1use crate::{
2 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
3 AvailableSpace, Bounds, Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId,
4 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
5 GlobalElementId, Hsla, KeyBinding, KeyContext, KeyDownEvent, KeystrokeEvent, Model,
6 ModelContext, Modifiers, MouseButton, MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas,
7 PlatformDisplay, PlatformInput, PlatformWindow, Point, PromptLevel, Render, ScaledPixels,
8 SharedString, Size, SubscriberSet, Subscription, TaffyLayoutEngine, Task, View, VisualContext,
9 WeakView, WindowBounds, WindowOptions,
10};
11use anyhow::{anyhow, Context as _, Result};
12use collections::FxHashSet;
13use derive_more::{Deref, DerefMut};
14use futures::{
15 channel::{mpsc, oneshot},
16 StreamExt,
17};
18use parking_lot::RwLock;
19use slotmap::SlotMap;
20use smallvec::SmallVec;
21use std::{
22 any::{Any, TypeId},
23 borrow::{Borrow, BorrowMut},
24 cell::RefCell,
25 collections::hash_map::Entry,
26 fmt::{Debug, Display},
27 future::Future,
28 hash::{Hash, Hasher},
29 marker::PhantomData,
30 mem,
31 rc::Rc,
32 sync::{
33 atomic::{AtomicUsize, Ordering::SeqCst},
34 Arc,
35 },
36};
37use util::{measure, ResultExt};
38
39mod element_cx;
40pub use element_cx::*;
41
42const ACTIVE_DRAG_Z_INDEX: u16 = 1;
43
44/// A global stacking order, which is created by stacking successive z-index values.
45/// Each z-index will always be interpreted in the context of its parent z-index.
46#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
47pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
48
49/// A single entry in a primitive's z-index stacking order
50#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
51pub struct StackingContext {
52 pub(crate) z_index: u16,
53 pub(crate) id: u16,
54}
55
56impl std::fmt::Debug for StackingContext {
57 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
58 write!(f, "{{{}.{}}} ", self.z_index, self.id)
59 }
60}
61
62/// Represents the two different phases when dispatching events.
63#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
64pub enum DispatchPhase {
65 /// After the capture phase comes the bubble phase, in which mouse event listeners are
66 /// invoked front to back and keyboard event listeners are invoked from the focused element
67 /// to the root of the element tree. This is the phase you'll most commonly want to use when
68 /// registering event listeners.
69 #[default]
70 Bubble,
71 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
72 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
73 /// is used for special purposes such as clearing the "pressed" state for click events. If
74 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
75 /// outside of the immediate region may rely on detecting non-local events during this phase.
76 Capture,
77}
78
79impl DispatchPhase {
80 /// Returns true if this represents the "bubble" phase.
81 pub fn bubble(self) -> bool {
82 self == DispatchPhase::Bubble
83 }
84
85 /// Returns true if this represents the "capture" phase.
86 pub fn capture(self) -> bool {
87 self == DispatchPhase::Capture
88 }
89}
90
91type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
92
93type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
94
95struct FocusEvent {
96 previous_focus_path: SmallVec<[FocusId; 8]>,
97 current_focus_path: SmallVec<[FocusId; 8]>,
98}
99
100slotmap::new_key_type! {
101 /// A globally unique identifier for a focusable element.
102 pub struct FocusId;
103}
104
105thread_local! {
106 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(4 * 1024 * 1024));
107}
108
109impl FocusId {
110 /// Obtains whether the element associated with this handle is currently focused.
111 pub fn is_focused(&self, cx: &WindowContext) -> bool {
112 cx.window.focus == Some(*self)
113 }
114
115 /// Obtains whether the element associated with this handle contains the focused
116 /// element or is itself focused.
117 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
118 cx.focused()
119 .map_or(false, |focused| self.contains(focused.id, cx))
120 }
121
122 /// Obtains whether the element associated with this handle is contained within the
123 /// focused element or is itself focused.
124 pub fn within_focused(&self, cx: &WindowContext) -> bool {
125 let focused = cx.focused();
126 focused.map_or(false, |focused| focused.id.contains(*self, cx))
127 }
128
129 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
130 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
131 cx.window
132 .rendered_frame
133 .dispatch_tree
134 .focus_contains(*self, other)
135 }
136}
137
138/// A handle which can be used to track and manipulate the focused element in a window.
139pub struct FocusHandle {
140 pub(crate) id: FocusId,
141 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
142}
143
144impl std::fmt::Debug for FocusHandle {
145 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
146 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
147 }
148}
149
150impl FocusHandle {
151 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
152 let id = handles.write().insert(AtomicUsize::new(1));
153 Self {
154 id,
155 handles: handles.clone(),
156 }
157 }
158
159 pub(crate) fn for_id(
160 id: FocusId,
161 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
162 ) -> Option<Self> {
163 let lock = handles.read();
164 let ref_count = lock.get(id)?;
165 if ref_count.load(SeqCst) == 0 {
166 None
167 } else {
168 ref_count.fetch_add(1, SeqCst);
169 Some(Self {
170 id,
171 handles: handles.clone(),
172 })
173 }
174 }
175
176 /// Moves the focus to the element associated with this handle.
177 pub fn focus(&self, cx: &mut WindowContext) {
178 cx.focus(self)
179 }
180
181 /// Obtains whether the element associated with this handle is currently focused.
182 pub fn is_focused(&self, cx: &WindowContext) -> bool {
183 self.id.is_focused(cx)
184 }
185
186 /// Obtains whether the element associated with this handle contains the focused
187 /// element or is itself focused.
188 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
189 self.id.contains_focused(cx)
190 }
191
192 /// Obtains whether the element associated with this handle is contained within the
193 /// focused element or is itself focused.
194 pub fn within_focused(&self, cx: &WindowContext) -> bool {
195 self.id.within_focused(cx)
196 }
197
198 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
199 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
200 self.id.contains(other.id, cx)
201 }
202}
203
204impl Clone for FocusHandle {
205 fn clone(&self) -> Self {
206 Self::for_id(self.id, &self.handles).unwrap()
207 }
208}
209
210impl PartialEq for FocusHandle {
211 fn eq(&self, other: &Self) -> bool {
212 self.id == other.id
213 }
214}
215
216impl Eq for FocusHandle {}
217
218impl Drop for FocusHandle {
219 fn drop(&mut self) {
220 self.handles
221 .read()
222 .get(self.id)
223 .unwrap()
224 .fetch_sub(1, SeqCst);
225 }
226}
227
228/// FocusableView allows users of your view to easily
229/// focus it (using cx.focus_view(view))
230pub trait FocusableView: 'static + Render {
231 /// Returns the focus handle associated with this view.
232 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
233}
234
235/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
236/// where the lifecycle of the view is handled by another view.
237pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
238
239impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
240
241/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
242pub struct DismissEvent;
243
244// Holds the state for a specific window.
245#[doc(hidden)]
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 pub(crate) rem_size: Pixels,
253 pub(crate) 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 pub(crate) dirty_views: FxHashSet<EntityId>,
260 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
261 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
262 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
263 default_prevented: bool,
264 mouse_position: Point<Pixels>,
265 modifiers: Modifiers,
266 scale_factor: f32,
267 bounds: WindowBounds,
268 bounds_observers: SubscriberSet<(), AnyObserver>,
269 active: bool,
270 pub(crate) dirty: bool,
271 pub(crate) refreshing: 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 pub(crate) inner: Box<dyn Any>,
283 pub(crate) parent_view_id: EntityId,
284 #[cfg(debug_assertions)]
285 pub(crate) type_name: &'static str,
286}
287
288impl Window {
289 pub(crate) fn new(
290 handle: AnyWindowHandle,
291 options: WindowOptions,
292 cx: &mut AppContext,
293 ) -> Self {
294 let platform_window = cx.platform.open_window(handle, options);
295 let display_id = platform_window.display().id();
296 let sprite_atlas = platform_window.sprite_atlas();
297 let mouse_position = platform_window.mouse_position();
298 let modifiers = platform_window.modifiers();
299 let content_size = platform_window.content_size();
300 let scale_factor = platform_window.scale_factor();
301 let bounds = platform_window.bounds();
302
303 platform_window.on_request_frame(Box::new({
304 let mut cx = cx.to_async();
305 move || {
306 measure("frame duration", || {
307 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
308 })
309 }
310 }));
311 platform_window.on_resize(Box::new({
312 let mut cx = cx.to_async();
313 move |_, _| {
314 handle
315 .update(&mut cx, |_, cx| cx.window_bounds_changed())
316 .log_err();
317 }
318 }));
319 platform_window.on_moved(Box::new({
320 let mut cx = cx.to_async();
321 move || {
322 handle
323 .update(&mut cx, |_, cx| cx.window_bounds_changed())
324 .log_err();
325 }
326 }));
327 platform_window.on_active_status_change(Box::new({
328 let mut cx = cx.to_async();
329 move |active| {
330 handle
331 .update(&mut cx, |_, cx| {
332 cx.window.active = active;
333 cx.window
334 .activation_observers
335 .clone()
336 .retain(&(), |callback| callback(cx));
337 })
338 .log_err();
339 }
340 }));
341
342 platform_window.on_input({
343 let mut cx = cx.to_async();
344 Box::new(move |event| {
345 handle
346 .update(&mut cx, |_, cx| cx.dispatch_event(event))
347 .log_err()
348 .unwrap_or(false)
349 })
350 });
351
352 Window {
353 handle,
354 removed: false,
355 platform_window,
356 display_id,
357 sprite_atlas,
358 rem_size: px(16.),
359 viewport_size: content_size,
360 layout_engine: Some(TaffyLayoutEngine::new()),
361 root_view: None,
362 element_id_stack: GlobalElementId::default(),
363 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
364 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
365 dirty_views: FxHashSet::default(),
366 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
367 focus_listeners: SubscriberSet::new(),
368 focus_lost_listeners: SubscriberSet::new(),
369 default_prevented: true,
370 mouse_position,
371 modifiers,
372 scale_factor,
373 bounds,
374 bounds_observers: SubscriberSet::new(),
375 active: false,
376 dirty: false,
377 refreshing: false,
378 drawing: false,
379 activation_observers: SubscriberSet::new(),
380 focus: None,
381 focus_enabled: true,
382
383 #[cfg(any(test, feature = "test-support"))]
384 focus_invalidated: false,
385 }
386 }
387}
388
389/// Indicates which region of the window is visible. Content falling outside of this mask will not be
390/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
391/// to leave room to support more complex shapes in the future.
