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 // Capture phase
1354 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1355 self.propagate_event = true;
1356
1357 for node_id in &dispatch_path {
1358 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1359
1360 if !node.context.is_empty() {
1361 context_stack.push(node.context.clone());
1362 }
1363
1364 for key_listener in node.key_listeners.clone() {
1365 key_listener(event, DispatchPhase::Capture, self);
1366 if !self.propagate_event {
1367 return;
1368 }
1369 }
1370 }
1371
1372 // Bubble phase
1373 for node_id in dispatch_path.iter().rev() {
1374 // Handle low level key events
1375 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1376 for key_listener in node.key_listeners.clone() {
1377 key_listener(event, DispatchPhase::Bubble, self);
1378 if !self.propagate_event {
1379 return;
1380 }
1381 }
1382
1383 // Match keystrokes
1384 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1385 if !node.context.is_empty() {
1386 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1387 if let Some(action) = self
1388 .window
1389 .current_frame
1390 .dispatch_tree
1391 .dispatch_key(&key_down_event.keystroke, &context_stack)
1392 {
1393 self.dispatch_action_on_node(*node_id, action);
1394 if !self.propagate_event {
1395 return;
1396 }
1397 }
1398 }
1399
1400 context_stack.pop();
1401 }
1402 }
1403 }
1404 }
1405
1406 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1407 let dispatch_path = self
1408 .window
1409 .current_frame
1410 .dispatch_tree
1411 .dispatch_path(node_id);
1412
1413 // Capture phase
1414 for node_id in &dispatch_path {
1415 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1416 for DispatchActionListener {
1417 action_type,
1418 listener,
1419 } in node.action_listeners.clone()
1420 {
1421 let any_action = action.as_any();
1422 if action_type == any_action.type_id() {
1423 listener(any_action, DispatchPhase::Capture, self);
1424 if !self.propagate_event {
1425 return;
1426 }
1427 }
1428 }
1429 }
1430
1431 // Bubble phase
1432 for node_id in dispatch_path.iter().rev() {
1433 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1434 for DispatchActionListener {
1435 action_type,
1436 listener,
1437 } in node.action_listeners.clone()
1438 {
1439 let any_action = action.as_any();
1440 if action_type == any_action.type_id() {
1441 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1442 listener(any_action, DispatchPhase::Bubble, self);
1443 if !self.propagate_event {
1444 return;
1445 }
1446 }
1447 }
1448 }
1449 }
1450
1451 /// Register the given handler to be invoked whenever the global of the given type
1452 /// is updated.
1453 pub fn observe_global<G: 'static>(
1454 &mut self,
1455 f: impl Fn(&mut WindowContext<'_>) + 'static,
1456 ) -> Subscription {
1457 let window_handle = self.window.handle;
1458 let (subscription, activate) = self.global_observers.insert(
1459 TypeId::of::<G>(),
1460 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1461 );
1462 self.app.defer(move |_| activate());
1463 subscription
1464 }
1465
1466 pub fn activate_window(&self) {
1467 self.window.platform_window.activate();
1468 }
1469
1470 pub fn minimize_window(&self) {
1471 self.window.platform_window.minimize();
1472 }
1473
1474 pub fn toggle_full_screen(&self) {
1475 self.window.platform_window.toggle_full_screen();
1476 }
1477
1478 pub fn prompt(
1479 &self,
1480 level: PromptLevel,
1481 msg: &str,
1482 answers: &[&str],
1483 ) -> oneshot::Receiver<usize> {
1484 self.window.platform_window.prompt(level, msg, answers)
1485 }
1486
1487 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1488 if let Some(focus_id) = self.window.focus {
1489 let mut actions = self
1490 .window
1491 .current_frame
1492 .dispatch_tree
1493 .available_actions(focus_id);
1494 actions.extend(
1495 self.app
1496 .global_action_listeners
1497 .keys()
1498 .filter_map(|type_id| self.app.actions.build_action_type(type_id).ok()),
1499 );
1500 actions
1501 } else {
1502 Vec::new()
1503 }
1504 }
1505
1506 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1507 self.window
1508 .current_frame
1509 .dispatch_tree
1510 .bindings_for_action(action)
1511 }
1512
1513 pub fn listener_for<V: Render, E>(
1514 &self,
1515 view: &View<V>,
1516 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1517 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1518 let view = view.downgrade();
1519 move |e: &E, cx: &mut WindowContext| {
1520 view.update(cx, |view, cx| f(view, e, cx)).ok();
1521 }
1522 }
1523
1524 pub fn handler_for<V: Render>(
1525 &self,
1526 view: &View<V>,
1527 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1528 ) -> impl Fn(&mut WindowContext) {
1529 let view = view.downgrade();
1530 move |cx: &mut WindowContext| {
1531 view.update(cx, |view, cx| f(view, cx)).ok();
1532 }
1533 }
1534
1535 //========== ELEMENT RELATED FUNCTIONS ===========
1536 pub fn with_key_dispatch<R>(
1537 &mut self,
1538 context: KeyContext,
1539 focus_handle: Option<FocusHandle>,
1540 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1541 ) -> R {
1542 let window = &mut self.window;
1543 window
1544 .current_frame
1545 .dispatch_tree
1546 .push_node(context.clone());
1547 if let Some(focus_handle) = focus_handle.as_ref() {
1548 window
1549 .current_frame
1550 .dispatch_tree
1551 .make_focusable(focus_handle.id);
1552 }
1553 let result = f(focus_handle, self);
1554
1555 self.window.current_frame.dispatch_tree.pop_node();
1556
1557 result
1558 }
1559
1560 /// Register a focus listener for the current frame only. It will be cleared
1561 /// on the next frame render. You should use this method only from within elements,
1562 /// and we may want to enforce that better via a different context type.
