1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyBox, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle,
4 DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId,
5 EventEmitter, FileDropEvent, FocusEvent, FontId, GlobalElementId, GlyphId, Hsla, ImageData,
6 InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, LayoutId, Model, ModelContext,
7 Modifiers, MonochromeSprite, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path,
8 Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler, PlatformWindow, Point,
9 PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams, RenderImageParams,
10 RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size, Style, SubscriberSet,
11 Subscription, TaffyLayoutEngine, Task, Underline, UnderlineStyle, View, VisualContext,
12 WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Context as _, 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 AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
64type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
65type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
66
67slotmap::new_key_type! { pub struct FocusId; }
68
69impl FocusId {
70 /// Obtains whether the element associated with this handle is currently focused.
71 pub fn is_focused(&self, cx: &WindowContext) -> bool {
72 cx.window.focus == Some(*self)
73 }
74
75 /// Obtains whether the element associated with this handle contains the focused
76 /// element or is itself focused.
77 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
78 cx.focused()
79 .map_or(false, |focused| self.contains(focused.id, cx))
80 }
81
82 /// Obtains whether the element associated with this handle is contained within the
83 /// focused element or is itself focused.
84 pub fn within_focused(&self, cx: &WindowContext) -> bool {
85 let focused = cx.focused();
86 focused.map_or(false, |focused| focused.id.contains(*self, cx))
87 }
88
89 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
90 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
91 cx.window
92 .current_frame
93 .dispatch_tree
94 .focus_contains(*self, other)
95 }
96}
97
98/// A handle which can be used to track and manipulate the focused element in a window.
99pub struct FocusHandle {
100 pub(crate) id: FocusId,
101 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
102}
103
104impl std::fmt::Debug for FocusHandle {
105 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
106 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
107 }
108}
109
110impl FocusHandle {
111 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
112 let id = handles.write().insert(AtomicUsize::new(1));
113 Self {
114 id,
115 handles: handles.clone(),
116 }
117 }
118
119 pub(crate) fn for_id(
120 id: FocusId,
121 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
122 ) -> Option<Self> {
123 let lock = handles.read();
124 let ref_count = lock.get(id)?;
125 if ref_count.load(SeqCst) == 0 {
126 None
127 } else {
128 ref_count.fetch_add(1, SeqCst);
129 Some(Self {
130 id,
131 handles: handles.clone(),
132 })
133 }
134 }
135
136 /// Moves the focus to the element associated with this handle.
137 pub fn focus(&self, cx: &mut WindowContext) {
138 cx.focus(self)
139 }
140
141 /// Obtains whether the element associated with this handle is currently focused.
142 pub fn is_focused(&self, cx: &WindowContext) -> bool {
143 self.id.is_focused(cx)
144 }
145
146 /// Obtains whether the element associated with this handle contains the focused
147 /// element or is itself focused.
148 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
149 self.id.contains_focused(cx)
150 }
151
152 /// Obtains whether the element associated with this handle is contained within the
153 /// focused element or is itself focused.
154 pub fn within_focused(&self, cx: &WindowContext) -> bool {
155 self.id.within_focused(cx)
156 }
157
158 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
159 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
160 self.id.contains(other.id, cx)
161 }
162}
163
164impl Clone for FocusHandle {
165 fn clone(&self) -> Self {
166 Self::for_id(self.id, &self.handles).unwrap()
167 }
168}
169
170impl PartialEq for FocusHandle {
171 fn eq(&self, other: &Self) -> bool {
172 self.id == other.id
173 }
174}
175
176impl Eq for FocusHandle {}
177
178impl Drop for FocusHandle {
179 fn drop(&mut self) {
180 self.handles
181 .read()
182 .get(self.id)
183 .unwrap()
184 .fetch_sub(1, SeqCst);
185 }
186}
187
188// Holds the state for a specific window.
189pub struct Window {
190 pub(crate) handle: AnyWindowHandle,
191 pub(crate) removed: bool,
192 pub(crate) platform_window: Box<dyn PlatformWindow>,
193 display_id: DisplayId,
194 sprite_atlas: Arc<dyn PlatformAtlas>,
195 rem_size: Pixels,
196 viewport_size: Size<Pixels>,
197 pub(crate) layout_engine: TaffyLayoutEngine,
198 pub(crate) root_view: Option<AnyView>,
199 pub(crate) element_id_stack: GlobalElementId,
200 pub(crate) previous_frame: Frame,
201 pub(crate) current_frame: Frame,
202 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
203 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
204 default_prevented: bool,
205 mouse_position: Point<Pixels>,
206 requested_cursor_style: Option<CursorStyle>,
207 scale_factor: f32,
208 bounds: WindowBounds,
209 bounds_observers: SubscriberSet<(), AnyObserver>,
210 active: bool,
211 activation_observers: SubscriberSet<(), AnyObserver>,
212 pub(crate) dirty: bool,
213 pub(crate) last_blur: Option<Option<FocusId>>,
214 pub(crate) focus: Option<FocusId>,
215}
216
217// #[derive(Default)]
218pub(crate) struct Frame {
219 pub(crate) element_states: HashMap<GlobalElementId, AnyBox>,
220 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
221 pub(crate) dispatch_tree: DispatchTree,
222 pub(crate) focus_listeners: Vec<AnyFocusListener>,
223 pub(crate) scene_builder: SceneBuilder,
224 z_index_stack: StackingOrder,
225 content_mask_stack: Vec<ContentMask<Pixels>>,
226 element_offset_stack: Vec<Point<Pixels>>,
227}
228
229impl Frame {
230 pub fn new(dispatch_tree: DispatchTree) -> Self {
231 Frame {
232 element_states: HashMap::default(),
233 mouse_listeners: HashMap::default(),
234 dispatch_tree,
235 focus_listeners: Vec::new(),
236 scene_builder: SceneBuilder::default(),
237 z_index_stack: StackingOrder::default(),
238 content_mask_stack: Vec::new(),
239 element_offset_stack: Vec::new(),
240 }
241 }
242}
243
244impl Window {
245 pub(crate) fn new(
246 handle: AnyWindowHandle,
247 options: WindowOptions,
248 cx: &mut AppContext,
249 ) -> Self {
250 let platform_window = cx.platform.open_window(handle, options);
251 let display_id = platform_window.display().id();
252 let sprite_atlas = platform_window.sprite_atlas();
253 let mouse_position = platform_window.mouse_position();
254 let content_size = platform_window.content_size();
255 let scale_factor = platform_window.scale_factor();
256 let bounds = platform_window.bounds();
257
258 platform_window.on_resize(Box::new({
259 let mut cx = cx.to_async();
260 move |_, _| {
261 handle
262 .update(&mut cx, |_, cx| cx.window_bounds_changed())
263 .log_err();
264 }
265 }));
266 platform_window.on_moved(Box::new({
267 let mut cx = cx.to_async();
268 move || {
269 handle
270 .update(&mut cx, |_, cx| cx.window_bounds_changed())
271 .log_err();
272 }
273 }));
274 platform_window.on_active_status_change(Box::new({
275 let mut cx = cx.to_async();
276 move |active| {
277 handle
278 .update(&mut cx, |_, cx| {
279 cx.window.active = active;
280 cx.window
281 .activation_observers
282 .clone()
283 .retain(&(), |callback| callback(cx));
284 })
285 .log_err();
286 }
287 }));
288
289 platform_window.on_input({
290 let mut cx = cx.to_async();
291 Box::new(move |event| {
292 handle
293 .update(&mut cx, |_, cx| cx.dispatch_event(event))
294 .log_err()
295 .unwrap_or(false)
296 })
297 });
298
299 Window {
300 handle,
301 removed: false,
302 platform_window,
303 display_id,
304 sprite_atlas,
305 rem_size: px(16.),
306 viewport_size: content_size,
307 layout_engine: TaffyLayoutEngine::new(),
308 root_view: None,
309 element_id_stack: GlobalElementId::default(),
310 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone())),
311 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone())),
312 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
313 focus_listeners: SubscriberSet::new(),
314 default_prevented: true,
315 mouse_position,
316 requested_cursor_style: None,
317 scale_factor,
318 bounds,
319 bounds_observers: SubscriberSet::new(),
320 active: false,
321 activation_observers: SubscriberSet::new(),
322 dirty: true,
323 last_blur: None,
324 focus: None,
325 }
326 }
327}
328
329/// Indicates which region of the window is visible. Content falling outside of this mask will not be
330/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
331/// to leave room to support more complex shapes in the future.
332#[derive(Clone, Debug, Default, PartialEq, Eq)]
333#[repr(C)]
334pub struct ContentMask<P: Clone + Default + Debug> {
335 pub bounds: Bounds<P>,
336}
337
338impl ContentMask<Pixels> {
339 /// Scale the content mask's pixel units by the given scaling factor.
