1use crate::{
2 px, size, Action, AnyBox, AnyDrag, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
3 Bounds, BoxShadow, Context, Corners, CursorStyle, DevicePixels, DispatchContext, DisplayId,
4 Edges, Effect, Entity, EntityId, EventEmitter, FileDropEvent, FocusEvent, FontId,
5 GlobalElementId, GlyphId, Hsla, ImageData, InputEvent, InputHandler, IsZero, KeyListener,
6 KeyMatch, KeyMatcher, Keystroke, LayoutId, Model, ModelContext, Modifiers, MonochromeSprite,
7 MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas,
8 PlatformDisplay, PlatformInputHandler, PlatformWindow, Point, PolychromeSprite, PromptLevel,
9 Quad, Render, RenderGlyphParams, RenderImageParams, RenderSvgParams, ScaledPixels,
10 SceneBuilder, Shadow, SharedString, Size, Style, SubscriberSet, Subscription,
11 TaffyLayoutEngine, Task, Underline, UnderlineStyle, View, VisualContext, WeakView,
12 WindowBounds, WindowInputHandler, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use parking_lot::RwLock;
22use slotmap::SlotMap;
23use smallvec::SmallVec;
24use std::{
25 any::{Any, TypeId},
26 borrow::{Borrow, BorrowMut, Cow},
27 fmt::Debug,
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37};
38use util::ResultExt;
39
40/// A global stacking order, which is created by stacking successive z-index values.
41/// Each z-index will always be interpreted in the context of its parent z-index.
42#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
43pub(crate) struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
44
45/// Represents the two different phases when dispatching events.
46#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
47pub enum DispatchPhase {
48 /// After the capture phase comes the bubble phase, in which mouse event listeners are
49 /// invoked front to back and keyboard event listeners are invoked from the focused element
50 /// to the root of the element tree. This is the phase you'll most commonly want to use when
51 /// registering event listeners.
52 #[default]
53 Bubble,
54 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
55 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
56 /// is used for special purposes such as clearing the "pressed" state for click events. If
57 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
58 /// outside of the immediate region may rely on detecting non-local events during this phase.
59 Capture,
60}
61
62type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
63type AnyListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
64type AnyKeyListener = Box<
65 dyn Fn(
66 &dyn Any,
67 &[&DispatchContext],
68 DispatchPhase,
69 &mut WindowContext,
70 ) -> Option<Box<dyn Action>>
71 + 'static,
72>;
73type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
74type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
75
76slotmap::new_key_type! { pub struct FocusId; }
77
78impl FocusId {
79 /// Obtains whether the element associated with this handle is currently focused.
80 pub fn is_focused(&self, cx: &WindowContext) -> bool {
81 cx.window.focus == Some(*self)
82 }
83
84 /// Obtains whether the element associated with this handle contains the focused
85 /// element or is itself focused.
86 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
87 cx.focused()
88 .map_or(false, |focused| self.contains(focused.id, cx))
89 }
90
91 /// Obtains whether the element associated with this handle is contained within the
92 /// focused element or is itself focused.
93 pub fn within_focused(&self, cx: &WindowContext) -> bool {
94 let focused = cx.focused();
95 focused.map_or(false, |focused| focused.id.contains(*self, cx))
96 }
97
98 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
99 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
100 let mut ancestor = Some(other);
101 while let Some(ancestor_id) = ancestor {
102 if *self == ancestor_id {
103 return true;
104 } else {
105 ancestor = cx
106 .window
107 .current_frame
108 .focus_parents_by_child
109 .get(&ancestor_id)
110 .copied();
111 }
112 }
113 false
114 }
115}
116
117/// A handle which can be used to track and manipulate the focused element in a window.
118pub struct FocusHandle {
119 pub(crate) id: FocusId,
120 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
121}
122
123impl FocusHandle {
124 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
125 let id = handles.write().insert(AtomicUsize::new(1));
126 Self {
127 id,
128 handles: handles.clone(),
129 }
130 }
131
132 pub(crate) fn for_id(
133 id: FocusId,
134 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
135 ) -> Option<Self> {
136 let lock = handles.read();
137 let ref_count = lock.get(id)?;
138 if ref_count.load(SeqCst) == 0 {
139 None
140 } else {
141 ref_count.fetch_add(1, SeqCst);
142 Some(Self {
143 id,
144 handles: handles.clone(),
145 })
146 }
147 }
148
149 /// Obtains whether the element associated with this handle is currently focused.
150 pub fn is_focused(&self, cx: &WindowContext) -> bool {
151 self.id.is_focused(cx)
152 }
153
154 /// Obtains whether the element associated with this handle contains the focused
155 /// element or is itself focused.
156 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
157 self.id.contains_focused(cx)
158 }
159
160 /// Obtains whether the element associated with this handle is contained within the
161 /// focused element or is itself focused.
162 pub fn within_focused(&self, cx: &WindowContext) -> bool {
163 self.id.within_focused(cx)
164 }
165
166 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
167 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
168 self.id.contains(other.id, cx)
169 }
170}
171
172impl Clone for FocusHandle {
173 fn clone(&self) -> Self {
174 Self::for_id(self.id, &self.handles).unwrap()
175 }
176}
177
178impl PartialEq for FocusHandle {
179 fn eq(&self, other: &Self) -> bool {
180 self.id == other.id
181 }
182}
183
184impl Eq for FocusHandle {}
185
186impl Drop for FocusHandle {
187 fn drop(&mut self) {
188 self.handles
189 .read()
190 .get(self.id)
191 .unwrap()
192 .fetch_sub(1, SeqCst);
193 }
194}
195
196// Holds the state for a specific window.
197pub struct Window {
198 pub(crate) handle: AnyWindowHandle,
199 pub(crate) removed: bool,
200 platform_window: Box<dyn PlatformWindow>,
201 display_id: DisplayId,
202 sprite_atlas: Arc<dyn PlatformAtlas>,
203 rem_size: Pixels,
204 content_size: Size<Pixels>,
205 pub(crate) layout_engine: TaffyLayoutEngine,
206 pub(crate) root_view: Option<AnyView>,
207 pub(crate) element_id_stack: GlobalElementId,
208 pub(crate) previous_frame: Frame,
209 pub(crate) current_frame: Frame,
210 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
211 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
212 default_prevented: bool,
213 mouse_position: Point<Pixels>,
214 requested_cursor_style: Option<CursorStyle>,
215 requested_input_handler: Option<Box<dyn PlatformInputHandler>>,
216 scale_factor: f32,
217 bounds: WindowBounds,
218 bounds_observers: SubscriberSet<(), AnyObserver>,
219 active: bool,
220 activation_observers: SubscriberSet<(), AnyObserver>,
221 pub(crate) dirty: bool,
222 pub(crate) last_blur: Option<Option<FocusId>>,
223 pub(crate) focus: Option<FocusId>,
224}
225
226#[derive(Default)]
227pub(crate) struct Frame {
228 element_states: HashMap<GlobalElementId, AnyBox>,
229 key_matchers: HashMap<GlobalElementId, KeyMatcher>,
230 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyListener)>>,
231 pub(crate) focus_listeners: Vec<AnyFocusListener>,
232 key_dispatch_stack: Vec<KeyDispatchStackFrame>,
233 freeze_key_dispatch_stack: bool,
234 focus_parents_by_child: HashMap<FocusId, FocusId>,
235 pub(crate) scene_builder: SceneBuilder,
236 z_index_stack: StackingOrder,
237 content_mask_stack: Vec<ContentMask<Pixels>>,
238 element_offset_stack: Vec<Point<Pixels>>,
239 focus_stack: Vec<FocusId>,
240}
241
242impl Window {
243 pub(crate) fn new(
244 handle: AnyWindowHandle,
245 options: WindowOptions,
246 cx: &mut AppContext,
247 ) -> Self {
248 let platform_window = cx.platform.open_window(handle, options);
249 let display_id = platform_window.display().id();
250 let sprite_atlas = platform_window.sprite_atlas();
251 let mouse_position = platform_window.mouse_position();
252 let content_size = platform_window.content_size();
253 let scale_factor = platform_window.scale_factor();
254 let bounds = platform_window.bounds();
255
256 platform_window.on_resize(Box::new({
257 let mut cx = cx.to_async();
258 move |_, _| {
259 handle
260 .update(&mut cx, |_, cx| cx.window_bounds_changed())
261 .log_err();
262 }
263 }));
264 platform_window.on_moved(Box::new({
265 let mut cx = cx.to_async();
266 move || {
267 handle
268 .update(&mut cx, |_, cx| cx.window_bounds_changed())
269 .log_err();
270 }
271 }));
272 platform_window.on_active_status_change(Box::new({
273 let mut cx = cx.to_async();
274 move |active| {
275 handle
276 .update(&mut cx, |_, cx| {
277 cx.window.active = active;
278 cx.window
279 .activation_observers
280 .clone()
281 .retain(&(), |callback| callback(cx));
282 })
283 .log_err();
284 }
285 }));
286
287 platform_window.on_input({
288 let mut cx = cx.to_async();
289 Box::new(move |event| {
290 handle
291 .update(&mut cx, |_, cx| cx.dispatch_event(event))
292 .log_err()
293 .unwrap_or(false)
294 })
295 });
296
297 Window {
298 handle,
299 removed: false,
300 platform_window,
301 display_id,
302 sprite_atlas,
303 rem_size: px(16.),
304 content_size,
305 layout_engine: TaffyLayoutEngine::new(),
306 root_view: None,
307 element_id_stack: GlobalElementId::default(),
308 previous_frame: Frame::default(),
309 current_frame: Frame::default(),
310 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
311 focus_listeners: SubscriberSet::new(),
312 default_prevented: true,
313 mouse_position,
314 requested_cursor_style: None,
315 requested_input_handler: None,
316 scale_factor,
317 bounds,
318 bounds_observers: SubscriberSet::new(),
319 active: false,
320 activation_observers: SubscriberSet::new(),
321 dirty: true,
322 last_blur: None,
323 focus: None,
324 }
325 }
326}
327
328/// When constructing the element tree, we maintain a stack of key dispatch frames until we
329/// find the focused element. We interleave key listeners with dispatch contexts so we can use the
330/// contexts when matching key events against the keymap. A key listener can be either an action
331/// handler or a [KeyDown] / [KeyUp] event listener.
