1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle,
4 DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId,
5 EventEmitter, FileDropEvent, Flatten, FocusEvent, FontId, GlobalElementId, GlyphId, Hsla,
6 ImageData, InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, LayoutId, Model,
7 ModelContext, Modifiers, MonochromeSprite, MouseButton, MouseDownEvent, MouseMoveEvent,
8 MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler,
9 PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams,
10 RenderImageParams, RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size,
11 Style, SubscriberSet, Subscription, TaffyLayoutEngine, Task, Underline, UnderlineStyle, View,
12 VisualContext, 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, Debug)]
43pub 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/// FocusableView allows users of your view to easily
189/// focus it (using cx.focus_view(view))
190pub trait FocusableView: 'static + Render {
191 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
192}
193
194/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
195/// where the lifecycle of the view is handled by another view.
196pub trait ManagedView: FocusableView + EventEmitter<DismissEvent> {}
197
198impl<M: FocusableView + EventEmitter<DismissEvent>> ManagedView for M {}
199
200pub enum DismissEvent {
201 Dismiss,
202}
203
204// Holds the state for a specific window.
205pub struct Window {
206 pub(crate) handle: AnyWindowHandle,
207 pub(crate) removed: bool,
208 pub(crate) platform_window: Box<dyn PlatformWindow>,
209 display_id: DisplayId,
210 sprite_atlas: Arc<dyn PlatformAtlas>,
211 rem_size: Pixels,
212 viewport_size: Size<Pixels>,
213 pub(crate) layout_engine: TaffyLayoutEngine,
214 pub(crate) root_view: Option<AnyView>,
215 pub(crate) element_id_stack: GlobalElementId,
216 pub(crate) previous_frame: Frame,
217 pub(crate) current_frame: Frame,
218 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
219 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
220 default_prevented: bool,
221 mouse_position: Point<Pixels>,
222 requested_cursor_style: Option<CursorStyle>,
223 scale_factor: f32,
224 bounds: WindowBounds,
225 bounds_observers: SubscriberSet<(), AnyObserver>,
226 active: bool,
227 activation_observers: SubscriberSet<(), AnyObserver>,
228 pub(crate) dirty: bool,
229 pub(crate) last_blur: Option<Option<FocusId>>,
230 pub(crate) focus: Option<FocusId>,
231}
232
233pub(crate) struct ElementStateBox {
234 inner: Box<dyn Any>,
235 #[cfg(debug_assertions)]
236 type_name: &'static str,
237}
238
239// #[derive(Default)]
240pub(crate) struct Frame {
241 pub(crate) element_states: HashMap<GlobalElementId, ElementStateBox>,
242 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
243 pub(crate) dispatch_tree: DispatchTree,
244 pub(crate) focus_listeners: Vec<AnyFocusListener>,
245 pub(crate) scene_builder: SceneBuilder,
246 pub(crate) depth_map: Vec<(StackingOrder, Bounds<Pixels>)>,
247 pub(crate) z_index_stack: StackingOrder,
248 content_mask_stack: Vec<ContentMask<Pixels>>,
249 element_offset_stack: Vec<Point<Pixels>>,
250}
251
252impl Frame {
253 pub fn new(dispatch_tree: DispatchTree) -> Self {
254 Frame {
255 element_states: HashMap::default(),
256 mouse_listeners: HashMap::default(),
257 dispatch_tree,
258 focus_listeners: Vec::new(),
259 scene_builder: SceneBuilder::default(),
260 z_index_stack: StackingOrder::default(),
261 depth_map: Default::default(),
262 content_mask_stack: Vec::new(),
263 element_offset_stack: Vec::new(),
264 }
265 }
266}
267
268impl Window {
269 pub(crate) fn new(
270 handle: AnyWindowHandle,
271 options: WindowOptions,
272 cx: &mut AppContext,
273 ) -> Self {
274 let platform_window = cx.platform.open_window(handle, options);
275 let display_id = platform_window.display().id();
276 let sprite_atlas = platform_window.sprite_atlas();
277 let mouse_position = platform_window.mouse_position();
278 let content_size = platform_window.content_size();
279 let scale_factor = platform_window.scale_factor();
280 let bounds = platform_window.bounds();
281
282 platform_window.on_resize(Box::new({
283 let mut cx = cx.to_async();
284 move |_, _| {
285 handle
286 .update(&mut cx, |_, cx| cx.window_bounds_changed())
287 .log_err();
288 }
289 }));
290 platform_window.on_moved(Box::new({
291 let mut cx = cx.to_async();
292 move || {
293 handle
294 .update(&mut cx, |_, cx| cx.window_bounds_changed())
295 .log_err();
296 }
297 }));
298 platform_window.on_active_status_change(Box::new({
299 let mut cx = cx.to_async();
300 move |active| {
301 handle
302 .update(&mut cx, |_, cx| {
303 cx.window.active = active;
304 cx.window
305 .activation_observers
306 .clone()
307 .retain(&(), |callback| callback(cx));
308 })
309 .log_err();
310 }
311 }));
312
313 platform_window.on_input({
314 let mut cx = cx.to_async();
315 Box::new(move |event| {
316 handle
317 .update(&mut cx, |_, cx| cx.dispatch_event(event))
318 .log_err()
319 .unwrap_or(false)
320 })
321 });
322
323 Window {
324 handle,
325 removed: false,
326 platform_window,
327 display_id,
328 sprite_atlas,
329 rem_size: px(16.),
330 viewport_size: content_size,
331 layout_engine: TaffyLayoutEngine::new(),
332 root_view: None,
333 element_id_stack: GlobalElementId::default(),
334 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
335 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
336 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
337 focus_listeners: SubscriberSet::new(),
338 default_prevented: true,
339 mouse_position,
340 requested_cursor_style: None,
341 scale_factor,
342 bounds,
343 bounds_observers: SubscriberSet::new(),
344 active: false,
345 activation_observers: SubscriberSet::new(),
346 dirty: true,
347 last_blur: None,
348 focus: None,
349 }
350 }
351}
352
353/// Indicates which region of the window is visible. Content falling outside of this mask will not be
354/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
355/// to leave room to support more complex shapes in the future.
356#[derive(Clone, Debug, Default, PartialEq, Eq)]
357#[repr(C)]
358pub struct ContentMask<P: Clone + Default + Debug> {
359 pub bounds: Bounds<P>,
360}
361
362impl ContentMask<Pixels> {
363 /// Scale the content mask's pixel units by the given scaling factor.
364 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
365 ContentMask {
366 bounds: self.bounds.scale(factor),
367 }
368 }
369
370 /// Intersect the content mask with the given content mask.
371 pub fn intersect(&self, other: &Self) -> Self {
372 let bounds = self.bounds.intersect(&other.bounds);
373 ContentMask { bounds }
374 }
375}
376
377/// Provides access to application state in the context of a single window. Derefs
378/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
379/// an `AppContext` and call any `AppContext` methods.
380pub struct WindowContext<'a> {
381 pub(crate) app: &'a mut AppContext,
382 pub(crate) window: &'a mut Window,
383}
384
385impl<'a> WindowContext<'a> {
386 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
387 Self { app, window }
388 }
389
390 /// Obtain a handle to the window that belongs to this context.
391 pub fn window_handle(&self) -> AnyWindowHandle {
392 self.window.handle
393 }
394
395 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
396 pub fn notify(&mut self) {
397 self.window.dirty = true;
398 }
399
400 /// Close this window.
401 pub fn remove_window(&mut self) {
402 self.window.removed = true;
403 }
404
405 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
406 /// for elements rendered within this window.
407 pub fn focus_handle(&mut self) -> FocusHandle {
408 FocusHandle::new(&self.window.focus_handles)
409 }
410
411 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
412 pub fn focused(&self) -> Option<FocusHandle> {
413 self.window
414 .focus
415 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
416 }
417
418 /// Move focus to the element associated with the given `FocusHandle`.
419 pub fn focus(&mut self, handle: &FocusHandle) {
420 if self.window.focus == Some(handle.id) {
421 return;
422 }
423
424 let focus_id = handle.id;
425
426 if self.window.last_blur.is_none() {
427 self.window.last_blur = Some(self.window.focus);
428 }
429
430 self.window.focus = Some(focus_id);
431 self.window
432 .current_frame
433 .dispatch_tree
434 .clear_keystroke_matchers();
435 self.app.push_effect(Effect::FocusChanged {
436 window_handle: self.window.handle,
437 focused: Some(focus_id),
438 });
439 self.notify();
440 }
441
442 /// Remove focus from all elements within this context's window.
443 pub fn blur(&mut self) {
444 if self.window.last_blur.is_none() {
445 self.window.last_blur = Some(self.window.focus);
446 }
447
448 self.window.focus = None;
449 self.app.push_effect(Effect::FocusChanged {
450 window_handle: self.window.handle,
451 focused: None,
452 });
453 self.notify();
454 }
455
456 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
457 if let Some(focus_handle) = self.focused() {
458 self.defer(move |cx| {
459 if let Some(node_id) = cx
460 .window
461 .current_frame
462 .dispatch_tree
463 .focusable_node_id(focus_handle.id)
464 {
465 cx.propagate_event = true;
466 cx.dispatch_action_on_node(node_id, action);
467 }
468 })
469 }
470 }
471
472 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
473 /// that are currently on the stack to be returned to the app.