340 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
341 ContentMask {
342 bounds: self.bounds.scale(factor),
343 }
344 }
345
346 /// Intersect the content mask with the given content mask.
347 pub fn intersect(&self, other: &Self) -> Self {
348 let bounds = self.bounds.intersect(&other.bounds);
349 ContentMask { bounds }
350 }
351}
352
353/// Provides access to application state in the context of a single window. Derefs
354/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
355/// an `AppContext` and call any `AppContext` methods.
356pub struct WindowContext<'a> {
357 pub(crate) app: &'a mut AppContext,
358 pub(crate) window: &'a mut Window,
359}
360
361impl<'a> WindowContext<'a> {
362 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
363 Self { app, window }
364 }
365
366 /// Obtain a handle to the window that belongs to this context.
367 pub fn window_handle(&self) -> AnyWindowHandle {
368 self.window.handle
369 }
370
371 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
372 pub fn notify(&mut self) {
373 self.window.dirty = true;
374 }
375
376 /// Close this window.
377 pub fn remove_window(&mut self) {
378 self.window.removed = true;
379 }
380
381 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
382 /// for elements rendered within this window.
383 pub fn focus_handle(&mut self) -> FocusHandle {
384 FocusHandle::new(&self.window.focus_handles)
385 }
386
387 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
388 pub fn focused(&self) -> Option<FocusHandle> {
389 self.window
390 .focus
391 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
392 }
393
394 /// Move focus to the element associated with the given `FocusHandle`.
395 pub fn focus(&mut self, handle: &FocusHandle) {
396 if self.window.focus == Some(handle.id) {
397 return;
398 }
399
400 let focus_id = handle.id;
401
402 if self.window.last_blur.is_none() {
403 self.window.last_blur = Some(self.window.focus);
404 }
405
406 self.window.focus = Some(focus_id);
407 self.window
408 .current_frame
409 .dispatch_tree
410 .clear_keystroke_matchers();
411 self.app.push_effect(Effect::FocusChanged {
412 window_handle: self.window.handle,
413 focused: Some(focus_id),
414 });
415 self.notify();
416 }
417
418 /// Remove focus from all elements within this context's window.
419 pub fn blur(&mut self) {
420 if self.window.last_blur.is_none() {
421 self.window.last_blur = Some(self.window.focus);
422 }
423
424 self.window.focus = None;
425 self.app.push_effect(Effect::FocusChanged {
426 window_handle: self.window.handle,
427 focused: None,
428 });
429 self.notify();
430 }
431
432 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
433 if let Some(focus_handle) = self.focused() {
434 self.defer(move |cx| {
435 if let Some(node_id) = cx
436 .window
437 .current_frame
438 .dispatch_tree
439 .focusable_node_id(focus_handle.id)
440 {
441 cx.propagate_event = true;
442 cx.dispatch_action_on_node(node_id, action);
443 }
444 })
445 }
446 }
447
448 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
449 /// that are currently on the stack to be returned to the app.
450 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
451 let handle = self.window.handle;
452 self.app.defer(move |cx| {
453 handle.update(cx, |_, cx| f(cx)).ok();
454 });
455 }
456
457 pub fn subscribe<Emitter, E, Evt>(
458 &mut self,
459 entity: &E,
460 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
461 ) -> Subscription
462 where
463 Emitter: EventEmitter<Evt>,
464 E: Entity<Emitter>,
465 Evt: 'static,
466 {
467 let entity_id = entity.entity_id();
468 let entity = entity.downgrade();
469 let window_handle = self.window.handle;
470 self.app.event_listeners.insert(
471 entity_id,
472 (
473 TypeId::of::<Evt>(),
474 Box::new(move |event, cx| {
475 window_handle
476 .update(cx, |_, cx| {
477 if let Some(handle) = E::upgrade_from(&entity) {
478 let event = event.downcast_ref().expect("invalid event type");
479 on_event(handle, event, cx);
480 true
481 } else {
482 false
483 }
484 })
485 .unwrap_or(false)
486 }),
487 ),
488 )
489 }
490
491 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
492 /// await points in async code.
493 pub fn to_async(&self) -> AsyncWindowContext {
494 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
495 }
496
497 /// Schedule the given closure to be run directly after the current frame is rendered.
498 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
499 let handle = self.window.handle;
500 let display_id = self.window.display_id;
501
502 if !self.frame_consumers.contains_key(&display_id) {
503 let (tx, mut rx) = mpsc::unbounded::<()>();
504 self.platform.set_display_link_output_callback(
505 display_id,
506 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
507 );
508
509 let consumer_task = self.app.spawn(|cx| async move {
510 while rx.next().await.is_some() {
511 cx.update(|cx| {
512 for callback in cx
513 .next_frame_callbacks
514 .get_mut(&display_id)
515 .unwrap()
516 .drain(..)
517 .collect::<SmallVec<[_; 32]>>()
518 {
519 callback(cx);
520 }
521 })
522 .ok();
523
524 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
525
526 cx.update(|cx| {
527 if cx.next_frame_callbacks.is_empty() {
528 cx.platform.stop_display_link(display_id);
529 }
530 })
531 .ok();
532 }
533 });
534 self.frame_consumers.insert(display_id, consumer_task);
535 }
536
537 if self.next_frame_callbacks.is_empty() {
538 self.platform.start_display_link(display_id);
539 }
540
541 self.next_frame_callbacks
542 .entry(display_id)
543 .or_default()
544 .push(Box::new(move |cx: &mut AppContext| {
545 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
546 }));
547 }
548
549 /// Spawn the future returned by the given closure on the application thread pool.
550 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
551 /// use within your future.
552 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
553 where
554 R: 'static,
555 Fut: Future<Output = R> + 'static,
556 {
557 self.app
558 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
559 }
560
561 /// Update the global of the given type. The given closure is given simultaneous mutable
562 /// access both to the global and the context.
563 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
564 where
565 G: 'static,
566 {
567 let mut global = self.app.lease_global::<G>();
568 let result = f(&mut global, self);
569 self.app.end_global_lease(global);
570 result
571 }
572
573 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
574 /// layout is being requested, along with the layout ids of any children. This method is called during
575 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
576 pub fn request_layout(
577 &mut self,
578 style: &Style,
579 children: impl IntoIterator<Item = LayoutId>,
580 ) -> LayoutId {
581 self.app.layout_id_buffer.clear();
582 self.app.layout_id_buffer.extend(children.into_iter());
583 let rem_size = self.rem_size();
584
585 self.window
586 .layout_engine
587 .request_layout(style, rem_size, &self.app.layout_id_buffer)
588 }
589
590 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
591 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
592 /// determine the element's size. One place this is used internally is when measuring text.
593 ///
594 /// The given closure is invoked at layout time with the known dimensions and available space and
595 /// returns a `Size`.
596 pub fn request_measured_layout<
597 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
598 >(
599 &mut self,
600 style: Style,
601 rem_size: Pixels,
602 measure: F,
603 ) -> LayoutId {
604 self.window
605 .layout_engine
606 .request_measured_layout(style, rem_size, measure)
607 }
608
609 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
610 self.window
611 .layout_engine
612 .compute_layout(layout_id, available_space)
613 }
614
615 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
616 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
617 /// in order to pass your element its `Bounds` automatically.
618 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
619 let mut bounds = self
620 .window
621 .layout_engine
622 .layout_bounds(layout_id)
623 .map(Into::into);
624 bounds.origin += self.element_offset();
625 bounds
626 }
627
628 fn window_bounds_changed(&mut self) {
629 self.window.scale_factor = self.window.platform_window.scale_factor();
630 self.window.viewport_size = self.window.platform_window.content_size();
631 self.window.bounds = self.window.platform_window.bounds();
632 self.window.display_id = self.window.platform_window.display().id();
633 self.window.dirty = true;
634
635 self.window
636 .bounds_observers
637 .clone()
638 .retain(&(), |callback| callback(self));
639 }
640
641 pub fn window_bounds(&self) -> WindowBounds {
642 self.window.bounds
643 }
644
645 pub fn viewport_size(&self) -> Size<Pixels> {
646 self.window.viewport_size
647 }
648
649 pub fn is_window_active(&self) -> bool {
650 self.window.active
651 }
652
653 pub fn zoom_window(&self) {
654 self.window.platform_window.zoom();
655 }
656
657 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
658 self.platform
659 .displays()
660 .into_iter()
661 .find(|display| display.id() == self.window.display_id)
662 }
663
664 pub fn show_character_palette(&self) {
665 self.window.platform_window.show_character_palette();
666 }
667
668 /// The scale factor of the display associated with the window. For example, it could
669 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
670 /// be rendered as two pixels on screen.