332enum KeyDispatchStackFrame {
333 Listener {
334 event_type: TypeId,
335 listener: AnyKeyListener,
336 },
337 Context(DispatchContext),
338}
339
340/// Indicates which region of the window is visible. Content falling outside of this mask will not be
341/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
342/// to leave room to support more complex shapes in the future.
343#[derive(Clone, Debug, Default, PartialEq, Eq)]
344#[repr(C)]
345pub struct ContentMask<P: Clone + Default + Debug> {
346 pub bounds: Bounds<P>,
347}
348
349impl ContentMask<Pixels> {
350 /// Scale the content mask's pixel units by the given scaling factor.
351 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
352 ContentMask {
353 bounds: self.bounds.scale(factor),
354 }
355 }
356
357 /// Intersect the content mask with the given content mask.
358 pub fn intersect(&self, other: &Self) -> Self {
359 let bounds = self.bounds.intersect(&other.bounds);
360 ContentMask { bounds }
361 }
362}
363
364/// Provides access to application state in the context of a single window. Derefs
365/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
366/// an `AppContext` and call any `AppContext` methods.
367pub struct WindowContext<'a> {
368 pub(crate) app: &'a mut AppContext,
369 pub(crate) window: &'a mut Window,
370}
371
372impl<'a> WindowContext<'a> {
373 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
374 Self { app, window }
375 }
376
377 /// Obtain a handle to the window that belongs to this context.
378 pub fn window_handle(&self) -> AnyWindowHandle {
379 self.window.handle
380 }
381
382 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
383 pub fn notify(&mut self) {
384 self.window.dirty = true;
385 }
386
387 /// Close this window.
388 pub fn remove_window(&mut self) {
389 self.window.removed = true;
390 }
391
392 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
393 /// for elements rendered within this window.
394 pub fn focus_handle(&mut self) -> FocusHandle {
395 FocusHandle::new(&self.window.focus_handles)
396 }
397
398 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
399 pub fn focused(&self) -> Option<FocusHandle> {
400 self.window
401 .focus
402 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
403 }
404
405 /// Move focus to the element associated with the given `FocusHandle`.
406 pub fn focus(&mut self, handle: &FocusHandle) {
407 if self.window.last_blur.is_none() {
408 self.window.last_blur = Some(self.window.focus);
409 }
410
411 self.window.focus = Some(handle.id);
412 self.app.push_effect(Effect::FocusChanged {
413 window_handle: self.window.handle,
414 focused: Some(handle.id),
415 });
416 self.notify();
417 }
418
419 /// Remove focus from all elements within this context's window.
420 pub fn blur(&mut self) {
421 if self.window.last_blur.is_none() {
422 self.window.last_blur = Some(self.window.focus);
423 }
424
425 self.window.focus = None;
426 self.app.push_effect(Effect::FocusChanged {
427 window_handle: self.window.handle,
428 focused: None,
429 });
430 self.notify();
431 }
432
433 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
434 /// that are currently on the stack to be returned to the app.
435 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
436 let handle = self.window.handle;
437 self.app.defer(move |cx| {
438 handle.update(cx, |_, cx| f(cx)).ok();
439 });
440 }
441
442 pub fn subscribe<Emitter, E>(
443 &mut self,
444 entity: &E,
445 mut on_event: impl FnMut(E, &Emitter::Event, &mut WindowContext<'_>) + 'static,
446 ) -> Subscription
447 where
448 Emitter: EventEmitter,
449 E: Entity<Emitter>,
450 {
451 let entity_id = entity.entity_id();
452 let entity = entity.downgrade();
453 let window_handle = self.window.handle;
454 self.app.event_listeners.insert(
455 entity_id,
456 Box::new(move |event, cx| {
457 window_handle
458 .update(cx, |_, cx| {
459 if let Some(handle) = E::upgrade_from(&entity) {
460 let event = event.downcast_ref().expect("invalid event type");
461 on_event(handle, event, cx);
462 true
463 } else {
464 false
465 }
466 })
467 .unwrap_or(false)
468 }),
469 )
470 }
471
472 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
473 /// await points in async code.
474 pub fn to_async(&self) -> AsyncWindowContext {
475 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
476 }
477
478 /// Schedule the given closure to be run directly after the current frame is rendered.
479 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
480 let handle = self.window.handle;
481 let display_id = self.window.display_id;
482
483 if !self.frame_consumers.contains_key(&display_id) {
484 let (tx, mut rx) = mpsc::unbounded::<()>();
485 self.platform.set_display_link_output_callback(
486 display_id,
487 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
488 );
489
490 let consumer_task = self.app.spawn(|cx| async move {
491 while rx.next().await.is_some() {
492 cx.update(|cx| {
493 for callback in cx
494 .next_frame_callbacks
495 .get_mut(&display_id)
496 .unwrap()
497 .drain(..)
498 .collect::<SmallVec<[_; 32]>>()
499 {
500 callback(cx);
501 }
502 })
503 .ok();
504
505 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
506
507 cx.update(|cx| {
508 if cx.next_frame_callbacks.is_empty() {
509 cx.platform.stop_display_link(display_id);
510 }
511 })
512 .ok();
513 }
514 });
515 self.frame_consumers.insert(display_id, consumer_task);
516 }
517
518 if self.next_frame_callbacks.is_empty() {
519 self.platform.start_display_link(display_id);
520 }
521
522 self.next_frame_callbacks
523 .entry(display_id)
524 .or_default()
525 .push(Box::new(move |cx: &mut AppContext| {
526 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
527 }));
528 }
529
530 /// Spawn the future returned by the given closure on the application thread pool.
531 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
532 /// use within your future.
533 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
534 where
535 R: 'static,
536 Fut: Future<Output = R> + 'static,
537 {
538 self.app
539 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
540 }
541
542 /// Update the global of the given type. The given closure is given simultaneous mutable
543 /// access both to the global and the context.
544 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
545 where
546 G: 'static,
547 {
548 let mut global = self.app.lease_global::<G>();
549 let result = f(&mut global, self);
550 self.app.end_global_lease(global);
551 result
552 }
553
554 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
555 /// layout is being requested, along with the layout ids of any children. This method is called during
556 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
557 pub fn request_layout(
558 &mut self,
559 style: &Style,
560 children: impl IntoIterator<Item = LayoutId>,
561 ) -> LayoutId {
562 self.app.layout_id_buffer.clear();
563 self.app.layout_id_buffer.extend(children.into_iter());
564 let rem_size = self.rem_size();
565
566 self.window
567 .layout_engine
568 .request_layout(style, rem_size, &self.app.layout_id_buffer)
569 }
570
571 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
572 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
573 /// determine the element's size. One place this is used internally is when measuring text.
574 ///
575 /// The given closure is invoked at layout time with the known dimensions and available space and
576 /// returns a `Size`.