1563 // todo!() Move this to `FrameContext` to emphasize its individuality?
1564 pub fn on_focus_changed(
1565 &mut self,
1566 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1567 ) {
1568 self.window
1569 .current_frame
1570 .focus_listeners
1571 .push(Box::new(move |event, cx| {
1572 listener(event, cx);
1573 }));
1574 }
1575
1576 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1577 /// platform to receive textual input with proper integration with concerns such
1578 /// as IME interactions.
1579 pub fn handle_input(
1580 &mut self,
1581 focus_handle: &FocusHandle,
1582 input_handler: impl PlatformInputHandler,
1583 ) {
1584 if focus_handle.is_focused(self) {
1585 self.window
1586 .platform_window
1587 .set_input_handler(Box::new(input_handler));
1588 }
1589 }
1590
1591 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1592 let mut this = self.to_async();
1593 self.window
1594 .platform_window
1595 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1596 }
1597}
1598
1599impl Context for WindowContext<'_> {
1600 type Result<T> = T;
1601
1602 fn build_model<T>(
1603 &mut self,
1604 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1605 ) -> Model<T>
1606 where
1607 T: 'static,
1608 {
1609 let slot = self.app.entities.reserve();
1610 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1611 self.entities.insert(slot, model)
1612 }
1613
1614 fn update_model<T: 'static, R>(
1615 &mut self,
1616 model: &Model<T>,
1617 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1618 ) -> R {
1619 let mut entity = self.entities.lease(model);
1620 let result = update(
1621 &mut *entity,
1622 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1623 );
1624 self.entities.end_lease(entity);
1625 result
1626 }
1627
1628 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1629 where
1630 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1631 {
1632 if window == self.window.handle {
1633 let root_view = self.window.root_view.clone().unwrap();
1634 Ok(update(root_view, self))
1635 } else {
1636 window.update(self.app, update)
1637 }
1638 }
1639
1640 fn read_model<T, R>(
1641 &self,
1642 handle: &Model<T>,
1643 read: impl FnOnce(&T, &AppContext) -> R,
1644 ) -> Self::Result<R>
1645 where
1646 T: 'static,
1647 {
1648 let entity = self.entities.read(handle);
1649 read(&*entity, &*self.app)
1650 }
1651
1652 fn read_window<T, R>(
1653 &self,
1654 window: &WindowHandle<T>,
1655 read: impl FnOnce(View<T>, &AppContext) -> R,
1656 ) -> Result<R>
1657 where
1658 T: 'static,
1659 {
1660 if window.any_handle == self.window.handle {
1661 let root_view = self
1662 .window
1663 .root_view
1664 .clone()
1665 .unwrap()
1666 .downcast::<T>()
1667 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1668 Ok(read(root_view, self))
1669 } else {
1670 self.app.read_window(window, read)
1671 }
1672 }
1673}
1674
1675impl VisualContext for WindowContext<'_> {
1676 fn build_view<V>(
1677 &mut self,
1678 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1679 ) -> Self::Result<View<V>>
1680 where
1681 V: 'static + Render,
1682 {
1683 let slot = self.app.entities.reserve();
1684 let view = View {
1685 model: slot.clone(),
1686 };
1687 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1688 let entity = build_view_state(&mut cx);
1689 cx.entities.insert(slot, entity);
1690
1691 cx.new_view_observers
1692 .clone()
1693 .retain(&TypeId::of::<V>(), |observer| {
1694 let any_view = AnyView::from(view.clone());
1695 (observer)(any_view, self);
1696 true
1697 });
1698
1699 view
1700 }
1701
1702 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1703 fn update_view<T: 'static, R>(
1704 &mut self,
1705 view: &View<T>,
1706 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1707 ) -> Self::Result<R> {
1708 let mut lease = self.app.entities.lease(&view.model);
1709 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1710 let result = update(&mut *lease, &mut cx);
1711 cx.app.entities.end_lease(lease);
1712 result
1713 }
1714
1715 fn replace_root_view<V>(
1716 &mut self,
1717 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1718 ) -> Self::Result<View<V>>
1719 where
1720 V: 'static + Render,
1721 {
1722 let slot = self.app.entities.reserve();
1723 let view = View {
1724 model: slot.clone(),
1725 };
