1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyBox, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle,
4 DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId,
5 EventEmitter, FileDropEvent, FocusEvent, FontId, GlobalElementId, GlyphId, Hsla, ImageData,
6 InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, LayoutId, Model, ModelContext,
7 Modifiers, MonochromeSprite, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path,
8 Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler, PlatformWindow, Point,
9 PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams, RenderImageParams,
10 RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size, Style, SubscriberSet,
11 Subscription, TaffyLayoutEngine, Task, Underline, UnderlineStyle, View, VisualContext,
12 WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Context as _, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use parking_lot::RwLock;
22use slotmap::SlotMap;
23use smallvec::SmallVec;
24use std::{
25 any::{Any, TypeId},
26 borrow::{Borrow, BorrowMut, Cow},
27 fmt::Debug,
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37};
38use util::ResultExt;
39
40/// A global stacking order, which is created by stacking successive z-index values.
41/// Each z-index will always be interpreted in the context of its parent z-index.
42#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
43pub(crate) struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
44
45/// Represents the two different phases when dispatching events.
46#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
47pub enum DispatchPhase {
48 /// After the capture phase comes the bubble phase, in which mouse event listeners are
49 /// invoked front to back and keyboard event listeners are invoked from the focused element
50 /// to the root of the element tree. This is the phase you'll most commonly want to use when
51 /// registering event listeners.
52 #[default]
53 Bubble,
54 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
55 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
56 /// is used for special purposes such as clearing the "pressed" state for click events. If
57 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
58 /// outside of the immediate region may rely on detecting non-local events during this phase.
59 Capture,
60}
61
62type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
63type AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
64type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
65type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
66
67slotmap::new_key_type! { pub struct FocusId; }
68
69impl FocusId {
70 /// Obtains whether the element associated with this handle is currently focused.
71 pub fn is_focused(&self, cx: &WindowContext) -> bool {
72 cx.window.focus == Some(*self)
73 }
74
75 /// Obtains whether the element associated with this handle contains the focused
76 /// element or is itself focused.
77 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
78 cx.focused()
79 .map_or(false, |focused| self.contains(focused.id, cx))
80 }
81
82 /// Obtains whether the element associated with this handle is contained within the
83 /// focused element or is itself focused.
84 pub fn within_focused(&self, cx: &WindowContext) -> bool {
85 let focused = cx.focused();
86 focused.map_or(false, |focused| focused.id.contains(*self, cx))
87 }
88
89 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
90 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
91 cx.window
92 .current_frame
93 .dispatch_tree
94 .focus_contains(*self, other)
95 }
96}
97
98/// A handle which can be used to track and manipulate the focused element in a window.
99pub struct FocusHandle {
100 pub(crate) id: FocusId,
101 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
102}
103
104impl std::fmt::Debug for FocusHandle {
105 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
106 f.write_fmt(format_args!("FocusHandle({:?})", self.id))
107 }
108}
109
110impl FocusHandle {
111 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
112 let id = handles.write().insert(AtomicUsize::new(1));
113 Self {
114 id,
115 handles: handles.clone(),
116 }
117 }
118
119 pub(crate) fn for_id(
120 id: FocusId,
121 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
122 ) -> Option<Self> {
123 let lock = handles.read();
124 let ref_count = lock.get(id)?;
125 if ref_count.load(SeqCst) == 0 {
126 None
127 } else {
128 ref_count.fetch_add(1, SeqCst);
129 Some(Self {
130 id,
131 handles: handles.clone(),
132 })
133 }
134 }
135
136 /// Moves the focus to the element associated with this handle.
137 pub fn focus(&self, cx: &mut WindowContext) {
138 cx.focus(self)
139 }
140
141 /// Obtains whether the element associated with this handle is currently focused.
142 pub fn is_focused(&self, cx: &WindowContext) -> bool {
143 self.id.is_focused(cx)
144 }
145
146 /// Obtains whether the element associated with this handle contains the focused
147 /// element or is itself focused.
148 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
149 self.id.contains_focused(cx)
150 }
151
152 /// Obtains whether the element associated with this handle is contained within the
153 /// focused element or is itself focused.
154 pub fn within_focused(&self, cx: &WindowContext) -> bool {
155 self.id.within_focused(cx)
156 }
157
158 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
159 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
160 self.id.contains(other.id, cx)
161 }
162}
163
164impl Clone for FocusHandle {
165 fn clone(&self) -> Self {
166 Self::for_id(self.id, &self.handles).unwrap()
167 }
168}
169
170impl PartialEq for FocusHandle {
171 fn eq(&self, other: &Self) -> bool {
172 self.id == other.id
173 }
174}
175
176impl Eq for FocusHandle {}
177
178impl Drop for FocusHandle {
179 fn drop(&mut self) {
180 self.handles
181 .read()
182 .get(self.id)
183 .unwrap()
184 .fetch_sub(1, SeqCst);
185 }
186}
187
188/// FocusableView allows users of your view to easily
189/// focus it (using cx.focus_view(view))
190pub trait FocusableView: 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: Render {
197 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
198}
199
200pub struct Dismiss;
201impl<T: ManagedView> EventEmitter<Dismiss> for T {}
202
203impl<T: ManagedView> FocusableView for T {
204 fn focus_handle(&self, cx: &AppContext) -> FocusHandle {
205 self.focus_handle(cx)
206 }
207}
208
209// Holds the state for a specific window.
210pub struct Window {
211 pub(crate) handle: AnyWindowHandle,
212 pub(crate) removed: bool,
213 pub(crate) platform_window: Box<dyn PlatformWindow>,
214 display_id: DisplayId,
215 sprite_atlas: Arc<dyn PlatformAtlas>,
216 rem_size: Pixels,
217 viewport_size: Size<Pixels>,
218 pub(crate) layout_engine: TaffyLayoutEngine,
219 pub(crate) root_view: Option<AnyView>,
220 pub(crate) element_id_stack: GlobalElementId,
221 pub(crate) previous_frame: Frame,
222 pub(crate) current_frame: Frame,
223 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
224 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
225 default_prevented: bool,
226 mouse_position: Point<Pixels>,
227 requested_cursor_style: Option<CursorStyle>,
228 scale_factor: f32,
229 bounds: WindowBounds,
230 bounds_observers: SubscriberSet<(), AnyObserver>,
231 active: bool,
232 activation_observers: SubscriberSet<(), AnyObserver>,
233 pub(crate) dirty: bool,
234 pub(crate) last_blur: Option<Option<FocusId>>,
235 pub(crate) focus: Option<FocusId>,
236}
237
238// #[derive(Default)]
239pub(crate) struct Frame {
240 pub(crate) element_states: HashMap<GlobalElementId, AnyBox>,
241 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
242 pub(crate) dispatch_tree: DispatchTree,
243 pub(crate) focus_listeners: Vec<AnyFocusListener>,
244 pub(crate) scene_builder: SceneBuilder,
245 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 content_mask_stack: Vec::new(),
260 element_offset_stack: Vec::new(),
261 }
262 }
263}
264
265impl Window {
266 pub(crate) fn new(
267 handle: AnyWindowHandle,
268 options: WindowOptions,
269 cx: &mut AppContext,
270 ) -> Self {
271 let platform_window = cx.platform.open_window(handle, options);
272 let display_id = platform_window.display().id();
273 let sprite_atlas = platform_window.sprite_atlas();
274 let mouse_position = platform_window.mouse_position();
275 let content_size = platform_window.content_size();
276 let scale_factor = platform_window.scale_factor();
277 let bounds = platform_window.bounds();
278
279 platform_window.on_resize(Box::new({
280 let mut cx = cx.to_async();
281 move |_, _| {
282 handle
283 .update(&mut cx, |_, cx| cx.window_bounds_changed())
284 .log_err();
285 }
286 }));
287 platform_window.on_moved(Box::new({
288 let mut cx = cx.to_async();
289 move || {
290 handle
291 .update(&mut cx, |_, cx| cx.window_bounds_changed())
292 .log_err();
293 }
294 }));
295 platform_window.on_active_status_change(Box::new({
296 let mut cx = cx.to_async();
297 move |active| {
298 handle
299 .update(&mut cx, |_, cx| {
300 cx.window.active = active;
301 cx.window
302 .activation_observers
303 .clone()
304 .retain(&(), |callback| callback(cx));
305 })
306 .log_err();
307 }
308 }));
309
310 platform_window.on_input({
311 let mut cx = cx.to_async();
312 Box::new(move |event| {
313 handle
314 .update(&mut cx, |_, cx| cx.dispatch_event(event))
315 .log_err()
316 .unwrap_or(false)
317 })
318 });
319
320 Window {
321 handle,
322 removed: false,
323 platform_window,
324 display_id,
325 sprite_atlas,
326 rem_size: px(16.),
327 viewport_size: content_size,
328 layout_engine: TaffyLayoutEngine::new(),
329 root_view: None,
330 element_id_stack: GlobalElementId::default(),
331 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
332 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
333 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
334 focus_listeners: SubscriberSet::new(),
335 default_prevented: true,
336 mouse_position,
337 requested_cursor_style: None,
338 scale_factor,
339 bounds,
340 bounds_observers: SubscriberSet::new(),
341 active: false,
342 activation_observers: SubscriberSet::new(),
343 dirty: true,
344 last_blur: None,
345 focus: None,
346 }
347 }
348}
349
350/// Indicates which region of the window is visible. Content falling outside of this mask will not be
351/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
352/// to leave room to support more complex shapes in the future.