577 pub fn request_measured_layout<
578 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
579 >(
580 &mut self,
581 style: Style,
582 rem_size: Pixels,
583 measure: F,
584 ) -> LayoutId {
585 self.window
586 .layout_engine
587 .request_measured_layout(style, rem_size, measure)
588 }
589
590 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
591 self.window
592 .layout_engine
593 .compute_layout(layout_id, available_space)
594 }
595
596 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
597 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
598 /// in order to pass your element its `Bounds` automatically.
599 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
600 let mut bounds = self
601 .window
602 .layout_engine
603 .layout_bounds(layout_id)
604 .map(Into::into);
605 bounds.origin += self.element_offset();
606 bounds
607 }
608
609 fn window_bounds_changed(&mut self) {
610 self.window.scale_factor = self.window.platform_window.scale_factor();
611 self.window.content_size = self.window.platform_window.content_size();
612 self.window.bounds = self.window.platform_window.bounds();
613 self.window.display_id = self.window.platform_window.display().id();
614 self.window.dirty = true;
615
616 self.window
617 .bounds_observers
618 .clone()
619 .retain(&(), |callback| callback(self));
620 }
621
622 pub fn window_bounds(&self) -> WindowBounds {
623 self.window.bounds
624 }
625
626 pub fn is_window_active(&self) -> bool {
627 self.window.active
628 }
629
630 pub fn zoom_window(&self) {
631 self.window.platform_window.zoom();
632 }
633
634 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
635 self.platform
636 .displays()
637 .into_iter()
638 .find(|display| display.id() == self.window.display_id)
639 }
640
641 pub fn show_character_palette(&self) {
642 self.window.platform_window.show_character_palette();
643 }
644
645 /// The scale factor of the display associated with the window. For example, it could
646 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
647 /// be rendered as two pixels on screen.
648 pub fn scale_factor(&self) -> f32 {
649 self.window.scale_factor
650 }
651
652 /// The size of an em for the base font of the application. Adjusting this value allows the
653 /// UI to scale, just like zooming a web page.
654 pub fn rem_size(&self) -> Pixels {
655 self.window.rem_size
656 }
657
658 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
659 /// UI to scale, just like zooming a web page.
660 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
661 self.window.rem_size = rem_size.into();
662 }
663
664 /// The line height associated with the current text style.
665 pub fn line_height(&self) -> Pixels {
666 let rem_size = self.rem_size();
667 let text_style = self.text_style();
668 text_style
669 .line_height
670 .to_pixels(text_style.font_size.into(), rem_size)
671 }
672
673 /// Call to prevent the default action of an event. Currently only used to prevent
674 /// parent elements from becoming focused on mouse down.
675 pub fn prevent_default(&mut self) {
676 self.window.default_prevented = true;
677 }
678
679 /// Obtain whether default has been prevented for the event currently being dispatched.
680 pub fn default_prevented(&self) -> bool {
681 self.window.default_prevented
682 }
683
684 /// Register a mouse event listener on the window for the current frame. The type of event
685 /// is determined by the first parameter of the given listener. When the next frame is rendered
686 /// the listener will be cleared.
687 ///
688 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
689 /// a specific need to register a global listener.
690 pub fn on_mouse_event<Event: 'static>(
691 &mut self,
692 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
693 ) {
694 let order = self.window.current_frame.z_index_stack.clone();
695 self.window
696 .current_frame
697 .mouse_listeners
698 .entry(TypeId::of::<Event>())
699 .or_default()
700 .push((
701 order,
702 Box::new(move |event: &dyn Any, phase, cx| {
703 handler(event.downcast_ref().unwrap(), phase, cx)
704 }),
705 ))
706 }
707
708 /// The position of the mouse relative to the window.
709 pub fn mouse_position(&self) -> Point<Pixels> {
710 self.window.mouse_position
711 }
712
713 pub fn set_cursor_style(&mut self, style: CursorStyle) {
714 self.window.requested_cursor_style = Some(style)
715 }
716
717 /// Called during painting to invoke the given closure in a new stacking context. The given
718 /// z-index is interpreted relative to the previous call to `stack`.
719 pub fn stack<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
720 self.window.current_frame.z_index_stack.push(z_index);
721 let result = f(self);
722 self.window.current_frame.z_index_stack.pop();
723 result
724 }
725
726 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
727 pub fn paint_shadows(
728 &mut self,
729 bounds: Bounds<Pixels>,
730 corner_radii: Corners<Pixels>,
731 shadows: &[BoxShadow],
732 ) {
733 let scale_factor = self.scale_factor();
734 let content_mask = self.content_mask();
735 let window = &mut *self.window;
736 for shadow in shadows {
737 let mut shadow_bounds = bounds;
738 shadow_bounds.origin += shadow.offset;
739 shadow_bounds.dilate(shadow.spread_radius);
740 window.current_frame.scene_builder.insert(
741 &window.current_frame.z_index_stack,
742 Shadow {
743 order: 0,
744 bounds: shadow_bounds.scale(scale_factor),
745 content_mask: content_mask.scale(scale_factor),
746 corner_radii: corner_radii.scale(scale_factor),
747 color: shadow.color,
748 blur_radius: shadow.blur_radius.scale(scale_factor),
749 },
750 );
751 }
752 }
753
754 /// Paint one or more quads into the scene for the current frame at the current stacking context.
755 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
756 pub fn paint_quad(
757 &mut self,
758 bounds: Bounds<Pixels>,
759 corner_radii: Corners<Pixels>,
760 background: impl Into<Hsla>,
761 border_widths: Edges<Pixels>,
762 border_color: impl Into<Hsla>,
763 ) {
764 let scale_factor = self.scale_factor();
765 let content_mask = self.content_mask();
766
767 let window = &mut *self.window;
768 window.current_frame.scene_builder.insert(
769 &window.current_frame.z_index_stack,
770 Quad {
771 order: 0,
772 bounds: bounds.scale(scale_factor),
773 content_mask: content_mask.scale(scale_factor),
774 background: background.into(),
775 border_color: border_color.into(),
776 corner_radii: corner_radii.scale(scale_factor),
777 border_widths: border_widths.scale(scale_factor),
778 },
779 );
780 }
781
782 /// Paint the given `Path` into the scene for the current frame at the current z-index.
783 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
784 let scale_factor = self.scale_factor();
785 let content_mask = self.content_mask();
786 path.content_mask = content_mask;
787 path.color = color.into();
788 let window = &mut *self.window;
789 window.current_frame.scene_builder.insert(
790 &window.current_frame.z_index_stack,
791 path.scale(scale_factor),
792 );
793 }
794
795 /// Paint an underline into the scene for the current frame at the current z-index.
796 pub fn paint_underline(
797 &mut self,
798 origin: Point<Pixels>,
799 width: Pixels,
800 style: &UnderlineStyle,
801 ) -> Result<()> {
802 let scale_factor = self.scale_factor();
803 let height = if style.wavy {
804 style.thickness * 3.
805 } else {
806 style.thickness
807 };
808 let bounds = Bounds {
809 origin,
810 size: size(width, height),
811 };
812 let content_mask = self.content_mask();
813 let window = &mut *self.window;
814 window.current_frame.scene_builder.insert(
815 &window.current_frame.z_index_stack,
816 Underline {
817 order: 0,
818 bounds: bounds.scale(scale_factor),
819 content_mask: content_mask.scale(scale_factor),
820 thickness: style.thickness.scale(scale_factor),
821 color: style.color.unwrap_or_default(),
822 wavy: style.wavy,
823 },
824 );
825 Ok(())
826 }
827
828 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
829 /// The y component of the origin is the baseline of the glyph.
830 pub fn paint_glyph(
831 &mut self,
832 origin: Point<Pixels>,
833 font_id: FontId,
834 glyph_id: GlyphId,
835 font_size: Pixels,
836 color: Hsla,
837 ) -> Result<()> {
838 let scale_factor = self.scale_factor();
839 let glyph_origin = origin.scale(scale_factor);
840 let subpixel_variant = Point {
841 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
842 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
843 };
844 let params = RenderGlyphParams {
845 font_id,
846 glyph_id,
847 font_size,
848 subpixel_variant,
849 scale_factor,
850 is_emoji: false,
851 };
852
853 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
854 if !raster_bounds.is_zero() {
855 let tile =
856 self.window
857 .sprite_atlas
858 .get_or_insert_with(¶ms.clone().into(), &mut || {
859 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
860 Ok((size, Cow::Owned(bytes)))
861 })?;
862 let bounds = Bounds {
863 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
864 size: tile.bounds.size.map(Into::into),
865 };
866 let content_mask = self.content_mask().scale(scale_factor);
867 let window = &mut *self.window;
868 window.current_frame.scene_builder.insert(
869 &window.current_frame.z_index_stack,
870 MonochromeSprite {
871 order: 0,
872 bounds,
873 content_mask,
874 color,
875 tile,
876 },
877 );
878 }
879 Ok(())
880 }
881
882 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
883 /// The y component of the origin is the baseline of the glyph.
