1#![deny(missing_docs)]
2
3use crate::{
4 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
5 AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle, DevicePixels,
6 DispatchActionListener, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity,
7 EntityId, EventEmitter, FileDropEvent, Flatten, FontId, GlobalElementId, GlyphId, Hsla,
8 ImageData, InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, KeystrokeEvent, LayoutId,
9 Model, ModelContext, Modifiers, MonochromeSprite, MouseButton, MouseMoveEvent, MouseUpEvent,
10 Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler, PlatformWindow, Point,
11 PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams, RenderImageParams,
12 RenderSvgParams, ScaledPixels, Scene, Shadow, SharedString, Size, Style, SubscriberSet,
13 Subscription, Surface, TaffyLayoutEngine, Task, Underline, UnderlineStyle, View, VisualContext,
14 WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
15};
16use anyhow::{anyhow, Context as _, Result};
17use collections::{FxHashMap, FxHashSet};
18use derive_more::{Deref, DerefMut};
19use futures::{
20 channel::{mpsc, oneshot},
21 StreamExt,
22};
23use media::core_video::CVImageBuffer;
24use parking_lot::RwLock;
25use slotmap::SlotMap;
26use smallvec::SmallVec;
27use std::{
28 any::{Any, TypeId},
29 borrow::{Borrow, BorrowMut, Cow},
30 cell::RefCell,
31 collections::hash_map::Entry,
32 fmt::Debug,
33 future::Future,
34 hash::{Hash, Hasher},
35 marker::PhantomData,
36 mem,
37 rc::Rc,
38 sync::{
39 atomic::{AtomicUsize, Ordering::SeqCst},
40 Arc,
41 },
42};
43use util::{post_inc, ResultExt};
44
45const ACTIVE_DRAG_Z_INDEX: u8 = 1;
46
47/// A global stacking order, which is created by stacking successive z-index values.
48/// Each z-index will always be interpreted in the context of its parent z-index.
49#[derive(Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
50pub struct StackingOrder {
51 #[deref]
52 #[deref_mut]
53 context_stack: SmallVec<[u8; 64]>,
54 id: u32,
55}
56
57impl std::fmt::Debug for StackingOrder {
58 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
59 let mut stacks = self.context_stack.iter().peekable();
60 write!(f, "[({}): ", self.id)?;
61 while let Some(z_index) = stacks.next() {
62 write!(f, "{z_index}")?;
63 if stacks.peek().is_some() {
64 write!(f, "->")?;
65 }
66 }
67 write!(f, "]")?;
68 Ok(())
69 }
70}
71
72/// Represents the two different phases when dispatching events.
73#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
74pub enum DispatchPhase {
75 /// After the capture phase comes the bubble phase, in which mouse event listeners are
76 /// invoked front to back and keyboard event listeners are invoked from the focused element
77 /// to the root of the element tree. This is the phase you'll most commonly want to use when
78 /// registering event listeners.
79 #[default]
80 Bubble,
81 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
82 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
83 /// is used for special purposes such as clearing the "pressed" state for click events. If
84 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
85 /// outside of the immediate region may rely on detecting non-local events during this phase.
86 Capture,
87}
88
89impl DispatchPhase {
90 /// Returns true if this represents the "bubble" phase.
91 pub fn bubble(self) -> bool {
92 self == DispatchPhase::Bubble
93 }
94
95 /// Returns true if this represents the "capture" phase.
96 pub fn capture(self) -> bool {
97 self == DispatchPhase::Capture
98 }
99}
100
101type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
102type AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
103type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
104
105struct FocusEvent {
106 previous_focus_path: SmallVec<[FocusId; 8]>,
107 current_focus_path: SmallVec<[FocusId; 8]>,
108}
109
110slotmap::new_key_type! {
111 /// A globally unique identifier for a focusable element.
112 pub struct FocusId;
113}
114
115thread_local! {
116 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(4 * 1024 * 1024));
117}
118
119impl FocusId {
120 /// Obtains whether the element associated with this handle is currently focused.
121 pub fn is_focused(&self, cx: &WindowContext) -> bool {
122 cx.window.focus == Some(*self)
123 }
124
125 /// Obtains whether the element associated with this handle contains the focused
126 /// element or is itself focused.
127 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
128 cx.focused()
129 .map_or(false, |focused| self.contains(focused.id, cx))
130 }
131
132 /// Obtains whether the element associated with this handle is contained within the
133 /// focused element or is itself focused.
134 pub fn within_focused(&self, cx: &WindowContext) -> bool {
135 let focused = cx.focused();
136 focused.map_or(false, |focused| focused.id.contains(*self, cx))
137 }
138
139 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
140 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
141 cx.window
142 .rendered_frame
143 .dispatch_tree
144 .focus_contains(*self, other)
145 }
146}
147
148/// A handle which can be used to track and manipulate the focused element in a window.
149pub struct FocusHandle {
150 pub(crate) id: FocusId,
151 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
152}
153
154impl std::fmt::Debug for FocusHandle {
155 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
156 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
157 }
158}
159
160impl FocusHandle {
161 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
162 let id = handles.write().insert(AtomicUsize::new(1));
163 Self {
164 id,
165 handles: handles.clone(),
166 }
167 }
168
169 pub(crate) fn for_id(
170 id: FocusId,
171 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
172 ) -> Option<Self> {
173 let lock = handles.read();
174 let ref_count = lock.get(id)?;
175 if ref_count.load(SeqCst) == 0 {
176 None
177 } else {
178 ref_count.fetch_add(1, SeqCst);
179 Some(Self {
180 id,
181 handles: handles.clone(),
182 })
183 }
184 }
185
186 /// Moves the focus to the element associated with this handle.
187 pub fn focus(&self, cx: &mut WindowContext) {
188 cx.focus(self)
189 }
190
191 /// Obtains whether the element associated with this handle is currently focused.
192 pub fn is_focused(&self, cx: &WindowContext) -> bool {
193 self.id.is_focused(cx)
194 }
195
196 /// Obtains whether the element associated with this handle contains the focused
197 /// element or is itself focused.
198 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
199 self.id.contains_focused(cx)
200 }
201
202 /// Obtains whether the element associated with this handle is contained within the
203 /// focused element or is itself focused.
204 pub fn within_focused(&self, cx: &WindowContext) -> bool {
205 self.id.within_focused(cx)
206 }
207
208 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
209 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
210 self.id.contains(other.id, cx)
211 }
212}
213
214impl Clone for FocusHandle {
215 fn clone(&self) -> Self {
216 Self::for_id(self.id, &self.handles).unwrap()
217 }
218}
219
220impl PartialEq for FocusHandle {
221 fn eq(&self, other: &Self) -> bool {
222 self.id == other.id
223 }
224}
225
226impl Eq for FocusHandle {}
227
228impl Drop for FocusHandle {
229 fn drop(&mut self) {
230 self.handles
231 .read()
232 .get(self.id)
233 .unwrap()
234 .fetch_sub(1, SeqCst);
235 }
236}
237
238/// FocusableView allows users of your view to easily
239/// focus it (using cx.focus_view(view))
240pub trait FocusableView: 'static + Render {
241 /// Returns the focus handle associated with this view.
242 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
243}
244
245/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
246/// where the lifecycle of the view is handled by another view.
247pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
248
249impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
250
251/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
252pub struct DismissEvent;
253
254// Holds the state for a specific window.
255#[doc(hidden)]
256pub struct Window {
257 pub(crate) handle: AnyWindowHandle,
258 pub(crate) removed: bool,
259 pub(crate) platform_window: Box<dyn PlatformWindow>,
260 display_id: DisplayId,
261 sprite_atlas: Arc<dyn PlatformAtlas>,
262 rem_size: Pixels,
263 viewport_size: Size<Pixels>,
264 layout_engine: Option<TaffyLayoutEngine>,
265 pub(crate) root_view: Option<AnyView>,
266 pub(crate) element_id_stack: GlobalElementId,
267 pub(crate) rendered_frame: Frame,
268 pub(crate) next_frame: Frame,
269 pub(crate) dirty_views: FxHashSet<EntityId>,
270 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
271 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
272 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
273 default_prevented: bool,
274 mouse_position: Point<Pixels>,
275 modifiers: Modifiers,
276 requested_cursor_style: Option<CursorStyle>,
277 scale_factor: f32,
278 bounds: WindowBounds,
279 bounds_observers: SubscriberSet<(), AnyObserver>,
280 active: bool,
281 pub(crate) dirty: bool,
282 pub(crate) refreshing: bool,
283 pub(crate) drawing: bool,
284 activation_observers: SubscriberSet<(), AnyObserver>,
285 pub(crate) focus: Option<FocusId>,
286 focus_enabled: bool,
287
288 #[cfg(any(test, feature = "test-support"))]
289 pub(crate) focus_invalidated: bool,
290}
291
292pub(crate) struct ElementStateBox {
293 inner: Box<dyn Any>,
294 parent_view_id: EntityId,
295 #[cfg(debug_assertions)]
296 type_name: &'static str,
297}
298
299pub(crate) struct Frame {
300 focus: Option<FocusId>,
301 window_active: bool,
302 pub(crate) element_states: FxHashMap<GlobalElementId, ElementStateBox>,
303 mouse_listeners: FxHashMap<TypeId, Vec<(StackingOrder, EntityId, AnyMouseListener)>>,
304 pub(crate) dispatch_tree: DispatchTree,
305 pub(crate) scene: Scene,
306 pub(crate) depth_map: Vec<(StackingOrder, EntityId, Bounds<Pixels>)>,
307 pub(crate) z_index_stack: StackingOrder,
308 pub(crate) next_stacking_order_id: u32,
309 content_mask_stack: Vec<ContentMask<Pixels>>,
310 element_offset_stack: Vec<Point<Pixels>>,
311 pub(crate) view_stack: Vec<EntityId>,
312 pub(crate) reused_views: FxHashSet<EntityId>,
313}
314
315impl Frame {
316 fn new(dispatch_tree: DispatchTree) -> Self {
317 Frame {
318 focus: None,
319 window_active: false,
320 element_states: FxHashMap::default(),
321 mouse_listeners: FxHashMap::default(),
322 dispatch_tree,
323 scene: Scene::default(),
324 z_index_stack: StackingOrder::default(),
325 next_stacking_order_id: 0,
326 depth_map: Default::default(),
327 content_mask_stack: Vec::new(),
328 element_offset_stack: Vec::new(),
329 view_stack: Vec::new(),
330 reused_views: FxHashSet::default(),
331 }
332 }
333
334 fn clear(&mut self) {
335 self.element_states.clear();
336 self.mouse_listeners.values_mut().for_each(Vec::clear);
337 self.dispatch_tree.clear();
338 self.depth_map.clear();
339 self.next_stacking_order_id = 0;
340 self.reused_views.clear();
341 self.scene.clear();
342 debug_assert_eq!(self.view_stack.len(), 0);
343 }
344
345 fn focus_path(&self) -> SmallVec<[FocusId; 8]> {
346 self.focus
347 .map(|focus_id| self.dispatch_tree.focus_path(focus_id))
348 .unwrap_or_default()
349 }
350}
351
352impl Window {
353 pub(crate) fn new(
354 handle: AnyWindowHandle,
355 options: WindowOptions,
356 cx: &mut AppContext,
357 ) -> Self {
358 let platform_window = cx.platform.open_window(handle, options);
359 let display_id = platform_window.display().id();
360 let sprite_atlas = platform_window.sprite_atlas();
361 let mouse_position = platform_window.mouse_position();
362 let modifiers = platform_window.modifiers();
363 let content_size = platform_window.content_size();
364 let scale_factor = platform_window.scale_factor();
365 let bounds = platform_window.bounds();
366
367 platform_window.on_request_frame(Box::new({
368 let mut cx = cx.to_async();
369 move || {
370 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
371 }
372 }));
373 platform_window.on_resize(Box::new({
374 let mut cx = cx.to_async();
375 move |_, _| {
376 handle
377 .update(&mut cx, |_, cx| cx.window_bounds_changed())
378 .log_err();
379 }
380 }));
381 platform_window.on_moved(Box::new({
382 let mut cx = cx.to_async();
383 move || {
384 handle
385 .update(&mut cx, |_, cx| cx.window_bounds_changed())
386 .log_err();
387 }
388 }));
389 platform_window.on_active_status_change(Box::new({
390 let mut cx = cx.to_async();
391 move |active| {
392 handle
393 .update(&mut cx, |_, cx| {
394 cx.window.active = active;
395 cx.window
396 .activation_observers
397 .clone()
398 .retain(&(), |callback| callback(cx));
399 })
400 .log_err();
401 }
402 }));
403
404 platform_window.on_input({
405 let mut cx = cx.to_async();
406 Box::new(move |event| {
407 handle
408 .update(&mut cx, |_, cx| cx.dispatch_event(event))
409 .log_err()
410 .unwrap_or(false)
411 })
412 });
413
414 Window {
415 handle,
416 removed: false,
417 platform_window,
418 display_id,
419 sprite_atlas,
420 rem_size: px(16.),
421 viewport_size: content_size,
422 layout_engine: Some(TaffyLayoutEngine::new()),
423 root_view: None,
424 element_id_stack: GlobalElementId::default(),
425 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
426 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
427 dirty_views: FxHashSet::default(),
428 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
429 focus_listeners: SubscriberSet::new(),
430 focus_lost_listeners: SubscriberSet::new(),
431 default_prevented: true,
432 mouse_position,
433 modifiers,
434 requested_cursor_style: None,
435 scale_factor,
436 bounds,
437 bounds_observers: SubscriberSet::new(),
438 active: false,
439 dirty: false,
440 refreshing: false,
441 drawing: false,
442 activation_observers: SubscriberSet::new(),
443 focus: None,
444 focus_enabled: true,
445
446 #[cfg(any(test, feature = "test-support"))]
447 focus_invalidated: false,
448 }
449 }
450}
451
452/// Indicates which region of the window is visible. Content falling outside of this mask will not be
453/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
454/// to leave room to support more complex shapes in the future.
