1use crate::{
2 px, size, Action, AnyBox, AnyDrag, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
3 Bounds, BoxShadow, Context, Corners, CursorStyle, DevicePixels, DisplayId, Edges, Effect,
4 Entity, EntityId, EventEmitter, FileDropEvent, FocusEvent, FontId, GlobalElementId, GlyphId,
5 Hsla, ImageData, InputEvent, IsZero, KeyContext, KeyDispatcher, LayoutId, Model, ModelContext,
6 Modifiers, MonochromeSprite, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path,
7 Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler, PlatformWindow, Point,
8 PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams, RenderImageParams,
9 RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size, Style, SubscriberSet,
10 Subscription, TaffyLayoutEngine, Task, Underline, UnderlineStyle, View, VisualContext,
11 WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
12};
13use anyhow::{anyhow, Result};
14use collections::HashMap;
15use derive_more::{Deref, DerefMut};
16use futures::{
17 channel::{mpsc, oneshot},
18 StreamExt,
19};
20use parking_lot::RwLock;
21use slotmap::SlotMap;
22use smallvec::SmallVec;
23use std::{
24 any::{Any, TypeId},
25 borrow::{Borrow, BorrowMut, Cow},
26 fmt::Debug,
27 future::Future,
28 hash::{Hash, Hasher},
29 marker::PhantomData,
30 mem,
31 rc::Rc,
32 sync::{
33 atomic::{AtomicUsize, Ordering::SeqCst},
34 Arc,
35 },
36};
37use util::ResultExt;
38
39/// A global stacking order, which is created by stacking successive z-index values.
40/// Each z-index will always be interpreted in the context of its parent z-index.
41#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
42pub(crate) struct StackingOrder(pub(crate) SmallVec<[u32; 16]>);
43
44/// Represents the two different phases when dispatching events.
45#[derive(Default, Copy, Clone, Debug, Eq, PartialEq)]
46pub enum DispatchPhase {
47 /// After the capture phase comes the bubble phase, in which mouse event listeners are
48 /// invoked front to back and keyboard event listeners are invoked from the focused element
49 /// to the root of the element tree. This is the phase you'll most commonly want to use when
50 /// registering event listeners.
51 #[default]
52 Bubble,
53 /// During the initial capture phase, mouse event listeners are invoked back to front, and keyboard
54 /// listeners are invoked from the root of the tree downward toward the focused element. This phase
55 /// is used for special purposes such as clearing the "pressed" state for click events. If
56 /// you stop event propagation during this phase, you need to know what you're doing. Handlers
57 /// outside of the immediate region may rely on detecting non-local events during this phase.
58 Capture,
59}
60
61type AnyObserver = Box<dyn FnMut(&mut WindowContext) -> bool + 'static>;
62type AnyMouseListener = Box<dyn FnMut(&dyn Any, DispatchPhase, &mut WindowContext) + 'static>;
63type AnyFocusListener = Box<dyn Fn(&FocusEvent, &mut WindowContext) + 'static>;
64type AnyWindowFocusListener = Box<dyn FnMut(&FocusEvent, &mut WindowContext) -> bool + 'static>;
65
66slotmap::new_key_type! { pub struct FocusId; }
67
68impl FocusId {
69 /// Obtains whether the element associated with this handle is currently focused.
70 pub fn is_focused(&self, cx: &WindowContext) -> bool {
71 cx.window.focus == Some(*self)
72 }
73
74 /// Obtains whether the element associated with this handle contains the focused
75 /// element or is itself focused.
76 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
77 cx.focused()
78 .map_or(false, |focused| self.contains(focused.id, cx))
79 }
80
81 /// Obtains whether the element associated with this handle is contained within the
82 /// focused element or is itself focused.
83 pub fn within_focused(&self, cx: &WindowContext) -> bool {
84 let focused = cx.focused();
85 focused.map_or(false, |focused| focused.id.contains(*self, cx))
86 }
87
88 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
89 pub(crate) fn contains(&self, other: Self, cx: &WindowContext) -> bool {
90 cx.window
91 .current_frame
92 .key_dispatcher
93 .as_ref()
94 .unwrap()
95 .focus_contains(*self, other)
96 }
97}
98
99/// A handle which can be used to track and manipulate the focused element in a window.
100pub struct FocusHandle {
101 pub(crate) id: FocusId,
102 handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
103}
104
105impl FocusHandle {
106 pub(crate) fn new(handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>) -> Self {
107 let id = handles.write().insert(AtomicUsize::new(1));
108 Self {
109 id,
110 handles: handles.clone(),
111 }
112 }
113
114 pub(crate) fn for_id(
115 id: FocusId,
116 handles: &Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
117 ) -> Option<Self> {
118 let lock = handles.read();
119 let ref_count = lock.get(id)?;
120 if ref_count.load(SeqCst) == 0 {
121 None
122 } else {
123 ref_count.fetch_add(1, SeqCst);
124 Some(Self {
125 id,
126 handles: handles.clone(),
127 })
128 }
129 }
130
131 /// Moves the focus to the element associated with this handle.
132 pub fn focus(&self, cx: &mut WindowContext) {
133 cx.focus(self)
134 }
135
136 /// Obtains whether the element associated with this handle is currently focused.
137 pub fn is_focused(&self, cx: &WindowContext) -> bool {
138 self.id.is_focused(cx)
139 }
140
141 /// Obtains whether the element associated with this handle contains the focused
142 /// element or is itself focused.
143 pub fn contains_focused(&self, cx: &WindowContext) -> bool {
144 self.id.contains_focused(cx)
145 }
146
147 /// Obtains whether the element associated with this handle is contained within the
148 /// focused element or is itself focused.
149 pub fn within_focused(&self, cx: &WindowContext) -> bool {
150 self.id.within_focused(cx)
151 }
152
153 /// Obtains whether this handle contains the given handle in the most recently rendered frame.
154 pub(crate) fn contains(&self, other: &Self, cx: &WindowContext) -> bool {
155 self.id.contains(other.id, cx)
156 }
157}
158
159impl Clone for FocusHandle {
160 fn clone(&self) -> Self {
161 Self::for_id(self.id, &self.handles).unwrap()
162 }
163}
164
165impl PartialEq for FocusHandle {
166 fn eq(&self, other: &Self) -> bool {
167 self.id == other.id
168 }
169}
170
171impl Eq for FocusHandle {}
172
173impl Drop for FocusHandle {
174 fn drop(&mut self) {
175 self.handles
176 .read()
177 .get(self.id)
178 .unwrap()
179 .fetch_sub(1, SeqCst);
180 }
181}
182
183// Holds the state for a specific window.
