1use crate::{
2 px, size, transparent_black, Action, AnyDrag, AnyView, AppContext, Arena, AsyncWindowContext,
3 AvailableSpace, Bounds, Context, Corners, CursorStyle, DispatchActionListener, DispatchNodeId,
4 DispatchTree, DisplayId, Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten,
5 GlobalElementId, Hsla, KeyBinding, KeyContext, KeyDownEvent, KeystrokeEvent, Model,
6 ModelContext, Modifiers, MouseButton, MouseMoveEvent, MouseUpEvent, Pixels, PlatformAtlas,
7 PlatformDisplay, PlatformInput, PlatformWindow, Point, PromptLevel, Render, ScaledPixels,
8 SharedString, Size, SubscriberSet, Subscription, TaffyLayoutEngine, Task, View, VisualContext,
9 WeakView, WindowBounds, WindowOptions,
10};
11use anyhow::{anyhow, Context as _, Result};
12use collections::FxHashSet;
13use derive_more::{Deref, DerefMut};
14use futures::{
15 channel::{mpsc, oneshot},
16 StreamExt,
17};
18use parking_lot::RwLock;
19use slotmap::SlotMap;
20use smallvec::SmallVec;
21use std::{
22 any::{Any, TypeId},
23 borrow::{Borrow, BorrowMut},
24 cell::RefCell,
25 collections::hash_map::Entry,
26 fmt::{Debug, Display},
27 future::Future,
28 hash::{Hash, Hasher},
29 marker::PhantomData,
30 mem,
31 rc::Rc,
32 sync::{
33 atomic::{AtomicUsize, Ordering::SeqCst},
34 Arc,
35 },
36};
37use util::{measure, ResultExt};
38
39mod element_cx;
40pub use element_cx::*;
41
42const ACTIVE_DRAG_Z_INDEX: u16 = 1;
43
44/// A global stacking order, which is created by stacking successive z-index values.
45/// Each z-index will always be interpreted in the context of its parent z-index.
46#[derive(Debug, Deref, DerefMut, Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
47pub struct StackingOrder(SmallVec<[StackingContext; 64]>);
48
49/// A single entry in a primitive's z-index stacking order
50#[derive(Clone, Ord, PartialOrd, PartialEq, Eq, Default)]
51pub struct StackingContext {
52 pub(crate) z_index: u16,
53 pub(crate) id: u16,
54}
55
56impl std::fmt::Debug for StackingContext {
57 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
58 write!(f, "{{{}.{}}} ", self.z_index, self.id)
59 }
60}
61
62/// Represents the two different phases when dispatching events.
63#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
64pub enum DispatchPhase {
65 /// After the capture phase comes the bubble phase, in which mouse event listeners are
66 /// invoked front to back and keyboard event listeners are invoked from the focused element
67 /// to the root of the element tree. This is the phase you'll most commonly want to use when
68 /// registering event listeners.
69 #[default]
70 Bubble,
71 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
72 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
73 /// is used for special purposes such as clearing the "pressed" state for click events. If
74 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
75 /// outside of the immediate region may rely on detecting non-local events during this phase.
76 Capture,
77}
78
79impl DispatchPhase {
80 /// Returns true if this represents the "bubble" phase.
81 pub fn bubble(self) -> bool {
82 self == DispatchPhase::Bubble
83 }
84
85 /// Returns true if this represents the "capture" phase.
86 pub fn capture(self) -> bool {
87 self == DispatchPhase::Capture
88 }
89}
90
91type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
92
93type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
94
95struct FocusEvent {
96 previous_focus_path: SmallVec<[FocusId; 8]>,
97 current_focus_path: SmallVec<[FocusId; 8]>,
98}
99
100slotmap::new_key_type! {
101 /// A globally unique identifier for a focusable element.
102 pub struct FocusId;
103}
104
105thread_local! {
106 pub(crate) static ELEMENT_ARENA: RefCell<Arena> = RefCell::new(Arena::new(4 * 1024 * 1024));
107}
108
109impl FocusId {
110 /// Obtains whether the element associated with this handle is currently focused.
111 pub fn is_focused(&self, cx: &WindowContext) -> bool {
112 cx.window.focus == Some(*self)
113 }
114
115 /// Obtains whether the element associated with this handle contains the focused
116 /// element or is itself focused.
117 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
118 cx.focused()
119 .map_or(false, |focused| self.contains(focused.id, cx))
120 }
121
122 /// Obtains whether the element associated with this handle is contained within the
123 /// focused element or is itself focused.
124 pub fn within_focused(&self, cx: &WindowContext) -> bool {
125 let focused = cx.focused();
126 focused.map_or(false, |focused| focused.id.contains(*self, cx))
127 }
128
129 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
130 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
131 cx.window
132 .rendered_frame
133 .dispatch_tree
134 .focus_contains(*self, other)
135 }
136}
137
138/// A handle which can be used to track and manipulate the focused element in a window.
139pub struct FocusHandle {
140 pub(crate) id: FocusId,
141 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
142}
143
144impl std::fmt::Debug for FocusHandle {
145 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
146 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
147 }
148}
149
150impl FocusHandle {
151 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
152 let id = handles.write().insert(AtomicUsize::new(1));
153 Self {
154 id,
155 handles: handles.clone(),
156 }
157 }
158
159 pub(crate) fn for_id(
160 id: FocusId,
161 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
162 ) -> Option<Self> {
163 let lock = handles.read();
164 let ref_count = lock.get(id)?;
165 if ref_count.load(SeqCst) == 0 {
166 None
167 } else {
168 ref_count.fetch_add(1, SeqCst);
169 Some(Self {
170 id,
171 handles: handles.clone(),
172 })
173 }
174 }
175
176 /// Moves the focus to the element associated with this handle.
177 pub fn focus(&self, cx: &mut WindowContext) {
178 cx.focus(self)
179 }
180
181 /// Obtains whether the element associated with this handle is currently focused.
182 pub fn is_focused(&self, cx: &WindowContext) -> bool {
183 self.id.is_focused(cx)
184 }
185
186 /// Obtains whether the element associated with this handle contains the focused
187 /// element or is itself focused.
188 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
189 self.id.contains_focused(cx)
190 }
191
192 /// Obtains whether the element associated with this handle is contained within the
193 /// focused element or is itself focused.
194 pub fn within_focused(&self, cx: &WindowContext) -> bool {
195 self.id.within_focused(cx)
196 }
197
198 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
199 pub fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
200 self.id.contains(other.id, cx)
201 }
202}
203
204impl Clone for FocusHandle {
205 fn clone(&self) -> Self {
206 Self::for_id(self.id, &self.handles).unwrap()
207 }
208}
209
210impl PartialEq for FocusHandle {
211 fn eq(&self, other: &Self) -> bool {
212 self.id == other.id
213 }
214}
215
216impl Eq for FocusHandle {}
217
218impl Drop for FocusHandle {
219 fn drop(&mut self) {
220 self.handles
221 .read()
222 .get(self.id)
223 .unwrap()
224 .fetch_sub(1, SeqCst);
225 }
226}
227
228/// FocusableView allows users of your view to easily
229/// focus it (using cx.focus_view(view))
230pub trait FocusableView: 'static + Render {
231 /// Returns the focus handle associated with this view.
232 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
233}
234
235/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
236/// where the lifecycle of the view is handled by another view.
237pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
238
239impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
240
241/// Emitted by implementers of [`ManagedView`] to indicate the view should be dismissed, such as when a view is presented as a modal.
242pub struct DismissEvent;
243
244// Holds the state for a specific window.