455#[derive(Clone, Debug, Default, PartialEq, Eq)]
456#[repr(C)]
457pub struct ContentMask<P: Clone + Default + Debug> {
458 /// The bounds
459 pub bounds: Bounds<P>,
460}
461
462impl ContentMask<Pixels> {
463 /// Scale the content mask's pixel units by the given scaling factor.
464 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
465 ContentMask {
466 bounds: self.bounds.scale(factor),
467 }
468 }
469
470 /// Intersect the content mask with the given content mask.
471 pub fn intersect(&self, other: &Self) -> Self {
472 let bounds = self.bounds.intersect(&other.bounds);
473 ContentMask { bounds }
474 }
475}
476
477/// Provides access to application state in the context of a single window. Derefs
478/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
479/// an [`AppContext`] and call any [`AppContext`] methods.
480pub struct WindowContext<'a> {
481 pub(crate) app: &'a mut AppContext,
482 pub(crate) window: &'a mut Window,
483}
484
485impl<'a> WindowContext<'a> {
486 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
487 Self { app, window }
488 }
489
490 /// Obtain a handle to the window that belongs to this context.
491 pub fn window_handle(&self) -> AnyWindowHandle {
492 self.window.handle
493 }
494
495 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
496 pub fn refresh(&mut self) {
497 if !self.window.drawing {
498 self.window.refreshing = true;
499 self.window.dirty = true;
500 }
501 }
502
503 /// Close this window.
504 pub fn remove_window(&mut self) {
505 self.window.removed = true;
506 }
507
508 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
509 /// for elements rendered within this window.
510 pub fn focus_handle(&mut self) -> FocusHandle {
511 FocusHandle::new(&self.window.focus_handles)
512 }
513
514 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
515 pub fn focused(&self) -> Option<FocusHandle> {
516 self.window
517 .focus
518 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
519 }
520
521 /// Move focus to the element associated with the given [`FocusHandle`].
522 pub fn focus(&mut self, handle: &FocusHandle) {
523 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
524 return;
525 }
526
527 self.window.focus = Some(handle.id);
528 self.window
529 .rendered_frame
530 .dispatch_tree
531 .clear_pending_keystrokes();
532
533 #[cfg(any(test, feature = "test-support"))]
534 {
535 self.window.focus_invalidated = true;
536 }
537
538 self.refresh();
539 }
540
541 /// Remove focus from all elements within this context's window.
542 pub fn blur(&mut self) {
543 if !self.window.focus_enabled {
544 return;
545 }
546
547 self.window.focus = None;
548 self.refresh();
549 }
550
551 /// Blur the window and don't allow anything in it to be focused again.
552 pub fn disable_focus(&mut self) {
553 self.blur();
554 self.window.focus_enabled = false;
555 }
556
557 /// Dispatch the given action on the currently focused element.
558 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
559 let focus_handle = self.focused();
560
561 self.defer(move |cx| {
562 let node_id = focus_handle
563 .and_then(|handle| {
564 cx.window
565 .rendered_frame
566 .dispatch_tree
567 .focusable_node_id(handle.id)
568 })
569 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
570
571 cx.propagate_event = true;
572 cx.dispatch_action_on_node(node_id, action);
573 })
574 }
575
576 pub(crate) fn dispatch_keystroke_observers(
577 &mut self,
578 event: &dyn Any,
579 action: Option<Box<dyn Action>>,
580 ) {
581 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
582 return;
583 };
584
585 self.keystroke_observers
586 .clone()
587 .retain(&(), move |callback| {
588 (callback)(
589 &KeystrokeEvent {
590 keystroke: key_down_event.keystroke.clone(),
591 action: action.as_ref().map(|action| action.boxed_clone()),
592 },
593 self,
594 );
595 true
596 });
597 }
598
599 pub(crate) fn clear_pending_keystrokes(&mut self) {
600 self.window
601 .rendered_frame
602 .dispatch_tree
603 .clear_pending_keystrokes();
604 self.window
605 .next_frame
606 .dispatch_tree
607 .clear_pending_keystrokes();
608 }
609
610 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
611 /// that are currently on the stack to be returned to the app.
612 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
613 let handle = self.window.handle;
614 self.app.defer(move |cx| {
615 handle.update(cx, |_, cx| f(cx)).ok();
616 });
617 }
618
619 /// Subscribe to events emitted by a model or view.
620 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
621 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
622 pub fn subscribe<Emitter, E, Evt>(
623 &mut self,
624 entity: &E,
625 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
626 ) -> Subscription
627 where
628 Emitter: EventEmitter<Evt>,
629 E: Entity<Emitter>,
630 Evt: 'static,
631 {
632 let entity_id = entity.entity_id();
633 let entity = entity.downgrade();
634 let window_handle = self.window.handle;
635 let (subscription, activate) = self.app.event_listeners.insert(
636 entity_id,
637 (
638 TypeId::of::<Evt>(),
639 Box::new(move |event, cx| {
640 window_handle
641 .update(cx, |_, cx| {
642 if let Some(handle) = E::upgrade_from(&entity) {
643 let event = event.downcast_ref().expect("invalid event type");
644 on_event(handle, event, cx);
645 true
646 } else {
647 false
648 }
649 })
650 .unwrap_or(false)
651 }),
652 ),
653 );
654 self.app.defer(move |_| activate());
655 subscription
656 }
657
658 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
659 /// await points in async code.
660 pub fn to_async(&self) -> AsyncWindowContext {
661 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
662 }
663
664 /// Schedule the given closure to be run directly after the current frame is rendered.
665 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
666 let handle = self.window.handle;
667 let display_id = self.window.display_id;
668
669 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
670 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
671 let (tx, mut rx) = mpsc::unbounded::<()>();
672 self.platform.set_display_link_output_callback(
673 display_id,
674 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
675 );
676
677 let consumer_task = self.app.spawn(|cx| async move {
678 while rx.next().await.is_some() {
679 cx.update(|cx| {
680 for callback in cx
681 .next_frame_callbacks
682 .get_mut(&display_id)
683 .unwrap()
684 .drain(..)
685 .collect::<SmallVec<[_; 32]>>()
686 {
687 callback(cx);
688 }
689 })
690 .ok();
691
692 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
693
694 cx.update(|cx| {
695 if cx.next_frame_callbacks.is_empty() {
696 cx.platform.stop_display_link(display_id);
697 }
698 })
699 .ok();
700 }
701 });
702 e.insert(consumer_task);
703 }
704 debug_assert!(self.app.frame_consumers.is_empty());
705 self.app.frame_consumers = frame_consumers;
706
707 if self.next_frame_callbacks.is_empty() {
708 self.platform.start_display_link(display_id);
709 }
710
711 self.next_frame_callbacks
712 .entry(display_id)
713 .or_default()
714 .push(Box::new(move |cx: &mut AppContext| {
715 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
716 }));
717 }
718
719 /// Spawn the future returned by the given closure on the application thread pool.
720 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
721 /// use within your future.
722 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
723 where
724 R: 'static,
725 Fut: Future<Output = R> + 'static,
726 {
727 self.app
728 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
729 }
730
731 /// Update the global of the given type. The given closure is given simultaneous mutable
732 /// access both to the global and the context.
733 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
734 where
735 G: 'static,
736 {
737 let mut global = self.app.lease_global::<G>();
738 let result = f(&mut global, self);
739 self.app.end_global_lease(global);
740 result
741 }
742
743 #[must_use]
744 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
745 /// layout is being requested, along with the layout ids of any children. This method is called during
746 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
747 pub fn request_layout(
748 &mut self,
749 style: &Style,
750 children: impl IntoIterator<Item = LayoutId>,
751 ) -> LayoutId {
752 self.app.layout_id_buffer.clear();
753 self.app.layout_id_buffer.extend(children);
754 let rem_size = self.rem_size();
755
756 self.window.layout_engine.as_mut().unwrap().request_layout(
757 style,
758 rem_size,
759 &self.app.layout_id_buffer,
760 )
761 }
762
763 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
764 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
765 /// determine the element's size. One place this is used internally is when measuring text.
766 ///
767 /// The given closure is invoked at layout time with the known dimensions and available space and
768 /// returns a `Size`.
769 pub fn request_measured_layout<
770 F: FnMut(Size<Option<Pixels>>, Size<AvailableSpace>, &mut WindowContext) -> Size<Pixels>
771 + 'static,
772 >(
773 &mut self,
774 style: Style,
775 measure: F,
776 ) -> LayoutId {
777 let rem_size = self.rem_size();
778 self.window
779 .layout_engine
780 .as_mut()
781 .unwrap()
782 .request_measured_layout(style, rem_size, measure)
783 }
784
785 pub(crate) fn layout_style(&self, layout_id: LayoutId) -> Option<&Style> {
786 self.window
787 .layout_engine
788 .as_ref()
789 .unwrap()
790 .requested_style(layout_id)
791 }
792
793 /// Compute the layout for the given id within the given available space.
794 /// This method is called for its side effect, typically by the framework prior to painting.
795 /// After calling it, you can request the bounds of the given layout node id or any descendant.
796 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
797 let mut layout_engine = self.window.layout_engine.take().unwrap();
798 layout_engine.compute_layout(layout_id, available_space, self);
799 self.window.layout_engine = Some(layout_engine);
800 }
801
802 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
803 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
804 /// in order to pass your element its `Bounds` automatically.
805 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
806 let mut bounds = self
807 .window
808 .layout_engine
809 .as_mut()
810 .unwrap()
811 .layout_bounds(layout_id)
812 .map(Into::into);
813 bounds.origin += self.element_offset();
814 bounds
815 }
816
817 fn window_bounds_changed(&mut self) {
818 self.window.scale_factor = self.window.platform_window.scale_factor();
819 self.window.viewport_size = self.window.platform_window.content_size();
820 self.window.bounds = self.window.platform_window.bounds();
821 self.window.display_id = self.window.platform_window.display().id();
822 self.refresh();
823
824 self.window
825 .bounds_observers
826 .clone()
827 .retain(&(), |callback| callback(self));
828 }
829
830 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
831 pub fn window_bounds(&self) -> WindowBounds {
832 self.window.bounds
833 }
834
835 /// Returns the size of the drawable area within the window.
836 pub fn viewport_size(&self) -> Size<Pixels> {
837 self.window.viewport_size
838 }
839
840 /// Returns whether this window is focused by the operating system (receiving key events).
841 pub fn is_window_active(&self) -> bool {
842 self.window.active
843 }
844
845 /// Toggle zoom on the window.
846 pub fn zoom_window(&self) {
847 self.window.platform_window.zoom();
848 }
849
850 /// Update the window's title at the platform level.
851 pub fn set_window_title(&mut self, title: &str) {
852 self.window.platform_window.set_title(title);
853 }
854
855 /// Mark the window as dirty at the platform level.
856 pub fn set_window_edited(&mut self, edited: bool) {
857 self.window.platform_window.set_edited(edited);
858 }
859
860 /// Determine the display on which the window is visible.
861 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
862 self.platform
863 .displays()
864 .into_iter()
865 .find(|display| display.id() == self.window.display_id)
866 }
867
868 /// Show the platform character palette.
869 pub fn show_character_palette(&self) {
870 self.window.platform_window.show_character_palette();
871 }
872
873 /// The scale factor of the display associated with the window. For example, it could
874 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
875 /// be rendered as two pixels on screen.
876 pub fn scale_factor(&self) -> f32 {
877 self.window.scale_factor
878 }
879
880 /// The size of an em for the base font of the application. Adjusting this value allows the
881 /// UI to scale, just like zooming a web page.
