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