1use crate::{
2 key_dispatch::DispatchActionListener, px, size, Action, AnyDrag, AnyView, AppContext,
3 AsyncWindowContext, AvailableSpace, Bounds, BoxShadow, Context, Corners, CursorStyle,
4 DevicePixels, DispatchNodeId, DispatchTree, DisplayId, Edges, Effect, Entity, EntityId,
5 EventEmitter, FileDropEvent, Flatten, FocusEvent, FontId, GlobalElementId, GlyphId, Hsla,
6 ImageData, InputEvent, IsZero, KeyBinding, KeyContext, KeyDownEvent, LayoutId, Model,
7 ModelContext, Modifiers, MonochromeSprite, MouseButton, MouseDownEvent, MouseMoveEvent,
8 MouseUpEvent, Path, Pixels, PlatformAtlas, PlatformDisplay, PlatformInputHandler,
9 PlatformWindow, Point, PolychromeSprite, PromptLevel, Quad, Render, RenderGlyphParams,
10 RenderImageParams, RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size,
11 Style, SubscriberSet, Subscription, TaffyLayoutEngine, Task, Underline, UnderlineStyle, View,
12 VisualContext, WeakView, WindowBounds, WindowOptions, SUBPIXEL_VARIANTS,
13};
14use anyhow::{anyhow, Context as _, Result};
15use collections::HashMap;
16use derive_more::{Deref, DerefMut};
17use futures::{
18 channel::{mpsc, oneshot},
19 StreamExt,
20};
21use parking_lot::RwLock;
22use slotmap::SlotMap;
23use smallvec::SmallVec;
24use std::{
25 any::{Any, TypeId},
26 borrow::{Borrow, BorrowMut, Cow},
27 fmt::Debug,
28 future::Future,
29 hash::{Hash, Hasher},
30 marker::PhantomData,
31 mem,
32 rc::Rc,
33 sync::{
34 atomic::{AtomicUsize, Ordering::SeqCst},
35 Arc,
36 },
37};
38use util::ResultExt;
39
40/// A global stacking order, which is created by stacking successive z-index values.
41/// Each z-index will always be interpreted in the context of its parent z-index.
42#[derive(Deref, DerefMut, Ord, PartialOrd, Eq, PartialEq, Clone, Default)]
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: 'static + Render {
191 fn focus_handle(&self, cx: &AppContext) -> FocusHandle;
192}
193
194/// ManagedView is a view (like a Modal, Popover, Menu, etc.)
195/// where the lifecycle of the view is handled by another view.
196pub trait ManagedView: FocusableView + EventEmitter<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
233pub(crate) struct ElementStateBox {
234 inner: Box<dyn Any>,
235 #[cfg(debug_assertions)]
236 type_name: &'static str,
237}
238
239// #[derive(Default)]
240pub(crate) struct Frame {
241 pub(crate) element_states: HashMap<GlobalElementId, ElementStateBox>,
242 mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
243 pub(crate) dispatch_tree: DispatchTree,
244 pub(crate) focus_listeners: Vec<AnyFocusListener>,
245 pub(crate) scene_builder: SceneBuilder,
246 z_index_stack: StackingOrder,
247 content_mask_stack: Vec<ContentMask<Pixels>>,
248 element_offset_stack: Vec<Point<Pixels>>,
249}
250
251impl Frame {
252 pub fn new(dispatch_tree: DispatchTree) -> Self {
253 Frame {
254 element_states: HashMap::default(),
255 mouse_listeners: HashMap::default(),
256 dispatch_tree,
257 focus_listeners: Vec::new(),
258 scene_builder: SceneBuilder::default(),
259 z_index_stack: StackingOrder::default(),
260 content_mask_stack: Vec::new(),
261 element_offset_stack: Vec::new(),
262 }
263 }
264}
265
266impl Window {
267 pub(crate) fn new(
268 handle: AnyWindowHandle,
269 options: WindowOptions,
270 cx: &mut AppContext,
271 ) -> Self {
272 let platform_window = cx.platform.open_window(handle, options);
273 let display_id = platform_window.display().id();
274 let sprite_atlas = platform_window.sprite_atlas();
275 let mouse_position = platform_window.mouse_position();
276 let content_size = platform_window.content_size();
277 let scale_factor = platform_window.scale_factor();
278 let bounds = platform_window.bounds();
279
280 platform_window.on_resize(Box::new({
281 let mut cx = cx.to_async();
282 move |_, _| {
283 handle
284 .update(&mut cx, |_, cx| cx.window_bounds_changed())
285 .log_err();
286 }
287 }));
288 platform_window.on_moved(Box::new({
289 let mut cx = cx.to_async();
290 move || {
291 handle
292 .update(&mut cx, |_, cx| cx.window_bounds_changed())
293 .log_err();
294 }
295 }));
296 platform_window.on_active_status_change(Box::new({
297 let mut cx = cx.to_async();
298 move |active| {
299 handle
300 .update(&mut cx, |_, cx| {
301 cx.window.active = active;
302 cx.window
303 .activation_observers
304 .clone()
305 .retain(&(), |callback| callback(cx));
306 })
307 .log_err();
308 }
309 }));
310
311 platform_window.on_input({
312 let mut cx = cx.to_async();
313 Box::new(move |event| {
314 handle
315 .update(&mut cx, |_, cx| cx.dispatch_event(event))
316 .log_err()
317 .unwrap_or(false)
318 })
319 });
320
321 Window {
322 handle,
323 removed: false,
324 platform_window,
325 display_id,
326 sprite_atlas,
327 rem_size: px(16.),
328 viewport_size: content_size,
329 layout_engine: TaffyLayoutEngine::new(),
330 root_view: None,
331 element_id_stack: GlobalElementId::default(),
332 previous_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
333 current_frame: Frame::new(DispatchTree::new(cx.keymap.clone(), cx.actions.clone())),
334 focus_handles: Arc::new(RwLock::new(SlotMap::with_key())),
335 focus_listeners: SubscriberSet::new(),
336 default_prevented: true,
337 mouse_position,
338 requested_cursor_style: None,
339 scale_factor,
340 bounds,
341 bounds_observers: SubscriberSet::new(),
342 active: false,
343 activation_observers: SubscriberSet::new(),
344 dirty: true,
345 last_blur: None,
346 focus: None,
347 }
348 }
349}
350
351/// Indicates which region of the window is visible. Content falling outside of this mask will not be
352/// rendered. Currently, only rectangular content masks are supported, but we give the mask its own type
353/// to leave room to support more complex shapes in the future.
354#[derive(Clone, Debug, Default, PartialEq, Eq)]
355#[repr(C)]
356pub struct ContentMask<P: Clone + Default + Debug> {
357 pub bounds: Bounds<P>,
358}
359
360impl ContentMask<Pixels> {
361 /// Scale the content mask's pixel units by the given scaling factor.
362 pub fn scale(&self, factor: f32) -> ContentMask<ScaledPixels> {
363 ContentMask {
364 bounds: self.bounds.scale(factor),
365 }
366 }
367
368 /// Intersect the content mask with the given content mask.
369 pub fn intersect(&self, other: &Self) -> Self {
370 let bounds = self.bounds.intersect(&other.bounds);
371 ContentMask { bounds }
372 }
373}
374
375/// Provides access to application state in the context of a single window. Derefs
376/// to an `AppContext`, so you can also pass a `WindowContext` to any method that takes
377/// an `AppContext` and call any `AppContext` methods.
378pub struct WindowContext<'a> {
379 pub(crate) app: &'a mut AppContext,
380 pub(crate) window: &'a mut Window,
381}
382
383impl<'a> WindowContext<'a> {
384 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window) -> Self {
385 Self { app, window }
386 }
387
388 /// Obtain a handle to the window that belongs to this context.
389 pub fn window_handle(&self) -> AnyWindowHandle {
390 self.window.handle
391 }
392
393 /// Mark the window as dirty, scheduling it to be redrawn on the next frame.
394 pub fn notify(&mut self) {
395 self.window.dirty = true;
396 }
397
398 /// Close this window.
399 pub fn remove_window(&mut self) {
400 self.window.removed = true;
401 }
402
403 /// Obtain a new `FocusHandle`, which allows you to track and manipulate the keyboard focus
404 /// for elements rendered within this window.
405 pub fn focus_handle(&mut self) -> FocusHandle {
406 FocusHandle::new(&self.window.focus_handles)
407 }
408
409 /// Obtain the currently focused `FocusHandle`. If no elements are focused, returns `None`.
410 pub fn focused(&self) -> Option<FocusHandle> {
411 self.window
412 .focus
413 .and_then(|id| FocusHandle::for_id(id, &self.window.focus_handles))
414 }
415
416 /// Move focus to the element associated with the given `FocusHandle`.
417 pub fn focus(&mut self, handle: &FocusHandle) {
418 if self.window.focus == Some(handle.id) {
419 return;
420 }
421
422 let focus_id = handle.id;
423
424 if self.window.last_blur.is_none() {
425 self.window.last_blur = Some(self.window.focus);
426 }
427
428 self.window.focus = Some(focus_id);
429 self.window
430 .current_frame
431 .dispatch_tree
432 .clear_keystroke_matchers();
433 self.app.push_effect(Effect::FocusChanged {
434 window_handle: self.window.handle,
435 focused: Some(focus_id),
436 });
437 self.notify();
438 }
439
440 /// Remove focus from all elements within this context's window.
