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 ) -> Result<()> {
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 Ok(())
909 }
910
911 /// Paint a monochrome (non-emoji) glyph into the scene for the current frame at the current z-index.
912 /// The y component of the origin is the baseline of the glyph.
913 pub fn paint_glyph(
914 &mut self,
915 origin: Point<Pixels>,
916 font_id: FontId,
917 glyph_id: GlyphId,
918 font_size: Pixels,
919 color: Hsla,
920 ) -> Result<()> {
921 let scale_factor = self.scale_factor();
922 let glyph_origin = origin.scale(scale_factor);
923 let subpixel_variant = Point {
924 x: (glyph_origin.x.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
925 y: (glyph_origin.y.0.fract() * SUBPIXEL_VARIANTS as f32).floor() as u8,
926 };
927 let params = RenderGlyphParams {
928 font_id,
929 glyph_id,
930 font_size,
931 subpixel_variant,
932 scale_factor,
933 is_emoji: false,
934 };
935
936 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
937 if !raster_bounds.is_zero() {
938 let tile =
939 self.window
940 .sprite_atlas
941 .get_or_insert_with(¶ms.clone().into(), &mut || {
942 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
943 Ok((size, Cow::Owned(bytes)))
944 })?;
945 let bounds = Bounds {
946 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
947 size: tile.bounds.size.map(Into::into),
948 };
949 let content_mask = self.content_mask().scale(scale_factor);
950 let window = &mut *self.window;
951 window.current_frame.scene_builder.insert(
952 &window.current_frame.z_index_stack,
953 MonochromeSprite {
954 order: 0,
955 bounds,
956 content_mask,
957 color,
958 tile,
959 },
960 );
961 }
962 Ok(())
963 }
964
965 /// Paint an emoji glyph into the scene for the current frame at the current z-index.
966 /// The y component of the origin is the baseline of the glyph.
967 pub fn paint_emoji(
968 &mut self,
969 origin: Point<Pixels>,
970 font_id: FontId,
971 glyph_id: GlyphId,
972 font_size: Pixels,
973 ) -> Result<()> {
974 let scale_factor = self.scale_factor();
975 let glyph_origin = origin.scale(scale_factor);
976 let params = RenderGlyphParams {
977 font_id,
978 glyph_id,
979 font_size,
980 // We don't render emojis with subpixel variants.
981 subpixel_variant: Default::default(),
982 scale_factor,
983 is_emoji: true,
984 };
985
986 let raster_bounds = self.text_system().raster_bounds(¶ms)?;
987 if !raster_bounds.is_zero() {
988 let tile =
989 self.window
990 .sprite_atlas
991 .get_or_insert_with(¶ms.clone().into(), &mut || {
992 let (size, bytes) = self.text_system().rasterize_glyph(¶ms)?;
993 Ok((size, Cow::Owned(bytes)))
994 })?;
995 let bounds = Bounds {
996 origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
997 size: tile.bounds.size.map(Into::into),
998 };
999 let content_mask = self.content_mask().scale(scale_factor);
1000 let window = &mut *self.window;
1001
1002 window.current_frame.scene_builder.insert(
1003 &window.current_frame.z_index_stack,
1004 PolychromeSprite {
1005 order: 0,
1006 bounds,
1007 corner_radii: Default::default(),
1008 content_mask,
1009 tile,
1010 grayscale: false,
1011 },
1012 );
1013 }
1014 Ok(())
1015 }
1016
1017 /// Paint a monochrome SVG into the scene for the current frame at the current stacking context.
1018 pub fn paint_svg(
1019 &mut self,
1020 bounds: Bounds<Pixels>,
1021 path: SharedString,
1022 color: Hsla,
1023 ) -> Result<()> {
1024 let scale_factor = self.scale_factor();
1025 let bounds = bounds.scale(scale_factor);
1026 // Render the SVG at twice the size to get a higher quality result.
1027 let params = RenderSvgParams {
1028 path,
1029 size: bounds
1030 .size
1031 .map(|pixels| DevicePixels::from((pixels.0 * 2.).ceil() as i32)),
1032 };
1033
1034 let tile =
1035 self.window
1036 .sprite_atlas
1037 .get_or_insert_with(¶ms.clone().into(), &mut || {
1038 let bytes = self.svg_renderer.render(¶ms)?;
1039 Ok((params.size, Cow::Owned(bytes)))
1040 })?;
1041 let content_mask = self.content_mask().scale(scale_factor);
1042
1043 let window = &mut *self.window;
1044 window.current_frame.scene_builder.insert(
1045 &window.current_frame.z_index_stack,
1046 MonochromeSprite {
1047 order: 0,
1048 bounds,
1049 content_mask,
1050 color,
1051 tile,
1052 },
1053 );
1054
1055 Ok(())
1056 }
1057
1058 /// Paint an image into the scene for the current frame at the current z-index.
1059 pub fn paint_image(
1060 &mut self,
1061 bounds: Bounds<Pixels>,
1062 corner_radii: Corners<Pixels>,
1063 data: Arc<ImageData>,
1064 grayscale: bool,
1065 ) -> Result<()> {
1066 let scale_factor = self.scale_factor();
1067 let bounds = bounds.scale(scale_factor);
1068 let params = RenderImageParams { image_id: data.id };
1069
1070 let tile = self
1071 .window
1072 .sprite_atlas
1073 .get_or_insert_with(¶ms.clone().into(), &mut || {
1074 Ok((data.size(), Cow::Borrowed(data.as_bytes())))
1075 })?;
1076 let content_mask = self.content_mask().scale(scale_factor);
1077 let corner_radii = corner_radii.scale(scale_factor);
1078
1079 let window = &mut *self.window;
1080 window.current_frame.scene_builder.insert(
1081 &window.current_frame.z_index_stack,
1082 PolychromeSprite {
1083 order: 0,
1084 bounds,
1085 content_mask,
1086 corner_radii,
1087 tile,
1088 grayscale,
1089 },
1090 );
1091 Ok(())
1092 }
1093
1094 /// Draw pixels to the display for this window based on the contents of its scene.
1095 pub(crate) fn draw(&mut self) {
1096 let root_view = self.window.root_view.take().unwrap();
1097
1098 self.start_frame();
1099
1100 self.with_z_index(0, |cx| {
1101 let available_space = cx.window.viewport_size.map(Into::into);
1102 root_view.draw(Point::zero(), available_space, cx);
1103 });
1104
1105 if let Some(active_drag) = self.app.active_drag.take() {
1106 self.with_z_index(1, |cx| {
1107 let offset = cx.mouse_position() - active_drag.cursor_offset;
1108 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1109 active_drag.view.draw(offset, available_space, cx);
1110 cx.active_drag = Some(active_drag);
1111 });
1112 } else if let Some(active_tooltip) = self.app.active_tooltip.take() {
1113 self.with_z_index(1, |cx| {
1114 let available_space = size(AvailableSpace::MinContent, AvailableSpace::MinContent);
1115 active_tooltip
1116 .view
1117 .draw(active_tooltip.cursor_offset, available_space, cx);
1118 });
1119 }
1120
1121 self.window
1122 .current_frame
1123 .dispatch_tree
1124 .preserve_keystroke_matchers(
1125 &mut self.window.previous_frame.dispatch_tree,
1126 self.window.focus,
1127 );
1128
1129 self.window.root_view = Some(root_view);
1130 let scene = self.window.current_frame.scene_builder.build();
1131
1132 self.window.platform_window.draw(scene);
1133 let cursor_style = self
1134 .window
1135 .requested_cursor_style
1136 .take()
1137 .unwrap_or(CursorStyle::Arrow);
1138 self.platform.set_cursor_style(cursor_style);
1139
1140 self.window.dirty = false;
1141 }
1142
1143 /// Rotate the current frame and the previous frame, then clear the current frame.
