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::ResultExt;
38
39mod element_cx;
40pub use element_cx::*;
41
42const ACTIVE_DRAG_Z_INDEX: u8 = 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(Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
47pub struct StackingOrder {
48 #[deref]
49 #[deref_mut]
50 context_stack: SmallVec<[u8; 64]>,
51 pub(crate) id: u32,
52}
53
54impl std::fmt::Debug for StackingOrder {
55 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
56 let mut stacks = self.context_stack.iter().peekable();
57 write!(f, "[({}): ", self.id)?;
58 while let Some(z_index) = stacks.next() {
59 write!(f, "{z_index}")?;
60 if stacks.peek().is_some() {
61 write!(f, "->")?;
62 }
63 }
64 write!(f, "]")?;
65 Ok(())
66 }
67}
68
69/// Represents the two different phases when dispatching events.
70#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
71pub enum DispatchPhase {
72 /// After the capture phase comes the bubble phase, in which mouse event listeners are
73 /// invoked front to back and keyboard event listeners are invoked from the focused element
74 /// to the root of the element tree. This is the phase you'll most commonly want to use when
75 /// registering event listeners.
76 #[default]
77 Bubble,
78 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
79 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
80 /// is used for special purposes such as clearing the "pressed" state for click events. If
81 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
82 /// outside of the immediate region may rely on detecting non-local events during this phase.
83 Capture,
84}
85
86impl DispatchPhase {
87 /// Returns true if this represents the "bubble" phase.
88 pub fn bubble(self) -> bool {
89 self == DispatchPhase::Bubble
90 }
91
92 /// Returns true if this represents the "capture" phase.
93 pub fn capture(self) -> bool {
94 self == DispatchPhase::Capture
95 }
96}
97
98type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
99
100type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
101
102struct FocusEvent {
103 previous_focus_path: SmallVec<[FocusId; 8]>,
104 current_focus_path: SmallVec<[FocusId; 8]>,
105}
106
107slotmap::new_key_type! {
108 /// A globally unique identifier for a focusable element.
109 pub struct FocusId;
110}
111
112thread_local! {
113 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(4 * 1024 * 1024));
114}
115
116impl FocusId {
117 /// Obtains whether the element associated with this handle is currently focused.
118 pub fn is_focused(&self, cx: &WindowContext) -> bool {
119 cx.window.focus == Some(*self)
120 }
121
122 /// Obtains whether the element associated with this handle contains the focused
123 /// element or is itself focused.
124 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
125 cx.focused()
126 .map_or(false, |focused| self.contains(focused.id, cx))
127 }
128
129 /// Obtains whether the element associated with this handle is contained within the
130 /// focused element or is itself focused.
131 pub fn within_focused(&self, cx: &WindowContext) -> bool {
132 let focused = cx.focused();
133 focused.map_or(false, |focused| focused.id.contains(*self, cx))
134 }
135
136 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
137 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
138 cx.window
139 .rendered_frame
140 .dispatch_tree
141 .focus_contains(*self, other)
142 }
143}
144
145/// A handle which can be used to track and manipulate the focused element in a window.
146pub struct FocusHandle {
147 pub(crate) id: FocusId,
148 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
149}
150
151impl std::fmt::Debug for FocusHandle {
152 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
153 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
154 }
155}
156
157impl FocusHandle {
158 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
159 let id = handles.write().insert(AtomicUsize::new(1));
160 Self {
161 id,
162 handles: handles.clone(),
163 }
164 }
165
166 pub(crate) fn for_id(
167 id: FocusId,
168 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
169 ) -> Option<Self> {
170 let lock = handles.read();
171 let ref_count = lock.get(id)?;
172 if ref_count.load(SeqCst) == 0 {
173 None
174 } else {
175 ref_count.fetch_add(1, SeqCst);
176 Some(Self {
177 id,
178 handles: handles.clone(),
179 })
180 }
181 }
182
183 /// Moves the focus to the element associated with this handle.
184 pub fn focus(&self, cx: &mut WindowContext) {
185 cx.focus(self)
186 }
187
188 /// Obtains whether the element associated with this handle is currently focused.
189 pub fn is_focused(&self, cx: &WindowContext) -> bool {
190 self.id.is_focused(cx)
191 }
192
193 /// Obtains whether the element associated with this handle contains the focused
194 /// element or is itself focused.
195 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
196 self.id.contains_focused(cx)
197 }
198
199 /// Obtains whether the element associated with this handle is contained within the
200 /// focused element or is itself focused.
201 pub fn within_focused(&self, cx: &WindowContext) -> bool {
202 self.id.within_focused(cx)
203 }
204
205 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
206 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
207 self.id.contains(other.id, cx)
208 }
209}
210
211impl Clone for FocusHandle {
212 fn clone(&self) -> Self {
213 Self::for_id(self.id, &self.handles).unwrap()
214 }
215}
216
217impl PartialEq for FocusHandle {
218 fn eq(&self, other: &Self) -> bool {
219 self.id == other.id
220 }
221}
222
223impl Eq for FocusHandle {}
224
225impl Drop for FocusHandle {
226 fn drop(&mut self) {
227 self.handles
228 .read()
229 .get(self.id)
230 .unwrap()
231 .fetch_sub(1, SeqCst);
232 }
233}
234
235/// FocusableView allows users of your view to easily
236/// focus it (using cx.focus_view(view))
237pub trait FocusableView: 'static + Render {
238 /// Returns the focus handle associated with this view.
239 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
240}
241
242/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
243/// where the lifecycle of the view is handled by another view.
244pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
245
246impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
247
248/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
249pub struct DismissEvent;
250
251// Holds the state for a specific window.
252#[doc(hidden)]
253pub struct Window {
254 pub(crate) handle: AnyWindowHandle,
255 pub(crate) removed: bool,
256 pub(crate) platform_window: Box<dyn PlatformWindow>,
257 display_id: DisplayId,
258 sprite_atlas: Arc<dyn PlatformAtlas>,
259 pub(crate) rem_size: Pixels,
260 pub(crate) viewport_size: Size<Pixels>,
261 layout_engine: Option<TaffyLayoutEngine>,
262 pub(crate) root_view: Option<AnyView>,
263 pub(crate) element_id_stack: GlobalElementId,
264 pub(crate) rendered_frame: Frame,
265 pub(crate) next_frame: Frame,
266 pub(crate) dirty_views: FxHashSet<EntityId>,
267 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
268 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
269 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
270 default_prevented: bool,
271 mouse_position: Point<Pixels>,
272 modifiers: Modifiers,
273 scale_factor: f32,
274 bounds: WindowBounds,
275 bounds_observers: SubscriberSet<(), AnyObserver>,
276 active: bool,
277 pub(crate) dirty: bool,
278 pub(crate) refreshing: bool,
279 pub(crate) drawing: bool,
280 activation_observers: SubscriberSet<(), AnyObserver>,
281 pub(crate) focus: Option<FocusId>,
282 focus_enabled: bool,
283
284 #[cfg(any(test, feature = "test-support"))]
285 pub(crate) focus_invalidated: bool,
286}
287
288pub(crate) struct ElementStateBox {
289 pub(crate) inner: Box<dyn Any>,
290 pub(crate) parent_view_id: EntityId,
291 #[cfg(debug_assertions)]
292 pub(crate) type_name: &'static str,
293}
294
295impl Window {
296 pub(crate) fn new(
297 handle: AnyWindowHandle,
298 options: WindowOptions,
299 cx: &mut AppContext,
300 ) -> Self {
301 let platform_window = cx.platform.open_window(handle, options);
302 let display_id = platform_window.display().id();
303 let sprite_atlas = platform_window.sprite_atlas();
304 let mouse_position = platform_window.mouse_position();
305 let modifiers = platform_window.modifiers();
306 let content_size = platform_window.content_size();
307 let scale_factor = platform_window.scale_factor();
308 let bounds = platform_window.bounds();
309
310 platform_window.on_request_frame(Box::new({
311 let mut cx = cx.to_async();
312 move || {
313 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
314 }
315 }));
316 platform_window.on_resize(Box::new({
317 let mut cx = cx.to_async();
318 move |_, _| {
319 handle
320 .update(&mut cx, |_, cx| cx.window_bounds_changed())
321 .log_err();
322 }
323 }));
324 platform_window.on_moved(Box::new({
325 let mut cx = cx.to_async();
326 move || {
327 handle
328 .update(&mut cx, |_, cx| cx.window_bounds_changed())
329 .log_err();
330 }
331 }));
332 platform_window.on_active_status_change(Box::new({
333 let mut cx = cx.to_async();
334 move |active| {
335 handle
336 .update(&mut cx, |_, cx| {
337 cx.window.active = active;
338 cx.window
339 .activation_observers
340 .clone()
341 .retain(&(), |callback| callback(cx));
342 })
343 .log_err();
344 }
345 }));
346
347 platform_window.on_input({
348 let mut cx = cx.to_async();
349 Box::new(move |event| {
350 handle
351 .update(&mut cx, |_, cx| cx.dispatch_event(event))
352 .log_err()
353 .unwrap_or(false)
354 })
355 });
356
357 Window {
358 handle,
359 removed: false,
360 platform_window,
361 display_id,
362 sprite_atlas,
363 rem_size: px(16.),
364 viewport_size: content_size,
365 layout_engine: Some(TaffyLayoutEngine::new()),
366 root_view: None,
367 element_id_stack: GlobalElementId::default(),
368 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
369 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
370 dirty_views: FxHashSet::default(),
371 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
372 focus_listeners: SubscriberSet::new(),
373 focus_lost_listeners: SubscriberSet::new(),
374 default_prevented: true,
375 mouse_position,
376 modifiers,
377 scale_factor,
378 bounds,
379 bounds_observers: SubscriberSet::new(),
380 active: false,
381 dirty: false,
382 refreshing: false,
383 drawing: false,
384 activation_observers: SubscriberSet::new(),
385 focus: None,
386 focus_enabled: true,
387
388 #[cfg(any(test, feature = "test-support"))]
389 focus_invalidated: false,
390 }
391 }
392}
393
394/// Indicates which region of the window is visible. Content falling outside of this mask will not be
395/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
396/// to leave room to support more complex shapes in the future.