882 pub fn rem_size(&self) -> Pixels {
883 self.window.rem_size
884 }
885
886 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
887 /// UI to scale, just like zooming a web page.
888 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
889 self.window.rem_size = rem_size.into();
890 }
891
892 /// The line height associated with the current text style.
893 pub fn line_height(&self) -> Pixels {
894 let rem_size = self.rem_size();
895 let text_style = self.text_style();
896 text_style
897 .line_height
898 .to_pixels(text_style.font_size, rem_size)
899 }
900
901 /// Call to prevent the default action of an event. Currently only used to prevent
902 /// parent elements from becoming focused on mouse down.
903 pub fn prevent_default(&mut self) {
904 self.window.default_prevented = true;
905 }
906
907 /// Obtain whether default has been prevented for the event currently being dispatched.
908 pub fn default_prevented(&self) -> bool {
909 self.window.default_prevented
910 }
911
912 /// Register a mouse event listener on the window for the next frame. The type of event
913 /// is determined by the first parameter of the given listener. When the next frame is rendered
914 /// the listener will be cleared.
915 pub fn on_mouse_event<Event: 'static>(
916 &mut self,
917 mut handler: impl FnMut(&Event, DispatchPhase, &mut WindowContext) + 'static,
918 ) {
919 let view_id = self.parent_view_id().unwrap();
920 let order = self.window.next_frame.z_index_stack.clone();
921 self.window
922 .next_frame
923 .mouse_listeners
924 .entry(TypeId::of::<Event>())
925 .or_default()
926 .push((
927 order,
928 view_id,
929 Box::new(
930 move |event: &dyn Any, phase: DispatchPhase, cx: &mut WindowContext<'_>| {
931 handler(event.downcast_ref().unwrap(), phase, cx)
932 },
933 ),
934 ))
935 }
936
937 /// Register a key event listener on the window for the next frame. The type of event
938 /// is determined by the first parameter of the given listener. When the next frame is rendered
939 /// the listener will be cleared.
940 ///
941 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
942 /// a specific need to register a global listener.
943 pub fn on_key_event<Event: 'static>(
944 &mut self,
945 listener: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
946 ) {
947 self.window.next_frame.dispatch_tree.on_key_event(Rc::new(
948 move |event: &dyn Any, phase, cx: &mut WindowContext<'_>| {
949 if let Some(event) = event.downcast_ref::<Event>() {
950 listener(event, phase, cx)
951 }
952 },
953 ));
954 }
955
956 /// Register an action listener on the window for the next frame. The type of action
957 /// is determined by the first parameter of the given listener. When the next frame is rendered
958 /// the listener will be cleared.
959 ///
960 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
961 /// a specific need to register a global listener.
962 pub fn on_action(
963 &mut self,
964 action_type: TypeId,
965 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
966 ) {
967 self.window
968 .next_frame
969 .dispatch_tree
970 .on_action(action_type, Rc::new(listener));
971 }
972
973 /// Determine whether the given action is available along the dispatch path to the currently focused element.
974 pub fn is_action_available(&self, action: &dyn Action) -> bool {
975 let target = self
976 .focused()
977 .and_then(|focused_handle| {
978 self.window
979 .rendered_frame
980 .dispatch_tree
981 .focusable_node_id(focused_handle.id)
982 })
983 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
984 self.window
985 .rendered_frame
986 .dispatch_tree
987 .is_action_available(action, target)
988 }
989
990 /// The position of the mouse relative to the window.
991 pub fn mouse_position(&self) -> Point<Pixels> {
992 self.window.mouse_position
993 }
994
995 /// The current state of the keyboard's modifiers
996 pub fn modifiers(&self) -> Modifiers {
997 self.window.modifiers
998 }
999
1000 /// Update the cursor style at the platform level.
1001 pub fn set_cursor_style(&mut self, style: CursorStyle) {
1002 self.window.requested_cursor_style = Some(style)
1003 }
1004
1005 /// Called during painting to track which z-index is on top at each pixel position
1006 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
1007 let stacking_order = self.window.next_frame.z_index_stack.clone();
1008 let view_id = self.parent_view_id().unwrap();
1009 self.window
1010 .next_frame
1011 .depth_map
1012 .push((stacking_order, view_id, bounds));
1013 }
1014
1015 /// Returns true if there is no opaque layer containing the given point
1016 /// on top of the given level. Layers whose level is an extension of the
1017 /// level are not considered to be on top of the level.
1018 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
1019 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
1020 if level >= opaque_level {
1021 break;
1022 }
1023
1024 if bounds.contains(point) && !opaque_level.starts_with(level) {
1025 return false;
1026 }
1027 }
1028 true
1029 }
1030
1031 pub(crate) fn was_top_layer_under_active_drag(
1032 &self,
1033 point: &Point<Pixels>,
1034 level: &StackingOrder,
1035 ) -> bool {
1036 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
1037 if level >= opaque_level {
1038 break;
1039 }
1040 if opaque_level.starts_with(&[ACTIVE_DRAG_Z_INDEX]) {
1041 continue;
1042 }
1043
1044 if bounds.contains(point) && !opaque_level.starts_with(level) {
1045 return false;
1046 }
1047 }
1048 true
1049 }
1050
1051 /// Called during painting to get the current stacking order.
1052 pub fn stacking_order(&self) -> &StackingOrder {
1053 &self.window.next_frame.z_index_stack
1054 }
1055
1056 /// Paint one or more drop shadows into the scene for the next frame at the current z-index.
1057 pub fn paint_shadows(
1058 &mut self,
1059 bounds: Bounds<Pixels>,
1060 corner_radii: Corners<Pixels>,
1061 shadows: &[BoxShadow],
1062 ) {
1063 let scale_factor = self.scale_factor();
1064 let content_mask = self.content_mask();
1065 let view_id = self.parent_view_id().unwrap();
1066 let window = &mut *self.window;
1067 for shadow in shadows {
1068 let mut shadow_bounds = bounds;
1069 shadow_bounds.origin += shadow.offset;
1070 shadow_bounds.dilate(shadow.spread_radius);
1071 window.next_frame.scene.insert(
1072 &window.next_frame.z_index_stack,
1073 Shadow {
1074 view_id: view_id.as_u64() as u32,
1075 layer_id: 0,
1076 order: 0,
1077 bounds: shadow_bounds.scale(scale_factor),
1078 content_mask: content_mask.scale(scale_factor),
1079 corner_radii: corner_radii.scale(scale_factor),
1080 color: shadow.color,
1081 blur_radius: shadow.blur_radius.scale(scale_factor),
1082 },
1083 );
1084 }
1085 }
1086
1087 /// Paint one or more quads into the scene for the next frame at the current stacking context.
1088 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
1089 /// see [`fill`], [`outline`], and [`quad`] to construct this type.
1090 pub fn paint_quad(&mut self, quad: PaintQuad) {
1091 let scale_factor = self.scale_factor();
1092 let content_mask = self.content_mask();
1093 let view_id = self.parent_view_id().unwrap();
1094
1095 let window = &mut *self.window;
1096 window.next_frame.scene.insert(
1097 &window.next_frame.z_index_stack,
1098 Quad {
1099 view_id: view_id.as_u64() as u32,
1100 layer_id: 0,
1101 order: 0,
1102 bounds: quad.bounds.scale(scale_factor),
1103 content_mask: content_mask.scale(scale_factor),
1104 background: quad.background,
1105 border_color: quad.border_color,
1106 corner_radii: quad.corner_radii.scale(scale_factor),
1107 border_widths: quad.border_widths.scale(scale_factor),
1108 },
1109 );
1110 }
1111
1112 /// Paint the given `Path` into the scene for the next frame at the current z-index.
1113 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
1114 let scale_factor = self.scale_factor();
1115 let content_mask = self.content_mask();
1116 let view_id = self.parent_view_id().unwrap();
1117
1118 path.content_mask = content_mask;
1119 path.color = color.into();
1120 path.view_id = view_id.as_u64() as u32;
1121 let window = &mut *self.window;
1122 window
1123 .next_frame
1124 .scene
1125 .insert(&window.next_frame.z_index_stack, path.scale(scale_factor));
1126 }
1127
1128 /// Paint an underline into the scene for the next frame at the current z-index.
1129 pub fn paint_underline(
1130 &mut self,
1131 origin: Point<Pixels>,
1132 width: Pixels,
1133 style: &UnderlineStyle,
1134 ) {
1135 let scale_factor = self.scale_factor();
1136 let height = if style.wavy {
1137 style.thickness * 3.
1138 } else {
1139 style.thickness
1140 };
1141 let bounds = Bounds {
1142 origin,
1143 size: size(width, height),
1144 };
1145 let content_mask = self.content_mask();
1146 let view_id = self.parent_view_id().unwrap();
1147
1148 let window = &mut *self.window;
1149 window.next_frame.scene.insert(
1150 &window.next_frame.z_index_stack,
1151 Underline {
1152 view_id: view_id.as_u64() as u32,
1153 layer_id: 0,
1154 order: 0,
1155 bounds: bounds.scale(scale_factor),
1156 content_mask: content_mask.scale(scale_factor),
1157 thickness: style.thickness.scale(scale_factor),
1158 color: style.color.unwrap_or_default(),
1159 wavy: style.wavy,
1160 },
1161 );
1162 }
1163
1164 /// Paint a monochrome (non-emoji) glyph into the scene for the next frame at the current z-index.
1165 /// The y component of the origin is the baseline of the glyph.
1166 pub fn paint_glyph(
1167 &mut self,
1168 origin: Point<Pixels>,
1169 font_id: FontId,
1170 glyph_id: GlyphId,
1171 font_size: Pixels,
1172 color: Hsla,
1173 ) -> Result<()> {
1174 let scale_factor = self.scale_factor();
1175 let glyph_origin = origin.scale(scale_factor);
1176 let subpixel_variant = Point {
1177 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
1178 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
1179 };
1180 let params = RenderGlyphParams {
1181 font_id,
1182 glyph_id,
1183 font_size,
1184 subpixel_variant,
1185 scale_factor,
1186 is_emoji: false,
1187 };
1188
1189 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1190 if !raster_bounds.is_zero() {
1191 let tile =
1192 self.window
1193 .sprite_atlas
1194 .get_or_insert_with(¶ms.clone().into(), &mut || {
1195 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1196 Ok((size, Cow::Owned(bytes)))
1197 })?;
1198 let bounds = Bounds {
1199 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1200 size: tile.bounds.size.map(Into::into),
1201 };
1202 let content_mask = self.content_mask().scale(scale_factor);
1203 let view_id = self.parent_view_id().unwrap();
1204 let window = &mut *self.window;
1205 window.next_frame.scene.insert(
1206 &window.next_frame.z_index_stack,
1207 MonochromeSprite {
1208 view_id: view_id.as_u64() as u32,
1209 layer_id: 0,
1210 order: 0,
1211 bounds,
1212 content_mask,
1213 color,
1214 tile,
1215 },
1216 );
1217 }
1218 Ok(())
1219 }
1220
1221 /// Paint an emoji glyph into the scene for the next frame at the current z-index.
1222 /// The y component of the origin is the baseline of the glyph.
1223 pub fn paint_emoji(
1224 &mut self,
1225 origin: Point<Pixels>,
1226 font_id: FontId,
1227 glyph_id: GlyphId,
1228 font_size: Pixels,
1229 ) -> Result<()> {
1230 let scale_factor = self.scale_factor();
1231 let glyph_origin = origin.scale(scale_factor);
1232 let params = RenderGlyphParams {
1233 font_id,
1234 glyph_id,
1235 font_size,
1236 // We don't render emojis with subpixel variants.
1237 subpixel_variant: Default::default(),
1238 scale_factor,
1239 is_emoji: true,
1240 };
1241
1242 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1243 if !raster_bounds.is_zero() {
1244 let tile =
1245 self.window
1246 .sprite_atlas
1247 .get_or_insert_with(¶ms.clone().into(), &mut || {
1248 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1249 Ok((size, Cow::Owned(bytes)))
1250 })?;
1251 let bounds = Bounds {
1252 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1253 size: tile.bounds.size.map(Into::into),
1254 };
1255 let content_mask = self.content_mask().scale(scale_factor);
1256 let view_id = self.parent_view_id().unwrap();
1257 let window = &mut *self.window;
1258
1259 window.next_frame.scene.insert(
1260 &window.next_frame.z_index_stack,
1261 PolychromeSprite {
1262 view_id: view_id.as_u64() as u32,
1263 layer_id: 0,
1264 order: 0,
1265 bounds,
1266 corner_radii: Default::default(),
1267 content_mask,
1268 tile,
1269 grayscale: false,
1270 },
1271 );
1272 }
1273 Ok(())
1274 }
1275
1276 /// Paint a monochrome SVG into the scene for the next frame at the current stacking context.