1726 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1727 let entity = build_view(&mut cx);
1728 self.entities.insert(slot, entity);
1729 self.window.root_view = Some(view.clone().into());
1730 view
1731 }
1732
1733 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1734 self.update_view(view, |view, cx| {
1735 view.focus_handle(cx).clone().focus(cx);
1736 })
1737 }
1738
1739 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1740 where
1741 V: ManagedView,
1742 {
1743 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1744 }
1745}
1746
1747impl<'a> std::ops::Deref for WindowContext<'a> {
1748 type Target = AppContext;
1749
1750 fn deref(&self) -> &Self::Target {
1751 &self.app
1752 }
1753}
1754
1755impl<'a> std::ops::DerefMut for WindowContext<'a> {
1756 fn deref_mut(&mut self) -> &mut Self::Target {
1757 &mut self.app
1758 }
1759}
1760
1761impl<'a> Borrow<AppContext> for WindowContext<'a> {
1762 fn borrow(&self) -> &AppContext {
1763 &self.app
1764 }
1765}
1766
1767impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1768 fn borrow_mut(&mut self) -> &mut AppContext {
1769 &mut self.app
1770 }
1771}
1772
1773pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1774 fn app_mut(&mut self) -> &mut AppContext {
1775 self.borrow_mut()
1776 }
1777
1778 fn app(&self) -> &AppContext {
1779 self.borrow()
1780 }
1781
1782 fn window(&self) -> &Window {
1783 self.borrow()
1784 }
1785
1786 fn window_mut(&mut self) -> &mut Window {
1787 self.borrow_mut()
1788 }
1789
1790 /// Pushes the given element id onto the global stack and invokes the given closure
1791 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1792 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1793 /// used to associate state with identified elements across separate frames.
1794 fn with_element_id<R>(
1795 &mut self,
1796 id: Option<impl Into<ElementId>>,
1797 f: impl FnOnce(&mut Self) -> R,
1798 ) -> R {
1799 if let Some(id) = id.map(Into::into) {
1800 let window = self.window_mut();
1801 window.element_id_stack.push(id.into());
1802 let result = f(self);
1803 let window: &mut Window = self.borrow_mut();
1804 window.element_id_stack.pop();
1805 result
1806 } else {
1807 f(self)
1808 }
1809 }
1810
1811 /// Invoke the given function with the given content mask after intersecting it
1812 /// with the current mask.
1813 fn with_content_mask<R>(
1814 &mut self,
1815 mask: Option<ContentMask<Pixels>>,
1816 f: impl FnOnce(&mut Self) -> R,
1817 ) -> R {
1818 if let Some(mask) = mask {
1819 let mask = mask.intersect(&self.content_mask());
1820 self.window_mut()
1821 .current_frame
1822 .content_mask_stack
1823 .push(mask);
1824 let result = f(self);
1825 self.window_mut().current_frame.content_mask_stack.pop();
1826 result
1827 } else {
1828 f(self)
1829 }
1830 }
1831
1832 /// Invoke the given function with the content mask reset to that
1833 /// of the window.
1834 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1835 let mask = ContentMask {
1836 bounds: Bounds {
1837 origin: Point::default(),
1838 size: self.window().viewport_size,
1839 },
1840 };
1841 self.window_mut()
1842 .current_frame
1843 .content_mask_stack
1844 .push(mask);
1845 let result = f(self);
1846 self.window_mut().current_frame.content_mask_stack.pop();
1847 result
1848 }
1849
1850 /// Update the global element offset relative to the current offset. This is used to implement
1851 /// scrolling.
1852 fn with_element_offset<R>(
1853 &mut self,
1854 offset: Point<Pixels>,
1855 f: impl FnOnce(&mut Self) -> R,
1856 ) -> R {
1857 if offset.is_zero() {
1858 return f(self);
1859 };
1860
1861 let abs_offset = self.element_offset() + offset;
1862 self.with_absolute_element_offset(abs_offset, f)
1863 }
1864
1865 /// Update the global element offset based on the given offset. This is used to implement
1866 /// drag handles and other manual painting of elements.
1867 fn with_absolute_element_offset<R>(
1868 &mut self,
1869 offset: Point<Pixels>,
1870 f: impl FnOnce(&mut Self) -> R,
1871 ) -> R {
1872 self.window_mut()
1873 .current_frame
1874 .element_offset_stack
1875 .push(offset);
1876 let result = f(self);
1877 self.window_mut().current_frame.element_offset_stack.pop();
1878 result
1879 }
1880
1881 /// Obtain the current element offset.