474 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
475 let handle = self.window.handle;
476 self.app.defer(move |cx| {
477 handle.update(cx, |_, cx| f(cx)).ok();
478 });
479 }
480
481 pub fn subscribe<Emitter, E, Evt>(
482 &mut self,
483 entity: &E,
484 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
485 ) -> Subscription
486 where
487 Emitter: EventEmitter<Evt>,
488 E: Entity<Emitter>,
489 Evt: 'static,
490 {
491 let entity_id = entity.entity_id();
492 let entity = entity.downgrade();
493 let window_handle = self.window.handle;
494 self.app.event_listeners.insert(
495 entity_id,
496 (
497 TypeId::of::<Evt>(),
498 Box::new(move |event, cx| {
499 window_handle
500 .update(cx, |_, cx| {
501 if let Some(handle) = E::upgrade_from(&entity) {
502 let event = event.downcast_ref().expect("invalid event type");
503 on_event(handle, event, cx);
504 true
505 } else {
506 false
507 }
508 })
509 .unwrap_or(false)
510 }),
511 ),
512 )
513 }
514
515 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
516 /// await points in async code.
517 pub fn to_async(&self) -> AsyncWindowContext {
518 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
519 }
520
521 /// Schedule the given closure to be run directly after the current frame is rendered.
522 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
523 let handle = self.window.handle;
524 let display_id = self.window.display_id;
525
526 if !self.frame_consumers.contains_key(&display_id) {
527 let (tx, mut rx) = mpsc::unbounded::<()>();
528 self.platform.set_display_link_output_callback(
529 display_id,
530 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
531 );
532
533 let consumer_task = self.app.spawn(|cx| async move {
534 while rx.next().await.is_some() {
535 cx.update(|cx| {
536 for callback in cx
537 .next_frame_callbacks
538 .get_mut(&display_id)
539 .unwrap()
540 .drain(..)
541 .collect::<SmallVec<[_; 32]>>()
542 {
543 callback(cx);
544 }
545 })
546 .ok();
547
548 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
549
550 cx.update(|cx| {
551 if cx.next_frame_callbacks.is_empty() {
552 cx.platform.stop_display_link(display_id);
553 }
554 })
555 .ok();
556 }
557 });
558 self.frame_consumers.insert(display_id, consumer_task);
559 }
560
561 if self.next_frame_callbacks.is_empty() {
562 self.platform.start_display_link(display_id);
563 }
564
565 self.next_frame_callbacks
566 .entry(display_id)
567 .or_default()
568 .push(Box::new(move |cx: &mut AppContext| {
569 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
570 }));
571 }
572
573 /// Spawn the future returned by the given closure on the application thread pool.
574 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
575 /// use within your future.
576 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
577 where
578 R: 'static,
579 Fut: Future<Output = R> + 'static,
580 {
581 self.app
582 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
583 }
584
585 /// Update the global of the given type. The given closure is given simultaneous mutable
586 /// access both to the global and the context.
587 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
588 where
589 G: 'static,
590 {
591 let mut global = self.app.lease_global::<G>();
592 let result = f(&mut global, self);
593 self.app.end_global_lease(global);
594 result
595 }
596
597 #[must_use]
598 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
599 /// layout is being requested, along with the layout ids of any children. This method is called during
600 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
601 pub fn request_layout(
602 &mut self,
603 style: &Style,
604 children: impl IntoIterator<Item = LayoutId>,
605 ) -> LayoutId {
606 self.app.layout_id_buffer.clear();
607 self.app.layout_id_buffer.extend(children.into_iter());
608 let rem_size = self.rem_size();
609
610 self.window
611 .layout_engine
612 .request_layout(style, rem_size, &self.app.layout_id_buffer)
613 }
614
615 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
616 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
617 /// determine the element's size. One place this is used internally is when measuring text.
618 ///
619 /// The given closure is invoked at layout time with the known dimensions and available space and
620 /// returns a `Size`.
621 pub fn request_measured_layout<
622 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
623 >(
624 &mut self,
625 style: Style,
626 rem_size: Pixels,
627 measure: F,
628 ) -> LayoutId {
629 self.window
630 .layout_engine
631 .request_measured_layout(style, rem_size, measure)
632 }
633
634 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
635 self.window
636 .layout_engine
637 .compute_layout(layout_id, available_space)
638 }
639
640 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
641 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
642 /// in order to pass your element its `Bounds` automatically.
643 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
644 let mut bounds = self
645 .window
646 .layout_engine
647 .layout_bounds(layout_id)
648 .map(Into::into);
649 bounds.origin += self.element_offset();
650 bounds
651 }
652
653 fn window_bounds_changed(&mut self) {
654 self.window.scale_factor = self.window.platform_window.scale_factor();
655 self.window.viewport_size = self.window.platform_window.content_size();
656 self.window.bounds = self.window.platform_window.bounds();
657 self.window.display_id = self.window.platform_window.display().id();
658 self.window.dirty = true;
659
660 self.window
661 .bounds_observers
662 .clone()
663 .retain(&(), |callback| callback(self));
664 }
665
666 pub fn window_bounds(&self) -> WindowBounds {
667 self.window.bounds
668 }
669
670 pub fn viewport_size(&self) -> Size<Pixels> {
671 self.window.viewport_size
672 }
673
674 pub fn is_window_active(&self) -> bool {
675 self.window.active
676 }
677
678 pub fn zoom_window(&self) {
679 self.window.platform_window.zoom();
680 }
681
682 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
683 self.platform
684 .displays()
685 .into_iter()
686 .find(|display| display.id() == self.window.display_id)
687 }
688
689 pub fn show_character_palette(&self) {
690 self.window.platform_window.show_character_palette();
691 }
692
693 /// The scale factor of the display associated with the window. For example, it could
694 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
695 /// be rendered as two pixels on screen.
696 pub fn scale_factor(&self) -> f32 {
697 self.window.scale_factor
698 }
699
700 /// The size of an em for the base font of the application. Adjusting this value allows the
701 /// UI to scale, just like zooming a web page.
702 pub fn rem_size(&self) -> Pixels {
703 self.window.rem_size
704 }
705
706 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
707 /// UI to scale, just like zooming a web page.
708 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
709 self.window.rem_size = rem_size.into();
710 }
711
712 /// The line height associated with the current text style.
713 pub fn line_height(&self) -> Pixels {
714 let rem_size = self.rem_size();
715 let text_style = self.text_style();
716 text_style
717 .line_height
718 .to_pixels(text_style.font_size.into(), rem_size)
719 }
720
721 /// Call to prevent the default action of an event. Currently only used to prevent
722 /// parent elements from becoming focused on mouse down.
723 pub fn prevent_default(&mut self) {
724 self.window.default_prevented = true;
725 }
726
727 /// Obtain whether default has been prevented for the event currently being dispatched.
728 pub fn default_prevented(&self) -> bool {
729 self.window.default_prevented
730 }
731
732 /// Register a mouse event listener on the window for the current frame. The type of event
733 /// is determined by the first parameter of the given listener. When the next frame is rendered
734 /// the listener will be cleared.
735 ///
736 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
737 /// a specific need to register a global listener.
738 pub fn on_mouse_event<Event: 'static>(
739 &mut self,
740 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
741 ) {
742 let order = self.window.current_frame.z_index_stack.clone();
743 self.window
744 .current_frame
745 .mouse_listeners
746 .entry(TypeId::of::<Event>())
747 .or_default()
748 .push((
749 order,
750 Box::new(move |event: &dyn Any, phase, cx| {
751 handler(event.downcast_ref().unwrap(), phase, cx)
752 }),
753 ))
754 }
755
756 /// Register a key event listener on the window for the current frame. The type of event
757 /// is determined by the first parameter of the given listener. When the next frame is rendered
758 /// the listener will be cleared.
759 ///
760 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
761 /// a specific need to register a global listener.
762 pub fn on_key_event<Event: 'static>(
763 &mut self,
764 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
765 ) {
766 self.window
767 .current_frame
768 .dispatch_tree
769 .on_key_event(Rc::new(move |event, phase, cx| {
770 if let Some(event) = event.downcast_ref::<Event>() {
771 handler(event, phase, cx)
772 }
773 }));
774 }
775
776 /// Register an action listener on the window for the current frame. The type of action
777 /// is determined by the first parameter of the given listener. When the next frame is rendered
778 /// the listener will be cleared.
779 ///
780 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
781 /// a specific need to register a global listener.
782 pub fn on_action(
783 &mut self,
784 action_type: TypeId,
785 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
786 ) {
787 self.window.current_frame.dispatch_tree.on_action(
788 action_type,
789 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
790 );
791 }
792
793 /// The position of the mouse relative to the window.