1144 /// We repopulate all state in the current frame during each paint.
1145 fn start_frame(&mut self) {
1146 self.text_system().start_frame();
1147
1148 let window = &mut *self.window;
1149 window.layout_engine.clear();
1150
1151 mem::swap(&mut window.previous_frame, &mut window.current_frame);
1152 let frame = &mut window.current_frame;
1153 frame.element_states.clear();
1154 frame.mouse_listeners.values_mut().for_each(Vec::clear);
1155 frame.focus_listeners.clear();
1156 frame.dispatch_tree.clear();
1157 }
1158
1159 /// Dispatch a mouse or keyboard event on the window.
1160 pub fn dispatch_event(&mut self, event: InputEvent) -> bool {
1161 // Handlers may set this to false by calling `stop_propagation`
1162 self.app.propagate_event = true;
1163 self.window.default_prevented = false;
1164
1165 let event = match event {
1166 // Track the mouse position with our own state, since accessing the platform
1167 // API for the mouse position can only occur on the main thread.
1168 InputEvent::MouseMove(mouse_move) => {
1169 self.window.mouse_position = mouse_move.position;
1170 InputEvent::MouseMove(mouse_move)
1171 }
1172 InputEvent::MouseDown(mouse_down) => {
1173 self.window.mouse_position = mouse_down.position;
1174 InputEvent::MouseDown(mouse_down)
1175 }
1176 InputEvent::MouseUp(mouse_up) => {
1177 self.window.mouse_position = mouse_up.position;
1178 InputEvent::MouseUp(mouse_up)
1179 }
1180 // Translate dragging and dropping of external files from the operating system
1181 // to internal drag and drop events.
1182 InputEvent::FileDrop(file_drop) => match file_drop {
1183 FileDropEvent::Entered { position, files } => {
1184 self.window.mouse_position = position;
1185 if self.active_drag.is_none() {
1186 self.active_drag = Some(AnyDrag {
1187 view: self.build_view(|_| files).into(),
1188 cursor_offset: position,
1189 });
1190 }
1191 InputEvent::MouseDown(MouseDownEvent {
1192 position,
1193 button: MouseButton::Left,
1194 click_count: 1,
1195 modifiers: Modifiers::default(),
1196 })
1197 }
1198 FileDropEvent::Pending { position } => {
1199 self.window.mouse_position = position;
1200 InputEvent::MouseMove(MouseMoveEvent {
1201 position,
1202 pressed_button: Some(MouseButton::Left),
1203 modifiers: Modifiers::default(),
1204 })
1205 }
1206 FileDropEvent::Submit { position } => {
1207 self.window.mouse_position = position;
1208 InputEvent::MouseUp(MouseUpEvent {
1209 button: MouseButton::Left,
1210 position,
1211 modifiers: Modifiers::default(),
1212 click_count: 1,
1213 })
1214 }
1215 FileDropEvent::Exited => InputEvent::MouseUp(MouseUpEvent {
1216 button: MouseButton::Left,
1217 position: Point::default(),
1218 modifiers: Modifiers::default(),
1219 click_count: 1,
1220 }),
1221 },
1222 _ => event,
1223 };
1224
1225 if let Some(any_mouse_event) = event.mouse_event() {
1226 self.dispatch_mouse_event(any_mouse_event);
1227 } else if let Some(any_key_event) = event.keyboard_event() {
1228 self.dispatch_key_event(any_key_event);
1229 }
1230
1231 !self.app.propagate_event
1232 }
1233
1234 fn dispatch_mouse_event(&mut self, event: &dyn Any) {
1235 if let Some(mut handlers) = self
1236 .window
1237 .current_frame
1238 .mouse_listeners
1239 .remove(&event.type_id())
1240 {
1241 // Because handlers may add other handlers, we sort every time.
1242 handlers.sort_by(|(a, _), (b, _)| a.cmp(b));
1243
1244 // Capture phase, events bubble from back to front. Handlers for this phase are used for
1245 // special purposes, such as detecting events outside of a given Bounds.
1246 for (_, handler) in &mut handlers {
1247 handler(event, DispatchPhase::Capture, self);
1248 if !self.app.propagate_event {
1249 break;
1250 }
1251 }
1252
1253 // Bubble phase, where most normal handlers do their work.
1254 if self.app.propagate_event {
1255 for (_, handler) in handlers.iter_mut().rev() {
1256 handler(event, DispatchPhase::Bubble, self);
1257 if !self.app.propagate_event {
1258 break;
1259 }
1260 }
1261 }
1262
1263 if self.app.propagate_event && event.downcast_ref::<MouseUpEvent>().is_some() {
1264 self.active_drag = None;
1265 }
1266
1267 // Just in case any handlers added new handlers, which is weird, but possible.