1882 fn element_offset(&self) -> Point<Pixels> {
1883 self.window()
1884 .current_frame
1885 .element_offset_stack
1886 .last()
1887 .copied()
1888 .unwrap_or_default()
1889 }
1890
1891 /// Update or intialize state for an element with the given id that lives across multiple
1892 /// frames. If an element with this id existed in the previous frame, its state will be passed
1893 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1894 /// when drawing the next frame.
1895 fn with_element_state<S, R>(
1896 &mut self,
1897 id: ElementId,
1898 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1899 ) -> R
1900 where
1901 S: 'static,
1902 {
1903 self.with_element_id(Some(id), |cx| {
1904 let global_id = cx.window().element_id_stack.clone();
1905
1906 if let Some(any) = cx
1907 .window_mut()
1908 .current_frame
1909 .element_states
1910 .remove(&global_id)
1911 .or_else(|| {
1912 cx.window_mut()
1913 .previous_frame
1914 .element_states
1915 .remove(&global_id)
1916 })
1917 {
1918 let ElementStateBox {
1919 inner,
1920
1921 #[cfg(debug_assertions)]
1922 type_name
1923 } = any;
1924 // Using the extra inner option to avoid needing to reallocate a new box.
1925 let mut state_box = inner
1926 .downcast::<Option<S>>()
1927 .map_err(|_| {
1928 #[cfg(debug_assertions)]
1929 {
1930 anyhow!(
1931 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1932 std::any::type_name::<S>(),
1933 type_name
1934 )
1935 }
1936
1937 #[cfg(not(debug_assertions))]
1938 {
1939 anyhow!(
1940 "invalid element state type for id, requested_type {:?}",
1941 std::any::type_name::<S>(),
1942 )
1943 }
1944 })
1945 .unwrap();
1946
1947 // Actual: Option<AnyElement> <- View
1948 // Requested: () <- AnyElemet
1949 let state = state_box
1950 .take()
1951 .expect("element state is already on the stack");
1952 let (result, state) = f(Some(state), cx);
1953 state_box.replace(state);
1954 cx.window_mut()
1955 .current_frame
1956 .element_states
1957 .insert(global_id, ElementStateBox {
1958 inner: state_box,
1959
1960 #[cfg(debug_assertions)]
1961 type_name
1962 });
1963 result
1964 } else {
1965 let (result, state) = f(None, cx);
1966 cx.window_mut()
1967 .current_frame
1968 .element_states
1969 .insert(global_id,
1970 ElementStateBox {
1971 inner: Box::new(Some(state)),
1972
1973 #[cfg(debug_assertions)]
1974 type_name: std::any::type_name::<S>()
1975 }
1976
1977 );
1978 result
1979 }
1980 })
1981 }
1982
1983 /// Obtain the current content mask.
1984 fn content_mask(&self) -> ContentMask<Pixels> {
1985 self.window()
1986 .current_frame
1987 .content_mask_stack
1988 .last()
1989 .cloned()
1990 .unwrap_or_else(|| ContentMask {
1991 bounds: Bounds {
1992 origin: Point::default(),
1993 size: self.window().viewport_size,
1994 },
1995 })
1996 }
1997
1998 /// The size of an em for the base font of the application. Adjusting this value allows the
1999 /// UI to scale, just like zooming a web page.
2000 fn rem_size(&self) -> Pixels {
2001 self.window().rem_size
2002 }
2003}
2004
2005impl Borrow<Window> for WindowContext<'_> {
2006 fn borrow(&self) -> &Window {
2007 &self.window
2008 }
2009}
2010
2011impl BorrowMut<Window> for WindowContext<'_> {
2012 fn borrow_mut(&mut self) -> &mut Window {
2013 &mut self.window
2014 }
2015}
2016
2017impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
2018
2019pub struct ViewContext<'a, V> {
2020 window_cx: WindowContext<'a>,
2021 view: &'a View<V>,
2022}
2023
2024impl<V> Borrow<AppContext> for ViewContext<'_, V> {
2025 fn borrow(&self) -> &AppContext {
2026 &*self.window_cx.app
2027 }
2028}
2029
2030impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
2031 fn borrow_mut(&mut self) -> &mut AppContext {
2032 &mut *self.window_cx.app
2033 }
2034}
2035
2036impl<V> Borrow<Window> for ViewContext<'_, V> {
2037 fn borrow(&self) -> &Window {
2038 &*self.window_cx.window
2039 }
2040}
2041
2042impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2043 fn borrow_mut(&mut self) -> &mut Window {
2044 &mut *self.window_cx.window
2045 }
2046}
2047
2048impl<'a, V: 'static> ViewContext<'a, V> {
2049 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2050 Self {
2051 window_cx: WindowContext::new(app, window),
2052 view,
2053 }
2054 }
2055
2056 pub fn entity_id(&self) -> EntityId {
2057 self.view.entity_id()
2058 }
2059
2060 pub fn view(&self) -> &View<V> {
2061 self.view
2062 }
2063
2064 pub fn model(&self) -> &Model<V> {
2065 &self.view.model
2066 }
2067
2068 /// Access the underlying window context.