441 pub fn blur(&mut self) {
442 if self.window.last_blur.is_none() {
443 self.window.last_blur = Some(self.window.focus);
444 }
445
446 self.window.focus = None;
447 self.app.push_effect(Effect::FocusChanged {
448 window_handle: self.window.handle,
449 focused: None,
450 });
451 self.notify();
452 }
453
454 pub fn dispatch_action(&mut self, action: Box<dyn Action>) {
455 if let Some(focus_handle) = self.focused() {
456 self.defer(move |cx| {
457 if let Some(node_id) = cx
458 .window
459 .current_frame
460 .dispatch_tree
461 .focusable_node_id(focus_handle.id)
462 {
463 cx.propagate_event = true;
464 cx.dispatch_action_on_node(node_id, action);
465 }
466 })
467 }
468 }
469
470 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
471 /// that are currently on the stack to be returned to the app.
472 pub fn defer(&mut self, f: impl FnOnce(&mut WindowContext) + 'static) {
473 let handle = self.window.handle;
474 self.app.defer(move |cx| {
475 handle.update(cx, |_, cx| f(cx)).ok();
476 });
477 }
478
479 pub fn subscribe<Emitter, E, Evt>(
480 &mut self,
481 entity: &E,
482 mut on_event: impl FnMut(E, &Evt, &mut WindowContext<'_>) + 'static,
483 ) -> Subscription
484 where
485 Emitter: EventEmitter<Evt>,
486 E: Entity<Emitter>,
487 Evt: 'static,
488 {
489 let entity_id = entity.entity_id();
490 let entity = entity.downgrade();
491 let window_handle = self.window.handle;
492 self.app.event_listeners.insert(
493 entity_id,
494 (
495 TypeId::of::<Evt>(),
496 Box::new(move |event, cx| {
497 window_handle
498 .update(cx, |_, cx| {
499 if let Some(handle) = E::upgrade_from(&entity) {
500 let event = event.downcast_ref().expect("invalid event type");
501 on_event(handle, event, cx);
502 true
503 } else {
504 false
505 }
506 })
507 .unwrap_or(false)
508 }),
509 ),
510 )
511 }
512
513 /// Create an `AsyncWindowContext`, which has a static lifetime and can be held across
514 /// await points in async code.
515 pub fn to_async(&self) -> AsyncWindowContext {
516 AsyncWindowContext::new(self.app.to_async(), self.window.handle)
517 }
518
519 /// Schedule the given closure to be run directly after the current frame is rendered.
520 pub fn on_next_frame(&mut self, callback: impl FnOnce(&mut WindowContext) + 'static) {
521 let handle = self.window.handle;
522 let display_id = self.window.display_id;
523
524 if !self.frame_consumers.contains_key(&display_id) {
525 let (tx, mut rx) = mpsc::unbounded::<()>();
526 self.platform.set_display_link_output_callback(
527 display_id,
528 Box::new(move |_current_time, _output_time| _ = tx.unbounded_send(())),
529 );
530
531 let consumer_task = self.app.spawn(|cx| async move {
532 while rx.next().await.is_some() {
533 cx.update(|cx| {
534 for callback in cx
535 .next_frame_callbacks
536 .get_mut(&display_id)
537 .unwrap()
538 .drain(..)
539 .collect::<SmallVec<[_; 32]>>()
540 {
541 callback(cx);
542 }
543 })
544 .ok();
545
546 // Flush effects, then stop the display link if no new next_frame_callbacks have been added.
547
548 cx.update(|cx| {
549 if cx.next_frame_callbacks.is_empty() {
550 cx.platform.stop_display_link(display_id);
551 }
552 })
553 .ok();
554 }
555 });
556 self.frame_consumers.insert(display_id, consumer_task);
557 }
558
559 if self.next_frame_callbacks.is_empty() {
560 self.platform.start_display_link(display_id);
561 }
562
563 self.next_frame_callbacks
564 .entry(display_id)
565 .or_default()
566 .push(Box::new(move |cx: &mut AppContext| {
567 cx.update_window(handle, |_root_view, cx| callback(cx)).ok();
568 }));
569 }
570
571 /// Spawn the future returned by the given closure on the application thread pool.
572 /// The closure is provided a handle to the current window and an `AsyncWindowContext` for
573 /// use within your future.
574 pub fn spawn<Fut, R>(&mut self, f: impl FnOnce(AsyncWindowContext) -> Fut) -> Task<R>
575 where
576 R: 'static,
577 Fut: Future<Output = R> + 'static,
578 {
579 self.app
580 .spawn(|app| f(AsyncWindowContext::new(app, self.window.handle)))
581 }
582
583 /// Update the global of the given type. The given closure is given simultaneous mutable
584 /// access both to the global and the context.
585 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
586 where
587 G: 'static,
588 {
589 let mut global = self.app.lease_global::<G>();
590 let result = f(&mut global, self);
591 self.app.end_global_lease(global);
592 result
593 }
594
595 #[must_use]
596 /// Add a node to the layout tree for the current frame. Takes the `Style` of the element for which
597 /// layout is being requested, along with the layout ids of any children. This method is called during
598 /// calls to the `Element::layout` trait method and enables any element to participate in layout.
599 pub fn request_layout(
600 &mut self,
601 style: &Style,
602 children: impl IntoIterator<Item = LayoutId>,
603 ) -> LayoutId {
604 self.app.layout_id_buffer.clear();
605 self.app.layout_id_buffer.extend(children.into_iter());
606 let rem_size = self.rem_size();
607
608 self.window
609 .layout_engine
610 .request_layout(style, rem_size, &self.app.layout_id_buffer)
611 }
612
613 /// Add a node to the layout tree for the current frame. Instead of taking a `Style` and children,
614 /// this variant takes a function that is invoked during layout so you can use arbitrary logic to
615 /// determine the element's size. One place this is used internally is when measuring text.
616 ///
617 /// The given closure is invoked at layout time with the known dimensions and available space and
618 /// returns a `Size`.
619 pub fn request_measured_layout<
620 F: Fn(Size<Option<Pixels>>, Size<AvailableSpace>) -> Size<Pixels> + Send + Sync + 'static,
621 >(
622 &mut self,
623 style: Style,
624 rem_size: Pixels,
625 measure: F,
626 ) -> LayoutId {
627 self.window
628 .layout_engine
629 .request_measured_layout(style, rem_size, measure)
630 }
631
632 pub fn compute_layout(&mut self, layout_id: LayoutId, available_space: Size<AvailableSpace>) {
633 self.window
634 .layout_engine
635 .compute_layout(layout_id, available_space)
636 }
637
638 /// Obtain the bounds computed for the given LayoutId relative to the window. This method should not
639 /// be invoked until the paint phase begins, and will usually be invoked by GPUI itself automatically
640 /// in order to pass your element its `Bounds` automatically.
641 pub fn layout_bounds(&mut self, layout_id: LayoutId) -> Bounds<Pixels> {
642 let mut bounds = self
643 .window
644 .layout_engine
645 .layout_bounds(layout_id)
646 .map(Into::into);
647 bounds.origin += self.element_offset();
648 bounds
649 }
650
651 fn window_bounds_changed(&mut self) {
652 self.window.scale_factor = self.window.platform_window.scale_factor();
653 self.window.viewport_size = self.window.platform_window.content_size();
654 self.window.bounds = self.window.platform_window.bounds();
655 self.window.display_id = self.window.platform_window.display().id();
656 self.window.dirty = true;
657
658 self.window
659 .bounds_observers
660 .clone()
661 .retain(&(), |callback| callback(self));
662 }
663
664 pub fn window_bounds(&self) -> WindowBounds {
665 self.window.bounds
666 }
667
668 pub fn viewport_size(&self) -> Size<Pixels> {
669 self.window.viewport_size
670 }
671
672 pub fn is_window_active(&self) -> bool {
673 self.window.active
674 }
675
676 pub fn zoom_window(&self) {
677 self.window.platform_window.zoom();
678 }
679
680 pub fn display(&self) -> Option<Rc<dyn PlatformDisplay>> {
681 self.platform
682 .displays()
683 .into_iter()
684 .find(|display| display.id() == self.window.display_id)
685 }
686
687 pub fn show_character_palette(&self) {
688 self.window.platform_window.show_character_palette();
689 }
690
691 /// The scale factor of the display associated with the window. For example, it could
692 /// return 2.0 for a "retina" display, indicating that each logical pixel should actually
693 /// be rendered as two pixels on screen.
694 pub fn scale_factor(&self) -> f32 {
695 self.window.scale_factor
696 }
697
698 /// The size of an em for the base font of the application. Adjusting this value allows the
699 /// UI to scale, just like zooming a web page.
700 pub fn rem_size(&self) -> Pixels {
701 self.window.rem_size
702 }
703
704 /// Sets the size of an em for the base font of the application. Adjusting this value allows the
705 /// UI to scale, just like zooming a web page.
706 pub fn set_rem_size(&mut self, rem_size: impl Into<Pixels>) {
707 self.window.rem_size = rem_size.into();
708 }
709
710 /// The line height associated with the current text style.