671 pub fn scale_factor(&self) -> f32 {
672 self.window.scale_factor
673 }
674
675 /// The size of an em for the base font of the application. Adjusting this value allows the
676 /// UI to scale, just like zooming a web page.
677 pub fn rem_size(&self) -> Pixels {
678 self.window.rem_size
679 }
680
681 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
682 /// UI to scale, just like zooming a web page.
683 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
684 self.window.rem_size = rem_size.into();
685 }
686
687 /// The line height associated with the current text style.
688 pub fn line_height(&self) -> Pixels {
689 let rem_size = self.rem_size();
690 let text_style = self.text_style();
691 text_style
692 .line_height
693 .to_pixels(text_style.font_size.into(), rem_size)
694 }
695
696 /// Call to prevent the default action of an event. Currently only used to prevent
697 /// parent elements from becoming focused on mouse down.
698 pub fn prevent_default(&mut self) {
699 self.window.default_prevented = true;
700 }
701
702 /// Obtain whether default has been prevented for the event currently being dispatched.
703 pub fn default_prevented(&self) -> bool {
704 self.window.default_prevented
705 }
706
707 /// Register a mouse event listener on the window for the current frame. The type of event
708 /// is determined by the first parameter of the given listener. When the next frame is rendered
709 /// the listener will be cleared.
710 ///
711 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
712 /// a specific need to register a global listener.
713 pub fn on_mouse_event<Event: 'static>(
714 &mut self,
715 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
716 ) {
717 let order = self.window.current_frame.z_index_stack.clone();
718 self.window
719 .current_frame
720 .mouse_listeners
721 .entry(TypeId::of::<Event>())
722 .or_default()
723 .push((
724 order,
725 Box::new(move |event: &dyn Any, phase, cx| {
726 handler(event.downcast_ref().unwrap(), phase, cx)
727 }),
728 ))
729 }
730
731 /// Register a key event listener on the window for the current frame. The type of event
732 /// is determined by the first parameter of the given listener. When the next frame is rendered
733 /// the listener will be cleared.
734 ///
735 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
736 /// a specific need to register a global listener.
737 pub fn on_key_event<Event: 'static>(
738 &mut self,
739 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
740 ) {
741 self.window
742 .current_frame
743 .dispatch_tree
744 .on_key_event(Rc::new(move |event, phase, cx| {
745 if let Some(event) = event.downcast_ref::<Event>() {
746 handler(event, phase, cx)
747 }
748 }));
749 }
750
751 /// Register an action listener on the window for the current frame. The type of action
752 /// is determined by the first parameter of the given listener. When the next frame is rendered
753 /// the listener will be cleared.
754 ///
755 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
756 /// a specific need to register a global listener.
757 pub fn on_action(
758 &mut self,
759 action_type: TypeId,
760 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
761 ) {
762 self.window.current_frame.dispatch_tree.on_action(
763 action_type,
764 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
765 );
766 }
767
768 /// The position of the mouse relative to the window.
769 pub fn mouse_position(&self) -> Point<Pixels> {
770 self.window.mouse_position
771 }
772
773 pub fn set_cursor_style(&mut self, style: CursorStyle) {
774 self.window.requested_cursor_style = Some(style)
775 }
776
777 /// Called during painting to invoke the given closure in a new stacking context. The given
778 /// z-index is interpreted relative to the previous call to `stack`.
779 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
780 self.window.current_frame.z_index_stack.push(z_index);
781 let result = f(self);
782 self.window.current_frame.z_index_stack.pop();
783 result
784 }
785
786 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
787 pub fn paint_shadows(
788 &mut self,
789 bounds: Bounds<Pixels>,
790 corner_radii: Corners<Pixels>,
791 shadows: &[BoxShadow],
792 ) {
793 let scale_factor = self.scale_factor();
794 let content_mask = self.content_mask();
795 let window = &mut *self.window;
796 for shadow in shadows {
797 let mut shadow_bounds = bounds;
798 shadow_bounds.origin += shadow.offset;
799 shadow_bounds.dilate(shadow.spread_radius);
800 window.current_frame.scene_builder.insert(
801 &window.current_frame.z_index_stack,
802 Shadow {
803 order: 0,
804 bounds: shadow_bounds.scale(scale_factor),
805 content_mask: content_mask.scale(scale_factor),
806 corner_radii: corner_radii.scale(scale_factor),
807 color: shadow.color,
808 blur_radius: shadow.blur_radius.scale(scale_factor),
809 },
810 );
811 }
812 }
813
814 /// Paint one or more quads into the scene for the current frame at the current stacking context.
815 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
816 pub fn paint_quad(
817 &mut self,
818 bounds: Bounds<Pixels>,
819 corner_radii: Corners<Pixels>,
820 background: impl Into<Hsla>,
821 border_widths: Edges<Pixels>,
822 border_color: impl Into<Hsla>,
823 ) {
824 let scale_factor = self.scale_factor();
825 let content_mask = self.content_mask();
826
827 let window = &mut *self.window;
828 window.current_frame.scene_builder.insert(
829 &window.current_frame.z_index_stack,
830 Quad {
831 order: 0,
832 bounds: bounds.scale(scale_factor),
833 content_mask: content_mask.scale(scale_factor),
834 background: background.into(),
835 border_color: border_color.into(),
836 corner_radii: corner_radii.scale(scale_factor),
837 border_widths: border_widths.scale(scale_factor),
838 },
839 );
840 }
841
842 /// Paint the given `Path` into the scene for the current frame at the current z-index.
843 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
844 let scale_factor = self.scale_factor();
845 let content_mask = self.content_mask();
846 path.content_mask = content_mask;
847 path.color = color.into();
848 let window = &mut *self.window;
849 window.current_frame.scene_builder.insert(
850 &window.current_frame.z_index_stack,
851 path.scale(scale_factor),
852 );
853 }
854
855 /// Paint an underline into the scene for the current frame at the current z-index.
856 pub fn paint_underline(
857 &mut self,
858 origin: Point<Pixels>,
859 width: Pixels,
860 style: &UnderlineStyle,
861 ) -> Result<()> {
862 let scale_factor = self.scale_factor();
863 let height = if style.wavy {
864 style.thickness * 3.
865 } else {
866 style.thickness
867 };
868 let bounds = Bounds {
869 origin,
870 size: size(width, height),
871 };
872 let content_mask = self.content_mask();
873 let window = &mut *self.window;
874 window.current_frame.scene_builder.insert(
875 &window.current_frame.z_index_stack,
876 Underline {
877 order: 0,
878 bounds: bounds.scale(scale_factor),
879 content_mask: content_mask.scale(scale_factor),
880 thickness: style.thickness.scale(scale_factor),
881 color: style.color.unwrap_or_default(),
882 wavy: style.wavy,
883 },
884 );
885 Ok(())
886 }
887
888 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
889 /// The y component of the origin is the baseline of the glyph.
890 pub fn paint_glyph(
891 &mut self,
892 origin: Point<Pixels>,
893 font_id: FontId,
894 glyph_id: GlyphId,
895 font_size: Pixels,
896 color: Hsla,
897 ) -> Result<()> {
898 let scale_factor = self.scale_factor();
899 let glyph_origin = origin.scale(scale_factor);
900 let subpixel_variant = Point {
901 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
902 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
903 };
904 let params = RenderGlyphParams {
905 font_id,
906 glyph_id,
907 font_size,
908 subpixel_variant,
909 scale_factor,
910 is_emoji: false,
911 };
912
913 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
914 if !raster_bounds.is_zero() {
915 let tile =
916 self.window
917 .sprite_atlas
918 .get_or_insert_with(¶ms.clone().into(), &mut || {
919 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
920 Ok((size, Cow::Owned(bytes)))
921 })?;
922 let bounds = Bounds {
923 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
924 size: tile.bounds.size.map(Into::into),
925 };
926 let content_mask = self.content_mask().scale(scale_factor);
927 let window = &mut *self.window;
928 window.current_frame.scene_builder.insert(
929 &window.current_frame.z_index_stack,
930 MonochromeSprite {
931 order: 0,
932 bounds,
933 content_mask,
934 color,
935 tile,
936 },
937 );
938 }
939 Ok(())
940 }
941
942 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
943 /// The y component of the origin is the baseline of the glyph.
944 pub fn paint_emoji(
945 &mut self,
946 origin: Point<Pixels>,
947 font_id: FontId,
948 glyph_id: GlyphId,
949 font_size: Pixels,
950 ) -> Result<()> {
951 let scale_factor = self.scale_factor();
952 let glyph_origin = origin.scale(scale_factor);
953 let params = RenderGlyphParams {
954 font_id,
955 glyph_id,
956 font_size,
957 // We don't render emojis with subpixel variants.
