1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyBox, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, CallbackHandle, ConstructorHandle,
4 Context, Corners, CursorStyle, DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges,
5 Effect, Entity, EntityId, EventEmitter, FileDropEvent, Flatten, FocusEvent, FontId,
6 GlobalElementId, GlyphId, Hsla, ImageData, InputEvent, IsZero, KeyBinding, KeyContext,
7 KeyDownEvent, LayoutId, Model, ModelContext, Modifiers, MonochromeSprite, MouseButton,
8 MouseDownEvent, MouseMoveEvent, MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay,
9 PlatformInputHandler, PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render,
10 RenderGlyphParams, RenderImageParams, RenderSvgParams, ScaledPixels, SceneBuilder, Shadow,
11 SharedString, Size, Style, SubscriberSet, Subscription, TaffyLayoutEngine, Task, Underline,
12 UnderlineStyle, View, VisualContext, WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Context as _, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use parking_lot::RwLock;
22use slotmap::SlotMap;
23use smallvec::SmallVec;
24use std::{
25 any::{Any, TypeId},
26 borrow::{Borrow, BorrowMut, Cow},
27 fmt::Debug,
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37};
38use util::ResultExt;
39
40/// A global stacking order, which is created by stacking successive z-index values.
41/// Each z-index will always be interpreted in the context of its parent z-index.
42#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
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: FocusableView + EventEmitter<Manager> {}
197
198impl<M: FocusableView + EventEmitter<Manager>> ManagedView for M {}
199
200pub enum Manager {
201 Dismiss,
202}
203
204// Holds the state for a specific window.
205pub struct Window {
206 pub(crate) handle: AnyWindowHandle,
207 pub(crate) removed: bool,
208 pub(crate) platform_window: Box<dyn PlatformWindow>,
209 display_id: DisplayId,
210 sprite_atlas: Arc<dyn PlatformAtlas>,
211 rem_size: Pixels,
212 viewport_size: Size<Pixels>,
213 pub(crate) layout_engine: TaffyLayoutEngine,
214 pub(crate) root_view: Option<AnyView>,
215 pub(crate) element_id_stack: GlobalElementId,
216 pub(crate) previous_frame: Frame,
217 pub(crate) current_frame: Frame,
218 pub(crate) focus_handles: Arc<RwLock<SlotMap<FocusId, AtomicUsize>>>,
219 pub(crate) focus_listeners: SubscriberSet<(), AnyWindowFocusListener>,
220 default_prevented: bool,
221 mouse_position: Point<Pixels>,
222 requested_cursor_style: Option<CursorStyle>,
223 scale_factor: f32,
224 bounds: WindowBounds,
225 bounds_observers: SubscriberSet<(), AnyObserver>,
226 active: bool,
227 activation_observers: SubscriberSet<(), AnyObserver>,
228 pub(crate) dirty: bool,
229 pub(crate) last_blur: Option<Option<FocusId>>,
230 pub(crate) focus: Option<FocusId>,
231}
232
233// #[derive(Default)]
234pub(crate) struct Frame {
235 pub(crate) element_states: HashMap<GlobalElementId, AnyBox>,
236 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
237 pub(crate) dispatch_tree: DispatchTree,
238 pub(crate) focus_listeners: Vec<AnyFocusListener>,
239 pub(crate) scene_builder: SceneBuilder,
240 z_index_stack: StackingOrder,
241 content_mask_stack: Vec<ContentMask<Pixels>>,
242 element_offset_stack: Vec<Point<Pixels>>,
243}
244
245impl Frame {
246 pub fn new(dispatch_tree: DispatchTree) -> Self {
247 Frame {
248 element_states: HashMap::default(),
249 mouse_listeners: HashMap::default(),
250 dispatch_tree,
251 focus_listeners: Vec::new(),
252 scene_builder: SceneBuilder::default(),
253 z_index_stack: StackingOrder::default(),
254 content_mask_stack: Vec::new(),
255 element_offset_stack: Vec::new(),
256 }
257 }
258}
259
260impl Window {
261 pub(crate) fn new(
262 handle: AnyWindowHandle,
263 options: WindowOptions,
264 cx: &mut AppContext,
265 ) -> Self {
266 let platform_window = cx.platform.open_window(handle, options);
267 let display_id = platform_window.display().id();
268 let sprite_atlas = platform_window.sprite_atlas();
269 let mouse_position = platform_window.mouse_position();
270 let content_size = platform_window.content_size();
271 let scale_factor = platform_window.scale_factor();
272 let bounds = platform_window.bounds();
273
274 platform_window.on_resize(Box::new({
275 let mut cx = cx.to_async();
276 move |_, _| {
277 handle
278 .update(&mut cx, |_, cx| cx.window_bounds_changed())
279 .log_err();
280 }
281 }));
282 platform_window.on_moved(Box::new({
283 let mut cx = cx.to_async();
284 move || {
285 handle
286 .update(&mut cx, |_, cx| cx.window_bounds_changed())
287 .log_err();
288 }
289 }));
290 platform_window.on_active_status_change(Box::new({
291 let mut cx = cx.to_async();
292 move |active| {
293 handle
294 .update(&mut cx, |_, cx| {
295 cx.window.active = active;
296 cx.window
297 .activation_observers
298 .clone()
299 .retain(&(), |callback| callback(cx));
300 })
301 .log_err();
302 }
303 }));
304
305 platform_window.on_input({
306 let mut cx = cx.to_async();
307 Box::new(move |event| {
308 handle
309 .update(&mut cx, |_, cx| cx.dispatch_event(event))
310 .log_err()
311 .unwrap_or(false)
312 })
313 });
314
315 Window {
316 handle,
317 removed: false,
318 platform_window,
319 display_id,
320 sprite_atlas,
321 rem_size: px(16.),
322 viewport_size: content_size,
323 layout_engine: TaffyLayoutEngine::new(),
324 root_view: None,
325 element_id_stack: GlobalElementId::default(),
326 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
327 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
328 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
329 focus_listeners: SubscriberSet::new(),
330 default_prevented: true,
331 mouse_position,
332 requested_cursor_style: None,
333 scale_factor,
334 bounds,
335 bounds_observers: SubscriberSet::new(),
336 active: false,
337 activation_observers: SubscriberSet::new(),
338 dirty: true,
339 last_blur: None,
340 focus: None,
341 }
342 }
343}
344
345/// Indicates which region of the window is visible. Content falling outside of this mask will not be
346/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
347/// to leave room to support more complex shapes in the future.
348#[derive(Clone, Debug, Default, PartialEq, Eq)]
349#[repr(C)]
350pub struct ContentMask<P: Clone + Default + Debug> {
351 pub bounds: Bounds<P>,
352}
353
354impl ContentMask<Pixels> {
355 /// Scale the content mask's pixel units by the given scaling factor.
356 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
357 ContentMask {
358 bounds: self.bounds.scale(factor),
359 }
360 }
361
362 /// Intersect the content mask with the given content mask.
363 pub fn intersect(&self, other: &Self) -> Self {
364 let bounds = self.bounds.intersect(&other.bounds);
365 ContentMask { bounds }
366 }
367}
368
369/// Provides access to application state in the context of a single window. Derefs
370/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
371/// an `AppContext` and call any `AppContext` methods.
372pub struct WindowContext<'a> {
373 pub(crate) app: &'a mut AppContext,
374 pub(crate) window: &'a mut Window,
375}
376
377impl<'a> WindowContext<'a> {
378 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
379 Self { app, window }
380 }
381
382 /// Obtain a handle to the window that belongs to this context.
383 pub fn window_handle(&self) -> AnyWindowHandle {
384 self.window.handle
385 }
386
387 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
388 pub fn notify(&mut self) {
389 self.window.dirty = true;
390 }
391
392 /// Close this window.
393 pub fn remove_window(&mut self) {
394 self.window.removed = true;
395 }
396
397 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
398 /// for elements rendered within this window.
399 pub fn focus_handle(&mut self) -> FocusHandle {
400 FocusHandle::new(&self.window.focus_handles)
401 }
402
403 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
404 pub fn focused(&self) -> Option<FocusHandle> {
405 self.window
406 .focus
407 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
408 }
409
410 /// Move focus to the element associated with the given `FocusHandle`.