794 pub fn mouse_position(&self) -> Point<Pixels> {
795 self.window.mouse_position
796 }
797
798 pub fn set_cursor_style(&mut self, style: CursorStyle) {
799 self.window.requested_cursor_style = Some(style)
800 }
801
802 /// Called during painting to invoke the given closure in a new stacking context. The given
803 /// z-index is interpreted relative to the previous call to `stack`.
804 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
805 self.window.current_frame.z_index_stack.push(z_index);
806 let result = f(self);
807 self.window.current_frame.z_index_stack.pop();
808 result
809 }
810
811 /// Called during painting to track which z-index is on top at each pixel position
812 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
813 let stacking_order = self.window.current_frame.z_index_stack.clone();
814 let depth_map = &mut self.window.current_frame.depth_map;
815 match depth_map.binary_search_by(|(level, _)| stacking_order.cmp(&level)) {
816 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, bounds)),
817 }
818 }
819
820 /// Returns true if the top-most opaque layer painted over this point was part of the
821 /// same layer as the given stacking order.
822 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
823 for (stack, bounds) in self.window.previous_frame.depth_map.iter() {
824 if bounds.contains_point(point) {
825 return level.starts_with(stack) || stack.starts_with(level);
826 }
827 }
828
829 false
830 }
831
832 /// Called during painting to get the current stacking order.
833 pub fn stacking_order(&self) -> &StackingOrder {
834 &self.window.current_frame.z_index_stack
835 }
836
837 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
838 pub fn paint_shadows(
839 &mut self,
840 bounds: Bounds<Pixels>,
841 corner_radii: Corners<Pixels>,
842 shadows: &[BoxShadow],
843 ) {
844 let scale_factor = self.scale_factor();
845 let content_mask = self.content_mask();
846 let window = &mut *self.window;
847 for shadow in shadows {
848 let mut shadow_bounds = bounds;
849 shadow_bounds.origin += shadow.offset;
850 shadow_bounds.dilate(shadow.spread_radius);
851 window.current_frame.scene_builder.insert(
852 &window.current_frame.z_index_stack,
853 Shadow {
854 order: 0,
855 bounds: shadow_bounds.scale(scale_factor),
856 content_mask: content_mask.scale(scale_factor),
857 corner_radii: corner_radii.scale(scale_factor),
858 color: shadow.color,
859 blur_radius: shadow.blur_radius.scale(scale_factor),
860 },
861 );
862 }
863 }
864
865 /// Paint one or more quads into the scene for the current frame at the current stacking context.
866 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
867 pub fn paint_quad(
868 &mut self,
869 bounds: Bounds<Pixels>,
870 corner_radii: Corners<Pixels>,
871 background: impl Into<Hsla>,
872 border_widths: Edges<Pixels>,
873 border_color: impl Into<Hsla>,
874 ) {
875 let scale_factor = self.scale_factor();
876 let content_mask = self.content_mask();
877
878 let window = &mut *self.window;
879 window.current_frame.scene_builder.insert(
880 &window.current_frame.z_index_stack,
881 Quad {
882 order: 0,
883 bounds: bounds.scale(scale_factor),
884 content_mask: content_mask.scale(scale_factor),
885 background: background.into(),
886 border_color: border_color.into(),
887 corner_radii: corner_radii.scale(scale_factor),
888 border_widths: border_widths.scale(scale_factor),
889 },
890 );
891 }
892
893 /// Paint the given `Path` into the scene for the current frame at the current z-index.
894 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
895 let scale_factor = self.scale_factor();
896 let content_mask = self.content_mask();
897 path.content_mask = content_mask;
898 path.color = color.into();
899 let window = &mut *self.window;
900 window.current_frame.scene_builder.insert(
901 &window.current_frame.z_index_stack,
902 path.scale(scale_factor),
903 );
904 }
905
906 /// Paint an underline into the scene for the current frame at the current z-index.
907 pub fn paint_underline(
908 &mut self,
909 origin: Point<Pixels>,
910 width: Pixels,
911 style: &UnderlineStyle,
912 ) {
913 let scale_factor = self.scale_factor();
914 let height = if style.wavy {
915 style.thickness * 3.
916 } else {
917 style.thickness
918 };
919 let bounds = Bounds {
920 origin,
921 size: size(width, height),
922 };
923 let content_mask = self.content_mask();
924 let window = &mut *self.window;
925 window.current_frame.scene_builder.insert(
926 &window.current_frame.z_index_stack,
927 Underline {
928 order: 0,
929 bounds: bounds.scale(scale_factor),
930 content_mask: content_mask.scale(scale_factor),
931 thickness: style.thickness.scale(scale_factor),
932 color: style.color.unwrap_or_default(),
933 wavy: style.wavy,
934 },
935 );
936 }
937
938 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
939 /// The y component of the origin is the baseline of the glyph.
940 pub fn paint_glyph(
941 &mut self,
942 origin: Point<Pixels>,
943 font_id: FontId,
944 glyph_id: GlyphId,
945 font_size: Pixels,
946 color: Hsla,
947 ) -> Result<()> {
948 let scale_factor = self.scale_factor();
949 let glyph_origin = origin.scale(scale_factor);
950 let subpixel_variant = Point {
951 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
952 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
953 };
954 let params = RenderGlyphParams {
955 font_id,
956 glyph_id,
957 font_size,
958 subpixel_variant,
959 scale_factor,
960 is_emoji: false,
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 window.current_frame.scene_builder.insert(
979 &window.current_frame.z_index_stack,
980 MonochromeSprite {
981 order: 0,
982 bounds,
983 content_mask,
984 color,
985 tile,
986 },
987 );
988 }
989 Ok(())
990 }
991
992 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
993 /// The y component of the origin is the baseline of the glyph.
994 pub fn paint_emoji(
995 &mut self,
996 origin: Point<Pixels>,
997 font_id: FontId,
998 glyph_id: GlyphId,
999 font_size: Pixels,
1000 ) -> Result<()> {
1001 let scale_factor = self.scale_factor();
1002 let glyph_origin = origin.scale(scale_factor);
1003 let params = RenderGlyphParams {
1004 font_id,
1005 glyph_id,
1006 font_size,
1007 // We don't render emojis with subpixel variants.
1008 subpixel_variant: Default::default(),
1009 scale_factor,
1010 is_emoji: true,
1011 };
1012
1013 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1014 if !raster_bounds.is_zero() {
1015 let tile =
1016 self.window
1017 .sprite_atlas
1018 .get_or_insert_with(¶ms.clone().into(), &mut || {
1019 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1020 Ok((size, Cow::Owned(bytes)))
1021 })?;
1022 let bounds = Bounds {
1023 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1024 size: tile.bounds.size.map(Into::into),
1025 };
1026 let content_mask = self.content_mask().scale(scale_factor);
1027 let window = &mut *self.window;
1028
1029 window.current_frame.scene_builder.insert(
1030 &window.current_frame.z_index_stack,
1031 PolychromeSprite {
1032 order: 0,
1033 bounds,
1034 corner_radii: Default::default(),
1035 content_mask,
1036 tile,
1037 grayscale: false,
1038 },
1039 );
1040 }
1041 Ok(())
1042 }
1043
1044 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1045 pub fn paint_svg(
1046 &mut self,
1047 bounds: Bounds<Pixels>,
1048 path: SharedString,
1049 color: Hsla,
1050 ) -> Result<()> {
1051 let scale_factor = self.scale_factor();
1052 let bounds = bounds.scale(scale_factor);
1053 // Render the SVG at twice the size to get a higher quality result.
1054 let params = RenderSvgParams {
1055 path,
1056 size: bounds
1057 .size
1058 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1059 };
1060
1061 let tile =
1062 self.window
1063 .sprite_atlas
1064 .get_or_insert_with(¶ms.clone().into(), &mut || {
1065 let bytes = self.svg_renderer.render(¶ms)?;
1066 Ok((params.size, Cow::Owned(bytes)))
1067 })?;
1068 let content_mask = self.content_mask().scale(scale_factor);
1069
1070 let window = &mut *self.window;
1071 window.current_frame.scene_builder.insert(
1072 &window.current_frame.z_index_stack,
1073 MonochromeSprite {
1074 order: 0,
1075 bounds,
1076 content_mask,
1077 color,
1078 tile,
1079 },
1080 );
1081
1082 Ok(())
1083 }
1084
1085 /// Paint an image into the scene for the current frame at the current z-index.