1277 pub fn paint_svg(
1278 &mut self,
1279 bounds: Bounds<Pixels>,
1280 path: SharedString,
1281 color: Hsla,
1282 ) -> Result<()> {
1283 let scale_factor = self.scale_factor();
1284 let bounds = bounds.scale(scale_factor);
1285 // Render the SVG at twice the size to get a higher quality result.
1286 let params = RenderSvgParams {
1287 path,
1288 size: bounds
1289 .size
1290 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1291 };
1292
1293 let tile =
1294 self.window
1295 .sprite_atlas
1296 .get_or_insert_with(¶ms.clone().into(), &mut || {
1297 let bytes = self.svg_renderer.render(¶ms)?;
1298 Ok((params.size, Cow::Owned(bytes)))
1299 })?;
1300 let content_mask = self.content_mask().scale(scale_factor);
1301 let view_id = self.parent_view_id().unwrap();
1302
1303 let window = &mut *self.window;
1304 window.next_frame.scene.insert(
1305 &window.next_frame.z_index_stack,
1306 MonochromeSprite {
1307 view_id: view_id.as_u64() as u32,
1308 layer_id: 0,
1309 order: 0,
1310 bounds,
1311 content_mask,
1312 color,
1313 tile,
1314 },
1315 );
1316
1317 Ok(())
1318 }
1319
1320 /// Paint an image into the scene for the next frame at the current z-index.
1321 pub fn paint_image(
1322 &mut self,
1323 bounds: Bounds<Pixels>,
1324 corner_radii: Corners<Pixels>,
1325 data: Arc<ImageData>,
1326 grayscale: bool,
1327 ) -> Result<()> {
1328 let scale_factor = self.scale_factor();
1329 let bounds = bounds.scale(scale_factor);
1330 let params = RenderImageParams { image_id: data.id };
1331
1332 let tile = self
1333 .window
1334 .sprite_atlas
1335 .get_or_insert_with(¶ms.clone().into(), &mut || {
1336 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1337 })?;
1338 let content_mask = self.content_mask().scale(scale_factor);
1339 let corner_radii = corner_radii.scale(scale_factor);
1340 let view_id = self.parent_view_id().unwrap();
1341
1342 let window = &mut *self.window;
1343 window.next_frame.scene.insert(
1344 &window.next_frame.z_index_stack,
1345 PolychromeSprite {
1346 view_id: view_id.as_u64() as u32,
1347 layer_id: 0,
1348 order: 0,
1349 bounds,
1350 content_mask,
1351 corner_radii,
1352 tile,
1353 grayscale,
1354 },
1355 );
1356 Ok(())
1357 }
1358
1359 /// Paint a surface into the scene for the next frame at the current z-index.
1360 pub fn paint_surface(&mut self, bounds: Bounds<Pixels>, image_buffer: CVImageBuffer) {
1361 let scale_factor = self.scale_factor();
1362 let bounds = bounds.scale(scale_factor);
1363 let content_mask = self.content_mask().scale(scale_factor);
1364 let view_id = self.parent_view_id().unwrap();
1365 let window = &mut *self.window;
1366 window.next_frame.scene.insert(
1367 &window.next_frame.z_index_stack,
1368 Surface {
1369 view_id: view_id.as_u64() as u32,
1370 layer_id: 0,
1371 order: 0,
1372 bounds,
1373 content_mask,
1374 image_buffer,
1375 },
1376 );
1377 }
1378
1379 pub(crate) fn reuse_geometry(&mut self) {
1380 let view_id = self.parent_view_id().unwrap();
1381 let window = &mut self.window;
1382 let grafted_view_ids = window
1383 .next_frame
1384 .dispatch_tree
1385 .graft(view_id, &mut window.rendered_frame.dispatch_tree);
1386 for view_id in grafted_view_ids {
1387 assert!(window.next_frame.reused_views.insert(view_id));
1388 }
1389 }
1390
1391 /// Draw pixels to the display for this window based on the contents of its scene.
1392 pub(crate) fn draw(&mut self) {
1393 self.window.dirty = false;
1394 self.window.drawing = true;
1395
1396 #[cfg(any(test, feature = "test-support"))]
1397 {
1398 self.window.focus_invalidated = false;
1399 }
1400
1401 self.text_system().start_frame();
1402 self.window.platform_window.clear_input_handler();
1403 self.window.layout_engine.as_mut().unwrap().clear();
1404 self.window.next_frame.clear();
1405 let root_view = self.window.root_view.take().unwrap();
1406
1407 self.with_z_index(0, |cx| {
1408 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
1409 for (action_type, action_listeners) in &cx.app.global_action_listeners {
1410 for action_listener in action_listeners.iter().cloned() {
1411 cx.window.next_frame.dispatch_tree.on_action(
1412 *action_type,
1413 Rc::new(move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
1414 action_listener(action, phase, cx)
1415 }),
1416 )
1417 }
1418 }
1419
1420 let available_space = cx.window.viewport_size.map(Into::into);
1421 root_view.draw(Point::default(), available_space, cx);
1422 })
1423 });
1424
1425 if let Some(active_drag) = self.app.active_drag.take() {
1426 self.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
1427 let offset = cx.mouse_position() - active_drag.cursor_offset;
1428 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1429 active_drag.view.draw(offset, available_space, cx);
1430 });
1431 self.active_drag = Some(active_drag);
1432 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1433 self.with_z_index(1, |cx| {
1434 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1435 active_tooltip
1436 .view
1437 .draw(active_tooltip.cursor_offset, available_space, cx);
1438 });
1439 }
1440 self.window.dirty_views.clear();
1441
1442 self.window
1443 .next_frame
1444 .dispatch_tree
1445 .preserve_pending_keystrokes(
1446 &mut self.window.rendered_frame.dispatch_tree,
1447 self.window.focus,
1448 );
1449 self.window.next_frame.focus = self.window.focus;
1450 self.window.next_frame.window_active = self.window.active;
1451 self.window.root_view = Some(root_view);
1452
1453 // Reuse mouse listeners that didn't change since the last frame.
1454 for (type_id, listeners) in &mut self.window.rendered_frame.mouse_listeners {
1455 let next_listeners = self
1456 .window
1457 .next_frame
1458 .mouse_listeners
1459 .entry(*type_id)
1460 .or_default();
1461 for (order, view_id, listener) in listeners.drain(..) {
1462 if self.window.next_frame.reused_views.contains(&view_id) {
1463 next_listeners.push((order, view_id, listener));
1464 }
1465 }
1466 }
1467
1468 // Reuse entries in the depth map that didn't change since the last frame.
1469 for (order, view_id, bounds) in self.window.rendered_frame.depth_map.drain(..) {
1470 if self.window.next_frame.reused_views.contains(&view_id) {
1471 self.window
1472 .next_frame
1473 .depth_map
1474 .push((order, view_id, bounds));
1475 }
1476 }
1477 self.window
1478 .next_frame
1479 .depth_map
1480 .sort_by(|a, b| a.0.cmp(&b.0));
1481
1482 // Retain element states for views that didn't change since the last frame.
1483 for (element_id, state) in self.window.rendered_frame.element_states.drain() {
1484 if self
1485 .window
1486 .next_frame
1487 .reused_views
1488 .contains(&state.parent_view_id)
1489 {
1490 self.window
1491 .next_frame
1492 .element_states
1493 .entry(element_id)
1494 .or_insert(state);
1495 }
1496 }
1497
1498 // Reuse geometry that didn't change since the last frame.
1499 self.window.next_frame.scene.insert_views_from_scene(
1500 &self.window.next_frame.reused_views,
1501 &mut self.window.rendered_frame.scene,
1502 );
1503 self.window.next_frame.scene.finish();
1504
1505 let previous_focus_path = self.window.rendered_frame.focus_path();
1506 let previous_window_active = self.window.rendered_frame.window_active;
1507 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
1508 let current_focus_path = self.window.rendered_frame.focus_path();
1509 let current_window_active = self.window.rendered_frame.window_active;
1510
1511 // Set the cursor only if we're the active window.
1512 let cursor_style = self
1513 .window
1514 .requested_cursor_style
1515 .take()
1516 .unwrap_or(CursorStyle::Arrow);
1517 if self.is_window_active() {
1518 self.platform.set_cursor_style(cursor_style);
1519 }
1520
1521 self.window.refreshing = false;
1522 self.window.drawing = false;
1523 ELEMENT_ARENA.with_borrow_mut(|element_arena| element_arena.clear());
1524
1525 if previous_focus_path != current_focus_path
1526 || previous_window_active != current_window_active
1527 {
1528 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
1529 self.window
1530 .focus_lost_listeners
1531 .clone()
1532 .retain(&(), |listener| listener(self));
1533 }
1534
1535 let event = FocusEvent {
1536 previous_focus_path: if previous_window_active {
1537 previous_focus_path
1538 } else {
1539 Default::default()
1540 },
1541 current_focus_path: if current_window_active {
1542 current_focus_path
1543 } else {
1544 Default::default()
1545 },
1546 };
1547 self.window
1548 .focus_listeners
1549 .clone()
1550 .retain(&(), |listener| listener(&event, self));
1551 }
1552
1553 self.window
1554 .platform_window
1555 .draw(&self.window.rendered_frame.scene);
1556 }
1557
1558 /// Dispatch a mouse or keyboard event on the window.
1559 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1560 // Handlers may set this to false by calling `stop_propagation`.
1561 self.app.propagate_event = true;
1562 // Handlers may set this to true by calling `prevent_default`.
1563 self.window.default_prevented = false;
1564
1565 let event = match event {
1566 // Track the mouse position with our own state, since accessing the platform
1567 // API for the mouse position can only occur on the main thread.
1568 InputEvent::MouseMove(mouse_move) => {
1569 self.window.mouse_position = mouse_move.position;
1570 self.window.modifiers = mouse_move.modifiers;
1571 InputEvent::MouseMove(mouse_move)
1572 }
1573 InputEvent::MouseDown(mouse_down) => {
1574 self.window.mouse_position = mouse_down.position;
1575 self.window.modifiers = mouse_down.modifiers;
1576 InputEvent::MouseDown(mouse_down)
1577 }
1578 InputEvent::MouseUp(mouse_up) => {
1579 self.window.mouse_position = mouse_up.position;
1580 self.window.modifiers = mouse_up.modifiers;
1581 InputEvent::MouseUp(mouse_up)
1582 }
1583 InputEvent::MouseExited(mouse_exited) => {
1584 self.window.modifiers = mouse_exited.modifiers;
1585 InputEvent::MouseExited(mouse_exited)
1586 }
1587 InputEvent::ModifiersChanged(modifiers_changed) => {
1588 self.window.modifiers = modifiers_changed.modifiers;
1589 InputEvent::ModifiersChanged(modifiers_changed)
1590 }
1591 InputEvent::ScrollWheel(scroll_wheel) => {
1592 self.window.mouse_position = scroll_wheel.position;
1593 self.window.modifiers = scroll_wheel.modifiers;
1594 InputEvent::ScrollWheel(scroll_wheel)
1595 }
1596 // Translate dragging and dropping of external files from the operating system
1597 // to internal drag and drop events.
1598 InputEvent::FileDrop(file_drop) => match file_drop {
1599 FileDropEvent::Entered { position, paths } => {
1600 self.window.mouse_position = position;
1601 if self.active_drag.is_none() {
1602 self.active_drag = Some(AnyDrag {
1603 value: Box::new(paths.clone()),
1604 view: self.new_view(|_| paths).into(),
1605 cursor_offset: position,
1606 });
1607 }
1608 InputEvent::MouseMove(MouseMoveEvent {
1609 position,
1610 pressed_button: Some(MouseButton::Left),
1611 modifiers: Modifiers::default(),
1612 })
1613 }
1614 FileDropEvent::Pending { position } => {
1615 self.window.mouse_position = position;
1616 InputEvent::MouseMove(MouseMoveEvent {
1617 position,
1618 pressed_button: Some(MouseButton::Left),
1619 modifiers: Modifiers::default(),
1620 })
1621 }
1622 FileDropEvent::Submit { position } => {
1623 self.activate(true);
1624 self.window.mouse_position = position;
1625 InputEvent::MouseUp(MouseUpEvent {
1626 button: MouseButton::Left,
1627 position,
1628 modifiers: Modifiers::default(),
1629 click_count: 1,
1630 })
1631 }
1632 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1633 button: MouseButton::Left,
1634 position: Point::default(),
1635 modifiers: Modifiers::default(),
1636 click_count: 1,
1637 }),
1638 },
1639 InputEvent::KeyDown(_) | InputEvent::KeyUp(_) => event,
1640 };
1641
1642 if let Some(any_mouse_event) = event.mouse_event() {
1643 self.dispatch_mouse_event(any_mouse_event);
1644 } else if let Some(any_key_event) = event.keyboard_event() {
1645 self.dispatch_key_event(any_key_event);
1646 }
1647
1648 !self.app.propagate_event
1649 }
1650
1651 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1652 if let Some(mut handlers) = self
1653 .window
1654 .rendered_frame
1655 .mouse_listeners
1656 .remove(&event.type_id())
1657 {
1658 // Because handlers may add other handlers, we sort every time.