353#[derive(Clone, Debug, Default, PartialEq, Eq)]
354#[repr(C)]
355pub struct ContentMask<P: Clone + Default + Debug> {
356 pub bounds: Bounds<P>,
357}
358
359impl ContentMask<Pixels> {
360 /// Scale the content mask's pixel units by the given scaling factor.
361 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
362 ContentMask {
363 bounds: self.bounds.scale(factor),
364 }
365 }
366
367 /// Intersect the content mask with the given content mask.
368 pub fn intersect(&self, other: &Self) -> Self {
369 let bounds = self.bounds.intersect(&other.bounds);
370 ContentMask { bounds }
371 }
372}
373
374/// Provides access to application state in the context of a single window. Derefs
375/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
376/// an `AppContext` and call any `AppContext` methods.
377pub struct WindowContext<'a> {
378 pub(crate) app: &'a mut AppContext,
379 pub(crate) window: &'a mut Window,
380}
381
382impl<'a> WindowContext<'a> {
383 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
384 Self { app, window }
385 }
386
387 /// Obtain a handle to the window that belongs to this context.
388 pub fn window_handle(&self) -> AnyWindowHandle {
389 self.window.handle
390 }
391
392 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
393 pub fn notify(&mut self) {
394 self.window.dirty = true;
395 }
396
397 /// Close this window.
398 pub fn remove_window(&mut self) {
399 self.window.removed = true;
400 }
401
402 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
403 /// for elements rendered within this window.
404 pub fn focus_handle(&mut self) -> FocusHandle {
405 FocusHandle::new(&self.window.focus_handles)
406 }
407
408 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
409 pub fn focused(&self) -> Option<FocusHandle> {
410 self.window
411 .focus
412 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
413 }
414
415 /// Move focus to the element associated with the given `FocusHandle`.
416 pub fn focus(&mut self, handle: &FocusHandle) {
417 if self.window.focus == Some(handle.id) {
418 return;
419 }
420
421 let focus_id = handle.id;
422
423 if self.window.last_blur.is_none() {
424 self.window.last_blur = Some(self.window.focus);
425 }
426
427 self.window.focus = Some(focus_id);
428 self.window
429 .current_frame
430 .dispatch_tree
431 .clear_keystroke_matchers();
432 self.app.push_effect(Effect::FocusChanged {
433 window_handle: self.window.handle,
434 focused: Some(focus_id),
435 });
436 self.notify();
437 }
438
439 /// Remove focus from all elements within this context's window.
440 pub fn blur(&mut self) {
441 if self.window.last_blur.is_none() {
442 self.window.last_blur = Some(self.window.focus);
443 }
444
445 self.window.focus = None;
446 self.app.push_effect(Effect::FocusChanged {
447 window_handle: self.window.handle,
448 focused: None,
449 });
450 self.notify();
451 }
452
453 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
454 if let Some(focus_handle) = self.focused() {
455 self.defer(move |cx| {
456 if let Some(node_id) = cx
457 .window
458 .current_frame
459 .dispatch_tree
460 .focusable_node_id(focus_handle.id)
461 {
462 cx.propagate_event = true;
463 cx.dispatch_action_on_node(node_id, action);
464 }
465 })
466 }
467 }
468
469 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
470 /// that are currently on the stack to be returned to the app.
471 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
472 let handle = self.window.handle;
473 self.app.defer(move |cx| {
474 handle.update(cx, |_, cx| f(cx)).ok();
475 });
476 }
477
478 pub fn subscribe<Emitter, E, Evt>(
479 &mut self,
480 entity: &E,
481 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
482 ) -> Subscription
483 where
484 Emitter: EventEmitter<Evt>,
485 E: Entity<Emitter>,
486 Evt: 'static,
487 {
488 let entity_id = entity.entity_id();
489 let entity = entity.downgrade();
490 let window_handle = self.window.handle;
491 self.app.event_listeners.insert(
492 entity_id,
493 (
494 TypeId::of::<Evt>(),
495 Box::new(move |event, cx| {
496 window_handle
497 .update(cx, |_, cx| {
498 if let Some(handle) = E::upgrade_from(&entity) {
499 let event = event.downcast_ref().expect("invalid event type");
500 on_event(handle, event, cx);
501 true
502 } else {
503 false
504 }
505 })
506 .unwrap_or(false)
507 }),
508 ),
509 )
510 }
511
512 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
513 /// await points in async code.
514 pub fn to_async(&self) -> AsyncWindowContext {
515 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
516 }
517
518 /// Schedule the given closure to be run directly after the current frame is rendered.
519 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
520 let handle = self.window.handle;
521 let display_id = self.window.display_id;
522
523 if !self.frame_consumers.contains_key(&display_id) {
524 let (tx, mut rx) = mpsc::unbounded::<()>();
525 self.platform.set_display_link_output_callback(
526 display_id,
527 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
528 );
529
530 let consumer_task = self.app.spawn(|cx| async move {
531 while rx.next().await.is_some() {
532 cx.update(|cx| {
533 for callback in cx
534 .next_frame_callbacks
535 .get_mut(&display_id)
536 .unwrap()
537 .drain(..)
538 .collect::<SmallVec<[_; 32]>>()
539 {
540 callback(cx);
541 }
542 })
543 .ok();
544
545 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
546
547 cx.update(|cx| {
548 if cx.next_frame_callbacks.is_empty() {
549 cx.platform.stop_display_link(display_id);
550 }
551 })
552 .ok();
553 }
554 });
555 self.frame_consumers.insert(display_id, consumer_task);
556 }
557
558 if self.next_frame_callbacks.is_empty() {
559 self.platform.start_display_link(display_id);
560 }
561
562 self.next_frame_callbacks
563 .entry(display_id)
564 .or_default()
565 .push(Box::new(move |cx: &mut AppContext| {
566 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
567 }));
568 }
569
570 /// Spawn the future returned by the given closure on the application thread pool.
571 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
572 /// use within your future.
573 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
574 where
575 R: 'static,
576 Fut: Future<Output = R> + 'static,
577 {
578 self.app
579 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
580 }
581
582 /// Update the global of the given type. The given closure is given simultaneous mutable
583 /// access both to the global and the context.
584 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
585 where
586 G: 'static,
587 {
588 let mut global = self.app.lease_global::<G>();
589 let result = f(&mut global, self);
590 self.app.end_global_lease(global);
591 result
592 }
593
594 #[must_use]
595 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
596 /// layout is being requested, along with the layout ids of any children. This method is called during
597 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
598 pub fn request_layout(
599 &mut self,
600 style: &Style,
601 children: impl IntoIterator<Item = LayoutId>,
602 ) -> LayoutId {
603 self.app.layout_id_buffer.clear();
604 self.app.layout_id_buffer.extend(children.into_iter());
605 let rem_size = self.rem_size();
606
607 self.window
608 .layout_engine
609 .request_layout(style, rem_size, &self.app.layout_id_buffer)
610 }
611
612 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
613 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
614 /// determine the element's size. One place this is used internally is when measuring text.
615 ///
616 /// The given closure is invoked at layout time with the known dimensions and available space and
617 /// returns a `Size`.
618 pub fn request_measured_layout<
619 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
620 >(
621 &mut self,
622 style: Style,
623 rem_size: Pixels,
624 measure: F,
625 ) -> LayoutId {
626 self.window
627 .layout_engine
628 .request_measured_layout(style, rem_size, measure)
629 }
630
631 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
632 self.window
633 .layout_engine
634 .compute_layout(layout_id, available_space)
635 }
636
637 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
638 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
639 /// in order to pass your element its `Bounds` automatically.
640 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
641 let mut bounds = self
642 .window
643 .layout_engine
644 .layout_bounds(layout_id)
645 .map(Into::into);
646 bounds.origin += self.element_offset();
647 bounds
648 }
649
650 fn window_bounds_changed(&mut self) {
651 self.window.scale_factor = self.window.platform_window.scale_factor();
652 self.window.viewport_size = self.window.platform_window.content_size();
653 self.window.bounds = self.window.platform_window.bounds();
654 self.window.display_id = self.window.platform_window.display().id();
655 self.window.dirty = true;
656
657 self.window
658 .bounds_observers
659 .clone()
660 .retain(&(), |callback| callback(self));
661 }
662
663 pub fn window_bounds(&self) -> WindowBounds {
664 self.window.bounds
665 }
666
667 pub fn viewport_size(&self) -> Size<Pixels> {
668 self.window.viewport_size
669 }
670
671 pub fn is_window_active(&self) -> bool {
672 self.window.active
673 }
674
675 pub fn zoom_window(&self) {
676 self.window.platform_window.zoom();
677 }
678
679 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
680 self.platform
681 .displays()
682 .into_iter()
683 .find(|display| display.id() == self.window.display_id)
684 }
685
686 pub fn show_character_palette(&self) {
687 self.window.platform_window.show_character_palette();
688 }
689
690 /// The scale factor of the display associated with the window. For example, it could
691 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
692 /// be rendered as two pixels on screen.