884 pub fn paint_emoji(
885 &mut self,
886 origin: Point<Pixels>,
887 font_id: FontId,
888 glyph_id: GlyphId,
889 font_size: Pixels,
890 ) -> Result<()> {
891 let scale_factor = self.scale_factor();
892 let glyph_origin = origin.scale(scale_factor);
893 let params = RenderGlyphParams {
894 font_id,
895 glyph_id,
896 font_size,
897 // We don't render emojis with subpixel variants.
898 subpixel_variant: Default::default(),
899 scale_factor,
900 is_emoji: true,
901 };
902
903 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
904 if !raster_bounds.is_zero() {
905 let tile =
906 self.window
907 .sprite_atlas
908 .get_or_insert_with(¶ms.clone().into(), &mut || {
909 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
910 Ok((size, Cow::Owned(bytes)))
911 })?;
912 let bounds = Bounds {
913 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
914 size: tile.bounds.size.map(Into::into),
915 };
916 let content_mask = self.content_mask().scale(scale_factor);
917 let window = &mut *self.window;
918
919 window.current_frame.scene_builder.insert(
920 &window.current_frame.z_index_stack,
921 PolychromeSprite {
922 order: 0,
923 bounds,
924 corner_radii: Default::default(),
925 content_mask,
926 tile,
927 grayscale: false,
928 },
929 );
930 }
931 Ok(())
932 }
933
934 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
935 pub fn paint_svg(
936 &mut self,
937 bounds: Bounds<Pixels>,
938 path: SharedString,
939 color: Hsla,
940 ) -> Result<()> {
941 let scale_factor = self.scale_factor();
942 let bounds = bounds.scale(scale_factor);
943 // Render the SVG at twice the size to get a higher quality result.
944 let params = RenderSvgParams {
945 path,
946 size: bounds
947 .size
948 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
949 };
950
951 let tile =
952 self.window
953 .sprite_atlas
954 .get_or_insert_with(¶ms.clone().into(), &mut || {
955 let bytes = self.svg_renderer.render(¶ms)?;
956 Ok((params.size, Cow::Owned(bytes)))
957 })?;
958 let content_mask = self.content_mask().scale(scale_factor);
959
960 let window = &mut *self.window;
961 window.current_frame.scene_builder.insert(
962 &window.current_frame.z_index_stack,
963 MonochromeSprite {
964 order: 0,
965 bounds,
966 content_mask,
967 color,
968 tile,
969 },
970 );
971
972 Ok(())
973 }
974
975 /// Paint an image into the scene for the current frame at the current z-index.
976 pub fn paint_image(
977 &mut self,
978 bounds: Bounds<Pixels>,
979 corner_radii: Corners<Pixels>,
980 data: Arc<ImageData>,
981 grayscale: bool,
982 ) -> Result<()> {
983 let scale_factor = self.scale_factor();
984 let bounds = bounds.scale(scale_factor);
985 let params = RenderImageParams { image_id: data.id };
986
987 let tile = self
988 .window
989 .sprite_atlas
990 .get_or_insert_with(¶ms.clone().into(), &mut || {
991 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
992 })?;
993 let content_mask = self.content_mask().scale(scale_factor);
994 let corner_radii = corner_radii.scale(scale_factor);
995
996 let window = &mut *self.window;
997 window.current_frame.scene_builder.insert(
998 &window.current_frame.z_index_stack,
999 PolychromeSprite {
1000 order: 0,
1001 bounds,
1002 content_mask,
1003 corner_radii,
1004 tile,
1005 grayscale,
1006 },
1007 );
1008 Ok(())
1009 }
1010
1011 /// Draw pixels to the display for this window based on the contents of its scene.
1012 pub(crate) fn draw(&mut self) {
1013 let root_view = self.window.root_view.take().unwrap();
1014
1015 self.start_frame();
1016
1017 self.stack(0, |cx| {
1018 let available_space = cx.window.content_size.map(Into::into);
1019 root_view.draw(available_space, cx);
1020 });
1021
1022 if let Some(active_drag) = self.app.active_drag.take() {
1023 self.stack(1, |cx| {
1024 let offset = cx.mouse_position() - active_drag.cursor_offset;
1025 cx.with_element_offset(Some(offset), |cx| {
1026 let available_space =
1027 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1028 active_drag.view.draw(available_space, cx);
1029 cx.active_drag = Some(active_drag);
1030 });
1031 });
1032 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1033 self.stack(1, |cx| {
1034 cx.with_element_offset(Some(active_tooltip.cursor_offset), |cx| {
1035 let available_space =
1036 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1037 active_tooltip.view.draw(available_space, cx);
1038 });
1039 });
1040 }
1041
1042 self.window.root_view = Some(root_view);
1043 let scene = self.window.current_frame.scene_builder.build();
1044
1045 self.window.platform_window.draw(scene);
1046 let cursor_style = self
1047 .window
1048 .requested_cursor_style
1049 .take()
1050 .unwrap_or(CursorStyle::Arrow);
1051 self.platform.set_cursor_style(cursor_style);
1052 if let Some(handler) = self.window.requested_input_handler.take() {
1053 self.window.platform_window.set_input_handler(handler);
1054 }
1055
1056 self.window.dirty = false;
1057 }
1058
1059 /// Rotate the current frame and the previous frame, then clear the current frame.
1060 /// We repopulate all state in the current frame during each paint.
1061 fn start_frame(&mut self) {
1062 self.text_system().start_frame();
1063
1064 let window = &mut *self.window;
1065 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1066 let frame = &mut window.current_frame;
1067 frame.element_states.clear();
1068 frame.key_matchers.clear();
1069 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1070 frame.focus_listeners.clear();
1071 frame.key_dispatch_stack.clear();
1072 frame.focus_parents_by_child.clear();
1073 frame.freeze_key_dispatch_stack = false;
1074 }
1075
1076 /// Dispatch a mouse or keyboard event on the window.
1077 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1078 // Handlers may set this to false by calling `stop_propagation`
1079 self.app.propagate_event = true;
1080 self.window.default_prevented = false;
1081
1082 let event = match event {
1083 // Track the mouse position with our own state, since accessing the platform
1084 // API for the mouse position can only occur on the main thread.
1085 InputEvent::MouseMove(mouse_move) => {
1086 self.window.mouse_position = mouse_move.position;
1087 InputEvent::MouseMove(mouse_move)
1088 }
1089 // Translate dragging and dropping of external files from the operating system
1090 // to internal drag and drop events.
1091 InputEvent::FileDrop(file_drop) => match file_drop {
1092 FileDropEvent::Entered { position, files } => {
1093 self.window.mouse_position = position;
1094 if self.active_drag.is_none() {
1095 self.active_drag = Some(AnyDrag {
1096 view: self.build_view(|_| files).into(),
1097 cursor_offset: position,
1098 });
1099 }
1100 InputEvent::MouseDown(MouseDownEvent {
1101 position,
1102 button: MouseButton::Left,
1103 click_count: 1,
1104 modifiers: Modifiers::default(),
1105 })
1106 }
1107 FileDropEvent::Pending { position } => {
1108 self.window.mouse_position = position;
1109 InputEvent::MouseMove(MouseMoveEvent {
1110 position,
1111 pressed_button: Some(MouseButton::Left),
1112 modifiers: Modifiers::default(),
1113 })
1114 }
1115 FileDropEvent::Submit { position } => {
1116 self.window.mouse_position = position;
1117 InputEvent::MouseUp(MouseUpEvent {
1118 button: MouseButton::Left,
1119 position,
1120 modifiers: Modifiers::default(),
1121 click_count: 1,
1122 })
1123 }
1124 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1125 button: MouseButton::Left,
1126 position: Point::default(),
1127 modifiers: Modifiers::default(),
1128 click_count: 1,
1129 }),
1130 },
1131 _ => event,
1132 };
1133
1134 if let Some(any_mouse_event) = event.mouse_event() {
1135 if let Some(mut handlers) = self
1136 .window
1137 .current_frame
1138 .mouse_listeners
1139 .remove(&any_mouse_event.type_id())
1140 {
1141 // Because handlers may add other handlers, we sort every time.
1142 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1143
1144 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1145 // special purposes, such as detecting events outside of a given Bounds.
1146 for (_, handler) in &mut handlers {
1147 handler(any_mouse_event, DispatchPhase::Capture, self);
1148 if !self.app.propagate_event {
1149 break;
1150 }
1151 }
1152
1153 // Bubble phase, where most normal handlers do their work.