711 pub fn line_height(&self) -> Pixels {
712 let rem_size = self.rem_size();
713 let text_style = self.text_style();
714 text_style
715 .line_height
716 .to_pixels(text_style.font_size.into(), rem_size)
717 }
718
719 /// Call to prevent the default action of an event. Currently only used to prevent
720 /// parent elements from becoming focused on mouse down.
721 pub fn prevent_default(&mut self) {
722 self.window.default_prevented = true;
723 }
724
725 /// Obtain whether default has been prevented for the event currently being dispatched.
726 pub fn default_prevented(&self) -> bool {
727 self.window.default_prevented
728 }
729
730 /// Register a mouse event listener on the window for the current frame. The type of event
731 /// is determined by the first parameter of the given listener. When the next frame is rendered
732 /// the listener will be cleared.
733 ///
734 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
735 /// a specific need to register a global listener.
736 pub fn on_mouse_event<Event: 'static>(
737 &mut self,
738 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
739 ) {
740 let order = self.window.current_frame.z_index_stack.clone();
741 self.window
742 .current_frame
743 .mouse_listeners
744 .entry(TypeId::of::<Event>())
745 .or_default()
746 .push((
747 order,
748 Box::new(move |event: &dyn Any, phase, cx| {
749 handler(event.downcast_ref().unwrap(), phase, cx)
750 }),
751 ))
752 }
753
754 /// Register a key event listener on the window for the current frame. The type of event
755 /// is determined by the first parameter of the given listener. When the next frame is rendered
756 /// the listener will be cleared.
757 ///
758 /// This is a fairly low-level method, so prefer using event handlers on elements unless you have
759 /// a specific need to register a global listener.
760 pub fn on_key_event<Event: 'static>(
761 &mut self,
762 handler: impl Fn(&Event, DispatchPhase, &mut WindowContext) + 'static,
763 ) {
764 self.window
765 .current_frame
766 .dispatch_tree
767 .on_key_event(Rc::new(move |event, phase, cx| {
768 if let Some(event) = event.downcast_ref::<Event>() {
769 handler(event, phase, cx)
770 }
771 }));
772 }
773
774 /// Register an action listener on the window for the current frame. The type of action
775 /// is determined by the first parameter of the given listener. When the next frame is rendered
776 /// the listener will be cleared.
777 ///
778 /// This is a fairly low-level method, so prefer using action handlers on elements unless you have
779 /// a specific need to register a global listener.
780 pub fn on_action(
781 &mut self,
782 action_type: TypeId,
783 handler: impl Fn(&dyn Any, DispatchPhase, &mut WindowContext) + 'static,
784 ) {
785 self.window.current_frame.dispatch_tree.on_action(
786 action_type,
787 Rc::new(move |action, phase, cx| handler(action, phase, cx)),
788 );
789 }
790
791 /// The position of the mouse relative to the window.
792 pub fn mouse_position(&self) -> Point<Pixels> {
793 self.window.mouse_position
794 }
795
796 pub fn set_cursor_style(&mut self, style: CursorStyle) {
797 self.window.requested_cursor_style = Some(style)
798 }
799
800 /// Called during painting to invoke the given closure in a new stacking context. The given
801 /// z-index is interpreted relative to the previous call to `stack`.
802 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
803 self.window.current_frame.z_index_stack.push(z_index);
804 let result = f(self);
805 self.window.current_frame.z_index_stack.pop();
806 result
807 }
808
809 /// Paint one or more drop shadows into the scene for the current frame at the current z-index.
810 pub fn paint_shadows(
811 &mut self,
812 bounds: Bounds<Pixels>,
813 corner_radii: Corners<Pixels>,
814 shadows: &[BoxShadow],
815 ) {
816 let scale_factor = self.scale_factor();
817 let content_mask = self.content_mask();
818 let window = &mut *self.window;
819 for shadow in shadows {
820 let mut shadow_bounds = bounds;
821 shadow_bounds.origin += shadow.offset;
822 shadow_bounds.dilate(shadow.spread_radius);
823 window.current_frame.scene_builder.insert(
824 &window.current_frame.z_index_stack,
825 Shadow {
826 order: 0,
827 bounds: shadow_bounds.scale(scale_factor),
828 content_mask: content_mask.scale(scale_factor),
829 corner_radii: corner_radii.scale(scale_factor),
830 color: shadow.color,
831 blur_radius: shadow.blur_radius.scale(scale_factor),
832 },
833 );
834 }
835 }
836
837 /// Paint one or more quads into the scene for the current frame at the current stacking context.
838 /// Quads are colored rectangular regions with an optional background, border, and corner radius.
839 pub fn paint_quad(
840 &mut self,
841 bounds: Bounds<Pixels>,
842 corner_radii: Corners<Pixels>,
843 background: impl Into<Hsla>,
844 border_widths: Edges<Pixels>,
845 border_color: impl Into<Hsla>,
846 ) {
847 let scale_factor = self.scale_factor();
848 let content_mask = self.content_mask();
849
850 let window = &mut *self.window;
851 window.current_frame.scene_builder.insert(
852 &window.current_frame.z_index_stack,
853 Quad {
854 order: 0,
855 bounds: bounds.scale(scale_factor),
856 content_mask: content_mask.scale(scale_factor),
857 background: background.into(),
858 border_color: border_color.into(),
859 corner_radii: corner_radii.scale(scale_factor),
860 border_widths: border_widths.scale(scale_factor),
861 },
862 );
863 }
864
865 /// Paint the given `Path` into the scene for the current frame at the current z-index.
866 pub fn paint_path(&mut self, mut path: Path<Pixels>, color: impl Into<Hsla>) {
867 let scale_factor = self.scale_factor();
868 let content_mask = self.content_mask();
869 path.content_mask = content_mask;
870 path.color = color.into();
871 let window = &mut *self.window;
872 window.current_frame.scene_builder.insert(
873 &window.current_frame.z_index_stack,
874 path.scale(scale_factor),
875 );
876 }
877
878 /// Paint an underline into the scene for the current frame at the current z-index.
879 pub fn paint_underline(
880 &mut self,
881 origin: Point<Pixels>,
882 width: Pixels,
883 style: &UnderlineStyle,
884 ) {
885 let scale_factor = self.scale_factor();
886 let height = if style.wavy {
887 style.thickness * 3.
888 } else {
889 style.thickness
890 };
891 let bounds = Bounds {
892 origin,
893 size: size(width, height),
894 };
895 let content_mask = self.content_mask();
896 let window = &mut *self.window;
897 window.current_frame.scene_builder.insert(
898 &window.current_frame.z_index_stack,
899 Underline {
900 order: 0,
901 bounds: bounds.scale(scale_factor),
902 content_mask: content_mask.scale(scale_factor),
903 thickness: style.thickness.scale(scale_factor),
904 color: style.color.unwrap_or_default(),
905 wavy: style.wavy,
906 },
907 );
908 }
909
910 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
911 /// The y component of the origin is the baseline of the glyph.
912 pub fn paint_glyph(
913 &mut self,
914 origin: Point<Pixels>,
915 font_id: FontId,
916 glyph_id: GlyphId,
917 font_size: Pixels,
918 color: Hsla,
919 ) -> Result<()> {
920 let scale_factor = self.scale_factor();
921 let glyph_origin = origin.scale(scale_factor);
922 let subpixel_variant = Point {
923 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
924 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
925 };
926 let params = RenderGlyphParams {
927 font_id,
928 glyph_id,
929 font_size,
930 subpixel_variant,
931 scale_factor,
932 is_emoji: false,
933 };
934
935 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
936 if !raster_bounds.is_zero() {
937 let tile =
938 self.window
939 .sprite_atlas
940 .get_or_insert_with(¶ms.clone().into(), &mut || {
941 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
942 Ok((size, Cow::Owned(bytes)))
943 })?;
944 let bounds = Bounds {
945 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
946 size: tile.bounds.size.map(Into::into),
947 };
948 let content_mask = self.content_mask().scale(scale_factor);
949 let window = &mut *self.window;
950 window.current_frame.scene_builder.insert(
951 &window.current_frame.z_index_stack,
952 MonochromeSprite {
953 order: 0,
954 bounds,
955 content_mask,
956 color,
957 tile,
958 },
959 );
960 }
961 Ok(())
962 }
963
964 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
965 /// The y component of the origin is the baseline of the glyph.
966 pub fn paint_emoji(
967 &mut self,
968 origin: Point<Pixels>,
969 font_id: FontId,
970 glyph_id: GlyphId,
971 font_size: Pixels,
972 ) -> Result<()> {
973 let scale_factor = self.scale_factor();
974 let glyph_origin = origin.scale(scale_factor);
975 let params = RenderGlyphParams {
976 font_id,
977 glyph_id,
978 font_size,
979 // We don't render emojis with subpixel variants.