2069 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2070 &mut self.window_cx
2071 }
2072
2073 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2074 self.window.current_frame.z_index_stack.push(z_index);
2075 let result = f(self);
2076 self.window.current_frame.z_index_stack.pop();
2077 result
2078 }
2079
2080 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2081 where
2082 V: 'static,
2083 {
2084 let view = self.view().clone();
2085 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2086 }
2087
2088 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2089 /// that are currently on the stack to be returned to the app.
2090 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2091 let view = self.view().downgrade();
2092 self.window_cx.defer(move |cx| {
2093 view.update(cx, f).ok();
2094 });
2095 }
2096
2097 pub fn observe<V2, E>(
2098 &mut self,
2099 entity: &E,
2100 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2101 ) -> Subscription
2102 where
2103 V2: 'static,
2104 V: 'static,
2105 E: Entity<V2>,
2106 {
2107 let view = self.view().downgrade();
2108 let entity_id = entity.entity_id();
2109 let entity = entity.downgrade();
2110 let window_handle = self.window.handle;
2111 let (subscription, activate) = self.app.observers.insert(
2112 entity_id,
2113 Box::new(move |cx| {
2114 window_handle
2115 .update(cx, |_, cx| {
2116 if let Some(handle) = E::upgrade_from(&entity) {
2117 view.update(cx, |this, cx| on_notify(this, handle, cx))
2118 .is_ok()
2119 } else {
2120 false
2121 }
2122 })
2123 .unwrap_or(false)
2124 }),
2125 );
2126 self.app.defer(move |_| activate());
2127 subscription
2128 }
2129
2130 pub fn subscribe<V2, E, Evt>(
2131 &mut self,
2132 entity: &E,
2133 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2134 ) -> Subscription
2135 where
2136 V2: EventEmitter<Evt>,
2137 E: Entity<V2>,
2138 Evt: 'static,
2139 {
2140 let view = self.view().downgrade();
2141 let entity_id = entity.entity_id();
2142 let handle = entity.downgrade();
2143 let window_handle = self.window.handle;
2144 let (subscription, activate) = self.app.event_listeners.insert(
2145 entity_id,
2146 (
2147 TypeId::of::<Evt>(),
2148 Box::new(move |event, cx| {
2149 window_handle
2150 .update(cx, |_, cx| {
2151 if let Some(handle) = E::upgrade_from(&handle) {
2152 let event = event.downcast_ref().expect("invalid event type");
2153 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2154 .is_ok()
2155 } else {
2156 false
2157 }
2158 })
2159 .unwrap_or(false)
2160 }),
2161 ),
2162 );
2163 self.app.defer(move |_| activate());
2164 subscription
2165 }
2166
2167 pub fn on_release(
2168 &mut self,
2169 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2170 ) -> Subscription {
2171 let window_handle = self.window.handle;
2172 let (subscription, activate) = self.app.release_listeners.insert(
2173 self.view.model.entity_id,
2174 Box::new(move |this, cx| {
2175 let this = this.downcast_mut().expect("invalid entity type");
2176 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2177 }),
2178 );
2179 activate();
2180 subscription
2181 }
2182
2183 pub fn observe_release<V2, E>(
2184 &mut self,
2185 entity: &E,
2186 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2187 ) -> Subscription
2188 where
2189 V: 'static,
2190 V2: 'static,
2191 E: Entity<V2>,
2192 {
2193 let view = self.view().downgrade();
2194 let entity_id = entity.entity_id();
2195 let window_handle = self.window.handle;
2196 let (subscription, activate) = self.app.release_listeners.insert(
2197 entity_id,
2198 Box::new(move |entity, cx| {
2199 let entity = entity.downcast_mut().expect("invalid entity type");
2200 let _ = window_handle.update(cx, |_, cx| {
2201 view.update(cx, |this, cx| on_release(this, entity, cx))
2202 });
2203 }),
2204 );
2205 activate();
2206 subscription
2207 }
2208
2209 pub fn notify(&mut self) {
2210 self.window_cx.notify();
2211 self.window_cx.app.push_effect(Effect::Notify {
2212 emitter: self.view.model.entity_id,
2213 });
2214 }
2215
2216 pub fn observe_window_bounds(
2217 &mut self,
2218 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2219 ) -> Subscription {
2220 let view = self.view.downgrade();
2221 let (subscription, activate) = self.window.bounds_observers.insert(
2222 (),
2223 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2224 );
2225 activate();
2226 subscription
2227 }
2228
2229 pub fn observe_window_activation(
2230 &mut self,
2231 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2232 ) -> Subscription {
2233 let view = self.view.downgrade();
2234 let (subscription, activate) = self.window.activation_observers.insert(
2235 (),
2236 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2237 );
2238 activate();
2239 subscription
2240 }
2241
2242 /// Register a listener to be called when the given focus handle receives focus.