184pub struct Window {
185 pub(crate) handle: AnyWindowHandle,
186 pub(crate) removed: bool,
187 platform_window: Box<dyn PlatformWindow>,
188 display_id: DisplayId,
189 sprite_atlas: Arc<dyn PlatformAtlas>,
190 rem_size: Pixels,
191 viewport_size: Size<Pixels>,
192 pub(crate) layout_engine: TaffyLayoutEngine,
193 pub(crate) root_view: Option<AnyView>,
194 pub(crate) element_id_stack: GlobalElementId,
195 pub(crate) previous_frame: Frame,
196 pub(crate) current_frame: Frame,
197 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
198 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
199 default_prevented: bool,
200 mouse_position: Point<Pixels>,
201 requested_cursor_style: Option<CursorStyle>,
202 scale_factor: f32,
203 bounds: WindowBounds,
204 bounds_observers: SubscriberSet<(), AnyObserver>,
205 active: bool,
206 activation_observers: SubscriberSet<(), AnyObserver>,
207 pub(crate) dirty: bool,
208 pub(crate) last_blur: Option<Option<FocusId>>,
209 pub(crate) focus: Option<FocusId>,
210}
211
212// #[derive(Default)]
213pub(crate) struct Frame {
214 element_states: HashMap<GlobalElementId, AnyBox>,
215 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
216 pub(crate) key_dispatcher: Option<KeyDispatcher>,
217 pub(crate) focus_listeners: Vec<AnyFocusListener>,
218 pub(crate) scene_builder: SceneBuilder,
219 z_index_stack: StackingOrder,
220 content_mask_stack: Vec<ContentMask<Pixels>>,
221 element_offset_stack: Vec<Point<Pixels>>,
222}
223
224impl Frame {
225 pub fn new(key_dispatcher: KeyDispatcher) -> Self {
226 Frame {
227 element_states: HashMap::default(),
228 mouse_listeners: HashMap::default(),
229 key_dispatcher: Some(key_dispatcher),
230 focus_listeners: Vec::new(),
231 scene_builder: SceneBuilder::default(),
232 z_index_stack: StackingOrder::default(),
233 content_mask_stack: Vec::new(),
234 element_offset_stack: Vec::new(),
235 }
236 }
237}
238
239impl Window {
240 pub(crate) fn new(
241 handle: AnyWindowHandle,
242 options: WindowOptions,
243 cx: &mut AppContext,
244 ) -> Self {
245 let platform_window = cx.platform.open_window(handle, options);
246 let display_id = platform_window.display().id();
247 let sprite_atlas = platform_window.sprite_atlas();
248 let mouse_position = platform_window.mouse_position();
249 let content_size = platform_window.content_size();
250 let scale_factor = platform_window.scale_factor();
251 let bounds = platform_window.bounds();
252
253 platform_window.on_resize(Box::new({
254 let mut cx = cx.to_async();
255 move |_, _| {
256 handle
257 .update(&mut cx, |_, cx| cx.window_bounds_changed())
258 .log_err();
259 }
260 }));
261 platform_window.on_moved(Box::new({
262 let mut cx = cx.to_async();
263 move || {
264 handle
265 .update(&mut cx, |_, cx| cx.window_bounds_changed())
266 .log_err();
267 }
268 }));
269 platform_window.on_active_status_change(Box::new({
270 let mut cx = cx.to_async();
271 move |active| {
272 handle
273 .update(&mut cx, |_, cx| {
274 cx.window.active = active;
275 cx.window
276 .activation_observers
277 .clone()
278 .retain(&(), |callback| callback(cx));
279 })
280 .log_err();
281 }
282 }));
283
284 platform_window.on_input({
285 let mut cx = cx.to_async();
286 Box::new(move |event| {
287 handle
288 .update(&mut cx, |_, cx| cx.dispatch_event(event))
289 .log_err()
290 .unwrap_or(false)
291 })
292 });
293
294 Window {
295 handle,
296 removed: false,
297 platform_window,
298 display_id,
299 sprite_atlas,
300 rem_size: px(16.),
301 viewport_size: content_size,
302 layout_engine: TaffyLayoutEngine::new(),
303 root_view: None,
304 element_id_stack: GlobalElementId::default(),
305 previous_frame: Frame::new(KeyDispatcher::new(cx.keymap.clone())),
306 current_frame: Frame::new(KeyDispatcher::new(cx.keymap.clone())),
307 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
308 focus_listeners: SubscriberSet::new(),
309 default_prevented: true,
310 mouse_position,
311 requested_cursor_style: None,
312 scale_factor,
313 bounds,
314 bounds_observers: SubscriberSet::new(),
315 active: false,
316 activation_observers: SubscriberSet::new(),
317 dirty: true,
318 last_blur: None,
319 focus: None,
320 }
321 }
322}
323
324/// Indicates which region of the window is visible. Content falling outside of this mask will not be
325/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
326/// to leave room to support more complex shapes in the future.
327#[derive(Clone, Debug, Default, PartialEq, Eq)]
328#[repr(C)]
329pub struct ContentMask<P: Clone + Default + Debug> {
330 pub bounds: Bounds<P>,
331}
332
333impl ContentMask<Pixels> {
334 /// Scale the content mask's pixel units by the given scaling factor.
335 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
336 ContentMask {
337 bounds: self.bounds.scale(factor),
338 }
339 }
340
341 /// Intersect the content mask with the given content mask.
342 pub fn intersect(&self, other: &Self) -> Self {
343 let bounds = self.bounds.intersect(&other.bounds);
344 ContentMask { bounds }
345 }
346}
347
348/// Provides access to application state in the context of a single window. Derefs
349/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
350/// an `AppContext` and call any `AppContext` methods.
351pub struct WindowContext<'a> {
352 pub(crate) app: &'a mut AppContext,
353 pub(crate) window: &'a mut Window,
354}
355
356impl<'a> WindowContext<'a> {
357 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
358 Self { app, window }
359 }
360
361 /// Obtain a handle to the window that belongs to this context.
362 pub fn window_handle(&self) -> AnyWindowHandle {
363 self.window.handle
364 }
365
366 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
367 pub fn notify(&mut self) {
368 self.window.dirty = true;
369 }
370
371 /// Close this window.
372 pub fn remove_window(&mut self) {
373 self.window.removed = true;
374 }
375
376 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
377 /// for elements rendered within this window.
378 pub fn focus_handle(&mut self) -> FocusHandle {
379 FocusHandle::new(&self.window.focus_handles)
380 }
381
382 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
383 pub fn focused(&self) -> Option<FocusHandle> {
384 self.window
385 .focus
386 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
387 }
388
389 /// Move focus to the element associated with the given `FocusHandle`.
390 pub fn focus(&mut self, handle: &FocusHandle) {
391 let focus_id = handle.id;
392
393 if self.window.focus == Some(focus_id) {
394 return;
395 }
396
397 if self.window.last_blur.is_none() {
398 self.window.last_blur = Some(self.window.focus);
399 }
400
401 self.window.focus = Some(focus_id);
402 self.app.push_effect(Effect::FocusChanged {
403 window_handle: self.window.handle,
404 focused: Some(focus_id),
405 });
406 self.notify();
407 }
408
409 /// Remove focus from all elements within this context's window.
410 pub fn blur(&mut self) {
411 if self.window.last_blur.is_none() {
412 self.window.last_blur = Some(self.window.focus);
413 }
414
415 self.window.focus = None;
416 self.app.push_effect(Effect::FocusChanged {
417 window_handle: self.window.handle,
418 focused: None,
419 });
420 self.notify();
421 }
422
423 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
424 if let Some(focus_handle) = self.focused() {
425 self.defer(move |cx| {
426 let dispatcher = cx.window.current_frame.key_dispatcher.take().unwrap();
427 dispatcher.dispatch_action(focus_handle.id, action, cx);
428 cx.window.current_frame.key_dispatcher = Some(dispatcher);
429 })
430 }
431 }
432
433 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
434 /// that are currently on the stack to be returned to the app.
435 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
436 let handle = self.window.handle;
437 self.app.defer(move |cx| {
438 handle.update(cx, |_, cx| f(cx)).ok();
439 });
440 }
441
442 pub fn subscribe<Emitter, E, Evt>(
443 &mut self,
444 entity: &E,
445 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
446 ) -> Subscription
447 where
448 Emitter: EventEmitter<Evt>,
449 E: Entity<Emitter>,
450 Evt: 'static,
451 {
452 let entity_id = entity.entity_id();
453 let entity = entity.downgrade();
454 let window_handle = self.window.handle;
455 self.app.event_listeners.insert(
456 entity_id,
457 (
458 TypeId::of::<Evt>(),
459 Box::new(move |event, cx| {
460 window_handle
461 .update(cx, |_, cx| {
462 if let Some(handle) = E::upgrade_from(&entity) {
463 let event = event.downcast_ref().expect("invalid event type");
464 on_event(handle, event, cx);
465 true
466 } else {
467 false
468 }
469 })
470 .unwrap_or(false)
471 }),
472 ),
473 )
474 }
475
476 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
477 /// await points in async code.
478 pub fn to_async(&self) -> AsyncWindowContext {
479 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
480 }
481
482 /// Schedule the given closure to be run directly after the current frame is rendered.
483 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
484 let handle = self.window.handle;
485 let display_id = self.window.display_id;
486
487 if !self.frame_consumers.contains_key(&display_id) {
488 let (tx, mut rx) = mpsc::unbounded::<()>();
489 self.platform.set_display_link_output_callback(
490 display_id,
491 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
492 );
493
494 let consumer_task = self.app.spawn(|cx| async move {
495 while rx.next().await.is_some() {
496 cx.update(|cx| {
497 for callback in cx
498 .next_frame_callbacks
499 .get_mut(&display_id)
500 .unwrap()
501 .drain(..)
502 .collect::<SmallVec<[_; 32]>>()
503 {
504 callback(cx);
505 }
506 })
507 .ok();
508
509 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
510
511 cx.update(|cx| {
512 if cx.next_frame_callbacks.is_empty() {
513 cx.platform.stop_display_link(display_id);
514 }
515 })
516 .ok();
517 }
518 });
519 self.frame_consumers.insert(display_id, consumer_task);
520 }
521
522 if self.next_frame_callbacks.is_empty() {
523 self.platform.start_display_link(display_id);
524 }
525
526 self.next_frame_callbacks
527 .entry(display_id)
528 .or_default()
529 .push(Box::new(move |cx: &mut AppContext| {
530 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
531 }));
532 }
533
534 /// Spawn the future returned by the given closure on the application thread pool.