1086 pub fn paint_image(
1087 &mut self,
1088 bounds: Bounds<Pixels>,
1089 corner_radii: Corners<Pixels>,
1090 data: Arc<ImageData>,
1091 grayscale: bool,
1092 ) -> Result<()> {
1093 let scale_factor = self.scale_factor();
1094 let bounds = bounds.scale(scale_factor);
1095 let params = RenderImageParams { image_id: data.id };
1096
1097 let tile = self
1098 .window
1099 .sprite_atlas
1100 .get_or_insert_with(¶ms.clone().into(), &mut || {
1101 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1102 })?;
1103 let content_mask = self.content_mask().scale(scale_factor);
1104 let corner_radii = corner_radii.scale(scale_factor);
1105
1106 let window = &mut *self.window;
1107 window.current_frame.scene_builder.insert(
1108 &window.current_frame.z_index_stack,
1109 PolychromeSprite {
1110 order: 0,
1111 bounds,
1112 content_mask,
1113 corner_radii,
1114 tile,
1115 grayscale,
1116 },
1117 );
1118 Ok(())
1119 }
1120
1121 /// Draw pixels to the display for this window based on the contents of its scene.
1122 pub(crate) fn draw(&mut self) {
1123 let root_view = self.window.root_view.take().unwrap();
1124
1125 self.start_frame();
1126
1127 self.with_z_index(0, |cx| {
1128 let available_space = cx.window.viewport_size.map(Into::into);
1129 root_view.draw(Point::zero(), available_space, cx);
1130 });
1131
1132 if let Some(active_drag) = self.app.active_drag.take() {
1133 self.with_z_index(1, |cx| {
1134 let offset = cx.mouse_position() - active_drag.cursor_offset;
1135 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1136 active_drag.view.draw(offset, available_space, cx);
1137 cx.active_drag = Some(active_drag);
1138 });
1139 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1140 self.with_z_index(1, |cx| {
1141 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1142 active_tooltip
1143 .view
1144 .draw(active_tooltip.cursor_offset, available_space, cx);
1145 });
1146 }
1147
1148 self.window
1149 .current_frame
1150 .dispatch_tree
1151 .preserve_keystroke_matchers(
1152 &mut self.window.previous_frame.dispatch_tree,
1153 self.window.focus,
1154 );
1155
1156 self.window.root_view = Some(root_view);
1157 let scene = self.window.current_frame.scene_builder.build();
1158
1159 self.window.platform_window.draw(scene);
1160 let cursor_style = self
1161 .window
1162 .requested_cursor_style
1163 .take()
1164 .unwrap_or(CursorStyle::Arrow);
1165 self.platform.set_cursor_style(cursor_style);
1166
1167 self.window.dirty = false;
1168 }
1169
1170 /// Rotate the current frame and the previous frame, then clear the current frame.
1171 /// We repopulate all state in the current frame during each paint.
1172 fn start_frame(&mut self) {
1173 self.text_system().start_frame();
1174
1175 let window = &mut *self.window;
1176 window.layout_engine.clear();
1177
1178 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1179 let frame = &mut window.current_frame;
1180 frame.element_states.clear();
1181 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1182 frame.focus_listeners.clear();
1183 frame.dispatch_tree.clear();
1184 frame.depth_map.clear();
1185 }
1186
1187 /// Dispatch a mouse or keyboard event on the window.
1188 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1189 // Handlers may set this to false by calling `stop_propagation`
1190 self.app.propagate_event = true;
1191 self.window.default_prevented = false;
1192
1193 let event = match event {
1194 // Track the mouse position with our own state, since accessing the platform
1195 // API for the mouse position can only occur on the main thread.
1196 InputEvent::MouseMove(mouse_move) => {
1197 self.window.mouse_position = mouse_move.position;
1198 InputEvent::MouseMove(mouse_move)
1199 }
1200 InputEvent::MouseDown(mouse_down) => {
1201 self.window.mouse_position = mouse_down.position;
1202 InputEvent::MouseDown(mouse_down)
1203 }
1204 InputEvent::MouseUp(mouse_up) => {
1205 self.window.mouse_position = mouse_up.position;
1206 InputEvent::MouseUp(mouse_up)
1207 }
1208 // Translate dragging and dropping of external files from the operating system
1209 // to internal drag and drop events.
1210 InputEvent::FileDrop(file_drop) => match file_drop {
1211 FileDropEvent::Entered { position, files } => {
1212 self.window.mouse_position = position;
1213 if self.active_drag.is_none() {
1214 self.active_drag = Some(AnyDrag {
1215 view: self.build_view(|_| files).into(),
1216 cursor_offset: position,
1217 });
1218 }
1219 InputEvent::MouseDown(MouseDownEvent {
1220 position,
1221 button: MouseButton::Left,
1222 click_count: 1,
1223 modifiers: Modifiers::default(),
1224 })
1225 }
1226 FileDropEvent::Pending { position } => {
1227 self.window.mouse_position = position;
1228 InputEvent::MouseMove(MouseMoveEvent {
1229 position,
1230 pressed_button: Some(MouseButton::Left),
1231 modifiers: Modifiers::default(),
1232 })
1233 }
1234 FileDropEvent::Submit { position } => {
1235 self.window.mouse_position = position;
1236 InputEvent::MouseUp(MouseUpEvent {
1237 button: MouseButton::Left,
1238 position,
1239 modifiers: Modifiers::default(),
1240 click_count: 1,
1241 })
1242 }
1243 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1244 button: MouseButton::Left,
1245 position: Point::default(),
1246 modifiers: Modifiers::default(),
1247 click_count: 1,
1248 }),
1249 },
1250 _ => event,
1251 };
1252
1253 if let Some(any_mouse_event) = event.mouse_event() {
1254 self.dispatch_mouse_event(any_mouse_event);
1255 } else if let Some(any_key_event) = event.keyboard_event() {
1256 self.dispatch_key_event(any_key_event);
1257 }
1258
1259 !self.app.propagate_event
1260 }
1261
1262 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1263 if let Some(mut handlers) = self
1264 .window
1265 .current_frame
1266 .mouse_listeners
1267 .remove(&event.type_id())
1268 {
1269 // Because handlers may add other handlers, we sort every time.
1270 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1271
1272 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1273 // special purposes, such as detecting events outside of a given Bounds.
1274 for (_, handler) in &mut handlers {
1275 handler(event, DispatchPhase::Capture, self);
1276 if !self.app.propagate_event {
1277 break;
1278 }
1279 }
1280
1281 // Bubble phase, where most normal handlers do their work.
1282 if self.app.propagate_event {
1283 for (_, handler) in handlers.iter_mut().rev() {
1284 handler(event, DispatchPhase::Bubble, self);
1285 if !self.app.propagate_event {
1286 break;
1287 }
1288 }
1289 }
1290
1291 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1292 self.active_drag = None;
1293 }
1294
1295 // Just in case any handlers added new handlers, which is weird, but possible.
1296 handlers.extend(
1297 self.window
1298 .current_frame
1299 .mouse_listeners
1300 .get_mut(&event.type_id())
1301 .into_iter()
1302 .flat_map(|handlers| handlers.drain(..)),
1303 );
1304 self.window
1305 .current_frame
1306 .mouse_listeners
1307 .insert(event.type_id(), handlers);
1308 }
1309 }
1310
1311 fn dispatch_key_event(&mut self, event: &dyn Any) {
1312 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1313 self.window
1314 .current_frame
1315 .dispatch_tree
1316 .focusable_node_id(focus_id)
1317 }) {
1318 let dispatch_path = self
1319 .window
1320 .current_frame
1321 .dispatch_tree
1322 .dispatch_path(node_id);
1323
1324 // Capture phase
1325 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1326 self.propagate_event = true;
1327
1328 for node_id in &dispatch_path {
1329 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1330
1331 if !node.context.is_empty() {
1332 context_stack.push(node.context.clone());
1333 }
1334
1335 for key_listener in node.key_listeners.clone() {
1336 key_listener(event, DispatchPhase::Capture, self);
1337 if !self.propagate_event {
1338 return;
1339 }
1340 }
1341 }
1342
1343 // Bubble phase
1344 for node_id in dispatch_path.iter().rev() {
1345 // Handle low level key events
1346 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1347 for key_listener in node.key_listeners.clone() {
1348 key_listener(event, DispatchPhase::Bubble, self);
1349 if !self.propagate_event {
1350 return;
1351 }
1352 }
1353
1354 // Match keystrokes
1355 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1356 if !node.context.is_empty() {
1357 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1358 if let Some(action) = self
1359 .window
1360 .current_frame
1361 .dispatch_tree
1362 .dispatch_key(&key_down_event.keystroke, &context_stack)
1363 {
1364 self.dispatch_action_on_node(*node_id, action);
1365 if !self.propagate_event {
1366 return;
1367 }
1368 }
1369 }
1370
1371 context_stack.pop();
1372 }
1373 }
1374 }
1375 }
1376
1377 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1378 let dispatch_path = self
1379 .window
1380 .current_frame
1381 .dispatch_tree
1382 .dispatch_path(node_id);
1383
1384 // Capture phase
1385 for node_id in &dispatch_path {
1386 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1387 for DispatchActionListener {
1388 action_type,
1389 listener,
1390 } in node.action_listeners.clone()
1391 {
1392 let any_action = action.as_any();
1393 if action_type == any_action.type_id() {
1394 listener(any_action, DispatchPhase::Capture, self);
1395 if !self.propagate_event {
1396 return;
1397 }
1398 }
1399 }
1400 }
1401
1402 // Bubble phase
1403 for node_id in dispatch_path.iter().rev() {
1404 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1405 for DispatchActionListener {
1406 action_type,
1407 listener,
1408 } in node.action_listeners.clone()
1409 {
1410 let any_action = action.as_any();
1411 if action_type == any_action.type_id() {
1412 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1413 listener(any_action, DispatchPhase::Bubble, self);
1414 if !self.propagate_event {
1415 return;
1416 }
1417 }
1418 }
1419 }
1420 }
1421
1422 /// Register the given handler to be invoked whenever the global of the given type
1423 /// is updated.