397#[derive(Clone, Debug, Default, PartialEq, Eq)]
398#[repr(C)]
399pub struct ContentMask<P: Clone + Default + Debug> {
400 /// The bounds
401 pub bounds: Bounds<P>,
402}
403
404impl ContentMask<Pixels> {
405 /// Scale the content mask's pixel units by the given scaling factor.
406 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
407 ContentMask {
408 bounds: self.bounds.scale(factor),
409 }
410 }
411
412 /// Intersect the content mask with the given content mask.
413 pub fn intersect(&self, other: &Self) -> Self {
414 let bounds = self.bounds.intersect(&other.bounds);
415 ContentMask { bounds }
416 }
417}
418
419/// Provides access to application state in the context of a single window. Derefs
420/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
421/// an [`AppContext`] and call any [`AppContext`] methods.
422pub struct WindowContext<'a> {
423 pub(crate) app: &'a mut AppContext,
424 pub(crate) window: &'a mut Window,
425}
426
427impl<'a> WindowContext<'a> {
428 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
429 Self { app, window }
430 }
431
432 /// Obtain a handle to the window that belongs to this context.
433 pub fn window_handle(&self) -> AnyWindowHandle {
434 self.window.handle
435 }
436
437 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
438 pub fn refresh(&mut self) {
439 if !self.window.drawing {
440 self.window.refreshing = true;
441 self.window.dirty = true;
442 }
443 }
444
445 /// Close this window.
446 pub fn remove_window(&mut self) {
447 self.window.removed = true;
448 }
449
450 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
451 /// for elements rendered within this window.
452 pub fn focus_handle(&mut self) -> FocusHandle {
453 FocusHandle::new(&self.window.focus_handles)
454 }
455
456 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
457 pub fn focused(&self) -> Option<FocusHandle> {
458 self.window
459 .focus
460 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
461 }
462
463 /// Move focus to the element associated with the given [`FocusHandle`].
464 pub fn focus(&mut self, handle: &FocusHandle) {
465 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
466 return;
467 }
468
469 self.window.focus = Some(handle.id);
470 self.window
471 .rendered_frame
472 .dispatch_tree
473 .clear_pending_keystrokes();
474
475 #[cfg(any(test, feature = "test-support"))]
476 {
477 self.window.focus_invalidated = true;
478 }
479
480 self.refresh();
481 }
482
483 /// Remove focus from all elements within this context's window.
484 pub fn blur(&mut self) {
485 if !self.window.focus_enabled {
486 return;
487 }
488
489 self.window.focus = None;
490 self.refresh();
491 }
492
493 /// Blur the window and don't allow anything in it to be focused again.
494 pub fn disable_focus(&mut self) {
495 self.blur();
496 self.window.focus_enabled = false;
497 }
498
499 /// Dispatch the given action on the currently focused element.
500 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
501 let focus_handle = self.focused();
502
503 self.defer(move |cx| {
504 let node_id = focus_handle
505 .and_then(|handle| {
506 cx.window
507 .rendered_frame
508 .dispatch_tree
509 .focusable_node_id(handle.id)
510 })
511 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
512
513 cx.propagate_event = true;
514 cx.dispatch_action_on_node(node_id, action);
515 })
516 }
517
518 pub(crate) fn dispatch_keystroke_observers(
519 &mut self,
520 event: &dyn Any,
521 action: Option<Box<dyn Action>>,
522 ) {
523 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
524 return;
525 };
526
527 self.keystroke_observers
528 .clone()
529 .retain(&(), move |callback| {
530 (callback)(
531 &KeystrokeEvent {
532 keystroke: key_down_event.keystroke.clone(),
533 action: action.as_ref().map(|action| action.boxed_clone()),
534 },
535 self,
536 );
537 true
538 });
539 }
540
541 pub(crate) fn clear_pending_keystrokes(&mut self) {
542 self.window
543 .rendered_frame
544 .dispatch_tree
545 .clear_pending_keystrokes();
546 self.window
547 .next_frame
548 .dispatch_tree
549 .clear_pending_keystrokes();
550 }
551
552 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
553 /// that are currently on the stack to be returned to the app.
554 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
555 let handle = self.window.handle;
556 self.app.defer(move |cx| {
557 handle.update(cx, |_, cx| f(cx)).ok();
558 });
559 }
560
561 /// Subscribe to events emitted by a model or view.
562 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
563 /// 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.
564 pub fn subscribe<Emitter, E, Evt>(
565 &mut self,
566 entity: &E,
567 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
568 ) -> Subscription
569 where
570 Emitter: EventEmitter<Evt>,
571 E: Entity<Emitter>,
572 Evt: 'static,
573 {
574 let entity_id = entity.entity_id();
575 let entity = entity.downgrade();
576 let window_handle = self.window.handle;
577 let (subscription, activate) = self.app.event_listeners.insert(
578 entity_id,
579 (
580 TypeId::of::<Evt>(),
581 Box::new(move |event, cx| {
582 window_handle
583 .update(cx, |_, cx| {
584 if let Some(handle) = E::upgrade_from(&entity) {
585 let event = event.downcast_ref().expect("invalid event type");
586 on_event(handle, event, cx);
587 true
588 } else {
589 false
590 }
591 })
592 .unwrap_or(false)
593 }),
594 ),
595 );
596 self.app.defer(move |_| activate());
597 subscription
598 }
599
600 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
601 /// await points in async code.
602 pub fn to_async(&self) -> AsyncWindowContext {
603 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
604 }
605
606 /// Schedule the given closure to be run directly after the current frame is rendered.
607 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
608 let handle = self.window.handle;
609 let display_id = self.window.display_id;
610
611 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
612 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
613 let (tx, mut rx) = mpsc::unbounded::<()>();
614 self.platform.set_display_link_output_callback(
615 display_id,
616 Box::new(move || _ = tx.unbounded_send(())),
617 );
618
619 let consumer_task = self.app.spawn(|cx| async move {
620 while rx.next().await.is_some() {
621 cx.update(|cx| {
622 for callback in cx
623 .next_frame_callbacks
624 .get_mut(&display_id)
625 .unwrap()
626 .drain(..)
627 .collect::<SmallVec<[_; 32]>>()
628 {
629 callback(cx);
630 }
631 })
632 .ok();
633
634 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
635
636 cx.update(|cx| {
637 if cx.next_frame_callbacks.is_empty() {
638 cx.platform.stop_display_link(display_id);
639 }
640 })
641 .ok();
642 }
643 });
644 e.insert(consumer_task);
645 }
646 debug_assert!(self.app.frame_consumers.is_empty());
647 self.app.frame_consumers = frame_consumers;
648
649 if self.next_frame_callbacks.is_empty() {
650 self.platform.start_display_link(display_id);
651 }
652
653 self.next_frame_callbacks
654 .entry(display_id)
655 .or_default()
656 .push(Box::new(move |cx: &mut AppContext| {
657 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
658 }));
659 }
660
661 /// Spawn the future returned by the given closure on the application thread pool.
662 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
663 /// use within your future.
664 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
665 where
666 R: 'static,
667 Fut: Future<Output = R> + 'static,
668 {
669 self.app
670 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
671 }
672
673 /// Updates the global of the given type. The given closure is given simultaneous mutable
674 /// access both to the global and the context.
675 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
676 where
677 G: 'static,
678 {
679 let mut global = self.app.lease_global::<G>();
680 let result = f(&mut global, self);
681 self.app.end_global_lease(global);
682 result
683 }
684
685 fn window_bounds_changed(&mut self) {
686 self.window.scale_factor = self.window.platform_window.scale_factor();
687 self.window.viewport_size = self.window.platform_window.content_size();
688 self.window.bounds = self.window.platform_window.bounds();
689 self.window.display_id = self.window.platform_window.display().id();
690 self.refresh();
691
692 self.window
693 .bounds_observers
694 .clone()
695 .retain(&(), |callback| callback(self));
696 }
697
698 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
699 pub fn window_bounds(&self) -> WindowBounds {
700 self.window.bounds
701 }
702
703 /// Returns the size of the drawable area within the window.
