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)]
44pub(crate) 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 enum DismissEvent {
202 Dismiss,
203}
204
205// Holds the state for a specific window.
206pub struct Window {
207 pub(crate) handle: AnyWindowHandle,
208 pub(crate) removed: bool,
209 pub(crate) platform_window: Box<dyn PlatformWindow>,
210 display_id: DisplayId,
211 sprite_atlas: Arc<dyn PlatformAtlas>,
212 rem_size: Pixels,
213 viewport_size: Size<Pixels>,
214 pub(crate) layout_engine: TaffyLayoutEngine,
215 pub(crate) root_view: Option<AnyView>,
216 pub(crate) element_id_stack: GlobalElementId,
217 pub(crate) previous_frame: Frame,
218 pub(crate) current_frame: Frame,
219 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
220 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
221 default_prevented: bool,
222 mouse_position: Point<Pixels>,
223 requested_cursor_style: Option<CursorStyle>,
224 scale_factor: f32,
225 bounds: WindowBounds,
226 bounds_observers: SubscriberSet<(), AnyObserver>,
227 active: bool,
228 activation_observers: SubscriberSet<(), AnyObserver>,
229 pub(crate) dirty: bool,
230 pub(crate) last_blur: Option<Option<FocusId>>,
231 pub(crate) focus: Option<FocusId>,
232}
233
234pub(crate) struct ElementStateBox {
235 inner: Box<dyn Any>,
236 #[cfg(debug_assertions)]
237 type_name: &'static str,
238}
239
240// #[derive(Default)]
241pub(crate) struct Frame {
242 pub(crate) element_states: HashMap<GlobalElementId, ElementStateBox>,
243 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
244 pub(crate) dispatch_tree: DispatchTree,
245 pub(crate) focus_listeners: Vec<AnyFocusListener>,
246 pub(crate) scene_builder: SceneBuilder,
247 z_index_stack: StackingOrder,
248 content_mask_stack: Vec<ContentMask<Pixels>>,
249 element_offset_stack: Vec<Point<Pixels>>,
250}
251
252impl Frame {
253 pub fn new(dispatch_tree: DispatchTree) -> Self {
254 Frame {
255 element_states: HashMap::default(),
256 mouse_listeners: HashMap::default(),
257 dispatch_tree,
258 focus_listeners: Vec::new(),
259 scene_builder: SceneBuilder::default(),
260 z_index_stack: StackingOrder::default(),
261 content_mask_stack: Vec::new(),
262 element_offset_stack: Vec::new(),
263 }
264 }
265}
266
267impl Window {
268 pub(crate) fn new(
269 handle: AnyWindowHandle,
270 options: WindowOptions,
271 cx: &mut AppContext,
272 ) -> Self {
273 let platform_window = cx.platform.open_window(handle, options);
274 let display_id = platform_window.display().id();
275 let sprite_atlas = platform_window.sprite_atlas();
276 let mouse_position = platform_window.mouse_position();
277 let content_size = platform_window.content_size();
278 let scale_factor = platform_window.scale_factor();
279 let bounds = platform_window.bounds();
280
281 platform_window.on_resize(Box::new({
282 let mut cx = cx.to_async();
283 move |_, _| {
284 handle
285 .update(&mut cx, |_, cx| cx.window_bounds_changed())
286 .log_err();
287 }
288 }));
289 platform_window.on_moved(Box::new({
290 let mut cx = cx.to_async();
291 move || {
292 handle
293 .update(&mut cx, |_, cx| cx.window_bounds_changed())
294 .log_err();
295 }
296 }));
297 platform_window.on_active_status_change(Box::new({
298 let mut cx = cx.to_async();
299 move |active| {
300 handle
301 .update(&mut cx, |_, cx| {
302 cx.window.active = active;
303 cx.window
304 .activation_observers
305 .clone()
306 .retain(&(), |callback| callback(cx));
307 })
308 .log_err();
309 }
310 }));
311
312 platform_window.on_input({
313 let mut cx = cx.to_async();
314 Box::new(move |event| {
315 handle
316 .update(&mut cx, |_, cx| cx.dispatch_event(event))
317 .log_err()
318 .unwrap_or(false)
319 })
320 });
321
322 Window {
323 handle,
324 removed: false,
325 platform_window,
326 display_id,
327 sprite_atlas,
328 rem_size: px(16.),
329 viewport_size: content_size,
330 layout_engine: TaffyLayoutEngine::new(),
331 root_view: None,
332 element_id_stack: GlobalElementId::default(),
333 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
334 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
335 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
336 focus_listeners: SubscriberSet::new(),
337 default_prevented: true,
338 mouse_position,
339 requested_cursor_style: None,
340 scale_factor,
341 bounds,
342 bounds_observers: SubscriberSet::new(),
343 active: false,
344 activation_observers: SubscriberSet::new(),
345 dirty: true,
346 last_blur: None,
347 focus: None,
348 }
349 }
350}
351
352/// Indicates which region of the window is visible. Content falling outside of this mask will not be
353/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
354/// to leave room to support more complex shapes in the future.
355#[derive(Clone, Debug, Default, PartialEq, Eq)]
356#[repr(C)]
357pub struct ContentMask<P: Clone + Default + Debug> {
358 pub bounds: Bounds<P>,
359}
360
361impl ContentMask<Pixels> {
362 /// Scale the content mask's pixel units by the given scaling factor.
363 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
364 ContentMask {
365 bounds: self.bounds.scale(factor),
366 }
367 }
368
369 /// Intersect the content mask with the given content mask.
370 pub fn intersect(&self, other: &Self) -> Self {
371 let bounds = self.bounds.intersect(&other.bounds);
372 ContentMask { bounds }
373 }
374}
375
376/// Provides access to application state in the context of a single window. Derefs
377/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
378/// an `AppContext` and call any `AppContext` methods.
379pub struct WindowContext<'a> {
380 pub(crate) app: &'a mut AppContext,
381 pub(crate) window: &'a mut Window,
382}
383
384impl<'a> WindowContext<'a> {
385 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
386 Self { app, window }
387 }
388
389 /// Obtain a handle to the window that belongs to this context.
390 pub fn window_handle(&self) -> AnyWindowHandle {
391 self.window.handle
392 }
393
394 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
395 pub fn notify(&mut self) {
396 self.window.dirty = true;
397 }
398
399 /// Close this window.
400 pub fn remove_window(&mut self) {
401 self.window.removed = true;
402 }
403
404 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
405 /// for elements rendered within this window.
406 pub fn focus_handle(&mut self) -> FocusHandle {
407 FocusHandle::new(&self.window.focus_handles)
408 }
409
410 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
411 pub fn focused(&self) -> Option<FocusHandle> {
412 self.window
413 .focus
414 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
415 }
416
417 /// Move focus to the element associated with the given `FocusHandle`.
418 pub fn focus(&mut self, handle: &FocusHandle) {
419 if self.window.focus == Some(handle.id) {
420 return;
421 }
422
423 let focus_id = handle.id;
424
425 if self.window.last_blur.is_none() {
426 self.window.last_blur = Some(self.window.focus);
427 }
428
429 self.window.focus = Some(focus_id);
430 self.window
431 .current_frame
432 .dispatch_tree
433 .clear_keystroke_matchers();
434 self.app.push_effect(Effect::FocusChanged {
435 window_handle: self.window.handle,
436 focused: Some(focus_id),
437 });
438 self.notify();
439 }
440
441 /// Remove focus from all elements within this context's window.
442 pub fn blur(&mut self) {
443 if self.window.last_blur.is_none() {
444 self.window.last_blur = Some(self.window.focus);
445 }
446
447 self.window.focus = None;
448 self.app.push_effect(Effect::FocusChanged {
449 window_handle: self.window.handle,
450 focused: None,
451 });
452 self.notify();
453 }
454
455 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
456 if let Some(focus_handle) = self.focused() {
457 self.defer(move |cx| {
458 if let Some(node_id) = cx
459 .window
460 .current_frame
461 .dispatch_tree
462 .focusable_node_id(focus_handle.id)
463 {
464 cx.propagate_event = true;
465 cx.dispatch_action_on_node(node_id, action);
466 }
467 })
468 }
469 }
470
471 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
472 /// that are currently on the stack to be returned to the app.
473 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
474 let handle = self.window.handle;
475 self.app.defer(move |cx| {
476 handle.update(cx, |_, cx| f(cx)).ok();
477 });
478 }
479
480 pub fn subscribe<Emitter, E, Evt>(
481 &mut self,
482 entity: &E,
483 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
484 ) -> Subscription
485 where
486 Emitter: EventEmitter<Evt>,
487 E: Entity<Emitter>,
488 Evt: 'static,
489 {
490 let entity_id = entity.entity_id();
491 let entity = entity.downgrade();
492 let window_handle = self.window.handle;
493 self.app.event_listeners.insert(
494 entity_id,
495 (
496 TypeId::of::<Evt>(),
497 Box::new(move |event, cx| {
498 window_handle
499 .update(cx, |_, cx| {
500 if let Some(handle) = E::upgrade_from(&entity) {
501 let event = event.downcast_ref().expect("invalid event type");
502 on_event(handle, event, cx);
503 true
504 } else {
505 false
506 }
507 })
508 .unwrap_or(false)
509 }),
510 ),
511 )
512 }
513
514 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
515 /// await points in async code.