958 subpixel_variant: Default::default(),
959 scale_factor,
960 is_emoji: true,
961 };
962
963 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
964 if !raster_bounds.is_zero() {
965 let tile =
966 self.window
967 .sprite_atlas
968 .get_or_insert_with(¶ms.clone().into(), &mut || {
969 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
970 Ok((size, Cow::Owned(bytes)))
971 })?;
972 let bounds = Bounds {
973 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
974 size: tile.bounds.size.map(Into::into),
975 };
976 let content_mask = self.content_mask().scale(scale_factor);
977 let window = &mut *self.window;
978
979 window.current_frame.scene_builder.insert(
980 &window.current_frame.z_index_stack,
981 PolychromeSprite {
982 order: 0,
983 bounds,
984 corner_radii: Default::default(),
985 content_mask,
986 tile,
987 grayscale: false,
988 },
989 );
990 }
991 Ok(())
992 }
993
994 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
995 pub fn paint_svg(
996 &mut self,
997 bounds: Bounds<Pixels>,
998 path: SharedString,
999 color: Hsla,
1000 ) -> Result<()> {
1001 let scale_factor = self.scale_factor();
1002 let bounds = bounds.scale(scale_factor);
1003 // Render the SVG at twice the size to get a higher quality result.
1004 let params = RenderSvgParams {
1005 path,
1006 size: bounds
1007 .size
1008 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1009 };
1010
1011 let tile =
1012 self.window
1013 .sprite_atlas
1014 .get_or_insert_with(¶ms.clone().into(), &mut || {
1015 let bytes = self.svg_renderer.render(¶ms)?;
1016 Ok((params.size, Cow::Owned(bytes)))
1017 })?;
1018 let content_mask = self.content_mask().scale(scale_factor);
1019
1020 let window = &mut *self.window;
1021 window.current_frame.scene_builder.insert(
1022 &window.current_frame.z_index_stack,
1023 MonochromeSprite {
1024 order: 0,
1025 bounds,
1026 content_mask,
1027 color,
1028 tile,
1029 },
1030 );
1031
1032 Ok(())
1033 }
1034
1035 /// Paint an image into the scene for the current frame at the current z-index.
1036 pub fn paint_image(
1037 &mut self,
1038 bounds: Bounds<Pixels>,
1039 corner_radii: Corners<Pixels>,
1040 data: Arc<ImageData>,
1041 grayscale: bool,
1042 ) -> Result<()> {
1043 let scale_factor = self.scale_factor();
1044 let bounds = bounds.scale(scale_factor);
1045 let params = RenderImageParams { image_id: data.id };
1046
1047 let tile = self
1048 .window
1049 .sprite_atlas
1050 .get_or_insert_with(¶ms.clone().into(), &mut || {
1051 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1052 })?;
1053 let content_mask = self.content_mask().scale(scale_factor);
1054 let corner_radii = corner_radii.scale(scale_factor);
1055
1056 let window = &mut *self.window;
1057 window.current_frame.scene_builder.insert(
1058 &window.current_frame.z_index_stack,
1059 PolychromeSprite {
1060 order: 0,
1061 bounds,
1062 content_mask,
1063 corner_radii,
1064 tile,
1065 grayscale,
1066 },
1067 );
1068 Ok(())
1069 }
1070
1071 /// Draw pixels to the display for this window based on the contents of its scene.
1072 pub(crate) fn draw(&mut self) {
1073 let root_view = self.window.root_view.take().unwrap();
1074
1075 self.start_frame();
1076
1077 self.with_z_index(0, |cx| {
1078 let available_space = cx.window.viewport_size.map(Into::into);
1079 root_view.draw(available_space, cx);
1080 });
1081
1082 if let Some(active_drag) = self.app.active_drag.take() {
1083 self.with_z_index(1, |cx| {
1084 let offset = cx.mouse_position() - active_drag.cursor_offset;
1085 cx.with_element_offset(offset, |cx| {
1086 let available_space =
1087 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1088 active_drag.view.draw(available_space, cx);
1089 cx.active_drag = Some(active_drag);
1090 });
1091 });
1092 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1093 self.with_z_index(1, |cx| {
1094 cx.with_element_offset(active_tooltip.cursor_offset, |cx| {
1095 let available_space = Size {
1096 width: cx.window.viewport_size.width - active_tooltip.cursor_offset.x,
1097 height: cx.window.viewport_size.height - active_tooltip.cursor_offset.y,
1098 }
1099 .map(Into::into);
1100 active_tooltip.view.draw(available_space, cx);
1101 });
1102 });
1103 }
1104
1105 self.window
1106 .current_frame
1107 .dispatch_tree
1108 .preserve_keystroke_matchers(
1109 &mut self.window.previous_frame.dispatch_tree,
1110 self.window.focus,
1111 );
1112
1113 self.window.root_view = Some(root_view);
1114 let scene = self.window.current_frame.scene_builder.build();
1115
1116 self.window.platform_window.draw(scene);
1117 let cursor_style = self
1118 .window
1119 .requested_cursor_style
1120 .take()
1121 .unwrap_or(CursorStyle::Arrow);
1122 self.platform.set_cursor_style(cursor_style);
1123
1124 self.window.dirty = false;
1125 }
1126
1127 /// Rotate the current frame and the previous frame, then clear the current frame.
1128 /// We repopulate all state in the current frame during each paint.
1129 fn start_frame(&mut self) {
1130 self.text_system().start_frame();
1131
1132 let window = &mut *self.window;
1133 window.layout_engine.clear();
1134
1135 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1136 let frame = &mut window.current_frame;
1137 frame.element_states.clear();
1138 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1139 frame.focus_listeners.clear();
1140 frame.dispatch_tree.clear();
1141 }
1142
1143 /// Dispatch a mouse or keyboard event on the window.
1144 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1145 // Handlers may set this to false by calling `stop_propagation`
1146 self.app.propagate_event = true;
1147 self.window.default_prevented = false;
1148
1149 let event = match event {
1150 // Track the mouse position with our own state, since accessing the platform
1151 // API for the mouse position can only occur on the main thread.
1152 InputEvent::MouseMove(mouse_move) => {
1153 self.window.mouse_position = mouse_move.position;
1154 InputEvent::MouseMove(mouse_move)
1155 }
1156 // Translate dragging and dropping of external files from the operating system
1157 // to internal drag and drop events.
1158 InputEvent::FileDrop(file_drop) => match file_drop {
1159 FileDropEvent::Entered { position, files } => {
1160 self.window.mouse_position = position;
1161 if self.active_drag.is_none() {
1162 self.active_drag = Some(AnyDrag {
1163 view: self.build_view(|_| files).into(),
1164 cursor_offset: position,
1165 });
1166 }
1167 InputEvent::MouseDown(MouseDownEvent {
1168 position,
1169 button: MouseButton::Left,
1170 click_count: 1,
1171 modifiers: Modifiers::default(),
1172 })
1173 }
1174 FileDropEvent::Pending { position } => {
1175 self.window.mouse_position = position;
1176 InputEvent::MouseMove(MouseMoveEvent {
1177 position,
1178 pressed_button: Some(MouseButton::Left),
1179 modifiers: Modifiers::default(),
1180 })
1181 }
1182 FileDropEvent::Submit { position } => {
1183 self.window.mouse_position = position;
1184 InputEvent::MouseUp(MouseUpEvent {
1185 button: MouseButton::Left,
1186 position,
1187 modifiers: Modifiers::default(),
1188 click_count: 1,
1189 })
1190 }
1191 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1192 button: MouseButton::Left,
1193 position: Point::default(),
1194 modifiers: Modifiers::default(),
1195 click_count: 1,
1196 }),
1197 },
1198 _ => event,
1199 };
1200
1201 if let Some(any_mouse_event) = event.mouse_event() {
1202 self.dispatch_mouse_event(any_mouse_event);
1203 } else if let Some(any_key_event) = event.keyboard_event() {
1204 self.dispatch_key_event(any_key_event);
1205 }
1206
1207 !self.app.propagate_event
1208 }
1209
1210 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1211 if let Some(mut handlers) = self
1212 .window
1213 .current_frame
1214 .mouse_listeners
1215 .remove(&event.type_id())
1216 {
1217 // Because handlers may add other handlers, we sort every time.
1218 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1219
1220 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1221 // special purposes, such as detecting events outside of a given Bounds.
1222 for (_, handler) in &mut handlers {
1223 handler(event, DispatchPhase::Capture, self);
1224 if !self.app.propagate_event {
1225 break;
1226 }
1227 }
1228
1229 // Bubble phase, where most normal handlers do their work.