411 pub fn focus(&mut self, handle: &FocusHandle) {
412 if self.window.focus == Some(handle.id) {
413 return;
414 }
415
416 let focus_id = handle.id;
417
418 if self.window.last_blur.is_none() {
419 self.window.last_blur = Some(self.window.focus);
420 }
421
422 self.window.focus = Some(focus_id);
423 self.window
424 .current_frame
425 .dispatch_tree
426 .clear_keystroke_matchers();
427 self.app.push_effect(Effect::FocusChanged {
428 window_handle: self.window.handle,
429 focused: Some(focus_id),
430 });
431 self.notify();
432 }
433
434 /// Remove focus from all elements within this context's window.
435 pub fn blur(&mut self) {
436 if self.window.last_blur.is_none() {
437 self.window.last_blur = Some(self.window.focus);
438 }
439
440 self.window.focus = None;
441 self.app.push_effect(Effect::FocusChanged {
442 window_handle: self.window.handle,
443 focused: None,
444 });
445 self.notify();
446 }
447
448 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
449 if let Some(focus_handle) = self.focused() {
450 self.defer(move |cx| {
451 if let Some(node_id) = cx
452 .window
453 .current_frame
454 .dispatch_tree
455 .focusable_node_id(focus_handle.id)
456 {
457 cx.propagate_event = true;
458 cx.dispatch_action_on_node(node_id, action);
459 }
460 })
461 }
462 }
463
464 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
465 /// that are currently on the stack to be returned to the app.
466 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
467 let handle = self.window.handle;
468 self.app.defer(move |cx| {
469 handle.update(cx, |_, cx| f(cx)).ok();
470 });
471 }
472
473 pub fn subscribe<Emitter, E, Evt>(
474 &mut self,
475 entity: &E,
476 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
477 ) -> Subscription
478 where
479 Emitter: EventEmitter<Evt>,
480 E: Entity<Emitter>,
481 Evt: 'static,
482 {
483 let entity_id = entity.entity_id();
484 let entity = entity.downgrade();
485 let window_handle = self.window.handle;
486 self.app.event_listeners.insert(
487 entity_id,
488 (
489 TypeId::of::<Evt>(),
490 Box::new(move |event, cx| {
491 window_handle
492 .update(cx, |_, cx| {
493 if let Some(handle) = E::upgrade_from(&entity) {
494 let event = event.downcast_ref().expect("invalid event type");
495 on_event(handle, event, cx);
496 true
497 } else {
498 false
499 }
500 })
501 .unwrap_or(false)
502 }),
503 ),
504 )
505 }
506
507 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
508 /// await points in async code.
509 pub fn to_async(&self) -> AsyncWindowContext {
510 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
511 }
512
513 /// Schedule the given closure to be run directly after the current frame is rendered.
514 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
515 let handle = self.window.handle;
516 let display_id = self.window.display_id;
517
518 if !self.frame_consumers.contains_key(&display_id) {
519 let (tx, mut rx) = mpsc::unbounded::<()>();
520 self.platform.set_display_link_output_callback(
521 display_id,
522 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
523 );
524
525 let consumer_task = self.app.spawn(|cx| async move {
526 while rx.next().await.is_some() {
527 cx.update(|cx| {
528 for callback in cx
529 .next_frame_callbacks
530 .get_mut(&display_id)
531 .unwrap()
532 .drain(..)
533 .collect::<SmallVec<[_; 32]>>()
534 {
535 callback(cx);
536 }
537 })
538 .ok();
539
540 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
541
542 cx.update(|cx| {
543 if cx.next_frame_callbacks.is_empty() {
544 cx.platform.stop_display_link(display_id);
545 }
546 })
547 .ok();
548 }
549 });
550 self.frame_consumers.insert(display_id, consumer_task);
551 }
552
553 if self.next_frame_callbacks.is_empty() {
554 self.platform.start_display_link(display_id);
555 }
556
557 self.next_frame_callbacks
558 .entry(display_id)
559 .or_default()
560 .push(Box::new(move |cx: &mut AppContext| {
561 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
562 }));
563 }
564
565 /// Spawn the future returned by the given closure on the application thread pool.
566 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
567 /// use within your future.
568 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
569 where
570 R: 'static,
571 Fut: Future<Output = R> + 'static,
572 {
573 self.app
574 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
575 }
576
577 /// Update the global of the given type. The given closure is given simultaneous mutable
578 /// access both to the global and the context.
579 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
580 where
581 G: 'static,
582 {
583 let mut global = self.app.lease_global::<G>();
584 let result = f(&mut global, self);
585 self.app.end_global_lease(global);
586 result
587 }
588
589 #[must_use]
590 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
591 /// layout is being requested, along with the layout ids of any children. This method is called during
592 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
593 pub fn request_layout(
594 &mut self,
595 style: &Style,
596 children: impl IntoIterator<Item = LayoutId>,
597 ) -> LayoutId {
598 self.app.layout_id_buffer.clear();
599 self.app.layout_id_buffer.extend(children.into_iter());
600 let rem_size = self.rem_size();
601
602 self.window
603 .layout_engine
604 .request_layout(style, rem_size, &self.app.layout_id_buffer)
605 }
606
607 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
608 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
609 /// determine the element's size. One place this is used internally is when measuring text.
610 ///
611 /// The given closure is invoked at layout time with the known dimensions and available space and
612 /// returns a `Size`.
613 pub fn request_measured_layout<
614 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
615 >(
616 &mut self,
617 style: Style,
618 rem_size: Pixels,
619 measure: F,
620 ) -> LayoutId {
621 self.window
622 .layout_engine
623 .request_measured_layout(style, rem_size, measure)
624 }
625
626 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
627 self.window
628 .layout_engine
629 .compute_layout(layout_id, available_space)
630 }
631
632 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
633 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
634 /// in order to pass your element its `Bounds` automatically.
635 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
636 let mut bounds = self
637 .window
638 .layout_engine
639 .layout_bounds(layout_id)
640 .map(Into::into);
641 bounds.origin += self.element_offset();
642 bounds
643 }
644
645 fn window_bounds_changed(&mut self) {
646 self.window.scale_factor = self.window.platform_window.scale_factor();
647 self.window.viewport_size = self.window.platform_window.content_size();
648 self.window.bounds = self.window.platform_window.bounds();
649 self.window.display_id = self.window.platform_window.display().id();
650 self.window.dirty = true;
651
652 self.window
653 .bounds_observers
654 .clone()
655 .retain(&(), |callback| callback(self));
656 }
657
658 pub fn window_bounds(&self) -> WindowBounds {
659 self.window.bounds
660 }
661
662 pub fn viewport_size(&self) -> Size<Pixels> {
663 self.window.viewport_size
664 }
665
666 pub fn is_window_active(&self) -> bool {
667 self.window.active
668 }
669
670 pub fn zoom_window(&self) {
671 self.window.platform_window.zoom();
672 }
673
674 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
675 self.platform
676 .displays()
677 .into_iter()
678 .find(|display| display.id() == self.window.display_id)
679 }
680
681 pub fn show_character_palette(&self) {
682 self.window.platform_window.show_character_palette();
683 }
684
685 /// The scale factor of the display associated with the window. For example, it could
686 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
687 /// be rendered as two pixels on screen.
688 pub fn scale_factor(&self) -> f32 {
689 self.window.scale_factor
690 }
691
692 /// The size of an em for the base font of the application. Adjusting this value allows the
693 /// UI to scale, just like zooming a web page.
694 pub fn rem_size(&self) -> Pixels {
695 self.window.rem_size
696 }
697
698 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
699 /// UI to scale, just like zooming a web page.
700 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
701 self.window.rem_size = rem_size.into();
702 }
703
704 /// The line height associated with the current text style.
705 pub fn line_height(&self) -> Pixels {
706 let rem_size = self.rem_size();
707 let text_style = self.text_style();
708 text_style
709 .line_height
710 .to_pixels(text_style.font_size.into(), rem_size)
711 }
712
713 /// Call to prevent the default action of an event. Currently only used to prevent
714 /// parent elements from becoming focused on mouse down.
715 pub fn prevent_default(&mut self) {
716 self.window.default_prevented = true;
717 }
718
719 /// Obtain whether default has been prevented for the event currently being dispatched.
720 pub fn default_prevented(&self) -> bool {
721 self.window.default_prevented
722 }
723
724 /// Register a mouse event listener on the window for the current frame. The type of event
725 /// is determined by the first parameter of the given listener. When the next frame is rendered
726 /// the listener will be cleared.