392#[derive(Clone, Debug, Default, PartialEq, Eq)]
393#[repr(C)]
394pub struct ContentMask<P: Clone + Default + Debug> {
395 /// The bounds
396 pub bounds: Bounds<P>,
397}
398
399impl ContentMask<Pixels> {
400 /// Scale the content mask's pixel units by the given scaling factor.
401 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
402 ContentMask {
403 bounds: self.bounds.scale(factor),
404 }
405 }
406
407 /// Intersect the content mask with the given content mask.
408 pub fn intersect(&self, other: &Self) -> Self {
409 let bounds = self.bounds.intersect(&other.bounds);
410 ContentMask { bounds }
411 }
412}
413
414/// Provides access to application state in the context of a single window. Derefs
415/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
416/// an [`AppContext`] and call any [`AppContext`] methods.
417pub struct WindowContext<'a> {
418 pub(crate) app: &'a mut AppContext,
419 pub(crate) window: &'a mut Window,
420}
421
422impl<'a> WindowContext<'a> {
423 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
424 Self { app, window }
425 }
426
427 /// Obtain a handle to the window that belongs to this context.
428 pub fn window_handle(&self) -> AnyWindowHandle {
429 self.window.handle
430 }
431
432 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
433 pub fn refresh(&mut self) {
434 if !self.window.drawing {
435 self.window.refreshing = true;
436 self.window.dirty = true;
437 }
438 }
439
440 /// Close this window.
441 pub fn remove_window(&mut self) {
442 self.window.removed = true;
443 }
444
445 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
446 /// for elements rendered within this window.
447 pub fn focus_handle(&mut self) -> FocusHandle {
448 FocusHandle::new(&self.window.focus_handles)
449 }
450
451 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
452 pub fn focused(&self) -> Option<FocusHandle> {
453 self.window
454 .focus
455 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
456 }
457
458 /// Move focus to the element associated with the given [`FocusHandle`].
459 pub fn focus(&mut self, handle: &FocusHandle) {
460 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
461 return;
462 }
463
464 self.window.focus = Some(handle.id);
465 self.window
466 .rendered_frame
467 .dispatch_tree
468 .clear_pending_keystrokes();
469
470 #[cfg(any(test, feature = "test-support"))]
471 {
472 self.window.focus_invalidated = true;
473 }
474
475 self.refresh();
476 }
477
478 /// Remove focus from all elements within this context's window.
479 pub fn blur(&mut self) {
480 if !self.window.focus_enabled {
481 return;
482 }
483
484 self.window.focus = None;
485 self.refresh();
486 }
487
488 /// Blur the window and don't allow anything in it to be focused again.
489 pub fn disable_focus(&mut self) {
490 self.blur();
491 self.window.focus_enabled = false;
492 }
493
494 /// Dispatch the given action on the currently focused element.
495 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
496 let focus_handle = self.focused();
497
498 self.defer(move |cx| {
499 let node_id = focus_handle
500 .and_then(|handle| {
501 cx.window
502 .rendered_frame
503 .dispatch_tree
504 .focusable_node_id(handle.id)
505 })
506 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
507
508 cx.propagate_event = true;
509 cx.dispatch_action_on_node(node_id, action);
510 })
511 }
512
513 pub(crate) fn dispatch_keystroke_observers(
514 &mut self,
515 event: &dyn Any,
516 action: Option<Box<dyn Action>>,
517 ) {
518 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
519 return;
520 };
521
522 self.keystroke_observers
523 .clone()
524 .retain(&(), move |callback| {
525 (callback)(
526 &KeystrokeEvent {
527 keystroke: key_down_event.keystroke.clone(),
528 action: action.as_ref().map(|action| action.boxed_clone()),
529 },
530 self,
531 );
532 true
533 });
534 }
535
536 pub(crate) fn clear_pending_keystrokes(&mut self) {
537 self.window
538 .rendered_frame
539 .dispatch_tree
540 .clear_pending_keystrokes();
541 self.window
542 .next_frame
543 .dispatch_tree
544 .clear_pending_keystrokes();
545 }
546
547 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
548 /// that are currently on the stack to be returned to the app.
549 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
550 let handle = self.window.handle;
551 self.app.defer(move |cx| {
552 handle.update(cx, |_, cx| f(cx)).ok();
553 });
554 }
555
556 /// Subscribe to events emitted by a model or view.
557 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
558 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
559 pub fn subscribe<Emitter, E, Evt>(
560 &mut self,
561 entity: &E,
562 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
563 ) -> Subscription
564 where
565 Emitter: EventEmitter<Evt>,
566 E: Entity<Emitter>,
567 Evt: 'static,
568 {
569 let entity_id = entity.entity_id();
570 let entity = entity.downgrade();
571 let window_handle = self.window.handle;
572 let (subscription, activate) = self.app.event_listeners.insert(
573 entity_id,
574 (
575 TypeId::of::<Evt>(),
576 Box::new(move |event, cx| {
577 window_handle
578 .update(cx, |_, cx| {
579 if let Some(handle) = E::upgrade_from(&entity) {
580 let event = event.downcast_ref().expect("invalid event type");
581 on_event(handle, event, cx);
582 true
583 } else {
584 false
585 }
586 })
587 .unwrap_or(false)
588 }),
589 ),
590 );
591 self.app.defer(move |_| activate());
592 subscription
593 }
594
595 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
596 /// await points in async code.
597 pub fn to_async(&self) -> AsyncWindowContext {
598 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
599 }
600
601 /// Schedule the given closure to be run directly after the current frame is rendered.
602 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
603 let handle = self.window.handle;
604 let display_id = self.window.display_id;
605
606 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
607 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
608 let (tx, mut rx) = mpsc::unbounded::<()>();
609 self.platform.set_display_link_output_callback(
610 display_id,
611 Box::new(move || _ = tx.unbounded_send(())),
612 );
613
614 let consumer_task = self.app.spawn(|cx| async move {
615 while rx.next().await.is_some() {
616 cx.update(|cx| {
617 for callback in cx
618 .next_frame_callbacks
619 .get_mut(&display_id)
620 .unwrap()
621 .drain(..)
622 .collect::<SmallVec<[_; 32]>>()
623 {
624 callback(cx);
625 }
626 })
627 .ok();
628
629 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
630
631 cx.update(|cx| {
632 if cx.next_frame_callbacks.is_empty() {
633 cx.platform.stop_display_link(display_id);
634 }
635 })
636 .ok();
637 }
638 });
639 e.insert(consumer_task);
640 }
641 debug_assert!(self.app.frame_consumers.is_empty());
642 self.app.frame_consumers = frame_consumers;
643
644 if self.next_frame_callbacks.is_empty() {
645 self.platform.start_display_link(display_id);
646 }
647
648 self.next_frame_callbacks
649 .entry(display_id)
650 .or_default()
651 .push(Box::new(move |cx: &mut AppContext| {
652 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
653 }));
654 }
655
656 /// Spawn the future returned by the given closure on the application thread pool.
657 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
658 /// use within your future.
659 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
660 where
661 R: 'static,
662 Fut: Future<Output = R> + 'static,
663 {
664 self.app
665 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
666 }
667
668 /// Updates the global of the given type. The given closure is given simultaneous mutable
669 /// access both to the global and the context.