516 pub fn to_async(&self) -> AsyncWindowContext {
517 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
518 }
519
520 /// Schedule the given closure to be run directly after the current frame is rendered.
521 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
522 let handle = self.window.handle;
523 let display_id = self.window.display_id;
524
525 if !self.frame_consumers.contains_key(&display_id) {
526 let (tx, mut rx) = mpsc::unbounded::<()>();
527 self.platform.set_display_link_output_callback(
528 display_id,
529 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
530 );
531
532 let consumer_task = self.app.spawn(|cx| async move {
533 while rx.next().await.is_some() {
534 cx.update(|cx| {
535 for callback in cx
536 .next_frame_callbacks
537 .get_mut(&display_id)
538 .unwrap()
539 .drain(..)
540 .collect::<SmallVec<[_; 32]>>()
541 {
542 callback(cx);
543 }
544 })
545 .ok();
546
547 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
548
549 cx.update(|cx| {
550 if cx.next_frame_callbacks.is_empty() {
551 cx.platform.stop_display_link(display_id);
552 }
553 })
554 .ok();
555 }
556 });
557 self.frame_consumers.insert(display_id, consumer_task);
558 }
559
560 if self.next_frame_callbacks.is_empty() {
561 self.platform.start_display_link(display_id);
562 }
563
564 self.next_frame_callbacks
565 .entry(display_id)
566 .or_default()
567 .push(Box::new(move |cx: &mut AppContext| {
568 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
569 }));
570 }
571
572 /// Spawn the future returned by the given closure on the application thread pool.
573 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
574 /// use within your future.
575 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
576 where
577 R: 'static,
578 Fut: Future<Output = R> + 'static,
579 {
580 self.app
581 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
582 }
583
584 /// Update the global of the given type. The given closure is given simultaneous mutable
585 /// access both to the global and the context.
586 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
587 where
588 G: 'static,
589 {
590 let mut global = self.app.lease_global::<G>();
591 let result = f(&mut global, self);
592 self.app.end_global_lease(global);
593 result
594 }
595
596 #[must_use]
597 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
598 /// layout is being requested, along with the layout ids of any children. This method is called during
599 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
600 pub fn request_layout(
601 &mut self,
602 style: &Style,
603 children: impl IntoIterator<Item = LayoutId>,
604 ) -> LayoutId {
605 self.app.layout_id_buffer.clear();
606 self.app.layout_id_buffer.extend(children.into_iter());
607 let rem_size = self.rem_size();
608
609 self.window
610 .layout_engine
611 .request_layout(style, rem_size, &self.app.layout_id_buffer)
612 }
613
614 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
615 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
616 /// determine the element's size. One place this is used internally is when measuring text.
617 ///
618 /// The given closure is invoked at layout time with the known dimensions and available space and
619 /// returns a `Size`.
620 pub fn request_measured_layout<
621 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
622 >(
623 &mut self,
624 style: Style,
625 rem_size: Pixels,
626 measure: F,
627 ) -> LayoutId {
628 self.window
629 .layout_engine
630 .request_measured_layout(style, rem_size, measure)
631 }
632
633 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
634 self.window
635 .layout_engine
636 .compute_layout(layout_id, available_space)
637 }
638
639 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
640 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
641 /// in order to pass your element its `Bounds` automatically.
642 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
643 let mut bounds = self
644 .window
645 .layout_engine
646 .layout_bounds(layout_id)
647 .map(Into::into);
648 bounds.origin += self.element_offset();
649 bounds
650 }
651
652 fn window_bounds_changed(&mut self) {
653 self.window.scale_factor = self.window.platform_window.scale_factor();
654 self.window.viewport_size = self.window.platform_window.content_size();
655 self.window.bounds = self.window.platform_window.bounds();
656 self.window.display_id = self.window.platform_window.display().id();
657 self.window.dirty = true;
658
659 self.window
660 .bounds_observers
661 .clone()
662 .retain(&(), |callback| callback(self));
663 }
664
665 pub fn window_bounds(&self) -> WindowBounds {
666 self.window.bounds
667 }
668
669 pub fn viewport_size(&self) -> Size<Pixels> {
670 self.window.viewport_size
671 }
672
673 pub fn is_window_active(&self) -> bool {
674 self.window.active
675 }
676
677 pub fn zoom_window(&self) {
678 self.window.platform_window.zoom();
679 }
680
681 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
682 self.platform
683 .displays()
684 .into_iter()
685 .find(|display| display.id() == self.window.display_id)
686 }
687
688 pub fn show_character_palette(&self) {
689 self.window.platform_window.show_character_palette();
690 }
691
692 /// The scale factor of the display associated with the window. For example, it could
693 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
694 /// be rendered as two pixels on screen.
695 pub fn scale_factor(&self) -> f32 {
696 self.window.scale_factor
697 }
698
699 /// The size of an em for the base font of the application. Adjusting this value allows the
700 /// UI to scale, just like zooming a web page.
701 pub fn rem_size(&self) -> Pixels {
702 self.window.rem_size
703 }
704
705 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
706 /// UI to scale, just like zooming a web page.
707 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
708 self.window.rem_size = rem_size.into();
709 }
710
711 /// The line height associated with the current text style.
712 pub fn line_height(&self) -> Pixels {
713 let rem_size = self.rem_size();
714 let text_style = self.text_style();
715 text_style
716 .line_height
717 .to_pixels(text_style.font_size.into(), rem_size)
718 }
719
720 /// Call to prevent the default action of an event. Currently only used to prevent
721 /// parent elements from becoming focused on mouse down.
722 pub fn prevent_default(&mut self) {
723 self.window.default_prevented = true;
724 }
725
726 /// Obtain whether default has been prevented for the event currently being dispatched.
727 pub fn default_prevented(&self) -> bool {
728 self.window.default_prevented
729 }
730
731 /// Register a mouse event listener on the window for the current frame. The type of event
732 /// is determined by the first parameter of the given listener. When the next frame is rendered
733 /// the listener will be cleared.
734 ///
735 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
736 /// a specific need to register a global listener.
737 pub fn on_mouse_event<Event: 'static>(
738 &mut self,
739 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
740 ) {
741 let order = self.window.current_frame.z_index_stack.clone();
742 self.window
743 .current_frame
744 .mouse_listeners
745 .entry(TypeId::of::<Event>())
746 .or_default()
747 .push((
748 order,
749 Box::new(move |event: &dyn Any, phase, cx| {
750 handler(event.downcast_ref().unwrap(), phase, cx)
751 }),
752 ))
753 }
754
755 /// Register a key event listener on the window for the current frame. The type of event
756 /// is determined by the first parameter of the given listener. When the next frame is rendered
757 /// the listener will be cleared.
758 ///
759 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
760 /// a specific need to register a global listener.
761 pub fn on_key_event<Event: 'static>(
762 &mut self,
763 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
764 ) {
765 self.window
766 .current_frame
767 .dispatch_tree
768 .on_key_event(Rc::new(move |event, phase, cx| {
769 if let Some(event) = event.downcast_ref::<Event>() {
770 handler(event, phase, cx)
771 }
772 }));
773 }
774
775 /// Register an action listener on the window for the current frame. The type of action
776 /// is determined by the first parameter of the given listener. When the next frame is rendered
777 /// the listener will be cleared.
778 ///
779 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
780 /// a specific need to register a global listener.
781 pub fn on_action(
782 &mut self,
783 action_type: TypeId,
784 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
785 ) {
786 self.window.current_frame.dispatch_tree.on_action(
787 action_type,
788 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
789 );
790 }
791
792 /// The position of the mouse relative to the window.
793 pub fn mouse_position(&self) -> Point<Pixels> {
794 self.window.mouse_position
795 }
796
797 pub fn set_cursor_style(&mut self, style: CursorStyle) {
798 self.window.requested_cursor_style = Some(style)
799 }
800
801 /// Called during painting to invoke the given closure in a new stacking context. The given
802 /// z-index is interpreted relative to the previous call to `stack`.