1659 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1660
1661 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1662 // special purposes, such as detecting events outside of a given Bounds.
1663 for (_, _, handler) in &mut handlers {
1664 handler(event, DispatchPhase::Capture, self);
1665 if !self.app.propagate_event {
1666 break;
1667 }
1668 }
1669
1670 // Bubble phase, where most normal handlers do their work.
1671 if self.app.propagate_event {
1672 for (_, _, handler) in handlers.iter_mut().rev() {
1673 handler(event, DispatchPhase::Bubble, self);
1674 if !self.app.propagate_event {
1675 break;
1676 }
1677 }
1678 }
1679
1680 self.window
1681 .rendered_frame
1682 .mouse_listeners
1683 .insert(event.type_id(), handlers);
1684 }
1685
1686 if self.app.propagate_event && self.has_active_drag() {
1687 if event.is::<MouseMoveEvent>() {
1688 // If this was a mouse move event, redraw the window so that the
1689 // active drag can follow the mouse cursor.
1690 self.refresh();
1691 } else if event.is::<MouseUpEvent>() {
1692 // If this was a mouse up event, cancel the active drag and redraw
1693 // the window.
1694 self.active_drag = None;
1695 self.refresh();
1696 }
1697 }
1698 }
1699
1700 fn dispatch_key_event(&mut self, event: &dyn Any) {
1701 let node_id = self
1702 .window
1703 .focus
1704 .and_then(|focus_id| {
1705 self.window
1706 .rendered_frame
1707 .dispatch_tree
1708 .focusable_node_id(focus_id)
1709 })
1710 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1711
1712 let dispatch_path = self
1713 .window
1714 .rendered_frame
1715 .dispatch_tree
1716 .dispatch_path(node_id);
1717
1718 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1719
1720 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1721 for node_id in &dispatch_path {
1722 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1723
1724 if let Some(context) = node.context.clone() {
1725 context_stack.push(context);
1726 }
1727 }
1728
1729 for node_id in dispatch_path.iter().rev() {
1730 // Match keystrokes
1731 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1732 if node.context.is_some() {
1733 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1734 let mut new_actions = self
1735 .window
1736 .rendered_frame
1737 .dispatch_tree
1738 .dispatch_key(&key_down_event.keystroke, &context_stack);
1739 actions.append(&mut new_actions);
1740 }
1741
1742 context_stack.pop();
1743 }
1744 }
1745
1746 if !actions.is_empty() {
1747 self.clear_pending_keystrokes();
1748 }
1749
1750 self.propagate_event = true;
1751 for action in actions {
1752 self.dispatch_action_on_node(node_id, action.boxed_clone());
1753 if !self.propagate_event {
1754 self.dispatch_keystroke_observers(event, Some(action));
1755 return;
1756 }
1757 }
1758
1759 // Capture phase
1760 for node_id in &dispatch_path {
1761 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1762
1763 for key_listener in node.key_listeners.clone() {
1764 key_listener(event, DispatchPhase::Capture, self);
1765 if !self.propagate_event {
1766 return;
1767 }
1768 }
1769 }
1770
1771 // Bubble phase
1772 for node_id in dispatch_path.iter().rev() {
1773 // Handle low level key events
1774 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1775 for key_listener in node.key_listeners.clone() {
1776 key_listener(event, DispatchPhase::Bubble, self);
1777 if !self.propagate_event {
1778 return;
1779 }
1780 }
1781 }
1782
1783 self.dispatch_keystroke_observers(event, None);
1784 }
1785
1786 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1787 pub fn has_pending_keystrokes(&self) -> bool {
1788 self.window
1789 .rendered_frame
1790 .dispatch_tree
1791 .has_pending_keystrokes()
1792 }
1793
1794 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1795 let dispatch_path = self
1796 .window
1797 .rendered_frame
1798 .dispatch_tree
1799 .dispatch_path(node_id);
1800
1801 // Capture phase
1802 for node_id in &dispatch_path {
1803 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1804 for DispatchActionListener {
1805 action_type,
1806 listener,
1807 } in node.action_listeners.clone()
1808 {
1809 let any_action = action.as_any();
1810 if action_type == any_action.type_id() {
1811 listener(any_action, DispatchPhase::Capture, self);
1812 if !self.propagate_event {
1813 return;
1814 }
1815 }
1816 }
1817 }
1818 // Bubble phase
1819 for node_id in dispatch_path.iter().rev() {
1820 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1821 for DispatchActionListener {
1822 action_type,
1823 listener,
1824 } in node.action_listeners.clone()
1825 {
1826 let any_action = action.as_any();
1827 if action_type == any_action.type_id() {
1828 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1829 listener(any_action, DispatchPhase::Bubble, self);
1830 if !self.propagate_event {
1831 return;
1832 }
1833 }
1834 }
1835 }
1836 }
1837
1838 /// Register the given handler to be invoked whenever the global of the given type
1839 /// is updated.
1840 pub fn observe_global<G: 'static>(
1841 &mut self,
1842 f: impl Fn(&mut WindowContext<'_>) + 'static,
1843 ) -> Subscription {
1844 let window_handle = self.window.handle;
1845 let (subscription, activate) = self.global_observers.insert(
1846 TypeId::of::<G>(),
1847 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1848 );
1849 self.app.defer(move |_| activate());
1850 subscription
1851 }
1852
1853 /// Focus the current window and bring it to the foreground at the platform level.
1854 pub fn activate_window(&self) {
1855 self.window.platform_window.activate();
1856 }
1857
1858 /// Minimize the current window at the platform level.
1859 pub fn minimize_window(&self) {
1860 self.window.platform_window.minimize();
1861 }
1862
1863 /// Toggle full screen status on the current window at the platform level.
1864 pub fn toggle_full_screen(&self) {
1865 self.window.platform_window.toggle_full_screen();
1866 }
1867
1868 /// Present a platform dialog.
1869 /// The provided message will be presented, along with buttons for each answer.
1870 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1871 pub fn prompt(
1872 &self,
1873 level: PromptLevel,
1874 message: &str,
1875 answers: &[&str],
1876 ) -> oneshot::Receiver<usize> {
1877 self.window.platform_window.prompt(level, message, answers)
1878 }
1879
1880 /// Returns all available actions for the focused element.
1881 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1882 let node_id = self
1883 .window
1884 .focus
1885 .and_then(|focus_id| {
1886 self.window
1887 .rendered_frame
1888 .dispatch_tree
1889 .focusable_node_id(focus_id)
1890 })
1891 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1892
1893 self.window
1894 .rendered_frame
1895 .dispatch_tree
1896 .available_actions(node_id)
1897 }
1898
1899 /// Returns key bindings that invoke the given action on the currently focused element.
1900 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1901 self.window
1902 .rendered_frame
1903 .dispatch_tree
1904 .bindings_for_action(
1905 action,
1906 &self.window.rendered_frame.dispatch_tree.context_stack,
1907 )
1908 }
1909
1910 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1911 pub fn bindings_for_action_in(
1912 &self,
1913 action: &dyn Action,
1914 focus_handle: &FocusHandle,
1915 ) -> Vec<KeyBinding> {
1916 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1917
1918 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1919 return vec![];
1920 };
1921 let context_stack = dispatch_tree
1922 .dispatch_path(node_id)
1923 .into_iter()
1924 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1925 .collect();
1926 dispatch_tree.bindings_for_action(action, &context_stack)
1927 }
1928
1929 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1930 pub fn listener_for<V: Render, E>(
1931 &self,
1932 view: &View<V>,
1933 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1934 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1935 let view = view.downgrade();
1936 move |e: &E, cx: &mut WindowContext| {
1937 view.update(cx, |view, cx| f(view, e, cx)).ok();
1938 }
1939 }
1940
1941 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1942 pub fn handler_for<V: Render>(
1943 &self,
1944 view: &View<V>,
1945 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1946 ) -> impl Fn(&mut WindowContext) {
1947 let view = view.downgrade();
1948 move |cx: &mut WindowContext| {
1949 view.update(cx, |view, cx| f(view, cx)).ok();
1950 }
1951 }
1952
1953 /// Invoke the given function with the given focus handle present on the key dispatch stack.
1954 /// If you want an element to participate in key dispatch, use this method to push its key context and focus handle into the stack during paint.
1955 pub fn with_key_dispatch<R>(
1956 &mut self,
1957 context: Option<KeyContext>,
1958 focus_handle: Option<FocusHandle>,
1959 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1960 ) -> R {
1961 let parent_view_id = self.parent_view_id();
1962 let window = &mut self.window;
1963 let focus_id = focus_handle.as_ref().map(|handle| handle.id);
1964 window
1965 .next_frame
1966 .dispatch_tree
1967 .push_node(context.clone(), focus_id, parent_view_id);
1968
1969 let result = f(focus_handle, self);
1970
1971 self.window.next_frame.dispatch_tree.pop_node();
1972
1973 result
1974 }
1975
1976 pub(crate) fn with_view_id<R>(
1977 &mut self,
1978 view_id: EntityId,
1979 f: impl FnOnce(&mut Self) -> R,
1980 ) -> R {
1981 self.window.next_frame.view_stack.push(view_id);
1982 let result = f(self);
1983 self.window.next_frame.view_stack.pop();
1984 result
1985 }
1986
1987 /// Update or initialize state for an element with the given id that lives across multiple
1988 /// frames. If an element with this id existed in the rendered frame, its state will be passed
1989 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1990 /// when drawing the next frame.
1991 pub(crate) fn with_element_state<S, R>(
1992 &mut self,
1993 id: ElementId,
1994 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1995 ) -> R
1996 where
1997 S: 'static,
1998 {
1999 self.with_element_id(Some(id), |cx| {
2000 let global_id = cx.window().element_id_stack.clone();
2001
2002 if let Some(any) = cx
2003 .window_mut()
2004 .next_frame
2005 .element_states
2006 .remove(&global_id)
2007 .or_else(|| {
2008 cx.window_mut()
2009 .rendered_frame
2010 .element_states
2011 .remove(&global_id)
2012 })
2013 {
2014 let ElementStateBox {
2015 inner,
2016 parent_view_id,
2017 #[cfg(debug_assertions)]
2018 type_name
2019 } = any;
2020 // Using the extra inner option to avoid needing to reallocate a new box.
2021 let mut state_box = inner
2022 .downcast::<Option<S>>()
2023 .map_err(|_| {
2024 #[cfg(debug_assertions)]
2025 {
2026 anyhow!(
2027 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
2028 std::any::type_name::<S>(),
2029 type_name
2030 )
2031 }
2032
2033 #[cfg(not(debug_assertions))]
2034 {
2035 anyhow!(
2036 "invalid element state type for id, requested_type {:?}",
2037 std::any::type_name::<S>(),
2038 )
2039 }
2040 })
2041 .unwrap();
2042
2043 // Actual: Option<AnyElement> <- View
2044 // Requested: () <- AnyElemet
2045 let state = state_box
2046 .take()
2047 .expect("element state is already on the stack");
2048 let (result, state) = f(Some(state), cx);
2049 state_box.replace(state);
2050 cx.window_mut()
2051 .next_frame
2052 .element_states
2053 .insert(global_id, ElementStateBox {
2054 inner: state_box,
2055 parent_view_id,
2056 #[cfg(debug_assertions)]
2057 type_name
2058 });
2059 result
2060 } else {
2061 let (result, state) = f(None, cx);
2062 let parent_view_id = cx.parent_view_id().unwrap();
2063 cx.window_mut()
2064 .next_frame
2065 .element_states
2066 .insert(global_id,
2067 ElementStateBox {
2068 inner: Box::new(Some(state)),
2069 parent_view_id,
2070 #[cfg(debug_assertions)]
2071 type_name: std::any::type_name::<S>()
2072 }
2073
2074 );
2075 result
2076 }
2077 })
2078 }
2079
2080 fn parent_view_id(&self) -> Option<EntityId> {
2081 self.window.next_frame.view_stack.last().copied()
2082 }
2083
2084 /// Set an input handler, such as [`ElementInputHandler`][element_input_handler], which interfaces with the
2085 /// platform to receive textual input with proper integration with concerns such
2086 /// as IME interactions.