535 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
536 /// use within your future.
537 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
538 where
539 R: 'static,
540 Fut: Future<Output = R> + 'static,
541 {
542 self.app
543 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
544 }
545
546 /// Update the global of the given type. The given closure is given simultaneous mutable
547 /// access both to the global and the context.
548 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
549 where
550 G: 'static,
551 {
552 let mut global = self.app.lease_global::<G>();
553 let result = f(&mut global, self);
554 self.app.end_global_lease(global);
555 result
556 }
557
558 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
559 /// layout is being requested, along with the layout ids of any children. This method is called during
560 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
561 pub fn request_layout(
562 &mut self,
563 style: &Style,
564 children: impl IntoIterator<Item = LayoutId>,
565 ) -> LayoutId {
566 self.app.layout_id_buffer.clear();
567 self.app.layout_id_buffer.extend(children.into_iter());
568 let rem_size = self.rem_size();
569
570 self.window
571 .layout_engine
572 .request_layout(style, rem_size, &self.app.layout_id_buffer)
573 }
574
575 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
576 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
577 /// determine the element's size. One place this is used internally is when measuring text.
578 ///
579 /// The given closure is invoked at layout time with the known dimensions and available space and
580 /// returns a `Size`.
581 pub fn request_measured_layout<
582 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
583 >(
584 &mut self,
585 style: Style,
586 rem_size: Pixels,
587 measure: F,
588 ) -> LayoutId {
589 self.window
590 .layout_engine
591 .request_measured_layout(style, rem_size, measure)
592 }
593
594 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
595 self.window
596 .layout_engine
597 .compute_layout(layout_id, available_space)
598 }
599
600 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
601 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
602 /// in order to pass your element its `Bounds` automatically.
603 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
604 let mut bounds = self
605 .window
606 .layout_engine
607 .layout_bounds(layout_id)
608 .map(Into::into);
609 bounds.origin += self.element_offset();
610 bounds
611 }
612
613 fn window_bounds_changed(&mut self) {
614 self.window.scale_factor = self.window.platform_window.scale_factor();
615 self.window.viewport_size = self.window.platform_window.content_size();
616 self.window.bounds = self.window.platform_window.bounds();
617 self.window.display_id = self.window.platform_window.display().id();
618 self.window.dirty = true;
619
620 self.window
621 .bounds_observers
622 .clone()
623 .retain(&(), |callback| callback(self));
624 }
625
626 pub fn window_bounds(&self) -> WindowBounds {
627 self.window.bounds
628 }
629
630 pub fn viewport_size(&self) -> Size<Pixels> {
631 self.window.viewport_size
632 }
633
634 pub fn is_window_active(&self) -> bool {
635 self.window.active
636 }
637
638 pub fn zoom_window(&self) {
639 self.window.platform_window.zoom();
640 }
641
642 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
643 self.platform
644 .displays()
645 .into_iter()
646 .find(|display| display.id() == self.window.display_id)
647 }
648
649 pub fn show_character_palette(&self) {
650 self.window.platform_window.show_character_palette();
651 }
652
653 /// The scale factor of the display associated with the window. For example, it could
654 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
655 /// be rendered as two pixels on screen.
656 pub fn scale_factor(&self) -> f32 {
657 self.window.scale_factor
658 }
659
660 /// The size of an em for the base font of the application. Adjusting this value allows the
661 /// UI to scale, just like zooming a web page.
662 pub fn rem_size(&self) -> Pixels {
663 self.window.rem_size
664 }
665
666 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
667 /// UI to scale, just like zooming a web page.
668 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
669 self.window.rem_size = rem_size.into();
670 }
671
672 /// The line height associated with the current text style.
673 pub fn line_height(&self) -> Pixels {
674 let rem_size = self.rem_size();
675 let text_style = self.text_style();
676 text_style
677 .line_height
678 .to_pixels(text_style.font_size.into(), rem_size)
679 }
680
681 /// Call to prevent the default action of an event. Currently only used to prevent
682 /// parent elements from becoming focused on mouse down.
683 pub fn prevent_default(&mut self) {
684 self.window.default_prevented = true;
685 }
686
687 /// Obtain whether default has been prevented for the event currently being dispatched.
688 pub fn default_prevented(&self) -> bool {
689 self.window.default_prevented
690 }
691
692 /// Register a mouse event listener on the window for the current frame. The type of event
693 /// is determined by the first parameter of the given listener. When the next frame is rendered
694 /// the listener will be cleared.
695 ///
696 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
697 /// a specific need to register a global listener.
698 pub fn on_mouse_event<Event: 'static>(
699 &mut self,
700 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
701 ) {
702 let order = self.window.current_frame.z_index_stack.clone();
703 self.window
704 .current_frame
705 .mouse_listeners
706 .entry(TypeId::of::<Event>())
707 .or_default()
708 .push((
709 order,
710 Box::new(move |event: &dyn Any, phase, cx| {
711 handler(event.downcast_ref().unwrap(), phase, cx)
712 }),
713 ))
714 }
715
716 /// Register a key event listener on the window for the current frame. The type of event
717 /// is determined by the first parameter of the given listener. When the next frame is rendered
718 /// the listener will be cleared.
719 ///
720 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
721 /// a specific need to register a global listener.
722 pub fn on_key_event<Event: 'static>(
723 &mut self,
724 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
725 ) {
726 let key_dispatcher = self.window.current_frame.key_dispatcher.as_mut().unwrap();
727 key_dispatcher.on_key_event(Box::new(move |event, phase, cx| {
728 if let Some(event) = event.downcast_ref::<Event>() {
729 handler(event, phase, cx)
730 }
731 }));
732 }
733
734 /// Register an action listener on the window for the current frame. The type of action
735 /// is determined by the first parameter of the given listener. When the next frame is rendered
736 /// the listener will be cleared.
737 ///
738 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
739 /// a specific need to register a global listener.
740 pub fn on_action(
741 &mut self,
742 action_type: TypeId,
743 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
744 ) {
745 let key_dispatcher = self.window.current_frame.key_dispatcher.as_mut().unwrap();
746 key_dispatcher.on_action(
747 action_type,
748 Box::new(move |action, phase, cx| handler(action, phase, cx)),
749 );
750 }
751
752 /// The position of the mouse relative to the window.
753 pub fn mouse_position(&self) -> Point<Pixels> {
754 self.window.mouse_position
755 }
756
757 pub fn set_cursor_style(&mut self, style: CursorStyle) {
758 self.window.requested_cursor_style = Some(style)
759 }
760
761 /// Called during painting to invoke the given closure in a new stacking context. The given
762 /// z-index is interpreted relative to the previous call to `stack`.
763 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
764 self.window.current_frame.z_index_stack.push(z_index);
765 let result = f(self);
766 self.window.current_frame.z_index_stack.pop();
767 result
768 }
769
770 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
771 pub fn paint_shadows(
772 &mut self,
773 bounds: Bounds<Pixels>,
774 corner_radii: Corners<Pixels>,
775 shadows: &[BoxShadow],
776 ) {
777 let scale_factor = self.scale_factor();
778 let content_mask = self.content_mask();
779 let window = &mut *self.window;
780 for shadow in shadows {
781 let mut shadow_bounds = bounds;
782 shadow_bounds.origin += shadow.offset;
783 shadow_bounds.dilate(shadow.spread_radius);
784 window.current_frame.scene_builder.insert(
785 &window.current_frame.z_index_stack,
786 Shadow {
787 order: 0,
788 bounds: shadow_bounds.scale(scale_factor),
789 content_mask: content_mask.scale(scale_factor),
790 corner_radii: corner_radii.scale(scale_factor),
791 color: shadow.color,
792 blur_radius: shadow.blur_radius.scale(scale_factor),
793 },
794 );
795 }
796 }
797
798 /// Paint one or more quads into the scene for the current frame at the current stacking context.