693 pub fn scale_factor(&self) -> f32 {
694 self.window.scale_factor
695 }
696
697 /// The size of an em for the base font of the application. Adjusting this value allows the
698 /// UI to scale, just like zooming a web page.
699 pub fn rem_size(&self) -> Pixels {
700 self.window.rem_size
701 }
702
703 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
704 /// UI to scale, just like zooming a web page.
705 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
706 self.window.rem_size = rem_size.into();
707 }
708
709 /// The line height associated with the current text style.
710 pub fn line_height(&self) -> Pixels {
711 let rem_size = self.rem_size();
712 let text_style = self.text_style();
713 text_style
714 .line_height
715 .to_pixels(text_style.font_size.into(), rem_size)
716 }
717
718 /// Call to prevent the default action of an event. Currently only used to prevent
719 /// parent elements from becoming focused on mouse down.
720 pub fn prevent_default(&mut self) {
721 self.window.default_prevented = true;
722 }
723
724 /// Obtain whether default has been prevented for the event currently being dispatched.
725 pub fn default_prevented(&self) -> bool {
726 self.window.default_prevented
727 }
728
729 /// Register a mouse event listener on the window for the current frame. The type of event
730 /// is determined by the first parameter of the given listener. When the next frame is rendered
731 /// the listener will be cleared.
732 ///
733 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
734 /// a specific need to register a global listener.
735 pub fn on_mouse_event<Event: 'static>(
736 &mut self,
737 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
738 ) {
739 let order = self.window.current_frame.z_index_stack.clone();
740 self.window
741 .current_frame
742 .mouse_listeners
743 .entry(TypeId::of::<Event>())
744 .or_default()
745 .push((
746 order,
747 Box::new(move |event: &dyn Any, phase, cx| {
748 handler(event.downcast_ref().unwrap(), phase, cx)
749 }),
750 ))
751 }
752
753 /// Register a key event listener on the window for the current frame. The type of event
754 /// is determined by the first parameter of the given listener. When the next frame is rendered
755 /// the listener will be cleared.
756 ///
757 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
758 /// a specific need to register a global listener.
759 pub fn on_key_event<Event: 'static>(
760 &mut self,
761 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
762 ) {
763 self.window
764 .current_frame
765 .dispatch_tree
766 .on_key_event(Rc::new(move |event, phase, cx| {
767 if let Some(event) = event.downcast_ref::<Event>() {
768 handler(event, phase, cx)
769 }
770 }));
771 }
772
773 /// Register an action listener on the window for the current frame. The type of action
774 /// is determined by the first parameter of the given listener. When the next frame is rendered
775 /// the listener will be cleared.
776 ///
777 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
778 /// a specific need to register a global listener.
779 pub fn on_action(
780 &mut self,
781 action_type: TypeId,
782 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
783 ) {
784 self.window.current_frame.dispatch_tree.on_action(
785 action_type,
786 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
787 );
788 }
789
790 /// The position of the mouse relative to the window.
791 pub fn mouse_position(&self) -> Point<Pixels> {
792 self.window.mouse_position
793 }
794
795 pub fn set_cursor_style(&mut self, style: CursorStyle) {
796 self.window.requested_cursor_style = Some(style)
797 }
798
799 /// Called during painting to invoke the given closure in a new stacking context. The given
800 /// z-index is interpreted relative to the previous call to `stack`.
801 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
802 self.window.current_frame.z_index_stack.push(z_index);
803 let result = f(self);
804 self.window.current_frame.z_index_stack.pop();
805 result
806 }
807
808 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
809 pub fn paint_shadows(
810 &mut self,
811 bounds: Bounds<Pixels>,
812 corner_radii: Corners<Pixels>,
813 shadows: &[BoxShadow],
814 ) {
815 let scale_factor = self.scale_factor();
816 let content_mask = self.content_mask();
817 let window = &mut *self.window;
818 for shadow in shadows {
819 let mut shadow_bounds = bounds;
820 shadow_bounds.origin += shadow.offset;
821 shadow_bounds.dilate(shadow.spread_radius);
822 window.current_frame.scene_builder.insert(
823 &window.current_frame.z_index_stack,
824 Shadow {
825 order: 0,
826 bounds: shadow_bounds.scale(scale_factor),
827 content_mask: content_mask.scale(scale_factor),
828 corner_radii: corner_radii.scale(scale_factor),
829 color: shadow.color,
830 blur_radius: shadow.blur_radius.scale(scale_factor),
831 },
832 );
833 }
834 }
835
836 /// Paint one or more quads into the scene for the current frame at the current stacking context.
837 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
838 pub fn paint_quad(
839 &mut self,
840 bounds: Bounds<Pixels>,
841 corner_radii: Corners<Pixels>,
842 background: impl Into<Hsla>,
843 border_widths: Edges<Pixels>,
844 border_color: impl Into<Hsla>,
845 ) {
846 let scale_factor = self.scale_factor();
847 let content_mask = self.content_mask();
848
849 let window = &mut *self.window;
850 window.current_frame.scene_builder.insert(
851 &window.current_frame.z_index_stack,
852 Quad {
853 order: 0,
854 bounds: bounds.scale(scale_factor),
855 content_mask: content_mask.scale(scale_factor),
856 background: background.into(),
857 border_color: border_color.into(),
858 corner_radii: corner_radii.scale(scale_factor),
859 border_widths: border_widths.scale(scale_factor),
860 },
861 );
862 }
863
864 /// Paint the given `Path` into the scene for the current frame at the current z-index.
865 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
866 let scale_factor = self.scale_factor();
867 let content_mask = self.content_mask();
868 path.content_mask = content_mask;
869 path.color = color.into();
870 let window = &mut *self.window;
871 window.current_frame.scene_builder.insert(
872 &window.current_frame.z_index_stack,
873 path.scale(scale_factor),
874 );
875 }
876
877 /// Paint an underline into the scene for the current frame at the current z-index.
878 pub fn paint_underline(
879 &mut self,
880 origin: Point<Pixels>,
881 width: Pixels,
882 style: &UnderlineStyle,
883 ) -> Result<()> {
884 let scale_factor = self.scale_factor();
885 let height = if style.wavy {
886 style.thickness * 3.
887 } else {
888 style.thickness
889 };
890 let bounds = Bounds {
891 origin,
892 size: size(width, height),
893 };
894 let content_mask = self.content_mask();
895 let window = &mut *self.window;
896 window.current_frame.scene_builder.insert(
897 &window.current_frame.z_index_stack,
898 Underline {
899 order: 0,
900 bounds: bounds.scale(scale_factor),
901 content_mask: content_mask.scale(scale_factor),
902 thickness: style.thickness.scale(scale_factor),
903 color: style.color.unwrap_or_default(),
904 wavy: style.wavy,
905 },
906 );
907 Ok(())
908 }
909
910 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
911 /// The y component of the origin is the baseline of the glyph.
912 pub fn paint_glyph(
913 &mut self,
914 origin: Point<Pixels>,
915 font_id: FontId,
916 glyph_id: GlyphId,
917 font_size: Pixels,
918 color: Hsla,
919 ) -> Result<()> {
920 let scale_factor = self.scale_factor();
921 let glyph_origin = origin.scale(scale_factor);
922 let subpixel_variant = Point {
923 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
924 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
925 };
926 let params = RenderGlyphParams {
927 font_id,
928 glyph_id,
929 font_size,
930 subpixel_variant,
931 scale_factor,
932 is_emoji: false,
933 };
934
935 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
936 if !raster_bounds.is_zero() {
937 let tile =
938 self.window
939 .sprite_atlas
940 .get_or_insert_with(¶ms.clone().into(), &mut || {
941 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
942 Ok((size, Cow::Owned(bytes)))
943 })?;
944 let bounds = Bounds {
945 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
946 size: tile.bounds.size.map(Into::into),
947 };
948 let content_mask = self.content_mask().scale(scale_factor);
949 let window = &mut *self.window;
950 window.current_frame.scene_builder.insert(
951 &window.current_frame.z_index_stack,
952 MonochromeSprite {
953 order: 0,
954 bounds,
955 content_mask,
956 color,
957 tile,
958 },
959 );
960 }
961 Ok(())
962 }
963
964 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
965 /// The y component of the origin is the baseline of the glyph.
