some(layout_engine);
644 }
645
646 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
647 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
648 /// in order to pass your element its `Bounds` automatically.
649 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
650 let mut bounds = self
651 .window
652 .layout_engine
653 .as_mut()
654 .unwrap()
655 .layout_bounds(layout_id)
656 .map(Into::into);
657 bounds.origin += self.element_offset();
658 bounds
659 }
660
661 fn window_bounds_changed(&mut self) {
662 self.window.scale_factor = self.window.platform_window.scale_factor();
663 self.window.viewport_size = self.window.platform_window.content_size();
664 self.window.bounds = self.window.platform_window.bounds();
665 self.window.display_id = self.window.platform_window.display().id();
666 self.window.dirty = true;
667
668 self.window
669 .bounds_observers
670 .clone()
671 .retain(&(), |callback| callback(self));
672 }
673
674 pub fn window_bounds(&self) -> WindowBounds {
675 self.window.bounds
676 }
677
678 pub fn viewport_size(&self) -> Size<Pixels> {
679 self.window.viewport_size
680 }
681
682 pub fn is_window_active(&self) -> bool {
683 self.window.active
684 }
685
686 pub fn zoom_window(&self) {
687 self.window.platform_window.zoom();
688 }
689
690 pub fn set_window_title(&mut self, title: &str) {
691 self.window.platform_window.set_title(title);
692 }
693
694 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
695 self.platform
696 .displays()
697 .into_iter()
698 .find(|display| display.id() == self.window.display_id)
699 }
700
701 pub fn show_character_palette(&self) {
702 self.window.platform_window.show_character_palette();
703 }
704
705 /// The scale factor of the display associated with the window. For example, it could
706 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
707 /// be rendered as two pixels on screen.
708 pub fn scale_factor(&self) -> f32 {
709 self.window.scale_factor
710 }
711
712 /// The size of an em for the base font of the application. Adjusting this value allows the
713 /// UI to scale, just like zooming a web page.
714 pub fn rem_size(&self) -> Pixels {
715 self.window.rem_size
716 }
717
718 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
719 /// UI to scale, just like zooming a web page.
720 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
721 self.window.rem_size = rem_size.into();
722 }
723
724 /// The line height associated with the current text style.
725 pub fn line_height(&self) -> Pixels {
726 let rem_size = self.rem_size();
727 let text_style = self.text_style();
728 text_style
729 .line_height
730 .to_pixels(text_style.font_size.into(), rem_size)
731 }
732
733 /// Call to prevent the default action of an event. Currently only used to prevent
734 /// parent elements from becoming focused on mouse down.
735 pub fn prevent_default(&mut self) {
736 self.window.default_prevented = true;
737 }
738
739 /// Obtain whether default has been prevented for the event currently being dispatched.
740 pub fn default_prevented(&self) -> bool {
741 self.window.default_prevented
742 }
743
744 /// Register a mouse event listener on the window for the current frame. The type of event
745 /// is determined by the first parameter of the given listener. When the next frame is rendered
746 /// the listener will be cleared.
747 ///
748 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
749 /// a specific need to register a global listener.
750 pub fn on_mouse_event<Event: 'static>(
751 &mut self,
752 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
753 ) {
754 let order = self.window.current_frame.z_index_stack.clone();
755 self.window
756 .current_frame
757 .mouse_listeners
758 .entry(TypeId::of::<Event>())
759 .or_default()
760 .push((
761 order,
762 Box::new(move |event: &dyn Any, phase, cx| {
763 handler(event.downcast_ref().unwrap(), phase, cx)
764 }),
765 ))
766 }
767
768 /// Register a key event listener on the window for the current frame. The type of event
769 /// is determined by the first parameter of the given listener. When the next frame is rendered
770 /// the listener will be cleared.
771 ///
772 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
773 /// a specific need to register a global listener.
774 pub fn on_key_event<Event: 'static>(
775 &mut self,
776 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
777 ) {
778 self.window
779 .current_frame
780 .dispatch_tree
781 .on_key_event(Rc::new(move |event, phase, cx| {
782 if let Some(event) = event.downcast_ref::<Event>() {
783 handler(event, phase, cx)
784 }
785 }));
786 }
787
788 /// Register an action listener on the window for the current frame. The type of action
789 /// is determined by the first parameter of the given listener. When the next frame is rendered
790 /// the listener will be cleared.
791 ///
792 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
793 /// a specific need to register a global listener.
794 pub fn on_action(
795 &mut self,
796 action_type: TypeId,
797 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
798 ) {
799 self.window.current_frame.dispatch_tree.on_action(
800 action_type,
801 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
802 );
803 }
804
805 /// The position of the mouse relative to the window.
806 pub fn mouse_position(&self) -> Point<Pixels> {
807 self.window.mouse_position
808 }
809
810 pub fn set_cursor_style(&mut self, style: CursorStyle) {
811 self.window.requested_cursor_style = Some(style)
812 }
813
814 /// Called during painting to invoke the given closure in a new stacking context. The given
815 /// z-index is interpreted relative to the previous call to `stack`.
816 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
817 self.window.current_frame.z_index_stack.push(z_index);
818 let result = f(self);
819 self.window.current_frame.z_index_stack.pop();
820 result
821 }
822
823 /// Called during painting to track which z-index is on top at each pixel position
824 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
825 let stacking_order = self.window.current_frame.z_index_stack.clone();
826 let depth_map = &mut self.window.current_frame.depth_map;
827 match depth_map.binary_search_by(|(level, _)| stacking_order.cmp(&level)) {
828 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, bounds)),
829 }
830 }
831
832 /// Returns true if the top-most opaque layer painted over this point was part of the
833 /// same layer as the given stacking order.
834 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
835 for (stack, bounds) in self.window.previous_frame.depth_map.iter() {
836 if bounds.contains_point(point) {
837 return level.starts_with(stack) || stack.starts_with(level);
838 }
839 }
840
841 false
842 }
843
844 /// Called during painting to get the current stacking order.
845 pub fn stacking_order(&self) -> &StackingOrder {
846 &self.window.current_frame.z_index_stack
847 }
848
849 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
850 pub fn paint_shadows(
851 &mut self,
852 bounds: Bounds<Pixels>,
853 corner_radii: Corners<Pixels>,
854 shadows: &[BoxShadow],
855 ) {
856 let scale_factor = self.scale_factor();
857 let content_mask = self.content_mask();
858 let window = &mut *self.window;
859 for shadow in shadows {
860 let mut shadow_bounds = bounds;
861 shadow_bounds.origin += shadow.offset;
862 shadow_bounds.dilate(shadow.spread_radius);
863 window.current_frame.scene_builder.insert(
864 &window.current_frame.z_index_stack,
865 Shadow {
866 order: 0,
867 bounds: shadow_bounds.scale(scale_factor),
868 content_mask: content_mask.scale(scale_factor),
869 corner_radii: corner_radii.scale(scale_factor),
870 color: shadow.color,
871 blur_radius: shadow.blur_radius.scale(scale_factor),
872 },
873 );
874 }
875 }
876
877 /// Paint one or more quads into the scene for the current frame at the current stacking context.
878 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
879 pub fn paint_quad(
880 &mut self,
881 bounds: Bounds<Pixels>,
882 corner_radii: Corners<Pixels>,
883 background: impl Into<Hsla>,
884 border_widths: Edges<Pixels>,
885 border_color: impl Into<Hsla>,
886 ) {
887 let scale_factor = self.scale_factor();
888 let content_mask = self.content_mask();
889
890 let window = &mut *self.window;
891 window.current_frame.scene_builder.insert(
892 &window.current_frame.z_index_stack,
893 Quad {
894 order: 0,
895 bounds: bounds.scale(scale_factor),
896 content_mask: content_mask.scale(scale_factor),
897 background: background.into(),
898 border_color: border_color.into(),
899 corner_radii: corner_radii.scale(scale_factor),
900 border_widths: border_widths.scale(scale_factor),
901 },
902 );
903 }
904
905 /// Paint the given `Path` into the scene for the current frame at the current z-index.