980 subpixel_variant: Default::default(),
981 scale_factor,
982 is_emoji: true,
983 };
984
985 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
986 if !raster_bounds.is_zero() {
987 let tile =
988 self.window
989 .sprite_atlas
990 .get_or_insert_with(¶ms.clone().into(), &mut || {
991 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
992 Ok((size, Cow::Owned(bytes)))
993 })?;
994 let bounds = Bounds {
995 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
996 size: tile.bounds.size.map(Into::into),
997 };
998 let content_mask = self.content_mask().scale(scale_factor);
999 let window = &mut *self.window;
1000
1001 window.current_frame.scene_builder.insert(
1002 &window.current_frame.z_index_stack,
1003 PolychromeSprite {
1004 order: 0,
1005 bounds,
1006 corner_radii: Default::default(),
1007 content_mask,
1008 tile,
1009 grayscale: false,
1010 },
1011 );
1012 }
1013 Ok(())
1014 }
1015
1016 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1017 pub fn paint_svg(
1018 &mut self,
1019 bounds: Bounds<Pixels>,
1020 path: SharedString,
1021 color: Hsla,
1022 ) -> Result<()> {
1023 let scale_factor = self.scale_factor();
1024 let bounds = bounds.scale(scale_factor);
1025 // Render the SVG at twice the size to get a higher quality result.
1026 let params = RenderSvgParams {
1027 path,
1028 size: bounds
1029 .size
1030 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1031 };
1032
1033 let tile =
1034 self.window
1035 .sprite_atlas
1036 .get_or_insert_with(¶ms.clone().into(), &mut || {
1037 let bytes = self.svg_renderer.render(¶ms)?;
1038 Ok((params.size, Cow::Owned(bytes)))
1039 })?;
1040 let content_mask = self.content_mask().scale(scale_factor);
1041
1042 let window = &mut *self.window;
1043 window.current_frame.scene_builder.insert(
1044 &window.current_frame.z_index_stack,
1045 MonochromeSprite {
1046 order: 0,
1047 bounds,
1048 content_mask,
1049 color,
1050 tile,
1051 },
1052 );
1053
1054 Ok(())
1055 }
1056
1057 /// Paint an image into the scene for the current frame at the current z-index.
1058 pub fn paint_image(
1059 &mut self,
1060 bounds: Bounds<Pixels>,
1061 corner_radii: Corners<Pixels>,
1062 data: Arc<ImageData>,
1063 grayscale: bool,
1064 ) -> Result<()> {
1065 let scale_factor = self.scale_factor();
1066 let bounds = bounds.scale(scale_factor);
1067 let params = RenderImageParams { image_id: data.id };
1068
1069 let tile = self
1070 .window
1071 .sprite_atlas
1072 .get_or_insert_with(¶ms.clone().into(), &mut || {
1073 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1074 })?;
1075 let content_mask = self.content_mask().scale(scale_factor);
1076 let corner_radii = corner_radii.scale(scale_factor);
1077
1078 let window = &mut *self.window;
1079 window.current_frame.scene_builder.insert(
1080 &window.current_frame.z_index_stack,
1081 PolychromeSprite {
1082 order: 0,
1083 bounds,
1084 content_mask,
1085 corner_radii,
1086 tile,
1087 grayscale,
1088 },
1089 );
1090 Ok(())
1091 }
1092
1093 /// Draw pixels to the display for this window based on the contents of its scene.
1094 pub(crate) fn draw(&mut self) {
1095 let root_view = self.window.root_view.take().unwrap();
1096
1097 self.start_frame();
1098
1099 self.with_z_index(0, |cx| {
1100 let available_space = cx.window.viewport_size.map(Into::into);
1101 root_view.draw(Point::zero(), available_space, cx);
1102 });
1103
1104 if let Some(active_drag) = self.app.active_drag.take() {
1105 self.with_z_index(1, |cx| {
1106 let offset = cx.mouse_position() - active_drag.cursor_offset;
1107 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1108 active_drag.view.draw(offset, available_space, cx);
1109 cx.active_drag = Some(active_drag);
1110 });
1111 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1112 self.with_z_index(1, |cx| {
1113 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1114 active_tooltip
1115 .view
1116 .draw(active_tooltip.cursor_offset, available_space, cx);
1117 });
1118 }
1119
1120 self.window
1121 .current_frame
1122 .dispatch_tree
1123 .preserve_keystroke_matchers(
1124 &mut self.window.previous_frame.dispatch_tree,
1125 self.window.focus,
1126 );
1127
1128 self.window.root_view = Some(root_view);
1129 let scene = self.window.current_frame.scene_builder.build();
1130
1131 self.window.platform_window.draw(scene);
1132 let cursor_style = self
1133 .window
1134 .requested_cursor_style
1135 .take()
1136 .unwrap_or(CursorStyle::Arrow);
1137 self.platform.set_cursor_style(cursor_style);
1138
1139 self.window.dirty = false;
1140 }
1141
1142 /// Rotate the current frame and the previous frame, then clear the current frame.
1143 /// We repopulate all state in the current frame during each paint.
1144 fn start_frame(&mut self) {
1145 self.text_system().start_frame();
1146
1147 let window = &mut *self.window;
1148 window.layout_engine.clear();
1149
1150 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1151 let frame = &mut window.current_frame;
1152 frame.element_states.clear();
1153 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1154 frame.focus_listeners.clear();
1155 frame.dispatch_tree.clear();
1156 }
1157
1158 /// Dispatch a mouse or keyboard event on the window.
1159 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1160 // Handlers may set this to false by calling `stop_propagation`
1161 self.app.propagate_event = true;
1162 self.window.default_prevented = false;
1163
1164 let event = match event {
1165 // Track the mouse position with our own state, since accessing the platform
1166 // API for the mouse position can only occur on the main thread.
1167 InputEvent::MouseMove(mouse_move) => {
1168 self.window.mouse_position = mouse_move.position;
1169 InputEvent::MouseMove(mouse_move)
1170 }
1171 InputEvent::MouseDown(mouse_down) => {
1172 self.window.mouse_position = mouse_down.position;
1173 InputEvent::MouseDown(mouse_down)
1174 }
1175 InputEvent::MouseUp(mouse_up) => {
1176 self.window.mouse_position = mouse_up.position;
1177 InputEvent::MouseUp(mouse_up)
1178 }
1179 // Translate dragging and dropping of external files from the operating system
1180 // to internal drag and drop events.
1181 InputEvent::FileDrop(file_drop) => match file_drop {
1182 FileDropEvent::Entered { position, files } => {
1183 self.window.mouse_position = position;
1184 if self.active_drag.is_none() {
1185 self.active_drag = Some(AnyDrag {
1186 view: self.build_view(|_| files).into(),
1187 cursor_offset: position,
1188 });
1189 }
1190 InputEvent::MouseDown(MouseDownEvent {
1191 position,
1192 button: MouseButton::Left,
1193 click_count: 1,
1194 modifiers: Modifiers::default(),
1195 })
1196 }
1197 FileDropEvent::Pending { position } => {
1198 self.window.mouse_position = position;
1199 InputEvent::MouseMove(MouseMoveEvent {
1200 position,
1201 pressed_button: Some(MouseButton::Left),
1202 modifiers: Modifiers::default(),
1203 })
1204 }
1205 FileDropEvent::Submit { position } => {
1206 self.window.mouse_position = position;
1207 InputEvent::MouseUp(MouseUpEvent {
1208 button: MouseButton::Left,
1209 position,
1210 modifiers: Modifiers::default(),
1211 click_count: 1,
1212 })
1213 }
1214 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1215 button: MouseButton::Left,
1216 position: Point::default(),
1217 modifiers: Modifiers::default(),
1218 click_count: 1,
1219 }),
1220 },
1221 _ => event,
1222 };
1223
1224 if let Some(any_mouse_event) = event.mouse_event() {
1225 self.dispatch_mouse_event(any_mouse_event);
1226 } else if let Some(any_key_event) = event.keyboard_event() {
1227 self.dispatch_key_event(any_key_event);
1228 }
1229
1230 !self.app.propagate_event
1231 }
1232
1233 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1234 if let Some(mut handlers) = self
1235 .window
1236 .current_frame
1237 .mouse_listeners
1238 .remove(&event.type_id())
1239 {
1240 // Because handlers may add other handlers, we sort every time.
1241 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1242
1243 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1244 // special purposes, such as detecting events outside of a given Bounds.
1245 for (_, handler) in &mut handlers {
1246 handler(event, DispatchPhase::Capture, self);
1247 if !self.app.propagate_event {
1248 break;
1249 }
1250 }
1251
1252 // Bubble phase, where most normal handlers do their work.
1253 if self.app.propagate_event {
1254 for (_, handler) in handlers.iter_mut().rev() {
1255 handler(event, DispatchPhase::Bubble, self);
1256 if !self.app.propagate_event {
1257 break;
1258 }
1259 }
1260 }
1261
1262 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1263 self.active_drag = None;
1264 }
1265
1266 // Just in case any handlers added new handlers, which is weird, but possible.