704 pub fn viewport_size(&self) -> Size<Pixels> {
705 self.window.viewport_size
706 }
707
708 /// Returns whether this window is focused by the operating system (receiving key events).
709 pub fn is_window_active(&self) -> bool {
710 self.window.active
711 }
712
713 /// Toggle zoom on the window.
714 pub fn zoom_window(&self) {
715 self.window.platform_window.zoom();
716 }
717
718 /// Updates the window's title at the platform level.
719 pub fn set_window_title(&mut self, title: &str) {
720 self.window.platform_window.set_title(title);
721 }
722
723 /// Mark the window as dirty at the platform level.
724 pub fn set_window_edited(&mut self, edited: bool) {
725 self.window.platform_window.set_edited(edited);
726 }
727
728 /// Determine the display on which the window is visible.
729 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
730 self.platform
731 .displays()
732 .into_iter()
733 .find(|display| display.id() == self.window.display_id)
734 }
735
736 /// Show the platform character palette.
737 pub fn show_character_palette(&self) {
738 self.window.platform_window.show_character_palette();
739 }
740
741 /// The scale factor of the display associated with the window. For example, it could
742 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
743 /// be rendered as two pixels on screen.
744 pub fn scale_factor(&self) -> f32 {
745 self.window.scale_factor
746 }
747
748 /// The size of an em for the base font of the application. Adjusting this value allows the
749 /// UI to scale, just like zooming a web page.
750 pub fn rem_size(&self) -> Pixels {
751 self.window.rem_size
752 }
753
754 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
755 /// UI to scale, just like zooming a web page.
756 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
757 self.window.rem_size = rem_size.into();
758 }
759
760 /// The line height associated with the current text style.
761 pub fn line_height(&self) -> Pixels {
762 let rem_size = self.rem_size();
763 let text_style = self.text_style();
764 text_style
765 .line_height
766 .to_pixels(text_style.font_size, rem_size)
767 }
768
769 /// Call to prevent the default action of an event. Currently only used to prevent
770 /// parent elements from becoming focused on mouse down.
771 pub fn prevent_default(&mut self) {
772 self.window.default_prevented = true;
773 }
774
775 /// Obtain whether default has been prevented for the event currently being dispatched.
776 pub fn default_prevented(&self) -> bool {
777 self.window.default_prevented
778 }
779
780 /// Determine whether the given action is available along the dispatch path to the currently focused element.
781 pub fn is_action_available(&self, action: &dyn Action) -> bool {
782 let target = self
783 .focused()
784 .and_then(|focused_handle| {
785 self.window
786 .rendered_frame
787 .dispatch_tree
788 .focusable_node_id(focused_handle.id)
789 })
790 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
791 self.window
792 .rendered_frame
793 .dispatch_tree
794 .is_action_available(action, target)
795 }
796
797 /// The position of the mouse relative to the window.
798 pub fn mouse_position(&self) -> Point<Pixels> {
799 self.window.mouse_position
800 }
801
802 /// The current state of the keyboard's modifiers
803 pub fn modifiers(&self) -> Modifiers {
804 self.window.modifiers
805 }
806
807 /// Returns true if there is no opaque layer containing the given point
808 /// on top of the given level. Layers whose level is an extension of the
809 /// level are not considered to be on top of the level.
810 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
811 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
812 if level >= opaque_level {
813 break;
814 }
815
816 if bounds.contains(point) && !opaque_level.starts_with(level) {
817 return false;
818 }
819 }
820 true
821 }
822
823 pub(crate) fn was_top_layer_under_active_drag(
824 &self,
825 point: &Point<Pixels>,
826 level: &StackingOrder,
827 ) -> bool {
828 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
829 if level >= opaque_level {
830 break;
831 }
832 if opaque_level.starts_with(&[ACTIVE_DRAG_Z_INDEX]) {
833 continue;
834 }
835
836 if bounds.contains(point) && !opaque_level.starts_with(level) {
837 return false;
838 }
839 }
840 true
841 }
842
843 /// Called during painting to get the current stacking order.
844 pub fn stacking_order(&self) -> &StackingOrder {
845 &self.window.next_frame.z_index_stack
846 }
847
848 /// Draw pixels to the display for this window based on the contents of its scene.
849 pub(crate) fn draw(&mut self) {
850 self.window.dirty = false;
851 self.window.drawing = true;
852
853 #[cfg(any(test, feature = "test-support"))]
854 {
855 self.window.focus_invalidated = false;
856 }
857
858 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
859 {
860 let input_handler = self.window.platform_window.take_input_handler();
861 requested_handler.handler = input_handler;
862 }
863
864 let root_view = self.window.root_view.take().unwrap();
865 self.with_element_context(|cx| {
866 cx.with_z_index(0, |cx| {
867 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
868 // We need to use cx.cx here so we can utilize borrow splitting
869 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
870 for action_listener in action_listeners.iter().cloned() {
871 cx.cx.window.next_frame.dispatch_tree.on_action(
872 *action_type,
873 Rc::new(
874 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
875 action_listener(action, phase, cx)
876 },
877 ),
878 )
879 }
880 }
881
882 let available_space = cx.window.viewport_size.map(Into::into);
883 root_view.draw(Point::default(), available_space, cx);
884 })
885 })
886 });
887
888 if let Some(active_drag) = self.app.active_drag.take() {
889 self.with_element_context(|cx| {
890 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
891 let offset = cx.mouse_position() - active_drag.cursor_offset;
892 let available_space =
893 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
894 active_drag.view.draw(offset, available_space, cx);
895 })
896 });
897 self.active_drag = Some(active_drag);
898 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
899 self.with_element_context(|cx| {
900 cx.with_z_index(1, |cx| {
901 let available_space =
902 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
903 tooltip_request.tooltip.view.draw(
904 tooltip_request.tooltip.cursor_offset,
905 available_space,
906 cx,
907 );
908 })
909 });
910 self.window.next_frame.tooltip_request = Some(tooltip_request);
911 }
912 self.window.dirty_views.clear();
913
914 self.window
915 .next_frame
916 .dispatch_tree
917 .preserve_pending_keystrokes(
918 &mut self.window.rendered_frame.dispatch_tree,
919 self.window.focus,
920 );
921 self.window.next_frame.focus = self.window.focus;
922 self.window.next_frame.window_active = self.window.active;
923 self.window.root_view = Some(root_view);
924
925 // Set the cursor only if we're the active window.
926 let cursor_style = self
927 .window
928 .next_frame
929 .requested_cursor_style
930 .take()
931 .unwrap_or(CursorStyle::Arrow);
932 if self.is_window_active() {
933 self.platform.set_cursor_style(cursor_style);
934 }
935
936 // Register requested input handler with the platform window.
937 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
938 if let Some(handler) = requested_input.handler.take() {
939 self.window.platform_window.set_input_handler(handler);
940 }
941 }
942
943 self.window.layout_engine.as_mut().unwrap().clear();
944 self.text_system()
945 .finish_frame(&self.window.next_frame.reused_views);
946 self.window
947 .next_frame
948 .finish(&mut self.window.rendered_frame);
949 ELEMENT_ARENA.with_borrow_mut(|element_arena| element_arena.clear());
950
951 let previous_focus_path = self.window.rendered_frame.focus_path();
952 let previous_window_active = self.window.rendered_frame.window_active;
953 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
954 self.window.next_frame.clear();
955 let current_focus_path = self.window.rendered_frame.focus_path();
956 let current_window_active = self.window.rendered_frame.window_active;
957
958 if previous_focus_path != current_focus_path
959 || previous_window_active != current_window_active
960 {
961 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
962 self.window
963 .focus_lost_listeners
964 .clone()
965 .retain(&(), |listener| listener(self));
966 }
967
968 let event = FocusEvent {
969 previous_focus_path: if previous_window_active {
970 previous_focus_path
971 } else {
972 Default::default()
973 },
974 current_focus_path: if current_window_active {
975 current_focus_path
976 } else {
977 Default::default()
978 },
979 };
980 self.window
981 .focus_listeners
982 .clone()
983 .retain(&(), |listener| listener(&event, self));
984 }
985
986 self.window
987 .platform_window
988 .draw(&self.window.rendered_frame.scene);
989 self.window.refreshing = false;
990 self.window.drawing = false;
991 }
992
993 /// Dispatch a mouse or keyboard event on the window.
994 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
995 // Handlers may set this to false by calling `stop_propagation`.
996 self.app.propagate_event = true;
997 // Handlers may set this to true by calling `prevent_default`.
998 self.window.default_prevented = false;
999
1000 let event = match event {
1001 // Track the mouse position with our own state, since accessing the platform
1002 // API for the mouse position can only occur on the main thread.