727 ///
728 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
729 /// a specific need to register a global listener.
730 pub fn on_mouse_event<Event: 'static>(
731 &mut self,
732 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
733 ) {
734 let order = self.window.current_frame.z_index_stack.clone();
735 self.window
736 .current_frame
737 .mouse_listeners
738 .entry(TypeId::of::<Event>())
739 .or_default()
740 .push((
741 order,
742 Box::new(move |event: &dyn Any, phase, cx| {
743 handler(event.downcast_ref().unwrap(), phase, cx)
744 }),
745 ))
746 }
747
748 /// Register a key event listener on the window for the current frame. The type of event
749 /// is determined by the first parameter of the given listener. When the next frame is rendered
750 /// the listener will be cleared.
751 ///
752 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
753 /// a specific need to register a global listener.
754 pub fn on_key_event<Event: 'static>(
755 &mut self,
756 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
757 ) {
758 self.window
759 .current_frame
760 .dispatch_tree
761 .on_key_event(Rc::new(move |event, phase, cx| {
762 if let Some(event) = event.downcast_ref::<Event>() {
763 handler(event, phase, cx)
764 }
765 }));
766 }
767
768 /// Register an action listener on the window for the current frame. The type of action
769 /// is determined by the first parameter of the given listener. When the next frame is rendered
770 /// the listener will be cleared.
771 ///
772 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
773 /// a specific need to register a global listener.
774 pub fn on_action(
775 &mut self,
776 action_type: TypeId,
777 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
778 ) {
779 self.window.current_frame.dispatch_tree.on_action(
780 action_type,
781 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
782 );
783 }
784
785 /// The position of the mouse relative to the window.
786 pub fn mouse_position(&self) -> Point<Pixels> {
787 self.window.mouse_position
788 }
789
790 pub fn set_cursor_style(&mut self, style: CursorStyle) {
791 self.window.requested_cursor_style = Some(style)
792 }
793
794 /// Called during painting to invoke the given closure in a new stacking context. The given
795 /// z-index is interpreted relative to the previous call to `stack`.
796 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
797 self.window.current_frame.z_index_stack.push(z_index);
798 let result = f(self);
799 self.window.current_frame.z_index_stack.pop();
800 result
801 }
802
803 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
804 pub fn paint_shadows(
805 &mut self,
806 bounds: Bounds<Pixels>,
807 corner_radii: Corners<Pixels>,
808 shadows: &[BoxShadow],
809 ) {
810 let scale_factor = self.scale_factor();
811 let content_mask = self.content_mask();
812 let window = &mut *self.window;
813 for shadow in shadows {
814 let mut shadow_bounds = bounds;
815 shadow_bounds.origin += shadow.offset;
816 shadow_bounds.dilate(shadow.spread_radius);
817 window.current_frame.scene_builder.insert(
818 &window.current_frame.z_index_stack,
819 Shadow {
820 order: 0,
821 bounds: shadow_bounds.scale(scale_factor),
822 content_mask: content_mask.scale(scale_factor),
823 corner_radii: corner_radii.scale(scale_factor),
824 color: shadow.color,
825 blur_radius: shadow.blur_radius.scale(scale_factor),
826 },
827 );
828 }
829 }
830
831 /// Paint one or more quads into the scene for the current frame at the current stacking context.
832 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
833 pub fn paint_quad(
834 &mut self,
835 bounds: Bounds<Pixels>,
836 corner_radii: Corners<Pixels>,
837 background: impl Into<Hsla>,
838 border_widths: Edges<Pixels>,
839 border_color: impl Into<Hsla>,
840 ) {
841 let scale_factor = self.scale_factor();
842 let content_mask = self.content_mask();
843
844 let window = &mut *self.window;
845 window.current_frame.scene_builder.insert(
846 &window.current_frame.z_index_stack,
847 Quad {
848 order: 0,
849 bounds: bounds.scale(scale_factor),
850 content_mask: content_mask.scale(scale_factor),
851 background: background.into(),
852 border_color: border_color.into(),
853 corner_radii: corner_radii.scale(scale_factor),
854 border_widths: border_widths.scale(scale_factor),
855 },
856 );
857 }
858
859 /// Paint the given `Path` into the scene for the current frame at the current z-index.
860 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
861 let scale_factor = self.scale_factor();
862 let content_mask = self.content_mask();
863 path.content_mask = content_mask;
864 path.color = color.into();
865 let window = &mut *self.window;
866 window.current_frame.scene_builder.insert(
867 &window.current_frame.z_index_stack,
868 path.scale(scale_factor),
869 );
870 }
871
872 /// Paint an underline into the scene for the current frame at the current z-index.
873 pub fn paint_underline(
874 &mut self,
875 origin: Point<Pixels>,
876 width: Pixels,
877 style: &UnderlineStyle,
878 ) -> Result<()> {
879 let scale_factor = self.scale_factor();
880 let height = if style.wavy {
881 style.thickness * 3.
882 } else {
883 style.thickness
884 };
885 let bounds = Bounds {
886 origin,
887 size: size(width, height),
888 };
889 let content_mask = self.content_mask();
890 let window = &mut *self.window;
891 window.current_frame.scene_builder.insert(
892 &window.current_frame.z_index_stack,
893 Underline {
894 order: 0,
895 bounds: bounds.scale(scale_factor),
896 content_mask: content_mask.scale(scale_factor),
897 thickness: style.thickness.scale(scale_factor),
898 color: style.color.unwrap_or_default(),
899 wavy: style.wavy,
900 },
901 );
902 Ok(())
903 }
904
905 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
906 /// The y component of the origin is the baseline of the glyph.
907 pub fn paint_glyph(
908 &mut self,
909 origin: Point<Pixels>,
910 font_id: FontId,
911 glyph_id: GlyphId,
912 font_size: Pixels,
913 color: Hsla,
914 ) -> Result<()> {
915 let scale_factor = self.scale_factor();
916 let glyph_origin = origin.scale(scale_factor);
917 let subpixel_variant = Point {
918 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
919 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
920 };
921 let params = RenderGlyphParams {
922 font_id,
923 glyph_id,
924 font_size,
925 subpixel_variant,
926 scale_factor,
927 is_emoji: false,
928 };
929
930 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
931 if !raster_bounds.is_zero() {
932 let tile =
933 self.window
934 .sprite_atlas
935 .get_or_insert_with(¶ms.clone().into(), &mut || {
936 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
937 Ok((size, Cow::Owned(bytes)))
938 })?;
939 let bounds = Bounds {
940 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
941 size: tile.bounds.size.map(Into::into),
942 };
943 let content_mask = self.content_mask().scale(scale_factor);
944 let window = &mut *self.window;
945 window.current_frame.scene_builder.insert(
946 &window.current_frame.z_index_stack,
947 MonochromeSprite {
948 order: 0,
949 bounds,
950 content_mask,
951 color,
952 tile,
953 },
954 );
955 }
956 Ok(())
957 }
958
959 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
960 /// The y component of the origin is the baseline of the glyph.
961 pub fn paint_emoji(
962 &mut self,
963 origin: Point<Pixels>,
964 font_id: FontId,
965 glyph_id: GlyphId,
966 font_size: Pixels,
967 ) -> Result<()> {
968 let scale_factor = self.scale_factor();
969 let glyph_origin = origin.scale(scale_factor);
970 let params = RenderGlyphParams {
971 font_id,
972 glyph_id,
973 font_size,
974 // We don't render emojis with subpixel variants.
975 subpixel_variant: Default::default(),
976 scale_factor,
977 is_emoji: true,
978 };
979
980 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
981 if !raster_bounds.is_zero() {
982 let tile =
983 self.window
984 .sprite_atlas
985 .get_or_insert_with(¶ms.clone().into(), &mut || {
986 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
987 Ok((size, Cow::Owned(bytes)))
988 })?;
989 let bounds = Bounds {
990 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
991 size: tile.bounds.size.map(Into::into),
992 };
993 let content_mask = self.content_mask().scale(scale_factor);
994 let window = &mut *self.window;
995
996 window.current_frame.scene_builder.insert(
997 &window.current_frame.z_index_stack,
998 PolychromeSprite {
999 order: 0,
1000 bounds,
1001 corner_radii: Default::default(),
1002 content_mask,
1003 tile,
1004 grayscale: false,
1005 },
1006 );
1007 }
1008 Ok(())
1009 }
1010
1011 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1012 pub fn paint_svg(
1013 &mut self,
1014 bounds: Bounds<Pixels>,
1015 path: SharedString,
1016 color: Hsla,
1017 ) -> Result<()> {
1018 let scale_factor = self.scale_factor();
1019 let bounds = bounds.scale(scale_factor);
1020 // Render the SVG at twice the size to get a higher quality result.