803 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
804 self.window.current_frame.z_index_stack.push(z_index);
805 let result = f(self);
806 self.window.current_frame.z_index_stack.pop();
807 result
808 }
809
810 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
811 pub fn paint_shadows(
812 &mut self,
813 bounds: Bounds<Pixels>,
814 corner_radii: Corners<Pixels>,
815 shadows: &[BoxShadow],
816 ) {
817 let scale_factor = self.scale_factor();
818 let content_mask = self.content_mask();
819 let window = &mut *self.window;
820 for shadow in shadows {
821 let mut shadow_bounds = bounds;
822 shadow_bounds.origin += shadow.offset;
823 shadow_bounds.dilate(shadow.spread_radius);
824 window.current_frame.scene_builder.insert(
825 &window.current_frame.z_index_stack,
826 Shadow {
827 order: 0,
828 bounds: shadow_bounds.scale(scale_factor),
829 content_mask: content_mask.scale(scale_factor),
830 corner_radii: corner_radii.scale(scale_factor),
831 color: shadow.color,
832 blur_radius: shadow.blur_radius.scale(scale_factor),
833 },
834 );
835 }
836 }
837
838 /// Paint one or more quads into the scene for the current frame at the current stacking context.
839 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
840 pub fn paint_quad(
841 &mut self,
842 bounds: Bounds<Pixels>,
843 corner_radii: Corners<Pixels>,
844 background: impl Into<Hsla>,
845 border_widths: Edges<Pixels>,
846 border_color: impl Into<Hsla>,
847 ) {
848 let scale_factor = self.scale_factor();
849 let content_mask = self.content_mask();
850
851 let window = &mut *self.window;
852 window.current_frame.scene_builder.insert(
853 &window.current_frame.z_index_stack,
854 Quad {
855 order: 0,
856 bounds: bounds.scale(scale_factor),
857 content_mask: content_mask.scale(scale_factor),
858 background: background.into(),
859 border_color: border_color.into(),
860 corner_radii: corner_radii.scale(scale_factor),
861 border_widths: border_widths.scale(scale_factor),
862 },
863 );
864 }
865
866 /// Paint the given `Path` into the scene for the current frame at the current z-index.
867 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
868 let scale_factor = self.scale_factor();
869 let content_mask = self.content_mask();
870 path.content_mask = content_mask;
871 path.color = color.into();
872 let window = &mut *self.window;
873 window.current_frame.scene_builder.insert(
874 &window.current_frame.z_index_stack,
875 path.scale(scale_factor),
876 );
877 }
878
879 /// Paint an underline into the scene for the current frame at the current z-index.
880 pub fn paint_underline(
881 &mut self,
882 origin: Point<Pixels>,
883 width: Pixels,
884 style: &UnderlineStyle,
885 ) {
886 let scale_factor = self.scale_factor();
887 let height = if style.wavy {
888 style.thickness * 3.
889 } else {
890 style.thickness
891 };
892 let bounds = Bounds {
893 origin,
894 size: size(width, height),
895 };
896 let content_mask = self.content_mask();
897 let window = &mut *self.window;
898 window.current_frame.scene_builder.insert(
899 &window.current_frame.z_index_stack,
900 Underline {
901 order: 0,
902 bounds: bounds.scale(scale_factor),
903 content_mask: content_mask.scale(scale_factor),
904 thickness: style.thickness.scale(scale_factor),
905 color: style.color.unwrap_or_default(),
906 wavy: style.wavy,
907 },
908 );
909 }
910
911 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
912 /// The y component of the origin is the baseline of the glyph.
913 pub fn paint_glyph(
914 &mut self,
915 origin: Point<Pixels>,
916 font_id: FontId,
917 glyph_id: GlyphId,
918 font_size: Pixels,
919 color: Hsla,
920 ) -> Result<()> {
921 let scale_factor = self.scale_factor();
922 let glyph_origin = origin.scale(scale_factor);
923 let subpixel_variant = Point {
924 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
925 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
926 };
927 let params = RenderGlyphParams {
928 font_id,
929 glyph_id,
930 font_size,
931 subpixel_variant,
932 scale_factor,
933 is_emoji: false,
934 };
935
936 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
937 if !raster_bounds.is_zero() {
938 let tile =
939 self.window
940 .sprite_atlas
941 .get_or_insert_with(¶ms.clone().into(), &mut || {
942 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
943 Ok((size, Cow::Owned(bytes)))
944 })?;
945 let bounds = Bounds {
946 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
947 size: tile.bounds.size.map(Into::into),
948 };
949 let content_mask = self.content_mask().scale(scale_factor);
950 let window = &mut *self.window;
951 window.current_frame.scene_builder.insert(
952 &window.current_frame.z_index_stack,
953 MonochromeSprite {
954 order: 0,
955 bounds,
956 content_mask,
957 color,
958 tile,
959 },
960 );
961 }
962 Ok(())
963 }
964
965 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
966 /// The y component of the origin is the baseline of the glyph.
967 pub fn paint_emoji(
968 &mut self,
969 origin: Point<Pixels>,
970 font_id: FontId,
971 glyph_id: GlyphId,
972 font_size: Pixels,
973 ) -> Result<()> {
974 let scale_factor = self.scale_factor();
975 let glyph_origin = origin.scale(scale_factor);
976 let params = RenderGlyphParams {
977 font_id,
978 glyph_id,
979 font_size,
980 // We don't render emojis with subpixel variants.
981 subpixel_variant: Default::default(),
982 scale_factor,
983 is_emoji: true,
984 };
985
986 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
987 if !raster_bounds.is_zero() {
988 let tile =
989 self.window
990 .sprite_atlas
991 .get_or_insert_with(¶ms.clone().into(), &mut || {
992 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
993 Ok((size, Cow::Owned(bytes)))
994 })?;
995 let bounds = Bounds {
996 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
997 size: tile.bounds.size.map(Into::into),
998 };
999 let content_mask = self.content_mask().scale(scale_factor);
1000 let window = &mut *self.window;
1001
1002 window.current_frame.scene_builder.insert(
1003 &window.current_frame.z_index_stack,
1004 PolychromeSprite {
1005 order: 0,
1006 bounds,
1007 corner_radii: Default::default(),
1008 content_mask,
1009 tile,
1010 grayscale: false,
1011 },
1012 );
1013 }
1014 Ok(())
1015 }
1016
1017 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1018 pub fn paint_svg(
1019 &mut self,
1020 bounds: Bounds<Pixels>,
1021 path: SharedString,
1022 color: Hsla,
1023 ) -> Result<()> {
1024 let scale_factor = self.scale_factor();
1025 let bounds = bounds.scale(scale_factor);
1026 // Render the SVG at twice the size to get a higher quality result.
1027 let params = RenderSvgParams {
1028 path,
1029 size: bounds
1030 .size
1031 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1032 };
1033
1034 let tile =
1035 self.window
1036 .sprite_atlas
1037 .get_or_insert_with(¶ms.clone().into(), &mut || {
1038 let bytes = self.svg_renderer.render(¶ms)?;
1039 Ok((params.size, Cow::Owned(bytes)))
1040 })?;
1041 let content_mask = self.content_mask().scale(scale_factor);
1042
1043 let window = &mut *self.window;
1044 window.current_frame.scene_builder.insert(
1045 &window.current_frame.z_index_stack,
1046 MonochromeSprite {
1047 order: 0,
1048 bounds,
1049 content_mask,
1050 color,
1051 tile,
1052 },
1053 );
1054
1055 Ok(())
1056 }
1057
1058 /// Paint an image into the scene for the current frame at the current z-index.
1059 pub fn paint_image(
1060 &mut self,
1061 bounds: Bounds<Pixels>,
1062 corner_radii: Corners<Pixels>,
1063 data: Arc<ImageData>,
1064 grayscale: bool,
1065 ) -> Result<()> {
1066 let scale_factor = self.scale_factor();
1067 let bounds = bounds.scale(scale_factor);
1068 let params = RenderImageParams { image_id: data.id };
1069
1070 let tile = self
1071 .window
1072 .sprite_atlas
1073 .get_or_insert_with(¶ms.clone().into(), &mut || {
1074 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1075 })?;
1076 let content_mask = self.content_mask().scale(scale_factor);
1077 let corner_radii = corner_radii.scale(scale_factor);
1078
1079 let window = &mut *self.window;
1080 window.current_frame.scene_builder.insert(
1081 &window.current_frame.z_index_stack,
1082 PolychromeSprite {
1083 order: 0,
1084 bounds,
1085 content_mask,
1086 corner_radii,
1087 tile,
1088 grayscale,
1089 },
1090 );
1091 Ok(())
1092 }
1093
1094 /// Paint a surface into the scene for the current frame at the current z-index.
1095 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
1096 let scale_factor = self.scale_factor();
1097 let bounds = bounds.scale(scale_factor);
1098 let content_mask = self.content_mask().scale(scale_factor);
1099 let window = &mut *self.window;
1100 window.current_frame.scene_builder.insert(
1101 &window.current_frame.z_index_stack,
1102 Surface {
1103 order: 0,
1104 bounds,
1105 content_mask,
1106 image_buffer,
1107 },
1108 );
1109 }
1110
1111 /// Draw pixels to the display for this window based on the contents of its scene.