799 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
800 pub fn paint_quad(
801 &mut self,
802 bounds: Bounds<Pixels>,
803 corner_radii: Corners<Pixels>,
804 background: impl Into<Hsla>,
805 border_widths: Edges<Pixels>,
806 border_color: impl Into<Hsla>,
807 ) {
808 let scale_factor = self.scale_factor();
809 let content_mask = self.content_mask();
810
811 let window = &mut *self.window;
812 window.current_frame.scene_builder.insert(
813 &window.current_frame.z_index_stack,
814 Quad {
815 order: 0,
816 bounds: bounds.scale(scale_factor),
817 content_mask: content_mask.scale(scale_factor),
818 background: background.into(),
819 border_color: border_color.into(),
820 corner_radii: corner_radii.scale(scale_factor),
821 border_widths: border_widths.scale(scale_factor),
822 },
823 );
824 }
825
826 /// Paint the given `Path` into the scene for the current frame at the current z-index.
827 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
828 let scale_factor = self.scale_factor();
829 let content_mask = self.content_mask();
830 path.content_mask = content_mask;
831 path.color = color.into();
832 let window = &mut *self.window;
833 window.current_frame.scene_builder.insert(
834 &window.current_frame.z_index_stack,
835 path.scale(scale_factor),
836 );
837 }
838
839 /// Paint an underline into the scene for the current frame at the current z-index.
840 pub fn paint_underline(
841 &mut self,
842 origin: Point<Pixels>,
843 width: Pixels,
844 style: &UnderlineStyle,
845 ) -> Result<()> {
846 let scale_factor = self.scale_factor();
847 let height = if style.wavy {
848 style.thickness * 3.
849 } else {
850 style.thickness
851 };
852 let bounds = Bounds {
853 origin,
854 size: size(width, height),
855 };
856 let content_mask = self.content_mask();
857 let window = &mut *self.window;
858 window.current_frame.scene_builder.insert(
859 &window.current_frame.z_index_stack,
860 Underline {
861 order: 0,
862 bounds: bounds.scale(scale_factor),
863 content_mask: content_mask.scale(scale_factor),
864 thickness: style.thickness.scale(scale_factor),
865 color: style.color.unwrap_or_default(),
866 wavy: style.wavy,
867 },
868 );
869 Ok(())
870 }
871
872 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
873 /// The y component of the origin is the baseline of the glyph.
874 pub fn paint_glyph(
875 &mut self,
876 origin: Point<Pixels>,
877 font_id: FontId,
878 glyph_id: GlyphId,
879 font_size: Pixels,
880 color: Hsla,
881 ) -> Result<()> {
882 let scale_factor = self.scale_factor();
883 let glyph_origin = origin.scale(scale_factor);
884 let subpixel_variant = Point {
885 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
886 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
887 };
888 let params = RenderGlyphParams {
889 font_id,
890 glyph_id,
891 font_size,
892 subpixel_variant,
893 scale_factor,
894 is_emoji: false,
895 };
896
897 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
898 if !raster_bounds.is_zero() {
899 let tile =
900 self.window
901 .sprite_atlas
902 .get_or_insert_with(¶ms.clone().into(), &mut || {
903 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
904 Ok((size, Cow::Owned(bytes)))
905 })?;
906 let bounds = Bounds {
907 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
908 size: tile.bounds.size.map(Into::into),
909 };
910 let content_mask = self.content_mask().scale(scale_factor);
911 let window = &mut *self.window;
912 window.current_frame.scene_builder.insert(
913 &window.current_frame.z_index_stack,
914 MonochromeSprite {
915 order: 0,
916 bounds,
917 content_mask,
918 color,
919 tile,
920 },
921 );
922 }
923 Ok(())
924 }
925
926 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
927 /// The y component of the origin is the baseline of the glyph.
928 pub fn paint_emoji(
929 &mut self,
930 origin: Point<Pixels>,
931 font_id: FontId,
932 glyph_id: GlyphId,
933 font_size: Pixels,
934 ) -> Result<()> {
935 let scale_factor = self.scale_factor();
936 let glyph_origin = origin.scale(scale_factor);
937 let params = RenderGlyphParams {
938 font_id,
939 glyph_id,
940 font_size,
941 // We don't render emojis with subpixel variants.
942 subpixel_variant: Default::default(),
943 scale_factor,
944 is_emoji: true,
945 };
946
947 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
948 if !raster_bounds.is_zero() {
949 let tile =
950 self.window
951 .sprite_atlas
952 .get_or_insert_with(¶ms.clone().into(), &mut || {
953 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
954 Ok((size, Cow::Owned(bytes)))
955 })?;
956 let bounds = Bounds {
957 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
958 size: tile.bounds.size.map(Into::into),
959 };
960 let content_mask = self.content_mask().scale(scale_factor);
961 let window = &mut *self.window;
962
963 window.current_frame.scene_builder.insert(
964 &window.current_frame.z_index_stack,
965 PolychromeSprite {
966 order: 0,
967 bounds,
968 corner_radii: Default::default(),
969 content_mask,
970 tile,
971 grayscale: false,
972 },
973 );
974 }
975 Ok(())
976 }
977
978 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
979 pub fn paint_svg(
980 &mut self,
981 bounds: Bounds<Pixels>,
982 path: SharedString,
983 color: Hsla,
984 ) -> Result<()> {
985 let scale_factor = self.scale_factor();
986 let bounds = bounds.scale(scale_factor);
987 // Render the SVG at twice the size to get a higher quality result.
988 let params = RenderSvgParams {
989 path,
990 size: bounds
991 .size
992 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
993 };
994
995 let tile =
996 self.window
997 .sprite_atlas
998 .get_or_insert_with(¶ms.clone().into(), &mut || {
999 let bytes = self.svg_renderer.render(¶ms)?;
1000 Ok((params.size, Cow::Owned(bytes)))
1001 })?;
1002 let content_mask = self.content_mask().scale(scale_factor);
1003
1004 let window = &mut *self.window;
1005 window.current_frame.scene_builder.insert(
1006 &window.current_frame.z_index_stack,
1007 MonochromeSprite {
1008 order: 0,
1009 bounds,
1010 content_mask,
1011 color,
1012 tile,
1013 },
1014 );
1015
1016 Ok(())
1017 }
1018
1019 /// Paint an image into the scene for the current frame at the current z-index.
1020 pub fn paint_image(
1021 &mut self,
1022 bounds: Bounds<Pixels>,
1023 corner_radii: Corners<Pixels>,
1024 data: Arc<ImageData>,
1025 grayscale: bool,
1026 ) -> Result<()> {
1027 let scale_factor = self.scale_factor();
1028 let bounds = bounds.scale(scale_factor);
1029 let params = RenderImageParams { image_id: data.id };
1030
1031 let tile = self
1032 .window
1033 .sprite_atlas
1034 .get_or_insert_with(¶ms.clone().into(), &mut || {
1035 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1036 })?;
1037 let content_mask = self.content_mask().scale(scale_factor);
1038 let corner_radii = corner_radii.scale(scale_factor);
1039
1040 let window = &mut *self.window;
1041 window.current_frame.scene_builder.insert(
1042 &window.current_frame.z_index_stack,
1043 PolychromeSprite {
1044 order: 0,
1045 bounds,
1046 content_mask,
1047 corner_radii,
1048 tile,
1049 grayscale,
1050 },
1051 );
1052 Ok(())
1053 }
1054
1055 /// Draw pixels to the display for this window based on the contents of its scene.
1056 pub(crate) fn draw(&mut self) {
1057 let root_view = self.window.root_view.take().unwrap();
1058
1059 self.start_frame();
1060
1061 self.with_z_index(0, |cx| {
1062 let available_space = cx.window.viewport_size.map(Into::into);
1063 root_view.draw(available_space, cx);
1064 });
1065
1066 if let Some(active_drag) = self.app.active_drag.take() {
1067 self.with_z_index(1, |cx| {
1068 let offset = cx.mouse_position() - active_drag.cursor_offset;
1069 cx.with_element_offset(Some(offset), |cx| {
1070 let available_space =
1071 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1072 active_drag.view.draw(available_space, cx);
1073 cx.active_drag = Some(active_drag);
1074 });
1075 });
1076 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1077 self.with_z_index(1, |cx| {
1078 cx.with_element_offset(Some(active_tooltip.cursor_offset), |cx| {
1079 let available_space =
1080 size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1081 active_tooltip.view.draw(available_space, cx);
1082 });
1083 });
1084 }
1085
1086 self.window.root_view = Some(root_view);
1087 let scene = self.window.current_frame.scene_builder.build();
1088
1089 self.window.platform_window.draw(scene);
1090 let cursor_style = self
1091 .window
1092 .requested_cursor_style
1093 .take()
1094 .unwrap_or(CursorStyle::Arrow);
1095 self.platform.set_cursor_style(cursor_style);
1096
1097 self.window.dirty = false;
1098 }
1099
1100 /// Rotate the current frame and the previous frame, then clear the current frame.