906 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
907 let scale_factor = self.scale_factor();
908 let content_mask = self.content_mask();
909 path.content_mask = content_mask;
910 path.color = color.into();
911 let window = &mut *self.window;
912 window.current_frame.scene_builder.insert(
913 &window.current_frame.z_index_stack,
914 path.scale(scale_factor),
915 );
916 }
917
918 /// Paint an underline into the scene for the current frame at the current z-index.
919 pub fn paint_underline(
920 &mut self,
921 origin: Point<Pixels>,
922 width: Pixels,
923 style: &UnderlineStyle,
924 ) {
925 let scale_factor = self.scale_factor();
926 let height = if style.wavy {
927 style.thickness * 3.
928 } else {
929 style.thickness
930 };
931 let bounds = Bounds {
932 origin,
933 size: size(width, height),
934 };
935 let content_mask = self.content_mask();
936 let window = &mut *self.window;
937 window.current_frame.scene_builder.insert(
938 &window.current_frame.z_index_stack,
939 Underline {
940 order: 0,
941 bounds: bounds.scale(scale_factor),
942 content_mask: content_mask.scale(scale_factor),
943 thickness: style.thickness.scale(scale_factor),
944 color: style.color.unwrap_or_default(),
945 wavy: style.wavy,
946 },
947 );
948 }
949
950 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
951 /// The y component of the origin is the baseline of the glyph.
952 pub fn paint_glyph(
953 &mut self,
954 origin: Point<Pixels>,
955 font_id: FontId,
956 glyph_id: GlyphId,
957 font_size: Pixels,
958 color: Hsla,
959 ) -> Result<()> {
960 let scale_factor = self.scale_factor();
961 let glyph_origin = origin.scale(scale_factor);
962 let subpixel_variant = Point {
963 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
964 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
965 };
966 let params = RenderGlyphParams {
967 font_id,
968 glyph_id,
969 font_size,
970 subpixel_variant,
971 scale_factor,
972 is_emoji: false,
973 };
974
975 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
976 if !raster_bounds.is_zero() {
977 let tile =
978 self.window
979 .sprite_atlas
980 .get_or_insert_with(¶ms.clone().into(), &mut || {
981 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
982 Ok((size, Cow::Owned(bytes)))
983 })?;
984 let bounds = Bounds {
985 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
986 size: tile.bounds.size.map(Into::into),
987 };
988 let content_mask = self.content_mask().scale(scale_factor);
989 let window = &mut *self.window;
990 window.current_frame.scene_builder.insert(
991 &window.current_frame.z_index_stack,
992 MonochromeSprite {
993 order: 0,
994 bounds,
995 content_mask,
996 color,
997 tile,
998 },
999 );
1000 }
1001 Ok(())
1002 }
1003
1004 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
1005 /// The y component of the origin is the baseline of the glyph.
1006 pub fn paint_emoji(
1007 &mut self,
1008 origin: Point<Pixels>,
1009 font_id: FontId,
1010 glyph_id: GlyphId,
1011 font_size: Pixels,
1012 ) -> Result<()> {
1013 let scale_factor = self.scale_factor();
1014 let glyph_origin = origin.scale(scale_factor);
1015 let params = RenderGlyphParams {
1016 font_id,
1017 glyph_id,
1018 font_size,
1019 // We don't render emojis with subpixel variants.
1020 subpixel_variant: Default::default(),
1021 scale_factor,
1022 is_emoji: true,
1023 };
1024
1025 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1026 if !raster_bounds.is_zero() {
1027 let tile =
1028 self.window
1029 .sprite_atlas
1030 .get_or_insert_with(¶ms.clone().into(), &mut || {
1031 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1032 Ok((size, Cow::Owned(bytes)))
1033 })?;
1034 let bounds = Bounds {
1035 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1036 size: tile.bounds.size.map(Into::into),
1037 };
1038 let content_mask = self.content_mask().scale(scale_factor);
1039 let window = &mut *self.window;
1040
1041 window.current_frame.scene_builder.insert(
1042 &window.current_frame.z_index_stack,
1043 PolychromeSprite {
1044 order: 0,
1045 bounds,
1046 corner_radii: Default::default(),
1047 content_mask,
1048 tile,
1049 grayscale: false,
1050 },
1051 );
1052 }
1053 Ok(())
1054 }
1055
1056 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1057 pub fn paint_svg(
1058 &mut self,
1059 bounds: Bounds<Pixels>,
1060 path: SharedString,
1061 color: Hsla,
1062 ) -> Result<()> {
1063 let scale_factor = self.scale_factor();
1064 let bounds = bounds.scale(scale_factor);
1065 // Render the SVG at twice the size to get a higher quality result.
1066 let params = RenderSvgParams {
1067 path,
1068 size: bounds
1069 .size
1070 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1071 };
1072
1073 let tile =
1074 self.window
1075 .sprite_atlas
1076 .get_or_insert_with(¶ms.clone().into(), &mut || {
1077 let bytes = self.svg_renderer.render(¶ms)?;
1078 Ok((params.size, Cow::Owned(bytes)))
1079 })?;
1080 let content_mask = self.content_mask().scale(scale_factor);
1081
1082 let window = &mut *self.window;
1083 window.current_frame.scene_builder.insert(
1084 &window.current_frame.z_index_stack,
1085 MonochromeSprite {
1086 order: 0,
1087 bounds,
1088 content_mask,
1089 color,
1090 tile,
1091 },
1092 );
1093
1094 Ok(())
1095 }
1096
1097 /// Paint an image into the scene for the current frame at the current z-index.
1098 pub fn paint_image(
1099 &mut self,
1100 bounds: Bounds<Pixels>,
1101 corner_radii: Corners<Pixels>,
1102 data: Arc<ImageData>,
1103 grayscale: bool,
1104 ) -> Result<()> {
1105 let scale_factor = self.scale_factor();
1106 let bounds = bounds.scale(scale_factor);
1107 let params = RenderImageParams { image_id: data.id };
1108
1109 let tile = self
1110 .window
1111 .sprite_atlas
1112 .get_or_insert_with(¶ms.clone().into(), &mut || {
1113 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1114 })?;
1115 let content_mask = self.content_mask().scale(scale_factor);
1116 let corner_radii = corner_radii.scale(scale_factor);
1117
1118 let window = &mut *self.window;
1119 window.current_frame.scene_builder.insert(
1120 &window.current_frame.z_index_stack,
1121 PolychromeSprite {
1122 order: 0,
1123 bounds,
1124 content_mask,
1125 corner_radii,
1126 tile,
1127 grayscale,
1128 },
1129 );
1130 Ok(())
1131 }
1132
1133 /// Paint a surface into the scene for the current frame at the current z-index.
1134 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
1135 let scale_factor = self.scale_factor();
1136 let bounds = bounds.scale(scale_factor);
1137 let content_mask = self.content_mask().scale(scale_factor);
1138 let window = &mut *self.window;
1139 window.current_frame.scene_builder.insert(
1140 &window.current_frame.z_index_stack,
1141 Surface {
1142 order: 0,
1143 bounds,
1144 content_mask,
1145 image_buffer,
1146 },
1147 );
1148 }
1149
1150 /// Draw pixels to the display for this window based on the contents of its scene.