1112 pub(crate) fn draw(&mut self) {
1113 let root_view = self.window.root_view.take().unwrap();
1114
1115 self.start_frame();
1116
1117 self.with_z_index(0, |cx| {
1118 let available_space = cx.window.viewport_size.map(Into::into);
1119 root_view.draw(Point::zero(), available_space, cx);
1120 });
1121
1122 if let Some(active_drag) = self.app.active_drag.take() {
1123 self.with_z_index(1, |cx| {
1124 let offset = cx.mouse_position() - active_drag.cursor_offset;
1125 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1126 active_drag.view.draw(offset, available_space, cx);
1127 cx.active_drag = Some(active_drag);
1128 });
1129 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1130 self.with_z_index(1, |cx| {
1131 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1132 active_tooltip
1133 .view
1134 .draw(active_tooltip.cursor_offset, available_space, cx);
1135 });
1136 }
1137
1138 self.window
1139 .current_frame
1140 .dispatch_tree
1141 .preserve_keystroke_matchers(
1142 &mut self.window.previous_frame.dispatch_tree,
1143 self.window.focus,
1144 );
1145
1146 self.window.root_view = Some(root_view);
1147 let scene = self.window.current_frame.scene_builder.build();
1148
1149 self.window.platform_window.draw(scene);
1150 let cursor_style = self
1151 .window
1152 .requested_cursor_style
1153 .take()
1154 .unwrap_or(CursorStyle::Arrow);
1155 self.platform.set_cursor_style(cursor_style);
1156
1157 self.window.dirty = false;
1158 }
1159
1160 /// Rotate the current frame and the previous frame, then clear the current frame.
1161 /// We repopulate all state in the current frame during each paint.
1162 fn start_frame(&mut self) {
1163 self.text_system().start_frame();
1164
1165 let window = &mut *self.window;
1166 window.layout_engine.clear();
1167
1168 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1169 let frame = &mut window.current_frame;
1170 frame.element_states.clear();
1171 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1172 frame.focus_listeners.clear();
1173 frame.dispatch_tree.clear();
1174 }
1175
1176 /// Dispatch a mouse or keyboard event on the window.
1177 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1178 // Handlers may set this to false by calling `stop_propagation`
1179 self.app.propagate_event = true;
1180 self.window.default_prevented = false;
1181
1182 let event = match event {
1183 // Track the mouse position with our own state, since accessing the platform
1184 // API for the mouse position can only occur on the main thread.
1185 InputEvent::MouseMove(mouse_move) => {
1186 self.window.mouse_position = mouse_move.position;
1187 InputEvent::MouseMove(mouse_move)
1188 }
1189 InputEvent::MouseDown(mouse_down) => {
1190 self.window.mouse_position = mouse_down.position;
1191 InputEvent::MouseDown(mouse_down)
1192 }
1193 InputEvent::MouseUp(mouse_up) => {
1194 self.window.mouse_position = mouse_up.position;
1195 InputEvent::MouseUp(mouse_up)
1196 }
1197 // Translate dragging and dropping of external files from the operating system
1198 // to internal drag and drop events.
1199 InputEvent::FileDrop(file_drop) => match file_drop {
1200 FileDropEvent::Entered { position, files } => {
1201 self.window.mouse_position = position;
1202 if self.active_drag.is_none() {
1203 self.active_drag = Some(AnyDrag {
1204 view: self.build_view(|_| files).into(),
1205 cursor_offset: position,
1206 });
1207 }
1208 InputEvent::MouseDown(MouseDownEvent {
1209 position,
1210 button: MouseButton::Left,
1211 click_count: 1,
1212 modifiers: Modifiers::default(),
1213 })
1214 }
1215 FileDropEvent::Pending { position } => {
1216 self.window.mouse_position = position;
1217 InputEvent::MouseMove(MouseMoveEvent {
1218 position,
1219 pressed_button: Some(MouseButton::Left),
1220 modifiers: Modifiers::default(),
1221 })
1222 }
1223 FileDropEvent::Submit { position } => {
1224 self.window.mouse_position = position;
1225 InputEvent::MouseUp(MouseUpEvent {
1226 button: MouseButton::Left,
1227 position,
1228 modifiers: Modifiers::default(),
1229 click_count: 1,
1230 })
1231 }
1232 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1233 button: MouseButton::Left,
1234 position: Point::default(),
1235 modifiers: Modifiers::default(),
1236 click_count: 1,
1237 }),
1238 },
1239 _ => event,
1240 };
1241
1242 if let Some(any_mouse_event) = event.mouse_event() {
1243 self.dispatch_mouse_event(any_mouse_event);
1244 } else if let Some(any_key_event) = event.keyboard_event() {
1245 self.dispatch_key_event(any_key_event);
1246 }
1247
1248 !self.app.propagate_event
1249 }
1250
1251 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1252 if let Some(mut handlers) = self
1253 .window
1254 .current_frame
1255 .mouse_listeners
1256 .remove(&event.type_id())
1257 {
1258 // Because handlers may add other handlers, we sort every time.
1259 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1260
1261 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1262 // special purposes, such as detecting events outside of a given Bounds.
1263 for (_, handler) in &mut handlers {
1264 handler(event, DispatchPhase::Capture, self);
1265 if !self.app.propagate_event {
1266 break;
1267 }
1268 }
1269
1270 // Bubble phase, where most normal handlers do their work.
1271 if self.app.propagate_event {
1272 for (_, handler) in handlers.iter_mut().rev() {
1273 handler(event, DispatchPhase::Bubble, self);
1274 if !self.app.propagate_event {
1275 break;
1276 }
1277 }
1278 }
1279
1280 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1281 self.active_drag = None;
1282 }
1283
1284 // Just in case any handlers added new handlers, which is weird, but possible.
1285 handlers.extend(
1286 self.window
1287 .current_frame
1288 .mouse_listeners
1289 .get_mut(&event.type_id())
1290 .into_iter()
1291 .flat_map(|handlers| handlers.drain(..)),
1292 );
1293 self.window
1294 .current_frame
1295 .mouse_listeners
1296 .insert(event.type_id(), handlers);
1297 }
1298 }
1299
1300 fn dispatch_key_event(&mut self, event: &dyn Any) {
1301 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1302 self.window
1303 .current_frame
1304 .dispatch_tree
1305 .focusable_node_id(focus_id)
1306 }) {
1307 let dispatch_path = self
1308 .window
1309 .current_frame
1310 .dispatch_tree
1311 .dispatch_path(node_id);
1312
1313 // Capture phase
1314 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1315 self.propagate_event = true;
1316
1317 for node_id in &dispatch_path {
1318 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1319
1320 if !node.context.is_empty() {
1321 context_stack.push(node.context.clone());
1322 }
1323
1324 for key_listener in node.key_listeners.clone() {
1325 key_listener(event, DispatchPhase::Capture, self);
1326 if !self.propagate_event {
1327 return;
1328 }
1329 }
1330 }
1331
1332 // Bubble phase
1333 for node_id in dispatch_path.iter().rev() {
1334 // Handle low level key events
1335 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1336 for key_listener in node.key_listeners.clone() {
1337 key_listener(event, DispatchPhase::Bubble, self);
1338 if !self.propagate_event {
1339 return;
1340 }
1341 }
1342
1343 // Match keystrokes
1344 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1345 if !node.context.is_empty() {
1346 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1347 if let Some(action) = self
1348 .window
1349 .current_frame
1350 .dispatch_tree
1351 .dispatch_key(&key_down_event.keystroke, &context_stack)
1352 {
1353 self.dispatch_action_on_node(*node_id, action);
1354 if !self.propagate_event {
1355 return;
1356 }
1357 }
1358 }
1359
1360 context_stack.pop();
1361 }
1362 }
1363 }
1364 }
1365
1366 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1367 let dispatch_path = self
1368 .window
1369 .current_frame
1370 .dispatch_tree
1371 .dispatch_path(node_id);
1372
1373 // Capture phase
1374 for node_id in &dispatch_path {
1375 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1376 for DispatchActionListener {
1377 action_type,
1378 listener,
1379 } in node.action_listeners.clone()
1380 {
1381 let any_action = action.as_any();
1382 if action_type == any_action.type_id() {
1383 listener(any_action, DispatchPhase::Capture, self);
1384 if !self.propagate_event {
1385 return;
1386 }
1387 }
1388 }
1389 }
1390
1391 // Bubble phase
1392 for node_id in dispatch_path.iter().rev() {
1393 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1394 for DispatchActionListener {
1395 action_type,
1396 listener,
1397 } in node.action_listeners.clone()
1398 {
1399 let any_action = action.as_any();
1400 if action_type == any_action.type_id() {
1401 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1402 listener(any_action, DispatchPhase::Bubble, self);
1403 if !self.propagate_event {
1404 return;
1405 }
1406 }
1407 }
1408 }
1409 }
1410
1411 /// Register the given handler to be invoked whenever the global of the given type
1412 /// is updated.