1101 /// We repopulate all state in the current frame during each paint.
1102 fn start_frame(&mut self) {
1103 self.text_system().start_frame();
1104
1105 let window = &mut *self.window;
1106 window.layout_engine.clear();
1107
1108 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1109 let frame = &mut window.current_frame;
1110 frame.element_states.clear();
1111 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1112 frame.focus_listeners.clear();
1113 frame.key_dispatcher.as_mut().map(KeyDispatcher::clear);
1114 }
1115
1116 /// Dispatch a mouse or keyboard event on the window.
1117 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1118 // Handlers may set this to false by calling `stop_propagation`
1119 self.app.propagate_event = true;
1120 self.window.default_prevented = false;
1121
1122 let event = match event {
1123 // Track the mouse position with our own state, since accessing the platform
1124 // API for the mouse position can only occur on the main thread.
1125 InputEvent::MouseMove(mouse_move) => {
1126 self.window.mouse_position = mouse_move.position;
1127 InputEvent::MouseMove(mouse_move)
1128 }
1129 // Translate dragging and dropping of external files from the operating system
1130 // to internal drag and drop events.
1131 InputEvent::FileDrop(file_drop) => match file_drop {
1132 FileDropEvent::Entered { position, files } => {
1133 self.window.mouse_position = position;
1134 if self.active_drag.is_none() {
1135 self.active_drag = Some(AnyDrag {
1136 view: self.build_view(|_| files).into(),
1137 cursor_offset: position,
1138 });
1139 }
1140 InputEvent::MouseDown(MouseDownEvent {
1141 position,
1142 button: MouseButton::Left,
1143 click_count: 1,
1144 modifiers: Modifiers::default(),
1145 })
1146 }
1147 FileDropEvent::Pending { position } => {
1148 self.window.mouse_position = position;
1149 InputEvent::MouseMove(MouseMoveEvent {
1150 position,
1151 pressed_button: Some(MouseButton::Left),
1152 modifiers: Modifiers::default(),
1153 })
1154 }
1155 FileDropEvent::Submit { position } => {
1156 self.window.mouse_position = position;
1157 InputEvent::MouseUp(MouseUpEvent {
1158 button: MouseButton::Left,
1159 position,
1160 modifiers: Modifiers::default(),
1161 click_count: 1,
1162 })
1163 }
1164 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1165 button: MouseButton::Left,
1166 position: Point::default(),
1167 modifiers: Modifiers::default(),
1168 click_count: 1,
1169 }),
1170 },
1171 _ => event,
1172 };
1173
1174 if let Some(any_mouse_event) = event.mouse_event() {
1175 if let Some(mut handlers) = self
1176 .window
1177 .current_frame
1178 .mouse_listeners
1179 .remove(&any_mouse_event.type_id())
1180 {
1181 // Because handlers may add other handlers, we sort every time.
1182 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1183
1184 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1185 // special purposes, such as detecting events outside of a given Bounds.
1186 for (_, handler) in &mut handlers {
1187 handler(any_mouse_event, DispatchPhase::Capture, self);
1188 if !self.app.propagate_event {
1189 break;
1190 }
1191 }
1192
1193 // Bubble phase, where most normal handlers do their work.
1194 if self.app.propagate_event {
1195 for (_, handler) in handlers.iter_mut().rev() {
1196 handler(any_mouse_event, DispatchPhase::Bubble, self);
1197 if !self.app.propagate_event {
1198 break;
1199 }
1200 }
1201 }
1202
1203 if self.app.propagate_event
1204 && any_mouse_event.downcast_ref::<MouseUpEvent>().is_some()
1205 {
1206 self.active_drag = None;
1207 }
1208
1209 // Just in case any handlers added new handlers, which is weird, but possible.
1210 handlers.extend(
1211 self.window
1212 .current_frame
1213 .mouse_listeners
1214 .get_mut(&any_mouse_event.type_id())
1215 .into_iter()
1216 .flat_map(|handlers| handlers.drain(..)),
1217 );
1218 self.window
1219 .current_frame
1220 .mouse_listeners
1221 .insert(any_mouse_event.type_id(), handlers);
1222 }
1223 } else if let Some(any_key_event) = event.keyboard_event() {
1224 if let Some(focus_id) = self.window.focus {
1225 let mut dispatcher = self.window.current_frame.key_dispatcher.take().unwrap();
1226 dispatcher.dispatch_key(focus_id, any_key_event, self);
1227 self.window.current_frame.key_dispatcher = Some(dispatcher);
1228 }
1229 }
1230
1231 !self.app.propagate_event
1232 }
1233
1234 /// Register the given handler to be invoked whenever the global of the given type
1235 /// is updated.
1236 pub fn observe_global<G: 'static>(
1237 &mut self,
1238 f: impl Fn(&mut WindowContext<'_>) + 'static,
1239 ) -> Subscription {
1240 let window_handle = self.window.handle;
1241 self.global_observers.insert(
1242 TypeId::of::<G>(),
1243 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1244 )
1245 }
1246
1247 pub fn activate_window(&self) {
1248 self.window.platform_window.activate();
1249 }
1250
1251 pub fn prompt(
1252 &self,
1253 level: PromptLevel,
1254 msg: &str,
1255 answers: &[&str],
1256 ) -> oneshot::Receiver<usize> {
1257 self.window.platform_window.prompt(level, msg, answers)
1258 }
1259
1260 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1261 if let Some(focus_id) = self.window.focus {
1262 self.window
1263 .current_frame
1264 .key_dispatcher
1265 .as_ref()
1266 .unwrap()
1267 .available_actions(focus_id)
1268 } else {
1269 Vec::new()
1270 }
1271 }
1272}
1273
1274impl Context for WindowContext<'_> {
1275 type Result<T> = T;
1276
1277 fn build_model<T>(
1278 &mut self,
1279 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1280 ) -> Model<T>
1281 where
1282 T: 'static,
1283 {
1284 let slot = self.app.entities.reserve();
1285 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1286 self.entities.insert(slot, model)
1287 }
1288
1289 fn update_model<T: 'static, R>(
1290 &mut self,
1291 model: &Model<T>,
1292 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1293 ) -> R {
1294 let mut entity = self.entities.lease(model);
1295 let result = update(
1296 &mut *entity,
1297 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1298 );
1299 self.entities.end_lease(entity);
1300 result
1301 }
1302
1303 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1304 where
1305 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1306 {
1307 if window == self.window.handle {
1308 let root_view = self.window.root_view.clone().unwrap();
1309 Ok(update(root_view, self))
1310 } else {
1311 window.update(self.app, update)
1312 }
1313 }
1314
1315 fn read_model<T, R>(
1316 &self,
1317 handle: &Model<T>,
1318 read: impl FnOnce(&T, &AppContext) -> R,
1319 ) -> Self::Result<R>
1320 where
1321 T: 'static,
1322 {
1323 let entity = self.entities.read(handle);
1324 read(&*entity, &*self.app)
1325 }
1326}
1327
1328impl VisualContext for WindowContext<'_> {
1329 fn build_view<V>(
1330 &mut self,
1331 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1332 ) -> Self::Result<View<V>>
1333 where
1334 V: 'static + Render,
1335 {
1336 let slot = self.app.entities.reserve();
1337 let view = View {
1338 model: slot.clone(),
1339 };
1340 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1341 let entity = build_view_state(&mut cx);
1342 cx.entities.insert(slot, entity);
1343
1344 cx.new_view_observers
1345 .clone()
1346 .retain(&TypeId::of::<V>(), |observer| {
1347 let any_view = AnyView::from(view.clone());
1348 (observer)(any_view, self);
1349 true
1350 });
1351
1352 view
1353 }
1354
1355 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1356 fn update_view<T: 'static, R>(
1357 &mut self,
1358 view: &View<T>,
1359 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1360 ) -> Self::Result<R> {
1361 let mut lease = self.app.entities.lease(&view.model);
1362 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1363 let result = update(&mut *lease, &mut cx);
1364 cx.app.entities.end_lease(lease);
1365 result
1366 }
1367
1368 fn replace_root_view<V>(
1369 &mut self,
1370 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1371 ) -> Self::Result<View<V>>
1372 where
1373 V: Render,
1374 {
1375 let slot = self.app.entities.reserve();
1376 let view = View {
1377 model: slot.clone(),
1378 };
1379 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1380 let entity = build_view(&mut cx);
1381 self.entities.insert(slot, entity);
1382 self.window.root_view = Some(view.clone().into());
1383 view
1384 }
1385}
1386
1387impl<'a> std::ops::Deref for WindowContext<'a> {
1388 type Target = AppContext;
1389
1390 fn deref(&self) -> &Self::Target {
1391 &self.app
1392 }
1393}
1394
1395impl<'a> std::ops::DerefMut for WindowContext<'a> {
1396 fn deref_mut(&mut self) -> &mut Self::Target {
1397 &mut self.app
1398 }
1399}
1400
1401impl<'a> Borrow<AppContext> for WindowContext<'a> {
1402 fn borrow(&self) -> &AppContext {
1403 &self.app
1404 }
1405}
1406
1407impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1408 fn borrow_mut(&mut self) -> &mut AppContext {
1409 &mut self.app
1410 }
1411}
1412
1413pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1414 fn app_mut(&mut self) -> &mut AppContext {
1415 self.borrow_mut()
1416 }
1417
1418 fn window(&self) -> &Window {
1419 self.borrow()
1420 }
1421
1422 fn window_mut(&mut self) -> &mut Window {
1423 self.borrow_mut()
1424 }
1425
1426 /// Pushes the given element id onto the global stack and invokes the given closure
1427 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1428 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1429 /// used to associate state with identified elements across separate frames.