2087 ///
2088 /// [element_input_handler]: crate::ElementInputHandler
2089 pub fn handle_input(
2090 &mut self,
2091 focus_handle: &FocusHandle,
2092 input_handler: impl PlatformInputHandler,
2093 ) {
2094 if focus_handle.is_focused(self) {
2095 self.window
2096 .platform_window
2097 .set_input_handler(Box::new(input_handler));
2098 }
2099 }
2100
2101 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
2102 /// If the callback returns false, the window won't be closed.
2103 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
2104 let mut this = self.to_async();
2105 self.window
2106 .platform_window
2107 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
2108 }
2109}
2110
2111impl Context for WindowContext<'_> {
2112 type Result<T> = T;
2113
2114 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
2115 where
2116 T: 'static,
2117 {
2118 let slot = self.app.entities.reserve();
2119 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
2120 self.entities.insert(slot, model)
2121 }
2122
2123 fn update_model<T: 'static, R>(
2124 &mut self,
2125 model: &Model<T>,
2126 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2127 ) -> R {
2128 let mut entity = self.entities.lease(model);
2129 let result = update(
2130 &mut *entity,
2131 &mut ModelContext::new(&mut *self.app, model.downgrade()),
2132 );
2133 self.entities.end_lease(entity);
2134 result
2135 }
2136
2137 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2138 where
2139 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2140 {
2141 if window == self.window.handle {
2142 let root_view = self.window.root_view.clone().unwrap();
2143 Ok(update(root_view, self))
2144 } else {
2145 window.update(self.app, update)
2146 }
2147 }
2148
2149 fn read_model<T, R>(
2150 &self,
2151 handle: &Model<T>,
2152 read: impl FnOnce(&T, &AppContext) -> R,
2153 ) -> Self::Result<R>
2154 where
2155 T: 'static,
2156 {
2157 let entity = self.entities.read(handle);
2158 read(entity, &*self.app)
2159 }
2160
2161 fn read_window<T, R>(
2162 &self,
2163 window: &WindowHandle<T>,
2164 read: impl FnOnce(View<T>, &AppContext) -> R,
2165 ) -> Result<R>
2166 where
2167 T: 'static,
2168 {
2169 if window.any_handle == self.window.handle {
2170 let root_view = self
2171 .window
2172 .root_view
2173 .clone()
2174 .unwrap()
2175 .downcast::<T>()
2176 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2177 Ok(read(root_view, self))
2178 } else {
2179 self.app.read_window(window, read)
2180 }
2181 }
2182}
2183
2184impl VisualContext for WindowContext<'_> {
2185 fn new_view<V>(
2186 &mut self,
2187 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
2188 ) -> Self::Result<View<V>>
2189 where
2190 V: 'static + Render,
2191 {
2192 let slot = self.app.entities.reserve();
2193 let view = View {
2194 model: slot.clone(),
2195 };
2196 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
2197 let entity = build_view_state(&mut cx);
2198 cx.entities.insert(slot, entity);
2199
2200 cx.new_view_observers
2201 .clone()
2202 .retain(&TypeId::of::<V>(), |observer| {
2203 let any_view = AnyView::from(view.clone());
2204 (observer)(any_view, self);
2205 true
2206 });
2207
2208 view
2209 }
2210
2211 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
2212 fn update_view<T: 'static, R>(
2213 &mut self,
2214 view: &View<T>,
2215 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
2216 ) -> Self::Result<R> {
2217 let mut lease = self.app.entities.lease(&view.model);
2218 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
2219 let result = update(&mut *lease, &mut cx);
2220 cx.app.entities.end_lease(lease);
2221 result
2222 }
2223
2224 fn replace_root_view<V>(
2225 &mut self,
2226 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
2227 ) -> Self::Result<View<V>>
2228 where
2229 V: 'static + Render,
2230 {
2231 let view = self.new_view(build_view);
2232 self.window.root_view = Some(view.clone().into());
2233 self.refresh();
2234 view
2235 }
2236
2237 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
2238 self.update_view(view, |view, cx| {
2239 view.focus_handle(cx).clone().focus(cx);
2240 })
2241 }
2242
2243 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
2244 where
2245 V: ManagedView,
2246 {
2247 self.update_view(view, |_, cx| cx.emit(DismissEvent))
2248 }
2249}
2250
2251impl<'a> std::ops::Deref for WindowContext<'a> {
2252 type Target = AppContext;
2253
2254 fn deref(&self) -> &Self::Target {
2255 self.app
2256 }
2257}
2258
2259impl<'a> std::ops::DerefMut for WindowContext<'a> {
2260 fn deref_mut(&mut self) -> &mut Self::Target {
2261 self.app
2262 }
2263}
2264
2265impl<'a> Borrow<AppContext> for WindowContext<'a> {
2266 fn borrow(&self) -> &AppContext {
2267 self.app
2268 }
2269}
2270
2271impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
2272 fn borrow_mut(&mut self) -> &mut AppContext {
2273 self.app
2274 }
2275}
2276
2277/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
2278pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
2279 #[doc(hidden)]
2280 fn app_mut(&mut self) -> &mut AppContext {
2281 self.borrow_mut()
2282 }
2283
2284 #[doc(hidden)]
2285 fn app(&self) -> &AppContext {
2286 self.borrow()
2287 }
2288
2289 #[doc(hidden)]
2290 fn window(&self) -> &Window {
2291 self.borrow()
2292 }
2293
2294 #[doc(hidden)]
2295 fn window_mut(&mut self) -> &mut Window {
2296 self.borrow_mut()
2297 }
2298
2299 /// Pushes the given element id onto the global stack and invokes the given closure
2300 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
2301 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
2302 /// used to associate state with identified elements across separate frames.
2303 fn with_element_id<R>(
2304 &mut self,
2305 id: Option<impl Into<ElementId>>,
2306 f: impl FnOnce(&mut Self) -> R,
2307 ) -> R {
2308 if let Some(id) = id.map(Into::into) {
2309 let window = self.window_mut();
2310 window.element_id_stack.push(id);
2311 let result = f(self);
2312 let window: &mut Window = self.borrow_mut();
2313 window.element_id_stack.pop();
2314 result
2315 } else {
2316 f(self)
2317 }
2318 }
2319
2320 /// Invoke the given function with the given content mask after intersecting it
2321 /// with the current mask.
2322 fn with_content_mask<R>(
2323 &mut self,
2324 mask: Option<ContentMask<Pixels>>,
2325 f: impl FnOnce(&mut Self) -> R,
2326 ) -> R {
2327 if let Some(mask) = mask {
2328 let mask = mask.intersect(&self.content_mask());
2329 self.window_mut().next_frame.content_mask_stack.push(mask);
2330 let result = f(self);
2331 self.window_mut().next_frame.content_mask_stack.pop();
2332 result
2333 } else {
2334 f(self)
2335 }
2336 }
2337
2338 /// Invoke the given function with the content mask reset to that
2339 /// of the window.
2340 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
2341 let mask = ContentMask {
2342 bounds: Bounds {
2343 origin: Point::default(),
2344 size: self.window().viewport_size,
2345 },
2346 };
2347 let new_stacking_order_id =
2348 post_inc(&mut self.window_mut().next_frame.next_stacking_order_id);
2349 let old_stacking_order = mem::take(&mut self.window_mut().next_frame.z_index_stack);
2350 self.window_mut().next_frame.z_index_stack.id = new_stacking_order_id;
2351 self.window_mut().next_frame.content_mask_stack.push(mask);
2352 let result = f(self);
2353 self.window_mut().next_frame.content_mask_stack.pop();
2354 self.window_mut().next_frame.z_index_stack = old_stacking_order;
2355 result
2356 }
2357
2358 /// Called during painting to invoke the given closure in a new stacking context. The given
2359 /// z-index is interpreted relative to the previous call to `stack`.
2360 fn with_z_index<R>(&mut self, z_index: u8, f: impl FnOnce(&mut Self) -> R) -> R {
2361 let new_stacking_order_id =
2362 post_inc(&mut self.window_mut().next_frame.next_stacking_order_id);
2363 let old_stacking_order_id = mem::replace(
2364 &mut self.window_mut().next_frame.z_index_stack.id,
2365 new_stacking_order_id,
2366 );
2367 self.window_mut().next_frame.z_index_stack.id = new_stacking_order_id;
2368 self.window_mut().next_frame.z_index_stack.push(z_index);
2369 let result = f(self);
2370 self.window_mut().next_frame.z_index_stack.id = old_stacking_order_id;
2371 self.window_mut().next_frame.z_index_stack.pop();
2372 result
2373 }
2374
2375 /// Update the global element offset relative to the current offset. This is used to implement
2376 /// scrolling.
2377 fn with_element_offset<R>(
2378 &mut self,
2379 offset: Point<Pixels>,
2380 f: impl FnOnce(&mut Self) -> R,
2381 ) -> R {
2382 if offset.is_zero() {
2383 return f(self);
2384 };
2385
2386 let abs_offset = self.element_offset() + offset;
2387 self.with_absolute_element_offset(abs_offset, f)
2388 }
2389
2390 /// Update the global element offset based on the given offset. This is used to implement
2391 /// drag handles and other manual painting of elements.
2392 fn with_absolute_element_offset<R>(
2393 &mut self,
2394 offset: Point<Pixels>,
2395 f: impl FnOnce(&mut Self) -> R,
2396 ) -> R {
2397 self.window_mut()
2398 .next_frame
2399 .element_offset_stack
2400 .push(offset);
2401 let result = f(self);
2402 self.window_mut().next_frame.element_offset_stack.pop();
2403 result
2404 }
2405
2406 /// Obtain the current element offset.
2407 fn element_offset(&self) -> Point<Pixels> {
2408 self.window()
2409 .next_frame
2410 .element_offset_stack
2411 .last()
2412 .copied()
2413 .unwrap_or_default()
2414 }
2415
2416 /// Obtain the current content mask.
2417 fn content_mask(&self) -> ContentMask<Pixels> {
2418 self.window()
2419 .next_frame
2420 .content_mask_stack
2421 .last()
2422 .cloned()
2423 .unwrap_or_else(|| ContentMask {
2424 bounds: Bounds {
2425 origin: Point::default(),
2426 size: self.window().viewport_size,
2427 },
2428 })
2429 }
2430
2431 /// The size of an em for the base font of the application. Adjusting this value allows the
2432 /// UI to scale, just like zooming a web page.
2433 fn rem_size(&self) -> Pixels {
2434 self.window().rem_size
2435 }
2436}
2437
2438impl Borrow<Window> for WindowContext<'_> {
2439 fn borrow(&self) -> &Window {
2440 self.window
2441 }
2442}
2443
2444impl BorrowMut<Window> for WindowContext<'_> {
2445 fn borrow_mut(&mut self) -> &mut Window {
2446 self.window
2447 }
2448}
2449
2450impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
2451
2452/// Provides access to application state that is specialized for a particular [`View`].
2453/// Allows you to interact with focus, emit events, etc.
2454/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
2455/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
2456pub struct ViewContext<'a, V> {
2457 window_cx: WindowContext<'a>,
2458 view: &'a View<V>,
2459}
2460
2461impl<V> Borrow<AppContext> for ViewContext<'_, V> {
2462 fn borrow(&self) -> &AppContext {
2463 &*self.window_cx.app
2464 }
2465}
2466
2467impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
2468 fn borrow_mut(&mut self) -> &mut AppContext {
2469 &mut *self.window_cx.app
2470 }
2471}
2472
2473impl<V> Borrow<Window> for ViewContext<'_, V> {
2474 fn borrow(&self) -> &Window {
2475 &*self.window_cx.window
2476 }
2477}
2478
2479impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2480 fn borrow_mut(&mut self) -> &mut Window {
2481 &mut *self.window_cx.window
2482 }
2483}
2484
2485impl<'a, V: 'static> ViewContext<'a, V> {
2486 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2487 Self {
2488 window_cx: WindowContext::new(app, window),
2489 view,
2490 }
2491 }
2492
2493 /// Get the entity_id of this view.
2494 pub fn entity_id(&self) -> EntityId {
2495 self.view.entity_id()
2496 }
2497
2498 /// Get the view pointer underlying this context.
2499 pub fn view(&self) -> &View<V> {
2500 self.view
2501 }
2502
2503 /// Get the model underlying this view.
2504 pub fn model(&self) -> &Model<V> {
2505 &self.view.model
2506 }
2507
2508 /// Access the underlying window context.
2509 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2510 &mut self.window_cx
2511 }
2512
2513 /// Set a given callback to be run on the next frame.
2514 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2515 where
2516 V: 'static,
2517 {
2518 let view = self.view().clone();
2519 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2520 }
2521
2522 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2523 /// that are currently on the stack to be returned to the app.
