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 struct DismissEvent;
201
202// Holds the state for a specific window.
203pub struct Window {
204 pub(crate) handle: AnyWindowHandle,
205 pub(crate) removed: bool,
206 pub(crate) platform_window: Box<dyn PlatformWindow>,
207 display_id: DisplayId,
208 sprite_atlas: Arc<dyn PlatformAtlas>,
209 rem_size: Pixels,
210 viewport_size: Size<Pixels>,
211 pub(crate) layout_engine: TaffyLayoutEngine,
212 pub(crate) root_view: Option<AnyView>,
213 pub(crate) element_id_stack: GlobalElementId,
214 pub(crate) previous_frame: Frame,
215 pub(crate) current_frame: Frame,
216 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
217 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
218 default_prevented: bool,
219 mouse_position: Point<Pixels>,
220 requested_cursor_style: Option<CursorStyle>,
221 scale_factor: f32,
222 bounds: WindowBounds,
223 bounds_observers: SubscriberSet<(), AnyObserver>,
224 active: bool,
225 activation_observers: SubscriberSet<(), AnyObserver>,
226 pub(crate) dirty: bool,
227 pub(crate) last_blur: Option<Option<FocusId>>,
228 pub(crate) focus: Option<FocusId>,
229}
230
231pub(crate) struct ElementStateBox {
232 inner: Box<dyn Any>,
233 #[cfg(debug_assertions)]
234 type_name: &'static str,
235}
236
237// #[derive(Default)]
238pub(crate) struct Frame {
239 pub(crate) element_states: HashMap<GlobalElementId, ElementStateBox>,
240 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
241 pub(crate) dispatch_tree: DispatchTree,
242 pub(crate) focus_listeners: Vec<AnyFocusListener>,
243 pub(crate) scene_builder: SceneBuilder,
244 pub(crate) depth_map: Vec<(StackingOrder, Bounds<Pixels>)>,
245 pub(crate) z_index_stack: StackingOrder,
246 content_mask_stack: Vec<ContentMask<Pixels>>,
247 element_offset_stack: Vec<Point<Pixels>>,
248}
249
250impl Frame {
251 pub fn new(dispatch_tree: DispatchTree) -> Self {
252 Frame {
253 element_states: HashMap::default(),
254 mouse_listeners: HashMap::default(),
255 dispatch_tree,
256 focus_listeners: Vec::new(),
257 scene_builder: SceneBuilder::default(),
258 z_index_stack: StackingOrder::default(),
259 depth_map: Default::default(),
260 content_mask_stack: Vec::new(),
261 element_offset_stack: Vec::new(),
262 }
263 }
264}
265
266impl Window {
267 pub(crate) fn new(
268 handle: AnyWindowHandle,
269 options: WindowOptions,
270 cx: &mut AppContext,
271 ) -> Self {
272 let platform_window = cx.platform.open_window(handle, options);
273 let display_id = platform_window.display().id();
274 let sprite_atlas = platform_window.sprite_atlas();
275 let mouse_position = platform_window.mouse_position();
276 let content_size = platform_window.content_size();
277 let scale_factor = platform_window.scale_factor();
278 let bounds = platform_window.bounds();
279
280 platform_window.on_resize(Box::new({
281 let mut cx = cx.to_async();
282 move |_, _| {
283 handle
284 .update(&mut cx, |_, cx| cx.window_bounds_changed())
285 .log_err();
286 }
287 }));
288 platform_window.on_moved(Box::new({
289 let mut cx = cx.to_async();
290 move || {
291 handle
292 .update(&mut cx, |_, cx| cx.window_bounds_changed())
293 .log_err();
294 }
295 }));
296 platform_window.on_active_status_change(Box::new({
297 let mut cx = cx.to_async();
298 move |active| {
299 handle
300 .update(&mut cx, |_, cx| {
301 cx.window.active = active;
302 cx.window
303 .activation_observers
304 .clone()
305 .retain(&(), |callback| callback(cx));
306 })
307 .log_err();
308 }
309 }));
310
311 platform_window.on_input({
312 let mut cx = cx.to_async();
313 Box::new(move |event| {
314 handle
315 .update(&mut cx, |_, cx| cx.dispatch_event(event))
316 .log_err()
317 .unwrap_or(false)
318 })
319 });
320
321 Window {
322 handle,
323 removed: false,
324 platform_window,
325 display_id,
326 sprite_atlas,
327 rem_size: px(16.),
328 viewport_size: content_size,
329 layout_engine: TaffyLayoutEngine::new(),
330 root_view: None,
331 element_id_stack: GlobalElementId::default(),
332 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
333 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
334 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
335 focus_listeners: SubscriberSet::new(),
336 default_prevented: true,
337 mouse_position,
338 requested_cursor_style: None,
339 scale_factor,
340 bounds,
341 bounds_observers: SubscriberSet::new(),
342 active: false,
343 activation_observers: SubscriberSet::new(),
344 dirty: true,
345 last_blur: None,
346 focus: None,
347 }
348 }
349}
350
351/// Indicates which region of the window is visible. Content falling outside of this mask will not be
352/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
353/// to leave room to support more complex shapes in the future.