1430 fn with_element_id<R>(
1431 &mut self,
1432 id: impl Into<ElementId>,
1433 f: impl FnOnce(GlobalElementId, &mut Self) -> R,
1434 ) -> R {
1435 let window = self.window_mut();
1436 window.element_id_stack.push(id.into());
1437 let global_id = window.element_id_stack.clone();
1438 let result = f(global_id, self);
1439 let window: &mut Window = self.borrow_mut();
1440 window.element_id_stack.pop();
1441 result
1442 }
1443
1444 /// Invoke the given function with the given content mask after intersecting it
1445 /// with the current mask.
1446 fn with_content_mask<R>(
1447 &mut self,
1448 mask: ContentMask<Pixels>,
1449 f: impl FnOnce(&mut Self) -> R,
1450 ) -> R {
1451 let mask = mask.intersect(&self.content_mask());
1452 self.window_mut()
1453 .current_frame
1454 .content_mask_stack
1455 .push(mask);
1456 let result = f(self);
1457 self.window_mut().current_frame.content_mask_stack.pop();
1458 result
1459 }
1460
1461 /// Update the global element offset based on the given offset. This is used to implement
1462 /// scrolling and position drag handles.
1463 fn with_element_offset<R>(
1464 &mut self,
1465 offset: Option<Point<Pixels>>,
1466 f: impl FnOnce(&mut Self) -> R,
1467 ) -> R {
1468 let Some(offset) = offset else {
1469 return f(self);
1470 };
1471
1472 let offset = self.element_offset() + offset;
1473 self.window_mut()
1474 .current_frame
1475 .element_offset_stack
1476 .push(offset);
1477 let result = f(self);
1478 self.window_mut().current_frame.element_offset_stack.pop();
1479 result
1480 }
1481
1482 /// Obtain the current element offset.
1483 fn element_offset(&self) -> Point<Pixels> {
1484 self.window()
1485 .current_frame
1486 .element_offset_stack
1487 .last()
1488 .copied()
1489 .unwrap_or_default()
1490 }
1491
1492 /// Update or intialize state for an element with the given id that lives across multiple
1493 /// frames. If an element with this id existed in the previous frame, its state will be passed
1494 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1495 /// when drawing the next frame.
1496 fn with_element_state<S, R>(
1497 &mut self,
1498 id: ElementId,
1499 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1500 ) -> R
1501 where
1502 S: 'static,
1503 {
1504 self.with_element_id(id, |global_id, cx| {
1505 if let Some(any) = cx
1506 .window_mut()
1507 .current_frame
1508 .element_states
1509 .remove(&global_id)
1510 .or_else(|| {
1511 cx.window_mut()
1512 .previous_frame
1513 .element_states
1514 .remove(&global_id)
1515 })
1516 {
1517 // Using the extra inner option to avoid needing to reallocate a new box.
1518 let mut state_box = any
1519 .downcast::<Option<S>>()
1520 .expect("invalid element state type for id");
1521 let state = state_box
1522 .take()
1523 .expect("element state is already on the stack");
1524 let (result, state) = f(Some(state), cx);
1525 state_box.replace(state);
1526 cx.window_mut()
1527 .current_frame
1528 .element_states
1529 .insert(global_id, state_box);
1530 result
1531 } else {
1532 let (result, state) = f(None, cx);
1533 cx.window_mut()
1534 .current_frame
1535 .element_states
1536 .insert(global_id, Box::new(Some(state)));
1537 result
1538 }
1539 })
1540 }
1541
1542 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1543 /// id is `None`, no state will be retrieved or stored.
1544 fn with_optional_element_state<S, R>(
1545 &mut self,
1546 element_id: Option<ElementId>,
1547 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1548 ) -> R
1549 where
1550 S: 'static,
1551 {
1552 if let Some(element_id) = element_id {
1553 self.with_element_state(element_id, f)
1554 } else {
1555 f(None, self).0
1556 }
1557 }
1558
1559 /// Obtain the current content mask.
1560 fn content_mask(&self) -> ContentMask<Pixels> {
1561 self.window()
1562 .current_frame
1563 .content_mask_stack
1564 .last()
1565 .cloned()
1566 .unwrap_or_else(|| ContentMask {
1567 bounds: Bounds {
1568 origin: Point::default(),
1569 size: self.window().viewport_size,
1570 },
1571 })
1572 }
1573
1574 /// The size of an em for the base font of the application. Adjusting this value allows the
1575 /// UI to scale, just like zooming a web page.
1576 fn rem_size(&self) -> Pixels {
1577 self.window().rem_size
1578 }
1579}
1580
1581impl Borrow<Window> for WindowContext<'_> {
1582 fn borrow(&self) -> &Window {
1583 &self.window
1584 }
1585}
1586
1587impl BorrowMut<Window> for WindowContext<'_> {
1588 fn borrow_mut(&mut self) -> &mut Window {
1589 &mut self.window
1590 }
1591}
1592
1593impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1594
1595pub struct ViewContext<'a, V> {
1596 window_cx: WindowContext<'a>,
1597 view: &'a View<V>,
1598}
1599
1600impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1601 fn borrow(&self) -> &AppContext {
1602 &*self.window_cx.app
1603 }
1604}
1605
1606impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1607 fn borrow_mut(&mut self) -> &mut AppContext {
1608 &mut *self.window_cx.app
1609 }
1610}
1611
1612impl<V> Borrow<Window> for ViewContext<'_, V> {
1613 fn borrow(&self) -> &Window {
1614 &*self.window_cx.window
1615 }
1616}
1617
1618impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1619 fn borrow_mut(&mut self) -> &mut Window {
1620 &mut *self.window_cx.window
1621 }
1622}
1623
1624impl<'a, V: 'static> ViewContext<'a, V> {
1625 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1626 Self {
1627 window_cx: WindowContext::new(app, window),
1628 view,
1629 }
1630 }
1631
1632 // todo!("change this to return a reference");
1633 pub fn view(&self) -> View<V> {
1634 self.view.clone()
1635 }
1636
1637 pub fn model(&self) -> Model<V> {
1638 self.view.model.clone()
1639 }
1640
1641 /// Access the underlying window context.
1642 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1643 &mut self.window_cx
1644 }
1645
1646 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1647 self.window.current_frame.z_index_stack.push(z_index);
1648 let result = f(self);
1649 self.window.current_frame.z_index_stack.pop();
1650 result
1651 }
1652
1653 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1654 where
1655 V: 'static,
1656 {
1657 let view = self.view();
1658 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1659 }
1660
1661 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1662 /// that are currently on the stack to be returned to the app.