1003 PlatformInput::MouseMove(mouse_move) => {
1004 self.window.mouse_position = mouse_move.position;
1005 self.window.modifiers = mouse_move.modifiers;
1006 PlatformInput::MouseMove(mouse_move)
1007 }
1008 PlatformInput::MouseDown(mouse_down) => {
1009 self.window.mouse_position = mouse_down.position;
1010 self.window.modifiers = mouse_down.modifiers;
1011 PlatformInput::MouseDown(mouse_down)
1012 }
1013 PlatformInput::MouseUp(mouse_up) => {
1014 self.window.mouse_position = mouse_up.position;
1015 self.window.modifiers = mouse_up.modifiers;
1016 PlatformInput::MouseUp(mouse_up)
1017 }
1018 PlatformInput::MouseExited(mouse_exited) => {
1019 self.window.modifiers = mouse_exited.modifiers;
1020 PlatformInput::MouseExited(mouse_exited)
1021 }
1022 PlatformInput::ModifiersChanged(modifiers_changed) => {
1023 self.window.modifiers = modifiers_changed.modifiers;
1024 PlatformInput::ModifiersChanged(modifiers_changed)
1025 }
1026 PlatformInput::ScrollWheel(scroll_wheel) => {
1027 self.window.mouse_position = scroll_wheel.position;
1028 self.window.modifiers = scroll_wheel.modifiers;
1029 PlatformInput::ScrollWheel(scroll_wheel)
1030 }
1031 // Translate dragging and dropping of external files from the operating system
1032 // to internal drag and drop events.
1033 PlatformInput::FileDrop(file_drop) => match file_drop {
1034 FileDropEvent::Entered { position, paths } => {
1035 self.window.mouse_position = position;
1036 if self.active_drag.is_none() {
1037 self.active_drag = Some(AnyDrag {
1038 value: Box::new(paths.clone()),
1039 view: self.new_view(|_| paths).into(),
1040 cursor_offset: position,
1041 });
1042 }
1043 PlatformInput::MouseMove(MouseMoveEvent {
1044 position,
1045 pressed_button: Some(MouseButton::Left),
1046 modifiers: Modifiers::default(),
1047 })
1048 }
1049 FileDropEvent::Pending { position } => {
1050 self.window.mouse_position = position;
1051 PlatformInput::MouseMove(MouseMoveEvent {
1052 position,
1053 pressed_button: Some(MouseButton::Left),
1054 modifiers: Modifiers::default(),
1055 })
1056 }
1057 FileDropEvent::Submit { position } => {
1058 self.activate(true);
1059 self.window.mouse_position = position;
1060 PlatformInput::MouseUp(MouseUpEvent {
1061 button: MouseButton::Left,
1062 position,
1063 modifiers: Modifiers::default(),
1064 click_count: 1,
1065 })
1066 }
1067 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1068 button: MouseButton::Left,
1069 position: Point::default(),
1070 modifiers: Modifiers::default(),
1071 click_count: 1,
1072 }),
1073 },
1074 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1075 };
1076
1077 if let Some(any_mouse_event) = event.mouse_event() {
1078 self.dispatch_mouse_event(any_mouse_event);
1079 } else if let Some(any_key_event) = event.keyboard_event() {
1080 self.dispatch_key_event(any_key_event);
1081 }
1082
1083 !self.app.propagate_event
1084 }
1085
1086 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1087 if let Some(mut handlers) = self
1088 .window
1089 .rendered_frame
1090 .mouse_listeners
1091 .remove(&event.type_id())
1092 {
1093 // Because handlers may add other handlers, we sort every time.
1094 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1095
1096 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1097 // special purposes, such as detecting events outside of a given Bounds.
1098 for (_, _, handler) in &mut handlers {
1099 self.with_element_context(|cx| {
1100 handler(event, DispatchPhase::Capture, cx);
1101 });
1102 if !self.app.propagate_event {
1103 break;
1104 }
1105 }
1106
1107 // Bubble phase, where most normal handlers do their work.
1108 if self.app.propagate_event {
1109 for (_, _, handler) in handlers.iter_mut().rev() {
1110 self.with_element_context(|cx| {
1111 handler(event, DispatchPhase::Bubble, cx);
1112 });
1113 if !self.app.propagate_event {
1114 break;
1115 }
1116 }
1117 }
1118
1119 self.window
1120 .rendered_frame
1121 .mouse_listeners
1122 .insert(event.type_id(), handlers);
1123 }
1124
1125 if self.app.propagate_event && self.has_active_drag() {
1126 if event.is::<MouseMoveEvent>() {
1127 // If this was a mouse move event, redraw the window so that the
1128 // active drag can follow the mouse cursor.
1129 self.refresh();
1130 } else if event.is::<MouseUpEvent>() {
1131 // If this was a mouse up event, cancel the active drag and redraw
1132 // the window.
1133 self.active_drag = None;
1134 self.refresh();
1135 }
1136 }
1137 }
1138
1139 fn dispatch_key_event(&mut self, event: &dyn Any) {
1140 let node_id = self
1141 .window
1142 .focus
1143 .and_then(|focus_id| {
1144 self.window
1145 .rendered_frame
1146 .dispatch_tree
1147 .focusable_node_id(focus_id)
1148 })
1149 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1150
1151 let dispatch_path = self
1152 .window
1153 .rendered_frame
1154 .dispatch_tree
1155 .dispatch_path(node_id);
1156
1157 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1158
1159 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1160 for node_id in &dispatch_path {
1161 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1162
1163 if let Some(context) = node.context.clone() {
1164 context_stack.push(context);
1165 }
1166 }
1167
1168 for node_id in dispatch_path.iter().rev() {
1169 // Match keystrokes
1170 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1171 if node.context.is_some() {
1172 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1173 let mut new_actions = self
1174 .window
1175 .rendered_frame
1176 .dispatch_tree
1177 .dispatch_key(&key_down_event.keystroke, &context_stack);
1178 actions.append(&mut new_actions);
1179 }
1180
1181 context_stack.pop();
1182 }
1183 }
1184
1185 if !actions.is_empty() {
1186 self.clear_pending_keystrokes();
1187 }
1188
1189 self.propagate_event = true;
1190 for action in actions {
1191 self.dispatch_action_on_node(node_id, action.boxed_clone());
1192 if !self.propagate_event {
1193 self.dispatch_keystroke_observers(event, Some(action));
1194 return;
1195 }
1196 }
1197
1198 // Capture phase
1199 for node_id in &dispatch_path {
1200 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1201
1202 for key_listener in node.key_listeners.clone() {
1203 self.with_element_context(|cx| {
1204 key_listener(event, DispatchPhase::Capture, cx);
1205 });
1206 if !self.propagate_event {
1207 return;
1208 }
1209 }
1210 }
1211
1212 // Bubble phase
1213 for node_id in dispatch_path.iter().rev() {
1214 // Handle low level key events
1215 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1216 for key_listener in node.key_listeners.clone() {
1217 self.with_element_context(|cx| {
1218 key_listener(event, DispatchPhase::Bubble, cx);
1219 });
1220 if !self.propagate_event {
1221 return;
1222 }
1223 }
1224 }
1225
1226 self.dispatch_keystroke_observers(event, None);
1227 }
1228
1229 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1230 pub fn has_pending_keystrokes(&self) -> bool {
1231 self.window
1232 .rendered_frame
1233 .dispatch_tree
1234 .has_pending_keystrokes()
1235 }
1236
1237 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1238 let dispatch_path = self
1239 .window
1240 .rendered_frame
1241 .dispatch_tree
1242 .dispatch_path(node_id);
1243
1244 // Capture phase
1245 for node_id in &dispatch_path {
1246 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1247 for DispatchActionListener {
1248 action_type,
1249 listener,
1250 } in node.action_listeners.clone()
1251 {
1252 let any_action = action.as_any();
1253 if action_type == any_action.type_id() {
1254 self.with_element_context(|cx| {
1255 listener(any_action, DispatchPhase::Capture, cx);
1256 });
1257
1258 if !self.propagate_event {
1259 return;
1260 }
1261 }
1262 }
1263 }
1264 // Bubble phase
1265 for node_id in dispatch_path.iter().rev() {
1266 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1267 for DispatchActionListener {
1268 action_type,
1269 listener,
1270 } in node.action_listeners.clone()
1271 {
1272 let any_action = action.as_any();
1273 if action_type == any_action.type_id() {
1274 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1275
1276 self.with_element_context(|cx| {
1277 listener(any_action, DispatchPhase::Bubble, cx);
1278 });
1279
1280 if !self.propagate_event {
1281 return;
1282 }
1283 }
1284 }
1285 }
1286 }
1287
1288 /// Register the given handler to be invoked whenever the global of the given type
1289 /// is updated.