245#[doc(hidden)]
246pub struct Window {
247 pub(crate) handle: AnyWindowHandle,
248 pub(crate) removed: bool,
249 pub(crate) platform_window: Box<dyn PlatformWindow>,
250 display_id: DisplayId,
251 sprite_atlas: Arc<dyn PlatformAtlas>,
252 pub(crate) rem_size: Pixels,
253 pub(crate) viewport_size: Size<Pixels>,
254 layout_engine: Option<TaffyLayoutEngine>,
255 pub(crate) root_view: Option<AnyView>,
256 pub(crate) element_id_stack: GlobalElementId,
257 pub(crate) rendered_frame: Frame,
258 pub(crate) next_frame: Frame,
259 pub(crate) dirty_views: FxHashSet<EntityId>,
260 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
261 focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
262 focus_lost_listeners: SubscriberSet<(), AnyObserver>,
263 default_prevented: bool,
264 mouse_position: Point<Pixels>,
265 modifiers: Modifiers,
266 scale_factor: f32,
267 bounds: WindowBounds,
268 bounds_observers: SubscriberSet<(), AnyObserver>,
269 active: bool,
270 pub(crate) dirty: bool,
271 pub(crate) refreshing: bool,
272 pub(crate) drawing: bool,
273 activation_observers: SubscriberSet<(), AnyObserver>,
274 pub(crate) focus: Option<FocusId>,
275 focus_enabled: bool,
276
277 #[cfg(any(test, feature = "test-support"))]
278 pub(crate) focus_invalidated: bool,
279}
280
281pub(crate) struct ElementStateBox {
282 pub(crate) inner: Box<dyn Any>,
283 pub(crate) parent_view_id: EntityId,
284 #[cfg(debug_assertions)]
285 pub(crate) type_name: &'static str,
286}
287
288impl Window {
289 pub(crate) fn new(
290 handle: AnyWindowHandle,
291 options: WindowOptions,
292 cx: &mut AppContext,
293 ) -> Self {
294 let platform_window = cx.platform.open_window(handle, options);
295 let display_id = platform_window.display().id();
296 let sprite_atlas = platform_window.sprite_atlas();
297 let mouse_position = platform_window.mouse_position();
298 let modifiers = platform_window.modifiers();
299 let content_size = platform_window.content_size();
300 let scale_factor = platform_window.scale_factor();
301 let bounds = platform_window.bounds();
302
303 platform_window.on_request_frame(Box::new({
304 let mut cx = cx.to_async();
305 move || {
306 measure("frame duration", || {
307 handle.update(&mut cx, |_, cx| cx.draw()).log_err();
308 })
309 }
310 }));
311 platform_window.on_resize(Box::new({
312 let mut cx = cx.to_async();
313 move |_, _| {
314 handle
315 .update(&mut cx, |_, cx| cx.window_bounds_changed())
316 .log_err();
317 }
318 }));
319 platform_window.on_moved(Box::new({
320 let mut cx = cx.to_async();
321 move || {
322 handle
323 .update(&mut cx, |_, cx| cx.window_bounds_changed())
324 .log_err();
325 }
326 }));
327 platform_window.on_active_status_change(Box::new({
328 let mut cx = cx.to_async();
329 move |active| {
330 handle
331 .update(&mut cx, |_, cx| {
332 cx.window.active = active;
333 cx.window
334 .activation_observers
335 .clone()
336 .retain(&(), |callback| callback(cx));
337 })
338 .log_err();
339 }
340 }));
341
342 platform_window.on_input({
343 let mut cx = cx.to_async();
344 Box::new(move |event| {
345 handle
346 .update(&mut cx, |_, cx| cx.dispatch_event(event))
347 .log_err()
348 .unwrap_or(false)
349 })
350 });
351
352 Window {
353 handle,
354 removed: false,
355 platform_window,
356 display_id,
357 sprite_atlas,
358 rem_size: px(16.),
359 viewport_size: content_size,
360 layout_engine: Some(TaffyLayoutEngine::new()),
361 root_view: None,
362 element_id_stack: GlobalElementId::default(),
363 rendered_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
364 next_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
365 dirty_views: FxHashSet::default(),
366 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
367 focus_listeners: SubscriberSet::new(),
368 focus_lost_listeners: SubscriberSet::new(),
369 default_prevented: true,
370 mouse_position,
371 modifiers,
372 scale_factor,
373 bounds,
374 bounds_observers: SubscriberSet::new(),
375 active: false,
376 dirty: false,
377 refreshing: false,
378 drawing: false,
379 activation_observers: SubscriberSet::new(),
380 focus: None,
381 focus_enabled: true,
382
383 #[cfg(any(test, feature = "test-support"))]
384 focus_invalidated: false,
385 }
386 }
387}
388
389/// Indicates which region of the window is visible. Content falling outside of this mask will not be
390/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
391/// to leave room to support more complex shapes in the future.
392#[derive(Clone, Debug, Default, PartialEq, Eq)]
393#[repr(C)]
394pub struct ContentMask<P: Clone + Default + Debug> {
395 /// The bounds
396 pub bounds: Bounds<P>,
397}
398
399impl ContentMask<Pixels> {
400 /// Scale the content mask's pixel units by the given scaling factor.
401 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
402 ContentMask {
403 bounds: self.bounds.scale(factor),
404 }
405 }
406
407 /// Intersect the content mask with the given content mask.
408 pub fn intersect(&self, other: &Self) -> Self {
409 let bounds = self.bounds.intersect(&other.bounds);
410 ContentMask { bounds }
411 }
412}
413
414/// Provides access to application state in the context of a single window. Derefs
415/// to an [`AppContext`], so you can also pass a [`WindowContext`] to any method that takes
416/// an [`AppContext`] and call any [`AppContext`] methods.
417pub struct WindowContext<'a> {
418 pub(crate) app: &'a mut AppContext,
419 pub(crate) window: &'a mut Window,
420}
421
422impl<'a> WindowContext<'a> {
423 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
424 Self { app, window }
425 }
426
427 /// Obtain a handle to the window that belongs to this context.
428 pub fn window_handle(&self) -> AnyWindowHandle {
429 self.window.handle
430 }
431
432 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
433 pub fn refresh(&mut self) {
434 if !self.window.drawing {
435 self.window.refreshing = true;
436 self.window.dirty = true;
437 }
438 }
439
440 /// Close this window.
441 pub fn remove_window(&mut self) {
442 self.window.removed = true;
443 }
444
445 /// Obtain a new [`FocusHandle`], which allows you to track and manipulate the keyboard focus
446 /// for elements rendered within this window.
447 pub fn focus_handle(&mut self) -> FocusHandle {
448 FocusHandle::new(&self.window.focus_handles)
449 }
450
451 /// Obtain the currently focused [`FocusHandle`]. If no elements are focused, returns `None`.
452 pub fn focused(&self) -> Option<FocusHandle> {
453 self.window
454 .focus
455 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
456 }
457
458 /// Move focus to the element associated with the given [`FocusHandle`].
459 pub fn focus(&mut self, handle: &FocusHandle) {
460 if !self.window.focus_enabled || self.window.focus == Some(handle.id) {
461 return;
462 }
463
464 self.window.focus = Some(handle.id);
465 self.window
466 .rendered_frame
467 .dispatch_tree
468 .clear_pending_keystrokes();
469
470 #[cfg(any(test, feature = "test-support"))]
471 {
472 self.window.focus_invalidated = true;
473 }
474
475 self.refresh();
476 }
477
478 /// Remove focus from all elements within this context's window.
479 pub fn blur(&mut self) {
480 if !self.window.focus_enabled {
481 return;
482 }
483
484 self.window.focus = None;
485 self.refresh();
486 }
487
488 /// Blur the window and don't allow anything in it to be focused again.
489 pub fn disable_focus(&mut self) {
490 self.blur();
491 self.window.focus_enabled = false;
492 }
493
494 /// Dispatch the given action on the currently focused element.
495 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
496 let focus_handle = self.focused();
497
498 self.defer(move |cx| {
499 let node_id = focus_handle
500 .and_then(|handle| {
501 cx.window
502 .rendered_frame
503 .dispatch_tree
504 .focusable_node_id(handle.id)
505 })
506 .unwrap_or_else(|| cx.window.rendered_frame.dispatch_tree.root_node_id());
507
508 cx.propagate_event = true;
509 cx.dispatch_action_on_node(node_id, action);
510 })
511 }
512
513 pub(crate) fn dispatch_keystroke_observers(
514 &mut self,
515 event: &dyn Any,
516 action: Option<Box<dyn Action>>,
517 ) {
518 let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() else {
519 return;
520 };
521
522 self.keystroke_observers
523 .clone()
524 .retain(&(), move |callback| {
525 (callback)(
526 &KeystrokeEvent {
527 keystroke: key_down_event.keystroke.clone(),
528 action: action.as_ref().map(|action| action.boxed_clone()),
529 },
530 self,
531 );
532 true
533 });
534 }
535
536 pub(crate) fn clear_pending_keystrokes(&mut self) {
537 self.window
538 .rendered_frame
539 .dispatch_tree
540 .clear_pending_keystrokes();
541 self.window
542 .next_frame
543 .dispatch_tree
544 .clear_pending_keystrokes();
545 }
546
547 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
548 /// that are currently on the stack to be returned to the app.
549 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
550 let handle = self.window.handle;
551 self.app.defer(move |cx| {
552 handle.update(cx, |_, cx| f(cx)).ok();
553 });
554 }
555
556 /// Subscribe to events emitted by a model or view.
557 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
558 /// The callback will be invoked a handle to the emitting entity (either a [`View`] or [`Model`]), the event, and a window context for the current window.
559 pub fn subscribe<Emitter, E, Evt>(
560 &mut self,
561 entity: &E,
562 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
563 ) -> Subscription
564 where
565 Emitter: EventEmitter<Evt>,
566 E: Entity<Emitter>,
567 Evt: 'static,
568 {
569 let entity_id = entity.entity_id();
570 let entity = entity.downgrade();
571 let window_handle = self.window.handle;
572 let (subscription, activate) = self.app.event_listeners.insert(
573 entity_id,
574 (
575 TypeId::of::<Evt>(),
576 Box::new(move |event, cx| {
577 window_handle
578 .update(cx, |_, cx| {
579 if let Some(handle) = E::upgrade_from(&entity) {
580 let event = event.downcast_ref().expect("invalid event type");
581 on_event(handle, event, cx);
582 true
583 } else {
584 false
585 }
586 })
587 .unwrap_or(false)
588 }),
589 ),
590 );
591 self.app.defer(move |_| activate());
592 subscription
593 }
594
595 /// Creates an [`AsyncWindowContext`], which has a static lifetime and can be held across
596 /// await points in async code.
597 pub fn to_async(&self) -> AsyncWindowContext {
598 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
599 }
600
601 /// Schedule the given closure to be run directly after the current frame is rendered.
602 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
603 let handle = self.window.handle;
604 let display_id = self.window.display_id;
605
606 let mut frame_consumers = std::mem::take(&mut self.app.frame_consumers);
607 if let Entry::Vacant(e) = frame_consumers.entry(display_id) {
608 let (tx, mut rx) = mpsc::unbounded::<()>();
609 self.platform.set_display_link_output_callback(
610 display_id,
611 Box::new(move || _ = tx.unbounded_send(())),
612 );
613
614 let consumer_task = self.app.spawn(|cx| async move {
615 while rx.next().await.is_some() {
616 cx.update(|cx| {
617 for callback in cx
618 .next_frame_callbacks
619 .get_mut(&display_id)
620 .unwrap()
621 .drain(..)
622 .collect::<SmallVec<[_; 32]>>()
623 {
624 callback(cx);
625 }
626 })
627 .ok();
628
629 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
630
631 cx.update(|cx| {
632 if cx.next_frame_callbacks.is_empty() {
633 cx.platform.stop_display_link(display_id);
634 }
635 })
636 .ok();
637 }
638 });
639 e.insert(consumer_task);
640 }
641 debug_assert!(self.app.frame_consumers.is_empty());
642 self.app.frame_consumers = frame_consumers;
643
644 if self.next_frame_callbacks.is_empty() {
645 self.platform.start_display_link(display_id);
646 }
647
648 self.next_frame_callbacks
649 .entry(display_id)
650 .or_default()
651 .push(Box::new(move |cx: &mut AppContext| {
652 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
653 }));
654 }
655
656 /// Spawn the future returned by the given closure on the application thread pool.