1424 pub fn observe_global<G: 'static>(
1425 &mut self,
1426 f: impl Fn(&mut WindowContext<'_>) + 'static,
1427 ) -> Subscription {
1428 let window_handle = self.window.handle;
1429 self.global_observers.insert(
1430 TypeId::of::<G>(),
1431 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1432 )
1433 }
1434
1435 pub fn activate_window(&self) {
1436 self.window.platform_window.activate();
1437 }
1438
1439 pub fn minimize_window(&self) {
1440 self.window.platform_window.minimize();
1441 }
1442
1443 pub fn toggle_full_screen(&self) {
1444 self.window.platform_window.toggle_full_screen();
1445 }
1446
1447 pub fn prompt(
1448 &self,
1449 level: PromptLevel,
1450 msg: &str,
1451 answers: &[&str],
1452 ) -> oneshot::Receiver<usize> {
1453 self.window.platform_window.prompt(level, msg, answers)
1454 }
1455
1456 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1457 if let Some(focus_id) = self.window.focus {
1458 self.window
1459 .current_frame
1460 .dispatch_tree
1461 .available_actions(focus_id)
1462 } else {
1463 Vec::new()
1464 }
1465 }
1466
1467 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1468 self.window
1469 .current_frame
1470 .dispatch_tree
1471 .bindings_for_action(action)
1472 }
1473
1474 pub fn listener_for<V: Render, E>(
1475 &self,
1476 view: &View<V>,
1477 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1478 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1479 let view = view.downgrade();
1480 move |e: &E, cx: &mut WindowContext| {
1481 view.update(cx, |view, cx| f(view, e, cx)).ok();
1482 }
1483 }
1484
1485 pub fn constructor_for<V: Render, R>(
1486 &self,
1487 view: &View<V>,
1488 f: impl Fn(&mut V, &mut ViewContext<V>) -> R + 'static,
1489 ) -> impl Fn(&mut WindowContext) -> R + 'static {
1490 let view = view.clone();
1491 move |cx: &mut WindowContext| view.update(cx, |view, cx| f(view, cx))
1492 }
1493
1494 //========== ELEMENT RELATED FUNCTIONS ===========
1495 pub fn with_key_dispatch<R>(
1496 &mut self,
1497 context: KeyContext,
1498 focus_handle: Option<FocusHandle>,
1499 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1500 ) -> R {
1501 let window = &mut self.window;
1502 window
1503 .current_frame
1504 .dispatch_tree
1505 .push_node(context.clone());
1506 if let Some(focus_handle) = focus_handle.as_ref() {
1507 window
1508 .current_frame
1509 .dispatch_tree
1510 .make_focusable(focus_handle.id);
1511 }
1512 let result = f(focus_handle, self);
1513
1514 self.window.current_frame.dispatch_tree.pop_node();
1515
1516 result
1517 }
1518
1519 /// Register a focus listener for the current frame only. It will be cleared
1520 /// on the next frame render. You should use this method only from within elements,
1521 /// and we may want to enforce that better via a different context type.
1522 // todo!() Move this to `FrameContext` to emphasize its individuality?
1523 pub fn on_focus_changed(
1524 &mut self,
1525 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1526 ) {
1527 self.window
1528 .current_frame
1529 .focus_listeners
1530 .push(Box::new(move |event, cx| {
1531 listener(event, cx);
1532 }));
1533 }
1534
1535 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1536 /// platform to receive textual input with proper integration with concerns such
1537 /// as IME interactions.
1538 pub fn handle_input(
1539 &mut self,
1540 focus_handle: &FocusHandle,
1541 input_handler: impl PlatformInputHandler,
1542 ) {
1543 if focus_handle.is_focused(self) {
1544 self.window
1545 .platform_window
1546 .set_input_handler(Box::new(input_handler));
1547 }
1548 }
1549
1550 pub fn on_window_should_close(&mut self, f: impl Fn(&mut WindowContext) -> bool + 'static) {
1551 let mut this = self.to_async();
1552 self.window
1553 .platform_window
1554 .on_should_close(Box::new(move || this.update(|_, cx| f(cx)).unwrap_or(true)))
1555 }
1556}
1557
1558impl Context for WindowContext<'_> {
1559 type Result<T> = T;
1560
1561 fn build_model<T>(
1562 &mut self,
1563 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1564 ) -> Model<T>
1565 where
1566 T: 'static,
1567 {
1568 let slot = self.app.entities.reserve();
1569 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1570 self.entities.insert(slot, model)
1571 }
1572
1573 fn update_model<T: 'static, R>(
1574 &mut self,
1575 model: &Model<T>,
1576 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1577 ) -> R {
1578 let mut entity = self.entities.lease(model);
1579 let result = update(
1580 &mut *entity,
1581 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1582 );
1583 self.entities.end_lease(entity);
1584 result
1585 }
1586
1587 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1588 where
1589 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1590 {
1591 if window == self.window.handle {
1592 let root_view = self.window.root_view.clone().unwrap();
1593 Ok(update(root_view, self))
1594 } else {
1595 window.update(self.app, update)
1596 }
1597 }
1598
1599 fn read_model<T, R>(
1600 &self,
1601 handle: &Model<T>,
1602 read: impl FnOnce(&T, &AppContext) -> R,
1603 ) -> Self::Result<R>
1604 where
1605 T: 'static,
1606 {
1607 let entity = self.entities.read(handle);
1608 read(&*entity, &*self.app)
1609 }
1610
1611 fn read_window<T, R>(
1612 &self,
1613 window: &WindowHandle<T>,
1614 read: impl FnOnce(View<T>, &AppContext) -> R,
1615 ) -> Result<R>
1616 where
1617 T: 'static,
1618 {
1619 if window.any_handle == self.window.handle {
1620 let root_view = self
1621 .window
1622 .root_view
1623 .clone()
1624 .unwrap()
1625 .downcast::<T>()
1626 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1627 Ok(read(root_view, self))
1628 } else {
1629 self.app.read_window(window, read)
1630 }
1631 }
1632}
1633
1634impl VisualContext for WindowContext<'_> {
1635 fn build_view<V>(
1636 &mut self,
1637 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1638 ) -> Self::Result<View<V>>
1639 where
1640 V: 'static + Render,
1641 {
1642 let slot = self.app.entities.reserve();
1643 let view = View {
1644 model: slot.clone(),
1645 };
1646 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1647 let entity = build_view_state(&mut cx);
1648 cx.entities.insert(slot, entity);
1649
1650 cx.new_view_observers
1651 .clone()
1652 .retain(&TypeId::of::<V>(), |observer| {
1653 let any_view = AnyView::from(view.clone());
1654 (observer)(any_view, self);
1655 true
1656 });
1657
1658 view
1659 }
1660
1661 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1662 fn update_view<T: 'static, R>(
1663 &mut self,
1664 view: &View<T>,
1665 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1666 ) -> Self::Result<R> {
1667 let mut lease = self.app.entities.lease(&view.model);
1668 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1669 let result = update(&mut *lease, &mut cx);
1670 cx.app.entities.end_lease(lease);
1671 result
1672 }
1673
1674 fn replace_root_view<V>(
1675 &mut self,
1676 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1677 ) -> Self::Result<View<V>>
1678 where
1679 V: 'static + Render,
1680 {
1681 let slot = self.app.entities.reserve();
1682 let view = View {
1683 model: slot.clone(),
1684 };
1685 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1686 let entity = build_view(&mut cx);
1687 self.entities.insert(slot, entity);
1688 self.window.root_view = Some(view.clone().into());
1689 view
1690 }
1691
1692 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1693 self.update_view(view, |view, cx| {
1694 view.focus_handle(cx).clone().focus(cx);
1695 })
1696 }
1697
1698 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1699 where
1700 V: ManagedView,
1701 {
1702 self.update_view(view, |_, cx| cx.emit(DismissEvent::Dismiss))
1703 }
1704}
1705
1706impl<'a> std::ops::Deref for WindowContext<'a> {
1707 type Target = AppContext;
1708
1709 fn deref(&self) -> &Self::Target {
1710 &self.app
1711 }
1712}
1713
1714impl<'a> std::ops::DerefMut for WindowContext<'a> {
1715 fn deref_mut(&mut self) -> &mut Self::Target {
1716 &mut self.app
1717 }
1718}
1719
1720impl<'a> Borrow<AppContext> for WindowContext<'a> {
1721 fn borrow(&self) -> &AppContext {
1722 &self.app
1723 }
1724}
1725
1726impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1727 fn borrow_mut(&mut self) -> &mut AppContext {
1728 &mut self.app
1729 }
1730}
1731
1732pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1733 fn app_mut(&mut self) -> &mut AppContext {
1734 self.borrow_mut()
1735 }
1736
1737 fn app(&self) -> &AppContext {
1738 self.borrow()
1739 }
1740
1741 fn window(&self) -> &Window {
1742 self.borrow()
1743 }
1744
1745 fn window_mut(&mut self) -> &mut Window {
1746 self.borrow_mut()
1747 }
1748
1749 /// Pushes the given element id onto the global stack and invokes the given closure
1750 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1751 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1752 /// used to associate state with identified elements across separate frames.
