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