354#[derive(Clone, Debug, Default, PartialEq, Eq)]
355#[repr(C)]
356pub struct ContentMask<P: Clone + Default + Debug> {
357 pub bounds: Bounds<P>,
358}
359
360impl ContentMask<Pixels> {
361 /// Scale the content mask's pixel units by the given scaling factor.
362 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
363 ContentMask {
364 bounds: self.bounds.scale(factor),
365 }
366 }
367
368 /// Intersect the content mask with the given content mask.
369 pub fn intersect(&self, other: &Self) -> Self {
370 let bounds = self.bounds.intersect(&other.bounds);
371 ContentMask { bounds }
372 }
373}
374
375/// Provides access to application state in the context of a single window. Derefs
376/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
377/// an `AppContext` and call any `AppContext` methods.
378pub struct WindowContext<'a> {
379 pub(crate) app: &'a mut AppContext,
380 pub(crate) window: &'a mut Window,
381}
382
383impl<'a> WindowContext<'a> {
384 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
385 Self { app, window }
386 }
387
388 /// Obtain a handle to the window that belongs to this context.
389 pub fn window_handle(&self) -> AnyWindowHandle {
390 self.window.handle
391 }
392
393 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
394 pub fn notify(&mut self) {
395 self.window.dirty = true;
396 }
397
398 /// Close this window.
399 pub fn remove_window(&mut self) {
400 self.window.removed = true;
401 }
402
403 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
404 /// for elements rendered within this window.
405 pub fn focus_handle(&mut self) -> FocusHandle {
406 FocusHandle::new(&self.window.focus_handles)
407 }
408
409 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
410 pub fn focused(&self) -> Option<FocusHandle> {
411 self.window
412 .focus
413 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
414 }
415
416 /// Move focus to the element associated with the given `FocusHandle`.
417 pub fn focus(&mut self, handle: &FocusHandle) {
418 if self.window.focus == Some(handle.id) {
419 return;
420 }
421
422 let focus_id = handle.id;
423
424 if self.window.last_blur.is_none() {
425 self.window.last_blur = Some(self.window.focus);
426 }
427
428 self.window.focus = Some(focus_id);
429 self.window
430 .current_frame
431 .dispatch_tree
432 .clear_keystroke_matchers();
433 self.app.push_effect(Effect::FocusChanged {
434 window_handle: self.window.handle,
435 focused: Some(focus_id),
436 });
437 self.notify();
438 }
439
440 /// Remove focus from all elements within this context's window.
441 pub fn blur(&mut self) {
442 if self.window.last_blur.is_none() {
443 self.window.last_blur = Some(self.window.focus);
444 }
445
446 self.window.focus = None;
447 self.app.push_effect(Effect::FocusChanged {
448 window_handle: self.window.handle,
449 focused: None,
450 });
451 self.notify();
452 }
453
454 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
455 if let Some(focus_handle) = self.focused() {
456 self.defer(move |cx| {
457 if let Some(node_id) = cx
458 .window
459 .current_frame
460 .dispatch_tree
461 .focusable_node_id(focus_handle.id)
462 {
463 cx.propagate_event = true;
464 cx.dispatch_action_on_node(node_id, action);
465 }
466 })
467 }
468 }
469
470 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
471 /// that are currently on the stack to be returned to the app.
472 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
473 let handle = self.window.handle;
474 self.app.defer(move |cx| {
475 handle.update(cx, |_, cx| f(cx)).ok();
476 });
477 }
478
479 pub fn subscribe<Emitter, E, Evt>(
480 &mut self,
481 entity: &E,
482 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
483 ) -> Subscription
484 where
485 Emitter: EventEmitter<Evt>,
486 E: Entity<Emitter>,
487 Evt: 'static,
488 {
489 let entity_id = entity.entity_id();
490 let entity = entity.downgrade();
491 let window_handle = self.window.handle;
492 self.app.event_listeners.insert(
493 entity_id,
494 (
495 TypeId::of::<Evt>(),
496 Box::new(move |event, cx| {
497 window_handle
498 .update(cx, |_, cx| {
499 if let Some(handle) = E::upgrade_from(&entity) {
500 let event = event.downcast_ref().expect("invalid event type");
501 on_event(handle, event, cx);
502 true
503 } else {
504 false
505 }
506 })
507 .unwrap_or(false)
508 }),
509 ),
510 )
511 }
512
513 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
514 /// await points in async code.
515 pub fn to_async(&self) -> AsyncWindowContext {
516 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
517 }
518
519 /// Schedule the given closure to be run directly after the current frame is rendered.