1268 handlers.extend(
1269 self.window
1270 .current_frame
1271 .mouse_listeners
1272 .get_mut(&event.type_id())
1273 .into_iter()
1274 .flat_map(|handlers| handlers.drain(..)),
1275 );
1276 self.window
1277 .current_frame
1278 .mouse_listeners
1279 .insert(event.type_id(), handlers);
1280 }
1281 }
1282
1283 fn dispatch_key_event(&mut self, event: &dyn Any) {
1284 if let Some(node_id) = self.window.focus.and_then(|focus_id| {
1285 self.window
1286 .current_frame
1287 .dispatch_tree
1288 .focusable_node_id(focus_id)
1289 }) {
1290 let dispatch_path = self
1291 .window
1292 .current_frame
1293 .dispatch_tree
1294 .dispatch_path(node_id);
1295
1296 // Capture phase
1297 let mut context_stack: SmallVec<[KeyContext; 16]> = SmallVec::new();
1298 self.propagate_event = true;
1299
1300 for node_id in &dispatch_path {
1301 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1302
1303 if !node.context.is_empty() {
1304 context_stack.push(node.context.clone());
1305 }
1306
1307 for key_listener in node.key_listeners.clone() {
1308 key_listener(event, DispatchPhase::Capture, self);
1309 if !self.propagate_event {
1310 return;
1311 }
1312 }
1313 }
1314
1315 // Bubble phase
1316 for node_id in dispatch_path.iter().rev() {
1317 // Handle low level key events
1318 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1319 for key_listener in node.key_listeners.clone() {
1320 key_listener(event, DispatchPhase::Bubble, self);
1321 if !self.propagate_event {
1322 return;
1323 }
1324 }
1325
1326 // Match keystrokes
1327 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1328 if !node.context.is_empty() {
1329 if let Some(key_down_event) = event.downcast_ref::<KeyDownEvent>() {
1330 if let Some(action) = self
1331 .window
1332 .current_frame
1333 .dispatch_tree
1334 .dispatch_key(&key_down_event.keystroke, &context_stack)
1335 {
1336 self.dispatch_action_on_node(*node_id, action);
1337 if !self.propagate_event {
1338 return;
1339 }
1340 }
1341 }
1342
1343 context_stack.pop();
1344 }
1345 }
1346 }
1347 }
1348
1349 fn dispatch_action_on_node(&mut self, node_id: DispatchNodeId, action: Box<dyn Action>) {
1350 let dispatch_path = self
1351 .window
1352 .current_frame
1353 .dispatch_tree
1354 .dispatch_path(node_id);
1355
1356 // Capture phase
1357 for node_id in &dispatch_path {
1358 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1359 for DispatchActionListener {
1360 action_type,
1361 listener,
1362 } in node.action_listeners.clone()
1363 {
1364 let any_action = action.as_any();
1365 if action_type == any_action.type_id() {
1366 listener(any_action, DispatchPhase::Capture, self);
1367 if !self.propagate_event {
1368 return;
1369 }
1370 }
1371 }
1372 }
1373
1374 // Bubble phase
1375 for node_id in dispatch_path.iter().rev() {
1376 let node = self.window.current_frame.dispatch_tree.node(*node_id);
1377 for DispatchActionListener {
1378 action_type,
1379 listener,
1380 } in node.action_listeners.clone()
1381 {
1382 let any_action = action.as_any();
1383 if action_type == any_action.type_id() {
1384 self.propagate_event = false; // Actions stop propagation by default during the bubble phase
1385 listener(any_action, DispatchPhase::Bubble, self);
1386 if !self.propagate_event {
1387 return;
1388 }
1389 }
1390 }
1391 }
1392 }
1393
1394 /// Register the given handler to be invoked whenever the global of the given type
1395 /// is updated.
1396 pub fn observe_global<G: 'static>(
1397 &mut self,
1398 f: impl Fn(&mut WindowContext<'_>) + 'static,
1399 ) -> Subscription {
1400 let window_handle = self.window.handle;
1401 self.global_observers.insert(
1402 TypeId::of::<G>(),
1403 Box::new(move |cx| window_handle.update(cx, |_, cx| f(cx)).is_ok()),
1404 )
1405 }
1406
1407 pub fn activate_window(&self) {
1408 self.window.platform_window.activate();
1409 }
1410
1411 pub fn minimize_window(&self) {
1412 self.window.platform_window.minimize();
1413 }
1414
1415 pub fn toggle_full_screen(&self) {
1416 self.window.platform_window.toggle_full_screen();
1417 }
1418
1419 pub fn prompt(
1420 &self,
1421 level: PromptLevel,
1422 msg: &str,
1423 answers: &[&str],
1424 ) -> oneshot::Receiver<usize> {
1425 self.window.platform_window.prompt(level, msg, answers)
1426 }
1427
1428 pub fn available_actions(&self) -> Vec<Box<dyn Action>> {
1429 if let Some(focus_id) = self.window.focus {
1430 self.window
1431 .current_frame
1432 .dispatch_tree
1433 .available_actions(focus_id)
1434 } else {
1435 Vec::new()
1436 }
1437 }
1438
1439 pub fn bindings_for_action(&self, action: &dyn Action) -> Vec<KeyBinding> {
1440 self.window
1441 .current_frame
1442 .dispatch_tree
1443 .bindings_for_action(action)
1444 }
1445
1446 pub fn listener_for<V: Render, E>(
1447 &self,
1448 view: &View<V>,
1449 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
1450 ) -> impl Fn(&E, &mut WindowContext) + 'static {
1451 let view = view.downgrade();
1452 move |e: &E, cx: &mut WindowContext| {
1453 view.update(cx, |view, cx| f(view, e, cx)).ok();
1454 }
1455 }
1456
1457 pub fn constructor_for<V: Render, R>(
1458 &self,
1459 view: &View<V>,
1460 f: impl Fn(&mut V, &mut ViewContext<V>) -> R + 'static,
1461 ) -> impl Fn(&mut WindowContext) -> R + 'static {
1462 let view = view.clone();
1463 move |cx: &mut WindowContext| view.update(cx, |view, cx| f(view, cx))
1464 }
1465
1466 //========== ELEMENT RELATED FUNCTIONS ===========
1467 pub fn with_key_dispatch<R>(
1468 &mut self,
1469 context: KeyContext,
1470 focus_handle: Option<FocusHandle>,
1471 f: impl FnOnce(Option<FocusHandle>, &mut Self) -> R,
1472 ) -> R {
1473 let window = &mut self.window;
1474 window
1475 .current_frame
1476 .dispatch_tree
1477 .push_node(context.clone());
1478 if let Some(focus_handle) = focus_handle.as_ref() {
1479 window
1480 .current_frame
1481 .dispatch_tree
1482 .make_focusable(focus_handle.id);
1483 }
1484 let result = f(focus_handle, self);
1485
1486 self.window.current_frame.dispatch_tree.pop_node();
1487
1488 result
1489 }
1490
1491 /// Register a focus listener for the current frame only. It will be cleared
1492 /// on the next frame render. You should use this method only from within elements,
1493 /// and we may want to enforce that better via a different context type.
1494 // todo!() Move this to `FrameContext` to emphasize its individuality?
1495 pub fn on_focus_changed(
1496 &mut self,
1497 listener: impl Fn(&FocusEvent, &mut WindowContext) + 'static,
1498 ) {
1499 self.window
1500 .current_frame
1501 .focus_listeners
1502 .push(Box::new(move |event, cx| {
1503 listener(event, cx);
1504 }));
1505 }
1506
1507 /// Set an input handler, such as [ElementInputHandler], which interfaces with the
1508 /// platform to receive textual input with proper integration with concerns such
1509 /// as IME interactions.