1290 pub fn observe_global<G: 'static>(
1291 &mut self,
1292 f: impl Fn(&mut WindowContext<'_>) + 'static,
1293 ) -> Subscription {
1294 let window_handle = self.window.handle;
1295 let (subscription, activate) = self.global_observers.insert(
1296 TypeId::of::<G>(),
1297 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1298 );
1299 self.app.defer(move |_| activate());
1300 subscription
1301 }
1302
1303 /// Focus the current window and bring it to the foreground at the platform level.
1304 pub fn activate_window(&self) {
1305 self.window.platform_window.activate();
1306 }
1307
1308 /// Minimize the current window at the platform level.
1309 pub fn minimize_window(&self) {
1310 self.window.platform_window.minimize();
1311 }
1312
1313 /// Toggle full screen status on the current window at the platform level.
1314 pub fn toggle_full_screen(&self) {
1315 self.window.platform_window.toggle_full_screen();
1316 }
1317
1318 /// Present a platform dialog.
1319 /// The provided message will be presented, along with buttons for each answer.
1320 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1321 pub fn prompt(
1322 &self,
1323 level: PromptLevel,
1324 message: &str,
1325 answers: &[&str],
1326 ) -> oneshot::Receiver<usize> {
1327 self.window.platform_window.prompt(level, message, answers)
1328 }
1329
1330 /// Returns all available actions for the focused element.
1331 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1332 let node_id = self
1333 .window
1334 .focus
1335 .and_then(|focus_id| {
1336 self.window
1337 .rendered_frame
1338 .dispatch_tree
1339 .focusable_node_id(focus_id)
1340 })
1341 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1342
1343 self.window
1344 .rendered_frame
1345 .dispatch_tree
1346 .available_actions(node_id)
1347 }
1348
1349 /// Returns key bindings that invoke the given action on the currently focused element.
1350 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1351 self.window
1352 .rendered_frame
1353 .dispatch_tree
1354 .bindings_for_action(
1355 action,
1356 &self.window.rendered_frame.dispatch_tree.context_stack,
1357 )
1358 }
1359
1360 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1361 pub fn bindings_for_action_in(
1362 &self,
1363 action: &dyn Action,
1364 focus_handle: &FocusHandle,
1365 ) -> Vec<KeyBinding> {
1366 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1367
1368 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1369 return vec![];
1370 };
1371 let context_stack = dispatch_tree
1372 .dispatch_path(node_id)
1373 .into_iter()
1374 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1375 .collect();
1376 dispatch_tree.bindings_for_action(action, &context_stack)
1377 }
1378
1379 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1380 pub fn listener_for<V: Render, E>(
1381 &self,
1382 view: &View<V>,
1383 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1384 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1385 let view = view.downgrade();
1386 move |e: &E, cx: &mut WindowContext| {
1387 view.update(cx, |view, cx| f(view, e, cx)).ok();
1388 }
1389 }
1390
1391 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1392 pub fn handler_for<V: Render>(
1393 &self,
1394 view: &View<V>,
1395 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1396 ) -> impl Fn(&mut WindowContext) {
1397 let view = view.downgrade();
1398 move |cx: &mut WindowContext| {
1399 view.update(cx, |view, cx| f(view, cx)).ok();
1400 }
1401 }
1402
1403 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1404 /// If the callback returns false, the window won't be closed.
1405 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1406 let mut this = self.to_async();
1407 self.window
1408 .platform_window
1409 .on_should_close(Box::new(move || {
1410 this.update(|cx| {
1411 // Ensure that the window is removed from the app if it's been closed
1412 // by always pre-empting the system close event.
1413 if f(cx) {
1414 cx.remove_window();
1415 }
1416 false
1417 })
1418 .unwrap_or(true)
1419 }))
1420 }
1421
1422 pub(crate) fn parent_view_id(&self) -> EntityId {
1423 *self
1424 .window
1425 .next_frame
1426 .view_stack
1427 .last()
1428 .expect("a view should always be on the stack while drawing")
1429 }
1430
1431 /// Register an action listener on the window for the next frame. The type of action
1432 /// is determined by the first parameter of the given listener. When the next frame is rendered
1433 /// the listener will be cleared.
1434 ///
1435 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1436 /// a specific need to register a global listener.
1437 pub fn on_action(
1438 &mut self,
1439 action_type: TypeId,
1440 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1441 ) {
1442 self.window
1443 .next_frame
1444 .dispatch_tree
1445 .on_action(action_type, Rc::new(listener));
1446 }
1447}
1448
1449impl Context for WindowContext<'_> {
1450 type Result<T> = T;
1451
1452 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1453 where
1454 T: 'static,
1455 {
1456 let slot = self.app.entities.reserve();
1457 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1458 self.entities.insert(slot, model)
1459 }
1460
1461 fn update_model<T: 'static, R>(
1462 &mut self,
1463 model: &Model<T>,
1464 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1465 ) -> R {
1466 let mut entity = self.entities.lease(model);
1467 let result = update(
1468 &mut *entity,
1469 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1470 );
1471 self.entities.end_lease(entity);
1472 result
1473 }
1474
1475 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1476 where
1477 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1478 {
1479 if window == self.window.handle {
1480 let root_view = self.window.root_view.clone().unwrap();
1481 Ok(update(root_view, self))
1482 } else {
1483 window.update(self.app, update)
1484 }
1485 }
1486
1487 fn read_model<T, R>(
1488 &self,
1489 handle: &Model<T>,
1490 read: impl FnOnce(&T, &AppContext) -> R,
1491 ) -> Self::Result<R>
1492 where
1493 T: 'static,
1494 {
1495 let entity = self.entities.read(handle);
1496 read(entity, &*self.app)
1497 }
1498
1499 fn read_window<T, R>(
1500 &self,
1501 window: &WindowHandle<T>,
1502 read: impl FnOnce(View<T>, &AppContext) -> R,
1503 ) -> Result<R>
1504 where
1505 T: 'static,
1506 {
1507 if window.any_handle == self.window.handle {
1508 let root_view = self
1509 .window
1510 .root_view
1511 .clone()
1512 .unwrap()
1513 .downcast::<T>()
1514 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1515 Ok(read(root_view, self))
1516 } else {
1517 self.app.read_window(window, read)
1518 }
1519 }
1520}
1521
1522impl VisualContext for WindowContext<'_> {
1523 fn new_view<V>(
1524 &mut self,
1525 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1526 ) -> Self::Result<View<V>>
1527 where
1528 V: 'static + Render,
1529 {
1530 let slot = self.app.entities.reserve();
1531 let view = View {
1532 model: slot.clone(),
1533 };
1534 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1535 let entity = build_view_state(&mut cx);
1536 cx.entities.insert(slot, entity);
1537
1538 cx.new_view_observers
1539 .clone()
1540 .retain(&TypeId::of::<V>(), |observer| {
1541 let any_view = AnyView::from(view.clone());
1542 (observer)(any_view, self);
1543 true
1544 });
1545
1546 view
1547 }
1548
1549 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1550 fn update_view<T: 'static, R>(
1551 &mut self,
1552 view: &View<T>,
1553 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1554 ) -> Self::Result<R> {
1555 let mut lease = self.app.entities.lease(&view.model);
1556 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1557 let result = update(&mut *lease, &mut cx);
1558 cx.app.entities.end_lease(lease);
1559 result
1560 }
1561
1562 fn replace_root_view<V>(
1563 &mut self,
1564 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1565 ) -> Self::Result<View<V>>
1566 where
1567 V: 'static + Render,
1568 {
1569 let view = self.new_view(build_view);
1570 self.window.root_view = Some(view.clone().into());
1571 self.refresh();
1572 view
1573 }
1574
1575 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1576 self.update_view(view, |view, cx| {
1577 view.focus_handle(cx).clone().focus(cx);
1578 })
1579 }
1580
1581 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1582 where
1583 V: ManagedView,
1584 {
1585 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1586 }
1587}
1588
1589impl<'a> std::ops::Deref for WindowContext<'a> {
1590 type Target = AppContext;
1591
1592 fn deref(&self) -> &Self::Target {
1593 self.app
1594 }
1595}
1596
1597impl<'a> std::ops::DerefMut for WindowContext<'a> {
1598 fn deref_mut(&mut self) -> &mut Self::Target {
1599 self.app
1600 }
1601}
1602
1603impl<'a> Borrow<AppContext> for WindowContext<'a> {
1604 fn borrow(&self) -> &AppContext {
1605 self.app
1606 }
1607}
1608
1609impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1610 fn borrow_mut(&mut self) -> &mut AppContext {
1611 self.app
1612 }
1613}
1614
1615/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1616pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1617 #[doc(hidden)]
1618 fn app_mut(&mut self) -> &mut AppContext {
1619 self.borrow_mut()
1620 }
1621
1622 #[doc(hidden)]
1623 fn app(&self) -> &AppContext {
1624 self.borrow()
1625 }
1626
1627 #[doc(hidden)]
1628 fn window(&self) -> &Window {
1629 self.borrow()
1630 }
1631
1632 #[doc(hidden)]
1633 fn window_mut(&mut self) -> &mut Window {
1634 self.borrow_mut()
1635 }
1636}
1637
1638impl Borrow<Window> for WindowContext<'_> {
1639 fn borrow(&self) -> &Window {
1640 self.window
1641 }
1642}
1643
1644impl BorrowMut<Window> for WindowContext<'_> {
1645 fn borrow_mut(&mut self) -> &mut Window {
1646 self.window
1647 }
1648}
1649
1650impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1651
1652/// Provides access to application state that is specialized for a particular [`View`].