520 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
521 let handle = self.window.handle;
522 let display_id = self.window.display_id;
523
524 if !self.frame_consumers.contains_key(&display_id) {
525 let (tx, mut rx) = mpsc::unbounded::<()>();
526 self.platform.set_display_link_output_callback(
527 display_id,
528 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
529 );
530
531 let consumer_task = self.app.spawn(|cx| async move {
532 while rx.next().await.is_some() {
533 cx.update(|cx| {
534 for callback in cx
535 .next_frame_callbacks
536 .get_mut(&display_id)
537 .unwrap()
538 .drain(..)
539 .collect::<SmallVec<[_; 32]>>()
540 {
541 callback(cx);
542 }
543 })
544 .ok();
545
546 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
547
548 cx.update(|cx| {
549 if cx.next_frame_callbacks.is_empty() {
550 cx.platform.stop_display_link(display_id);
551 }
552 })
553 .ok();
554 }
555 });
556 self.frame_consumers.insert(display_id, consumer_task);
557 }
558
559 if self.next_frame_callbacks.is_empty() {
560 self.platform.start_display_link(display_id);
561 }
562
563 self.next_frame_callbacks
564 .entry(display_id)
565 .or_default()
566 .push(Box::new(move |cx: &mut AppContext| {
567 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
568 }));
569 }
570
571 /// Spawn the future returned by the given closure on the application thread pool.
572 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
573 /// use within your future.
574 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
575 where
576 R: 'static,
577 Fut: Future<Output = R> + 'static,
578 {
579 self.app
580 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
581 }
582
583 /// Update the global of the given type. The given closure is given simultaneous mutable
584 /// access both to the global and the context.
585 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
586 where
587 G: 'static,
588 {
589 let mut global = self.app.lease_global::<G>();
590 let result = f(&mut global, self);
591 self.app.end_global_lease(global);
592 result
593 }
594
595 #[must_use]
596 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
597 /// layout is being requested, along with the layout ids of any children. This method is called during
598 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
599 pub fn request_layout(
600 &mut self,
601 style: &Style,
602 children: impl IntoIterator<Item = LayoutId>,
603 ) -> LayoutId {
604 self.app.layout_id_buffer.clear();
605 self.app.layout_id_buffer.extend(children.into_iter());
606 let rem_size = self.rem_size();
607
608 self.window
609 .layout_engine
610 .request_layout(style, rem_size, &self.app.layout_id_buffer)
611 }
612
613 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
614 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
615 /// determine the element's size. One place this is used internally is when measuring text.
616 ///
617 /// The given closure is invoked at layout time with the known dimensions and available space and
618 /// returns a `Size`.
619 pub fn request_measured_layout<
620 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
621 >(
622 &mut self,
623 style: Style,
624 rem_size: Pixels,
625 measure: F,
626 ) -> LayoutId {
627 self.window
628 .layout_engine
629 .request_measured_layout(style, rem_size, measure)
630 }
631
632 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
633 self.window
634 .layout_engine
635 .compute_layout(layout_id, available_space)
636 }
637
638 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
639 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
640 /// in order to pass your element its `Bounds` automatically.
641 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
642 let mut bounds = self
643 .window
644 .layout_engine
645 .layout_bounds(layout_id)
646 .map(Into::into);
647 bounds.origin += self.element_offset();
648 bounds
649 }
650
651 fn window_bounds_changed(&mut self) {
652 self.window.scale_factor = self.window.platform_window.scale_factor();
653 self.window.viewport_size = self.window.platform_window.content_size();
654 self.window.bounds = self.window.platform_window.bounds();
655 self.window.display_id = self.window.platform_window.display().id();
656 self.window.dirty = true;
657
658 self.window
659 .bounds_observers
660 .clone()
661 .retain(&(), |callback| callback(self));
662 }
663
664 pub fn window_bounds(&self) -> WindowBounds {
665 self.window.bounds
666 }
667
668 pub fn viewport_size(&self) -> Size<Pixels> {
669 self.window.viewport_size
670 }
671
672 pub fn is_window_active(&self) -> bool {
673 self.window.active
674 }
675
676 pub fn zoom_window(&self) {
677 self.window.platform_window.zoom();
678 }
679
680 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
681 self.platform
682 .displays()
683 .into_iter()
684 .find(|display| display.id() == self.window.display_id)
685 }
686
687 pub fn show_character_palette(&self) {
688 self.window.platform_window.show_character_palette();
689 }
690
691 /// The scale factor of the display associated with the window. For example, it could
692 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
693 /// be rendered as two pixels on screen.
694 pub fn scale_factor(&self) -> f32 {
695 self.window.scale_factor
696 }
697
698 /// The size of an em for the base font of the application. Adjusting this value allows the
699 /// UI to scale, just like zooming a web page.
