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