1653/// Allows you to interact with focus, emit events, etc.
1654/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1655/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1656pub struct ViewContext<'a, V> {
1657 window_cx: WindowContext<'a>,
1658 view: &'a View<V>,
1659}
1660
1661impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1662 fn borrow(&self) -> &AppContext {
1663 &*self.window_cx.app
1664 }
1665}
1666
1667impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1668 fn borrow_mut(&mut self) -> &mut AppContext {
1669 &mut *self.window_cx.app
1670 }
1671}
1672
1673impl<V> Borrow<Window> for ViewContext<'_, V> {
1674 fn borrow(&self) -> &Window {
1675 &*self.window_cx.window
1676 }
1677}
1678
1679impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1680 fn borrow_mut(&mut self) -> &mut Window {
1681 &mut *self.window_cx.window
1682 }
1683}
1684
1685impl<'a, V: 'static> ViewContext<'a, V> {
1686 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1687 Self {
1688 window_cx: WindowContext::new(app, window),
1689 view,
1690 }
1691 }
1692
1693 /// Get the entity_id of this view.
1694 pub fn entity_id(&self) -> EntityId {
1695 self.view.entity_id()
1696 }
1697
1698 /// Get the view pointer underlying this context.
1699 pub fn view(&self) -> &View<V> {
1700 self.view
1701 }
1702
1703 /// Get the model underlying this view.
1704 pub fn model(&self) -> &Model<V> {
1705 &self.view.model
1706 }
1707
1708 /// Access the underlying window context.
1709 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1710 &mut self.window_cx
1711 }
1712
1713 /// Sets a given callback to be run on the next frame.
1714 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1715 where
1716 V: 'static,
1717 {
1718 let view = self.view().clone();
1719 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1720 }
1721
1722 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1723 /// that are currently on the stack to be returned to the app.
1724 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1725 let view = self.view().downgrade();
1726 self.window_cx.defer(move |cx| {
1727 view.update(cx, f).ok();
1728 });
1729 }
1730
1731 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1732 pub fn observe<V2, E>(
1733 &mut self,
1734 entity: &E,
1735 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1736 ) -> Subscription
1737 where
1738 V2: 'static,
1739 V: 'static,
1740 E: Entity<V2>,
1741 {
1742 let view = self.view().downgrade();
1743 let entity_id = entity.entity_id();
1744 let entity = entity.downgrade();
1745 let window_handle = self.window.handle;
1746 let (subscription, activate) = self.app.observers.insert(
1747 entity_id,
1748 Box::new(move |cx| {
1749 window_handle
1750 .update(cx, |_, cx| {
1751 if let Some(handle) = E::upgrade_from(&entity) {
1752 view.update(cx, |this, cx| on_notify(this, handle, cx))
1753 .is_ok()
1754 } else {
1755 false
1756 }
1757 })
1758 .unwrap_or(false)
1759 }),
1760 );
1761 self.app.defer(move |_| activate());
1762 subscription
1763 }
1764
1765 /// Subscribe to events emitted by another model or view.
1766 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1767 /// 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.
1768 pub fn subscribe<V2, E, Evt>(
1769 &mut self,
1770 entity: &E,
1771 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1772 ) -> Subscription
1773 where
1774 V2: EventEmitter<Evt>,
1775 E: Entity<V2>,
1776 Evt: 'static,
1777 {
1778 let view = self.view().downgrade();
1779 let entity_id = entity.entity_id();
1780 let handle = entity.downgrade();
1781 let window_handle = self.window.handle;
1782 let (subscription, activate) = self.app.event_listeners.insert(
1783 entity_id,
1784 (
1785 TypeId::of::<Evt>(),
1786 Box::new(move |event, cx| {
1787 window_handle
1788 .update(cx, |_, cx| {
1789 if let Some(handle) = E::upgrade_from(&handle) {
1790 let event = event.downcast_ref().expect("invalid event type");
1791 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1792 .is_ok()
1793 } else {
1794 false
1795 }
1796 })
1797 .unwrap_or(false)
1798 }),
1799 ),
1800 );
1801 self.app.defer(move |_| activate());
1802 subscription
1803 }
1804
1805 /// Register a callback to be invoked when the view is released.
1806 ///
1807 /// The callback receives a handle to the view's window. This handle may be
1808 /// invalid, if the window was closed before the view was released.
1809 pub fn on_release(
1810 &mut self,
1811 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1812 ) -> Subscription {
1813 let window_handle = self.window.handle;
1814 let (subscription, activate) = self.app.release_listeners.insert(
1815 self.view.model.entity_id,
1816 Box::new(move |this, cx| {
1817 let this = this.downcast_mut().expect("invalid entity type");
1818 on_release(this, window_handle, cx)
1819 }),
1820 );
1821 activate();
1822 subscription
1823 }
1824
1825 /// Register a callback to be invoked when the given Model or View is released.
1826 pub fn observe_release<V2, E>(
1827 &mut self,
1828 entity: &E,
1829 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1830 ) -> Subscription
1831 where
1832 V: 'static,
1833 V2: 'static,
1834 E: Entity<V2>,
1835 {
1836 let view = self.view().downgrade();
1837 let entity_id = entity.entity_id();
1838 let window_handle = self.window.handle;
1839 let (subscription, activate) = self.app.release_listeners.insert(
1840 entity_id,
1841 Box::new(move |entity, cx| {
1842 let entity = entity.downcast_mut().expect("invalid entity type");
1843 let _ = window_handle.update(cx, |_, cx| {
1844 view.update(cx, |this, cx| on_release(this, entity, cx))
1845 });
1846 }),
1847 );
1848 activate();
1849 subscription
1850 }
1851
1852 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
1853 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
1854 pub fn notify(&mut self) {
1855 for view_id in self
1856 .window
1857 .rendered_frame
1858 .dispatch_tree
1859 .view_path(self.view.entity_id())
1860 .into_iter()
1861 .rev()
1862 {
1863 if !self.window.dirty_views.insert(view_id) {
1864 break;
1865 }
1866 }
1867
1868 if !self.window.drawing {
1869 self.window_cx.window.dirty = true;
1870 self.window_cx.app.push_effect(Effect::Notify {
1871 emitter: self.view.model.entity_id,
1872 });
1873 }
1874 }
1875
1876 /// Register a callback to be invoked when the window is resized.
1877 pub fn observe_window_bounds(
1878 &mut self,
1879 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1880 ) -> Subscription {
1881 let view = self.view.downgrade();
1882 let (subscription, activate) = self.window.bounds_observers.insert(
1883 (),
1884 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1885 );
1886 activate();
1887 subscription
1888 }
1889
1890 /// Register a callback to be invoked when the window is activated or deactivated.
1891 pub fn observe_window_activation(
1892 &mut self,
1893 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1894 ) -> Subscription {
1895 let view = self.view.downgrade();
1896 let (subscription, activate) = self.window.activation_observers.insert(
1897 (),
1898 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1899 );
1900 activate();
1901 subscription
1902 }
1903
1904 /// Register a listener to be called when the given focus handle receives focus.
1905 /// Returns a subscription and persists until the subscription is dropped.
1906 pub fn on_focus(
1907 &mut self,
1908 handle: &FocusHandle,
1909 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1910 ) -> Subscription {
1911 let view = self.view.downgrade();
1912 let focus_id = handle.id;
1913 let (subscription, activate) = self.window.focus_listeners.insert(
1914 (),
1915 Box::new(move |event, cx| {
1916 view.update(cx, |view, cx| {
1917 if event.previous_focus_path.last() != Some(&focus_id)
1918 && event.current_focus_path.last() == Some(&focus_id)
1919 {
1920 listener(view, cx)
1921 }
1922 })
1923 .is_ok()
1924 }),
1925 );
1926 self.app.defer(move |_| activate());
1927 subscription
1928 }
1929
1930 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
1931 /// Returns a subscription and persists until the subscription is dropped.
1932 pub fn on_focus_in(
1933 &mut self,
1934 handle: &FocusHandle,
1935 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1936 ) -> Subscription {
1937 let view = self.view.downgrade();
1938 let focus_id = handle.id;
1939 let (subscription, activate) = self.window.focus_listeners.insert(
1940 (),
1941 Box::new(move |event, cx| {
1942 view.update(cx, |view, cx| {
1943 if !event.previous_focus_path.contains(&focus_id)
1944 && event.current_focus_path.contains(&focus_id)
1945 {
1946 listener(view, cx)
1947 }
1948 })
1949 .is_ok()
1950 }),
1951 );
1952 self.app.defer(move |_| activate());
1953 subscription
1954 }
1955
1956 /// Register a listener to be called when the given focus handle loses focus.