670 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
671 where
672 G: 'static,
673 {
674 let mut global = self.app.lease_global::<G>();
675 let result = f(&mut global, self);
676 self.app.end_global_lease(global);
677 result
678 }
679
680 fn window_bounds_changed(&mut self) {
681 self.window.scale_factor = self.window.platform_window.scale_factor();
682 self.window.viewport_size = self.window.platform_window.content_size();
683 self.window.bounds = self.window.platform_window.bounds();
684 self.window.display_id = self.window.platform_window.display().id();
685 self.refresh();
686
687 self.window
688 .bounds_observers
689 .clone()
690 .retain(&(), |callback| callback(self));
691 }
692
693 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
694 pub fn window_bounds(&self) -> WindowBounds {
695 self.window.bounds
696 }
697
698 /// Returns the size of the drawable area within the window.
699 pub fn viewport_size(&self) -> Size<Pixels> {
700 self.window.viewport_size
701 }
702
703 /// Returns whether this window is focused by the operating system (receiving key events).
704 pub fn is_window_active(&self) -> bool {
705 self.window.active
706 }
707
708 /// Toggle zoom on the window.
709 pub fn zoom_window(&self) {
710 self.window.platform_window.zoom();
711 }
712
713 /// Updates the window's title at the platform level.
714 pub fn set_window_title(&mut self, title: &str) {
715 self.window.platform_window.set_title(title);
716 }
717
718 /// Mark the window as dirty at the platform level.
719 pub fn set_window_edited(&mut self, edited: bool) {
720 self.window.platform_window.set_edited(edited);
721 }
722
723 /// Determine the display on which the window is visible.
724 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
725 self.platform
726 .displays()
727 .into_iter()
728 .find(|display| display.id() == self.window.display_id)
729 }
730
731 /// Show the platform character palette.
732 pub fn show_character_palette(&self) {
733 self.window.platform_window.show_character_palette();
734 }
735
736 /// The scale factor of the display associated with the window. For example, it could
737 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
738 /// be rendered as two pixels on screen.
739 pub fn scale_factor(&self) -> f32 {
740 self.window.scale_factor
741 }
742
743 /// The size of an em for the base font of the application. Adjusting this value allows the
744 /// UI to scale, just like zooming a web page.
745 pub fn rem_size(&self) -> Pixels {
746 self.window.rem_size
747 }
748
749 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
750 /// UI to scale, just like zooming a web page.
751 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
752 self.window.rem_size = rem_size.into();
753 }
754
755 /// The line height associated with the current text style.
756 pub fn line_height(&self) -> Pixels {
757 let rem_size = self.rem_size();
758 let text_style = self.text_style();
759 text_style
760 .line_height
761 .to_pixels(text_style.font_size, rem_size)
762 }
763
764 /// Call to prevent the default action of an event. Currently only used to prevent
765 /// parent elements from becoming focused on mouse down.
766 pub fn prevent_default(&mut self) {
767 self.window.default_prevented = true;
768 }
769
770 /// Obtain whether default has been prevented for the event currently being dispatched.
771 pub fn default_prevented(&self) -> bool {
772 self.window.default_prevented
773 }
774
775 /// Determine whether the given action is available along the dispatch path to the currently focused element.
776 pub fn is_action_available(&self, action: &dyn Action) -> bool {
777 let target = self
778 .focused()
779 .and_then(|focused_handle| {
780 self.window
781 .rendered_frame
782 .dispatch_tree
783 .focusable_node_id(focused_handle.id)
784 })
785 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
786 self.window
787 .rendered_frame
788 .dispatch_tree
789 .is_action_available(action, target)
790 }
791
792 /// The position of the mouse relative to the window.
793 pub fn mouse_position(&self) -> Point<Pixels> {
794 self.window.mouse_position
795 }
796
797 /// The current state of the keyboard's modifiers
798 pub fn modifiers(&self) -> Modifiers {
799 self.window.modifiers
800 }
801
802 /// Returns true if there is no opaque layer containing the given point
803 /// on top of the given level. Layers whose level is an extension of the
804 /// level are not considered to be on top of the level.
805 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
806 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
807 if level >= opaque_level {
808 break;
809 }
810
811 if bounds.contains(point) {
812 let starts_with = opaque_level
813 .iter()
814 .zip(level.iter())
815 .all(|(a, b)| a.z_index == b.z_index)
816 && opaque_level.len() >= level.len();
817
818 if !starts_with {
819 return false;
820 }
821 }
822 }
823 true
824 }
825
826 pub(crate) fn was_top_layer_under_active_drag(
827 &self,
828 point: &Point<Pixels>,
829 level: &StackingOrder,
830 ) -> bool {
831 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
832 if level >= opaque_level {
833 break;
834 }
835 if opaque_level
836 .first()
837 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
838 .unwrap_or(false)
839 {
840 continue;
841 }
842
843 if bounds.contains(point) && !opaque_level.starts_with(level) {
844 return false;
845 }
846 }
847 true
848 }
849
850 /// Called during painting to get the current stacking order.
851 pub fn stacking_order(&self) -> &StackingOrder {
852 &self.window.next_frame.z_index_stack
853 }
854
855 /// Draw pixels to the display for this window based on the contents of its scene.
856 pub(crate) fn draw(&mut self) {
857 self.window.dirty = false;
858 self.window.drawing = true;
859
860 #[cfg(any(test, feature = "test-support"))]
861 {
862 self.window.focus_invalidated = false;
863 }
864
865 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
866 {
867 let input_handler = self.window.platform_window.take_input_handler();
868 requested_handler.handler = input_handler;
869 }
870
871 let root_view = self.window.root_view.take().unwrap();
872 self.with_element_context(|cx| {
873 cx.with_z_index(0, |cx| {
874 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
875 // We need to use cx.cx here so we can utilize borrow splitting
876 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
877 for action_listener in action_listeners.iter().cloned() {
878 cx.cx.window.next_frame.dispatch_tree.on_action(
879 *action_type,
880 Rc::new(
881 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
882 action_listener(action, phase, cx)
883 },
884 ),
885 )
886 }
887 }
888
889 let available_space = cx.window.viewport_size.map(Into::into);
890 root_view.draw(Point::default(), available_space, cx);
891 })
892 })
893 });
894
895 if let Some(active_drag) = self.app.active_drag.take() {
896 self.with_element_context(|cx| {
897 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
898 let offset = cx.mouse_position() - active_drag.cursor_offset;
899 let available_space =
900 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
901 active_drag.view.draw(offset, available_space, cx);
902 })
903 });
904 self.active_drag = Some(active_drag);
905 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
906 self.with_element_context(|cx| {
907 cx.with_z_index(1, |cx| {
908 let available_space =
909 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
910 tooltip_request.tooltip.view.draw(
911 tooltip_request.tooltip.cursor_offset,
912 available_space,
913 cx,
914 );
915 })
916 });
917 self.window.next_frame.tooltip_request = Some(tooltip_request);
918 }
919 self.window.dirty_views.clear();
920
921 self.window
922 .next_frame
923 .dispatch_tree
924 .preserve_pending_keystrokes(
925 &mut self.window.rendered_frame.dispatch_tree,
926 self.window.focus,
927 );
928 self.window.next_frame.focus = self.window.focus;
929 self.window.next_frame.window_active = self.window.active;
930 self.window.root_view = Some(root_view);
931
932 // Set the cursor only if we're the active window.
933 let cursor_style = self
934 .window
935 .next_frame
936 .requested_cursor_style
937 .take()
938 .unwrap_or(CursorStyle::Arrow);
939 if self.is_window_active() {
940 self.platform.set_cursor_style(cursor_style);
941 }
942
943 // Register requested input handler with the platform window.
944 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
945 if let Some(handler) = requested_input.handler.take() {
946 self.window.platform_window.set_input_handler(handler);
947 }
948 }
949
950 self.window.layout_engine.as_mut().unwrap().clear();
951 self.text_system()
952 .finish_frame(&self.window.next_frame.reused_views);
953 self.window
954 .next_frame
955 .finish(&mut self.window.rendered_frame);
956 ELEMENT_ARENA.with_borrow_mut(|element_arena| element_arena.clear());
957
958 let previous_focus_path = self.window.rendered_frame.focus_path();
959 let previous_window_active = self.window.rendered_frame.window_active;
960 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
961 self.window.next_frame.clear();
962 let current_focus_path = self.window.rendered_frame.focus_path();
963 let current_window_active = self.window.rendered_frame.window_active;
964
965 if previous_focus_path != current_focus_path
966 || previous_window_active != current_window_active
967 {
968 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
969 self.window
970 .focus_lost_listeners
971 .clone()
972 .retain(&(), |listener| listener(self));
973 }
974
975 let event = FocusEvent {
976 previous_focus_path: if previous_window_active {
977 previous_focus_path
978 } else {
979 Default::default()
980 },
981 current_focus_path: if current_window_active {
982 current_focus_path
983 } else {
984 Default::default()
985 },
986 };
987 self.window
988 .focus_listeners
989 .clone()
990 .retain(&(), |listener| listener(&event, self));
991 }
992
993 self.window
994 .platform_window
995 .draw(&self.window.rendered_frame.scene);
996 self.window.refreshing = false;
997 self.window.drawing = false;
998 }
999
1000 /// Dispatch a mouse or keyboard event on the window.
1001 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
1002 // Handlers may set this to false by calling `stop_propagation`.