966 pub fn paint_emoji(
967 &mut self,
968 origin: Point<Pixels>,
969 font_id: FontId,
970 glyph_id: GlyphId,
971 font_size: Pixels,
972 ) -> Result<()> {
973 let scale_factor = self.scale_factor();
974 let glyph_origin = origin.scale(scale_factor);
975 let params = RenderGlyphParams {
976 font_id,
977 glyph_id,
978 font_size,
979 // We don't render emojis with subpixel variants.
980 subpixel_variant: Default::default(),
981 scale_factor,
982 is_emoji: true,
983 };
984
985 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
986 if !raster_bounds.is_zero() {
987 let tile =
988 self.window
989 .sprite_atlas
990 .get_or_insert_with(¶ms.clone().into(), &mut || {
991 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
992 Ok((size, Cow::Owned(bytes)))
993 })?;
994 let bounds = Bounds {
995 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
996 size: tile.bounds.size.map(Into::into),
997 };
998 let content_mask = self.content_mask().scale(scale_factor);
999 let window = &mut *self.window;
1000
1001 window.current_frame.scene_builder.insert(
1002 &window.current_frame.z_index_stack,
1003 PolychromeSprite {
1004 order: 0,
1005 bounds,
1006 corner_radii: Default::default(),
1007 content_mask,
1008 tile,
1009 grayscale: false,
1010 },
1011 );
1012 }
1013 Ok(())
1014 }
1015
1016 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1017 pub fn paint_svg(
1018 &mut self,
1019 bounds: Bounds<Pixels>,
1020 path: SharedString,
1021 color: Hsla,
1022 ) -> Result<()> {
1023 let scale_factor = self.scale_factor();
1024 let bounds = bounds.scale(scale_factor);
1025 // Render the SVG at twice the size to get a higher quality result.
1026 let params = RenderSvgParams {
1027 path,
1028 size: bounds
1029 .size
1030 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1031 };
1032
1033 let tile =
1034 self.window
1035 .sprite_atlas
1036 .get_or_insert_with(¶ms.clone().into(), &mut || {
1037 let bytes = self.svg_renderer.render(¶ms)?;
1038 Ok((params.size, Cow::Owned(bytes)))
1039 })?;
1040 let content_mask = self.content_mask().scale(scale_factor);
1041
1042 let window = &mut *self.window;
1043 window.current_frame.scene_builder.insert(
1044 &window.current_frame.z_index_stack,
1045 MonochromeSprite {
1046 order: 0,
1047 bounds,
1048 content_mask,
1049 color,
1050 tile,
1051 },
1052 );
1053
1054 Ok(())
1055 }
1056
1057 /// Paint an image into the scene for the current frame at the current z-index.
1058 pub fn paint_image(
1059 &mut self,
1060 bounds: Bounds<Pixels>,
1061 corner_radii: Corners<Pixels>,
1062 data: Arc<ImageData>,
1063 grayscale: bool,
1064 ) -> Result<()> {
1065 let scale_factor = self.scale_factor();
1066 let bounds = bounds.scale(scale_factor);
1067 let params = RenderImageParams { image_id: data.id };
1068
1069 let tile = self
1070 .window
1071 .sprite_atlas
1072 .get_or_insert_with(¶ms.clone().into(), &mut || {
1073 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1074 })?;
1075 let content_mask = self.content_mask().scale(scale_factor);
1076 let corner_radii = corner_radii.scale(scale_factor);
1077
1078 let window = &mut *self.window;
1079 window.current_frame.scene_builder.insert(
1080 &window.current_frame.z_index_stack,
1081 PolychromeSprite {
1082 order: 0,
1083 bounds,
1084 content_mask,
1085 corner_radii,
1086 tile,
1087 grayscale,
1088 },
1089 );
1090 Ok(())
1091 }
1092
1093 /// Draw pixels to the display for this window based on the contents of its scene.
1094 pub(crate) fn draw(&mut self) {
1095 let root_view = self.window.root_view.take().unwrap();
1096
1097 self.start_frame();
1098
1099 self.with_z_index(0, |cx| {
1100 let available_space = cx.window.viewport_size.map(Into::into);
1101 root_view.draw(Point::zero(), available_space, cx);
1102 });
1103
1104 if let Some(active_drag) = self.app.active_drag.take() {
1105 self.with_z_index(1, |cx| {
1106 let offset = cx.mouse_position() - active_drag.cursor_offset;
1107 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1108 active_drag.view.draw(offset, available_space, cx);
1109 cx.active_drag = Some(active_drag);
1110 });
1111 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1112 self.with_z_index(1, |cx| {
1113 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1114 active_tooltip
1115 .view
1116 .draw(active_tooltip.cursor_offset, available_space, cx);
1117 });
1118 }
1119
1120 self.window
1121 .current_frame
1122 .dispatch_tree
1123 .preserve_keystroke_matchers(
1124 &mut self.window.previous_frame.dispatch_tree,
1125 self.window.focus,
1126 );
1127
1128 self.window.root_view = Some(root_view);
1129 let scene = self.window.current_frame.scene_builder.build();
1130
1131 self.window.platform_window.draw(scene);
1132 let cursor_style = self
1133 .window
1134 .requested_cursor_style
1135 .take()
1136 .unwrap_or(CursorStyle::Arrow);
1137 self.platform.set_cursor_style(cursor_style);
1138
1139 self.window.dirty = false;
1140 }
1141
1142 /// Rotate the current frame and the previous frame, then clear the current frame.
1143 /// We repopulate all state in the current frame during each paint.
1144 fn start_frame(&mut self) {
1145 self.text_system().start_frame();
1146
1147 let window = &mut *self.window;
1148 window.layout_engine.clear();
1149
1150 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1151 let frame = &mut window.current_frame;
1152 frame.element_states.clear();
1153 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1154 frame.focus_listeners.clear();
1155 frame.dispatch_tree.clear();
1156 }
1157
1158 /// Dispatch a mouse or keyboard event on the window.
1159 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1160 // Handlers may set this to false by calling `stop_propagation`
1161 self.app.propagate_event = true;
1162 self.window.default_prevented = false;
1163
1164 let event = match event {
1165 // Track the mouse position with our own state, since accessing the platform
1166 // API for the mouse position can only occur on the main thread.
1167 InputEvent::MouseMove(mouse_move) => {
1168 self.window.mouse_position = mouse_move.position;
1169 InputEvent::MouseMove(mouse_move)
1170 }
1171 InputEvent::MouseDown(mouse_down) => {
1172 self.window.mouse_position = mouse_down.position;
1173 InputEvent::MouseDown(mouse_down)
1174 }
1175 InputEvent::MouseUp(mouse_up) => {
1176 self.window.mouse_position = mouse_up.position;
1177 InputEvent::MouseUp(mouse_up)
1178 }
1179 // Translate dragging and dropping of external files from the operating system
1180 // to internal drag and drop events.
1181 InputEvent::FileDrop(file_drop) => match file_drop {
1182 FileDropEvent::Entered { position, files } => {
1183 self.window.mouse_position = position;
1184 if self.active_drag.is_none() {
1185 self.active_drag = Some(AnyDrag {
1186 view: self.build_view(|_| files).into(),
1187 cursor_offset: position,
1188 });
1189 }
1190 InputEvent::MouseDown(MouseDownEvent {
1191 position,
1192 button: MouseButton::Left,
1193 click_count: 1,
1194 modifiers: Modifiers::default(),
1195 })
1196 }
1197 FileDropEvent::Pending { position } => {
1198 self.window.mouse_position = position;
1199 InputEvent::MouseMove(MouseMoveEvent {
1200 position,
1201 pressed_button: Some(MouseButton::Left),
1202 modifiers: Modifiers::default(),
1203 })
1204 }
1205 FileDropEvent::Submit { position } => {
1206 self.window.mouse_position = position;
1207 InputEvent::MouseUp(MouseUpEvent {
1208 button: MouseButton::Left,
1209 position,
1210 modifiers: Modifiers::default(),
1211 click_count: 1,
1212 })
1213 }
1214 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1215 button: MouseButton::Left,
1216 position: Point::default(),
1217 modifiers: Modifiers::default(),
1218 click_count: 1,
1219 }),
1220 },
1221 _ => event,
1222 };
1223
1224 if let Some(any_mouse_event) = event.mouse_event() {
1225 self.dispatch_mouse_event(any_mouse_event);
1226 } else if let Some(any_key_event) = event.keyboard_event() {
1227 self.dispatch_key_event(any_key_event);
1228 }
1229
1230 !self.app.propagate_event
1231 }
1232
1233 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1234 if let Some(mut handlers) = self
1235 .window
1236 .current_frame
1237 .mouse_listeners
1238 .remove(&event.type_id())
1239 {
1240 // Because handlers may add other handlers, we sort every time.
1241 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1242
1243 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1244 // special purposes, such as detecting events outside of a given Bounds.