1154 if self.app.propagate_event {
1155 for (_, handler) in handlers.iter_mut().rev() {
1156 handler(any_mouse_event, DispatchPhase::Bubble, self);
1157 if !self.app.propagate_event {
1158 break;
1159 }
1160 }
1161 }
1162
1163 if self.app.propagate_event
1164 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
1165 {
1166 self.active_drag = None;
1167 }
1168
1169 // Just in case any handlers added new handlers, which is weird, but possible.
1170 handlers.extend(
1171 self.window
1172 .current_frame
1173 .mouse_listeners
1174 .get_mut(&any_mouse_event.type_id())
1175 .into_iter()
1176 .flat_map(|handlers| handlers.drain(..)),
1177 );
1178 self.window
1179 .current_frame
1180 .mouse_listeners
1181 .insert(any_mouse_event.type_id(), handlers);
1182 }
1183 } else if let Some(any_key_event) = event.keyboard_event() {
1184 let mut did_handle_action = false;
1185 let key_dispatch_stack = mem::take(&mut self.window.current_frame.key_dispatch_stack);
1186 let key_event_type = any_key_event.type_id();
1187 let mut context_stack = SmallVec::<[&DispatchContext; 16]>::new();
1188
1189 for (ix, frame) in key_dispatch_stack.iter().enumerate() {
1190 match frame {
1191 KeyDispatchStackFrame::Listener {
1192 event_type,
1193 listener,
1194 } => {
1195 if key_event_type == *event_type {
1196 if let Some(action) = listener(
1197 any_key_event,
1198 &context_stack,
1199 DispatchPhase::Capture,
1200 self,
1201 ) {
1202 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1203 }
1204 if !self.app.propagate_event {
1205 did_handle_action = true;
1206 break;
1207 }
1208 }
1209 }
1210 KeyDispatchStackFrame::Context(context) => {
1211 context_stack.push(&context);
1212 }
1213 }
1214 }
1215
1216 if self.app.propagate_event {
1217 for (ix, frame) in key_dispatch_stack.iter().enumerate().rev() {
1218 match frame {
1219 KeyDispatchStackFrame::Listener {
1220 event_type,
1221 listener,
1222 } => {
1223 if key_event_type == *event_type {
1224 if let Some(action) = listener(
1225 any_key_event,
1226 &context_stack,
1227 DispatchPhase::Bubble,
1228 self,
1229 ) {
1230 self.dispatch_action(action, &key_dispatch_stack[..ix]);
1231 }
1232
1233 if !self.app.propagate_event {
1234 did_handle_action = true;
1235 break;
1236 }
1237 }
1238 }
1239 KeyDispatchStackFrame::Context(_) => {
1240 context_stack.pop();
1241 }
1242 }
1243 }
1244 }
1245
1246 drop(context_stack);
1247 self.window.current_frame.key_dispatch_stack = key_dispatch_stack;
1248 return did_handle_action;
1249 }
1250
1251 true
1252 }
1253
1254 /// Attempt to map a keystroke to an action based on the keymap.
1255 pub fn match_keystroke(
1256 &mut self,
1257 element_id: &GlobalElementId,
1258 keystroke: &Keystroke,
1259 context_stack: &[&DispatchContext],
1260 ) -> KeyMatch {
1261 let key_match = self
1262 .window
1263 .current_frame
1264 .key_matchers
1265 .get_mut(element_id)
1266 .unwrap()
1267 .match_keystroke(keystroke, context_stack);
1268
1269 if key_match.is_some() {
1270 for matcher in self.window.current_frame.key_matchers.values_mut() {
1271 matcher.clear_pending();
1272 }
1273 }
1274
1275 key_match
1276 }
1277
1278 /// Register the given handler to be invoked whenever the global of the given type
1279 /// is updated.
1280 pub fn observe_global<G: 'static>(
1281 &mut self,
1282 f: impl Fn(&mut WindowContext<'_>) + 'static,
1283 ) -> Subscription {
1284 let window_handle = self.window.handle;
1285 self.global_observers.insert(
1286 TypeId::of::<G>(),
1287 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1288 )
1289 }
1290
1291 pub fn activate_window(&self) {
1292 self.window.platform_window.activate();
1293 }
1294
1295 pub fn prompt(
1296 &self,
1297 level: PromptLevel,
1298 msg: &str,
1299 answers: &[&str],
1300 ) -> oneshot::Receiver<usize> {
1301 self.window.platform_window.prompt(level, msg, answers)
1302 }
1303
1304 fn dispatch_action(
1305 &mut self,
1306 action: Box<dyn Action>,
1307 dispatch_stack: &[KeyDispatchStackFrame],
1308 ) {
1309 let action_type = action.as_any().type_id();
1310
1311 if let Some(mut global_listeners) = self.app.global_action_listeners.remove(&action_type) {
1312 for listener in &global_listeners {
1313 listener(action.as_ref(), DispatchPhase::Capture, self);
1314 if !self.app.propagate_event {
1315 break;
1316 }
1317 }
1318 global_listeners.extend(
1319 self.global_action_listeners
1320 .remove(&action_type)
1321 .unwrap_or_default(),
1322 );
1323 self.global_action_listeners
1324 .insert(action_type, global_listeners);
1325 }
1326
1327 if self.app.propagate_event {
1328 for stack_frame in dispatch_stack {
1329 if let KeyDispatchStackFrame::Listener {
1330 event_type,
1331 listener,
1332 } = stack_frame
1333 {
1334 if action_type == *event_type {
1335 listener(action.as_any(), &[], DispatchPhase::Capture, self);
1336 if !self.app.propagate_event {
1337 break;
1338 }
1339 }
1340 }
1341 }
1342 }
1343
1344 if self.app.propagate_event {
1345 for stack_frame in dispatch_stack.iter().rev() {
1346 if let KeyDispatchStackFrame::Listener {
1347 event_type,
1348 listener,
1349 } = stack_frame
1350 {
1351 if action_type == *event_type {
1352 self.app.propagate_event = false;
1353 listener(action.as_any(), &[], DispatchPhase::Bubble, self);
1354 if !self.app.propagate_event {
1355 break;
1356 }
1357 }
1358 }
1359 }
1360 }
1361
1362 if self.app.propagate_event {
1363 if let Some(mut global_listeners) =
1364 self.app.global_action_listeners.remove(&action_type)
1365 {
1366 for listener in global_listeners.iter().rev() {
1367 self.app.propagate_event = false;
1368 listener(action.as_ref(), DispatchPhase::Bubble, self);
1369 if !self.app.propagate_event {
1370 break;
1371 }
1372 }
1373 global_listeners.extend(
1374 self.global_action_listeners
1375 .remove(&action_type)
1376 .unwrap_or_default(),
1377 );
1378 self.global_action_listeners
1379 .insert(action_type, global_listeners);
1380 }
1381 }
1382 }
1383}
1384
1385impl Context for WindowContext<'_> {
1386 type Result<T> = T;
1387
1388 fn build_model<T>(
1389 &mut self,
1390 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1391 ) -> Model<T>
1392 where
1393 T: 'static,
1394 {
1395 let slot = self.app.entities.reserve();
1396 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1397 self.entities.insert(slot, model)
1398 }
1399
1400 fn update_model<T: 'static, R>(
1401 &mut self,
1402 model: &Model<T>,
1403 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1404 ) -> R {
1405 let mut entity = self.entities.lease(model);
1406 let result = update(
1407 &mut *entity,
1408 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1409 );
1410 self.entities.end_lease(entity);
1411 result
1412 }
1413
1414 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1415 where
1416 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1417 {
1418 if window == self.window.handle {
1419 let root_view = self.window.root_view.clone().unwrap();
1420 Ok(update(root_view, self))
1421 } else {
1422 window.update(self.app, update)
1423 }
1424 }
1425}
1426
1427impl VisualContext for WindowContext<'_> {
1428 fn build_view<V>(
1429 &mut self,
1430 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1431 ) -> Self::Result<View<V>>
1432 where
1433 V: 'static,
1434 {
1435 let slot = self.app.entities.reserve();
1436 let view = View {
1437 model: slot.clone(),
1438 };
1439 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1440 let entity = build_view_state(&mut cx);
1441 self.entities.insert(slot, entity);
1442 view
1443 }
1444
1445 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1446 fn update_view<T: 'static, R>(
1447 &mut self,
1448 view: &View<T>,
1449 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1450 ) -> Self::Result<R> {
1451 let mut lease = self.app.entities.lease(&view.model);
1452 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1453 let result = update(&mut *lease, &mut cx);
1454 cx.app.entities.end_lease(lease);
1455 result
1456 }
1457
1458 fn replace_root_view<V>(
1459 &mut self,
1460 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1461 ) -> Self::Result<View<V>>
1462 where
1463 V: Render,
1464 {
1465 let slot = self.app.entities.reserve();
1466 let view = View {
1467 model: slot.clone(),
1468 };
1469 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1470 let entity = build_view(&mut cx);
1471 self.entities.insert(slot, entity);
1472 self.window.root_view = Some(view.clone().into());
1473 view
1474 }
1475}
1476
1477impl<'a> std::ops::Deref for WindowContext<'a> {
1478 type Target = AppContext;
1479
1480 fn deref(&self) -> &Self::Target {
1481 &self.app
1482 }
1483}
1484
1485impl<'a> std::ops::DerefMut for WindowContext<'a> {
1486 fn deref_mut(&mut self) -> &mut Self::Target {
1487 &mut self.app
1488 }
1489}
1490
1491impl<'a> Borrow<AppContext> for WindowContext<'a> {
1492 fn borrow(&self) -> &AppContext {
1493 &self.app
1494 }
1495}
1496
1497impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1498 fn borrow_mut(&mut self) -> &mut AppContext {
1499 &mut self.app
1500 }
1501}
1502
1503pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1504 fn app_mut(&mut self) -> &mut AppContext {
1505 self.borrow_mut()
1506 }
1507
1508 fn window(&self) -> &Window {
1509 self.borrow()
1510 }
1511
1512 fn window_mut(&mut self) -> &mut Window {
1513 self.borrow_mut()
1514 }
1515
1516 /// Pushes the given element id onto the global stack and invokes the given closure
1517 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1518 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1519 /// used to associate state with identified elements across separate frames.