657 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
658 /// use within your future.
659 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
660 where
661 R: 'static,
662 Fut: Future<Output = R> + 'static,
663 {
664 self.app
665 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
666 }
667
668 /// Updates the global of the given type. The given closure is given simultaneous mutable
669 /// access both to the global and the context.
670 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
671 where
672 G: 'static,
673 {
674 let mut global = self.app.lease_global::<G>();
675 let result = f(&mut global, self);
676 self.app.end_global_lease(global);
677 result
678 }
679
680 fn window_bounds_changed(&mut self) {
681 self.window.scale_factor = self.window.platform_window.scale_factor();
682 self.window.viewport_size = self.window.platform_window.content_size();
683 self.window.bounds = self.window.platform_window.bounds();
684 self.window.display_id = self.window.platform_window.display().id();
685 self.refresh();
686
687 self.window
688 .bounds_observers
689 .clone()
690 .retain(&(), |callback| callback(self));
691 }
692
693 /// Returns the bounds of the current window in the global coordinate space, which could span across multiple displays.
694 pub fn window_bounds(&self) -> WindowBounds {
695 self.window.bounds
696 }
697
698 /// Returns the size of the drawable area within the window.
699 pub fn viewport_size(&self) -> Size<Pixels> {
700 self.window.viewport_size
701 }
702
703 /// Returns whether this window is focused by the operating system (receiving key events).
704 pub fn is_window_active(&self) -> bool {
705 self.window.active
706 }
707
708 /// Toggle zoom on the window.
709 pub fn zoom_window(&self) {
710 self.window.platform_window.zoom();
711 }
712
713 /// Updates the window's title at the platform level.
714 pub fn set_window_title(&mut self, title: &str) {
715 self.window.platform_window.set_title(title);
716 }
717
718 /// Mark the window as dirty at the platform level.
719 pub fn set_window_edited(&mut self, edited: bool) {
720 self.window.platform_window.set_edited(edited);
721 }
722
723 /// Determine the display on which the window is visible.
724 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
725 self.platform
726 .displays()
727 .into_iter()
728 .find(|display| display.id() == self.window.display_id)
729 }
730
731 /// Show the platform character palette.
732 pub fn show_character_palette(&self) {
733 self.window.platform_window.show_character_palette();
734 }
735
736 /// The scale factor of the display associated with the window. For example, it could
737 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
738 /// be rendered as two pixels on screen.
739 pub fn scale_factor(&self) -> f32 {
740 self.window.scale_factor
741 }
742
743 /// The size of an em for the base font of the application. Adjusting this value allows the
744 /// UI to scale, just like zooming a web page.
745 pub fn rem_size(&self) -> Pixels {
746 self.window.rem_size
747 }
748
749 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
750 /// UI to scale, just like zooming a web page.
751 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
752 self.window.rem_size = rem_size.into();
753 }
754
755 /// The line height associated with the current text style.
756 pub fn line_height(&self) -> Pixels {
757 let rem_size = self.rem_size();
758 let text_style = self.text_style();
759 text_style
760 .line_height
761 .to_pixels(text_style.font_size, rem_size)
762 }
763
764 /// Call to prevent the default action of an event. Currently only used to prevent
765 /// parent elements from becoming focused on mouse down.
766 pub fn prevent_default(&mut self) {
767 self.window.default_prevented = true;
768 }
769
770 /// Obtain whether default has been prevented for the event currently being dispatched.
771 pub fn default_prevented(&self) -> bool {
772 self.window.default_prevented
773 }
774
775 /// Determine whether the given action is available along the dispatch path to the currently focused element.
776 pub fn is_action_available(&self, action: &dyn Action) -> bool {
777 let target = self
778 .focused()
779 .and_then(|focused_handle| {
780 self.window
781 .rendered_frame
782 .dispatch_tree
783 .focusable_node_id(focused_handle.id)
784 })
785 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
786 self.window
787 .rendered_frame
788 .dispatch_tree
789 .is_action_available(action, target)
790 }
791
792 /// The position of the mouse relative to the window.
793 pub fn mouse_position(&self) -> Point<Pixels> {
794 self.window.mouse_position
795 }
796
797 /// The current state of the keyboard's modifiers
798 pub fn modifiers(&self) -> Modifiers {
799 self.window.modifiers
800 }
801
802 /// Returns true if there is no opaque layer containing the given point
803 /// on top of the given level. Layers whose level is an extension of the
804 /// level are not considered to be on top of the level.
805 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
806 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
807 if level >= opaque_level {
808 break;
809 }
810
811 if bounds.contains(point) && !opaque_level.starts_with(level) {
812 return false;
813 }
814 }
815 true
816 }
817
818 pub(crate) fn was_top_layer_under_active_drag(
819 &self,
820 point: &Point<Pixels>,
821 level: &StackingOrder,
822 ) -> bool {
823 for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
824 if level >= opaque_level {
825 break;
826 }
827 if opaque_level
828 .first()
829 .map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
830 .unwrap_or(false)
831 {
832 continue;
833 }
834
835 if bounds.contains(point) && !opaque_level.starts_with(level) {
836 return false;
837 }
838 }
839 true
840 }
841
842 /// Called during painting to get the current stacking order.
843 pub fn stacking_order(&self) -> &StackingOrder {
844 &self.window.next_frame.z_index_stack
845 }
846
847 /// Draw pixels to the display for this window based on the contents of its scene.
848 pub(crate) fn draw(&mut self) {
849 self.window.dirty = false;
850 self.window.drawing = true;
851
852 #[cfg(any(test, feature = "test-support"))]
853 {
854 self.window.focus_invalidated = false;
855 }
856
857 if let Some(requested_handler) = self.window.rendered_frame.requested_input_handler.as_mut()
858 {
859 let input_handler = self.window.platform_window.take_input_handler();
860 requested_handler.handler = input_handler;
861 }
862
863 let root_view = self.window.root_view.take().unwrap();
864 self.with_element_context(|cx| {
865 cx.with_z_index(0, |cx| {
866 cx.with_key_dispatch(Some(KeyContext::default()), None, |_, cx| {
867 // We need to use cx.cx here so we can utilize borrow splitting
868 for (action_type, action_listeners) in &cx.cx.app.global_action_listeners {
869 for action_listener in action_listeners.iter().cloned() {
870 cx.cx.window.next_frame.dispatch_tree.on_action(
871 *action_type,
872 Rc::new(
873 move |action: &dyn Any, phase, cx: &mut WindowContext<'_>| {
874 action_listener(action, phase, cx)
875 },
876 ),
877 )
878 }
879 }
880
881 let available_space = cx.window.viewport_size.map(Into::into);
882 root_view.draw(Point::default(), available_space, cx);
883 })
884 })
885 });
886
887 if let Some(active_drag) = self.app.active_drag.take() {
888 self.with_element_context(|cx| {
889 cx.with_z_index(ACTIVE_DRAG_Z_INDEX, |cx| {
890 let offset = cx.mouse_position() - active_drag.cursor_offset;
891 let available_space =
892 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
893 active_drag.view.draw(offset, available_space, cx);
894 })
895 });
896 self.active_drag = Some(active_drag);
897 } else if let Some(tooltip_request) = self.window.next_frame.tooltip_request.take() {
898 self.with_element_context(|cx| {
899 cx.with_z_index(1, |cx| {
900 let available_space =
901 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
902 tooltip_request.tooltip.view.draw(
903 tooltip_request.tooltip.cursor_offset,
904 available_space,
905 cx,
906 );
907 })
908 });
909 self.window.next_frame.tooltip_request = Some(tooltip_request);
910 }
911 self.window.dirty_views.clear();
912
913 self.window
914 .next_frame
915 .dispatch_tree
916 .preserve_pending_keystrokes(
917 &mut self.window.rendered_frame.dispatch_tree,
918 self.window.focus,
919 );
920 self.window.next_frame.focus = self.window.focus;
921 self.window.next_frame.window_active = self.window.active;
922 self.window.root_view = Some(root_view);
923
924 // Set the cursor only if we're the active window.
925 let cursor_style = self
926 .window
927 .next_frame
928 .requested_cursor_style
929 .take()
930 .unwrap_or(CursorStyle::Arrow);
931 if self.is_window_active() {
932 self.platform.set_cursor_style(cursor_style);
933 }
934
935 // Register requested input handler with the platform window.
936 if let Some(requested_input) = self.window.next_frame.requested_input_handler.as_mut() {
937 if let Some(handler) = requested_input.handler.take() {
938 self.window.platform_window.set_input_handler(handler);
939 }
940 }
941
942 self.window.layout_engine.as_mut().unwrap().clear();
943 self.text_system()
944 .finish_frame(&self.window.next_frame.reused_views);
945 self.window
946 .next_frame
947 .finish(&mut self.window.rendered_frame);
948 ELEMENT_ARENA.with_borrow_mut(|element_arena| element_arena.clear());
949
950 let previous_focus_path = self.window.rendered_frame.focus_path();
951 let previous_window_active = self.window.rendered_frame.window_active;
952 mem::swap(&mut self.window.rendered_frame, &mut self.window.next_frame);
953 self.window.next_frame.clear();
954 let current_focus_path = self.window.rendered_frame.focus_path();
955 let current_window_active = self.window.rendered_frame.window_active;
956
957 if previous_focus_path != current_focus_path
958 || previous_window_active != current_window_active
959 {
960 if !previous_focus_path.is_empty() && current_focus_path.is_empty() {
961 self.window
962 .focus_lost_listeners
963 .clone()
964 .retain(&(), |listener| listener(self));
965 }
966
967 let event = FocusEvent {
968 previous_focus_path: if previous_window_active {
969 previous_focus_path
970 } else {
971 Default::default()
972 },
973 current_focus_path: if current_window_active {
974 current_focus_path
975 } else {
976 Default::default()
977 },
978 };
979 self.window
980 .focus_listeners
981 .clone()
982 .retain(&(), |listener| listener(&event, self));
983 }
984
985 self.window
986 .platform_window
987 .draw(&self.window.rendered_frame.scene);
988 self.window.refreshing = false;
989 self.window.drawing = false;
990 }
991
992 /// Dispatch a mouse or keyboard event on the window.