1021 let params = RenderSvgParams {
1022 path,
1023 size: bounds
1024 .size
1025 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1026 };
1027
1028 let tile =
1029 self.window
1030 .sprite_atlas
1031 .get_or_insert_with(¶ms.clone().into(), &mut || {
1032 let bytes = self.svg_renderer.render(¶ms)?;
1033 Ok((params.size, Cow::Owned(bytes)))
1034 })?;
1035 let content_mask = self.content_mask().scale(scale_factor);
1036
1037 let window = &mut *self.window;
1038 window.current_frame.scene_builder.insert(
1039 &window.current_frame.z_index_stack,
1040 MonochromeSprite {
1041 order: 0,
1042 bounds,
1043 content_mask,
1044 color,
1045 tile,
1046 },
1047 );
1048
1049 Ok(())
1050 }
1051
1052 /// Paint an image into the scene for the current frame at the current z-index.
1053 pub fn paint_image(
1054 &mut self,
1055 bounds: Bounds<Pixels>,
1056 corner_radii: Corners<Pixels>,
1057 data: Arc<ImageData>,
1058 grayscale: bool,
1059 ) -> Result<()> {
1060 let scale_factor = self.scale_factor();
1061 let bounds = bounds.scale(scale_factor);
1062 let params = RenderImageParams { image_id: data.id };
1063
1064 let tile = self
1065 .window
1066 .sprite_atlas
1067 .get_or_insert_with(¶ms.clone().into(), &mut || {
1068 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1069 })?;
1070 let content_mask = self.content_mask().scale(scale_factor);
1071 let corner_radii = corner_radii.scale(scale_factor);
1072
1073 let window = &mut *self.window;
1074 window.current_frame.scene_builder.insert(
1075 &window.current_frame.z_index_stack,
1076 PolychromeSprite {
1077 order: 0,
1078 bounds,
1079 content_mask,
1080 corner_radii,
1081 tile,
1082 grayscale,
1083 },
1084 );
1085 Ok(())
1086 }
1087
1088 /// Draw pixels to the display for this window based on the contents of its scene.
1089 pub(crate) fn draw(&mut self) {
1090 let root_view = self.window.root_view.take().unwrap();
1091
1092 self.start_frame();
1093
1094 self.with_z_index(0, |cx| {
1095 let available_space = cx.window.viewport_size.map(Into::into);
1096 root_view.draw(Point::zero(), available_space, cx);
1097 });
1098
1099 if let Some(active_drag) = self.app.active_drag.take() {
1100 self.with_z_index(1, |cx| {
1101 let offset = cx.mouse_position() - active_drag.cursor_offset;
1102 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1103 active_drag.view.draw(offset, available_space, cx);
1104 cx.active_drag = Some(active_drag);
1105 });
1106 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1107 self.with_z_index(1, |cx| {
1108 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1109 active_tooltip
1110 .view
1111 .draw(active_tooltip.cursor_offset, available_space, cx);
1112 });
1113 }
1114
1115 self.window
1116 .current_frame
1117 .dispatch_tree
1118 .preserve_keystroke_matchers(
1119 &mut self.window.previous_frame.dispatch_tree,
1120 self.window.focus,
1121 );
1122
1123 self.window.root_view = Some(root_view);
1124 let scene = self.window.current_frame.scene_builder.build();
1125
1126 self.window.platform_window.draw(scene);
1127 let cursor_style = self
1128 .window
1129 .requested_cursor_style
1130 .take()
1131 .unwrap_or(CursorStyle::Arrow);
1132 self.platform.set_cursor_style(cursor_style);
1133
1134 self.window.dirty = false;
1135 }
1136
1137 /// Rotate the current frame and the previous frame, then clear the current frame.
1138 /// We repopulate all state in the current frame during each paint.
1139 fn start_frame(&mut self) {
1140 self.text_system().start_frame();
1141
1142 let window = &mut *self.window;
1143 window.layout_engine.clear();
1144
1145 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1146 let frame = &mut window.current_frame;
1147 frame.element_states.clear();
1148 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1149 frame.focus_listeners.clear();
1150 frame.dispatch_tree.clear();
1151 }
1152
1153 /// Dispatch a mouse or keyboard event on the window.
1154 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1155 // Handlers may set this to false by calling `stop_propagation`
1156 self.app.propagate_event = true;
1157 self.window.default_prevented = false;
1158
1159 let event = match event {
1160 // Track the mouse position with our own state, since accessing the platform
1161 // API for the mouse position can only occur on the main thread.
1162 InputEvent::MouseMove(mouse_move) => {
1163 self.window.mouse_position = mouse_move.position;
1164 InputEvent::MouseMove(mouse_move)
1165 }
1166 InputEvent::MouseDown(mouse_down) => {
1167 self.window.mouse_position = mouse_down.position;
1168 InputEvent::MouseDown(mouse_down)
1169 }
1170 InputEvent::MouseUp(mouse_up) => {
1171 self.window.mouse_position = mouse_up.position;
1172 InputEvent::MouseUp(mouse_up)
1173 }
1174 // Translate dragging and dropping of external files from the operating system
1175 // to internal drag and drop events.
1176 InputEvent::FileDrop(file_drop) => match file_drop {
1177 FileDropEvent::Entered { position, files } => {
1178 self.window.mouse_position = position;
1179 if self.active_drag.is_none() {
1180 self.active_drag = Some(AnyDrag {
1181 view: self.build_view(|_| files).into(),
1182 cursor_offset: position,
1183 });
1184 }
1185 InputEvent::MouseDown(MouseDownEvent {
1186 position,
1187 button: MouseButton::Left,
1188 click_count: 1,
1189 modifiers: Modifiers::default(),
1190 })
1191 }
1192 FileDropEvent::Pending { position } => {
1193 self.window.mouse_position = position;
1194 InputEvent::MouseMove(MouseMoveEvent {
1195 position,
1196 pressed_button: Some(MouseButton::Left),
1197 modifiers: Modifiers::default(),
1198 })
1199 }
1200 FileDropEvent::Submit { position } => {
1201 self.window.mouse_position = position;
1202 InputEvent::MouseUp(MouseUpEvent {
1203 button: MouseButton::Left,
1204 position,
1205 modifiers: Modifiers::default(),
1206 click_count: 1,
1207 })
1208 }
1209 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1210 button: MouseButton::Left,
1211 position: Point::default(),
1212 modifiers: Modifiers::default(),
1213 click_count: 1,
1214 }),
1215 },
1216 _ => event,
1217 };
1218
1219 if let Some(any_mouse_event) = event.mouse_event() {
1220 self.dispatch_mouse_event(any_mouse_event);
1221 } else if let Some(any_key_event) = event.keyboard_event() {
1222 self.dispatch_key_event(any_key_event);
1223 }
1224
1225 !self.app.propagate_event
1226 }
1227
1228 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1229 if let Some(mut handlers) = self
1230 .window
1231 .current_frame
1232 .mouse_listeners
1233 .remove(&event.type_id())
1234 {
1235 // Because handlers may add other handlers, we sort every time.
1236 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1237
1238 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1239 // special purposes, such as detecting events outside of a given Bounds.
1240 for (_, handler) in &mut handlers {
1241 handler(event, DispatchPhase::Capture, self);
1242 if !self.app.propagate_event {
1243 break;
1244 }
1245 }
1246
1247 // Bubble phase, where most normal handlers do their work.
1248 if self.app.propagate_event {
1249 for (_, handler) in handlers.iter_mut().rev() {
1250 handler(event, DispatchPhase::Bubble, self);
1251 if !self.app.propagate_event {
1252 break;
1253 }
1254 }
1255 }
1256
1257 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1258 self.active_drag = None;
1259 }
1260
1261 // Just in case any handlers added new handlers, which is weird, but possible.