1003 self.app.propagate_event = true;
1004 // Handlers may set this to true by calling `prevent_default`.
1005 self.window.default_prevented = false;
1006
1007 let event = match event {
1008 // Track the mouse position with our own state, since accessing the platform
1009 // API for the mouse position can only occur on the main thread.
1010 PlatformInput::MouseMove(mouse_move) => {
1011 self.window.mouse_position = mouse_move.position;
1012 self.window.modifiers = mouse_move.modifiers;
1013 PlatformInput::MouseMove(mouse_move)
1014 }
1015 PlatformInput::MouseDown(mouse_down) => {
1016 self.window.mouse_position = mouse_down.position;
1017 self.window.modifiers = mouse_down.modifiers;
1018 PlatformInput::MouseDown(mouse_down)
1019 }
1020 PlatformInput::MouseUp(mouse_up) => {
1021 self.window.mouse_position = mouse_up.position;
1022 self.window.modifiers = mouse_up.modifiers;
1023 PlatformInput::MouseUp(mouse_up)
1024 }
1025 PlatformInput::MouseExited(mouse_exited) => {
1026 self.window.modifiers = mouse_exited.modifiers;
1027 PlatformInput::MouseExited(mouse_exited)
1028 }
1029 PlatformInput::ModifiersChanged(modifiers_changed) => {
1030 self.window.modifiers = modifiers_changed.modifiers;
1031 PlatformInput::ModifiersChanged(modifiers_changed)
1032 }
1033 PlatformInput::ScrollWheel(scroll_wheel) => {
1034 self.window.mouse_position = scroll_wheel.position;
1035 self.window.modifiers = scroll_wheel.modifiers;
1036 PlatformInput::ScrollWheel(scroll_wheel)
1037 }
1038 // Translate dragging and dropping of external files from the operating system
1039 // to internal drag and drop events.
1040 PlatformInput::FileDrop(file_drop) => match file_drop {
1041 FileDropEvent::Entered { position, paths } => {
1042 self.window.mouse_position = position;
1043 if self.active_drag.is_none() {
1044 self.active_drag = Some(AnyDrag {
1045 value: Box::new(paths.clone()),
1046 view: self.new_view(|_| paths).into(),
1047 cursor_offset: position,
1048 });
1049 }
1050 PlatformInput::MouseMove(MouseMoveEvent {
1051 position,
1052 pressed_button: Some(MouseButton::Left),
1053 modifiers: Modifiers::default(),
1054 })
1055 }
1056 FileDropEvent::Pending { position } => {
1057 self.window.mouse_position = position;
1058 PlatformInput::MouseMove(MouseMoveEvent {
1059 position,
1060 pressed_button: Some(MouseButton::Left),
1061 modifiers: Modifiers::default(),
1062 })
1063 }
1064 FileDropEvent::Submit { position } => {
1065 self.activate(true);
1066 self.window.mouse_position = position;
1067 PlatformInput::MouseUp(MouseUpEvent {
1068 button: MouseButton::Left,
1069 position,
1070 modifiers: Modifiers::default(),
1071 click_count: 1,
1072 })
1073 }
1074 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1075 button: MouseButton::Left,
1076 position: Point::default(),
1077 modifiers: Modifiers::default(),
1078 click_count: 1,
1079 }),
1080 },
1081 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1082 };
1083
1084 if let Some(any_mouse_event) = event.mouse_event() {
1085 self.dispatch_mouse_event(any_mouse_event);
1086 } else if let Some(any_key_event) = event.keyboard_event() {
1087 self.dispatch_key_event(any_key_event);
1088 }
1089
1090 !self.app.propagate_event
1091 }
1092
1093 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1094 if let Some(mut handlers) = self
1095 .window
1096 .rendered_frame
1097 .mouse_listeners
1098 .remove(&event.type_id())
1099 {
1100 // Because handlers may add other handlers, we sort every time.
1101 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1102
1103 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1104 // special purposes, such as detecting events outside of a given Bounds.
1105 for (_, _, handler) in &mut handlers {
1106 self.with_element_context(|cx| {
1107 handler(event, DispatchPhase::Capture, cx);
1108 });
1109 if !self.app.propagate_event {
1110 break;
1111 }
1112 }
1113
1114 // Bubble phase, where most normal handlers do their work.
1115 if self.app.propagate_event {
1116 for (_, _, handler) in handlers.iter_mut().rev() {
1117 self.with_element_context(|cx| {
1118 handler(event, DispatchPhase::Bubble, cx);
1119 });
1120 if !self.app.propagate_event {
1121 break;
1122 }
1123 }
1124 }
1125
1126 self.window
1127 .rendered_frame
1128 .mouse_listeners
1129 .insert(event.type_id(), handlers);
1130 }
1131
1132 if self.app.propagate_event && self.has_active_drag() {
1133 if event.is::<MouseMoveEvent>() {
1134 // If this was a mouse move event, redraw the window so that the
1135 // active drag can follow the mouse cursor.
1136 self.refresh();
1137 } else if event.is::<MouseUpEvent>() {
1138 // If this was a mouse up event, cancel the active drag and redraw
1139 // the window.
1140 self.active_drag = None;
1141 self.refresh();
1142 }
1143 }
1144 }
1145
1146 fn dispatch_key_event(&mut self, event: &dyn Any) {
1147 let node_id = self
1148 .window
1149 .focus
1150 .and_then(|focus_id| {
1151 self.window
1152 .rendered_frame
1153 .dispatch_tree
1154 .focusable_node_id(focus_id)
1155 })
1156 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1157
1158 let dispatch_path = self
1159 .window
1160 .rendered_frame
1161 .dispatch_tree
1162 .dispatch_path(node_id);
1163
1164 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1165
1166 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1167 for node_id in &dispatch_path {
1168 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1169
1170 if let Some(context) = node.context.clone() {
1171 context_stack.push(context);
1172 }
1173 }
1174
1175 for node_id in dispatch_path.iter().rev() {
1176 // Match keystrokes
1177 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1178 if node.context.is_some() {
1179 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1180 let mut new_actions = self
1181 .window
1182 .rendered_frame
1183 .dispatch_tree
1184 .dispatch_key(&key_down_event.keystroke, &context_stack);
1185 actions.append(&mut new_actions);
1186 }
1187
1188 context_stack.pop();
1189 }
1190 }
1191
1192 if !actions.is_empty() {
1193 self.clear_pending_keystrokes();
1194 }
1195
1196 self.propagate_event = true;
1197 for action in actions {
1198 self.dispatch_action_on_node(node_id, action.boxed_clone());
1199 if !self.propagate_event {
1200 self.dispatch_keystroke_observers(event, Some(action));
1201 return;
1202 }
1203 }
1204
1205 // Capture phase
1206 for node_id in &dispatch_path {
1207 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1208
1209 for key_listener in node.key_listeners.clone() {
1210 self.with_element_context(|cx| {
1211 key_listener(event, DispatchPhase::Capture, cx);
1212 });
1213 if !self.propagate_event {
1214 return;
1215 }
1216 }
1217 }
1218
1219 // Bubble phase
1220 for node_id in dispatch_path.iter().rev() {
1221 // Handle low level key events
1222 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1223 for key_listener in node.key_listeners.clone() {
1224 self.with_element_context(|cx| {
1225 key_listener(event, DispatchPhase::Bubble, cx);
1226 });
1227 if !self.propagate_event {
1228 return;
1229 }
1230 }
1231 }
1232
1233 self.dispatch_keystroke_observers(event, None);
1234 }
1235
1236 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1237 pub fn has_pending_keystrokes(&self) -> bool {
1238 self.window
1239 .rendered_frame
1240 .dispatch_tree
1241 .has_pending_keystrokes()
1242 }
1243
1244 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1245 let dispatch_path = self
1246 .window
1247 .rendered_frame
1248 .dispatch_tree
1249 .dispatch_path(node_id);
1250
1251 // Capture phase
1252 for node_id in &dispatch_path {
1253 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1254 for DispatchActionListener {
1255 action_type,
1256 listener,
1257 } in node.action_listeners.clone()
1258 {
1259 let any_action = action.as_any();
1260 if action_type == any_action.type_id() {
1261 self.with_element_context(|cx| {
1262 listener(any_action, DispatchPhase::Capture, cx);
1263 });
1264
1265 if !self.propagate_event {
1266 return;
1267 }
1268 }
1269 }
1270 }
1271 // Bubble phase
1272 for node_id in dispatch_path.iter().rev() {
1273 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1274 for DispatchActionListener {
1275 action_type,
1276 listener,
1277 } in node.action_listeners.clone()
1278 {
1279 let any_action = action.as_any();
1280 if action_type == any_action.type_id() {
1281 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1282
1283 self.with_element_context(|cx| {
1284 listener(any_action, DispatchPhase::Bubble, cx);
1285 });
1286
1287 if !self.propagate_event {
1288 return;
1289 }
1290 }
1291 }
1292 }
1293 }
1294
1295 /// Register the given handler to be invoked whenever the global of the given type
1296 /// is updated.
