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