1151 pub(crate) fn draw(&mut self) {
1152 let root_view = self.window.root_view.take().unwrap();
1153
1154 self.start_frame();
1155
1156 self.with_z_index(0, |cx| {
1157 let available_space = cx.window.viewport_size.map(Into::into);
1158 root_view.draw(Point::zero(), available_space, cx);
1159 });
1160
1161 if let Some(active_drag) = self.app.active_drag.take() {
1162 self.with_z_index(1, |cx| {
1163 let offset = cx.mouse_position() - active_drag.cursor_offset;
1164 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1165 active_drag.view.draw(offset, available_space, cx);
1166 cx.active_drag = Some(active_drag);
1167 });
1168 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1169 self.with_z_index(1, |cx| {
1170 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1171 active_tooltip
1172 .view
1173 .draw(active_tooltip.cursor_offset, available_space, cx);
1174 });
1175 }
1176
1177 self.window
1178 .current_frame
1179 .dispatch_tree
1180 .preserve_keystroke_matchers(
1181 &mut self.window.previous_frame.dispatch_tree,
1182 self.window.focus,
1183 );
1184
1185 self.window.root_view = Some(root_view);
1186 let scene = self.window.current_frame.scene_builder.build();
1187
1188 self.window.platform_window.draw(scene);
1189 let cursor_style = self
1190 .window
1191 .requested_cursor_style
1192 .take()
1193 .unwrap_or(CursorStyle::Arrow);
1194 self.platform.set_cursor_style(cursor_style);
1195
1196 self.window.dirty = false;
1197 }
1198
1199 /// Rotate the current frame and the previous frame, then clear the current frame.
1200 /// We repopulate all state in the current frame during each paint.
1201 fn start_frame(&mut self) {
1202 self.text_system().start_frame();
1203
1204 let window = &mut *self.window;
1205 window.layout_engine.as_mut().unwrap().clear();
1206
1207 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1208 let frame = &mut window.current_frame;
1209 frame.element_states.clear();
1210 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1211 frame.focus_listeners.clear();
1212 frame.dispatch_tree.clear();
1213 frame.depth_map.clear();
1214 }
1215
1216 /// Dispatch a mouse or keyboard event on the window.
1217 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1218 // Handlers may set this to false by calling `stop_propagation`
1219 self.app.propagate_event = true;
1220 self.window.default_prevented = false;
1221
1222 let event = match event {
1223 // Track the mouse position with our own state, since accessing the platform
1224 // API for the mouse position can only occur on the main thread.
1225 InputEvent::MouseMove(mouse_move) => {
1226 self.window.mouse_position = mouse_move.position;
1227 InputEvent::MouseMove(mouse_move)
1228 }
1229 InputEvent::MouseDown(mouse_down) => {
1230 self.window.mouse_position = mouse_down.position;
1231 InputEvent::MouseDown(mouse_down)
1232 }
1233 InputEvent::MouseUp(mouse_up) => {
1234 self.window.mouse_position = mouse_up.position;
1235 InputEvent::MouseUp(mouse_up)
1236 }
1237 // Translate dragging and dropping of external files from the operating system
1238 // to internal drag and drop events.
1239 InputEvent::FileDrop(file_drop) => match file_drop {
1240 FileDropEvent::Entered { position, files } => {
1241 self.window.mouse_position = position;
1242 if self.active_drag.is_none() {
1243 self.active_drag = Some(AnyDrag {
1244 view: self.build_view(|_| files).into(),
1245 cursor_offset: position,
1246 });
1247 }
1248 InputEvent::MouseDown(MouseDownEvent {
1249 position,
1250 button: MouseButton::Left,
1251 click_count: 1,
1252 modifiers: Modifiers::default(),
1253 })
1254 }
1255 FileDropEvent::Pending { position } => {
1256 self.window.mouse_position = position;
1257 InputEvent::MouseMove(MouseMoveEvent {
1258 position,
1259 pressed_button: Some(MouseButton::Left),
1260 modifiers: Modifiers::default(),
1261 })
1262 }
1263 FileDropEvent::Submit { position } => {
1264 self.window.mouse_position = position;
1265 InputEvent::MouseUp(MouseUpEvent {
1266 button: MouseButton::Left,
1267 position,
1268 modifiers: Modifiers::default(),
1269 click_count: 1,
1270 })
1271 }
1272 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1273 button: MouseButton::Left,
1274 position: Point::default(),
1275 modifiers: Modifiers::default(),
1276 click_count: 1,
1277 }),
1278 },
1279 _ => event,
1280 };
1281
1282 if let Some(any_mouse_event) = event.mouse_event() {
1283 self.dispatch_mouse_event(any_mouse_event);
1284 } else if let Some(any_key_event) = event.keyboard_event() {
1285 self.dispatch_key_event(any_key_event);
1286 }
1287
1288 !self.app.propagate_event
1289 }
1290
1291 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1292 if let Some(mut handlers) = self
1293 .window
1294 .current_frame
1295 .mouse_listeners
1296 .remove(&event.type_id())
1297 {
1298 // Because handlers may add other handlers, we sort every time.
1299 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1300
1301 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1302 // special purposes, such as detecting events outside of a given Bounds.
1303 for (_, handler) in &mut handlers {
1304 handler(event, DispatchPhase::Capture, self);
1305 if !self.app.propagate_event {
1306 break;
1307 }
1308 }
1309
1310 // Bubble phase, where most normal handlers do their work.
1311 if self.app.propagate_event {
1312 for (_, handler) in handlers.iter_mut().rev() {
1313 handler(event, DispatchPhase::Bubble, self);
1314 if !self.app.propagate_event {
1315 break;
1316 }
1317 }
1318 }
1319
1320 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1321 self.active_drag = None;
1322 }
1323
1324 // Just in case any handlers added new handlers, which is weird, but possible.
1325 handlers.extend(
1326 self.window
1327 .current_frame
1328 .mouse_listeners
1329 .get_mut(&event.type_id())
1330 .into_iter()
1331 .flat_map(|handlers| handlers.drain(..)),
1332 );
1333 self.window
1334 .current_frame
1335 .mouse_listeners
1336 .insert(event.type_id(), handlers);
1337 }
1338 }
1339
1340 fn dispatch_key_event(&mut self, event: &dyn Any) {
1341 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1342 self.window
1343 .current_frame
1344 .dispatch_tree
1345 .focusable_node_id(focus_id)
1346 }) {
1347 let dispatch_path = self
1348 .window
1349 .current_frame
1350 .dispatch_tree
1351 .dispatch_path(node_id);
1352
1353 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1354
1355 // Capture phase
1356 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1357 self.propagate_event = true;
1358
1359 for node_id in &dispatch_path {
1360 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1361
1362 if !node.context.is_empty() {
1363 context_stack.push(node.context.clone());
1364 }
1365
1366 for key_listener in node.key_listeners.clone() {
1367 key_listener(event, DispatchPhase::Capture, self);
1368 if !self.propagate_event {
1369 return;
1370 }
1371 }
1372 }
1373
1374 // Bubble phase
1375 for node_id in dispatch_path.iter().rev() {
1376 // Handle low level key events
1377 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1378 for key_listener in node.key_listeners.clone() {
1379 key_listener(event, DispatchPhase::Bubble, self);
1380 if !self.propagate_event {
1381 return;
1382 }
1383 }
1384
1385 // Match keystrokes
1386 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1387 if !node.context.is_empty() {
1388 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1389 if let Some(found) = self
1390 .window
1391 .current_frame
1392 .dispatch_tree
1393 .dispatch_key(&key_down_event.keystroke, &context_stack)
1394 {
1395 actions.push(found.boxed_clone())
1396 }
1397 }
1398
1399 context_stack.pop();
1400 }
1401 }
1402
1403 for action in actions {
1404 self.dispatch_action_on_node(node_id, action);
1405 if !self.propagate_event {
1406 return;
1407 }
1408 }
1409 }
1410 }
1411
1412 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1413 let dispatch_path = self
1414 .window
1415 .current_frame
1416 .dispatch_tree
1417 .dispatch_path(node_id);
1418
1419 // Capture phase
1420 for node_id in &dispatch_path {
1421 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1422 for DispatchActionListener {
1423 action_type,
1424 listener,
1425 } in node.action_listeners.clone()
1426 {
1427 let any_action = action.as_any();
1428 if action_type == any_action.type_id() {
1429 listener(any_action, DispatchPhase::Capture, self);
1430 if !self.propagate_event {
1431 return;
1432 }
1433 }
1434 }
1435 }
1436 // Bubble phase
1437 for node_id in dispatch_path.iter().rev() {
1438 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1439 for DispatchActionListener {
1440 action_type,
1441 listener,
1442 } in node.action_listeners.clone()
1443 {
1444 let any_action = action.as_any();
1445 if action_type == any_action.type_id() {
1446 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1447 listener(any_action, DispatchPhase::Bubble, self);
1448 if !self.propagate_event {
1449 return;
1450 }
1451 }
1452 }
1453 }
1454 }
1455
1456 /// Register the given handler to be invoked whenever the global of the given type
1457 /// is updated.