1267 handlers.extend(
1268 self.window
1269 .current_frame
1270 .mouse_listeners
1271 .get_mut(&event.type_id())
1272 .into_iter()
1273 .flat_map(|handlers| handlers.drain(..)),
1274 );
1275 self.window
1276 .current_frame
1277 .mouse_listeners
1278 .insert(event.type_id(), handlers);
1279 }
1280 }
1281
1282 fn dispatch_key_event(&mut self, event: &dyn Any) {
1283 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1284 self.window
1285 .current_frame
1286 .dispatch_tree
1287 .focusable_node_id(focus_id)
1288 }) {
1289 let dispatch_path = self
1290 .window
1291 .current_frame
1292 .dispatch_tree
1293 .dispatch_path(node_id);
1294
1295 // Capture phase
1296 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1297 self.propagate_event = true;
1298
1299 for node_id in &dispatch_path {
1300 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1301
1302 if !node.context.is_empty() {
1303 context_stack.push(node.context.clone());
1304 }
1305
1306 for key_listener in node.key_listeners.clone() {
1307 key_listener(event, DispatchPhase::Capture, self);
1308 if !self.propagate_event {
1309 return;
1310 }
1311 }
1312 }
1313
1314 // Bubble phase
1315 for node_id in dispatch_path.iter().rev() {
1316 // Handle low level key events
1317 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1318 for key_listener in node.key_listeners.clone() {
1319 key_listener(event, DispatchPhase::Bubble, self);
1320 if !self.propagate_event {
1321 return;
1322 }
1323 }
1324
1325 // Match keystrokes
1326 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1327 if !node.context.is_empty() {
1328 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1329 if let Some(action) = self
1330 .window
1331 .current_frame
1332 .dispatch_tree
1333 .dispatch_key(&key_down_event.keystroke, &context_stack)
1334 {
1335 self.dispatch_action_on_node(*node_id, action);
1336 if !self.propagate_event {
1337 return;
1338 }
1339 }
1340 }
1341
1342 context_stack.pop();
1343 }
1344 }
1345 }
1346 }
1347
1348 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1349 let dispatch_path = self
1350 .window
1351 .current_frame
1352 .dispatch_tree
1353 .dispatch_path(node_id);
1354
1355 // Capture phase
1356 for node_id in &dispatch_path {
1357 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1358 for DispatchActionListener {
1359 action_type,
1360 listener,
1361 } in node.action_listeners.clone()
1362 {
1363 let any_action = action.as_any();
1364 if action_type == any_action.type_id() {
1365 listener(any_action, DispatchPhase::Capture, self);
1366 if !self.propagate_event {
1367 return;
1368 }
1369 }
1370 }
1371 }
1372
1373 // Bubble phase
1374 for node_id in dispatch_path.iter().rev() {
1375 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1376 for DispatchActionListener {
1377 action_type,
1378 listener,
1379 } in node.action_listeners.clone()
1380 {
1381 let any_action = action.as_any();
1382 if action_type == any_action.type_id() {
1383 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1384 listener(any_action, DispatchPhase::Bubble, self);
1385 if !self.propagate_event {
1386 return;
1387 }
1388 }
1389 }
1390 }
1391 }
1392
1393 /// Register the given handler to be invoked whenever the global of the given type
1394 /// is updated.
1395 pub fn observe_global<G: 'static>(
1396 &mut self,
1397 f: impl Fn(&mut WindowContext<'_>) + 'static,
1398 ) -> Subscription {
1399 let window_handle = self.window.handle;
1400 self.global_observers.insert(
1401 TypeId::of::<G>(),
1402 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1403 )
1404 }
1405
1406 pub fn activate_window(&self) {
1407 self.window.platform_window.activate();
1408 }
1409
1410 pub fn minimize_window(&self) {
1411 self.window.platform_window.minimize();
1412 }
1413
1414 pub fn toggle_full_screen(&self) {
1415 self.window.platform_window.toggle_full_screen();
1416 }
1417
1418 pub fn prompt(
1419 &self,
1420 level: PromptLevel,
1421 msg: &str,
1422 answers: &[&str],
1423 ) -> oneshot::Receiver<usize> {
1424 self.window.platform_window.prompt(level, msg, answers)
1425 }
1426
1427 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1428 if let Some(focus_id) = self.window.focus {
1429 self.window
1430 .current_frame
1431 .dispatch_tree
1432 .available_actions(focus_id)
1433 } else {
1434 Vec::new()
1435 }
1436 }
1437
1438 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1439 self.window
1440 .current_frame
1441 .dispatch_tree
1442 .bindings_for_action(action)
1443 }
1444
1445 pub fn listener_for<V: Render, E>(
1446 &self,
1447 view: &View<V>,
1448 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1449 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1450 let view = view.downgrade();
1451 move |e: &E, cx: &mut WindowContext| {
1452 view.update(cx, |view, cx| f(view, e, cx)).ok();
1453 }
1454 }
1455
1456 pub fn constructor_for<V: Render, R>(
1457 &self,
1458 view: &View<V>,
1459 f: impl Fn(&mut V, &mut ViewContext<V>) -> R + 'static,
1460 ) -> impl Fn(&mut WindowContext) -> R + 'static {
1461 let view = view.clone();
1462 move |cx: &mut WindowContext| view.update(cx, |view, cx| f(view, cx))
1463 }
1464
1465 //========== ELEMENT RELATED FUNCTIONS ===========
1466 pub fn with_key_dispatch<R>(
1467 &mut self,
1468 context: KeyContext,
1469 focus_handle: Option<FocusHandle>,
1470 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1471 ) -> R {
1472 let window = &mut self.window;
1473 window
1474 .current_frame
1475 .dispatch_tree
1476 .push_node(context.clone());
1477 if let Some(focus_handle) = focus_handle.as_ref() {
1478 window
1479 .current_frame
1480 .dispatch_tree
1481 .make_focusable(focus_handle.id);
1482 }
1483 let result = f(focus_handle, self);
1484
1485 self.window.current_frame.dispatch_tree.pop_node();
1486
1487 result
1488 }
1489
1490 /// Register a focus listener for the current frame only. It will be cleared
1491 /// on the next frame render. You should use this method only from within elements,
1492 /// and we may want to enforce that better via a different context type.
1493 // todo!() Move this to `FrameContext` to emphasize its individuality?
1494 pub fn on_focus_changed(
1495 &mut self,
1496 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1497 ) {
1498 self.window
1499 .current_frame
1500 .focus_listeners
1501 .push(Box::new(move |event, cx| {
1502 listener(event, cx);
1503 }));
1504 }
1505
1506 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1507 /// platform to receive textual input with proper integration with concerns such
1508 /// as IME interactions.
1509 pub fn handle_input(
1510 &mut self,
1511 focus_handle: &FocusHandle,
1512 input_handler: impl PlatformInputHandler,
1513 ) {
1514 if focus_handle.is_focused(self) {
1515 self.window
1516 .platform_window
1517 .set_input_handler(Box::new(input_handler));
1518 }
1519 }
1520}
1521
1522impl Context for WindowContext<'_> {
1523 type Result<T> = T;
1524
1525 fn build_model<T>(
1526 &mut self,
1527 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1528 ) -> Model<T>
1529 where
1530 T: 'static,
1531 {
1532 let slot = self.app.entities.reserve();
1533 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1534 self.entities.insert(slot, model)
1535 }
1536
1537 fn update_model<T: 'static, R>(
1538 &mut self,
1539 model: &Model<T>,
1540 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1541 ) -> R {
1542 let mut entity = self.entities.lease(model);
1543 let result = update(
1544 &mut *entity,
1545 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1546 );
1547 self.entities.end_lease(entity);
1548 result
1549 }
1550
1551 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1552 where
1553 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1554 {
1555 if window == self.window.handle {
1556 let root_view = self.window.root_view.clone().unwrap();
1557 Ok(update(root_view, self))
1558 } else {
1559 window.update(self.app, update)
1560 }
1561 }
1562
1563 fn read_model<T, R>(
1564 &self,
1565 handle: &Model<T>,
1566 read: impl FnOnce(&T, &AppContext) -> R,
1567 ) -> Self::Result<R>
1568 where
1569 T: 'static,
1570 {
1571 let entity = self.entities.read(handle);
1572 read(&*entity, &*self.app)
1573 }
1574
1575 fn read_window<T, R>(
1576 &self,
1577 window: &WindowHandle<T>,
1578 read: impl FnOnce(View<T>, &AppContext) -> R,
1579 ) -> Result<R>
1580 where
1581 T: 'static,
1582 {
1583 if window.any_handle == self.window.handle {
1584 let root_view = self
1585 .window
1586 .root_view
1587 .clone()
1588 .unwrap()
1589 .downcast::<T>()
1590 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1591 Ok(read(root_view, self))
1592 } else {
1593 self.app.read_window(window, read)
1594 }
1595 }
1596}
1597
1598impl VisualContext for WindowContext<'_> {
1599 fn build_view<V>(
1600 &mut self,
1601 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1602 ) -> Self::Result<View<V>>
1603 where
1604 V: 'static + Render,
1605 {
1606 let slot = self.app.entities.reserve();
1607 let view = View {
1608 model: slot.clone(),
1609 };
1610 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1611 let entity = build_view_state(&mut cx);
1612 cx.entities.insert(slot, entity);
1613
1614 cx.new_view_observers
1615 .clone()
1616 .retain(&TypeId::of::<V>(), |observer| {
1617 let any_view = AnyView::from(view.clone());
1618 (observer)(any_view, self);
1619 true
1620 });
1621
1622 view
1623 }
1624
1625 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1626 fn update_view<T: 'static, R>(
1627 &mut self,
1628 view: &View<T>,
1629 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1630 ) -> Self::Result<R> {
1631 let mut lease = self.app.entities.lease(&view.model);
1632 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1633 let result = update(&mut *lease, &mut cx);
1634 cx.app.entities.end_lease(lease);
1635 result
1636 }
1637
1638 fn replace_root_view<V>(
1639 &mut self,
1640 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1641 ) -> Self::Result<View<V>>
1642 where
1643 V: 'static + Render,
1644 {
1645 let slot = self.app.entities.reserve();
1646 let view = View {
1647 model: slot.clone(),
1648 };
1649 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1650 let entity = build_view(&mut cx);
1651 self.entities.insert(slot, entity);
1652 self.window.root_view = Some(view.clone().into());
1653 view
1654 }
1655
1656 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1657 self.update_view(view, |view, cx| {
1658 view.focus_handle(cx).clone().focus(cx);
1659 })
1660 }
1661
1662 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1663 where
1664 V: ManagedView,
1665 {
1666 self.update_view(view, |_, cx| cx.emit(Manager::Dismiss))
1667 }
1668}
1669
1670impl<'a> std::ops::Deref for WindowContext<'a> {
1671 type Target = AppContext;
1672
1673 fn deref(&self) -> &Self::Target {
1674 &self.app
1675 }
1676}
1677
1678impl<'a> std::ops::DerefMut for WindowContext<'a> {
1679 fn deref_mut(&mut self) -> &mut Self::Target {
1680 &mut self.app
1681 }
1682}
1683
1684impl<'a> Borrow<AppContext> for WindowContext<'a> {
1685 fn borrow(&self) -> &AppContext {
1686 &self.app
1687 }
1688}
1689
1690impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1691 fn borrow_mut(&mut self) -> &mut AppContext {
1692 &mut self.app
1693 }
1694}
1695
1696pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1697 fn app_mut(&mut self) -> &mut AppContext {
1698 self.borrow_mut()
1699 }
1700
1701 fn app(&self) -> &AppContext {
1702 self.borrow()
1703 }
1704
1705 fn window(&self) -> &Window {
1706 self.borrow()
1707 }
1708
1709 fn window_mut(&mut self) -> &mut Window {
1710 self.borrow_mut()
1711 }
1712
1713 /// Pushes the given element id onto the global stack and invokes the given closure
1714 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1715 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1716 /// used to associate state with identified elements across separate frames.