1510 pub fn handle_input(
1511 &mut self,
1512 focus_handle: &FocusHandle,
1513 input_handler: impl PlatformInputHandler,
1514 ) {
1515 if focus_handle.is_focused(self) {
1516 self.window
1517 .platform_window
1518 .set_input_handler(Box::new(input_handler));
1519 }
1520 }
1521}
1522
1523impl Context for WindowContext<'_> {
1524 type Result<T> = T;
1525
1526 fn build_model<T>(
1527 &mut self,
1528 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
1529 ) -> Model<T>
1530 where
1531 T: 'static,
1532 {
1533 let slot = self.app.entities.reserve();
1534 let model = build_model(&mut ModelContext::new(&mut *self.app, slot.downgrade()));
1535 self.entities.insert(slot, model)
1536 }
1537
1538 fn update_model<T: 'static, R>(
1539 &mut self,
1540 model: &Model<T>,
1541 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
1542 ) -> R {
1543 let mut entity = self.entities.lease(model);
1544 let result = update(
1545 &mut *entity,
1546 &mut ModelContext::new(&mut *self.app, model.downgrade()),
1547 );
1548 self.entities.end_lease(entity);
1549 result
1550 }
1551
1552 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
1553 where
1554 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
1555 {
1556 if window == self.window.handle {
1557 let root_view = self.window.root_view.clone().unwrap();
1558 Ok(update(root_view, self))
1559 } else {
1560 window.update(self.app, update)
1561 }
1562 }
1563
1564 fn read_model<T, R>(
1565 &self,
1566 handle: &Model<T>,
1567 read: impl FnOnce(&T, &AppContext) -> R,
1568 ) -> Self::Result<R>
1569 where
1570 T: 'static,
1571 {
1572 let entity = self.entities.read(handle);
1573 read(&*entity, &*self.app)
1574 }
1575
1576 fn read_window<T, R>(
1577 &self,
1578 window: &WindowHandle<T>,
1579 read: impl FnOnce(View<T>, &AppContext) -> R,
1580 ) -> Result<R>
1581 where
1582 T: 'static,
1583 {
1584 if window.any_handle == self.window.handle {
1585 let root_view = self
1586 .window
1587 .root_view
1588 .clone()
1589 .unwrap()
1590 .downcast::<T>()
1591 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
1592 Ok(read(root_view, self))
1593 } else {
1594 self.app.read_window(window, read)
1595 }
1596 }
1597}
1598
1599impl VisualContext for WindowContext<'_> {
1600 fn build_view<V>(
1601 &mut self,
1602 build_view_state: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1603 ) -> Self::Result<View<V>>
1604 where
1605 V: 'static + Render,
1606 {
1607 let slot = self.app.entities.reserve();
1608 let view = View {
1609 model: slot.clone(),
1610 };
1611 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1612 let entity = build_view_state(&mut cx);
1613 cx.entities.insert(slot, entity);
1614
1615 cx.new_view_observers
1616 .clone()
1617 .retain(&TypeId::of::<V>(), |observer| {
1618 let any_view = AnyView::from(view.clone());
1619 (observer)(any_view, self);
1620 true
1621 });
1622
1623 view
1624 }
1625
1626 /// Update the given view. Prefer calling `View::update` instead, which calls this method.
1627 fn update_view<T: 'static, R>(
1628 &mut self,
1629 view: &View<T>,
1630 update: impl FnOnce(&mut T, &mut ViewContext<'_, T>) -> R,
1631 ) -> Self::Result<R> {
1632 let mut lease = self.app.entities.lease(&view.model);
1633 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1634 let result = update(&mut *lease, &mut cx);
1635 cx.app.entities.end_lease(lease);
1636 result
1637 }
1638
1639 fn replace_root_view<V>(
1640 &mut self,
1641 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
1642 ) -> Self::Result<View<V>>
1643 where
1644 V: 'static + Render,
1645 {
1646 let slot = self.app.entities.reserve();
1647 let view = View {
1648 model: slot.clone(),
1649 };
1650 let mut cx = ViewContext::new(&mut *self.app, &mut *self.window, &view);
1651 let entity = build_view(&mut cx);
1652 self.entities.insert(slot, entity);
1653 self.window.root_view = Some(view.clone().into());
1654 view
1655 }
1656
1657 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
1658 self.update_view(view, |view, cx| {
1659 view.focus_handle(cx).clone().focus(cx);
1660 })
1661 }
1662
1663 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
1664 where
1665 V: ManagedView,
1666 {
1667 self.update_view(view, |_, cx| cx.emit(Manager::Dismiss))
1668 }
1669}
1670
1671impl<'a> std::ops::Deref for WindowContext<'a> {
1672 type Target = AppContext;
1673
1674 fn deref(&self) -> &Self::Target {
1675 &self.app
1676 }
1677}
1678
1679impl<'a> std::ops::DerefMut for WindowContext<'a> {
1680 fn deref_mut(&mut self) -> &mut Self::Target {
1681 &mut self.app
1682 }
1683}
1684
1685impl<'a> Borrow<AppContext> for WindowContext<'a> {
1686 fn borrow(&self) -> &AppContext {
1687 &self.app
1688 }
1689}
1690
1691impl<'a> BorrowMut<AppContext> for WindowContext<'a> {
1692 fn borrow_mut(&mut self) -> &mut AppContext {
1693 &mut self.app
1694 }
1695}
1696
1697pub trait BorrowWindow: BorrowMut<Window> + BorrowMut<AppContext> {
1698 fn app_mut(&mut self) -> &mut AppContext {
1699 self.borrow_mut()
1700 }
1701
1702 fn app(&self) -> &AppContext {
1703 self.borrow()
1704 }
1705
1706 fn window(&self) -> &Window {
1707 self.borrow()
1708 }
1709
1710 fn window_mut(&mut self) -> &mut Window {
1711 self.borrow_mut()
1712 }
1713
1714 /// Pushes the given element id onto the global stack and invokes the given closure
1715 /// with a `GlobalElementId`, which disambiguates the given id in the context of its ancestor
1716 /// ids. Because elements are discarded and recreated on each frame, the `GlobalElementId` is
1717 /// used to associate state with identified elements across separate frames.
1718 fn with_element_id<R>(
1719 &mut self,
1720 id: Option<impl Into<ElementId>>,
1721 f: impl FnOnce(&mut Self) -> R,
1722 ) -> R {
1723 if let Some(id) = id.map(Into::into) {
1724 let window = self.window_mut();
1725 window.element_id_stack.push(id.into());
1726 let result = f(self);
1727 let window: &mut Window = self.borrow_mut();
1728 window.element_id_stack.pop();
1729 result
1730 } else {
1731 f(self)
1732 }
1733 }
1734
1735 /// Invoke the given function with the given content mask after intersecting it
1736 /// with the current mask.
1737 fn with_content_mask<R>(
1738 &mut self,
1739 mask: Option<ContentMask<Pixels>>,
1740 f: impl FnOnce(&mut Self) -> R,
1741 ) -> R {
1742 if let Some(mask) = mask {
1743 let mask = mask.intersect(&self.content_mask());
1744 self.window_mut()
1745 .current_frame
1746 .content_mask_stack
1747 .push(mask);
1748 let result = f(self);
1749 self.window_mut().current_frame.content_mask_stack.pop();
1750 result
1751 } else {
1752 f(self)
1753 }
1754 }
1755
1756 /// Update the global element offset relative to the current offset. This is used to implement
1757 /// scrolling.
1758 fn with_element_offset<R>(
1759 &mut self,
1760 offset: Point<Pixels>,
1761 f: impl FnOnce(&mut Self) -> R,
1762 ) -> R {
1763 if offset.is_zero() {
1764 return f(self);
1765 };
1766
1767 let abs_offset = self.element_offset() + offset;
1768 self.with_absolute_element_offset(abs_offset, f)
1769 }
1770
1771 /// Update the global element offset based on the given offset. This is used to implement
1772 /// drag handles and other manual painting of elements.
1773 fn with_absolute_element_offset<R>(
1774 &mut self,
1775 offset: Point<Pixels>,
1776 f: impl FnOnce(&mut Self) -> R,
1777 ) -> R {
1778 self.window_mut()
1779 .current_frame
1780 .element_offset_stack
1781 .push(offset);
1782 let result = f(self);
1783 self.window_mut().current_frame.element_offset_stack.pop();
1784 result
1785 }
1786
1787 /// Obtain the current element offset.