1753 fn with_element_id<R>(
1754 &mut self,
1755 id: Option<impl Into<ElementId>>,
1756 f: impl FnOnce(&mut Self) -> R,
1757 ) -> R {
1758 if let Some(id) = id.map(Into::into) {
1759 let window = self.window_mut();
1760 window.element_id_stack.push(id.into());
1761 let result = f(self);
1762 let window: &mut Window = self.borrow_mut();
1763 window.element_id_stack.pop();
1764 result
1765 } else {
1766 f(self)
1767 }
1768 }
1769
1770 /// Invoke the given function with the given content mask after intersecting it
1771 /// with the current mask.
1772 fn with_content_mask<R>(
1773 &mut self,
1774 mask: Option<ContentMask<Pixels>>,
1775 f: impl FnOnce(&mut Self) -> R,
1776 ) -> R {
1777 if let Some(mask) = mask {
1778 let mask = mask.intersect(&self.content_mask());
1779 self.window_mut()
1780 .current_frame
1781 .content_mask_stack
1782 .push(mask);
1783 let result = f(self);
1784 self.window_mut().current_frame.content_mask_stack.pop();
1785 result
1786 } else {
1787 f(self)
1788 }
1789 }
1790
1791 /// Invoke the given function with the content mask reset to that
1792 /// of the window.
1793 fn break_content_mask<R>(&mut self, f: impl FnOnce(&mut Self) -> R) -> R {
1794 let mask = ContentMask {
1795 bounds: Bounds {
1796 origin: Point::default(),
1797 size: self.window().viewport_size,
1798 },
1799 };
1800 self.window_mut()
1801 .current_frame
1802 .content_mask_stack
1803 .push(mask);
1804 let result = f(self);
1805 self.window_mut().current_frame.content_mask_stack.pop();
1806 result
1807 }
1808
1809 /// Update the global element offset relative to the current offset. This is used to implement
1810 /// scrolling.
1811 fn with_element_offset<R>(
1812 &mut self,
1813 offset: Point<Pixels>,
1814 f: impl FnOnce(&mut Self) -> R,
1815 ) -> R {
1816 if offset.is_zero() {
1817 return f(self);
1818 };
1819
1820 let abs_offset = self.element_offset() + offset;
1821 self.with_absolute_element_offset(abs_offset, f)
1822 }
1823
1824 /// Update the global element offset based on the given offset. This is used to implement
1825 /// drag handles and other manual painting of elements.
1826 fn with_absolute_element_offset<R>(
1827 &mut self,
1828 offset: Point<Pixels>,
1829 f: impl FnOnce(&mut Self) -> R,
1830 ) -> R {
1831 self.window_mut()
1832 .current_frame
1833 .element_offset_stack
1834 .push(offset);
1835 let result = f(self);
1836 self.window_mut().current_frame.element_offset_stack.pop();
1837 result
1838 }
1839
1840 /// Obtain the current element offset.
1841 fn element_offset(&self) -> Point<Pixels> {
1842 self.window()
1843 .current_frame
1844 .element_offset_stack
1845 .last()
1846 .copied()
1847 .unwrap_or_default()
1848 }
1849
1850 /// Update or intialize state for an element with the given id that lives across multiple
1851 /// frames. If an element with this id existed in the previous frame, its state will be passed
1852 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1853 /// when drawing the next frame.
1854 fn with_element_state<S, R>(
1855 &mut self,
1856 id: ElementId,
1857 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1858 ) -> R
1859 where
1860 S: 'static,
1861 {
1862 self.with_element_id(Some(id), |cx| {
1863 let global_id = cx.window().element_id_stack.clone();
1864
1865 if let Some(any) = cx
1866 .window_mut()
1867 .current_frame
1868 .element_states
1869 .remove(&global_id)
1870 .or_else(|| {
1871 cx.window_mut()
1872 .previous_frame
1873 .element_states
1874 .remove(&global_id)
1875 })
1876 {
1877 let ElementStateBox {
1878 inner,
1879
1880 #[cfg(debug_assertions)]
1881 type_name
1882 } = any;
1883 // Using the extra inner option to avoid needing to reallocate a new box.
1884 let mut state_box = inner
1885 .downcast::<Option<S>>()
1886 .map_err(|_| {
1887 #[cfg(debug_assertions)]
1888 {
1889 anyhow!(
1890 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1891 std::any::type_name::<S>(),
1892 type_name
1893 )
1894 }
1895
1896 #[cfg(not(debug_assertions))]
1897 {
1898 anyhow!(
1899 "invalid element state type for id, requested_type {:?}",
1900 std::any::type_name::<S>(),
1901 )
1902 }
1903 })
1904 .unwrap();
1905
1906 // Actual: Option<AnyElement> <- View
1907 // Requested: () <- AnyElemet
1908 let state = state_box
1909 .take()
1910 .expect("element state is already on the stack");
1911 let (result, state) = f(Some(state), cx);
1912 state_box.replace(state);
1913 cx.window_mut()
1914 .current_frame
1915 .element_states
1916 .insert(global_id, ElementStateBox {
1917 inner: state_box,
1918
1919 #[cfg(debug_assertions)]
1920 type_name
1921 });
1922 result
1923 } else {
1924 let (result, state) = f(None, cx);
1925 cx.window_mut()
1926 .current_frame
1927 .element_states
1928 .insert(global_id,
1929 ElementStateBox {
1930 inner: Box::new(Some(state)),
1931
1932 #[cfg(debug_assertions)]
1933 type_name: std::any::type_name::<S>()
1934 }
1935
1936 );
1937 result
1938 }
1939 })
1940 }
1941
1942 /// Obtain the current content mask.
1943 fn content_mask(&self) -> ContentMask<Pixels> {
1944 self.window()
1945 .current_frame
1946 .content_mask_stack
1947 .last()
1948 .cloned()
1949 .unwrap_or_else(|| ContentMask {
1950 bounds: Bounds {
1951 origin: Point::default(),
1952 size: self.window().viewport_size,
1953 },
1954 })
1955 }
1956
1957 /// The size of an em for the base font of the application. Adjusting this value allows the
1958 /// UI to scale, just like zooming a web page.
1959 fn rem_size(&self) -> Pixels {
1960 self.window().rem_size
1961 }
1962}
1963
1964impl Borrow<Window> for WindowContext<'_> {
1965 fn borrow(&self) -> &Window {
1966 &self.window
1967 }
1968}
1969
1970impl BorrowMut<Window> for WindowContext<'_> {
1971 fn borrow_mut(&mut self) -> &mut Window {
1972 &mut self.window
1973 }
1974}
1975
1976impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1977
1978pub struct ViewContext<'a, V> {
1979 window_cx: WindowContext<'a>,
1980 view: &'a View<V>,
1981}
1982
1983impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1984 fn borrow(&self) -> &AppContext {
1985 &*self.window_cx.app
1986 }
1987}
1988
1989impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1990 fn borrow_mut(&mut self) -> &mut AppContext {
1991 &mut *self.window_cx.app
1992 }
1993}
1994
1995impl<V> Borrow<Window> for ViewContext<'_, V> {
1996 fn borrow(&self) -> &Window {
1997 &*self.window_cx.window
1998 }
1999}
2000
2001impl<V> BorrowMut<Window> for ViewContext<'_, V> {
2002 fn borrow_mut(&mut self) -> &mut Window {
2003 &mut *self.window_cx.window
2004 }
2005}
2006
2007impl<'a, V: 'static> ViewContext<'a, V> {
2008 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
2009 Self {
2010 window_cx: WindowContext::new(app, window),
2011 view,
2012 }
2013 }
2014
2015 pub fn entity_id(&self) -> EntityId {
2016 self.view.entity_id()
2017 }
2018
2019 pub fn view(&self) -> &View<V> {
2020 self.view
2021 }
2022
2023 pub fn model(&self) -> &Model<V> {
2024 &self.view.model
2025 }
2026
2027 /// Access the underlying window context.