1717 fn with_element_id<R>(
1718 &mut self,
1719 id: Option<impl Into<ElementId>>,
1720 f: impl FnOnce(&mut Self) -> R,
1721 ) -> R {
1722 if let Some(id) = id.map(Into::into) {
1723 let window = self.window_mut();
1724 window.element_id_stack.push(id.into());
1725 let result = f(self);
1726 let window: &mut Window = self.borrow_mut();
1727 window.element_id_stack.pop();
1728 result
1729 } else {
1730 f(self)
1731 }
1732 }
1733
1734 /// Invoke the given function with the given content mask after intersecting it
1735 /// with the current mask.
1736 fn with_content_mask<R>(
1737 &mut self,
1738 mask: Option<ContentMask<Pixels>>,
1739 f: impl FnOnce(&mut Self) -> R,
1740 ) -> R {
1741 if let Some(mask) = mask {
1742 let mask = mask.intersect(&self.content_mask());
1743 self.window_mut()
1744 .current_frame
1745 .content_mask_stack
1746 .push(mask);
1747 let result = f(self);
1748 self.window_mut().current_frame.content_mask_stack.pop();
1749 result
1750 } else {
1751 f(self)
1752 }
1753 }
1754
1755 /// Update the global element offset relative to the current offset. This is used to implement
1756 /// scrolling.
1757 fn with_element_offset<R>(
1758 &mut self,
1759 offset: Point<Pixels>,
1760 f: impl FnOnce(&mut Self) -> R,
1761 ) -> R {
1762 if offset.is_zero() {
1763 return f(self);
1764 };
1765
1766 let abs_offset = self.element_offset() + offset;
1767 self.with_absolute_element_offset(abs_offset, f)
1768 }
1769
1770 /// Update the global element offset based on the given offset. This is used to implement
1771 /// drag handles and other manual painting of elements.
1772 fn with_absolute_element_offset<R>(
1773 &mut self,
1774 offset: Point<Pixels>,
1775 f: impl FnOnce(&mut Self) -> R,
1776 ) -> R {
1777 self.window_mut()
1778 .current_frame
1779 .element_offset_stack
1780 .push(offset);
1781 let result = f(self);
1782 self.window_mut().current_frame.element_offset_stack.pop();
1783 result
1784 }
1785
1786 /// Obtain the current element offset.
1787 fn element_offset(&self) -> Point<Pixels> {
1788 self.window()
1789 .current_frame
1790 .element_offset_stack
1791 .last()
1792 .copied()
1793 .unwrap_or_default()
1794 }
1795
1796 /// Update or intialize state for an element with the given id that lives across multiple
1797 /// frames. If an element with this id existed in the previous frame, its state will be passed
1798 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1799 /// when drawing the next frame.
1800 fn with_element_state<S, R>(
1801 &mut self,
1802 id: ElementId,
1803 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1804 ) -> R
1805 where
1806 S: 'static,
1807 {
1808 self.with_element_id(Some(id), |cx| {
1809 let global_id = cx.window().element_id_stack.clone();
1810
1811 if let Some(any) = cx
1812 .window_mut()
1813 .current_frame
1814 .element_states
1815 .remove(&global_id)
1816 .or_else(|| {
1817 cx.window_mut()
1818 .previous_frame
1819 .element_states
1820 .remove(&global_id)
1821 })
1822 {
1823 let ElementStateBox {
1824 inner,
1825
1826 #[cfg(debug_assertions)]
1827 type_name
1828 } = any;
1829 // Using the extra inner option to avoid needing to reallocate a new box.
1830 let mut state_box = inner
1831 .downcast::<Option<S>>()
1832 .map_err(|_| {
1833 #[cfg(debug_assertions)]
1834 {
1835 anyhow!(
1836 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1837 std::any::type_name::<S>(),
1838 type_name
1839 )
1840 }
1841
1842 #[cfg(not(debug_assertions))]
1843 {
1844 anyhow!(
1845 "invalid element state type for id, requested_type {:?}",
1846 std::any::type_name::<S>(),
1847 )
1848 }
1849 })
1850 .unwrap();
1851
1852 // Actual: Option<AnyElement> <- View
1853 // Requested: () <- AnyElemet
1854 let state = state_box
1855 .take()
1856 .expect("element state is already on the stack");
1857 let (result, state) = f(Some(state), cx);
1858 state_box.replace(state);
1859 cx.window_mut()
1860 .current_frame
1861 .element_states
1862 .insert(global_id, ElementStateBox {
1863 inner: state_box,
1864
1865 #[cfg(debug_assertions)]
1866 type_name
1867 });
1868 result
1869 } else {
1870 let (result, state) = f(None, cx);
1871 cx.window_mut()
1872 .current_frame
1873 .element_states
1874 .insert(global_id,
1875 ElementStateBox {
1876 inner: Box::new(Some(state)),
1877
1878 #[cfg(debug_assertions)]
1879 type_name: std::any::type_name::<S>()
1880 }
1881
1882 );
1883 result
1884 }
1885 })
1886 }
1887
1888 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1889 /// id is `None`, no state will be retrieved or stored.
1890 fn with_optional_element_state<S, R>(
1891 &mut self,
1892 element_id: Option<ElementId>,
1893 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1894 ) -> R
1895 where
1896 S: 'static,
1897 {
1898 if let Some(element_id) = element_id {
1899 self.with_element_state(element_id, f)
1900 } else {
1901 f(None, self).0
1902 }
1903 }
1904
1905 /// Obtain the current content mask.
1906 fn content_mask(&self) -> ContentMask<Pixels> {
1907 self.window()
1908 .current_frame
1909 .content_mask_stack
1910 .last()
1911 .cloned()
1912 .unwrap_or_else(|| ContentMask {
1913 bounds: Bounds {
1914 origin: Point::default(),
1915 size: self.window().viewport_size,
1916 },
1917 })
1918 }
1919
1920 /// The size of an em for the base font of the application. Adjusting this value allows the
1921 /// UI to scale, just like zooming a web page.
1922 fn rem_size(&self) -> Pixels {
1923 self.window().rem_size
1924 }
1925}
1926
1927impl Borrow<Window> for WindowContext<'_> {
1928 fn borrow(&self) -> &Window {
1929 &self.window
1930 }
1931}
1932
1933impl BorrowMut<Window> for WindowContext<'_> {
1934 fn borrow_mut(&mut self) -> &mut Window {
1935 &mut self.window
1936 }
1937}
1938
1939impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1940
1941pub struct ViewContext<'a, V> {
1942 window_cx: WindowContext<'a>,
1943 view: &'a View<V>,
1944}
1945
1946impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1947 fn borrow(&self) -> &AppContext {
1948 &*self.window_cx.app
1949 }
1950}
1951
1952impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1953 fn borrow_mut(&mut self) -> &mut AppContext {
1954 &mut *self.window_cx.app
1955 }
1956}
1957
1958impl<V> Borrow<Window> for ViewContext<'_, V> {
1959 fn borrow(&self) -> &Window {
1960 &*self.window_cx.window
1961 }
1962}
1963
1964impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1965 fn borrow_mut(&mut self) -> &mut Window {
1966 &mut *self.window_cx.window
1967 }
1968}
1969
1970impl<'a, V: 'static> ViewContext<'a, V> {
1971 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1972 Self {
1973 window_cx: WindowContext::new(app, window),
1974 view,
1975 }
1976 }
1977
1978 pub fn entity_id(&self) -> EntityId {
1979 self.view.entity_id()
1980 }
1981
1982 pub fn view(&self) -> &View<V> {
1983 self.view
1984 }
1985
1986 pub fn model(&self) -> &Model<V> {
1987 &self.view.model
1988 }
1989
1990 /// Access the underlying window context.