1458 pub fn observe_global<G: 'static>(
1459 &mut self,
1460 f: impl Fn(&mut WindowContext<'_>) + 'static,
1461 ) -> Subscription {
1462 let window_handle = self.window.handle;
1463 let (subscription, activate) = self.global_observers.insert(
1464 TypeId::of::<G>(),
1465 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1466 );
1467 self.app.defer(move |_| activate());
1468 subscription
1469 }
1470
1471 pub fn activate_window(&self) {
1472 self.window.platform_window.activate();
1473 }
1474
1475 pub fn minimize_window(&self) {
1476 self.window.platform_window.minimize();
1477 }
1478
1479 pub fn toggle_full_screen(&self) {
1480 self.window.platform_window.toggle_full_screen();
1481 }
1482
1483 pub fn prompt(
1484 &self,
1485 level: PromptLevel,
1486 msg: &str,
1487 answers: &[&str],
1488 ) -> oneshot::Receiver<usize> {
1489 self.window.platform_window.prompt(level, msg, answers)
1490 }
1491
1492 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1493 if let Some(focus_id) = self.window.focus {
1494 let mut actions = self
1495 .window
1496 .current_frame
1497 .dispatch_tree
1498 .available_actions(focus_id);
1499 actions.extend(
1500 self.app
1501 .global_action_listeners
1502 .keys()
1503 .filter_map(|type_id| self.app.actions.build_action_type(type_id).ok()),
1504 );
1505 actions
1506 } else {
1507 Vec::new()
1508 }
1509 }
1510
1511 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1512 self.window
1513 .previous_frame
1514 .dispatch_tree
1515 .bindings_for_action(
1516 action,
1517 &self.window.previous_frame.dispatch_tree.context_stack,
1518 )
1519 }
1520
1521 pub fn bindings_for_action_in(
1522 &self,
1523 action: &dyn Action,
1524 focus_handle: &FocusHandle,
1525 ) -> Vec<KeyBinding> {
1526 let dispatch_tree = &self.window.previous_frame.dispatch_tree;
1527
1528 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1529 return vec![];
1530 };
1531 let context_stack = dispatch_tree
1532 .dispatch_path(node_id)
1533 .into_iter()
1534 .map(|node_id| dispatch_tree.node(node_id).context.clone())
1535 .collect();
1536 dispatch_tree.bindings_for_action(action, &context_stack)
1537 }
1538
1539 pub fn listener_for<V: Render, E>(
1540 &self,
1541 view: &View<V>,
1542 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1543 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1544 let view = view.downgrade();
1545 move |e: &E, cx: &mut WindowContext| {
1546 view.update(cx, |view, cx| f(view, e, cx)).ok();
1547 }
1548 }
1549
1550 pub fn handler_for<V: Render>(
1551 &self,
1552 view: &View<V>,
1553 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1554 ) -> impl Fn(&mut WindowContext) {
1555 let view = view.downgrade();
1556 move |cx: &mut WindowContext| {
1557 view.update(cx, |view, cx| f(view, cx)).ok();
1558 }
1559 }
1560
1561 //========== ELEMENT RELATED FUNCTIONS ===========
1562 pub fn with_key_dispatch<R>(
1563 &mut self,
1564 context: KeyContext,
1565 focus_handle: Option<FocusHandle>,
1566 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1567 ) -> R {
1568 let window = &mut self.window;
1569 window
1570 .current_frame
1571 .dispatch_tree
1572 .push_node(context.clone());
1573 if let Some(focus_handle) = focus_handle.as_ref() {
1574 window
1575 .current_frame
1576 .dispatch_tree
1577 .make_focusable(focus_handle.id);
1578 }
1579 let result = f(focus_handle, self);
1580
1581 self.window.current_frame.dispatch_tree.pop_node();
1582
1583 result
1584 }
1585
1586 /// Register a focus listener for the current frame only. It will be cleared
1587 /// on the next frame render. You should use this method only from within elements,
1588 /// and we may want to enforce that better via a different context type.
1589 // todo!() Move this to `FrameContext` to emphasize its individuality?
1590 pub fn on_focus_changed(
1591 &mut self,
1592 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1593 ) {
1594 self.window
1595 .current_frame
1596 .focus_listeners
1597 .push(Box::new(move |event, cx| {
1598 listener(event, cx);
1599 }));
1600 }
1601
1602 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1603 /// platform to receive textual input with proper integration with concerns such
1604 /// as IME interactions.