1788 fn element_offset(&self) -> Point<Pixels> {
1789 self.window()
1790 .current_frame
1791 .element_offset_stack
1792 .last()
1793 .copied()
1794 .unwrap_or_default()
1795 }
1796
1797 /// Update or intialize state for an element with the given id that lives across multiple
1798 /// frames. If an element with this id existed in the previous frame, its state will be passed
1799 /// to the given closure. The state returned by the closure will be stored so it can be referenced
1800 /// when drawing the next frame.
1801 fn with_element_state<S, R>(
1802 &mut self,
1803 id: ElementId,
1804 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1805 ) -> R
1806 where
1807 S: 'static,
1808 {
1809 self.with_element_id(Some(id), |cx| {
1810 let global_id = cx.window().element_id_stack.clone();
1811
1812 if let Some(any) = cx
1813 .window_mut()
1814 .current_frame
1815 .element_states
1816 .remove(&global_id)
1817 .or_else(|| {
1818 cx.window_mut()
1819 .previous_frame
1820 .element_states
1821 .remove(&global_id)
1822 })
1823 {
1824 let ElementStateBox {
1825 inner,
1826
1827 #[cfg(debug_assertions)]
1828 type_name
1829 } = any;
1830 // Using the extra inner option to avoid needing to reallocate a new box.
1831 let mut state_box = inner
1832 .downcast::<Option<S>>()
1833 .map_err(|_| {
1834 #[cfg(debug_assertions)]
1835 {
1836 anyhow!(
1837 "invalid element state type for id, requested_type {:?}, actual type: {:?}",
1838 std::any::type_name::<S>(),
1839 type_name
1840 )
1841 }
1842
1843 #[cfg(not(debug_assertions))]
1844 {
1845 anyhow!(
1846 "invalid element state type for id, requested_type {:?}",
1847 std::any::type_name::<S>(),
1848 )
1849 }
1850 })
1851 .unwrap();
1852
1853 // Actual: Option<AnyElement> <- View
1854 // Requested: () <- AnyElemet
1855 let state = state_box
1856 .take()
1857 .expect("element state is already on the stack");
1858 let (result, state) = f(Some(state), cx);
1859 state_box.replace(state);
1860 cx.window_mut()
1861 .current_frame
1862 .element_states
1863 .insert(global_id, ElementStateBox {
1864 inner: state_box,
1865
1866 #[cfg(debug_assertions)]
1867 type_name
1868 });
1869 result
1870 } else {
1871 let (result, state) = f(None, cx);
1872 cx.window_mut()
1873 .current_frame
1874 .element_states
1875 .insert(global_id,
1876 ElementStateBox {
1877 inner: Box::new(Some(state)),
1878
1879 #[cfg(debug_assertions)]
1880 type_name: std::any::type_name::<S>()
1881 }
1882
1883 );
1884 result
1885 }
1886 })
1887 }
1888
1889 /// Like `with_element_state`, but for situations where the element_id is optional. If the
1890 /// id is `None`, no state will be retrieved or stored.
1891 fn with_optional_element_state<S, R>(
1892 &mut self,
1893 element_id: Option<ElementId>,
1894 f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
1895 ) -> R
1896 where
1897 S: 'static,
1898 {
1899 if let Some(element_id) = element_id {
1900 self.with_element_state(element_id, f)
1901 } else {
1902 f(None, self).0
1903 }
1904 }
1905
1906 /// Obtain the current content mask.
1907 fn content_mask(&self) -> ContentMask<Pixels> {
1908 self.window()
1909 .current_frame
1910 .content_mask_stack
1911 .last()
1912 .cloned()
1913 .unwrap_or_else(|| ContentMask {
1914 bounds: Bounds {
1915 origin: Point::default(),
1916 size: self.window().viewport_size,
1917 },
1918 })
1919 }
1920
1921 /// The size of an em for the base font of the application. Adjusting this value allows the
1922 /// UI to scale, just like zooming a web page.
1923 fn rem_size(&self) -> Pixels {
1924 self.window().rem_size
1925 }
1926}
1927
1928impl Borrow<Window> for WindowContext<'_> {
1929 fn borrow(&self) -> &Window {
1930 &self.window
1931 }
1932}
1933
1934impl BorrowMut<Window> for WindowContext<'_> {
1935 fn borrow_mut(&mut self) -> &mut Window {
1936 &mut self.window
1937 }
1938}
1939
1940impl<T> BorrowWindow for T where T: BorrowMut<AppContext> + BorrowMut<Window> {}
1941
1942pub struct ViewContext<'a, V> {
1943 window_cx: WindowContext<'a>,
1944 view: &'a View<V>,
1945}
1946
1947impl<V> Borrow<AppContext> for ViewContext<'_, V> {
1948 fn borrow(&self) -> &AppContext {
1949 &*self.window_cx.app
1950 }
1951}
1952
1953impl<V> BorrowMut<AppContext> for ViewContext<'_, V> {
1954 fn borrow_mut(&mut self) -> &mut AppContext {
1955 &mut *self.window_cx.app
1956 }
1957}
1958
1959impl<V> Borrow<Window> for ViewContext<'_, V> {
1960 fn borrow(&self) -> &Window {
1961 &*self.window_cx.window
1962 }
1963}
1964
1965impl<V> BorrowMut<Window> for ViewContext<'_, V> {
1966 fn borrow_mut(&mut self) -> &mut Window {
1967 &mut *self.window_cx.window
1968 }
1969}
1970
1971impl<'a, V: 'static> ViewContext<'a, V> {
1972 pub(crate) fn new(app: &'a mut AppContext, window: &'a mut Window, view: &'a View<V>) -> Self {
1973 Self {
1974 window_cx: WindowContext::new(app, window),
1975 view,
1976 }
1977 }
1978
1979 pub fn entity_id(&self) -> EntityId {
1980 self.view.entity_id()
1981 }
1982
1983 pub fn view(&self) -> &View<V> {
1984 self.view
1985 }
1986
1987 pub fn model(&self) -> &Model<V> {
1988 &self.view.model
1989 }
1990
1991 /// Access the underlying window context.
1992 pub fn window_context(&mut self) -> &mut WindowContext<'a> {
1993 &mut self.window_cx
1994 }
1995
1996 pub fn with_z_index<R>(&mut self, z_index: u32, f: impl FnOnce(&mut Self) -> R) -> R {
1997 self.window.current_frame.z_index_stack.push(z_index);
1998 let result = f(self);
1999 self.window.current_frame.z_index_stack.pop();
2000 result
2001 }
2002
2003 pub fn on_next_frame(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static)
2004 where
2005 V: 'static,
2006 {
2007 let view = self.view().clone();
2008 self.window_cx.on_next_frame(move |cx| view.update(cx, f));
2009 }
2010
2011 /// Schedules the given function to be run at the end of the current effect cycle, allowing entities
2012 /// that are currently on the stack to be returned to the app.