993 pub fn dispatch_event(&mut self, event: PlatformInput) -> bool {
994 // Handlers may set this to false by calling `stop_propagation`.
995 self.app.propagate_event = true;
996 // Handlers may set this to true by calling `prevent_default`.
997 self.window.default_prevented = false;
998
999 let event = match event {
1000 // Track the mouse position with our own state, since accessing the platform
1001 // API for the mouse position can only occur on the main thread.
1002 PlatformInput::MouseMove(mouse_move) => {
1003 self.window.mouse_position = mouse_move.position;
1004 self.window.modifiers = mouse_move.modifiers;
1005 PlatformInput::MouseMove(mouse_move)
1006 }
1007 PlatformInput::MouseDown(mouse_down) => {
1008 self.window.mouse_position = mouse_down.position;
1009 self.window.modifiers = mouse_down.modifiers;
1010 PlatformInput::MouseDown(mouse_down)
1011 }
1012 PlatformInput::MouseUp(mouse_up) => {
1013 self.window.mouse_position = mouse_up.position;
1014 self.window.modifiers = mouse_up.modifiers;
1015 PlatformInput::MouseUp(mouse_up)
1016 }
1017 PlatformInput::MouseExited(mouse_exited) => {
1018 self.window.modifiers = mouse_exited.modifiers;
1019 PlatformInput::MouseExited(mouse_exited)
1020 }
1021 PlatformInput::ModifiersChanged(modifiers_changed) => {
1022 self.window.modifiers = modifiers_changed.modifiers;
1023 PlatformInput::ModifiersChanged(modifiers_changed)
1024 }
1025 PlatformInput::ScrollWheel(scroll_wheel) => {
1026 self.window.mouse_position = scroll_wheel.position;
1027 self.window.modifiers = scroll_wheel.modifiers;
1028 PlatformInput::ScrollWheel(scroll_wheel)
1029 }
1030 // Translate dragging and dropping of external files from the operating system
1031 // to internal drag and drop events.
1032 PlatformInput::FileDrop(file_drop) => match file_drop {
1033 FileDropEvent::Entered { position, paths } => {
1034 self.window.mouse_position = position;
1035 if self.active_drag.is_none() {
1036 self.active_drag = Some(AnyDrag {
1037 value: Box::new(paths.clone()),
1038 view: self.new_view(|_| paths).into(),
1039 cursor_offset: position,
1040 });
1041 }
1042 PlatformInput::MouseMove(MouseMoveEvent {
1043 position,
1044 pressed_button: Some(MouseButton::Left),
1045 modifiers: Modifiers::default(),
1046 })
1047 }
1048 FileDropEvent::Pending { position } => {
1049 self.window.mouse_position = position;
1050 PlatformInput::MouseMove(MouseMoveEvent {
1051 position,
1052 pressed_button: Some(MouseButton::Left),
1053 modifiers: Modifiers::default(),
1054 })
1055 }
1056 FileDropEvent::Submit { position } => {
1057 self.activate(true);
1058 self.window.mouse_position = position;
1059 PlatformInput::MouseUp(MouseUpEvent {
1060 button: MouseButton::Left,
1061 position,
1062 modifiers: Modifiers::default(),
1063 click_count: 1,
1064 })
1065 }
1066 FileDropEvent::Exited => PlatformInput::MouseUp(MouseUpEvent {
1067 button: MouseButton::Left,
1068 position: Point::default(),
1069 modifiers: Modifiers::default(),
1070 click_count: 1,
1071 }),
1072 },
1073 PlatformInput::KeyDown(_) | PlatformInput::KeyUp(_) => event,
1074 };
1075
1076 if let Some(any_mouse_event) = event.mouse_event() {
1077 self.dispatch_mouse_event(any_mouse_event);
1078 } else if let Some(any_key_event) = event.keyboard_event() {
1079 self.dispatch_key_event(any_key_event);
1080 }
1081
1082 !self.app.propagate_event
1083 }
1084
1085 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1086 if let Some(mut handlers) = self
1087 .window
1088 .rendered_frame
1089 .mouse_listeners
1090 .remove(&event.type_id())
1091 {
1092 // Because handlers may add other handlers, we sort every time.
1093 handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));
1094
1095 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1096 // special purposes, such as detecting events outside of a given Bounds.
1097 for (_, _, handler) in &mut handlers {
1098 self.with_element_context(|cx| {
1099 handler(event, DispatchPhase::Capture, cx);
1100 });
1101 if !self.app.propagate_event {
1102 break;
1103 }
1104 }
1105
1106 // Bubble phase, where most normal handlers do their work.
1107 if self.app.propagate_event {
1108 for (_, _, handler) in handlers.iter_mut().rev() {
1109 self.with_element_context(|cx| {
1110 handler(event, DispatchPhase::Bubble, cx);
1111 });
1112 if !self.app.propagate_event {
1113 break;
1114 }
1115 }
1116 }
1117
1118 self.window
1119 .rendered_frame
1120 .mouse_listeners
1121 .insert(event.type_id(), handlers);
1122 }
1123
1124 if self.app.propagate_event && self.has_active_drag() {
1125 if event.is::<MouseMoveEvent>() {
1126 // If this was a mouse move event, redraw the window so that the
1127 // active drag can follow the mouse cursor.
1128 self.refresh();
1129 } else if event.is::<MouseUpEvent>() {
1130 // If this was a mouse up event, cancel the active drag and redraw
1131 // the window.
1132 self.active_drag = None;
1133 self.refresh();
1134 }
1135 }
1136 }
1137
1138 fn dispatch_key_event(&mut self, event: &dyn Any) {
1139 let node_id = self
1140 .window
1141 .focus
1142 .and_then(|focus_id| {
1143 self.window
1144 .rendered_frame
1145 .dispatch_tree
1146 .focusable_node_id(focus_id)
1147 })
1148 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1149
1150 let dispatch_path = self
1151 .window
1152 .rendered_frame
1153 .dispatch_tree
1154 .dispatch_path(node_id);
1155
1156 let mut actions: Vec<Box<dyn Action>> = Vec::new();
1157
1158 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1159 for node_id in &dispatch_path {
1160 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1161
1162 if let Some(context) = node.context.clone() {
1163 context_stack.push(context);
1164 }
1165 }
1166
1167 for node_id in dispatch_path.iter().rev() {
1168 // Match keystrokes
1169 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1170 if node.context.is_some() {
1171 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1172 let mut new_actions = self
1173 .window
1174 .rendered_frame
1175 .dispatch_tree
1176 .dispatch_key(&key_down_event.keystroke, &context_stack);
1177 actions.append(&mut new_actions);
1178 }
1179
1180 context_stack.pop();
1181 }
1182 }
1183
1184 if !actions.is_empty() {
1185 self.clear_pending_keystrokes();
1186 }
1187
1188 self.propagate_event = true;
1189 for action in actions {
1190 self.dispatch_action_on_node(node_id, action.boxed_clone());
1191 if !self.propagate_event {
1192 self.dispatch_keystroke_observers(event, Some(action));
1193 return;
1194 }
1195 }
1196
1197 // Capture phase
1198 for node_id in &dispatch_path {
1199 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1200
1201 for key_listener in node.key_listeners.clone() {
1202 self.with_element_context(|cx| {
1203 key_listener(event, DispatchPhase::Capture, cx);
1204 });
1205 if !self.propagate_event {
1206 return;
1207 }
1208 }
1209 }
1210
1211 // Bubble phase
1212 for node_id in dispatch_path.iter().rev() {
1213 // Handle low level key events
1214 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1215 for key_listener in node.key_listeners.clone() {
1216 self.with_element_context(|cx| {
1217 key_listener(event, DispatchPhase::Bubble, cx);
1218 });
1219 if !self.propagate_event {
1220 return;
1221 }
1222 }
1223 }
1224
1225 self.dispatch_keystroke_observers(event, None);
1226 }
1227
1228 /// Determine whether a potential multi-stroke key binding is in progress on this window.
1229 pub fn has_pending_keystrokes(&self) -> bool {
1230 self.window
1231 .rendered_frame
1232 .dispatch_tree
1233 .has_pending_keystrokes()
1234 }
1235
1236 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1237 let dispatch_path = self
1238 .window
1239 .rendered_frame
1240 .dispatch_tree
1241 .dispatch_path(node_id);
1242
1243 // Capture phase
1244 for node_id in &dispatch_path {
1245 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1246 for DispatchActionListener {
1247 action_type,
1248 listener,
1249 } in node.action_listeners.clone()
1250 {
1251 let any_action = action.as_any();
1252 if action_type == any_action.type_id() {
1253 self.with_element_context(|cx| {
1254 listener(any_action, DispatchPhase::Capture, cx);
1255 });
1256
1257 if !self.propagate_event {
1258 return;
1259 }
1260 }
1261 }
1262 }
1263 // Bubble phase
1264 for node_id in dispatch_path.iter().rev() {
1265 let node = self.window.rendered_frame.dispatch_tree.node(*node_id);
1266 for DispatchActionListener {
1267 action_type,
1268 listener,
1269 } in node.action_listeners.clone()
1270 {
1271 let any_action = action.as_any();
1272 if action_type == any_action.type_id() {
1273 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1274
1275 self.with_element_context(|cx| {
1276 listener(any_action, DispatchPhase::Bubble, cx);
1277 });
1278
1279 if !self.propagate_event {
1280 return;
1281 }
1282 }
1283 }
1284 }
1285 }
1286
1287 /// Register the given handler to be invoked whenever the global of the given type
1288 /// is updated.