2028 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
2029 &mut self.window_cx
2030 }
2031
2032 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
2033 self.window.current_frame.z_index_stack.push(z_index);
2034 let result = f(self);
2035 self.window.current_frame.z_index_stack.pop();
2036 result
2037 }
2038
2039 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2040 where
2041 V: 'static,
2042 {
2043 let view = self.view().clone();
2044 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2045 }
2046
2047 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2048 /// that are currently on the stack to be returned to the app.
2049 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2050 let view = self.view().downgrade();
2051 self.window_cx.defer(move |cx| {
2052 view.update(cx, f).ok();
2053 });
2054 }
2055
2056 pub fn observe<V2, E>(
2057 &mut self,
2058 entity: &E,
2059 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2060 ) -> Subscription
2061 where
2062 V2: 'static,
2063 V: 'static,
2064 E: Entity<V2>,
2065 {
2066 let view = self.view().downgrade();
2067 let entity_id = entity.entity_id();
2068 let entity = entity.downgrade();
2069 let window_handle = self.window.handle;
2070 self.app.observers.insert(
2071 entity_id,
2072 Box::new(move |cx| {
2073 window_handle
2074 .update(cx, |_, cx| {
2075 if let Some(handle) = E::upgrade_from(&entity) {
2076 view.update(cx, |this, cx| on_notify(this, handle, cx))
2077 .is_ok()
2078 } else {
2079 false
2080 }
2081 })
2082 .unwrap_or(false)
2083 }),
2084 )
2085 }
2086
2087 pub fn subscribe<V2, E, Evt>(
2088 &mut self,
2089 entity: &E,
2090 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2091 ) -> Subscription
2092 where
2093 V2: EventEmitter<Evt>,
2094 E: Entity<V2>,
2095 Evt: 'static,
2096 {
2097 let view = self.view().downgrade();
2098 let entity_id = entity.entity_id();
2099 let handle = entity.downgrade();
2100 let window_handle = self.window.handle;
2101 self.app.event_listeners.insert(
2102 entity_id,
2103 (
2104 TypeId::of::<Evt>(),
2105 Box::new(move |event, cx| {
2106 window_handle
2107 .update(cx, |_, cx| {
2108 if let Some(handle) = E::upgrade_from(&handle) {
2109 let event = event.downcast_ref().expect("invalid event type");
2110 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2111 .is_ok()
2112 } else {
2113 false
2114 }
2115 })
2116 .unwrap_or(false)
2117 }),
2118 ),
2119 )
2120 }
2121
2122 pub fn on_release(
2123 &mut self,
2124 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2125 ) -> Subscription {
2126 let window_handle = self.window.handle;
2127 self.app.release_listeners.insert(
2128 self.view.model.entity_id,
2129 Box::new(move |this, cx| {
2130 let this = this.downcast_mut().expect("invalid entity type");
2131 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2132 }),
2133 )
2134 }
2135
2136 pub fn observe_release<V2, E>(
2137 &mut self,
2138 entity: &E,
2139 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2140 ) -> Subscription
2141 where
2142 V: 'static,
2143 V2: 'static,
2144 E: Entity<V2>,
2145 {
2146 let view = self.view().downgrade();
2147 let entity_id = entity.entity_id();
2148 let window_handle = self.window.handle;
2149 self.app.release_listeners.insert(
2150 entity_id,
2151 Box::new(move |entity, cx| {
2152 let entity = entity.downcast_mut().expect("invalid entity type");
2153 let _ = window_handle.update(cx, |_, cx| {
2154 view.update(cx, |this, cx| on_release(this, entity, cx))
2155 });
2156 }),
2157 )
2158 }
2159
2160 pub fn notify(&mut self) {
2161 self.window_cx.notify();
2162 self.window_cx.app.push_effect(Effect::Notify {
2163 emitter: self.view.model.entity_id,
2164 });
2165 }
2166
2167 pub fn observe_window_bounds(
2168 &mut self,
2169 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2170 ) -> Subscription {
2171 let view = self.view.downgrade();
2172 self.window.bounds_observers.insert(
2173 (),
2174 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2175 )
2176 }
2177
2178 pub fn observe_window_activation(
2179 &mut self,
2180 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2181 ) -> Subscription {
2182 let view = self.view.downgrade();
2183 self.window.activation_observers.insert(
2184 (),
2185 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2186 )
2187 }
2188
2189 /// Register a listener to be called when the given focus handle receives focus.
2190 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2191 /// is dropped.
2192 pub fn on_focus(
2193 &mut self,
2194 handle: &FocusHandle,
2195 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2196 ) -> Subscription {
2197 let view = self.view.downgrade();
2198 let focus_id = handle.id;
2199 self.window.focus_listeners.insert(
2200 (),
2201 Box::new(move |event, cx| {
2202 view.update(cx, |view, cx| {
2203 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2204 listener(view, cx)
2205 }
2206 })
2207 .is_ok()
2208 }),
2209 )
2210 }
2211
2212 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2213 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2214 /// is dropped.
2215 pub fn on_focus_in(
2216 &mut self,
2217 handle: &FocusHandle,
2218 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2219 ) -> Subscription {
2220 let view = self.view.downgrade();
2221 let focus_id = handle.id;
2222 self.window.focus_listeners.insert(
2223 (),
2224 Box::new(move |event, cx| {
2225 view.update(cx, |view, cx| {
2226 if event
2227 .focused
2228 .as_ref()
2229 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2230 {
2231 listener(view, cx)
2232 }
2233 })
2234 .is_ok()
2235 }),
2236 )
2237 }
2238
2239 /// Register a listener to be called when the given focus handle loses focus.
2240 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2241 /// is dropped.
2242 pub fn on_blur(
2243 &mut self,
2244 handle: &FocusHandle,
2245 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2246 ) -> Subscription {
2247 let view = self.view.downgrade();
2248 let focus_id = handle.id;
2249 self.window.focus_listeners.insert(
2250 (),
2251 Box::new(move |event, cx| {
2252 view.update(cx, |view, cx| {
2253 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2254 listener(view, cx)
2255 }
2256 })
2257 .is_ok()
2258 }),
2259 )
2260 }
2261
2262 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2263 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2264 /// is dropped.
2265 pub fn on_focus_out(
2266 &mut self,
2267 handle: &FocusHandle,
2268 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2269 ) -> Subscription {
2270 let view = self.view.downgrade();
2271 let focus_id = handle.id;
2272 self.window.focus_listeners.insert(
2273 (),
2274 Box::new(move |event, cx| {
2275 view.update(cx, |view, cx| {
2276 if event
2277 .blurred
2278 .as_ref()
2279 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2280 {
2281 listener(view, cx)
2282 }
2283 })
2284 .is_ok()
2285 }),
2286 )
2287 }
2288
2289 pub fn spawn<Fut, R>(
2290 &mut self,
2291 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2292 ) -> Task<R>
2293 where
2294 R: 'static,
2295 Fut: Future<Output = R> + 'static,
2296 {
2297 let view = self.view().downgrade();
2298 self.window_cx.spawn(|cx| f(view, cx))
2299 }
2300
2301 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2302 where
2303 G: 'static,
2304 {
2305 let mut global = self.app.lease_global::<G>();
2306 let result = f(&mut global, self);
2307 self.app.end_global_lease(global);
2308 result
2309 }
2310
2311 pub fn observe_global<G: 'static>(
2312 &mut self,
2313 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2314 ) -> Subscription {
2315 let window_handle = self.window.handle;
2316 let view = self.view().downgrade();
2317 self.global_observers.insert(
2318 TypeId::of::<G>(),
2319 Box::new(move |cx| {
2320 window_handle
2321 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2322 .unwrap_or(false)
2323 }),
2324 )
2325 }
2326
2327 pub fn on_mouse_event<Event: 'static>(
2328 &mut self,
2329 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2330 ) {
2331 let handle = self.view().clone();
2332 self.window_cx.on_mouse_event(move |event, phase, cx| {
2333 handle.update(cx, |view, cx| {
2334 handler(view, event, phase, cx);
2335 })
2336 });
2337 }
2338
2339 pub fn on_key_event<Event: 'static>(
2340 &mut self,
2341 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2342 ) {
2343 let handle = self.view().clone();
2344 self.window_cx.on_key_event(move |event, phase, cx| {
2345 handle.update(cx, |view, cx| {
2346 handler(view, event, phase, cx);
2347 })
2348 });
2349 }
2350
2351 pub fn on_action(
2352 &mut self,
2353 action_type: TypeId,
2354 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2355 ) {
2356 let handle = self.view().clone();
2357 self.window_cx
2358 .on_action(action_type, move |action, phase, cx| {