2013 pub fn defer(&mut self, f: impl FnOnce(&mut V, &mut ViewContext<V>) + 'static) {
2014 let view = self.view().downgrade();
2015 self.window_cx.defer(move |cx| {
2016 view.update(cx, f).ok();
2017 });
2018 }
2019
2020 pub fn observe<V2, E>(
2021 &mut self,
2022 entity: &E,
2023 mut on_notify: impl FnMut(&mut V, E, &mut ViewContext<'_, V>) + 'static,
2024 ) -> Subscription
2025 where
2026 V2: 'static,
2027 V: 'static,
2028 E: Entity<V2>,
2029 {
2030 let view = self.view().downgrade();
2031 let entity_id = entity.entity_id();
2032 let entity = entity.downgrade();
2033 let window_handle = self.window.handle;
2034 self.app.observers.insert(
2035 entity_id,
2036 Box::new(move |cx| {
2037 window_handle
2038 .update(cx, |_, cx| {
2039 if let Some(handle) = E::upgrade_from(&entity) {
2040 view.update(cx, |this, cx| on_notify(this, handle, cx))
2041 .is_ok()
2042 } else {
2043 false
2044 }
2045 })
2046 .unwrap_or(false)
2047 }),
2048 )
2049 }
2050
2051 pub fn subscribe<V2, E, Evt>(
2052 &mut self,
2053 entity: &E,
2054 mut on_event: impl FnMut(&mut V, E, &Evt, &mut ViewContext<'_, V>) + 'static,
2055 ) -> Subscription
2056 where
2057 V2: EventEmitter<Evt>,
2058 E: Entity<V2>,
2059 Evt: 'static,
2060 {
2061 let view = self.view().downgrade();
2062 let entity_id = entity.entity_id();
2063 let handle = entity.downgrade();
2064 let window_handle = self.window.handle;
2065 self.app.event_listeners.insert(
2066 entity_id,
2067 (
2068 TypeId::of::<Evt>(),
2069 Box::new(move |event, cx| {
2070 window_handle
2071 .update(cx, |_, cx| {
2072 if let Some(handle) = E::upgrade_from(&handle) {
2073 let event = event.downcast_ref().expect("invalid event type");
2074 view.update(cx, |this, cx| on_event(this, handle, event, cx))
2075 .is_ok()
2076 } else {
2077 false
2078 }
2079 })
2080 .unwrap_or(false)
2081 }),
2082 ),
2083 )
2084 }
2085
2086 pub fn on_release(
2087 &mut self,
2088 on_release: impl FnOnce(&mut V, &mut WindowContext) + 'static,
2089 ) -> Subscription {
2090 let window_handle = self.window.handle;
2091 self.app.release_listeners.insert(
2092 self.view.model.entity_id,
2093 Box::new(move |this, cx| {
2094 let this = this.downcast_mut().expect("invalid entity type");
2095 let _ = window_handle.update(cx, |_, cx| on_release(this, cx));
2096 }),
2097 )
2098 }
2099
2100 pub fn observe_release<V2, E>(
2101 &mut self,
2102 entity: &E,
2103 mut on_release: impl FnMut(&mut V, &mut V2, &mut ViewContext<'_, V>) + 'static,
2104 ) -> Subscription
2105 where
2106 V: 'static,
2107 V2: 'static,
2108 E: Entity<V2>,
2109 {
2110 let view = self.view().downgrade();
2111 let entity_id = entity.entity_id();
2112 let window_handle = self.window.handle;
2113 self.app.release_listeners.insert(
2114 entity_id,
2115 Box::new(move |entity, cx| {
2116 let entity = entity.downcast_mut().expect("invalid entity type");
2117 let _ = window_handle.update(cx, |_, cx| {
2118 view.update(cx, |this, cx| on_release(this, entity, cx))
2119 });
2120 }),
2121 )
2122 }
2123
2124 pub fn notify(&mut self) {
2125 self.window_cx.notify();
2126 self.window_cx.app.push_effect(Effect::Notify {
2127 emitter: self.view.model.entity_id,
2128 });
2129 }
2130
2131 pub fn observe_window_bounds(
2132 &mut self,
2133 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2134 ) -> Subscription {
2135 let view = self.view.downgrade();
2136 self.window.bounds_observers.insert(
2137 (),
2138 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2139 )
2140 }
2141
2142 pub fn observe_window_activation(
2143 &mut self,
2144 mut callback: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2145 ) -> Subscription {
2146 let view = self.view.downgrade();
2147 self.window.activation_observers.insert(
2148 (),
2149 Box::new(move |cx| view.update(cx, |view, cx| callback(view, cx)).is_ok()),
2150 )
2151 }
2152
2153 /// Register a listener to be called when the given focus handle receives focus.
2154 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2155 /// is dropped.
2156 pub fn on_focus(
2157 &mut self,
2158 handle: &FocusHandle,
2159 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2160 ) -> Subscription {
2161 let view = self.view.downgrade();
2162 let focus_id = handle.id;
2163 self.window.focus_listeners.insert(
2164 (),
2165 Box::new(move |event, cx| {
2166 view.update(cx, |view, cx| {
2167 if event.focused.as_ref().map(|focused| focused.id) == Some(focus_id) {
2168 listener(view, cx)
2169 }
2170 })
2171 .is_ok()
2172 }),
2173 )
2174 }
2175
2176 /// Register a listener to be called when the given focus handle or one of its descendants receives focus.
2177 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2178 /// is dropped.
2179 pub fn on_focus_in(
2180 &mut self,
2181 handle: &FocusHandle,
2182 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2183 ) -> Subscription {
2184 let view = self.view.downgrade();
2185 let focus_id = handle.id;
2186 self.window.focus_listeners.insert(
2187 (),
2188 Box::new(move |event, cx| {
2189 view.update(cx, |view, cx| {
2190 if event
2191 .focused
2192 .as_ref()
2193 .map_or(false, |focused| focus_id.contains(focused.id, cx))
2194 {
2195 listener(view, cx)
2196 }
2197 })
2198 .is_ok()
2199 }),
2200 )
2201 }
2202
2203 /// Register a listener to be called when the given focus handle loses focus.
2204 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2205 /// is dropped.
2206 pub fn on_blur(
2207 &mut self,
2208 handle: &FocusHandle,
2209 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2210 ) -> Subscription {
2211 let view = self.view.downgrade();
2212 let focus_id = handle.id;
2213 self.window.focus_listeners.insert(
2214 (),
2215 Box::new(move |event, cx| {
2216 view.update(cx, |view, cx| {
2217 if event.blurred.as_ref().map(|blurred| blurred.id) == Some(focus_id) {
2218 listener(view, cx)
2219 }
2220 })
2221 .is_ok()
2222 }),
2223 )
2224 }
2225
2226 /// Register a listener to be called when the given focus handle or one of its descendants loses focus.
2227 /// Unlike [on_focus_changed], returns a subscription and persists until the subscription
2228 /// is dropped.