1663 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1664 let view = self.view().downgrade();
1665 self.window_cx.defer(move |cx| {
1666 view.update(cx, f).ok();
1667 });
1668 }
1669
1670 pub fn observe<V2, E>(
1671 &mut self,
1672 entity: &E,
1673 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1674 ) -> Subscription
1675 where
1676 V2: 'static,
1677 V: 'static,
1678 E: Entity<V2>,
1679 {
1680 let view = self.view().downgrade();
1681 let entity_id = entity.entity_id();
1682 let entity = entity.downgrade();
1683 let window_handle = self.window.handle;
1684 self.app.observers.insert(
1685 entity_id,
1686 Box::new(move |cx| {
1687 window_handle
1688 .update(cx, |_, cx| {
1689 if let Some(handle) = E::upgrade_from(&entity) {
1690 view.update(cx, |this, cx| on_notify(this, handle, cx))
1691 .is_ok()
1692 } else {
1693 false
1694 }
1695 })
1696 .unwrap_or(false)
1697 }),
1698 )
1699 }
1700
1701 pub fn subscribe<V2, E, Evt>(
1702 &mut self,
1703 entity: &E,
1704 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1705 ) -> Subscription
1706 where
1707 V2: EventEmitter<Evt>,
1708 E: Entity<V2>,
1709 Evt: 'static,
1710 {
1711 let view = self.view().downgrade();
1712 let entity_id = entity.entity_id();
1713 let handle = entity.downgrade();
1714 let window_handle = self.window.handle;
1715 self.app.event_listeners.insert(
1716 entity_id,
1717 (
1718 TypeId::of::<Evt>(),
1719 Box::new(move |event, cx| {
1720 window_handle
1721 .update(cx, |_, cx| {
1722 if let Some(handle) = E::upgrade_from(&handle) {
1723 let event = event.downcast_ref().expect("invalid event type");
1724 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1725 .is_ok()
1726 } else {
1727 false
1728 }
1729 })
1730 .unwrap_or(false)
1731 }),
1732 ),
1733 )
1734 }
1735
1736 pub fn on_release(
1737 &mut self,
1738 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
1739 ) -> Subscription {
1740 let window_handle = self.window.handle;
1741 self.app.release_listeners.insert(
1742 self.view.model.entity_id,
1743 Box::new(move |this, cx| {
1744 let this = this.downcast_mut().expect("invalid entity type");
1745 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
1746 }),
1747 )
1748 }
1749
1750 pub fn observe_release<V2, E>(
1751 &mut self,
1752 entity: &E,
1753 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
1754 ) -> Subscription
1755 where
1756 V: 'static,
1757 V2: 'static,
1758 E: Entity<V2>,
1759 {
1760 let view = self.view().downgrade();
1761 let entity_id = entity.entity_id();
1762 let window_handle = self.window.handle;
1763 self.app.release_listeners.insert(
1764 entity_id,
1765 Box::new(move |entity, cx| {
1766 let entity = entity.downcast_mut().expect("invalid entity type");
1767 let _ = window_handle.update(cx, |_, cx| {
1768 view.update(cx, |this, cx| on_release(this, entity, cx))
1769 });
1770 }),
1771 )
1772 }
1773
1774 pub fn notify(&mut self) {
1775 self.window_cx.notify();
1776 self.window_cx.app.push_effect(Effect::Notify {
1777 emitter: self.view.model.entity_id,
1778 });
1779 }
1780
1781 pub fn observe_window_bounds(
1782 &mut self,
1783 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1784 ) -> Subscription {
1785 let view = self.view.downgrade();
1786 self.window.bounds_observers.insert(
1787 (),
1788 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1789 )
1790 }
1791
1792 pub fn observe_window_activation(
1793 &mut self,
1794 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1795 ) -> Subscription {
1796 let view = self.view.downgrade();
1797 self.window.activation_observers.insert(
1798 (),
1799 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
1800 )
1801 }
1802
1803 /// Register a listener to be called when the given focus handle receives focus.
1804 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1805 /// is dropped.
1806 pub fn on_focus(
1807 &mut self,
1808 handle: &FocusHandle,
1809 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1810 ) -> Subscription {
1811 let view = self.view.downgrade();
1812 let focus_id = handle.id;
1813 self.window.focus_listeners.insert(
1814 (),
1815 Box::new(move |event, cx| {
1816 view.update(cx, |view, cx| {
1817 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
1818 listener(view, cx)
1819 }
1820 })
1821 .is_ok()
1822 }),
1823 )
1824 }
1825
1826 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
1827 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1828 /// is dropped.
1829 pub fn on_focus_in(
1830 &mut self,
1831 handle: &FocusHandle,
1832 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1833 ) -> Subscription {
1834 let view = self.view.downgrade();
1835 let focus_id = handle.id;
1836 self.window.focus_listeners.insert(
1837 (),
1838 Box::new(move |event, cx| {
1839 view.update(cx, |view, cx| {
1840 if event
1841 .focused
1842 .as_ref()
1843 .map_or(false, |focused| focus_id.contains(focused.id, cx))
1844 {
1845 listener(view, cx)
1846 }
1847 })
1848 .is_ok()
1849 }),
1850 )
1851 }
1852
1853 /// Register a listener to be called when the given focus handle loses focus.
1854 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1855 /// is dropped.
1856 pub fn on_blur(
1857 &mut self,
1858 handle: &FocusHandle,
1859 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1860 ) -> Subscription {
1861 let view = self.view.downgrade();
1862 let focus_id = handle.id;
1863 self.window.focus_listeners.insert(
1864 (),
1865 Box::new(move |event, cx| {
1866 view.update(cx, |view, cx| {
1867 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
1868 listener(view, cx)
1869 }
1870 })
1871 .is_ok()
1872 }),
1873 )
1874 }
1875
1876 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
1877 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
1878 /// is dropped.
1879 pub fn on_focus_out(
1880 &mut self,
1881 handle: &FocusHandle,
1882 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
1883 ) -> Subscription {
1884 let view = self.view.downgrade();
1885 let focus_id = handle.id;
1886 self.window.focus_listeners.insert(
1887 (),
1888 Box::new(move |event, cx| {
1889 view.update(cx, |view, cx| {
1890 if event
1891 .blurred
1892 .as_ref()
1893 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
1894 {
1895 listener(view, cx)
1896 }
1897 })
1898 .is_ok()
1899 }),
1900 )
1901 }
1902
1903 /// Register a focus listener for the current frame only. It will be cleared
1904 /// on the next frame render. You should use this method only from within elements,
1905 /// and we may want to enforce that better via a different context type.
1906 // todo!() Move this to `FrameContext` to emphasize its individuality?
1907 pub fn on_focus_changed(
1908 &mut self,
1909 listener: impl Fn(&mut V, &FocusEvent, &mut ViewContext<V>) + 'static,
1910 ) {
1911 let handle = self.view().downgrade();
1912 self.window
1913 .current_frame
1914 .focus_listeners
1915 .push(Box::new(move |event, cx| {
1916 handle
1917 .update(cx, |view, cx| listener(view, event, cx))
1918 .log_err();
1919 }));
1920 }
1921
1922 pub fn with_key_dispatch<R>(
1923 &mut self,
1924 context: KeyContext,
1925 focus_handle: Option<FocusHandle>,
1926 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1927 ) -> R {
1928 let window = &mut self.window;
1929 let old_dispatcher = window.previous_frame.key_dispatcher.as_mut().unwrap();
1930 let current_dispatcher = window.current_frame.key_dispatcher.as_mut().unwrap();
1931
1932 current_dispatcher.push_node(context, old_dispatcher);
1933 if let Some(focus_handle) = focus_handle.as_ref() {
1934 current_dispatcher.make_focusable(focus_handle.id);
1935 }
1936 let result = f(focus_handle, self);
1937
1938 let current_dispatcher = self.window.current_frame.key_dispatcher.as_mut().unwrap();
1939 current_dispatcher.pop_node();
1940
1941 result
1942 }
1943
1944 pub fn spawn<Fut, R>(
1945 &mut self,
1946 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
1947 ) -> Task<R>
1948 where
1949 R: 'static,
1950 Fut: Future<Output = R> + 'static,
1951 {
1952 let view = self.view().downgrade();
1953 self.window_cx.spawn(|cx| f(view, cx))
1954 }
1955
1956 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
1957 where
1958 G: 'static,
1959 {
1960 let mut global = self.app.lease_global::<G>();
1961 let result = f(&mut global, self);
1962 self.app.end_global_lease(global);
1963 result
1964 }
1965
1966 pub fn observe_global<G: 'static>(
1967 &mut self,
1968 f: impl Fn(&mut V, &mut ViewContext<'_, V>) + 'static,
1969 ) -> Subscription {
1970 let window_handle = self.window.handle;
1971 let view = self.view().downgrade();
1972 self.global_observers.insert(
1973 TypeId::of::<G>(),
1974 Box::new(move |cx| {
1975 window_handle
1976 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
1977 .unwrap_or(false)
1978 }),
1979 )
1980 }
1981
1982 pub fn on_mouse_event<Event: 'static>(
1983 &mut self,
1984 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
1985 ) {
1986 let handle = self.view();
1987 self.window_cx.on_mouse_event(move |event, phase, cx| {
1988 handle.update(cx, |view, cx| {
1989 handler(view, event, phase, cx);
1990 })
1991 });
1992 }
1993
1994 pub fn on_key_event<Event: 'static>(
1995 &mut self,
1996 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
1997 ) {
1998 let handle = self.view();
1999 self.window_cx.on_key_event(move |event, phase, cx| {
2000 handle.update(cx, |view, cx| {
2001 handler(view, event, phase, cx);
2002 })
2003 });
2004 }
2005
2006 pub fn on_action(
2007 &mut self,
2008 action_type: TypeId,
2009 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2010 ) {
2011 let handle = self.view();
2012 self.window_cx
2013 .on_action(action_type, move |action, phase, cx| {
2014 handle.update(cx, |view, cx| {
2015 handler(view, action, phase, cx);
2016 })
2017 });
2018 }
2019
2020 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
2021 /// platform to receive textual input with proper integration with concerns such
2022 /// as IME interactions.