1230 if self.app.propagate_event {
1231 for (_, handler) in handlers.iter_mut().rev() {
1232 handler(event, DispatchPhase::Bubble, self);
1233 if !self.app.propagate_event {
1234 break;
1235 }
1236 }
1237 }
1238
1239 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1240 self.active_drag = None;
1241 }
1242
1243 // Just in case any handlers added new handlers, which is weird, but possible.
1244 handlers.extend(
1245 self.window
1246 .current_frame
1247 .mouse_listeners
1248 .get_mut(&event.type_id())
1249 .into_iter()
1250 .flat_map(|handlers| handlers.drain(..)),
1251 );
1252 self.window
1253 .current_frame
1254 .mouse_listeners
1255 .insert(event.type_id(), handlers);
1256 }
1257 }
1258
1259 fn dispatch_key_event(&mut self, event: &dyn Any) {
1260 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1261 self.window
1262 .current_frame
1263 .dispatch_tree
1264 .focusable_node_id(focus_id)
1265 }) {
1266 let dispatch_path = self
1267 .window
1268 .current_frame
1269 .dispatch_tree
1270 .dispatch_path(node_id);
1271
1272 // Capture phase
1273 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1274 self.propagate_event = true;
1275
1276 for node_id in &dispatch_path {
1277 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1278
1279 if !node.context.is_empty() {
1280 context_stack.push(node.context.clone());
1281 }
1282
1283 for key_listener in node.key_listeners.clone() {
1284 key_listener(event, DispatchPhase::Capture, self);
1285 if !self.propagate_event {
1286 return;
1287 }
1288 }
1289 }
1290
1291 // Bubble phase
1292 for node_id in dispatch_path.iter().rev() {
1293 // Handle low level key events
1294 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1295 for key_listener in node.key_listeners.clone() {
1296 key_listener(event, DispatchPhase::Bubble, self);
1297 if !self.propagate_event {
1298 return;
1299 }
1300 }
1301
1302 // Match keystrokes
1303 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1304 if !node.context.is_empty() {
1305 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1306 if let Some(action) = self
1307 .window
1308 .current_frame
1309 .dispatch_tree
1310 .dispatch_key(&key_down_event.keystroke, &context_stack)
1311 {
1312 self.dispatch_action_on_node(*node_id, action);
1313 if !self.propagate_event {
1314 return;
1315 }
1316 }
1317 }
1318
1319 context_stack.pop();
1320 }
1321 }
1322 }
1323 }
1324
1325 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1326 let dispatch_path = self
1327 .window
1328 .current_frame
1329 .dispatch_tree
1330 .dispatch_path(node_id);
1331
1332 // Capture phase
1333 for node_id in &dispatch_path {
1334 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1335 for DispatchActionListener {
1336 action_type,
1337 listener,
1338 } in node.action_listeners.clone()
1339 {
1340 let any_action = action.as_any();
1341 if action_type == any_action.type_id() {
1342 listener(any_action, DispatchPhase::Capture, self);
1343 if !self.propagate_event {
1344 return;
1345 }
1346 }
1347 }
1348 }
1349
1350 // Bubble phase
1351 for node_id in dispatch_path.iter().rev() {
1352 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1353 for DispatchActionListener {
1354 action_type,
1355 listener,
1356 } in node.action_listeners.clone()
1357 {
1358 let any_action = action.as_any();
1359 if action_type == any_action.type_id() {
1360 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1361 listener(any_action, DispatchPhase::Bubble, self);
1362 if !self.propagate_event {
1363 return;
1364 }
1365 }
1366 }
1367 }
1368 }
1369
1370 /// Register the given handler to be invoked whenever the global of the given type
1371 /// is updated.
1372 pub fn observe_global<G: 'static>(
1373 &mut self,
1374 f: impl Fn(&mut WindowContext<'_>) + 'static,
1375 ) -> Subscription {
1376 let window_handle = self.window.handle;
1377 self.global_observers.insert(
1378 TypeId::of::<G>(),
1379 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1380 )
1381 }
1382
1383 pub fn activate_window(&self) {
1384 self.window.platform_window.activate();
1385 }
1386
1387 pub fn minimize_window(&self) {
1388 self.window.platform_window.minimize();
1389 }
1390
1391 pub fn toggle_full_screen(&self) {
1392 self.window.platform_window.toggle_full_screen();
1393 }
1394
1395 pub fn prompt(
1396 &self,
1397 level: PromptLevel,
1398 msg: &str,
1399 answers: &[&str],
1400 ) -> oneshot::Receiver<usize> {
1401 self.window.platform_window.prompt(level, msg, answers)
1402 }
1403
1404 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1405 if let Some(focus_id) = self.window.focus {
1406 self.window
1407 .current_frame
1408 .dispatch_tree
1409 .available_actions(focus_id)
1410 } else {
1411 Vec::new()
1412 }
1413 }
1414
1415 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1416 self.window
1417 .current_frame
1418 .dispatch_tree
1419 .bindings_for_action(action)
1420 }
1421}
1422
1423impl Context for WindowContext<'_> {
1424 type Result<T> = T;
1425
1426 fn build_model<T>(
1427 &mut self,
1428 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1429 ) -> Model<T>
1430 where
1431 T: 'static,
1432 {
1433 let slot = self.app.entities.reserve();
1434 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1435 self.entities.insert(slot, model)
1436 }
1437
1438 fn update_model<T: 'static, R>(
1439 &mut self,
1440 model: &Model<T>,
1441 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1442 ) -> R {
1443 let mut entity = self.entities.lease(model);
1444 let result = update(
1445 &mut *entity,
1446 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1447 );
1448 self.entities.end_lease(entity);
1449 result
1450 }
1451
1452 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1453 where
1454 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1455 {
1456 if window == self.window.handle {
1457 let root_view = self.window.root_view.clone().unwrap();
1458 Ok(update(root_view, self))
1459 } else {
1460 window.update(self.app, update)
1461 }
1462 }
1463
1464 fn read_model<T, R>(
1465 &self,
1466 handle: &Model<T>,
1467 read: impl FnOnce(&T, &AppContext) -> R,
1468 ) -> Self::Result<R>
1469 where
1470 T: 'static,
1471 {
1472 let entity = self.entities.read(handle);
1473 read(&*entity, &*self.app)
1474 }
1475
1476 fn read_window<T, R>(
1477 &self,
1478 window: &WindowHandle<T>,
1479 read: impl FnOnce(View<T>, &AppContext) -> R,
1480 ) -> Result<R>
1481 where
1482 T: 'static,
1483 {
1484 if window.any_handle == self.window.handle {
1485 let root_view = self
1486 .window
1487 .root_view
1488 .clone()
1489 .unwrap()
1490 .downcast::<T>()
1491 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1492 Ok(read(root_view, self))
1493 } else {
1494 self.app.read_window(window, read)
1495 }
1496 }
1497}
1498
1499impl VisualContext for WindowContext<'_> {
1500 fn build_view<V>(
1501 &mut self,
1502 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1503 ) -> Self::Result<View<V>>
1504 where
1505 V: 'static + Render,
1506 {
1507 let slot = self.app.entities.reserve();
1508 let view = View {
1509 model: slot.clone(),
1510 };
1511 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1512 let entity = build_view_state(&mut cx);
1513 cx.entities.insert(slot, entity);
1514
1515 cx.new_view_observers
1516 .clone()
1517 .retain(&TypeId::of::<V>(), |observer| {
1518 let any_view = AnyView::from(view.clone());
1519 (observer)(any_view, self);
1520 true
1521 });
1522
1523 view
1524 }
1525
1526 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1527 fn update_view<T: 'static, R>(
1528 &mut self,
1529 view: &View<T>,
1530 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1531 ) -> Self::Result<R> {
1532 let mut lease = self.app.entities.lease(&view.model);
1533 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1534 let result = update(&mut *lease, &mut cx);
1535 cx.app.entities.end_lease(lease);
1536 result
1537 }
1538
1539 fn replace_root_view<V>(
1540 &mut self,
1541 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1542 ) -> Self::Result<View<V>>
1543 where
1544 V: Render,
1545 {
1546 let slot = self.app.entities.reserve();
1547 let view = View {
1548 model: slot.clone(),
1549 };
1550 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1551 let entity = build_view(&mut cx);
1552 self.entities.insert(slot, entity);
1553 self.window.root_view = Some(view.clone().into());
1554 view
1555 }
1556}
1557
1558impl<'a> std::ops::Deref for WindowContext<'a> {
1559 type Target = AppContext;
1560
1561 fn deref(&self) -> &Self::Target {
1562 &self.app
1563 }
1564}
1565
1566impl<'a> std::ops::DerefMut for WindowContext<'a> {
1567 fn deref_mut(&mut self) -> &mut Self::Target {
1568 &mut self.app
1569 }
1570}
1571
1572impl<'a> Borrow<AppContext> for WindowContext<'a> {
1573 fn borrow(&self) -> &AppContext {
1574 &self.app
1575 }
1576}
1577
1578impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1579 fn borrow_mut(&mut self) -> &mut AppContext {
1580 &mut self.app
1581 }
1582}
1583
1584pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1585 fn app_mut(&mut self) -> &mut AppContext {
1586 self.borrow_mut()
1587 }
1588
1589 fn window(&self) -> &Window {
1590 self.borrow()
1591 }
1592
1593 fn window_mut(&mut self) -> &mut Window {
1594 self.borrow_mut()
1595 }
1596
1597 /// Pushes the given element id onto the global stack and invokes the given closure
1598 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1599 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1600 /// used to associate state with identified elements across separate frames.