2229 pub fn on_focus_out(
2230 &mut self,
2231 handle: &FocusHandle,
2232 mut listener: impl FnMut(&mut V, &mut ViewContext<V>) + 'static,
2233 ) -> Subscription {
2234 let view = self.view.downgrade();
2235 let focus_id = handle.id;
2236 self.window.focus_listeners.insert(
2237 (),
2238 Box::new(move |event, cx| {
2239 view.update(cx, |view, cx| {
2240 if event
2241 .blurred
2242 .as_ref()
2243 .map_or(false, |blurred| focus_id.contains(blurred.id, cx))
2244 {
2245 listener(view, cx)
2246 }
2247 })
2248 .is_ok()
2249 }),
2250 )
2251 }
2252
2253 pub fn spawn<Fut, R>(
2254 &mut self,
2255 f: impl FnOnce(WeakView<V>, AsyncWindowContext) -> Fut,
2256 ) -> Task<R>
2257 where
2258 R: 'static,
2259 Fut: Future<Output = R> + 'static,
2260 {
2261 let view = self.view().downgrade();
2262 self.window_cx.spawn(|cx| f(view, cx))
2263 }
2264
2265 pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
2266 where
2267 G: 'static,
2268 {
2269 let mut global = self.app.lease_global::<G>();
2270 let result = f(&mut global, self);
2271 self.app.end_global_lease(global);
2272 result
2273 }
2274
2275 pub fn observe_global<G: 'static>(
2276 &mut self,
2277 mut f: impl FnMut(&mut V, &mut ViewContext<'_, V>) + 'static,
2278 ) -> Subscription {
2279 let window_handle = self.window.handle;
2280 let view = self.view().downgrade();
2281 self.global_observers.insert(
2282 TypeId::of::<G>(),
2283 Box::new(move |cx| {
2284 window_handle
2285 .update(cx, |_, cx| view.update(cx, |view, cx| f(view, cx)).is_ok())
2286 .unwrap_or(false)
2287 }),
2288 )
2289 }
2290
2291 pub fn on_mouse_event<Event: 'static>(
2292 &mut self,
2293 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2294 ) {
2295 let handle = self.view().clone();
2296 self.window_cx.on_mouse_event(move |event, phase, cx| {
2297 handle.update(cx, |view, cx| {
2298 handler(view, event, phase, cx);
2299 })
2300 });
2301 }
2302
2303 pub fn on_key_event<Event: 'static>(
2304 &mut self,
2305 handler: impl Fn(&mut V, &Event, DispatchPhase, &mut ViewContext<V>) + 'static,
2306 ) {
2307 let handle = self.view().clone();
2308 self.window_cx.on_key_event(move |event, phase, cx| {
2309 handle.update(cx, |view, cx| {
2310 handler(view, event, phase, cx);
2311 })
2312 });
2313 }
2314
2315 pub fn on_action(
2316 &mut self,
2317 action_type: TypeId,
2318 handler: impl Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) + 'static,
2319 ) {
2320 let handle = self.view().clone();
2321 self.window_cx
2322 .on_action(action_type, move |action, phase, cx| {
2323 handle.update(cx, |view, cx| {
2324 handler(view, action, phase, cx);
2325 })
2326 });
2327 }
2328
2329 pub fn emit<Evt>(&mut self, event: Evt)
2330 where
2331 Evt: 'static,
2332 V: EventEmitter<Evt>,
2333 {
2334 let emitter = self.view.model.entity_id;
2335 self.app.push_effect(Effect::Emit {
2336 emitter,
2337 event_type: TypeId::of::<Evt>(),
2338 event: Box::new(event),
2339 });
2340 }
2341
2342 pub fn focus_self(&mut self)
2343 where
2344 V: FocusableView,
2345 {
2346 self.defer(|view, cx| view.focus_handle(cx).focus(cx))
2347 }
2348
2349 pub fn dismiss_self(&mut self)
2350 where
2351 V: ManagedView,
2352 {
2353 self.defer(|_, cx| cx.emit(Manager::Dismiss))
2354 }
2355
2356 pub fn listener<E>(
2357 &self,
2358 f: impl Fn(&mut V, &E, &mut ViewContext<V>) + 'static,
2359 ) -> impl Fn(&E, &mut WindowContext) + 'static {
2360 let view = self.view().downgrade();
2361 move |e: &E, cx: &mut WindowContext| {
2362 view.update(cx, |view, cx| f(view, e, cx)).ok();
2363 }
2364 }
2365}
2366
2367impl<V> Context for ViewContext<'_, V> {
2368 type Result<U> = U;
2369
2370 fn build_model<T: 'static>(
2371 &mut self,
2372 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
2373 ) -> Model<T> {
2374 self.window_cx.build_model(build_model)
2375 }
2376
2377 fn update_model<T: 'static, R>(
2378 &mut self,
2379 model: &Model<T>,
2380 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
2381 ) -> R {
2382 self.window_cx.update_model(model, update)
2383 }
2384
2385 fn update_window<T, F>(&mut self, window: AnyWindowHandle, update: F) -> Result<T>
2386 where
2387 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
2388 {
2389 self.window_cx.update_window(window, update)
2390 }
2391
2392 fn read_model<T, R>(
2393 &self,
2394 handle: &Model<T>,
2395 read: impl FnOnce(&T, &AppContext) -> R,
2396 ) -> Self::Result<R>
2397 where
2398 T: 'static,
2399 {
2400 self.window_cx.read_model(handle, read)
2401 }
2402
2403 fn read_window<T, R>(
2404 &self,
2405 window: &WindowHandle<T>,
2406 read: impl FnOnce(View<T>, &AppContext) -> R,
2407 ) -> Result<R>
2408 where
2409 T: 'static,
2410 {
2411 self.window_cx.read_window(window, read)
2412 }
2413}
2414
2415impl<V: 'static> VisualContext for ViewContext<'_, V> {
2416 fn build_view<W: Render + 'static>(
2417 &mut self,
2418 build_view_state: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2419 ) -> Self::Result<View<W>> {
2420 self.window_cx.build_view(build_view_state)
2421 }
2422
2423 fn update_view<V2: 'static, R>(
2424 &mut self,
2425 view: &View<V2>,
2426 update: impl FnOnce(&mut V2, &mut ViewContext<'_, V2>) -> R,
2427 ) -> Self::Result<R> {
2428 self.window_cx.update_view(view, update)
2429 }
2430
2431 fn replace_root_view<W>(
2432 &mut self,
2433 build_view: impl FnOnce(&mut ViewContext<'_, W>) -> W,
2434 ) -> Self::Result<View<W>>
2435 where
2436 W: 'static + Render,
2437 {
2438 self.window_cx.replace_root_view(build_view)
2439 }
2440
2441 fn focus_view<W: FocusableView>(&mut self, view: &View<W>) -> Self::Result<()> {
2442 self.window_cx.focus_view(view)
2443 }
2444
2445 fn dismiss_view<W: ManagedView>(&mut self, view: &View<W>) -> Self::Result<()> {
2446 self.window_cx.dismiss_view(view)
2447 }
2448}
2449
2450impl<'a, V> std::ops::Deref for ViewContext<'a, V> {
2451 type Target = WindowContext<'a>;
2452
2453 fn deref(&self) -> &Self::Target {
2454 &self.window_cx
2455 }
2456}
2457
2458impl<'a, V> std::ops::DerefMut for ViewContext<'a, V> {
2459 fn deref_mut(&mut self) -> &mut Self::Target {
2460 &mut self.window_cx
2461 }
2462}
2463
2464// #[derive(Clone, Copy, Eq, PartialEq, Hash)]
2465slotmap::new_key_type! { pub struct WindowId; }
2466
2467impl WindowId {
2468 pub fn as_u64(&self) -> u64 {
2469 self.0.as_ffi()
2470 }
2471}
2472
2473#[derive(Deref, DerefMut)]
2474pub struct WindowHandle<V> {
2475 #[deref]
2476 #[deref_mut]
2477 pub(crate) any_handle: AnyWindowHandle,
2478 state_type: PhantomData<V>,
2479}
2480
2481impl<V: 'static + Render> WindowHandle<V> {
2482 pub fn new(id: WindowId) -> Self {
2483 WindowHandle {
2484 any_handle: AnyWindowHandle {
2485 id,
2486 state_type: TypeId::of::<V>(),
2487 },
2488 state_type: PhantomData,
2489 }
2490 }
2491
2492 pub fn root<C>(&self, cx: &mut C) -> Result<View<V>>
2493 where
2494 C: Context,
2495 {
2496 Flatten::flatten(cx.update_window(self.any_handle, |root_view, _| {
2497 root_view
2498 .downcast::<V>()
2499 .map_err(|_| anyhow!("the type of the window's root view has changed"))
2500 }))
2501 }
2502
2503 pub fn update<C, R>(
2504 &self,
2505 cx: &mut C,
2506 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
2507 ) -> Result<R>
2508 where
2509 C: Context,
2510 {
2511 cx.update_window(self.any_handle, |root_view, cx| {
2512 let view = root_view
2513 .downcast::<V>()
2514 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2515 Ok(cx.update_view(&view, update))
2516 })?