1605 pub fn handle_input(
1606 &mut self,
1607 focus_handle: &FocusHandle,
1608 input_handler: impl PlatformInputHandler,
1609 ) {
1610 if focus_handle.is_focused(self) {
1611 self.window
1612 .platform_window
1613 .set_input_handler(Box::new(input_handler));
1614 }
1615 }
1616
1617 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1618 let mut this = self.to_async();
1619 self.window
1620 .platform_window
1621 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1622 }
1623}
1624
1625impl Context for WindowContext<'_> {
1626 type Result<T> = T;
1627
1628 fn build_model<T>(
1629 &mut self,
1630 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1631 ) -> Model<T>
1632 where
1633 T: 'static,
1634 {
1635 let slot = self.app.entities.reserve();
1636 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1637 self.entities.insert(slot, model)
1638 }
1639
1640 fn update_model<T: 'static, R>(
1641 &mut self,
1642 model: &Model<T>,
1643 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1644 ) -> R {
1645 let mut entity = self.entities.lease(model);
1646 let result = update(
1647 &mut *entity,
1648 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1649 );
1650 self.entities.end_lease(entity);
1651 result
1652 }
1653
1654 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1655 where
1656 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1657 {
1658 if window == self.window.handle {
1659 let root_view = self.window.root_view.clone().unwrap();
1660 Ok(update(root_view, self))
1661 } else {
1662 window.update(self.app, update)
1663 }
1664 }
1665
1666 fn read_model<T, R>(
1667 &self,
1668 handle: &Model<T>,
1669 read: impl FnOnce(&T, &AppContext) -> R,
1670 ) -> Self::Result<R>
1671 where
1672 T: 'static,
1673 {
1674 let entity = self.entities.read(handle);
1675 read(&*entity, &*self.app)
1676 }
1677
1678 fn read_window<T, R>(
1679 &self,
1680 window: &WindowHandle<T>,
1681 read: impl FnOnce(View<T>, &AppContext) -> R,
1682 ) -> Result<R>
1683 where
1684 T: 'static,
1685 {
1686 if window.any_handle == self.window.handle {
1687 let root_view = self
1688 .window
1689 .root_view
1690 .clone()
1691 .unwrap()
1692 .downcast::<T>()
1693 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1694 Ok(read(root_view, self))
1695 } else {
1696 self.app.read_window(window, read)
1697 }
1698 }
1699}
1700
1701impl VisualContext for WindowContext<'_> {
1702 fn build_view<V>(
1703 &mut self,
1704 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1705 ) -> Self::Result<View<V>>
1706 where
1707 V: 'static + Render,
1708 {
1709 let slot = self.app.entities.reserve();
1710 let view = View {
1711 model: slot.clone(),
1712 };
1713 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1714 let entity = build_view_state(&mut cx);
1715 cx.entities.insert(slot, entity);
1716
1717 cx.new_view_observers
1718 .clone()
1719 .retain(&TypeId::of::<V>(), |observer| {
1720 let any_view = AnyView::from(view.clone());
1721 (observer)(any_view, self);
1722 true
1723 });
1724
1725 view
1726 }
1727
1728 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1729 fn update_view<T: 'static, R>(
1730 &mut self,
1731 view: &View<T>,
1732 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1733 ) -> Self::Result<R> {
1734 let mut lease = self.app.entities.lease(&view.model);
1735 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1736 let result = update(&mut *lease, &mut cx);
1737 cx.app.entities.end_lease(lease);
1738 result
1739 }
1740
1741 fn replace_root_view<V>(
1742 &mut self,
1743 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1744 ) -> Self::Result<View<V>>
1745 where
1746 V: 'static + Render,
1747 {
1748 let slot = self.app.entities.reserve();
1749 let view = View {
1750 model: slot.clone(),
1751 };
1752 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1753 let entity = build_view(&mut cx);
1754 self.entities.insert(slot, entity);
1755 self.window.root_view = Some(view.clone().into());
1756 view
1757 }
1758
1759 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1760 self.update_view(view, |view, cx| {
1761 view.focus_handle(cx).clone().focus(cx);
1762 })
1763 }
1764
1765 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1766 where
1767 V: ManagedView,
1768 {
1769 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1770 }
1771}
1772
1773impl<'a> std::ops::Deref for WindowContext<'a> {
1774 type Target = AppContext;
1775
1776 fn deref(&self) -> &Self::Target {
1777 &self.app
1778 }
1779}
1780
1781impl<'a> std::ops::DerefMut for WindowContext<'a> {
1782 fn deref_mut(&mut self) -> &mut Self::Target {
1783 &mut self.app
1784 }
1785}
1786
1787impl<'a> Borrow<AppContext> for WindowContext<'a> {
1788 fn borrow(&self) -> &AppContext {
1789 &self.app
1790 }
1791}
1792
1793impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1794 fn borrow_mut(&mut self) -> &mut AppContext {
1795 &mut self.app
1796 }
1797}
1798
1799pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1800 fn app_mut(&mut self) -> &mut AppContext {
1801 self.borrow_mut()
1802 }
1803
1804 fn app(&self) -> &AppContext {
1805 self.borrow()
1806 }
1807
1808 fn window(&self) -> &Window {
1809 self.borrow()
1810 }
1811
1812 fn window_mut(&mut self) -> &mut Window {
1813 self.borrow_mut()
1814 }
1815
1816 /// Pushes the given element id onto the global stack and invokes the given closure
1817 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1818 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1819 /// used to associate state with identified elements across separate frames.
1820 fn with_element_id<R>(
1821 &mut self,
1822 id: Option<impl Into<ElementId>>,
1823 f: impl FnOnce(&mut Self) -> R,
1824 ) -> R {
1825 if let Some(id) = id.map(Into::into) {
1826 let window = self.window_mut();
1827 window.element_id_stack.push(id.into());
1828 let result = f(self);
1829 let window: &mut Window = self.borrow_mut();
1830 window.element_id_stack.pop();
1831 result
1832 } else {
1833 f(self)
1834 }
1835 }
1836
1837 /// Invoke the given function with the given content mask after intersecting it
1838 /// with the current mask.
1839 fn with_content_mask<R>(
1840 &mut self,
1841 mask: Option<ContentMask<Pixels>>,
1842 f: impl FnOnce(&mut Self) -> R,
1843 ) -> R {
1844 if let Some(mask) = mask {
1845 let mask = mask.intersect(&self.content_mask());
1846 self.window_mut()
1847 .current_frame
1848 .content_mask_stack
1849 .push(mask);
1850 let result = f(self);
1851 self.window_mut().current_frame.content_mask_stack.pop();
1852 result
1853 } else {
1854 f(self)
1855 }
1856 }
1857
1858 /// Invoke the given function with the content mask reset to that
1859 /// of the window.
1860 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1861 let mask = ContentMask {
1862 bounds: Bounds {
1863 origin: Point::default(),
1864 size: self.window().viewport_size,
1865 },
1866 };
1867 self.window_mut()
1868 .current_frame
1869 .content_mask_stack
1870 .push(mask);
1871 let result = f(self);
1872 self.window_mut().current_frame.content_mask_stack.pop();
1873 result
1874 }
1875
1876 /// Update the global element offset relative to the current offset. This is used to implement
1877 /// scrolling.
1878 fn with_element_offset<R>(
1879 &mut self,
1880 offset: Point<Pixels>,
1881 f: impl FnOnce(&mut Self) -> R,
1882 ) -> R {
1883 if offset.is_zero() {
1884 return f(self);
1885 };
1886
1887 let abs_offset = self.element_offset() + offset;
1888 self.with_absolute_element_offset(abs_offset, f)
1889 }
1890
1891 /// Update the global element offset based on the given offset. This is used to implement
1892 /// drag handles and other manual painting of elements.
1893 fn with_absolute_element_offset<R>(
1894 &mut self,
1895 offset: Point<Pixels>,
1896 f: impl FnOnce(&mut Self) -> R,
1897 ) -> R {
1898 self.window_mut()
1899 .current_frame
1900 .element_offset_stack
1901 .push(offset);
1902 let result = f(self);
1903 self.window_mut().current_frame.element_offset_stack.pop();
1904 result
1905 }
1906
1907 /// Obtain the current element offset.
1908 fn element_offset(&self) -> Point<Pixels> {
1909 self.window()
1910 .current_frame
1911 .element_offset_stack
1912 .last()
1913 .copied()
1914 .unwrap_or_default()
1915 }
1916
1917 /// Update or intialize state for an element with the given id that lives across multiple
1918 /// frames. If an element with this id existed in the previous frame, its state will be passed
1919 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1920 /// when drawing the next frame.
1921 fn with_element_state<S, R>(
1922 &mut self,
1923 id: ElementId,
1924 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1925 ) -> R
1926 where
1927 S: 'static,
1928 {
1929 self.with_element_id(Some(id), |cx| {
1930 let global_id = cx.window().element_id_stack.clone();
1931
1932 if let Some(any) = cx
1933 .window_mut()
1934 .current_frame
1935 .element_states
1936 .remove(&global_id)
1937 .or_else(|| {
1938 cx.window_mut()
1939 .previous_frame
1940 .element_states
1941 .remove(&global_id)
1942 })
1943 {
1944 let ElementStateBox {
1945 inner,
1946
1947 #[cfg(debug_assertions)]
1948 type_name
1949 } = any;
1950 // Using the extra inner option to avoid needing to reallocate a new box.