1601 fn with_element_id<R>(
1602 &mut self,
1603 id: Option<impl Into<ElementId>>,
1604 f: impl FnOnce(&mut Self) -> R,
1605 ) -> R {
1606 if let Some(id) = id.map(Into::into) {
1607 let window = self.window_mut();
1608 window.element_id_stack.push(id.into());
1609 let result = f(self);
1610 let window: &mut Window = self.borrow_mut();
1611 window.element_id_stack.pop();
1612 result
1613 } else {
1614 f(self)
1615 }
1616 }
1617
1618 /// Invoke the given function with the given content mask after intersecting it
1619 /// with the current mask.
1620 fn with_content_mask<R>(
1621 &mut self,
1622 mask: Option<ContentMask<Pixels>>,
1623 f: impl FnOnce(&mut Self) -> R,
1624 ) -> R {
1625 if let Some(mask) = mask {
1626 let mask = mask.intersect(&self.content_mask());
1627 self.window_mut()
1628 .current_frame
1629 .content_mask_stack
1630 .push(mask);
1631 let result = f(self);
1632 self.window_mut().current_frame.content_mask_stack.pop();
1633 result
1634 } else {
1635 f(self)
1636 }
1637 }
1638
1639 /// Update the global element offset based on the given offset. This is used to implement
1640 /// scrolling and position drag handles.
1641 fn with_element_offset<R>(
1642 &mut self,
1643 offset: Point<Pixels>,
1644 f: impl FnOnce(&mut Self) -> R,
1645 ) -> R {
1646 if offset.is_zero() {
1647 return f(self);
1648 };
1649
1650 let offset = self.element_offset() + offset;
1651 self.window_mut()
1652 .current_frame
1653 .element_offset_stack
1654 .push(offset);
1655 let result = f(self);
1656 self.window_mut().current_frame.element_offset_stack.pop();
1657 result
1658 }
1659
1660 /// Obtain the current element offset.
1661 fn element_offset(&self) -> Point<Pixels> {
1662 self.window()
1663 .current_frame
1664 .element_offset_stack
1665 .last()
1666 .copied()
1667 .unwrap_or_default()
1668 }
1669
1670 /// Update or intialize state for an element with the given id that lives across multiple
1671 /// frames. If an element with this id existed in the previous frame, its state will be passed
1672 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1673 /// when drawing the next frame.
1674 fn with_element_state<S, R>(
1675 &mut self,
1676 id: ElementId,
1677 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1678 ) -> R
1679 where
1680 S: 'static,
1681 {
1682 self.with_element_id(Some(id), |cx| {
1683 let global_id = cx.window().element_id_stack.clone();
1684
1685 if let Some(any) = cx
1686 .window_mut()
1687 .current_frame
1688 .element_states
1689 .remove(&global_id)
1690 .or_else(|| {
1691 cx.window_mut()
1692 .previous_frame
1693 .element_states
1694 .remove(&global_id)
1695 })
1696 {
1697 // Using the extra inner option to avoid needing to reallocate a new box.
1698 let mut state_box = any
1699 .downcast::<Option<S>>()
1700 .expect("invalid element state type for id");
1701 let state = state_box
1702 .take()
1703 .expect("element state is already on the stack");
1704 let (result, state) = f(Some(state), cx);
1705 state_box.replace(state);
1706 cx.window_mut()
1707 .current_frame
1708 .element_states
1709 .insert(global_id, state_box);
1710 result
1711 } else {
1712 let (result, state) = f(None, cx);
1713 cx.window_mut()
1714 .current_frame
1715 .element_states
1716 .insert(global_id, Box::new(Some(state)));
1717 result
1718 }
1719 })
1720 }
1721
1722 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1723 /// id is `None`, no state will be retrieved or stored.
1724 fn with_optional_element_state<S, R>(
1725 &mut self,
1726 element_id: Option<ElementId>,
1727 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1728 ) -> R
1729 where
1730 S: 'static,
1731 {
1732 if let Some(element_id) = element_id {
1733 self.with_element_state(element_id, f)
1734 } else {
1735 f(None, self).0
1736 }
1737 }
1738
1739 /// Obtain the current content mask.
1740 fn content_mask(&self) -> ContentMask<Pixels> {
1741 self.window()
1742 .current_frame
1743 .content_mask_stack
1744 .last()
1745 .cloned()
1746 .unwrap_or_else(|| ContentMask {
1747 bounds: Bounds {
1748 origin: Point::default(),
1749 size: self.window().viewport_size,
1750 },
1751 })
1752 }
1753
1754 /// The size of an em for the base font of the application. Adjusting this value allows the
1755 /// UI to scale, just like zooming a web page.
1756 fn rem_size(&self) -> Pixels {
1757 self.window().rem_size
1758 }
1759}
1760
1761impl Borrow<Window> for WindowContext<'_> {
1762 fn borrow(&self) -> &Window {
1763 &self.window
1764 }
1765}
1766
1767impl BorrowMut<Window> for WindowContext<'_> {
1768 fn borrow_mut(&mut self) -> &mut Window {
1769 &mut self.window
1770 }
1771}
1772
1773impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1774
1775pub struct ViewContext<'a, V> {
1776 window_cx: WindowContext<'a>,
1777 view: &'a View<V>,
1778}
1779
1780impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1781 fn borrow(&self) -> &AppContext {
1782 &*self.window_cx.app
1783 }
1784}
1785
1786impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1787 fn borrow_mut(&mut self) -> &mut AppContext {
1788 &mut *self.window_cx.app
1789 }
1790}
1791
1792impl<V> Borrow<Window> for ViewContext<'_, V> {
1793 fn borrow(&self) -> &Window {
1794 &*self.window_cx.window
1795 }
1796}
1797
1798impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1799 fn borrow_mut(&mut self) -> &mut Window {
1800 &mut *self.window_cx.window
1801 }
1802}
1803
1804impl<'a, V: 'static> ViewContext<'a, V> {
1805 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1806 Self {
1807 window_cx: WindowContext::new(app, window),
1808 view,
1809 }
1810 }
1811
1812 pub fn entity_id(&self) -> EntityId {
1813 self.view.entity_id()
1814 }
1815
1816 pub fn view(&self) -> &View<V> {
1817 self.view
1818 }
1819
1820 pub fn model(&self) -> Model<V> {
1821 self.view.model.clone()
1822 }
1823
1824 /// Access the underlying window context.
1825 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1826 &mut self.window_cx
1827 }
1828
1829 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1830 self.window.current_frame.z_index_stack.push(z_index);
1831 let result = f(self);
1832 self.window.current_frame.z_index_stack.pop();
1833 result
1834 }
1835
1836 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1837 where
1838 V: 'static,
1839 {
1840 let view = self.view().clone();
1841 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1842 }
1843
1844 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1845 /// that are currently on the stack to be returned to the app.