1245 for (_, handler) in &mut handlers {
1246 handler(event, DispatchPhase::Capture, self);
1247 if !self.app.propagate_event {
1248 break;
1249 }
1250 }
1251
1252 // Bubble phase, where most normal handlers do their work.
1253 if self.app.propagate_event {
1254 for (_, handler) in handlers.iter_mut().rev() {
1255 handler(event, DispatchPhase::Bubble, self);
1256 if !self.app.propagate_event {
1257 break;
1258 }
1259 }
1260 }
1261
1262 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1263 self.active_drag = None;
1264 }
1265
1266 // Just in case any handlers added new handlers, which is weird, but possible.
1267 handlers.extend(
1268 self.window
1269 .current_frame
1270 .mouse_listeners
1271 .get_mut(&event.type_id())
1272 .into_iter()
1273 .flat_map(|handlers| handlers.drain(..)),
1274 );
1275 self.window
1276 .current_frame
1277 .mouse_listeners
1278 .insert(event.type_id(), handlers);
1279 }
1280 }
1281
1282 fn dispatch_key_event(&mut self, event: &dyn Any) {
1283 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1284 self.window
1285 .current_frame
1286 .dispatch_tree
1287 .focusable_node_id(focus_id)
1288 }) {
1289 let dispatch_path = self
1290 .window
1291 .current_frame
1292 .dispatch_tree
1293 .dispatch_path(node_id);
1294
1295 // Capture phase
1296 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1297 self.propagate_event = true;
1298
1299 for node_id in &dispatch_path {
1300 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1301
1302 if !node.context.is_empty() {
1303 context_stack.push(node.context.clone());
1304 }
1305
1306 for key_listener in node.key_listeners.clone() {
1307 key_listener(event, DispatchPhase::Capture, self);
1308 if !self.propagate_event {
1309 return;
1310 }
1311 }
1312 }
1313
1314 // Bubble phase
1315 for node_id in dispatch_path.iter().rev() {
1316 // Handle low level key events
1317 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1318 for key_listener in node.key_listeners.clone() {
1319 key_listener(event, DispatchPhase::Bubble, self);
1320 if !self.propagate_event {
1321 return;
1322 }
1323 }
1324
1325 // Match keystrokes
1326 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1327 if !node.context.is_empty() {
1328 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1329 if let Some(action) = self
1330 .window
1331 .current_frame
1332 .dispatch_tree
1333 .dispatch_key(&key_down_event.keystroke, &context_stack)
1334 {
1335 self.dispatch_action_on_node(*node_id, action);
1336 if !self.propagate_event {
1337 return;
1338 }
1339 }
1340 }
1341
1342 context_stack.pop();
1343 }
1344 }
1345 }
1346 }
1347
1348 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1349 let dispatch_path = self
1350 .window
1351 .current_frame
1352 .dispatch_tree
1353 .dispatch_path(node_id);
1354
1355 // Capture phase
1356 for node_id in &dispatch_path {
1357 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1358 for DispatchActionListener {
1359 action_type,
1360 listener,
1361 } in node.action_listeners.clone()
1362 {
1363 let any_action = action.as_any();
1364 if action_type == any_action.type_id() {
1365 listener(any_action, DispatchPhase::Capture, self);
1366 if !self.propagate_event {
1367 return;
1368 }
1369 }
1370 }
1371 }
1372
1373 // Bubble phase
1374 for node_id in dispatch_path.iter().rev() {
1375 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1376 for DispatchActionListener {
1377 action_type,
1378 listener,
1379 } in node.action_listeners.clone()
1380 {
1381 let any_action = action.as_any();
1382 if action_type == any_action.type_id() {
1383 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1384 listener(any_action, DispatchPhase::Bubble, self);
1385 if !self.propagate_event {
1386 return;
1387 }
1388 }
1389 }
1390 }
1391 }
1392
1393 /// Register the given handler to be invoked whenever the global of the given type
1394 /// is updated.
1395 pub fn observe_global<G: 'static>(
1396 &mut self,
1397 f: impl Fn(&mut WindowContext<'_>) + 'static,
1398 ) -> Subscription {
1399 let window_handle = self.window.handle;
1400 self.global_observers.insert(
1401 TypeId::of::<G>(),
1402 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1403 )
1404 }
1405
1406 pub fn activate_window(&self) {
1407 self.window.platform_window.activate();
1408 }
1409
1410 pub fn minimize_window(&self) {
1411 self.window.platform_window.minimize();
1412 }
1413
1414 pub fn toggle_full_screen(&self) {
1415 self.window.platform_window.toggle_full_screen();
1416 }
1417
1418 pub fn prompt(
1419 &self,
1420 level: PromptLevel,
1421 msg: &str,
1422 answers: &[&str],
1423 ) -> oneshot::Receiver<usize> {
1424 self.window.platform_window.prompt(level, msg, answers)
1425 }
1426
1427 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1428 if let Some(focus_id) = self.window.focus {
1429 self.window
1430 .current_frame
1431 .dispatch_tree
1432 .available_actions(focus_id)
1433 } else {
1434 Vec::new()
1435 }
1436 }
1437
1438 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1439 self.window
1440 .current_frame
1441 .dispatch_tree
1442 .bindings_for_action(action)
1443 }
1444}
1445
1446impl Context for WindowContext<'_> {
1447 type Result<T> = T;
1448
1449 fn build_model<T>(
1450 &mut self,
1451 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1452 ) -> Model<T>
1453 where
1454 T: 'static,
1455 {
1456 let slot = self.app.entities.reserve();
1457 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1458 self.entities.insert(slot, model)
1459 }
1460
1461 fn update_model<T: 'static, R>(
1462 &mut self,
1463 model: &Model<T>,
1464 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1465 ) -> R {
1466 let mut entity = self.entities.lease(model);
1467 let result = update(
1468 &mut *entity,
1469 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1470 );
1471 self.entities.end_lease(entity);
1472 result
1473 }
1474
1475 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1476 where
1477 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1478 {
1479 if window == self.window.handle {
1480 let root_view = self.window.root_view.clone().unwrap();
1481 Ok(update(root_view, self))
1482 } else {
1483 window.update(self.app, update)
1484 }
1485 }
1486
1487 fn read_model<T, R>(
1488 &self,
1489 handle: &Model<T>,
1490 read: impl FnOnce(&T, &AppContext) -> R,
1491 ) -> Self::Result<R>
1492 where
1493 T: 'static,
1494 {
1495 let entity = self.entities.read(handle);
1496 read(&*entity, &*self.app)
1497 }
1498
1499 fn read_window<T, R>(
1500 &self,
1501 window: &WindowHandle<T>,
1502 read: impl FnOnce(View<T>, &AppContext) -> R,
1503 ) -> Result<R>
1504 where
1505 T: 'static,
1506 {
1507 if window.any_handle == self.window.handle {
1508 let root_view = self
1509 .window
1510 .root_view
1511 .clone()
1512 .unwrap()
1513 .downcast::<T>()
1514 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1515 Ok(read(root_view, self))
1516 } else {
1517 self.app.read_window(window, read)
1518 }
1519 }
1520}
1521
1522impl VisualContext for WindowContext<'_> {
1523 fn build_view<V>(
1524 &mut self,
1525 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1526 ) -> Self::Result<View<V>>
1527 where
1528 V: 'static + Render,
1529 {
1530 let slot = self.app.entities.reserve();
1531 let view = View {
1532 model: slot.clone(),
1533 };
1534 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1535 let entity = build_view_state(&mut cx);
1536 cx.entities.insert(slot, entity);
1537
1538 cx.new_view_observers
1539 .clone()
1540 .retain(&TypeId::of::<V>(), |observer| {
1541 let any_view = AnyView::from(view.clone());
1542 (observer)(any_view, self);
1543 true
1544 });
1545
1546 view
1547 }
1548
1549 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1550 fn update_view<T: 'static, R>(
1551 &mut self,
1552 view: &View<T>,
1553 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1554 ) -> Self::Result<R> {
1555 let mut lease = self.app.entities.lease(&view.model);
1556 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1557 let result = update(&mut *lease, &mut cx);
1558 cx.app.entities.end_lease(lease);
1559 result
1560 }
1561
1562 fn replace_root_view<V>(
1563 &mut self,
1564 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1565 ) -> Self::Result<View<V>>
1566 where
1567 V: Render,
1568 {
1569 let slot = self.app.entities.reserve();
1570 let view = View {
1571 model: slot.clone(),
1572 };
1573 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1574 let entity = build_view(&mut cx);
1575 self.entities.insert(slot, entity);
1576 self.window.root_view = Some(view.clone().into());
1577 view
1578 }
1579
1580 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1581 self.update_view(view, |view, cx| {
1582 view.focus_handle(cx).clone().focus(cx);
1583 })
1584 }
1585}
1586
1587impl<'a> std::ops::Deref for WindowContext<'a> {
1588 type Target = AppContext;
1589
1590 fn deref(&self) -> &Self::Target {
1591 &self.app
1592 }
1593}
1594
1595impl<'a> std::ops::DerefMut for WindowContext<'a> {
1596 fn deref_mut(&mut self) -> &mut Self::Target {
1597 &mut self.app
1598 }
1599}
1600
1601impl<'a> Borrow<AppContext> for WindowContext<'a> {
1602 fn borrow(&self) -> &AppContext {
1603 &self.app
1604 }
1605}
1606
1607impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1608 fn borrow_mut(&mut self) -> &mut AppContext {
1609 &mut self.app
1610 }
1611}
1612
1613pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1614 fn app_mut(&mut self) -> &mut AppContext {
1615 self.borrow_mut()
1616 }
1617
1618 fn window(&self) -> &Window {
1619 self.borrow()
1620 }
1621
1622 fn window_mut(&mut self) -> &mut Window {
1623 self.borrow_mut()
1624 }
1625
1626 /// Pushes the given element id onto the global stack and invokes the given closure
1627 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1628 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1629 /// used to associate state with identified elements across separate frames.