1297 pub fn observe_global<G: 'static>(
1298 &mut self,
1299 f: impl Fn(&mut WindowContext<'_>) + 'static,
1300 ) -> Subscription {
1301 let window_handle = self.window.handle;
1302 let (subscription, activate) = self.global_observers.insert(
1303 TypeId::of::<G>(),
1304 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1305 );
1306 self.app.defer(move |_| activate());
1307 subscription
1308 }
1309
1310 /// Focus the current window and bring it to the foreground at the platform level.
1311 pub fn activate_window(&self) {
1312 self.window.platform_window.activate();
1313 }
1314
1315 /// Minimize the current window at the platform level.
1316 pub fn minimize_window(&self) {
1317 self.window.platform_window.minimize();
1318 }
1319
1320 /// Toggle full screen status on the current window at the platform level.
1321 pub fn toggle_full_screen(&self) {
1322 self.window.platform_window.toggle_full_screen();
1323 }
1324
1325 /// Present a platform dialog.
1326 /// The provided message will be presented, along with buttons for each answer.
1327 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1328 pub fn prompt(
1329 &self,
1330 level: PromptLevel,
1331 message: &str,
1332 answers: &[&str],
1333 ) -> oneshot::Receiver<usize> {
1334 self.window.platform_window.prompt(level, message, answers)
1335 }
1336
1337 /// Returns all available actions for the focused element.
1338 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1339 let node_id = self
1340 .window
1341 .focus
1342 .and_then(|focus_id| {
1343 self.window
1344 .rendered_frame
1345 .dispatch_tree
1346 .focusable_node_id(focus_id)
1347 })
1348 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1349
1350 self.window
1351 .rendered_frame
1352 .dispatch_tree
1353 .available_actions(node_id)
1354 }
1355
1356 /// Returns key bindings that invoke the given action on the currently focused element.
1357 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1358 self.window
1359 .rendered_frame
1360 .dispatch_tree
1361 .bindings_for_action(
1362 action,
1363 &self.window.rendered_frame.dispatch_tree.context_stack,
1364 )
1365 }
1366
1367 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1368 pub fn bindings_for_action_in(
1369 &self,
1370 action: &dyn Action,
1371 focus_handle: &FocusHandle,
1372 ) -> Vec<KeyBinding> {
1373 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1374
1375 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1376 return vec![];
1377 };
1378 let context_stack = dispatch_tree
1379 .dispatch_path(node_id)
1380 .into_iter()
1381 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1382 .collect();
1383 dispatch_tree.bindings_for_action(action, &context_stack)
1384 }
1385
1386 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1387 pub fn listener_for<V: Render, E>(
1388 &self,
1389 view: &View<V>,
1390 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1391 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1392 let view = view.downgrade();
1393 move |e: &E, cx: &mut WindowContext| {
1394 view.update(cx, |view, cx| f(view, e, cx)).ok();
1395 }
1396 }
1397
1398 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1399 pub fn handler_for<V: Render>(
1400 &self,
1401 view: &View<V>,
1402 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1403 ) -> impl Fn(&mut WindowContext) {
1404 let view = view.downgrade();
1405 move |cx: &mut WindowContext| {
1406 view.update(cx, |view, cx| f(view, cx)).ok();
1407 }
1408 }
1409
1410 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1411 /// If the callback returns false, the window won't be closed.
1412 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1413 let mut this = self.to_async();
1414 self.window
1415 .platform_window
1416 .on_should_close(Box::new(move || {
1417 this.update(|cx| {
1418 // Ensure that the window is removed from the app if it's been closed
1419 // by always pre-empting the system close event.
1420 if f(cx) {
1421 cx.remove_window();
1422 }
1423 false
1424 })
1425 .unwrap_or(true)
1426 }))
1427 }
1428
1429 pub(crate) fn parent_view_id(&self) -> EntityId {
1430 *self
1431 .window
1432 .next_frame
1433 .view_stack
1434 .last()
1435 .expect("a view should always be on the stack while drawing")
1436 }
1437
1438 /// Register an action listener on the window for the next frame. The type of action
1439 /// is determined by the first parameter of the given listener. When the next frame is rendered
1440 /// the listener will be cleared.
1441 ///
1442 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1443 /// a specific need to register a global listener.
1444 pub fn on_action(
1445 &mut self,
1446 action_type: TypeId,
1447 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1448 ) {
1449 self.window
1450 .next_frame
1451 .dispatch_tree
1452 .on_action(action_type, Rc::new(listener));
1453 }
1454}
1455
1456impl Context for WindowContext<'_> {
1457 type Result<T> = T;
1458
1459 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1460 where
1461 T: 'static,
1462 {
1463 let slot = self.app.entities.reserve();
1464 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1465 self.entities.insert(slot, model)
1466 }
1467
1468 fn update_model<T: 'static, R>(
1469 &mut self,
1470 model: &Model<T>,
1471 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1472 ) -> R {
1473 let mut entity = self.entities.lease(model);
1474 let result = update(
1475 &mut *entity,
1476 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1477 );
1478 self.entities.end_lease(entity);
1479 result
1480 }
1481
1482 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1483 where
1484 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1485 {
1486 if window == self.window.handle {
1487 let root_view = self.window.root_view.clone().unwrap();
1488 Ok(update(root_view, self))
1489 } else {
1490 window.update(self.app, update)
1491 }
1492 }
1493
1494 fn read_model<T, R>(
1495 &self,
1496 handle: &Model<T>,
1497 read: impl FnOnce(&T, &AppContext) -> R,
1498 ) -> Self::Result<R>
1499 where
1500 T: 'static,
1501 {
1502 let entity = self.entities.read(handle);
1503 read(entity, &*self.app)
1504 }
1505
1506 fn read_window<T, R>(
1507 &self,
1508 window: &WindowHandle<T>,
1509 read: impl FnOnce(View<T>, &AppContext) -> R,
1510 ) -> Result<R>
1511 where
1512 T: 'static,
1513 {
1514 if window.any_handle == self.window.handle {
1515 let root_view = self
1516 .window
1517 .root_view
1518 .clone()
1519 .unwrap()
1520 .downcast::<T>()
1521 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1522 Ok(read(root_view, self))
1523 } else {
1524 self.app.read_window(window, read)
1525 }
1526 }
1527}
1528
1529impl VisualContext for WindowContext<'_> {
1530 fn new_view<V>(
1531 &mut self,
1532 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1533 ) -> Self::Result<View<V>>
1534 where
1535 V: 'static + Render,
1536 {
1537 let slot = self.app.entities.reserve();
1538 let view = View {
1539 model: slot.clone(),
1540 };
1541 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1542 let entity = build_view_state(&mut cx);
1543 cx.entities.insert(slot, entity);
1544
1545 cx.new_view_observers
1546 .clone()
1547 .retain(&TypeId::of::<V>(), |observer| {
1548 let any_view = AnyView::from(view.clone());
1549 (observer)(any_view, self);
1550 true
1551 });
1552
1553 view
1554 }
1555
1556 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1557 fn update_view<T: 'static, R>(
1558 &mut self,
1559 view: &View<T>,
1560 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1561 ) -> Self::Result<R> {
1562 let mut lease = self.app.entities.lease(&view.model);
1563 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1564 let result = update(&mut *lease, &mut cx);
1565 cx.app.entities.end_lease(lease);
1566 result
1567 }
1568
1569 fn replace_root_view<V>(
1570 &mut self,
1571 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1572 ) -> Self::Result<View<V>>
1573 where
1574 V: 'static + Render,
1575 {
1576 let view = self.new_view(build_view);
1577 self.window.root_view = Some(view.clone().into());
1578 self.refresh();
1579 view
1580 }
1581
1582 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1583 self.update_view(view, |view, cx| {
1584 view.focus_handle(cx).clone().focus(cx);
1585 })
1586 }
1587
1588 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1589 where
1590 V: ManagedView,
1591 {
1592 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1593 }
1594}
1595
1596impl<'a> std::ops::Deref for WindowContext<'a> {
1597 type Target = AppContext;
1598
1599 fn deref(&self) -> &Self::Target {
1600 self.app
1601 }
1602}
1603
1604impl<'a> std::ops::DerefMut for WindowContext<'a> {
1605 fn deref_mut(&mut self) -> &mut Self::Target {
1606 self.app
1607 }
1608}
1609
1610impl<'a> Borrow<AppContext> for WindowContext<'a> {
1611 fn borrow(&self) -> &AppContext {
1612 self.app
1613 }
1614}
1615
1616impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1617 fn borrow_mut(&mut self) -> &mut AppContext {
1618 self.app
1619 }
1620}
1621
1622/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1623pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1624 #[doc(hidden)]
1625 fn app_mut(&mut self) -> &mut AppContext {
1626 self.borrow_mut()
1627 }
1628
1629 #[doc(hidden)]
1630 fn app(&self) -> &AppContext {
1631 self.borrow()
1632 }
1633
1634 #[doc(hidden)]
1635 fn window(&self) -> &Window {
1636 self.borrow()
1637 }
1638
1639 #[doc(hidden)]
1640 fn window_mut(&mut self) -> &mut Window {
1641 self.borrow_mut()
1642 }
1643}
1644
1645impl Borrow<Window> for WindowContext<'_> {
1646 fn borrow(&self) -> &Window {
1647 self.window
1648 }
1649}
1650
1651impl BorrowMut<Window> for WindowContext<'_> {
1652 fn borrow_mut(&mut self) -> &mut Window {
1653 self.window
1654 }
1655}
1656
1657impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1658
1659/// Provides access to application state that is specialized for a particular [`View`].