2243 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2244 /// is dropped.
2245 pub fn on_focus(
2246 &mut self,
2247 handle: &FocusHandle,
2248 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2249 ) -> Subscription {
2250 let view = self.view.downgrade();
2251 let focus_id = handle.id;
2252 let (subscription, activate) = self.window.focus_listeners.insert(
2253 (),
2254 Box::new(move |event, cx| {
2255 view.update(cx, |view, cx| {
2256 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2257 listener(view, cx)
2258 }
2259 })
2260 .is_ok()
2261 }),
2262 );
2263 self.app.defer(move |_| activate());
2264 subscription
2265 }
2266
2267 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2268 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2269 /// is dropped.
2270 pub fn on_focus_in(
2271 &mut self,
2272 handle: &FocusHandle,
2273 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2274 ) -> Subscription {
2275 let view = self.view.downgrade();
2276 let focus_id = handle.id;
2277 let (subscription, activate) = self.window.focus_listeners.insert(
2278 (),
2279 Box::new(move |event, cx| {
2280 view.update(cx, |view, cx| {
2281 if event
2282 .focused
2283 .as_ref()
2284 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2285 {
2286 listener(view, cx)
2287 }
2288 })
2289 .is_ok()
2290 }),
2291 );
2292 self.app.defer(move |_| activate());
2293 subscription
2294 }
2295
2296 /// Register a listener to be called when the given focus handle loses focus.
2297 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2298 /// is dropped.
2299 pub fn on_blur(
2300 &mut self,
2301 handle: &FocusHandle,
2302 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2303 ) -> Subscription {
2304 let view = self.view.downgrade();
2305 let focus_id = handle.id;
2306 let (subscription, activate) = self.window.focus_listeners.insert(
2307 (),
2308 Box::new(move |event, cx| {
2309 view.update(cx, |view, cx| {
2310 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2311 listener(view, cx)
2312 }
2313 })
2314 .is_ok()
2315 }),
2316 );
2317 self.app.defer(move |_| activate());
2318 subscription
2319 }
2320
2321 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2322 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2323 /// is dropped.
2324 pub fn on_focus_out(
2325 &mut self,
2326 handle: &FocusHandle,
2327 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2328 ) -> Subscription {
2329 let view = self.view.downgrade();
2330 let focus_id = handle.id;
2331 let (subscription, activate) = self.window.focus_listeners.insert(
2332 (),
2333 Box::new(move |event, cx| {
2334 view.update(cx, |view, cx| {
2335 if event
2336 .blurred
2337 .as_ref()
2338 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2339 {
2340 listener(view, cx)
2341 }
2342 })
2343 .is_ok()
2344 }),
2345 );
2346 self.app.defer(move |_| activate());
2347 subscription
2348 }
2349
2350 pub fn spawn<Fut, R>(
2351 &mut self,
2352 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2353 ) -> Task<R>
2354 where
2355 R: 'static,
2356 Fut: Future<Output = R> + 'static,
2357 {
2358 let view = self.view().downgrade();
2359 self.window_cx.spawn(|cx| f(view, cx))
2360 }
2361
2362 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2363 where
2364 G: 'static,
2365 {
2366 let mut global = self.app.lease_global::<G>();
2367 let result = f(&mut global, self);
2368 self.app.end_global_lease(global);
2369 result
2370 }
2371
2372 pub fn observe_global<G: 'static>(
2373 &mut self,
2374 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2375 ) -> Subscription {
2376 let window_handle = self.window.handle;
2377 let view = self.view().downgrade();
2378 let (subscription, activate) = self.global_observers.insert(
2379 TypeId::of::<G>(),
2380 Box::new(move |cx| {
2381 window_handle
2382 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2383 .unwrap_or(false)
2384 }),
2385 );
2386 self.app.defer(move |_| activate());
2387 subscription
2388 }
2389
2390 pub fn on_mouse_event<Event: 'static>(
2391 &mut self,
2392 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2393 ) {
2394 let handle = self.view().clone();
2395 self.window_cx.on_mouse_event(move |event, phase, cx| {
2396 handle.update(cx, |view, cx| {
2397 handler(view, event, phase, cx);
2398 })
2399 });
2400 }
2401
2402 pub fn on_key_event<Event: 'static>(
2403 &mut self,
2404 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2405 ) {
2406 let handle = self.view().clone();
2407 self.window_cx.on_key_event(move |event, phase, cx| {
2408 handle.update(cx, |view, cx| {
2409 handler(view, event, phase, cx);
2410 })
2411 });
2412 }
2413
2414 pub fn on_action(
2415 &mut self,
2416 action_type: TypeId,
2417 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2418 ) {
2419 let handle = self.view().clone();