1630 fn with_element_id<R>(
1631 &mut self,
1632 id: Option<impl Into<ElementId>>,
1633 f: impl FnOnce(&mut Self) -> R,
1634 ) -> R {
1635 if let Some(id) = id.map(Into::into) {
1636 let window = self.window_mut();
1637 window.element_id_stack.push(id.into());
1638 let result = f(self);
1639 let window: &mut Window = self.borrow_mut();
1640 window.element_id_stack.pop();
1641 result
1642 } else {
1643 f(self)
1644 }
1645 }
1646
1647 /// Invoke the given function with the given content mask after intersecting it
1648 /// with the current mask.
1649 fn with_content_mask<R>(
1650 &mut self,
1651 mask: Option<ContentMask<Pixels>>,
1652 f: impl FnOnce(&mut Self) -> R,
1653 ) -> R {
1654 if let Some(mask) = mask {
1655 let mask = mask.intersect(&self.content_mask());
1656 self.window_mut()
1657 .current_frame
1658 .content_mask_stack
1659 .push(mask);
1660 let result = f(self);
1661 self.window_mut().current_frame.content_mask_stack.pop();
1662 result
1663 } else {
1664 f(self)
1665 }
1666 }
1667
1668 /// Update the global element offset relative to the current offset. This is used to implement
1669 /// scrolling.
1670 fn with_element_offset<R>(
1671 &mut self,
1672 offset: Point<Pixels>,
1673 f: impl FnOnce(&mut Self) -> R,
1674 ) -> R {
1675 if offset.is_zero() {
1676 return f(self);
1677 };
1678
1679 let abs_offset = self.element_offset() + offset;
1680 self.with_absolute_element_offset(abs_offset, f)
1681 }
1682
1683 /// Update the global element offset based on the given offset. This is used to implement
1684 /// drag handles and other manual painting of elements.
1685 fn with_absolute_element_offset<R>(
1686 &mut self,
1687 offset: Point<Pixels>,
1688 f: impl FnOnce(&mut Self) -> R,
1689 ) -> R {
1690 self.window_mut()
1691 .current_frame
1692 .element_offset_stack
1693 .push(offset);
1694 let result = f(self);
1695 self.window_mut().current_frame.element_offset_stack.pop();
1696 result
1697 }
1698
1699 /// Obtain the current element offset.
1700 fn element_offset(&self) -> Point<Pixels> {
1701 self.window()
1702 .current_frame
1703 .element_offset_stack
1704 .last()
1705 .copied()
1706 .unwrap_or_default()
1707 }
1708
1709 /// Update or intialize state for an element with the given id that lives across multiple
1710 /// frames. If an element with this id existed in the previous frame, its state will be passed
1711 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1712 /// when drawing the next frame.
1713 fn with_element_state<S, R>(
1714 &mut self,
1715 id: ElementId,
1716 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1717 ) -> R
1718 where
1719 S: 'static,
1720 {
1721 self.with_element_id(Some(id), |cx| {
1722 let global_id = cx.window().element_id_stack.clone();
1723
1724 if let Some(any) = cx
1725 .window_mut()
1726 .current_frame
1727 .element_states
1728 .remove(&global_id)
1729 .or_else(|| {
1730 cx.window_mut()
1731 .previous_frame
1732 .element_states
1733 .remove(&global_id)
1734 })
1735 {
1736 // Using the extra inner option to avoid needing to reallocate a new box.
1737 let mut state_box = any
1738 .downcast::<Option<S>>()
1739 .expect("invalid element state type for id");
1740 let state = state_box
1741 .take()
1742 .expect("element state is already on the stack");
1743 let (result, state) = f(Some(state), cx);
1744 state_box.replace(state);
1745 cx.window_mut()
1746 .current_frame
1747 .element_states
1748 .insert(global_id, state_box);
1749 result
1750 } else {
1751 let (result, state) = f(None, cx);
1752 cx.window_mut()
1753 .current_frame
1754 .element_states
1755 .insert(global_id, Box::new(Some(state)));
1756 result
1757 }
1758 })
1759 }
1760
1761 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1762 /// id is `None`, no state will be retrieved or stored.
1763 fn with_optional_element_state<S, R>(
1764 &mut self,
1765 element_id: Option<ElementId>,
1766 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1767 ) -> R
1768 where
1769 S: 'static,
1770 {
1771 if let Some(element_id) = element_id {
1772 self.with_element_state(element_id, f)
1773 } else {
1774 f(None, self).0
1775 }
1776 }
1777
1778 /// Obtain the current content mask.
1779 fn content_mask(&self) -> ContentMask<Pixels> {
1780 self.window()
1781 .current_frame
1782 .content_mask_stack
1783 .last()
1784 .cloned()
1785 .unwrap_or_else(|| ContentMask {
1786 bounds: Bounds {
1787 origin: Point::default(),
1788 size: self.window().viewport_size,
1789 },
1790 })
1791 }
1792
1793 /// The size of an em for the base font of the application. Adjusting this value allows the
1794 /// UI to scale, just like zooming a web page.
1795 fn rem_size(&self) -> Pixels {
1796 self.window().rem_size
1797 }
1798}
1799
1800impl Borrow<Window> for WindowContext<'_> {
1801 fn borrow(&self) -> &Window {
1802 &self.window
1803 }
1804}
1805
1806impl BorrowMut<Window> for WindowContext<'_> {
1807 fn borrow_mut(&mut self) -> &mut Window {
1808 &mut self.window
1809 }
1810}
1811
1812impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1813
1814pub struct ViewContext<'a, V> {
1815 window_cx: WindowContext<'a>,
1816 view: &'a View<V>,
1817}
1818
1819impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1820 fn borrow(&self) -> &AppContext {
1821 &*self.window_cx.app
1822 }
1823}
1824
1825impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1826 fn borrow_mut(&mut self) -> &mut AppContext {
1827 &mut *self.window_cx.app
1828 }
1829}
1830
1831impl<V> Borrow<Window> for ViewContext<'_, V> {
1832 fn borrow(&self) -> &Window {
1833 &*self.window_cx.window
1834 }
1835}
1836
1837impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1838 fn borrow_mut(&mut self) -> &mut Window {
1839 &mut *self.window_cx.window
1840 }
1841}
1842
1843impl<'a, V: 'static> ViewContext<'a, V> {
1844 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1845 Self {
1846 window_cx: WindowContext::new(app, window),
1847 view,
1848 }
1849 }
1850
1851 pub fn entity_id(&self) -> EntityId {
1852 self.view.entity_id()
1853 }
1854
1855 pub fn view(&self) -> &View<V> {
1856 self.view
1857 }
1858
1859 pub fn model(&self) -> &Model<V> {
1860 &self.view.model
1861 }
1862
1863 /// Access the underlying window context.
1864 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1865 &mut self.window_cx
1866 }
1867
1868 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1869 self.window.current_frame.z_index_stack.push(z_index);
1870 let result = f(self);
1871 self.window.current_frame.z_index_stack.pop();
1872 result
1873 }
1874
1875 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1876 where
1877 V: 'static,
1878 {
1879 let view = self.view().clone();
1880 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1881 }
1882
1883 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1884 /// that are currently on the stack to be returned to the app.