1520 fn with_element_id<R>(
1521 &mut self,
1522 id: impl Into<ElementId>,
1523 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1524 ) -> R {
1525 let keymap = self.app_mut().keymap.clone();
1526 let window = self.window_mut();
1527 window.element_id_stack.push(id.into());
1528 let global_id = window.element_id_stack.clone();
1529
1530 if window.current_frame.key_matchers.get(&global_id).is_none() {
1531 window.current_frame.key_matchers.insert(
1532 global_id.clone(),
1533 window
1534 .previous_frame
1535 .key_matchers
1536 .remove(&global_id)
1537 .unwrap_or_else(|| KeyMatcher::new(keymap)),
1538 );
1539 }
1540
1541 let result = f(global_id, self);
1542 let window: &mut Window = self.borrow_mut();
1543 window.element_id_stack.pop();
1544 result
1545 }
1546
1547 /// Invoke the given function with the given content mask after intersecting it
1548 /// with the current mask.
1549 fn with_content_mask<R>(
1550 &mut self,
1551 mask: ContentMask<Pixels>,
1552 f: impl FnOnce(&mut Self) -> R,
1553 ) -> R {
1554 let mask = mask.intersect(&self.content_mask());
1555 self.window_mut()
1556 .current_frame
1557 .content_mask_stack
1558 .push(mask);
1559 let result = f(self);
1560 self.window_mut().current_frame.content_mask_stack.pop();
1561 result
1562 }
1563
1564 /// Update the global element offset based on the given offset. This is used to implement
1565 /// scrolling and position drag handles.
1566 fn with_element_offset<R>(
1567 &mut self,
1568 offset: Option<Point<Pixels>>,
1569 f: impl FnOnce(&mut Self) -> R,
1570 ) -> R {
1571 let Some(offset) = offset else {
1572 return f(self);
1573 };
1574
1575 let offset = self.element_offset() + offset;
1576 self.window_mut()
1577 .current_frame
1578 .element_offset_stack
1579 .push(offset);
1580 let result = f(self);
1581 self.window_mut().current_frame.element_offset_stack.pop();
1582 result
1583 }
1584
1585 /// Obtain the current element offset.
1586 fn element_offset(&self) -> Point<Pixels> {
1587 self.window()
1588 .current_frame
1589 .element_offset_stack
1590 .last()
1591 .copied()
1592 .unwrap_or_default()
1593 }
1594
1595 /// Update or intialize state for an element with the given id that lives across multiple
1596 /// frames. If an element with this id existed in the previous frame, its state will be passed
1597 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1598 /// when drawing the next frame.
1599 fn with_element_state<S, R>(
1600 &mut self,
1601 id: ElementId,
1602 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1603 ) -> R
1604 where
1605 S: 'static,
1606 {
1607 self.with_element_id(id, |global_id, cx| {
1608 if let Some(any) = cx
1609 .window_mut()
1610 .current_frame
1611 .element_states
1612 .remove(&global_id)
1613 .or_else(|| {
1614 cx.window_mut()
1615 .previous_frame
1616 .element_states
1617 .remove(&global_id)
1618 })
1619 {
1620 // Using the extra inner option to avoid needing to reallocate a new box.
1621 let mut state_box = any
1622 .downcast::<Option<S>>()
1623 .expect("invalid element state type for id");
1624 let state = state_box
1625 .take()
1626 .expect("element state is already on the stack");
1627 let (result, state) = f(Some(state), cx);
1628 state_box.replace(state);
1629 cx.window_mut()
1630 .current_frame
1631 .element_states
1632 .insert(global_id, state_box);
1633 result
1634 } else {
1635 let (result, state) = f(None, cx);
1636 cx.window_mut()
1637 .current_frame
1638 .element_states
1639 .insert(global_id, Box::new(Some(state)));
1640 result
1641 }
1642 })
1643 }
1644
1645 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1646 /// id is `None`, no state will be retrieved or stored.
1647 fn with_optional_element_state<S, R>(
1648 &mut self,
1649 element_id: Option<ElementId>,
1650 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1651 ) -> R
1652 where
1653 S: 'static,
1654 {
1655 if let Some(element_id) = element_id {
1656 self.with_element_state(element_id, f)
1657 } else {
1658 f(None, self).0
1659 }
1660 }
1661
1662 /// Obtain the current content mask.
1663 fn content_mask(&self) -> ContentMask<Pixels> {
1664 self.window()
1665 .current_frame
1666 .content_mask_stack
1667 .last()
1668 .cloned()
1669 .unwrap_or_else(|| ContentMask {
1670 bounds: Bounds {
1671 origin: Point::default(),
1672 size: self.window().content_size,
1673 },
1674 })
1675 }
1676
1677 /// The size of an em for the base font of the application. Adjusting this value allows the
1678 /// UI to scale, just like zooming a web page.
1679 fn rem_size(&self) -> Pixels {
1680 self.window().rem_size
1681 }
1682}
1683
1684impl Borrow<Window> for WindowContext<'_> {
1685 fn borrow(&self) -> &Window {
1686 &self.window
1687 }
1688}
1689
1690impl BorrowMut<Window> for WindowContext<'_> {
1691 fn borrow_mut(&mut self) -> &mut Window {
1692 &mut self.window
1693 }
1694}
1695
1696impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1697
1698pub struct ViewContext<'a, V> {
1699 window_cx: WindowContext<'a>,
1700 view: &'a View<V>,
1701}
1702
1703impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1704 fn borrow(&self) -> &AppContext {
1705 &*self.window_cx.app
1706 }
1707}
1708
1709impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1710 fn borrow_mut(&mut self) -> &mut AppContext {
1711 &mut *self.window_cx.app
1712 }
1713}
1714
1715impl<V> Borrow<Window> for ViewContext<'_, V> {
1716 fn borrow(&self) -> &Window {
1717 &*self.window_cx.window
1718 }
1719}
1720
1721impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1722 fn borrow_mut(&mut self) -> &mut Window {
1723 &mut *self.window_cx.window
1724 }
1725}
1726
1727impl<'a, V: 'static> ViewContext<'a, V> {
1728 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1729 Self {
1730 window_cx: WindowContext::new(app, window),
1731 view,
1732 }
1733 }
1734
1735 // todo!("change this to return a reference");
1736 pub fn view(&self) -> View<V> {
1737 self.view.clone()
1738 }
1739
1740 pub fn model(&self) -> Model<V> {
1741 self.view.model.clone()
1742 }
1743
1744 /// Access the underlying window context.
1745 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1746 &mut self.window_cx
1747 }
1748
1749 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1750 self.window.current_frame.z_index_stack.push(z_index);
1751 let result = f(self);
1752 self.window.current_frame.z_index_stack.pop();
1753 result
1754 }
1755
1756 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1757 where
1758 V: 'static,
1759 {
1760 let view = self.view();
1761 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1762 }
1763
1764 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1765 /// that are currently on the stack to be returned to the app.