1413 pub fn observe_global<G: 'static>(
1414 &mut self,
1415 f: impl Fn(&mut WindowContext<'_>) + 'static,
1416 ) -> Subscription {
1417 let window_handle = self.window.handle;
1418 self.global_observers.insert(
1419 TypeId::of::<G>(),
1420 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1421 )
1422 }
1423
1424 pub fn activate_window(&self) {
1425 self.window.platform_window.activate();
1426 }
1427
1428 pub fn minimize_window(&self) {
1429 self.window.platform_window.minimize();
1430 }
1431
1432 pub fn toggle_full_screen(&self) {
1433 self.window.platform_window.toggle_full_screen();
1434 }
1435
1436 pub fn prompt(
1437 &self,
1438 level: PromptLevel,
1439 msg: &str,
1440 answers: &[&str],
1441 ) -> oneshot::Receiver<usize> {
1442 self.window.platform_window.prompt(level, msg, answers)
1443 }
1444
1445 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1446 if let Some(focus_id) = self.window.focus {
1447 self.window
1448 .current_frame
1449 .dispatch_tree
1450 .available_actions(focus_id)
1451 } else {
1452 Vec::new()
1453 }
1454 }
1455
1456 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1457 self.window
1458 .current_frame
1459 .dispatch_tree
1460 .bindings_for_action(action)
1461 }
1462
1463 pub fn listener_for<V: Render, E>(
1464 &self,
1465 view: &View<V>,
1466 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1467 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1468 let view = view.downgrade();
1469 move |e: &E, cx: &mut WindowContext| {
1470 view.update(cx, |view, cx| f(view, e, cx)).ok();
1471 }
1472 }
1473
1474 pub fn constructor_for<V: Render, R>(
1475 &self,
1476 view: &View<V>,
1477 f: impl Fn(&mut V, &mut ViewContext<V>) -> R + 'static,
1478 ) -> impl Fn(&mut WindowContext) -> R + 'static {
1479 let view = view.clone();
1480 move |cx: &mut WindowContext| view.update(cx, |view, cx| f(view, cx))
1481 }
1482
1483 //========== ELEMENT RELATED FUNCTIONS ===========
1484 pub fn with_key_dispatch<R>(
1485 &mut self,
1486 context: KeyContext,
1487 focus_handle: Option<FocusHandle>,
1488 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1489 ) -> R {
1490 let window = &mut self.window;
1491 window
1492 .current_frame
1493 .dispatch_tree
1494 .push_node(context.clone());
1495 if let Some(focus_handle) = focus_handle.as_ref() {
1496 window
1497 .current_frame
1498 .dispatch_tree
1499 .make_focusable(focus_handle.id);
1500 }
1501 let result = f(focus_handle, self);
1502
1503 self.window.current_frame.dispatch_tree.pop_node();
1504
1505 result
1506 }
1507
1508 /// Register a focus listener for the current frame only. It will be cleared
1509 /// on the next frame render. You should use this method only from within elements,
1510 /// and we may want to enforce that better via a different context type.
1511 // todo!() Move this to `FrameContext` to emphasize its individuality?
1512 pub fn on_focus_changed(
1513 &mut self,
1514 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1515 ) {
1516 self.window
1517 .current_frame
1518 .focus_listeners
1519 .push(Box::new(move |event, cx| {
1520 listener(event, cx);
1521 }));
1522 }
1523
1524 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1525 /// platform to receive textual input with proper integration with concerns such
1526 /// as IME interactions.
1527 pub fn handle_input(
1528 &mut self,
1529 focus_handle: &FocusHandle,
1530 input_handler: impl PlatformInputHandler,
1531 ) {
1532 if focus_handle.is_focused(self) {
1533 self.window
1534 .platform_window
1535 .set_input_handler(Box::new(input_handler));
1536 }
1537 }
1538
1539 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1540 let mut this = self.to_async();
1541 self.window
1542 .platform_window
1543 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1544 }
1545}
1546
1547impl Context for WindowContext<'_> {
1548 type Result<T> = T;
1549
1550 fn build_model<T>(
1551 &mut self,
1552 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1553 ) -> Model<T>
1554 where
1555 T: 'static,
1556 {
1557 let slot = self.app.entities.reserve();
1558 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1559 self.entities.insert(slot, model)
1560 }
1561
1562 fn update_model<T: 'static, R>(
1563 &mut self,
1564 model: &Model<T>,
1565 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1566 ) -> R {
1567 let mut entity = self.entities.lease(model);
1568 let result = update(
1569 &mut *entity,
1570 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1571 );
1572 self.entities.end_lease(entity);
1573 result
1574 }
1575
1576 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1577 where
1578 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1579 {
1580 if window == self.window.handle {
1581 let root_view = self.window.root_view.clone().unwrap();
1582 Ok(update(root_view, self))
1583 } else {
1584 window.update(self.app, update)
1585 }
1586 }
1587
1588 fn read_model<T, R>(
1589 &self,
1590 handle: &Model<T>,
1591 read: impl FnOnce(&T, &AppContext) -> R,
1592 ) -> Self::Result<R>
1593 where
1594 T: 'static,
1595 {
1596 let entity = self.entities.read(handle);
1597 read(&*entity, &*self.app)
1598 }
1599
1600 fn read_window<T, R>(
1601 &self,
1602 window: &WindowHandle<T>,
1603 read: impl FnOnce(View<T>, &AppContext) -> R,
1604 ) -> Result<R>
1605 where
1606 T: 'static,
1607 {
1608 if window.any_handle == self.window.handle {
1609 let root_view = self
1610 .window
1611 .root_view
1612 .clone()
1613 .unwrap()
1614 .downcast::<T>()
1615 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1616 Ok(read(root_view, self))
1617 } else {
1618 self.app.read_window(window, read)
1619 }
1620 }
1621}
1622
1623impl VisualContext for WindowContext<'_> {
1624 fn build_view<V>(
1625 &mut self,
1626 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1627 ) -> Self::Result<View<V>>
1628 where
1629 V: 'static + Render,
1630 {
1631 let slot = self.app.entities.reserve();
1632 let view = View {
1633 model: slot.clone(),
1634 };
1635 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1636 let entity = build_view_state(&mut cx);
1637 cx.entities.insert(slot, entity);
1638
1639 cx.new_view_observers
1640 .clone()
1641 .retain(&TypeId::of::<V>(), |observer| {
1642 let any_view = AnyView::from(view.clone());
1643 (observer)(any_view, self);
1644 true
1645 });
1646
1647 view
1648 }
1649
1650 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1651 fn update_view<T: 'static, R>(
1652 &mut self,
1653 view: &View<T>,
1654 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1655 ) -> Self::Result<R> {
1656 let mut lease = self.app.entities.lease(&view.model);
1657 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1658 let result = update(&mut *lease, &mut cx);
1659 cx.app.entities.end_lease(lease);
1660 result
1661 }
1662
1663 fn replace_root_view<V>(
1664 &mut self,
1665 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1666 ) -> Self::Result<View<V>>
1667 where
1668 V: 'static + Render,
1669 {
1670 let slot = self.app.entities.reserve();
1671 let view = View {
1672 model: slot.clone(),
1673 };
1674 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1675 let entity = build_view(&mut cx);
1676 self.entities.insert(slot, entity);
1677 self.window.root_view = Some(view.clone().into());
1678 view
1679 }
1680
1681 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1682 self.update_view(view, |view, cx| {
1683 view.focus_handle(cx).clone().focus(cx);
1684 })
1685 }
1686
1687 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1688 where
1689 V: ManagedView,
1690 {
1691 self.update_view(view, |_, cx| cx.emit(DismissEvent::Dismiss))
1692 }
1693}
1694
1695impl<'a> std::ops::Deref for WindowContext<'a> {
1696 type Target = AppContext;
1697
1698 fn deref(&self) -> &Self::Target {
1699 &self.app
1700 }
1701}
1702
1703impl<'a> std::ops::DerefMut for WindowContext<'a> {
1704 fn deref_mut(&mut self) -> &mut Self::Target {
1705 &mut self.app
1706 }
1707}
1708
1709impl<'a> Borrow<AppContext> for WindowContext<'a> {
1710 fn borrow(&self) -> &AppContext {
1711 &self.app
1712 }
1713}
1714
1715impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1716 fn borrow_mut(&mut self) -> &mut AppContext {
1717 &mut self.app
1718 }
1719}
1720
1721pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1722 fn app_mut(&mut self) -> &mut AppContext {
1723 self.borrow_mut()
1724 }
1725
1726 fn app(&self) -> &AppContext {
1727 self.borrow()
1728 }
1729
1730 fn window(&self) -> &Window {
1731 self.borrow()
1732 }
1733
1734 fn window_mut(&mut self) -> &mut Window {
1735 self.borrow_mut()
1736 }
1737
1738 /// Pushes the given element id onto the global stack and invokes the given closure
1739 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1740 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1741 /// used to associate state with identified elements across separate frames.