1660/// Allows you to interact with focus, emit events, etc.
1661/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1662/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1663pub struct ViewContext<'a, V> {
1664 window_cx: WindowContext<'a>,
1665 view: &'a View<V>,
1666}
1667
1668impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1669 fn borrow(&self) -> &AppContext {
1670 &*self.window_cx.app
1671 }
1672}
1673
1674impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1675 fn borrow_mut(&mut self) -> &mut AppContext {
1676 &mut *self.window_cx.app
1677 }
1678}
1679
1680impl<V> Borrow<Window> for ViewContext<'_, V> {
1681 fn borrow(&self) -> &Window {
1682 &*self.window_cx.window
1683 }
1684}
1685
1686impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1687 fn borrow_mut(&mut self) -> &mut Window {
1688 &mut *self.window_cx.window
1689 }
1690}
1691
1692impl<'a, V: 'static> ViewContext<'a, V> {
1693 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1694 Self {
1695 window_cx: WindowContext::new(app, window),
1696 view,
1697 }
1698 }
1699
1700 /// Get the entity_id of this view.
1701 pub fn entity_id(&self) -> EntityId {
1702 self.view.entity_id()
1703 }
1704
1705 /// Get the view pointer underlying this context.
1706 pub fn view(&self) -> &View<V> {
1707 self.view
1708 }
1709
1710 /// Get the model underlying this view.
1711 pub fn model(&self) -> &Model<V> {
1712 &self.view.model
1713 }
1714
1715 /// Access the underlying window context.
1716 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1717 &mut self.window_cx
1718 }
1719
1720 /// Sets a given callback to be run on the next frame.
1721 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1722 where
1723 V: 'static,
1724 {
1725 let view = self.view().clone();
1726 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1727 }
1728
1729 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1730 /// that are currently on the stack to be returned to the app.
1731 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1732 let view = self.view().downgrade();
1733 self.window_cx.defer(move |cx| {
1734 view.update(cx, f).ok();
1735 });
1736 }
1737
1738 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1739 pub fn observe<V2, E>(
1740 &mut self,
1741 entity: &E,
1742 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1743 ) -> Subscription
1744 where
1745 V2: 'static,
1746 V: 'static,
1747 E: Entity<V2>,
1748 {
1749 let view = self.view().downgrade();
1750 let entity_id = entity.entity_id();
1751 let entity = entity.downgrade();
1752 let window_handle = self.window.handle;
1753 let (subscription, activate) = self.app.observers.insert(
1754 entity_id,
1755 Box::new(move |cx| {
1756 window_handle
1757 .update(cx, |_, cx| {
1758 if let Some(handle) = E::upgrade_from(&entity) {
1759 view.update(cx, |this, cx| on_notify(this, handle, cx))
1760 .is_ok()
1761 } else {
1762 false
1763 }
1764 })
1765 .unwrap_or(false)
1766 }),
1767 );
1768 self.app.defer(move |_| activate());
1769 subscription
1770 }
1771
1772 /// Subscribe to events emitted by another model or view.
1773 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1774 /// The callback will be invoked with a reference to the current view, a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a view context for the current view.
1775 pub fn subscribe<V2, E, Evt>(
1776 &mut self,
1777 entity: &E,
1778 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1779 ) -> Subscription
1780 where
1781 V2: EventEmitter<Evt>,
1782 E: Entity<V2>,
1783 Evt: 'static,
1784 {
1785 let view = self.view().downgrade();
1786 let entity_id = entity.entity_id();
1787 let handle = entity.downgrade();
1788 let window_handle = self.window.handle;
1789 let (subscription, activate) = self.app.event_listeners.insert(
1790 entity_id,
1791 (
1792 TypeId::of::<Evt>(),
1793 Box::new(move |event, cx| {
1794 window_handle
1795 .update(cx, |_, cx| {
1796 if let Some(handle) = E::upgrade_from(&handle) {
1797 let event = event.downcast_ref().expect("invalid event type");
1798 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1799 .is_ok()
1800 } else {
1801 false
1802 }
1803 })
1804 .unwrap_or(false)
1805 }),
1806 ),
1807 );
1808 self.app.defer(move |_| activate());
1809 subscription
1810 }
1811
1812 /// Register a callback to be invoked when the view is released.
1813 ///
1814 /// The callback receives a handle to the view's window. This handle may be
1815 /// invalid, if the window was closed before the view was released.
1816 pub fn on_release(
1817 &mut self,
1818 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1819 ) -> Subscription {
1820 let window_handle = self.window.handle;
1821 let (subscription, activate) = self.app.release_listeners.insert(
1822 self.view.model.entity_id,
1823 Box::new(move |this, cx| {
1824 let this = this.downcast_mut().expect("invalid entity type");
1825 on_release(this, window_handle, cx)
1826 }),
1827 );
1828 activate();
1829 subscription
1830 }
1831
1832 /// Register a callback to be invoked when the given Model or View is released.
1833 pub fn observe_release<V2, E>(
1834 &mut self,
1835 entity: &E,
1836 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1837 ) -> Subscription
1838 where
1839 V: 'static,
1840 V2: 'static,
1841 E: Entity<V2>,
1842 {
1843 let view = self.view().downgrade();
1844 let entity_id = entity.entity_id();
1845 let window_handle = self.window.handle;
1846 let (subscription, activate) = self.app.release_listeners.insert(
1847 entity_id,
1848 Box::new(move |entity, cx| {
1849 let entity = entity.downcast_mut().expect("invalid entity type");
1850 let _ = window_handle.update(cx, |_, cx| {
1851 view.update(cx, |this, cx| on_release(this, entity, cx))
1852 });
1853 }),
1854 );
1855 activate();
1856 subscription
1857 }
1858
1859 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
1860 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
1861 pub fn notify(&mut self) {
1862 for view_id in self
1863 .window
1864 .rendered_frame
1865 .dispatch_tree
1866 .view_path(self.view.entity_id())
1867 .into_iter()
1868 .rev()
1869 {
1870 if !self.window.dirty_views.insert(view_id) {
1871 break;
1872 }
1873 }
1874
1875 if !self.window.drawing {
1876 self.window_cx.window.dirty = true;
1877 self.window_cx.app.push_effect(Effect::Notify {
1878 emitter: self.view.model.entity_id,
1879 });
1880 }
1881 }
1882
1883 /// Register a callback to be invoked when the window is resized.
1884 pub fn observe_window_bounds(
1885 &mut self,
1886 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1887 ) -> Subscription {
1888 let view = self.view.downgrade();
1889 let (subscription, activate) = self.window.bounds_observers.insert(
1890 (),
1891 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1892 );
1893 activate();
1894 subscription
1895 }
1896
1897 /// Register a callback to be invoked when the window is activated or deactivated.
1898 pub fn observe_window_activation(
1899 &mut self,
1900 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1901 ) -> Subscription {
1902 let view = self.view.downgrade();
1903 let (subscription, activate) = self.window.activation_observers.insert(
1904 (),
1905 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1906 );
1907 activate();
1908 subscription
1909 }
1910
1911 /// Register a listener to be called when the given focus handle receives focus.
1912 /// Returns a subscription and persists until the subscription is dropped.
1913 pub fn on_focus(
1914 &mut self,
1915 handle: &FocusHandle,
1916 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1917 ) -> Subscription {
1918 let view = self.view.downgrade();
1919 let focus_id = handle.id;
1920 let (subscription, activate) = self.window.focus_listeners.insert(
1921 (),
1922 Box::new(move |event, cx| {
1923 view.update(cx, |view, cx| {
1924 if event.previous_focus_path.last() != Some(&focus_id)
1925 && event.current_focus_path.last() == Some(&focus_id)
1926 {
1927 listener(view, cx)
1928 }
1929 })
1930 .is_ok()
1931 }),
1932 );
1933 self.app.defer(move |_| activate());
1934 subscription
1935 }
1936
1937 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
1938 /// Returns a subscription and persists until the subscription is dropped.
1939 pub fn on_focus_in(
1940 &mut self,
1941 handle: &FocusHandle,
1942 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1943 ) -> Subscription {
1944 let view = self.view.downgrade();
1945 let focus_id = handle.id;
1946 let (subscription, activate) = self.window.focus_listeners.insert(
1947 (),
1948 Box::new(move |event, cx| {
1949 view.update(cx, |view, cx| {
1950 if !event.previous_focus_path.contains(&focus_id)
1951 && event.current_focus_path.contains(&focus_id)
1952 {
1953 listener(view, cx)
1954 }
1955 })
1956 .is_ok()
1957 }),
1958 );
1959 self.app.defer(move |_| activate());
1960 subscription
1961 }
1962
1963 /// Register a listener to be called when the given focus handle loses focus.