1289 pub fn observe_global<G: 'static>(
1290 &mut self,
1291 f: impl Fn(&mut WindowContext<'_>) + 'static,
1292 ) -> Subscription {
1293 let window_handle = self.window.handle;
1294 let (subscription, activate) = self.global_observers.insert(
1295 TypeId::of::<G>(),
1296 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1297 );
1298 self.app.defer(move |_| activate());
1299 subscription
1300 }
1301
1302 /// Focus the current window and bring it to the foreground at the platform level.
1303 pub fn activate_window(&self) {
1304 self.window.platform_window.activate();
1305 }
1306
1307 /// Minimize the current window at the platform level.
1308 pub fn minimize_window(&self) {
1309 self.window.platform_window.minimize();
1310 }
1311
1312 /// Toggle full screen status on the current window at the platform level.
1313 pub fn toggle_full_screen(&self) {
1314 self.window.platform_window.toggle_full_screen();
1315 }
1316
1317 /// Present a platform dialog.
1318 /// The provided message will be presented, along with buttons for each answer.
1319 /// When a button is clicked, the returned Receiver will receive the index of the clicked button.
1320 pub fn prompt(
1321 &self,
1322 level: PromptLevel,
1323 message: &str,
1324 answers: &[&str],
1325 ) -> oneshot::Receiver<usize> {
1326 self.window.platform_window.prompt(level, message, answers)
1327 }
1328
1329 /// Returns all available actions for the focused element.
1330 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1331 let node_id = self
1332 .window
1333 .focus
1334 .and_then(|focus_id| {
1335 self.window
1336 .rendered_frame
1337 .dispatch_tree
1338 .focusable_node_id(focus_id)
1339 })
1340 .unwrap_or_else(|| self.window.rendered_frame.dispatch_tree.root_node_id());
1341
1342 self.window
1343 .rendered_frame
1344 .dispatch_tree
1345 .available_actions(node_id)
1346 }
1347
1348 /// Returns key bindings that invoke the given action on the currently focused element.
1349 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1350 self.window
1351 .rendered_frame
1352 .dispatch_tree
1353 .bindings_for_action(
1354 action,
1355 &self.window.rendered_frame.dispatch_tree.context_stack,
1356 )
1357 }
1358
1359 /// Returns any bindings that would invoke the given action on the given focus handle if it were focused.
1360 pub fn bindings_for_action_in(
1361 &self,
1362 action: &dyn Action,
1363 focus_handle: &FocusHandle,
1364 ) -> Vec<KeyBinding> {
1365 let dispatch_tree = &self.window.rendered_frame.dispatch_tree;
1366
1367 let Some(node_id) = dispatch_tree.focusable_node_id(focus_handle.id) else {
1368 return vec![];
1369 };
1370 let context_stack = dispatch_tree
1371 .dispatch_path(node_id)
1372 .into_iter()
1373 .filter_map(|node_id| dispatch_tree.node(node_id).context.clone())
1374 .collect();
1375 dispatch_tree.bindings_for_action(action, &context_stack)
1376 }
1377
1378 /// Returns a generic event listener that invokes the given listener with the view and context associated with the given view handle.
1379 pub fn listener_for<V: Render, E>(
1380 &self,
1381 view: &View<V>,
1382 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1383 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1384 let view = view.downgrade();
1385 move |e: &E, cx: &mut WindowContext| {
1386 view.update(cx, |view, cx| f(view, e, cx)).ok();
1387 }
1388 }
1389
1390 /// Returns a generic handler that invokes the given handler with the view and context associated with the given view handle.
1391 pub fn handler_for<V: Render>(
1392 &self,
1393 view: &View<V>,
1394 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1395 ) -> impl Fn(&mut WindowContext) {
1396 let view = view.downgrade();
1397 move |cx: &mut WindowContext| {
1398 view.update(cx, |view, cx| f(view, cx)).ok();
1399 }
1400 }
1401
1402 /// Register a callback that can interrupt the closing of the current window based the returned boolean.
1403 /// If the callback returns false, the window won't be closed.
1404 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1405 let mut this = self.to_async();
1406 self.window
1407 .platform_window
1408 .on_should_close(Box::new(move || {
1409 this.update(|cx| {
1410 // Ensure that the window is removed from the app if it's been closed
1411 // by always pre-empting the system close event.
1412 if f(cx) {
1413 cx.remove_window();
1414 }
1415 false
1416 })
1417 .unwrap_or(true)
1418 }))
1419 }
1420
1421 pub(crate) fn parent_view_id(&self) -> EntityId {
1422 *self
1423 .window
1424 .next_frame
1425 .view_stack
1426 .last()
1427 .expect("a view should always be on the stack while drawing")
1428 }
1429
1430 /// Register an action listener on the window for the next frame. The type of action
1431 /// is determined by the first parameter of the given listener. When the next frame is rendered
1432 /// the listener will be cleared.
1433 ///
1434 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
1435 /// a specific need to register a global listener.
1436 pub fn on_action(
1437 &mut self,
1438 action_type: TypeId,
1439 listener: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
1440 ) {
1441 self.window
1442 .next_frame
1443 .dispatch_tree
1444 .on_action(action_type, Rc::new(listener));
1445 }
1446}
1447
1448impl Context for WindowContext<'_> {
1449 type Result<T> = T;
1450
1451 fn new_model<T>(&mut self, build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T) -> Model<T>
1452 where
1453 T: 'static,
1454 {
1455 let slot = self.app.entities.reserve();
1456 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1457 self.entities.insert(slot, model)
1458 }
1459
1460 fn update_model<T: 'static, R>(
1461 &mut self,
1462 model: &Model<T>,
1463 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1464 ) -> R {
1465 let mut entity = self.entities.lease(model);
1466 let result = update(
1467 &mut *entity,
1468 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1469 );
1470 self.entities.end_lease(entity);
1471 result
1472 }
1473
1474 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1475 where
1476 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1477 {
1478 if window == self.window.handle {
1479 let root_view = self.window.root_view.clone().unwrap();
1480 Ok(update(root_view, self))
1481 } else {
1482 window.update(self.app, update)
1483 }
1484 }
1485
1486 fn read_model<T, R>(
1487 &self,
1488 handle: &Model<T>,
1489 read: impl FnOnce(&T, &AppContext) -> R,
1490 ) -> Self::Result<R>
1491 where
1492 T: 'static,
1493 {
1494 let entity = self.entities.read(handle);
1495 read(entity, &*self.app)
1496 }
1497
1498 fn read_window<T, R>(
1499 &self,
1500 window: &WindowHandle<T>,
1501 read: impl FnOnce(View<T>, &AppContext) -> R,
1502 ) -> Result<R>
1503 where
1504 T: 'static,
1505 {
1506 if window.any_handle == self.window.handle {
1507 let root_view = self
1508 .window
1509 .root_view
1510 .clone()
1511 .unwrap()
1512 .downcast::<T>()
1513 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1514 Ok(read(root_view, self))
1515 } else {
1516 self.app.read_window(window, read)
1517 }
1518 }
1519}
1520
1521impl VisualContext for WindowContext<'_> {
1522 fn new_view<V>(
1523 &mut self,
1524 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1525 ) -> Self::Result<View<V>>
1526 where
1527 V: 'static + Render,
1528 {
1529 let slot = self.app.entities.reserve();
1530 let view = View {
1531 model: slot.clone(),
1532 };
1533 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1534 let entity = build_view_state(&mut cx);
1535 cx.entities.insert(slot, entity);
1536
1537 cx.new_view_observers
1538 .clone()
1539 .retain(&TypeId::of::<V>(), |observer| {
1540 let any_view = AnyView::from(view.clone());
1541 (observer)(any_view, self);
1542 true
1543 });
1544
1545 view
1546 }
1547
1548 /// Updates the given view. Prefer calling [`View::update`] instead, which calls this method.
1549 fn update_view<T: 'static, R>(
1550 &mut self,
1551 view: &View<T>,
1552 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1553 ) -> Self::Result<R> {
1554 let mut lease = self.app.entities.lease(&view.model);
1555 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, view);
1556 let result = update(&mut *lease, &mut cx);
1557 cx.app.entities.end_lease(lease);
1558 result
1559 }
1560
1561 fn replace_root_view<V>(
1562 &mut self,
1563 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1564 ) -> Self::Result<View<V>>
1565 where
1566 V: 'static + Render,
1567 {
1568 let view = self.new_view(build_view);
1569 self.window.root_view = Some(view.clone().into());
1570 self.refresh();
1571 view
1572 }
1573
1574 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1575 self.update_view(view, |view, cx| {
1576 view.focus_handle(cx).clone().focus(cx);
1577 })
1578 }
1579
1580 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1581 where
1582 V: ManagedView,
1583 {
1584 self.update_view(view, |_, cx| cx.emit(DismissEvent))
1585 }
1586}
1587
1588impl<'a> std::ops::Deref for WindowContext<'a> {
1589 type Target = AppContext;
1590
1591 fn deref(&self) -> &Self::Target {
1592 self.app
1593 }
1594}
1595
1596impl<'a> std::ops::DerefMut for WindowContext<'a> {
1597 fn deref_mut(&mut self) -> &mut Self::Target {
1598 self.app
1599 }
1600}
1601
1602impl<'a> Borrow<AppContext> for WindowContext<'a> {
1603 fn borrow(&self) -> &AppContext {
1604 self.app
1605 }
1606}
1607
1608impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1609 fn borrow_mut(&mut self) -> &mut AppContext {
1610 self.app
1611 }
1612}
1613
1614/// This trait contains functionality that is shared across [`ViewContext`] and [`WindowContext`]
1615pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1616 #[doc(hidden)]
1617 fn app_mut(&mut self) -> &mut AppContext {
1618 self.borrow_mut()
1619 }
1620
1621 #[doc(hidden)]
1622 fn app(&self) -> &AppContext {
1623 self.borrow()
1624 }
1625
1626 #[doc(hidden)]
1627 fn window(&self) -> &Window {
1628 self.borrow()
1629 }
1630
1631 #[doc(hidden)]
1632 fn window_mut(&mut self) -> &mut Window {
1633 self.borrow_mut()
1634 }
1635}
1636
1637impl Borrow<Window> for WindowContext<'_> {
1638 fn borrow(&self) -> &Window {
1639 self.window
1640 }
1641}
1642
1643impl BorrowMut<Window> for WindowContext<'_> {
1644 fn borrow_mut(&mut self) -> &mut Window {
1645 self.window
1646 }
1647}
1648
1649impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1650
1651/// Provides access to application state that is specialized for a particular [`View`].