1742 fn with_element_id<R>(
1743 &mut self,
1744 id: Option<impl Into<ElementId>>,
1745 f: impl FnOnce(&mut Self) -> R,
1746 ) -> R {
1747 if let Some(id) = id.map(Into::into) {
1748 let window = self.window_mut();
1749 window.element_id_stack.push(id.into());
1750 let result = f(self);
1751 let window: &mut Window = self.borrow_mut();
1752 window.element_id_stack.pop();
1753 result
1754 } else {
1755 f(self)
1756 }
1757 }
1758
1759 /// Invoke the given function with the given content mask after intersecting it
1760 /// with the current mask.
1761 fn with_content_mask<R>(
1762 &mut self,
1763 mask: Option<ContentMask<Pixels>>,
1764 f: impl FnOnce(&mut Self) -> R,
1765 ) -> R {
1766 if let Some(mask) = mask {
1767 let mask = mask.intersect(&self.content_mask());
1768 self.window_mut()
1769 .current_frame
1770 .content_mask_stack
1771 .push(mask);
1772 let result = f(self);
1773 self.window_mut().current_frame.content_mask_stack.pop();
1774 result
1775 } else {
1776 f(self)
1777 }
1778 }
1779
1780 /// Invoke the given function with the content mask reset to that
1781 /// of the window.
1782 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1783 let mask = ContentMask {
1784 bounds: Bounds {
1785 origin: Point::default(),
1786 size: self.window().viewport_size,
1787 },
1788 };
1789 self.window_mut()
1790 .current_frame
1791 .content_mask_stack
1792 .push(mask);
1793 let result = f(self);
1794 self.window_mut().current_frame.content_mask_stack.pop();
1795 result
1796 }
1797
1798 /// Update the global element offset relative to the current offset. This is used to implement
1799 /// scrolling.
1800 fn with_element_offset<R>(
1801 &mut self,
1802 offset: Point<Pixels>,
1803 f: impl FnOnce(&mut Self) -> R,
1804 ) -> R {
1805 if offset.is_zero() {
1806 return f(self);
1807 };
1808
1809 let abs_offset = self.element_offset() + offset;
1810 self.with_absolute_element_offset(abs_offset, f)
1811 }
1812
1813 /// Update the global element offset based on the given offset. This is used to implement
1814 /// drag handles and other manual painting of elements.
1815 fn with_absolute_element_offset<R>(
1816 &mut self,
1817 offset: Point<Pixels>,
1818 f: impl FnOnce(&mut Self) -> R,
1819 ) -> R {
1820 self.window_mut()
1821 .current_frame
1822 .element_offset_stack
1823 .push(offset);
1824 let result = f(self);
1825 self.window_mut().current_frame.element_offset_stack.pop();
1826 result
1827 }
1828
1829 /// Obtain the current element offset.
1830 fn element_offset(&self) -> Point<Pixels> {
1831 self.window()
1832 .current_frame
1833 .element_offset_stack
1834 .last()
1835 .copied()
1836 .unwrap_or_default()
1837 }
1838
1839 /// Update or intialize state for an element with the given id that lives across multiple
1840 /// frames. If an element with this id existed in the previous frame, its state will be passed
1841 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1842 /// when drawing the next frame.
1843 fn with_element_state<S, R>(
1844 &mut self,
1845 id: ElementId,
1846 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1847 ) -> R
1848 where
1849 S: 'static,
1850 {
1851 self.with_element_id(Some(id), |cx| {
1852 let global_id = cx.window().element_id_stack.clone();
1853
1854 if let Some(any) = cx
1855 .window_mut()
1856 .current_frame
1857 .element_states
1858 .remove(&global_id)
1859 .or_else(|| {
1860 cx.window_mut()
1861 .previous_frame
1862 .element_states
1863 .remove(&global_id)
1864 })
1865 {
1866 let ElementStateBox {
1867 inner,
1868
1869 #[cfg(debug_assertions)]
1870 type_name
1871 } = any;
1872 // Using the extra inner option to avoid needing to reallocate a new box.
1873 let mut state_box = inner
1874 .downcast::<Option<S>>()
1875 .map_err(|_| {
1876 #[cfg(debug_assertions)]
1877 {
1878 anyhow!(
1879 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1880 std::any::type_name::<S>(),
1881 type_name
1882 )
1883 }
1884
1885 #[cfg(not(debug_assertions))]
1886 {
1887 anyhow!(
1888 "invalid element state type for id, requested_type {:?}",
1889 std::any::type_name::<S>(),
1890 )
1891 }
1892 })
1893 .unwrap();
1894
1895 // Actual: Option<AnyElement> <- View
1896 // Requested: () <- AnyElemet
1897 let state = state_box
1898 .take()
1899 .expect("element state is already on the stack");
1900 let (result, state) = f(Some(state), cx);
1901 state_box.replace(state);
1902 cx.window_mut()
1903 .current_frame
1904 .element_states
1905 .insert(global_id, ElementStateBox {
1906 inner: state_box,
1907
1908 #[cfg(debug_assertions)]
1909 type_name
1910 });
1911 result
1912 } else {
1913 let (result, state) = f(None, cx);
1914 cx.window_mut()
1915 .current_frame
1916 .element_states
1917 .insert(global_id,
1918 ElementStateBox {
1919 inner: Box::new(Some(state)),
1920
1921 #[cfg(debug_assertions)]
1922 type_name: std::any::type_name::<S>()
1923 }
1924
1925 );
1926 result
1927 }
1928 })
1929 }
1930
1931 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1932 /// id is `None`, no state will be retrieved or stored.
1933 fn with_optional_element_state<S, R>(
1934 &mut self,
1935 element_id: Option<ElementId>,
1936 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1937 ) -> R
1938 where
1939 S: 'static,
1940 {
1941 if let Some(element_id) = element_id {
1942 self.with_element_state(element_id, f)
1943 } else {
1944 f(None, self).0
1945 }
1946 }
1947
1948 /// Obtain the current content mask.
1949 fn content_mask(&self) -> ContentMask<Pixels> {
1950 self.window()
1951 .current_frame
1952 .content_mask_stack
1953 .last()
1954 .cloned()
1955 .unwrap_or_else(|| ContentMask {
1956 bounds: Bounds {
1957 origin: Point::default(),
1958 size: self.window().viewport_size,
1959 },
1960 })
1961 }
1962
1963 /// The size of an em for the base font of the application. Adjusting this value allows the
1964 /// UI to scale, just like zooming a web page.
1965 fn rem_size(&self) -> Pixels {
1966 self.window().rem_size
1967 }
1968}
1969
1970impl Borrow<Window> for WindowContext<'_> {
1971 fn borrow(&self) -> &Window {
1972 &self.window
1973 }
1974}
1975
1976impl BorrowMut<Window> for WindowContext<'_> {
1977 fn borrow_mut(&mut self) -> &mut Window {
1978 &mut self.window
1979 }
1980}
1981
1982impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1983
1984pub struct ViewContext<'a, V> {
1985 window_cx: WindowContext<'a>,
1986 view: &'a View<V>,
1987}
1988
1989impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1990 fn borrow(&self) -> &AppContext {
1991 &*self.window_cx.app
1992 }
1993}
1994
1995impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1996 fn borrow_mut(&mut self) -> &mut AppContext {
1997 &mut *self.window_cx.app
1998 }
1999}
2000
2001impl<V> Borrow<Window> for ViewContext<'_, V> {
2002 fn borrow(&self) -> &Window {
2003 &*self.window_cx.window
2004 }
2005}
2006
2007impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2008 fn borrow_mut(&mut self) -> &mut Window {
2009 &mut *self.window_cx.window
2010 }
2011}
2012
2013impl<'a, V: 'static> ViewContext<'a, V> {
2014 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2015 Self {
2016 window_cx: WindowContext::new(app, window),
2017 view,
2018 }
2019 }
2020
2021 pub fn entity_id(&self) -> EntityId {
2022 self.view.entity_id()
2023 }
2024
2025 pub fn view(&self) -> &View<V> {
2026 self.view
2027 }
2028
2029 pub fn model(&self) -> &Model<V> {
2030 &self.view.model
2031 }
2032
2033 /// Access the underlying window context.
2034 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2035 &mut self.window_cx
2036 }
2037
2038 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2039 self.window.current_frame.z_index_stack.push(z_index);
2040 let result = f(self);
2041 self.window.current_frame.z_index_stack.pop();
2042 result
2043 }
2044
2045 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2046 where
2047 V: 'static,
2048 {
2049 let view = self.view().clone();
2050 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2051 }
2052
2053 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2054 /// that are currently on the stack to be returned to the app.