700 pub fn rem_size(&self) -> Pixels {
701 self.window.rem_size
702 }
703
704 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
705 /// UI to scale, just like zooming a web page.
706 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
707 self.window.rem_size = rem_size.into();
708 }
709
710 /// The line height associated with the current text style.
711 pub fn line_height(&self) -> Pixels {
712 let rem_size = self.rem_size();
713 let text_style = self.text_style();
714 text_style
715 .line_height
716 .to_pixels(text_style.font_size.into(), rem_size)
717 }
718
719 /// Call to prevent the default action of an event. Currently only used to prevent
720 /// parent elements from becoming focused on mouse down.
721 pub fn prevent_default(&mut self) {
722 self.window.default_prevented = true;
723 }
724
725 /// Obtain whether default has been prevented for the event currently being dispatched.
726 pub fn default_prevented(&self) -> bool {
727 self.window.default_prevented
728 }
729
730 /// Register a mouse event listener on the window for the current frame. The type of event
731 /// is determined by the first parameter of the given listener. When the next frame is rendered
732 /// the listener will be cleared.
733 ///
734 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
735 /// a specific need to register a global listener.
736 pub fn on_mouse_event<Event: 'static>(
737 &mut self,
738 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
739 ) {
740 let order = self.window.current_frame.z_index_stack.clone();
741 self.window
742 .current_frame
743 .mouse_listeners
744 .entry(TypeId::of::<Event>())
745 .or_default()
746 .push((
747 order,
748 Box::new(move |event: &dyn Any, phase, cx| {
749 handler(event.downcast_ref().unwrap(), phase, cx)
750 }),
751 ))
752 }
753
754 /// Register a key event listener on the window for the current frame. The type of event
755 /// is determined by the first parameter of the given listener. When the next frame is rendered
756 /// the listener will be cleared.
757 ///
758 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
759 /// a specific need to register a global listener.
760 pub fn on_key_event<Event: 'static>(
761 &mut self,
762 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
763 ) {
764 self.window
765 .current_frame
766 .dispatch_tree
767 .on_key_event(Rc::new(move |event, phase, cx| {
768 if let Some(event) = event.downcast_ref::<Event>() {
769 handler(event, phase, cx)
770 }
771 }));
772 }
773
774 /// Register an action listener on the window for the current frame. The type of action
775 /// is determined by the first parameter of the given listener. When the next frame is rendered
776 /// the listener will be cleared.
777 ///
778 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
779 /// a specific need to register a global listener.
780 pub fn on_action(
781 &mut self,
782 action_type: TypeId,
783 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
784 ) {
785 self.window.current_frame.dispatch_tree.on_action(
786 action_type,
787 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
788 );
789 }
790
791 /// The position of the mouse relative to the window.
792 pub fn mouse_position(&self) -> Point<Pixels> {
793 self.window.mouse_position
794 }
795
796 pub fn set_cursor_style(&mut self, style: CursorStyle) {
797 self.window.requested_cursor_style = Some(style)
798 }
799
800 /// Called during painting to invoke the given closure in a new stacking context. The given
801 /// z-index is interpreted relative to the previous call to `stack`.
802 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
803 self.window.current_frame.z_index_stack.push(z_index);
804 let result = f(self);
805 self.window.current_frame.z_index_stack.pop();
806 result
807 }
808
809 /// Called during painting to track which z-index is on top at each pixel position
810 pub fn add_opaque_layer(&mut self, bounds: Bounds<Pixels>) {
811 let stacking_order = self.window.current_frame.z_index_stack.clone();
812 let depth_map = &mut self.window.current_frame.depth_map;
813 match depth_map.binary_search_by(|(level, _)| stacking_order.cmp(&level)) {
814 Ok(i) | Err(i) => depth_map.insert(i, (stacking_order, bounds)),
815 }
816 }
817
818 /// Returns true if the top-most opaque layer painted over this point was part of the
819 /// same layer as the given stacking order.
820 pub fn was_top_layer(&self, point: &Point<Pixels>, level: &StackingOrder) -> bool {
821 for (stack, bounds) in self.window.previous_frame.depth_map.iter() {
822 if bounds.contains_point(point) {
823 return level.starts_with(stack) || stack.starts_with(level);
824 }
825 }
826
827 false
828 }
829
830 /// Called during painting to get the current stacking order.
831 pub fn stacking_order(&self) -> &StackingOrder {
832 &self.window.current_frame.z_index_stack
833 }
834
835 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
836 pub fn paint_shadows(
837 &mut self,
838 bounds: Bounds<Pixels>,
839 corner_radii: Corners<Pixels>,
840 shadows: &[BoxShadow],
841 ) {
842 let scale_factor = self.scale_factor();
843 let content_mask = self.content_mask();
844 let window = &mut *self.window;
845 for shadow in shadows {
846 let mut shadow_bounds = bounds;
847 shadow_bounds.origin += shadow.offset;
848 shadow_bounds.dilate(shadow.spread_radius);
849 window.current_frame.scene_builder.insert(
850 &window.current_frame.z_index_stack,
851 Shadow {
852 order: 0,
853 bounds: shadow_bounds.scale(scale_factor),
854 content_mask: content_mask.scale(scale_factor),
855 corner_radii: corner_radii.scale(scale_factor),
856 color: shadow.color,
857 blur_radius: shadow.blur_radius.scale(scale_factor),
858 },
859 );
860 }
861 }
862
863 /// Paint one or more quads into the scene for the current frame at the current stacking context.