1846 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1847 let view = self.view().downgrade();
1848 self.window_cx.defer(move |cx| {
1849 view.update(cx, f).ok();
1850 });
1851 }
1852
1853 pub fn observe<V2, E>(
1854 &mut self,
1855 entity: &E,
1856 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1857 ) -> Subscription
1858 where
1859 V2: 'static,
1860 V: 'static,
1861 E: Entity<V2>,
1862 {
1863 let view = self.view().downgrade();
1864 let entity_id = entity.entity_id();
1865 let entity = entity.downgrade();
1866 let window_handle = self.window.handle;
1867 self.app.observers.insert(
1868 entity_id,
1869 Box::new(move |cx| {
1870 window_handle
1871 .update(cx, |_, cx| {
1872 if let Some(handle) = E::upgrade_from(&entity) {
1873 view.update(cx, |this, cx| on_notify(this, handle, cx))
1874 .is_ok()
1875 } else {
1876 false
1877 }
1878 })
1879 .unwrap_or(false)
1880 }),
1881 )
1882 }
1883
1884 pub fn subscribe<V2, E, Evt>(
1885 &mut self,
1886 entity: &E,
1887 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1888 ) -> Subscription
1889 where
1890 V2: EventEmitter<Evt>,
1891 E: Entity<V2>,
1892 Evt: 'static,
1893 {
1894 let view = self.view().downgrade();
1895 let entity_id = entity.entity_id();
1896 let handle = entity.downgrade();
1897 let window_handle = self.window.handle;
1898 self.app.event_listeners.insert(
1899 entity_id,
1900 (
1901 TypeId::of::<Evt>(),
1902 Box::new(move |event, cx| {
1903 window_handle
1904 .update(cx, |_, cx| {
1905 if let Some(handle) = E::upgrade_from(&handle) {
1906 let event = event.downcast_ref().expect("invalid event type");
1907 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1908 .is_ok()
1909 } else {
1910 false
1911 }
1912 })
1913 .unwrap_or(false)
1914 }),
1915 ),
1916 )
1917 }
1918
1919 pub fn on_release(
1920 &mut self,
1921 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
1922 ) -> Subscription {
1923 let window_handle = self.window.handle;
1924 self.app.release_listeners.insert(
1925 self.view.model.entity_id,
1926 Box::new(move |this, cx| {
1927 let this = this.downcast_mut().expect("invalid entity type");
1928 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
1929 }),
1930 )
1931 }
1932
1933 pub fn observe_release<V2, E>(
1934 &mut self,
1935 entity: &E,
1936 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1937 ) -> Subscription
1938 where
1939 V: 'static,
1940 V2: 'static,
1941 E: Entity<V2>,
1942 {
1943 let view = self.view().downgrade();
1944 let entity_id = entity.entity_id();
1945 let window_handle = self.window.handle;
1946 self.app.release_listeners.insert(
1947 entity_id,
1948 Box::new(move |entity, cx| {
1949 let entity = entity.downcast_mut().expect("invalid entity type");
1950 let _ = window_handle.update(cx, |_, cx| {
1951 view.update(cx, |this, cx| on_release(this, entity, cx))
1952 });
1953 }),
1954 )
1955 }
1956
1957 pub fn notify(&mut self) {
1958 self.window_cx.notify();
1959 self.window_cx.app.push_effect(Effect::Notify {
1960 emitter: self.view.model.entity_id,
1961 });
1962 }
1963
1964 pub fn observe_window_bounds(
1965 &mut self,
1966 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1967 ) -> Subscription {
1968 let view = self.view.downgrade();
1969 self.window.bounds_observers.insert(
1970 (),
1971 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1972 )
1973 }
1974
1975 pub fn observe_window_activation(
1976 &mut self,
1977 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1978 ) -> Subscription {
1979 let view = self.view.downgrade();
1980 self.window.activation_observers.insert(
1981 (),
1982 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1983 )
1984 }
1985
1986 /// Register a listener to be called when the given focus handle receives focus.
1987 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1988 /// is dropped.
1989 pub fn on_focus(
1990 &mut self,
1991 handle: &FocusHandle,
1992 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1993 ) -> Subscription {
1994 let view = self.view.downgrade();
1995 let focus_id = handle.id;
1996 self.window.focus_listeners.insert(
1997 (),
1998 Box::new(move |event, cx| {
1999 view.update(cx, |view, cx| {
2000 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2001 listener(view, cx)
2002 }
2003 })
2004 .is_ok()
2005 }),
2006 )
2007 }
2008
2009 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2010 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2011 /// is dropped.
2012 pub fn on_focus_in(
2013 &mut self,
2014 handle: &FocusHandle,
2015 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2016 ) -> Subscription {
2017 let view = self.view.downgrade();
2018 let focus_id = handle.id;
2019 self.window.focus_listeners.insert(
2020 (),
2021 Box::new(move |event, cx| {
2022 view.update(cx, |view, cx| {
2023 if event
2024 .focused
2025 .as_ref()
2026 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2027 {
2028 listener(view, cx)
2029 }
2030 })
2031 .is_ok()
2032 }),
2033 )
2034 }
2035
2036 /// Register a listener to be called when the given focus handle loses focus.
2037 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2038 /// is dropped.
2039 pub fn on_blur(
2040 &mut self,
2041 handle: &FocusHandle,
2042 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2043 ) -> Subscription {
2044 let view = self.view.downgrade();
2045 let focus_id = handle.id;
2046 self.window.focus_listeners.insert(
2047 (),
2048 Box::new(move |event, cx| {
2049 view.update(cx, |view, cx| {
2050 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2051 listener(view, cx)
2052 }
2053 })
2054 .is_ok()
2055 }),
2056 )
2057 }
2058
2059 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2060 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2061 /// is dropped.
2062 pub fn on_focus_out(
2063 &mut self,
2064 handle: &FocusHandle,
2065 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2066 ) -> Subscription {
2067 let view = self.view.downgrade();
2068 let focus_id = handle.id;
2069 self.window.focus_listeners.insert(
2070 (),
2071 Box::new(move |event, cx| {
2072 view.update(cx, |view, cx| {
2073 if event
2074 .blurred
2075 .as_ref()
2076 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2077 {
2078 listener(view, cx)
2079 }
2080 })
2081 .is_ok()
2082 }),
2083 )
2084 }
2085
2086 /// Register a focus listener for the current frame only. It will be cleared
2087 /// on the next frame render. You should use this method only from within elements,
2088 /// and we may want to enforce that better via a different context type.
2089 // todo!() Move this to `FrameContext` to emphasize its individuality?
2090 pub fn on_focus_changed(
2091 &mut self,
2092 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + 'static,
2093 ) {
2094 let handle = self.view().downgrade();
2095 self.window
2096 .current_frame
2097 .focus_listeners
2098 .push(Box::new(move |event, cx| {
2099 handle
2100 .update(cx, |view, cx| listener(view, event, cx))
2101 .log_err();
2102 }));
2103 }
2104
2105 pub fn with_key_dispatch<R>(
2106 &mut self,
2107 context: KeyContext,
2108 focus_handle: Option<FocusHandle>,
2109 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
2110 ) -> R {
2111 let window = &mut self.window;
2112 window
2113 .current_frame
2114 .dispatch_tree
2115 .push_node(context.clone());
2116 if let Some(focus_handle) = focus_handle.as_ref() {
2117 window
2118 .current_frame
2119 .dispatch_tree
2120 .make_focusable(focus_handle.id);
2121 }
2122 let result = f(focus_handle, self);
2123
2124 self.window.current_frame.dispatch_tree.pop_node();
2125
2126 result
2127 }
2128
2129 pub fn spawn<Fut, R>(
2130 &mut self,
2131 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2132 ) -> Task<R>
2133 where
2134 R: 'static,
2135 Fut: Future<Output = R> + 'static,
2136 {
2137 let view = self.view().downgrade();
2138 self.window_cx.spawn(|cx| f(view, cx))
2139 }
2140
2141 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2142 where
2143 G: 'static,
2144 {
2145 let mut global = self.app.lease_global::<G>();
2146 let result = f(&mut global, self);
2147 self.app.end_global_lease(global);
2148 result
2149 }
2150
2151 pub fn observe_global<G: 'static>(
2152 &mut self,
2153 f: impl Fn(&mut V, &mut ViewContext<'_, V>) + 'static,
2154 ) -> Subscription {
2155 let window_handle = self.window.handle;
2156 let view = self.view().downgrade();
2157 self.global_observers.insert(
2158 TypeId::of::<G>(),
2159 Box::new(move |cx| {
2160 window_handle
2161 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2162 .unwrap_or(false)
2163 }),
2164 )
2165 }
2166
2167 pub fn on_mouse_event<Event: 'static>(
2168 &mut self,
2169 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2170 ) {
2171 let handle = self.view().clone();
2172 self.window_cx.on_mouse_event(move |event, phase, cx| {
2173 handle.update(cx, |view, cx| {
2174 handler(view, event, phase, cx);
2175 })
2176 });
2177 }
2178
2179 pub fn on_key_event<Event: 'static>(
2180 &mut self,
2181 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2182 ) {
2183 let handle = self.view().clone();
2184 self.window_cx.on_key_event(move |event, phase, cx| {
2185 handle.update(cx, |view, cx| {
2186 handler(view, event, phase, cx);
2187 })
2188 });
2189 }
2190
2191 pub fn on_action(
2192 &mut self,
2193 action_type: TypeId,
2194 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2195 ) {
2196 let handle = self.view().clone();
2197 self.window_cx
2198 .on_action(action_type, move |action, phase, cx| {
2199 handle.update(cx, |view, cx| {
2200 handler(view, action, phase, cx);
2201 })
2202 });
2203 }
2204
2205 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
2206 /// platform to receive textual input with proper integration with concerns such
2207 /// as IME interactions.