2420 self.window_cx
2421 .on_action(action_type, move |action, phase, cx| {
2422 handle.update(cx, |view, cx| {
2423 handler(view, action, phase, cx);
2424 })
2425 });
2426 }
2427
2428 pub fn emit<Evt>(&mut self, event: Evt)
2429 where
2430 Evt: 'static,
2431 V: EventEmitter<Evt>,
2432 {
2433 let emitter = self.view.model.entity_id;
2434 self.app.push_effect(Effect::Emit {
2435 emitter,
2436 event_type: TypeId::of::<Evt>(),
2437 event: Box::new(event),
2438 });
2439 }
2440
2441 pub fn focus_self(&mut self)
2442 where
2443 V: FocusableView,
2444 {
2445 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2446 }
2447
2448 pub fn dismiss_self(&mut self)
2449 where
2450 V: ManagedView,
2451 {
2452 self.defer(|_, cx| cx.emit(DismissEvent))
2453 }
2454
2455 pub fn listener<E>(
2456 &self,
2457 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2458 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2459 let view = self.view().downgrade();
2460 move |e: &E, cx: &mut WindowContext| {
2461 view.update(cx, |view, cx| f(view, e, cx)).ok();
2462 }
2463 }
2464}
2465
2466impl<V> Context for ViewContext<'_, V> {
2467 type Result<U> = U;
2468
2469 fn build_model<T: 'static>(
2470 &mut self,
2471 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2472 ) -> Model<T> {
2473 self.window_cx.build_model(build_model)
2474 }
2475
2476 fn update_model<T: 'static, R>(
2477 &mut self,
2478 model: &Model<T>,
2479 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2480 ) -> R {
2481 self.window_cx.update_model(model, update)
2482 }
2483
2484 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2485 where
2486 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2487 {
2488 self.window_cx.update_window(window, update)
2489 }
2490
2491 fn read_model<T, R>(
2492 &self,
2493 handle: &Model<T>,
2494 read: impl FnOnce(&T, &AppContext) -> R,
2495 ) -> Self::Result<R>
2496 where
2497 T: 'static,
2498 {
2499 self.window_cx.read_model(handle, read)
2500 }
2501
2502 fn read_window<T, R>(
2503 &self,
2504 window: &WindowHandle<T>,
2505 read: impl FnOnce(View<T>, &AppContext) -> R,
2506 ) -> Result<R>
2507 where
2508 T: 'static,
2509 {
2510 self.window_cx.read_window(window, read)
2511 }
2512}
2513
2514impl<V: 'static> VisualContext for ViewContext<'_, V> {
2515 fn build_view<W: Render + 'static>(
2516 &mut self,
2517 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2518 ) -> Self::Result<View<W>> {
2519 self.window_cx.build_view(build_view_state)
2520 }
2521
2522 fn update_view<V2: 'static, R>(
2523 &mut self,
2524 view: &View<V2>,
2525 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2526 ) -> Self::Result<R> {
2527 self.window_cx.update_view(view, update)
2528 }
2529
2530 fn replace_root_view<W>(
2531 &mut self,
2532 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2533 ) -> Self::Result<View<W>>
2534 where
2535 W: 'static + Render,
2536 {
2537 self.window_cx.replace_root_view(build_view)
2538 }
2539
2540 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2541 self.window_cx.focus_view(view)
2542 }
2543
2544 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2545 self.window_cx.dismiss_view(view)
2546 }
2547}
2548
2549impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2550 type Target = WindowContext<'a>;
2551
2552 fn deref(&self) -> &Self::Target {
2553 &self.window_cx
2554 }
2555}
2556
2557impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2558 fn deref_mut(&mut self) -> &mut Self::Target {
2559 &mut self.window_cx
2560 }
2561}
2562
2563// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2564slotmap::new_key_type! { pub struct WindowId; }
2565
2566impl WindowId {
2567 pub fn as_u64(&self) -> u64 {
2568 self.0.as_ffi()
2569 }
2570}
2571
2572#[derive(Deref, DerefMut)]
2573pub struct WindowHandle<V> {
2574 #[deref]
2575 #[deref_mut]
2576 pub(crate) any_handle: AnyWindowHandle,
2577 state_type: PhantomData<V>,
2578}
2579
2580impl<V: 'static + Render> WindowHandle<V> {
2581 pub fn new(id: WindowId) -> Self {
2582 WindowHandle {
2583 any_handle: AnyWindowHandle {
2584 id,
2585 state_type: TypeId::of::<V>(),
2586 },
2587 state_type: PhantomData,
2588 }
2589 }
2590
2591 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2592 where
2593 C: Context,
2594 {
2595 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2596 root_view
2597 .downcast::<V>()
2598 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2599 }))
2600 }
2601
2602 pub fn update<C, R>(
2603 &self,
2604 cx: &mut C,
2605 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2606 ) -> Result<R>
2607 where
2608 C: Context,
2609 {
2610 cx.update_window(self.any_handle, |root_view, cx| {
2611 let view = root_view
2612 .downcast::<V>()
2613 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2614 Ok(cx.update_view(&view, update))
2615 })?