864 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
865 pub fn paint_quad(
866 &mut self,
867 bounds: Bounds<Pixels>,
868 corner_radii: Corners<Pixels>,
869 background: impl Into<Hsla>,
870 border_widths: Edges<Pixels>,
871 border_color: impl Into<Hsla>,
872 ) {
873 let scale_factor = self.scale_factor();
874 let content_mask = self.content_mask();
875
876 let window = &mut *self.window;
877 window.current_frame.scene_builder.insert(
878 &window.current_frame.z_index_stack,
879 Quad {
880 order: 0,
881 bounds: bounds.scale(scale_factor),
882 content_mask: content_mask.scale(scale_factor),
883 background: background.into(),
884 border_color: border_color.into(),
885 corner_radii: corner_radii.scale(scale_factor),
886 border_widths: border_widths.scale(scale_factor),
887 },
888 );
889 }
890
891 /// Paint the given `Path` into the scene for the current frame at the current z-index.
892 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
893 let scale_factor = self.scale_factor();
894 let content_mask = self.content_mask();
895 path.content_mask = content_mask;
896 path.color = color.into();
897 let window = &mut *self.window;
898 window.current_frame.scene_builder.insert(
899 &window.current_frame.z_index_stack,
900 path.scale(scale_factor),
901 );
902 }
903
904 /// Paint an underline into the scene for the current frame at the current z-index.
905 pub fn paint_underline(
906 &mut self,
907 origin: Point<Pixels>,
908 width: Pixels,
909 style: &UnderlineStyle,
910 ) {
911 let scale_factor = self.scale_factor();
912 let height = if style.wavy {
913 style.thickness * 3.
914 } else {
915 style.thickness
916 };
917 let bounds = Bounds {
918 origin,
919 size: size(width, height),
920 };
921 let content_mask = self.content_mask();
922 let window = &mut *self.window;
923 window.current_frame.scene_builder.insert(
924 &window.current_frame.z_index_stack,
925 Underline {
926 order: 0,
927 bounds: bounds.scale(scale_factor),
928 content_mask: content_mask.scale(scale_factor),
929 thickness: style.thickness.scale(scale_factor),
930 color: style.color.unwrap_or_default(),
931 wavy: style.wavy,
932 },
933 );
934 }
935
936 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
937 /// The y component of the origin is the baseline of the glyph.
938 pub fn paint_glyph(
939 &mut self,
940 origin: Point<Pixels>,
941 font_id: FontId,
942 glyph_id: GlyphId,
943 font_size: Pixels,
944 color: Hsla,
945 ) -> Result<()> {
946 let scale_factor = self.scale_factor();
947 let glyph_origin = origin.scale(scale_factor);
948 let subpixel_variant = Point {
949 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
950 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
951 };
952 let params = RenderGlyphParams {
953 font_id,
954 glyph_id,
955 font_size,
956 subpixel_variant,
957 scale_factor,
958 is_emoji: false,
959 };
960
961 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
962 if !raster_bounds.is_zero() {
963 let tile =
964 self.window
965 .sprite_atlas
966 .get_or_insert_with(¶ms.clone().into(), &mut || {
967 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
968 Ok((size, Cow::Owned(bytes)))
969 })?;
970 let bounds = Bounds {
971 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
972 size: tile.bounds.size.map(Into::into),
973 };
974 let content_mask = self.content_mask().scale(scale_factor);
975 let window = &mut *self.window;
976 window.current_frame.scene_builder.insert(
977 &window.current_frame.z_index_stack,
978 MonochromeSprite {
979 order: 0,
980 bounds,
981 content_mask,
982 color,
983 tile,
984 },
985 );
986 }
987 Ok(())
988 }
989
990 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
991 /// The y component of the origin is the baseline of the glyph.
992 pub fn paint_emoji(
993 &mut self,
994 origin: Point<Pixels>,
995 font_id: FontId,
996 glyph_id: GlyphId,
997 font_size: Pixels,
998 ) -> Result<()> {
999 let scale_factor = self.scale_factor();
1000 let glyph_origin = origin.scale(scale_factor);
1001 let params = RenderGlyphParams {
1002 font_id,
1003 glyph_id,
1004 font_size,
1005 // We don't render emojis with subpixel variants.