1652/// Allows you to interact with focus, emit events, etc.
1653/// ViewContext also derefs to [`WindowContext`], giving you access to all of its methods as well.
1654/// When you call [`View::update`], you're passed a `&mut V` and an `&mut ViewContext<V>`.
1655pub struct ViewContext<'a, V> {
1656 window_cx: WindowContext<'a>,
1657 view: &'a View<V>,
1658}
1659
1660impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1661 fn borrow(&self) -> &AppContext {
1662 &*self.window_cx.app
1663 }
1664}
1665
1666impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1667 fn borrow_mut(&mut self) -> &mut AppContext {
1668 &mut *self.window_cx.app
1669 }
1670}
1671
1672impl<V> Borrow<Window> for ViewContext<'_, V> {
1673 fn borrow(&self) -> &Window {
1674 &*self.window_cx.window
1675 }
1676}
1677
1678impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1679 fn borrow_mut(&mut self) -> &mut Window {
1680 &mut *self.window_cx.window
1681 }
1682}
1683
1684impl<'a, V: 'static> ViewContext<'a, V> {
1685 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1686 Self {
1687 window_cx: WindowContext::new(app, window),
1688 view,
1689 }
1690 }
1691
1692 /// Get the entity_id of this view.
1693 pub fn entity_id(&self) -> EntityId {
1694 self.view.entity_id()
1695 }
1696
1697 /// Get the view pointer underlying this context.
1698 pub fn view(&self) -> &View<V> {
1699 self.view
1700 }
1701
1702 /// Get the model underlying this view.
1703 pub fn model(&self) -> &Model<V> {
1704 &self.view.model
1705 }
1706
1707 /// Access the underlying window context.
1708 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1709 &mut self.window_cx
1710 }
1711
1712 /// Sets a given callback to be run on the next frame.
1713 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1714 where
1715 V: 'static,
1716 {
1717 let view = self.view().clone();
1718 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1719 }
1720
1721 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1722 /// that are currently on the stack to be returned to the app.
1723 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1724 let view = self.view().downgrade();
1725 self.window_cx.defer(move |cx| {
1726 view.update(cx, f).ok();
1727 });
1728 }
1729
1730 /// Observe another model or view for changes to its state, as tracked by [`ModelContext::notify`].
1731 pub fn observe<V2, E>(
1732 &mut self,
1733 entity: &E,
1734 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1735 ) -> Subscription
1736 where
1737 V2: 'static,
1738 V: 'static,
1739 E: Entity<V2>,
1740 {
1741 let view = self.view().downgrade();
1742 let entity_id = entity.entity_id();
1743 let entity = entity.downgrade();
1744 let window_handle = self.window.handle;
1745 let (subscription, activate) = self.app.observers.insert(
1746 entity_id,
1747 Box::new(move |cx| {
1748 window_handle
1749 .update(cx, |_, cx| {
1750 if let Some(handle) = E::upgrade_from(&entity) {
1751 view.update(cx, |this, cx| on_notify(this, handle, cx))
1752 .is_ok()
1753 } else {
1754 false
1755 }
1756 })
1757 .unwrap_or(false)
1758 }),
1759 );
1760 self.app.defer(move |_| activate());
1761 subscription
1762 }
1763
1764 /// Subscribe to events emitted by another model or view.
1765 /// The entity to which you're subscribing must implement the [`EventEmitter`] trait.
1766 /// 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.
1767 pub fn subscribe<V2, E, Evt>(
1768 &mut self,
1769 entity: &E,
1770 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1771 ) -> Subscription
1772 where
1773 V2: EventEmitter<Evt>,
1774 E: Entity<V2>,
1775 Evt: 'static,
1776 {
1777 let view = self.view().downgrade();
1778 let entity_id = entity.entity_id();
1779 let handle = entity.downgrade();
1780 let window_handle = self.window.handle;
1781 let (subscription, activate) = self.app.event_listeners.insert(
1782 entity_id,
1783 (
1784 TypeId::of::<Evt>(),
1785 Box::new(move |event, cx| {
1786 window_handle
1787 .update(cx, |_, cx| {
1788 if let Some(handle) = E::upgrade_from(&handle) {
1789 let event = event.downcast_ref().expect("invalid event type");
1790 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1791 .is_ok()
1792 } else {
1793 false
1794 }
1795 })
1796 .unwrap_or(false)
1797 }),
1798 ),
1799 );
1800 self.app.defer(move |_| activate());
1801 subscription
1802 }
1803
1804 /// Register a callback to be invoked when the view is released.
1805 ///
1806 /// The callback receives a handle to the view's window. This handle may be
1807 /// invalid, if the window was closed before the view was released.
1808 pub fn on_release(
1809 &mut self,
1810 on_release: impl FnOnce(&mut V, AnyWindowHandle, &mut AppContext) + 'static,
1811 ) -> Subscription {
1812 let window_handle = self.window.handle;
1813 let (subscription, activate) = self.app.release_listeners.insert(
1814 self.view.model.entity_id,
1815 Box::new(move |this, cx| {
1816 let this = this.downcast_mut().expect("invalid entity type");
1817 on_release(this, window_handle, cx)
1818 }),
1819 );
1820 activate();
1821 subscription
1822 }
1823
1824 /// Register a callback to be invoked when the given Model or View is released.
1825 pub fn observe_release<V2, E>(
1826 &mut self,
1827 entity: &E,
1828 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1829 ) -> Subscription
1830 where
1831 V: 'static,
1832 V2: 'static,
1833 E: Entity<V2>,
1834 {
1835 let view = self.view().downgrade();
1836 let entity_id = entity.entity_id();
1837 let window_handle = self.window.handle;
1838 let (subscription, activate) = self.app.release_listeners.insert(
1839 entity_id,
1840 Box::new(move |entity, cx| {
1841 let entity = entity.downcast_mut().expect("invalid entity type");
1842 let _ = window_handle.update(cx, |_, cx| {
1843 view.update(cx, |this, cx| on_release(this, entity, cx))
1844 });
1845 }),
1846 );
1847 activate();
1848 subscription
1849 }
1850
1851 /// Indicate that this view has changed, which will invoke any observers and also mark the window as dirty.
1852 /// If this view or any of its ancestors are *cached*, notifying it will cause it or its ancestors to be redrawn.
1853 pub fn notify(&mut self) {
1854 for view_id in self
1855 .window
1856 .rendered_frame
1857 .dispatch_tree
1858 .view_path(self.view.entity_id())
1859 .into_iter()
1860 .rev()
1861 {
1862 if !self.window.dirty_views.insert(view_id) {
1863 break;
1864 }
1865 }
1866
1867 if !self.window.drawing {
1868 self.window_cx.window.dirty = true;
1869 self.window_cx.app.push_effect(Effect::Notify {
1870 emitter: self.view.model.entity_id,
1871 });
1872 }
1873 }
1874
1875 /// Register a callback to be invoked when the window is resized.
1876 pub fn observe_window_bounds(
1877 &mut self,
1878 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1879 ) -> Subscription {
1880 let view = self.view.downgrade();
1881 let (subscription, activate) = self.window.bounds_observers.insert(
1882 (),
1883 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1884 );
1885 activate();
1886 subscription
1887 }
1888
1889 /// Register a callback to be invoked when the window is activated or deactivated.
1890 pub fn observe_window_activation(
1891 &mut self,
1892 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1893 ) -> Subscription {
1894 let view = self.view.downgrade();
1895 let (subscription, activate) = self.window.activation_observers.insert(
1896 (),
1897 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1898 );
1899 activate();
1900 subscription
1901 }
1902
1903 /// Register a listener to be called when the given focus handle receives focus.
1904 /// Returns a subscription and persists until the subscription is dropped.
1905 pub fn on_focus(
1906 &mut self,
1907 handle: &FocusHandle,
1908 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1909 ) -> Subscription {
1910 let view = self.view.downgrade();
1911 let focus_id = handle.id;
1912 let (subscription, activate) = self.window.focus_listeners.insert(
1913 (),
1914 Box::new(move |event, cx| {
1915 view.update(cx, |view, cx| {
1916 if event.previous_focus_path.last() != Some(&focus_id)
1917 && event.current_focus_path.last() == Some(&focus_id)
1918 {
1919 listener(view, cx)
1920 }
1921 })
1922 .is_ok()
1923 }),
1924 );
1925 self.app.defer(move |_| activate());
1926 subscription
1927 }
1928
1929 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
1930 /// Returns a subscription and persists until the subscription is dropped.
1931 pub fn on_focus_in(
1932 &mut self,
1933 handle: &FocusHandle,
1934 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1935 ) -> Subscription {
1936 let view = self.view.downgrade();
1937 let focus_id = handle.id;
1938 let (subscription, activate) = self.window.focus_listeners.insert(
1939 (),
1940 Box::new(move |event, cx| {
1941 view.update(cx, |view, cx| {
1942 if !event.previous_focus_path.contains(&focus_id)
1943 && event.current_focus_path.contains(&focus_id)
1944 {
1945 listener(view, cx)
1946 }
1947 })
1948 .is_ok()
1949 }),
1950 );
1951 self.app.defer(move |_| activate());
1952 subscription
1953 }
1954
1955 /// Register a listener to be called when the given focus handle loses focus.