1957 /// Returns a subscription and persists until the subscription is dropped.
1958 pub fn on_blur(
1959 &mut self,
1960 handle: &FocusHandle,
1961 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1962 ) -> Subscription {
1963 let view = self.view.downgrade();
1964 let focus_id = handle.id;
1965 let (subscription, activate) = self.window.focus_listeners.insert(
1966 (),
1967 Box::new(move |event, cx| {
1968 view.update(cx, |view, cx| {
1969 if event.previous_focus_path.last() == Some(&focus_id)
1970 && event.current_focus_path.last() != Some(&focus_id)
1971 {
1972 listener(view, cx)
1973 }
1974 })
1975 .is_ok()
1976 }),
1977 );
1978 self.app.defer(move |_| activate());
1979 subscription
1980 }
1981
1982 /// Register a listener to be called when nothing in the window has focus.
1983 /// This typically happens when the node that was focused is removed from the tree,
1984 /// and this callback lets you chose a default place to restore the users focus.
1985 /// Returns a subscription and persists until the subscription is dropped.
1986 pub fn on_focus_lost(
1987 &mut self,
1988 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1989 ) -> Subscription {
1990 let view = self.view.downgrade();
1991 let (subscription, activate) = self.window.focus_lost_listeners.insert(
1992 (),
1993 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
1994 );
1995 activate();
1996 subscription
1997 }
1998
1999 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2000 /// Returns a subscription and persists until the subscription is dropped.
2001 pub fn on_focus_out(
2002 &mut self,
2003 handle: &FocusHandle,
2004 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2005 ) -> Subscription {
2006 let view = self.view.downgrade();
2007 let focus_id = handle.id;
2008 let (subscription, activate) = self.window.focus_listeners.insert(
2009 (),
2010 Box::new(move |event, cx| {
2011 view.update(cx, |view, cx| {
2012 if event.previous_focus_path.contains(&focus_id)
2013 && !event.current_focus_path.contains(&focus_id)
2014 {
2015 listener(view, cx)
2016 }
2017 })
2018 .is_ok()
2019 }),
2020 );
2021 self.app.defer(move |_| activate());
2022 subscription
2023 }
2024
2025 /// Schedule a future to be run asynchronously.
2026 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2027 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2028 /// The returned future will be polled on the main thread.
2029 pub fn spawn<Fut, R>(
2030 &mut self,
2031 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2032 ) -> Task<R>
2033 where
2034 R: 'static,
2035 Fut: Future<Output = R> + 'static,
2036 {
2037 let view = self.view().downgrade();
2038 self.window_cx.spawn(|cx| f(view, cx))
2039 }
2040
2041 /// Updates the global state of the given type.
2042 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2043 where
2044 G: 'static,
2045 {
2046 let mut global = self.app.lease_global::<G>();
2047 let result = f(&mut global, self);
2048 self.app.end_global_lease(global);
2049 result
2050 }
2051
2052 /// Register a callback to be invoked when the given global state changes.
2053 pub fn observe_global<G: 'static>(
2054 &mut self,
2055 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2056 ) -> Subscription {
2057 let window_handle = self.window.handle;
2058 let view = self.view().downgrade();
2059 let (subscription, activate) = self.global_observers.insert(
2060 TypeId::of::<G>(),
2061 Box::new(move |cx| {
2062 window_handle
2063 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2064 .unwrap_or(false)
2065 }),
2066 );
2067 self.app.defer(move |_| activate());
2068 subscription
2069 }
2070
2071 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2072 pub fn on_action(
2073 &mut self,
2074 action_type: TypeId,
2075 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2076 ) {
2077 let handle = self.view().clone();
2078 self.window_cx
2079 .on_action(action_type, move |action, phase, cx| {
2080 handle.update(cx, |view, cx| {
2081 listener(view, action, phase, cx);
2082 })
2083 });
2084 }
2085
2086 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2087 pub fn emit<Evt>(&mut self, event: Evt)
2088 where
2089 Evt: 'static,
2090 V: EventEmitter<Evt>,
2091 {
2092 let emitter = self.view.model.entity_id;
2093 self.app.push_effect(Effect::Emit {
2094 emitter,
2095 event_type: TypeId::of::<Evt>(),
2096 event: Box::new(event),
2097 });
2098 }
2099
2100 /// Move focus to the current view, assuming it implements [`FocusableView`].
2101 pub fn focus_self(&mut self)
2102 where
2103 V: FocusableView,
2104 {
2105 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2106 }
2107
2108 /// Convenience method for accessing view state in an event callback.
2109 ///
2110 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2111 /// but it's often useful to be able to access view state in these
2112 /// callbacks. This method provides a convenient way to do so.
2113 pub fn listener<E>(
2114 &self,
2115 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2116 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2117 let view = self.view().downgrade();
2118 move |e: &E, cx: &mut WindowContext| {
2119 view.update(cx, |view, cx| f(view, e, cx)).ok();
2120 }
2121 }
2122}
2123
2124impl<V> Context for ViewContext<'_, V> {
2125 type Result<U> = U;
2126
2127 fn new_model<T: 'static>(
2128 &mut self,
2129 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2130 ) -> Model<T> {
2131 self.window_cx.new_model(build_model)
2132 }
2133
2134 fn update_model<T: 'static, R>(
2135 &mut self,
2136 model: &Model<T>,
2137 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2138 ) -> R {
2139 self.window_cx.update_model(model, update)
2140 }
2141
2142 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2143 where
2144 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2145 {
2146 self.window_cx.update_window(window, update)
2147 }
2148
2149 fn read_model<T, R>(
2150 &self,
2151 handle: &Model<T>,
2152 read: impl FnOnce(&T, &AppContext) -> R,
2153 ) -> Self::Result<R>
2154 where
2155 T: 'static,
2156 {
2157 self.window_cx.read_model(handle, read)
2158 }
2159
2160 fn read_window<T, R>(
2161 &self,
2162 window: &WindowHandle<T>,
2163 read: impl FnOnce(View<T>, &AppContext) -> R,
2164 ) -> Result<R>
2165 where
2166 T: 'static,
2167 {
2168 self.window_cx.read_window(window, read)
2169 }
2170}
2171
2172impl<V: 'static> VisualContext for ViewContext<'_, V> {
2173 fn new_view<W: Render + 'static>(
2174 &mut self,
2175 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2176 ) -> Self::Result<View<W>> {
2177 self.window_cx.new_view(build_view_state)
2178 }
2179
2180 fn update_view<V2: 'static, R>(
2181 &mut self,
2182 view: &View<V2>,
2183 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2184 ) -> Self::Result<R> {
2185 self.window_cx.update_view(view, update)
2186 }
2187
2188 fn replace_root_view<W>(
2189 &mut self,
2190 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2191 ) -> Self::Result<View<W>>
2192 where
2193 W: 'static + Render,
2194 {
2195 self.window_cx.replace_root_view(build_view)
2196 }
2197
2198 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2199 self.window_cx.focus_view(view)
2200 }
2201
2202 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2203 self.window_cx.dismiss_view(view)
2204 }
2205}
2206
2207impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2208 type Target = WindowContext<'a>;
2209
2210 fn deref(&self) -> &Self::Target {
2211 &self.window_cx
2212 }
2213}
2214
2215impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2216 fn deref_mut(&mut self) -> &mut Self::Target {
2217 &mut self.window_cx
2218 }
2219}
2220
2221// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2222slotmap::new_key_type! {
2223 /// A unique identifier for a window.
2224 pub struct WindowId;
2225}
2226
2227impl WindowId {
2228 /// Converts this window ID to a `u64`.
2229 pub fn as_u64(&self) -> u64 {
2230 self.0.as_ffi()
2231 }
2232}
2233
2234/// A handle to a window with a specific root view type.
2235/// Note that this does not keep the window alive on its own.
2236#[derive(Deref, DerefMut)]
2237pub struct WindowHandle<V> {
2238 #[deref]
2239 #[deref_mut]
2240 pub(crate) any_handle: AnyWindowHandle,
2241 state_type: PhantomData<V>,
2242}
2243
2244impl<V: 'static + Render> WindowHandle<V> {
2245 /// Creates a new handle from a window ID.
2246 /// This does not check if the root type of the window is `V`.
2247 pub fn new(id: WindowId) -> Self {
2248 WindowHandle {
2249 any_handle: AnyWindowHandle {
2250 id,
2251 state_type: TypeId::of::<V>(),
2252 },
2253 state_type: PhantomData,
2254 }
2255 }
2256
2257 /// Get the root view out of this window.
2258 ///
2259 /// This will fail if the window is closed or if the root view's type does not match `V`.
2260 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2261 where
2262 C: Context,
2263 {
2264 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2265 root_view
2266 .downcast::<V>()
2267 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2268 }))
2269 }
2270
2271 /// Updates the root view of this window.