1006 subpixel_variant: Default::default(),
1007 scale_factor,
1008 is_emoji: true,
1009 };
1010
1011 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
1012 if !raster_bounds.is_zero() {
1013 let tile =
1014 self.window
1015 .sprite_atlas
1016 .get_or_insert_with(¶ms.clone().into(), &mut || {
1017 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
1018 Ok((size, Cow::Owned(bytes)))
1019 })?;
1020 let bounds = Bounds {
1021 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
1022 size: tile.bounds.size.map(Into::into),
1023 };
1024 let content_mask = self.content_mask().scale(scale_factor);
1025 let window = &mut *self.window;
1026
1027 window.current_frame.scene_builder.insert(
1028 &window.current_frame.z_index_stack,
1029 PolychromeSprite {
1030 order: 0,
1031 bounds,
1032 corner_radii: Default::default(),
1033 content_mask,
1034 tile,
1035 grayscale: false,
1036 },
1037 );
1038 }
1039 Ok(())
1040 }
1041
1042 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1043 pub fn paint_svg(
1044 &mut self,
1045 bounds: Bounds<Pixels>,
1046 path: SharedString,
1047 color: Hsla,
1048 ) -> Result<()> {
1049 let scale_factor = self.scale_factor();
1050 let bounds = bounds.scale(scale_factor);
1051 // Render the SVG at twice the size to get a higher quality result.
1052 let params = RenderSvgParams {
1053 path,
1054 size: bounds
1055 .size
1056 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1057 };
1058
1059 let tile =
1060 self.window
1061 .sprite_atlas
1062 .get_or_insert_with(¶ms.clone().into(), &mut || {
1063 let bytes = self.svg_renderer.render(¶ms)?;
1064 Ok((params.size, Cow::Owned(bytes)))
1065 })?;
1066 let content_mask = self.content_mask().scale(scale_factor);
1067
1068 let window = &mut *self.window;
1069 window.current_frame.scene_builder.insert(
1070 &window.current_frame.z_index_stack,
1071 MonochromeSprite {
1072 order: 0,
1073 bounds,
1074 content_mask,
1075 color,
1076 tile,
1077 },
1078 );
1079
1080 Ok(())
1081 }
1082
1083 /// Paint an image into the scene for the current frame at the current z-index.
1084 pub fn paint_image(
1085 &mut self,
1086 bounds: Bounds<Pixels>,
1087 corner_radii: Corners<Pixels>,
1088 data: Arc<ImageData>,
1089 grayscale: bool,
1090 ) -> Result<()> {
1091 let scale_factor = self.scale_factor();
1092 let bounds = bounds.scale(scale_factor);
1093 let params = RenderImageParams { image_id: data.id };
1094
1095 let tile = self
1096 .window
1097 .sprite_atlas
1098 .get_or_insert_with(¶ms.clone().into(), &mut || {
1099 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1100 })?;
1101 let content_mask = self.content_mask().scale(scale_factor);
1102 let corner_radii = corner_radii.scale(scale_factor);
1103
1104 let window = &mut *self.window;
1105 window.current_frame.scene_builder.insert(
1106 &window.current_frame.z_index_stack,
1107 PolychromeSprite {
1108 order: 0,
1109 bounds,
1110 content_mask,
1111 corner_radii,
1112 tile,
1113 grayscale,
1114 },
1115 );
1116 Ok(())
1117 }
1118
1119 /// Draw pixels to the display for this window based on the contents of its scene.
1120 pub(crate) fn draw(&mut self) {
1121 let root_view = self.window.root_view.take().unwrap();
1122
1123 self.start_frame();
1124
1125 self.with_z_index(0, |cx| {
1126 let available_space = cx.window.viewport_size.map(Into::into);
1127 root_view.draw(Point::zero(), available_space, cx);
1128 });
1129
1130 if let Some(active_drag) = self.app.active_drag.take() {
1131 self.with_z_index(1, |cx| {
1132 let offset = cx.mouse_position() - active_drag.cursor_offset;
1133 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1134 active_drag.view.draw(offset, available_space, cx);
1135 cx.active_drag = Some(active_drag);
1136 });
1137 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1138 self.with_z_index(1, |cx| {
1139 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1140 active_tooltip
1141 .view
1142 .draw(active_tooltip.cursor_offset, available_space, cx);
1143 });
1144 }
1145
1146 self.window
1147 .current_frame
1148 .dispatch_tree
1149 .preserve_keystroke_matchers(
1150 &mut self.window.previous_frame.dispatch_tree,
1151 self.window.focus,
1152 );
1153
1154 self.window.root_view = Some(root_view);
1155 let scene = self.window.current_frame.scene_builder.build();
1156
1157 self.window.platform_window.draw(scene);
1158 let cursor_style = self
1159 .window
1160 .requested_cursor_style
1161 .take()
1162 .unwrap_or(CursorStyle::Arrow);
1163 self.platform.set_cursor_style(cursor_style);
1164
1165 self.window.dirty = false;
1166 }
1167
1168 /// Rotate the current frame and the previous frame, then clear the current frame.