2359 handle.update(cx, |view, cx| {
2360 handler(view, action, phase, cx);
2361 })
2362 });
2363 }
2364
2365 pub fn emit<Evt>(&mut self, event: Evt)
2366 where
2367 Evt: 'static,
2368 V: EventEmitter<Evt>,
2369 {
2370 let emitter = self.view.model.entity_id;
2371 self.app.push_effect(Effect::Emit {
2372 emitter,
2373 event_type: TypeId::of::<Evt>(),
2374 event: Box::new(event),
2375 });
2376 }
2377
2378 pub fn focus_self(&mut self)
2379 where
2380 V: FocusableView,
2381 {
2382 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2383 }
2384
2385 pub fn dismiss_self(&mut self)
2386 where
2387 V: ManagedView,
2388 {
2389 self.defer(|_, cx| cx.emit(DismissEvent::Dismiss))
2390 }
2391
2392 pub fn listener<E>(
2393 &self,
2394 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2395 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2396 let view = self.view().downgrade();
2397 move |e: &E, cx: &mut WindowContext| {
2398 view.update(cx, |view, cx| f(view, e, cx)).ok();
2399 }
2400 }
2401}
2402
2403impl<V> Context for ViewContext<'_, V> {
2404 type Result<U> = U;
2405
2406 fn build_model<T: 'static>(
2407 &mut self,
2408 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2409 ) -> Model<T> {
2410 self.window_cx.build_model(build_model)
2411 }
2412
2413 fn update_model<T: 'static, R>(
2414 &mut self,
2415 model: &Model<T>,
2416 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2417 ) -> R {
2418 self.window_cx.update_model(model, update)
2419 }
2420
2421 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2422 where
2423 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2424 {
2425 self.window_cx.update_window(window, update)
2426 }
2427
2428 fn read_model<T, R>(
2429 &self,
2430 handle: &Model<T>,
2431 read: impl FnOnce(&T, &AppContext) -> R,
2432 ) -> Self::Result<R>
2433 where
2434 T: 'static,
2435 {
2436 self.window_cx.read_model(handle, read)
2437 }
2438
2439 fn read_window<T, R>(
2440 &self,
2441 window: &WindowHandle<T>,
2442 read: impl FnOnce(View<T>, &AppContext) -> R,
2443 ) -> Result<R>
2444 where
2445 T: 'static,
2446 {
2447 self.window_cx.read_window(window, read)
2448 }
2449}
2450
2451impl<V: 'static> VisualContext for ViewContext<'_, V> {
2452 fn build_view<W: Render + 'static>(
2453 &mut self,
2454 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2455 ) -> Self::Result<View<W>> {
2456 self.window_cx.build_view(build_view_state)
2457 }
2458
2459 fn update_view<V2: 'static, R>(
2460 &mut self,
2461 view: &View<V2>,
2462 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2463 ) -> Self::Result<R> {
2464 self.window_cx.update_view(view, update)
2465 }
2466
2467 fn replace_root_view<W>(
2468 &mut self,
2469 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2470 ) -> Self::Result<View<W>>
2471 where
2472 W: 'static + Render,
2473 {
2474 self.window_cx.replace_root_view(build_view)
2475 }
2476
2477 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2478 self.window_cx.focus_view(view)
2479 }
2480
2481 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2482 self.window_cx.dismiss_view(view)
2483 }
2484}
2485
2486impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2487 type Target = WindowContext<'a>;
2488
2489 fn deref(&self) -> &Self::Target {
2490 &self.window_cx
2491 }
2492}
2493
2494impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2495 fn deref_mut(&mut self) -> &mut Self::Target {
2496 &mut self.window_cx
2497 }
2498}
2499
2500// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2501slotmap::new_key_type! { pub struct WindowId; }
2502
2503impl WindowId {
2504 pub fn as_u64(&self) -> u64 {
2505 self.0.as_ffi()
2506 }
2507}
2508
2509#[derive(Deref, DerefMut)]
2510pub struct WindowHandle<V> {
2511 #[deref]
2512 #[deref_mut]
2513 pub(crate) any_handle: AnyWindowHandle,
2514 state_type: PhantomData<V>,
2515}
2516
2517impl<V: 'static + Render> WindowHandle<V> {
2518 pub fn new(id: WindowId) -> Self {
2519 WindowHandle {
2520 any_handle: AnyWindowHandle {
2521 id,
2522 state_type: TypeId::of::<V>(),
2523 },
2524 state_type: PhantomData,
2525 }
2526 }
2527
2528 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2529 where
2530 C: Context,
2531 {
2532 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2533 root_view
2534 .downcast::<V>()
2535 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2536 }))
2537 }
2538
2539 pub fn update<C, R>(
2540 &self,
2541 cx: &mut C,
2542 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2543 ) -> Result<R>
2544 where
2545 C: Context,
2546 {
2547 cx.update_window(self.any_handle, |root_view, cx| {
2548 let view = root_view
2549 .downcast::<V>()
2550 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2551 Ok(cx.update_view(&view, update))
2552 })?
2553 }
2554
2555 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2556 let x = cx
2557 .windows
2558 .get(self.id)
2559 .and_then(|window| {
2560 window
2561 .as_ref()
2562 .and_then(|window| window.root_view.clone())
2563 .map(|root_view| root_view.downcast::<V>())
2564 })
2565 .ok_or_else(|| anyhow!("window not found"))?
2566 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2567
2568 Ok(x.read(cx))
2569 }
2570
2571 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2572 where
2573 C: Context,
2574 {
2575 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2576 }
2577
2578 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2579 where
2580 C: Context,
2581 {
2582 cx.read_window(self, |root_view, _cx| root_view.clone())
2583 }
2584
2585 pub fn is_active(&self, cx: &WindowContext) -> Option<bool> {
2586 cx.windows
2587 .get(self.id)
2588 .and_then(|window| window.as_ref().map(|window| window.active))
2589 }
2590}
2591
2592impl<V> Copy for WindowHandle<V> {}
2593
2594impl<V> Clone for WindowHandle<V> {
2595 fn clone(&self) -> Self {
2596 WindowHandle {
2597 any_handle: self.any_handle,
2598 state_type: PhantomData,
2599 }
2600 }
2601}
2602
2603impl<V> PartialEq for WindowHandle<V> {
2604 fn eq(&self, other: &Self) -> bool {
2605 self.any_handle == other.any_handle
2606 }
2607}
2608
2609impl<V> Eq for WindowHandle<V> {}
2610
2611impl<V> Hash for WindowHandle<V> {
2612 fn hash<H: Hasher>(&self, state: &mut H) {
2613 self.any_handle.hash(state);
2614 }
2615}
2616
2617impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2618 fn into(self) -> AnyWindowHandle {
2619 self.any_handle
2620 }
2621}
2622
2623#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2624pub struct AnyWindowHandle {
2625 pub(crate) id: WindowId,
2626 state_type: TypeId,
2627}
2628
2629impl AnyWindowHandle {
2630 pub fn window_id(&self) -> WindowId {
2631 self.id
2632 }
2633
2634 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2635 if TypeId::of::<T>() == self.state_type {
2636 Some(WindowHandle {
2637 any_handle: *self,
2638 state_type: PhantomData,
2639 })
2640 } else {
2641 None
2642 }
2643 }
2644
2645 pub fn update<C, R>(
2646 self,
2647 cx: &mut C,
2648 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2649 ) -> Result<R>
2650 where
2651 C: Context,
2652 {
2653 cx.update_window(self, update)
2654 }
2655
2656 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2657 where
2658 C: Context,
2659 T: 'static,
2660 {
2661 let view = self
2662 .downcast::<T>()
2663 .context("the type of the window's root view has changed")?;
2664
2665 cx.read_window(&view, read)
2666 }
2667}
2668
2669#[cfg(any(test, feature = "test-support"))]
2670impl From<SmallVec<[u32; 16]>> for StackingOrder {
2671 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2672 StackingOrder(small_vec)
2673 }
2674}
2675
2676#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2677pub enum ElementId {
2678 View(EntityId),
2679 Integer(usize),
2680 Name(SharedString),
2681 FocusHandle(FocusId),
2682}
2683
2684impl ElementId {
2685 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2686 ElementId::View(entity_id)
2687 }
2688}
2689
2690impl TryInto<SharedString> for ElementId {
2691 type Error = anyhow::Error;
2692
2693 fn try_into(self) -> anyhow::Result<SharedString> {
2694 if let ElementId::Name(name) = self {
2695 Ok(name)
2696 } else {
2697 Err(anyhow!("element id is not string"))
2698 }
2699 }
2700}
2701
2702impl From<usize> for ElementId {
2703 fn from(id: usize) -> Self {
2704 ElementId::Integer(id)
2705 }
2706}
2707
2708impl From<i32> for ElementId {
2709 fn from(id: i32) -> Self {
2710 Self::Integer(id as usize)
2711 }
2712}
2713
2714impl From<SharedString> for ElementId {
2715 fn from(name: SharedString) -> Self {
2716 ElementId::Name(name)
2717 }
2718}
2719
2720impl From<&'static str> for ElementId {
2721 fn from(name: &'static str) -> Self {
2722 ElementId::Name(name.into())
2723 }
2724}
2725
2726impl<'a> From<&'a FocusHandle> for ElementId {
2727 fn from(handle: &'a FocusHandle) -> Self {
2728 ElementId::FocusHandle(handle.id)
2729 }
2730}