1991 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1992 &mut self.window_cx
1993 }
1994
1995 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1996 self.window.current_frame.z_index_stack.push(z_index);
1997 let result = f(self);
1998 self.window.current_frame.z_index_stack.pop();
1999 result
2000 }
2001
2002 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2003 where
2004 V: 'static,
2005 {
2006 let view = self.view().clone();
2007 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2008 }
2009
2010 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2011 /// that are currently on the stack to be returned to the app.
2012 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2013 let view = self.view().downgrade();
2014 self.window_cx.defer(move |cx| {
2015 view.update(cx, f).ok();
2016 });
2017 }
2018
2019 pub fn observe<V2, E>(
2020 &mut self,
2021 entity: &E,
2022 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2023 ) -> Subscription
2024 where
2025 V2: 'static,
2026 V: 'static,
2027 E: Entity<V2>,
2028 {
2029 let view = self.view().downgrade();
2030 let entity_id = entity.entity_id();
2031 let entity = entity.downgrade();
2032 let window_handle = self.window.handle;
2033 self.app.observers.insert(
2034 entity_id,
2035 Box::new(move |cx| {
2036 window_handle
2037 .update(cx, |_, cx| {
2038 if let Some(handle) = E::upgrade_from(&entity) {
2039 view.update(cx, |this, cx| on_notify(this, handle, cx))
2040 .is_ok()
2041 } else {
2042 false
2043 }
2044 })
2045 .unwrap_or(false)
2046 }),
2047 )
2048 }
2049
2050 pub fn subscribe<V2, E, Evt>(
2051 &mut self,
2052 entity: &E,
2053 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2054 ) -> Subscription
2055 where
2056 V2: EventEmitter<Evt>,
2057 E: Entity<V2>,
2058 Evt: 'static,
2059 {
2060 let view = self.view().downgrade();
2061 let entity_id = entity.entity_id();
2062 let handle = entity.downgrade();
2063 let window_handle = self.window.handle;
2064 self.app.event_listeners.insert(
2065 entity_id,
2066 (
2067 TypeId::of::<Evt>(),
2068 Box::new(move |event, cx| {
2069 window_handle
2070 .update(cx, |_, cx| {
2071 if let Some(handle) = E::upgrade_from(&handle) {
2072 let event = event.downcast_ref().expect("invalid event type");
2073 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2074 .is_ok()
2075 } else {
2076 false
2077 }
2078 })
2079 .unwrap_or(false)
2080 }),
2081 ),
2082 )
2083 }
2084
2085 pub fn on_release(
2086 &mut self,
2087 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2088 ) -> Subscription {
2089 let window_handle = self.window.handle;
2090 self.app.release_listeners.insert(
2091 self.view.model.entity_id,
2092 Box::new(move |this, cx| {
2093 let this = this.downcast_mut().expect("invalid entity type");
2094 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2095 }),
2096 )
2097 }
2098
2099 pub fn observe_release<V2, E>(
2100 &mut self,
2101 entity: &E,
2102 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2103 ) -> Subscription
2104 where
2105 V: 'static,
2106 V2: 'static,
2107 E: Entity<V2>,
2108 {
2109 let view = self.view().downgrade();
2110 let entity_id = entity.entity_id();
2111 let window_handle = self.window.handle;
2112 self.app.release_listeners.insert(
2113 entity_id,
2114 Box::new(move |entity, cx| {
2115 let entity = entity.downcast_mut().expect("invalid entity type");
2116 let _ = window_handle.update(cx, |_, cx| {
2117 view.update(cx, |this, cx| on_release(this, entity, cx))
2118 });
2119 }),
2120 )
2121 }
2122
2123 pub fn notify(&mut self) {
2124 self.window_cx.notify();
2125 self.window_cx.app.push_effect(Effect::Notify {
2126 emitter: self.view.model.entity_id,
2127 });
2128 }
2129
2130 pub fn observe_window_bounds(
2131 &mut self,
2132 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2133 ) -> Subscription {
2134 let view = self.view.downgrade();
2135 self.window.bounds_observers.insert(
2136 (),
2137 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2138 )
2139 }
2140
2141 pub fn observe_window_activation(
2142 &mut self,
2143 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2144 ) -> Subscription {
2145 let view = self.view.downgrade();
2146 self.window.activation_observers.insert(
2147 (),
2148 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2149 )
2150 }
2151
2152 /// Register a listener to be called when the given focus handle receives focus.
2153 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2154 /// is dropped.
2155 pub fn on_focus(
2156 &mut self,
2157 handle: &FocusHandle,
2158 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2159 ) -> Subscription {
2160 let view = self.view.downgrade();
2161 let focus_id = handle.id;
2162 self.window.focus_listeners.insert(
2163 (),
2164 Box::new(move |event, cx| {
2165 view.update(cx, |view, cx| {
2166 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2167 listener(view, cx)
2168 }
2169 })
2170 .is_ok()
2171 }),
2172 )
2173 }
2174
2175 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2176 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2177 /// is dropped.
2178 pub fn on_focus_in(
2179 &mut self,
2180 handle: &FocusHandle,
2181 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2182 ) -> Subscription {
2183 let view = self.view.downgrade();
2184 let focus_id = handle.id;
2185 self.window.focus_listeners.insert(
2186 (),
2187 Box::new(move |event, cx| {
2188 view.update(cx, |view, cx| {
2189 if event
2190 .focused
2191 .as_ref()
2192 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2193 {
2194 listener(view, cx)
2195 }
2196 })
2197 .is_ok()
2198 }),
2199 )
2200 }
2201
2202 /// Register a listener to be called when the given focus handle loses focus.
2203 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2204 /// is dropped.
2205 pub fn on_blur(
2206 &mut self,
2207 handle: &FocusHandle,
2208 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2209 ) -> Subscription {
2210 let view = self.view.downgrade();
2211 let focus_id = handle.id;
2212 self.window.focus_listeners.insert(
2213 (),
2214 Box::new(move |event, cx| {
2215 view.update(cx, |view, cx| {
2216 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2217 listener(view, cx)
2218 }
2219 })
2220 .is_ok()
2221 }),
2222 )
2223 }
2224
2225 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2226 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2227 /// is dropped.