2055 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2056 let view = self.view().downgrade();
2057 self.window_cx.defer(move |cx| {
2058 view.update(cx, f).ok();
2059 });
2060 }
2061
2062 pub fn observe<V2, E>(
2063 &mut self,
2064 entity: &E,
2065 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2066 ) -> Subscription
2067 where
2068 V2: 'static,
2069 V: 'static,
2070 E: Entity<V2>,
2071 {
2072 let view = self.view().downgrade();
2073 let entity_id = entity.entity_id();
2074 let entity = entity.downgrade();
2075 let window_handle = self.window.handle;
2076 self.app.observers.insert(
2077 entity_id,
2078 Box::new(move |cx| {
2079 window_handle
2080 .update(cx, |_, cx| {
2081 if let Some(handle) = E::upgrade_from(&entity) {
2082 view.update(cx, |this, cx| on_notify(this, handle, cx))
2083 .is_ok()
2084 } else {
2085 false
2086 }
2087 })
2088 .unwrap_or(false)
2089 }),
2090 )
2091 }
2092
2093 pub fn subscribe<V2, E, Evt>(
2094 &mut self,
2095 entity: &E,
2096 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2097 ) -> Subscription
2098 where
2099 V2: EventEmitter<Evt>,
2100 E: Entity<V2>,
2101 Evt: 'static,
2102 {
2103 let view = self.view().downgrade();
2104 let entity_id = entity.entity_id();
2105 let handle = entity.downgrade();
2106 let window_handle = self.window.handle;
2107 self.app.event_listeners.insert(
2108 entity_id,
2109 (
2110 TypeId::of::<Evt>(),
2111 Box::new(move |event, cx| {
2112 window_handle
2113 .update(cx, |_, cx| {
2114 if let Some(handle) = E::upgrade_from(&handle) {
2115 let event = event.downcast_ref().expect("invalid event type");
2116 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2117 .is_ok()
2118 } else {
2119 false
2120 }
2121 })
2122 .unwrap_or(false)
2123 }),
2124 ),
2125 )
2126 }
2127
2128 pub fn on_release(
2129 &mut self,
2130 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2131 ) -> Subscription {
2132 let window_handle = self.window.handle;
2133 self.app.release_listeners.insert(
2134 self.view.model.entity_id,
2135 Box::new(move |this, cx| {
2136 let this = this.downcast_mut().expect("invalid entity type");
2137 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2138 }),
2139 )
2140 }
2141
2142 pub fn observe_release<V2, E>(
2143 &mut self,
2144 entity: &E,
2145 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2146 ) -> Subscription
2147 where
2148 V: 'static,
2149 V2: 'static,
2150 E: Entity<V2>,
2151 {
2152 let view = self.view().downgrade();
2153 let entity_id = entity.entity_id();
2154 let window_handle = self.window.handle;
2155 self.app.release_listeners.insert(
2156 entity_id,
2157 Box::new(move |entity, cx| {
2158 let entity = entity.downcast_mut().expect("invalid entity type");
2159 let _ = window_handle.update(cx, |_, cx| {
2160 view.update(cx, |this, cx| on_release(this, entity, cx))
2161 });
2162 }),
2163 )
2164 }
2165
2166 pub fn notify(&mut self) {
2167 self.window_cx.notify();
2168 self.window_cx.app.push_effect(Effect::Notify {
2169 emitter: self.view.model.entity_id,
2170 });
2171 }
2172
2173 pub fn observe_window_bounds(
2174 &mut self,
2175 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2176 ) -> Subscription {
2177 let view = self.view.downgrade();
2178 self.window.bounds_observers.insert(
2179 (),
2180 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2181 )
2182 }
2183
2184 pub fn observe_window_activation(
2185 &mut self,
2186 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2187 ) -> Subscription {
2188 let view = self.view.downgrade();
2189 self.window.activation_observers.insert(
2190 (),
2191 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2192 )
2193 }
2194
2195 /// Register a listener to be called when the given focus handle receives focus.
2196 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2197 /// is dropped.
2198 pub fn on_focus(
2199 &mut self,
2200 handle: &FocusHandle,
2201 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2202 ) -> Subscription {
2203 let view = self.view.downgrade();
2204 let focus_id = handle.id;
2205 self.window.focus_listeners.insert(
2206 (),
2207 Box::new(move |event, cx| {
2208 view.update(cx, |view, cx| {
2209 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2210 listener(view, cx)
2211 }
2212 })
2213 .is_ok()
2214 }),
2215 )
2216 }
2217
2218 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2219 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2220 /// is dropped.
2221 pub fn on_focus_in(
2222 &mut self,
2223 handle: &FocusHandle,
2224 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2225 ) -> Subscription {
2226 let view = self.view.downgrade();
2227 let focus_id = handle.id;
2228 self.window.focus_listeners.insert(
2229 (),
2230 Box::new(move |event, cx| {
2231 view.update(cx, |view, cx| {
2232 if event
2233 .focused
2234 .as_ref()
2235 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2236 {
2237 listener(view, cx)
2238 }
2239 })
2240 .is_ok()
2241 }),
2242 )
2243 }
2244
2245 /// Register a listener to be called when the given focus handle loses focus.
2246 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2247 /// is dropped.
2248 pub fn on_blur(
2249 &mut self,
2250 handle: &FocusHandle,
2251 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2252 ) -> Subscription {
2253 let view = self.view.downgrade();
2254 let focus_id = handle.id;
2255 self.window.focus_listeners.insert(
2256 (),
2257 Box::new(move |event, cx| {
2258 view.update(cx, |view, cx| {
2259 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2260 listener(view, cx)
2261 }
2262 })
2263 .is_ok()
2264 }),
2265 )
2266 }
2267
2268 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2269 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2270 /// is dropped.
2271 pub fn on_focus_out(
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 self.window.focus_listeners.insert(
2279 (),
2280 Box::new(move |event, cx| {
2281 view.update(cx, |view, cx| {
2282 if event
2283 .blurred
2284 .as_ref()
2285 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2286 {
2287 listener(view, cx)
2288 }
2289 })
2290 .is_ok()
2291 }),
2292 )
2293 }
2294
2295 pub fn spawn<Fut, R>(
2296 &mut self,
2297 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2298 ) -> Task<R>
2299 where
2300 R: 'static,
2301 Fut: Future<Output = R> + 'static,
2302 {
2303 let view = self.view().downgrade();
2304 self.window_cx.spawn(|cx| f(view, cx))
2305 }
2306
2307 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2308 where
2309 G: 'static,
2310 {
2311 let mut global = self.app.lease_global::<G>();
2312 let result = f(&mut global, self);
2313 self.app.end_global_lease(global);
2314 result
2315 }
2316
2317 pub fn observe_global<G: 'static>(
2318 &mut self,
2319 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2320 ) -> Subscription {
2321 let window_handle = self.window.handle;
2322 let view = self.view().downgrade();
2323 self.global_observers.insert(
2324 TypeId::of::<G>(),
2325 Box::new(move |cx| {
2326 window_handle
2327 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2328 .unwrap_or(false)
2329 }),
2330 )
2331 }
2332
2333 pub fn on_mouse_event<Event: 'static>(
2334 &mut self,
2335 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2336 ) {
2337 let handle = self.view().clone();
2338 self.window_cx.on_mouse_event(move |event, phase, cx| {
2339 handle.update(cx, |view, cx| {
2340 handler(view, event, phase, cx);
2341 })
2342 });
2343 }
2344
2345 pub fn on_key_event<Event: 'static>(
2346 &mut self,
2347 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2348 ) {
2349 let handle = self.view().clone();
2350 self.window_cx.on_key_event(move |event, phase, cx| {
2351 handle.update(cx, |view, cx| {
2352 handler(view, event, phase, cx);
2353 })
2354 });
2355 }
2356
2357 pub fn on_action(
2358 &mut self,
2359 action_type: TypeId,
2360 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2361 ) {
2362 let handle = self.view().clone();
2363 self.window_cx
2364 .on_action(action_type, move |action, phase, cx| {
2365 handle.update(cx, |view, cx| {
2366 handler(view, action, phase, cx);
2367 })
2368 });
2369 }
2370
2371 pub fn emit<Evt>(&mut self, event: Evt)
2372 where
2373 Evt: 'static,
2374 V: EventEmitter<Evt>,
2375 {
2376 let emitter = self.view.model.entity_id;
2377 self.app.push_effect(Effect::Emit {
2378 emitter,
2379 event_type: TypeId::of::<Evt>(),
2380 event: Box::new(event),
2381 });
2382 }
2383