1766 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1767 let view = self.view().downgrade();
1768 self.window_cx.defer(move |cx| {
1769 view.update(cx, f).ok();
1770 });
1771 }
1772
1773 pub fn observe<V2, E>(
1774 &mut self,
1775 entity: &E,
1776 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1777 ) -> Subscription
1778 where
1779 V2: 'static,
1780 V: 'static,
1781 E: Entity<V2>,
1782 {
1783 let view = self.view().downgrade();
1784 let entity_id = entity.entity_id();
1785 let entity = entity.downgrade();
1786 let window_handle = self.window.handle;
1787 self.app.observers.insert(
1788 entity_id,
1789 Box::new(move |cx| {
1790 window_handle
1791 .update(cx, |_, cx| {
1792 if let Some(handle) = E::upgrade_from(&entity) {
1793 view.update(cx, |this, cx| on_notify(this, handle, cx))
1794 .is_ok()
1795 } else {
1796 false
1797 }
1798 })
1799 .unwrap_or(false)
1800 }),
1801 )
1802 }
1803
1804 pub fn subscribe<V2, E>(
1805 &mut self,
1806 entity: &E,
1807 mut on_event: impl FnMut(&mut V, E, &V2::Event, &mut ViewContext<'_, V>) + 'static,
1808 ) -> Subscription
1809 where
1810 V2: EventEmitter,
1811 E: Entity<V2>,
1812 {
1813 let view = self.view().downgrade();
1814 let entity_id = entity.entity_id();
1815 let handle = entity.downgrade();
1816 let window_handle = self.window.handle;
1817 self.app.event_listeners.insert(
1818 entity_id,
1819 Box::new(move |event, cx| {
1820 window_handle
1821 .update(cx, |_, cx| {
1822 if let Some(handle) = E::upgrade_from(&handle) {
1823 let event = event.downcast_ref().expect("invalid event type");
1824 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1825 .is_ok()
1826 } else {
1827 false
1828 }
1829 })
1830 .unwrap_or(false)
1831 }),
1832 )
1833 }
1834
1835 pub fn on_release(
1836 &mut self,
1837 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
1838 ) -> Subscription {
1839 let window_handle = self.window.handle;
1840 self.app.release_listeners.insert(
1841 self.view.model.entity_id,
1842 Box::new(move |this, cx| {
1843 let this = this.downcast_mut().expect("invalid entity type");
1844 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
1845 }),
1846 )
1847 }
1848
1849 pub fn observe_release<V2, E>(
1850 &mut self,
1851 entity: &E,
1852 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1853 ) -> Subscription
1854 where
1855 V: 'static,
1856 V2: 'static,
1857 E: Entity<V2>,
1858 {
1859 let view = self.view().downgrade();
1860 let entity_id = entity.entity_id();
1861 let window_handle = self.window.handle;
1862 self.app.release_listeners.insert(
1863 entity_id,
1864 Box::new(move |entity, cx| {
1865 let entity = entity.downcast_mut().expect("invalid entity type");
1866 let _ = window_handle.update(cx, |_, cx| {
1867 view.update(cx, |this, cx| on_release(this, entity, cx))
1868 });
1869 }),
1870 )
1871 }
1872
1873 pub fn notify(&mut self) {
1874 self.window_cx.notify();
1875 self.window_cx.app.push_effect(Effect::Notify {
1876 emitter: self.view.model.entity_id,
1877 });
1878 }
1879
1880 pub fn observe_window_bounds(
1881 &mut self,
1882 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1883 ) -> Subscription {
1884 let view = self.view.downgrade();
1885 self.window.bounds_observers.insert(
1886 (),
1887 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1888 )
1889 }
1890
1891 pub fn observe_window_activation(
1892 &mut self,
1893 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1894 ) -> Subscription {
1895 let view = self.view.downgrade();
1896 self.window.activation_observers.insert(
1897 (),
1898 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1899 )
1900 }
1901
1902 /// Register a listener to be called when the given focus handle receives focus.
1903 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1904 /// 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 self.window.focus_listeners.insert(
1913 (),
1914 Box::new(move |event, cx| {
1915 view.update(cx, |view, cx| {
1916 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
1917 listener(view, cx)
1918 }
1919 })
1920 .is_ok()
1921 }),
1922 )
1923 }
1924
1925 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
1926 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1927 /// is dropped.
1928 pub fn on_focus_in(
1929 &mut self,
1930 handle: &FocusHandle,
1931 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1932 ) -> Subscription {
1933 let view = self.view.downgrade();
1934 let focus_id = handle.id;
1935 self.window.focus_listeners.insert(
1936 (),
1937 Box::new(move |event, cx| {
1938 view.update(cx, |view, cx| {
1939 if event
1940 .focused
1941 .as_ref()
1942 .map_or(false, |focused| focus_id.contains(focused.id, cx))
1943 {
1944 listener(view, cx)
1945 }
1946 })
1947 .is_ok()
1948 }),
1949 )
1950 }
1951
1952 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
1953 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1954 /// is dropped.
1955 pub fn on_focus_out(
1956 &mut self,
1957 handle: &FocusHandle,
1958 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1959 ) -> Subscription {
1960 let view = self.view.downgrade();
1961 let focus_id = handle.id;
1962 self.window.focus_listeners.insert(
1963 (),
1964 Box::new(move |event, cx| {
1965 view.update(cx, |view, cx| {
1966 if event
1967 .blurred
1968 .as_ref()
1969 .map_or(false, |focused| focus_id.contains(focused.id, cx))
1970 {
1971 listener(view, cx)
1972 }
1973 })
1974 .is_ok()
1975 }),
1976 )
1977 }
1978
1979 /// Register a focus listener for the current frame only. It will be cleared
1980 /// on the next frame render. You should use this method only from within elements,
1981 /// and we may want to enforce that better via a different context type.
1982 // todo!() Move this to `FrameContext` to emphasize its individuality?
1983 pub fn on_focus_changed(
1984 &mut self,
1985 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + 'static,
1986 ) {
1987 let handle = self.view().downgrade();
1988 self.window
1989 .current_frame
1990 .focus_listeners
1991 .push(Box::new(move |event, cx| {
1992 handle
1993 .update(cx, |view, cx| listener(view, event, cx))
1994 .log_err();
1995 }));
1996 }
1997
1998 pub fn with_key_listeners<R>(
1999 &mut self,
2000 key_listeners: impl IntoIterator<Item = (TypeId, KeyListener<V>)>,
2001 f: impl FnOnce(&mut Self) -> R,
2002 ) -> R {
2003 let old_stack_len = self.window.current_frame.key_dispatch_stack.len();
2004 if !self.window.current_frame.freeze_key_dispatch_stack {
2005 for (event_type, listener) in key_listeners {
2006 let handle = self.view().downgrade();
2007 let listener = Box::new(
2008 move |event: &dyn Any,
2009 context_stack: &[&DispatchContext],
2010 phase: DispatchPhase,
2011 cx: &mut WindowContext<'_>| {
2012 handle
2013 .update(cx, |view, cx| {
2014 listener(view, event, context_stack, phase, cx)
2015 })
2016 .log_err()
2017 .flatten()
2018 },
2019 );
2020 self.window.current_frame.key_dispatch_stack.push(
2021 KeyDispatchStackFrame::Listener {
2022 event_type,
2023 listener,
2024 },
2025 );
2026 }
2027 }
2028
2029 let result = f(self);
2030
2031 if !self.window.current_frame.freeze_key_dispatch_stack {
2032 self.window
2033 .current_frame
2034 .key_dispatch_stack
2035 .truncate(old_stack_len);
2036 }
2037
2038 result
2039 }
2040
2041 pub fn with_key_dispatch_context<R>(
2042 &mut self,
2043 context: DispatchContext,
2044 f: impl FnOnce(&mut Self) -> R,
2045 ) -> R {
2046 if context.is_empty() {
2047 return f(self);
2048 }
2049
2050 if !self.window.current_frame.freeze_key_dispatch_stack {
2051 self.window
2052 .current_frame
2053 .key_dispatch_stack
2054 .push(KeyDispatchStackFrame::Context(context));
2055 }
2056
2057 let result = f(self);
2058
2059 if !self.window.previous_frame.freeze_key_dispatch_stack {
2060 self.window.previous_frame.key_dispatch_stack.pop();
2061 }
2062
2063 result
2064 }
2065
2066 pub fn with_focus<R>(
2067 &mut self,
2068 focus_handle: FocusHandle,
