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