1956 /// Returns a subscription and persists until the subscription is dropped.
1957 pub fn on_blur(
1958 &mut self,
1959 handle: &FocusHandle,
1960 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1961 ) -> Subscription {
1962 let view = self.view.downgrade();
1963 let focus_id = handle.id;
1964 let (subscription, activate) = self.window.focus_listeners.insert(
1965 (),
1966 Box::new(move |event, cx| {
1967 view.update(cx, |view, cx| {
1968 if event.previous_focus_path.last() == Some(&focus_id)
1969 && event.current_focus_path.last() != Some(&focus_id)
1970 {
1971 listener(view, cx)
1972 }
1973 })
1974 .is_ok()
1975 }),
1976 );
1977 self.app.defer(move |_| activate());
1978 subscription
1979 }
1980
1981 /// Register a listener to be called when nothing in the window has focus.
1982 /// This typically happens when the node that was focused is removed from the tree,
1983 /// and this callback lets you chose a default place to restore the users focus.
1984 /// Returns a subscription and persists until the subscription is dropped.
1985 pub fn on_focus_lost(
1986 &mut self,
1987 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1988 ) -> Subscription {
1989 let view = self.view.downgrade();
1990 let (subscription, activate) = self.window.focus_lost_listeners.insert(
1991 (),
1992 Box::new(move |cx| view.update(cx, |view, cx| listener(view, cx)).is_ok()),
1993 );
1994 activate();
1995 subscription
1996 }
1997
1998 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
1999 /// Returns a subscription and persists until the subscription is dropped.
2000 pub fn on_focus_out(
2001 &mut self,
2002 handle: &FocusHandle,
2003 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2004 ) -> Subscription {
2005 let view = self.view.downgrade();
2006 let focus_id = handle.id;
2007 let (subscription, activate) = self.window.focus_listeners.insert(
2008 (),
2009 Box::new(move |event, cx| {
2010 view.update(cx, |view, cx| {
2011 if event.previous_focus_path.contains(&focus_id)
2012 && !event.current_focus_path.contains(&focus_id)
2013 {
2014 listener(view, cx)
2015 }
2016 })
2017 .is_ok()
2018 }),
2019 );
2020 self.app.defer(move |_| activate());
2021 subscription
2022 }
2023
2024 /// Schedule a future to be run asynchronously.
2025 /// The given callback is invoked with a [`WeakView<V>`] to avoid leaking the view for a long-running process.
2026 /// It's also given an [`AsyncWindowContext`], which can be used to access the state of the view across await points.
2027 /// The returned future will be polled on the main thread.
2028 pub fn spawn<Fut, R>(
2029 &mut self,
2030 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2031 ) -> Task<R>
2032 where
2033 R: 'static,
2034 Fut: Future<Output = R> + 'static,
2035 {
2036 let view = self.view().downgrade();
2037 self.window_cx.spawn(|cx| f(view, cx))
2038 }
2039
2040 /// Updates the global state of the given type.
2041 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2042 where
2043 G: 'static,
2044 {
2045 let mut global = self.app.lease_global::<G>();
2046 let result = f(&mut global, self);
2047 self.app.end_global_lease(global);
2048 result
2049 }
2050
2051 /// Register a callback to be invoked when the given global state changes.
2052 pub fn observe_global<G: 'static>(
2053 &mut self,
2054 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2055 ) -> Subscription {
2056 let window_handle = self.window.handle;
2057 let view = self.view().downgrade();
2058 let (subscription, activate) = self.global_observers.insert(
2059 TypeId::of::<G>(),
2060 Box::new(move |cx| {
2061 window_handle
2062 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2063 .unwrap_or(false)
2064 }),
2065 );
2066 self.app.defer(move |_| activate());
2067 subscription
2068 }
2069
2070 /// Register a callback to be invoked when the given Action type is dispatched to the window.
2071 pub fn on_action(
2072 &mut self,
2073 action_type: TypeId,
2074 listener: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2075 ) {
2076 let handle = self.view().clone();
2077 self.window_cx
2078 .on_action(action_type, move |action, phase, cx| {
2079 handle.update(cx, |view, cx| {
2080 listener(view, action, phase, cx);
2081 })
2082 });
2083 }
2084
2085 /// Emit an event to be handled any other views that have subscribed via [ViewContext::subscribe].
2086 pub fn emit<Evt>(&mut self, event: Evt)
2087 where
2088 Evt: 'static,
2089 V: EventEmitter<Evt>,
2090 {
2091 let emitter = self.view.model.entity_id;
2092 self.app.push_effect(Effect::Emit {
2093 emitter,
2094 event_type: TypeId::of::<Evt>(),
2095 event: Box::new(event),
2096 });
2097 }
2098
2099 /// Move focus to the current view, assuming it implements [`FocusableView`].
2100 pub fn focus_self(&mut self)
2101 where
2102 V: FocusableView,
2103 {
2104 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2105 }
2106
2107 /// Convenience method for accessing view state in an event callback.
2108 ///
2109 /// Many GPUI callbacks take the form of `Fn(&E, &mut WindowContext)`,
2110 /// but it's often useful to be able to access view state in these
2111 /// callbacks. This method provides a convenient way to do so.
2112 pub fn listener<E>(
2113 &self,
2114 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2115 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2116 let view = self.view().downgrade();
2117 move |e: &E, cx: &mut WindowContext| {
2118 view.update(cx, |view, cx| f(view, e, cx)).ok();
2119 }
2120 }
2121}
2122
2123impl<V> Context for ViewContext<'_, V> {
2124 type Result<U> = U;
2125
2126 fn new_model<T: 'static>(
2127 &mut self,
2128 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2129 ) -> Model<T> {
2130 self.window_cx.new_model(build_model)
2131 }
2132
2133 fn update_model<T: 'static, R>(
2134 &mut self,
2135 model: &Model<T>,
2136 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2137 ) -> R {
2138 self.window_cx.update_model(model, update)
2139 }
2140
2141 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2142 where
2143 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2144 {
2145 self.window_cx.update_window(window, update)
2146 }
2147
2148 fn read_model<T, R>(
2149 &self,
2150 handle: &Model<T>,
2151 read: impl FnOnce(&T, &AppContext) -> R,
2152 ) -> Self::Result<R>
2153 where
2154 T: 'static,
2155 {
2156 self.window_cx.read_model(handle, read)
2157 }
2158
2159 fn read_window<T, R>(
2160 &self,
2161 window: &WindowHandle<T>,
2162 read: impl FnOnce(View<T>, &AppContext) -> R,
2163 ) -> Result<R>
2164 where
2165 T: 'static,
2166 {
2167 self.window_cx.read_window(window, read)
2168 }
2169}
2170
2171impl<V: 'static> VisualContext for ViewContext<'_, V> {
2172 fn new_view<W: Render + 'static>(
2173 &mut self,
2174 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2175 ) -> Self::Result<View<W>> {
2176 self.window_cx.new_view(build_view_state)
2177 }
2178
2179 fn update_view<V2: 'static, R>(
2180 &mut self,
2181 view: &View<V2>,
2182 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2183 ) -> Self::Result<R> {
2184 self.window_cx.update_view(view, update)
2185 }
2186
2187 fn replace_root_view<W>(
2188 &mut self,
2189 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2190 ) -> Self::Result<View<W>>
2191 where
2192 W: 'static + Render,
2193 {
2194 self.window_cx.replace_root_view(build_view)
2195 }
2196
2197 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2198 self.window_cx.focus_view(view)
2199 }
2200
2201 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2202 self.window_cx.dismiss_view(view)
2203 }
2204}
2205
2206impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2207 type Target = WindowContext<'a>;
2208
2209 fn deref(&self) -> &Self::Target {
2210 &self.window_cx
2211 }
2212}
2213
2214impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2215 fn deref_mut(&mut self) -> &mut Self::Target {
2216 &mut self.window_cx
2217 }
2218}
2219
2220// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2221slotmap::new_key_type! {
2222 /// A unique identifier for a window.
2223 pub struct WindowId;
2224}
2225
2226impl WindowId {
2227 /// Converts this window ID to a `u64`.
2228 pub fn as_u64(&self) -> u64 {
2229 self.0.as_ffi()
2230 }
2231}
2232
2233/// A handle to a window with a specific root view type.
2234/// Note that this does not keep the window alive on its own.
2235#[derive(Deref, DerefMut)]
2236pub struct WindowHandle<V> {
2237 #[deref]
2238 #[deref_mut]
2239 pub(crate) any_handle: AnyWindowHandle,
2240 state_type: PhantomData<V>,
2241}
2242
2243impl<V: 'static + Render> WindowHandle<V> {
2244 /// Creates a new handle from a window ID.
2245 /// This does not check if the root type of the window is `V`.
2246 pub fn new(id: WindowId) -> Self {
2247 WindowHandle {
2248 any_handle: AnyWindowHandle {
2249 id,
2250 state_type: TypeId::of::<V>(),
2251 },
2252 state_type: PhantomData,
2253 }
2254 }
2255
2256 /// Get the root view out of this window.
2257 ///
2258 /// This will fail if the window is closed or if the root view's type does not match `V`.
2259 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2260 where
2261 C: Context,
2262 {
2263 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2264 root_view
2265 .downcast::<V>()
2266 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2267 }))
2268 }
2269
2270 /// Updates the root view of this window.
2271 ///
2272 /// This will fail if the window has been closed or if the root view's type does not match
2273 pub fn update<C, R>(
2274 &self,
2275 cx: &mut C,
2276 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2277 ) -> Result<R>
2278 where
2279 C: Context,
2280 {
2281 cx.update_window(self.any_handle, |root_view, cx| {
2282 let view = root_view
2283 .downcast::<V>()
2284 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2285 Ok(cx.update_view(&view, update))
2286 })?