1885 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1886 let view = self.view().downgrade();
1887 self.window_cx.defer(move |cx| {
1888 view.update(cx, f).ok();
1889 });
1890 }
1891
1892 pub fn observe<V2, E>(
1893 &mut self,
1894 entity: &E,
1895 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1896 ) -> Subscription
1897 where
1898 V2: 'static,
1899 V: 'static,
1900 E: Entity<V2>,
1901 {
1902 let view = self.view().downgrade();
1903 let entity_id = entity.entity_id();
1904 let entity = entity.downgrade();
1905 let window_handle = self.window.handle;
1906 self.app.observers.insert(
1907 entity_id,
1908 Box::new(move |cx| {
1909 window_handle
1910 .update(cx, |_, cx| {
1911 if let Some(handle) = E::upgrade_from(&entity) {
1912 view.update(cx, |this, cx| on_notify(this, handle, cx))
1913 .is_ok()
1914 } else {
1915 false
1916 }
1917 })
1918 .unwrap_or(false)
1919 }),
1920 )
1921 }
1922
1923 pub fn subscribe<V2, E, Evt>(
1924 &mut self,
1925 entity: &E,
1926 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1927 ) -> Subscription
1928 where
1929 V2: EventEmitter<Evt>,
1930 E: Entity<V2>,
1931 Evt: 'static,
1932 {
1933 let view = self.view().downgrade();
1934 let entity_id = entity.entity_id();
1935 let handle = entity.downgrade();
1936 let window_handle = self.window.handle;
1937 self.app.event_listeners.insert(
1938 entity_id,
1939 (
1940 TypeId::of::<Evt>(),
1941 Box::new(move |event, cx| {
1942 window_handle
1943 .update(cx, |_, cx| {
1944 if let Some(handle) = E::upgrade_from(&handle) {
1945 let event = event.downcast_ref().expect("invalid event type");
1946 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1947 .is_ok()
1948 } else {
1949 false
1950 }
1951 })
1952 .unwrap_or(false)
1953 }),
1954 ),
1955 )
1956 }
1957
1958 pub fn on_release(
1959 &mut self,
1960 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
1961 ) -> Subscription {
1962 let window_handle = self.window.handle;
1963 self.app.release_listeners.insert(
1964 self.view.model.entity_id,
1965 Box::new(move |this, cx| {
1966 let this = this.downcast_mut().expect("invalid entity type");
1967 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
1968 }),
1969 )
1970 }
1971
1972 pub fn observe_release<V2, E>(
1973 &mut self,
1974 entity: &E,
1975 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1976 ) -> Subscription
1977 where
1978 V: 'static,
1979 V2: 'static,
1980 E: Entity<V2>,
1981 {
1982 let view = self.view().downgrade();
1983 let entity_id = entity.entity_id();
1984 let window_handle = self.window.handle;
1985 self.app.release_listeners.insert(
1986 entity_id,
1987 Box::new(move |entity, cx| {
1988 let entity = entity.downcast_mut().expect("invalid entity type");
1989 let _ = window_handle.update(cx, |_, cx| {
1990 view.update(cx, |this, cx| on_release(this, entity, cx))
1991 });
1992 }),
1993 )
1994 }
1995
1996 pub fn notify(&mut self) {
1997 self.window_cx.notify();
1998 self.window_cx.app.push_effect(Effect::Notify {
1999 emitter: self.view.model.entity_id,
2000 });
2001 }
2002
2003 pub fn observe_window_bounds(
2004 &mut self,
2005 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2006 ) -> Subscription {
2007 let view = self.view.downgrade();
2008 self.window.bounds_observers.insert(
2009 (),
2010 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2011 )
2012 }
2013
2014 pub fn observe_window_activation(
2015 &mut self,
2016 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2017 ) -> Subscription {
2018 let view = self.view.downgrade();
2019 self.window.activation_observers.insert(
2020 (),
2021 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2022 )
2023 }
2024
2025 /// Register a listener to be called when the given focus handle receives focus.
2026 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2027 /// is dropped.
2028 pub fn on_focus(
2029 &mut self,
2030 handle: &FocusHandle,
2031 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2032 ) -> Subscription {
2033 let view = self.view.downgrade();
2034 let focus_id = handle.id;
2035 self.window.focus_listeners.insert(
2036 (),
2037 Box::new(move |event, cx| {
2038 view.update(cx, |view, cx| {
2039 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2040 listener(view, cx)
2041 }
2042 })
2043 .is_ok()
2044 }),
2045 )
2046 }
2047
2048 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2049 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2050 /// is dropped.
2051 pub fn on_focus_in(
2052 &mut self,
2053 handle: &FocusHandle,
2054 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2055 ) -> Subscription {
2056 let view = self.view.downgrade();
2057 let focus_id = handle.id;
2058 self.window.focus_listeners.insert(
2059 (),
2060 Box::new(move |event, cx| {
2061 view.update(cx, |view, cx| {
2062 if event
2063 .focused
2064 .as_ref()
2065 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2066 {
2067 listener(view, cx)
2068 }
2069 })
2070 .is_ok()
2071 }),
2072 )
2073 }
2074
2075 /// Register a listener to be called when the given focus handle loses focus.
2076 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2077 /// is dropped.
2078 pub fn on_blur(
2079 &mut self,
2080 handle: &FocusHandle,
2081 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2082 ) -> Subscription {
2083 let view = self.view.downgrade();
2084 let focus_id = handle.id;
2085 self.window.focus_listeners.insert(
2086 (),
2087 Box::new(move |event, cx| {
2088 view.update(cx, |view, cx| {
2089 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2090 listener(view, cx)
2091 }
2092 })
2093 .is_ok()
2094 }),
2095 )
2096 }
2097
2098 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2099 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2100 /// is dropped.
2101 pub fn on_focus_out(
2102 &mut self,
2103 handle: &FocusHandle,
2104 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2105 ) -> Subscription {
2106 let view = self.view.downgrade();
2107 let focus_id = handle.id;
2108 self.window.focus_listeners.insert(
2109 (),
2110 Box::new(move |event, cx| {
2111 view.update(cx, |view, cx| {
2112 if event
2113 .blurred
2114 .as_ref()
2115 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2116 {
2117 listener(view, cx)
2118 }
2119 })
2120 .is_ok()
2121 }),
2122 )
2123 }
2124
2125 /// Register a focus listener for the current frame only. It will be cleared
2126 /// on the next frame render. You should use this method only from within elements,
2127 /// and we may want to enforce that better via a different context type.
2128 // todo!() Move this to `FrameContext` to emphasize its individuality?
2129 pub fn on_focus_changed(
2130 &mut self,
2131 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + 'static,
2132 ) {
2133 let handle = self.view().downgrade();
2134 self.window
2135 .current_frame
2136 .focus_listeners
2137 .push(Box::new(move |event, cx| {
2138 handle
2139 .update(cx, |view, cx| listener(view, event, cx))
2140 .log_err();
2141 }));
2142 }
2143
2144 pub fn with_key_dispatch<R>(
2145 &mut self,
2146 context: KeyContext,
2147 focus_handle: Option<FocusHandle>,
2148 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
2149 ) -> R {
2150 let window = &mut self.window;
2151 window
2152 .current_frame
2153 .dispatch_tree
2154 .push_node(context.clone());
2155 if let Some(focus_handle) = focus_handle.as_ref() {
2156 window
2157 .current_frame
2158 .dispatch_tree
2159 .make_focusable(focus_handle.id);
2160 }
2161 let result = f(focus_handle, self);
2162
2163 self.window.current_frame.dispatch_tree.pop_node();
2164
2165 result
2166 }
2167
2168 pub fn spawn<Fut, R>(
2169 &mut self,
2170 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2171 ) -> Task<R>
2172 where
2173 R: 'static,
2174 Fut: Future<Output = R> + 'static,
2175 {
2176 let view = self.view().downgrade();
2177 self.window_cx.spawn(|cx| f(view, cx))
2178 }
2179
2180 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2181 where
2182 G: 'static,
2183 {
2184 let mut global = self.app.lease_global::<G>();
2185 let result = f(&mut global, self);
2186 self.app.end_global_lease(global);
2187 result
2188 }
2189
2190 pub fn observe_global<G: 'static>(
2191 &mut self,
2192 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2193 ) -> Subscription {
2194 let window_handle = self.window.handle;
2195 let view = self.view().downgrade();
2196 self.global_observers.insert(
2197 TypeId::of::<G>(),
2198 Box::new(move |cx| {
2199 window_handle
2200 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2201 .unwrap_or(false)
2202 }),
2203 )
2204 }
2205
2206 pub fn on_mouse_event<Event: 'static>(
2207 &mut self,
2208 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2209 ) {
2210 let handle = self.view().clone();
2211 self.window_cx.on_mouse_event(move |event, phase, cx| {
2212 handle.update(cx, |view, cx| {
2213 handler(view, event, phase, cx);
2214 })
2215 });
2216 }
2217
2218 pub fn on_key_event<Event: 'static>(
2219 &mut self,
2220 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2221 ) {
2222 let handle = self.view().clone();
2223 self.window_cx.on_key_event(move |event, phase, cx| {
2224 handle.update(cx, |view, cx| {
2225 handler(view, event, phase, cx);
2226 })
2227 });
2228 }
2229
2230 pub fn on_action(
2231 &mut self,
2232 action_type: TypeId,
2233 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2234 ) {
2235 let handle = self.view().clone();
2236 self.window_cx
2237 .on_action(action_type, move |action, phase, cx| {
2238 handle.update(cx, |view, cx| {
2239 handler(view, action, phase, cx);
2240 })
2241 });
2242 }
2243
2244 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
2245 /// platform to receive textual input with proper integration with concerns such
2246 /// as IME interactions.