2616 }
2617
2618 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2619 let x = cx
2620 .windows
2621 .get(self.id)
2622 .and_then(|window| {
2623 window
2624 .as_ref()
2625 .and_then(|window| window.root_view.clone())
2626 .map(|root_view| root_view.downcast::<V>())
2627 })
2628 .ok_or_else(|| anyhow!("window not found"))?
2629 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2630
2631 Ok(x.read(cx))
2632 }
2633
2634 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2635 where
2636 C: Context,
2637 {
2638 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2639 }
2640
2641 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2642 where
2643 C: Context,
2644 {
2645 cx.read_window(self, |root_view, _cx| root_view.clone())
2646 }
2647
2648 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2649 cx.windows
2650 .get(self.id)
2651 .and_then(|window| window.as_ref().map(|window| window.active))
2652 }
2653}
2654
2655impl<V> Copy for WindowHandle<V> {}
2656
2657impl<V> Clone for WindowHandle<V> {
2658 fn clone(&self) -> Self {
2659 WindowHandle {
2660 any_handle: self.any_handle,
2661 state_type: PhantomData,
2662 }
2663 }
2664}
2665
2666impl<V> PartialEq for WindowHandle<V> {
2667 fn eq(&self, other: &Self) -> bool {
2668 self.any_handle == other.any_handle
2669 }
2670}
2671
2672impl<V> Eq for WindowHandle<V> {}
2673
2674impl<V> Hash for WindowHandle<V> {
2675 fn hash<H: Hasher>(&self, state: &mut H) {
2676 self.any_handle.hash(state);
2677 }
2678}
2679
2680impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2681 fn into(self) -> AnyWindowHandle {
2682 self.any_handle
2683 }
2684}
2685
2686#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2687pub struct AnyWindowHandle {
2688 pub(crate) id: WindowId,
2689 state_type: TypeId,
2690}
2691
2692impl AnyWindowHandle {
2693 pub fn window_id(&self) -> WindowId {
2694 self.id
2695 }
2696
2697 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2698 if TypeId::of::<T>() == self.state_type {
2699 Some(WindowHandle {
2700 any_handle: *self,
2701 state_type: PhantomData,
2702 })
2703 } else {
2704 None
2705 }
2706 }
2707
2708 pub fn update<C, R>(
2709 self,
2710 cx: &mut C,
2711 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2712 ) -> Result<R>
2713 where
2714 C: Context,
2715 {
2716 cx.update_window(self, update)
2717 }
2718
2719 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2720 where
2721 C: Context,
2722 T: 'static,
2723 {
2724 let view = self
2725 .downcast::<T>()
2726 .context("the type of the window's root view has changed")?;
2727
2728 cx.read_window(&view, read)
2729 }
2730}
2731
2732#[cfg(any(test, feature = "test-support"))]
2733impl From<SmallVec<[u32; 16]>> for StackingOrder {
2734 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2735 StackingOrder(small_vec)
2736 }
2737}
2738
2739#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2740pub enum ElementId {
2741 View(EntityId),
2742 Integer(usize),
2743 Name(SharedString),
2744 FocusHandle(FocusId),
2745}
2746
2747impl ElementId {
2748 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2749 ElementId::View(entity_id)
2750 }
2751}
2752
2753impl TryInto<SharedString> for ElementId {
2754 type Error = anyhow::Error;
2755
2756 fn try_into(self) -> anyhow::Result<SharedString> {
2757 if let ElementId::Name(name) = self {
2758 Ok(name)
2759 } else {
2760 Err(anyhow!("element id is not string"))
2761 }
2762 }
2763}
2764
2765impl From<usize> for ElementId {
2766 fn from(id: usize) -> Self {
2767 ElementId::Integer(id)
2768 }
2769}
2770
2771impl From<i32> for ElementId {
2772 fn from(id: i32) -> Self {
2773 Self::Integer(id as usize)
2774 }
2775}
2776
2777impl From<SharedString> for ElementId {
2778 fn from(name: SharedString) -> Self {
2779 ElementId::Name(name)
2780 }
2781}
2782
2783impl From<&'static str> for ElementId {
2784 fn from(name: &'static str) -> Self {
2785 ElementId::Name(name.into())
2786 }
2787}
2788
2789impl<'a> From<&'a FocusHandle> for ElementId {
2790 fn from(handle: &'a FocusHandle) -> Self {
2791 ElementId::FocusHandle(handle.id)
2792 }
2793}