2287 }
2288
2289 /// Read the root view out of this window.
2290 ///
2291 /// This will fail if the window is closed or if the root view's type does not match `V`.
2292 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2293 let x = cx
2294 .windows
2295 .get(self.id)
2296 .and_then(|window| {
2297 window
2298 .as_ref()
2299 .and_then(|window| window.root_view.clone())
2300 .map(|root_view| root_view.downcast::<V>())
2301 })
2302 .ok_or_else(|| anyhow!("window not found"))?
2303 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2304
2305 Ok(x.read(cx))
2306 }
2307
2308 /// Read the root view out of this window, with a callback
2309 ///
2310 /// This will fail if the window is closed or if the root view's type does not match `V`.
2311 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2312 where
2313 C: Context,
2314 {
2315 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2316 }
2317
2318 /// Read the root view pointer off of this window.
2319 ///
2320 /// This will fail if the window is closed or if the root view's type does not match `V`.
2321 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2322 where
2323 C: Context,
2324 {
2325 cx.read_window(self, |root_view, _cx| root_view.clone())
2326 }
2327
2328 /// Check if this window is 'active'.
2329 ///
2330 /// Will return `None` if the window is closed.
2331 pub fn is_active(&self, cx: &AppContext) -> Option<bool> {
2332 cx.windows
2333 .get(self.id)
2334 .and_then(|window| window.as_ref().map(|window| window.active))
2335 }
2336}
2337
2338impl<V> Copy for WindowHandle<V> {}
2339
2340impl<V> Clone for WindowHandle<V> {
2341 fn clone(&self) -> Self {
2342 *self
2343 }
2344}
2345
2346impl<V> PartialEq for WindowHandle<V> {
2347 fn eq(&self, other: &Self) -> bool {
2348 self.any_handle == other.any_handle
2349 }
2350}
2351
2352impl<V> Eq for WindowHandle<V> {}
2353
2354impl<V> Hash for WindowHandle<V> {
2355 fn hash<H: Hasher>(&self, state: &mut H) {
2356 self.any_handle.hash(state);
2357 }
2358}
2359
2360impl<V: 'static> From<WindowHandle<V>> for AnyWindowHandle {
2361 fn from(val: WindowHandle<V>) -> Self {
2362 val.any_handle
2363 }
2364}
2365
2366/// A handle to a window with any root view type, which can be downcast to a window with a specific root view type.
2367#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2368pub struct AnyWindowHandle {
2369 pub(crate) id: WindowId,
2370 state_type: TypeId,
2371}
2372
2373impl AnyWindowHandle {
2374 /// Get the ID of this window.
2375 pub fn window_id(&self) -> WindowId {
2376 self.id
2377 }
2378
2379 /// Attempt to convert this handle to a window handle with a specific root view type.
2380 /// If the types do not match, this will return `None`.
2381 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2382 if TypeId::of::<T>() == self.state_type {
2383 Some(WindowHandle {
2384 any_handle: *self,
2385 state_type: PhantomData,
2386 })
2387 } else {
2388 None
2389 }
2390 }
2391
2392 /// Updates the state of the root view of this window.
2393 ///
2394 /// This will fail if the window has been closed.
2395 pub fn update<C, R>(
2396 self,
2397 cx: &mut C,
2398 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2399 ) -> Result<R>
2400 where
2401 C: Context,
2402 {
2403 cx.update_window(self, update)
2404 }
2405
2406 /// Read the state of the root view of this window.
2407 ///
2408 /// This will fail if the window has been closed.
2409 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2410 where
2411 C: Context,
2412 T: 'static,
2413 {
2414 let view = self
2415 .downcast::<T>()
2416 .context("the type of the window's root view has changed")?;
2417
2418 cx.read_window(&view, read)
2419 }
2420}
2421
2422/// An identifier for an [`Element`](crate::Element).
2423///
2424/// Can be constructed with a string, a number, or both, as well
2425/// as other internal representations.
2426#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2427pub enum ElementId {
2428 /// The ID of a View element
2429 View(EntityId),
2430 /// An integer ID.
2431 Integer(usize),
2432 /// A string based ID.
2433 Name(SharedString),
2434 /// An ID that's equated with a focus handle.
2435 FocusHandle(FocusId),
2436 /// A combination of a name and an integer.
2437 NamedInteger(SharedString, usize),
2438}
2439
2440impl Display for ElementId {
2441 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
2442 match self {
2443 ElementId::View(entity_id) => write!(f, "view-{}", entity_id)?,
2444 ElementId::Integer(ix) => write!(f, "{}", ix)?,
2445 ElementId::Name(name) => write!(f, "{}", name)?,
2446 ElementId::FocusHandle(__) => write!(f, "FocusHandle")?,
2447 ElementId::NamedInteger(s, i) => write!(f, "{}-{}", s, i)?,
2448 }
2449
2450 Ok(())
2451 }
2452}
2453
2454impl ElementId {
2455 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2456 ElementId::View(entity_id)
2457 }
2458}
2459
2460impl TryInto<SharedString> for ElementId {
2461 type Error = anyhow::Error;
2462
2463 fn try_into(self) -> anyhow::Result<SharedString> {
2464 if let ElementId::Name(name) = self {
2465 Ok(name)
2466 } else {
2467 Err(anyhow!("element id is not string"))
2468 }
2469 }
2470}
2471
2472impl From<usize> for ElementId {
2473 fn from(id: usize) -> Self {
2474 ElementId::Integer(id)
2475 }
2476}
2477
2478impl From<i32> for ElementId {
2479 fn from(id: i32) -> Self {
2480 Self::Integer(id as usize)
2481 }
2482}
2483
2484impl From<SharedString> for ElementId {
2485 fn from(name: SharedString) -> Self {
2486 ElementId::Name(name)
2487 }
2488}
2489
2490impl From<&'static str> for ElementId {
2491 fn from(name: &'static str) -> Self {
2492 ElementId::Name(name.into())
2493 }
2494}
2495
2496impl<'a> From<&'a FocusHandle> for ElementId {
2497 fn from(handle: &'a FocusHandle) -> Self {
2498 ElementId::FocusHandle(handle.id)
2499 }
2500}
2501
2502impl From<(&'static str, EntityId)> for ElementId {
2503 fn from((name, id): (&'static str, EntityId)) -> Self {
2504 ElementId::NamedInteger(name.into(), id.as_u64() as usize)
2505 }
2506}
2507
2508impl From<(&'static str, usize)> for ElementId {
2509 fn from((name, id): (&'static str, usize)) -> Self {
2510 ElementId::NamedInteger(name.into(), id)
2511 }
2512}
2513
2514impl From<(&'static str, u64)> for ElementId {
2515 fn from((name, id): (&'static str, u64)) -> Self {
2516 ElementId::NamedInteger(name.into(), id as usize)
2517 }
2518}
2519
2520/// A rectangle to be rendered in the window at the given position and size.
2521/// Passed as an argument [`WindowContext::paint_quad`].
2522#[derive(Clone)]
2523pub struct PaintQuad {
2524 bounds: Bounds<Pixels>,
2525 corner_radii: Corners<Pixels>,
2526 background: Hsla,
2527 border_widths: Edges<Pixels>,
2528 border_color: Hsla,
2529}
2530
2531impl PaintQuad {
2532 /// Sets the corner radii of the quad.
2533 pub fn corner_radii(self, corner_radii: impl Into<Corners<Pixels>>) -> Self {
2534 PaintQuad {
2535 corner_radii: corner_radii.into(),
2536 ..self
2537 }
2538 }
2539
2540 /// Sets the border widths of the quad.
2541 pub fn border_widths(self, border_widths: impl Into<Edges<Pixels>>) -> Self {
2542 PaintQuad {
2543 border_widths: border_widths.into(),
2544 ..self
2545 }
2546 }
2547
2548 /// Sets the border color of the quad.
2549 pub fn border_color(self, border_color: impl Into<Hsla>) -> Self {
2550 PaintQuad {
2551 border_color: border_color.into(),
2552 ..self
2553 }
2554 }
2555
2556 /// Sets the background color of the quad.
2557 pub fn background(self, background: impl Into<Hsla>) -> Self {
2558 PaintQuad {
2559 background: background.into(),
2560 ..self
2561 }
2562 }
2563}
2564
2565/// Creates a quad with the given parameters.
2566pub fn quad(
2567 bounds: Bounds<Pixels>,
2568 corner_radii: impl Into<Corners<Pixels>>,
2569 background: impl Into<Hsla>,
2570 border_widths: impl Into<Edges<Pixels>>,
2571 border_color: impl Into<Hsla>,
2572) -> PaintQuad {
2573 PaintQuad {
2574 bounds,
2575 corner_radii: corner_radii.into(),
2576 background: background.into(),
2577 border_widths: border_widths.into(),
2578 border_color: border_color.into(),
2579 }
2580}
2581
2582/// Creates a filled quad with the given bounds and background color.
2583pub fn fill(bounds: impl Into<Bounds<Pixels>>, background: impl Into<Hsla>) -> PaintQuad {
2584 PaintQuad {
2585 bounds: bounds.into(),
2586 corner_radii: (0.).into(),
2587 background: background.into(),
2588 border_widths: (0.).into(),
2589 border_color: transparent_black(),
2590 }
2591}
2592
2593/// Creates a rectangle outline with the given bounds, border color, and a 1px border width
2594pub fn outline(bounds: impl Into<Bounds<Pixels>>, border_color: impl Into<Hsla>) -> PaintQuad {
2595 PaintQuad {
2596 bounds: bounds.into(),
2597 corner_radii: (0.).into(),
2598 background: transparent_black(),
2599 border_widths: (1.).into(),
2600 border_color: border_color.into(),
2601 }
2602}