1964 /// Returns a subscription and persists until the subscription is dropped.
1965 pub fn on_blur(
1966 &mut self,
1967 handle: &FocusHandle,
1968 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1969 ) -> Subscription {
1970 let view = self.view.downgrade();
1971 let focus_id = handle.id;
1972 let (subscription, activate) = self.window.focus_listeners.insert(
1973 (),
1974 Box::new(move |event, cx| {
1975 view.update(cx, |view, cx| {
1976 if event.previous_focus_path.last() == Some(&focus_id)
1977 && event.current_focus_path.last() != Some(&focus_id)
1978 {
1979 listener(view, cx)
1980 }
1981 })
1982 .is_ok()
1983 }),
1984 );
1985 self.app.defer(move |_| activate());
1986 subscription
1987 }
1988
1989 /// Register a listener to be called when nothing in the window has focus.
1990 /// This typically happens when the node that was focused is removed from the tree,
1991 /// and this callback lets you chose a default place to restore the users focus.
1992 /// Returns a subscription and persists until the subscription is dropped.
1993 pub fn on_focus_lost(
1994 &mut self,
1995 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1996 ) -> Subscription {
1997 let view = self.view.downgrade();
1998 let (subscription, activate) = self.window.focus_lost_listeners.insert(
1999 (),
2000 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
2001 );
2002 activate();
2003 subscription
2004 }
2005
2006 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2007 /// Returns a subscription and persists until the subscription is dropped.
2008 pub fn on_focus_out(
2009 &mut self,
2010 handle: &FocusHandle,
2011 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2012 ) -> Subscription {
2013 let view = self.view.downgrade();
2014 let focus_id = handle.id;
2015 let (subscription, activate) = self.window.focus_listeners.insert(
2016 (),
2017 Box::new(move |event, cx| {
2018 view.update(cx, |view, cx| {
2019 if event.previous_focus_path.contains(&focus_id)
2020 && !event.current_focus_path.contains(&focus_id)
2021 {
2022 listener(view, cx)
2023 }
2024 })
2025 .is_ok()
2026 }),
2027 );
2028 self.app.defer(move |_| activate());
2029 subscription
2030 }
2031
2032 /// Schedule a future to be run asynchronously.
2033 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2034 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2035 /// The returned future will be polled on the main thread.
2036 pub fn spawn<Fut, R>(
2037 &mut self,
2038 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2039 ) -> Task<R>
2040 where
2041 R: 'static,
2042 Fut: Future<Output = R> + 'static,
2043 {
2044 let view = self.view().downgrade();
2045 self.window_cx.spawn(|cx| f(view, cx))
2046 }
2047
2048 /// Updates the global state of the given type.
2049 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2050 where
2051 G: 'static,
2052 {
2053 let mut global = self.app.lease_global::<G>();
2054 let result = f(&mut global, self);
2055 self.app.end_global_lease(global);
2056 result
2057 }
2058
2059 /// Register a callback to be invoked when the given global state changes.
2060 pub fn observe_global<G: 'static>(
2061 &mut self,
2062 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2063 ) -> Subscription {
2064 let window_handle = self.window.handle;
2065 let view = self.view().downgrade();
2066 let (subscription, activate) = self.global_observers.insert(
2067 TypeId::of::<G>(),
2068 Box::new(move |cx| {
2069 window_handle
2070 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2071 .unwrap_or(false)
2072 }),
2073 );
2074 self.app.defer(move |_| activate());
2075 subscription
2076 }
2077
2078 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2079 pub fn on_action(
2080 &mut self,
2081 action_type: TypeId,
2082 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2083 ) {
2084 let handle = self.view().clone();
2085 self.window_cx
2086 .on_action(action_type, move |action, phase, cx| {
2087 handle.update(cx, |view, cx| {
2088 listener(view, action, phase, cx);
2089 })
2090 });
2091 }
2092
2093 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2094 pub fn emit<Evt>(&mut self, event: Evt)
2095 where
2096 Evt: 'static,
2097 V: EventEmitter<Evt>,
2098 {
2099 let emitter = self.view.model.entity_id;
2100 self.app.push_effect(Effect::Emit {
2101 emitter,
2102 event_type: TypeId::of::<Evt>(),
2103 event: Box::new(event),
2104 });
2105 }
2106
2107 /// Move focus to the current view, assuming it implements [`FocusableView`].
2108 pub fn focus_self(&mut self)
2109 where
2110 V: FocusableView,
2111 {
2112 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2113 }
2114
2115 /// Convenience method for accessing view state in an event callback.
2116 ///
2117 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2118 /// but it's often useful to be able to access view state in these
2119 /// callbacks. This method provides a convenient way to do so.
2120 pub fn listener<E>(
2121 &self,
2122 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2123 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2124 let view = self.view().downgrade();
2125 move |e: &E, cx: &mut WindowContext| {
2126 view.update(cx, |view, cx| f(view, e, cx)).ok();
2127 }
2128 }
2129}
2130
2131impl<V> Context for ViewContext<'_, V> {
2132 type Result<U> = U;
2133
2134 fn new_model<T: 'static>(
2135 &mut self,
2136 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2137 ) -> Model<T> {
2138 self.window_cx.new_model(build_model)
2139 }
2140
2141 fn update_model<T: 'static, R>(
2142 &mut self,
2143 model: &Model<T>,
2144 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2145 ) -> R {
2146 self.window_cx.update_model(model, update)
2147 }
2148
2149 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2150 where
2151 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2152 {
2153 self.window_cx.update_window(window, update)
2154 }
2155
2156 fn read_model<T, R>(
2157 &self,
2158 handle: &Model<T>,
2159 read: impl FnOnce(&T, &AppContext) -> R,
2160 ) -> Self::Result<R>
2161 where
2162 T: 'static,
2163 {
2164 self.window_cx.read_model(handle, read)
2165 }
2166
2167 fn read_window<T, R>(
2168 &self,
2169 window: &WindowHandle<T>,
2170 read: impl FnOnce(View<T>, &AppContext) -> R,
2171 ) -> Result<R>
2172 where
2173 T: 'static,
2174 {
2175 self.window_cx.read_window(window, read)
2176 }
2177}
2178
2179impl<V: 'static> VisualContext for ViewContext<'_, V> {
2180 fn new_view<W: Render + 'static>(
2181 &mut self,
2182 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2183 ) -> Self::Result<View<W>> {
2184 self.window_cx.new_view(build_view_state)
2185 }
2186
2187 fn update_view<V2: 'static, R>(
2188 &mut self,
2189 view: &View<V2>,
2190 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2191 ) -> Self::Result<R> {
2192 self.window_cx.update_view(view, update)
2193 }
2194
2195 fn replace_root_view<W>(
2196 &mut self,
2197 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2198 ) -> Self::Result<View<W>>
2199 where
2200 W: 'static + Render,
2201 {
2202 self.window_cx.replace_root_view(build_view)
2203 }
2204
2205 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2206 self.window_cx.focus_view(view)
2207 }
2208
2209 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2210 self.window_cx.dismiss_view(view)
2211 }
2212}
2213
2214impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2215 type Target = WindowContext<'a>;
2216
2217 fn deref(&self) -> &Self::Target {
2218 &self.window_cx
2219 }
2220}
2221
2222impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2223 fn deref_mut(&mut self) -> &mut Self::Target {
2224 &mut self.window_cx
2225 }
2226}
2227
2228// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2229slotmap::new_key_type! {
2230 /// A unique identifier for a window.
2231 pub struct WindowId;
2232}
2233
2234impl WindowId {
2235 /// Converts this window ID to a `u64`.
2236 pub fn as_u64(&self) -> u64 {
2237 self.0.as_ffi()
2238 }
2239}
2240
2241/// A handle to a window with a specific root view type.
2242/// Note that this does not keep the window alive on its own.
2243#[derive(Deref, DerefMut)]
2244pub struct WindowHandle<V> {
2245 #[deref]
2246 #[deref_mut]
2247 pub(crate) any_handle: AnyWindowHandle,
2248 state_type: PhantomData<V>,
2249}
2250
2251impl<V: 'static + Render> WindowHandle<V> {
2252 /// Creates a new handle from a window ID.
2253 /// This does not check if the root type of the window is `V`.
2254 pub fn new(id: WindowId) -> Self {
2255 WindowHandle {
2256 any_handle: AnyWindowHandle {
2257 id,
2258 state_type: TypeId::of::<V>(),
2259 },
2260 state_type: PhantomData,
2261 }
2262 }
2263
2264 /// Get the root view out of this window.
2265 ///
2266 /// This will fail if the window is closed or if the root view's type does not match `V`.
2267 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2268 where
2269 C: Context,
2270 {
2271 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2272 root_view
2273 .downcast::<V>()
2274 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2275 }))
2276 }
2277
2278 /// Updates the root view of this window.