2208 pub fn handle_input(
2209 &mut self,
2210 focus_handle: &FocusHandle,
2211 input_handler: impl PlatformInputHandler,
2212 ) {
2213 if focus_handle.is_focused(self) {
2214 self.window
2215 .platform_window
2216 .set_input_handler(Box::new(input_handler));
2217 }
2218 }
2219}
2220
2221impl<V> ViewContext<'_, V> {
2222 pub fn emit<Evt>(&mut self, event: Evt)
2223 where
2224 Evt: 'static,
2225 V: EventEmitter<Evt>,
2226 {
2227 let emitter = self.view.model.entity_id;
2228 self.app.push_effect(Effect::Emit {
2229 emitter,
2230 event_type: TypeId::of::<Evt>(),
2231 event: Box::new(event),
2232 });
2233 }
2234}
2235
2236impl<V> Context for ViewContext<'_, V> {
2237 type Result<U> = U;
2238
2239 fn build_model<T: 'static>(
2240 &mut self,
2241 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2242 ) -> Model<T> {
2243 self.window_cx.build_model(build_model)
2244 }
2245
2246 fn update_model<T: 'static, R>(
2247 &mut self,
2248 model: &Model<T>,
2249 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2250 ) -> R {
2251 self.window_cx.update_model(model, update)
2252 }
2253
2254 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2255 where
2256 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2257 {
2258 self.window_cx.update_window(window, update)
2259 }
2260
2261 fn read_model<T, R>(
2262 &self,
2263 handle: &Model<T>,
2264 read: impl FnOnce(&T, &AppContext) -> R,
2265 ) -> Self::Result<R>
2266 where
2267 T: 'static,
2268 {
2269 self.window_cx.read_model(handle, read)
2270 }
2271
2272 fn read_window<T, R>(
2273 &self,
2274 window: &WindowHandle<T>,
2275 read: impl FnOnce(View<T>, &AppContext) -> R,
2276 ) -> Result<R>
2277 where
2278 T: 'static,
2279 {
2280 self.window_cx.read_window(window, read)
2281 }
2282}
2283
2284impl<V: 'static> VisualContext for ViewContext<'_, V> {
2285 fn build_view<W: Render + 'static>(
2286 &mut self,
2287 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2288 ) -> Self::Result<View<W>> {
2289 self.window_cx.build_view(build_view_state)
2290 }
2291
2292 fn update_view<V2: 'static, R>(
2293 &mut self,
2294 view: &View<V2>,
2295 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2296 ) -> Self::Result<R> {
2297 self.window_cx.update_view(view, update)
2298 }
2299
2300 fn replace_root_view<W>(
2301 &mut self,
2302 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2303 ) -> Self::Result<View<W>>
2304 where
2305 W: Render,
2306 {
2307 self.window_cx.replace_root_view(build_view)
2308 }
2309}
2310
2311impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2312 type Target = WindowContext<'a>;
2313
2314 fn deref(&self) -> &Self::Target {
2315 &self.window_cx
2316 }
2317}
2318
2319impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2320 fn deref_mut(&mut self) -> &mut Self::Target {
2321 &mut self.window_cx
2322 }
2323}
2324
2325// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2326slotmap::new_key_type! { pub struct WindowId; }
2327
2328impl WindowId {
2329 pub fn as_u64(&self) -> u64 {
2330 self.0.as_ffi()
2331 }
2332}
2333
2334#[derive(Deref, DerefMut)]
2335pub struct WindowHandle<V> {
2336 #[deref]
2337 #[deref_mut]
2338 pub(crate) any_handle: AnyWindowHandle,
2339 state_type: PhantomData<V>,
2340}
2341
2342impl<V: 'static + Render> WindowHandle<V> {
2343 pub fn new(id: WindowId) -> Self {
2344 WindowHandle {
2345 any_handle: AnyWindowHandle {
2346 id,
2347 state_type: TypeId::of::<V>(),
2348 },
2349 state_type: PhantomData,
2350 }
2351 }
2352
2353 pub fn update<C, R>(
2354 &self,
2355 cx: &mut C,
2356 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2357 ) -> Result<R>
2358 where
2359 C: Context,
2360 {
2361 cx.update_window(self.any_handle, |root_view, cx| {
2362 let view = root_view
2363 .downcast::<V>()
2364 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2365 Ok(cx.update_view(&view, update))
2366 })?
2367 }
2368
2369 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2370 let x = cx
2371 .windows
2372 .get(self.id)
2373 .and_then(|window| {
2374 window
2375 .as_ref()
2376 .and_then(|window| window.root_view.clone())
2377 .map(|root_view| root_view.downcast::<V>())
2378 })
2379 .ok_or_else(|| anyhow!("window not found"))?
2380 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2381
2382 Ok(x.read(cx))
2383 }
2384
2385 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2386 where
2387 C: Context,
2388 {
2389 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2390 }
2391
2392 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2393 where
2394 C: Context,
2395 {
2396 cx.read_window(self, |root_view, _cx| root_view.clone())
2397 }
2398
2399 pub fn is_active(&self, cx: &WindowContext) -> Option<bool> {
2400 cx.windows
2401 .get(self.id)
2402 .and_then(|window| window.as_ref().map(|window| window.active))
2403 }
2404}
2405
2406impl<V> Copy for WindowHandle<V> {}
2407
2408impl<V> Clone for WindowHandle<V> {
2409 fn clone(&self) -> Self {
2410 WindowHandle {
2411 any_handle: self.any_handle,
2412 state_type: PhantomData,
2413 }
2414 }
2415}
2416
2417impl<V> PartialEq for WindowHandle<V> {
2418 fn eq(&self, other: &Self) -> bool {
2419 self.any_handle == other.any_handle
2420 }
2421}
2422
2423impl<V> Eq for WindowHandle<V> {}
2424
2425impl<V> Hash for WindowHandle<V> {
2426 fn hash<H: Hasher>(&self, state: &mut H) {
2427 self.any_handle.hash(state);
2428 }
2429}
2430
2431impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2432 fn into(self) -> AnyWindowHandle {
2433 self.any_handle
2434 }
2435}
2436
2437#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2438pub struct AnyWindowHandle {
2439 pub(crate) id: WindowId,
2440 state_type: TypeId,
2441}
2442
2443impl AnyWindowHandle {
2444 pub fn window_id(&self) -> WindowId {
2445 self.id
2446 }
2447
2448 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2449 if TypeId::of::<T>() == self.state_type {
2450 Some(WindowHandle {
2451 any_handle: *self,
2452 state_type: PhantomData,
2453 })
2454 } else {
2455 None
2456 }
2457 }
2458
2459 pub fn update<C, R>(
2460 self,
2461 cx: &mut C,
2462 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2463 ) -> Result<R>
2464 where
2465 C: Context,
2466 {
2467 cx.update_window(self, update)
2468 }
2469
2470 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2471 where
2472 C: Context,
2473 T: 'static,
2474 {
2475 let view = self
2476 .downcast::<T>()
2477 .context("the type of the window's root view has changed")?;
2478
2479 cx.read_window(&view, read)
2480 }
2481}
2482
2483#[cfg(any(test, feature = "test-support"))]
2484impl From<SmallVec<[u32; 16]>> for StackingOrder {
2485 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2486 StackingOrder(small_vec)
2487 }
2488}
2489
2490#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2491pub enum ElementId {
2492 View(EntityId),
2493 Integer(usize),
2494 Name(SharedString),
2495 FocusHandle(FocusId),
2496}
2497
2498impl From<EntityId> for ElementId {
2499 fn from(id: EntityId) -> Self {
2500 ElementId::View(id)
2501 }
2502}
2503
2504impl From<usize> for ElementId {
2505 fn from(id: usize) -> Self {
2506 ElementId::Integer(id)
2507 }
2508}
2509
2510impl From<i32> for ElementId {
2511 fn from(id: i32) -> Self {
2512 Self::Integer(id as usize)
2513 }
2514}
2515
2516impl From<SharedString> for ElementId {
2517 fn from(name: SharedString) -> Self {
2518 ElementId::Name(name)
2519 }
2520}
2521
2522impl From<&'static str> for ElementId {
2523 fn from(name: &'static str) -> Self {
2524 ElementId::Name(name.into())
2525 }
2526}
2527
2528impl<'a> From<&'a FocusHandle> for ElementId {
2529 fn from(handle: &'a FocusHandle) -> Self {
2530 ElementId::FocusHandle(handle.id)
2531 }
2532}