2384 pub fn focus_self(&mut self)
2385 where
2386 V: FocusableView,
2387 {
2388 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2389 }
2390
2391 pub fn dismiss_self(&mut self)
2392 where
2393 V: ManagedView,
2394 {
2395 self.defer(|_, cx| cx.emit(DismissEvent::Dismiss))
2396 }
2397
2398 pub fn listener<E>(
2399 &self,
2400 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2401 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2402 let view = self.view().downgrade();
2403 move |e: &E, cx: &mut WindowContext| {
2404 view.update(cx, |view, cx| f(view, e, cx)).ok();
2405 }
2406 }
2407}
2408
2409impl<V> Context for ViewContext<'_, V> {
2410 type Result<U> = U;
2411
2412 fn build_model<T: 'static>(
2413 &mut self,
2414 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2415 ) -> Model<T> {
2416 self.window_cx.build_model(build_model)
2417 }
2418
2419 fn update_model<T: 'static, R>(
2420 &mut self,
2421 model: &Model<T>,
2422 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2423 ) -> R {
2424 self.window_cx.update_model(model, update)
2425 }
2426
2427 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2428 where
2429 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2430 {
2431 self.window_cx.update_window(window, update)
2432 }
2433
2434 fn read_model<T, R>(
2435 &self,
2436 handle: &Model<T>,
2437 read: impl FnOnce(&T, &AppContext) -> R,
2438 ) -> Self::Result<R>
2439 where
2440 T: 'static,
2441 {
2442 self.window_cx.read_model(handle, read)
2443 }
2444
2445 fn read_window<T, R>(
2446 &self,
2447 window: &WindowHandle<T>,
2448 read: impl FnOnce(View<T>, &AppContext) -> R,
2449 ) -> Result<R>
2450 where
2451 T: 'static,
2452 {
2453 self.window_cx.read_window(window, read)
2454 }
2455}
2456
2457impl<V: 'static> VisualContext for ViewContext<'_, V> {
2458 fn build_view<W: Render + 'static>(
2459 &mut self,
2460 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2461 ) -> Self::Result<View<W>> {
2462 self.window_cx.build_view(build_view_state)
2463 }
2464
2465 fn update_view<V2: 'static, R>(
2466 &mut self,
2467 view: &View<V2>,
2468 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2469 ) -> Self::Result<R> {
2470 self.window_cx.update_view(view, update)
2471 }
2472
2473 fn replace_root_view<W>(
2474 &mut self,
2475 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2476 ) -> Self::Result<View<W>>
2477 where
2478 W: 'static + Render,
2479 {
2480 self.window_cx.replace_root_view(build_view)
2481 }
2482
2483 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2484 self.window_cx.focus_view(view)
2485 }
2486
2487 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2488 self.window_cx.dismiss_view(view)
2489 }
2490}
2491
2492impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2493 type Target = WindowContext<'a>;
2494
2495 fn deref(&self) -> &Self::Target {
2496 &self.window_cx
2497 }
2498}
2499
2500impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2501 fn deref_mut(&mut self) -> &mut Self::Target {
2502 &mut self.window_cx
2503 }
2504}
2505
2506// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2507slotmap::new_key_type! { pub struct WindowId; }
2508
2509impl WindowId {
2510 pub fn as_u64(&self) -> u64 {
2511 self.0.as_ffi()
2512 }
2513}
2514
2515#[derive(Deref, DerefMut)]
2516pub struct WindowHandle<V> {
2517 #[deref]
2518 #[deref_mut]
2519 pub(crate) any_handle: AnyWindowHandle,
2520 state_type: PhantomData<V>,
2521}
2522
2523impl<V: 'static + Render> WindowHandle<V> {
2524 pub fn new(id: WindowId) -> Self {
2525 WindowHandle {
2526 any_handle: AnyWindowHandle {
2527 id,
2528 state_type: TypeId::of::<V>(),
2529 },
2530 state_type: PhantomData,
2531 }
2532 }
2533
2534 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2535 where
2536 C: Context,
2537 {
2538 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2539 root_view
2540 .downcast::<V>()
2541 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2542 }))
2543 }
2544
2545 pub fn update<C, R>(
2546 &self,
2547 cx: &mut C,
2548 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2549 ) -> Result<R>
2550 where
2551 C: Context,
2552 {
2553 cx.update_window(self.any_handle, |root_view, cx| {
2554 let view = root_view
2555 .downcast::<V>()
2556 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2557 Ok(cx.update_view(&view, update))
2558 })?
2559 }
2560
2561 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2562 let x = cx
2563 .windows
2564 .get(self.id)
2565 .and_then(|window| {
2566 window
2567 .as_ref()
2568 .and_then(|window| window.root_view.clone())
2569 .map(|root_view| root_view.downcast::<V>())
2570 })
2571 .ok_or_else(|| anyhow!("window not found"))?
2572 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2573
2574 Ok(x.read(cx))
2575 }
2576
2577 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2578 where
2579 C: Context,
2580 {
2581 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2582 }
2583
2584 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2585 where
2586 C: Context,
2587 {
2588 cx.read_window(self, |root_view, _cx| root_view.clone())
2589 }
2590
2591 pub fn is_active(&self, cx: &WindowContext) -> Option<bool> {
2592 cx.windows
2593 .get(self.id)
2594 .and_then(|window| window.as_ref().map(|window| window.active))
2595 }
2596}
2597
2598impl<V> Copy for WindowHandle<V> {}
2599
2600impl<V> Clone for WindowHandle<V> {
2601 fn clone(&self) -> Self {
2602 WindowHandle {
2603 any_handle: self.any_handle,
2604 state_type: PhantomData,
2605 }
2606 }
2607}
2608
2609impl<V> PartialEq for WindowHandle<V> {
2610 fn eq(&self, other: &Self) -> bool {
2611 self.any_handle == other.any_handle
2612 }
2613}
2614
2615impl<V> Eq for WindowHandle<V> {}
2616
2617impl<V> Hash for WindowHandle<V> {
2618 fn hash<H: Hasher>(&self, state: &mut H) {
2619 self.any_handle.hash(state);
2620 }
2621}
2622
2623impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2624 fn into(self) -> AnyWindowHandle {
2625 self.any_handle
2626 }
2627}
2628
2629#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2630pub struct AnyWindowHandle {
2631 pub(crate) id: WindowId,
2632 state_type: TypeId,
2633}
2634
2635impl AnyWindowHandle {
2636 pub fn window_id(&self) -> WindowId {
2637 self.id
2638 }
2639
2640 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2641 if TypeId::of::<T>() == self.state_type {
2642 Some(WindowHandle {
2643 any_handle: *self,
2644 state_type: PhantomData,
2645 })
2646 } else {
2647 None
2648 }
2649 }
2650
2651 pub fn update<C, R>(
2652 self,
2653 cx: &mut C,
2654 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2655 ) -> Result<R>
2656 where
2657 C: Context,
2658 {
2659 cx.update_window(self, update)
2660 }
2661
2662 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2663 where
2664 C: Context,
2665 T: 'static,
2666 {
2667 let view = self
2668 .downcast::<T>()
2669 .context("the type of the window's root view has changed")?;
2670
2671 cx.read_window(&view, read)
2672 }
2673}
2674
2675#[cfg(any(test, feature = "test-support"))]
2676impl From<SmallVec<[u32; 16]>> for StackingOrder {
2677 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2678 StackingOrder(small_vec)
2679 }
2680}
2681
2682#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2683pub enum ElementId {
2684 View(EntityId),
2685 Integer(usize),
2686 Name(SharedString),
2687 FocusHandle(FocusId),
2688}
2689
2690impl ElementId {
2691 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2692 ElementId::View(entity_id)
2693 }
2694}
2695
2696impl TryInto<SharedString> for ElementId {
2697 type Error = anyhow::Error;
2698
2699 fn try_into(self) -> anyhow::Result<SharedString> {
2700 if let ElementId::Name(name) = self {
2701 Ok(name)
2702 } else {
2703 Err(anyhow!("element id is not string"))
2704 }
2705 }
2706}
2707
2708impl From<usize> for ElementId {
2709 fn from(id: usize) -> Self {
2710 ElementId::Integer(id)
2711 }
2712}
2713
2714impl From<i32> for ElementId {
2715 fn from(id: i32) -> Self {
2716 Self::Integer(id as usize)
2717 }
2718}
2719
2720impl From<SharedString> for ElementId {
2721 fn from(name: SharedString) -> Self {
2722 ElementId::Name(name)
2723 }
2724}
2725
2726impl From<&'static str> for ElementId {
2727 fn from(name: &'static str) -> Self {
2728 ElementId::Name(name.into())
2729 }
2730}
2731
2732impl<'a> From<&'a FocusHandle> for ElementId {
2733 fn from(handle: &'a FocusHandle) -> Self {
2734 ElementId::FocusHandle(handle.id)
2735 }
2736}