2517 }
2518
2519 pub fn read<'a>(&self, cx: &'a AppContext) -> Result<&'a V> {
2520 let x = cx
2521 .windows
2522 .get(self.id)
2523 .and_then(|window| {
2524 window
2525 .as_ref()
2526 .and_then(|window| window.root_view.clone())
2527 .map(|root_view| root_view.downcast::<V>())
2528 })
2529 .ok_or_else(|| anyhow!("window not found"))?
2530 .map_err(|_| anyhow!("the type of the window's root view has changed"))?;
2531
2532 Ok(x.read(cx))
2533 }
2534
2535 pub fn read_with<C, R>(&self, cx: &C, read_with: impl FnOnce(&V, &AppContext) -> R) -> Result<R>
2536 where
2537 C: Context,
2538 {
2539 cx.read_window(self, |root_view, cx| read_with(root_view.read(cx), cx))
2540 }
2541
2542 pub fn root_view<C>(&self, cx: &C) -> Result<View<V>>
2543 where
2544 C: Context,
2545 {
2546 cx.read_window(self, |root_view, _cx| root_view.clone())
2547 }
2548
2549 pub fn is_active(&self, cx: &WindowContext) -> Option<bool> {
2550 cx.windows
2551 .get(self.id)
2552 .and_then(|window| window.as_ref().map(|window| window.active))
2553 }
2554}
2555
2556impl<V> Copy for WindowHandle<V> {}
2557
2558impl<V> Clone for WindowHandle<V> {
2559 fn clone(&self) -> Self {
2560 WindowHandle {
2561 any_handle: self.any_handle,
2562 state_type: PhantomData,
2563 }
2564 }
2565}
2566
2567impl<V> PartialEq for WindowHandle<V> {
2568 fn eq(&self, other: &Self) -> bool {
2569 self.any_handle == other.any_handle
2570 }
2571}
2572
2573impl<V> Eq for WindowHandle<V> {}
2574
2575impl<V> Hash for WindowHandle<V> {
2576 fn hash<H: Hasher>(&self, state: &mut H) {
2577 self.any_handle.hash(state);
2578 }
2579}
2580
2581impl<V: 'static> Into<AnyWindowHandle> for WindowHandle<V> {
2582 fn into(self) -> AnyWindowHandle {
2583 self.any_handle
2584 }
2585}
2586
2587#[derive(Copy, Clone, PartialEq, Eq, Hash)]
2588pub struct AnyWindowHandle {
2589 pub(crate) id: WindowId,
2590 state_type: TypeId,
2591}
2592
2593impl AnyWindowHandle {
2594 pub fn window_id(&self) -> WindowId {
2595 self.id
2596 }
2597
2598 pub fn downcast<T: 'static>(&self) -> Option<WindowHandle<T>> {
2599 if TypeId::of::<T>() == self.state_type {
2600 Some(WindowHandle {
2601 any_handle: *self,
2602 state_type: PhantomData,
2603 })
2604 } else {
2605 None
2606 }
2607 }
2608
2609 pub fn update<C, R>(
2610 self,
2611 cx: &mut C,
2612 update: impl FnOnce(AnyView, &mut WindowContext<'_>) -> R,
2613 ) -> Result<R>
2614 where
2615 C: Context,
2616 {
2617 cx.update_window(self, update)
2618 }
2619
2620 pub fn read<T, C, R>(self, cx: &C, read: impl FnOnce(View<T>, &AppContext) -> R) -> Result<R>
2621 where
2622 C: Context,
2623 T: 'static,
2624 {
2625 let view = self
2626 .downcast::<T>()
2627 .context("the type of the window's root view has changed")?;
2628
2629 cx.read_window(&view, read)
2630 }
2631}
2632
2633#[cfg(any(test, feature = "test-support"))]
2634impl From<SmallVec<[u32; 16]>> for StackingOrder {
2635 fn from(small_vec: SmallVec<[u32; 16]>) -> Self {
2636 StackingOrder(small_vec)
2637 }
2638}
2639
2640#[derive(Clone, Debug, Eq, PartialEq, Hash)]
2641pub enum ElementId {
2642 View(EntityId),
2643 Integer(usize),
2644 Name(SharedString),
2645 FocusHandle(FocusId),
2646}
2647
2648impl ElementId {
2649 pub(crate) fn from_entity_id(entity_id: EntityId) -> Self {
2650 ElementId::View(entity_id)
2651 }
2652}
2653
2654impl TryInto<SharedString> for ElementId {
2655 type Error = anyhow::Error;
2656
2657 fn try_into(self) -> anyhow::Result<SharedString> {
2658 if let ElementId::Name(name) = self {
2659 Ok(name)
2660 } else {
2661 Err(anyhow!("element id is not string"))
2662 }
2663 }
2664}
2665
2666impl From<usize> for ElementId {
2667 fn from(id: usize) -> Self {
2668 ElementId::Integer(id)
2669 }
2670}
2671
2672impl From<i32> for ElementId {
2673 fn from(id: i32) -> Self {
2674 Self::Integer(id as usize)
2675 }
2676}
2677
2678impl From<SharedString> for ElementId {
2679 fn from(name: SharedString) -> Self {
2680 ElementId::Name(name)
2681 }
2682}
2683
2684impl From<&'static str> for ElementId {
2685 fn from(name: &'static str) -> Self {
2686 ElementId::Name(name.into())
2687 }
2688}
2689
2690impl<'a> From<&'a FocusHandle> for ElementId {
2691 fn from(handle: &'a FocusHandle) -> Self {
2692 ElementId::FocusHandle(handle.id)
2693 }
2694}