1262 handlers.extend(
1263 self.window
1264 .current_frame
1265 .mouse_listeners
1266 .get_mut(&event.type_id())
1267 .into_iter()
1268 .flat_map(|handlers| handlers.drain(..)),
1269 );
1270 self.window
1271 .current_frame
1272 .mouse_listeners
1273 .insert(event.type_id(), handlers);
1274 }
1275 }
1276
1277 fn dispatch_key_event(&mut self, event: &dyn Any) {
1278 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1279 self.window
1280 .current_frame
1281 .dispatch_tree
1282 .focusable_node_id(focus_id)
1283 }) {
1284 let dispatch_path = self
1285 .window
1286 .current_frame
1287 .dispatch_tree
1288 .dispatch_path(node_id);
1289
1290 // Capture phase
1291 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1292 self.propagate_event = true;
1293
1294 for node_id in &dispatch_path {
1295 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1296
1297 if !node.context.is_empty() {
1298 context_stack.push(node.context.clone());
1299 }
1300
1301 for key_listener in node.key_listeners.clone() {
1302 key_listener(event, DispatchPhase::Capture, self);
1303 if !self.propagate_event {
1304 return;
1305 }
1306 }
1307 }
1308
1309 // Bubble phase
1310 for node_id in dispatch_path.iter().rev() {
1311 // Handle low level key events
1312 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1313 for key_listener in node.key_listeners.clone() {
1314 key_listener(event, DispatchPhase::Bubble, self);
1315 if !self.propagate_event {
1316 return;
1317 }
1318 }
1319
1320 // Match keystrokes
1321 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1322 if !node.context.is_empty() {
1323 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1324 if let Some(action) = self
1325 .window
1326 .current_frame
1327 .dispatch_tree
1328 .dispatch_key(&key_down_event.keystroke, &context_stack)
1329 {
1330 self.dispatch_action_on_node(*node_id, action);
1331 if !self.propagate_event {
1332 return;
1333 }
1334 }
1335 }
1336
1337 context_stack.pop();
1338 }
1339 }
1340 }
1341 }
1342
1343 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1344 let dispatch_path = self
1345 .window
1346 .current_frame
1347 .dispatch_tree
1348 .dispatch_path(node_id);
1349
1350 // Capture phase
1351 for node_id in &dispatch_path {
1352 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1353 for DispatchActionListener {
1354 action_type,
1355 listener,
1356 } in node.action_listeners.clone()
1357 {
1358 let any_action = action.as_any();
1359 if action_type == any_action.type_id() {
1360 listener(any_action, DispatchPhase::Capture, self);
1361 if !self.propagate_event {
1362 return;
1363 }
1364 }
1365 }
1366 }
1367
1368 // Bubble phase
1369 for node_id in dispatch_path.iter().rev() {
1370 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1371 for DispatchActionListener {
1372 action_type,
1373 listener,
1374 } in node.action_listeners.clone()
1375 {
1376 let any_action = action.as_any();
1377 if action_type == any_action.type_id() {
1378 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1379 listener(any_action, DispatchPhase::Bubble, self);
1380 if !self.propagate_event {
1381 return;
1382 }
1383 }
1384 }
1385 }
1386 }
1387
1388 /// Register the given handler to be invoked whenever the global of the given type
1389 /// is updated.
1390 pub fn observe_global<G: 'static>(
1391 &mut self,
1392 f: impl Fn(&mut WindowContext<'_>) + 'static,
1393 ) -> Subscription {
1394 let window_handle = self.window.handle;
1395 self.global_observers.insert(
1396 TypeId::of::<G>(),
1397 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1398 )
1399 }
1400
1401 pub fn activate_window(&self) {
1402 self.window.platform_window.activate();
1403 }
1404
1405 pub fn minimize_window(&self) {
1406 self.window.platform_window.minimize();
1407 }
1408
1409 pub fn toggle_full_screen(&self) {
1410 self.window.platform_window.toggle_full_screen();
1411 }
1412
1413 pub fn prompt(
1414 &self,
1415 level: PromptLevel,
1416 msg: &str,
1417 answers: &[&str],
1418 ) -> oneshot::Receiver<usize> {
1419 self.window.platform_window.prompt(level, msg, answers)
1420 }
1421
1422 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1423 if let Some(focus_id) = self.window.focus {
1424 self.window
1425 .current_frame
1426 .dispatch_tree
1427 .available_actions(focus_id)
1428 } else {
1429 Vec::new()
1430 }
1431 }
1432
1433 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1434 self.window
1435 .current_frame
1436 .dispatch_tree
1437 .bindings_for_action(action)
1438 }
1439
1440 ///========== ELEMENT RELATED FUNCTIONS ===========
1441 pub fn with_key_dispatch<R>(
1442 &mut self,
1443 context: KeyContext,
1444 focus_handle: Option<FocusHandle>,
1445 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1446 ) -> R {
1447 let window = &mut self.window;
1448 window
1449 .current_frame
1450 .dispatch_tree
1451 .push_node(context.clone());
1452 if let Some(focus_handle) = focus_handle.as_ref() {
1453 window
1454 .current_frame
1455 .dispatch_tree
1456 .make_focusable(focus_handle.id);
1457 }
1458 let result = f(focus_handle, self);
1459
1460 self.window.current_frame.dispatch_tree.pop_node();
1461
1462 result
1463 }
1464
1465 /// Register a focus listener for the current frame only. It will be cleared
1466 /// on the next frame render. You should use this method only from within elements,
1467 /// and we may want to enforce that better via a different context type.
1468 // todo!() Move this to `FrameContext` to emphasize its individuality?
1469 pub fn on_focus_changed(
1470 &mut self,
1471 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1472 ) {
1473 self.window
1474 .current_frame
1475 .focus_listeners
1476 .push(Box::new(move |event, cx| {
1477 listener(event, cx);
1478 }));
1479 }
1480}
1481
1482impl Context for WindowContext<'_> {
1483 type Result<T> = T;
1484
1485 fn build_model<T>(
1486 &mut self,
1487 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1488 ) -> Model<T>
1489 where
1490 T: 'static,
1491 {
1492 let slot = self.app.entities.reserve();
1493 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1494 self.entities.insert(slot, model)
1495 }
1496
1497 fn update_model<T: 'static, R>(
1498 &mut self,
1499 model: &Model<T>,
1500 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1501 ) -> R {
1502 let mut entity = self.entities.lease(model);
1503 let result = update(
1504 &mut *entity,
1505 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1506 );
1507 self.entities.end_lease(entity);
1508 result
1509 }
1510
1511 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1512 where
1513 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1514 {
1515 if window == self.window.handle {
1516 let root_view = self.window.root_view.clone().unwrap();
1517 Ok(update(root_view, self))
1518 } else {
1519 window.update(self.app, update)
1520 }
1521 }
1522
1523 fn read_model<T, R>(
1524 &self,
1525 handle: &Model<T>,
1526 read: impl FnOnce(&T, &AppContext) -> R,
1527 ) -> Self::Result<R>
1528 where
1529 T: 'static,
1530 {
1531 let entity = self.entities.read(handle);
1532 read(&*entity, &*self.app)
1533 }
1534
1535 fn read_window<T, R>(
1536 &self,
1537 window: &WindowHandle<T>,
1538 read: impl FnOnce(View<T>, &AppContext) -> R,
1539 ) -> Result<R>
1540 where
1541 T: 'static,
1542 {
1543 if window.any_handle == self.window.handle {
1544 let root_view = self
1545 .window
1546 .root_view
1547 .clone()
1548 .unwrap()
1549 .downcast::<T>()
1550 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1551 Ok(read(root_view, self))
1552 } else {
1553 self.app.read_window(window, read)
1554 }
1555 }
1556}
1557
1558impl VisualContext for WindowContext<'_> {
1559 fn build_view<V>(
1560 &mut self,
1561 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1562 ) -> Self::Result<View<V>>
1563 where
1564 V: 'static + Render,
1565 {
1566 let slot = self.app.entities.reserve();
1567 let view = View {
1568 model: slot.clone(),
1569 };
1570 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1571 let entity = build_view_state(&mut cx);
1572 cx.entities.insert(slot, entity);
1573
1574 cx.new_view_observers
1575 .clone()
1576 .retain(&TypeId::of::<V>(), |observer| {
1577 let any_view = AnyView::from(view.clone());
1578 (observer)(any_view, self);
1579 true
1580 });
1581
1582 view
1583 }
1584
1585 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1586 fn update_view<T: 'static, R>(
1587 &mut self,
1588 view: &View<T>,
1589 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1590 ) -> Self::Result<R> {
1591 let mut lease = self.app.entities.lease(&view.model);
1592 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1593 let result = update(&mut *lease, &mut cx);
1594 cx.app.entities.end_lease(lease);
1595 result
1596 }
1597
1598 fn replace_root_view<V>(
1599 &mut self,
1600 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1601 ) -> Self::Result<View<V>>
1602 where
1603 V: Render,
1604 {
1605 let slot = self.app.entities.reserve();
1606 let view = View {
1607 model: slot.clone(),
1608 };
1609 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1610 let entity = build_view(&mut cx);
1611 self.entities.insert(slot, entity);
1612 self.window.root_view = Some(view.clone().into());
1613 view
1614 }
1615
1616 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1617 self.update_view(view, |view, cx| {
1618 view.focus_handle(cx).clone().focus(cx);
1619 })
1620 }
1621
1622 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1623 where
1624 V: ManagedView,
1625 {
1626 self.update_view(view, |_, cx| cx.emit(Manager::Dismiss))
1627 }
1628}
1629
1630impl<'a> std::ops::Deref for WindowContext<'a> {
1631 type Target = AppContext;
1632
1633 fn deref(&self) -> &Self::Target {
1634 &self.app
1635 }
1636}
1637
1638impl<'a> std::ops::DerefMut for WindowContext<'a> {
1639 fn deref_mut(&mut self) -> &mut Self::Target {
1640 &mut self.app
1641 }
1642}
1643
1644impl<'a> Borrow<AppContext> for WindowContext<'a> {
1645 fn borrow(&self) -> &AppContext {
1646 &self.app
1647 }
1648}
1649
1650impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1651 fn borrow_mut(&mut self) -> &mut AppContext {
1652 &mut self.app
1653 }
1654}
1655
1656pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1657 fn app_mut(&mut self) -> &mut AppContext {
1658 self.borrow_mut()
1659 }
1660
1661 fn window(&self) -> &Window {
1662 self.borrow()
1663 }
1664
1665 fn window_mut(&mut self) -> &mut Window {
1666 self.borrow_mut()
1667 }
1668
1669 /// Pushes the given element id onto the global stack and invokes the given closure
1670 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1671 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1672 /// used to associate state with identified elements across separate frames.