2524 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2525 let view = self.view().downgrade();
2526 self.window_cx.defer(move |cx| {
2527 view.update(cx, f).ok();
2528 });
2529 }
2530
2531 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
2532 pub fn observe<V2, E>(
2533 &mut self,
2534 entity: &E,
2535 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2536 ) -> Subscription
2537 where
2538 V2: 'static,
2539 V: 'static,
2540 E: Entity<V2>,
2541 {
2542 let view = self.view().downgrade();
2543 let entity_id = entity.entity_id();
2544 let entity = entity.downgrade();
2545 let window_handle = self.window.handle;
2546 let (subscription, activate) = self.app.observers.insert(
2547 entity_id,
2548 Box::new(move |cx| {
2549 window_handle
2550 .update(cx, |_, cx| {
2551 if let Some(handle) = E::upgrade_from(&entity) {
2552 view.update(cx, |this, cx| on_notify(this, handle, cx))
2553 .is_ok()
2554 } else {
2555 false
2556 }
2557 })
2558 .unwrap_or(false)
2559 }),
2560 );
2561 self.app.defer(move |_| activate());
2562 subscription
2563 }
2564
2565 /// Subscribe to events emitted by another model or view.
2566 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
2567 /// The callback will be invoked with a reference to the current view, a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a view context for the current view.
2568 pub fn subscribe<V2, E, Evt>(
2569 &mut self,
2570 entity: &E,
2571 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2572 ) -> Subscription
2573 where
2574 V2: EventEmitter<Evt>,
2575 E: Entity<V2>,
2576 Evt: 'static,
2577 {
2578 let view = self.view().downgrade();
2579 let entity_id = entity.entity_id();
2580 let handle = entity.downgrade();
2581 let window_handle = self.window.handle;
2582 let (subscription, activate) = self.app.event_listeners.insert(
2583 entity_id,
2584 (
2585 TypeId::of::<Evt>(),
2586 Box::new(move |event, cx| {
2587 window_handle
2588 .update(cx, |_, cx| {
2589 if let Some(handle) = E::upgrade_from(&handle) {
2590 let event = event.downcast_ref().expect("invalid event type");
2591 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2592 .is_ok()
2593 } else {
2594 false
2595 }
2596 })
2597 .unwrap_or(false)
2598 }),
2599 ),
2600 );
2601 self.app.defer(move |_| activate());
2602 subscription
2603 }
2604
2605 /// Register a callback to be invoked when the view is released.
2606 ///
2607 /// The callback receives a handle to the view's window. This handle may be
2608 /// invalid, if the window was closed before the view was released.
2609 pub fn on_release(
2610 &mut self,
2611 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
2612 ) -> Subscription {
2613 let window_handle = self.window.handle;
2614 let (subscription, activate) = self.app.release_listeners.insert(
2615 self.view.model.entity_id,
2616 Box::new(move |this, cx| {
2617 let this = this.downcast_mut().expect("invalid entity type");
2618 on_release(this, window_handle, cx)
2619 }),
2620 );
2621 activate();
2622 subscription
2623 }
2624
2625 /// Register a callback to be invoked when the given Model or View is released.
2626 pub fn observe_release<V2, E>(
2627 &mut self,
2628 entity: &E,
2629 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2630 ) -> Subscription
2631 where
2632 V: 'static,
2633 V2: 'static,
2634 E: Entity<V2>,
2635 {
2636 let view = self.view().downgrade();
2637 let entity_id = entity.entity_id();
2638 let window_handle = self.window.handle;
2639 let (subscription, activate) = self.app.release_listeners.insert(
2640 entity_id,
2641 Box::new(move |entity, cx| {
2642 let entity = entity.downcast_mut().expect("invalid entity type");
2643 let _ = window_handle.update(cx, |_, cx| {
2644 view.update(cx, |this, cx| on_release(this, entity, cx))
2645 });
2646 }),
2647 );
2648 activate();
2649 subscription
2650 }
2651
2652 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
2653 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
2654 pub fn notify(&mut self) {
2655 for view_id in self
2656 .window
2657 .rendered_frame
2658 .dispatch_tree
2659 .view_path(self.view.entity_id())
2660 {
2661 if !self.window.dirty_views.insert(view_id) {
2662 break;
2663 }
2664 }
2665
2666 if !self.window.drawing {
2667 self.window_cx.window.dirty = true;
2668 self.window_cx.app.push_effect(Effect::Notify {
2669 emitter: self.view.model.entity_id,
2670 });
2671 }
2672 }
2673
2674 /// Register a callback to be invoked when the window is resized.
2675 pub fn observe_window_bounds(
2676 &mut self,
2677 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2678 ) -> Subscription {
2679 let view = self.view.downgrade();
2680 let (subscription, activate) = self.window.bounds_observers.insert(
2681 (),
2682 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2683 );
2684 activate();
2685 subscription
2686 }
2687
2688 /// Register a callback to be invoked when the window is activated or deactivated.
2689 pub fn observe_window_activation(
2690 &mut self,
2691 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2692 ) -> Subscription {
2693 let view = self.view.downgrade();
2694 let (subscription, activate) = self.window.activation_observers.insert(
2695 (),
2696 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2697 );
2698 activate();
2699 subscription
2700 }
2701
2702 /// Register a listener to be called when the given focus handle receives focus.
2703 /// Returns a subscription and persists until the subscription is dropped.
2704 pub fn on_focus(
2705 &mut self,
2706 handle: &FocusHandle,
2707 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2708 ) -> Subscription {
2709 let view = self.view.downgrade();
2710 let focus_id = handle.id;
2711 let (subscription, activate) = self.window.focus_listeners.insert(
2712 (),
2713 Box::new(move |event, cx| {
2714 view.update(cx, |view, cx| {
2715 if event.previous_focus_path.last() != Some(&focus_id)
2716 && event.current_focus_path.last() == Some(&focus_id)
2717 {
2718 listener(view, cx)
2719 }
2720 })
2721 .is_ok()
2722 }),
2723 );
2724 self.app.defer(move |_| activate());
2725 subscription
2726 }
2727
2728 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2729 /// Returns a subscription and persists until the subscription is dropped.
2730 pub fn on_focus_in(
2731 &mut self,
2732 handle: &FocusHandle,
2733 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2734 ) -> Subscription {
2735 let view = self.view.downgrade();
2736 let focus_id = handle.id;
2737 let (subscription, activate) = self.window.focus_listeners.insert(
2738 (),
2739 Box::new(move |event, cx| {
2740 view.update(cx, |view, cx| {
2741 if !event.previous_focus_path.contains(&focus_id)
2742 && event.current_focus_path.contains(&focus_id)
2743 {
2744 listener(view, cx)
2745 }
2746 })
2747 .is_ok()
2748 }),
2749 );
2750 self.app.defer(move |_| activate());
2751 subscription
2752 }
2753
2754 /// Register a listener to be called when the given focus handle loses focus.
2755 /// Returns a subscription and persists until the subscription is dropped.
2756 pub fn on_blur(
2757 &mut self,
2758 handle: &FocusHandle,
2759 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2760 ) -> Subscription {
2761 let view = self.view.downgrade();
2762 let focus_id = handle.id;
2763 let (subscription, activate) = self.window.focus_listeners.insert(
2764 (),
2765 Box::new(move |event, cx| {
2766 view.update(cx, |view, cx| {
2767 if event.previous_focus_path.last() == Some(&focus_id)
2768 && event.current_focus_path.last() != Some(&focus_id)
2769 {
2770 listener(view, cx)
2771 }
2772 })
2773 .is_ok()
2774 }),
2775 );
2776 self.app.defer(move |_| activate());
2777 subscription
2778 }
2779
2780 /// Register a listener to be called when nothing in the window has focus.
2781 /// This typically happens when the node that was focused is removed from the tree,
2782 /// and this callback lets you chose a default place to restore the users focus.
2783 /// Returns a subscription and persists until the subscription is dropped.
2784 pub fn on_focus_lost(
2785 &mut self,
2786 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2787 ) -> Subscription {
2788 let view = self.view.downgrade();
2789 let (subscription, activate) = self.window.focus_lost_listeners.insert(
2790 (),
2791 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2792 );
2793 activate();
2794 subscription
2795 }
2796
2797 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2798 /// Returns a subscription and persists until the subscription is dropped.
2799 pub fn on_focus_out(
2800 &mut self,
2801 handle: &FocusHandle,
2802 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2803 ) -> Subscription {
2804 let view = self.view.downgrade();
2805 let focus_id = handle.id;
2806 let (subscription, activate) = self.window.focus_listeners.insert(
2807 (),
2808 Box::new(move |event, cx| {
2809 view.update(cx, |view, cx| {
2810 if event.previous_focus_path.contains(&focus_id)
2811 && !event.current_focus_path.contains(&focus_id)
2812 {
2813 listener(view, cx)
2814 }
2815 })
2816 .is_ok()
2817 }),
2818 );
2819 self.app.defer(move |_| activate());
2820 subscription
2821 }
2822
2823 /// Schedule a future to be run asynchronously.
2824 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2825 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2826 /// The returned future will be polled on the main thread.
2827 pub fn spawn<Fut, R>(
2828 &mut self,
2829 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2830 ) -> Task<R>
2831 where
2832 R: 'static,
2833 Fut: Future<Output = R> + 'static,
2834 {
2835 let view = self.view().downgrade();
2836 self.window_cx.spawn(|cx| f(view, cx))
2837 }
2838
2839 /// Update the global state of the given type.
2840 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2841 where
2842 G: 'static,
2843 {
2844 let mut global = self.app.lease_global::<G>();
2845 let result = f(&mut global, self);
2846 self.app.end_global_lease(global);
2847 result
2848 }
2849
2850 /// Register a callback to be invoked when the given global state changes.
2851 pub fn observe_global<G: 'static>(
2852 &mut self,
2853 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2854 ) -> Subscription {
2855 let window_handle = self.window.handle;
2856 let view = self.view().downgrade();
2857 let (subscription, activate) = self.global_observers.insert(
2858 TypeId::of::<G>(),
2859 Box::new(move |cx| {
2860 window_handle
2861 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2862 .unwrap_or(false)
2863 }),
2864 );
2865 self.app.defer(move |_| activate());
2866 subscription
2867 }
2868
2869 /// Add a listener for any mouse event that occurs in the window.
2870 /// This is a fairly low level method.
2871 /// Typically, you'll want to use methods on UI elements, which perform bounds checking etc.
2872 pub fn on_mouse_event<Event: 'static>(
2873 &mut self,
2874 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2875 ) {
2876 let handle = self.view().clone();
2877 self.window_cx.on_mouse_event(move |event, phase, cx| {
2878 handle.update(cx, |view, cx| {
2879 handler(view, event, phase, cx);
2880 })
2881 });
2882 }
2883
2884 /// Register a callback to be invoked when the given Key Event is dispatched to the window.
2885 pub fn on_key_event<Event: 'static>(
2886 &mut self,
2887 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2888 ) {
2889 let handle = self.view().clone();
2890 self.window_cx.on_key_event(move |event, phase, cx| {
2891 handle.update(cx, |view, cx| {
2892 handler(view, event, phase, cx);
2893 })
2894 });
2895 }
2896
2897 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2898 pub fn on_action(
2899 &mut self,
2900 action_type: TypeId,
2901 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2902 ) {
2903 let handle = self.view().clone();
2904 self.window_cx
2905 .on_action(action_type, move |action, phase, cx| {
2906 handle.update(cx, |view, cx| {
2907 listener(view, action, phase, cx);
2908 })
2909 });
2910 }
2911
2912 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2913 pub fn emit<Evt>(&mut self, event: Evt)
2914 where
2915 Evt: 'static,
2916 V: EventEmitter<Evt>,
2917 {
2918 let emitter = self.view.model.entity_id;
2919 self.app.push_effect(Effect::Emit {
2920 emitter,
2921 event_type: TypeId::of::<Evt>(),
2922 event: Box::new(event),
2923 });
2924 }
2925
2926 /// Move focus to the current view, assuming it implements [`FocusableView`].
2927 pub fn focus_self(&mut self)
2928 where
2929 V: FocusableView,
2930 {
2931 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2932 }
2933
2934 /// Convenience method for accessing view state in an event callback.
2935 ///
2936 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2937 /// but it's often useful to be able to access view state in these
2938 /// callbacks. This method provides a convenient way to do so.