2279 ///
2280 /// This will fail if the window has been closed or if the root view's type does not match
2281 pub fn update<C, R>(
2282 &self,
2283 cx: &mut C,
2284 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2285 ) -> Result<R>
2286 where
2287 C: Context,
2288 {
2289 cx.update_window(self.any_handle, |root_view, cx| {
2290 let view = root_view
2291 .downcast::<V>()
2292 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2293 Ok(cx.update_view(&view, update))
2294 })?
2295 }
2296
2297 /// Read the root view out of this window.
2298 ///
2299 /// This will fail if the window is closed or if the root view's type does not match `V`.
2300 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2301 let x = cx
2302 .windows
2303 .get(self.id)
2304 .and_then(|window| {
2305 window
2306 .as_ref()
2307 .and_then(|window| window.root_view.clone())
2308 .map(|root_view| root_view.downcast::<V>())
2309 })
2310 .ok_or_else(|| anyhow!("window not found"))?
2311 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2312
2313 Ok(x.read(cx))
2314 }
2315
2316 /// Read the root view out of this window, with a callback
2317 ///
2318 /// This will fail if the window is closed or if the root view's type does not match `V`.
2319 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2320 where
2321 C: Context,
2322 {
2323 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2324 }
2325
2326 /// Read the root view pointer off of this window.
2327 ///
2328 /// This will fail if the window is closed or if the root view's type does not match `V`.
2329 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2330 where
2331 C: Context,
2332 {
2333 cx.read_window(self, |root_view, _cx| root_view.clone())
2334 }
2335
2336 /// Check if this window is 'active'.
2337 ///
2338 /// Will return `None` if the window is closed.
2339 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2340 cx.windows
2341 .get(self.id)
2342 .and_then(|window| window.as_ref().map(|window| window.active))
2343 }
2344}
2345
2346impl<V> Copy for WindowHandle<V> {}
2347
2348impl<V> Clone for WindowHandle<V> {
2349 fn clone(&self) -> Self {
2350 *self
2351 }
2352}
2353
2354impl<V> PartialEq for WindowHandle<V> {
2355 fn eq(&self, other: &Self) -> bool {
2356 self.any_handle == other.any_handle
2357 }
2358}
2359
2360impl<V> Eq for WindowHandle<V> {}
2361
2362impl<V> Hash for WindowHandle<V> {
2363 fn hash<H: Hasher>(&self, state: &mut H) {
2364 self.any_handle.hash(state);
2365 }
2366}
2367
2368impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2369 fn from(val: WindowHandle<V>) -> Self {
2370 val.any_handle
2371 }
2372}
2373
2374/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2375#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2376pub struct AnyWindowHandle {
2377 pub(crate) id: WindowId,
2378 state_type: TypeId,
2379}
2380
2381impl AnyWindowHandle {
2382 /// Get the ID of this window.
2383 pub fn window_id(&self) -> WindowId {
2384 self.id
2385 }
2386
2387 /// Attempt to convert this handle to a window handle with a specific root view type.
2388 /// If the types do not match, this will return `None`.
2389 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2390 if TypeId::of::<T>() == self.state_type {
2391 Some(WindowHandle {
2392 any_handle: *self,
2393 state_type: PhantomData,
2394 })
2395 } else {
2396 None
2397 }
2398 }
2399
2400 /// Updates the state of the root view of this window.
2401 ///
2402 /// This will fail if the window has been closed.
2403 pub fn update<C, R>(
2404 self,
2405 cx: &mut C,
2406 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2407 ) -> Result<R>
2408 where
2409 C: Context,
2410 {
2411 cx.update_window(self, update)
2412 }
2413
2414 /// Read the state of the root view of this window.
2415 ///
2416 /// This will fail if the window has been closed.
2417 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2418 where
2419 C: Context,
2420 T: 'static,
2421 {
2422 let view = self
2423 .downcast::<T>()
2424 .context("the type of the window's root view has changed")?;
2425
2426 cx.read_window(&view, read)
2427 }
2428}
2429
2430/// An identifier for an [`Element`](crate::Element).
2431///
2432/// Can be constructed with a string, a number, or both, as well
2433/// as other internal representations.
2434#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2435pub enum ElementId {
2436 /// The ID of a View element
2437 View(EntityId),
2438 /// An integer ID.
2439 Integer(usize),
2440 /// A string based ID.
2441 Name(SharedString),
2442 /// An ID that's equated with a focus handle.
2443 FocusHandle(FocusId),
2444 /// A combination of a name and an integer.
2445 NamedInteger(SharedString, usize),
2446}
2447
2448impl Display for ElementId {
2449 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2450 match self {
2451 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2452 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2453 ElementId::Name(name) => write!(f, "{}", name)?,
2454 ElementId::FocusHandle(__) => write!(f, "FocusHandle")?,
2455 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2456 }
2457
2458 Ok(())
2459 }
2460}
2461
2462impl ElementId {
2463 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2464 ElementId::View(entity_id)
2465 }
2466}
2467
2468impl TryInto<SharedString> for ElementId {
2469 type Error = anyhow::Error;
2470
2471 fn try_into(self) -> anyhow::Result<SharedString> {
2472 if let ElementId::Name(name) = self {
2473 Ok(name)
2474 } else {
2475 Err(anyhow!("element id is not string"))
2476 }
2477 }
2478}
2479
2480impl From<usize> for ElementId {
2481 fn from(id: usize) -> Self {
2482 ElementId::Integer(id)
2483 }
2484}
2485
2486impl From<i32> for ElementId {
2487 fn from(id: i32) -> Self {
2488 Self::Integer(id as usize)
2489 }
2490}
2491
2492impl From<SharedString> for ElementId {
2493 fn from(name: SharedString) -> Self {
2494 ElementId::Name(name)
2495 }
2496}
2497
2498impl From<&'static str> for ElementId {
2499 fn from(name: &'static str) -> Self {
2500 ElementId::Name(name.into())
2501 }
2502}
2503
2504impl<'a> From<&'a FocusHandle> for ElementId {
2505 fn from(handle: &'a FocusHandle) -> Self {
2506 ElementId::FocusHandle(handle.id)
2507 }
2508}
2509
2510impl From<(&'static str, EntityId)> for ElementId {
2511 fn from((name, id): (&'static str, EntityId)) -> Self {
2512 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2513 }
2514}
2515
2516impl From<(&'static str, usize)> for ElementId {
2517 fn from((name, id): (&'static str, usize)) -> Self {
2518 ElementId::NamedInteger(name.into(), id)
2519 }
2520}
2521
2522impl From<(&'static str, u64)> for ElementId {
2523 fn from((name, id): (&'static str, u64)) -> Self {
2524 ElementId::NamedInteger(name.into(), id as usize)
2525 }
2526}
2527
2528/// A rectangle to be rendered in the window at the given position and size.
2529/// Passed as an argument [`WindowContext::paint_quad`].
2530#[derive(Clone)]
2531pub struct PaintQuad {
2532 bounds: Bounds<Pixels>,
2533 corner_radii: Corners<Pixels>,
2534 background: Hsla,
2535 border_widths: Edges<Pixels>,
2536 border_color: Hsla,
2537}
2538
2539impl PaintQuad {
2540 /// Sets the corner radii of the quad.
2541 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2542 PaintQuad {
2543 corner_radii: corner_radii.into(),
2544 ..self
2545 }
2546 }
2547
2548 /// Sets the border widths of the quad.
2549 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2550 PaintQuad {
2551 border_widths: border_widths.into(),
2552 ..self
2553 }
2554 }
2555
2556 /// Sets the border color of the quad.
2557 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2558 PaintQuad {
2559 border_color: border_color.into(),
2560 ..self
2561 }
2562 }
2563
2564 /// Sets the background color of the quad.
2565 pub fn background(self, background: impl Into<Hsla>) -> Self {
2566 PaintQuad {
2567 background: background.into(),
2568 ..self
2569 }
2570 }
2571}
2572
2573/// Creates a quad with the given parameters.
2574pub fn quad(
2575 bounds: Bounds<Pixels>,
2576 corner_radii: impl Into<Corners<Pixels>>,
2577 background: impl Into<Hsla>,
2578 border_widths: impl Into<Edges<Pixels>>,
2579 border_color: impl Into<Hsla>,
2580) -> PaintQuad {
2581 PaintQuad {
2582 bounds,
2583 corner_radii: corner_radii.into(),
2584 background: background.into(),
2585 border_widths: border_widths.into(),
2586 border_color: border_color.into(),
2587 }
2588}
2589
2590/// Creates a filled quad with the given bounds and background color.
2591pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2592 PaintQuad {
2593 bounds: bounds.into(),
2594 corner_radii: (0.).into(),
2595 background: background.into(),
2596 border_widths: (0.).into(),
2597 border_color: transparent_black(),
2598 }
2599}
2600
2601/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2602pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2603 PaintQuad {
2604 bounds: bounds.into(),
2605 corner_radii: (0.).into(),
2606 background: transparent_black(),
2607 border_widths: (1.).into(),
2608 border_color: border_color.into(),
2609 }
2610}