2247 pub fn handle_input(
2248 &mut self,
2249 focus_handle: &FocusHandle,
2250 input_handler: impl PlatformInputHandler,
2251 ) {
2252 if focus_handle.is_focused(self) {
2253 self.window
2254 .platform_window
2255 .set_input_handler(Box::new(input_handler));
2256 }
2257 }
2258
2259 pub fn emit<Evt>(&mut self, event: Evt)
2260 where
2261 Evt: 'static,
2262 V: EventEmitter<Evt>,
2263 {
2264 let emitter = self.view.model.entity_id;
2265 self.app.push_effect(Effect::Emit {
2266 emitter,
2267 event_type: TypeId::of::<Evt>(),
2268 event: Box::new(event),
2269 });
2270 }
2271
2272 pub fn focus_self(&mut self)
2273 where
2274 V: FocusableView,
2275 {
2276 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2277 }
2278}
2279
2280impl<V> Context for ViewContext<'_, V> {
2281 type Result<U> = U;
2282
2283 fn build_model<T: 'static>(
2284 &mut self,
2285 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2286 ) -> Model<T> {
2287 self.window_cx.build_model(build_model)
2288 }
2289
2290 fn update_model<T: 'static, R>(
2291 &mut self,
2292 model: &Model<T>,
2293 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2294 ) -> R {
2295 self.window_cx.update_model(model, update)
2296 }
2297
2298 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2299 where
2300 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2301 {
2302 self.window_cx.update_window(window, update)
2303 }
2304
2305 fn read_model<T, R>(
2306 &self,
2307 handle: &Model<T>,
2308 read: impl FnOnce(&T, &AppContext) -> R,
2309 ) -> Self::Result<R>
2310 where
2311 T: 'static,
2312 {
2313 self.window_cx.read_model(handle, read)
2314 }
2315
2316 fn read_window<T, R>(
2317 &self,
2318 window: &WindowHandle<T>,
2319 read: impl FnOnce(View<T>, &AppContext) -> R,
2320 ) -> Result<R>
2321 where
2322 T: 'static,
2323 {
2324 self.window_cx.read_window(window, read)
2325 }
2326}
2327
2328impl<V: 'static> VisualContext for ViewContext<'_, V> {
2329 fn build_view<W: Render + 'static>(
2330 &mut self,
2331 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2332 ) -> Self::Result<View<W>> {
2333 self.window_cx.build_view(build_view_state)
2334 }
2335
2336 fn update_view<V2: 'static, R>(
2337 &mut self,
2338 view: &View<V2>,
2339 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2340 ) -> Self::Result<R> {
2341 self.window_cx.update_view(view, update)
2342 }
2343
2344 fn replace_root_view<W>(
2345 &mut self,
2346 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2347 ) -> Self::Result<View<W>>
2348 where
2349 W: Render,
2350 {
2351 self.window_cx.replace_root_view(build_view)
2352 }
2353
2354 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2355 self.window_cx.focus_view(view)
2356 }
2357}
2358
2359impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2360 type Target = WindowContext<'a>;
2361
2362 fn deref(&self) -> &Self::Target {
2363 &self.window_cx
2364 }
2365}
2366
2367impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2368 fn deref_mut(&mut self) -> &mut Self::Target {
2369 &mut self.window_cx
2370 }
2371}
2372
2373// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2374slotmap::new_key_type! { pub struct WindowId; }
2375
2376impl WindowId {
2377 pub fn as_u64(&self) -> u64 {
2378 self.0.as_ffi()
2379 }
2380}
2381
2382#[derive(Deref, DerefMut)]
2383pub struct WindowHandle<V> {
2384 #[deref]
2385 #[deref_mut]
2386 pub(crate) any_handle: AnyWindowHandle,
2387 state_type: PhantomData<V>,
2388}
2389
2390impl<V: 'static + Render> WindowHandle<V> {
2391 pub fn new(id: WindowId) -> Self {
2392 WindowHandle {
2393 any_handle: AnyWindowHandle {
2394 id,
2395 state_type: TypeId::of::<V>(),
2396 },
2397 state_type: PhantomData,
2398 }
2399 }
2400
2401 pub fn update<C, R>(
2402 &self,
2403 cx: &mut C,
2404 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2405 ) -> Result<R>
2406 where
2407 C: Context,
2408 {
2409 cx.update_window(self.any_handle, |root_view, cx| {
2410 let view = root_view
2411 .downcast::<V>()
2412 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2413 Ok(cx.update_view(&view, update))
2414 })?
2415 }
2416
2417 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2418 let x = cx
2419 .windows
2420 .get(self.id)
2421 .and_then(|window| {
2422 window
2423 .as_ref()
2424 .and_then(|window| window.root_view.clone())
2425 .map(|root_view| root_view.downcast::<V>())
2426 })
2427 .ok_or_else(|| anyhow!("window not found"))?
2428 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2429
2430 Ok(x.read(cx))
2431 }
2432
2433 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2434 where
2435 C: Context,
2436 {
2437 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2438 }
2439
2440 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2441 where
2442 C: Context,
2443 {
2444 cx.read_window(self, |root_view, _cx| root_view.clone())
2445 }
2446
2447 pub fn is_active(&self, cx: &WindowContext) -> Option<bool> {
2448 cx.windows
2449 .get(self.id)
2450 .and_then(|window| window.as_ref().map(|window| window.active))
2451 }
2452}
2453
2454impl<V> Copy for WindowHandle<V> {}
2455
2456impl<V> Clone for WindowHandle<V> {
2457 fn clone(&self) -> Self {
2458 WindowHandle {
2459 any_handle: self.any_handle,
2460 state_type: PhantomData,
2461 }
2462 }
2463}
2464
2465impl<V> PartialEq for WindowHandle<V> {
2466 fn eq(&self, other: &Self) -> bool {
2467 self.any_handle == other.any_handle
2468 }
2469}
2470
2471impl<V> Eq for WindowHandle<V> {}
2472
2473impl<V> Hash for WindowHandle<V> {
2474 fn hash<H: Hasher>(&self, state: &mut H) {
2475 self.any_handle.hash(state);
2476 }
2477}
2478
2479impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2480 fn into(self) -> AnyWindowHandle {
2481 self.any_handle
2482 }
2483}
2484
2485#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2486pub struct AnyWindowHandle {
2487 pub(crate) id: WindowId,
2488 state_type: TypeId,
2489}
2490
2491impl AnyWindowHandle {
2492 pub fn window_id(&self) -> WindowId {
2493 self.id
2494 }
2495
2496 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2497 if TypeId::of::<T>() == self.state_type {
2498 Some(WindowHandle {
2499 any_handle: *self,
2500 state_type: PhantomData,
2501 })
2502 } else {
2503 None
2504 }
2505 }
2506
2507 pub fn update<C, R>(
2508 self,
2509 cx: &mut C,
2510 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2511 ) -> Result<R>
2512 where
2513 C: Context,
2514 {
2515 cx.update_window(self, update)
2516 }
2517
2518 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2519 where
2520 C: Context,
2521 T: 'static,
2522 {
2523 let view = self
2524 .downcast::<T>()
2525 .context("the type of the window's root view has changed")?;
2526
2527 cx.read_window(&view, read)
2528 }
2529}
2530
2531#[cfg(any(test, feature = "test-support"))]
2532impl From<SmallVec<[u32; 16]>> for StackingOrder {
2533 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2534 StackingOrder(small_vec)
2535 }
2536}
2537
2538#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2539pub enum ElementId {
2540 View(EntityId),
2541 Integer(usize),
2542 Name(SharedString),
2543 FocusHandle(FocusId),
2544}
2545
2546impl From<EntityId> for ElementId {
2547 fn from(id: EntityId) -> Self {
2548 ElementId::View(id)
2549 }
2550}
2551
2552impl From<usize> for ElementId {
2553 fn from(id: usize) -> Self {
2554 ElementId::Integer(id)
2555 }
2556}
2557
2558impl From<i32> for ElementId {
2559 fn from(id: i32) -> Self {
2560 Self::Integer(id as usize)
2561 }
2562}
2563
2564impl From<SharedString> for ElementId {
2565 fn from(name: SharedString) -> Self {
2566 ElementId::Name(name)
2567 }
2568}
2569
2570impl From<&'static str> for ElementId {
2571 fn from(name: &'static str) -> Self {
2572 ElementId::Name(name.into())
2573 }
2574}
2575
2576impl<'a> From<&'a FocusHandle> for ElementId {
2577 fn from(handle: &'a FocusHandle) -> Self {
2578 ElementId::FocusHandle(handle.id)
2579 }
2580}