2939 pub fn listener<E>(
2940 &self,
2941 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2942 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2943 let view = self.view().downgrade();
2944 move |e: &E, cx: &mut WindowContext| {
2945 view.update(cx, |view, cx| f(view, e, cx)).ok();
2946 }
2947 }
2948}
2949
2950impl<V> Context for ViewContext<'_, V> {
2951 type Result<U> = U;
2952
2953 fn new_model<T: 'static>(
2954 &mut self,
2955 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2956 ) -> Model<T> {
2957 self.window_cx.new_model(build_model)
2958 }
2959
2960 fn update_model<T: 'static, R>(
2961 &mut self,
2962 model: &Model<T>,
2963 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2964 ) -> R {
2965 self.window_cx.update_model(model, update)
2966 }
2967
2968 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2969 where
2970 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2971 {
2972 self.window_cx.update_window(window, update)
2973 }
2974
2975 fn read_model<T, R>(
2976 &self,
2977 handle: &Model<T>,
2978 read: impl FnOnce(&T, &AppContext) -> R,
2979 ) -> Self::Result<R>
2980 where
2981 T: 'static,
2982 {
2983 self.window_cx.read_model(handle, read)
2984 }
2985
2986 fn read_window<T, R>(
2987 &self,
2988 window: &WindowHandle<T>,
2989 read: impl FnOnce(View<T>, &AppContext) -> R,
2990 ) -> Result<R>
2991 where
2992 T: 'static,
2993 {
2994 self.window_cx.read_window(window, read)
2995 }
2996}
2997
2998impl<V: 'static> VisualContext for ViewContext<'_, V> {
2999 fn new_view<W: Render + 'static>(
3000 &mut self,
3001 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
3002 ) -> Self::Result<View<W>> {
3003 self.window_cx.new_view(build_view_state)
3004 }
3005
3006 fn update_view<V2: 'static, R>(
3007 &mut self,
3008 view: &View<V2>,
3009 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
3010 ) -> Self::Result<R> {
3011 self.window_cx.update_view(view, update)
3012 }
3013
3014 fn replace_root_view<W>(
3015 &mut self,
3016 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
3017 ) -> Self::Result<View<W>>
3018 where
3019 W: 'static + Render,
3020 {
3021 self.window_cx.replace_root_view(build_view)
3022 }
3023
3024 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
3025 self.window_cx.focus_view(view)
3026 }
3027
3028 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
3029 self.window_cx.dismiss_view(view)
3030 }
3031}
3032
3033impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
3034 type Target = WindowContext<'a>;
3035
3036 fn deref(&self) -> &Self::Target {
3037 &self.window_cx
3038 }
3039}
3040
3041impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
3042 fn deref_mut(&mut self) -> &mut Self::Target {
3043 &mut self.window_cx
3044 }
3045}
3046
3047// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
3048slotmap::new_key_type! {
3049 /// A unique identifier for a window.
3050 pub struct WindowId;
3051}
3052
3053impl WindowId {
3054 /// Converts this window ID to a `u64`.
3055 pub fn as_u64(&self) -> u64 {
3056 self.0.as_ffi()
3057 }
3058}
3059
3060/// A handle to a window with a specific root view type.
3061/// Note that this does not keep the window alive on its own.
3062#[derive(Deref, DerefMut)]
3063pub struct WindowHandle<V> {
3064 #[deref]
3065 #[deref_mut]
3066 pub(crate) any_handle: AnyWindowHandle,
3067 state_type: PhantomData<V>,
3068}
3069
3070impl<V: 'static + Render> WindowHandle<V> {
3071 /// Create a new handle from a window ID.
3072 /// This does not check if the root type of the window is `V`.
3073 pub fn new(id: WindowId) -> Self {
3074 WindowHandle {
3075 any_handle: AnyWindowHandle {
3076 id,
3077 state_type: TypeId::of::<V>(),
3078 },
3079 state_type: PhantomData,
3080 }
3081 }
3082
3083 /// Get the root view out of this window.
3084 ///
3085 /// This will fail if the window is closed or if the root view's type does not match `V`.
3086 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
3087 where
3088 C: Context,
3089 {
3090 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
3091 root_view
3092 .downcast::<V>()
3093 .map_err(|_| anyhow!("the type of the window's root view has changed"))
3094 }))
3095 }
3096
3097 /// Update the root view of this window.
3098 ///
3099 /// This will fail if the window has been closed or if the root view's type does not match
3100 pub fn update<C, R>(
3101 &self,
3102 cx: &mut C,
3103 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
3104 ) -> Result<R>
3105 where
3106 C: Context,
3107 {
3108 cx.update_window(self.any_handle, |root_view, cx| {
3109 let view = root_view
3110 .downcast::<V>()
3111 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3112 Ok(cx.update_view(&view, update))
3113 })?
3114 }
3115
3116 /// Read the root view out of this window.
3117 ///
3118 /// This will fail if the window is closed or if the root view's type does not match `V`.
3119 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
3120 let x = cx
3121 .windows
3122 .get(self.id)
3123 .and_then(|window| {
3124 window
3125 .as_ref()
3126 .and_then(|window| window.root_view.clone())
3127 .map(|root_view| root_view.downcast::<V>())
3128 })
3129 .ok_or_else(|| anyhow!("window not found"))?
3130 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
3131
3132 Ok(x.read(cx))
3133 }
3134
3135 /// Read the root view out of this window, with a callback
3136 ///
3137 /// This will fail if the window is closed or if the root view's type does not match `V`.
3138 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
3139 where
3140 C: Context,
3141 {
3142 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
3143 }
3144
3145 /// Read the root view pointer off of this window.
3146 ///
3147 /// This will fail if the window is closed or if the root view's type does not match `V`.
3148 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
3149 where
3150 C: Context,
3151 {
3152 cx.read_window(self, |root_view, _cx| root_view.clone())
3153 }
3154
3155 /// Check if this window is 'active'.
3156 ///
3157 /// Will return `None` if the window is closed.
3158 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
3159 cx.windows
3160 .get(self.id)
3161 .and_then(|window| window.as_ref().map(|window| window.active))
3162 }
3163}
3164
3165impl<V> Copy for WindowHandle<V> {}
3166
3167impl<V> Clone for WindowHandle<V> {
3168 fn clone(&self) -> Self {
3169 *self
3170 }
3171}
3172
3173impl<V> PartialEq for WindowHandle<V> {
3174 fn eq(&self, other: &Self) -> bool {
3175 self.any_handle == other.any_handle
3176 }
3177}
3178
3179impl<V> Eq for WindowHandle<V> {}
3180
3181impl<V> Hash for WindowHandle<V> {
3182 fn hash<H: Hasher>(&self, state: &mut H) {
3183 self.any_handle.hash(state);
3184 }
3185}
3186
3187impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
3188 fn from(val: WindowHandle<V>) -> Self {
3189 val.any_handle
3190 }
3191}
3192
3193/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
3194#[derive(Copy, Clone, PartialEq, Eq, Hash)]
3195pub struct AnyWindowHandle {
3196 pub(crate) id: WindowId,
3197 state_type: TypeId,
3198}
3199
3200impl AnyWindowHandle {
3201 /// Get the ID of this window.
3202 pub fn window_id(&self) -> WindowId {
3203 self.id
3204 }
3205
3206 /// Attempt to convert this handle to a window handle with a specific root view type.
3207 /// If the types do not match, this will return `None`.
3208 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
3209 if TypeId::of::<T>() == self.state_type {
3210 Some(WindowHandle {
3211 any_handle: *self,
3212 state_type: PhantomData,
3213 })
3214 } else {
3215 None
3216 }
3217 }
3218
3219 /// Update the state of the root view of this window.
3220 ///
3221 /// This will fail if the window has been closed.
3222 pub fn update<C, R>(
3223 self,
3224 cx: &mut C,
3225 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
3226 ) -> Result<R>
3227 where
3228 C: Context,
3229 {
3230 cx.update_window(self, update)
3231 }
3232
3233 /// Read the state of the root view of this window.
3234 ///
3235 /// This will fail if the window has been closed.
3236 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
3237 where
3238 C: Context,
3239 T: 'static,
3240 {
3241 let view = self
3242 .downcast::<T>()
3243 .context("the type of the window's root view has changed")?;
3244
3245 cx.read_window(&view, read)
3246 }
3247}
3248
3249// #[cfg(any(test, feature = "test-support"))]
3250// impl From<SmallVec<[u32; 16]>> for StackingOrder {
3251// fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
3252// StackingOrder(small_vec)
3253// }
3254// }
3255
3256/// An identifier for an [`Element`](crate::Element).
3257///
3258/// Can be constructed with a string, a number, or both, as well
3259/// as other internal representations.
3260#[derive(Clone, Debug, Eq, PartialEq, Hash)]
3261pub enum ElementId {
3262 /// The ID of a View element
3263 View(EntityId),
3264 /// An integer ID.
3265 Integer(usize),
3266 /// A string based ID.
3267 Name(SharedString),
3268 /// An ID that's equated with a focus handle.
3269 FocusHandle(FocusId),
3270 /// A combination of a name and an integer.
3271 NamedInteger(SharedString, usize),
3272}
3273
3274impl ElementId {
3275 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
3276 ElementId::View(entity_id)
3277 }
3278}
3279
3280impl TryInto<SharedString> for ElementId {
3281 type Error = anyhow::Error;
3282
3283 fn try_into(self) -> anyhow::Result<SharedString> {
3284 if let ElementId::Name(name) = self {
3285 Ok(name)
3286 } else {
3287 Err(anyhow!("element id is not string"))
3288 }
3289 }
3290}
3291
3292impl From<usize> for ElementId {
3293 fn from(id: usize) -> Self {
3294 ElementId::Integer(id)
3295 }
3296}
3297
3298impl From<i32> for ElementId {
3299 fn from(id: i32) -> Self {
3300 Self::Integer(id as usize)
3301 }
3302}
3303
3304impl From<SharedString> for ElementId {
3305 fn from(name: SharedString) -> Self {
3306 ElementId::Name(name)
3307 }
3308}
3309
3310impl From<&'static str> for ElementId {
3311 fn from(name: &'static str) -> Self {
3312 ElementId::Name(name.into())
3313 }
3314}
3315
3316impl<'a> From<&'a FocusHandle> for ElementId {
3317 fn from(handle: &'a FocusHandle) -> Self {
3318 ElementId::FocusHandle(handle.id)
3319 }
3320}
3321
3322impl From<(&'static str, EntityId)> for ElementId {
3323 fn from((name, id): (&'static str, EntityId)) -> Self {
3324 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
3325 }
3326}
3327
3328impl From<(&'static str, usize)> for ElementId {
3329 fn from((name, id): (&'static str, usize)) -> Self {
3330 ElementId::NamedInteger(name.into(), id)
3331 }
3332}
3333
3334impl From<(&'static str, u64)> for ElementId {
3335 fn from((name, id): (&'static str, u64)) -> Self {
3336 ElementId::NamedInteger(name.into(), id as usize)
3337 }
3338}
3339
3340/// A rectangle to be rendered in the window at the given position and size.
3341/// Passed as an argument [`WindowContext::paint_quad`].
3342#[derive(Clone)]
3343pub struct PaintQuad {
3344 bounds: Bounds<Pixels>,
3345 corner_radii: Corners<Pixels>,
3346 background: Hsla,
3347 border_widths: Edges<Pixels>,
3348 border_color: Hsla,
3349}
3350
3351impl PaintQuad {
3352 /// Set the corner radii of the quad.
3353 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
3354 PaintQuad {
3355 corner_radii: corner_radii.into(),
3356 ..self
3357 }
3358 }
3359
3360 /// Set the border widths of the quad.
3361 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
3362 PaintQuad {
3363 border_widths: border_widths.into(),
3364 ..self
3365 }
3366 }
3367
3368 /// Set the border color of the quad.
3369 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
3370 PaintQuad {
3371 border_color: border_color.into(),
3372 ..self
3373 }
3374 }
3375
3376 /// Set the background color of the quad.
3377 pub fn background(self, background: impl Into<Hsla>) -> Self {
3378 PaintQuad {
3379 background: background.into(),
3380 ..self
3381 }
3382 }
3383}
3384
3385/// Create a quad with the given parameters.
3386pub fn quad(
3387 bounds: Bounds<Pixels>,
3388 corner_radii: impl Into<Corners<Pixels>>,
3389 background: impl Into<Hsla>,
3390 border_widths: impl Into<Edges<Pixels>>,
3391 border_color: impl Into<Hsla>,
3392) -> PaintQuad {
3393 PaintQuad {
3394 bounds,
3395 corner_radii: corner_radii.into(),
3396 background: background.into(),
3397 border_widths: border_widths.into(),
3398 border_color: border_color.into(),
3399 }
3400}
3401
3402/// Create a filled quad with the given bounds and background color.
3403pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
3404 PaintQuad {
3405 bounds: bounds.into(),
3406 corner_radii: (0.).into(),
3407 background: background.into(),
3408 border_widths: (0.).into(),
3409 border_color: transparent_black(),
3410 }
3411}
3412
3413/// Create a rectangle outline with the given bounds, border color, and a 1px border width
3414pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
3415 PaintQuad {
3416 bounds: bounds.into(),
3417 corner_radii: (0.).into(),
3418 background: transparent_black(),
3419 border_widths: (1.).into(),
3420 border_color: border_color.into(),
3421 }
3422}