1951 let mut state_box = inner
1952 .downcast::<Option<S>>()
1953 .map_err(|_| {
1954 #[cfg(debug_assertions)]
1955 {
1956 anyhow!(
1957 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1958 std::any::type_name::<S>(),
1959 type_name
1960 )
1961 }
1962
1963 #[cfg(not(debug_assertions))]
1964 {
1965 anyhow!(
1966 "invalid element state type for id, requested_type {:?}",
1967 std::any::type_name::<S>(),
1968 )
1969 }
1970 })
1971 .unwrap();
1972
1973 // Actual: Option<AnyElement> <- View
1974 // Requested: () <- AnyElemet
1975 let state = state_box
1976 .take()
1977 .expect("element state is already on the stack");
1978 let (result, state) = f(Some(state), cx);
1979 state_box.replace(state);
1980 cx.window_mut()
1981 .current_frame
1982 .element_states
1983 .insert(global_id, ElementStateBox {
1984 inner: state_box,
1985
1986 #[cfg(debug_assertions)]
1987 type_name
1988 });
1989 result
1990 } else {
1991 let (result, state) = f(None, cx);
1992 cx.window_mut()
1993 .current_frame
1994 .element_states
1995 .insert(global_id,
1996 ElementStateBox {
1997 inner: Box::new(Some(state)),
1998
1999 #[cfg(debug_assertions)]
2000 type_name: std::any::type_name::<S>()
2001 }
2002
2003 );
2004 result
2005 }
2006 })
2007 }
2008
2009 /// Obtain the current content mask.
2010 fn content_mask(&self) -> ContentMask<Pixels> {
2011 self.window()
2012 .current_frame
2013 .content_mask_stack
2014 .last()
2015 .cloned()
2016 .unwrap_or_else(|| ContentMask {
2017 bounds: Bounds {
2018 origin: Point::default(),
2019 size: self.window().viewport_size,
2020 },
2021 })
2022 }
2023
2024 /// The size of an em for the base font of the application. Adjusting this value allows the
2025 /// UI to scale, just like zooming a web page.
2026 fn rem_size(&self) -> Pixels {
2027 self.window().rem_size
2028 }
2029}
2030
2031impl Borrow<Window> for WindowContext<'_> {
2032 fn borrow(&self) -> &Window {
2033 &self.window
2034 }
2035}
2036
2037impl BorrowMut<Window> for WindowContext<'_> {
2038 fn borrow_mut(&mut self) -> &mut Window {
2039 &mut self.window
2040 }
2041}
2042
2043impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
2044
2045pub struct ViewContext<'a, V> {
2046 window_cx: WindowContext<'a>,
2047 view: &'a View<V>,
2048}
2049
2050impl<V> Borrow<AppContext> for ViewContext<'_, V> {
2051 fn borrow(&self) -> &AppContext {
2052 &*self.window_cx.app
2053 }
2054}
2055
2056impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
2057 fn borrow_mut(&mut self) -> &mut AppContext {
2058 &mut *self.window_cx.app
2059 }
2060}
2061
2062impl<V> Borrow<Window> for ViewContext<'_, V> {
2063 fn borrow(&self) -> &Window {
2064 &*self.window_cx.window
2065 }
2066}
2067
2068impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2069 fn borrow_mut(&mut self) -> &mut Window {
2070 &mut *self.window_cx.window
2071 }
2072}
2073
2074impl<'a, V: 'static> ViewContext<'a, V> {
2075 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2076 Self {
2077 window_cx: WindowContext::new(app, window),
2078 view,
2079 }
2080 }
2081
2082 pub fn entity_id(&self) -> EntityId {
2083 self.view.entity_id()
2084 }
2085
2086 pub fn view(&self) -> &View<V> {
2087 self.view
2088 }
2089
2090 pub fn model(&self) -> &Model<V> {
2091 &self.view.model
2092 }
2093
2094 /// Access the underlying window context.
2095 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2096 &mut self.window_cx
2097 }
2098
2099 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2100 self.window.current_frame.z_index_stack.push(z_index);
2101 let result = f(self);
2102 self.window.current_frame.z_index_stack.pop();
2103 result
2104 }
2105
2106 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2107 where
2108 V: 'static,
2109 {
2110 let view = self.view().clone();
2111 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2112 }
2113
2114 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2115 /// that are currently on the stack to be returned to the app.
2116 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2117 let view = self.view().downgrade();
2118 self.window_cx.defer(move |cx| {
2119 view.update(cx, f).ok();
2120 });
2121 }
2122
2123 pub fn observe<V2, E>(
2124 &mut self,
2125 entity: &E,
2126 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2127 ) -> Subscription
2128 where
2129 V2: 'static,
2130 V: 'static,
2131 E: Entity<V2>,
2132 {
2133 let view = self.view().downgrade();
2134 let entity_id = entity.entity_id();
2135 let entity = entity.downgrade();
2136 let window_handle = self.window.handle;
2137 let (subscription, activate) = self.app.observers.insert(
2138 entity_id,
2139 Box::new(move |cx| {
2140 window_handle
2141 .update(cx, |_, cx| {
2142 if let Some(handle) = E::upgrade_from(&entity) {
2143 view.update(cx, |this, cx| on_notify(this, handle, cx))
2144 .is_ok()
2145 } else {
2146 false
2147 }
2148 })
2149 .unwrap_or(false)
2150 }),
2151 );
2152 self.app.defer(move |_| activate());
2153 subscription
2154 }
2155
2156 pub fn subscribe<V2, E, Evt>(
2157 &mut self,
2158 entity: &E,
2159 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2160 ) -> Subscription
2161 where
2162 V2: EventEmitter<Evt>,
2163 E: Entity<V2>,
2164 Evt: 'static,
2165 {
2166 let view = self.view().downgrade();
2167 let entity_id = entity.entity_id();
2168 let handle = entity.downgrade();
2169 let window_handle = self.window.handle;
2170 let (subscription, activate) = self.app.event_listeners.insert(
2171 entity_id,
2172 (
2173 TypeId::of::<Evt>(),
2174 Box::new(move |event, cx| {
2175 window_handle
2176 .update(cx, |_, cx| {
2177 if let Some(handle) = E::upgrade_from(&handle) {
2178 let event = event.downcast_ref().expect("invalid event type");
2179 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2180 .is_ok()
2181 } else {
2182 false
2183 }
2184 })
2185 .unwrap_or(false)
2186 }),
2187 ),
2188 );
2189 self.app.defer(move |_| activate());
2190 subscription
2191 }
2192
2193 pub fn on_release(
2194 &mut self,
2195 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2196 ) -> Subscription {
2197 let window_handle = self.window.handle;
2198 let (subscription, activate) = self.app.release_listeners.insert(
2199 self.view.model.entity_id,
2200 Box::new(move |this, cx| {
2201 let this = this.downcast_mut().expect("invalid entity type");
2202 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2203 }),
2204 );
2205 activate();
2206 subscription
2207 }
2208
2209 pub fn observe_release<V2, E>(
2210 &mut self,
2211 entity: &E,
2212 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2213 ) -> Subscription
2214 where
2215 V: 'static,
2216 V2: 'static,
2217 E: Entity<V2>,
2218 {
2219 let view = self.view().downgrade();
2220 let entity_id = entity.entity_id();
2221 let window_handle = self.window.handle;
2222 let (subscription, activate) = self.app.release_listeners.insert(
2223 entity_id,
2224 Box::new(move |entity, cx| {
2225 let entity = entity.downcast_mut().expect("invalid entity type");
2226 let _ = window_handle.update(cx, |_, cx| {
2227 view.update(cx, |this, cx| on_release(this, entity, cx))
2228 });
2229 }),
2230 );
2231 activate();
2232 subscription
2233 }
2234
2235 pub fn notify(&mut self) {
2236 self.window_cx.notify();
2237 self.window_cx.app.push_effect(Effect::Notify {
2238 emitter: self.view.model.entity_id,
2239 });
2240 }
2241
2242 pub fn observe_window_bounds(
2243 &mut self,
2244 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2245 ) -> Subscription {
2246 let view = self.view.downgrade();
2247 let (subscription, activate) = self.window.bounds_observers.insert(
2248 (),
2249 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2250 );
2251 activate();
2252 subscription
2253 }
2254
2255 pub fn observe_window_activation(
2256 &mut self,
2257 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2258 ) -> Subscription {
2259 let view = self.view.downgrade();
2260 let (subscription, activate) = self.window.activation_observers.insert(
2261 (),
2262 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2263 );
2264 activate();
2265 subscription
2266 }
2267
2268 /// Register a listener to be called when the given focus handle receives focus.