2069 f: impl FnOnce(&mut Self) -> R,
2070 ) -> R {
2071 if let Some(parent_focus_id) = self.window.current_frame.focus_stack.last().copied() {
2072 self.window
2073 .current_frame
2074 .focus_parents_by_child
2075 .insert(focus_handle.id, parent_focus_id);
2076 }
2077 self.window.current_frame.focus_stack.push(focus_handle.id);
2078
2079 if Some(focus_handle.id) == self.window.focus {
2080 self.window.current_frame.freeze_key_dispatch_stack = true;
2081 }
2082
2083 let result = f(self);
2084
2085 self.window.current_frame.focus_stack.pop();
2086 result
2087 }
2088
2089 pub fn spawn<Fut, R>(
2090 &mut self,
2091 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2092 ) -> Task<R>
2093 where
2094 R: 'static,
2095 Fut: Future<Output = R> + 'static,
2096 {
2097 let view = self.view().downgrade();
2098 self.window_cx.spawn(|cx| f(view, cx))
2099 }
2100
2101 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2102 where
2103 G: 'static,
2104 {
2105 let mut global = self.app.lease_global::<G>();
2106 let result = f(&mut global, self);
2107 self.app.end_global_lease(global);
2108 result
2109 }
2110
2111 pub fn observe_global<G: 'static>(
2112 &mut self,
2113 f: impl Fn(&mut V, &mut ViewContext<'_, V>) + 'static,
2114 ) -> Subscription {
2115 let window_handle = self.window.handle;
2116 let view = self.view().downgrade();
2117 self.global_observers.insert(
2118 TypeId::of::<G>(),
2119 Box::new(move |cx| {
2120 window_handle
2121 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2122 .unwrap_or(false)
2123 }),
2124 )
2125 }
2126
2127 pub fn on_mouse_event<Event: 'static>(
2128 &mut self,
2129 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2130 ) {
2131 let handle = self.view();
2132 self.window_cx.on_mouse_event(move |event, phase, cx| {
2133 handle.update(cx, |view, cx| {
2134 handler(view, event, phase, cx);
2135 })
2136 });
2137 }
2138}
2139
2140impl<V> ViewContext<'_, V>
2141where
2142 V: InputHandler + 'static,
2143{
2144 pub fn handle_text_input(&mut self) {
2145 self.window.requested_input_handler = Some(Box::new(WindowInputHandler {
2146 cx: self.app.this.clone(),
2147 window: self.window_handle(),
2148 handler: self.view().downgrade(),
2149 }));
2150 }
2151}
2152
2153impl<V> ViewContext<'_, V>
2154where
2155 V: EventEmitter,
2156 V::Event: 'static,
2157{
2158 pub fn emit(&mut self, event: V::Event) {
2159 let emitter = self.view.model.entity_id;
2160 self.app.push_effect(Effect::Emit {
2161 emitter,
2162 event: Box::new(event),
2163 });
2164 }
2165}
2166
2167impl<V> Context for ViewContext<'_, V> {
2168 type Result<U> = U;
2169
2170 fn build_model<T: 'static>(
2171 &mut self,
2172 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2173 ) -> Model<T> {
2174 self.window_cx.build_model(build_model)
2175 }
2176
2177 fn update_model<T: 'static, R>(
2178 &mut self,
2179 model: &Model<T>,
2180 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2181 ) -> R {
2182 self.window_cx.update_model(model, update)
2183 }
2184
2185 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2186 where
2187 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2188 {
2189 self.window_cx.update_window(window, update)
2190 }
2191}
2192
2193impl<V: 'static> VisualContext for ViewContext<'_, V> {
2194 fn build_view<W: 'static>(
2195 &mut self,
2196 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2197 ) -> Self::Result<View<W>> {
2198 self.window_cx.build_view(build_view_state)
2199 }
2200
2201 fn update_view<V2: 'static, R>(
2202 &mut self,
2203 view: &View<V2>,
2204 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2205 ) -> Self::Result<R> {
2206 self.window_cx.update_view(view, update)
2207 }
2208
2209 fn replace_root_view<W>(
2210 &mut self,
2211 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2212 ) -> Self::Result<View<W>>
2213 where
2214 W: Render,
2215 {
2216 self.window_cx.replace_root_view(build_view)
2217 }
2218}
2219
2220impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2221 type Target = WindowContext<'a>;
2222
2223 fn deref(&self) -> &Self::Target {
2224 &self.window_cx
2225 }
2226}
2227
2228impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2229 fn deref_mut(&mut self) -> &mut Self::Target {
2230 &mut self.window_cx
2231 }
2232}
2233
2234// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2235slotmap::new_key_type! { pub struct WindowId; }
2236
2237impl WindowId {
2238 pub fn as_u64(&self) -> u64 {
2239 self.0.as_ffi()
2240 }
2241}
2242
2243#[derive(Deref, DerefMut)]
2244pub struct WindowHandle<V> {
2245 #[deref]
2246 #[deref_mut]
2247 pub(crate) any_handle: AnyWindowHandle,
2248 state_type: PhantomData<V>,
2249}
2250
2251impl<V: 'static + Render> WindowHandle<V> {
2252 pub fn new(id: WindowId) -> Self {
2253 WindowHandle {
2254 any_handle: AnyWindowHandle {
2255 id,
2256 state_type: TypeId::of::<V>(),
2257 },
2258 state_type: PhantomData,
2259 }
2260 }
2261
2262 pub fn update<C, R>(
2263 self,
2264 cx: &mut C,
2265 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2266 ) -> Result<R>
2267 where
2268 C: Context,
2269 {
2270 cx.update_window(self.any_handle, |root_view, cx| {
2271 let view = root_view
2272 .downcast::<V>()
2273 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2274 Ok(cx.update_view(&view, update))
2275 })?
2276 }
2277}
2278
2279impl<V> Copy for WindowHandle<V> {}
2280
2281impl<V> Clone for WindowHandle<V> {
2282 fn clone(&self) -> Self {
2283 WindowHandle {
2284 any_handle: self.any_handle,
2285 state_type: PhantomData,
2286 }
2287 }
2288}
2289
2290impl<V> PartialEq for WindowHandle<V> {
2291 fn eq(&self, other: &Self) -> bool {
2292 self.any_handle == other.any_handle
2293 }
2294}
2295
2296impl<V> Eq for WindowHandle<V> {}
2297
2298impl<V> Hash for WindowHandle<V> {
2299 fn hash<H: Hasher>(&self, state: &mut H) {
2300 self.any_handle.hash(state);
2301 }
2302}
2303
2304impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2305 fn into(self) -> AnyWindowHandle {
2306 self.any_handle
2307 }
2308}
2309
2310#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2311pub struct AnyWindowHandle {
2312 pub(crate) id: WindowId,
2313 state_type: TypeId,
2314}
2315
2316impl AnyWindowHandle {
2317 pub fn window_id(&self) -> WindowId {
2318 self.id
2319 }
2320
2321 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2322 if TypeId::of::<T>() == self.state_type {
2323 Some(WindowHandle {
2324 any_handle: *self,
2325 state_type: PhantomData,
2326 })
2327 } else {
2328 None
2329 }
2330 }
2331
2332 pub fn update<C, R>(
2333 self,
2334 cx: &mut C,
2335 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2336 ) -> Result<R>
2337 where
2338 C: Context,
2339 {
2340 cx.update_window(self, update)
2341 }
2342}
2343
2344#[cfg(any(test, feature = "test-support"))]
2345impl From<SmallVec<[u32; 16]>> for StackingOrder {
2346 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2347 StackingOrder(small_vec)
2348 }
2349}
2350
2351#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2352pub enum ElementId {
2353 View(EntityId),
2354 Number(usize),
2355 Name(SharedString),
2356 FocusHandle(FocusId),
2357}
2358
2359impl From<EntityId> for ElementId {
2360 fn from(id: EntityId) -> Self {
2361 ElementId::View(id)
2362 }
2363}
2364
2365impl From<usize> for ElementId {
2366 fn from(id: usize) -> Self {
2367 ElementId::Number(id)
2368 }
2369}
2370
2371impl From<i32> for ElementId {
2372 fn from(id: i32) -> Self {
2373 Self::Number(id as usize)
2374 }
2375}
2376
2377impl From<SharedString> for ElementId {
2378 fn from(name: SharedString) -> Self {
2379 ElementId::Name(name)
2380 }
2381}
2382
2383impl From<&'static str> for ElementId {
2384 fn from(name: &'static str) -> Self {
2385 ElementId::Name(name.into())
2386 }
2387}
2388
2389impl<'a> From<&'a FocusHandle> for ElementId {
2390 fn from(handle: &'a FocusHandle) -> Self {
2391 ElementId::FocusHandle(handle.id)
2392 }
2393}