2228 pub fn on_focus_out(
2229 &mut self,
2230 handle: &FocusHandle,
2231 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2232 ) -> Subscription {
2233 let view = self.view.downgrade();
2234 let focus_id = handle.id;
2235 self.window.focus_listeners.insert(
2236 (),
2237 Box::new(move |event, cx| {
2238 view.update(cx, |view, cx| {
2239 if event
2240 .blurred
2241 .as_ref()
2242 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2243 {
2244 listener(view, cx)
2245 }
2246 })
2247 .is_ok()
2248 }),
2249 )
2250 }
2251
2252 pub fn spawn<Fut, R>(
2253 &mut self,
2254 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2255 ) -> Task<R>
2256 where
2257 R: 'static,
2258 Fut: Future<Output = R> + 'static,
2259 {
2260 let view = self.view().downgrade();
2261 self.window_cx.spawn(|cx| f(view, cx))
2262 }
2263
2264 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2265 where
2266 G: 'static,
2267 {
2268 let mut global = self.app.lease_global::<G>();
2269 let result = f(&mut global, self);
2270 self.app.end_global_lease(global);
2271 result
2272 }
2273
2274 pub fn observe_global<G: 'static>(
2275 &mut self,
2276 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2277 ) -> Subscription {
2278 let window_handle = self.window.handle;
2279 let view = self.view().downgrade();
2280 self.global_observers.insert(
2281 TypeId::of::<G>(),
2282 Box::new(move |cx| {
2283 window_handle
2284 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2285 .unwrap_or(false)
2286 }),
2287 )
2288 }
2289
2290 pub fn on_mouse_event<Event: 'static>(
2291 &mut self,
2292 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2293 ) {
2294 let handle = self.view().clone();
2295 self.window_cx.on_mouse_event(move |event, phase, cx| {
2296 handle.update(cx, |view, cx| {
2297 handler(view, event, phase, cx);
2298 })
2299 });
2300 }
2301
2302 pub fn on_key_event<Event: 'static>(
2303 &mut self,
2304 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2305 ) {
2306 let handle = self.view().clone();
2307 self.window_cx.on_key_event(move |event, phase, cx| {
2308 handle.update(cx, |view, cx| {
2309 handler(view, event, phase, cx);
2310 })
2311 });
2312 }
2313
2314 pub fn on_action(
2315 &mut self,
2316 action_type: TypeId,
2317 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2318 ) {
2319 let handle = self.view().clone();
2320 self.window_cx
2321 .on_action(action_type, move |action, phase, cx| {
2322 handle.update(cx, |view, cx| {
2323 handler(view, action, phase, cx);
2324 })
2325 });
2326 }
2327
2328 pub fn emit<Evt>(&mut self, event: Evt)
2329 where
2330 Evt: 'static,
2331 V: EventEmitter<Evt>,
2332 {
2333 let emitter = self.view.model.entity_id;
2334 self.app.push_effect(Effect::Emit {
2335 emitter,
2336 event_type: TypeId::of::<Evt>(),
2337 event: Box::new(event),
2338 });
2339 }
2340
2341 pub fn focus_self(&mut self)
2342 where
2343 V: FocusableView,
2344 {
2345 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2346 }
2347
2348 pub fn dismiss_self(&mut self)
2349 where
2350 V: ManagedView,
2351 {
2352 self.defer(|_, cx| cx.emit(Manager::Dismiss))
2353 }
2354
2355 pub fn listener<E>(
2356 &self,
2357 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2358 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2359 let view = self.view().downgrade();
2360 move |e: &E, cx: &mut WindowContext| {
2361 view.update(cx, |view, cx| f(view, e, cx)).ok();
2362 }
2363 }
2364}
2365
2366impl<V> Context for ViewContext<'_, V> {
2367 type Result<U> = U;
2368
2369 fn build_model<T: 'static>(
2370 &mut self,
2371 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2372 ) -> Model<T> {
2373 self.window_cx.build_model(build_model)
2374 }
2375
2376 fn update_model<T: 'static, R>(
2377 &mut self,
2378 model: &Model<T>,
2379 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2380 ) -> R {
2381 self.window_cx.update_model(model, update)
2382 }
2383
2384 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2385 where
2386 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2387 {
2388 self.window_cx.update_window(window, update)
2389 }
2390
2391 fn read_model<T, R>(
2392 &self,
2393 handle: &Model<T>,
2394 read: impl FnOnce(&T, &AppContext) -> R,
2395 ) -> Self::Result<R>
2396 where
2397 T: 'static,
2398 {
2399 self.window_cx.read_model(handle, read)
2400 }
2401
2402 fn read_window<T, R>(
2403 &self,
2404 window: &WindowHandle<T>,
2405 read: impl FnOnce(View<T>, &AppContext) -> R,
2406 ) -> Result<R>
2407 where
2408 T: 'static,
2409 {
2410 self.window_cx.read_window(window, read)
2411 }
2412}
2413
2414impl<V: 'static> VisualContext for ViewContext<'_, V> {
2415 fn build_view<W: Render + 'static>(
2416 &mut self,
2417 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2418 ) -> Self::Result<View<W>> {
2419 self.window_cx.build_view(build_view_state)
2420 }
2421
2422 fn update_view<V2: 'static, R>(
2423 &mut self,
2424 view: &View<V2>,
2425 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2426 ) -> Self::Result<R> {
2427 self.window_cx.update_view(view, update)
2428 }
2429
2430 fn replace_root_view<W>(
2431 &mut self,
2432 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2433 ) -> Self::Result<View<W>>
2434 where
2435 W: 'static + Render,
2436 {
2437 self.window_cx.replace_root_view(build_view)
2438 }
2439
2440 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2441 self.window_cx.focus_view(view)
2442 }
2443
2444 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2445 self.window_cx.dismiss_view(view)
2446 }
2447}
2448
2449impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2450 type Target = WindowContext<'a>;
2451
2452 fn deref(&self) -> &Self::Target {
2453 &self.window_cx
2454 }
2455}
2456
2457impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2458 fn deref_mut(&mut self) -> &mut Self::Target {
2459 &mut self.window_cx
2460 }
2461}
2462
2463// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2464slotmap::new_key_type! { pub struct WindowId; }
2465
2466impl WindowId {
2467 pub fn as_u64(&self) -> u64 {
2468 self.0.as_ffi()
2469 }
2470}
2471
2472#[derive(Deref, DerefMut)]
2473pub struct WindowHandle<V> {
2474 #[deref]
2475 #[deref_mut]
2476 pub(crate) any_handle: AnyWindowHandle,
2477 state_type: PhantomData<V>,
2478}
2479
2480impl<V: 'static + Render> WindowHandle<V> {
2481 pub fn new(id: WindowId) -> Self {
2482 WindowHandle {
2483 any_handle: AnyWindowHandle {
2484 id,
2485 state_type: TypeId::of::<V>(),
2486 },
2487 state_type: PhantomData,
2488 }
2489 }
2490
2491 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2492 where
2493 C: Context,
2494 {
2495 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2496 root_view
2497 .downcast::<V>()
2498 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2499 }))
2500 }
2501
2502 pub fn update<C, R>(
2503 &self,
2504 cx: &mut C,
2505 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2506 ) -> Result<R>
2507 where
2508 C: Context,
2509 {
2510 cx.update_window(self.any_handle, |root_view, cx| {
2511 let view = root_view
2512 .downcast::<V>()
2513 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2514 Ok(cx.update_view(&view, update))
2515 })?
2516 }
2517
2518 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2519 let x = cx
2520 .windows
2521 .get(self.id)
2522 .and_then(|window| {
2523 window
2524 .as_ref()
2525 .and_then(|window| window.root_view.clone())
2526 .map(|root_view| root_view.downcast::<V>())
2527 })
2528 .ok_or_else(|| anyhow!("window not found"))?
2529 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2530
2531 Ok(x.read(cx))
2532 }
2533
2534 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2535 where
2536 C: Context,
2537 {
2538 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2539 }
2540
2541 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2542 where
2543 C: Context,
2544 {
2545 cx.read_window(self, |root_view, _cx| root_view.clone())
2546 }
2547
2548 pub fn is_active(&self, cx: &WindowContext) -> Option<bool> {
2549 cx.windows
2550 .get(self.id)
2551 .and_then(|window| window.as_ref().map(|window| window.active))
2552 }
2553}
2554
2555impl<V> Copy for WindowHandle<V> {}
2556
2557impl<V> Clone for WindowHandle<V> {
2558 fn clone(&self) -> Self {
2559 WindowHandle {
2560 any_handle: self.any_handle,
2561 state_type: PhantomData,
2562 }
2563 }
2564}
2565
2566impl<V> PartialEq for WindowHandle<V> {
2567 fn eq(&self, other: &Self) -> bool {
2568 self.any_handle == other.any_handle
2569 }
2570}
2571
2572impl<V> Eq for WindowHandle<V> {}
2573
2574impl<V> Hash for WindowHandle<V> {
2575 fn hash<H: Hasher>(&self, state: &mut H) {
2576 self.any_handle.hash(state);
2577 }
2578}
2579
2580impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2581 fn into(self) -> AnyWindowHandle {
2582 self.any_handle
2583 }
2584}
2585
2586#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2587pub struct AnyWindowHandle {
2588 pub(crate) id: WindowId,
2589 state_type: TypeId,
2590}
2591
2592impl AnyWindowHandle {
2593 pub fn window_id(&self) -> WindowId {
2594 self.id
2595 }
2596
2597 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2598 if TypeId::of::<T>() == self.state_type {
2599 Some(WindowHandle {
2600 any_handle: *self,
2601 state_type: PhantomData,
2602 })
2603 } else {
2604 None
2605 }
2606 }
2607
2608 pub fn update<C, R>(
2609 self,
2610 cx: &mut C,
2611 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2612 ) -> Result<R>
2613 where
2614 C: Context,
2615 {
2616 cx.update_window(self, update)
2617 }
2618
2619 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2620 where
2621 C: Context,
2622 T: 'static,
2623 {
2624 let view = self
2625 .downcast::<T>()
2626 .context("the type of the window's root view has changed")?;
2627
2628 cx.read_window(&view, read)
2629 }
2630}
2631
2632#[cfg(any(test, feature = "test-support"))]
2633impl From<SmallVec<[u32; 16]>> for StackingOrder {
2634 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2635 StackingOrder(small_vec)
2636 }
2637}
2638
2639#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2640pub enum ElementId {
2641 View(EntityId),
2642 Integer(usize),
2643 Name(SharedString),
2644 FocusHandle(FocusId),
2645}
2646
2647impl ElementId {
2648 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2649 ElementId::View(entity_id)
2650 }
2651}
2652
2653impl TryInto<SharedString> for ElementId {
2654 type Error = anyhow::Error;
2655
2656 fn try_into(self) -> anyhow::Result<SharedString> {
2657 if let ElementId::Name(name) = self {
2658 Ok(name)
2659 } else {
2660 Err(anyhow!("element id is not string"))
2661 }
2662 }
2663}
2664
2665impl From<usize> for ElementId {
2666 fn from(id: usize) -> Self {
2667 ElementId::Integer(id)
2668 }
2669}
2670
2671impl From<i32> for ElementId {
2672 fn from(id: i32) -> Self {
2673 Self::Integer(id as usize)
2674 }
2675}
2676
2677impl From<SharedString> for ElementId {
2678 fn from(name: SharedString) -> Self {
2679 ElementId::Name(name)
2680 }
2681}
2682
2683impl From<&'static str> for ElementId {
2684 fn from(name: &'static str) -> Self {
2685 ElementId::Name(name.into())
2686 }
2687}
2688
2689impl<'a> From<&'a FocusHandle> for ElementId {
2690 fn from(handle: &'a FocusHandle) -> Self {
2691 ElementId::FocusHandle(handle.id)
2692 }
2693}