1673 fn with_element_id<R>(
1674 &mut self,
1675 id: Option<impl Into<ElementId>>,
1676 f: impl FnOnce(&mut Self) -> R,
1677 ) -> R {
1678 if let Some(id) = id.map(Into::into) {
1679 let window = self.window_mut();
1680 window.element_id_stack.push(id.into());
1681 let result = f(self);
1682 let window: &mut Window = self.borrow_mut();
1683 window.element_id_stack.pop();
1684 result
1685 } else {
1686 f(self)
1687 }
1688 }
1689
1690 /// Invoke the given function with the given content mask after intersecting it
1691 /// with the current mask.
1692 fn with_content_mask<R>(
1693 &mut self,
1694 mask: Option<ContentMask<Pixels>>,
1695 f: impl FnOnce(&mut Self) -> R,
1696 ) -> R {
1697 if let Some(mask) = mask {
1698 let mask = mask.intersect(&self.content_mask());
1699 self.window_mut()
1700 .current_frame
1701 .content_mask_stack
1702 .push(mask);
1703 let result = f(self);
1704 self.window_mut().current_frame.content_mask_stack.pop();
1705 result
1706 } else {
1707 f(self)
1708 }
1709 }
1710
1711 /// Update the global element offset relative to the current offset. This is used to implement
1712 /// scrolling.
1713 fn with_element_offset<R>(
1714 &mut self,
1715 offset: Point<Pixels>,
1716 f: impl FnOnce(&mut Self) -> R,
1717 ) -> R {
1718 if offset.is_zero() {
1719 return f(self);
1720 };
1721
1722 let abs_offset = self.element_offset() + offset;
1723 self.with_absolute_element_offset(abs_offset, f)
1724 }
1725
1726 /// Update the global element offset based on the given offset. This is used to implement
1727 /// drag handles and other manual painting of elements.
1728 fn with_absolute_element_offset<R>(
1729 &mut self,
1730 offset: Point<Pixels>,
1731 f: impl FnOnce(&mut Self) -> R,
1732 ) -> R {
1733 self.window_mut()
1734 .current_frame
1735 .element_offset_stack
1736 .push(offset);
1737 let result = f(self);
1738 self.window_mut().current_frame.element_offset_stack.pop();
1739 result
1740 }
1741
1742 /// Obtain the current element offset.
1743 fn element_offset(&self) -> Point<Pixels> {
1744 self.window()
1745 .current_frame
1746 .element_offset_stack
1747 .last()
1748 .copied()
1749 .unwrap_or_default()
1750 }
1751
1752 /// Update or intialize state for an element with the given id that lives across multiple
1753 /// frames. If an element with this id existed in the previous frame, its state will be passed
1754 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1755 /// when drawing the next frame.
1756 fn with_element_state<S, R>(
1757 &mut self,
1758 id: ElementId,
1759 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1760 ) -> R
1761 where
1762 S: 'static,
1763 {
1764 self.with_element_id(Some(id), |cx| {
1765 let global_id = cx.window().element_id_stack.clone();
1766
1767 if let Some(any) = cx
1768 .window_mut()
1769 .current_frame
1770 .element_states
1771 .remove(&global_id)
1772 .or_else(|| {
1773 cx.window_mut()
1774 .previous_frame
1775 .element_states
1776 .remove(&global_id)
1777 })
1778 {
1779 // Using the extra inner option to avoid needing to reallocate a new box.
1780 let mut state_box = any
1781 .downcast::<Option<S>>()
1782 .expect("invalid element state type for id");
1783 let state = state_box
1784 .take()
1785 .expect("element state is already on the stack");
1786 let (result, state) = f(Some(state), cx);
1787 state_box.replace(state);
1788 cx.window_mut()
1789 .current_frame
1790 .element_states
1791 .insert(global_id, state_box);
1792 result
1793 } else {
1794 let (result, state) = f(None, cx);
1795 cx.window_mut()
1796 .current_frame
1797 .element_states
1798 .insert(global_id, Box::new(Some(state)));
1799 result
1800 }
1801 })
1802 }
1803
1804 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1805 /// id is `None`, no state will be retrieved or stored.
1806 fn with_optional_element_state<S, R>(
1807 &mut self,
1808 element_id: Option<ElementId>,
1809 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1810 ) -> R
1811 where
1812 S: 'static,
1813 {
1814 if let Some(element_id) = element_id {
1815 self.with_element_state(element_id, f)
1816 } else {
1817 f(None, self).0
1818 }
1819 }
1820
1821 /// Obtain the current content mask.
1822 fn content_mask(&self) -> ContentMask<Pixels> {
1823 self.window()
1824 .current_frame
1825 .content_mask_stack
1826 .last()
1827 .cloned()
1828 .unwrap_or_else(|| ContentMask {
1829 bounds: Bounds {
1830 origin: Point::default(),
1831 size: self.window().viewport_size,
1832 },
1833 })
1834 }
1835
1836 /// The size of an em for the base font of the application. Adjusting this value allows the
1837 /// UI to scale, just like zooming a web page.
1838 fn rem_size(&self) -> Pixels {
1839 self.window().rem_size
1840 }
1841}
1842
1843impl Borrow<Window> for WindowContext<'_> {
1844 fn borrow(&self) -> &Window {
1845 &self.window
1846 }
1847}
1848
1849impl BorrowMut<Window> for WindowContext<'_> {
1850 fn borrow_mut(&mut self) -> &mut Window {
1851 &mut self.window
1852 }
1853}
1854
1855impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1856
1857pub struct ViewContext<'a, V> {
1858 window_cx: WindowContext<'a>,
1859 view: &'a View<V>,
1860}
1861
1862impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1863 fn borrow(&self) -> &AppContext {
1864 &*self.window_cx.app
1865 }
1866}
1867
1868impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1869 fn borrow_mut(&mut self) -> &mut AppContext {
1870 &mut *self.window_cx.app
1871 }
1872}
1873
1874impl<V> Borrow<Window> for ViewContext<'_, V> {
1875 fn borrow(&self) -> &Window {
1876 &*self.window_cx.window
1877 }
1878}
1879
1880impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1881 fn borrow_mut(&mut self) -> &mut Window {
1882 &mut *self.window_cx.window
1883 }
1884}
1885
1886impl<'a, V: 'static> ViewContext<'a, V> {
1887 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1888 Self {
1889 window_cx: WindowContext::new(app, window),
1890 view,
1891 }
1892 }
1893
1894 pub fn entity_id(&self) -> EntityId {
1895 self.view.entity_id()
1896 }
1897
1898 pub fn view(&self) -> &View<V> {
1899 self.view
1900 }
1901
1902 pub fn model(&self) -> &Model<V> {
1903 &self.view.model
1904 }
1905
1906 /// Access the underlying window context.