1169 /// We repopulate all state in the current frame during each paint.
1170 fn start_frame(&mut self) {
1171 self.text_system().start_frame();
1172
1173 let window = &mut *self.window;
1174 window.layout_engine.clear();
1175
1176 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1177 let frame = &mut window.current_frame;
1178 frame.element_states.clear();
1179 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1180 frame.focus_listeners.clear();
1181 frame.dispatch_tree.clear();
1182 frame.depth_map.clear();
1183 }
1184
1185 /// Dispatch a mouse or keyboard event on the window.
1186 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1187 // Handlers may set this to false by calling `stop_propagation`
1188 self.app.propagate_event = true;
1189 self.window.default_prevented = false;
1190
1191 let event = match event {
1192 // Track the mouse position with our own state, since accessing the platform
1193 // API for the mouse position can only occur on the main thread.
1194 InputEvent::MouseMove(mouse_move) => {
1195 self.window.mouse_position = mouse_move.position;
1196 InputEvent::MouseMove(mouse_move)
1197 }
1198 InputEvent::MouseDown(mouse_down) => {
1199 self.window.mouse_position = mouse_down.position;
1200 InputEvent::MouseDown(mouse_down)
1201 }
1202 InputEvent::MouseUp(mouse_up) => {
1203 self.window.mouse_position = mouse_up.position;
1204 InputEvent::MouseUp(mouse_up)
1205 }
1206 // Translate dragging and dropping of external files from the operating system
1207 // to internal drag and drop events.
1208 InputEvent::FileDrop(file_drop) => match file_drop {
1209 FileDropEvent::Entered { position, files } => {
1210 self.window.mouse_position = position;
1211 if self.active_drag.is_none() {
1212 self.active_drag = Some(AnyDrag {
1213 view: self.build_view(|_| files).into(),
1214 cursor_offset: position,
1215 });
1216 }
1217 InputEvent::MouseDown(MouseDownEvent {
1218 position,
1219 button: MouseButton::Left,
1220 click_count: 1,
1221 modifiers: Modifiers::default(),
1222 })
1223 }
1224 FileDropEvent::Pending { position } => {
1225 self.window.mouse_position = position;
1226 InputEvent::MouseMove(MouseMoveEvent {
1227 position,
1228 pressed_button: Some(MouseButton::Left),
1229 modifiers: Modifiers::default(),
1230 })
1231 }
1232 FileDropEvent::Submit { position } => {
1233 self.window.mouse_position = position;
1234 InputEvent::MouseUp(MouseUpEvent {
1235 button: MouseButton::Left,
1236 position,
1237 modifiers: Modifiers::default(),
1238 click_count: 1,
1239 })
1240 }
1241 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1242 button: MouseButton::Left,
1243 position: Point::default(),
1244 modifiers: Modifiers::default(),
1245 click_count: 1,
1246 }),
1247 },
1248 _ => event,
1249 };
1250
1251 if let Some(any_mouse_event) = event.mouse_event() {
1252 self.dispatch_mouse_event(any_mouse_event);
1253 } else if let Some(any_key_event) = event.keyboard_event() {
1254 self.dispatch_key_event(any_key_event);
1255 }
1256
1257 !self.app.propagate_event
1258 }
1259
1260 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1261 if let Some(mut handlers) = self
1262 .window
1263 .current_frame
1264 .mouse_listeners
1265 .remove(&event.type_id())
1266 {
1267 // Because handlers may add other handlers, we sort every time.
1268 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1269
1270 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1271 // special purposes, such as detecting events outside of a given Bounds.
1272 for (_, handler) in &mut handlers {
1273 handler(event, DispatchPhase::Capture, self);
1274 if !self.app.propagate_event {
1275 break;
1276 }
1277 }
1278
1279 // Bubble phase, where most normal handlers do their work.
1280 if self.app.propagate_event {
1281 for (_, handler) in handlers.iter_mut().rev() {
1282 handler(event, DispatchPhase::Bubble, self);
1283 if !self.app.propagate_event {
1284 break;
1285 }
1286 }
1287 }
1288
1289 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1290 self.active_drag = None;
1291 }
1292
1293 // Just in case any handlers added new handlers, which is weird, but possible.