2269 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2270 /// is dropped.
2271 pub fn on_focus(
2272 &mut self,
2273 handle: &FocusHandle,
2274 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2275 ) -> Subscription {
2276 let view = self.view.downgrade();
2277 let focus_id = handle.id;
2278 let (subscription, activate) = self.window.focus_listeners.insert(
2279 (),
2280 Box::new(move |event, cx| {
2281 view.update(cx, |view, cx| {
2282 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2283 listener(view, cx)
2284 }
2285 })
2286 .is_ok()
2287 }),
2288 );
2289 self.app.defer(move |_| activate());
2290 subscription
2291 }
2292
2293 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2294 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2295 /// is dropped.
2296 pub fn on_focus_in(
2297 &mut self,
2298 handle: &FocusHandle,
2299 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2300 ) -> Subscription {
2301 let view = self.view.downgrade();
2302 let focus_id = handle.id;
2303 let (subscription, activate) = self.window.focus_listeners.insert(
2304 (),
2305 Box::new(move |event, cx| {
2306 view.update(cx, |view, cx| {
2307 if event
2308 .focused
2309 .as_ref()
2310 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2311 {
2312 listener(view, cx)
2313 }
2314 })
2315 .is_ok()
2316 }),
2317 );
2318 self.app.defer(move |_| activate());
2319 subscription
2320 }
2321
2322 /// Register a listener to be called when the given focus handle loses focus.
2323 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2324 /// is dropped.
2325 pub fn on_blur(
2326 &mut self,
2327 handle: &FocusHandle,
2328 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2329 ) -> Subscription {
2330 let view = self.view.downgrade();
2331 let focus_id = handle.id;
2332 let (subscription, activate) = self.window.focus_listeners.insert(
2333 (),
2334 Box::new(move |event, cx| {
2335 view.update(cx, |view, cx| {
2336 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2337 listener(view, cx)
2338 }
2339 })
2340 .is_ok()
2341 }),
2342 );
2343 self.app.defer(move |_| activate());
2344 subscription
2345 }
2346
2347 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2348 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2349 /// is dropped.
2350 pub fn on_focus_out(
2351 &mut self,
2352 handle: &FocusHandle,
2353 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2354 ) -> Subscription {
2355 let view = self.view.downgrade();
2356 let focus_id = handle.id;
2357 let (subscription, activate) = self.window.focus_listeners.insert(
2358 (),
2359 Box::new(move |event, cx| {
2360 view.update(cx, |view, cx| {
2361 if event
2362 .blurred
2363 .as_ref()
2364 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2365 {
2366 listener(view, cx)
2367 }
2368 })
2369 .is_ok()
2370 }),
2371 );
2372 self.app.defer(move |_| activate());
2373 subscription
2374 }
2375
2376 pub fn spawn<Fut, R>(
2377 &mut self,
2378 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2379 ) -> Task<R>
2380 where
2381 R: 'static,
2382 Fut: Future<Output = R> + 'static,
2383 {
2384 let view = self.view().downgrade();
2385 self.window_cx.spawn(|cx| f(view, cx))
2386 }
2387
2388 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2389 where
2390 G: 'static,
2391 {
2392 let mut global = self.app.lease_global::<G>();
2393 let result = f(&mut global, self);
2394 self.app.end_global_lease(global);
2395 result
2396 }
2397
2398 pub fn observe_global<G: 'static>(
2399 &mut self,
2400 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2401 ) -> Subscription {
2402 let window_handle = self.window.handle;
2403 let view = self.view().downgrade();
2404 let (subscription, activate) = self.global_observers.insert(
2405 TypeId::of::<G>(),
2406 Box::new(move |cx| {
2407 window_handle
2408 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2409 .unwrap_or(false)
2410 }),
2411 );
2412 self.app.defer(move |_| activate());
2413 subscription
2414 }
2415
2416 pub fn on_mouse_event<Event: 'static>(
2417 &mut self,
2418 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2419 ) {
2420 let handle = self.view().clone();
2421 self.window_cx.on_mouse_event(move |event, phase, cx| {
2422 handle.update(cx, |view, cx| {
2423 handler(view, event, phase, cx);
2424 })
2425 });
2426 }
2427
2428 pub fn on_key_event<Event: 'static>(
2429 &mut self,
2430 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2431 ) {
2432 let handle = self.view().clone();
2433 self.window_cx.on_key_event(move |event, phase, cx| {
2434 handle.update(cx, |view, cx| {
2435 handler(view, event, phase, cx);
2436 })
2437 });
2438 }
2439
2440 pub fn on_action(
2441 &mut self,
2442 action_type: TypeId,
2443 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2444 ) {
2445 let handle = self.view().clone();
2446 self.window_cx
2447 .on_action(action_type, move |action, phase, cx| {
2448 handle.update(cx, |view, cx| {
2449 handler(view, action, phase, cx);
2450 })
2451 });
2452 }
2453
2454 pub fn emit<Evt>(&mut self, event: Evt)
2455 where
2456 Evt: 'static,
2457 V: EventEmitter<Evt>,
2458 {
2459 let emitter = self.view.model.entity_id;
2460 self.app.push_effect(Effect::Emit {
2461 emitter,
2462 event_type: TypeId::of::<Evt>(),
2463 event: Box::new(event),
2464 });
2465 }
2466
2467 pub fn focus_self(&mut self)
2468 where
2469 V: FocusableView,
2470 {
2471 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2472 }
2473
2474 pub fn dismiss_self(&mut self)
2475 where
2476 V: ManagedView,
2477 {
2478 self.defer(|_, cx| cx.emit(DismissEvent))
2479 }
2480
2481 pub fn listener<E>(
2482 &self,
2483 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2484 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2485 let view = self.view().downgrade();
2486 move |e: &E, cx: &mut WindowContext| {
2487 view.update(cx, |view, cx| f(view, e, cx)).ok();
2488 }
2489 }
2490}
2491
2492impl<V> Context for ViewContext<'_, V> {
2493 type Result<U> = U;
2494
2495 fn build_model<T: 'static>(
2496 &mut self,
2497 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2498 ) -> Model<T> {
2499 self.window_cx.build_model(build_model)
2500 }
2501
2502 fn update_model<T: 'static, R>(
2503 &mut self,
2504 model: &Model<T>,
2505 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2506 ) -> R {
2507 self.window_cx.update_model(model, update)
2508 }
2509
2510 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2511 where
2512 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2513 {
2514 self.window_cx.update_window(window, update)
2515 }
2516
2517 fn read_model<T, R>(
2518 &self,
2519 handle: &Model<T>,
2520 read: impl FnOnce(&T, &AppContext) -> R,
2521 ) -> Self::Result<R>
2522 where
2523 T: 'static,
2524 {
2525 self.window_cx.read_model(handle, read)
2526 }
2527
2528 fn read_window<T, R>(
2529 &self,
2530 window: &WindowHandle<T>,
2531 read: impl FnOnce(View<T>, &AppContext) -> R,
2532 ) -> Result<R>
2533 where
2534 T: 'static,
2535 {
2536 self.window_cx.read_window(window, read)
2537 }
2538}
2539
2540impl<V: 'static> VisualContext for ViewContext<'_, V> {