1907 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1908 &mut self.window_cx
1909 }
1910
1911 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1912 self.window.current_frame.z_index_stack.push(z_index);
1913 let result = f(self);
1914 self.window.current_frame.z_index_stack.pop();
1915 result
1916 }
1917
1918 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
1919 where
1920 V: 'static,
1921 {
1922 let view = self.view().clone();
1923 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
1924 }
1925
1926 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
1927 /// that are currently on the stack to be returned to the app.
1928 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
1929 let view = self.view().downgrade();
1930 self.window_cx.defer(move |cx| {
1931 view.update(cx, f).ok();
1932 });
1933 }
1934
1935 pub fn observe<V2, E>(
1936 &mut self,
1937 entity: &E,
1938 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
1939 ) -> Subscription
1940 where
1941 V2: 'static,
1942 V: 'static,
1943 E: Entity<V2>,
1944 {
1945 let view = self.view().downgrade();
1946 let entity_id = entity.entity_id();
1947 let entity = entity.downgrade();
1948 let window_handle = self.window.handle;
1949 self.app.observers.insert(
1950 entity_id,
1951 Box::new(move |cx| {
1952 window_handle
1953 .update(cx, |_, cx| {
1954 if let Some(handle) = E::upgrade_from(&entity) {
1955 view.update(cx, |this, cx| on_notify(this, handle, cx))
1956 .is_ok()
1957 } else {
1958 false
1959 }
1960 })
1961 .unwrap_or(false)
1962 }),
1963 )
1964 }
1965
1966 pub fn subscribe<V2, E, Evt>(
1967 &mut self,
1968 entity: &E,
1969 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
1970 ) -> Subscription
1971 where
1972 V2: EventEmitter<Evt>,
1973 E: Entity<V2>,
1974 Evt: 'static,
1975 {
1976 let view = self.view().downgrade();
1977 let entity_id = entity.entity_id();
1978 let handle = entity.downgrade();
1979 let window_handle = self.window.handle;
1980 self.app.event_listeners.insert(
1981 entity_id,
1982 (
1983 TypeId::of::<Evt>(),
1984 Box::new(move |event, cx| {
1985 window_handle
1986 .update(cx, |_, cx| {
1987 if let Some(handle) = E::upgrade_from(&handle) {
1988 let event = event.downcast_ref().expect("invalid event type");
1989 view.update(cx, |this, cx| on_event(this, handle, event, cx))
1990 .is_ok()
1991 } else {
1992 false
1993 }
1994 })
1995 .unwrap_or(false)
1996 }),
1997 ),
1998 )
1999 }
2000
2001 pub fn on_release(
2002 &mut self,
2003 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2004 ) -> Subscription {
2005 let window_handle = self.window.handle;
2006 self.app.release_listeners.insert(
2007 self.view.model.entity_id,
2008 Box::new(move |this, cx| {
2009 let this = this.downcast_mut().expect("invalid entity type");
2010 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2011 }),
2012 )
2013 }
2014
2015 pub fn observe_release<V2, E>(
2016 &mut self,
2017 entity: &E,
2018 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2019 ) -> Subscription
2020 where
2021 V: 'static,
2022 V2: 'static,
2023 E: Entity<V2>,
2024 {
2025 let view = self.view().downgrade();
2026 let entity_id = entity.entity_id();
2027 let window_handle = self.window.handle;
2028 self.app.release_listeners.insert(
2029 entity_id,
2030 Box::new(move |entity, cx| {
2031 let entity = entity.downcast_mut().expect("invalid entity type");
2032 let _ = window_handle.update(cx, |_, cx| {
2033 view.update(cx, |this, cx| on_release(this, entity, cx))
2034 });
2035 }),
2036 )
2037 }
2038
2039 pub fn notify(&mut self) {
2040 self.window_cx.notify();
2041 self.window_cx.app.push_effect(Effect::Notify {
2042 emitter: self.view.model.entity_id,
2043 });
2044 }
2045
2046 pub fn observe_window_bounds(
2047 &mut self,
2048 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2049 ) -> Subscription {
2050 let view = self.view.downgrade();
2051 self.window.bounds_observers.insert(
2052 (),
2053 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2054 )
2055 }
2056
2057 pub fn observe_window_activation(
2058 &mut self,
2059 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2060 ) -> Subscription {
2061 let view = self.view.downgrade();
2062 self.window.activation_observers.insert(
2063 (),
2064 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2065 )
2066 }
2067
2068 /// Register a listener to be called when the given focus handle receives focus.
2069 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2070 /// is dropped.
2071 pub fn on_focus(
2072 &mut self,
2073 handle: &FocusHandle,
2074 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2075 ) -> Subscription {
2076 let view = self.view.downgrade();
2077 let focus_id = handle.id;
2078 self.window.focus_listeners.insert(
2079 (),
2080 Box::new(move |event, cx| {
2081 view.update(cx, |view, cx| {
2082 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2083 listener(view, cx)
2084 }
2085 })
2086 .is_ok()
2087 }),
2088 )
2089 }
2090
2091 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2092 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2093 /// is dropped.
2094 pub fn on_focus_in(
2095 &mut self,
2096 handle: &FocusHandle,
2097 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2098 ) -> Subscription {
2099 let view = self.view.downgrade();
2100 let focus_id = handle.id;
2101 self.window.focus_listeners.insert(
2102 (),
2103 Box::new(move |event, cx| {
2104 view.update(cx, |view, cx| {
2105 if event
2106 .focused
2107 .as_ref()
2108 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2109 {
2110 listener(view, cx)
2111 }
2112 })
2113 .is_ok()
2114 }),
2115 )
2116 }
2117
2118 /// Register a listener to be called when the given focus handle loses focus.
2119 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2120 /// is dropped.
2121 pub fn on_blur(
2122 &mut self,
2123 handle: &FocusHandle,
2124 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2125 ) -> Subscription {
2126 let view = self.view.downgrade();
2127 let focus_id = handle.id;
2128 self.window.focus_listeners.insert(
2129 (),
2130 Box::new(move |event, cx| {
2131 view.update(cx, |view, cx| {
2132 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2133 listener(view, cx)
2134 }
2135 })
2136 .is_ok()
2137 }),
2138 )
2139 }
2140
2141 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2142 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2143 /// is dropped.