2023 pub fn handle_input(
2024 &mut self,
2025 focus_handle: &FocusHandle,
2026 input_handler: impl PlatformInputHandler,
2027 ) {
2028 if focus_handle.is_focused(self) {
2029 self.window
2030 .platform_window
2031 .set_input_handler(Box::new(input_handler));
2032 }
2033 }
2034}
2035
2036impl<V> ViewContext<'_, V> {
2037 pub fn emit<Evt>(&mut self, event: Evt)
2038 where
2039 Evt: 'static,
2040 V: EventEmitter<Evt>,
2041 {
2042 let emitter = self.view.model.entity_id;
2043 self.app.push_effect(Effect::Emit {
2044 emitter,
2045 event_type: TypeId::of::<Evt>(),
2046 event: Box::new(event),
2047 });
2048 }
2049}
2050
2051impl<V> Context for ViewContext<'_, V> {
2052 type Result<U> = U;
2053
2054 fn build_model<T: 'static>(
2055 &mut self,
2056 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2057 ) -> Model<T> {
2058 self.window_cx.build_model(build_model)
2059 }
2060
2061 fn update_model<T: 'static, R>(
2062 &mut self,
2063 model: &Model<T>,
2064 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2065 ) -> R {
2066 self.window_cx.update_model(model, update)
2067 }
2068
2069 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2070 where
2071 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2072 {
2073 self.window_cx.update_window(window, update)
2074 }
2075
2076 fn read_model<T, R>(
2077 &self,
2078 handle: &Model<T>,
2079 read: impl FnOnce(&T, &AppContext) -> R,
2080 ) -> Self::Result<R>
2081 where
2082 T: 'static,
2083 {
2084 self.window_cx.read_model(handle, read)
2085 }
2086}
2087
2088impl<V: 'static> VisualContext for ViewContext<'_, V> {
2089 fn build_view<W: Render + 'static>(
2090 &mut self,
2091 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2092 ) -> Self::Result<View<W>> {
2093 self.window_cx.build_view(build_view_state)
2094 }
2095
2096 fn update_view<V2: 'static, R>(
2097 &mut self,
2098 view: &View<V2>,
2099 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2100 ) -> Self::Result<R> {
2101 self.window_cx.update_view(view, update)
2102 }
2103
2104 fn replace_root_view<W>(
2105 &mut self,
2106 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2107 ) -> Self::Result<View<W>>
2108 where
2109 W: Render,
2110 {
2111 self.window_cx.replace_root_view(build_view)
2112 }
2113}
2114
2115impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2116 type Target = WindowContext<'a>;
2117
2118 fn deref(&self) -> &Self::Target {
2119 &self.window_cx
2120 }
2121}
2122
2123impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2124 fn deref_mut(&mut self) -> &mut Self::Target {
2125 &mut self.window_cx
2126 }
2127}
2128
2129// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2130slotmap::new_key_type! { pub struct WindowId; }
2131
2132impl WindowId {
2133 pub fn as_u64(&self) -> u64 {
2134 self.0.as_ffi()
2135 }
2136}
2137
2138#[derive(Deref, DerefMut)]
2139pub struct WindowHandle<V> {
2140 #[deref]
2141 #[deref_mut]
2142 pub(crate) any_handle: AnyWindowHandle,
2143 state_type: PhantomData<V>,
2144}
2145
2146impl<V: 'static + Render> WindowHandle<V> {
2147 pub fn new(id: WindowId) -> Self {
2148 WindowHandle {
2149 any_handle: AnyWindowHandle {
2150 id,
2151 state_type: TypeId::of::<V>(),
2152 },
2153 state_type: PhantomData,
2154 }
2155 }
2156
2157 pub fn update<C, R>(
2158 self,
2159 cx: &mut C,
2160 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2161 ) -> Result<R>
2162 where
2163 C: Context,
2164 {
2165 cx.update_window(self.any_handle, |root_view, cx| {
2166 let view = root_view
2167 .downcast::<V>()
2168 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2169 Ok(cx.update_view(&view, update))
2170 })?
2171 }
2172}
2173
2174impl<V> Copy for WindowHandle<V> {}
2175
2176impl<V> Clone for WindowHandle<V> {
2177 fn clone(&self) -> Self {
2178 WindowHandle {
2179 any_handle: self.any_handle,
2180 state_type: PhantomData,
2181 }
2182 }
2183}
2184
2185impl<V> PartialEq for WindowHandle<V> {
2186 fn eq(&self, other: &Self) -> bool {
2187 self.any_handle == other.any_handle
2188 }
2189}
2190
2191impl<V> Eq for WindowHandle<V> {}
2192
2193impl<V> Hash for WindowHandle<V> {
2194 fn hash<H: Hasher>(&self, state: &mut H) {
2195 self.any_handle.hash(state);
2196 }
2197}
2198
2199impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2200 fn into(self) -> AnyWindowHandle {
2201 self.any_handle
2202 }
2203}
2204
2205#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2206pub struct AnyWindowHandle {
2207 pub(crate) id: WindowId,
2208 state_type: TypeId,
2209}
2210
2211impl AnyWindowHandle {
2212 pub fn window_id(&self) -> WindowId {
2213 self.id
2214 }
2215
2216 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2217 if TypeId::of::<T>() == self.state_type {
2218 Some(WindowHandle {
2219 any_handle: *self,
2220 state_type: PhantomData,
2221 })
2222 } else {
2223 None
2224 }
2225 }
2226
2227 pub fn update<C, R>(
2228 self,
2229 cx: &mut C,
2230 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2231 ) -> Result<R>
2232 where
2233 C: Context,
2234 {
2235 cx.update_window(self, update)
2236 }
2237}
2238
2239#[cfg(any(test, feature = "test-support"))]
2240impl From<SmallVec<[u32; 16]>> for StackingOrder {
2241 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2242 StackingOrder(small_vec)
2243 }
2244}
2245
2246#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2247pub enum ElementId {
2248 View(EntityId),
2249 Number(usize),
2250 Name(SharedString),
2251 FocusHandle(FocusId),
2252}
2253
2254impl From<EntityId> for ElementId {
2255 fn from(id: EntityId) -> Self {
2256 ElementId::View(id)
2257 }
2258}
2259
2260impl From<usize> for ElementId {
2261 fn from(id: usize) -> Self {
2262 ElementId::Number(id)
2263 }
2264}
2265
2266impl From<i32> for ElementId {
2267 fn from(id: i32) -> Self {
2268 Self::Number(id as usize)
2269 }
2270}
2271
2272impl From<SharedString> for ElementId {
2273 fn from(name: SharedString) -> Self {
2274 ElementId::Name(name)
2275 }
2276}
2277
2278impl From<&'static str> for ElementId {
2279 fn from(name: &'static str) -> Self {
2280 ElementId::Name(name.into())
2281 }
2282}
2283
2284impl<'a> From<&'a FocusHandle> for ElementId {
2285 fn from(handle: &'a FocusHandle) -> Self {
2286 ElementId::FocusHandle(handle.id)
2287 }
2288}