1294 handlers.extend(
1295 self.window
1296 .current_frame
1297 .mouse_listeners
1298 .get_mut(&event.type_id())
1299 .into_iter()
1300 .flat_map(|handlers| handlers.drain(..)),
1301 );
1302 self.window
1303 .current_frame
1304 .mouse_listeners
1305 .insert(event.type_id(), handlers);
1306 }
1307 }
1308
1309 fn dispatch_key_event(&mut self, event: &dyn Any) {
1310 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1311 self.window
1312 .current_frame
1313 .dispatch_tree
1314 .focusable_node_id(focus_id)
1315 }) {
1316 let dispatch_path = self
1317 .window
1318 .current_frame
1319 .dispatch_tree
1320 .dispatch_path(node_id);
1321
1322 // Capture phase
1323 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1324 self.propagate_event = true;
1325
1326 for node_id in &dispatch_path {
1327 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1328
1329 if !node.context.is_empty() {
1330 context_stack.push(node.context.clone());
1331 }
1332
1333 for key_listener in node.key_listeners.clone() {
1334 key_listener(event, DispatchPhase::Capture, self);
1335 if !self.propagate_event {
1336 return;
1337 }
1338 }
1339 }
1340
1341 // Bubble phase
1342 for node_id in dispatch_path.iter().rev() {
1343 // Handle low level key events
1344 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1345 for key_listener in node.key_listeners.clone() {
1346 key_listener(event, DispatchPhase::Bubble, self);
1347 if !self.propagate_event {
1348 return;
1349 }
1350 }
1351
1352 // Match keystrokes
1353 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1354 if !node.context.is_empty() {
1355 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1356 if let Some(action) = self
1357 .window
1358 .current_frame
1359 .dispatch_tree
1360 .dispatch_key(&key_down_event.keystroke, &context_stack)
1361 {
1362 self.dispatch_action_on_node(*node_id, action);
1363 if !self.propagate_event {
1364 return;
1365 }
1366 }
1367 }
1368
1369 context_stack.pop();
1370 }
1371 }
1372 }
1373 }
1374
1375 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1376 let dispatch_path = self
1377 .window
1378 .current_frame
1379 .dispatch_tree
1380 .dispatch_path(node_id);
1381
1382 // Capture phase
1383 for node_id in &dispatch_path {
1384 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1385 for DispatchActionListener {
1386 action_type,
1387 listener,
1388 } in node.action_listeners.clone()
1389 {
1390 let any_action = action.as_any();
1391 if action_type == any_action.type_id() {
1392 listener(any_action, DispatchPhase::Capture, self);
1393 if !self.propagate_event {
1394 return;
1395 }
1396 }
1397 }
1398 }
1399
1400 // Bubble phase
1401 for node_id in dispatch_path.iter().rev() {
1402 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1403 for DispatchActionListener {
1404 action_type,
1405 listener,
1406 } in node.action_listeners.clone()
1407 {
1408 let any_action = action.as_any();
1409 if action_type == any_action.type_id() {
1410 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1411 listener(any_action, DispatchPhase::Bubble, self);
1412 if !self.propagate_event {
1413 return;
1414 }
1415 }
1416 }
1417 }
1418 }
1419
1420 /// Register the given handler to be invoked whenever the global of the given type
1421 /// is updated.
1422 pub fn observe_global<G: 'static>(
1423 &mut self,
1424 f: impl Fn(&mut WindowContext<'_>) + 'static,
1425 ) -> Subscription {
1426 let window_handle = self.window.handle;
1427 self.global_observers.insert(
1428 TypeId::of::<G>(),
1429 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1430 )
1431 }
1432
1433 pub fn activate_window(&self) {
1434 self.window.platform_window.activate();
1435 }
1436
1437 pub fn minimize_window(&self) {
1438 self.window.platform_window.minimize();
1439 }
1440
1441 pub fn toggle_full_screen(&self) {
1442 self.window.platform_window.toggle_full_screen();
1443 }
1444
1445 pub fn prompt(
1446 &self,
1447 level: PromptLevel,
1448 msg: &str,
1449 answers: &[&str],
1450 ) -> oneshot::Receiver<usize> {
1451 self.window.platform_window.prompt(level, msg, answers)
1452 }
1453
1454 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1455 if let Some(focus_id) = self.window.focus {
1456 self.window
1457 .current_frame
1458 .dispatch_tree
1459 .available_actions(focus_id)
1460 } else {
1461 Vec::new()
1462 }
1463 }
1464
1465 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1466 self.window
1467 .current_frame
1468 .dispatch_tree
1469 .bindings_for_action(action)
1470 }
1471
1472 pub fn listener_for<V: Render, E>(
1473 &self,
1474 view: &View<V>,
1475 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1476 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1477 let view = view.downgrade();
1478 move |e: &E, cx: &mut WindowContext| {
1479 view.update(cx, |view, cx| f(view, e, cx)).ok();
1480 }
1481 }
1482
1483 pub fn handler_for<V: Render>(
1484 &self,
1485 view: &View<V>,
1486 f: impl Fn(&mut V, &mut ViewContext<V>) + 'static,
1487 ) -> impl Fn(&mut WindowContext) {
1488 let view = view.downgrade();
1489 move |cx: &mut WindowContext| {
1490 view.update(cx, |view, cx| f(view, cx)).ok();
1491 }
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))
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))
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}