2144 pub fn on_focus_out(
2145 &mut self,
2146 handle: &FocusHandle,
2147 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2148 ) -> Subscription {
2149 let view = self.view.downgrade();
2150 let focus_id = handle.id;
2151 self.window.focus_listeners.insert(
2152 (),
2153 Box::new(move |event, cx| {
2154 view.update(cx, |view, cx| {
2155 if event
2156 .blurred
2157 .as_ref()
2158 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2159 {
2160 listener(view, cx)
2161 }
2162 })
2163 .is_ok()
2164 }),
2165 )
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 pub fn dismiss_self(&mut self)
2280 where
2281 V: ManagedView,
2282 {
2283 self.defer(|_, cx| cx.emit(Manager::Dismiss))
2284 }
2285
2286 pub fn callback<E>(
2287 &self,
2288 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2289 ) -> CallbackHandle<E> {
2290 let view = self.view().clone();
2291 (move |e: &E, cx: &mut WindowContext| {
2292 view.update(cx, |view, cx| f(view, e, cx));
2293 })
2294 .into()
2295 }
2296
2297 pub fn constructor<R>(
2298 &self,
2299 f: impl Fn(&mut V, &mut ViewContext<V>) -> R + 'static,
2300 ) -> ConstructorHandle<R> {
2301 let view = self.view().clone();
2302 (move |cx: &mut WindowContext| view.update(cx, |view, cx| f(view, cx))).into()
2303 }
2304}
2305
2306impl<V> Context for ViewContext<'_, V> {
2307 type Result<U> = U;
2308
2309 fn build_model<T: 'static>(
2310 &mut self,
2311 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2312 ) -> Model<T> {
2313 self.window_cx.build_model(build_model)
2314 }
2315
2316 fn update_model<T: 'static, R>(
2317 &mut self,
2318 model: &Model<T>,
2319 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2320 ) -> R {
2321 self.window_cx.update_model(model, update)
2322 }
2323
2324 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2325 where
2326 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2327 {
2328 self.window_cx.update_window(window, update)
2329 }
2330
2331 fn read_model<T, R>(
2332 &self,
2333 handle: &Model<T>,
2334 read: impl FnOnce(&T, &AppContext) -> R,
2335 ) -> Self::Result<R>
2336 where
2337 T: 'static,
2338 {
2339 self.window_cx.read_model(handle, read)
2340 }
2341
2342 fn read_window<T, R>(
2343 &self,
2344 window: &WindowHandle<T>,
2345 read: impl FnOnce(View<T>, &AppContext) -> R,
2346 ) -> Result<R>
2347 where
2348 T: 'static,
2349 {
2350 self.window_cx.read_window(window, read)
2351 }
2352}
2353
2354impl<V: 'static> VisualContext for ViewContext<'_, V> {
2355 fn build_view<W: Render + 'static>(
2356 &mut self,
2357 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2358 ) -> Self::Result<View<W>> {
2359 self.window_cx.build_view(build_view_state)
2360 }
2361
2362 fn update_view<V2: 'static, R>(
2363 &mut self,
2364 view: &View<V2>,
2365 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2366 ) -> Self::Result<R> {
2367 self.window_cx.update_view(view, update)
2368 }
2369
2370 fn replace_root_view<W>(
2371 &mut self,
2372 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2373 ) -> Self::Result<View<W>>
2374 where
2375 W: Render,
2376 {
2377 self.window_cx.replace_root_view(build_view)
2378 }
2379
2380 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2381 self.window_cx.focus_view(view)
2382 }
2383
2384 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2385 self.window_cx.dismiss_view(view)
2386 }
2387}
2388
2389impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2390 type Target = WindowContext<'a>;
2391
2392 fn deref(&self) -> &Self::Target {
2393 &self.window_cx
2394 }
2395}
2396
2397impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2398 fn deref_mut(&mut self) -> &mut Self::Target {
2399 &mut self.window_cx
2400 }
2401}
2402
2403// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2404slotmap::new_key_type! { pub struct WindowId; }
2405
2406impl WindowId {
2407 pub fn as_u64(&self) -> u64 {
2408 self.0.as_ffi()
2409 }
2410}
2411
2412#[derive(Deref, DerefMut)]
2413pub struct WindowHandle<V> {
2414 #[deref]
2415 #[deref_mut]
2416 pub(crate) any_handle: AnyWindowHandle,
2417 state_type: PhantomData<V>,
2418}
2419
2420impl<V: 'static + Render> WindowHandle<V> {
2421 pub fn new(id: WindowId) -> Self {
2422 WindowHandle {
2423 any_handle: AnyWindowHandle {
2424 id,
2425 state_type: TypeId::of::<V>(),
2426 },
2427 state_type: PhantomData,
2428 }
2429 }
2430
2431 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2432 where
2433 C: Context,
2434 {
2435 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2436 root_view
2437 .downcast::<V>()
2438 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2439 }))
2440 }
2441
2442 pub fn update<C, R>(
2443 &self,
2444 cx: &mut C,
2445 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2446 ) -> Result<R>
2447 where
2448 C: Context,
2449 {
2450 cx.update_window(self.any_handle, |root_view, cx| {
2451 let view = root_view
2452 .downcast::<V>()
2453 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2454 Ok(cx.update_view(&view, update))
2455 })?
2456 }
2457
2458 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2459 let x = cx
2460 .windows
2461 .get(self.id)
2462 .and_then(|window| {
2463 window
2464 .as_ref()
2465 .and_then(|window| window.root_view.clone())
2466 .map(|root_view| root_view.downcast::<V>())
2467 })
2468 .ok_or_else(|| anyhow!("window not found"))?
2469 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2470
2471 Ok(x.read(cx))
2472 }
2473
2474 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2475 where
2476 C: Context,
2477 {
2478 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2479 }
2480
2481 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2482 where
2483 C: Context,
2484 {
2485 cx.read_window(self, |root_view, _cx| root_view.clone())
2486 }
2487
2488 pub fn is_active(&self, cx: &WindowContext) -> Option<bool> {
2489 cx.windows
2490 .get(self.id)
2491 .and_then(|window| window.as_ref().map(|window| window.active))
2492 }
2493}
2494
2495impl<V> Copy for WindowHandle<V> {}
2496
2497impl<V> Clone for WindowHandle<V> {
2498 fn clone(&self) -> Self {
2499 WindowHandle {
2500 any_handle: self.any_handle,
2501 state_type: PhantomData,
2502 }
2503 }
2504}
2505
2506impl<V> PartialEq for WindowHandle<V> {
2507 fn eq(&self, other: &Self) -> bool {
2508 self.any_handle == other.any_handle
2509 }
2510}
2511
2512impl<V> Eq for WindowHandle<V> {}
2513
2514impl<V> Hash for WindowHandle<V> {
2515 fn hash<H: Hasher>(&self, state: &mut H) {
2516 self.any_handle.hash(state);
2517 }
2518}
2519
2520impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2521 fn into(self) -> AnyWindowHandle {
2522 self.any_handle
2523 }
2524}
2525
2526#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2527pub struct AnyWindowHandle {
2528 pub(crate) id: WindowId,
2529 state_type: TypeId,
2530}
2531
2532impl AnyWindowHandle {
2533 pub fn window_id(&self) -> WindowId {
2534 self.id
2535 }
2536
2537 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2538 if TypeId::of::<T>() == self.state_type {
2539 Some(WindowHandle {
2540 any_handle: *self,
2541 state_type: PhantomData,
2542 })
2543 } else {
2544 None
2545 }
2546 }
2547
2548 pub fn update<C, R>(
2549 self,
2550 cx: &mut C,
2551 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2552 ) -> Result<R>
2553 where
2554 C: Context,
2555 {
2556 cx.update_window(self, update)
2557 }
2558
2559 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2560 where
2561 C: Context,
2562 T: 'static,
2563 {
2564 let view = self
2565 .downcast::<T>()
2566 .context("the type of the window's root view has changed")?;
2567
2568 cx.read_window(&view, read)
2569 }
2570}
2571
2572#[cfg(any(test, feature = "test-support"))]
2573impl From<SmallVec<[u32; 16]>> for StackingOrder {
2574 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2575 StackingOrder(small_vec)
2576 }
2577}
2578
2579#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2580pub enum ElementId {
2581 View(EntityId),
2582 Integer(usize),
2583 Name(SharedString),
2584 FocusHandle(FocusId),
2585}
2586
2587impl TryInto<SharedString> for ElementId {
2588 type Error = anyhow::Error;
2589
2590 fn try_into(self) -> anyhow::Result<SharedString> {
2591 if let ElementId::Name(name) = self {
2592 Ok(name)
2593 } else {
2594 Err(anyhow!("element id is not string"))
2595 }
2596 }
2597}
2598
2599impl From<EntityId> for ElementId {
2600 fn from(id: EntityId) -> Self {
2601 ElementId::View(id)
2602 }
2603}
2604
2605impl From<usize> for ElementId {
2606 fn from(id: usize) -> Self {
2607 ElementId::Integer(id)
2608 }
2609}
2610
2611impl From<i32> for ElementId {
2612 fn from(id: i32) -> Self {
2613 Self::Integer(id as usize)
2614 }
2615}
2616
2617impl From<SharedString> for ElementId {
2618 fn from(name: SharedString) -> Self {
2619 ElementId::Name(name)
2620 }
2621}
2622
2623impl From<&'static str> for ElementId {
2624 fn from(name: &'static str) -> Self {
2625 ElementId::Name(name.into())
2626 }
2627}
2628
2629impl<'a> From<&'a FocusHandle> for ElementId {
2630 fn from(handle: &'a FocusHandle) -> Self {
2631 ElementId::FocusHandle(handle.id)
2632 }
2633}