2541 fn build_view<W: Render + 'static>(
2542 &mut self,
2543 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2544 ) -> Self::Result<View<W>> {
2545 self.window_cx.build_view(build_view_state)
2546 }
2547
2548 fn update_view<V2: 'static, R>(
2549 &mut self,
2550 view: &View<V2>,
2551 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2552 ) -> Self::Result<R> {
2553 self.window_cx.update_view(view, update)
2554 }
2555
2556 fn replace_root_view<W>(
2557 &mut self,
2558 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2559 ) -> Self::Result<View<W>>
2560 where
2561 W: 'static + Render,
2562 {
2563 self.window_cx.replace_root_view(build_view)
2564 }
2565
2566 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2567 self.window_cx.focus_view(view)
2568 }
2569
2570 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2571 self.window_cx.dismiss_view(view)
2572 }
2573}
2574
2575impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2576 type Target = WindowContext<'a>;
2577
2578 fn deref(&self) -> &Self::Target {
2579 &self.window_cx
2580 }
2581}
2582
2583impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2584 fn deref_mut(&mut self) -> &mut Self::Target {
2585 &mut self.window_cx
2586 }
2587}
2588
2589// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2590slotmap::new_key_type! { pub struct WindowId; }
2591
2592impl WindowId {
2593 pub fn as_u64(&self) -> u64 {
2594 self.0.as_ffi()
2595 }
2596}
2597
2598#[derive(Deref, DerefMut)]
2599pub struct WindowHandle<V> {
2600 #[deref]
2601 #[deref_mut]
2602 pub(crate) any_handle: AnyWindowHandle,
2603 state_type: PhantomData<V>,
2604}
2605
2606impl<V: 'static + Render> WindowHandle<V> {
2607 pub fn new(id: WindowId) -> Self {
2608 WindowHandle {
2609 any_handle: AnyWindowHandle {
2610 id,
2611 state_type: TypeId::of::<V>(),
2612 },
2613 state_type: PhantomData,
2614 }
2615 }
2616
2617 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2618 where
2619 C: Context,
2620 {
2621 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2622 root_view
2623 .downcast::<V>()
2624 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2625 }))
2626 }
2627
2628 pub fn update<C, R>(
2629 &self,
2630 cx: &mut C,
2631 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2632 ) -> Result<R>
2633 where
2634 C: Context,
2635 {
2636 cx.update_window(self.any_handle, |root_view, cx| {
2637 let view = root_view
2638 .downcast::<V>()
2639 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2640 Ok(cx.update_view(&view, update))
2641 })?
2642 }
2643
2644 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2645 let x = cx
2646 .windows
2647 .get(self.id)
2648 .and_then(|window| {
2649 window
2650 .as_ref()
2651 .and_then(|window| window.root_view.clone())
2652 .map(|root_view| root_view.downcast::<V>())
2653 })
2654 .ok_or_else(|| anyhow!("window not found"))?
2655 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2656
2657 Ok(x.read(cx))
2658 }
2659
2660 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2661 where
2662 C: Context,
2663 {
2664 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2665 }
2666
2667 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2668 where
2669 C: Context,
2670 {
2671 cx.read_window(self, |root_view, _cx| root_view.clone())
2672 }
2673
2674 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2675 cx.windows
2676 .get(self.id)
2677 .and_then(|window| window.as_ref().map(|window| window.active))
2678 }
2679}
2680
2681impl<V> Copy for WindowHandle<V> {}
2682
2683impl<V> Clone for WindowHandle<V> {
2684 fn clone(&self) -> Self {
2685 WindowHandle {
2686 any_handle: self.any_handle,
2687 state_type: PhantomData,
2688 }
2689 }
2690}
2691
2692impl<V> PartialEq for WindowHandle<V> {
2693 fn eq(&self, other: &Self) -> bool {
2694 self.any_handle == other.any_handle
2695 }
2696}
2697
2698impl<V> Eq for WindowHandle<V> {}
2699
2700impl<V> Hash for WindowHandle<V> {
2701 fn hash<H: Hasher>(&self, state: &mut H) {
2702 self.any_handle.hash(state);
2703 }
2704}
2705
2706impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2707 fn into(self) -> AnyWindowHandle {
2708 self.any_handle
2709 }
2710}
2711
2712#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2713pub struct AnyWindowHandle {
2714 pub(crate) id: WindowId,
2715 state_type: TypeId,
2716}
2717
2718impl AnyWindowHandle {
2719 pub fn window_id(&self) -> WindowId {
2720 self.id
2721 }
2722
2723 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2724 if TypeId::of::<T>() == self.state_type {
2725 Some(WindowHandle {
2726 any_handle: *self,
2727 state_type: PhantomData,
2728 })
2729 } else {
2730 None
2731 }
2732 }
2733
2734 pub fn update<C, R>(
2735 self,
2736 cx: &mut C,
2737 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2738 ) -> Result<R>
2739 where
2740 C: Context,
2741 {
2742 cx.update_window(self, update)
2743 }
2744
2745 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2746 where
2747 C: Context,
2748 T: 'static,
2749 {
2750 let view = self
2751 .downcast::<T>()
2752 .context("the type of the window's root view has changed")?;
2753
2754 cx.read_window(&view, read)
2755 }
2756}
2757
2758#[cfg(any(test, feature = "test-support"))]
2759impl From<SmallVec<[u32; 16]>> for StackingOrder {
2760 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2761 StackingOrder(small_vec)
2762 }
2763}
2764
2765#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2766pub enum ElementId {
2767 View(EntityId),
2768 Integer(usize),
2769 Name(SharedString),
2770 FocusHandle(FocusId),
2771 NamedInteger(SharedString, usize),
2772}
2773
2774impl ElementId {
2775 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2776 ElementId::View(entity_id)
2777 }
2778}
2779
2780impl TryInto<SharedString> for ElementId {
2781 type Error = anyhow::Error;
2782
2783 fn try_into(self) -> anyhow::Result<SharedString> {
2784 if let ElementId::Name(name) = self {
2785 Ok(name)
2786 } else {
2787 Err(anyhow!("element id is not string"))
2788 }
2789 }
2790}
2791
2792impl From<usize> for ElementId {
2793 fn from(id: usize) -> Self {
2794 ElementId::Integer(id)
2795 }
2796}
2797
2798impl From<i32> for ElementId {
2799 fn from(id: i32) -> Self {
2800 Self::Integer(id as usize)
2801 }
2802}
2803
2804impl From<SharedString> for ElementId {
2805 fn from(name: SharedString) -> Self {
2806 ElementId::Name(name)
2807 }
2808}
2809
2810impl From<&'static str> for ElementId {
2811 fn from(name: &'static str) -> Self {
2812 ElementId::Name(name.into())
2813 }
2814}
2815
2816impl<'a> From<&'a FocusHandle> for ElementId {
2817 fn from(handle: &'a FocusHandle) -> Self {
2818 ElementId::FocusHandle(handle.id)
2819 }
2820}
2821
2822impl From<(&'static str, EntityId)> for ElementId {
2823 fn from((name, id): (&'static str, EntityId)) -> Self {
2824 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2825 }
2826}
2827
2828impl From<(&'static str, usize)> for ElementId {
2829 fn from((name, id): (&'static str, usize)) -> Self {
2830 ElementId::NamedInteger(name.into(), id)
2831 }
2832}