2272 ///
2273 /// This will fail if the window has been closed or if the root view's type does not match
2274 pub fn update<C, R>(
2275 &self,
2276 cx: &mut C,
2277 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2278 ) -> Result<R>
2279 where
2280 C: Context,
2281 {
2282 cx.update_window(self.any_handle, |root_view, cx| {
2283 let view = root_view
2284 .downcast::<V>()
2285 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2286 Ok(cx.update_view(&view, update))
2287 })?
2288 }
2289
2290 /// Read the root view out of this window.
2291 ///
2292 /// This will fail if the window is closed or if the root view's type does not match `V`.
2293 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2294 let x = cx
2295 .windows
2296 .get(self.id)
2297 .and_then(|window| {
2298 window
2299 .as_ref()
2300 .and_then(|window| window.root_view.clone())
2301 .map(|root_view| root_view.downcast::<V>())
2302 })
2303 .ok_or_else(|| anyhow!("window not found"))?
2304 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2305
2306 Ok(x.read(cx))
2307 }
2308
2309 /// Read the root view out of this window, with a callback
2310 ///
2311 /// This will fail if the window is closed or if the root view's type does not match `V`.
2312 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2313 where
2314 C: Context,
2315 {
2316 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2317 }
2318
2319 /// Read the root view pointer off of this window.
2320 ///
2321 /// This will fail if the window is closed or if the root view's type does not match `V`.
2322 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2323 where
2324 C: Context,
2325 {
2326 cx.read_window(self, |root_view, _cx| root_view.clone())
2327 }
2328
2329 /// Check if this window is 'active'.
2330 ///
2331 /// Will return `None` if the window is closed.
2332 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2333 cx.windows
2334 .get(self.id)
2335 .and_then(|window| window.as_ref().map(|window| window.active))
2336 }
2337}
2338
2339impl<V> Copy for WindowHandle<V> {}
2340
2341impl<V> Clone for WindowHandle<V> {
2342 fn clone(&self) -> Self {
2343 *self
2344 }
2345}
2346
2347impl<V> PartialEq for WindowHandle<V> {
2348 fn eq(&self, other: &Self) -> bool {
2349 self.any_handle == other.any_handle
2350 }
2351}
2352
2353impl<V> Eq for WindowHandle<V> {}
2354
2355impl<V> Hash for WindowHandle<V> {
2356 fn hash<H: Hasher>(&self, state: &mut H) {
2357 self.any_handle.hash(state);
2358 }
2359}
2360
2361impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2362 fn from(val: WindowHandle<V>) -> Self {
2363 val.any_handle
2364 }
2365}
2366
2367/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2368#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2369pub struct AnyWindowHandle {
2370 pub(crate) id: WindowId,
2371 state_type: TypeId,
2372}
2373
2374impl AnyWindowHandle {
2375 /// Get the ID of this window.
2376 pub fn window_id(&self) -> WindowId {
2377 self.id
2378 }
2379
2380 /// Attempt to convert this handle to a window handle with a specific root view type.
2381 /// If the types do not match, this will return `None`.
2382 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2383 if TypeId::of::<T>() == self.state_type {
2384 Some(WindowHandle {
2385 any_handle: *self,
2386 state_type: PhantomData,
2387 })
2388 } else {
2389 None
2390 }
2391 }
2392
2393 /// Updates the state of the root view of this window.
2394 ///
2395 /// This will fail if the window has been closed.
2396 pub fn update<C, R>(
2397 self,
2398 cx: &mut C,
2399 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2400 ) -> Result<R>
2401 where
2402 C: Context,
2403 {
2404 cx.update_window(self, update)
2405 }
2406
2407 /// Read the state of the root view of this window.
2408 ///
2409 /// This will fail if the window has been closed.
2410 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2411 where
2412 C: Context,
2413 T: 'static,
2414 {
2415 let view = self
2416 .downcast::<T>()
2417 .context("the type of the window's root view has changed")?;
2418
2419 cx.read_window(&view, read)
2420 }
2421}
2422
2423/// An identifier for an [`Element`](crate::Element).
2424///
2425/// Can be constructed with a string, a number, or both, as well
2426/// as other internal representations.
2427#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2428pub enum ElementId {
2429 /// The ID of a View element
2430 View(EntityId),
2431 /// An integer ID.
2432 Integer(usize),
2433 /// A string based ID.
2434 Name(SharedString),
2435 /// An ID that's equated with a focus handle.
2436 FocusHandle(FocusId),
2437 /// A combination of a name and an integer.
2438 NamedInteger(SharedString, usize),
2439}
2440
2441impl Display for ElementId {
2442 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2443 match self {
2444 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2445 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2446 ElementId::Name(name) => write!(f, "{}", name)?,
2447 ElementId::FocusHandle(__) => write!(f, "FocusHandle")?,
2448 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2449 }
2450
2451 Ok(())
2452 }
2453}
2454
2455impl ElementId {
2456 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2457 ElementId::View(entity_id)
2458 }
2459}
2460
2461impl TryInto<SharedString> for ElementId {
2462 type Error = anyhow::Error;
2463
2464 fn try_into(self) -> anyhow::Result<SharedString> {
2465 if let ElementId::Name(name) = self {
2466 Ok(name)
2467 } else {
2468 Err(anyhow!("element id is not string"))
2469 }
2470 }
2471}
2472
2473impl From<usize> for ElementId {
2474 fn from(id: usize) -> Self {
2475 ElementId::Integer(id)
2476 }
2477}
2478
2479impl From<i32> for ElementId {
2480 fn from(id: i32) -> Self {
2481 Self::Integer(id as usize)
2482 }
2483}
2484
2485impl From<SharedString> for ElementId {
2486 fn from(name: SharedString) -> Self {
2487 ElementId::Name(name)
2488 }
2489}
2490
2491impl From<&'static str> for ElementId {
2492 fn from(name: &'static str) -> Self {
2493 ElementId::Name(name.into())
2494 }
2495}
2496
2497impl<'a> From<&'a FocusHandle> for ElementId {
2498 fn from(handle: &'a FocusHandle) -> Self {
2499 ElementId::FocusHandle(handle.id)
2500 }
2501}
2502
2503impl From<(&'static str, EntityId)> for ElementId {
2504 fn from((name, id): (&'static str, EntityId)) -> Self {
2505 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2506 }
2507}
2508
2509impl From<(&'static str, usize)> for ElementId {
2510 fn from((name, id): (&'static str, usize)) -> Self {
2511 ElementId::NamedInteger(name.into(), id)
2512 }
2513}
2514
2515impl From<(&'static str, u64)> for ElementId {
2516 fn from((name, id): (&'static str, u64)) -> Self {
2517 ElementId::NamedInteger(name.into(), id as usize)
2518 }
2519}
2520
2521/// A rectangle to be rendered in the window at the given position and size.
2522/// Passed as an argument [`WindowContext::paint_quad`].
2523#[derive(Clone)]
2524pub struct PaintQuad {
2525 bounds: Bounds<Pixels>,
2526 corner_radii: Corners<Pixels>,
2527 background: Hsla,
2528 border_widths: Edges<Pixels>,
2529 border_color: Hsla,
2530}
2531
2532impl PaintQuad {
2533 /// Sets the corner radii of the quad.
2534 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2535 PaintQuad {
2536 corner_radii: corner_radii.into(),
2537 ..self
2538 }
2539 }
2540
2541 /// Sets the border widths of the quad.
2542 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2543 PaintQuad {
2544 border_widths: border_widths.into(),
2545 ..self
2546 }
2547 }
2548
2549 /// Sets the border color of the quad.
2550 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2551 PaintQuad {
2552 border_color: border_color.into(),
2553 ..self
2554 }
2555 }
2556
2557 /// Sets the background color of the quad.
2558 pub fn background(self, background: impl Into<Hsla>) -> Self {
2559 PaintQuad {
2560 background: background.into(),
2561 ..self
2562 }
2563 }
2564}
2565
2566/// Creates a quad with the given parameters.
2567pub fn quad(
2568 bounds: Bounds<Pixels>,
2569 corner_radii: impl Into<Corners<Pixels>>,
2570 background: impl Into<Hsla>,
2571 border_widths: impl Into<Edges<Pixels>>,
2572 border_color: impl Into<Hsla>,
2573) -> PaintQuad {
2574 PaintQuad {
2575 bounds,
2576 corner_radii: corner_radii.into(),
2577 background: background.into(),
2578 border_widths: border_widths.into(),
2579 border_color: border_color.into(),
2580 }
2581}
2582
2583/// Creates a filled quad with the given bounds and background color.
2584pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2585 PaintQuad {
2586 bounds: bounds.into(),
2587 corner_radii: (0.).into(),
2588 background: background.into(),
2589 border_widths: (0.).into(),
2590 border_color: transparent_black(),
2591 }
2592}
2593
2594/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2595pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2596 PaintQuad {
2597 bounds: bounds.into(),
2598 corner_radii: (0.).into(),
2599 background: transparent_black(),
2600 border_widths: (1.).into(),
2601 border_color: border_color.into(),
2602 }
2603}